全自动微生物分析系统对布鲁杆菌属和种鉴定效果的研究

摘要

Objective To identify and analyse the biochemical characterization of brucella and to evaluate its clinical application by VITEK2 COMPACT automatic microbial identification analyzer.Methods Seventeen strains of standard strains and 121 strains of experimental strains were from bacteria storehouse of brucella disease,Institute of Infectious Diseases Prevention and Control,China Center for Disease Control and Prevention.Experimental strains were from 26 provinces (municipalities and autonomous regions) from 1957 to 2014,including all previous strains from patients and goats,antelope,sheep,cattle,and pig.Reference standard strains and experimental strains were analyzed using the GN identification card on VITEK2 COMPACT automatic microbial identification analyzer,and biochemical identification of brucella strains was done.Identified abnormal strains were rechecked by traditional test methods,including oxidase experiment,urease experiment,semisolid experiment,determination of hydrogen sulfide experiment,basic fuchsin susceptibility experiment,phage lysis experiment,and A/M single-phase specific serum agglutination experiment.Results Of the 138 strains of brucella analyzed by the automatic microbial identification system,the results showed that the main identification indicators of brucella genus were:L-proline arylamidase (ProA),tyrosine arylamidase (TyrA),urease (URE),glycine arylamidase (GlyA),L-lactate alkalinisation (1LATK),and ELLMAN (ELLM).Compared with the system values,all strains biochemical function similar rate was 97.99％ (135.23/138),including standard strains was 96.71％ (16.44/17),experimental strains was 98.17％ (118.79/ 121);time required for strains identification was 6.1-7.7 h,including standard strains was 7.3 h,experimental strains was 6.9 h.Identification indicators for distinguish brucella species were:ProA,TyrA,URE,and GlyA;for distinguish brucella melitensis was ELLM;for distinguish brucella abortus was 1LATK;for distinguish brucella suis was Ala-Phe-Pro-arylamidase (APPA);no obvious positive brucella indicator was found for brucella cains.From the experimental strains 4 strains of ochrobactrum anthropi were identified;the traditional methods showed that they were oxidase-positive,urase-positive,and hydrogen sulfide-positive,power-negative;basic fuchsin susceptibility test discovered 2 strains (burcella abortus),sensitive 2 strains (burcella suis);sulfur sensitive experiment 2 strains pansy (burcella abortus),resistant 2 strains (burcella suis);phage lysis test-positive 2 strains (burcella abortus),and negative 2 strains (burcella suis).A/M single-phase specific serum agglutination experiment showed that they were brucella abortus (A)-positive and brucella melitensis (M)-negative.They were not ochrobactrum anthropi.The identification results showed that they were brucella.Conclusions The VITEK2 COMPACT automatic microbial analysis system has a speed and high reliability in identification of brucella;the main positive indicators are clear for identification of different strains of genera and species;it can be used for clinical diagnosis.When the identification result is ochrobactrum anthropi,it should be identified with brucella in order to avoid misdiagnosis.%目的 鉴定与分析布鲁杆菌的生化特征,评价对全自动微生物分析系统的鉴定效果和临床意义.方法 17株标准菌株和121株实验菌株来自于中国疾病预防控制中心传染病预防控制所布鲁杆菌病(简称布病)研究室菌种库,实验菌株为全国26个省(市、自治区)1957-2014年历次流行自布病患者和羊、黄羊、岩羊、牛、猪分离的布鲁杆菌菌株.用GN鉴定卡在VITEK2 COMPACT全自动微生物分析系统上对标准菌株和实验菌株进行生化检测,根据布鲁杆菌属和种的生化阳性鉴定标准,通过对比分析,获得布鲁杆菌属和种的生化阳性鉴定结果.对系统鉴定异常的菌种,采用传统鉴定方法进行氧化酶、脲酶、动力、硫化氢测定和碱性复红敏感性试验、噬菌体裂解试验及A/M单相特异性血清凝集试验进行菌种的重新判定.结果 对138株布鲁杆菌菌株的全自动微生物分析系统生化鉴定结果显示,布鲁杆菌属的主要阳性鉴定指标为L-脯氨酸芳胺酶(ProA)、酪氨酸芳胺酶(TyrA)、尿素酶(URE)、氨基乙酸芳胺酶(GlyA)、乳酸盐产碱(1LATK)、ELLMAN (ELLM);与系统值比较,全部菌株生化功能相似率为97.99％(135.23/138),其中标准菌株为96.71％(16.44/ 17),实验菌株为98.17％(118.79/121);菌株鉴定需要的时间为6.1 ～ 7.7 h,其中标准菌株为7.3 h,实验菌株为6.9 h.区分是否为布鲁杆菌属的阳性鉴定指标为ProA、TyrA、URE、GlyA;区分羊种布鲁杆菌的阳性指标为ELLM;区分牛种布鲁杆菌的阳性指标为1LATK;区分猪种布鲁杆菌的阳性指标为丙氨酸-苯丙氨酸-脯氨酸芳胺酶(APPA);犬种无明显的阳性指标.从实验菌株中鉴定出4株人苍白杆菌,传统方法显示,氧化酶阳性、脲酶阳性、硫化氢阳性、动力阴性;碱性复红敏感性试验有抗性2株(牛种),敏感2株(猪种);硫堇实验敏感2株(牛种),有抗性2株(猪种);噬菌体裂解试验阳性2株(牛种),阴性2株(猪种).A/M因子单相特异性血清凝集试验,牛种布鲁杆菌(A)阳性,羊种布鲁杆菌(M)阴性,排除人苍白杆菌,最终鉴定均为布鲁杆菌种.结论 全自动微生物分析系统在鉴定布鲁杆菌时速度快,可靠性较高,对不同菌株属和种鉴定的主要阳性指标明确,可用于临床诊断.当鉴定为人苍白杆菌时,需与布鲁杆菌进行鉴别,以免误诊.