Association between genotype screening results obtained by PFGE and PCR for hypervariable regions of the mecA gene inmethicillin-resistant Staphylococcus aureus Asociación entre los criterios de clasificación genotípica de Staphylococcus aureus resistente a meticilina que se obtuvo mediante electroforesis en geles de campos pulsantes y mediante reacción en cadena de la polimerasa de regiones hipervariables del gen mecA

Medina G.; Otth, C; Fernandez, H; Otth, L; Wilson, M; Araya, P; Carlos Hormazabal J.; fernandez, j; Maldonado, A.

Keywords: sensitivity, proteins, isolation, chile, resistance, infections, infection, binding, field, protein, reproducibility, electrophoresis, patient, 2a, chain, specificity, bacterial, human, strain, gel, species, polymerase, genotype, penicillin, article, bacterium, resistant, staphylococcus, cross, methicillin-resistant, aureus, controlled, methicillin, results, study, hospital, of, Reaction, DNA,, Electrophoresis,, and, pulsed, Gel,, Pulsed-Field, Staphylococcal


Introduction: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has become a major epidemiological problem worldwide. Methods: We determined the degree of association between the genotype screening results obtained by pulse-field gel electrophoresis (PFGE) and polymerase chain reaction (PCR) for 7 hypervariable DNA regions associated with the mecA gene (HVR-mecA PCR),in the epidemiological analysis of 36MRSA strains unrelated to nosocomial out breaks, isolated from hospitalized patients at the County Hospital of Valdivia (Chile). Results: The strains were classified into 15pulse types (A-O) and 5genotypes (6,14,15,16,and 17)by PFGE and HVR-mecA PCR, respectively. Most of the strains were grouped in pulse types D, E and I,which presented 85.7% similarity. The most common genotypes were 14 (36.1%) and 15 (33.3%).Each genotype detected by HVR-mecA PCR was distributed in more than one pulse type. The degree of association between genotypic screening by PFGE or HVR-mecA PCR was determined by calculating Cramers Vstatistic and the contingency coefficient.In both cases, avaluenear 1(0.84 and 0.78,respectively) was btained, indicating a high association between these genotypic screenings. Thus these are complementary, note xclusionary techniques that can be equally applied. Conclusions: PFGE is a standardized, high-technology molecular tool with considerable discriminatory power. HVR-mecA PCR is a fast, simple, accessible tool that has lower discriminatory power; nonetheless it can serve as an alternative method for epidemiological research in MRSA strains.

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Volumen: 27
Número: 4
Editorial: Ediciones Doyma S.A.
Fecha de publicación: 2009
Página de inicio: 213
Página final: 218