Genetic and antigenic characterisation of serotype A FMD viruses from East Africa to select new vaccine strains

Vaccine strain selection for emerging foot-and-mouth disease virus (FMDV) outbreaks in enzootic countries can be addressed through antigenic and genetic characterisation of recently circulating viruses. A total of 56 serotype A FMDVs isolated between 1998 and 2012, from Central, East and North African countries were characterised antigenically by virus neutralisation test using antisera to three existing and four candidate vaccine strains and, genetically by characterising the full capsid sequence data. A Bayesian analysis of the capsid sequence data revealed the viruses to be of either African or Asian topotypes with subdivision of the African topotype viruses into four genotypes (Genotypes I, II, IV and VII). The existing vaccine strains were found to be least cross-reactive (good matches observed for only 5.4–46.4% of the sampled viruses). Three bovine antisera, raised against A-EA-2007, A-EA-1981 and A-EA-1984 viruses, exhibited broad cross-neutralisation, towards more than 85% of the circulating viruses. Of the three vaccines, A-EA-2007 was the best showing more than 90% in-vitro cross-protection, as well as being the most recent amongst the vaccine strains used in this study. It therefore appears antigenically suitable as a vaccine strain to be used in the region in FMD control programmes

Epidemiology of Avian Ectoparasitic Infestations Diagnosed in Osun State Veterinary Hospitals, Southwest Nigeria

Ectoparasitism is the most devastating parasitic condition of poultry after coccidiosis. This study was conducted to identify the risk factors associated with avian ectoparasitism in Osun State, Nigeria. Data was obtained from avian species presented at the major Veterinary Hospitals in Osun State between January 2006 and December 2015. A total of 4,584 avian species were presented in the period under review. Of the presented birds, 2,665 (58.14%) were young while 1,919 (41.86%) were adults. One thousand nine hundred and ninety four (43.50%) were male and 2,590 (56.50%) were female. More birds (2,868, 62.57%) were presented during the wet season compared to the dry season (1,716, 37.43%). Turkeys 2,088 (45.55%) were the most frequently presented bird type followed by layers 1,476 (32.20%) and local chickens 1,020 (22.25%). A total of 324 (7.07%) avian species was diagnosed for ectoparasitic infestations of which lice infestation was the most prevalent (216, 4.71%) followed by flea infestation (72, 1.57%), tick infestation (24, 0.52%) and mite infestation (12, 0.26%). There was no defined pattern in the yearly and monthly prevalence of ectoparasite infestations. Age, sex, seasons and species were significantly associated (P<0.05) with the prevalence of ectoparasitic infestations. This study showed a low prevalence of ectoparasite infestations among avian species in the study area; however strategic measures should be taken to control these ectoparasites in Osun State, Nigeria, so as to maximize productivity in the poultry sector

Sequencing and Analysis of Lumpy Skin Disease Virus Whole Genomes Reveals a New Viral Subgroup in West and Central Africa

Lumpy skin disease virus (LSDV) is a member of the capripoxvirus (CPPV) genus of the Poxviridae family. LSDV is a rapidly emerging, high-consequence pathogen of cattle, recently spreading from Africa and the Middle East into Europe and Asia. We have sequenced the whole genome of historical LSDV isolates from the Pirbright Institute virus archive, and field isolates from recent disease outbreaks in Sri Lanka, Mongolia, Nigeria and Ethiopia. These genome sequences were compared to published genomes and classified into different subgroups. Two subgroups contained vaccine or vaccine-like samples ("Neethling-like" clade 1.1 and "Kenya-like" subgroup, clade 1.2.2). One subgroup was associated with outbreaks of LSD in the Middle East/Europe (clade 1.2.1) and a previously unreported subgroup originated from cases of LSD in west and central Africa (clade 1.2.3). Isolates were also identified that contained a mix of genes from both wildtype and vaccine samples (vaccine-like recombinants, grouped in clade 2). Whole genome sequencing and analysis of LSDV strains isolated from different regions of Africa, Europe and Asia have provided new knowledge of the drivers of LSDV emergence, and will inform future disease control strategies.</p

Genetic Structure of Modern Durum Wheat Cultivars and Mediterranean Landraces Matches with Their Agronomic Performance

A collection of 172 durum wheat landraces from 21 Mediterranean countries and 20 modern cultivars were phenotyped in 6 environments for 14 traits including phenology, biomass, yield and yield components. The genetic structure of the collection was ascertained with 44 simple sequence repeat markers that identified 448 alleles, 226 of them with a frequency lower than 5%, and 10 alleles per locus on average. In the modern cultivars all the alleles were fixed in 59% of the markers. Total genetic diversity was HT = 0.7080 and the genetic differentiation value was GST = 0.1730. STRUCTURE software allocated 90.1% of the accessions in five subpopulations, one including all modern cultivars, and the four containing landrace related to their geographic origin: eastern Mediterranean, eastern Balkans and Turkey, western Balkans and Egypt, and western Mediterranean. Mean yield of subpopulations ranged from 2.6 t ha-1 for the western Balkan and Egyptian landraces to 4.0 t ha-1 for modern cultivars, with the remaining three subpopulations showing similar values of 3.1 t ha-1. Modern cultivars had the highest number of grains m-2 and harvest index, and the shortest cycle length. The diversity was lowest in modern cultivars (HT = 0.4835) and highest in landraces from the western Balkans and Egypt (HT = 0.6979). Genetic diversity and AMOVA indicated that variability between subpopulations was much lower (17%) than variability within them (83%), though all subpopulations had similar biomass values in all growth stages. A dendrogram based on simple sequence repeat data matched with the clusters obtained by STRUCTURE, improving this classification for some accessions that have a large admixture. landraces included in the subpopulation from the eastern Balkans and Turkey were separated into two branches in the dendrogram drawn with phenotypic data, suggesting a different origin for the landraces collected in Serbia and Macedonia. The current study shows a reliable relationship between genetic and phenotypic population structures, and the connection of both with the geographic origin of the landraces.The research was funded by the Ministerio de Economía y competitividad project AGL-2006-09226-C02-01, and Dr. Jose Miguel Soriano is funded by Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (http://www.mineco.gob.es/)

Geographic distribution of MERS coronavirus among dromedary camels, Africa

We found serologic evidence for the circulation of Middle East respiratory syndrome coronavirus among dromedary camels in Nigeria, Tunisia, and Ethiopia. Circulation of the virus among dromedaries across broad areas of Africa may indicate that this disease is currently underdiagnosed in humans outside the Arabian Peninsula

The RNA Polymerase II Elongation Factor ELL: Mechanism of Action and its Cross Regulation by Leukemogenic Oncoproteins

Transcription by RNA polymerase II (pol II) is a complex multistep process that encompasses pre-initiation complex (PIC) assembly, initiation, elongation and termination. The eleven-nineteen lysine-rich leukemia protein (ELL) is a pol II elongation factor that was initially discovered as a chromosomal translocation partner of the histone methyltransferase mixed lineage leukemia protein (MLL) in acute leukemia patients. Although biochemical and morphological studies in yeast and Drosophila have demonstrated significant insights into the role of ELL in transcription, the mechanisms underlying ELL function in mammalian systems and how its translocation with MLL leads to the progression of leukemia remain unclear. By applying combinations of gene depletion, subcellular localization, immunopurification and genome location analyses this study revealed that ELL bridges dynamic interactions that define two distinct rate-limiting steps in transcription. The first is early targeting and stabilization of the PIC containing pol II and the histone acetyltransferase p300. The second is stabilization and recruitment of additional transcription elongation factors including the positive transcription elongation factor b (P-TEFb), the AF4/FMR2 family member 4 protein (AFF4) and the pol II associated factor 1 (PAF1) to facilitate processive elongation and mRNA maturation. Furthermore, this study investigated the effects of MLL-ELL fusion and the human T cell lymphotropic/leukemia virus type I (HTLV-1) Tax oncoproteins on the assembly of cellular transcription complexes containing ELL. The results indicated that ELL is a "shared" or common transcriptional target of both MLL-ELL fusion and HTLV-1 Tax proteins. Enforced expression of either MLL-ELL fusion or Tax oncoprotein led to differential targeting of PIC containing ELL and p300 or elongation complex comprised of ELL in association with P-TEFb and AFF4 that culminate with activation of specific genes that promote proliferation. These finding suggest that due to its critical role in bridging dynamic interactions within the RNA pol II transcription cycle, ELL may represent a common point of vulnerability in multiple disease processes that is useful as a potential interface to exploit through therapeutic interventions