Pulsed-field gel electrophoresis (PFGE) was examined as a tool to differentiate strains of streptococci isolated from clinical and sub-clinical cases of @entity291 @entity1271 . Analysis of SmaI chromosomal digests of @entity5967 , @entity22193 . dysgalactiae and @entity8211 isolates revealed intraherd and interherd strain relationships within each species. Comparison of @entity5967 isolates from the same herd revealed little variability in their SmaI restriction patterns indicating a single strain originating from a common source of @entity281 . However, comparison of @entity5967 isolates between herds showed that each herd was infected with a distinct strain. The restriction profiles from @entity22193 . dysgalactiae and @entity8211 were more diverse and often multiple strains of both species were present within an individual herd, with some herds containing more than one representative of a particular strain. Interestingly, it was only observed with @entity22193 . dysgalactiae that some strains were present in more than one herd. PFGE was found to be a useful and reproducible method for the discrimination of different strains of the three most important species of streptococci responsible for @entity291 @entity1271 and to offer a means to identify environmental sources of @entity281 .

Strain differentiation of isolates of streptococci from @entity291 XXXX by pulsed-field gel electrophoresis.

@entity1271 :: ('MESH:D008413', 'Disease') :: ['mastitis'] @entity5967 :: ('1311', 'Species') :: ['Streptococcus agalactiae', 'S. agalactiae'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity8211 :: ('1349', 'Species') :: ['S. uberis'] @entity291 :: ('9913', 'Species') :: ['bovine'] @entity22193 :: ('1334', 'Species') :: ['S. dysgalactiae subsp']
@entity1271 :: (MESH:D008413,Disease) :: ['mastitis']
