Session Type: ePosters
Session Title: ePosters
Authors(s): H. Varadhan, T. Butler, K. Williamson, E. Green
Authors Affiliations(s): NSW Health Pathology, Australia
Background:
Streptococcus pyogenes (S. pyogenes) is a Gram-positive cocci bacteria and is a significant cause of invasive infections. Three-year moving case average suggests invasive Group A Streptococcus (iGAS) cases are increasing in Hunter New England Health District (HNELHD) from average of 32.0 cases/year for 2008-2010 to 57.3 cases/year for 2017-2019. The purpose of this study was to perform epidemiological typing of invasive S. pyogenes isolates by whole genome sequencing (WGS), attempt in-silico emm typing and identify resistance determinants. We sequenced 78 S. pyogenes specimens collected between 2009 and 2021 from patients located within HNELHD, Australia.
Methods:S. pyogenes strains were frozen after isolation and antimicrobial resistance (AMR) testing, which was performed and reported in accordance with European Committee for Antimicrobial susceptibility testing (EUCAST). Isolates sub-cultured on to blood agar were identified using a Bruker-MALDI Biotyper. Genomic DNA was extracted using ZymoBIOMICS DNA Microprep Kits. Illumina DNA Prep kits were used for library preparation and 2×300bp sequencing was performed on an Illumina MiSeq. A bioinformatics pipeline was established using Galaxy. Published databases were used to assess AMR genes.
Results:We hereby present the interim results for 38 S. pyogenes isolates. Analysis of strain relatedness, in-silico emm typing, and AMR results for the remaining 40 isolates, are in progress and will be presented at the conference. Thirty eight isolates were identified as S. pyogenes by MALDI-TOF and WGS. Resistance genes ImrP and mefE were reported in 100% of isolates, however, 95% of isolates exhibited phenotypic susceptibility to macrolides. Two isolates additionally harboured tetM of which one demonstrated phenotypic tetracycline resistance. Another harboured multiple additional resistance genes, with phenotypic resistance to tetracycline and erythromycin.
Conclusions:We report an increasing incidence of iGAS infections in our district. Further results on epidemiological typing and detailed analysis of resistance determinants will follow.
Session Type: ePosters
Session Title: ePosters
Authors(s): H. Varadhan, T. Butler, K. Williamson, E. Green
Authors Affiliations(s): NSW Health Pathology, Australia
Background:
Streptococcus pyogenes (S. pyogenes) is a Gram-positive cocci bacteria and is a significant cause of invasive infections. Three-year moving case average suggests invasive Group A Streptococcus (iGAS) cases are increasing in Hunter New England Health District (HNELHD) from average of 32.0 cases/year for 2008-2010 to 57.3 cases/year for 2017-2019. The purpose of this study was to perform epidemiological typing of invasive S. pyogenes isolates by whole genome sequencing (WGS), attempt in-silico emm typing and identify resistance determinants. We sequenced 78 S. pyogenes specimens collected between 2009 and 2021 from patients located within HNELHD, Australia.
Methods:S. pyogenes strains were frozen after isolation and antimicrobial resistance (AMR) testing, which was performed and reported in accordance with European Committee for Antimicrobial susceptibility testing (EUCAST). Isolates sub-cultured on to blood agar were identified using a Bruker-MALDI Biotyper. Genomic DNA was extracted using ZymoBIOMICS DNA Microprep Kits. Illumina DNA Prep kits were used for library preparation and 2×300bp sequencing was performed on an Illumina MiSeq. A bioinformatics pipeline was established using Galaxy. Published databases were used to assess AMR genes.
Results:We hereby present the interim results for 38 S. pyogenes isolates. Analysis of strain relatedness, in-silico emm typing, and AMR results for the remaining 40 isolates, are in progress and will be presented at the conference. Thirty eight isolates were identified as S. pyogenes by MALDI-TOF and WGS. Resistance genes ImrP and mefE were reported in 100% of isolates, however, 95% of isolates exhibited phenotypic susceptibility to macrolides. Two isolates additionally harboured tetM of which one demonstrated phenotypic tetracycline resistance. Another harboured multiple additional resistance genes, with phenotypic resistance to tetracycline and erythromycin.
Conclusions:We report an increasing incidence of iGAS infections in our district. Further results on epidemiological typing and detailed analysis of resistance determinants will follow.