宁夏桶装水中铜绿假单胞菌的污染情况、耐药性及同源性分析

Analysis of Contamination, Drug Resistance, and Homology of Pseudomonas aeruginosa Isolated from Barreled Water in Ningxia

摘要:

为综合评价宁夏桶装水生产企业铜绿假单胞菌污染情况、耐药性及系统进化关系，确定污染来源，提升产品质量，该研究对企业各生产环节的水样进行铜绿假单胞菌检测，并采用全自动微生物鉴定系统（VITEK-2）、基质辅助激光解吸电离-飞行时间质谱仪（Matrix Assisted Laser Desorption Ionization-time of Flight Mass Spectrometry，MALDI-TOF MS）、16S rRNA测序法对分离菌株进行鉴定。铜绿假单胞菌的耐药性实验应用微生物全自动鉴定及药敏系统检测，采用16S rRNA基因序列测序构建系统发育树，MALDI-TOF MS进行同源性分析。结果表明，VITEK-2、MALDI-TOF MS、16S rRNA鉴定结果与常规方法分离的24株阳性菌株鉴定结果100%相符。耐药性结果表明，24株铜绿假单胞菌中2株为耐药菌株，分别是5-B-1，7-C-5，耐药率为8.3%，说明水源性菌株的耐药水平总体偏低。质谱结果表明来自同一地区的阳性菌株亲缘关系较近；16S rRNA系统发育表明铜绿假单胞菌分离株与地域不存在明显的相关性，但同一来源的铜绿假单胞菌属于同一簇，其来源主要为水源。该研究为桶装水中铜绿假单胞菌的污染溯源积累了数据，为进一步研究菌种污染溯源提供理论依据。

Abstract:

The study objectives were to comprehensively evaluate the pollution situation, drug resistance, and phylogenetic relationship of Pseudomonas aeruginosa strains in Ningxia barreled water production enterprises; identify the pollution source; and improve the product quality. Detection of P. aeruginosa was conducted in water samples from each production link of the enterprise. The isolates in the water samples were identified using a VITEK-2 microbial identification system, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene sequencing. The antimicrobial resistance of P. aeruginosa was assessed using a compact VITEK 2 system, a phylogenetic tree was constructed using 16S rRNA gene sequencing data, and homology was analyzed using MALDI-TOF MS. The identification results of the VITEK-2 system, MALDI-TOF MS, and 16S rRNA gene sequencing were 100% consistent with the identification results of the 24 positive strains isolated using conventional methods. Two of the 24 P. aeruginosa strains, 5-B-1 and 7-C-5, were drug-resistant, and the drug resistance rate was 8.3%, indicating that the drug resistance level of waterborne strains was low. The mass spectrometry results showed that the positive strains from the same area were closely related. The phylogeny analysis showed that the isolates of P. aeruginosa were not related to the geographical region, but the strains of P. aeruginosa from the same source were in the same cluster, and the main source of P. aeruginosa was water. This study provides accumulated data for the contamination traceability of P. aeruginosa in barreled water and the theoretical basis for further research on contamination traceability of bacterial species.