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The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
| ArticleTitle |
Antimicrobial susceptibilities and serotypes of Streptococcus pneumoniae isolated from pediatric patients at Chiba Children's Hospital between 2001 and 2020 |
| Language |
J |
| AuthorList |
Yoko Kase1), Taizo Kusano2), Shota Yamamoto2), Mari Sato3), Noriko Takeuchi4), Misako Ohkusu4), Naruhiko Ishiwada4), Tadashi Hoshino2) |
| Affiliation |
1) Division of Clinical Laboratory, Chiba Cerebral and Cardiovascular Center
2) Division of Infectious Diseases, Chiba Children's Hospital
3) Division of Clinical Laboratory, Chiba Children's Hospital
4) Department of Infectious Diseases, Medical Mycology Research Center, Chiba University |
| Publication |
J.J.C.M.: 34 (4), 286-291, 2024 |
| Received |
June 20, 2024 |
| Accepted |
August 13, 2024 |
| Abstract |
We investigated the antimicrobial susceptibilities and serotypes of Streptococcus pneumoniae isolated from pediatric patients at Chiba Children's Hospital between 2001 and 2020. A total of 4,033 strains were isolated, of which 2,632 (65.3%) and 75 (1.9%) were isolated from the lower respiratory tract and sterile sites, respectively. The period covered was divided into period I (2001-2004), II (2005-2008), III (2009-2012), IV (2013-2016), and V (2017-2020), with penicillin G (PCG)-susceptible (MIC: ≤0.06) and -resistant (MIC: ≥2 μ g/mL) strains increasing and decreasing from period I to period V, respectively. The MIC50 of PCG and amoxicillin decreased four-fold. The serotypes were identified for 60 strains isolated from the sterile sites. Seven-valent pneumococcal conjugate vaccine (PCV7)-containing serotypes were not isolated after period IV, and the PCV13-containing serotype was not isolated in period V. The serotypes and frequencies of PCG-resistant strains were 19F (66.7%), 6B (36.4%), 35B (33.3%), and 23F (28.6%). All serotypes except 35B were PCV7-containing serotypes and isolated during period III. Although this was a single-center study, the PCG susceptibility of S. pneumoniae isolated from pediatric patients improved long-term. Based on the serotypes derived from sterile sites, serotype replacement owing to the widespread PCV use was considered to improve PCG susceptibility. |
| Keywords |
Streptococcus pneumoniae, penicillin G |
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