gram negative: salmonella and yersinia

salmonella genus overview:

-natural habitat: GI (of both warm-blooded and cold-blooded animals), subclinical carriers (don’t show issues, but gives to other animals), environment: feces, soil, feed, water (can survive in the environment for months)

-gram negative medium rods

-facultatively anaerobic

-colony morphology: 2-3mm smooth or rough colonies, low convex, moist, shiny, gray; no swarming and no mucous production

-lab results: catalase +, nitrate to nitrite, motility +, TSI H2S +, indole -, urease -, citrate +, MR +, VP -, lactose -, EMB light to grey to amber colonies ((+ growth - fermentation), brilliant green: white colonies with red halos

-salmonella species are split into 3 different species: bongori,enterica,and subterranea

salmonella tymphimurium:

• additional info.: NOT typhoid fever (salmonella typhi) or paratyphoid (salmonella paratyphi/schottmuelleri)

• diseases associated with it: enteritis, septicemia, can be subclinical (cattle, horses, pigs, cats, humans, exotics); fowlparathyroid (enteritis and sudden death in birds)

• organs: GI, systemic

• treatment: supportive care, antibiotics pending culture and sensitivity

equine: salmonella abortusequis

• diseases associated with it: abortion

• organs: reproductive

• treatment: antibiotics

Cattle: salmonella dublin and salmonella bovismorbificans:

• diseases associated with it: enteritis, septicemia, abortion (adults); meningitis, terminal dry gangrene (tissue death and blood loss before necrosis; thrombosis-abnormal clotting of platelets, and demarcation= a mark/line on the limb where the necrosis goes up to), joint illness, osteomyelitis (calves; inflammation of the bone marrow)

• organs: urinary, joints, GI

• treatment: antibiotics

swine: salmonella choleraesuis, salmonella typhisuis, salmonella derby

• diseases: septicemia, enteritis, hog cholera bacillus (choleraesuis- swine fever); chronic enteritis (young pigs)

• organs: GI, systemic (multi organ involvement)

• treatment: supportive care and antibiotics pending culture

***swine fever= skin hemorrhages (big hematomas on skin), diarrhea, fever, vomit, not risk to human health. no vaccine, no treatment, no zoonosis but we can carry it and give to another pig

Sheep: salmonella abortusovis and salmonella diarizonae

• diseases associated with it: abortion, diarrhea (ewes); subclinical carriers

• organs: reproductive and GI

• treatment: supportive care and antibiotics pending culture and sensitivity

Poultry: salmonella pullorum, salmonella gallinarum, salmonella arizonae, salmonella enteritidis

• diseases associated with it: pullorum disease (white diarrhea in neonates); fowl typhoid; severe enteritis, septicemia; fowl parathyroid (enteritis and sudden death)

• organs: GI, systemic

• treatment: supportive care and antibiotics pending culture and sensitivity (Gallinarum: eradication and control)

yersinia genus overview:

ZOONOTIC

-natural habitat: rodents are natural reservoirs(something that can hold on to what has the bacteria- like fleas on rats with the plague)

-gram negative rods/coccobacilli (bipolar)

-facultatively anaerobic

-is quickly inactivated by oxidizing agents (use rescue)

-plate morphology: slow growth, very small colonies, optimum ~ 28 degrees C; grows on blood agar and macconkey (pale, non-lactose)

-lab results: catalase +, oxidase -, indole -, urease + (all but pestis)

yersinia pseudotuberculosis:

ZOONOTIC

• Characteristics: not mentioned

• lab results: motility +, urease +, indole -, mannitol +, sucrose -, gas - (salt loving)

• diseases associated with it: pseudotuberculosis (hares, rabbits, guinea pigs, other rodents, captive birds, deer); epididymitis (inflammation of epididymis) and orchitis (sheep; inflammation of testicle(s)) ****pseudo TB: caseous abscesses(capsuled abscess- thick membrane) in mesenteric lymph nodes with spread to spleen and liver, may cause septicemia and high mortality in most hosts

• organs: GI, lymphatic system, spleen, liver, male reproductive

• treatment: antibiotics pending culture and sensitivity, cull

yersinia enterocolitica:

• reservoir: pigs

• characteristics: small grey colonies with gamma hemolysis, psychotropic (so is listeria; cold tolerant and capable of growing in refrigeration temperatures)

• lab results: urease +, indole -, glucose -, gas -, lactose -, sucrose +(weak positive with TSI)

• diseases associated with it: subclinical enteritis (pigs), sporadic abortion (sheep), yersiniosis (humans)

• organs: urinary, GI, and reproductive

• treatment: antibiotics pending culture and sensitivity

yersinia pestis:

ZOONOTIC AND A REPORTABLE DISEASE

-vector: fleas

-reservoirs: rodents

• characteristics: 1-2mm gray, raised irregular “fried-egg” colonies; grows on nutrient, blood, and macconkey agar

• lab results: motility -, lactose -, indole -, urease -, MR +

• diseases associated with it: BUBONIC PLAGUE (humans and cats); mandibular lymphadenitis, and systemic illness (cats); sylvatic plague-often latent-(rodents)

• organs: lymphatic (buboes), systemic, skin, respiratory

• treatment: vet med does not have treatment for this