title: Comparative genome analysis of multiple vancomycin-resistant Enterococcus faecium isolated from two fatal cases.
abstract: Enterococcus faecium is both a commensal of the human intestinal tract and an opportunistic pathogen. The increasing incidence of enterococcal infections is mainly due to the ability of this organism to develop resistance to multiple antibiotics, including vancomycin. The aim of this study was to perform comparative genome analyses on four vancomycin-resistant Enterococcus faecium (VREfm) strains isolated from two fatal cases in a tertiary hospital in Malaysia. Two sequence types, ST80 and ST203, were identified which belong to the clinically important clonal complex (CC) 17. This is the first report on the emergence of ST80 strains in Malaysia. Three of the studied strains (VREr5, VREr6, VREr7) were each isolated from different body sites of a single patient (patient Y) and had different PFGE patterns. While VREr6 and VREr7 were phenotypically and genotypically similar, the initial isolate, VREr5, was found to be more similar to VRE2 isolated from another patient (patient X), in terms of the genome contents, sequence types and phylogenomic relationship. Both the clinical records and genome sequence data suggested that patient Y was infected by multiple strains from different clones and the strain that infected patient Y could have derived from the same clone from patient X. These multidrug resistant strains harbored a number of virulence genes such as the epa locus and pilus-associated genes which could enhance their persistence. Apart from that, a homolog of E. faecalis bee locus was identified in VREr5 which might be involved in biofilm formation. Overall, our comparative genomic analyses had provided insight into the genetic relatedness, as well as the virulence potential, of the four clinical strains.
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Shu Yong
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Kien-Pong
authors.initials: KP
authors.lastname: Yap
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Cindy Shuan Ju
authors.initials: CS
authors.lastname: Teh
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Kartini Abdul
authors.initials: KA
authors.lastname: Jabar
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. Electronic address: thongkl@um.edu.my.
authors.forename: Kwai Lin
authors.initials: KL
authors.lastname: Thong
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity*; D017809:Fatal Outcome; D005798:Genes, Bacterial; D056426:Genetic Loci; D016680:Genome, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D008296:Malaysia; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D017211:Treatment Failure; D020713:Vancomycin Resistance / Q000235:genetics; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents
keywords: Comparative genomics; Enterococcus faecium; Multidrug resistant; Phylogenomic; Vancomycin-resistant; Virulence