Bacterio Exam 3 Review

what is the most important disease of horses?

strangles

what is the etiologic agent for strangles?

streptococcus equi subsp. equi

What gram is streptococcus equi subsp. equi?

gram-positive

What coagulase and catalase is streptococcus equi subsp. equi?

negative

How is streptococcus equi subsp. equi transmitted?

directly or by fomite (obligate parasite)

what is the resistance to strangles associated with?

serum and mucosal antibodies to the streptococcal M protein (SeM)

What is the virulence of S. equi atrributatable to?

M proteins, Hyaluronic acid capsule, leukocidal toxin

what provides resistance to phagocytosis in S. equi?

capsule

what causes cell damage from S. Equi?

toxins

what causes swelling and abscessation in S. equi?

migration of neutrophils

how does strangles manifest?

acute disease: infection of retropharyngeal lymph node and guttural pouch

chronic disease: metastatic infection of organs

what is the treatment/control of strangles?

penicillin, quarantine, live attenuated intranasal vaccine

What is another name for Pneumonic Pasteurellosis of Cattle or Bovine Respiratory Disease?

Shipping Fever

what is the most important bacterial pathogen in weaned calves?

mannheimia haemolytica serotype A1 and A6

what is a commonly isolated pathogen from the lower respiratory tract of younger calves?

Pasteurella multocida serotype A3

what gram is pasteurelaceae?

gram-negative

what is the most common illness among cattle in US feedlots?

shipping fever

what other bacteria does shipping fever co-infect with?

mycoplasma, histophilus somni, bibersteinia trehalosi

what is characteristic to shipping fever?

lobar fibrinopurulent bronchopneumonia

what are virulence factors of M. haemolyica and P. multocida? (shipping fever)

surface proteins and carbohydrates, toxins and extracellular enzymes (leukotoxin)

what is prevention for shipping fever?

reducing stressors that contribute to development of disease, modified-live vaccines

what is treatment for shipping fever?

metaphylaxis

what is atrophic rhinitis caused by?

pasteurella multocida types D and A

what is the nonprogressive atrophic rhinitis, due to? symptoms?

due to Bordetella bronchispetica. mild and transient (little effect on growth and performance)

what is the progressive atrophic rhinitis, due to? symptoms?

due to toxigenic pasteurella multocida. severe and permanent (accompanied by growth)

what are outbreaks atrophic rhinitis due to?

introduction of infected pigs or mixing of pigs from different sources

what are clinical findings of atrophic rhinits?

sneezing, coughing, and inflammation of lacrimal duct

what does the severity of atrophic rhinitis herd depend on?

presence of toxigenic strains of P. multocida, management practices and the immune status of the herd

what is pneumonia of foals caused by?

Rhodoccous equi

what is pneumonia of foals (caused by Rhodococcus equi) important

high incidence rate, high case-fatality, cost of treatment, lack of protective vaccine

what gram is Rhodococcus equi?

positive

what catalse is rhodococcus equi?

catalase-positive

what are the symptoms of rhodococcus equi?

pyogranulomatous bronchopenumonia, ulcerative coloitis and mesenteric lymphadentitis

what is the virulence of R. equi associated with?

virulence-associated protein (VapA)

what determines the resistance to intracellular killing for R. equi?

chain length of cell wall mycolic acid

How large are borrelia burgodorferi?

0.2-0.5 micro meter

what gram are borrelia burgodorferi?

gram negative

borrelia burgodorferi are ________ ________ in vertebrae hosts

obligate parasites

what do borrelia burgodoferi cause?

lyme disease

what is the clinical signs of lyme disease in dogs?

polyarthritis and glomerulopathy

If a dog in Lyme disease endemic area has leukopenia or thrombocytopenis, these hematologic changes are likely caused by infection or co infection with which pathogen?

rickettsial

what are the three serological assays to detect for lyme?

whole-cell ELISA, C6 peptide based assay, multiplex assay

what is special about C6-peptide based assay? in regards to lyme disease?

differentiate between vaccinated and naturally infected dogs (detect antibodies against C6-peptide, the invariable region of borrelial protein VIsE)

what is malignant edema (gas gangrene) caused by?

clostridium septicum

how does infection occur for malignant edema?

contamination of wounds

which species have dormant spores of clostridium septicum in musccle tissues?

horses and cattle

what are the clinical findings for malignant edema?

high fever, local sloughing of skin, severe edema of head, lacerations of vulva

how is malignant edema diganosed?

fluorescent-antibody straining, PCR assay, fine needle aspirates and gram stain

what is the treatment for malignant edema?

high doses of parenteral penicillin, vaccination

what is blackleg caused by?

clostridium chauvoei

what is blackleg characterized by?

emphysematous swelling and necrotizing myositis

how does blackleg differ in cattle and sheep?

cattle can get it without a history of wounds (endogenous), sheep always get it as a result of infection (both are highly fatal)

what is a highly fatal muscoloskeletal disease? Prostration, tremors, death within 12-48 hours, myocardium?

black leg

what are the standard methods for diagnosing black leg?

anaerobic culture and biochemical identification and fluorescent antibody test

what causes bovine footrot?

Fusobacterium necrophorum biotypes of A and AB

what is the colonial apperance of dichelobacter nodosus?

colonies of virulent strains from lesions of ovine foot rot usually have dark central zone, a pale granular middle zone, and a spreading irregular periphery with a ground glass apperance

what are signs of foot rot?

hindlimb more affected than forelimb, swelling and erythema of the soft tissue, inflammatory edema is uniformly distributed

how is foot rot treated?

penicillin G

how to prevent foot rot?

footbath with an antiseptic , high levels of zinc fed as a supplement have a beneficial effect

what is the cause of infectious footrot in sheep?

dichelobacter nodosus

what is the major virulence factor in foot rot of sheep?

Type IV fimbrae

how are sheep infected with foot rot?

D. nodosus infection is discharge from the active or chronically infected sheep

what is the most susceptible sheep breed to sheep foot rot?

merino

what are characteristics of the order rickettsiales?

pleomorphic, gram negative, obligate intracellular, host specific, tropism

what stain do rickettsiales respond to ?

romanowsky stains

what is the family for the order rickettsiales?

Anaplasmataceae (lack cell walls, tropism for cells hemopoietic system)

what is the other family for the order Rickettsiales?

Rickettsiaceae (contain peptidoglycan, tropism for vascular endothelium)

where are neorickettsia found?

vacuoles of monocytes, macrophages in lymphoid tissues and occasionally in enterocytes

what is salmon poisoning caused by?

Neorickettsia helminthoeca

what is the only obligate helminth-borne pathogenic bacterium?

neorickettsia helminthoeca

what are the clinical signs of salmon poisoning disease?

fever, depression, anorexia, diarrhea, and lymphadenopathy

how does elokomin fluke fever differ from salmon poisoning disease?

less virulent strain, incubation slightly longer, similar but less severe

what is the only way to distinguish salmon poisoning disease from Elokomin Fluke Fever in PCR?

using specific primer pairs

what causes potomac horse fever?

Neorickettsia risticii

what are the signs of potomac horse fever?

acute watery diarrhea

what does the neorickettsia risticii life cycle involve?

trematode vector and snail reservoir

what does Neorickettsia risticii (potomac horse fever) have affinity for?

monocytes, macrophages, and intestinal epithelial cells

what is a treatment for potomic horse fever early in infection?

oxytetracylines

what is bovine anaplasmosis caused by?

A. marginale

how is bovine anaplasmosis transmitted by?

ticks (boophilus, dermacentor, ixodes, rhipicephalus)

what are the clinical signs of bovine anaplasmosis?

progressive anemia, fever, because cattle <1 year old sho no or mild clinical signs

what are effective treatments for bovine anaplasmosis?

tetracyclines and imidocarb

what are the two species of ehrlichoiosis?

Ehrlichia canis (canine monocytic ehrlichiosis), and Ehrlichia ewingii (canine granulocytic ehrlichiosis)

what is the causative agent of canine monocytic ehrlichiosis?

ehrlichia canis

what the most clinically severe ehrlichiosis?

canine monocytic ehrlichiosis

what is the primary vector for canine monocytic ehrlichiosis?

brown dog tick

what causes canine granulocytic ehrlichiosis?

ehrlichia ewingii

what is the tick vector for canine granulocytic ehrlichiosis?

amblyomma americanum

what is rocky mountain spotted fever caused by?

ricketssia rickettsia

Rocky mountain spotted fever causes disease primarily attributable to what?

vasculitis

what are the primary vectors for rocky mountain spotted fever?

dermacentor variablis and D. andersoni

what is caseous lymphadenitis?

abscesses of peripheral and/or internal lymph nodes and organs

what is diagnostically definitive when diganosing caseous lymphadenitis?

corynebacterium pseudotuberculosis

what are characteristics of corynebacterium pseudotubercuolosis (caseous lymphadentitis)?

gram positive, catalse-positive, pleomoprhic, chinese characters, urease positive

how to bacteria (corynebacterium pseudotubercuolosis) move to lpymph nodes after they infected the body?

regional draining lymphatic system

what are the clinical signs of caseous lymphadentitis?

superficial: enlarged lymph nodes

visceral: abscesses of internal organs

what do the abscesses in caseous lymphadentitis look like?

onion rings

what is the virulence of corynebacterium pseudotubercuolosis associated with?

cell wall lipid, an exotoxin, phospholipase D (PLD)

what causes ulcerative lymphangitis in horse and cattle?

nitrate-reducing biotype of C. pseudotubaerculosis

how does ulcerative lymphangitis present?

lymphangitis of the lower limbs of abscessation in pectoral region