Epidemiology of Salmonella infections in Trinidadian livestock farms.

Faeces of 689 diarrhoeic and non-diarrhoeic livestock were examined for salmonellae and the antibiograms of isolates were determined. Twenty-nine (4.2%) animals were positive for Salmonella. The highest prevalence was detected amongst calves with 14 (4.8%) of 293 found positive and the lowest prevalence in kids with none of 18 sampled shedding salmonellae. Twelve (4.1%) of 294 piglets and 3 (3.6%) of 84 lambs tested were positive for Salmonella. There were no statistical differences (P > or = 0.05; chi 2) between animal semi-intensively managed (4.4%) and those intensively kept (4.3%), between diarrhoeic (5.0%) and non-diarrhoeic (3.3%), between females (5.2%) and males (3.4%). Nine serotypes were isolated with a predominance of S. hadar, S. gaminara and S. typhimurium in calves, piglets and lambs, respectively. Two serotypes, S. kinshasa and S. virchow are reported for the first time in animals in the West Indies. All Salmonella strains were sensitive to ampicillin and gentamycin whereas resistance was high to tetracycline (40.0%), triple sulphur (30.0%) and streptomycin (26.7%).