bacteriology 9 Flashcards
can not have
gram negative cocci
gram negative rods
oxidase negative
enterobacterales
enterobacterales
gram negative rods
facultative anaerobic
oxidase negative
motile-flagella
grows on blood agar-dirty grey colonies
some are hemolytic
growth on macconkey
tolerate bile salt
lactose fermentation
lactose positive (pink)
escherichia
klebsiella
lactose negative (yellow)
proteus
salmonella
yersinia
good pathogens
e coli
salmonella
yersinia
indermediate pathogen
klebsiella pneumoniae
proteus spp
poor pathogen
enterobacter, serratia
e coli
normal flora of most vertebrates
lower ileum
large intestine
colonizes neonatal GIT within hours of birth
urvives will in the environment
e coli transmitted
depends on site of infection
fecal oral
inhalation
direct inoculation
ascending infections
cystitis
pyometra
transient in urogenital tract
Virulence of e coli
Attachment-fimbriae or adhesion
avoidance of phagocytosis-casule
cellular effects-hemolysin and cytotoxin necrotizing factors
systemic effects-endotoxin
depend on site of infection
not all strains are virulent
diseases in different sites have different virulence factos
diseases of e coli
enteritis
mastitis
diskospondylitis
pyometra
osteomyelitis
cystitis
colibacillosis
endocarditis
arthritis
ompahalitiis
sepsis
diagnose e coli
4 point rule
treat e coli
non enteric infections
multiple drug resistant strains of enterobacterales
drug resistance plasmid are readily transfered among members of the family
most antibiotic resistant bacteria in existence
susceptibility test should be preformed
treat e coli
non enteric infection
ancillary therapies
critically important
surgery/drainage/debridement
fluid therapy
anti-enodoxin therapies
where is salmonella
not in normal flora
present in carrier animals-GIT which includes mammals, birds, reptiles and insects
survive long time in the environment
how is salmonella transmitted
feco oral
variety of species are carrier
reptiles
cattle
horses
recrudescence of infection in carrier animals
virulence factor of salmonella
avoidance of killing by phagocytes
facultative intracellular parasites
systemic carrier states-not just in the intestin
live in macrophages and in mediastinal lymph node and liver
enteritis
horse and cattle-less common in carnivores
hypersecretory component
hemorrhage and fibrin due to effects of exotoxin
septicemia with localization
after ingestion, some animals become septicemic with localization in a variety of organs
lungs, joints, kidney, heart, spleen
mostly in young animals
ability to invade intestine and survive inside macrophages
carrier state
salmonella can also localise in phagocytes
facultative intracellular parasites
inside macrophages they are transported to local lymph nodes, liver spleen and gallbladder and remain there for weeks to years
salmonella are shed intermittently and inapparently in their feces
infection may recrudesce and clinical disease (diarrhea)
host adapted strains more likely to cause carrier state
how tp diagnose non enteric
collection from sterile site and apply 4 point rule
where does yersinia come from
yersinia pestis
wild rodents are the reservoir
rodents (mice and rats) Prairie dogs and squirrels
flea-rodent-flea life cycle
virulence factors for yersinia
avoidance of killing my phagocytes
facultative intracellular parasites
enteric
y pseudotuberculosis
enteritis most common in ruminants (especially deer)
enteric
y enterocolitica
enteritis in humans (occasionally in animals)
non-enteric
y pestis
non-enteric
most virulent
plague (black death) humans and cats
rare in other species
bubonic form (lymph nodes)
pneumonic forms (lungs)
septicemic form (Systemic)
present in the us (AZ, NM, UT, CO, CA, OR)
cases of reported most years
cats more frequent than dogs
clinical signs-severe depression, fever, enlarged peripheral lymph nodes
non enteric
y pseudotuberculosis
sporadic abortion in ruminants
more severe disease including septicaemia, mostly birds and pocket pets
how do you diagnose
with caution
send aspirate of pus, blood LN to specialized labs
notify public health authorities
bipolar staining
PCR and culture
be carefu;
