mt pt1

• What is the morphology of Listeria?


  Small gram-positive rods
• Where can Listeria be found in the environment?

  On herbage and freshwater
• What is the typical form of L. monocytogenes?

  Typical coccobacilli
• How do Listeria colonies appear on culture media?

  Small, smooth, transparent colonies
• What type of media does Listeria grow on?

  Non-enriched media
• What is the oxygen requirement for Listeria?

  Facultative anaerobes
• What is the catalase reaction of Listeria?

  Catalase-positive
• What is the oxidase reaction of Listeria?

  Oxidase-negative
• How does Listeria move at 25°C?

  Motile with tumbling movement
• What diseases are caused by L. monocytogenes in different hosts?

  • Sheep, cattle, goats: Encephalitis, abortion, septicemia, endophthalmitis
  • Pigs: Abortion, septicemia, encephalitis
  • Birds: Septicemia
• What diseases are caused by L. ivanovii and L. innocua?

  • L. ivanovii: Abortion in sheep and cattle
  • L. innocua: Rare meningoencephalitis in sheep
• What is a key diagnostic method for Listeria?

  Pattern of hemolysis in sheep blood agar
• What tests are used to diagnose Listeria?

  CAMP tests and acid production from sugars
• What specimens should be sampled for Listeria diagnosis?

  Cerebrospinal fluid and tissue from medulla
• What are the identification criteria for L. monocytogenes?

  Small haemolytic colonies, aesculin hydrolysis
• How does L. monocytogenes spread in the body?

  Penetrates M cells and spreads via lymph and blood
• What is a significant transmission route for L. monocytogenes in pregnant animals?

  Transplacental transmission
• What are the signs of Listeria infection in animals?

  Dullness, circling, tilting of head
• What is the incubation period for neural listeriosis?

  14-40 days
• What is the morphology of Erysipelothrix?

  Gram-positive slender rods
• What is the catalase reaction of Erysipelothrix?

  Catalase-negative
• What diseases does Erysipelothrix rhusiopathiae cause in pigs?

  Septicemia and diamond skin lesions
• What are the forms of swine erysipelas caused by Erysipelothrix rhusiopathiae?

  1. Septicemic: Acute, febrile, may be found dead
  2. Cutaneous: Acute, systemic signs less severe, diamond-shaped plaques
  3. Arthritis: Chronic, stiffness, lameness
  4. Vegetative endocarditis: Chronic, wart-like thrombotic masses
• What vaccines are available for Erysipelothrix prevention?

  Live and attenuated vaccines
• What is the morphology of Corynebacterium?

  Small, gram-positive, pleomorphic
• What type of bacteria is Corynebacterium?

  Opportunistic pathogens
• What diseases are caused by Corynebacterium species in different hosts?

  • C. bovis: Subclinical mastitis in cattle
  • C. kutscheri: Superficial abscesses in rodents
  • C. pseudotuberculosis: Caseous lymphadenitis in sheep and goats
  • C. renale: Cystitis in cattle
• How does Corynebacterium pseudotuberculosis infect sheep?

  Through contamination of shearing wounds
• What is the incubation period for Corynebacterium pseudotuberculosis infection?

  About 3 months
• What is a characteristic appearance of affected lymph nodes in Corynebacterium pseudotuberculosis infection?

  Encapsulated abscess with 'onion ring' appearance
• What is the morphology of Rhodococcus?

  Gram-positive cocci and rods
• What is the primary disease caused by Rhodococcus equi in foals?

  Suppurative bronchopneumonia
• What is the mode of infection for Nocardia?

  Inhalation and through skin wounds
• What diseases are caused by Nocardia species in different hosts?

  • Nocardia asteroides: Canine nocardiosis, chronic mastitis in cattle
  • Nocardia farcinica: Bovine farcy
• What are the clinical signs of systemic nocardiosis in dogs?

  Pyrexia, emaciation, coughing, nervous signs
• How much more likely is nocardiosis in male dogs compared to females?

  Three times more likely
• What is the common disease caused by Nocardia in horses?

  Pulmonary and systemic infection
• What is the approximate diameter of Gram-positive cocci?

  1 um
• How do Gram-positive cocci react to ordinary stains?

  They are readily stained
• Where do Gram-positive cocci commonly occur?

  On skin and mucous membranes