Analysis of genetic heterogeneity of Staphylococcus aureus strains isolated from food and clinical samples from northern Jordan using VNTR, toxin profiles and antibiograms

Abstract

Aims: Staphylococcus aureus is a Gram positive pathogen distributed worldwide and represents a rising problem for both hospitals and community. The aims of the study were to examine the antibiograms, toxin profiles as well as the genetic diversity of a set of S. aureus isolates from clinical and food samples. Methodology and results: To get some insights on the genetic heterogeneity and test for the presence of certain virulence genes, all isolates were subjected to different PCR amplifications and antibiotic sensitivity analysis. The mecA gene was detected in both clinical and food isolates. Resistance to penicillin and amoxicillin was observed in both clinical and food isolates. About 88% of both food and clinical isolates harbored the toxin gene sea, while 70% and 29% of clinical and food isolates respectively, harbored sec. The seb gene was detected in 59% and 18% of clinical and food isolates, respectively. Dendrograms prepared from the VNTR, antibiograms and toxin profiles, revealed 89, 52 and 12 clusters, respectively. Thus, suggesting a very high heterogeneity among the isolates. Conclusion, significance and impact of study: Strains used in this study showed high heterogeneity when examined by VNTR or antibiograms, while appeared less heterogeneous when dendrogram was generated based on toxin profiles. This study highlights the fact that methicillin resistance in S. aureus might be generated within the health institutions or the community. Obtained results also might help health authorities understand the origin of methicillin resistant clones within the study area.