發(fā)布者：抗性基因網(wǎng) 時間：2023-06-14 瀏覽量：2140
摘要
出身背景
腸桿菌是一組革蘭氏陰性細菌，經(jīng)常表現(xiàn)出延長的抗微生物耐藥性（AMR），并參與耐藥性基因向同一環(huán)境中存在的其他細菌物種的傳播。由于碳青霉烯類抗生素對人類健康的影響以及新抗生素的缺乏，世界衛(wèi)生組織（WHO）將碳青霉素耐藥和ESBL產(chǎn)生列為關(guān)鍵因素。腸桿菌普遍存在，在一種健康方法下應(yīng)對人類和動物的AMR時，必須檢查環(huán)境在AMR生物體或抗微生物耐藥性基因（ARGs）傳播中的作用。動物糞便被認為是AMR細菌進入環(huán)境的重要來源，耐藥基因可以在環(huán)境中積累。
方法
為了更好地了解第三代頭孢菌素和氟喹諾酮耐藥性基因在環(huán)境中分離株之間的傳播，我們將全基因組測序（WGS）應(yīng)用于從愛爾蘭農(nóng)場廢水中分離的腸桿菌（79株大腸桿菌、1株陰溝腸桿菌、1例肺炎克雷伯菌和1株吉列尼檸檬酸桿菌）?=?72）和之后（n?=?10） 綜合人工濕地（ICW）處理。使用MagNA Pure 96系統(tǒng)（Roche Diagnostics，Rotkreuz，Switzerland）提取DNA，然后在MiSeq平臺（Illumina，Eindhoven，Netherlands）上使用v3化學(xué)作為300循環(huán)配對末端運行進行WGS。鑒定了AMR基因和點突變，并將其與表型結(jié)果進行比較，以更好地了解耐藥性和耐藥性傳播的機制。
后果
在分離株中發(fā)現(xiàn)了多種頭孢菌素和氟喹諾酮耐藥性基因（移動遺傳元件（MGE）和染色體突變），這些基因主要解釋了表型AMR模式。在82個分離株中共鑒定出31種質(zhì)粒復(fù)制子類型，其中一個子集（n?=?24），在大腸桿菌分離株中鑒定。五個質(zhì)粒復(fù)制子局限于陰溝腸桿菌分離株，兩個局限于肺炎克雷伯菌分離株。鑒定了與應(yīng)激、生存、調(diào)節(jié)、鐵攝取分泌系統(tǒng)、侵襲、粘附和毒素產(chǎn)生等功能相關(guān)的毒力基因。
結(jié)論
我們的研究表明，抗微生物微生物（ARO）即使在廢水處理后也可以持續(xù)存在，并可能將臨床相關(guān)的AMR傳播到環(huán)境中，最終對人類或動物健康構(gòu)成風(fēng)險。
Abstract?
Background
The Enterobacterales are a group of Gram-negative bacteria frequently exhibiting extended antimicrobial resistance (AMR) and involved in the transmission of resistance genes to other bacterial species present in the same environment. Due to their impact on human health and the paucity of new antibiotics, the World Health Organization (WHO) categorized carbapenem resistant and ESBL-producing as critical. Enterobacterales are ubiquitous and the role of the environment in the transmission of AMR organisms or antimicrobial resistance genes (ARGs) must be examined in tackling AMR in both humans and animals under the one health approach. Animal manure is recognized as an important source of AMR bacteria entering the environment, in which resistant genes can accumulate.
Methods
To gain a better understanding of the dissemination of third generation cephalosporin and fluoroquinolone resistance genes between isolates in the environment, we applied whole genome sequencing (WGS) to Enterobacterales (79 E. coli, 1 Enterobacter cloacae, 1 Klebsiella pneumoniae, and 1 Citrobacter gillenii) isolated from farm effluents in Ireland before (n?=?72) and after (n?=?10) treatment by integrated constructed wetlands (ICWs). DNA was extracted using the MagNA Pure 96 system (Roche Diagnostics, Rotkreuz, Switzerland) followed by WGS on a MiSeq platform (Illumina, Eindhoven, Netherlands) using v3 chemistry as 300-cycle paired-end runs. AMR genes and point mutations were identified and compared to the phenotypic results for better understanding of the mechanisms of resistance and resistance transmission.
Results
A wide variety of cephalosporin and fluoroquinolone resistance genes (mobile genetic elements (MGEs) and chromosomal mutations) were identified among isolates that mostly explained the phenotypic AMR patterns. A total of 31 plasmid replicon types were identified among the 82 isolates, with a subset of them (n?=?24), identified in E. coli isolates. Five plasmid replicons were confined to the Enterobacter cloacae isolate and two were confined to the Klebsiella pneumoniae isolate. Virulence genes associated with functions including stress, survival, regulation, iron uptake secretion systems, invasion, adherence and toxin production were identified.
Conclusion
Our study showed that antimicrobial resistant organisms (AROs) can persist even following wastewater treatment and could transmit AMR of clinical relevance to the environment and ultimately pose a risk to human or animal health.
https://europepmc.org/article/pmc/pmc10073600