Incidence of Salmonella in aquaculture farms of Kerala

Abstract

Presence of Salmonella in seafood is seen as a sign of poor standard of process hygiene and sanitation. Usually, Salmonella is not recognized as being part of the normal microflora in aquaculture environments. For this reason, the incidence of Salmonella in aquaculture farms indicates improper adoption of good management practices during pre-culture period, culture period and post culture conditions. Till date scant information is available regarding the prevalence of Salmonella in aquaculture farms in Indian context, especially from Kerala. So the present study reports the incidence of Salmonella in aquaculture farms in and around Cochin area. About 100 samples from different aquaculture farms were screened for the presence of Salmonella. These samples include water, sediment, fishes and feed generally. From poultry integrated aquaculture farming conditions poultry droppings and litter were also analyzed. This study revealed the prevalence of Salmonella in aquaculture farms is about 9.6% which is very low when compared with the occurrence in seafood. The positive samples include mullet intestine, mullet gills, tilapia intestine and poultry litter from various farms. Even though, none of the shrimp farms harbored Salmonella, the situation is quite alarming when finfishes are considered. All the isolates were confirmed by bio typing and PCR targeting invA gene with 284bp. Serotyping confirmed the presence of Salmonella typhimurium in mullet farms possibly the contamination is through feed or organic fertilizers