摘要
[背景]目前国内对嗜肺军团菌耐药研究较少。建立人工水环境嗜肺军团菌耐药表型和耐药基因分析方法具有重要意义。[目的]了解中山市人工水环境嗜肺军团菌的耐药特征,为军团菌感染防控提供科学依据。[方法]收集中山市2012—2024年分离自集中空调系统和热水系统的295株嗜肺军团菌,采用E-test法测定抗菌药物对菌株的最低抑菌浓度(MIC)。运用全基因组测序技术结合生物信息学技术对16株嗜肺军团菌进行耐药基因分析,基于全基因组单核苷酸多态性(wgSNPs)分析菌株与国内外不同来源克隆株之间的系统发育进化关系。[结果]药敏试验结果显示嗜肺军团菌对红霉素(ERY)耐药率最高(56.9%),其次为阿奇霉素(AZM)(27.1%)、左氧氟沙星(LEV)(12.2%);利福平(RIF)和头孢噻肟(CTX)耐药率低,对克拉霉素(CLA)、环丙沙星(CIP)和多西环素(DOX)完全敏感。相比热水系统分离株,集中空调系统分离株对ERY(70.9%vs. 28.1%)和AZM(34.2%vs. 12.5%)的耐药率更高,两者差异具有统计学意义(χ^(2)=48.226,P<0.001;χ^(2)=15.388,P<0.001)。嗜肺军团菌Lp1分离株在4种药物(AZM、CLA、DOX、CTX)的MIC值均高于Lp2~14分离株(Z=-3.490,P<0.001;Z=-3.035,P<0.05;Z=-2.662,P<0.05;Z=-2.973,P<0.05);Lp2~14分离株在RIF的MIC值高于Lp1分离株(Z=-3.190,P<0.05)。2019—2024年分离株对CLA和DOX的MIC值高于2012—2018年分离株(Z=-4.847,P<0.001;Z=–6.057,P<0.001)。全基因组序列分析显示,16株嗜肺军团菌携带氨基糖苷类、大环内酯类、头孢菌素和青霉素类等抗菌药物耐药基因;系统发育分析显示,本地区嗜肺军团菌呈现较高的遗传多样性,同时与国内外其他地区菌株流行趋势相一致。[结论]本研究的嗜肺军团菌分离株对大多数抗菌药物敏感性较高,但其耐药情况不容忽视,应持续加强耐药监测。
[Background]There is currently limited research on the antibiotic resistance of Legionella pneumophila in China.Establishing analytical methods for antibiotic resistance phenotypes and resistance genes of Legionella pneumophila in artificial water environment is of great significance.[Objective]To investigate the antibiotic resistance characteristics of Legionella pneumophila isolated from artificial water environment in Zhongshan,and to provide a scientific basis for the prevention and control of Legionella infection.[Methods]A total of 295 strains of Legionella pneumophila isolated from central air conditioning systems and hot water systems in Zhongshan from 2012 to 2024 were collected.The minimum inhibitory concentrations(MIC)of antimicrobial agents against the strains were determined using the E-test method.Whole genome sequencing combined with bioinformatics techniques was used to analyze the antibiotic resistance genes of 16 strains of Legionella pneumophila.The phylogenetic evolutionary relationships between these strains and clonal strains from different sources worldwide were analyzed based on whole genome single nucleotide polymorphisms(wgSNPs).[Results]The antimicrobial susceptibility testing results showed that the highest resistance rate of Legionella pneumophila was to erythromycin(ERY)(56.9%),followed by azithromycin(AZM)(27.1%)and levofloxacin(LEV)(12.2%).The antibiotic resistance rates to rifampicin(RIF)and cefotaxime(CTX)were low,and the strains were fully susceptible to clarithromycin(CLA),ciprofloxacin(CIP),and doxycycline(DOX).Compared to the isolates from the hot water systems,those from the central air conditioning systems exhibited higher resistance rates to ERY(70.9%vs.28.1%)and AZM(34.2%vs.12.5%),and the differences were statistically significant(χ^(2)=48.226,P<0.001;χ^(2)=15.388,P<0.001).The MIC values of Lp1 isolates for four antibiotics(AZM,CLA,DOX,and CTX)were significantly higher than those of Lp2-14 isolates(Z=−3.490,P<0.001;Z=−3.035,P<0.05;Z=−2.662,P<0.05;Z=−2.973,P<0.05).The MIC values of Lp2−14 isolates for RIF were significantly higher than those of Lp1 isolates(Z=−3.190,P<0.05).The strains isolated from 2019–2024 exhibited higher MIC values for both CLA and DOX than those isolated from 2012–2018(Z=−4.847,P<0.001;Z=−6.057,P<0.001).Whole genome sequencing analysis showed that the 16 strains of Legionella pneumophila carried antibiotic resistance genes for aminoglycosides,macrolides,cephalosporins,and penicillins.The phylogenetic analysis showed that Legionella pneumophila in this region exhibited high genetic diversity and was consistent with the epidemic trends of strains from other regions worldwide.[Conclusion]The isolates of Legionella pneumophila in this study are highly susceptible to most antimicrobial agents.However,the antibiotic resistance should not be ignored,and continuous monitoring of antibiotic resistance is necessary.
作者
刘绮明
袁展红
吴灿权
仇绮琳
郑悦康
LIU Qiming;YUAN Zhanhong;WU Canquan;QIU Qilin;ZHENG Yuekang(Institute of Pathogenic Microbiology and Biological Examination,Zhongshan Center for Disease Control and Prevention,Zhongshan,Guangdong 528403,China)
出处
《环境与职业医学》
北大核心
2025年第12期1497-1503,共7页
Journal of Environmental and Occupational Medicine
基金
中山市社会公益与基础研究专项资金项目(2024B1097)。
关键词
嗜肺军团菌
药敏试验
全基因组测序
耐药基因
系统发育分析
Legionella pneumophila
antimicrobial susceptibility testing
whole genome sequencing
antibiotic resistance gene
phylogenetic analysis
