Surveillance of Mycoplasma gallisepticum Infection in Mixed Thai Native Chickens in the Area of Nakornpathom Province

Abstract

This study was to conduct a surveillance of Mycoplasma gallisepticum (MG) infection in mixed Thai native chickens. Samples were submitted from 30 mixed Thai native chicken flocks, 15 birds per flock, aged between 1 and 4 months without MG vaccination in the area of Nakornpathom province during the September 2005 - October 2006 period. Each bird was bled for MG serology by a serum plate agglutination (SPA) test and enzyme linked immunosorbent assay (ELISA) test kits and swabbed for MG antigen detection by polymerase chain reaction (PCR) technique. Results revealed that the positive reactors detected by the SPA test, ELISA and PCR procedure were 7, 8 and 6 flocks, respectively. There were 5 flocks that were detected to have positive reactors in all tests. The percentage of positive results depending on age: 1 month, 1-2 months, 2-3 months and
3-4 months tested by SPA, ELISA and PCR was 18.2-40%, 16.7-40% and 18.2- 40%, respectively. This study found that the older the flock the higher the number of positive reactors was found. MG DNA was determined in birds older than 1 month. In addition, respiratory clinical signs were probably observed in the MG infected flocks.