Pathogenicity

PATHOGENECITY

Cattle : Bovine mastitis

  • It is caused by S. agalactiae (group B), S. dysgalactiae (grp C), S. equi subsp. zooepidemicus (grp. C), S. uberis (grp C, D, E, P, V).
  • Mastitis arises from the multiplication of streptococci in the teat sinus and extends into the ducts.
  • It causes parenchymatous mastitis, which is characterized by progressively chronic condition resulting in fibrosis.
  • In acute stages milk is composed of purulent exudate, dead tissue cells, coagulated milk protein and bacteria.
  • Peptostreptococcus indolicus is an anaerobic streptococcus, which is responsible for summer mastitis in cattle in association with Arcanobacterium pyogenes.

Horse

  • S. equi and S. equisimilis are the main causes of strangles in young horses.
  • It is characterized by a catarrhal discharge, with inflamation of the nasal mucous membranes, followed by swelling of pharyngeal LN’s in which abscesses develop.
  • The infection spreads through lymph channels. It also causes metritis and cervicitis in horses.
  • Purpura haemorrhagica, considered to be an immune mediated disease, occur in horses 1 to 3 weeks after illness.
  • Bastard strangles – in which abscesses developed in many organs. It is a very serious complication.

Chicken

  • S. gallinarum causes typical acute septicemia with peritonitis in chicken.

Dogs

  • S. canis is considered to be the cause of acid milk in puppies and canine tonsillitis. It is also associated with neonatal septicaemia and toxic shock syndrome.

Pigs

  • S. suis causes porcine cervical lymphadenitis and also isolated from pneumonia, septicaemia, arthritis, endocarditis, meningitis and reproductive tract infections.
  • It also causes erosive arthritis in young pigs.
Last modified: Monday, 4 June 2012, 4:11 AM