Methicillin susceptible teicoplanin resistant Staphylococcus haemolyticus from bloodstream infection: Novel mutation in teicoplanin resistant operon (tcaRAB).

Methicillin susceptible teicoplanin resistant Staphylococcus haemolyticus from bloodstream infection: Novel mutation in teicoplanin resistant operon (tcaRAB). Jpn J Infect Dis. 2017 Feb 28;: Authors: Bakthavatchalam YD, David Sudarsanam T, Babu P, Munuswamy E, Muthuirulandi Sethuvel DP, Devanga Ragupathi NK, Veeraraghavan B Abstract Staphylococcus haemolyticus is the frequently isolated coagulase-negative staphylococci (CoNS) from blood culture. Here we port a case of methicillin-susceptible S. haemolyticus resistant to teicoplanin and heteroresistant to vancomycin. The isolate was found to susceptible to cefoxitin and resistant to teicoplanin in E-test. PAP-AUC analysis confirmed the presence of vancomycin heteroresistant subpopulation. NGS analysis of the genome revealed the presence of blaZ, msr(A) codes for cross-resistance of macrolide, lincosamide and streptogramin B and quinolone resistance encoding norA gene. Amino acid substitution was observed in teicoplanin resistant operon tcaRAB genes such as tcaA (I3N, I390N,L450I) and tcaR (L44V, G52V, S87P), transpeptidase encoding walK gene (D336Y, R375L, V404A) and addition of amino acids (L315 and P316) in graS gene. This allow to hypothesis that these combined mutations could attribute for teicoplanin resistance and reduced vancomycin susceptibility. PMID: 28250264 [PubMed - as supplied by publisher]
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research