Abstract:
Pseudomonas aeruginosa is one of the most common opportunistic pathogens causing severe nosocomial infections for its patterns of multidrug resistance, particularly for carbapenems. Timely epidemiological surveillance could greatly facilitate infection control of P. aeruginosa and many deadly pathogens alike. IR Biotyper (IRBT), is a novel real-time typing tool, based on a Fourier-transform infrared (FTIR) spectroscopy system. It is critical to comprehensively establish and evaluate the feasibility of IRBT in P. aeruginosa strain typing. In the current study, we first established standards and schemes for its routine laboratory application, and we found that Mueller-Hinton agar plates give better discriminatory power than blood agar plates. Data showed that the cut-off value of 0.15 with an additional 0.025 range was optimal. Secondly, 27 clinically isolated carbapenem-resistant P. aeruginosa (CRPA) strains collected from October 2010 to September 2011 were evaluated for typing effectiveness by comparing IRBT to the other commonly used typing methods, such as multi-locus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS)-based typing. When using WGS-based typing as the reference method, the typing method of FTIR spectroscopy (AR = 0.757, SID = 0.749) could better cluster P. aeruginosa strains than MLST and in silico serotyping (AR = 0.544, SID = 0.470). Though PFGE showed the highest discriminatory power, low concordance was observed between PFGE and the other methods. Above all, this study demonstrates the utility of the IRBT as a quick, low-cost, real-time typing tool for the detection of CRPA strains.
摘要:
铜绿假单胞菌是引起严重医院感染的最常见的条件致病菌之一,特别是碳青霉烯类。及时的流行病学监测可以极大地促进铜绿假单胞菌和许多致命病原体的感染控制。红外生物分型仪(IRBT),是一种新颖的实时打字工具,基于傅里叶变换红外(FTIR)光谱系统。综合建立和评价IRBT在铜绿假单胞菌菌株分型中的可行性至关重要。在目前的研究中,我们首先为其常规实验室应用建立了标准和方案,我们发现Mueller-Hinton琼脂平板比血琼脂平板具有更好的鉴别力。数据显示,在额外的0.025范围内,0.15的截断值是最佳的。其次,从2010年10月至2011年9月收集的27个临床分离的耐碳青霉烯类铜绿假单胞菌(CRPA)菌株通过比较IRBT与其他常用的分型方法来评估分型有效性。例如多位点序列分型(MLST),脉冲场凝胶电泳(PFGE)和基于全基因组测序(WGS)的分型。使用基于WGS的类型作为参考方法时,FTIR光谱(AR=0.757,SID=0.749)的分型方法比MLST和计算机血清分型(AR=0.544,SID=0.470)能更好地对铜绿假单胞菌菌株进行聚类。尽管PFGE表现出最高的歧视能力,PFGE与其他方法的一致性较低。最重要的是,这项研究证明了IRBT作为一种快速、低成本,用于检测CRPA菌株的实时分型工具。