Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Department of Laboratory Medicine, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, Nagasaki, 852-8501, Japan.
Sci Rep. 2023 Apr 21;13(1):6571. doi: 10.1038/s41598-023-33265-1.
We investigated the clinical features of bloodstream infections (BSIs) caused by Klebsiella pneumoniae harboring rmpA and molecular characteristics of the bacteria. We retrospectively investigated adult patients with K. pneumoniae BSI from January 2010 to March 2021 at Nagasaki University Hospital. A matched case-control study in a 1:3 ratio was conducted to clarify the clinical and bacterial characteristics of BSI caused by rmpA-positive K. pneumoniae compared with those caused by rmpA-negative isolates. Antimicrobial susceptibility testing and multilocus sequence typing (MLST) were performed for rmpA-positive isolates. The rmpA was detected in 36 (13.4%) of the 268 isolates. Of these 36 isolates, 31 (86.1%) harbored iucA and 35 (97.2%) each possessed peg-344 and iroB; capsular types were identified as K1 in 9 (25.0%) and K2 in 10 isolates (27.8%). Contrarily, of the 108 rmpA-negative isolates, which were matched for case-control studies, 5 isolates (4.6%) harbored iucA and 1 (0.9%) each possessed peg-344 and iroB; 2 (1.9%) and 3 isolates (2.8%) had K1 and K2 capsular types, respectively. Among the rmpA-positive isolates, ST23/K1 (eight isolates) was the most frequent, followed by ST412/non-K1/K2 (seven isolates), ST86/K2 (five isolates), and ST268/non-K1/K2 (four isolates). In a multivariate analysis using clinical factors, liver abscess positively correlated with rmpA-positive isolates, whereas biliary tract infection and use of anticancer drugs negatively correlated with rmpA-positive isolates in patients with K. pneumoniae BSI. Considering the correlation between rmpA-positive isolates and clinical features, rmpA can be used as a marker for understanding the pathophysiology of K. pneumoniae BSI.
我们研究了产 rmpA 肺炎克雷伯菌血流感染（BSI）的临床特征和细菌的分子特征。我们回顾性调查了 2010 年 1 月至 2021 年 3 月在长崎大学医院住院的成人患者的肺炎克雷伯菌 BSI。采用 1:3 比例的病例对照研究，明确 rmpA 阳性肺炎克雷伯菌 BSI 与 rmpA 阴性分离株相比的临床和细菌特征。对 rmpA 阳性分离株进行了药敏试验和多位点序列分型（MLST）。在 268 株分离株中，有 36 株（13.4%）检测到 rmpA。在这 36 株分离株中，31 株（86.1%）携带 iucA，35 株（97.2%）各携带 peg-344 和 iroB；荚膜型鉴定为 K1 的有 9 株（25.0%），K2 有 10 株（27.8%）。相反，在匹配病例对照研究的 108 株 rmpA 阴性分离株中，有 5 株（4.6%）携带 iucA，1 株（0.9%）各携带 peg-344 和 iroB；2 株（1.9%）和 3 株（2.8%）分别为 K1 和 K2 荚膜型。在 rmpA 阳性分离株中，ST23/K1（8 株）最为常见，其次是 ST412/非-K1/K2（7 株）、ST86/K2（5 株）和 ST268/非-K1/K2（4 株）。在多变量分析中，使用临床因素，肝脓肿与 rmpA 阳性分离株呈正相关，而胆道感染和使用抗癌药物与 rmpA 阳性分离株呈负相关。考虑到 rmpA 阳性分离株与临床特征的相关性，rmpA 可作为了解肺炎克雷伯菌 BSI 病理生理学的标志物。
