Characterization and localization of drug resistance determinants in multidrug-resistant, integron-carrying Salmonella enterica serotype typhimurium strains
Characterization and localization of drug resistance determinants in multidrug-resistant, integron-carrying Salmonella enterica serotype typhimurium strains
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DOI：
10.1089/1076629041310136
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发表时间：
2004-06-01
影响因子：
2.6
通讯作者：
Mendoza, MC
中科院分区：
文献类型：
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作者：
Guerra, B;Junker, E;Mendoza, MC
对10株多耐药鼠伤寒沙门菌（S. Typhimurium）血清型菌株（包括新出现的单相菌株[4,5,12:i:-]）的耐药遗传背景进行了研究。所有菌株共有1类整合子（7个可变区），根据噬菌体类型、DNA多态性（PFGE）、整合子和/或抗性模式属于不同的谱系（L1-L6）。对这些菌株进行染色体或质粒筛选，以确定32个DNA序列的存在和定位，这些DNA序列代表整合子、tn21样转座子、抗性和毒力质粒基因。属于L1谱系（最终噬菌体型DT104）的菌株携带90 kb的沙门氏菌毒力质粒以及染色体定位的全部或部分沙门氏菌基因组岛1 （SGI1）。其他5个系的菌株均在不同的抗性质粒上携带抗性决定因子。其中两株表现出复杂的质粒谱，包括一个95kb的毒力质粒和两个或四个抗性质粒。两个菌株携带的抗性质粒缺乏毒力质粒编码序列。其余两株携带两种不同的杂交毒力抗性质粒。23个DNA序列可以被分配到不同的XbaI基因组限制模式（PFGE谱）。通过这种方法，确定了抗性和毒力质粒对PFGE谱的影响，并鉴定出了几组抗性基因。所获得的数据为追踪全球多重耐药鼠伤寒沙门氏菌的出现和分布提供了有用的流行病学工具。
The genetic background of the antimicrobial resistance of 10 selected multiresistant Salmonella serotype Typhimurium (S. Typhimurium) strains (including the emerging monophasic variant [4,5,12:i:-]) was investigated. All strains shared class 1 integrons (with seven types of variable regions) and belonged to different lineages (L1-L6) according to their phage types, DNA polymorphisms by XbaI-pulsed-field gel electrophoresis (PFGE), integrons, and/or resistance patterns. The strains were screened for the presence and localization (chromosomal or plasmid) of 32 DNA sequences representing integron-, Tn21-like transposon-, resistance-, and virulence-plasmid genes. Strains belonging to lineage L1 (definitive phage type DT104) carried the 90-kb Salmonella virulence plasmid together with the complete or partial chromosomally located Salmonella Genomic Island 1 (SGI1). All strains belonging to the other five lineages carried their resistance determinants on various resistance plasmids. Two of these strains showed complex plasmid profiles, which included a 95-kb virulence plasmid together with two or four resistance plasmids. Two strains carried a resistance plasmid that lacked the virulence-plasmid-encoding sequences. The remaining two strains carried two different hybrid virulence-resistance plasmids. Twenty-three of the DNA sequences could be assigned to distinct XbaI genomic restriction patterns (PFGE profiles). In this way, the influence of the resistance and virulence plasmids on the PFGE profiles was determined, and several groups of resistance genes could be identified. The data obtained represent a useful epidemiological tool for tracing the emergence and distribution of multiresistant S. Typhimurium worldwide.