Identification of Streptococcus canis isolated from milk of dairy cows with subclinical mastitis.
Streptococcus canis was isolated from 31 milk samples from 11 cows in a dairy herd (with 49 lactating cows) affected by subclinical mastitis in north Rhine-Westphalia, Germany. Thirty-one isolates from the infected udder quarters were further characterized for their phenotypic and molecular properties. Most isolates (83.9%) produced alpha-galactosidase, and all were negative for beta-d-glucuronidase. Amplification of the 16S rRNA gene by the PCR method and digestion with the restriction enzymes RsaI, MspI, and AvaII yielded species-specific patterns. Additional identification by species-specific amplification of the 16S rRNA gene, the 16S-23S rRNA gene intergenic spacer region, the CAMP factor-encoding gene cfg, and the internal fragments of the sodA gene was consistent with S. canis. Macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis showed that the S. canis isolates originated from a single clone or were very closely related.
Hassan
Abdulwahed Ahmed
AA
Institut für Tierärztliche Nahrungsmittelkunde, Justus-Liebig-Universität Giessen, Ludwigstrasse 21, D-35390 Giessen, Germany. Abdulwahed.Hassan@vetmed.uni-giessen.de
Akineden
Omer
O
Usleber
Ewald
E
D000818:Animals; D002417:Cattle / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D013291:Streptococcus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*