Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
PLoS One. 2012;7(2):e30070. doi: 10.1371/journal.pone.0030070. Epub 2012 Feb 15.
Species of the genus Aeromonas are native inhabitants of aquatic environments and have recently been considered emerging human pathogens. Although the gastrointestinal tract is by far the most common anatomic site from which aeromonads are recovered, their role as etiologic agents of bacterial diarrhea is still disputed. Aeromonas-associated diarrhea is a phenomenon occurring worldwide; however, the exact prevalence of Aeromonas infections on a global scale is unknown.
METHODOLOGY/PRINCIPAL FINDINGS: The prevalence and virulence potential of Aeromonas in patients suffering from diarrhea in Israel was studied using molecular methods. 1,033 diarrheal stools were sampled between April and September 2010 and Aeromonas species were identified in 17 (∼2%) patients by sequencing the rpoD gene. Aeromonas species identity and abundance was: A. caviae (65%), A. veronii (29%) and Aeromonas taiwanensis (6%). This is the first clinical record of A. taiwanensis as a diarrheal causative since its recent discovery from a wound infection in a patient in Taiwan. Most of the patients (77%) from which Aeromonas species were isolated were negative for any other pathogens. The patients ranged from 1 to 92 years in age. Aeromonas isolates were found to possess different virulence-associated genes: ahpB (88%), pla/lip/lipH3/apl-1 (71%), act/hlyA/aerA (35%), alt (18%), ast (6%), fla (65%), lafA (41%), TTSS ascV (12%), TTSS ascF-ascG (12%), TTSS-dependent ADP-ribosylating toxins aexU (41%) and aexT (6%) in various combinations. Most of the identified strains were resistant to beta-lactam antibiotics but susceptible to third-generation cephalosporin antibiotics.
Aeromonas may be a causative agent of diarrhea in patients in Israel and therefore should be included in routine bacteriological screenings.
气单胞菌属的物种是水生环境的本地居民，最近被认为是新兴的人类病原体。尽管胃肠道是迄今为止最常见的气单胞菌回收的解剖部位，但它们作为细菌性腹泻的病原体的作用仍存在争议。气单胞菌相关腹泻是一种发生在世界各地的现象；然而，全球范围内气单胞菌感染的确切流行率尚不清楚。
方法/主要发现：本研究采用分子方法研究了以色列腹泻患者中气单胞菌的流行率和毒力潜力。2010 年 4 月至 9 月期间采集了 1033 份腹泻粪便样本，通过测序 rpoD 基因在 17 名（约 2%）患者中鉴定出气单胞菌物种。气单胞菌物种的身份和丰度为：A. caviae（65%）、A. veronii（29%）和 Aeromonas taiwanensis（6%）。这是首次记录 A. taiwanensis 作为腹泻病原体的临床病例，因为它是最近从台湾一名伤口感染患者中发现的。从气单胞菌分离株中分离出的大多数患者（77%）均未检测到任何其他病原体。患者年龄在 1 至 92 岁之间。气单胞菌分离株被发现具有不同的毒力相关基因：ahpB（88%）、pla/lip/lipH3/apl-1（71%）、act/hlyA/aerA（35%）、alt（18%）、ast（6%）、fla（65%）、lafA（41%）、TTSS ascV（12%）、TTSS ascF-ascG（12%）、TTSS 依赖性 ADP-ribosylating 毒素 aexU（41%）和 aexT（6%）以不同的组合存在。大多数鉴定出的菌株对β-内酰胺类抗生素耐药，但对第三代头孢菌素类抗生素敏感。
气单胞菌可能是以色列患者腹泻的病原体，因此应纳入常规细菌筛查。
