Epidemiology Research Today is a free monthly online journal that collates and summarizes the latest research about Epidemiology, including details on twin studies, statistics, environmental and genetic factors.

Rapid and high-throughput genotyping of Staphylococcus epidermidis isolates by automated multilocus variable-number of tandem repeats: A tool for real-time epidemiology.

Francois P, Hochmann A, Huyghe A, Bonetti EJ, Renzi G, Harbarth S, Klingenberg C, Pittet D, Schrenzel J

Genomic Research Laboratory, Service of Infectious Diseases, University of Geneva Hospitals, CH-1211 Geneva 14, Switzerland.

Fast and reliable genotyping methods allowing real-time epidemiology would be instrumental to discriminate Staphylococcus epidermidis isolates, in order to evaluate potential cross-infections or to follow genome content of infecting strains of this important opportunistic pathogen. We describe an automated multilocus variable-number tandem repeat-based assay (MLVA) for the rapid genotyping of S. epidermidis. Multiplex PCR amplifications using 6 primer pairs targeting gene-regions containing variable numbers of tandem repeats and the mecA gene are resolved by micro-capillary electrophoresis and automatically assessed by cluster analysis. This genotyping technique was evaluated for discriminatory power and reproducibility on 2 sequenced strains, on a collection of 21 strains previously characterized using genotyping reference methods and finally on 65 clinical isolates identified in two different institutions. All steps of this new procedure were developed to ensure rapid turn-around time and moderate costs. Our results suggest that this rapid approach is a valuable epidemiological tool to genotype S. epidermidis isolates in real-time. The rapid analysis of a limited number of evolutionary markers showed a power of discrimination similar to that of pulse-field gel electrophoresis (PFGE) or multilocus sequence type (MLST). This type of rapid and high-throughput methodology opens the possibility to rapidly assess long-term nosocomial transmission or to characterize infecting strains in the general procedure of routine laboratories, in real-time.

Published 5 March 2008 in J Microbiol Methods, 72(3): 296-305.
Full-text of this article is available online (may require subscription).

© 2005-2008 Epidemiology Research Today. All Rights Reserved.