title: Phenotypic and genotypic characterization of vancomycin-resistant Enterococcus faecium clinical isolates from two hospitals in Mexico: First detection of VanB phenotype-vanA genotype.
abstract: BACKGROUND
  Enterococcus faecium has emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. Our aim was to determine the antimicrobial susceptibility, biofilm production, and clonal relatedness of vancomycin-resistant E. faecium (VREF) clinical isolates from two hospitals in Mexico.
  
  
  METHODS
  Consecutive clinical isolates (n=56) were collected in two tertiary care hospitals in Mexico from 2011 to 2014. VREF isolates were characterized by phenotypic and molecular methods including pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  VREF isolates were highly resistant to vancomycin, erythromycin, norfloxacin, high-level streptomycin, and teicoplanin, and showed lower resistance to tetracycline, nitrofurantoin and quinupristin-dalfopristin. None of the isolates were resistant to linezolid. The vanA gene was detected in all isolates. Two VanB phenotype-vanA genotype isolates, highly resistant to vancomycin and susceptible to teicoplanin, were detected. Furthermore, 17.9% of the isolates were classified as biofilm producers, and the espfm gene was found in 98.2% of the isolates. A total of 37 distinct PFGE patterns and 6 clones (25% of the isolates as clone A, 5.4% as clone B, and 3.6% each as clone C, D, E, and F) were detected. Clone A was detected in 5 different wards of the same hospital during 14 months of surveillance.
  
  
  CONCLUSIONS
  The high resistance to most antimicrobial agents and the moderate cross-transmission of VREF detected accentuates the need for continuous surveillance of E. faecium in the hospital setting. This is also the first reported incidence of the E. faecium VanB phenotype-vanA genotype in the Americas.
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Paola
authors.initials: P
authors.lastname: Bocanegra-Ibarias
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Samantha
authors.initials: S
authors.lastname: Flores-Treviño
authors.affiliation: Servicio de Infectología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Adrián
authors.initials: A
authors.lastname: Camacho-Ortiz
authors.affiliation: Hospital Civil de Guadalajara Fray Antonio Alcalde e Instituto de Patología Infecciosa y Experimental, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors.forename: Rayo
authors.initials: R
authors.lastname: Morfin-Otero
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, Mexico.
authors.forename: Licet
authors.initials: L
authors.lastname: Villarreal-Treviño
authors.affiliation: Departamento de Patología Clínica, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Llaca-Díaz
authors.affiliation: Servicio de Infectología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Erik Alan
authors.initials: EA
authors.lastname: Martínez-Landeros
authors.affiliation: Hospital Civil de Guadalajara Fray Antonio Alcalde e Instituto de Patología Infecciosa y Experimental, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rodríguez-Noriega
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, Mexico.
authors.forename: Andrés
authors.initials: A
authors.lastname: Calzada-Güereca
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors.forename: Héctor Jesús
authors.initials: HJ
authors.lastname: Maldonado-Garza
authors.affiliation: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico; Departamento de Patología Clínica, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico. Electronic address: elvira_garza_gzz@yahoo.com.
authors.forename: Elvira
authors.initials: E
authors.lastname: Garza-González
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development; D003428:Cross Infection / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D005260:Female; D005838:Genotype; D060005:Genotyping Techniques; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D008297:Male; D008800:Mexico; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010641:Phenotype; D013752:Tetracycline / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance / Q000235:genetics*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D013752:Tetracycline
keywords: Clonal diversity; Diversidad clonal; Enterococcus faecium; Fenotipo VanB-genotipo vanA; Mexico; México; Resistencia a vancomicina; VanB phenotype-vanA genotype; Vancomycin resistance