In Vivo Horizontal Gene Transfer of the Carbapenemase OXA-48 During a Nosocomial Outbreak
In Vivo Horizontal Gene Transfer of the Carbapenemase OXA-48 During a Nosocomial Outbreak
复制标题
DOI：
10.1093/cid/civ191
复制
发表时间：
2015-06-15
影响因子：
11.8
通讯作者：
Kempf, Volkhard A. J.
中科院分区：
文献类型：
--
作者：
Goettig, Stephan;Gruber, Teresa M.;Kempf, Volkhard A. J.
背景OXA-48是一种高度流行的碳青霉烯酶，已在全球范围内分离。在此，我们研究了在感染患者体内bla（OXA-48）从肺炎克雷伯菌到大肠杆菌的水平基因转移（HGT）。通过药敏试验、多位点序列分型、DiversiLab和质粒分析对细菌分离株进行表征。利用爆发菌株和大肠杆菌，通过体外转接合评价bla（OXA-48）的转移性。coli J53。利用大蜡螟（Galleria mellonella）幼虫和低复杂性微生物群小鼠研究体内转接合。OXA-48-携带K.属于ST 14的肺炎分离株在医院爆发期间从6名患者中分离。分子和流行病学分析表明，一个约60-kb的含OXA-48的IncL/M型质粒的HGT来自克雷伯氏菌。pneumoniae为E.大肠杆菌属于新的ST 666在患者。体外偶联实验显示转偶联频率为8.7 × 10 ~（-7）。在新开发的体内模型中，使用G.大蜡螟幼虫的转接合频率较高，为1.3 × 10 ~（-4）。从K.和E.低复杂性微生物群小鼠肠道中的大肠杆菌含量为2.9 x 10（-5）。在体外和2种体内模型中验证了OXA-48在感染患者肠道中的体内属间基因转移，这两种模型均显示出比体外条件更高的传播频率。这意味着目前的体外方案可能无法正确反映体内碳青霉烯酶基因的HGT。
Background. OXA-48 is a highly prevalent carbapenemase and has been isolated worldwide. Here, we investigate the in vivo horizontal gene transfer (HGT) of bla(OXA-48) from Klebsiella pneumoniae to Escherichia coli in an infected patient.Methods. Bacterial isolates were characterized by susceptibility testing, multilocus sequence typing, DiversiLab, and plasmid analyses. Transferability of bla(OXA-48) was evaluated by in vitro transconjugation using the outbreak strain and E. coli J53. In vivo transconjugation was investigated using the larvae of the greater wax moth (Galleria mellonella) and low-complexity-microbiota mice.Results. OXA-48-harboring K. pneumoniae isolates belonging to ST14 were isolated during a nosocomial outbreak from 6 patients. Molecular and epidemiological analyses revealed the HGT of an approximately 60-kb OXA-48-containing IncL/M-type plasmid from K. pneumoniae to E. coli belonging to the novel ST666 in a patient. In vitro conjugation experiments revealed a transconjugation frequency of 8.7 x 10(-7). HGT of OXA-48 in a newly developed in vivo model using G. mellonella larvae revealed a higher transconjugation frequency of 1.3 x 10(-4). The conjugation frequency of OXA-48 from K. pneumoniae and E. coli in the gut of low-complexity-microbiota mice was determined to be 2.9 x 10(-5).Conclusions. The in vivo intergenus gene transfer of OXA-48 in the gut of an infected patient was verified in vitro and in 2 in vivo models, which both showed even higher transmission frequencies vs in vitro conditions. This implies that the current in vitro protocols might not correctly reflect the HGT of carbapenemase genes in vivo.