Detection of presumed genes encoding beta-lactamases by sequence based screening of metagenomes derived from Antarctic microbial mats  

作　　者：Gaston Azziz Matias Gimenez Hector Romero Patricia M. Valdespino-Castillo Luisa I. Falcon Lucas A. M. Ruberto Walter P. Mac Cormack Silvia Batista 

机构地区：[1]Molecular Microbiology Unit, Clemente Estable Biological Research Insitute, Montevideo 11600, Uruguay [2]Microbiology Laboratory, Faculty of Agronomy, UdelaR, Montevideo 12900, Uruguay [3]Genome Organization and Evolution Laboratory, Ecology and Evolution Department, Faculty of Sciences, UdelaR, Montevideo 11400, Uruguay [4]Molecular Biophysics and Integrated Bioimaging, BSISB Imaging Program, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA [5]Bacteial Ecology Laboratory, Ecology Institute, National Autonomous University of Mexico, CDMX 04510, Mexico [6]UN AM, Yucatan Technology and Science Park, Merida 97302, Mexico [7]Argentine Antarctic Institute, Buenos Aires 1650, Argentina [8]Biotechnology Unit, Faculty of Pharmacy and Biochemistry, Nanobiotec Institute UBA-CONICET, Buenos Aires 1113, Argentina

出　　处：《Frontiers of Environmental Science & Engineering》2019年第3期173-184,共12页环境科学与工程前沿（英文）

摘　　要：Analysis of environmental samples for bacterial antibiotic resistance genes may have different objectives and analysis strategies. In some cases, the purpose was to study diversity and evolution of genes that could be grouped within a mechanism of antibiotic resistance. Different protocols have been designed for detection and confirmation that a functional gene was found. In this study, we present a sequence-based screening of candidate genes encoding beta-lactamases in 14 metagenomes of Antarctic microbial mats. The samples were obtained from different sites, representing diverse biogeographic regions of maritime and continental Antarctica. A protocol was designed based on generation of Hidden Markov Models from the four beta-lactamase classes by Ambler classification, using sequences from the Comprehensive Antibiotic Resistance Database (CARD). The models were used as queries for metagenome analysis and recovered contigs were subsequently annotated using RAST. According to our analysis, 14 metagenomes analyzed contain A, B and C beta-lactamase genes. Class D genes, however, were identified in 11 metagenomes. The most abundant was class C (46.8%), followed by classes B (35.5%), A (14.2%) and D (3.5%). A considerable number of sequences formed clusters which included, in some cases, contigs from different metagenomes. These assemblies are clearly separated from reference clusters, previously identified using CARD beta-lactamase sequences. While bacterial antibiotic resistance is a major challenge of public health worldwide, our results suggest that environmental diversity of beta-lactamase genes is higher than that currently reported, although this should be complemented with gene function analysis.

关 键 词：BETA-LACTAMASES Antibiotic resistance coding GENES Metagenomes ANTARCTIC MICROBIAL MATS 

分 类 号：T[一般工业技术]