Cls 271 Quiz 4

Front 1

Anaerobes Defined

Back 1

- Obligate anaerobes are killed by oxygen

- Can only grow in the absence of oxygen

- Do not require oxygen for life and reproduction

- Oxygen has a direct toxic effect. Anaerobes lack enzymes to break down toxic products. O2- superoxide, H2O2 hydrogen peroxide, OH- hydroxyl radical

Aerobic have enzymes that break down toxic products of oxygen and thats why they can survive

Front 2

Gram-Positive Spore Forming Anaerobic Bacilli

Back 2

- All in the genus Clostridium

- C. perfringens. Boxcar-shaped gram-positive, spore forming bacillus. Produces a double zone of hemolysis on Brucella blood agar or blood agar.

- C. tetani. Heavily swarming with terminal spores.

Anaerobes are classified as spore forming or non spore forming. Spore forming are more pathogenic.

C. Perfringens causes gastroenteritis and C. Tetani is found in soil, causing paralysis.

Front 3

Clinical Infections of Gram Positive Spore Forming Anaerobic Bacilli

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- Most frequently encountered in exogenous (bacteria from an outside source) infections. Wounds, ingesting toxins.

- Endogenous infections. C. difficile. Antibiotic associated diarrhea and pseudomembranous colitis.

- Diseases. Tetanus Clostridium tetani. Gas gangrene by Clostridium perfringens. Botulism from Clostridium botulinim. Other food poisoning from Clostridium sp.

- C. Diff from sequel of prolonged antibiotic therapy. Number one on list of diarrhea type problem in hospitals is C. Diff.

- C. Botulinum from canned goods. Grow anaerobically inside can, produce toxin, toxin very powerful and kills quite readily. neurotoxin. if edge of can is bulging, be mindful of canned goods.

Front 4

Antibiotic Associated Diarrhea

Back 4

- C. difficile. Most common isolate in antibiotic-associated diarrhea. Can cause pseudomembranous colitis, which is a necrosis of colon tissue and bloody diarrhea.

- Develops when normal flora are destroyed by antimicrobials that do not affect clostridium. Increased growth causing toxin production. Toxin A is enterotoxin and Toxin B is cytotoxin.

Most common isolate but usually dont culture for it because difficult to grow. Very distinctive odor associated with people with disease. 2 toxins. Just know has toxins that cause damage.

Front 5

Actinomycosis

What is the most important cause of actinomycosis?

Back 5

- Actinomyces israelii. Generally the most important cause of Actinomycosis. Pus drains from sinus wounds causing "sulfur granules" which are small bacterial colonies. Also Eubacterium and propionibacterium.

- Oral infections. Actinomyces "Lump Jaw" (Primary disease of Actinomyces)

- Colon infections causing seeding of the blood, bacterial endocarditis, and abscesses.

- Filamentous type bacteria

- Fungal like qualities and bacterial like qualities.

- Actinomyces are not acid fast.

- Carry in mouth, bad dental work, impacted molars, root canals, abscessces of jaw, can form granulomas, separate or form drainage channel to the outside, producing disfiguring type of disease called lump jaw.

- Cattle can also be infected.

Front 6

Anaerobic Culture quality and Collection method

Back 6

- Need proper education about which sites are appropriate for anaerobes.

- Requires rapid processing. Why? Because of toxicity to oxygen and drying of specimen.

- Aspirates (Best form of specimen)

- Swabs (Worst specimen except when pre reduced)

- Tissue

- Blood (Also good samples)

Front 7

Anaerobic Chambers Best Anaerobic System (Basic Components)

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- Gases. Hydrogen gas (5-10%), Carbon dioxide gas (5-10%), Nitrogen gas (80-90%).

- Catalysts. Palladium coated alumina pellets for removing any residual oxygen

Anaerobic jars use this catalyst and oxygen absorbing type material.

Front 8

What anaerobe causes double zone of hemolysis?

Back 8

C. Perfringens

Front 9

What is the initial ID for Anaerobic Isolates?

Back 9

- The gram stain is the initial ID

- Gram negative bacilli are the most common clinical isolate anaerobically.

- Gram positive bacilli, if spore forming and clostridium species, easy to identify

Front 10

Spirochetes

Back 10

- Helical-shaped motile bacteria. 0.1-3.0 nanometers in diameter by 5-20 nanometers in length. Maintain mobility in high viscosity liquids.

- Treponema pallidum subspecies pallidum causes syphilis. (Number 1 is treponema pallidum)

- Borrelia causes relapsing fever and Lyme disease.

- Leptospira causes leptospirosis. (From animals)

- Spirilum minor causes rat-bite fever.

Front 11

Leptospira Characteristics (Leptospires)

What causes leptospirosis?

Back 11

- Obligate aerobic helical rods 0.1 um by 6-12 um long.

- Motility by periplasmic flagella on cell wall.

- Leptospira interrogans causes Leptospirosis.

- Aerobic zoonotic type infection

Front 12

What epidemic did Leptospira cause?

Back 12

Eco-challenge Borneo epidemic

Front 13

Leptospira Virulence Factors

Back 13

- Unknown but may include reduced phagocytosis, Hemolysin, and Endotoxins

Front 14

What is the leptospires secondary immune phase about?

Back 14

- Begins after 1-3 day absence of symptoms.

- Spirochetes are rapidly cleared from the blood (Jarisch-Herxheimer reaction)

- Large amounts of inflammation, with pleocytosis (increased white blood cell count) of the CSF 90%.

- Half of these develop into aseptic meningitis. (Leptopspira mimic viral meningitis)

Front 15

Leptospire diseases

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- Weil's disease is a fatal systemic disease. Causes jaundice, acute renal failure, and liver dysfunction. Patient turns yellow. Associate Weil's disease with leptospirilla.

- Zoonotic disease. Animal workers or in rat infested surroundings. Dog and rats principal hosts but other animals have been implicated. Excretion in urine of rodents. Infection enters by contact with infected urine of infected animals.

Front 16

Lab Diagnosis of Leptospira

Back 16

- Culture. Fletcher's or Korthof's medium.

- Direct from blood and CSF the first week; then urine to one month.

- Serology. Microagglutination with formalin-killed leptospira > 1:200 titer is presumptive positive with clinical profile.

- PCR in the works.

Done through serological tests. Looking for antibody response to organism itself.

Front 17

Borreliae (Borrelia Charactersitics)

Back 17

- Helical bacteria 0.2-0.5 um by 3-20 um in length.

Front 18

Borelliae Diseases (B. recurrentis and B. hermsii)

Back 18

- Relapsing fever caused by B. recurrentis and B. hermsii.

- Borelliae recurrentis causes pediculus humanus louse-borne infection because overcrowding causes spread of infection.

- Frequent in Africa, Middle East, and Asia.

- Borelliae hermsii causes tick-borne infections from Ornithodoros ticks. This can have a worldwide distribution of infection.

Something you get from the tick. Arthropod borne type of infection. Lymes disease is the most famous here in this country. Lyme disease and relapsing fevers are 2 kinds of borelliae.

Front 19

Borelliae Diseases (B. burgdorferi)

Back 19

- Lyme disease. Lyme Conneticut (Named for having an outbreak of lyme disease)

- Spread through tick bites. Ixodes ticks that are active June through September.

Front 20

How can you prevent infection from Borreliae?

Back 20

Wear protective clothing and repellants

Front 21

How do you treat B. Burgdorferi?

Back 21

- Antibiotics. Early stages, use doxycycline. During the late stages, antibiotics are useless. Tetracycline preferred for use now because lower toxicity to patient.

Front 22

How is B. Burgdorferi detected in the lab?

Back 22

- Generally only screen those with symptoms and high risk factors.

- Direct Fluorescence Antibody test or direct detection of spirochetes in the blood. Use darkfield microscopy.

- Culture (modified Kelly's medium) for the early stages.

- PCR

- Culture is not effective. Direct field fluorescence stains are better.

Front 23

Syphilitic Infection (Primary Syphilis)

Back 23

- Chancre (painless ulcer) at infection site (usually one but sometimes several in HIV+). Clean, smooth base, edge slightly raised and firm. Painless but may be tender. Heals in 3-6 weeks.

- Base contains spirochetes that can be identified by dark field microscopy or immunofluorescence, serology.

Traditional way to diagnose is to unroof chancre and identify with dark field microscopy but that is cumbersome so they would rather just use serology.

Front 24

Syphilitic Infection (Secondary Syphilis)

Back 24

- Begins 2-8 weeks after chancre appearance.

- Widespread macular rash (Syphilitic roseola) particularly palms and soles of feet.

- Condyolomata lata appears, which are moist gray-white plaques teeming with spirochetes.

- Systemic symptoms occur. Lymphadenopathy, fever, headache, malaise, and other organ involvement such as liver or eye. Sometimes aseptic meningitis and culture of spirochetes from CSF even if no symptoms.

Front 25

Syphilitic Infection (Latent Syphilis)

Back 25

- Early latent phase. The initial 4 years relapses occur, then patient is infectious.

- Late latent phase. Indefinite duration. Sometimes no complications ever appear.

- Detected only through serology.

Front 26

Syphilitic Infection (Late Syphilis)(Tertiary)

Back 26

- Late complications of syphilis involving many organs.

- Manifests decades after primary infection.

Front 27

Syphilis Epidemiology (How is it transmitted?)

Back 27

- Sexual contact, direct injection, direct contact with lesions, transplacental transmission.

- Acquired on transplacental transmission from mother to child.

- Can acquire in lab

Front 28

Syphilis Detection in lab

Back 28

Serological Tests

- VDRL. Cardiolipin antigen is mixed with patient serum or CSF. If positive flocculation (clumping) occurs and can be read microscpically.

- RPR. Black carbon particles are bound to cardiolipin and mixed with patient sera. Particles agglutinate thus indicating positive test.

Fluorescent treponemal antibody absorption test (FTA-ABS) confirmatory test only

- patient serum is absorbed against nonpallidum spirochetes. Absorbed serum then placed with T. pallidum organisms. Secondary antihuman antibody conjugated to a fluorescin is added.

Microhemagglutination test (MHA-TP)

- antigens to T. pallidum are absorbed to RBCs. Patient serum added and RBCs agglutinate.

Pregnant mothers are part of prenatal work up.

RPR is used on serum and VDRL is used on serum or CSF.

FTA-ABS is most common test done.

Front 29

Chlamydia trachomatis description and symptoms

Back 29

- Obligate intracellular pathogenic parasites.

Symptoms

- Urethritis with purulent discharge #1 STD only second to HPV.

- Cervicitis, salpingitis (inflammation of fallopian tubes)

- Eye infections - conjunctivitis and scarring of the eye (mechanical deforming of eyelashes)

- #1 cause of preventable blindness worldwide

- Neonatal - eye infections and pneumonia

Incidence much greater than gonorrheae.

Ectopic pregnancies.

Front 30

When Chlamydia trachomatis gets into the lymphatics, what disease does this cause?

What serotypes cause this?

Where can you find this disease mostly?

Back 30

Lymphogranuloma Venereum (LVG)

- Chlamydia trachomatis serovars L1, L2, L2a, and L3 cause LVG.

- Survive in mononuclear cells. Bubo formation then can rupture lymph node.

- Uncommon in the US. Find most cases in Tropics and subtropical areas abroad like Africa and Asia.

Front 31

Other serotypes of Chlamydia trachomatis

Back 31

- Serovars D-K

Men

- nongonococcal urethritis (GNU)

- epididymitis

- Prostatitis

Women

- Cervicitis

- Endometritis

- Proctitis

- Salpingitis

- PID

Front 32

Rickettsiae General Characteristics

Back 32

Rickettsiae or Orienta

- Obligate intracellular bacteria

- Arthropod-borne

Front 33

Rickettsiae Spotted Fever Group

Back 33

Rocky Mountain spotted fever - RMSF

Rickettsia rickettii

- Humans are accidental hosts. Usually transmitted by D. variabilis and D. andersoni ticks.

Clinical Manifestations

- Flulike symptoms. Fever, headache, myalgia, nausea, and vomiting.

- Rash. Erythematous patch on ankles or wrists. May extend to hands and soles of the feet but not the face.

Connect Rocky Mountain spotted fever with Rickettsia rickettii.

Front 34

Rickettsiae Typhus Group

Back 34

Endemic typhus also known as murine typhus.

- Rickettsiae tyhpi

- Vector-Oriental rat flea and cat flea

- Rat as primary reservoir

- Typhus rickettsiae replicate in host cell cytoplasm causing cell lysis, other rickettsiae pass through host cell membrane leaving host cell intact.

Epidemic louse-borne typhus

- Also known as Brill Zinsser disease

- Caused by Rickettsiae prowazekii

Endemic is flea while epidemic is lice

Front 35

Endemic Typhus

Back 35

Vector

- The oriental rat flea is the Xenopsylla cheopis

- The cat flea is Ctenocephalides felis.

Reservoir

- Rat and transovarian transmission

Infection

- Occurs when flea defecates on skin. Scratching infects the bite.

Symptoms

- Fever, headache, and rash

Front 36

What two mycoplasma species are known human pathogens?

Back 36

- Mycoplasma pneumoniae

- Mycoplasma hominis

Front 37

Mycoplasma Detection

Back 37

Very difficult to detect.

- Common contaminant of cell culture. Important in research and in virus labs utilizing cell culture.

- Emerging pathogens.

Small, difficult to detect.

Causes antibody titer agglutination masking real problems. Gives blood bank problems

Front 38

Mycoplasma Characteristics

Back 38

- smallest free - living organism in nature

- Sometimes known as pleuropneumonia-like organism (PPLO)

- Colonies grow with center imbedded below agar surface so it appears as "fried eggs"

- First isolated from bovines as pleuropneumonia. Eaton agent from discoverer late 1800s.

Do not possess cell walls

- Sometimes referred to as CWD (cell wall deficients)

Resistant to cell wall active antibiotics

- Penicillins, cephalosporins

- Bonus is that above antibiotics can help reduce normal florae organisms that have a cell wall

Slow Growing

Fastidious Mycoplasma and Mycoplasma like organisms

- Require cholestrol and fatty acids for growth. Note these are conditions found in cultures growing eukaryotic cells. Human sites. 20% fetal calf serum added to media for growth.

Front 39

Clinical infections of Mycoplasma pneumoniae

Back 39

Diseases

- Bronchitis

- Pharyngitis

- Walking pneumonia (atypical pneumonia) (Number one)

- Mostly asymptomatic >90% (Patient only mildly ill)

Isolation always indicates pathogenicity

- 20% pneumonia in general populations. School-age children and young adults.

- 50% in military settings.

- College dorms

- Prisons and refugee settings

- Other Pneumoniae like K. Pneumoniae is symptomatic and puts patient on bed while this leaves them walking.

Front 40

Clinical infections of Mycoplasma hominis

Back 40

Infections of the urogenital tract

- Found as normal florae in patients. Difficult to determine if cause of symptoms.

- Can cause infections of the upper urinary tract in sexually active people.

- Opportunistic pathogen. May appear more often as a pathogen in immunocompromised.

- Salpingitis. inflammation of the fallopian tubes.

- Pyelonephritis - infection of kidney and ducts

- PID (Pelvic inflammatory disease)

Front 41

Clinical infections of Ureaplasma urealyticum

Back 41

Infections of the urogenital tract

- Normal florae of the lower urinary tract of women. Still can cause upper urinary tract infections.

- Significant due to infection of fetus. Chorioamnionitis ( infection of placental membrane.) Congenital pneumonia. Chronic lung disease in premature infants. Meningitis of newborns with negative cultures.

10% of cases of non-GB urethritis in men

Front 42

Mycoplasma specimen collection

Back 42

Extremely sensitive to drying due to lack of cell wall

Swabs in transport medium

- Trypticase soy broth

- 0.5% albumin and penicillin to remove normal florae

If not plated immediately freeze specimen at -70 degrees celsius. Why? So it does not form ice crystals