Gram (-) bacilli (Zoonotics) - Sketchy Copy Flashcards
Brucella
Labs
Bruce Farms
Cultivation is Not safe - Biological Weapon catagory B
Brucellin Skin test - Injection of Ag intradermally and demonstration of Delayed HSN.
Wright Reaction (Tube agglutination)
ELISA and IgM Chromatography
Brucella
General and Biochemical Features
Bruce Farms
gram (-) bacilli, Cryophille, Grows Slow
Facultative intracellular - Macrophages.
Urease (+),H2S (+)
Requires CO2 to grow
Large amounts of catalase an superoxide dismutase (SOD) to protect from respiratory bursts (against H2O2 and superoxide)
Brucella
signs and symptoms
Bruce Farms
Infected macrophages.
Fever, chills, and anorexia initially.
Undulant fever (rises and falls like a wave).
Enlargement of Spleen, Liver, and lymph nodes (Brucella travels through multiple endothelial organs).
Osteomyelitis from chronic infection.
Brucella
Source
Bruce Farms
Farm animal’s are the reservoir.
1) Directly: from cows, pigs, or goats.
Veterinarians, slaughterhouse workers, ranchers.
2) Indirectly: contact with milk or cheese products that are unpasteurized.
Brucella
treatment
Bruce Farms
a tetracycline like doxycycline
along with rifampin for primary tx
Francisella Tularensis (Tularemia)
lab tests
Francis the rabbit
radish shaped gram (-) coccobacilli
Facultative intracellular (can live inside or outside of host cells). Cell mediated immunity needed to kill it.
Francis Medium: Glucose, Cystein and Blood 37C.
BCYE agar (Like Legionella)
Direct IF or PCR
Francisella Tularensis (Tularemia)
Other forms of Tularemia
(Apart from Ulceroglandular form)
Francis the rabbit
- Gastrointestinal form (Eating Uncooked rabit)- causes gastrointestinal infections
- Pneumonic form (Inhalation) - causes pneumonia
- Conjunctival form (Eye Inoculation)- causes conjunctivitis
Francisella Tularensis (Tularemia)
Ulceroglandular form of Tularemia
Francis the rabbit
Causes painful ulcer.
Enters through ulcer → into macrophages → into lymph system → to reticulendothelial** organs** → causes caseation necrosis
(caseation: diseased tissue forms firm, dry, mass with cheese like appearance like in TB)
Regional lymphadenopathy (swollen lymph nodes)
Francisella Tularensis (Tularemia)
Source and Transmission
Francis the rabbit
Rabbit are the main reservoir (other: deer and rodents)
Direct contact- skin contact with the animal or eating
undercooked rabbit’s meat
Indirect contact- Dermacentor ticks bite, inhalation of secretion or inoculation in the eye.
Can be aerosolized and used for bioterrorism.
Francisella Tularensis (Tularemia)
treatment
Francis the rabbit
A aminoglycoside like streptomycin
Pastuerella multocidida
Transmission
Louis Pasteur’s Lab(rador!)
- Transmitted by a bite from dogs or cats (P.Multocidida-Cats/P. Canis-Dogs).
- In immunocompromised patients can be inhaled causing pneumonia or peritonitis.
Pastuerella multocidida
lab tests
Louis Pasteur’s Lab(rador!)
gram (-) bacilli
catalase (+) and oxidase (+)
Grown on 5% sheeps blood agar: Bipolar / safety pin staining (similar to Yersinia)
Capsular Antigen Agglutination
Pastuerella multocidida
VF
Louis Pasteur’s Lab(rador!)
Hyluronic Acid Capsule
Pastuerella multocidida
signs and symptoms
Louis Pasteur’s Lab(rador!)
Cellulitis after a bite.
May lead to Necrotizing fasciitis or Osteomyelitis.
Lymphadenopathy in pt with COPD or Liver disease.
Pastuerella multocidida
treatment
Louis Pasteur’s Lab(rador!)
Penicillin
or
Beta lactamase inhibitor to help prevent resistance
(amoxicillin and clavulanic acid)
Bartonella henselae
lab tests
Bart the Leopard
gram (-) bacilli
Wartharin starry silver stain needed to visualize it.
Bartonella henselae
Source
Bart the Leopard
Transmitted by cat scratches
“Cat scratch fever!”
Bartonella henselae
Cat-Scratch Disease (Bartonellosis)
Bart the Leopard
Happens in immunocompetent: Lymphadenitis- swollen lymph nodes (especially in axillary lymph nodes)
Subacute endocarditis
Fever
Bartonella henselae
Bacillary Angiomatosis
Bart the Leopard
Happens in immunocompromised: Raised red vascular lesions all over the Body!
Fever, chills, headache and weakness
(apear simillar to Kaposi Sarcoma)
Bartonella henselae
ddx Bacillary angiomatosis
vs
Karposi’s sarcoma
Bart the Leopard
ddx using Wartharin starry silver stain (Positive stain if Bacillary angiomatosis)
or ddx with biopsy (acute neutrophilic inflammation for Bacillary angiomatosis vs. lymphoplasmocytic inflammation for Karposi’s sarcome)
Bartonella henselae
Treatment
Bart the Leopard
Doxycycline and Macrolides (azithromycin) for both the swelling and pain of lymph nodes and for Bacillary angiomatosis
If Cat Scratch Disease is Painful - Erythromycin
