Week 3

• Salmonella enterica in fowl and poultry

  paratyphoid

  pulloum disease

  fowl typhoid

  arizonosis
• Paratyphoid - caused by S. Typhimurium, S. Enteritidis, S. Infantis 


  septicemic disease

  oral ingestion

  zoonotic potential

  depression, poor growth, weakness, diarrhea, dehydration
• Paratyphoid lesions in young birds

  • enlarged liver with focal necrosis
  • Unabsorbed yolk sac
  • Enteritis with necrotic lesions
  • Cecal cores  
  • Infections in the eye or synovial tissue
• Paratyphoid in pigeons

  chronic carrier in macrophages

  • Not zoonotic 
  • Systemic disease + diarrhea 
  • Acute paratyphusus - mainly during breeding 
  • Chronic - one wing is hanging down
• Pullorum disease - caused by S. Pullorum


  reportable disease

  • Infects ova (marked tropism) 
  • High mortality due to septicemia 
  • Greatest occurrence in 2-3 weeks of life 
  • Disease of mainly young chickens 
  • Typical granulomatous lesions - Stomach, liver, and myocardium
• Fowl typhoid - caused by S. Gallinarum


  reportable disease

  • Mainly disease in older animals (>3 weeks)
  • Egg-transmitted 
  • Acute septicemia or chronic disease 
  • Hyperacute mortality  
  • Swollen friable and otfen bile stained liver with or without necrotic foci 
  • Enlarged spleen and kidney
  • Hemolytic anemia
• Arizonosis - S. subspecies arizonae 


  reptiles are reservior

  turkeys most affected - younger animals more susceptible

  Acute septicemia, reduced hatching rates, hatching of weak chicks, corneal opacities

  Reduced feed intake, movement disorders, diarrhea, convulsions
• Salmonella enterica in horses

  subclinical (stress can trigger presentation)

  mild (diarrhea - soft, nonwatery feces; self-limiting disease)

  acute

  hyperacute in foals (septic arthritis)
• Salmonella enterica suspecies enterica serovar Abortusequi

  abortion in mares

  neonatal septicemia and polyarthritis

  testicular lesions (stallions)
• Salmonella enterica in dogs and cats

  uncommon

  enteritis and septicemia

  outbreaks associated with contaminated dog food or treats
• Salmonella enterica treatment 


  typhoid-like: reportable culling, difficult to eliminate by antimicrobial therapy

  non-typhoid: isolation of sick animals, antimicrobials, NSAID/corticoids, fluid therapy
• Yersinia 


  gram-negative coccobacilli

  tropism for lympoid tissues

  capactiy to resist nonspecific immune responses

  facultative intracellular pathogen

  ability to resist phagocytosis
• Yersinia pestis 


  vector - Xenopsylla cheopis

  humans (bubonic plague)

  felines - severe infection, lymphagenitis, systemic, fatal

  rodents - latent infection, occassionally outbreaks
• Yersinia pseudotuberculosis 


  fecal oral transmission

  feces of rodents and wild birds

  can multiply in the environment

  necrosis in internal organs
• Yersinia pseudotuberculosis in rodetns, rabbits, and captive birds 


  pseudotuberculosis

  septicemia, nodules in internal organs
• Yersinia pseudotuberculosis in farm animals

  latent infection

  mesenteric lymphadenitis, terminal ileitis, acute gastroenteritis

  orchitis and epididymitis
• Yersinia pseudotuberculosis in humans

  mesenteric lymphadenitis, acute terminal ileitis, septicemia
• Yersinia pseudotuberculosis in birds 


  major pathogen

  fatty liver disease, rodentiosis

  Apathy, water and feed intake, diarrhea 

  Chronic symptoms - weight loss and respiratory distress
• Yersinia enterocolitica 


  fecal oral transmission

  Source - GI tract

  • In domestic animals and primates
  • Mesenteric lymphadenitis, terminal ileitis, acute gastroenteritis, septicemia
  • Associated mainly in self-limiting diarrhea
  • Enteritis in humans (pig strains)
  • Zoonosis
  • Decreased thriftiness, diarrhea, dehydration
• Yersinia ruckeri


  causative agent of enteric redmouth disease in fish

  inflammation in most organs
• Klebsiella spp.


  coliform bacteria

  • Can be found in the environment 
  • Coliform mastitis in cattle 
  • Cervicitis and metritis in mares 
  • Urinary tract infections in dogs 
  • Pneumonia, septicemia and suppurative conditions in foals
  • Diverse infections in primates
• Klebsiella treatment 


  natural resistance/low susceptibility to amoxy/ampi

  • Susceptible to amoxicillin + clavulanic acid & cephalosporins
  • High level of acquired resistance
• Proteus spp. 


  Swarming bacterium

  • Could be a contaminant
  • Post-mortem multiplication
  • Facultative or opportunistic pathogen
  • Secondary infections 
  • Nosocomial infections
• Proteus disease 


  UTI (cystitis) in dogs, cats, and horses

  Otitis externa (dogs and cats, often as a component of mixed infection)
• Pseudomonas


  Gram negative bacilli

  • Non-spore forming, strict aerobes
  • Oxidase +, motile
  • Oxidative (non-fermenter)
  • Nitrate to nitrite to N2 gas
  • Environmental bacteria (found in water, soil, plants)
• Psuedomona aeruginosa 


  Transients in skin and GI tract 

  • Opportunistic pathogen
  • Broad antibiotic resistant (intrinsic and acquired)
  • Important nosocomial pathogen
  • Optimal growth at 37C
• P. aeruginosa pathogensis 


  Transmission usually through indirect contact with contaminated tools 

  Adherence & colonization (flagella & pilli adherence to host tissue, LPS protection of phagocytosis)

  Multiplication & growth (quorum sensing, biofilm formation, T3SS expressed, toxin delivered and secreted)

  Systemic disease (LPS, endotoxin A)
• P. aeruginosa in dogs and cats

  Otitis externa, may progress to otitis media (greenish malodorous discharge from ears)

  • Lower urinary tract infection
  • Pneumonia, ulcerative keratitis, pyoderma
• P. aeruginosa in horses

  Infectious endometritis 

  • Vaginitis
  • Abortion
  • Keratitis, conjunctivitis
• P. aeruginosa in ruminants

  Clinical to subclinical mastitis in dairy cows, sheep, and goats

  • Chronic infection - asymptomatic with high somatic cell count
  • Sheep and goats - Gangrenous mastitis, Pneumonia, mastitis, lung abscesses, green wool, Fleece rot (sheep) 
  • Cattle - Uterine infections, enteritis, arthritis, respiratory infections, botryomycosis
• Fleece rot 


  Superficial dermatitis 

  • Pigmentation of wool
  • Occurs following periods of excessive wetness 
  • Frequently together with Dermatophylus congolensis 
  • Association with mastitis and pneumonia
• P. aeruginosa in rabbits

  dermatitis

  sporadic pneumonia

  high use of disinfectanct
• P. aeruginosa in mink, chinchilla, guinea pigs, hamsters

  Hemorrhagic pneumonia & septicemia 

  • Mink are highly susceptible 
  • Pulmonary lesions (Focal inflammation, focal necrosis, widespread inflammation and necrosis)
  • Chinchillas (Septicemia, pneumonia, conjunctivits, enteritis, otitis media and interna with neurological manifestations, sudden death, abortion)
• P. aeruginosa in reptiles

  Necrotic stomatitis, multiple ulcers, pneumonia, septicemia

  Often secondary to poor sanitary housing conditions
• P. aeruginosa in birds 


  Psittaciformes - secondary infection (Conjunctivitis, rhinitis, pneumonia, airsacculitis, enteritis)

  Galliformes (Infections in the oviduct, Contamination of eggs, Exploding eggs (H2S odor); Neonatal mortality)

  Poultry (Septicemia)
• Pseudomonas fluorescens 


  Grow at 4C 

  • Fish (Septicemia, tail/fin rot)
  • Poultry (Embryonic mortality)
  • Cattle (Mastitis)
• Pseudomonas putida


  Opportunistic pathogen 

  • Normally occurs in aquatic environment and as part of the norma gut flora of healthy fish
  • Nile tilapia (Exophthalmia, ascites, ulceration on the fish body)
  • Rainbow trout (Ulceration on the dorsal surface)
• Pseudomonas diagnosis 


  Grow on typical lab media 

  Use selective media (Facilitate recovery from mixed flora)

  Incubate aerobically 35-37C for 24-48 hours

  Most strains give clear zone of hemolysis on blood agar 

  Pigments (Pyocyanin, blue-green color)

  Biochemical characteristics (Oxidase +, odor, reduction of nitrates to nitrogen gas)
• Pseudomonas treatment and prevention

  Treated with carefully selected antibiotics that avoid inherently high levels of resistances 

  Otitis - Enrofloxacin, neomycin, polymyxin, chloramphenicol, gentamicin

  Bacteriophage therapy - Alternative in wound infections 

  Vaccines - Only available for minks 

  Prevention of wet conditions
• Taylorella spp. 


  Gram negative rods 

  • Facultative anaerobes 
  • Non-motile
  • Fastidious and slow growing 
  • Highly contagious