Decreased susceptibility of Plasmodium falciparum to both dihydroartemisinin and lumefantrine in northern Uganda
Year: 2022
Type: preprint
Abstract: Artemisinin resistance may facilitate selection of Plasmodium falciparum resistant to combination therapy partner drugs. We evaluated 99 P. falciparum isolates collected in 2021 from northern Uganda, where resistance-associated PfK13 C469Y and A675V mutations have emerged, and eastern Uganda, where these mutations are uncommon. With the ex vivo ring survival assay, isolates with the 469Y mutation (median survival 7.3% for mutant, 2.5% mixed, and 1.4% wild type) and/or mutations in Pfcoronin or falcipain-2a, had significantly greater survival; all isolates with survival > 5% had mutations in at least one of these proteins. With ex vivo growth inhibition assays, susceptibility to lumefantrine (IC50 14.6 vs. 6.9 nM, p < 0.0001) and dihydroartemisinin (2.3 vs. 1.5 nM, p = 0.003) was decreased in northern vs. eastern Uganda; 14/49 northern vs. 0/38 eastern isolates had lumefantrine IC50 > 20 nM (p = 0.0002). Targeted sequencing of 819 isolates from 2015-21 identified multiple polymorphisms associated with altered drug susceptibility, notably decreased susceptibility to lumefantrine with PfK13 469Y (p = 6x10− 8) and chloroquine with PfCRT mutations (p = 1x10− 20). Our results raise concern regarding activity of artemether-lumefantrine, the first-line antimalarial in Uganda.
Source: Research Square
Language: English
Topic: Malaria Research and Control
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W4284967706