Genotypic characterization of methicillin-resistant Staphylococcus aureus strains isolated from the anterior nares and catheter of ambulatory hemodialysis patients in Mexico.

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is the causal agent of multiple nosocomial infections worldwide, including catheter-associated bacteremia in hemodialysis patients. The purposes of this work were to genetically characterize a group of MRSA isolates from catheter-related infections of ambulatory Mexican hemodialysis patients and to determine whether the strains are the same as those carried by the patients in their anterior nares. Sixteen pairs of MRSA isolates from the catheter (cat) and anterior nares (N) of hemodialysis patients were compared using pulsed-field gel electrophoresis (PFGE), PCR detection of adhesion genes and other virulence markers, and an antibiogram. Three pairs of N/cat MRSA isolates (18.7 %) with identical resistograms also showed the same combination of PCR-detected markers and PFGE pattern; one additional pair showed only an identical electrophoretic PFGE pattern. Of the MRSA isolates, 75 % (n = 24) were resistant to ≥ 7 antibiotics, 4 isolates were resistant to 11 antibiotics, and 7 isolates were resistant to the 12 antibiotics tested. The most frequent virulence marker combination found was spa, clfA, clfB, cna, bbp, ebps, map/eap, sdrC, sdrD, sdrE, ica, agr (65.6 %, n = 21). The SCCmec alleles of the 32 MRSA isolates were IV (n = 20), I (n = 7), II (n = 4), and V (n = 1), and no SCCmec type III MRSA was found. The genotypic characterization of the MRSA isolates studied in this work will contribute to a better understanding of the virulence gene makeup of catheter-colonizing S. aureus strains and will help to lower the infection risk in these patients.

• Authors: Gloria Paniagua-Contreras, Eric Monroy-Pérez, Raúl Gutiérrez-Lucas, Teresita Sainz-Espuñes, Jaime Bustos-Martínez, Sergio Vaca
• Journal: Folia microbiologica (Folia Microbiol (Praha)) Vol. 59 Issue 4 Pg. 295-302 (Jul 2014) ISSN: 1874-9356 [Electronic] United States
• PMID: 24424465 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Bacterial
• Virulence Factors

Topics

• Adult
• Aged
• Catheters (microbiology)
• Chi-Square Distribution
• DNA, Bacterial (chemistry, genetics)
• Electrophoresis, Gel, Pulsed-Field
• Humans
• Methicillin-Resistant Staphylococcus aureus (genetics, isolation & purification)
• Mexico
• Microbial Sensitivity Tests
• Middle Aged
• Polymerase Chain Reaction
• Renal Dialysis
• Staphylococcal Infections (microbiology)
• Virulence Factors (genetics)