Volume 30, Number 1—January 2024
Research
Molecular Evolution and Increasing Macrolide Resistance of Bordetella pertussis, Shanghai, China, 2016–2022
Figure 3

Figure 3. Changing macrolide resistance of circulating Bordetella pertussis strains, Shanghai, China, 2016–2022. A) ptxP3-strains showed very high resistance to macrolides after 2020. Resistance to macrolides was different in non-MT28 (0%) and MT28 (100%) isolates. B) Percentages of macrolide-sensitive BP, ptxP1-MRBP, and ptxP3-MRBP before and after 2020 show that ptxP1-MRBP strain was prevalent before 2020 but predominately ptxP3-MRBP spread after 2020. MRBP, macrolide-resistant Bordetella pertussis; MT, multilocus variable-number tandem-repeat analysis type.
1These first authors contributed equally to this article.