Providence virus (PrV) is a member of the family Tetraviridae, a family of small, positive-sense, ssRNA viruses that exclusively infect lepidopteran insects. PrV is the only known tetravirus that replicates in tissue culture. We have analysed the genome and characterized the viral translation products, showing that PrV has a monopartite genome encoding three ORFs: (i) p130, unique to PrV and of unknown function; (ii) p104, which contains a read-through stop signal, producing an N-terminal product of 40 kDa (p40) and (iii) the capsid protein precursor (p81). There are three 2A-like processing sequences: one at the N terminus of p130 (PrV-2A 1 ) and two more (PrV-2A 2 and PrV-2A 3 ) at the N terminus of p81. Metabolic radiolabelling identified viral translation products corresponding to all three ORFs in persistently infected cells and showed that the readthrough stop in p104 and PrV-2A 3 in p81 are functional in vivo and these results were confirmed by in vitro translation experiments. The RNA-dependent RNA polymerase domain of the PrV replicase is phylogenetically most closely related to members of the families Tombusviridae and Umbraviridae rather than to members of the family Tetraviridae. The unique genome organization, translational control systems and phylogenetic relationship with the replicases of (+ve) plant viruses lead us to propose that PrV represents a novel family of small insect RNA viruses, distinct from current members of the family Tetraviridae.

Phytopathogenic bacteria are economically important because they affect crop yields and threaten the livelihoods of farmers worldwide. The genus Xanthomonas is particularly significant because it is associated with some plant diseases that cause tremendous loss in yields of globally essential crops. Current management practices are ineffective, unsustainable and harmful to natural ecosystems. Bacteriophage (phage) biocontrol for plant disease management has been of particular interest from the early nineteenth century to date. Xanthomonas phage research for plant disease management continues to demonstrate promising results under laboratory and field conditions. AgriPhage has developed phage products for the control of Xanthomonas campestris pv. vesicatoria and Xanthomonas citri subsp. citri. These are causative agents for tomato, pepper spot and speck disease as well as citrus canker disease.Phage-mediated biocontrol is becoming a viable option because phages occur naturally and are safe for disease control and management. Thorough knowledge of biological characteristics of Xanthomonas phages is vital for developing effective biocontrol products. This review covers Xanthomonas phage research highlighting aspects of their ecology, biology and biocontrol applications.

BackgroundWorldwide, the burden of Sickle Cell disease (SCD) has not been amply addressed. In Africa, Uganda has the 5th highest burden, a situation aggravated by limited and inaccessible formal social support structures to aid patients and families cope better with the psychosocial burden of SCD. In addition, this has been coupled with stigmatization and discrimination of people living with sickle cell disease causing isolation from family and society.MethodThis cross sectional study therefore set out to determine the attitudes, perception and level of awareness towards Sickle Cell disease in Ugandan communities. The study used an interviewer administered questionnaires to collect the data.ResultsOut of 110 people sampled; 91.2% of the respondents had ever heard of SCD with the highest proportion 38.7% hearing of SCD from friends and family. Close to half of the respondents 48% knew that SCD is inherited, however a large proportion 44.2% did not know the cause of SCD. However, 68.7% of the respondents said they cannot marry a person with SCD.ConclusionThe study results indicate that more effort needs to be done to promote sickle cell awareness in Uganda communities with emphasis on the inclusion of sickle cell in health education campaigns.

Providence virus (PrV) is the sole member of the family Carmotetraviridae (formerly Tetraviridae) sharing the characteristic T54 capsid architecture with other tetravirus families. Despite significant structural similarities, PrV differs from other tetraviruses in terms of genome organization, non-structural protein sequence and regulation of gene expression. In addition, it is the only tetravirus that infects tissue culture cells. Previous studies showed that in persistently infected Helicoverpa zea MG8 cells, the PrV replicase associates with detergent-resistant membranes in punctate cytosolic structures, which is similar to the distribution of an alpha-like tetravirus replicase (Helicoverpa armigera stunt virus). Here, we demonstrate that the site of PrV vRNA replication coincides with the presence of PrV p40/p104 proteins in infected cells and that these replication proteins associate with the Golgi apparatus and secretory vesicles in transfected cells.

The problem of antimicrobial resistance has created a new need for alternative/ complementary treatments. To this end, bacteriophages offer an exciting prospect, as they can infect and kill specific bacteria without harming the host. This survey aimed to evaluate the state of applied phage research in Africa, among the members of the Africa phage Forum (APF). This was a cross-sectional survey whereby a google form was created for the members of the Africa Phage forum to fill so as to access the stage of phage research in Africa. Data was collected between June and July 2021 using a structured questionnaire form. A total of 65 out of a total of 101 forum members completed the questionnaire. The survey indicated that a majority 68% of phage researchers in Africa were at the training stages of their career. Some available participants were limited (8%). Most of the members identified funding, lack of skill set, near absence of adequate laboratory infrastructure as major hurdles for phage research. Despite these challenges, 73.3% of APF members work with the ESKAPE group with the majority of its members carrying out research in Phage in Biocontrol (80%), whereas others perform research related to human phage therapy (60%). However, it appeared this research has not yet reached the stage of commercialization. Overall, Phage research is in its infancy in Africa. Key challenges included poor laboratory infrastructure, lack of capacity building in the phage field, and lack of local awareness on the significance of phages for policymakers and governments. APF could, therefore, play a role in creating phage awareness in Africa; mobilizing resources; enhancing networks and collaborations amongst APF members and beyond, especially with more experienced phage mentors in the Western countries, to greatly reduce the gap in knowledge and enhance phage research in Africa.

Providence virus is the only member of the family Carmotetraviridae and carries a positive single stranded RNA genome that encodes three open reading frames. The smallest open reading frame encodes the structural proteins. The largest open reading frame encodes a large putative protein, p130. The second overlapping open reading frame encodes two non-structural proteins; p40, a proposed accessory protein and p104, the replicase, containing the RdRp domain. Till date, p130 and p40 are not associated with any related open reading frames in the databases. The purpose of this study is to identify sequences within these non-structural proteins with potential roles in replication and evolution using computational tools. Our results revealed that p130 has a putative arginine-rich sequence which lies in the disordered region also found in the Umbravirus, Groundnut rosette virus p27. Analysis of the p40 revealed a sequence with a coiled-coil conformation and surface-exposed characteristics comparable to the interaction domain of Tombusvirus, Tomato bushy stunt virus p33 accessory protein. The hypothetical two transmembrane helix topology of PrV p104 oriented the putative localization signal at the N-terminus, the same way the localization signal of Tomato bushy stunt virus p92 is oriented. This study concluded that Providence virus non-structural proteins are structurally related to Tombusvirus and Umbravirus accessory proteins and contain sequences with predicted functions in replication. Findings from this study have led us to propose a co-evolutionary event between an insect and plant virus resulting in a hybrid virus with the potential to infect and replicate in both host plant and animal systems.