Micro - Clinical Bacteriology (Gram - Spirochetes) Flashcards Preview

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Flashcards in Micro - Clinical Bacteriology (Gram - Spirochetes) Deck (30)
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1
Q

What kind of morphology do spirochetes have? What are examples of spirochetes?

A

The spirochetes are spiral-shaped bacteria with axial filaments and include: Borrelia (big size), Letospira, and Treponema

2
Q

Which spirochete is the largest?

A

Borrelia; Think: “Borrelia = Big size”

3
Q

How is Treponema visualized?

A

Treponema is visualized by dark-field microscopy

4
Q

How can Borrelia be visualized? What is important to know about this visualization?

A

Only Borrelia (of all spirochetes) can be visualized using aniline dyes (Wright’s or Giemsa stain) in light microscopy

5
Q

What is a source of Leptospira interrogans?

A

Found in water contaminated with animal urine

6
Q

What main disease/condition does Leptospira interrogans cause? What are the associated symptoms?

A

Leptospirosis: flu-like symptoms, jaundice, photophobia with conjunctival suffusion (erythema without exudate)

7
Q

Among what population(s) is L. interrogans prevalent?

A

Prevalent among surfers and in tropics (i.e., Hawaii)

8
Q

What is another name for Weil disease? What are its symptoms? With which pathogen is it associated?

A

Aka Ictohemorrhagic Leptospirosis = severe form with jaundice and azotemia from liver and kidney dysfunction; Fever, hemorrhage, anemia; Leptospira interrogans

9
Q

What pathogen causes Lyme disease?

A

Borrelia burgdorferi

10
Q

What is the vector for Borrelia burgdorferi? For what other pathogen is this also the vector?

A

Ixodes tick; Also vector for Babesia

11
Q

What is the natural reservoir for B. burgdorferi? Why is this significant?

A

Natural reservoir is the mouse; Mice are important to tick life cycle (recall: Ixodes tick = B. burgdorferi vector)

12
Q

What disease does B. burgdorferi cause? In what geographic location(s) Is it commonly found?

A

Lyme disease; Common in northeastern United States

13
Q

Again, what pathogen causes Lyme disease? How it is treated?

A

Borrelia burgdorferi; Doxycycline, Ceftriaxone

14
Q

What are initial versus later symptoms of Lyme disease?

A

INITIAL SYMPTOMS - erythema chronicum migrans, flu-like symptoms, +/- facial nerve palsy; LATER SYMPTOMS - monoarthritis (large joints) and migratory polyarthritis, cardiac (AV nodal block), neurologic (encephalopathy, facial nerve palsy, polyneuropathy); Think: “FAKE a Key Lyme pie = Facial nerve palsy (typically bilateral), Arthritis, Kardiac block, Erythema migrans.

15
Q

What is the morphology, genus, and species of the pathogen that causes Syphilis?

A

Caused by spirochete Treponema pallidum

16
Q

What is the treatment for Syphilis?

A

Penicillin G

17
Q

What kind of disease is Primary Syphilis, and how does it present?

A

Localized disease presenting with painless chancre

18
Q

How do you screen for and confirm a Primary syphilis diagnosis?

A

Serologic testing: VDRL/RPR (non-specific), confirm diagnosis with specific test (e.g., FTA-ABS)

19
Q

What kind of disease is Secondary Syphilis, and how does it present?

A

Disseminated disease with constitutional symptoms, maculopapular rash (palms and soles), condyloma lata (also confirmable with dark-field microscopy); Think: “Secondary syphilis = Systemic”

20
Q

In what kind of patient findings are treponemes actually present, and in what context do such findings occur? How are they visualized?

A

Treponemes are present in chancres of primary Syphilis and condyloma lata of secondary Syphilis; If available, use dark-field microscopy to visualize treponemes in fluid from chancre (primary syphilis) or condyloma lata (secondary Syphilis)

21
Q

How do you screen for and confirm diagnosis of Secondary Syphilis?

A

Screen with VDRL and confirm diagnosis with FTA-ABS

22
Q

What are the symptoms/signs associated with Tertiary syphilis?

A

Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, “general paresis”), Argyll Robertson pupil; Signs: Broad-based ataxia, Positive Romberg, Charcot joint, Stroke without hypertension

23
Q

What test is used for to test for neurosyphilis?

A

For neurosyphilis: test spinal fluid with VDRL or RPR

24
Q

What are symptoms/findings associated with Congenital syphilis?

A

Saber shins, Saddle nose, CN VIII deafness, Hutchinson’s teeth, Mulberry molars

25
Q

What is important to remember in terms of transmission of Congenital syphilis?

A

To prevent, treat mother early in pregnancy, as placental transmission typically occurs after first trimester

26
Q

What is Argyll Robertson pupil? What is another name for this condition? With what condition is Argyll Robertson pupil associated?

A

Pupil constricts with accommodation but is not reactive to light; “Prostitute’s pupil”; Associated with Tertiary syphilis

27
Q

What does VDRL detect?

A

VDRL detects nonspecific antibody that reacts with beef cardiolipin

28
Q

What condition/disease is VDRL used to diagnose?

A

Syphilis

29
Q

What are the false positives associated with VDRL?

A

May false positives, including viral infection (mononucleosis [EBV], hepatitis), some drugs, rheumatic fever, and SLE (also, leprosy); Think: “VDRL = Viruses (mono, hepatitis), Drugs, Rheumatic fever, Lupus and Leprosy”

30
Q

What is Jarisch-Herxheimer reaction, and what causes it?

A

Flu-like syndrome immediately after antibiotics are started, due to killed bacteria releasing pyrogens

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