發(fā)布者：抗性基因網(wǎng) 時(shí)間：2023-06-14 瀏覽量：484
摘要
? ? ? 幼崽中沙門氏菌的存在是將沙門氏菌引入家禽養(yǎng)殖場的唯一最重要的風(fēng)險(xiǎn)因素，耐藥菌株尤其令人擔(dān)憂，因?yàn)樗鼈兛赡軙?huì)影響因食用受污染的家禽產(chǎn)品而感染的人類的治療結(jié)果。這項(xiàng)研究估計(jì)了沙門氏菌的流行率，確定了從尼日利亞孵化的幼崽中回收的菌株的耐藥性，并確定了孵化的菌株和家禽養(yǎng)殖場的菌株之間的遺傳相關(guān)性。在這項(xiàng)研究中，收集了300份糞便樣本。通過培養(yǎng)分離沙門氏菌并通過PCR進(jìn)行確認(rèn)，并通過圓盤擴(kuò)散法檢測分離株對抗菌藥物的敏感性。對菌株進(jìn)行配對末端測序，并使用基因組獲得血清型和抗生素耐藥性基因。使用基于全基因組的系統(tǒng)發(fā)育分析來確定這些分離株與來自同一地理區(qū)域內(nèi)先前表征的年長雞的菌株之間的遺傳相關(guān)性。13種沙門氏菌血清型的患病率為10.7%。對卡那霉素（30/32）、環(huán)丙沙星（22/32）、萘啶酸（22/32。22株（68.8%）分離株表現(xiàn)出多藥耐藥性。計(jì)算機(jī)預(yù)測確定了36個(gè)抗微生物耐藥性基因。4株（12.5%）和22株（68.8%）gyrA和parC出現(xiàn)點(diǎn)突變。常見的獲得性抗性基因包括sul1、sul2、sul3和tet（A）以及各種氨基糖苷類修飾基因。11個(gè)（34.4%）分離株被預(yù)測具有對磷霉素（fosA7，fosB）產(chǎn)生耐藥性的基因。一株S.Stanleyville菌株被預(yù)測具有optrA，這賦予了對呋喃唑酮的抗性。從孵化的小雞身上獲得的肯塔基S.Kentucky、明斯特S.Muenster和門斯頓S.Menston菌株顯示出密切的遺傳相關(guān)性，因?yàn)樗鼈兣c之前從相同來源接收孵化小雞的農(nóng)場從雞身上回收的菌株的SNPs差異小于30。
ABSTRACT
The presence of Salmonella in hatchlings is the single most important risk factor for the introduction of Salmonella into poultry farms, and resistant strains are particularly worrisome, as they could affect treatment outcomes in humans infected through consumption of contaminated poultry products. This study estimated Salmonella prevalence, determined resistance profiles of strains recovered from hatchlings in Nigeria, and determined genetic relatedness between hatchling strains and strains from poultry farms. In this study, 300 fecal samples were collected. Salmonella was isolated by culture and confirmed by PCR, and isolates were tested for susceptibility to antimicrobials by the disk diffusion method. Strains were pair-end sequenced, and genomes were used to obtain serotypes and antibiotic resistance genes. Whole-genome based phylogenetic analysis was used to determine genetic relatedness between these isolates and strains from previously characterized older chicken within the same geographical area. A prevalence of 10.7% was obtained belonging to 13 Salmonella serovars. Resistance to kanamycin (30/32), ciprofloxacin (22/32), nalidixic acid (22/32), and sulfonamides (22/32) were the most commonly observed phenotypic resistances. Twenty-two (68.8%) isolates showed multidrug resistance. In silico predictions identified 36 antimicrobial resistance genes. Four (12.5%) and 22 (68.8%) strains showed point mutations in gyrA and parC. Commonly observed acquired resistance genes included sul1, sul2, sul3, and tet(A) as well as a variety of aminoglycoside-modifying genes. Eleven (34.4%) isolates were predicted to have genes that confer resistance to fosfomycin (fosA7, fosB). A strain of S. Stanleyville was predicted to have optrA, which confers resistance to furazolidone. Strains of S. Kentucky, S. Muenster, and S. Menston obtained from hatchlings showed close genetic relatedness by having less than 30 SNPs difference to strains recovered from chickens at farms previously receiving hatchlings from the same sources.
https://www.sciencedirect.com/science/article/pii/S0032579122007210