Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
133 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Virulence factors of N. Meningitidis?
|
Capsule
Endotoxin IgA1 protease - cleaves IgA in half Ability to extract iron from transferrin |
|
|
|
High risk groups for N. Meningitidis?
|
Infants 6 months to 2 years
Army recruits |
|
|
|
Where are N. meningitidis carriers colonized?
|
nasopharynx
|
|
|
|
Classic medium for culturing neisseria
|
Thayer Martin VCN media (vanc, colistin, nystatin)
|
|
|
|
How can N. meningitditis be seperated from N gonorrhoeae in the lab?
|
ability to produce acid from maltose metabolism
|
|
|
|
What are close contacts of meningococcus sufferers treated with as prophylaxis?
|
Rifampin
|
|
|
|
Virulence factors of gonococcus?
|
Pili
Protein II |
|
|
|
Complications of gonococcal urethritis in males?
|
epididymitis
prostatitis uretrhal stricture |
|
|
|
Complicatinos of gonocoocemia?
|
Pericarditis
Endocarditis Meningitis |
|
|
|
Onset of ophthalmia neonatorum from gonococcus?
|
first or second day of life
Corneal damage |
|
|
|
Treatment of moraxella catarrhalis?
|
azithromycin or clarithromycin
amoxicillin with clavulanate second or third generation cephalosoporin TMP-SMX |
|
|
|
What are the antigens on enterics and what are tehir functions?
|
O antigen - LPS (outer antigen)
K antigen - capsule that covers O antigen H antigen - subunits of flagella |
|
|
|
Virulence factors of E. coli?
|
Mucosal interactoin - adherence with pili, ability to invade intestinal epithelial cells
Exotoxin production - heat-labile and stable toxin, and shiga toxin Endo toxin Iron binding siderophore - obtains iron from transferring, lactoferrin |
|
|
|
Mechanism of E. coli heat labile and stable toxin effect?
|
inhibition of reabosorption of Na and stimulation of secretion of Cl and HCO3
|
|
|
|
Mechanism of Shiga like toxin?
|
inhibition of protein synthesis by inhibition of 60S ribosome
|
|
|
|
Testable feature of urine that can distinguish UTI from proteus (or other urease carrying bug) from other enterics?
|
pH - alkaline pH
|
|
|
|
What is the function of Salmonella's Vi antigen?
|
polysaccharide capsule that surrounds O antigen protecting bacteria from antibody attack on O antigen
|
|
|
|
Presentation of typhoid fever?
|
1-3 weeks after exposure
Fever, headache, abdominal pain that is diffuse or localized to RLQ Splenomegaly sometimes Diarrhea and rose spots on abdomen |
|
|
|
Treatment of typhoid fever?
|
Ciprofloxacin or cetftriaxone
|
|
|
|
Where is salmonella typhii in a chronic carrier state held?
|
Gall bladder - removal may cure carrier status
|
|
|
|
What species of salmonella usually causes sepsis?
|
Salmonella choleraesuis
|
|
|
|
Treatment for salmonella gastroenteritis?
|
fluid and electrolyte replacement
antibiotics do not shorten course |
|
|
|
How is Yersinia entrocolitica transferred?
|
Fecal - oral route
|
|
|
|
Presentation of yersinia gastroenteritis?
|
RLQ pain, fever, diarrhea, abdominal pain
|
|
|
|
Pathogenesis of yersinia gastroenteritis?
|
binding to intestinal wall and systemic invasion into regional lymph nodes and blood stream
Enterotoxin similar to heat stable toxin of E. coli causing diarrhea |
|
|
|
Mechanism of cholera toxin?
|
A and 5 B subunits
B binds to GM1 A activates G protein stimulating adenylate cyclase resulting in production of cAMP - active secretion of Na and Cl, inhibition of reabsorption |
|
|
|
Treatment of Cholera?
|
Fluid, electrolytes, doxycycline
|
|
|
|
What is the leading cause of diarrhea in Japan and how does one get it?
|
Vibrio parahaemolyticus
Uncooked seafood |
|
|
|
What are the three most common infectious agents causing diarrhea in the world?
|
Camplyobacter, ETEC, rotavirus
|
|
|
|
How does on get camplyobacter?
|
wild and domestic animal contact, poultry, unpastuerized milk
|
|
|
|
Types of infections caused by pseudomonas?
|
Pneumonia in immunocompromised and CF
Osteomyelitis in diabetics, IV drug users and children with puncture wounds of foot Burn wound infection Sepsis UTI, pyelo - debilitated patients in nursing homes nad hospitals with Foley catheters Endocarditis - right heart valve endocarditis in IV drug abusers Malignant external otitis - elderly diabetic patients Corneal infections - contact lens wearers |
|
|
|
Diseases caused by Haemophilus influenza type b?
|
Meningitis
Septic Arthritis Epiglottitis |
|
|
|
What agent most commonly causes septic arthritis in infants?
|
Hib
|
|
|
|
Presentation of Chancroid?
|
Unilateral painful swollen inguinal lymph nodes - nodes become matteted and rupture releasing pus
painful genital ulcer No systemic symptoms typicaly |
|
|
|
How does presentation of lymphogranulmoa venereum differ from that of Chancroid?
|
primary ulcer of LGV disappears before nodes enlarge; in chancroid they coexist
|
|
|
|
How should chancroid be treated?
|
erythromycin or TMP-SMX
|
|
|
|
What are the bordetella pertussis exotoxins?
|
Pertussis toxin - A subunit activated cell membrane bound G proteins causing rise in cAMP - effects: histamine sensitization, increase in insulin synthesis, promotion of lymphocyte production and inhibition of phagocytosis
Extra cytoplasmic adenylate cyclase - taken up by neutrophils, lymphocytes, monocytes - impaired chemotaxis, generation of H2O2, superoxide Filamentous hemagglutinin - pili rod used in binding, antigenic Tracheal cytotoxin - destroys ciliated epithelial cells, likely responsible for cough |
|
|
|
Stages of whooping cough and features?
|
Catarrhal stage - 1-2 weeks: low grade fever, runny nose, sneezing, mild cough; most contagious
Paroxysmal stage - bursts of nonproductive cough; increase in lymphocyte count with modest increase in neutrophils like viral picture Convalescent stage - less frequent attacks over month, no longer contagious |
|
|
|
How is bordetella pertussis diagnosed?
|
culture using swab made from calcium alginate
potato, blood, glycerol agar - Bordet - Gengou medium or ELISA |
|
|
|
What is the name of this amino acid?
|
Valine
|
V
|
|
|
Disease caused by Legionella Pneumophila and presentation?
|
Pontiac fever - headache, muscle aches, fatigue followed by fever and chills
Strikes suddenly and resolves in a week. Legionnaires disease - high fevers, severe penumonia Community acquired pneumonia |
|
|
|
Which animals does yersinia pestis live on?
|
prarie dogs and squirrels in the southwestern US
|
|
|
|
Virulence factors of yersinia pestis?
|
F1 - capsular antigen - antiphagocytic
V and W - protein and lipoprotein are antigenic |
|
|
|
What activities predispose individuals to yersinia pestis infection?
|
camping, hunting, hiking
touching infected dead rodent or being bitten by flea |
|
|
|
Presentation of bubonic plague?
|
movement to nearest lymph nodes (usually inguinal).
Lymph node swelling - red, hot painful Fever and headache following this Hemorrhages under skin (blackish discoloration) Death in a few days without treatment (during epidemics pneumonic plague as well) |
|
|
|
Treatment of bubonic plague?
|
Gentamicin
|
|
|
|
Risk factors for brucella exposure?
|
direct contact with infected animal meat or aborted cow placenta
Ingestion of infected milk products Meat factory worker (beef), veterinarian, farmer, traveler consuming dairy |
|
|
|
Presentation of brucella infection?
|
Systemic symptoms - fever, chills, sweats, loss of appetite, backache, headache, lymphadenopathy
Fever peaks in evening and slowly returns to normal by morning - undulant fever May last months to years Not often fatal |
|
|
|
Diagnosis of brucella?
|
Culture
Anti-brucella antibodies suggests active disease Skin test with brucellergin but positive test only indicated exposure and not active brucellosis |
|
|
|
What subtypes of chlamydia cause trachoma?
|
serotypes A, B, C
|
|
|
|
What diseases are caused by serotypes D through K of chlamydia?
|
Inclusion conjunctivitis (newborns)
Infant pneumonia Cervicitis Nongonococcal urethritis in men |
|
|
|
Most common group to get trachoma in US?
|
Native Americans
|
|
|
|
Transfer of organisms causing trachoma?
|
hand to hand transmission of infected eye secretions
Sharing of contaminated towels or clothing |
|
|
|
Treatment of trachoma?
|
topical tetracycline
|
|
|
|
Presentation of inclusion conjunctivitis?
|
purulent yellow discharge
swelling of eyelids 5-14 days after birth |
|
|
|
Prevention of inclusion conjunctivitis?
|
Erythromycin prophylaxis
|
|
|
|
Diagnosis of inclusion conjunctivitis?
|
basophilic intracytoplasmic inclusion bodies
|
|
|
|
When does infant pneumonia from chlamydia typically occur?
|
4-11 weeks of life
|
|
|
|
Presentation of infant pneumonia from chlamydia?
|
upper respiratory symptoms initially followed by rapid breathing, cough, respiratory distress
|
|
|
|
Diagnosis of infant pneumonia from chlamydia?
|
Initially clinical
Confirmation by presence of anti-chlamydial IgM |
|
|
|
Treatment of infant pneumonia from chlamydia?
|
oral erythromycin
|
|
|
|
What are the bugs that most commonly cause nongonoccocal urethritis?
|
Ureaplasma urealyticum, chlamydia trachomatis
|
|
|
|
Treatment regimen for urethritis?
|
IM ceftriaxone, 7 day course of doxy or 1 dose azithromycin
|
|
|
|
Demographics for Reiter's syndrome?
|
young men 20-40
|
|
|
|
Presentation of lymphogranuloma venereum?
|
painless papule or ulceration on genitals that heals spontaneously
Regional lymph node enlargement over next 2 months Node tenderness, may break open and drain pus |
|
|
|
How does one contract psittacosis?
|
inhalation of Chalmydia laden dust from feathers or dried out feces
|
|
|
|
Risk factors for psittacossis?
|
breeders of carrier pigeons, veterinarians, workers in pet-shops or poultry slaughterhouses
|
|
|
|
What unrelated bacteria do Rickettsia share antigenic characteristics with?
What test for Rickettsia makes use of this relationship? |
Proteus vulgaris bacteria
Weil-Felix reaction |
|
|
|
Diagnosis of Rickettsia?
|
Weil-Felix test
serologic tests (indirect immunofluorescence test, complment fixatino test, ELISA) |
|
|
|
How does one get rocky mountain spotted fever?
|
wood tick bite (Dermacentor andersoni)
dog tick bite (Dermacentor variabilis) |
|
|
|
Presentation of rocky mountain spotted fever?
|
Presentation 1 week after tick bite
fever, conjunctival redness, severe headache Rash appearing on wrists ankles, soles, palms --> spread to trunk Resolution in 3 weeks in most cases |
|
|
|
Presentation of rickettsial pox?
|
initial localized red skin bump at site of mite bite
bump turns to blister and days later fever and headahce develop other vescicles appear over the body |
|
|
|
Organism causing rickettsial pox?
|
Rickettsia akari
|
|
|
|
Treatment of rickettsial pox?
|
Doxy
|
|
|
|
What organism causes epidemic typhus?
|
rickettsia prowazekii
|
|
|
|
Reservoirs of ricketssia prowazekii ?
|
flying squirrels
|
|
|
|
How is epidemic typhus transferred?
|
lice of freas from infected squirrels bite humans
Usually in places with overcrowding, poverty, unsanitary conditions |
|
|
|
Presentation of epidemic typhus?
|
2 week incubation
onset of fever and headahce Small pink macules appear around 5th day on upper trunk and quickly cover entire body Rash spares palms, soles, face Delirium, stupor Resolution in 3 weeks |
|
|
|
What is Brill-Zinsser disease?
|
Epidemic typhus that is not treated with antibiotics often causes latent rickettsia to hang around patient
Brin Zinsser is a reactivation syndrom milder symptoms with no skin rash |
|
|
|
How is Brinn Zinsser disease diagnosed?
|
Early rapid rise in IgG titer for Rickettsia prowazekii rather than rise in IgM (primary infection)
|
|
|
|
What organism causes endemic or murine typhus?
|
Rickettsia typhi
|
|
|
|
What transfers endemic typhus to humans?
|
rat flea
|
|
|
|
Presentation of endemic typhus?
|
10 day incubation
fever, headache flat, sometimes bumpy rash |
|
|
|
What organism causes scrub typhus?
What is another name for this? |
Rickettsia tsutsugamushi
Tsutsugamushi fever |
|
|
|
Risk factors for Ricketssia tsutsugamushi?
|
Asia and southwest pacific
soldiers in south pacific during wold war II and vietnam |
|
|
|
How is rickettsia tsutsugamushi spread?
|
bite of larvae of mites (chiggers)
|
|
|
|
Presentation of Tsutsugamushi fever?
|
After 2 week incubation period - high fever, headhace, scab at orginal bite site
later a flat and sometimes bumpy rash |
|
|
|
What organism causes trench fever?
|
bartonella quintana
|
|
|
|
Presentation of trench fever?
|
high fevers, rash, headahce, severe back and leg pains
Relapse after 5 days of seeping recovery Multiple relapses but fatalities are rare |
|
|
|
In whom does bacillary angiomatosis typically occur?
|
AIDs patients with bartonella hensalae infections
|
|
|
|
Which gram negative zoonotic bug forms endospores?
|
Coxiella burnetii
|
|
|
|
Q fever presentation?
|
2-3 weeks after infection
abrupt onset of fever and soaking sweats pneumonia |
|
|
|
Presentation of erlichiosis?
|
High fever, severe headahce but rarely rash (20%)
|
|
|
|
How long after inoculation does syphilis ulcer present?
|
3-6 weeks
|
|
|
|
How long does it take for a syphilis ulcer to resolve?
|
4-6 weeks (without scar)
|
|
|
|
How long after primary syphillis does secondary syphilis develop?
|
6 weeks
|
|
|
|
What does secondary syphilis rash look like?
|
small red macular lesions symmetrically distributed over body - on palms, soles, mucous membranes of oral cavity
May become bumpy or pustular |
|
|
|
Presentation of condyloma latum?
|
Painless wart-like lesion in warm moist sites like vulva or scrotum
Ulcerates In areas of hair growth - patchy bald spots and loss of eyebrows |
|
|
|
Which organ systems are affected by secondary syphilis?
|
CNS, eyes, kidneys, bones
Also systemic signs such as lymphadenopathy, weight loss, fever |
|
|
|
How long do rash of secondary syphilis and condylmoa lata take to resolve?
|
6 weeks
|
|
|
|
What proportion of patients experience a relapse of secondary syphilis?
|
25%
|
|
|
|
How long after primary infection does Gummatous syphilis occur? In what proportion of untreated patients?
|
3-10 years
15% |
|
|
|
What are gummas?
|
granulomatous lesions which eventually necrose and become fibrotic
Mainly skin and bone lesions skin lesions - painless solitary lesions with sharp borders Bone lesions - deep gnawing pain Resolution with antibiotics |
|
|
|
How long after primary infection does Cardiovascular syphilis occur? In what proportion of untreated patients?
|
10 years in 10%
|
|
|
|
How does cardiovascular syphilis present?
|
aneurysm formation in ascending aorta or aortic arch
Resulting aortic valve insufficiency and occlusion of coronary arteries Abx do not help |
|
|
|
What are the five most common manifestations of neurosyphilis?
|
Asymptomatic neurosyphilis - clinically normal, positive CSF testing
Subacute meningitis - fever, stiff neck, headache; CSF shows high lymphocyte count, high protein, low glucose, positive syphilis tests Meningovascular syphilis - cerebrovascular occlusion and infarction of brain, spinal cord, meninges Tabes dorsalis - posterior coumn and dorsal roots of spinal cord affected General paresis - mental deterioration, and psychiatric symptoms |
|
|
|
In what manifestations of neurosyphilis is the argyll robertson pupil present?
|
Geneal paresis, tabes dorsalis
|
|
|
|
Grossly, what part of the brain is damaged to cause Argyll robertson pupil?
|
midbrain
|
|
|
|
Presentation of early congenital syphillis?
|
Occurs within 2 years and is like severe adult secondary syphilis
wide spread rash, condyloma latum snuffles lymph node, liver, spleen enlargement, bone infection |
|
|
|
How does late congenital syphilis present?
|
Like tertiary syphillis but cardiovascular involvement doesn't usually occur
Neurosyphillis is same as adults - 8th nerve palsy is common bone and teeth involved - saddle nose, saber shins, Hutchinson's teeth, mulberry molars Eye disease - corneal inflammation |
|
|
|
When in gestation does syphilis affect fetus?
|
fourth month of pregnancy
|
|
|
|
What are causes of false positive VDRLs, RPRs?
|
pregnancy, acute febrile illness, intravenous drugs, immunization
|
|
|
|
Causes of FTA-ABS positivity?
|
syphillis, yaws, pinta, leptospirosis, Lyme
|
|
|
|
What is the likely cause of a VDRL or RPR negative test with FTA-ABS positivity?
|
Successfully treated syphilis
|
|
|
|
Which patients with syphilis may have negative FTA-ABS testing?
|
HIV, recently infected
|
|
|
|
What organism causes yaws?
|
treponema pallidum subspecies pertenue
|
|
|
|
what organism causes pinta?
|
treponema pallidum subspecies carateum
|
|
|
|
What treponema subspecies causes endemic syphilis?
|
treponema pallidum endemicum
|
|
|
|
Where does endemic syhphilis occur?
|
desert zones of Africa or Middle East
|
|
|
|
how is endemic syphilis spread?
|
sharing drinking water and eating utensils
|
|
|
|
How does yaws spread?
|
contact with open ulcers
|
|
|
|
how does yaws present?
|
papule at site of initial inoculation which grows over months becoming wartlike
secondary lesions appear on exposed parts of body Later tertiary gummas in skin and long bones |
|
|
|
Where does pinta occur?
|
rural Latin America
|
|
|
|
How does pinta present?
|
purely skin disease
direct contact causes infection Papule develops which slowly expands - secondary eruption of numerous red lesions that turn blue in sun Within a year lesions become depigmented turning white |
|
|
|
Symptoms of early disseminated stage of lyme disease?
|
Multiple smaller ECM
Neurologic - aseptic meningitis, CN palsies, peripheral neuropathy Cardiac - transient heart block or myocarditis Brief attacks of arthritis of large joints |
|
|
|
Symptoms of late stage disseminated lyme disease?
|
chromic arthritis, encephalopathy
|
|
|
|
Ho long after initial bite does first stage of lyme disease occur and how long does it last?
|
10 days, 4 weeks
|
|
|
|
How does early stage lyme disease present?
|
erythema chronicum migrams, fluelike illness, regional lymphadenopathy
|
|
|
|
What does borrelia recurrentis cause?
|
relapsing fever
high fever, chills, headaches, muscle aches rash and meingeal involvment may follow drenching sweats --> fever and symptoms resolve after 3-6 days afebrile for 8 days tehn relapse |
|
|
|
Where is leptospira found?
|
urine of dogs, rats, livestock, wild animals
|
|
|
|
What are the two phases of leptospirosis and how do they present?
|
leptospiremic phase - abrupt onset of high spiking temps, headache malaise, severe muscle aches.
Classically - red conjunctiva, photophobia After 1 week - short afebrile period Then fever and earlier symptoms recur Second phase correlateds with appearance of IgM antibodies Meningismus |
|
|
|
What disease do leptospira interrogans cause?
|
Weil's disease (infectious jaundice)
renal failure, hepatitis with jaundice, change in mental status, hemorrhage in many organs |
|
|
|
Diagnosis of leptospira?
|
culture from blood or CSF in initial phase
culture from urine in second phase initiate treatment before culture positivity |
|
