Bac-T - Gram(-) 1

drraythe's version from 2015-06-08 23:09

Enterobacteria in general

Question Answer
gram/growth media of enterobact.? gram NEG, grow readily on BA and Mac (MacConkey)
where do entero bact. live in body? they can also be?in intestines. can be saphrophytes/parasites
2 main groups of enterobact?lactose fermentors/ non-lactose fermentors
how do you know if it's a lactose fermentor?pink colonies on Mac
exs of lactose fermentors?E coli, klebsiella
exs of non-lactose fermentors?salmonella, proteus

Escherichia Coli

Question Answer
Some e coli are _____ and some are _____ (in terms of dz)pathogenic, harmless (intestinal commensal)
how do you ID pathogenic strains of e.coli?serotyping/epidemiological study
serotype of hemorrhagic colitis? (this is an example)O157 H7
two extensions e coli has?fimbriae and flagellum
E coli can cause many dz's in humans and animals (8 on list)porcine neonatal diarrhea, porcine post-weaning diarrhea + edema dz, hemorrhagic colitis + hemolytic uremic syndrome of humans, white scours in calves, septicemia in young animals + chickens, watery mouth in lambs, UTI in dogs, metritis/mastitis
#1 cause of septicimia in farm animals?E. coli
Virulence factors of E. coli? (6)capsule, endotoxin, Pili (fimbriae), enterotoxins, shiga toxins, hemolysin
what can endotoxin cause?fever, intravascular clotting
what is the serotype for pili? what do they do?K88, help colonization
what do enterotoxins do?cause fluid secretion (loss of H2O and electrolytes)
how does E coli cause diarrhea?infection-->attach via pili-->enterotoxin-->fluid/electrolyte loss
predisposing factor to E coli diarrheal infection? (in young animals)not receiving colostrum
do E coli form spores? (CQ)no
what are the dz's caused by E coli in PIGS?(1) neonatal enteritis (<5 days old, often fatal). (2) post-weaning diarrhea (3) edema dz (any age, more common in weanlings)
how does edema dz in pigs progress?toxin in intestine--> blood--> damage BVs--> edema
what dz does e coli cause in CALVES?hemorrhagic colitis (shiga toxin strains), white scours/diarrhea (leads to colisepticemia/colibacillosis)
what dz's are in humans which are caused by calf e colis?hemorrhagic colitis and hemolytic uremic syndrome (shiga toxin producing strains)
what is the layman's name for hemorrhagic colitis?hamburger dz (usually O157:H7)
what can e coli cause in foals?septicemia
what can e coli cause in chickens?colibacillosis
what can e coli cause in lambs?watery mouth (due to endotoxin)
what can e coli cause in dogs/cats?UTI, pyometria
what can e coli cause in mares/cattle?metritis
what can e coli cause in cows/sows?coliform mastitis
if animals survive speticemia, what can happen after?arthritis
would e coli be the cause of chronic diarrhea in a 4 yr old cow? (CQ)no, not likely.... more likely to be Johne's dz
how do you diagnose E coli?culture feces, slide agglu. for fecal cultures, quantitative culture for urine (dogs, cats)
tx of E coli? (3)Fluid, electrolytes for diarrhea, antibodies orally for diarrhea/IV for speticemia, antibiotics (oral for diarrhea) systemic and local for bovine mastitis
do not treat E coli with what antibiotic? NO BETA-LACTAMS (lyse and release toxins)
control of e coli? (4)(1) vaccinate dam (pigs, cattle) (2) ensure colostrum for neonates (inclding watery mouth in lambs) (3) improve hygene/management (4) vaccinate COWS to reduce severity of endotoxemia
most important thing to do to treat an animal with diarrhea?WATER AND ELECTROLYTES
what is the name of the vaccine for cattle to reduce effects of endotoxemia?J5
to diagnose E coli diarrhea in piglets, the best diagnostic choice is...(CQ)test pink colonies from Mac agar by agglu test for pathogenic strains (NOT FECAL SMEAR FOR G NEG RODS b/c there are always g neg rods in feces/intestine)

Klebsiella Pneumoniae

Question Answer
does klebsiella have a capsule?yes, a thick, mucoid one
does kleb cause pneumonia?no, not really
color on Mac agar for kleb?PINK (lactose fermentor)
why is a mucoid strain so virulent?has a capsule, escape phagocytosis
is kleb. an intestinal commensal? does klebsiella cause diarrhea?it IS a intestinal commensal, no, it does not usually cause diarrhea(--only in birds) (they like to go to the intestine kleb, but they don't trash the place, except for rude chicks)
how often is there drug resistance with kleb?it is common, so you have to do sensitivity tests
what does kleb cause in **mares?metritis
what does kleb cause in cows? what is it associated with?mastitis, usually wood shaving related (a "kleb" made of wood beating on their udders)
what does kleb cause in **dogs?UTI and otitis externa
what does kleb cause in birds?resp infections, septicemia, diarrhea (ONLY IN BIRDS)
is klebsiella hemolytic?no


Question Answer
what is the color on Mac agar for salmonella?NLF (no color-no lactose fermentation) (E coli is pink on Mac)
are there many serotypes of salm? how is this organized?a LOT of serotypes, all have a name not a number
most common dz causing strain of salm?salmonella enterica
how do you ID suspected salmonella cultures?SEROLOGY. slide agglu test with polyvalent antiserum to tentatively ID (usually feces sample)
is salm a normal commensal?no, but many animals are carriers
most common carrier of salm? what is meant by carrier?esp rats/mice (carriers=sub-clinical infection)
what can cause spread of salm?transportation+stress, antibiotics, fasting ---> colonization ---> fecal shedding ---> spread to other animals
clinical manifestations of salmonella? (3)enteritis (diarrhea- mucus, fibrin, blood), septicemia (fever, depression, death), abortion (septicemia in preg animals leads to abortion)
can salmonella cause pneumonia?yes, after the septicemia
what salmonella is common in cattle?s typhimurium, s. dublin (both cause all 3 manifestations) (The cows of Dublin)
what salm is common in swine?s. typhimurium (enteritis), s. choleraesuis (septicemia)
what salm is common in horses? associated with? results?s. typhimurium.. associated with stress, immuno deficiency, causes diarrhea, endotoxima, death in foals
how common is salm in dogs/cats? when does it happen?rare, usually in immuno suppressed
salm found in birds?s. gallinarum, s. pullorum (enteritis/septicemia)
s. typhimurium has what host, what dz?non-specific hosts, causes enteritis, septicemia, abortion
s. choleraesuis has what host, what dz?pigs, enteritis and septicemia
s. pullorum/gallinarum has what host, what dz?poultry, pullorum dz, fowl typhoid
s. typhi has what host, what dz?humans, typhoid
how do you control salm?prevent exposure to contaminated feed/enviro/carriers (rat/mouse), reduce stress, avoid oral antibiotics
how do you treat salm?treat systemic infections with parenteral drugs
can you treat salm with antibiotics?NO. intercellular. wont help. (salmons in your cellsssss)
how do you treat salm endotoxiemia in horses?IV antiserum (serum+antibodies)
what salm serotype is a human dz carried by cane toads in Grenada?s. Javiana
can you treat cattle with tetracyclines for salmonellosis? (CQ)no. intracellular bact wont be affected.

Proteus (p. vulgaris, p. mirabilis)

Question Answer
what type of pathogen is proteus?opportunistic
how is proteus charaterized on on BA?swarming growth- cover whole plate even if you swab a tiny section-- looks like "waves"
is proteus a localized or systemic dz?localized and sporatic
what does proteus cause in dogs?UTI, otitis externa
how common is drug resistance in proteus?common. do sensitivity test.
does proteus cause abortion/diarrhea?no


Question Answer
what causes the plague?**Y. pestis
is Y. pestis a commensal?no
carriers of Y. pestis?rodents/fleas
what causes enteritis that is yersinia? how common is this?Y. enterocolitica....rarely in dogs
what can yersinia cause in humans? (not plague), which strain?mesenteric lymphadenitis-- Y. enterocolitica (same one that causes enteritis in dog)
who is a common carrier of Y. enterocolitica?swine
how common is Y. Pseudotuberculosis? what animals are affected?uncommon dz, affects wild deer and bovines
what is the carrier/cycle of yersinia pestis? who is highly susceptible, less susceptible, and not involved?carriers=rodents/fleas in nature. Humans+cats are highly susceptible, dogs are less susceptible, and cattle/horses/pigs not involved
what does a blood smear of yersinia pestis look like?bipolar staining rods
why is the plague called the black death? and how?can cause gangrene. Plague toxin--> hypotension, vascular collapse
how do you die from plague?die from shock/lack of circulation
how is feline plague (Y. pestis) transmitted to cat?ingestion of rodents/ flea bite
what is meant by bubonic form of plague? prognosis?enlarged LNs (BUBOES). it is less serious and easier to treat
prognosis/time table of septicemic form of plague?acute and serious
prognosis of pneumatic form of Y pestis?serious
how do you diagnose feline plague?blood/aspirate smear (bipolar staining rods), culture, serology (Id be bipolar if I had the plague, too)
how do you treat/control Y. pestis?antibiotics (tetracycline). Treat for fleas, rodent control.
temperature for Y. enterocolitica?PSYCHROPHILIC (can mult in fridge!)
symptoms of Y. enterocolitica?diarrhea, mesenteric lymphadenitis
will proteus cause septicemia and abortion in cattle? (CQ)no


Question Answer
what toxin does shigella produce?shigella toxin
what dz can shigella cause in humans and monkeys?bacillary dysentery
who is resistant to shigella?food animals, horses
how does shigella affect dogs?they can excrete it, but resistant to clinical dz
does shigella cause "shigellosis" in horses?no
are tetracyclines effective against feline plaque? can humans catch plague form the cat? (CQ)yes and yes
are beef cattle carriers of shigella? (CQ)no

Pseudomonas Aeruginosa and Burkholderia

Question Answer
how can you ID pseudomonas on an agar?most strains produce a green pigment
what does pseudo look like on MAC?colorless to greenish colonies
can pseudo live long outside a host?yes, it is a saphrophyte
does pseudo usually live in a host?yes, it is a minority commensal
what type of infection is psuedo usually causing? where?opportunistic, usually intestinal
shape and grams of pseudo?neg rods
predisposing factors of infection of pseudo? (8 total. 4 general, cow, sheep, dog, rabbit)immunosuppress, injury, excessive antibiotic use, contaminated surgical instruments, contaminated intramammary infusion in cows, excessive fleece wetting in sheep, ear mites+ other factors in dogs, dental dz in rabbits
disease pseudo can cause in all animals?wound/burn infections
dz in dogs/cats of pseudo?otitis, UTI, keratitis, pneumonia
dz in horses of pseudo?genital tract infection, ULCERATIVE KERATITIS
dz in sheep of pseudo?fleece rot "green wool dz"
dz in mink of pseudo?hemorrhagic pneumonia, septicemia
dz in rabbits of pseudo?blue fur dz (moist dermatitis)
dz in captive snakes of pseudo?necrotic stomatitis
diagnosis of P. aeruginosa?CULTURE-- charateristic pigment (green), oxidase +
response of oxidase test for pseudo?positive
#1 organism that like to get into burn wounds?pesudo
prevention of pesudo?prevent predisposing causes (eg ear mites, dental dz), vaccines for mink
treatment of pseudo?gentamicin/amikacin are good, polymyxin B good but ONLY TOPICAL
pseudo is resistant to....pretty much everything in resistance test except gentamycin
(CQ) is ampicillin effective on pseudo?no
(CQ) can pseudo cause keratitis?yes
(CQ) what can you treat for pseudo otitis externa in dogs?enrofloxacin-silver sulfadiazine

Burkholderia mallei (used to be pseudomonas mallei)

Question Answer
what are the glanders-free zones?USA and canada
dz burk causes?GLANDERS
how contagious is glanders?very
what does burk affect in the body?LNs, Lungs---> nodules (similar to TB in this regard)
what happens in the cutaneous form/farcy?nodular abscesses along lymph channels
is burk zoonotic? severity of infection?yes, human infection is serious
diag of burk?intrapalpebral mallein test on horses
how do you treat affected animals?NOT TREATED
which antibiotics work on glanders?DONT WORK
what is positive result of mallein test for glanders?purulent conjunctival discharge, swelling of lower eyelid
(CQ) how do you test for glanders in an imported horse?conduct mallein intrapalpebral test

Actinobacillus ligniersii/Equlii/suis

Question Answer
what animal does actinobacillus ligniersii affect?CATTLE
where does actinobacillus ligniersii live?commensal of mouth
how does actinobacillus ligniersii infect?opportunistic infection of mouth through a wound
what does actinobacillus ligniersii cause?WOODEN TONGUE granulomatous lesions in tongue, jaw, neck (bone not effected)
diagnose actinobacillus ligniersii by?take slide, look for mineralized clubs
treatment of actinobacillus ligniersii?surgical drainage, tetracyclines, trimethprim-sulfa
Actinobacillus Equlii causes?SLEEPY FOAL DZ arthritis, nephritis, enteritis
where does Actinobacillus Equlii live?commensal of alimentary tract
how is horse infected with Actinobacillus Equlii?oppostunistic infection via umbilicus or in utero
treatment of Actinobacillus Equlii?antibiotic (ceftiofur IV) may help.
prevention/control of Actinobacillus Equlii?admit of COLOSTRUM IMPORTANT. improve hygiene, naval disinfeciton
where does Actinobacillus suis live?commensal of adult pigs
how is a pigglett infected with Actinobacillus suis?infect via umbilicus/ skin abrasions
what does Actinobacillus suis cause?acute speticemia, petechial hemorrhages, penumonia, meningitis




Question Answer
(CQ) is sleepy foal dz zoonotic?no
(CQ) can sleepy foal dz be wrongly called shigellosis?yes
(CQ) infected surgical instruments most likely cause what?pseudomonas aerugniosa