title: Molecular characterization of TEM-type beta-lactamases identified in cold-seep sediments of Edison Seamount (south of Lihir Island, Papua New Guinea).
abstract: To determine the prevalence and genotypes of beta-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced beta-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five (16.7%) of thirty clones produced an extended-spectrum beta-lactamase. 837- and 259-bp fragments specific to blaTEM genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM-1 was the most prevalent beta-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type beta-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type beta-lactamases of the pre-antibiotic era indicates that TEM-type beta-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.
authors.affiliation: Department of Biological Sciences, Myongji University, San 38-2 Namdong, Yongin, Kyunggido, 449-728, Republic of Korea.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Song
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Jeon
authors.forename: Jung Hun
authors.initials: JH
authors.lastname: Lee
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.forename: Byeong Chul
authors.initials: BC
authors.lastname: Jeong
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Sang Hee
authors.initials: SH
authors.lastname: Lee
mesh_terms: D015723:Gene Library; D005838:Genotype; D019015:Geologic Sediments / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D010219:Papua New Guinea; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001618:beta-Lactamases