Micro - Clinical Bacteriology (Gram - Spirochetes) Flashcards Preview

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

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

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


Which spirochete is the largest?

Borrelia; Think: "Borrelia = Big size"


How is Treponema visualized?

Treponema is visualized by dark-field microscopy


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

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


What is a source of Leptospira interrogans?

Found in water contaminated with animal urine


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

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


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

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


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

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


What pathogen causes Lyme disease?

Borrelia burgdorferi


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

Ixodes tick; Also vector for Babesia


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

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


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

Lyme disease; Common in northeastern United States


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

Borrelia burgdorferi; Doxycycline, Ceftriaxone


What are initial versus later symptoms of Lyme disease?

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.


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

Caused by spirochete Treponema pallidum


What is the treatment for Syphilis?

Penicillin G


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

Localized disease presenting with painless chancre


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

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


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

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


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

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)


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

Screen with VDRL and confirm diagnosis with FTA-ABS


What are the symptoms/signs associated with Tertiary syphilis?

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


What test is used for to test for neurosyphilis?

For neurosyphilis: test spinal fluid with VDRL or RPR


What are symptoms/findings associated with Congenital syphilis?

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


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

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


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

Pupil constricts with accommodation but is not reactive to light; "Prostitute's pupil"; Associated with Tertiary syphilis


What does VDRL detect?

VDRL detects nonspecific antibody that reacts with beef cardiolipin


What condition/disease is VDRL used to diagnose?



What are the false positives associated with VDRL?

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"


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

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

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