final exam Flashcards
What are the factors that allow bacterial infection of the respiratory system to take place?
-impaired clearance (chronic airway disease- RAO/asthma)
-overwhelming inocula of pathogens (aspiration)
-Immune status/ nutritional status/stress
What organisms are urease producing?
Staphyloccoccus
Proteus spp
Enterbacter spp
Corynebacterium renale
How should you treat prostitis?
Few options because of acidic pH of prostatic acini, use only lipophilic/weak bases
-Enrofloxacin
-Trimethoprim/Sulfamethoxazole
-Clindamycin (only for staph/strep)
-Chloramphenicol (if highly suceptible)
What is true about complicated UTI in dogs
Complicated UTI are more common than uncomplicated UTI than dogs
What Leptospira serovar is most concerning for cattle?
Hardjo
How does leptospirosis pathogenesis occur?
organisms replicate in the blood, cause vasculitis in a variety of organs, ultimately reach the kidneys and cause interstitial nephritis with mixed inflammatory cells
Can you culture Leptospirosis?
NO
What should you order for culturing cytstitis
aerobic culture
What is a common cause of Poll evil and fistulous withers?
Brucella abortus
Can Chlamydia cause polyarthritis and conjunctivitis in lambs
Yes
What are reservoirs for contagious mastitis pathogens
Bedding, gloves, milk parlor, towels
Etiological agent of greasy pig disease
Staphylococcus hyicus
What species does Staphylococcus pseudointermedius primarily impact?
Primarily opportunistic of dogs
What causes Strawberry footrot
Treponema species
What is associated with contagious footrot in sheep?
Dichelobacter species
What is associated with noncontagious footrot in sheep?
Fusobacterium/ T. pyogenes
What agents are associated with causing bovine footrot
Fusobacterium necrophorum
Prevotella spp.
Bacterioides spp
Trueperella pyogenes
What are characteristics of all prokaryotic cells?
1) No membrane organelles
2) 70S ribosomes,
3) DNAp resent as a single circular chromosome
4) Replication through binary fission
What are bacteria cell wall made of
layer of cross-linked chains on N-acetyl glucosamine and N-acetyl muramic acid monomers
crosslinked by transpeptides and transglycosides
Does sporulation result in death of parent cell
YEs
Is sporulation more common in gram negative or gram positive bacteria?
Gram positive
Can you stain Mycoplasma?
NO
What is used for the phylogenic classification of bacteria?
16s rDNA sequence
What is true about MacConkey’s agar?
It is selective and differential
What are the targets of beta-lactams?
penicillin-binding proteins
What toxins produce a pharmacologically specific effect?
Exotoxins
Is endotoxin or exotoxin more heat stable
endotoxin
Chloramphenicol has action in what quadrants
gram negative and gram positive with activity against facultative anaerobes, aerobes, and obligate anaerobes
Four mechanisms of antimicrobial resistance
1) Inactivation of drugs through bacterial enzymes (ex: betalactamases, chloramphenicol acetyl transferase, etc.)
2) Mutations of drug targets
3) Efflux pumps (transmembrane proteins that actively export drug)
4) Preventing access to the cell (ex: porin mutations of transmembrane protein)
The minimum inhibitory concentration
the lowest concentration of drug in a two-fold dilution series in which there is no visible growth of bacteria
Is E. coli an important cause of diarrhea in horses?
NO
What is the pilli most often associated with ETEC causing disease in calves
K99 (F5)
What species is associated with F4 (K88) of ETEC
Swine
Edema disease of swine is caused by infection with
STEC
how does STEC impact cattle?
They show no clinical signs
What serotype of Salmonella enterica subsepcies enterica is host-restricted to human beings and NHPs
Typhi
Salmonella enterocolitis pathogenesis
suppurative (neutrophilic) infiltrate and associated prostaglandin release
Salmonella laboratory isolation timing and media
Multistep process using selective and differential media that takes at least 2 days.
Campylobacter bug basics
Gram negative, curved rod, nonspore forming, microaerohpile, and darting motility
What carrier state is associated with Salmonella enterica subspecies enterica serotype Dublin
Cattle
All Brachyspiras are__________
Obligately anaerobic, gram negative spirochetes
What is a risk factor for Brachyspira hyodysenteriae infections?
The level of fermentable carbohydrates in the pig ration is a risk factor
Lawsonia intracellularis is
gram negative obligately intracellular organims whose diagnostics are approached using PCR of intestinal scrapings
What species has the invasion of M cells as an aspect of pathogenesis
Salmonella enterica
Yersinia enterocolitica bug basic
gram negative facultative anaerobe
What is a potential consequence of STEC infection in humans?
Hemolytic-uremic syndrome
What pathogen can you diagnose using a urease test on fresh tissue?
Helicobacter species
Clostridium perfringens Type C infections
-Enterotoxemia
-Rapid acute progression
-Associated with dietary change to more grain and protein
-causes severe disease in neonatal calves, foals, lamb, and piglets
-Can cause disease in humans
-Trypsin inhibition of colostrum is a risk factor
What toxinotype is associated with Pulpy Kidney disease?
Type D
What would make a convincing diagnosis of C. perfringens?
Compatabile histopathological lesions plus isolation of the organism in culture
What is the causative agent of Tyzzer’s disease
Clostridium piliforme
What is the causative agent of Braxy (necrotizing abomasitis) in lambs
Clostridium septicum and Clostridium sordelli
How does Clostridium botulinum toxin (BoNT) cause deficits?
by blocking ACh release at the NMJ
What causes Blackleg?
Clostridium chauvoei
What causes Clostridium chavoei spores to germinate
when muscle tissues become anoxic
How would you manage tetanus in the dog?
-administer antimicrobial agents with gram positive, anaerobic spectrum
-Tube feeding
-Administration of tetanus antiserum
How is the definitive diagnosis of blackleg achieved?
Fluorescent antibody staining of the impacted tissues
How do you diagnose Campylobacter diarrhea in a dog?
Fecal culture and incubate under micoaerophilic with special campylobacter selective media to inhibit other GI flora
Saprophyte
a plant, fungus, or microorganism that lives on dead or decaying organic matter.
Would a 1st generation or a 3rd generation cephalosporin have better activity against E. Coli?
A third generation cephalosporin (like cefpodoxime) would have better activity against E. Coli because it is a gram negative
What organisms form sulfur granules in lesion?
Actinobacillus lignieresii
Actinomyces species
Kerion
fungal abscess
Pathogenesis of Dermatophilus congolensis
Proteases that breakdown keratin leading to rain rot in horses
What is the causative agent of Glanders?
Burkholderia mallei
What organism do you use a Mallein test to diagnose for?
Burkholderia mallei
Enterohemorrhagic E. Coli (EHEC)
causes hemorrhagic enteritis, hemolytic uremic syndrome in humans
How do you treat ETEC?
Fluid therapy, bottle feeding +/- antibiotics
prevent with colostrum, cow nutrition, hygiene, husbandry
What is the most common cause of E coli diarrhea in farm animals?
ETEC
Entertoxins of ETEC
work to cause fluid loss without inflammation
LT (heat-labile) and STa cause active sec of Cl-, impaired absorption of Na+ water (secretory diarrhea)
Stb (hear stabile toxin) works indirectly though enterendocrine cells to promote secretion of serotnin, vasoactive intestinal peptide
STEC/EHEC virulence factors
LEE: locus of enterocyte effacement (attaches to host epithelial cells) through gene cluster and type III secretion system
Shigatoxin (inhibit protein synthesis and induce apoptosis)
Hemolysin (aids survival of STEC in intestine
Acid Resistance- enhance in stomach
Acute mycoplasma haemofelis
fever, pale mucous membranes, lethargy, splenomegalu, icterus
regenerative anemia, hyperbilirubiemia, neutrophilia, moncytosis, lymphoctusos, +/- Coombs postive
