MALDI-TOF-MS在耐碳青霉烯肠杆菌多黏菌素B快速药敏试验中的应用

Application of MALDI-TOF-MS for rapid drug susceptibility test of polymyxin B in Carbapenem-resistant Enterobacteriaceae

目的构建一种耐碳青霉烯类肠杆菌科细菌(CRE)多黏菌素B的快速药敏试验方法,为临床抗生素的选择和精准调整提供依据。方法采用WHONET 5.6软件对分离自西安市第一医院2023年3月至2024年3月的108株CRE菌株信息进行筛选,以肉汤稀释法为参比方法,采用基质辅助激光解吸/电离飞行时间质谱仪(MALDI-TOF-MS)进行多黏菌素B快速药敏测定。结果108株CRE分离株以肺炎克雷伯菌为主(48.14%),其次是产气肠杆菌和奇异变形杆菌(各占13.89%)。标本来源以痰液为主(65.74%),其次尿液(18.52%)和血液(8.33%)。临床科室分布以神经外科为主(48.15%),其次为重症医学科(18.52%)和呼吸内科(14.81%)。CRE分离株对大部分药物呈现高度耐药,对常见β内酰胺类、喹诺酮类、氨基糖苷类、β内酰胺复合药物耐药率分别超过70%,80%,50%和75%。与肉汤稀释法相比,MALDI-TOF-MS法测定CRE对多黏菌素B药敏结果的分类一致率(CA)为98.1%,重大误差(ME)为1.85%,未出现非常重大误差(VME),均在可允许范围之内。结论本院分离的CRE对多种抗菌药物广泛耐药,基于MALDI-TOF-MS的快速药敏试验方法准确可靠,可用来评价CRE对多黏菌素B的敏感性,便于临床及时调整泛耐药细菌治疗方案。

Objective To establish a rapid drug susceptibility test method for Carbapenem-resistant Enterobacteriaceae(CRE)against polymyxin B for providing a foundation in the selection and precise adjustment of clinical antibiotics.Methods The clinical information of 108 CRE strains in Xi′an NO.1 Hospital from March 2023 to March 2024 was screened using WHONET 5.6 software.Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)was used for rapid drug susceptibility test of polymyxin B,with broth dilution method as the reference.Results The 108 CRE isolates were predominantly Klebsiella pneumoniae(48.14%),followed by Enterobacter aerogenes(13.89%)and Proteus mirabilis(13.89%).The majority of CRE strains were isolated from sputum samples(65.74%),followed by urine(18.52%)and blood(8.33%).The CRE strains were mainly from department of neurosurgery(48.15%),followed by department of intensive care medicine(18.52%)and department of respiratory medicine(14.81%).CRE isolates exhibited high resistance to most drugs.The rates of resistance toβ-Lactams,quinolones,aminoglycosides,andβ-lactam complex antibiotics exceeded 70%,80%,50%,and 75%,respectively.Compared with the broth dilution method,the MALDI-TOF-MS results presented 98.1%of category agreement(CA),1.85%of major error rate(ME),and no very major errors(VME),which all were within acceptable ranges.Conclusion The CRE strains isolated in this study exhibit extensive resistance to multiple antibiotics.The rapid drug susceptibility test method based on MALDI-TOF-MS is both accurate and reliable,which can be used to quickly detect the sensitivity of CRE to polymyxin B and timely facilitate adjustments of clinical treatment plans for extensively drug-resistant bacteria.