Dynamics of SARS-CoV-2 lineages in French Guiana in 2020-2021: 4 epidemic waves with cross-influences from Europe and South America.

Since the first cases of SARS-CoV-2 infection in Wuhan in December 2019, this RNA virus gave rise to different viral lineages with different virological, epidemiological and immunological properties. Here we describe the dynamics of circulation of SARS-CoV-2 lineages in an Amazonian South American French overseas territory, French Guiana (FG). The data analyzed are based on the general epidemic course, and genomic surveillance data come from whole genome sequencing (WGS) as well as typing PCRs.

Co-option of Plasmodium falciparum PP1 for egress from host erythrocytes.

Asexual proliferation of the Plasmodium parasites that cause malaria follows a developmental program that alternates non-canonical intraerythrocytic replication with dissemination to new host cells. We carried out a functional analysis of the Plasmodium falciparum homolog of Protein Phosphatase 1 (PfPP1), a universally conserved cell cycle factor in eukaryotes, to investigate regulation of parasite proliferation. PfPP1 is indeed required for efficient replication, but is absolutely essential for egress of parasites from host red blood cells.

Shelph2, a bacterial-like phosphatase of the malaria parasite Plasmodium falciparum, is dispensable during asexual blood stage.

During the erythrocytic cycle of the malaria parasite Plasmodium falciparum, egress and invasion are essential steps finely controlled by reversible phosphorylation. In contrast to the growing number of kinases identified as key regulators, phosphatases have been poorly studied, and calcineurin is the only one identified so far to play a role in invasion. PfShelph2, a bacterial-like phosphatase, is a promising candidate to participate in the invasion process, as it was reported to be expressed late during the asexual blood stage and to reside within an apical compartment, yet distinct from rhoptry bulb, micronemes, or dense granules.

Bistacrines as potential antitrypanosomal agents.

Human African Trypanosomiasis (HAT) is caused by two subspecies of the genus Trypanosoma, namely Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense. The disease is fatal if left untreated and therapy is limited due to only five non-adequate drugs currently available. In preliminary studies, dimeric tacrine derivatives were found to inhibit parasite growth with IC-values in the nanomolar concentration range.