Instituto de Acuicultura, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Appl Environ Microbiol. 2009 Dec;75(24):7700-9. doi: 10.1128/AEM.01852-09. Epub 2009 Oct 9.
The occurrence of Salmonella enterica in the environment of tropical and desert regions has remained largely uninvestigated in many areas of the world, including Africa. In the present study, we investigated the presence of Salmonella spp. along 122 km of the coastline of Agadir (southern Morocco) in relation to environmental parameters. A total of 801 samples of seawater (243), marine sediment (279), and mussels (279) were collected from six sites between July 2004 and May 2008. The overall prevalence of Salmonella spp. was 7.1%, with the highest occurrence in mussels (10%), followed by sediment (6.8%) and seawater (4.1%). Only three serotypes were identified among the 57 Salmonella sp. strains isolated. S. enterica serotype Blockley represented 43.8% of all Salmonella strains and was identified in mussel and sediment samples. S. enterica serotype Kentucky (29.8%) was found almost exclusively in mussels, whereas S. enterica serotype Senftenberg (26.3%) was detected in sediment and seawater. Statistical analysis using generalized additive models identified seawater temperature, environmental temperature, rainfall, and solar radiation as significant factors associated with the presence of Salmonella. Rainfall was the only variable showing a linear positive effect on the presence of Salmonella in the sea, whereas the remaining variables showed more complex nonlinear effects. Twenty-eight (49.1%) Salmonella isolates displayed resistance to ampicillin (22 isolates), nalidixic acid (9 isolates), sulfonamide compounds (2 isolates), and tetracycline (1 isolate), with six of these isolates displaying multiple resistance to two of these antimicrobial agents. Pulsed-field gel electrophoresis analysis revealed homogenous restriction patterns within each serotype that were uncorrelated with the resistance pattern profiles.
在世界上许多地区，包括非洲，热带和沙漠地区环境中沙门氏菌的发生情况在很大程度上仍未得到调查。在本研究中，我们调查了摩洛哥南部阿加迪尔（Agadir）沿海 122 公里沿线沙门氏菌属（Salmonella spp.）的存在情况，以及与环境参数的关系。我们于 2004 年 7 月至 2008 年 5 月期间在六个地点采集了 801 份海水（243 份）、海洋沉积物（279 份）和贻贝（279 份）样本。沙门氏菌属的总体流行率为 7.1%，贻贝中的发生率最高（10%），其次是沉积物（6.8%）和海水（4.1%）。在分离的 57 株沙门氏菌中仅鉴定出 3 种血清型。所有沙门氏菌菌株中，43.8%为肠炎沙门氏菌（S. enterica）血清型 Blockley，在贻贝和沉积物样本中均有发现。肠炎沙门氏菌血清型 Kentucky（29.8%）几乎仅在贻贝中发现，而肠炎沙门氏菌血清型 Senftenberg（26.3%）则在沉积物和海水中被检测到。广义加性模型的统计分析确定了海水温度、环境温度、降雨量和太阳辐射是与沙门氏菌存在相关的重要因素。降雨量是唯一对海水中沙门氏菌存在呈线性正影响的变量，而其余变量则表现出更复杂的非线性影响。28 株（49.1%）沙门氏菌分离株对氨苄西林（22 株）、萘啶酸（9 株）、磺胺类化合物（2 株）和四环素（1 株）具有耐药性，其中 6 株分离株对两种抗菌药物表现出多重耐药性。脉冲场凝胶电泳分析显示，每个血清型内的限制图谱均具有同源性，与耐药模式图谱无关。
