Antimicrobial resistance of Salmonella spp. from pigs at slaughter in Spain in 1993 and 2001.
OBJECTIVE
To compare the incidence of antimicrobial resistance among Salmonella serotypes isolated in a pig slaughterhouse in Zaragoza (Spain) during 1993 and 2001.


RESULTS
A total of 168 isolates representing 10 serotypes were examined by disc diffusion method using 17 antibiotics. Data showed that the majority of the strains were resistant to streptomycin (97%), sulfadiazine (93.4%) and tetracycline (83.3%). A large proportion of the collection was multidrug resistant (MDR, resistance to four or more antibiotics) with a greater incidence in 2001. The findings imply an increasing incidence of MDR amongst S. Typhimurium, and all S. Typhimurium-definitive phage type (DT) 104 isolates were resistant to ampicillin, chloramphenicol, streptomycin, sulphonamide and tetracycline (R-ACSSuT). This resistance phenotype had spread among other phage and serotypes. Salmonella Ohio was also a MDR serotype and this is not a serotype normally associated with drug resistance.


CONCLUSIONS
A large proportion of the strains were MDR and this showed that pork products could be a potential vehicle of MDR Salmonella food-borne infections.


CONCLUSIONS
The findings may have significant public health consequences and could contribute to the development of useful practices aimed at limiting the transmission of MDR Salmonella serotypes through the food chain.
Agustín
A I
AI
Department of Animal Production and Food Science, Food Hygiene, Inspection, Control, and Microbiology Unit, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain.
Carramiñana
J J
JJ
Rota
C
C
Herrera
A
A
D000003:Abattoirs / Q000592:standards; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005516:Food Microbiology / Q000592:standards; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D012703:Serotyping; D013030:Spain; D013307:Streptomycin / Q000494:pharmacology; D013411:Sulfadiazine / Q000494:pharmacology; D013552:Swine; D013752:Tetracycline / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D013411:Sulfadiazine; D013752:Tetracycline; D013307:Streptomycin