VMC 311: Systematic Veterinary Bacteriology and Mycology (2+1)

INTRODUCTION

• Streptococcus organisms are Gram positive, non-motile cocci occurring in chains or pairs when grown in liquid media.
• They are aerobic, facultatively anaerobic, catalase negative and oxidase negative.
• They ferment carbohydrates to produce acid but not gas. They do not form endospores.
• Streptococcus can be divided into six principal categories based on growth characteristics such as Type of hemolytic and Biochemical activities.
• These categories are
  • Pyogenic Streptococci
  • Oral Streptococci
  • Enterococci
  • Lactic group
  • Anaerobic Streptococci
  • Other Streptococci.
• Most of the disease producing Streptococci are in the pyogenic category, they are
  • S. equi sub sp equi -- Strangles
  • S.agalactiae subsp equisimilis -- Strangles
  • S. agalactiae -- Mastitis
  • S. dysgalactiae -- Mastitis
  • S. uberis -- Mastitis
  • S. zooepidemicus -- Mastitis.

Gram staining

• Smears from pus and exudates and deposits of milk or urine can be fixed and stained by Gram's method.
• Gram-positive cocci arranged in chains or pairs indicate the presence of streptococci.