The Gly152Val mutation possibly confers resistance to beta-lactam antibiotics in ovine isolates.

BACKGROUND

The gene is a key factor that allows bacterial cells to resist several antibiotics.

AIM

This study was conducted to detect the gene polymorphism in ovine wounds and its possible association with the structure and function of penicillin binding protein A2 (PBP2A).

METHODS

One genetic locus of 1,967 bp that covered the majority of the coding regions of the gene within methicillin-resistant (MRSA) DNA sequences was designed.

RESULTS

In addition to standard microbiological tests, PCR-sequencing reactions and phylogenetic analyses confirmed the identity of the targeted MRSA bacteria. Seven novel missense SNPs, including N57T, N115Y, D120N, D139N, G152V, E189K, and F211V, were observed in the A amplicons. Multiple state-of-the-art tools were utilized to assess the consequences of each observed SNP in terms of its effect on the corresponding PBP2A protein structure and function. It was shown that some MRSA isolates exhibited a highly PBP2A-damaging SNP, G152V, which showed an entirely deleterious effect on the PBP2A. Furthermore, G152V induced an alteration in the PBP2A interaction with its receptor, which presumably reduced its affinity to bind with the beta-lactams.

CONCLUSION

The present report indicated a possible role for the observed deleterious G152V SNP in the reduction of PBP2A binding with beta-lactams, which has led to a remarkable increase in MRSA's resistance to antibiotics.