Coronaviruses: a review of their properties and diversity

Human coronaviruses, which hitherto were causative agents of mild respiratory diseases of man, have recently become one of the most important groups of pathogens of humans the world over. In less than two decades, three members of the group, severe acute respiratory syndrome (SARS) coronavirus (CoV), Middle East respiratory syndrome (MERS)-CoV, and SARS-COV-2, have emerged causing disease outbreaks that affected millions and claimed the lives of thousands of people. In 2017, another coronavirus, the swine acute diarrhea syndrome (SADS) coronavirus (SADS-CoV) emerged in animals killing over 24,000 piglets in China. Because of the medical and veterinary importance of coronaviruses, we carried out a review of available literature and summarized the current information on their properties and diversity. Coronaviruses are single-stranded RNA viruses with some unique characteristics such as the possession of a very large nucleic acid, high infidelity of the RNA-dependent polymerase, and high rate of mutation and recombination in the genome. They are susceptible to a number of physical agents and several chemical agents used for disinfection procedures in hospitals and laboratories. They exhibit considerable genetic and host diversity, causing diseases of gastrointestinal and respiratory system in a wide range of vertebrate hosts including humans. The high prevalence of coronaviruses in domestic and wild animals, especially bats and birds, and the propensity for their genomes to undergo mutation and recombination may lead to emergence of new coronaviruses that could pose a serious threat to human and animal health. Keywords: coronaviruses; SARS-CoV; MERS-CoV; SARS-Cov-2; properties; diversity; review French Title: Coronavirus: revue de leurs propriétés et de leur diversité Les coronavirus humains, qui étaient jusqu'à présent des agents responsables de maladies respiratoires bénignes de l'homme, sont récemment devenus l'un des groupes les plus importants d'agents pathogènes humains dans le monde entier. En moins de deux décennies, trois membres du groupe, le coronavirus (CoV) du syndrome respiratoire aigu sévère (SRAS), le syndrome respiratoire du Moyen-Orient (MERS)-CoV et le SRAS-COV-2, sont apparus, provoquant des épidémies qui ont touché des millions et des personnes. a coûté la vie à des milliers de personnes. En 2017, un autre coronavirus, le coronavirus du syndrome de la diarrhée aiguë du porc (SADS) (SADS-CoV) est apparu chez des animaux tuant plus de 24000 porcelets en Chine. En raison de l'importance médicale et vétérinaire des coronavirus, nous avons effectué une revue de la littérature disponible et résumé les informations actuelles sur leurs propriétés et leur diversité. Les coronavirus sont des virus à ARN simple brin avec certaines caractéristiques uniques telles que la possession d'un très grand acide nucléique, une infidélité élevée de la polymérase dépendante de l'ARN, et un taux élevé de mutation et de recombinaison dans le génome. Ils sont sensibles à un certain nombre d'agents physiques et à plusieurs agents chimiques utilisés pour les procédures de désinfection dans les hôpitaux et les laboratoires. Ils présentent une diversité génétique et hôte considérable, provoquant des maladies du système gastro-intestinal et respiratoire dans un large éventail d'hôtes vertébrés, y compris les humains. La forte prévalence des coronavirus chez les animaux domestiques et sauvages, en particulier les chauves-souris et les oiseaux, et la propension de leurs génomes à subir des mutations et des recombinaisons peuvent conduire à l'émergence de nouveaux coronavirus qui pourraient constituer une menace sérieuse pour la santé humaine et animale. Mots-clés: coronavirus; SARS-CoV; MERS-CoV; SRAS-CoV-2; Propriétés; la diversité; la revue   &nbsp

Sylvatic Dengue Virus Type 2 Activity in Humans, Nigeria, 1966

Using phylogenetic analysis of complete virus genomes from human isolates obtained in Nigeria in 1966, we identified sylvatic dengue virus (DENV) strains from 3 febrile patients. This finding extends current understanding of the role of sylvatic DENV in febrile disease and documents another focus of sylvatic DENV transmission in West Africa

Transfusion transmissible viral infections among potential blood donors in Ibadan, Nigeria

It is evident that proper screening procedures prior blood transfusion is a cost-effective approach for prevention and control of transfusion-transmissible infections (TTIs). Also, it has been documented that sub-standard test kits are mostly used in resource limited settings for transfusion related diagnosis. However, the role of such practice in epidemiology of transfusion transmissible viral infections in a tertiary health care facility would give an insight to the rates of blood transfusion associated viral transmission in the community at large. Therefore, the study was designed to determine the prevalence of Human Immunodeficiency Virus (HIV), Hepatitis B and Hepatitis C viruses among blood donors in a tertiary hospital where quality diagnostic procedures are considered prior recruitment of donors. Post ethical approval, counselled and consenting 507(M= 426; F=81) aged 19 to 68 years (Median age:39) potential blood donors were recruited and tested for HIV, HBsAg and anti-HCV using commercial ELISA testkit in strict compliance with the manufacturer’sprocedures. Overall results show rates of 2.0%, 5.9% and 1.4% for HIV, HBsAg and HCV respectively. Also, highest prevalence rates were recorded among age group 26 to 35 years as 2.6%, 7.2% and 2.1% for HIV, HBV and HCV respectively. Furthermore, higher prevalences rates were noted among unmarried individuals as 2.6%, 6.8% and 2.1% for HIV, HBV and HCV respectively.Key words: Transfusion Transmissible Infections, HIV, Hepatitis B, Hepatitis C, Blood Donors, University College Hospital (UCH), ELISA

Prevalence of hepatitis B surface antigen, hepatitis C and Human Immunodeficiency Virus antibodies in a population of students of tertiary institution in Nigeria

Objective: Human immunodeficiency virus (HIV), hepatitis B virus, and hepatitis C viruses (HCV) are major causes of mortality and morbidity worldwide. They are also among the commonest transfusiontransmissible infectious agents. Students of higher institutions are often used as voluntary unpaid donors by many hospitals in Nigeria. In this study, the prevalence of HIV and HCV and HBsAg is determined in a population of students attending Ladoke Akintola University of Technology in south west Nigeria, to provide background information on the burden of these infections in this population. Materials and Methods: Serum samples were obtained from students of the Pre-degree Science programme of Ladoke Akintola University of Technology, Ogbomosho and tested for antibodies to HIV, HCV and HBsAg using the ELISA procedure. Results: The prevalence rates of antibodies to HIV and HCV in the student population were 0% and 4.8%, respectively and that of HBsAg was 9.5%. Conclusion: The findings of this study which showed that the prevalence of antibodies to HIV and of HBsAg in this group of students is somewhat similar to those carried out in similar populations. This strongly suggests that the viral burden amongst this population of students is similar and that probably similar factors (demographic) are responsible for maintaining this level of viral load. Further studies would be needed to elucidate the reasons why this is the case. Also it would be necessary to reemphasize the methods of prevention of transmission of these viruses, and to ensure their implementation in order to reduce the viral levels and therefore avoid the long term sequalae.Key words: Transfusion, Infection, Blood Donatio

Zika Virus Outside Africa

This should be considered an emerging pathogen

Effect of plant growth-promoting rhizobacteria and gibberellic acid on salt stress tolerance in tomato genotypes

Salinity stress is a limiting factor that affects attainment of optimal yield of many vegetable crops at various growth stages in many arid and semi-arid parts of sub-Saharan Africa. The objective of this study was to explore salt tolerance of tomato ( Solanum lycopersicum L.) genotypes under the influence of gibberellic acid (GA3) and Bacillus subtilis under screen house conditions. Tomato seeds were pre-soaked with 0, 0.4, 0.5 or 0.6 mM concentrations of GA3 and control in distilled water, respectively; for 12 hr at room temperature. The seeds were germinated in a screen house in 10 kg of soil contained 0, 100, or 200 mM NaCl treatment in polyethene bags. After two weeks of seed germination, the seedlings were inoculated with B. subtilis with the exception of controls. Results revealed that the single or combined treatments of GA3 (at different concentrations) and Bacillus subtilis significantly (P<0.05) increased photosynthetic pigments, and enhanced the concentrations of potassium, calcium, magnesium and phosphorus ions in the salt-stressed tomato. Both tomato genotypes showed low concentrations of sodium ions at all levels of gibberellic acid with Bacillus subtilis. Also, there were significant (P < 0.05) increases in the compatible solutes, antioxidant enzymes activity and antioxidant potential of salt-stressed tomato genotypes, in the combined treatments of GA3 and Bacillus subtilis. Tomato genotypes treated with GA3 and Bacillus subtilis, showed greater salt-tolerance even at high levels of salinity, than single treatment of either GA3 or Bacillus subtilis. Based on these findings, the genotypes are suitable for future breeding programmes to achieve optimal crop yield in saline conditions.Le stress de salinit\ue9 est un facteur limitant qui affecte la r\ue9alisation du rendement optimal de nombreuses cultures potag\ue8res dans de nombreuses r\ue9gions arides et semi-arides de l\u2019Afrique sub-saharienne. L\u2019objectif de cette \ue9tude \ue9tait d\u2019explorer la tol\ue9rance au sel des g\ue9notypes de tomate ( Solanum lycopersicum L.) sous l\u2019influence de l\u2019acide gibb\ue9rellique (GA3) et de Bacillus subtilis . Les graines de tomate ont \ue9t\ue9 pr\ue9alablement tremp\ue9es avec des concentrations de GA3 de 0, 0,4, 0,5 ou 0,6 mM et du contr\uf4le dans de l\u2019eau distill\ue9e, respectivement; pendant 12 heures \ue0 temp\ue9rature ambiante. Les graines ont germ\ue9 dans un abri grillag\ue9 dans 10 kg de sol contenant 0, 100 ou 200 mM de traitement au NaCl dans des sacs en poly\ue9thyl\ue8ne. Apr\ue8s deux semaines de germination des graines, les plants ont \ue9t\ue9 inocul\ue9s avec B. subtilis. Les r\ue9sultats ont r\ue9v\ue9l\ue9 que des traitements uniques ou combin\ue9s de GA3 (\ue0 diff\ue9rentes concentrations) et de Bacillus subtilis (P <0,05) augmentaient consid\ue9rablement les pigments photosynth\ue9tiques et augmentaient les concentrations d\u2019ions potassium, calcium, magn\ue9sium et phosphore dans la tomate stress\ue9e par le sel. Les deux g\ue9notypes de tomates ont montr\ue9 de faibles concentrations d\u2019ions sodium \ue0 tous les niveaux d\u2019acide gibb\ue9rellique avec Bacillus subtilis. En outre, il y a eu des augmentations significatives (P <0,05) des solut\ue9s compatibles, de l\u2019activit\ue9 des enzymes antioxydantes et du potentiel antioxydant des g\ue9notypes de tomates stress\ue9s par le sel, dans les traitements combin\ue9s de GA3 et de Bacillus subtilis. Les g\ue9notypes de tomates trait\ue9s avec GA3 et Bacillus subtilis ont montr\ue9 une plus grande tol\ue9rance au sel m\ueame \ue0 des niveaux \ue9lev\ue9s de salinit\ue9. Sur la base de ces r\ue9sultats, les g\ue9notypes conviennent aux futurs programmes de s\ue9lection pour obtenir un rendement optimal des cultures dans des conditions salines

IMMUNITY TO POLIOVIRUS SEROTYPES IN CHILDREN POPULATION OF SELECTED COMMUNITIES IN SOUTH-WEST, NIGERIA

Background: Poliovirus outbreaks are still reported in Nigeria despite renewed efforts to improve vaccine coverage, thus suggesting the existence of susceptible hosts. Also, there is anecdotal evidence of variation in vaccine coverage by region and specifically between urban and rural communities. Consequently, this study assessed neutralizing antibodies to poliovirus serotypes among children in selected urban and rural communities in south western Nigeria. Methodology: Two hundred and forty-four {(M=119, F=125); Urban: 142 (M=63, F=79); Rural: 102 (M=56, F=46)} children of consenting parent/guardian aged one week to 15 years were enrolled for the study. About 2-3ml of blood was collected from each child by venepuncture into a labelled sterile container free of anticoagulants. Subsequently, questionnaire was administered to the parent/guardian of each child to retrieve relevant information. Recovered sera were analysed for detectable neutralizing antibodies to poliovirus serotypes by the standard method of constant virus, varying serum dilutions. Results: Overall, 64.3% (n=157) of the children had detectable neutralizing antibodies to the three poliovirus serotypes. Also, 84.8% (n=207), 91.0% (n=222) and 75.0% (n=183) of the children had detectable antibodies to poliovirus serotypes 1, 2 and 3 respectively. Eighty seven (35.7%) of the children had no detectable neutralizing antibody to at least one of the three poliovirus serotypes, while 9 (3.7%) children had no detectable neutralizing antibody to the three poliovirus serotypes. Geometric mean titre (GMT) of neutralizing antibodies to the three poliovirus serotypes varied significantly (p=0.0005). Conclusion: Disparity in immunity to poliovirus infection and existence of children with low or zero neutralizing antibody levels were confirmed

Elucidating the path to Plasmodium prolyl-tRNA synthetase inhibitors that overcome halofuginone resistance

© The Author(s) 2022 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.The development of next-generation antimalarials that are efficacious against the human liver and asexual blood stages is recognized as one of the world's most pressing public health challenges. In recent years, aminoacyl-tRNA synthetases, including prolyl-tRNA synthetase, have emerged as attractive targets for malaria chemotherapy. We describe the development of a single-step biochemical assay for Plasmodium and human prolyl-tRNA synthetases that overcomes critical limitations of existing technologies and enables quantitative inhibitor profiling with high sensitivity and flexibility. Supported by this assay platform and co-crystal structures of representative inhibitor-target complexes, we develop a set of high-affinity prolyl-tRNA synthetase inhibitors, including previously elusive aminoacyl-tRNA synthetase triple-site ligands that simultaneously engage all three substrate-binding pockets. Several compounds exhibit potent dual-stage activity against Plasmodium parasites and display good cellular host selectivity. Our data inform the inhibitor requirements to overcome existing resistance mechanisms and establish a path for rational development of prolyl-tRNA synthetase-targeted anti-malarial therapies.This work was supported by NIH R01AI143723 (R.M. and D.F.W.), NIH R01AI152533 (M.R.L. and E.A.W.), 5F31AI129412 (L.F.), and the Bill & Melinda Gates Foundation (OPP1054480, E.A.W. and D.F.W.), LEAN program of the Leducq Foundation (U.O.), Arthritis Research UK 20522 (U.O.), Cancer Research UK A23900 (U.O.). N.C.P. was supported by a National Science Foundation Graduate Research Fellowship (DGE1745303). M.R.L. was supported in part by a Ruth L. Kirschstein Institutional National Research Award from the National Institute for General Medical Sciences (T32 GM008666). This publication includes data generated at the University of California, San Diego IGM Genomics Center utilizing an Illumina NovaSeq 6000 that was purchased with funding from a National Institutes of Health SIG grant (#S10 OD026929).info:eu-repo/semantics/publishedVersio