Streptococcus spp

From Cow
Streptococcal mastitis in a cow
Acute Streptococcus agalactiae mastitis in a cow

Streptococcus spp are a commensal bacteria of skin, mucous membranes and intestinal content of cattle worldwide.

This genus of bacteria are not normally pathogenic unless other conditions allow their superimposition over other bacteria.

Species of Streptococcus which have been recorded as pathogenic to cattle include:

S. infantarius subsp. infantarius[4]
  • S. pyogenes
  • S. salivarius

Diagnosis of the presence of this genus of bacteria can be confirmed by culturing in a laboratory. PCR assays are also available for further clasification of subspecies[5].

These bacteria are sensitive to broad-spectrum antimicrobial therapy, especially drugs such as penicillins, gentamicin, marbofloxacin[6], enrofloxacin and ceftiofur.


  1. Akerstedt M et al (2012) Protein degradation in bovine milk caused by Streptococcus agalactiae. J Dairy Res 79(3):297-303
  2. Paduch JH et al (2012) The association between teat end hyperkeratosis and teat canal microbial load in lactating dairy cattle. Vet Microbiol 158(3-4):353-359
  3. Reyher KK et al (2012) Evaluation of minor pathogen intramammary infection, susceptibility parameters, and somatic cell counts on the development of new intramammary infections with major mastitis pathogens. J Dairy Sci 95(7):3766-3780
  4. Jans C et al (2012) Complete genome sequence of the African dairy isolate Streptococcus infantarius subsp. infantarius strain CJ18. J Bacteriol 194(8):2105-2106
  5. Shome BR et al (2011) Multiplex PCR assay for species identification of bovine mastitis pathogens. J Appl Microbiol 111(6):1349-1356
  6. Kroemer S et al (2012) Survey of marbofloxacin susceptibility of bacteria isolated from cattle with respiratory disease and mastitis in Europe. Vet Rec 170(2):53