Brs Microbiology Flash Cards

Front 1

Gram Positive:

A normal inhabitant of the oral cavity, infection can be associated with dental procedures, with formation of lesions that erupt through the face with a purulent discharge

Back 1

Actinomycetes isrealii

[Diagnosis is by finding sulfur granules = tangles of filaments of organisms wrapped in a matrix of calcium phosphate, imparting a yellow (sulfur) color to the abscess and discharge]

Front 2

Gram Positive:

The most severe form of this disease results from the inhalation of spores with mediastinitis, pulmonary edema, and hemorrhage (Woolsorter's disease)

Back 2

Bacillus anthracis

[Can occur as an occupational disease of textile or agricultural personnel resulting from contact with infected hides or wool; it has been used as an agent of biowarfare and bioterrorism]

Front 3

Gram Positive:

Causes gastroenteritis and is typically associated with the consumption of reheated rice

Back 3

Bacillus cereus

[Rapid emesis or diarrhea is associated with an enterotoxin that increases cAMP and is produced by the organism as it germinates]

Front 4

Gram Positive:

Disease can be due to the ingestion of preformed toxin in home-canned foods or by the ingestion of spores in honey by an infant

Back 4

Clostridium botulinum

[Symptoms include flaccid paralysis, dry mouth, diplopia, dysphagia, and respiratory failure]

Front 5

Gram Positive:

Associated with the use of broad-spectrum antibiotics and the overgrowth of toxin-producing bacteria

Back 5

Clostridium difficile

[Results in pseudomembranous colitis and is also a major nosocomial disease]

Front 6

Gram Positive:

Causes gas gangrene and is often associated with automobile and motorcycle accidents

Back 6

Clostridium perfringens

[Spores are abundant in soil and germinate in wounds; treatment includes surgical debridement, antibiotics, and hyperbaric oxygen]

Front 7

Gram Positive:

Infection is associated with traumatic inoculation of spores that germinate and produce a toxin that causes spastic paralysis

Back 7

Clostridium tetani

[The organism looks like a long rod with a dilated terminal end containing spore that resembles a tennis racquet]

Front 8

Gram Positive:

Can cause risus sardonicus, the characteristic grimace of lockjaw

Back 8

Clostridium tetani

[Treatment includes the use of antitoxins produced in horses or hyperimmunized humans, and antispasmodics such as benzodiazepines]

Front 9

Gram Positive:

Causes gray pseudomembranes on the back of the throat

Back 9

Corynebacterium diphtheriae

[Organisms often viewed in a "Chinese-letter" configuration]

Front 10

Gram Positive:

A common cause of nosocomial infection, this organism is often resistant to many antibiotics, including vancomycin

Back 10

Enterococcus spp.

[Common cause of urinary tract infections, sepsis, meningitis, and endocarditis]

Front 11

Gram Positive:

Causes a fishy smelling vaginal discharge

Back 11

Gardnerella vaginalis

[Histologically characterized by the presence of "clue cells," vaginal epithelial cells covered with bacteria, seen on a Pap smear]

Front 12

Gram Positive:

As the dominant organism of normal vaginal flora, its metabolism helps maintain the low pH of the vagina

Back 12

Lactobacillus spp.

[The lactic acid produced helps prevent the overgrowth of potentially pathogenic organisms; with the use of broad-spectrum antibiotics, such acid-producing flora is lost, allowing for overgrowth of pathogenic species]

Front 13

Gram Positive:

This cause of late onset neonatal sepsis is a facultative intracellular parasite that spreads from cell to cell via actin rockets

Back 13

Listeria monocytogenes

[This organism can be detected as short non-spore-forming rods with a tumbling end-over-end motility]

Front 14

Gram Positive:

As well as being gram positive, this organism is also weakly acid fast and causes a pneumonia predominantly in immunocompromised patients

Back 14

Nocardia asteroides

[This aeroic bacteria with filamentous growth is a common soil organism]

Front 15

Gram Positive:

Part of the microbial flora of the skin, this bacilli contributes of the development of acne

Back 15

Propionibacterium acnes

[The organism produces lipases that split fatty acids that cause inflammation, resulting in the formation of comedones]

Front 16

Gram Positive:

A major cause of acute bacterial endocarditis, especially in IV drug users

Back 16

Staphylococcus aureus

[Unlike subacute bacterial endocarditis, this organism can cause infection of undamaged heart valves, typically on the right side (tricuspid) in IV drug users]

Front 17

Gram Positive:

A major cause of abscesses, furuncles, carbuncles, and other skin infections such as impetigo

Back 17

Staphylococcus aureus

[This beta-hemolytic cocci grows in grape-like clusters, produces coagulase, and grows in culture as yellowish colonies]

Front 18

Gram Positive:

Part of the normal flora of the skin, it causes infection of IV lines and catheters; it is a major cause of endocarditis in patients with prosthetic heart valves

Back 18

Staphylococcus epidermidis

[Similar to Staphylococcus aureus, but grows as white colonies, does not produce coagulase, does not ferment mannitol, and does not produce Protein A]

Front 19

Gram Positive:

The second leading cause of urinary tract infection in sexually active women

Back 19

Staphylococcus saprophyticus

[Differentiated from Staphylococcus epidermidis by its ability to ferment mannitol and its resistance to novobiocin]

Front 20

Gram Positive:

An important cause of neonatal sepsis and meningitis

Back 20

Streptococcus agalactiae (Group B)

[This beta-hemolytic, bacitracin-resistant cocci is a normal inhabitant of the female genital tract and can be acquired during vaginal delivery]

Front 21

Gram Positive:

A major cause of dental caries

Back 21

Streptococcus mutans

[A member of the viridans group, it is also alpha-hemolytic and optochin-resistant]

Front 22

Gram Positive:

Lancet-shaped diplococci found in a rusty brown sputum

Back 22

Streptococcus pneumoniae

[Causes >90% of all causes of lobar pneumonia]

Front 23

Gram Positive:

The use of a quellung reaction helps differentiate between the 85 different capsular subtypes

Back 23

Streptococcus pneumoniae

[This alpha-hemolytic, optochin-sensitive, bile-soluble coccus grows on sheep red blood cell agar; the vaccine contains at least 23 of these subtypes]

Front 24

Gram Positive:

Infection results in rheumatic fever

Back 24

Streptococcus pyogenes (Group A)

[Characterized by a constellation of symptoms including migratory polyarthritis, erythema marginatum, pancarditis, Syndeham chorea, and subcutaneous nodules]

Front 25

Gram Positive:

A major cause of pharyngitis, infection can also result in other suppurative symptoms such as erysipelas, cellulitis, and impetigo

Back 25

Streptococcus pyogenes (Group A)

[Infection with this beta-hemolytic, bacitracin-sensitive cocci can be serodiagnosed with the detection of host antibodies to bacterial DNase B and anti-streptolysin O (ASO)]

Front 26

Gram Positive:

Infection can lead to the development of acute glomerulonephritis and mitral and aortic stenosis

Back 26

Streptococcus pyogenes (Group A)

[Immunocomplex deposition in the kidney visualized by "lumpy bump" immunofluorescence; cross-reactive antibodies to the bacteria result in autoimmune destruction of the heart valves]

Front 27

Gram Positive:

Leading cause of subacute bacterial endocarditis

Back 27

Streptoccus viridans

[This alpha-hemolytic, optochin-resistant cocci is part of the normal flora of the human pharynx]

Front 28

Gram Positive:

Chronic exposure to this group of organisms leads to the development of hypersensitivity pneumonitis, including Farmer's Lung, Pigeon breeder's Lung, and Humidifier Lung

Back 28

Thermophilic Actinomycetes

[Exposure causes an immunologically mediated interstitial fibrosis, bronchiolitis, and granuloma formation with progresive respiratory failure and cyanosis]

Front 29

Gram Positive:

The organism is detected as PAS+ rods within the macrophages of the lamina propria of the small intestine

Back 29

Tropheryma whippelii

[The causative agent of Whipple's disease that results in abdominal pain, malabsorption with diarrhea and weight loss, and a migratory polyarthritis]

Front 30

Gram Negative:

Predominant organism in the human colon

Back 30

Bacteroides fragilis

[Most often the cause of serious anaerobic infection]

Front 31

Gram Negative:

Transmitted by the bite, scratch, or lick of an infected cat, resulting in low grade fever and a characteristic enlargement of lymph nodes for several weeks

Back 31

Bartonella henselae

[This is the causative agent of Cat scratch disease; infection of an immunocompromised patient can result in Bacillary angiomatosis, cranberry-like pustules resembling Kaposi's sarcoma]

Front 32

Gram Negative:

Causes a paroxysmal cough ending with an inspiratory "whoop" as air rushes over the swollen glottis

Back 32

Bordetella pertussis

[The vaccine includes the purified virulence factors filamentous hemagglutinin (FHA) and pertussis toxoid, and is administered at 2, 4, 6, and 18 months along with the vaccine for Corynebacterium diphtheriae and Clostridium tetani in the DaPT vaccine

Front 33

Gram Negative:

Transmitted by contaminated livestock and unpasteurized dairy products, infection results in a fever that rises in the morning and falls at night (Undulant fever)

Back 33

Brucella spp.

[This granulomatous infection invades the reticulo-endothelial cells of the lymph nodes, liver, spleen, and bone marrow]

Front 34

Gram Negative:

Endemic to tropical nations, this sexually transmitted organism results in granulomatous genital ulcers (pseudouboes) with the potential for autoamputation of genitalia

Back 34

Klebsiella granulomatis
(formerly Calymmatobacterium granulomatis)

[Diagnosis is based on finding intracellular organisms aggregated as 'Donovan Bodies"]

Front 35

Gram Negative:

A common cause of bloody diarrhea, particularly in children in close contact with puppues and kittens, which serve as reservoirs

Back 35

Campylobacter jejuni

[These rod-shaped organisms appear as "gull wing"-shaped colonies with a single flagellum]

Front 36

Gram Negative:

Causes a bloody diarrhea and is associated with the consumption of undercooked meat and dairy products

Back 36

Enterohemorrhagic Escherichia coli
(E. coli 0157:H7)

[This dysentery-like condition is due to the elaboration of verotoxins similar to Shiga toxin that causes cytotoxicity to the colonic mucosa]

Front 37

Gram Negative:

Infection may result in hemorrhagic colitis progressing to the hemolytic uremic syndrome (HUS)

Back 37

Enterohemorrhagic Escherichia coli
(E. coli 0157:H7)

[HUS is characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia in children]

Front 38

Gram Negative:

Leading cause of urinary tract infections

Back 38

Escherichia coli

[Other major causes of urinary tract infections include Proteus, Serratia, Enterococci, Klebsiella, Pseudomonas, and Staphylococcus saprophyticus]

Front 39

Gram Negative:

Causes "Traveler's diarrhea" and is also a major cause of death in children of developing nations

Back 39

Escherichia coli

[The enterotoxigenic strain produces a heat stable and a heat labile toxin that causes an explosive watery diarrhea with cramping, abdominal discomfort, and dehydration]

Front 40

Gram Negative:

This zoonotic organism can be transmitted by the bite of a deerfly or tick, or through handling or consuming rabbit products, which are the reservoir

Back 40

Francisella tularensis
(rabbit fever)

[Infection can result in necrotic ulcers at the site of entry: conjunctiva (oculoglandular), mouth (typhoidal), or lungs (pneumonic tularemia) with disseminated granulomatous lesions of the lung, spleen, and liver]

Front 41

Gram Negative:

Organism closely associated with chronic gastritis and peptic ulcer disease

Back 41

Helicobacter pylori

[Also associated with an increase in the development of gastric carcinoma and MALToma]

Front 42

Gram Negative:

A sexually transmitted disease, results in painful genital ulcers (chancroid)

Back 42

Haemophilus ducreyi

[Infection in the United States is rare, most infections occur in the tropics; painless ulcer = T. pallidum]

Front 43

Gram Negative:

Infection with this coccobacillus causes epiglottitis, otitis media in children, sinusitis, meningitis, and pneumonia in older patients with chronic respiratory disease

Back 43

Haemophilus influenzae

[Growth in culture of this organism requires Factor V (hemin) and Factor X (NAD), found in chocolate agar media]

Front 44

Gram Negative:

Formerly a leading cause of infection in children, the incidence of infection has dramatically decreased with the introduction of a vaccine

Back 44

Haemophilus influenzae

[Vaccine is composed of the capsular material, polyribitol phosphate (PRP), conjugated to diptheria toxin]

Front 45

Gram Negative:

Major cause of aspiration pneumonia in alcoholics

Back 45

Klebsiella pneumoniae

[Organism produces a large antiphagocytic capsule, giving it a mucoid appearance and producing a thick, bloody, "currant-jelly" sputum]

Front 46

Gram Negative:

Paired, kidney bean-shaped diplococci within leukocytes in a urethral discharge

Back 46

Neisseria gonorrhoeae

[Differentiated from N. meningitidis based on its ability to ferment glucose and maltose, whereas N. gonorrhoeae ferments glucose only]

Front 47

Gram Negative:

Leading cause of septic arthritis

Back 47

Neisseria gonorrhoeae

[Typically presents as monoarticular arthritis of the knee, ankle, or wrist after a bout of urethritis]

Front 48

Gram Negative:

Infection of a neonate passing through an infected birth canal results in ophthamia neonatorum and purulent conjunctivitis

Back 48

Neisseria gonorrhoeae

[Babies born in the United States receive a required administration of tetracycline, erythromycin, or silver nitrate drops to prevent this]

Front 49

Gram Negative:

Sexually transmitted disease that can lead to pelvic inflammatory disease that then predisposes to ectopic pregnancy

Back 49

Neisseria gonorrhoeae

[The second most common notifiable disease in the United States]

Front 50

Gram Negative:

Leading cause of meningitis among mililtary recruits and dormitory settings

Back 50

Neisseria meningitidis

[Patients with deficiencies in the complement components C6-9, "the membrane attack complex," are particularly susceptible to infection]

Front 51

Gram Negative:

Septicemia resulting from this organism can result in progressive hypotension, disseminated intravascular coagulation, widespread vascular purpura, and bilateral adrenal hemorrhage

Back 51

Neisseria meningitidis

[The shock and adrenocortical insufficiency of Waterhouse-Friderichsen Syndrome is rapidly fatal without antibiotic treatment]

Front 52

Gram Negative:

This organism is transmitted through the bite of a domestic cat or dog and can result in an abscess, cellulitis, and osteomyelitis

Back 52

Pasteurella multocida

[Short, encapsulated, bipolar staining organism is part of the nasopharyngeal flora of domestic dogs and cats]

Front 53

Gram Negative:

Urease-positive organism that causes an alkaline urine predisposing to the formation of urinary calculi

Back 53

Proteus spp.
(P. mirabilis and P. vulgaris)

[These highly motile organisms are often refractory to antibiotic treatment because they often become trapped within stones]

Front 54

Gram Negative:

Major cause of pneumonia in burn patients and cystic fibrosis patients

Back 54

Pseudomonas aeruginosa

[This obligate aerobe requires only trace elements for growth and is a major cause of nosocomial infections because it colonizes aspirators, water and ice dispensers, IV lines, and even dilute disinfectant solutions]

Front 55

Gram Negative:

Infection can result in folliculitis, swimmer's ear, pneumonia, and sepsis with the development of characteristic skin lesions (Ecthyma gangrenosum)

Back 55

Pseudomonas aeruginosa

[This organism grows well in water, especially in inadequately chlorinated hot tubs; culture results in green colonies resulting from pigments pyoverdin and pyocyanin, with a characteristic fruity odor]

Front 56

Gram Negative:

Causes a self-limiting enterocolitis associated with the consumption of contaminated eggs and poultry

Back 56

Salmonella enteritidis

[This highly motile organism requires a large infectious dose, which distinguishes it from Shigella spp.]

Front 57

Gram Negative:

Causes an enteric fever with the development of characteristic "rose spots" on the abdomen

Back 57

Salmonella typhi

[After recovery, a small percentage of patients may become carriers because the organisms colonize the gallbladder, a state that may require cholecystectomy]

Front 58

Gram Negative:

This organism is a common cause of nosocomial infections; some strains produce a red pigment

Back 58

Serratia marcescens

[Causes pneumonia, bacteremia, endocarditis, and is often multidrug-resistant]

Front 59

Gram Negative:

Infection with a small dose of organisms results in dysentery that is only transmitted among humans with no animal reservoir

Back 59

Shigella dysenteriae

[This cause of a bloody, mucoid, low-volume diarrhea can result in life-threatening dehydration and acidosis and is often associated with insanitary conditions]

Front 60

Gram Negative:

Major cause of secretory diarrhea with life-threatening dehydration, particularly in developing nations

Back 60

Vibrio cholerae

[These comma-shaped rods with a polar flagellum adhere to the intestinal mucosa and elaborate an exotoxin, but never invade]

Front 61

Gram Negative:

Causes nausea, cramping, and is associated with the consumption of raw shellfish

Back 61

Vibrio parahaemolyticus

[Although this free-living salt bacteria is related to Vibrio cholerae, the symptoms are much milder]

Front 62

Gram Negative:

Rodents are the reservoir for this organism, transmitted by the bite of a flea, resulting in the plague

Back 62

Yersinia pestis

[Transmission is also possible between humans in the case of the pneumonic plague]

Front 63

Gram Negative:

Infection can result in pustules and enlargement of draining lymph nodes that rupture through the skin to form buboes

Back 63

Yersinia pestis

[This organism displays bipolar staining resulting in a safety pin appearance]

Front 64

Poorly Staining:

Late stages of infection may lead to a severe autoimmune arthritis, life-threatening heart block, and facial nerve palsy

Back 64

Borrelia burgdorferi

[The vaccine was available for this organism to prevent development of Lyme disease, but was found to have autoimmune side effects and was withdrawn. There is a vaccine for dogs, and new vaccines are being researched using outer surface protein C (OspC) and glycolipoprotein as methods of immunization]

Front 65

Poorly Staining:

Transmitted by the Ixodes tick bite that results in a characteristic bull's eye lesion (Erythema chronicum migrans)

Back 65

Borrelia burgorferi

[Infection occurs mainly in the Northeast during the summer months, when the deer tick (Ixodes) is found]

Front 66

Poorly Staining:

Transmitted by the human body louse, this organism causes relapsing fever

Back 66

Borrelia recurrentis

[Causes a febrile disease that fades as antibodies develop and relapses as the organism undergoes antigenic variation of its variable major protein]

Front 67

Poorly Staining:

Previously known as the TWAR agent, it is a common cause of sore throats and interstitial pneumonia

Back 67

Chlamydia pneumoniae

[As with all Chlamydial species, it exists as either elementary bodies, the infectious form, or as intracellular reticular bodies, the metabolically active form]

Front 68

Poorly Staining:

Causes an interstitial type pneumonia and is associated with exposure to contaminated parrots and parakeets and other domestic birds

Back 68

Chlamydia psittaci

[The causative agent of Psittacosis, transmitted by birds of the psittacine family; a similar disease, Ornithosis, is also seen upon exposure to other birds such as pigeons, ducks, and chickens]

Front 69

Poorly Staining:

This cause of chronic keratoconjunctivitis results in corneal scarring and is one of the leading causes of blindness worldwide

Back 69

Chlamydia trachomatis

[Chlamydia tracomatis is divided into serovars based on serology and symptomatology; in this case, the pathology is due to C. trachomatis A, B, an C]

Front 70

Poorly Staining:

This organism is the leading cause of sexually transmitted bacterial disease, resulting in urethritis, cervicitis, salpingitis, and neonatal conjunctivitis

Back 70

Chlamydia trachomatis

[Infection in a female can progress to pelvic inflammatory disease, resulting in the potential for ectopic pregnancy or sterility]

Front 71

Poorly Staining:

This organism is closely associated with the development of conjunctivitis, urethritis, and arthritis (Reiter's syndrome)

Back 71

Chlamydia trachomatis

[This autoimmune phenomenon resulting from cross-reactive antigens between the organism and affected tissues is associated with the HLA-B27]

Front 72

Poorly Staining:

Causes Lymphogranuloma venereum, characterized by nodules and vesicles on the genitals, venereal buboes, and elephantiasis of the genitals with rectal strictures

Back 72

Chlamydia trachomatis

[Results from infection of the most invasive serovars L1, L2, and L3; this sexually transmitted disease progresses through primary, secondary, and tertiary stages]

Front 73

Poorly Staining:

Causes Q fever, an interstitial pneumonia, resulting from the inhalation of the organism

Back 73

Coxiella burnetii

[Unlike other rickettsial diseases, this organism is not transmitted by the bite of an arthropod, does not cause a rash, and cannot be detected by the classical serologic test for Rickettsia, the Weil-Felix Test]

Front 74

Poorly Staining:

This organism grows in warm, moist environments (contaminated air conditioner systems) and causes a potential life-threatening pneumonia in patients with lung disease

Back 74

Legionella pneumophila

[This organism, often visualized with Dieterle silver stain, also causes a less severe form of pneumonia known as Pontiac fever]

Front 75

Poorly Staining:

One of the most common opportunistic bacterial infections in AIDS patients

Back 75

Mycobacterium avium-intacellulare (MAC)

[This disease presents similarly to TB and is acquired from soil, birds, or other animals]

Front 76

Poorly Staining:

Infection results in the destruction of skin and cartilage, resulting in a leonine facies and limb deformities

Back 76

Mycobacterium leprae

[Leprosy, or Hansen disease, presents as a spectrum between two extremes, from tuberculoid leprosy associated with good prognosis to lepromatous leprosy, in which numerous acid-fast bacilli are stuffed in macrophages = Lepra cells]

Front 77

Poorly Staining:

Infection results in the destruction of peripheral nerves, resulting in anesthesia followed by atrophy and autoamputation

Back 77

Mycobacterium leprae

[This acid-fast bacilli has a long generation time, approximately 13 days, and cannot be cultivated in the laboratory]

Front 78

Poorly Staining:

Primary infection results in subpleural parenchymal lesions and enlarged caseous lymph nodes (Ghon complex) and reactivation can result in cavitary lesions in the upper lung lobes

Back 78

Mycobacterium tuberculosis

[Diagnosis is confirmed by finding acid-fast bacilli in the sputum or in cultures that take several weeks to grow]

Front 79

Poorly Staining:

The classic presentation of infection with this organism includes fever, night sweats, fatigue, and weight loss

Back 79

Mycobacterium tuberculosis

[Presents similarly to other granulomatous infections such as histoplasmosis or coccidiodomycosis]

Front 80

Poorly Staining:

Infection can result in the involvement of vertebrae (Pott's disease) with spread to form a psoas abscess and, in immunocompromised patients, overwhelming miliary dissemination

Back 80

Mycobacterium tuberculosis

[Although rare in the United States, incidences of infections are increasing in immunocompromised patients and urban populations, with high incidence of multidrug-resistant strains]

Front 81

Poorly Staining:

Immunization employs the use of Bacillus Calmette Guerin (BCG), one of the few live attenuated bacterial vaccines available

Back 81

Mycobacterium tuberculosis

[The test for exposure to TB involves injection of a small amount of partially purified derivative (PPD) and detecting a delayed type hypersensitivity reaction; recipients of the vaccine (an attenuated strain of M. bovis) have a positive PPD]

Front 82

Poorly Staining:

A prominent cause of community-acquired pneumonia, symptoms normally include a hacking, nonproductive cough (atypical pneumonia)

Back 82

Mycoplasma pneumonia

[One of the smallest free-living bacteria, has no cell wall, and causes an interstitial inflammation rather than intra-alveolar exudates]

Front 83

Poorly Staining:

Causes "Walking pneumonia" with the potential to develop a self-limiting hemolytic anemia

Back 83

Mycoplasma pneumoniae

[Untreated patients develop IgM autoantibodies to red blood cells, termed acute cold agglutinins]

Front 84

Poorly Staining:

Associated with overcrowding and transmitted by the human body louse, this organism causes Epidemic typhus

Back 84

Rickettsia prowazekii

[Characterized by extreme fever, myalgias, and a rash; a less sever form of the disease, Endemic typhus, results from Rickettsia typhi]

Front 85

Poorly Staining:

Transmitted by ticks, infection results in a petechial rash with involvement of the palms and soles

Back 85

Rickettsia rickettsii

[The causative agent of Rocky Mountain spotted fever is an obligate intracellular organism seen with Giemsa staining; despite its name, it is endemic to the eastern United States]

Front 86

Poorly Staining:

Transplacental infection can result in a triad of interstitial keratitis, Hutchinson teeth, and 8th cranial nerve deafness

Back 86

Treponema pallidum

[Infection results in osteochondritis and periostitis and contributing as well to other defects such as destruction of the vomer, leading to saddle nose deformity; other bone defects include mulberry molars and saber shin deformities]

Front 87

Poorly Staining:

Long-term consequences of untreated disease include tabes dorsalis and aneurysms of the ascending aorta

Back 87

Treponema pallidum

[Tertiary syphilis can lead to paresis and is the leading cause of aneurysms of the ascending aorta with a characteristic tree-barking appearance]

Front 88

Poorly Staining:

The disease can manifest with a maculopapular rash on the palms and soles, and condyloma lata

Back 88

Treponema pallidum

[Secondary syphilis presents with a rash and gray flattened wart-like lesions on the anogenital, axillary, and oral areas; these condyloma lata are not to be confused with condyloma acuminatum seen with HPV infection]

Front 89

Poorly Staining:

Initial infection presents with a painless ulcer on the genitals known as a chancre

Back 89

Treponema pallidum

[The characteristic lesion of primary syphilis is highly contagious and contains numerous spirochetes viewed by dark field light microscopy or by immunofluorescent microscopy]

Front 90

Poorly Staining:

Patients with SLE are often positive for serologic tests for this organism even if not infected (biologic false positive)

Back 90

Treponema pallidum

[Screening test like the rapid plasma reagin or Venereal Disease Research Laboratory (VDRL) are based on finding antibodies to cardiolipin, which patients with SLE make; the most specific test is the fluorescent treponemal antibody (FTA-Abs test)]

Front 91

Poorly Staining:

The organism is exquisitely sensitive to penicillins; treatment can result in rash, fever, and hypotension (Jarisch-Herxheimer reaction)

Back 91

Treponema pallidum

[Treatment results in rapid death of the organism with release of toxic products that cause symptoms that can be relieved by anti-inflammatory agents]

Front 92

Poorly Staining:

This organism that lacks a cell wall is the cause of recurrent urinary tract infections

Back 92

Ureaplasma urealyticum

[Related to Mycoplasma pneumoniae, infection is associated with the development of urinary calculi]

Front 93

Virulence Factors:

Produces a trivalent exotoxin composed of protective antigen, edema factor, and lethal factor

Back 93

Bacillus antracis

[Protective antigen mediates cell binding, edema factor is a secreted adenylate cyclase, and lethal factor causes CNS depression]

Front 94

Virulence Factors:

One of the virulence factors of this organism is an anti-phagocytic capsule composed of D-glutamic acid

Back 94

Bacillus anthracis

[Although typically composed of polysaccharides, other organisms with unique capsular components include sialic acid in Streptococcus agalactiae and hyaluronic acid in Pasteurella multocida]

Front 95

Virulence Factors:

Produces a typical AB toxin that catalyzes the transfer of ADP-ribose from NAD⁺ to the inhibitory G protein subunit (Gi)

Back 95

Bordetella pertussis

[Interference of G protein-coupled receptors such as those employed by chemokines results in significant lymphocytosis; other virulence factors include filamentous hemagluttinin and tracheal cytotoxin]

Front 96

Virulence Factors:

Produces and exotoxin that blocks the release of actylcholine at the neuromuscular junction

Back 96

Clostridium botulinum

[Treatment includes the used of an antitoxin produced in horses, with the possibility of serum sickness]

Front 97

Virulence Factors:

The toxin produced by this organism can be used in minute amounts to treat dystonias, strabismus, and wrinkles

Back 97

Clostridium botulinum

[Toxin causes a flaccid paralysis of the injected muscles]

Front 98

Virulence Factors:

Produces and AB toxin that ADP-ribosylates the small GTP binding protein Rho

Back 98

Clostridium difficile

[Results in the depolymerization of the cytoskeleton with necrosis of the colonic epithelium]

Front 99

Virulence Factors:

Produces a lecithinase and hyaluronidase that results in cellulitis and myonecrosis

Back 99

Clostridium perfringens

[The lecithinase can be demonstrated by culturing on egg yolk agar; normally the organism produces a double zone of hemolysis on blood agar]

Front 100

Virulence Factors:

The toxin elaborated by this organism inhibits the release of the inhibitory neurotransmitters, GABA and glycine, resulting in a spastic paralysis

Back 100

Clostridium tetani

[The DaPT vaccine includes the highly immunogenic tetanus toxoid; a booster is recommended every 10 years and also after a puncture wound]

Front 101

Virulence Factors:

A virulence factor produced by these two organisms is a typical AB toxin that catalyzes the transfer of ADP-ribose from NAD⁺ to elongation factor-2

Back 101

Corynebacterium diptheria and Pseudomonas aeruginosa

[ADP ribosylation of EF-2 (elongation factor-2) results in the inhibition of protein synthesis and death of the cell]

Front 102

Virulence Factors:

Produces a heat stable toxin Sta, that stimulates the production of cGMP, with similar effects to those of increased cAMP

Back 102

Enterotoxigenic Escherichia coli

[In addition, the organism produces a STb toxin that is cyclic nucleotide independent]

Front 103

Virulence Factors:

Virulence factor found in the outer leaflet of the cell wall of gram-negative organisms

Back 103

Lipopolysaccharide (LPS)

[Composed of Lipid A, a core polysaccharide, and O antigen, LPS leads to activation of macrophages with the release of IL-1, with the development of disseminated intravascular coagulation and septic shock]

Front 104

Virulence Factors:

The virulence factors associated with this organism include the ability to grow intracellularly and the production of cord factor

Back 104

Mycobacterium tuberculosis

[Cord factor is thought to contribute to the formation of granulomas]

Front 105

Virulence Factors:

Produces a toxin that irreversible inactivates the 60S ribosomal subunit with the cessation of protein synthesis and cell death

Back 105

Shigella dysenteriae

[Toxins similar to Shiga toxin are produced by enterohemorrhagic E. coli and are known as verotoxins]

Front 106

Virulence Factors:

Produces exfoliant toxin

Back 106

Staphylococcus aureus

[The toxin causes an exfoliative dermatitis, Scalded skin syndrome, that appears as a sunburn-like rash]

Front 107

Virulence Factors:

Produces Toxic shock syndrome toxin

Back 107

Staphylococcus aureus

[Toxic shock syndrome, associated with the use of superabsorbent tampons, results from the production of this toxin, which causes polyclonal activation of T cells through antigen-independent activation of the T-cell receptor]

Front 108

Virulence Factors:

Protein A is a major virulence factor

Back 108

Staphylococcus aureus

[Binds to the Fc region of the antibody, preventing complement fixation and phagocytosis]

Front 109

Virulence Factors:

The three major pyogens for which a polysaccharide capsule is the major virulence factor

Back 109

Streptococcus pneumoniae
Haemophilus influenzae
Neisseria meningitidis

[The capsule prevents opsonization by host cell immunoglobulins]

Front 110

Virulence Factors:

Produces erythrogenic toxin, resulting in Scarlet fever

Back 110

Streptococcus pyogenes (Group A)

[Erythrogenic toxin is a phage-encoded superantigen that causes the rash often accompanying pharyngitis]

Front 111

Virulence Factors:

M antigen is the most important virulence factor

Back 111

Streptococcus pyogenes (Group A)

[Prevents phagocytosis, and antibodies to this molecule underlie the long-term sequelae of infection, namely chronic rheumatic heart disease]

Front 112

Virulence Factors:

Produces an AB toxin that transfers ADP-ribose from NAD⁺ to the stimulatory G protein subunit (Gs)

Back 112

Vibrio cholerae

[Similar to the labile toxin (LT) of enterotoxigenic E. coli, this toxin results in the increase of cAMP with hypersecretion of Cl⁻ and HCO₃⁻ with the osmotic reflux of up to 30 L of water/day]

Front 113

Fungi:

Produces a toxin that results in liver damage upon ingestion of wild mushrooms

Back 113

Amanita species

[Ingestion may result in life-threatening fulminant hepatitis, requiring liver transplant]

Front 114

Fungi:

Produces the carcinogen aflatoxin and is a common contaminant of moldy nuts and grains

Back 114

Aspergillus favus

[Aflatoxins contribute to the development of hepatocellular carcinoma and act synergistically with HBV to promote carcinogenesis]

Front 115

Fungi:

Proliferation of this organism within the lung causes a "fungus ball" that must be removed surgically

Back 115

Aspergillus fumigatus

[Microscopically the organism grows as septate hyphae, branching at 45º angles]

Front 116

Fungi:

Although an opportunistic mycosis, it can cause hypersensitivity pneumonitis such as Farmer's Lung

Back 116

Aspergillus fumigatus

[Resulting from inhalation of moldy hay]

Front 117

Fungi:

Systemic mycosis that begins as lower respiratory tract infection and may disseminate to cause warty-like skin lesions

Back 117

Blastomyces dermatiditis

[Results in granulomatous lung lesions similar to tuberculosis; may also result in skeletal and genitourinary manifestations]

Front 118

Fungi:

Systemic mycosis endemic to the southeastern United States

Back 118

Blastomyces dermatitidis

[Fungi appears in infected tissue as yeast with broad-based budding]

Front 119

Fungi:

Causes a cottage cheese-like vaginal discharge

Back 119

Candida albicans

[Predisposing factors include immunosuppression, diabetes, obesity, and the use of broad-spectrum antibiotics]

Front 120

Fungi:

Causes white curd-like patches on mucocutaneous membranes of the mouth and extend downward to cause esophagitis in immunocompromised patients

Back 120

Candida albicans

[In addition to causing thrush, C. albicans is a common cause of tinea unguium (fungal infection of the nails) and diaper rash]

Front 121

Fungi:

Most common mycotic pathogen

Back 121

Candida albicans

[Although a yeast, it can form pseudohyphae in infected tissue and form characteristic germ tubes at 37ºC under laboratory conditions]

Front 122

Fungi:

Systemic mycosis endemic to the San Joaquin Valley in southern California

Back 122

Coccidioides immitis

[Causes "Valley Fever," characterized by arthralgias, cough, and fever]

Front 123

Fungi:

Found within infected tissue as spherules that rupture to release endospores

Back 123

Coccidioides immitis

[Dimorphic fungi with contraction of infection by inhalation of arthrospores in the sand and soil]

Front 124

Fungi:

The only mycotic pathogen with a capsule

Back 124

Cryptococcus neoformans

[Visualized with an India ink test; capsule excludes ink, providing contrast]

Front 125

Fungi:

Causes meningitis in patients with underlying immunodeficiency, especially AIDS

Back 125

Cryptococcus neoformans

[Associated with pigeon droppings, this fungus grows within the Virchow-Robin vascular spaces of the brain, resulting in "soap bubble lesions"]

Front 126

Fungi:

Causes cutaneous infections such as tinea corporis, tinea cruris (jock itch), and tinea pedis (athlete's foot)

Back 126

Dermatophytes

[Typically caused by dermatophytes of the genera Trichophyton spp. and result in scaly hypo- or hyperpigmented annular pruritic lesions]

Front 127

Fungi:

Associated with the inhalation of spores from bird or bat droppings in the Ohio and Mississippi River Valley

Back 127

Histoplasma capsulatum

[Histologically characterized by macrophages stuffed with numerous yeast cells]

Front 128

Fungi:

Causes tinea versicolor, which manifests as patches of hyper- and hypopigmentation on the trunk

Back 128

Malassezia furfur

[Found in skin scales and has a characteristic spaghetti and meatballs appearance (yeast clusters and short, curved septate hyphae)]

Front 129

Fungi:

Most common pulmonary mycotic infection with symptoms ranging from asymptomatic to tuberculosis-like symptoms

Back 129

Histoplasma capsulatum

[In immunocompetent individuals, infection often resolves, with calcification of hilar lymph nodes]

Front 130

Fungi:

Most common cause of tinea capitis, ringworm of the scalp

Back 130

Microsporum canis

[Common in prepubescent children with pets; the natural inhibitor or Microsporum spp. growth, undecylenic acid, is produced in the sebum of postpubertal individuals]

Front 131

Fungi:

Results in rhinocerebral disease, primarily in patients with diabetic ketoacidosis or leukemia

Back 131

Mucor and Rhizopus species

[Distinct from other human fungal pathogens in that these species cause disease in their sexual life cycle and display nonseptate hyphae branching at a 90º angle or wider]

Front 132

Fungi:

This organism grows as multiple budding yeasts that appear as a "captains wheel" and causes disease almost exclusively in men

Back 132

Paracoccidioides braziliense (brasiliensis)

[This granulomatous lung disease occurs primarily in Central and South America, with >90% of cases seen in males]

Front 133

Fungi:

Causes an alveolar pneumonia, typically in AIDS patients

Back 133

Pneumocystis (carinii) jirovecii

[Previously thought to be a protozoa, this fungus causes a foamy, amorphous alveolar exudate and is seen as cup- or boat-shaped cysts upon staining with silver methenamine]

Front 134

Fungi:

Causes the most common subcutaneous mycosis, Rose handler's disease

Back 134

Sporothrix schenckii

[Transmitted by the prick of a contaminated thorn; treated with a dilute solution of potassium iodide (KI) in milk]

Front 135

Protozoa:

Transmitted by the same tick as that which carries Lyme disease, infection results in similar manifestation as malaria

Back 135

Babesia microti

[Often mistaken for P. falciparum, the organism can be detected in RBCs as a "Maltese cross," which is diagnostic]

Front 136

Protozoa:

Causes a self-limiting diarrhea in immunocompetent individuals or life-threatening intractable diarrhea in AIDS patients

Back 136

Cryptosporidium parvum

[Infection is associated with the consumption of water contaminated with infected animal feces]

Front 137

Protozoa:

Dissemination to the liver can result in abscess formation with a characteristic anchovy paste aspirate

Back 137

Entamoeba histolytica

[The organism can form an amoeboma with the potential for penetration of the serosa and peritonitis]

Front 138

Protozoa:

Common cause of amebic dysentery, infection leads to the formation of flask-shaped ulcers in the colonic mucosa

Back 138

Entamoeba histolytica

[The finding of trophozoites with ingested RBCs is pathognomonic]

Front 139

Protozoa:

The only common pathogenic protozoa of the small intestine

Back 139

Giardia lamblia

[A heart-shaped symmetrical trophozoite with two nuclei, four pairs of flagella, and a large sucking disk for adherence to the mucosal surface]

Front 140

Protozoa:

Causes flatulence and diarrhea with steatorrhea and the production of bulky greasy foul-smelling stool

Back 140

Giardia lamblia

[Infection is more common among day-care children, campers consuming contaminated stream water, and homosexuals engaging in oral-anal contact]

Front 141

Protozoa:

Infection with different species results in dermal, mucocutaneous, and visceral forms of the disease

Back 141

Leishmania spp.

[Dermal leishmaniasis is due to L. tropica, the mucocutaneous form is due to L. braziliensis, and the most severe form, visceral leishmaniasis, is due to L. donovani and can result in skin hyperpigmentation of kala-azar]

Front 142

Protozoa:

Transmitted by the sandfly, the amastigote stage survives and multiplies within macrophages

Back 142

Leishmania spp.

[The only protozoan parasite capable of replication within the phagolysosomes of reticuloendothelial cells]

Front 143

Protozoa:

Free-living flagellated amoeba, acquired by swimming in freshwater ponds, causing a fulminant meningoencephalitis with death within a week

Back 143

Naegleria fowleri

[Another free-living amoebum, Acanthamoeba castellani, causes less severe disease, typically limited to corneal ulceration and keratitis]

Front 144

Protozoa:

Blackwater fever

Back 144

Plasmodium falciparum

[Seen in P. falciparum malaria, in which infected cells are abnormally adherent and cause thrombosis and ischemia with hemolysis, resulting in hemoglobinuria]

Front 145

Protozoa:

Transmitted by the female Anopheles mosquito, with infection of RBCs and hepatocytes

Back 145

Plasmodium spp.

[An obligate intracellular parasite, Plasmodium is typically seen as ring- or crescent-shaped forms within RBCs on a Giemsa-stained peripheral blood smear]

Front 146

Protozoa:

Some resistance to infection is provided to patients with sickle cell disease/trait, glucose-6-phosphate dehydrogenase deficiency, and thalassemia

Back 146

Plasmodium spp.

[Symptoms of malaria include cyclic fevers (every 48 hr = P. falciparum, every 72 hr = P. malariea), headache, anemia]

Front 147

Protozoa:

Exposure of nonimmune mothers results in fetal transmission with the potential for stillbirth and intracerebral calcifications

Back 147

Toxoplasma gondii

[Infection may be acquired from cysts in raw or undercooked meat or aerosolization of infected cat feces from litter boxes]

Front 148

Protozoa:

Usually asymptomatic in immunocompetent individuals, infection in an AIDS patient can result in fulminant, life-threatening encephalitis

Back 148

Toxoplasma gondii

[Visualized radiographically as a ring-enhancing mass on CT scan; other ring-enhancing masses include cerebral abscess and Glioblastoma multiforme]

Front 149

Protozoa:

A common cause of vaginitis, it often presents with vulvo-vaginal pruritis, with a profuse frothy discharge

Back 149

Trichomonas vaginalis

[Causes strawberry mucosa, spotty reddening and edema of the affected mucosa]

Front 150

Protozoa:

Identified as pear-shaped, flagellated trophozoites with undulating movements on a wet-mount slide of vaginal or urethral discharge

Back 150

Trichomonas vaginalis

[Typically a sexually transmitted disease, growth is associated with an abnormally alkaline pH of the vagina]

Front 151

Protozoa:

Transmitted by the tsetse fly, this protozoa causes African sleeping sickness, characterized by cyclic fevers, encephalitis, slurred speech, and somnolence

Back 151

Trypanosoma brucei

[The organism evades the immune system by genetic rearrangement of its variable surface glycoprotein (VSG)]

Front 152

Protozoa:

Can destroy the myenteric plexus, resulting in mega-esophagus and megacolon

Back 152

Trypanosoma cruzi

[Transmitted by the droppings of the reduviid bug ("kissing bug"), often with the initial development of unilateral swelling of the eyelids (Romana's sign)]

Front 153

Protozoa:

A major cause of heart disease in Central and South America

Back 153

Trypanosoma cruzi

[Acute forms of Chagas disease lead to direct invasion of the myocardium with inflammation; the chronic forms of disease involve autoimmune destruction with the development of dilated cardiomyopathy with life-threatening arrhythmias]

Front 154

Helminths:

Chronic infection with this hookworm constitutes an important cause of anemia worldwide

Back 154

Ancylostoma duodenale ("hookworm")

[Leads to iron deficiency anemia because each worm consumes as much as 0.25 ml blood/day]

Front 155

Helminths:

Migration of larval nematodes below the skin results in serpiginous urticarial trails on the skin (Creeping eruptions)

Back 155

Ancylostoma braziliense and other animal hookworms

[Infection is acquired by contact with sand-containing feces of dogs and cats]

Front 156

Helminths:

Most common helminth infection in humans worldwide

Back 156

Ascaris lumbricoides

[As much as ¼ of the world population is infected; infection causes GI obstruction, granulomas of the biliary tree, liver abscesses, and hypersensitivity pneumonitis]

Front 157

Helminths:

Infection is associated with damage to the biliary tract and development of cholangiocarcinoma

Back 157

Clonorchis sinensis

[Associated with the consumption of infected freshwater fish]

Front 158

Helminths:

Infection can be associated with megaloblastic anemia

Back 158

Diphyllobothrium latum

[This enormous fish tapeworm absorbs dietary vitamin B₁₂, resulting in B₁₂ deficiency in the host]

Front 159

Helminths:

Removal of this nematode is traditionally accomplished by slowly twisting it around a stick to remove it from beneath the skin

Back 159

Dracunculus medinensis

[Infection is acquired by consuming water contaminated by the intermediate host, the cyclops, a microscopic crustacean]

Front 160

Helminths:

Larvae form large space-occupying hydatid cysts in the liver and lung, and leakage of fluid can result in anaphylaxis

Back 160

Echinococcus granulosus (dog tapeworm)

[Because herbivores such as sheep are usually an intermediate host for the dog tapeworm, infection commonly presents in the context of a sheep farmer with many sheepdogs]

Front 161

Helminths:

Causes perianal pruritis, http://www.flashcardexchange.com/mycards/add/1342617with diagnosis confirmed by the recovery of eggs from the anus with scotch tape

Back 161

Enterobius vermicularis (pinworm)

[Most common helminth infection in the United States and often associated with day-care institutions]

Front 162

Helminths:

Infection results in subcutaneous "caliber/calabar" swellings and can be seen migrating across the eye beneath the conjunctiva

Back 162

Loa loa filariasis

[Infection is transmitted by the bite of a mango fly, Chrysops]

Front 163

Helminths:

Endemic to Africa, especially along river basins, infection can result in River blindness

Back 163

Oncocerca volvulus

[Transmitted by the blackfly, this nematode also causes loss of elasticity of the skin with significant dependent edema (i.e. hanging groin)]

Front 164

Helminths:

Infection of the bladder is associated with the development of squamous cell carcinoma of the bladder

Back 164

Schistosoma hematobium

[Endemic to Egypt and Sudan and associated with wading through moist soil while barefoot; diagnosis is confirmed by finding spherical eggs with a terminal spine in the urine]

Front 165

Helminths:

The smallest of all intestinal nematodes, high worm burden is possibly the result of autoinfection

Back 165

Strongyloides stercoralis

[It is the only intestinal nematode capable of completing its life cycle within the human host]

Front 166

Helminths:

One of the most common cestode infections in the United States, and associated with the consumption of improperly cooked contaminated beef

Back 166

Taenia saginata (beef tapeworm)

[Usually results in vague abdominal pain, although the tapeworm can grow to several meters in length]

Front 167

Helminths:

Infection with the larval form of this tapeworm from feces-contaminated water can lead to cysticercosis

Back 167

Taenia solium (pork tapeworm)

[Results in the growth of the larvae in brain, resulting in a Swiss cheese appearance of the cerebral hemispheres]

Front 168

Helminths:

Accidental transmission of these nematodes from pet feces (in sandboxes or on sandy beaches) results in Visceral larva migrans

Back 168

Toxocara canis and Toxocara cati

[Symptoms include eosinophilia, pneumonitis, and vision loss]

Front 169

Helminths:

Infection is acquired by consuming cysts in undercooked, contaminated pork

Back 169

Trichinella spiralis

[Infection results in flu-like symptoms, diarrhea, myalgias, and periorbital edema]

Front 170

Helminths:

Rectal prolapse is a potential complication in children resulting from straining during defecation with infection of this nematode

Back 170

Trichuris trichiura (whipworm)

[Diagnosis is based on finding bile-stained, barrel-shaped eggs with polar plugs]

Front 171

Helminths:

Filariasis (Elephantiasis)

Back 171

Wucheria bancrofti

[Organism causes obstruction of lymph vessels resulting in edema with swelling of the legs and genitalia]

Front 172

DNA Viruses:

Major cause of epidemic conjunctivitis (pink eye)

Back 172

Adenovirus

[Various subtypes are also associated with pharyngitis and gastroenteritis]

Front 173

DNA Viruses:

Major cause of retinitis, leading to blindness in an immunocompromised patient

Back 173

Cytomegalovirus (CMV)

[Can cause life-threatening interstitial pneumonia in such patients and heterophil-negative infectious mononucleosis in immunocompromised individuals]

Front 174

DNA Viruses:

Most common viral cause of congenital abnormalities in the United States

Back 174

Cytomegalovirus (CMV)

[Infected cells display characteristic "owl eye" intranuclear viral inclusions]

Front 175

DNA Viruses:

Infection results in the production of heterophil antibodies

Back 175

Epstein-Barr Virus (EBV)

[Viral infection results in the polyclonal activation of B cells with the production of antibodies to sheep RBCs (heterophil antibodies) that can be detected with the monospot test]

Front 176

DNA Viruses:

Major cause of infectious mononucleosis

Back 176

Epstein-Barr Virus (EBV)

[Characterized by weeks of fever, malaise, and lymphadenopathy, the peripheral blood contains an abundance of atypical lymphs, which are T cells that recognize EBV-infected cells]

Front 177

DNA Viruses:

Infection is associated with Burkitt's lymphoma and nasopharyngeal carcinoma

Back 177

Epstein-Barr virus (EBV)

[Burkitt's lymphoma is more commonly associated with EBV in Africa; nasopharyngeal carcinoma is more common in patients from Asia]

Front 178

DNA Viruses:

This virus encodes an RNA-dependent DNA polymerase (reverse transcriptase)

Back 178

Hepatitis B Virus (HBV)

[The virus produces its DNA genome through a single mRNA transcript, requiring the presence of a reverse transcriptase]

Front 179

DNA Viruses:

Appear in the serum as Dane particles and as large amounts of filaments of excess surface antigen

Back 179

Hepatitis B Virus (HBV)

[The surface antigen (HBsAg) is produced by recombinant DNA technology and is given as a vaccine]

Front 180

DNA Viruses:

A major cause of hepatocellular carcinoma worldwide

Back 180

Hepatitis B Virus (HBV)

[Although less likely to progress to either cirrhosis or carcinoma than is HCV, the worldwide prevalence especially in Africa makes HBV the leading cause]

Front 181

DNA Viruses:

Major cause of sexually transmitted and vertically transmitted hepatitis

Back 181

Hepatitis B Virus (HBV)

[Histologically, infected cells appear as ground glass hepatocytes because of the presence of excess surface antigen within the cytoplasm]

Front 182

DNA Viruses:

Infection with this virus is a leading cause of corneal blindness in the United States

Back 182

Herpes simplex virus-1 (HSV-1)

[Keratoconjunctivitis results in dendritic ulcers that can be visualized with fluorescein staining]

Front 183

DNA Viruses:

Infection results in Cowdry Type A intranuclear inclusions and multinucleated giant cells

Back 183

Herpes simplex virus-1 (HSV-1)

[One of the most common human viral infections, the virus enters broken skin and remains latent in the trigeminal ganglion, with spontaneous reactivation triggered by axonal injury, stress, or UV light]

Front 184

DNA Viruses:

Leading cause of sporadic encephalitis in the United States

Back 184

Herpes simplex virus-1 (HSV-1)

[Commonly affects the temporal lobe]

Front 185

DNA Viruses:

Most common cause of vesiculo-ulcerative lesions on the penis or vagina

Back 185

Herpes simplex virus-2 (HSV-2)

[Reactivation of the virus is common because the virus remains latent in the lumbar and sacral ganglia; detected using the Tzanck test]

Front 186

DNA Viruses:

Infection causes Roseola infantum or Sixth disease

Back 186

Herpes Virus 6

[A common, mild, childhood disease characterized by high fever and a skin rash]

Front 187

DNA Viruses:

Causes cranberry-pigmented lesions on AIDS patients

Back 187

Herpes Virus 8

[Kaposi sarcoma is a tumor of blood vessels characterized by a disarray of vascular channels filled with RBCs]

Front 188

DNA Viruses:

Infection is linked to premalignant lesions on the vulva, cervix, penis, and anus

Back 188

Human papilloma virus (HPV)

[Viral oncoprotein E6 binds to p53 and viral oncoprotein E7 binds to Rb, stimulating infected cells to undergo uncontrolled growth]

Front 189

DNA Viruses:

Infection of keratinized tissue results in the formation of warts on the hands and feet

Back 189

Human papilloma virus (HPV)

[Typically caused by infection with HPV 1-4, with the development of warts on the hands (Verruca Palmaris) and feet [Verruca Plantaris)]

Front 190

DNA Viruses:

Infection causes cauliflower-like lesions on the external genitals or perianal areas

Back 190

Human Papilloma Virus (HPV)

[Condyloma acuminatum is microscopically characterized by the presence of vacuolated infected cells, termed koilocytes]

Front 191

DNA Viruses:

Reactivation of latent viral infection in immunocompromised patients can result in Progressive multifocal leukoencephalopathy (PML)

Back 191

JC Virus

[This polyomavirus causes foci of demyelination surrounded by oligodendrocytes with viral inclusions]

Front 192

DNA Viruses:

This contagious virus causes benign epithelial tumors that appear as pearly, umbilicated nodules with a central caseous plug

Back 192

Molluscum contagiosum

[These lesions caused by the pox virus occur as clusters on the trunk, genitalia, and extremities; it is transmitted by towels, barbers, swimming pools, and sexual activity]

Front 193

DNA Viruses:

Causes aplastic crisis in patients with sickle cell anemia, thalassemias, and acquired hemolytic anemias

Back 193

Parvovirus B19

[Virion replicates best in rapidly dividing erythroblasts, resulting in cell lysis]

Front 194

DNA Viruses:

Infection of a child results in a "slapped cheek" appearance

Back 194

Parvovirus B19

[This single-stranded DNA virus causes Erythema infectiosum or Fifth disease]

Front 195

DNA Viruses:

The only DNA virus that replicates solely in the cytoplasm and that carries its own DNA-dependent polymerases

Back 195

Poxvirus

[The largest of all viruses, it appears brick-shaped by electron microscopy, and causes characteristic Guarnieri inclusion bodies when replicating in cells]

Front 196

DNA Viruses:

Found as a contaminant in preparations of polio vaccines produced in monkey cell culture

Back 196

SV40

[This polyoma virus is typically a simian virus, which can cause tumors in mice, although no pathogenic effects have been reported in humans]

Front 197

DNA Viruses:

Causes chickenpox upon initial infection, and shingles upon reactivation

Back 197

Varicella-zoster virus (VZV)

[The only herpes virus with a live attenuated vaccine; reactivation most commonly occurs along the dermatomal distribution of the ophthalmic division of the trigeminal nerve]

Front 198

DNA Viruses:

Infection results in the successive appearance of macules, papules, vesicles, and crusts all seen simultaneously

Back 198

Varicella-zoster virus (VZV)

[Severe infection can result in pneumonia with multinucleated giant cells]

Front 199

DNA Viruses:

Associated with Reye syndrome when the accompanying fever is treated with aspirin

Back 199

Varicella-zoster virus (VZV)

[Reye syndrome is an acute encephalopathy associated with fatty infiltration of the liver, which is often fatal]

Front 200

RNA Viruses:

Group of Togaviruses transmitted by mosquitoes leading to encephalitis

Back 200

Alphavirus

[This genus includes Eastern equine encephalitis virus (EEE), Western equine encephalitis virus (WEE), and Venezuelan equine encephalitis (VEE)]

Front 201

RNA Viruses:

A grouping of viruses that are transmitted by mosquitoes and ticks

Back 201

Arboviruses

[The group contains members of the Flavavirus family, Togavirus family, and Bunyavirus family]

Front 202

RNA Viruses:

Only bunyavirus member causing diseases endemic to the United States

Back 202

California encephalitis virus
(including La Crosse virus)

[Results in a mild encephalitis, sometimes only meningitis]

Front 203

RNA Viruses:

Causes pleurodynia (Bornholm disease)

Back 203

Coxsackie B virus

[Sudden onset of stabbing chest pain with waxing and waning symptoms]

Front 204

RNA Viruses:

Most common cause of viral myocarditis

Back 204

Coxsackie B Virus

[Usually self-limiting, but may cause fatal arrhythmias or lead to dilated cardiomyopathy]

Front 205

RNA Viruses:

Causes herpangina

Back 205

Coxsakievirus

[Discrete vesicles on the throat and tongue with pain and difficulty swallowing]

Front 206

RNA Viruses:

Infection may result in destruction of the pancreas with resultant insulin-dependent diabetes mellitus

Back 206

Coxsackieviruses B3 and B4

[May be due to molecular mimicry owing to shared antigens between virus and pancreatic beta cells]

Front 207

RNA Viruses:

Causes a severe hemorrhagic fever with outbreaks in Zaire and Sudan

Back 207

Ebola virus

[Another filovirus family member, Marburg virus, has been associated with infection of laboratory personnel working with monkey tissue]

Front 208

RNA Viruses:

Infection leads to severe hemorrhage and renal failure

Back 208

Hantavirus

[A member of the Bunyavirus family with three segments of RNA]

Front 209

RNA Viruses:

Infection is associated with ingestion of raw shellfish from fecally contaminated water

Back 209

Hepatitis A virus (HAV)

[The virus is transmitted via the fecal/oral route and causes an acute hepatitis with no chronic carrier state]

Front 210

RNA Viruses:

Major cause of post-transfusion hepatitis

Back 210

Hepatitis C virus (HCV)

[This Flavavirus often results initially in subclinical infection although it is a major cause of chronic hepatitis and cirrhosis in the United States; it is the hepatitis virus most likely to result in hepatocellular carcinoma]

Front 211

RNA Viruses:

Replication-deficient virus, requiring the presence of hepatitis B virus for productive infection

Back 211

Hepatitis D virus (HDV)

[The HDV viral particle, known as the Dane particle, requires packaging into hepatitis B surface antigen to be infectious]

Front 212

RNA Viruses:

Infection is associated with a high mortality rate in infected pregnant women

Back 212

Hepatitis E virus (HEV)

[This Calcivirus is transmitted by the fecal/oral route, as with hepatitis A, and is most prevalent in developing nations]

Front 213

RNA Viruses:

Infection leads to destruction of T cells, with the development of life-threatening opportutnistic infections

Back 213

Human immunodeficiency virus (HIV)

[Opportunistic infections include CMV infection, Kaposi sarcoma, Pneumocystis carinii, Toxoplasma gondii, and Mycobacterium avium-intracellulare]

Front 214

RNA Viruses:

Virus binds to CD4+ cells via viral glycorotein gp120

Back 214

Human immunodeficiency virus (HIV)

[Entry of virus requires the presence of chemokine receptors CCR5 on monocyte/macrophages or CXCR4 on T lymphocytes]

Front 215

RNA Viruses:

Retrovirus that causes oncogenic transformation of CD4+ T cells

Back 215

Human T-cell lymphotropic virus-1 (HTLV-1)

[This virus, related to HIV, is endemic to Japan and the Caribbean basin, and also causes Tropical spastic paraparesis]

Front 216

RNA Viruses:

Treatment with salicylates for this viral cause of respiratory symptoms may result in Reye syndrome in children

Back 216

Influenza virus (Orthomyxovirus)

[In children, this virus can also cause croup, otitis media, muscle aches, and a high fever; influenza and retroviruses are the only RNA viruses to replicate in the nucleus]

Front 217

RNA Viruses:

Changes in the viral surface proteins resulting from point mutations; reassortment of genome segments result in epidemics and pandemics

Back 217

Influenza virus (orthomyxovirus)

[Point mutations in viral hemagglutinin (HA) or neuraminidase (NA) result in antigen drift, whereas reassortment of genes results in antigenic shifts]

Front 218

RNA Viruses:

Major viral cause of pneumonia, and infection typically predisposes to secondary bacterial pneumonia

Back 218

Influenza virus (orthomyyxovirus)

[Decrease in respiratory mucosal viscosity by viral neuraminidase and destruction of the respiratory epithelium lower the resistance to bacterial superinfection by Staphylococcus spp., Streptococcus spp., and Haemophilus spp. infection]

Front 219

RNA Viruses:

Infection has been associated with subacute sclerosing panencephalitis (SSPE)

Back 219

Measles virus

[Caused by a defective virus encoding a defective M protein]

Front 220

RNA Viruses:

Infection leads to an immune-mediated maculopapular rash on the head, trunk, and limbs

Back 220

Measles virus

[The presence of Koplik spots, small bluish-white ulcerations on the oral mucosa, are pathognomonic]

Front 221

RNA Viruses:

Giant-cell pneumonia and encephalomyelitis are potential complications

Back 221

Measles virus

[Vaccination for this previously common viral infection is included in the MMR vaccine, along with mumps and rubella]

Front 222

RNA Viruses:

Infection can result in orchitis, which can lead to sterility

Back 222

Mumps virus

[Orchitis complicates parotidits in 20% of infected males]

Front 223

RNA Viruses:

Infection results in swelling of one or both parotids

Back 223

Mumps virus

[May result in aseptic meningitis and pancreatitis]

Front 224

RNA Viruses:

Major agent of epidemic gastroenteritis in adults

Back 224

Norwalk agent

[Outbreaks of this Calcivirus are common in institutional settings and on cruise ships]

Front 225

RNA Viruses:

Leading cause of croup

Back 225

Parainfluenza virus

[Also known as laryngotracheobronchitis, obstruction of the larynx results in a characteristic seal-bark cough]

Front 226

RNA Viruses:

Infection leads to the destruction of the cells of the anterior horn of the spinal cord

Back 226

Poliovirus

[Viral infection with this picornavirus can lead to denervation atrophy of innervated muscles with flaccid paralysis]

Front 227

RNA Viruses:

Infection is associated with an aversion to water, foaming at the mouth, and choking (hydrophobia)

Back 227

Rabies virus

["Bullet-shaped" virion can be seen by electron microscopy; causes intracellular viral inclusions in infected cells known as Negri bodies]

Front 228

RNA Viruses:

Only virus for which postexposure vaccination is indicated

Back 228

Rabies virus

[Long incubation period allows for the development of a protective immune response, without which CNS symptoms lead invariably to death]

Front 229

RNA Viruses:

Infection is associated with symptoms of sympathetic over-reactivity (i.e.salivation)

Back 229

Rabies virus

[Virus binds to the nicotinic acetylcholine receptor]

Front 230

RNA Viruses:

Most important cause of lower respiratory tract infection in infants

Back 230

Respiratory syncytial virus (RSV)

[Virally infected cells often form multinucleated syncytia]

Front 231

RNA Viruses:

Virion contains two identical strands of positive RNA (diploid-like genome)

Back 231

Retrovirus

[The virion also carries and RNA-dependent RNA polymerase, a reverse transcriptase, and an integrase for integration into the host cell genome]

Front 232

RNA Viruses:

Major cause of upper respiratory tract infections in humans

Back 232

Rhinovirus

[This picornavirus binds and enters epithelial cells via attachment to ICAM-1 and replicates best at 33⁰C, explaining its predilection for the mucosa of the nasopharynx]

Front 233

RNA Viruses:

Major cause of diarrhea (gastroenteritis) in young children

Back 233

Rotavirus

[This reovirus contains 10-12 segments of dsRNA within two concentric capsids]

Front 234

RNA Viruses:

Teratogenic virus leading to congenital defects of the heart, brain, and eye

Back 234

Rubella virus

[A member of the TORCH group of infectious agents that are capable of crossing the placenta and infecting the developing fetus]

Front 235

RNA Viruses:

This cause of mosquito-borne encephalitis can also be transmitted via blood transfusions and organ transplants, and causes life-threatening symptoms in elderly and immunosuppressed patients

Back 235

West Nile Virus

[Although first reported in Africa in the 1930's, the appearance of the Flavivirus family was first reported in the United States in 1999; recent years have seen large outbreaks with thousands of cases and nearly 200 deaths]

Front 236

RNA Viruses:

Arbovirus that causes severe hepatitis with jaundice and severe gastrointestinal hemorrhage with black vomit

Back 236

Yellow fever virus

[Infection by this Flavivirus, transmitted by the Aedes mosquito, can be prevented using a vaccine developed from the 17D strain]

Front 237

Disease:

A unique class of infectious agents that can result in Spongiform encephalitis

Back 237

Prions

[Composed only of proteinaceous material, it is highly resistant to most forms of sterilization and can be transmitted iatrogenically (e.g. surgical instruments, cadaveric material), or from consuming contaminated meats]

Front 238

Disease:

Opportunistic infections common in AIDS patients:

✦ Bacterial?

✦ Fungal?

✦ Protozoal?

✦ Viral?

Back 238

✦ Bacterial: Mycobacterium avium-intracellulare

✦ Fungal: Pneumocystis carinii

✦ Protozoal: Toxoplasma gondii & Cryptosporidium parvum

✦ Viral: Cytomegalovirus (CMV) & Kaposi sarcoma virus

Front 239

Disease:

Major sexually transmitted diseases in the United States:

✦ Bacterial?

✦ Protozoal?

✦ Viral?

Back 239

✦ Bacterial: Chlamydia trachomatis & Neisseria gonorrhoeae

✦ Protozoal: Trichomonas vaginalis

✦ Viral: Herpes simplex virus-2 (HSV-2), Human Immunodeficiency virus (HIV) & Human papilloma virus (HPV)

Front 240

Disease:

Major causes of meningitis:

✦ Newborns?

✦ Children?

✦ Young adults?

✦ Elderly (>60 years)?

✦ AIDS patients?

Back 240

✦ Newborns: Streptococcus agalactiae & Escherichia coli

✦ Children: Haemophilus influenzae

✦ Young adults: Neisseria meningitidis

✦ Elderly: Streptococcus pneumonia

✦ AIDS patients: Cryptococcus neoformans

Front 241

Disease:

Major cause of pneumonia:

✦ Neonates?

✦ Children (6 weeks-18 years)?

✦ Adults?

✦ Elderly (60 years)?

✦ Alcoholics & IV drug users?

✦ Post-viral?

✦ Cystic fibrosis patients?

Back 241

✦ Neonates: Streptococcus agalactiae & Escherichia coli

✦ Children: Respiratory syncytial virus (RSV) & Streptococcus pneumoniae (<4 years)

✦ Adults: Mycoplasma pneumonia

✦ Elderly: Streptococcus pneumoniae

✦ Alcoholics & IV drug users: Klebsiella pneumonia

✦ Post-viral: Haemophilus influenza

✦ Cystic fibrosis patients: Pseudomonas aeruginosa

Front 242

Disease:

Common nosocomial infections associated with:

✦ Newborns?

✦ Urinary catheterizations?

✦ Renal dialysis units?

✦ Respiratory therapy equipment?

✦ Water aerosols?

Back 242

✦ Newborns: Respiratory syncytial virus (RSV) & Cytomegalovirus (CMV)

✦ Urinary catheterizations: Escherichia coli & Proteus spp.

✦ Renal dialysis units: Hepatitis B virus (HBV)

✦ Respiratory therapy equipment: Pseudomonas aeruginosa

✦ Water aerosols: Legionella pneumophila

Front 243

Disease:

Major causes of endocarditis:

✦ Subacute endocarditis?

✦ Acute endocarditis?

✦ IV drug users?

✦ Patients with prosthetic valves?

Back 243

✦ Subacute endocarditis: Streptococcus viridans

✦ Acute endocarditis: Staphylococcus aureus

✦ IV drug users: Staphylococcus aureus

✦ Patients with prosthetic valves: Staphylococcus epidermidis

Front 244

Disease:

Major causes of osteomyelitis:

✦ General population?

✦ Sexually active?

✦ Drug users?

✦ Sickle cell anemia patients?

Back 244

✦ General population: Staphylococcus aureus

✦ Sexually active: Neisseria meningitidis

✦ Drug users: Pseudomonas aeruginosa

✦ Sickle cell anemia patients: Salmonella spp.

Front 245

Disease:

Organisms causing a watery diarrhea

Back 245

Cryptosporidium parvum
Escherichia coli
Vibrio cholerae
Giardia lamblia
Norwalk Agent
Rotavirus

Front 246

Disease:

Major causes of urinary tract infections

Back 246

Escherichia coli (most common)
Enterococcus faecalis
Klebsiella pneumonia
Proteus mirabilis
Proteus vulgaris
Pseudomonas aeruginosa
Serratia marcescens
Staphylococcus saprophyticus

Front 247

Disease:

Organisms causing a bloody diarrhea (dysentery)

Back 247

Campylobacter jejuni
Escherichia coli (enteroinvasive and enterohemorrhagic)
Salmonella spp.
Shigella dysenteriae
Entamoeba histolytica

Front 248

Disease:

Major causes of food poisoning

Back 248

Bacillus cereus
Clostridium perfringens
Staphylococcus aureus
Vibrio parahaemolyticus

Front 249

Disease:

Major cause of transplacental neonatal infections

Back 249

Toxoplasma gondii
Treponema pallidum
Rubella virus
Cytomegalovirus (CMV)
Herpes simplex virus (HSV)
Human immunodeficiency virus (HIV)

[Collectively known as the TORCH group, many of these infections can lead to congenital defects if acquired in utero]

Front 250

Disease:

Major causes of transcervical neonatal infections (acquired by vaginal delivery)

Back 250

Candida albicans
Escherichia coli
Listeria monocytogenes
Streptococcus agalactiae