Outbreak and management of <i>Salmonella</i> Enteritidis infection in 2-week-old Lohmann brown pullets

Abstract

Avian salmonellosis has huge economic and public health impact. In this manuscript, a case of S. Enteritidis and its management within Jos Metropolis was reported. Fiftythree carcasses of 2-weeks old pullets were presented at the poultry and fish clinic of the Veterinary Teaching Hospital, University of Jos, Nigeria for investigation. There was persistent mortality despite 5 days medication with 20% Enrofloxacin (Floxinor®, Shijiazhuang Guanghua Pharmaceutical co. Ltd, Hebei, China). Cumulative mortality within 14 days was 203 birds in a flock of 4,000. Necropsy was done and harvested were subjected to microbial analysis for bacterial isolation, identification and antibiotic susceptibility test while portions of these organs were preserved in 10% formalin for histopathology. Necropsy findings were empty crops, hepatitis with petechial hemorrhages, nephritis, congested and consolidated lungs, peritonitis, congested spleens and mild enteritis. Histologically, there were vacuolation and necrosis of renal tubular epithelia cells and interstitial infiltration with heterophils. Severe disorganization of hepatic cords, infiltration with inflammatory cells and mild necrosis of hepatocytes were observed, while there was severe congestion and diffuse hemorrhages in the lungs. Cellular infiltration within the lamina propria of small intestine with stunting and blunting of the villi were observed. Organism isolated on MacConkey agar was identified as Salmonella Enteritidis. Antibiotic susceptibility test showed the organism to be most susceptible to Streptomycin, which was administered via drinking water at dosage of 40mg/kg with good recovery of the flock. It was concluded that the occurrence of Salmonella Enteritidis infection in this flock might be from the hatchery or via ingestion of contaminated feed and water. Day old chicks should be screened for Salmonella infection and strict biosecurity should be instituted on poultry farms.

Keywords: Mortality, Necrosis, Pullets, Salmonella Enteritidis, streptomycin