Term
|
Definition
- general characteristics
- gram- plump rod
- bipolar staining
- encapsulated
- facultative intracellular growth
- clinical picture - plague
- acute febrile illness, malaise, vomiting
- delerium, neuro symptoms
- lymph nodes swell, darken, suppurate
- pneumonia if lungs infected --> droplet spread
- death in 2 - 7 days if untreated
- pathogenesis
- flea bites infected animal
- bacteria multiply in flea gut
- flea leaves animal and bites man
- coagulase causes flea to regurgitate bacteria containing blood into man
- plasmid encoded phospholipase D not found in nonpathogenic Yersenia allows for survival in flea gut
- epidemiology
- urban plague - fleas from rats
- sylvatic plague - fleas from other rodents - spread to lungs - contaminated droplets - person-to-person spread - epidemic
- plasmid encoded virulence factors
- thrombolytic
- antiphagocytic, type III secretion
- antiphagocytic capsule, neuro exotoxin
- phospholipase
- diagonisis
- symptoms + history of contact with reservoir animals
- gram- bipolar rod observable and/or culturable from infected areas
- API strip or PCR
- immunofluorescence assays
- treatment
- antibiotics
- prophylactic antibiotics for exposure
- prevention - control reservoir animal populations
|
|
|
Term
|
Definition
- general characteristics
- gram- coccobacillus
- requires chocolate agar
- facultative intracellular growth
- clinical picture of tularemia
- local ulcer in 4 days --> lymph nodes --> septicemia
- inhalation --> acute necrotizing bronchopneumonia
- ingestion --> typhoid like symptoms
- epidemiology
- large reservoir in mammals, birds, insects
- transmitted by insect bit or handling sick or dead animals
- diagnosis
- culture infected tissue
- detect Ag in blood
- treatment
- tetracyclines
- avoidance of sick animals
- vector control
|
|
|
Term
|
Definition
- Brucella melitensis and B. abortus
- gram- coccobacilli
- facultative intracellular growth
- slow growing in culture
- carried by diseased animals in lymph tissue
- lots of animal-specific species
- Clinical picture
- 1 - 5 wk incubation
- 3 mo. course of fever, headache, myalgia, malaise, osteomyelitis
- may become chronic with relapses for many years
- Pathogenesis
- reservoirs in animals
- organism infects lymph nodes --> milk glands
- transmission commonly by ingesting infected milk or cheese
- in US, cows inoculated and milk pasteurized
- can also be contracted by break in skin, inhalation, and ingestion of other contaminated materials
- Epidemiology - mostly travelors to underdeveloped countries
- Diagnosis
- blood culture of organisms
- serological tests for both Ag and Ab
- Treatment
- long-term tetracyclnie treatment, reinstituted during relapses
- prevention - slaughter of infected herds, immunization of animals, pasteurization of milk
|
|
|
Term
|
Definition
- gram- encapsulated coccobacillus
- canine normal flora - bite wound infections
- thoroughly cleans bites, penicillin
|
|
|
Term
|
Definition
- Spirullum minus and Streptobacillus moniliformis
- 10% fatal septicemia
|
|
|
Term
|
Definition
- Glanders - horse disease rarely passed to humans (pneumonia)
- potential biological weapon
|
|
|
Term
|
Definition
- melioidosis - pneumonia, septicemia
- rarely found in US, mostly Pacific rim
- associated with rat infestations
- can be inhaled or absorbed through break in skin
|
|
|
Term
|
Definition
- spirochete, causitive agent of Lyme disease
- clinical picture
- 1° - often self-resolving
- fever, malaise, myalgia
- ECM - bull's eye rash
- 2°
- arthiritis
- cardiac problems
- neurological damage
- pathogenesis
- deer and small mammals are reservoir
- carried by Ixodis deer tick nymphs
- requires 12-24 hr attachment for transmission
- sequellae due to Ag switch via DNA recombination mechanism requiring a linear virulence plasmid that carried multiple surface protein genes
- Epidemiology
- eastern and midwestern US
- spring/early summer when nymphs are born
- Diagnosis
- symptoms + history of tick bite or being in woods
- spirochetes are difficult to detect and culture
- free Ag difficult to detect
- IgM may be detected after 7 days, IgG after >4 wks
- overdiagnosed
- Treatment
- antibiotics
- 2° infections may require IV antibiotics
- prevention: promp inspection and tick removal
- vaccine against recombinant OspA protein from tick has been withdrawn because <80% effective
- prophylactic doxycycline after tick bite reduces chance of getting disease
|
|
|
Term
| Relapsing fever (Borreliosis) |
|
Definition
- Endemic form
- Borrelia hermsii, B. duttonii
- ticks spread from rodent reservoir to man
- <5% fatality in untreated adults
- Epidemic form - Africa
- Borrelia recurrentis
- not really zoonotic, spread by body lice (man-louse-man)
- scratching creates break in skin for entry
- 40% fatal without treatment
- Diagnosis
- history of animal contact, tick bite, or body lice
- spirochetes in Wright stained blood smear
- serology
- spirochete-specific Ag in blood
- may cross-react with Lyme Ag
- treatment - penicillin, tetracyclines
|
|
|
Term
|
Definition
- L. interrogans, L. carricola, L. pomona
- gram- spirochete with tight coils and terminal hook
- Clinical picture
- fever, meningitis, prostration, liver and renal involvement --> jaundice, renal failure, death
- Pathogenesis
- long-term parasite of many animals in renal carrier state (rats, dogs, pigs)
- transmitted via urine-contaminiated water
- can enter humans via ingestion, breaks in skin, conjunctiva, oral cavity
- Diagnosis
- finding organisms in blood or urine
- serology for Ab or Ag
- Treatment
- penicillin, tetracyclines, streptomycin
- avoid exposure to contaminated water
|
|
|
Term
|
Definition
- gram+, encapsulated, spore forming aerobic bacillus
- tripartate toxin - similar to AB toxin
- Factor I - edema (EF) - invasive adenylate cyclase
- Factor II - protective Ag (PA) - binding domain, antigenic
- Factor III - lethal (LF) - cell death
- Clinical picture
- cutaneous
- direct contact w/ skin, mucus mem.
- spores enter skin, germinate --> malignant, pustule
- curable if properly diagnosed and treated
- may disseminate --> fatal septicemia by toxins
- inhalation
- biological weapon
- ~5,000 spores needed for disease in healthy lungs
- abrupt high fever and chest pain
- systemic hemorrhagic pathology, sudden death, very high mortality
- gastrointestinal
- rare, but also highly fatal
- Pathogenesis
- large reservoir in domestic ruminants - pick up spores in soil --> animal dies --> back in soil
- humans get disease from contact or inhalation of spores
- Diagnosis
- culture of organism from pustule, blood, sputum, gastric washing
- Treatment
- kill infected cattle, incinerate carcasses and prevent contaminated hides from entering US
|
|
|
Term
|
Definition
- gram+ motile rod, causes Listeriosis
- grows at 4°C (refrigerator)
- facultative intracellular growth
- Clinical picture
- self-resolving mild flu-like illness --> fever, malaise, myalgia
- meningitis, brain abcess, systemic infections in immunocompromised
- crosses placenta - serious disease/lethality for fetus
- Pathogenesis
- normal intestinal flora of farm animals
- transmitted to produce via manure fertilizers
- Virulence
- actin polymerization
- move to cell surface and invade adjacent cells
- may prevent immune surveilance by keeping cells out of circulation
- flagella - shed when they enter cell
- Listeriolysin O - pore forming toxin believed to enable organism to escape phagosome
- Other phospholipases - may enhance intracellular growth
- Diagnosis
- β-hemolytic gram+ short rods in centrifuged CSF
- Treatment
- ampicillin
- thorough washing of produce and cooking of meats
|
|
|
Term
|
Definition
- Bartonella quintana - Trench fever
- facultative intracellular organism
- human body louse, infected needles?
- fever, anemia, malaise
- bacteremia, endocaditis in immunocompromised
- Bartonella hanselae - cat scratch disease
- self-limiting fever, lymphadenopathy
- bacillary angiomatosis and pelliosis hepatitis in immunocompromised
|
|
|
Term
|
Definition
- obligate intracellular organism
- causes psittacosis or ornithosis
- systemic infections with pneumonia, hepatitis, and endocarditis
- spread by inhalation of bird feces (birds not usually sick)
- risk groups - pet shop employees, poultry workers
- lower incidence believed to be due to antibiotics in poultry feed stocks
|
|
|
