blaNDM和mcr-1～ mcr-5基因在中国不同标本中的分布

目的 了解碳青霉烯类耐药基因(blaNDM)和多粘菌素耐药基因(mcr)在中国不同地区不同类型标本中的分布特征,为抗生素耐药的监督与控制提供理论依据.方法 2015-2020年在中国不同地区的城村养殖场及人烟稀少的高原牧区共采集人、家畜家禽、禽类屠宰环境和野生动物标本4324份,对标本进blaNDM和mcr基因的检测和...

Distribution of bla;and mcr-1~mcr-5 genes in different types of samples in China

Objective To understand the distribution characteristics of New Delhi metallo-β-lactamase(bla_NDM)and mobile colistin resistance(mcr-1~mcr-5)genes in different types of samples in different regions of China,so as to provide a theoretical basis for the supervision and control of antibiotic resistance.Methods From 2015 to 2020,a total of 4324 samples from human,livestock and poultry,poultry slaughter environment and wild animals were collected from urban and village farms and sparsely populated plateau pastoral areas in different regions of China,and nucleic acid extraction and ordinary PCR amplification were carried out to detect bla_NDM and mcr genes.Results The detection rate of drug resistance genes of bla_NDM and mcr-1~mcr-5was 5.16%,seven drug resistance gene subtypes including bla_NDM-1(0.58%),bla_NDM-24(0.07%),mcr-1.1(4.53%),mcr-1.29(0.02%),mcr-3.18(0.05%),mcr-3.3(0.05%),and mcr-4.3(0.12%)were detected,and the most samples of mcr-1.1 were detected,accounting for 87.89%of all positive samples;the samples carrying bla_NDM-1 and mcr-1.1coexisting genes,bla_NDM-24 and mcr-1.1 coexisting genes and mcr-1.1 and mcr-3.3 coexisting genes were detected;bla_NDM and mcr genes were most distributed in poultry slaughtering environment(3.14%,16.00%),and least in wild animals(0.00%,0.13%,both P<0.001,the absolute value of the adjusted standardized residual>3);bla_NDM was mostly distributed in wipe specimens(Fisher's exact P<0.001),and mcr was mostly distributed in the lower digestive tract of animals,environmental waters,and wipe specimens(χ²=230.564,P<0.001);the detection rate of genotype of bla_NDM and mcr genes in urban and village farms was 12.46%(203/1629),which was is higher than that in plateau pastoral areas(0.74%,20/2695)(χ²=285.096,P<0.01).Conclusion bla_NDM and mcr genes are common in different types of specimens in China,and the detection rate in sparsely populated area is lower than that in urban and village farms.