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finish of fastidious; Spirochetes


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What is the only contagious acid fast bacilli?
mycobacterium tuberculosis
which mycobacterium of them all is most commonly isolated?
m. tuberculosis
what bacteria is the leading cause of worldwide death?
Mycobacterium tuberculosis
What happens in the course of the disease tuberculosis?
1. Macrophages/PMNs trying to rid AFB form tubercle.
2. Tubercle may liquify, form AFB-filled cavity in lungs.
3. Symptoms manifest as chronic cough and low fever.
What are the symptoms of tuberculosis?
-Chronic cough
-LOW-grade fever
What is Miliary tb?
Tb disseminated beyond lungs due to tubercles rupturing.
-Indicated by positive urine.
2 types of TB skin tests:
What is the preferred TB skin test?
Why is Mantoux preferred to Tine for Tb skin test?
Mantoux is a good deep injection; the Tine uses a disk w/ little needles- less sensitive of test.
What is done if a TB skin test is +?
Chest x-ray; to see if tubercle is visible. (lesion) If no lesion is visible it's possible that a vaccine caused the postiive skin test.
What are the first line oral drugs for treatment of Tb?
-Isoniazid INH
-Rifampin RIF
-Pyrazinamide PZA
-Ethambutol EMB
What injectable drug treats Tb?
What AFB species is found in cows?
Disease it causes?
Mycobacterium bovis

Disease similar to Tb, but rare in U.S.
What is BCG?
an attenuated strain of M. bovis that is a vaccine for TB in endemic areas.
What are the four Runyon groups?
-Rapid growers
Distinguish. characteristic of Photochromogens
Develop a yellow-orange pigment only when exposed to light, after growth.
2 species of Photochromogens:
Mycobacterium kansasii
M. marinum
What disease does M. kansasii cause, what group is it in?
photochromogens; causes a chronic disease similar to Tuberculosis
What disease does m. marinum cause, what group is it in?

what specimen do you test for it?
Skin disease from a water source; called swimming pool granuloma.
Skin specimen, incubated at 30 C
Distinguishing feature of Scotochromogens:
produce a pigment in the DARK - before exposure to light
2 species of scotochromogens:
M. scrofulaceum
M. gordonae
What does M. scrofulaceum cause?
scrofula of the neck - lymph node inflammation.
what is M. gordonae known for?
being a tap water contaminant; it can show up on a gram stain as a result, so we use distilled H2O.
What is the distinguishing feature of non-photochromogens?
they do not produce a pigment in either light nor dark
what species of runyon group three is a very common isolate in AIDs patients?
M. avium intracellulare complex
What disease does M. avium intracel. complex cause?
Pneumonia, or it disseminates to the skin, intestine, liver, and bone marrow.
Where are M. ulcerans and M. haemophilum commonly found?
on skin/in skin ulcerations of AIDS patients
What is the disting. feature of Runyon group four?
Rapid growers - they grow within 7 days.
what is the most frequently isolated species of the rapid growers?
M. fortuitum
What does mycobacterium fortuitum cause?
Soft tissue and bone infections after an injury
Which of the rapid growers is a questionable pathogen
M. smegmatis
5 methods for identifying Mycobacterium Species:
1. Biochemical
2. HPLC (hipress. liq. chrom)
3. BActec/ESP/BacTAlert
4. Nucleic acid probe
5. PCR on specimen
Fast method of Mycobacterium species id:

what is it?
BacT Alert, Bactec, ESP

-detects the rate of growth of the bug
What bug causes leprosy?
Mycobacterium leprae
another name for M. leprae
Hansen's bacillus
2 forms of leprosy:
Symptoms of Leprosy


Lep: bacilli are just under the skin surface and cause deformity.

Tub: bacilli infect nerve cells; skin turns to parchment w/ no sensation
How do you diagnose Leprosy?
Test for mycobacterium leprae;

-AFB smear

-Grow it - but only In Vivo; in an animal. no labs can grow it.
-By process of elimination
What bacteria is found in Armadillo footpads?
M. leprae
What disease is Mycobacterium paratuberculosis possibly associated with?
Crohn's disease
How is M. leprae transmitted?
through EXTENDED, close and direct contact.
What's a key biochemical trait of M. tuberculosis?
It's always niacin positive, and the only Mycobact. (fortuitum is -/+)
What is the distinguishing requirement for a bacteria to be spirochete?
Bacillus with a minimum of 1 coil
name of the antigen common to all spirochetes:
Reiter protein - useful in identification
What type of microscopic examination do you do for spirochetes?
Darkfield; reflected light shows the organism as a light area on the slide.
What fact re: spirochetes makes lab i.d. difficult?
it can't be grown in lab
what is the second most commonly isolated mycobacterium species?
mycobacterium avium intracellulare complex (MAIC)
what are the 3 genera of spirochetes?
What disease does Borrelia burgdorferi cause?
LYMES disease
Where was lyme's disease discovered?
Old Lymes, Connecticuit
How is lyme's disease transferred?
by a vector - deer ticks; in places with high populations of white-tailed deer
what are the three stages of symptoms of lyme disease?
Stage 1: Skin lesion called erythema chronicum migrans; flu-like symptoms.

Stage 2: Neurologic or cardiac abnormalities.

Stage 3: Arthritis
How is lyme disease diagnosed/detected?
-by detection of antibody
-culture (but its not practical)
-PCR (but there arent any specs to test)
Is there a treatment for lymes disease?
YES -Doxycyline for 14-21 days;
What causes fusospirochetal disease?
Another name?
Vincent's angina;
caused by Borrelia + fusobacterium, they are in a symbiotic relationship.
What are the symptoms of Vincent's angina?

How do you confirm the diagnosis?
Gingivits with a pharyngeal membrane.
Confirmed with a direct smear from membrane - you'll see the fused complex.
What are the three diseases caused by Borrelia?
-Lyme disease
-Vincent's angina
-Relapsing fever
What is relapsing fever caused by?
9 different Borrelia species
How is relapsing fever transmitted?

What kind of disease is it?
How is it detected?
-ticks and lice;

-a Fevrile disease w/ a fever for 3-7 days, goes down, then goes back up.

-seen on a blood smear, so not detected in the microbiology lab, but haematology
What disease is caused by Leptospira, and what is it?
Leptospirosis; a zoonotic FEBRILE disease from rodent droppings.
(causes fever)
What is unique about the Leptospira genus compared to Borrelia and Treponoma?
It can be cultured in lab
What type of media is used for a Leptospira culture?
-Fletcher's media.
Incubation conditions for leptospira:
Fletcher's media, 30'C, up to 6 weeks.
What is the primary method of identifying Leptospira?
Serological tests for Antibody in the patient; not done in a typical lab, sent off to others.

NOT id'd with culture or stain.
what causes syphilis?
Treponoma pallidum
what is the most common species of Treponoma?
Treponoma pallidum
How is syphilis transmitted?
1. direct sexual contact

2. Congenitally; passes through the placenta during fetal development
What type of symptoms does an infant have when born with congenital syphilis?
2ndary symptoms - rash
Maybe Hutchinson's teeth
What do the 4 symptomatic phases of Syphilis consist of?
1. Hard chancre
2. rash
3. no symptoms
4. gummas
When are symptoms seen after initial Syphilis infection?
on avg, 3 weeks; can be 10-90 days
What happens during Primary Syphilis?
Hard chancre on genitalia, in mouth.

Disappears as bug goes into circulation.

A lesion smear is most reliable at this stage.
Problems with doing a lesion smear during primary syphilis:
-Other treponomas are normal flora; won't be abnormal to see on slide.

-Must use darkfield microscopy - not used to it, may have error.
Common I.D. method for Primary Syphilis:
Immunoflourescent stain from a Chancre lesion smear
What happens in 2ndary Syphilis - Symptoms, timecourse, then what?
-Rash appears mainly on trunk
-Represents hematogenous dissemination of the bug
-Appears 2-8 wks after chancre, resolves in 2-10 wks.

Serological identification is very reliable at this point.
When can/can't you do a Serological assay for antibody during Syphilis?
NOT during primary - 25% of positive patients will test negative! Use FTA-ABS

YES during 2ndary - dissemination, bug is everywhere in blood.
What happens in latent syphilis?
-Rash rarely re-appears,
-No symptoms visible.
What happens in Tertiary Syphilis?
GUMMAS develop - tissue lesions (CNS, Cardiovasc).

Cause loss of musc. coordination, congenital heart failure, seizures, and you go insane.
How is Syphilis treated?
In Primary/Secondary phases, very susceptible to Penicillin, one large dose intramuscularly.

In 3ary, longer treatment necessary.

Gummas are irreversible.
Main way to diagnostically test for Syphilis?
(Treponema pallidum)

Serological test on serum/plasma
2 broad categories of serol. testing:
-Non-treponemal tests - for reagin.

-Treponemal Ab tests - for Ab.
2 types of Non-treponemal tests:

-what is this type of testing?
-Why is it done? What does it show?
Screening. Shows every possible positive, and then some. Lots of false positives, but no false negatives.

1. VDRL (Venereal dis. research lab)
2. RPR (Rapid plasma reagin)
What is Reagin?
Produced in response to tissue damage, which occurs in Syphilis - chancre
What are 2 Treponomal Ab tests?

What are they for, what do they tell?
1. FTA-ABS (flouresc. treponemal antibody-absorbed)
2. Hemagglutination (MHATP)

Confirmatory tests, directly for treponema pallidum, no false positive.
Why do screening instead of just confirmatory testing for Syphilis?
Screening is faster, easier to perform, and there are no false negatives.
What Treponema species causes YAWS?
What is YAWS?
-Treponema pertenue

A skin disease in the tropics that causes hyperplasia - very very gross!!
Where are other Treponemes normal flora?
Which Treponeme is never normal flora?
Treponema pallidum
Pharyngeal membrane, gingivitis
Vincents Angina

(transmission reminder)
not just an STD; babies get it too

Sex w/ the whole course
Congenital w/ secondary symptoms

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