医疗场所室内空气微生物抗性基因流行状况

Prevalence of microbial resistance genes in indoor air of medical facilities

目的分析医疗场所室内空气微生物抗性基因(ARGs)流行情况。方法2021年1-6月沉降法收集医疗场所3处室内外空气沉降物,样本1来源于医疗场所中央空调管道内壁(毛刷收集);样本2来源于门诊大厅(距地面2.5 m的自然沉降);对照样本3来源于楼顶户外开放空间(距地面高度25 m的自然沉降),用试剂盒抽提微生物基因组DNA后行Illumina NovaSeq/Hiseq Xten二代测序。宏基因数据于美吉生物云平台经质量控制、数据比对及统计分析后,评估微生物抗性基因和可移动遗传元件(MGEs)的含量、种类、相关性等流行病学特征。结果3份样品在型水平上有82.6%的抗性基因(19/23)被检出,抗多药耐药、抗杆菌肽素、抗磷霉素等3型抗性基因最为常见。在类水平上,外排类含量最高,膜通透类次之,酶解类最低,4类抗性基因在3个样本间的构成差异无统计学意义(χ^(2)=3.75,P=0.71)。样本2和1可移动遗传元件含量高于样本3,其中,质粒序列与β-内酰胺、氨基糖甙类、甲氧苄啶、春雷霉素,及整合子序列与β-内酰胺的相关分析差异有统计学意义(Pearson相关系数=0.999、1.000、0.999、1.000、0.997,P=0.034、0.016、0.034、0.004、0.048)。结论医疗场所室内空气微生物抗性基因及可移动遗传元件含量、种类高于室外,空气环境卫生值得关注。

Objective To analyze the prevalence of antibiotic resistance genes(ARGs)in indoor air of medical facilities.Methods From January to June 2021,Three samples of air deposited dusts indoors and outdoors in a medical building were collected.Sample 1 was from the inner wall of the central air conditioning pipes in the building(brush collection);sample 2 was from the outpatient hall(2.5 m from the ground);sample 3 as control was from the open space on the roof(25 m from the ground).The microbial genome DNA was extracted with the kit followed by library construction,and the metagenomic sequencing was carried out using Illumina NovaSeq/Hiseq Xten system according to the manufacturer's instructions.After sequence quality control,genome assembly,and gene prediction,the data were analyzed on the online platform of Majorbio Cloud Platform to acquire the ARGs as well as mobile genetic elements(MGEs).Results Among 3 samples,a total of 82.6%(19/23)ARGs were identified;among which,the most abundant gene types were multidrug,bacitracin,and fosmidomycin.When compared within gene class,efflux pump genes were the most abundant,followed by membrane permeability genes,while the inactivation enzyme genes were the lowest.There was no significant difference in the composition of class 4 resistance genes among the three samples(χ^(2)=3.75,P=0.71).The amounts of MGEs indoors were higher than those outdoors,and the Pearson correlation analysis results showed that plasmids versus beta-lactam,aminoglycoside,trimethoprim,kasugamycin,in addition to integrons versus beta-lactam were statistically correlated(Pearson coefficient=0.999,1.000,0.999,1.000,0.997,P=0.034,0.016,0.034,0.004,0.048).Conclusion The diversity and abundance of antibiotic resistance genes indoors were higher than those outdoors,which might deserve more public health concerns.