Dataset Information

Foot-and-mouth disease outbreaks in Egypt during 2013-2014: Molecular characterization of serotypes A, O, and SAT2.

ABSTRACT: Background and Aim:Foot-and-mouth disease virus (FMDV) serotypes A, O and South African Territories (SAT2) are endemic in Egypt; each is presented by a number of partially related topotypes and lineages, depending on their geographical origin. Continuous mutations and the emergence of new topotypes that lead to occasional vaccination failures were frequently recorded, so this study aimed to genetically characterize the circulating FMD virus strains in Egypt during 2013 and 2014 outbreaks, focusing on amino acids variations in VP1 region. Materials and Methods:A total of 51 oral tissue samples were collected from cattle and buffaloes in 13 farms, and 38 individual cases showed clinical signs suspected to be FMD in six Egyptian Governorates (Cairo, Giza, Qaliubia, Fayoum, Sharquia, and Assiut). FMDV in collected samples was characterized by reverse transcription-polymerase chain reaction (RT-PCR) amplification of full VP1 region, sequencing, and phylogenetic analysis. Results:Out of 51 samples, 44 (86.27%) were positive by RT-PCR using universal primers. Serotype O was predominant and detected in 31 samples (70.45%), serotype A was detected in 9 samples (20.45%), and then serotype SAT2 was identified in 4 samples (9.10%). Sequencing and phylogenetic analysis of VP1 demonstrated clustering of serotype O, A, and SAT2 in EA-3 topotype, ASIA topotype, and topotype VII, respectively. Serotype O is closely related to O/SUD/8/2008 with 94.6% identity but showed 14.6% differences from vaccine strain (O/PanAsia-2) of ME-SA topotype. Furthermore, Serotype A and SAT2 were closely related to recent circulating Egyptian isolates and vaccine strains type A/EGY/1/2012 (Asia topotype, lineage Iran-05) with identity 96.4% and vaccine strain of SAT2/EGY/A/2012 (topotype VII, lineage SAT2/VII/ALX-12) with identity 95.3%, respectively. Conclusion:The present study recommended further studies of serotype O to determine the immunogenic relationship between the vaccine strain and the new strains to attain maximum protection against circulating viruses.

SUBMITTER: Diab E

PROVIDER: S-EPMC6460869 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Foot-and-mouth disease outbreaks in Egypt during 2013-2014: Molecular characterization of serotypes A, O, and SAT2.

Diab Emad E Bazid Abdel-Hamid I AI Fawzy Mohamed M El-Ashmawy Wagdy R WR El-Ashmawy Wagdy R WR Fayed Adel A AA El-Sayed Magdy M MM

Veterinary world 20190205 2

<h4>Background and aim</h4>Foot-and-mouth disease virus (FMDV) serotypes A, O and South African Territories (SAT2) are endemic in Egypt; each is presented by a number of partially related topotypes and lineages, depending on their geographical origin. Continuous mutations and the emergence of new topotypes that lead to occasional vaccination failures were frequently recorded, so this study aimed to genetically characterize the circulating FMD virus strains in Egypt during 2013 and 2014 outbreaks ...[more]

PMID: 31040557

Similar Datasets

Project description:African buffalo are the natural reservoirs of the SAT serotypes of foot-and-mouth disease virus (FMDV) in sub-Saharan Africa. Most buffalo are exposed to multiple FMDV serotypes early in life, and a proportion of them become persistently infected carriers. Understanding the genetic diversity and evolution of FMDV in carrier animals is critical to elucidate how FMDV persists in buffalo populations. In this study, we obtained oropharyngeal (OPF) fluid from naturally infected African buffalo, and characterized the genetic diversity of FMDV. Out of 54 FMDV-positive OPF, 5 were co-infected with SAT1 and SAT2 serotypes. From the five co-infected buffalo, we obtained eighty-nine plaque-purified isolates. Isolates obtained directly from OPF and plaque purification were sequenced using next-generation sequencing (NGS). Phylogenetic analyses of the sequences obtained from recombination-free protein-coding regions revealed a discrepancy in the topology of capsid proteins and non-structural proteins. Despite the high divergence in the capsid phylogeny between SAT1 and SAT2 serotypes, viruses from different serotypes that were collected from the same host had a high genetic similarity in non-structural protein-coding regions P2 and P3, suggesting interserotypic recombination. In two of the SAT1 and SAT2 co-infected buffalo identified at the first passage of viral isolation, the plaque-derived SAT2 genomes were distinctly grouped in two different genotypes. These genotypes were not initially detected with the NGS from the first passage (non-purified) virus isolation sample. In one animal with two SAT2 haplotypes, one plaque-derived chimeric sequence was found. These findings demonstrate within-host evolution through recombination and point mutation contributing to broad viral diversity in the wildlife reservoir. These mechanisms may be critical to FMDV persistence at the individual animal and population levels, and may contribute to the emergence of new viruses that have the ability to spill-over to livestock and other wildlife species.

Project description:Foot-and-mouth disease virus (FMDV), particularly strains of the O and SAT serotypes, is notoriously unstable. Consequently, vaccines derived from heat-labile SAT viruses have been linked to the induction of immunity with a poor duration and hence require more frequent vaccinations to ensure protection. In silico calculations predicted residue substitutions that would increase interactions at the interpentamer interface, supporting increased stability. We assessed the stability of the 18 recombinant mutant viruses in regard to their growth kinetics, antigenicity, plaque morphology, genetic stability, and temperature, ionic, and pH stability by using Thermofluor and inactivation assays in order to evaluate potential SAT2 vaccine candidates with improved stability. The most stable mutant for temperature and pH stability was the S2093Y single mutant, while other promising mutants were the E3198A, L2094V, and S2093H single mutants and the F2062Y-H2087M-H3143V triple mutant. Although the S2093Y mutant had the greatest stability, it exhibited smaller plaques, a reduced growth rate, a change in monoclonal antibody footprint, and poor genetic stability properties compared to those of the wild-type virus. However, these factors affecting production can be overcome. The addition of 1 M NaCl was found to further increase the stability of the SAT2 panel of viruses. The S2093Y and S2093H mutants were selected for future use in stabilizing SAT2 vaccines.IMPORTANCE Foot-and-mouth disease virus (FMDV) causes a highly contagious acute vesicular disease in cloven-hoofed livestock and wildlife. The control of the disease by vaccination is essential, especially at livestock-wildlife interfaces. The instability of some serotypes, such as SAT2, affects the quality of vaccines and therefore the duration of immunity. We have shown that we can improve the stability of SAT2 viruses by mutating residues at the capsid interface through predictive modeling. This is an important finding for the potential use of such mutants in improving the stability of SAT2 vaccines in countries where FMD is endemic, which rely heavily on the maintenance of the cold chain, with potential improvement to the duration of immune responses.

Dataset Information

Foot-and-mouth disease outbreaks in Egypt during 2013-2014: Molecular characterization of serotypes A, O, and SAT2.

Publications

Foot-and-mouth disease outbreaks in Egypt during 2013-2014: Molecular characterization of serotypes A, O, and SAT2.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets