Department of Pediatrics, Division of Pediatric Nephrology, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Pediatr Infect Dis J. 2010 Aug;29(8):736-40. doi: 10.1097/INF.0b013e3181dab249.
Despite recent advances in molecular epidemiology and pathogenecity analyses of extraintestinal Escherichia coli infections, detailed analyses identifying virulence factors of E. coli isolates from pediatric urosepsis patients have not been reported. This study was conducted to explore and differentiate bacterial virulence factors associated with urosepsis and 2 other severe parenchymal infections, acute pyelonephritis (APN) and acute lobar nephronia (ALN), in pediatric patients.
Patients included in this study were those who fulfilled the diagnostic criteria of urosepsis, APN, and ALN, without underlying disease or structural anomalies, excluding those with vesicoureteral reflux. Patients with cystitis were included as controls. E. coli isolates from urine (cystitis, APN, and ALN) or blood (urosepsis) specimens were analyzed using polymerase chain reaction (PCR) for 25 virulence genes.
A total of 147 children (24 cystitis, 45 APN, 48 ALN, and 30 urosepsis) were enrolled in the study. Distinct syndrome-specific differences in the distribution for certain virulence genes, but conservation across syndromes for others, were found. In addition, urosepsis isolates presented higher aggregate virulence factor scores (P < 0.0001) compared with cystitis, APN, and ALN isolates. By contrast, cystitis isolates showed significantly lower aggregate virulence factor scores than all 3 invasive urinary bacterial infections; APN (P < 0.01), ALN (P < 0.01), and urosepsis (P < 0.0001).
Our findings suggested that urosepsis isolates carry more virulence factors and are likely more urovirulent compared with cystitis, APN, and ALN isolates.
尽管近年来在肠外大肠埃希菌感染的分子流行病学和发病机制分析方面取得了进展，但尚未有研究详细分析儿科脓毒症患者分离的大肠埃希菌的毒力因子。本研究旨在探讨和区分与儿科脓毒症及另外两种严重实质感染（急性肾盂肾炎和急性小叶性肾炎）相关的细菌毒力因子。
本研究纳入符合脓毒症、急性肾盂肾炎和急性小叶性肾炎诊断标准且无基础疾病或结构异常（不包括有膀胱输尿管反流者）的患儿。将膀胱炎患儿作为对照。采用聚合酶链反应（PCR）对尿液（膀胱炎、急性肾盂肾炎和急性小叶性肾炎）或血液（脓毒症）标本中的大肠埃希菌分离株进行 25 种毒力基因分析。
共纳入 147 例患儿（膀胱炎 24 例、急性肾盂肾炎 45 例、急性小叶性肾炎 48 例和脓毒症 30 例）。发现某些毒力基因在特定综合征中的分布存在明显的综合征特异性差异，但在不同综合征中存在保守性。此外，脓毒症分离株的总毒力因子评分明显高于膀胱炎、急性肾盂肾炎和急性小叶性肾炎分离株（P<0.0001）。相比之下，膀胱炎分离株的总毒力因子评分明显低于所有 3 种侵袭性泌尿道细菌感染，即急性肾盂肾炎（P<0.01）、急性小叶性肾炎（P<0.01）和脓毒症（P<0.0001）。
本研究结果表明，与膀胱炎、急性肾盂肾炎和急性小叶性肾炎分离株相比，脓毒症分离株携带更多的毒力因子，可能具有更高的尿源性毒力。
