Diagnosis of bovine foot and mouth disease virus by real-time polymerase chain reaction and nucleotide sequencing from outbreak herd samples in Ilesha Baruba, Kwara state, Nigeria

Abstract

Aim: Molecular diagnosis of bovine foot and mouth disease virus (FMDV) from outbreak herd in Bukaru-Rontuwa, Sinawu/ Tumbunya ward of Ilesha Baruba, in Kwara state-Nigeria was conducted to establish the associated serotypes and disease control plan. Materials and Methods:Purposive study was conducted in cattle outbreak herds during the dry season of January-March, 2011. Random sampling of blood and observed epithelial tissues was collected, stored in accordance with standard methods and subjected to RNA extraction and real-time reverse transcription polymerase chain reaction (rRT-PCR). Positive samples for FMDV were further subjected to reverse transcription polymerase chain reaction (RT-PCR), nucleotide sequencing using sequence primers of serotypes O, A, SAT 1-3 and gel electrophoresis. Obtained data were interpreted based on NCBI BLASTN program.Results: Foot and mouth disease (FMD)-RNA extract was not found in all the blood tested with beta-actin range of Ct = 30-34. rRT-PCR assay showed two positive samples with Ct values of 18.79 and 15.28. Gel electrophoresis identified sequenced PCR amplicons as serotype A and SAT 2 respectively. Direct product sequencing confirmed SAT 2 serotype was closely related to SAT 2 isolate LIB/7/2003. Cloned RT-PCR product in pGEM-T easy vector confirmed serotype A as closely related to sequence of A/NIG/21/2009, though multiple NIG/2009 sequences were also identified as closely related. Both isolates showed marked genetic homogeneity with >93% genetic identity in the VP1 region which confirmed heterogeneity and antigenic variation nature of FMDV. Conclusion:Quasi species and subtypes of FMD serotypes A and SAT 2 similar to A/NIG/21/2009 and SAT 2/LIB/7/2003 respectively caused the reported FMD outbreaks in Fulani livestock herds investigated. A combined real-time and optimized RT-PCR protocols that would facilitate effective and timely FMD outbreak control plan based on identified serotypes is thus suggested.

Outbreak investigations and molecular characterization of foot-and-mouth disease viruses circulating in south-west Niger

“…According to a retrospective study that reviewed FMD outbreaks occurring between 1971 and 2001 (Couacy‐Hymann et al., ), four FMDV serotypes (namely O, A, SAT 1 and SAT 2) were suspected to be present in West African countries including Niger. Other published studies support the circulation of these four FMD serotypes in the region (Fasina et al., ; Gorna et al., ; Olabode, Kazeem, & Raji, ; Sangare, Bastos, Venter, & Vosloo, ; Sangare, Dungu, & Bastos, ; Sangare et al., , ; Ularamu et al., ), although a comprehensive understanding of FMD epidemiology that can be used to inform disease control programmes is currently lacking. Unfortunately, livestock in Niger have never been vaccinated against FMD.…”

“…Other published studies support the circulation of these four FMD serotypes in the region (Fasina et al, 2013;Gorna et al, 2014;Olabode, Kazeem, & Raji, 2014;Sangare, Bastos, Venter, & Vosloo, 2003;Sangare, Dungu, & Bastos, 2004;Sangare et al, 2001Ularamu et al, 2016), although a comprehensive understanding of FMD epidemiology that can be used to inform disease control programmes is currently lacking. Unfortunately, livestock in Niger have never been vaccinated against FMD.…”