Threlfall E J, Torre E, Ward L R, Rowe B, Gibert I
Laboratory of Enteric Pathogens, Central Public Health Laboratory, London.
J Med Microbiol. 1993 Dec;39(6):454-8. doi: 10.1099/00222615-39-6-454.
The type strains of Vi-phage types E1, M1 and A of Salmonella typhi, together with drug-resistant and drug-sensitive strains of phage types E1 and M1 isolated in 1992 from patients associated with India or Pakistan, and a drug-resistant strain of phage type A isolated in South Africa in 1991, were characterised with respect to the presence of plasmids conferring resistance to antimicrobial drugs and their chromosomal insertion sequence IS200 profiles. The three type strains, the drug-sensitive strains of Vi-phage types E1 and M1, and a strain of phage type M1 resistant to ampicillin and trimethoprim but not to chloramphenicol, did not contain plasmids. In contrast, for strains of phage types E1 and M1 resistant to chloramphenicol, ampicillin and trimethoprim, and for the drug-resistant strain of phage type A, the complete spectrum of resistance was encoded by high molecular mass plasmids belonging to the H1 incompatibility group. Characterisation of IS200 profiles demonstrated that at least 13 IS200 copies were distributed on the chromosome of all strains tested. Although the IS200 profiles of the type strains of Vi-phage types A, E1 and M1 were identical, it was possible to distinguish between drug-sensitive and drug-resistant strains of Vi-phage types E1 and M1 isolated from patients infected in India and Pakistan by this method. It was concluded that although IS200 typing is not as discriminatory as phage typing for the primary subdivision of S. typhi, it may be useful for certain epidemiological investigations and, in particular, for investigating the origins of strains with multiple drug resistance.
对伤寒沙门氏菌Vi噬菌体E1型、M1型和A 型的模式菌株，以及1992年从与印度或巴基斯坦有关的患者中分离出的噬菌体E1型和M1型的耐药和敏感菌株，和1991年在南非分离出的噬菌体A 型耐药菌株，就赋予抗菌药物耐药性的质粒的存在及其染色体插入序列IS200图谱进行了特征分析。这三株模式菌株、噬菌体E1型和M1型的敏感菌株，以及一株对氨苄青霉素和甲氧苄啶耐药但对氯霉素不耐药的噬菌体M1型菌株，均未含有质粒。相比之下，对于对氯霉素、氨苄青霉素和甲氧苄啶耐药的噬菌体E1型和M1型菌株，以及噬菌体A 型耐药菌株，其完整的耐药谱由属于H1不相容群的高分子质量质粒编码。IS200图谱特征分析表明，至少13个IS200拷贝分布在所有测试菌株的染色体上。尽管噬菌体A 型、E1型和M1型的模式菌株的IS200图谱相同，但通过这种方法可以区分从印度和巴基斯坦感染患者中分离出的噬菌体E1型和M1型的敏感和耐药菌株。得出的结论是，尽管IS200分型在伤寒沙门氏菌的初步细分中不如噬菌体分型具有鉴别力，但它可能对某些流行病学调查有用，特别是对于调查具有多重耐药性的菌株的来源。
