Assessment of the Molecular Diversity of Staphylococcus aureus Isolates from Bulk Tank Milk from Dairy Operations of the BiobioRegion, Chile

摘要

Staphylococcus aureus is a major bacterial agent of bovine intramammary infections (IMI) frequently isolated from bulk tank milk (BTM) in countries around the world. Milk from cows with S. aureus subclinically infected quarters usually shed the bacteria to bulk tanks of dairy operations. In Chile, S. aureus has been one of the most prevalent pathogen isolated from milk samples with IMI during the last 50 years (Munoz, 2011). Using molecular methods, a large diversity of S. aureus strains has been identified within dairy herds (Zadoks et. al, 2011). Moreover, adequate use of molecular methods for S. aureus strain typing may discriminate between different but otherwise phenotypically indistinguishable strains. Random Amplified Polymorphic DNA-PCR (RAPD-PCR) has been successfully used to evaluate strain diversity in S. aureus IMI outbreaks with different epidemiology (Gurjar et al., 2012). The estimation of S. aureus strain diversity in milk would be necessary for the choice and assessment of controlstrategies for IMI associated to this pathogen in dairy operations; prior step to the implementation of mastitis control programs. The objective of this study was to evaluate the diversity of S. aureus isolates from bulk tank milk from dairy herds of Biobio Region, Chile.