The Study Of The Antibiotic Resistance Dissemination In Poultry Production Chain In ShanDong

In order to identify the mechanism of antibiotic resistance dissemination in poultry production chain, this study collected 108 samples from the poultry production chain, screened resistant bacteria strains by six kinds of antibiotic tablets. Antibiotic susceptibilities were tested by agar dilution method. The presences of blacrx-M were detected by PCR and sequencing. And strain genotypes were identified by MLST or PFGE methods. The study isolated 562 strains in all, including 373 Escherichia coli strains,110 Klebsiella pneumoniae strains and 79 Proteus mirabilic strains from the 108 samples. E. colis, and Klebsiella pneumoniae strains were isolated from the three processes of poultry industry chain, and the Proteus mirabilis strains isolated from only the breeding process.More than 50% strains exhibited high MIC for the third-generation cephalosporin. The rates of multidrug resistant organisms in the three species strains were 88.2%,90.9% and 84.8%, respectively. Among the 562 strains,65.7% strains carried blacrx-M-type genes. For strains of E. coil, K. pneumoniae and P.mirabilic, the positive rates of blacrx-M-type genes were 54.7%,63.6% and 72.1%, respectively. PCR screening of blacrx-M-type resistance genes showed that the predominant subtypes carried by E. coli strains were blacrx-M-55, blaCTX-M-15 and blacrx-M-65. In K. pneumoniea strains, the predominant subtypes were blacrx-M-55 and blacrx-M-15. In P. mirabilis strains, the predominant subtypeswere blacrx-M-65 and blaCTX-M-55. blacrx-M-65,blacrx-M-55 and blacrx-M-14 were predominant in all the three specises strains.The blacrx-M-type genes were detected positive in breeding, slaughter and retailing processes of the poultry production chains. The blacrx-M-27, blaCTX-M-65, blacrx-M-55, blacrx-M-14, blacrx-M-15 and blacrx-M-90 genes were detected in the breeding process. blacrx-M-55 and blacrx-M-27 were detected in the retail process. While in the slaughter process, genotypes were much less than those of the other two processes. Only blacYx-M-27 and blacrx-M-55 were detected positive in slaughter process. Notablely, blacrx-M-3 was only detected positive in retail process.Multilocus sequences typing (MLST) analysis demonstrated that 110 strains of K. pneumoniea belonged to 32 sequence types (STs), in which 16 STs were noveL The STs of strains coming from different processes were almost different. Only 28 strains belonging to 3 STs came from two processes. There were 34 different PFGE patterns among 79 P. mirabilis strains. Strains of different PFGE patterns carried the identical blacrx-M-type genes.53 strains belonging to 25 PFGE patterns carried blacrx-M-65 genes. ST37 K. pneumoniea and 027 banding type P. mirabilis were detected both in samples recovered from chicken plant breeder and healthy chicken anal swab, which suggest that resistant strains could spread among human and animals.This study expressed the distribution situation and identified the transfer mechanism of antibiotic resistance among the three kinds of resistant strains in the poultry industry chain. These results will provide solid data for antibiotic resistance control in the poultry industry.