Krawiec Marta, Kuczkowski Maciej, Kruszewicz Andrzej Grzegorz, Wieliczko Alina
Department of Epizootiology and Clinic of Bird and Exotic Animals, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Pl. Grunwaldzki 45, 50-366, Wrocław, Poland.
Warsaw Zoological Garden, ul. Ratuszowa 1/3, 03-461, Warsaw, Poland.
BMC Vet Res. 2015 Jan 31;11:15. doi: 10.1186/s12917-015-0332-x.
Salmonella species are widespread in the environment, and occur in cattle, pigs, and birds, including poultry and free-living birds. In this study, we determined the occurrence of Salmonella in different wild bird species in Poland, focusing on five Salmonella serovars monitored in poultry by the European Union: Salmonella serovars Enteritidis, Typhimurium, Infantis, Virchow, and Hadar. We characterized their phenotypic and genetic variations. Isolates were classified into species and subspecies of the genus Salmonella with a polymerase chain reaction (PCR) assay. The prevalence of selected virulence genes (spvB, spiA, pagC, cdtB, msgA, invA, sipB, prgA, spaN, orgA, tolC, ironN, sitC, ipfC, sifA, sopB, and pefA) among the isolated strains was determined. We categorized all the Salmonella ser. Typhimurium strains with enterobacterial repetitive intergenic consensus (ERIC)-PCR.
Sixty-four Salmonella isolates were collected from 235 cloacal swabs, 699 fecal samples, and 66 tissue samples (6.4% of 1000 samples) taken from 40 different species of wild birds in Poland between September 2011 and August 2013. The largest numbers of isolates were collected from Eurasian siskin and greenfinch: 33.3% positive samples for both. The collected strains belonged to one of three Salmonella subspecies: enterica (81.25%), salamae (17.19%), or houtenae (1.56%). Eighteen strains belonged to Salmonella ser. Typhimurium (28.13%), one to ser. Infantis (1.56%), one to ser. Virchow (1.56%), and one to ser. Hadar (1.56%). All isolates contained spiA, msgA, invA, lpfC, and sifA genes; 94.45% of isolates also contained sitC and sopB genes. None of the Salmonella ser. Typhimurium strains contained the cdtB gene. The one Salmonella ser. Hadar strain contained all the tested genes, except spvB and pefA; the one Salmonella ser. Infantis strain contained all the tested genes, except tspvB, pefA, and cdtB; and the one Salmonella ser. Virchow strain contained all the tested genes, except spvB, pefA, cdtB, and tolC. The Salmonella ser. Typhimurium strains varied across the same host species, but similarity was observed among strains isolated from the same environment (e.g., the same bird feeder or the same lake).
Our results confirm that some wild avian species are reservoirs for Salmonella serotypes, especially Salmonella ser. Typhimurium.
沙门氏菌在环境中广泛存在，可在牛、猪和鸟类（包括家禽和野生鸟类）中出现。在本研究中，我们确定了波兰不同野生鸟类物种中沙门氏菌的存在情况，重点关注欧盟在家禽中监测的五种沙门氏菌血清型：肠炎沙门氏菌、鼠伤寒沙门氏菌、婴儿沙门氏菌、维尔肖沙门氏菌和哈达尔沙门氏菌。我们对其表型和基因变异进行了表征。通过聚合酶链反应（PCR）分析将分离株分类为沙门氏菌属的种和亚种。测定了分离菌株中选定毒力基因（spvB、spiA、pagC、cdtB、msgA、invA、sipB、prgA、spaN、orgA、tolC、ironN、sitC、ipfC、sifA、sopB和pefA）的流行情况。我们用肠杆菌重复基因间共有序列（ERIC）-PCR对所有鼠伤寒沙门氏菌血清型菌株进行了分类。
2011年9月至2013年8月期间，从波兰40种不同野生鸟类采集的235份泄殖腔拭子、699份粪便样本和66份组织样本（1000份样本中的6.4%）中收集到64株沙门氏菌分离株。分离株数量最多的是欧亚金翅雀和绿翅雀：两者的阳性样本均为33.3%。收集的菌株属于三种沙门氏菌亚种之一：肠道亚种（81.25%）、萨拉马亚种（17.19%）或豪滕亚种（1.56%）。18株属于鼠伤寒沙门氏菌血清型（28.13%），1株属于婴儿沙门氏菌血清型（1.56%），1株属于维尔肖沙门氏菌血清型（1.56%），1株属于哈达尔沙门氏菌血清型（1.56%）。所有分离株都含有spiA、msgA、invA、lpfC和sifA基因；94.45%的分离株还含有sitC和sopB基因。所有鼠伤寒沙门氏菌血清型菌株均不含cdtB基因。1株哈达尔沙门氏菌血清型菌株含有除spvB和pefA之外的所有测试基因；1株婴儿沙门氏菌血清型菌株含有除tspvB、pefA和cdtB之外的所有测试基因；1株维尔肖沙门氏菌血清型菌株含有除spvB、pefA、cdtB和tolC之外的所有测试基因。鼠伤寒沙门氏菌血清型菌株在同一宿主物种中存在差异，但在从相同环境（如同一鸟类喂食器或同一湖泊）分离的菌株中观察到相似性。
我们的结果证实，一些野生鸟类物种是沙门氏菌血清型的储存宿主，尤其是鼠伤寒沙门氏菌血清型。
