Airborne microbial communities in the atmospheric environment of urban hospitals in China

Clinically relevant antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in bioaerosols have become a greater threat to public health. However, few reports have shown that ARB and ARGs were found in the atmosphere. High-throughput sequencing applied to environmental sciences has enhanced the exploration of microbial populations in atmospheric samples. Thus, five nosocomial bioaerosols were collected, and the dominant microbial and pathogenic microorganisms were identified by high-throughput sequencing in this study. The results suggested that the dominant microorganisms at the genus level were Massilia, Sphingomonas, Methylobacterium, Methylophilus, Micrococcineae, and Corynebacterineae. The most abundant pathogenic microorganisms were Staphylococcus saprophyticus, Corynebacterium minutissimum, Streptococcus pneumoniae, Escherichia coil, Arcobacter butzleri, Aeromonas veronii, Pseudomonas aeruginosa, and Bacillus cereus. The relationship between microbial communities and environmental factors was evaluated with canonical correspondence analysis (CCA). Meanwhile, differences in the pathogenic bacteria between bioaerosols and dust in a typical hospital was investigated. Furthermore, cultivable Staphylococcus isolates with multi-drug resistance phenotype (> 3 antibiotics) in the inpatient departments were much higher than those in the transfusion area and out-patient departments, possibly attributed to the dense usage of antibiotics in inpatient departments. The results of this study might be helpful for scientifically air quality control in hospitals.

生物气溶胶中具有临床相关性的抗生素耐药细菌（ARB）和抗生素耐药基因（ARGs）对公共卫生构成了更大威胁。然而，鲜有报道表明在大气中发现了ARB和ARGs。应用于环境科学的高通量测序促进了对大气样本中微生物种群的探索。因此，本研究收集了五种医院生物气溶胶，并通过高通量测序鉴定了优势微生物和致病微生物。结果表明，在属水平上的优势微生物为马赛菌属（Massilia）、鞘氨醇单胞菌属（Sphingomonas）、甲基杆菌属（Methylobacterium）、嗜甲基菌属（Methylophilus）、微球菌亚目（Micrococcineae）和棒杆菌亚目（Corynebacterineae）。最丰富的致病微生物是腐生葡萄球菌（Staphylococcus saprophyticus）、极小棒杆菌（Corynebacterium minutissimum）、肺炎链球菌（Streptococcus pneumoniae）、大肠杆菌（Escherichia coli）、布氏弓形杆菌（Arcobacter butzleri）、维罗纳气单胞菌（Aeromonas veronii）、铜绿假单胞菌（Pseudomonas aeruginosa）和蜡样芽孢杆菌（Bacillus cereus）。采用典范对应分析（CCA）评估了微生物群落与环境因素之间的关系。同时，研究了一家典型医院生物气溶胶和灰尘中致病细菌的差异。此外，住院部具有多重耐药表型（对3种以上抗生素耐药）的可培养葡萄球菌分离株数量远高于输液区和门诊部，这可能是由于住院部大量使用抗生素所致。本研究结果可能有助于医院科学地进行空气质量控制。