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The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
| ArticleTitle |
Molecular epidemiology of Group B Streptococci with reduced penicillin susceptibility in Gunma Prefecture |
| Language |
J |
| AuthorList |
Shinichiro Kumagawa1), Koichi Tanimoto2), Yusuke Hashimoto3), Takahiro Nomura3), Haruyoshi Tomita2,3) |
| Affiliation |
1) Department of Clinical Laboratory, Isesaki Municipal Hospital
2) Laboratory of Bacterial Drug Resistance, Graduate School of Medicine, Gunma University
3) Department of Bacteriology, Graduate School of Medicine, Gunma University |
| Publication |
J.J.C.M.: 33 (3), 180-188, 2023 |
| Received |
August 16, 2022 |
| Accepted |
February 16, 2023 |
| Abstract |
Streptococcus agalactiae with reduced susceptibility to penicillin has emerged in recent years. According to the public information retrieved from the Japan Nosocomial Infections Surveillance (JANIS), published by the Ministry of Health, Labour and Welfare, the penicillin G susceptibility rate of group B streptococci is lower in Gunma than in other prefectures. Therefore, we performed molecular epidemiological analysis of group B streptococci with reduced penicillin susceptibility (PRGBS) in medical institutions in Gunma. Thirty-three PRGBS organisms were isolated between 2014 and 2020. All were found to have acquired the amino acid substitution V405A, Q557E, or both in penicillin-binding protein 2X (PBP2X), which are associated with low susceptibility to penicillin G. In addition, some strains acquired many amino acid substitutions, and one of them had asparagine at 585 position substituted by ricin/serine, which had not been reported previously. The accumulation of amino acid substitutions has increased the resistance of these streptococci to β-lactam antibiotics, and we observed a similar phenomenon in Gunma. We also found that PRGBS isolated in Gunma tended to be multidrug-resistant. Multilocus sequence typing (MLST) analysis revealed that infection with PRGBS of sequence type 458, which was reported to be frequently detected in PRGBS, was not isolated, but infection with PRGBS of sequence type 1665, which is currently reported only in Gunma, had spread instead. These findings indicate that this organism accumulated mutations while it spread within the region, not that particular strains from outside entered and spread through the region. |
| Keywords |
Streptococcus agalactiae, PBP2X, MLST, PFGE |
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