Yoshitaka Nakamura1, Tomohiro Oishi2, Kazunari Kaneko3, Tsuyoshi Kenri4, Takaaki Tanaka5, Shoko Wakabayashi6, Mina Kono7, Sahoko Ono8, Atsushi Kato9, Eisuke Kondo10, Yuhei Tanaka11, Hideto Teranishi12, Hiroto Akaike13, Ippei Miyata14, Satoko Ogita15, Naoki Ohno16, Takashi Nakano17, Kazunobu Ouchi18. 1. Department of Pediatrics, Kansai Medical School, Osaka, Japan; Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: ynakamura11@gmail.com. 2. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: oo0612@med.kawasaki-m.ac.jp. 3. Department of Pediatrics, Kansai Medical School, Osaka, Japan. Electronic address: kanekok@hirakata.kmu.ac.jp. 4. Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan. Electronic address: kenri@nih.go.jp. 5. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: takaaki51@hotmail.com. 6. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: putrid-bunny.321@hyper.ocn.ne.jp. 7. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: mi.horiya@med.kawasaki-m.ac.jp. 8. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: m0105023@kwmed.jp. 9. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: katoatsu@med.kawasaki-m.ac.jp. 10. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: ekondo@med.kawasaki-m.ac.jp. 11. Department of Pediatrics, Aso Iizuka Hospital, Fukuoka, Japan. Electronic address: yuhei.tuk.first@gmail.com. 12. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: teranishi_0203@yahoo.co.jp. 13. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: redpond@med.kawasaki-m.ac.jp. 14. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: ippei@med.kawasaki-m.ac.jp. 15. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: ogita@med.kawasaki-m.ac.jp. 16. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: pdnaoki@hotmail.com. 17. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: nakano@med.kawasaki-m.ac.jp. 18. Department of Pediatrics, Kawasaki Medical School, Okayama, Japan. Electronic address: kouchi@med.kawasaki-m.ac.jp.
Abstract
INTRODUCTION: Mycoplasma pneumoniae contributes to numerous pneumonia cases among children and young adults. Therefore, this study aimed to investigate the prevalence of M. pneumoniae infections among Japanese children, occurring since 2008. METHODS: Nasopharyngeal swab specimens were obtained from all cases, following which real-time PCR was performed to identify M. pneumoniae. Further, the p1 genotypes of isolates were determined using the PCR restriction fragment length polymorphism typing method. RESULTS: The annual rate of macrolide-resistant M. pneumoniae (MRMP) infections peaked at 81.8% in 2012 and decreased annually until 2015. Although the infection rate increased to 65.3% in 2016, it decreased again to 14.3% in 2018. Although >90% of isolates harbored the type 1 genotype until 2012, this rate decreased, and approximately 80% harbored p1 genotypes other than type 1 in 2018. Furthermore, the occurrence rate of MRMP among the type 1 isolates was very high (82.4%), whereas that among p1 genotypes other than type 1 was very low (6.5%). CONCLUSIONS: MRMP occurrence potentially decreased owing to changes in not only antibiotic usage but also in the distribution of p1 genotype among isolates.
INTRODUCTION:Mycoplasma pneumoniae contributes to numerous pneumonia cases among children and young adults. Therefore, this study aimed to investigate the prevalence of M. pneumoniae infections among Japanese children, occurring since 2008. METHODS: Nasopharyngeal swab specimens were obtained from all cases, following which real-time PCR was performed to identify M. pneumoniae. Further, the p1 genotypes of isolates were determined using the PCR restriction fragment length polymorphism typing method. RESULTS: The annual rate of macrolide-resistant M. pneumoniae (MRMP) infections peaked at 81.8% in 2012 and decreased annually until 2015. Although the infection rate increased to 65.3% in 2016, it decreased again to 14.3% in 2018. Although >90% of isolates harbored the type 1 genotype until 2012, this rate decreased, and approximately 80% harbored p1 genotypes other than type 1 in 2018. Furthermore, the occurrence rate of MRMP among the type 1 isolates was very high (82.4%), whereas that among p1 genotypes other than type 1 was very low (6.5%). CONCLUSIONS:MRMP occurrence potentially decreased owing to changes in not only antibiotic usage but also in the distribution of p1 genotype among isolates.