Microbiology-Zoonotic Bacterial Diseases Flashcards
Small gram negative rod that stains poorly and grows well on cysteine-enriched media? What diseases are caused by this bacteria?
Francisella tularensis: rabbit fever, tularemia and glandular fever.
Route of transmission of francisella tularensis
HIGHLY INFECTIOUS: arthropod bite (esp hard tick), mucous membrane exposure, aerosol and ingestion.
High risk groups for tularemia
Hunters, vets and lab workers
How is francisella tularensis identified?
Immunofluorescent assay, note that it grows inside of macrophages.
Spectrum of disease caused by francisella tularensis?
Primary infection: ulceroglandular (shown below), oculoglandular w/lymphadenopathy. Secondary infection: pneumonia (30% fatality), typhoidal (ingestion)
Lab diagnosis of tularemia
1) Serology. #2) Culture of bubos, sputum, blood, GI wash on chocolate cysteine agar and buffer charcoal yeast extract. ID confirmed with slide agglutination test.
Regions of the US with highest cases of tularemia?
Arkansas, Missouri, Kansas, Oklahoma w/greater incidence in males…lots of rabbit hunting going on here?
Primary skin infection to consider whenever you consider community acquired MRSA.
Tularemia
Main transmission route of brucella suis in humans
Infected milk, milk products and direct contact with infected animals. THERE IS NO ARTHROPOD VECTOR.
Where would you find brucella suis in humans after someone drank unpasteurized milk?
Brucella suis enters humans via mucous membranes, skin, ingestion or inhalation. They are then engulfed by phagocytes and taken to regional lymph nodes. They multiply within macrophages and form granulomas in the reticuloendothelial system, causing recurrent bacteremia. Note that in animals it is largely found in tissues rick in erythritol (milk, genitourinary).
Occupational exposures for brucellosis
Slaughterhouse, meat-packing, vets, lab workers, hunters (esp when hunting wild hogs, elk, bison, caribou and moose).
Regions at risk for brucellosis
Those with unpasteurized dairy products: Mediterranean basin, Latin America, Africa, Asia, Middle East.
Complications of chronic brucellosis?
UNDULANT FEVER: Reticuloendothelial organs are affected but NOT enlarged: hepatic lesions, arthritis, meningitis, endocarditis.
Bug that causes cat scratch disease? What is the vector?
Bartonella henselae from the flea
Bug that causes trench fever (5-days fever)? What is the vector?
Bartonella quintana from body louse causes febrile bacteremia. Note that humans are the reservoir.
Bug that causes Carrion’s disease? What is the vector?
Bartonella bacilliformis from the sand fly. Note that humans are the reservoir.
A 5 year old boy presents with the lymph node shown below. He has cats at home. What is the method of transmission of the bacteria that most likely caused his condition?
Bartonella henselae cause cat scratch disease with intense lymphadenopathy in an immunocompetent patient. Cats are the reservoir and can transmit it directly to humans or the cat flea can transmit it to humans.
How does bartonella henselae, bartonella quintana present in an immunocompromised patient?
Bacillary angiomatosis from endothelial colonization by bartonella that causes the endothelium to proliferate. Bartonella quintana can also cause endocarditis.
2 phases of Carrion’s disease
Bartonella bacilliformis can cause hemolytic anemia (Oroya fever) in phase I and verruga peruana in the second phase.
What type of bacteria are members of the Rickettsiaceae family? How are they spread?
Rickettsia and Orientia are obligate intracellular bacteria that are transmitted by arthropods.
Bacteria, vector and reservoir in Rocky Mountain Spotted Fever?
Bacteria: R. rickettsii. Vector: ticks. Reservoir: Ticks & rodents
Bacteria, vector and reservoir in Rickettsialpox?
Bacteria: R. akari. Vector: mites. Reservoir: mites & rodents.
Bacteria, vector and reservoir in scrub typhus?
Bacteria: O. tsutsugamushi. Vector: mites. Reservoir: mites (chiggers) and rodents. Note that this does not occur in the US, but was seen in Vietnam.
Bacteria, vector and reservoir in epidemic typhus?
Bacteria: R. prowazekii. Vector: louse. Reservoir: humans, squirrel fleas, flying squirrels. Note that this is not present in the US, but epidemic in places of war like Somalia.
