Prevalence of MRSA types in slaughter pigs in different German abattoirs

To investigate the prevalence of types of meticillinresistant Staphylococcus aureus (MRSA) in slaughter pigs in German abattoirs, nasal swabs were collected from a total of 1026 pigs in five abattoirs after stunning in the course of two studies, and examined for MRSA. Study 1 included four abattoirs; study 2 was carried out in one large abattoir. Isolates were tested for antimicrobial susceptibility and characterised using spa -typing, multilocus sequence typing (MLST) and typing of the staphylococcal cassette chromosome, SCC mec . Overall, MRSA was isolated from 70·8 per cent of 520 samples in study 1 and from 49·0 per cent of 506 samples in study 2. The proportion of positive samples varied substantially between the abattoirs in study 1. Most isolates belonged to spa -types t011 and t034 and SCC mec types III and V. MLST of selected isolates revealed that they were all MLST ST398. Besides β-lactams, 100 per cent of the isolates were resistant to tetracycline, 80·5 per cent were resistant to erythromycin and 80·7 per cent were resistant to clindamycin. Less than 5 per cent of the isolates were resistant to other antimicrobials.