PDF(Pubmed)
Abstract：
UNASSIGNED: Colistin is classified by the World Health Organization (WHO) as a critically important and last-resort antibiotic for the treatment of infections caused by carbapenem-resistant bacteria. However, colistin resistance mediated by chromosomal mutations or plasmid-linked mobilized colistin resistance (mcr) genes has emerged.
UNASSIGNED: Thirteen mcr-positive Aeromonas species isolated from water samples collected in Eastern Ghana were analyzed using whole-genome sequencing (WGS). Antimicrobial susceptibility was tested using the broth microdilution method. Resistome analysis was performed in silico using a web-based platform.
UNASSIGNED: The minimum inhibitory concentration (MIC) of colistin for all except three isolates was >4 µg/mL. Nine new sequence types were identified and whole-genome analysis revealed that the isolates harbored genes (mcr-3-related genes) that code for Lipid A phosphoethanolamine transferases on their chromosomes. BLAST analysis indicated that the amino acid sequences of the mcr-3-related genes detected varied from those previously reported and shared 79.04-99.86% nucleotide sequence identity with publicly available mcr-3 variants and mcr-3-related phosphoethanolamine transferases. Analysis of the genetic context of mcr-3-related genes revealed that the genetic environment surrounding mcr-3-related genes was diverse among the different species of Aeromonas but conserved among isolates of the same species. Mcr-3-related-gene-IS-mcr-3-related-gene segment was identified in three Aeromonas caviae strains.
UNASSIGNED: The presence of mcr-3-related genes close to insertion elements is important for continuous monitoring to better understand how to control the mobilization and dissemination of antibiotic resistance genes.
UNASSIGNED: Thirteen mcr-positive Aeromonas species isolated from water samples collected in Eastern Ghana were analyzed using whole-genome sequencing (WGS). Antimicrobial susceptibility was tested using the broth microdilution method. Resistome analysis was performed in silico using a web-based platform.
UNASSIGNED: The minimum inhibitory concentration (MIC) of colistin for all except three isolates was >4 µg/mL. Nine new sequence types were identified and whole-genome analysis revealed that the isolates harbored genes (mcr-3-related genes) that code for Lipid A phosphoethanolamine transferases on their chromosomes. BLAST analysis indicated that the amino acid sequences of the mcr-3-related genes detected varied from those previously reported and shared 79.04-99.86% nucleotide sequence identity with publicly available mcr-3 variants and mcr-3-related phosphoethanolamine transferases. Analysis of the genetic context of mcr-3-related genes revealed that the genetic environment surrounding mcr-3-related genes was diverse among the different species of Aeromonas but conserved among isolates of the same species. Mcr-3-related-gene-IS-mcr-3-related-gene segment was identified in three Aeromonas caviae strains.
UNASSIGNED: The presence of mcr-3-related genes close to insertion elements is important for continuous monitoring to better understand how to control the mobilization and dissemination of antibiotic resistance genes.
摘要：
粘菌素被世界卫生组织（WHO）列为治疗碳青霉烯类耐药细菌引起的感染的重要和最后手段的抗生素。然而,由染色体突变或质粒连接的动员粘菌素抗性（mcr）基因介导的粘菌素抗性已经出现。
■使用全基因组测序（WGS）分析了从加纳东部收集的水样中分离出的13种mcr阳性气单胞菌物种。使用肉汤微量稀释法测试抗菌药敏感性。使用基于网络的平台在计算机上进行抗性组分析。
■除三种分离株外，粘菌素的最小抑制浓度（MIC）均>4µg/mL。鉴定出9种新的序列类型，全基因组分析表明，这些分离株在其染色体上带有编码脂质A磷酸乙醇胺转移酶的基因（mcr-3相关基因）。BLAST分析表明，检测到的mcr-3相关基因的氨基酸序列与先前报道的序列不同，并且与公开可用的mcr-3变体和mcr-3相关的磷酸乙醇胺转移酶具有79.04-99.86％的核苷酸序列同一性。对mcr-3相关基因的遗传背景的分析表明，围绕mcr-3相关基因的遗传环境在气单胞菌的不同物种之间是多样的，但在同一物种的分离株之间是保守的。在三种鱼气单胞菌菌株中鉴定出Mcr-3相关基因-IS-mcr-3相关基因片段。
■靠近插入元件的mcr-3相关基因的存在对于持续监测以更好地了解如何控制抗生素抗性基因的动员和传播非常重要。
■使用全基因组测序（WGS）分析了从加纳东部收集的水样中分离出的13种mcr阳性气单胞菌物种。使用肉汤微量稀释法测试抗菌药敏感性。使用基于网络的平台在计算机上进行抗性组分析。
■除三种分离株外，粘菌素的最小抑制浓度（MIC）均>4µg/mL。鉴定出9种新的序列类型，全基因组分析表明，这些分离株在其染色体上带有编码脂质A磷酸乙醇胺转移酶的基因（mcr-3相关基因）。BLAST分析表明，检测到的mcr-3相关基因的氨基酸序列与先前报道的序列不同，并且与公开可用的mcr-3变体和mcr-3相关的磷酸乙醇胺转移酶具有79.04-99.86％的核苷酸序列同一性。对mcr-3相关基因的遗传背景的分析表明，围绕mcr-3相关基因的遗传环境在气单胞菌的不同物种之间是多样的，但在同一物种的分离株之间是保守的。在三种鱼气单胞菌菌株中鉴定出Mcr-3相关基因-IS-mcr-3相关基因片段。
■靠近插入元件的mcr-3相关基因的存在对于持续监测以更好地了解如何控制抗生素抗性基因的动员和传播非常重要。
