Chi Fang, Nolte Oliver, Bergmann Carina, Ip Margaret, Hakenbeck Regine
Department of Microbiology, University of Kaiserslautern, Paul Ehrlich Str. 23, D-67663 Kaiserslautern, Germany.
Int J Med Microbiol. 2007 Nov;297(7-8):503-12. doi: 10.1016/j.ijmm.2007.02.009. Epub 2007 Apr 24.
A paradigm for Streptococcus interspecies gene transfer is represented by the mosaic pbp genes encoding the target enzymes for beta-lactam antibiotics, the penicillin-binding proteins, in Streptococcus pneumoniae. We investigated a collection of oral streptococci from three continents by comprehensive multi-locus sequence typing analysis in order to trace the origin of a mosaic block belonging to a dominant family of mosaic pbp2x implicated in penicillin resistance of S. pneumoniae. One widespread family of mosaic pbp2x occurred in all three distinct clusters of S. pneumoniae, Streptococcus mitis and Streptococcus oralis, documenting independent inter- and intraspecies recombination events. Moreover, potential ancestor genes of this mosaic block could be identified in two penicillin-susceptible S. mitis strains from South Africa and Spain, facilitating the identification of pbp2x mutations relevant for resistance development.
肺炎链球菌中编码β-内酰胺抗生素作用靶酶（青霉素结合蛋白）的镶嵌型pbp基因代表了一种链球菌种间基因转移的模式。我们通过全面的多位点序列分型分析，对来自三大洲的一组口腔链球菌进行了研究，以追踪一个镶嵌片段的起源，该片段属于与肺炎链球菌青霉素耐药性相关的占主导地位的镶嵌型pbp2x家族。一个广泛存在的镶嵌型pbp2x家族出现在肺炎链球菌、缓症链球菌和口腔链球菌的所有三个不同菌群中，证明了种间和种内独立的重组事件。此外，在来自南非和西班牙的两株青霉素敏感缓症链球菌菌株中，可鉴定出该镶嵌片段的潜在祖先基因，这有助于鉴定与耐药性发展相关的pbp2x突变。
