Multiple-locus variable number of tandem repeat analysis standardization for community isolates methiciline resistant staphylococcus aureus study in Paraguay

Abstract

Staphylococcus aureus is a pathogen that can produce several infections with a wide range of severity and it has the hability to adapt to different tissues. The epidemiology is complex, by circulation of many differents clones worlwide, so the analysis for its identification requires reproducible and high discriminatory powder molecular methods. The aim of this study was to standardize the molecular technique multiple-locus variable number of tandem repeat analysis (MLVA) for the genetic variability analysis of S. aureus isolates, previously characterized by pulsed field gel electrophoresis (PFGE). The MLVA was made by PCR amplification of seven VNTR locus (clfA, clfB, sdrC, sdrD, sdrE, sspA y spA). A high level of reproducibility has reached in the study. The use of isolates previously typified by multi-locus secuencing typing (MLST), PFGE, locus spa and cassette SCCmec, allowed to validate the MLVA clusters comparatively. The isolates that were clustered by MLVA as the same isolate, showed the same results by other molecular techniques, and the MLVA can distinguish isolates with identical PFGE patterns. This technique have all criteria of a usefull molecular typification technique.

Keywords

• Staphylococcus aureus
• epidemiología
• técnicas de tipificación bacteriana
• tipificación molecular