Waymire Elizabeth, Getachew Dejene, Gunarathna Isuru, Spear Joseph, Lloyd Grace, Follis Madison, Kaye Avery A, Ali Said, Yared Solomon, Carter Tamar E
Department of Biology, Baylor University, Waco, TX, USA.
Department of Applied Biology, Adama Science and Technology University, Adama, Ethiopia.
Parasit Vectors. 2025 Aug 20;18(1):358. doi: 10.1186/s13071-025-06981-y.
Despite a previous decline in malaria in Ethiopia, an outbreak in Dire Dawa in 2022 implicated the invasive vector Anopheles stephensi as responsible. The efficient transmission of Plasmodium by invasive An. stephensi raises questions about the molecular basis of compatibility between parasite and vector, and the origin of the Plasmodium being transmitted. The Plasmodium P47 gene is involved in parasite-vector interactions in the mosquito, and along with the corresponding mosquito P47 receptor (P47Rec), can be critical in the establishment of Plasmodium infections in anophelines.
Herein, we analyzed P47 and P47Rec sequences to determine the origin of Plasmodium detected in An. stephensi during the outbreak and evaluate markers of compatibility. This was completed using polymerase chain reactions and Sanger sequencing.
Of 160 mosquitoes screened, 6.21% of the mosquitoes screened were positive for P. falciparum DNA and 4.37% were positive for P. vivax DNA. Analysis of geographically informative SNPs at positions 707 and 725 in Pfs47 revealed that these P. falciparum strains only exhibit the African haplotype. Minimum spanning network (MSN) analysis revealed connectivity between Pfs47 in Dire Dawa and Pfs47 sequences in Africa, further supporting that these Plasmodium strains are of African origin. We also evaluated the connectivity between Pv47 in this study and African and Asian Pv47 using MSN analysis. Pv47 in both continents displayed shared haplotypes, suggesting little differentiation between the African and Asian strains in P. vivax. Lastly, we identified a single amino acid change in the P47Rec within An. stephensi, which could act as a marker for the propensity of An. stephensi populations to outbreak.
Overall, these results provide evidence of African P. falciparum in invasive An. stephensi and identify P47Rec as a potential marker, which could be applied as a molecular diagnostic for propensity for an outbreak. The relatively high frequencies of Plasmodium parasites observed in An. stephensi may suggest that this mosquito species contributed to the malaria outbreak. Our findings lay the groundwork for further research into the interactions between the invasive mosquito species An. stephensi and African Plasmodium strains, with the goal of predicting future outbreaks.
尽管埃塞俄比亚此前疟疾有所减少，但2022年在德雷达瓦爆发的疫情表明，入侵性媒介斯氏按蚊是罪魁祸首。入侵性斯氏按蚊高效传播疟原虫引发了关于寄生虫与媒介之间相容性的分子基础以及所传播疟原虫起源的问题。疟原虫P47基因参与蚊子体内的寄生虫 - 媒介相互作用，并且与相应的蚊子P47受体（P47Rec）一起，对于在按蚊中建立疟原虫感染可能至关重要。
在此，我们分析了P47和P47Rec序列，以确定在疫情期间斯氏按蚊中检测到的疟原虫的起源，并评估相容性标记。这通过聚合酶链反应和桑格测序完成。
在筛查的160只蚊子中，6.21%的蚊子恶性疟原虫DNA呈阳性，4.37%的蚊子间日疟原虫DNA呈阳性。对Pfs47中第707和725位具有地理信息的单核苷酸多态性（SNP）的分析表明，这些恶性疟原虫菌株仅表现出非洲单倍型。最小生成网络（MSN）分析揭示了德雷达瓦的Pfs47与非洲的Pfs47序列之间的连通性，进一步支持这些疟原虫菌株起源于非洲。我们还使用MSN分析评估了本研究中的Pv47与非洲和亚洲Pv47之间的连通性。两大洲的Pv47显示出共享单倍型，表明间日疟原虫的非洲和亚洲菌株之间差异不大。最后，我们在斯氏按蚊中鉴定出P47Rec中的一个单氨基酸变化，它可以作为斯氏按蚊种群爆发倾向的标记。
总体而言，这些结果为入侵性斯氏按蚊中存在非洲恶性疟原虫提供了证据，并将P47Rec鉴定为一种潜在标记，可作为爆发倾向的分子诊断方法。在斯氏按蚊中观察到的疟原虫寄生虫相对高频率可能表明这种蚊子物种促成了疟疾爆发。我们的发现为进一步研究入侵蚊子物种斯氏按蚊与非洲疟原虫菌株之间的相互作用奠定了基础，目标是预测未来的疫情爆发。
