Departamento de Microbiología y Ecología, Universitat de València, E-46100 Burjassot, Valencia, Spain.
Microbes Environ. 2012;27(4):367-73. doi: 10.1264/jsme2.me12009. Epub 2012 Apr 3.
Eight Aeromonas hydrophila-like arabinose-negative isolates from diverse sources (i.e., river freshwater, cooling-system water pond, diseased wild European eels, and human stools) sampled in Valencia (Spain) during 2004-2005, were characterized by 16S rRNA gene sequencing and extensive biochemical testing along with reference strains of most Aeromonas species. These isolates and all reference strains of A. hydrophila subsp. dhakensis and A. aquariorum showed a 16S rRNA sequence similarity of 99.8-100%, and they all shared an identical phenotype. This matched exactly with that of A. hydrophila subsp. dhakensis since all strains displayed positive responses to the Voges-Prokauer test and to the use of dl-lactate. This is the first report of A. hydrophila subsp. dhakensis recovered from environmental samples, and further, from its original isolation in India during 1993-1994. This was accurately identified and segregated from other clinical aeromonads (A. hydrophila subsp. hydrophila, A. caviae, A. veronii biovars veronii and sobria, A. trota, A. schubertii and A. jandaei) by using biochemical key tests. The API 20 E profile for all strains included in A. hydrophila subsp. dhakensis was 7047125. The prevalence of this species in Spanish sources was higher for water (9.4%) than for feces (6%) or eels (1.3%). Isolates recovered as pure cultures from diseased eels were moderately virulent (LD(50) of 3.3×10(6) CFU fish(-1)) to challenged eels in experimental trials. They were all resistant to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and imipenem, regardless of its source. Our data point to A. hydrophila subsp. dhakensis as an emerging pathogen for humans and fish in temperate countries.
2004-2005 年期间，在西班牙巴伦西亚从不同来源（即河流淡水、冷却系统水池、患病野生欧洲鳗和人类粪便）采集的 8 株嗜水气单胞菌样阿拉伯糖阴性分离株，通过 16S rRNA 基因测序和广泛的生化试验以及大多数气单胞菌属的参考菌株进行了特征描述。这些分离株和所有参考菌株的嗜水气单胞菌亚种。dhakensis 和嗜水气单胞菌亚种。aquariorum 的 16S rRNA 序列相似性为 99.8-100%，它们都具有相同的表型。这与嗜水气单胞菌亚种完全吻合。dhakensis，因为所有菌株对 Voges-Prokauer 试验和使用 dl-乳酸的反应均呈阳性。这是首次从环境样本中分离出嗜水气单胞菌亚种。dhakensis，并且是从其在印度的原始分离物中分离出来的，时间是 1993-1994 年。通过使用生化关键试验，从其他临床气单胞菌（嗜水气单胞菌亚种。嗜水气单胞菌、豚鼠气单胞菌、维罗纳气单胞菌生物型 veronii 和 sobria、A. trota、A. schubertii 和 A. jandaei）中准确地鉴定和分离出来。所有包含在嗜水气单胞菌亚种中的菌株的 API 20E 图谱。dhakensis 为 7047125。该物种在西班牙水源中的流行率（9.4%）高于粪便（6%）或鳗鱼（1.3%）。从患病鳗鱼中分离出的纯培养物的分离株对实验性挑战鳗鱼具有中等毒力（LD(50)为 3.3×10(6) CFU 鱼(-1))。无论其来源如何，它们都对替卡西林、阿莫西林克拉维酸、头孢西丁和亚胺培南具有耐药性。我们的数据表明，嗜水气单胞菌亚种。dhakensis 是温带国家人类和鱼类的新兴病原体。
