Lecture 13 10/23/23 Flashcards
What are the general characteristics of Salmonella sp.?
-inhabit GI tract
-two species
-many subspecies
-transmission through contaminated food
What are the two species of Salmonella?
-S. enterica
-S. bongori
What are the characteristics of Salmonella virulence/pathogenesis?
-facultative intracellular
-cause inflammation and systemic dissemination
-septicemia is major problem
-have LPS, flagella, fimbriae, pathogenicity islands
-type 3 secretion system that injects proteins into host cells
What are the predisposition factors for Salmonella?
-age
-infectious dose
-alterations in normal flora
What disease does S. dublin cause in cattle?
dry gangrene
How can Salmonella be diagnosed?
-culture of fecal samples
-culture of blood
-liver, spleen, gall bladder culture
-selenite broth
-tetrathionate broth
-RV broth
-serology
-PCR
What are the potential treatments for Salmonella?
-supportive therapy
-possible antimicrobials (controversial)
What are the characteristics of Salmonella prevention?
-vaccines unsuccessful
-vx would need to induce both cellular and humoral immunity
-management/hygiene/isolation best practices
What does Salmonella cause in horses?
infectious diarrhea
Which Salmonella strains are common in horses?
-S. typhimurium
-S. muenchen
-S. newport
What are the predisposing factors for horses getting Salmonella?
-stress
-history of surgery
-transport
-feed changes
-GI disorders
-concurrent disease
-antibiotic treatment
How can Salmonella be treated in horses?
Polymyxin (binds to circulating endotoxin)
How can Salmonella be prevented in horses?
-ID and isolation
-biosecurity practices
-serotyping/genotyping
-awareness and education
What are the characteristics of S. pullorum in poultry?
-causes bacillary white diarrhea
-vertical, direct, or indirect transmission
-common in birds < 4 weeks
-survivors become asymptomatic carriers
-can cause septicemia, unabsorbed yolk sac, gray nodules in organs, and death
-testing and removal
What are the charactersitics of S. gallinarum in poultry?
-causes fowl typhoid
-vertical or direct transmission
-similar lesions to S. pullorum
-seen in growing or mature flocks
-swollen, friable, bile-stained liver
-necrotic foci
-enlarged GI organs/inflammation
-testing and removal
Which Salmonella sp. cause Avian Arizonosis?
S. arizonae and S. diarizonae
What are the charactersitics of S. enteritidis?
-very common serotype
-inside eggs that appear normal
-silently infects ovaries of healthy-looking hens
-contaminates inside of eggs before shell formation
What are the characteristics of Shigella sp.?
-cause bacillary dysentery
-fecal-oral transmission through contaminated food/water
-causes necrohemorrhagic periodontitis/gingivitis and arthritis
-low infectious dose
Which Shigella sp. is important to humans?
S. dysenteriae
What are the characteristics of Y. pestis?
-causes plague
-transmitted by wild rodents and their fleas
-bio-agent
What types of disease can be caused by Y. pestis in humans?
-bubonic: local lymph node involvement
-septicemic
-pneumonic
What does Y. pestis cause in mule deer?
ocular plague
How is Y. pestis diagnosed?
-direct smear/staining
-culture
-PCR
-serology
How is Y. pestis treated/prevented?
-antimicrobials (streptomycin, doxycycline, gentamicin, chloramphenicol)
-inactivated vx
What are the characteristics of Yersinia psuedotuberculosis and Yersinia enterocolitica?
-infections in birds, rodents, and cats
-cause mesenteric lymphadenitis, terminal ileitis, gastroenteritis, and septicemia
-often in colder months
-culture or PCR for diagnosis
What are the characteristics of Yersinia ruckeri?
-causes enteric red-mouth disease in fish
-hemorrhagic inflammation of organs causes death
What are the characteristics of Enterobacteriaceae generally?
-opportunistic
-emerging antimicrobial resistance
-Proteus, Klebsiella, and Enterobacter sp.
