Isolation,Identification,Pathogenicity and Drug Susceptibility of Mycoplasma gallisepticum from Dead Chicken Embryos in Large-scale Chicken Farms in Guangdong Province
The aim of this study was to isolate Mycoplasma gallisepticum(MG)from dead chick-en embryos in a large-scale chicken farm in Guangdong,and genetic evolution analysis,pathoge-nicity and drug susceptibility tests were carried out.Isolation of MG were conducted,then the i-solated strains were identified by colony observation,serological test and 16S rRNA sequencing.At the same time,the isolated strains were used to infect chicken embryos and SPF chickens,and were subjected to antimicrobial susceptibility tests.Under the microscope,the colonies showed typical'poached egg'.Plate agglutination test showed that it had agglutination reaction with MG positive serum and did not react with MS positive serum.The 16S rRNA sequencing showed that the homology of each isolate with MG was 99.9％,so the isolates were identified as MG strains.Each isolate was used to infect 7-day-old SPF chicken embryos,and the results showed that most of the infected chicken embryos died near hatching.After 3 weeks of infection in 3-week-old SPF chickens,significant pathological changes were found in the air sac of chickens,indicating that it had strong pathogenicity.The drug sensitivity test showed that the 5 isolates were highly sensi-tive to warnimulin hydrochloride,doxycycline,tywanmycin and tymectin,and were resistant to tilmicosin,tylosin,enrofloxacin,erythromycin,kitasamycin and lincomycin to varying degrees.Five MG isolates were successfully isolated from dead chicken embryos in a large-scale chicken farm in Guangdong province.All of the isolates could cause chicken embryo death and cause typi-cal air sac inflammatory symptoms to SPF chickens,and they had varying degrees of resistance to multiple drugs.This study provides reference technical methods and guidance for the isolation,identification and drug selection for clinical MG,and also provides a research basis for the estab-lishment of MG challenge model.
Mycoplasma galliscepticumdead chicken embryosisolation and identificationpathogenicitydrug susceptibility
国家科技期刊平台
NSTL
万方数据
维普
