Microbiological features and clinical impact of the type VI secretion system (T6SS) in Acinetobacter baumannii isolates causing bacteremia

被引：60

作者：

Kim, Jungok ^{[1
]}

Lee, Ji-Young ^{[2
]}

Lee, Haejeong ^{[2
]}

Choi, Ji Young ^{[2
]}

Kim, Dae Hun ^{[3
]}

Wi, Yu Mi ^{[4
]}

Peck, Kyong Ran ^{[5
]}

Ko, Kwan Soo ^{[2
]}

机构：

[1] Chungnam Natl Univ, Sch Med, Dept Internal Med, Div Infect Dis, Daejeon, South Korea

[2] Sungkyunkwan Univ, Dept Mol Cell Biol, Sch Med, 2066 Seobu Ro, Suwon 16419, South Korea

[3] Sungkyunkwan Univ, Samsung Med Ctr, Div Pulm & Crit Care Med, Sch Med, Seoul, South Korea

[4] Sungkyunkwan Univ, Samsung Changwon Hosp, Sch Med, Div Infect Dis, Chang Won, South Korea

[5] Sungkyunkwan Univ, Samsung Med Ctr, Div Infect Dis, Sch Med, Seoul, South Korea

来源：

VIRULENCE | 2017年 / 8卷 / 07期

基金：

新加坡国家研究基金会;

关键词：

biofilm formation; catheter-related bloodstream infection; hcp; serum resistance; type VI secretion system (T6SS); VIBRIO-CHOLERAE; VIRULENCE; IDENTIFICATION; INFECTIONS; RESISTANCE; MORTALITY; EFFECTORS; COLISTIN; LOCUS; GENE;

D O I：

10.1080/21505594.2017.1323164

中图分类号：

R392 [医学免疫学]; Q939.91 [免疫学];

学科分类号：

100102 ;

摘要：

We investigated the genetic background and microbiological features of T6SS-positive Acinetobacter baumannii isolates and clinical impact of the T6SS in patients with A. baumannii bacteremia. One hundred and 62 A. baumannii isolates from patients with bacteremia in 2 tertiary-care hospitals in Korea were included in this study. Approximately one-third (51/162, 31.5%) of the A. baumannii clinical isolates possessed the hcp gene, and the hcp-positive isolates were found in several genotypes in multilocus sequence typing. The expression and secretion of Hcp protein varied among the clinical isolates. A. baumannii isolates with detectable Hcp secretion (T6SS+) could better outcompete Escherichia coli compared with T6SS- isolates, including hcp-negative and inactivated hcp-positive isolates. In addition, T6SS+ isolates showed higher biofilm-forming activity and better survival in the presence of normal human serum than the T6SS- isolates. T6SS+ isolates were more frequently detected in patients with catheter-related bloodstream infection, haematopoietic stem cell transplant recipients, and patients receiving immunosuppressive agents. However, T6SS was not a prognostic factor for mortality. Our results suggest that the T6SS of A. baumannii is associated with virulence and contributes to infections in immunocompromised patients and those with implanted medical devices.

引用

页码：1378 / 1389

页数：12