上海でのマクロライド耐性百日咳の増加

Molecular Evolution and Increasing Macrolide Resistance of Bordetella pertussis,

Shanghai, China, 2016–2022

EID, 2024

要点

・上海でMT28のA2047G mutation（マクロライド耐性）をもつ百日咳が増加

・2020年以降　幼小児、青少年に報告例がシフト

・2022年に検出した百日咳株の97.2%でマクロライド耐性

要約：

2021-2022にかけて上海で、MT28のA2047G mutation（マクロライド耐性）をもつ百日咳が増加し2016-2022の小児施設例：1065例を調査

Fudan Universityの小児病院2016-2022の診断例1065名（培養、感受性、PCR）を調査

また、692株(65%)を解析： 2016 (11strains), 2017 (177 strains), 2018 (165 strains), 2019 (169 strains), 2020 (1 strain), 2021 (30 strains),   2022 (139 strains).

咳: 20.7日(1-130日)

2020年以前は大部分が1歳未満(84.7%–100%)

→2020年以降は年長児、青少年例(50.3%–56.8%)

2020年：MT27(29.1%–54.5%)→MT28(40.0% :2021, 77.8% :2022)

72.4% (205/283)でマクロライド耐性

＊（MT28 ptxP1/prn1/fhaB3-BP：97.2% で耐性, ptxP3/prn2/fhaB1：91.9%で耐性）、2016年は36.4% で耐性

2022年は 97.2%で耐性

Resurgence and spread of macrolide-resistant Bordetella pertussis (MRBP) threaten global public health. We collected 283 B. pertussis isolates during 2016–2022 in Shanghai, China, and conducted 23S rRNA gene A2047G mutation detection, multilocus variable-number tandem-repeat analysis, and virulence genotyping analysis. We performed whole-genome sequencing on representative strains. We detected pertussis primarily in infants (0–1 years of age) before 2020 and older children (>5–10 years of age) after 2020. The major genotypes were ptxP1/prn1/fhaB3/ptxA1/ptxC1/fim2–1/fim3–1 (48.7%) and ptxP3/prn2/fhaB1/ptxA1/ptxC2/fim2-1/fim3-1 (47.7%). MRBP increased remarkably from 2016 (36.4%) to 2022 (97.2%). All MRBPs before 2020 harbored ptxP1, and 51.4% belonged to multilocus variable-number tandem-repeat analysis type (MT) 195, whereas ptxP3-MRBP increased from 0% before 2020 to 66.7% after 2020, and all belonged to MT28. MT28 ptxP3-MRBP emerged only after 2020 and replaced the resident MT195 ptxP1-MRBP, revealing that 2020 was a watershed in the transformation of MRBP.