Identification of Anaplasma marginale adhesins for entry into Dermacentor andersoni tick cells using phage display.

Anaplasma marginale is an obligate, intracellular, tick-borne bacterial pathogen that causes bovine anaplasmosis, an often severe, production-limiting disease of cattle found worldwide. Methods to control this disease are lacking, in large part due to major knowledge gaps in our understanding of the molecular underpinnings of basic host-pathogen interactions. For example, the surface proteins that serve as adhesins and, thus, likely play a role in pathogen entry into tick cells are largely unknown. To address this knowledge gap, we developed a phage display library and screened 66 A. marginale proteins for their ability to adhere to Dermacentor andersoni tick cells. From this screen, 17 candidate adhesins were identified, including OmpA and multiple members of the Msp1 family, including Msp1b, Mlp3, and Mlp4. We then measured the transcript of ompA and all members of the msp1 gene family through time, and determined that msp1b, mlp2, and mlp4 have increased transcript during tick cell infection, suggesting a possible role in host cell binding or entry. Finally, Msp1a, Msp1b, Mlp3, and OmpA were expressed as recombinant protein. When added to cultured tick cells prior to A. marginale infection, all proteins except the C-terminus of Msp1a reduced A. marginale entry by 2.2- to 4.7-fold. Except OmpA, these adhesins lack orthologs in related pathogens of humans and animals, including Anaplasma phagocytophilum and the Ehrlichia spp., thus limiting their utility in a universal tick transmission-blocking vaccine. However, this work greatly advances efforts toward developing methods to control bovine anaplasmosis and, thus, may help improve global food security.

Molecular epidemiology and genetic evolution of avian influenza H5N1 subtype in Nigeria, 2006 to 2021.

Nigeria recorded one of the earliest outbreaks of the Highly Pathogenic Avian Influenza (HPAI) virus H5N1 in 2006, which spread to other African countries. In 2023, 18 countries reported outbreaks of H5N1 in poultry, with human cases documented in Egypt, Nigeria, and Djibouti. There is limited information on the molecular epidemiology of HPAI H5N1 in Nigeria. We determined the molecular epidemiology and genetic evolution of the virus from 2006 to 2021. We investigated the trend and geographical distribution across Nigeria. The evolutionary history of 61 full-length genomes was performed from 13 countries worldwide, and compared with sequences obtained from the early outbreaks in Nigeria up to 2021. MEGA 11 was used to determine the phylogenetic relationships of H5N1 strains, which revealed close ancestry between sequences in Nigeria and those from other African countries. Clade classification was performed using the subspecies classification tool for Bacterial and Viral Bioinformatics Research Center (BV-BRC) version 3.35.5. H5N1 Clade 2.2 was observed in 2006, with 2.3.2, 2.3.2.1f clades observed afterwards and 2.3.4.4b in 2021. Our findings underscore the need for genomics surveillance to track antigenic variation and clades switching to monitor the epidemiological of the virus and safeguard human and animal health.Impacts Specific variations in the hemagglutinin (HA) and neuraminidase (NA) genes of Avian influenza virus are consistent in different geographical regions. H5N1 Clade 2.2 was reported in 2006, with 2.3.2, 2.3.2.1f afterwards and 2.3.4.4b in 2021. Nigeria is an epicentre for avian influenza with three major migratory routes for wild birds transversing the country. It is plausible that the Avian influenza in Northern Nigeria may be linked to wild bird sanctuaries in the region.

The re-emergence and transmission of Monkeypox virus in Nigeria: the role of one health.

The Monkeypox virus, commonly abbreviated as mpox, is a viral zoonosis that is experiencing a resurgence in prevalence. It is endemic to regions of West and Central Africa that are characterized by dense forested areas. Various measures pertaining to animals, humans, and the environment have been recognized as potential factors and catalysts for the spread of the disease throughout the impacted regions of Africa. This study examines the various factors contributing to the transmission of the virus in Nigeria, with a particular focus on the animal-human and inter-human modes of transmission in rural communities and healthcare facilities. The One Health approach was emphasized as crucial in the prevention and management of this issue. Literature suggests that preventing repeated zoonotic introductions could potentially halt the transmission of the mpox virus from animal to human hosts, leading to a potential decrease in human infections.