| Abstrakt: |
An extensive survey was carried out on 849 biological samples (dead animals, organs and viscera, faeces, and rectal swabs) from pigs in the Latium Region (Central Italy) throughout the years 1980-1989. In total, 46 of the samples (5.4%) were found to be bacteriologically positive for salmonellae. Among dead animals, typical gross lesions were observed in 6 clinically infected animals. As far as serotypes are concerned, 11 different ones were isolated, with a predominance of Salmonella typhimurium (26.1%), S. anatum (21.7%), S. bovis-morbificans (15.2%), and S. heidelberg (10.8%). According to Kauffmann-White's classification scheme, 39.1% of the isolated strains belonged to serogroup B, 13% to serogroup C1, 17.4% tot serogroup C2, 6.5% to serogroup D, and 23.9% to serogroup E1. In conclusion, the authors speculate that the relatively low Salmonella isolation frequency (5.4%) reported in this study was not dependent upon the cultural procedures used, since different enrichment and plating methods were used, but rather upon the great number of rural-type herds which were investigated over the decade compared to industrial-type herds. Other factors such as stress conditions, which are particularly pronounced in industrial-type herds, and overall climatic situations, which tend to be characterised by warm, dry and long summers in the Latium Region, are also considered in this respect. |
