Distribution of type VI secretion system (T6SS) in clinical Klebsiella pneumoniae strains from a Chinese hospital and its potential relationship with virulence and drug resistance
Distribution of type VI secretion system (T6SS) in clinical Klebsiella pneumoniae strains from a Chinese hospital and its potential relationship with virulence and drug resistance
复制标题
中国某医院临床肺炎克雷伯菌VI型分泌系统（T6SS）分布及其与毒力和耐药性的潜在关系
DOI：
10.1016/j.micpath.2021.105085
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发表时间：
2022-01-09
影响因子：
3.8
通讯作者：
Yang Liu
中科院分区：
文献类型：
--
作者：
Liao, Wenjian;Huang, Hai-hua;Yang Liu
目的：从血流、肠道、化脓性肝脓肿中分离出的肺炎克雷伯菌菌株中的 VI 型分泌系统（T6SS）已有报道。本研究旨在对来自中国医院的各种标本的 248 株肺炎克雷伯菌分离株进行 T6SS 特征分析，并探讨 T6SS 与毒力和耐药性的潜在关联。方法：通过聚合酶链反应 (PCR) 鉴定 T6SS 基因、荚膜血清分型基因、耐药基因和毒力基因。通过纸片扩散法检查抗生素敏感性。为了评估这些临床肺炎克雷伯菌分离株的生物膜形成，进行了 96 孔微量滴定板测定。采用MLST对肺炎克雷伯菌进行基因型分析。结果：临床肺炎克雷伯菌中T6SS基因频率为72.2%。 T6SS阳性菌株对哌拉西林他唑巴坦、环丙沙星、左氧氟沙星、美罗培南的耐药性高于T6SS阴性菌株（P < 0.05）。 T6SS 阳性分离株形成的生物膜质量明显多于 T6SS 阴性分离株（平均值 +/- 标准差 [SD]，0.3 +/- 0.09 vs.0.16 +/- 0.06；P < 0.01）。与T6SS阴性分离株相比，T6SS阳性分离株毒力基因（rmpA、fimH、entB、kfu、ybtS）和pLVPK样质粒出现频率较高（P < 0.05）。 结论：综上所述，我国教学医院临床肺炎克雷伯菌VI型分泌系统的患病率较高。 T6SS阳性菌株表现出更高的生物膜形成活性和高耐药性，并表现出更高的毒力潜力。
Objectives: The type VI secretion system (T6SS) in Klebsiella pneumoniae strains isolated from the bloodstream, intestinal, the pyogenic liver abscess has been reported. Here we aimed to characterize T6SS in 248 Klebsiella pneumoniae isolates with all kinds of specimens from a Chinese hospital and to investigate the potential association of T6SS with virulence and drug resistance.Methods: T6SS genes, capsular serotyping genes, drug resistance genes, and virulence genes were identified by polymerase chain reaction (PCR). Antibiotic susceptibilities were examined by the disk diffusion method. To assess biofilm formation of these clinical Klebsiella pneumoniae isolates, 96-well microtiter plate assays were performed. MLST was used to analyze the genotypes of these Klebsiella pneumoniae isolates.Results: The frequency of T6SS genes among the clinical Klebsiella pneumoniae isolates was 72.2%. The T6SSpositive isolates displayed higher resistance to piperacillin-tazobactam, ciprofloxacin, levofloxacin, meropenem than the T6SS-negative isolates (P < 0.05). The T6SS-positive isolates formed significantly more biofilm mass than the T6SS-negative isolates (mean +/- standard deviation [SD], 0.3 +/- 0.09 vs.0.16 +/- 0.06; P < 0.01). Compared to the T6SS-negative isolates, the T6SS-positive isolates had a higher frequency of virulence genes (rmpA, fimH, entB, kfu, ybtS) and the pLVPK-like plasmid (P < 0.05).Conclusion: In conclusion, the prevalence of the type VI secretion system is high in clinical Klebsiella pneumoniae isolates in a Chinese teaching hospital. T6SS-positive strains show higher biofilm-forming activity with high drug resistance and exhibit higher virulence potential.