title: Characterization of novel ybjG and dacC variants in Escherichia coli.
abstract: A total of 69 strains of Escherichia coli from patients in the Taizhou Municipal Hospital, China, were isolated, and 11 strains were identified that were resistant to bacitracin, chloramphenicol, tetracycline and erythromycin. These strains were PCR positive for at least two out of three genes, ybjG, dacC and mdfA, by gene mapping with conventional PCR detection. Conjugation experiments demonstrated that these genes existed in plasmids that conferred resistance. Novel ybjG and dacC variants were isolated from E. coli strains EC2163 and EC2347, which were obtained from the sputum of intensive care unit patients. Genetic mapping showed that the genes were located on 8200 kb plasmid regions flanked by EcoRI restriction sites. Three distinct genetic structures were identified among the 11 PCR-positive strains of E. coli, and two contained the novel ybjG and dacC variants. The putative amino acid differences in the ybjG and dacC gene variants were characterized. These results provide evidence for novel variants of ybjG and dacC, and suggest that multiple drug resistance in hospital strains of E. coli depends on the synergistic function of ybjG, dacC and mdfA within three distinct genetic structures in conjugative plasmids.
authors.affiliation: Department of Clinical Lab Medicine, Taizhou University affiliated Taizhou Municipal Hospital, Taizhou, PR China.
authors.forename: Dongguo
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Urology Surgery, Taizhou University affiliated Taizhou Municipal Hospital, Taizhou, PR China.
authors.forename: Enping
authors.initials: E
authors.lastname: Hu
authors.affiliation: Department of Lab Medicine, Medical College of Taizhou University, Taizhou, PR China.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Urology Surgery, Taizhou University affiliated Taizhou Municipal Hospital, Taizhou, PR China.
authors.forename: Xiulin
authors.initials: X
authors.lastname: Tao
authors.affiliation: Department of Neurosurgery, Stanford University, Palo Alto, CA, USA.
authors.forename: Katelyn
authors.initials: K
authors.lastname: Gutierrez
authors.affiliation: Department of Lab Medicine, Medical College of Taizhou University, Taizhou, PR China.
authors.forename: Yongxiao
authors.initials: Y
authors.lastname: Qi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics*; D006764:Hospitals, Community; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C585154:YbjG protein, E coli; C569172:DacC protein, E coli; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase