Advanced Studies on Prevalence of Mycoplasma Infection In Backyard Chicken By Using Recent Techniques

The prevalence of of Mycoplasma infection in backyard chickens in Sharkia and Dakahlia was studies. For this aim four hundred and sevety five samples were collected.2- Primary isolation of Mycoplasma from different sites yielded 139 positive samples with a total prevalence rate 29.26%.3- Application of Digitonin test for characterization of the obtained isolates gave 139 out of 475 Mycoplasma isolates while the remaining were Acholeplasma.4- Biochemical characterization of the obtained isolates gave, 89 ioslates suspected to be MG from different sites of isolation with percentage of 64.28% and 50 isolates suspected to be M.gallinarium.5- Serological identification of isolates using specific antisera was applied which confirmed the presence of the previous mentioned genera.6- Serum samples were tested for detection of antibodies of both MG and MS by SPA and ELISA test which yielded 340 samples positive for MG while only 60 samples were positive for MS by SPA.7- Application of ELISA test gave 19 samples positive for MG, 28 suspect and 43 negative. Regarding MS , 10 samples were positive, 9 suspect and 71 were negative.8-Invitro sensitivity of isolated Mycoplasma was doen against aset of antibiotics which proved that spectinomycin was the most effective followed by lincomycin while erythromycin and enrofloxacin less effective aganist the tested isolates.9- Specific PCR technique was applied for confirmation of isolation in which all tested strains gave characteristic fragment at 824 bp.10- RAPD- PCR was applied for detection of similarity between different isolates with presence of reference and vaccinal strains .