Mycoplasma gallisepticum Infection in Drug‐treated Chickens: Comparison of Diagnosis Methods Including Polymerase Chain Reaction

Abstract
Ten chickens were inoculated with Mycoplasma gallisepticum (MG) and treated with enrofloxacine. On eight different dates post-inoculation (PI), tracheal swab samples were collected for mycoplasma culture or detection by polymerase chain reaction (PCR), and blood samples were analysed by slide-agglutination test (SA) and enzyme-linked immunosorbent assay (ELISA). Results showed that culture and PCR detected MG from 14/80 or 20/80 samples, respectively. The last culture-positive sample was collected on day 26 PI, whereas PCR still gave positive results on day 54 PI. This difference may be attributed to the high sensitivity of PCR and to its ability to detect non-viable or non-culturable pathogens. Sera were SA positive as early as 5 days PI and some of them remained positive up to day 47 PI. ELISA detected 53 suspicious or positive sera.