Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Zakir Hossain Road, Khulshi, Chattogram, 4225, Bangladesh.
EcoHealth Alliance, New York, NY, 10001-2320, USA.
Vet Res Commun. 2021 Dec;45(4):277-284. doi: 10.1007/s11259-021-09807-1. Epub 2021 Jun 29.
Salmonella is a globally distributed major food-borne pathogen and poultry is one of the predominant sources of salmonellosis in humans. To investigate the presence of motile Salmonella in the poultry hatchery environment, we collected 97 fluff samples from four selected broiler breeder chicken hatcheries from Chattogram, Bangladesh during July-December 2015. To isolate motile Salmonella enterica, we used conventional bacteriological techniques followed by serological verification using anti-Salmonella Poly A-E serum and species confirmation by conventional PCR assay. Antimicrobial susceptibility testing by Kirby-Bauer disc diffusion method for 10 commonly used antibiotics was performed on all isolates. Isolates displaying phenotypic resistance to ampicillin were tested by PCR for bla gene, whereas those resistant to tetracycline were tested for the presence of tetA, tetB and tetC genes. A total of 24 samples (24.7%; 95% CI: 16.5-34.5, N = 97) from 3 hatcheries were positive for motile Salmonella. Of them, 21 (87.5%) and 12 (50.0%) were resistant to ampicillin and tetracycline, respectively, 9 (37.5%) to nalidixic acid and sulphamethoxazole/trimethoprim. No resistance was detected to ceftriaxone, cefoxitin, gentamicin, neomycin, ciprofloxacin and colistin. Ten (42%) of 24 isolates from 2 hatcheries were multi-drug resistant (i.e. resistant to ≥ 3 antimicrobial classes). Six of 21 ampicillin resistant isolates contained bla gene and 10 of 12 tetracycline resistant isolates contained tetA gene. This study highlights the circulation of multi-drug resistant motile Salmonella in the hatchery environment for the first time in Bangladesh. Further epidemiological and molecular studies are therefore needed to identify the serotypes and source of the bacteria in hatcheries.
沙门氏菌是一种全球分布的主要食源性病原体，家禽是人类沙门氏菌病的主要来源之一。为了调查家禽孵化场环境中运动性沙门氏菌的存在，我们于 2015 年 7 月至 12 月期间从孟加拉国 Chattogram 的 4 个选定的肉鸡种鸡孵化场收集了 97 份绒毛样本。为了分离运动性沙门氏菌，我们使用了传统的细菌学技术，然后使用抗沙门氏菌多 A-E 血清进行血清学验证，并通过常规 PCR 检测进行种确认。对所有分离株进行了 Kirby-Bauer 纸片扩散法的 10 种常用抗生素的药敏试验。对显示对氨苄西林表型耐药的分离株进行 bla 基因 PCR 检测，对显示对四环素耐药的分离株进行 tetA、tetB 和 tetC 基因检测。在 3 个孵化场的 24 个样本（24.7%；95%CI：16.5-34.5，N=97）中检测到运动性沙门氏菌阳性。其中，21 个（87.5%）和 12 个（50.0%）对氨苄西林和四环素耐药，9 个（37.5%）对萘啶酸和磺胺甲恶唑/甲氧苄啶耐药。未检测到对头孢曲松、头孢西丁、庆大霉素、新霉素、环丙沙星和粘菌素的耐药性。来自 2 个孵化场的 24 个分离株中有 10 个（42%）为多药耐药（即对≥3 种抗菌药物类别耐药）。21 个氨苄西林耐药分离株中有 6 个含有 bla 基因，12 个四环素耐药分离株中有 10 个含有 tetA 基因。本研究首次在孟加拉国报告了孵化场环境中运动性多药耐药沙门氏菌的流行情况。因此，需要进一步进行流行病学和分子研究，以确定孵化场中细菌的血清型和来源。
