Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Rome, Italy.
PLoS One. 2011;6(8):e23147. doi: 10.1371/journal.pone.0023147. Epub 2011 Aug 10.
The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S. Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture, in human medicine or in veterinary medicine.
本研究旨在阐明人畜共患病病原体沙门氏菌与厄瓜多尔加拉帕戈斯群岛特有的陆地鬣蜥科动物群体之间的关联。我们评估了沙门氏菌亚种和血清型的存在，并估计了该种群中病原体的流行率。此外，我们利用 XbaI 消化 DNA 的脉冲场凝胶电泳 (PFGE) 研究了分离株和血清型之间的遗传相关性，并确定了对一组抗菌药物的药敏性。该研究通过在 Santa Cruz 岛的自然环境中对动物（n=63）的直肠拭子进行采样来进行。沙门氏菌亚种和血清型存在高度流行（62/63，98.4%），具有异质性，所有这些亚种和血清型都与爬行动物有关，也与人类的爬行动物相关沙门氏菌病有关。血清分型显示，在四个沙门氏菌肠亚种中发现了 14 种不同的血清型：肠沙门氏菌亚种（n=48）、沙门氏菌亚种 salamae（n=2）、沙门氏菌亚种 diarizonae（n=1）和沙门氏菌亚种 houtenae（n=7）。四种血清型占主导地位：S. Poona（n=18）、S. Pomona（n=10）、S. Abaetetuba（n=8）和 S. Newport（n=5）。S. Poona 分离株显示出 9 种独特的 XbaI PFGE 模式，其中 15 种分离株的相似度为 70%。9 种 S. Pomona 分离株的相似度为 84%。观察到一个主要聚类，其中有 7 个（88%）不可区分的 S. Abaetetuba 分离株。所有的沙门氏菌分离株对代表最相关治疗类别的抗菌药物均具有泛敏感性。高流行率和无临床症状表明，不同沙门氏菌血清型与宿主物种之间存在自然相互作用。这种相互作用可能是在鬣蜥和生物群落直接或间接暴露于受农业、人类医学或兽医学中使用抗菌药物影响的环境因素之前建立的。
