Spigaglia P, Cardines R, Rossi S, Menozzi M G, Mastrantonio P
Department of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome and *Institute of Microbiology, Faculty of Medicine and Surgery, University of Parma, Viale Gramsci 14, 43100 Parma, Italy.
J Med Microbiol. 2001 May;50(5):407-414. doi: 10.1099/0022-1317-50-5-407.
Thirty-two related and 68 unrelated isolates of Clostridium difficile, isolated in different Italian hospitals since 1987, were analysed by PFGE and PCR-ribotyping to investigate their genetic relatedness. The isolates were classified into 28 groups by PFGE and 20 ribotypes by PCR-ribotyping. A single clone of C. difficile was recognised as the cause of three geographically and chronologically distant outbreaks. The correlation between PFGE and PCR-ribotyping results was good, with agreement for 77 (84%) of the 92 isolates typed by both methods. However, among sporadic isolates the discriminatory power of PFGE was more evident. Eight isolates that were untypable by PFGE could be analysed by PCR-ribotyping. The dendrograms generated showed that the genetic relatedness of the C. difficile isolates obtained by both techniques was comparable. The majority of the isolates in recent years appeared to be genetically unrelated to isolates from past infections. However, two clonal groups identified in all time periods had a common origin and this seems to indicate that they share some advantageous biological characteristics. The constant monitoring of C. difficile epidemiology will allow acquisition of further important data on this nosocomial pathogen.
自1987年以来，从意大利不同医院分离出32株相关艰难梭菌菌株和68株不相关艰难梭菌菌株，采用脉冲场凝胶电泳（PFGE）和PCR核糖体分型法对其进行分析，以研究它们的遗传相关性。通过PFGE将这些菌株分为28组，通过PCR核糖体分型法分为20个核糖体分型。单一的艰难梭菌克隆被确认为三起在地理和时间上相隔较远的暴发的病因。PFGE和PCR核糖体分型结果之间的相关性良好，两种方法分型的92株菌株中有77株（84%）结果一致。然而，在散发菌株中，PFGE的鉴别力更为明显。8株无法用PFGE分型的菌株可用PCR核糖体分型法进行分析。生成的树形图表明，两种技术获得的艰难梭菌菌株的遗传相关性具有可比性。近年来的大多数菌株在基因上似乎与过去感染的菌株无关。然而，在所有时间段鉴定出的两个克隆组有共同起源，这似乎表明它们具有一些有利的生物学特性。对艰难梭菌流行病学的持续监测将有助于获取有关这种医院病原体的更多重要数据。
