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Characteristics of mycobacterium bovis. (2)
slow-growing, acid-fast
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Disease characteristics of mycobacterium. (3)
long incubation period, long-term infection, granulomatous inflammation
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3 manifestions of mycobacterial diseases.
lung lesions, leprosy skin lesions, Johne's intestinal lesions
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Is tuberculosis a common or rare disease globally?
COMMON- 1/3 of the worlds population is infected
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Majority of TB cases are __________, which has ___________ transmission.
Mycobacterium tuberculosis; person-to-person
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What is the zoonotic form of TB, and what is the reservoir?
Mycobacterium bovis; cattle
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Describe the clinical manifestation of M. bovis in humans.
indistinguishable from M. tuberculosis clinically
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What are the forms of TB in humans? (2)
active disease- infectious, clinical signs present; latent disease- no clinical signs, not infectious
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What are clinical signs of TB in humans? (4)
anorexia, fatigue, chronic cough, coughing up blood
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What is the incubation period of TB in humans?
3 weeks- several years
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Spread of TB in humans depends upon...
immune function- spreads to lymph nodes
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What antibiotics are some strains of mycobacterium resistant to?
isoniazid (MDR-TB,XDR-TB), rifampicin(MDR-TB,XDR-TB), floroquinolones (XDR-TB)
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Routes of transmission of TB b/w humans. (3)
inhalation (MAIN ROUTE), ingestion, abraded skin
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Routes of transmission of zoonotic TB. (2)
ingestion (unpasteurized milk), close contact with infected animals
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Clinical signs of TB in animals. (4)
chronic illness, respiratory signs, weight loss, decreased production
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Describe the TB eradication program in the US.
mandatory pasteurization of milk, herd depopulation protocols; Surveillance- screening and confirmatory tests in live animals, carcass inspections, histopath on all lymph node lesions, trace-backs to herd of origin
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What state was certified TB free then had a resurgence of the disease in white tailed deer?
michigan
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Describe the Brucella organisms. (3)
intracellular, gram-negative, host preference
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What 3 Brucella species cause more frequent disease in humans and have the potential to be bioweapons?
abortus, melitensis, suis
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Signs of Brucellosis in humans. (5)
fever, malaise, joint swelling, spontaneous abortion, orchitis/epididymitis
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Signs of Brucellosis in animals. (3)
abortions, RFM, joint infections (death is rare)
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How is Brucella organism shed from animals? (4)
HIGH CONC in fetal membranes and fluids, also in milk, urine, vaginal d/c
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Brucella has a _______ infective dose.
low
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Transmission of Brucella. (4)
direct contact, inhalation, ingestion, accidental injection
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How long is the incubation period of Brucellosis?
long- weeks to months
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Describe the Brucellosis Eradication program in the US.
test beef cattle at slaughter, biannual milk testing of dairy herds in certified free states, vaccination (Bang's vaccine for calves), permanent ID of tattoo and metal ear tag after vaccination
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What are the types of disease associated with Salmonella? (3)
enterocolitis/diarrhea, bacteremia, chronic asymptomatic carriage
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What are the most common symptoms of salmonella? (3)
bloody/mucusy diarrhea, cramps, fever
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Describe the pathogenesis of salmonella in humans.
ingestion--> overcome stomach acidity--> colonization of SI--> influx of neutrophils--> loss of epithelial integrity--> effusion of protein-rich exudate
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Transmission of salmonella.
feco-oral: food contamination, direct contact
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Incubation of salmonella.
6-72hrs
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Children shed salmonella ________ than adults after infection.
longer
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How do you treat salmonella in humans? (2)
fluid therapy, antibiotics (if bacteremia)- most cases are self-limiting
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Characteristics of salmonella organisms. (5)
gram negative, LPS, flagellated (H antigen), rod-shaped, facultative anaerobe
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What makes salmonella so successful? (4)
long-term infection, colonization of lymph nodes, stress-induced recrudescence, long duration of shedding
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Salmonella serogroups are based on ________.
O antigen
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Salmonella serovars are based on __________.
H antigen
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Compare typhoidal and non-typhoidal salmonella.
typhoidal: caused by Salmonella typhi, host specific for humans; non-typhoidal: many serovars, broad host range, zoonotic
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Salmonella is usually (95%) transmitted b/w reservoirs and humans through ____________.
foodborne transmission
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What is the primary reservoir for Salmonella infections in people?
livestock on intensively managed farms
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Horizontal transmission of salmonella on livestock farms occurs with _______ [serovars] in __(3)__ [species]; transmission is ________.
all serovars; cows, pigs, sheep; feco-oral
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Vertical transmission of salmonella on livestock farms occurs with _________ [serovar] in ________ [species]; transmission is __________.
Salmonella enteritidis; poultry; transovarial
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_________ animals shed salmonella more frequently and in higher numbers.
Stressed
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There is higher prevalence of salmonella infection on livestocks farms during __(2)__.
late summer and fall
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What are the most common subclinical isolates of salmonella on livestock farms? (3)
kentucky, montevideo, cerro
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What are the most common clinical isolates of salmonella from livestock farms? (2)
typhimirium and newport
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What are measures to prevent within herd transmission of salmonella on farms? (4)
lower stocking density, prevent fecal contamination of feed, don't spread manure on pastures, house sick cows alone
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How do you improve host resistance to salmonella on farms? (3)
decrease stress, vaccinate, competitive exclusion
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Important salmonella serovars on poultry farms. (2)
typhimurium and enteritidis
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What salmonella serovars that affect poultry is there a vaccine for?
gallinarum an pullorum
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Important salmonella serovars on hog farms. (3)
derby, typhimiurium, infantis
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Pigs often have _________ shedding of salmonella, leading to colonization in the _________ period.
stress-induced; lairage (transport/housing before slaughter)
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3 significant pathogenic salmonella serovars on cattle farms.
dublin, newport, typhimurium
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What is a major challenge of salmonella in the beef industry?
colonization of lymph nodes
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How do we prevent foodborne transmission of salmonella? (3)
prevent carcass contamination, carcass washes, product pasteurization
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What temperature should beef, pork, veal steaks, chops, and roasts be cooked to?
145 degrees F
-
What temperature should ground meat be cooked to?
160 degrees F
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What temperature should poultry be cooked to?
165 degrees F
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