Zoonotic Gram (-) Flashcards
Typical symptoms of infection caused by gram (-) zoonosis.
- Systemic febrile illness +/- rash
- Skin or soft tissue infection/OM
- Pneumonia
- Encephalitis
Bartonella henselae
Gram
Shape
Disease
Treatment
Gram (-)
Bacillus
Cat scratch disease
Doxycycline +/- rifampin
Chloramphenicol
Bartonella quintana
Disease?
Trench fever - single febrile episode for 4-5 days
Bartonella bacilliformis
Disease?
Oroya fever, verruga peruana (Carrion’s disease)
Parinaud oculoglandular syndrome
What bacteria?
Contamination of the eye - associated with Bartonella
Gram (-) Zoonotics
Big Bad Bugs From Your Pet Ella
Bartonella, Brucella, Borrelia, Francisella, Yersinia, Pasturella, Ehrlichia
Brucella
Gram
Shape
What agar does it grow on?
Gram (-)
Small, Coccobacillus, mostly single cells “fine sand”
Grows on chocolate agar and sheep blood agar, but not MAC or EMB - very smooth, pinpoint, and translucent, non-hemolytic
What temperature does Brucella grow at?
37 C, grows slowly
What four species cause Brucellosis?
- B abortus - people working with unvaccinated animals inhale aerosols
- B melitensis - unpasteurized milk
- B. suis - people who work with unvaccinated animals
- B. canis
Symptoms of Brucellosis?
“Great imitator”
Mild suppurative febrile infection –> fever, sweats, headache, back pain
Depression is common
Osteoarticular and lymphoreticular organs and kidney most commonly involved
Pathogenesis of Brucella
Adapts to intracellular conditions of macrophages to infect liver, spleen, bone marrow (reticuloendothelial system)
What disease?
Fever of unknown origin Culture-negative endocarditis Culture-negative osteomyelitis Aseptic meningitis Culture-negative epididymoorchitis
Brucellosis
Diagnosis of Brucellosis
Treatment
- Blood cultures, serology useful if cultures are negative
Treat: streptomycin + doxycycline
Oral combo: rifampin + doxycycline
Francisella
Gram Shape Catalase Motility Oxygen use Capsule? Disease
Gram (-) Coccobacillus Weakly positive Non-motile Obligate anaerobe Thick capsule Tularemia - 7 forms (ulcers, pneumonic, etc.)
Vectors of Francisella transmission
Ticks, mosquitoes, biting flies
Diagnosis & Treatment of Francisella
Diagnosis: culture and isolation, serology, PCR, immunofluorescent staining
Treatment: Streptomycin - you end up with long-term immunity after treatment
What part of the US is Yersinia endemic to?
Western United States
Acquisition of plague and high risk groups
Fleas or direct contact with infected animals (rats), inhalation of respiratory secretions
Hunters, trappers
Yersinia
Gram
Shape
Stain
Gram (-)
Single cells or short chains of rods
Bipolar stain w/ Giemsa or Wayson - “safety pin”
3 species of Yersinia
Y. pestis
Y. enterocolitica
Y. pseudotuberculosis
3 types of clinical presentation of Y. pestis infection
- Bubonic (most common) - bacteria proliferate at bite, swollen LNs (bubo)
- Septicemic - no bubo, but sepsis
- Pneumonic (very fatal) - rapidly progressive pneumonia w/ high rate of transmission
Diagnosis and treatment of Yersinia
Diagnosis: isolate from bubo, serology
Treatment: Gentamicin, maybe w/ tetracycline, supportive care is critical
Pasturella multocida
Gram
Oxygen use
Normal colonization site
Gram (-)
Facultative anaerobe
Upper respiratory tract of cats, dogs, rabbits
Symptoms of Pasturella multocida infection?
Skin and soft tissue infection –> necrotizing fasciitis
Septic arthritis/osteomyelitis
Bacteremia if there is liver dysfunction
