冠状动脉介入治疗患者感染MRSA耐药性及毒力基因分布研究

The epidemiological characteristics of MRSA infecting patients receiving a coronary artery intervention

目的分析医院冠状动脉介入治疗患者感染耐甲氧西林金黄色葡萄球菌(MRSA)流行特点及其毒力基因分布情况,为预防冠状动脉介入治疗患者感染发生及控制病原菌扩散提供指导。方法收集医院冠状动脉介入治疗患者的送检标本,从中分离MRSA,鉴定并剔除重复菌株。采用K-B法分析MRSA菌株对苯唑西林等5种常用抗生素的耐药情况,根据2015年CLSI标准判定结果,采用PCR扩增检测MRSA菌株的毒力基因分布情况。结果共分离164株MRSA,其中85株分离自痰液标本,占51.83%;34株分离自脓液标本,占20.73%;26株分离自血液标本,占15.85%;7株分离自穿刺液标本,占4.27%;12株分离自其他标本,占7.32%。MRSA分离株对5种常用抗菌药物的耐药程度从高到低依次为苯唑西林、头孢曲松、亚胺培南、环丙沙星、万古霉素,耐药率依次为100.00%、87.20%、51.22%、43.90%和0。PCR扩增MRSA菌株pvl基因为939bp,fnbA基因为642bp,clfA基因为292bp。130株MRSA菌株检出pvl基因,阳性率为79.27%;103株检出fnbA基因,阳性率为62.80%;67株检出clfA基因,阳性率为40.85%。结论在冠状动脉介入治疗患者MRSA主要分布于痰液中,治疗用药优先考虑万古霉素,其致病性可能与其毒力基因分布有关。

Objective To analyze the epidemiological characteristics of MRSA and the distribution of virulence genes of MRSA infecting patients receiving a coronary artery intervention at a hospital to prevent infections in patients receiving a coronary artery intervention and to control the spread of pathogenic bacteria. Methods Samples were collected from pa- tients receiving a coronary artery intervention, and strains of MRSA were isolated. The strains were identified and duplicate strains were excluded. The drug resistance of MRSA strains was analyzed using the K-B method, and the results were determined in accordance with the 2015 standards of the CLSI. Virulence genes in MRSA strains were detected via amplification with PCR. Results In total, 164 strains of MRSA were isolated. Eighty-five strains of MRSA were isola- ted from sputum specimens at a rate of 51.83 %. Thirty-four strains of MRSA were isolated from pus samples at a rate of 20. 73%. Twenty-six strains of MRSA were isolated from blood samples at a rate of 15.85%. Seven strains of MRSA were isolated from puncture fluid samples at a rate of 4.27 %. Twelve strains of MRSA were isolated from other samples at a rate of 7.32 %. The resistance of MRSA strains to commonly used antibiotics was determined. In order, the resist-ance of MRSA strains to oxacillin was 100.00%, resistance to ceftriaxone was 87.20%, resistance to imipenem was 51. 22 %, resistance to ciprofloxacin was 43. 90%, and resistance to vancomycin was 0%. MRSA strains infecting patients receiving a coronary artery intervention were not resistant to vancomycin and were still sensitive to it. Virulence genes in MRSA strains were detected. Amplification with PCR indicated that the pvl gene was 939 bp in length, the fnbA gene was 642 bp in length, and the clfA gene was 292 bp in length. The pvl gene was detected in 130 MRSA strains, and strains tested positive for the gene at a rate of 79.27%. The fnbA gene was detected in 103 MRSA strains, and strains tested positive for the gene at a rate of 62.80%. The clfA gene was detected in 67 MRSA strains, and strains tested positive for the gene at a rate of 40.85%. Conclusion MRSA was mainly found in sputum samples from patients receiving a coronary artery intervention, and vancomycin should be prioritized in the treatment of an infection. The prevalence of MRSA infecting patients receiving a coronary artery intervention may be related to the presence of virulence %enes.