title: Implementation of a novel in vitro model of infection of reconstituted human epithelium for expression of virulence genes in methicillin-resistant Staphylococcus aureus strains isolated from catheter-related infections in Mexico.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) are clinically relevant pathogens that cause severe catheter-related nosocomial infections driven by several virulence factors.
  
  
  METHODS
  We implemented a novel model of infection in vitro of reconstituted human epithelium (RHE) to analyze the expression patterns of virulence genes in 21 MRSA strains isolated from catheter-related infections in Mexican patients undergoing haemodialysis. We also determined the phenotypic and genotypic co-occurrence of antibiotic- and disinfectant-resistance traits in the S. aureus strains, which were also analysed by pulsed-field-gel electrophoresis (PFGE).
  
  
  RESULTS
  In this study, MRSA strains isolated from haemodialysis catheter-related infections expressed virulence markers that mediate adhesion to, and invasion of, RHE. The most frequent pattern of expression (present in 47.6% of the strains) was as follows: fnbA, fnbB, spa, clfA, clfB, cna, bbp, ebps, eap, sdrC, sdrD, sdrE, efb, icaA, and agr. Seventy-one percent of the strains harboured the antibiotic- and disinfectant-resistance genes ermA, ermB, tet(M), tet(K), blaZ, qacA, qacB, and qacC. PFGE of the isolated MRSA revealed three identical strains and two pairs of identical strains. The strains with identical PFGE patterns showed the same phenotypes and genotypes, including the same spa type (t895), suggesting hospital personnel manipulating the haemodialysis equipment could be the source of catheter contamination.
  
  
  CONCLUSIONS
  These findings help define the prevalence of MRSA virulence factors in catheter-related infections. Some of the products of the expressed genes that we detected in this work may serve as potential antigens for inclusion in a vaccine for the prevention of MRSA-catheter-related infections.
authors.forename: Gloria Luz
authors.initials: GL
authors.lastname: Paniagua-Contreras
authors.forename: Eric
authors.initials: E
authors.lastname: Monroy-Pérez
authors.forename: Felipe
authors.initials: F
authors.lastname: Vaca-Paniagua
authors.forename: José Raymundo
authors.initials: JR
authors.lastname: Rodríguez-Moctezuma
authors.forename: Erasmo
authors.initials: E
authors.lastname: Negrete-Abascal
authors.affiliation: FES-Iztacala, Universidad Nacional Autónoma de México, Av, de Los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Edo, de México, México. vacasergio@gmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: Vaca
mesh_terms: D055499:Catheter-Related Infections / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004848:Epithelium / Q000382:microbiology*; D015870:Gene Expression; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification; D008800:Mexico; D008962:Models, Theoretical; D058889:Molecular Typing; D009924:Organ Culture Techniques; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D037521:Virulence Factors