AN EPIDEMIOLOGIC-STUDY OF STAPHYLOCOCCUS-INTERMEDIUS STRAINS ISOLATEDFROM DOGS, THEIR OWNERS AND VETERINARY SURGEONS

Isolates of Staphylococcus intermedius recovered from dogs, their owne rs and veterinarians have been examined by restriction enzyme digestio n analysis and by pyrolysis mass spectrometry (PyMS). SmaI digests wer e only carried out where three or more isolates were available from a household and showed that, whilst some dogs carried the same strain th roughout, others acquired new strains. Similarly some owners shared st rains with their dogs but others did not. Curie-point pyrolysis mass s pectra were obtained from all 56 cutaneous S. intermedius strains. PyM S with cluster analysis was a valuable tool which enabled epidemiologi cal questions to be answered as follows: (1) there was no clear correl ation between the canine site sampled and the S. intermedius strain(s) recovered; (2) we observed acquisition of new strains at the expense of the older strains and the potential adaptation of strains to their new environment(s); (3) S intermedius was carried by humans in close c ontact with dogs, and strains from humans generally correlated with st rains recovered from their dog(s). Furthermore, analysis by PyMS has t hrown light on the phenotypic changes which may occur in bacteria grow n in a natural, polymicrobial habitat. (C) 1997 Elsevier Science Irela nd Ltd.