Ives A-K, Antaki E, Stewart K, Francis S, Jay-Russell M T, Sithole F, Kearney M T, Griffin M J, Soto E
Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Basseterre, St. Kitts.
Western Center for Food Safety, University of California, Davis, CA, USA.
Zoonoses Public Health. 2017 Sep;64(6):450-459. doi: 10.1111/zph.12324. Epub 2016 Dec 23.
Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.
沙门氏菌是革兰氏阴性人畜共患病细菌，常作为正常爬行动物胃肠道菌群的一部分。本项目的主要目的是估计圣基茨岛海龟筑巢和觅食群体以及已知筑巢海滩沙子中非伤寒型肠炎沙门氏菌的流行情况。结果表明，与觅食的绿海龟和玳瑁海龟相比，筑巢棱皮龟中沙门氏菌的流行率更高。从9只棱皮龟样本中的2只培养出沙门氏菌，并通过分子诊断方法在9只样本中的3只中鉴定出该菌。在1只玳瑁龟中检测到沙门氏菌DNA，但未从任何玳瑁海龟中分离出活菌。在绿海龟中未检测到沙门氏菌。在从筑巢海滩采集的样本中，仅从一个干沙样本中分离出沙门氏菌。所有分离株的wzx基因均为阳性，与O:7血清群一致。进一步的血清分型鉴定出泄殖腔和沙子样本中存在蒙得维的亚和纽波特血清型。对2014年从海龟和沙子中分离的菌株以及2012年和2013年从棱皮龟中回收的存档沙门氏菌分离株进行重复元件回文PCR（rep-PCR）指纹分析和脉冲场凝胶电泳，分别鉴定出两种不同的基因型和四种不同的脉冲型。基因分型和血清分型直接相关。为了确定每种血清型/基因型的代表性菌株在这些环境中的持久性，在25或35°C下孵育的水和沙子（干沙和湿沙）中进行了实验室控制的微观研究。在大多数微观环境中，分离株至少持续存在32天，尽管在几个微观环境中可培养细菌数量显著减少，在35°C下孵育的干沙中减少最多。这些信息有助于更好地了解自由放养海洋爬行动物中沙门氏菌的流行病学以及加勒比地区人类与这些动物相互作用所带来的潜在公共卫生风险。
