■不断增加的抗生素耐药性,例如耐碳青霉烯类肠杆菌(CRE)的出现,耐碳青霉烯类鲍曼不动杆菌(CRAB),和耐碳青霉烯类铜绿假单胞菌(CRPA)导致使用有毒和较老的药物,如粘菌素用于这些生物。但是在世界范围内,甚至对染色体和质粒介导的粘菌素的抗性也在增加。这就需要准确检测电阻。这受到无法用于常规临床微生物学实践的用户友好的表型方法的阻碍。本研究试图评估两种不同的方法-Vitek两种方法的粘菌素肉汤圆盘洗脱和MIC检测,与CLSI批准的用于肠杆菌的粘菌素微量稀释(BMD)相比,铜绿假单胞菌,和鲍曼不动杆菌临床分离株。
■6013个碳青霉烯类耐药菌株的粘菌素敏感性通过BMD测定,粘菌素肉汤盘洗脱液(CBDE),和Vitek两种方法,并按照CLSI指南进行解释。CBDE的MIC结果,Vitek两人与BMD和基本一致(EA)进行了比较,绝对协议(CA),灵敏度,特异性,非常主要的错误(VME),计算了主要误差(ME)和科恩的卡帕(CK)。通过常规聚合酶链反应在所有粘菌素抗性分离株中评估了任何质粒介导的粘菌素抗性(mcr-1、2、3、4和5)的存在。
■在碳青霉烯类耐药菌株中,有778株(12.9%)对粘菌素耐药。通过BMD方法,肺炎克雷伯菌对粘菌素的耐药性最高(18.9%)。Vitek2的MIC敏感性为78.2-84.8%,特异性>92%。通过Vitek两种方法,有171个VME和323个MEs,远超过CLSI可接受范围。鲍曼不动杆菌的错误百分比最高(VME的27.8%和ME的7.9%)。另一方面,CBDE方法与EA表现良好,CA,VME和ME在所有生物体可接受的范围内。与黄金标准BMD相比,CBDE方法的灵敏度在不同菌株的97.5-98.8%之间变化,特异性超过97.6%。分离出的粘菌素抗性生物均未携带mcr质粒。
■由于BMD具有许多技术复杂性,CBDE是印度等国家最可行的替代方案。Vitek两人报告的敏感MIC需要仔细考虑,因为VME的高倾向,特别是克雷伯菌属。
UNASSIGNED: The increasing antibiotic resistance like the advent of carbapenem resistant Enterobactarales (CRE), Carbapenem Resistant Acinetobacter baumanii (CRAB), and Carbapenem Resistant Pseudomonas aeruginosa (CRPA) has led to to the use of toxic and older drugs like colistin for these organisms. But worldwide there is an increase in resistance even to colistin mediated both by chromosomes and plasmids. This necessitates accurate detection of resistance. This is impeded by the unavailability of a user-friendly phenotypic methods for use in routine clinical microbiology practice. The present study attempts to evaluate two different methods - colistin broth disc elution and MIC detection by Vitek two in comparison to CLSI approved broth microdilution (BMD) for colistin for Enterobactarales, Pseudomonas aeruginosa , and Acinetobacter baumanii clinical isolates.
UNASSIGNED: Colistin susceptibility of 6013 carbapenem resistant isolates was determined by BMD, Colistin Broth Disc Elution (CBDE), and Vitek two methods and was interpreted as per CLSI guidelines. The MIC results of CBDE, Vitek two were compared with that of BMD and essential agreement (EA), categorical agreement (CA), sensitivity, specificity, very major error (VME), major error (ME) and Cohen\'s kappa (CK) was calculated. The presence of any plasmid-mediated colistin resistance (mcr-1, 2, 3, 4 and 5) was evaluated in all colistin-resistant isolates by conventional polymerase chain reaction.
UNASSIGNED: Colistin resistance was found in 778 (12.9 %) strains among the carbapenem resistant isolates. Klebsiella pneumoniae had the highest (18.9 %) colistin resistance by the BMD method. MIC of Vitek two had sensitivity ranging from 78.2-84.8% and specificity of >92 %. There were 171 VMEs and 323 MEs by Vitek two method, much more than CLSI acceptable range. The highest percentage of errors was committed for Acinetobacter baumanii (27.8 % of VME and 7.9 % ME). On the other hand, the CBDE method performed well with EA, CA, VME and ME within acceptable range for all the organisms. The sensitivity of the CBDE method compared to gold standard BMD varied from 97.5-98.8 % for different strains with a specificity of more than 97.6 %. None of the isolated colistin resistant organisms harboured mcr plasmids.
UNASSIGNED: As BMD has many technical complexities, CBDE is the best viable alternative available for countries like India. A sensitive MIC reported by Vitek two needs to be carefully considered due high propensity for VMEs particularly for Klebsiella spp.