Term
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Definition
-obligate pathogen (no commensal activity known)
-food poisoning / faecal contamination |
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Term
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Definition
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Term
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Definition
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Term
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Definition
-human and animal gut commensal
-soil / water |
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Term
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Definition
-otitis externa - C+D
-urinary tract inf. - dogs and horses
-diarrhoea - young of most spp.
-surgical problems
-wound infection |
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Term
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Definition
-commensal
-oppurtunistic pathogen
-obligate pathogens |
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Term
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Definition
-oppurtunistic E.coli is most common gram-ve cause of bovine mastitis
-opportunistic/commensals can also cause wound inf., surgical problems, UGT
-obligate pathogens cause enteritis +/- septicaemia |
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Term
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Definition
Enteritis:
ingestion --> diarrhoea --> dehydration --> death (<3days)
Septicaemia (over-reactive inflam. resp - organ failure and rapid death)
ingestion --> invasion
invasion -->deposition -->death (invasion --> shock --> death (<2days) |
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Term
| E.coli - how are categories of obligate pathogenic E.coli differentiated? |
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Definition
-have different fimbrial adhesions for binding so differnt binding capabilities
- serotype to get different categories |
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Term
| E.coli - categories of obligate pathogenic E.coli serotypes |
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Definition
-Enterotoxigenic E.coli (ETEC) - specific entertoxins resulting in enteritis
-Verotoxigenic E.coli (VTEC) - verotoxins - VT1+2 highly active against gut cells - resulting in enteritis
-Attaching and Effacing E.coli (AEEC) - initial attachment w. fimbria bas own intimin-R which it implants into host cell - results in close binding and means bact. doesnt have to rely on host cell for a R - results in enteritis
-Enteroinvasive E.coli (EIEC) - adhesions and surface proteins to induce PIE, capsule so can survive in blood, siderophores and endotoxin - results in septicemia (difficult to tx)
-Unclassfied e.g Mushy chick dz |
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Term
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Definition
-fimbrial antigens and toxins
-fluorescent AB tests and PCR |
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Term
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Definition
-care e. ABs esp in enteritis - could wipe out gut flora, incl. commensals and open up binding sites to pathogenic strains, esp. if R - do a sensitivity test before using
-fluid / electrolyte treatment |
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Term
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Definition
-good husbandry and hygiene
-E.coli is suscpetible to UV, drying, and disinfectants
-vaccines are available |
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Term
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Definition
| Almost all seroytpes can affect humans - except S. pullorum / poultry-adapted serovars
-Some are non-host adapted e.g. Salmonella typhimurium in all spp
-some are host-adapted e.g.
S. dublin - ruminants - assoc. w. abortion
S. pullorum - poultry
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Term
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Definition
-environment i.e. faecal-oral spread
-milk from carriers
-inf. from host / carriers
-vertical transmission
-in man- food poisoning |
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Term
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Definition
-sporadic
-indv. animals --> susceptible flock
-contaminated food /water
e.g. shedding from rodents / birds
esp in protein supplements
remember sal. is ubiquitous in the environment |
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Term
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Definition
| -enteritis and septicaemia |
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Term
| Salmonella - factors affecting dz. type |
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Definition
-virulence determinants
-innate and adaptive host defences
Primary infection may be clinical (remain localised =enteritis, or invade = septiceamia) or subclincal (may be overcome, or become chronic +/- sunblinical) |
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Term
| Salmonella - enteritis pathogenesis |
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Definition
-flagella move sal. to point of contact
-fimbrial mediated attachment
-PIE and survive in endosome
-endotoxin results in cell damage - activates AC and inflam |
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Term
| Salmonella - septicaemia pathogenesis |
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Definition
-flagella move sal. to point of contact
-fimbrial mediated attachment
-PIE and survive in endosome
-deeper invasion than in enteritis - results in endotoxic shock +/- deposition |
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Term
| Salmonella - septicaemic deposition |
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Definition
In joints = arthritis
Brain = meningitis
Lungs = pneumonia
Placenta/foetus = abortion |
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Term
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Definition
-biochem, serotypes, biotypes, phage types
-many polymorhs in faeces
-fluorescent Ab staining of PM material
-serolgy - ELISA - use for whole flock / herd |
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Term
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Definition
-good nursing
-fluid / electrolyte replacement
-parental antibiotics for septicaemia only
-NO antibiotics for enteritis - kills commensals and selects for salmonella R |
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Term
| Salmonella - use of antibiotics |
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Definition
-only in septiceamia!
-enteritis + antibiotics = septicaemia!! |
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Term
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Definition
animals - good husbandry
-vaccines (inactivated and live attenuated)
-competitive exclusion
humans - break chain of infection
i.e. clean water / food hygiene / sewage disposal |
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