Valisena S, Falci C, Mazzariol A, Cornaglia G, Cocuzza C E, Nicoletti P, Rescaldani R, Fontana R
Institute of Microbiology, University of Verona, Italy.
Eur J Clin Microbiol Infect Dis. 1999 Apr;18(4):260-4. doi: 10.1007/s100960050274.
To assess the spread of the new M phenotype, various erythromycin-resistant Streptococcus pyogenes strains from three Italian cities (Verona, Monza, Florence) were characterised. Each strain was analysed for the presence of genes ermAM and mefA, for the ability to accumulate radioactive erythromycin in the absence of sodium arsenate, for the protein T serological type, and for the DNA macrorestriction profile identified by means of pulsed-field gel electrophoresis. In a number of strains, the presence of the inducible ermAM gene was demonstrated; all these strains were negative in the efflux-pump detection assay, did not possess the mefA gene, and had similar restriction profiles. The strains with the efflux mechanism and mefA gene belonged to different serotypes. Of these, only one serotype, T4, was isolated in all three cities. The restriction profile analysis with SmaI and SfiI revealed a very close correlation between strains with the same serotype.
为评估新的M表型的传播情况，对来自意大利三个城市（维罗纳、蒙扎、佛罗伦萨）的多种耐红霉素化脓性链球菌菌株进行了特性分析。分析了每个菌株中ermAM和mefA基因的存在情况、在无砷酸钠时积累放射性红霉素的能力、蛋白T血清型以及通过脉冲场凝胶电泳确定的DNA宏观限制性图谱。在一些菌株中，证实存在可诱导的ermAM基因；所有这些菌株在流出泵检测试验中均为阴性，不具有mefA基因，且具有相似的限制性图谱。具有流出机制和mefA基因的菌株属于不同血清型。其中，只有一种血清型T4在所有三个城市均有分离。用SmaI和SfiI进行的限制性图谱分析显示，相同血清型的菌株之间存在非常密切的相关性。
