A case study of Streptococcus group G infection in a dairy herd.

Abstract

In this paper an outbreak of bovine mastitis in a dairy herd caused by Streptococcus group G is described. Initial identification of the organism as Streptococcus agalactiae was based upon hemolysis, esculin reaction, and CAMP reaction observed on blood agar used for bulk milk analysis. Initial therapy with a penicillin-containing, lactating cow product cured 24.4% of all streptococcal infections. Definitive serogrouping by coagglutination determined that the majority of infections were due to a weakly-hemolytic, esculin-negative Streptococcus group G. Treatment with a cephalosporin, lactating cow product was only moderately successful (54.9%). Dry-cow therapy with 300 mg cephalosporin eliminated 69.5% of refractory infections. Animals remaining infected following dry-cow therapy were culled. Histopathological study of parenchymal tissue in the lower portion of infected quarters revealed mild damage and slight involutionary changes, whereas, deep parenchymal areas appeared relatively unaffected.

• Authors: J L Watts, S C Nickerson, J W Pankey
• Journal: Veterinary microbiology (Vet Microbiol) Vol. 9 Issue 6 Pg. 571-9 (Oct 1984) ISSN: 0378-1135 [Print] Netherlands
• PMID: 6390932 (Publication Type: Journal Article)

Chemical References

• Cephalosporins

Topics

• Animals
• Cattle
• Cephalosporins (therapeutic use)
• Dairying
• Disease Outbreaks (veterinary)
• Female
• Lactation
• Mammary Glands, Animal (microbiology, pathology)
• Mastitis, Bovine (epidemiology, microbiology, pathology)
• Milk (microbiology)
• Pregnancy
• Serotyping
• Streptococcal Infections (epidemiology, microbiology, pathology, veterinary)
• Streptococcus (classification, isolation & purification)
• Streptococcus agalactiae (isolation & purification)