Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy.
Foodborne Pathog Dis. 2011 Sep;8(9):997-1003. doi: 10.1089/fpd.2010.0833. Epub 2011 May 11.
Salmonella enterica serovar Napoli is an emerging serovar in Italy, France, and Switzerland, but little is known about its pathogenicity to humans. A collection of 112 strains of Salmonella Napoli isolated in Italy from human cases, foods of animal origin, and the environment have been characterized by the detection of a set of virulence genes, pulsed-field gel electrophoresis (PFGE), and antibiotic susceptibility. All the strains examined were susceptible to all the antimicrobials tested. The Salmonella pathogenicity islands genes ssaQ, mgtC spi_4D, and sopB were present from 75.0% to 100% of the tested strains. Only one human and four environmental strains showed the avrA gene. The phage-related sopE1 gene was present in 93% of the strains, whereas sodC1 and gipA genes were only in four and two environmental strains, respectively. The bcfC fimbrial gene was present in all the animal/food strains, in the 71.4% of environmental strains, and in 46.8% of the human strains, respectively. Overall, we observed 10 distinct virulence profiles (VP), but VP1-2-3 included 99 out of 112 strains. PFGE showed that 103 out of 111 isolates were grouped in four major clusters and three minor clusters, whereas two strains were totally unrelated. The most represented PFGE clusters mainly correlated with the virulotypes are VP1, VP2, and VP3. Salmonella Napoli shows an array of virulence genes similar to other serovars considered of public health importance and confirming its capability to cause infection in human. Concerning possible source of infection or reservoirs, the results did not point out any, but our hypothesis is that the environment can act as the main reservoir for Salmonella Napoli, and from there it can spill over to animals and humans. Further studies are needed to increase the knowledge on the ecology of Salmonella Napoli serovar and on the main risk factors for human infection.
肠炎沙门氏菌血清型那不勒斯是一种在意大利、法国和瑞士新兴的血清型，但对其人类致病性知之甚少。从人类病例、动物源性食品和环境中分离出的 112 株肠炎沙门氏菌那不勒斯菌株，通过检测一组毒力基因、脉冲场凝胶电泳 (PFGE) 和抗生素敏感性进行了特征描述。所有检测到的菌株对所有测试的抗菌药物均敏感。肠炎沙门氏菌致病性岛基因 ssaQ、mgtC spi_4D 和 sopB 在 100%的测试菌株中存在。仅在 1 个人源和 4 株环境菌株中发现 avrA 基因。噬菌体相关 sopE1 基因存在于 93%的菌株中，而 sodC1 和 gipA 基因仅存在于 4 株和 2 株环境菌株中。bcfC 菌毛基因存在于所有动物/食品菌株中，71.4%的环境菌株中存在，46.8%的人源菌株中存在。总体而言，我们观察到 10 种不同的毒力谱 (VP)，但 VP1-2-3 包括 112 株中的 99 株。PFGE 显示，111 个分离株中有 103 个被分为四个主要聚类和三个小聚类，而两个菌株完全无关。代表最多的 PFGE 聚类主要与毒力型 VP1、VP2 和 VP3 相关。肠炎沙门氏菌那不勒斯显示出一系列与其他被认为对公共卫生重要的血清型相似的毒力基因，证实了其在人类中引起感染的能力。关于可能的感染源或储存库，结果没有指出任何，但我们的假设是，环境可以作为肠炎沙门氏菌那不勒斯的主要储存库，从那里它可以溢出到动物和人类。需要进一步的研究来增加对肠炎沙门氏菌那不勒斯血清型生态学和人类感染主要危险因素的了解。
