Salmonella infections in poultry flocks in the vicinity of Tehran

The purpose of this study was to survey infections with Salmonella spp. in poultry flocks in the vicinity of Tehran and to determine the most frequent serogroups and serotypes implicated. Twenty-eight samples of pullet, layer, and broiler flocks were randomly collected (n=1463), including freshly dropped feces from live birds or visceral organs from dead birds. In most flocks, 60 samples were taken and 10 fecal samples of each were pooled. Standard cultural methods were used for Salmonella spp. isolation. The slide agglutination or tube agglutination tests were performed using Salmonella somatic O poly A-S antisera, and different somatic O monovalent or flagellar H monovalent antisera. Thirty-one Salmonella isolates were recovered from 1,463 samples. Nine broiler flocks out of 14 (64.2%) and one layer flock out of 11 (9%) were positive for Salmonella spp. but all pullet flocks were negative. One isolate was obtained from the layer flock and the other 30 Salmonella isolates were obtained from broiler flocks. The slide agglutination test determined that all isolates belonged to one of the serogroups from A to S. The frequency of serogroups among 30 broiler isolates was found to be 76.6% and 13.3% for groups C and D, respectively. Three (10%) of the broiler isolates and one layer isolate did not belong to any of the A to D serogroups. All group D isolates were found to be Salmonella enteritidis. This study showed a high incidence of Salmonella in broilers. Infection of broilers with Salmonella spp. poses a high risk to public health.