Rajala Maitreyi S, Sullender Wayne M, Prasad A K, Dar Lalit, Broor Shobha
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
J Clin Microbiol. 2003 Jun;41(6):2311-6. doi: 10.1128/JCM.41.6.2311-2316.2003.
Respiratory syncytial virus (RSV) is an important childhood pathogen of acute lower respiratory infections in developed and developing countries. The molecular epidemiology of RSV in India is largely unknown. The present study was undertaken to standardize and evaluate reverse transcription-PCR (RT-PCR) for the rapid and simultaneous detection of RSV groups A and B in clinical samples and to study intragroup genetic variability. RT-PCR was evaluated by comparing the results of seminested RT-PCR with centrifugation-enhanced cultures on 200 nasopharyngeal aspirates from children with acute lower respiratory infections. RSV was isolated in 34 nasopharyngeal aspirates by centrifugation-enhanced cultures and identified in 45 samples by RT-PCR. In 15 samples RSV was identified by seminested RT-PCR alone and in four by centrifugation-enhanced cultures alone. Of the 45 samples positive for RSV by nested PCR, 15 belonged to group A, 29 to group B, and one sample suggested a mixed infection. Group B RSV predominated in both years of the 2-year study. Genetic variability within RSV groups was studied by restriction fragment analysis of 35 PCR products. Among both group A and group B RSV, two different composite patterns were observed. Thus, RSV was found to be a major pathogen of acute lower respiratory tract infections in India, as it was detected in 24.5% of children by RT-PCR. RT-PCR provides a sensitive method for detection and typing of RSV group A and B viruses in clinical samples as well as a means to study intragroup variations. However, a higher sensitivity of detection of RSV in clinical samples can be obtained by its combination with additional techniques, such as virus cultivation.
呼吸道合胞病毒(RSV)是发达国家和发展中国家儿童急性下呼吸道感染的一种重要病原体。RSV在印度的分子流行病学情况很大程度上尚不清楚。本研究旨在标准化和评估逆转录聚合酶链反应(RT-PCR),用于临床样本中RSV A组和B组的快速同时检测,并研究组内基因变异性。通过比较半巢式RT-PCR结果与离心增强培养法对200份急性下呼吸道感染儿童的鼻咽抽吸物检测结果,对RT-PCR进行评估。通过离心增强培养法在34份鼻咽抽吸物中分离出RSV,通过RT-PCR在45份样本中鉴定出RSV。在15份样本中仅通过半巢式RT-PCR鉴定出RSV,4份仅通过离心增强培养法鉴定出RSV。在通过巢式PCR检测为RSV阳性的45份样本中,15份属于A组,29份属于B组,1份样本提示为混合感染。在为期2年的研究的两年中,B组RSV均占主导。通过对35个PCR产物进行限制性片段分析,研究了RSV组内的基因变异性。在A组和B组RSV中均观察到两种不同的复合模式。因此,RSV被发现是印度急性下呼吸道感染的主要病原体,因为通过RT-PCR在24.5%的儿童中检测到了该病毒。RT-PCR为临床样本中RSV A组和B组病毒的检测和分型提供了一种灵敏的方法,也是研究组内变异的一种手段。然而,通过将其与其他技术(如病毒培养)相结合,可以在临床样本中获得更高的RSV检测灵敏度。