导管相关性血流感染患者中分离的金黄色葡萄球菌耐药性与毒力基因检出情况分析

Detection of drug resistance and virulence genes of Staphylococcus aureus isolated from patients with catheter related blood stream infection

目的探讨导管相关性血流感染患者中分离的金黄色葡萄球菌(Staphylococcus aureus,SA)耐药性与毒力基因的检出情况,为临床防治导管相关性血流感染提供依据。方法收集金华市人民医院2017年1月—2021年12月收治的导管相关性血流感染患者血液样本中分离的86株SA菌株,进行来源分析、药敏试验,检测其耐药基因mecA和毒力基因携带情况。结果86株SA菌株主要来源于ICU、外科、老年医学科,分布比例为36.05%、26.74%、12.79%;经过鉴定后,其中30株(34.88%)SA含有mecA基因,表型鉴定为耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA);经过药物敏感性试验,SA菌株对青霉素、红霉素耐药性高,耐药率分别为80.23%、73.26%,对利福平、克林霉素、环丙沙星、庆大霉素、替加环素、苯唑西林、左氧氟沙星存在不同程度敏感,对万古霉素、利奈唑胺完全敏感,耐药率为0%;SA菌株中sea、seb、pvl、tsst-I、hld、clfA、clfB均有检出,检出率为39.53%、44.19%、50.00%、40.70%、58.14%、59.30%、55.81%,并检出多种毒力基因共存,包括sea+seb+pvl+tsst-I+hld+clfA+clfB(18.60%)、sea+seb+tsst-I(13.95%)、tsst-I+hld+clfA(10.47%)和pvl+clfA(10.47%)。结论该院导管相关性血流感染患者中分离的SA菌株以MRSA为主,筛选出的敏感抗菌药物为利福平、万古霉素和利奈唑胺,检出毒力基因为sea、seb、pvl、tsst-I、hld、clfA、clfB,存在多种毒力基因共存现象。

Objective To explore the detection of drug resistance and virulence genes of Staphylococcus aureus(SA)isolated from patients with catheter related blood stream infection(CRBSI),and to provide a basis for clinical prevention and treatment of CRBSI.Methods We collected 86 strains of SA isolated from blood samples of CRBSI patients hospitalized in Jinhua People’s Hospital from January 2017 to December 2021,and then performed source analysis and drug sensitivity test.The resistance gene mecA and carrying of virulence genes were detected.Results The 86 strains of SA were mainly from the ICU(36.05%),surgery department(26.74%)and gerontology department(12.79%).It was found that 30(34.88%)strains of SA carried mecA,and phenotype identification results showed that they were methicillin-resistant Staphylococcus aureus(MRSA).Drug sensitivity test results displayed that the SA strains were highly resistant to penicillin and erythromycin,with the resistance rates being 80.23%and 73.26%respectively.The SA strains were sensitive to rifampicin,clindamycin,ciprofloxacin,gentamicin,tigecycline,oxacillin and levofloxacin,and completely sensitive to vancomycin and linezolid,with the resistance rates being 0%.sea,seb,pvl,tsst-I,hld,clfA and clfB were detected in the SA strains,with the detection rates being 39.53%,44.19%,50.00%,40.70%,58.14%,59.30%and 55.81%respectively.Co-existence of multiple virulence genes was detected,including sea+seb+pvl+tsst-I+hld+clfA+clfB(18.60%),sea+seb+tsst-I(13.95%),tsst-I+hld+clfA(10.47%)and pvl+clfA(10.47%).Conclusion The SA strains isolated from patients with CRBSI in this hospital are dominated by MRSA strains.The selected sensitive antibiotics include rifampicin,vancomycin and linezolid.The detected virulence genes include sea,seb,pvl,tsst-I,hld,clfA and clfB,with co-existence of multiple virulence genes.