MYCOPLASMA-GALLISEPTICUM INFECTION IN DRUG-TREATED CHICKENS - COMPARISON OF DIAGNOSIS METHODS INCLUDING POLYMERASE CHAIN-REACTION

Ten chickens were inoculated with Mycoplasma gallisepticum (MG) and tr eated with enrofloxacine. On eight different dates post-inoculation (P I), tracheal swab samples were collected for mycoplasma culture or det ection by polymerase chain reaction (PCR), and blood samples were anal ysed 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 w as collected on day 26 PI, whereas PCR still gave positive results on day 54 PI. This difference may be attributed to the high sensitivity o f PCR and to its ability to detect non-viable or non-culturable pathog ens. Sera were SA positive as early as 5 days PI and some of them rema ined positive up to day 47 PI. ELISA detected 53 suspicious or positiv e sera.