IncHI2 Plasmids Are Predominant in Antibiotic-Resistant Salmonella Isolates.
IncHI2 Plasmids Are Predominant in Antibiotic-Resistant Salmonella Isolates.
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IncHI2 质粒是主要的抗生素抗性沙门氏菌分离株。
DOI：
10.3389/fmicb.2016.01566
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发表时间：
2016
影响因子：
5.2
通讯作者：
Shi C
中科院分区：
文献类型：
--
作者：
Chen W;Fang T;Zhou X;Zhang D;Shi X;Shi C
抗生素的广泛使用导致耐药沙门氏菌的流行增加。质粒酶在沙门氏菌抗生素抗性标记的水平转移中起关键作用。本研究旨在筛选和表征沙门氏菌抗生素耐药性的质粒谱，并最终阐明可转移质粒介导的抗生素耐药性的分子机制。采用纸片扩散法对226株沙门氏菌进行了药敏试验。32株（14.2%）对至少一种抗生素耐药。通过PCR扩增确定质粒介导的喹诺酮类耐药（PMQR）基因和β-内酰胺酶基因的存在。基于PCR的复制子分型显示，这32个分离物代表7个质粒不相容性组（IncP、HI 2、A/C、FIIs、FIA、FIB和I1），其中IncHI 2（59.4%）占优势。通过质粒固化鉴定质粒上的耐药标记。共获得15个表型变异体，治愈率为46.9%（15/32）。治愈的质粒主要属于HI 2不亲和组。IncHI 2质粒的消除与β-内酰胺酶基因（blaOXA-1和blaTEM-1）和PMQR基因（qnrA和aac（6′）-Ib-cr）的丢失相关。IncHI 2和IncI 1质粒在一株S.肠道血清型印第安纳州分离株SJTUF 10584因治愈而丢失。对来自SJTUF 10584的携带blaCMY-2的质粒pS10584进行完全测序。序列分析表明，它具有IncI 1质粒的典型质粒骨架，具有插入大肠杆菌素基因cia中的IS 1294-Δ ISEcp 1-blaCMY-2-blc-sugE-ΔecnR的独特遗传排列。这些数据表明，IncHI 2是导致沙门氏菌抗生素耐药性传播的主要质粒谱系，多个移动的遗传元件的活性可能有助于抗生素耐药性进化和不同质粒复制子之间的传播。
The wide usage of antibiotics contributes to the increase in the prevalence of antibiotic-resistant Salmonella. Plasmids play a critical role in horizontal transfer of antibiotic resistance markers in Salmonella. This study aimed to screen and characterize plasmid profiles responsible for antibiotic resistance in Salmonella and ultimately to clarify the molecular mechanism of transferable plasmid-mediated antibiotic resistance. A total of 226 Salmonella isolates were examined for antimicrobial susceptibility by a disk diffusion method. Thirty-two isolates (14.2%) were resistant to at least one antibiotic. The presence of plasmid-mediated quinolone resistance (PMQR) genes and β-lactamase genes were established by PCR amplification. PCR-based replicon typing revealed that these 32 isolates represented seven plasmid incompatibility groups (IncP, HI2, A/C, FIIs, FIA, FIB, and I1), and the IncHI2 (59.4%) was predominant. Antibiotic resistance markers located on plasmids were identified through plasmid curing. Fifteen phenotypic variants were obtained with the curing efficiency of 46.9% (15/32). The cured plasmids mainly belong to the HI2 incompatibility group. The elimination of IncHI2 plasmids correlated with the loss of β-lactamase genes (blaOXA-1 and blaTEM-1) and PMQR genes (qnrA and aac(6′)-Ib-cr). Both IncHI2 and IncI1 plasmids in a S. enterica serovar Indiana isolate SJTUF 10584 were lost by curing. The blaCMY -2-carrying plasmid pS10584 from SJTUF 10584 was fully sequenced. Sequence analysis revealed that it possessed a plasmid scaffold typical for IncI1 plasmids with the unique genetic arrangement of IS1294-ΔISEcp1-blaCMY -2-blc-sugE-ΔecnR inserted into the colicin gene cia. These data suggested that IncHI2 was the major plasmid lineage contributing to the dissemination of antibiotic resistance in Salmonella and the activity of multiple mobile genetic elements may contribute to antibiotic resistance evolution and dissemination between different plasmid replicons.