Infection of the sheep headfly, Hydrotaea irritans with bacterial isolates from field cases of summer mastitis
Wright, C.L.; Titchener, R.N.
Veterinary Record 101(21): 426
1977
ISSN/ISBN: 0042-4900 PMID: 339478 Document Number: 123910
It has been suggested that the causal agent of summer mastitis in cows can be transmitted by flies. In tests in Scotland, field-collected adults of Hydrotaea irritans (Fall.) were kept in an outdoor insectary, provided with a 50% honey solution and allowed to feed for 30 min on infective material (pieces of blood agar cultures or sterile cotton wool soaked in broth cultures). Flies were killed 2-16 days after feeding on the isolates and it was found that they had been readily infected with Corynebacterium pyogenes, Streptococcus agalactiae and S. dysgalactiae but not with C. bovis or Micrococcus indolicus. Some infected flies were allowed to feed on sterile blood agar plates to determine if the infection could be transmitted during the feeding process. Only S. dysgalactiae and C. pyogenes were recovered, 1 and 2 days, respectively, after the initial infection. These results suggest that H. irritans feeding on the teats of animals with summer mastitis due to C. pyogenes and S. dysgalactiae could become infected and possibly transmit these agents.