异质性万古霉素中介金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌的临床特征及耐药分析

Clinical characteristics and antibiotic susceptibility analysis of heterogeneous vancomycin-intermediate Staphylococcus aureus and methicillin-resistant Staphylococcus aureus

目的 分析异质性万古霉素中介金黄色葡萄球菌(hVISA)和耐甲氧西林金黄色葡萄球菌(MRSA)的临床特征以及对常用抗菌药物的耐药情况,为临床用药以及控制MRSA和hVISA感染提供依据。方法 采用VITEK-2 Compact全自动细菌鉴定和药敏分析仪对临床分离的263株金黄色葡萄球菌进行药敏分析,MRSA菌株的鉴定根据CLSI规则进行;分别采用2、3和4 μg/ml的万古霉素脑心浸液琼脂平皿(BHIA2V、BHIA3V和BHIA4V)对263株金黄色葡萄球菌进行筛选,对筛选阳性的菌株用菌群分析-曲线下面积法(PAP/AUC法)进行确认;回顾性分析263名感染金黄色葡萄球菌患者的临床资料。结果 263株金黄色葡萄球菌中hVISA共22株,检出率为8.4%;MRSA共60株,检出率为22.8%。临床资料显示与甲氧西林敏感金黄色葡萄球菌组(MSSA组)和万古霉素敏感金黄色葡萄球菌组(VSSA组)相比,MRSA组和hVISA组在不同性别、年龄和科室中的检出均无统计学意义(P>0.05),在不同来源标本中的检出有统计学意义(P<0.05),且都是在血液标本中检出率最高。药敏结果显示金黄色葡萄球菌均对头孢洛林、利奈唑胺、达托霉素、替拉考宁、万古霉素以及米诺环素全敏感。MRSA组对苯唑西林、红霉素、克林霉素、头孢唑林和氯霉素的耐药率高于MSSA组(P<0.05),但对复方新诺明的耐药率低于MSSA组(P<0.05)。hVISA组的苯唑西林、利福平、阿米卡星和头孢唑林耐药率高于VSSA组(P<0.05)。hVISA组对苯唑西林、克林霉素和头孢唑林的耐药率低于MRSA组,但复方新诺明的耐药率高于MRSA组(P<0.05)。结论 临床分离的263株金黄色葡萄球菌中MRSA的检出率为22.8%,hVISA的检出率为8.4%。血液标本中MRSA和hVISA的检出率高于其它来源的标本。临床在治疗由金黄色葡萄球菌引起的感染时可以优先考虑头孢洛林、利奈唑胺、达托霉素、替拉考宁、万古霉素以及米诺环素,但需要警惕是否存在对万古霉素敏感性下降的情况,以便及时调整治疗方案,从而减少hVISA感染的发生。

objective To analyze the clinical characteristics of hVISA and MRSA and their resistance to common antibiotics, so as to provide basis for clinical antibiotics use and control of MRSA infection and hVISA infection.Methods VITEK-2 Compact automatic bacterial identification and antibiotic susceptibility analyzer were used to analyze the antibiotic susceptibility of 263 Staphylococcus aureus strains, and MRSA strains were identified according to CLSI rules.The 263 strains of Staphylococcus aureus were screened by BHIA2V, BHIA3V and BHIA4V respectively, and the positive strains were confirmed by PAP/AUC method;the clinical data of 263 patients infected with Staphylococcus aureus were reviewed retrospectively.Results Twenty-two strains were confirmed to be hVISA positive, 60 strains were identified as MRSA in 263 strains of Staphylococcus aureus, and the detection rates of hVISA and MRSA were 8.4% and 22.8%, respectively. The clinical data showed that compared with those of the MSSA group and the VSSA group, the detection rates of the MRSA group and the hVISA group did not show significant differences in different genders, ages and departments (P>0.05), while the detection rates of the MRSA group and the hVISA group in different samples were statistically significant (P<0.05), and the detection rates of both were the highest in blood samples. The results of antibiotic susceptibility showed that Staphylococcus aureus were fully sensitive to ceflosin, linezolid, daptomycin, tiraconine, vancomycin and minocycline. The resistance rate to oxacillin, erythromycin, clindamycin, cefazolin and chloramphenicol in the MRSA group was higher than that in the MSSA group (P<0.05), while the resistance rate to sulfamethoxazole in the MRSA group was lower than that in the MSSA group (P<0.05). The resistance rates of oxacillin, rifampicin, amikacin and cefazolin in the hVISA group were higher than those in the VSSA group (P<0.05). The resistance rates of the hVISA group to oxacillin, clindamycin and cefazolin were lower than those of the MRSA group, while the resistance rate of sulfamethoxazole compound was higher than that of the MRSA group (P<0.05).Conclusion The detection rate of MRSA in 263 strains of Staphylococcus aureus was 22.8% and the detection rate of hVISA was 8.4%. The detection rates of MRSA and hVISA in blood samples were higher than those from other sources. Ceflosin, linezolid, daptomycin, tiraconine, vancomycin and minocycline should be given priority in the clinical treatment of infection caused by MRSA, but we need to be vigilant about the decrease of sensitivity to vancomycin so that the treatment can be adjusted in time to reduce the occurrence of hVISA infection.