Comparative study on the sensitivity of bacteriology and immunohistochemical technique in the diagnosis of natural salmonellosis in chickens
Bacteriological and immunohistochemical diagnoses of natural salmonellosis in chickens were carried out on 36 cases, in order to compare the sensitivities of the two techniques. Samples of the lungs, heart, liver, spleen, kidneys, proventriculus, intestine and caecum were collected at postmortem for bacterial isolation and separately fixed in 10% formalin for immunohistochemistry. The frequencies of Salmonella isolation by bacteriology and antigen detection by immunohistochemical technique were determined from the tissue samples and overall percentages between the two were compared. Out of 36 cases of natural salmonellosis, 53 Salmonella isolates were obtained from different organs in 31 (86.1%) cases; 48 isolates from 28 (77.8%) cases tested biochemically positive; PCR confirmed 41 isolates from 25 (89.3%) cases. Immunohistochemical test was positive in all the 36 (100%) cases. In the present study, immunohistochemical technique was more sensitive than isolation and identification and can be used as an adjunct to bacteriology in the diagnosis of avian salmonellosis.
Keywords: Salmonellosis, Diagnosis, Bacteriology, Immunohistochemistry, Postmortem, Chicken