Browsing by Author "Okuni, Julius Boniface"

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    Application of antibodies to recombinant heat shock protein 70 in immunohistochemical diagnosis of mycobacterium avium subspecies paratuberculosis in tissues of naturally infected cattle
    (Irish veterinary journal, 2017) Okuni, Julius Boniface; Kateete, David Patrick; Okee, Moses; Nanteza, Anna; Joloba, Moses; Ojok, Lonzy
    Detection of Mycobacterium avium subspecies paratuberculosis (MAP) infection is key to the control of Johne’s disease. Immunohistochemistry is one of the methods of detection of MAP infection in tissues. However, unavailability of commercial antibodies that can detect the organism is a limiting factor for the use of immunohistochemistry. This study was aimed at developing an immunohistochemistry method to diagnose MAP in infected tissues using antibodies against MAP recombinant heat shock protein 70kd.MAP Heat shock protein 70 gene was amplified and cloned into an expression vector, Champion pET-SUMO, then expressed in E coli, purified and used to produce polyclonal rabbit antibodies against the Heat shock protein. Immunohistochemistry was performed in 35 MAP infected tissues with anti-HSP70 polyclonal antibodies. All 35 MAP infected tissues were positive for MAP within macrophages, epithelioid cells and giant cells either in clumps or singly as individual bacilli. No positive staining was seen in the three uninfected normal tissues and in MAP infected tissues where primary antibodies were substituted with PBS or pre-immune serum from the same rabbit.Anti-HSP70 produced in this study offers an opportunity for improved diagnosis, screening of MAP in animal tissues and in studies on the pathogenesis of MAP
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    Epidemiological Overview of African Swine Fever in Uganda (2001–2012)
    (Journal of Veterinary Medicine, 2013) Atuhaire, David Kalenzi; Ochwo, Sylvester; Afayoa, Mathias; Mwiine, Frank Norbert; Arinaitwe, Eugene; Ademun-Okurut, Rose Anna; Okuni, Julius Boniface; Nanteza, Ann; Ayebazibwe, Christosom; Okedi, Loyce; Olaho-Mukani, William; Ojok, Lonzy
    African swine fever (ASF) is a contagious viral disease, which can cause up to 100% mortality among domestic pigs. In Uganda there is paucity of information on the epidemiology of the disease, hence a study was carried out to elucidate the patterns of ASF outbreaks. Spatial and temporal analyses were performed with data collected monthly by the district veterinary officers (DVOs) and sent to the central administration at MAAIF from 2001 to 2012. Additionally, risk factors and the associated characteristics related to the disease were assessed based on semistructured questionnaires sent to the DVOs. A total of 388 ASF outbreaks were reported in 59 districts. Of these outbreaks, 201 (51.8%) were reported in districts adjacent to the national parks while 80 (20.6%) were adjacent to international borders. The number of reported ASF outbreaks changed over time and by geographical regions; however, no outbreak was reported in the North-Eastern region. ASF was ranked as second most important disease of pigs, and it occurred mostly during the dry season (𝑃 = 0.01). Pig movements due to trade (OR 15.5, CI 4.9–49.1) and restocking (OR 6.6, CI 2.5–17.3) were the major risk factors. ASF control strategies should focus on limiting pig movements in Uganda
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    Molecular characterization and phylogenetic study of African swine fever virus isolates from recent outbreaks in Uganda (2010–2013)
    (Virology journal, 2013) Kalenzi Atuhaire, David; Afayoa, Mathias; Ochwo, Sylvester; Mwesigwa, Savannah; Okuni, Julius Boniface; Olaho-Mukani, William; Ojok, Lonzy
    African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Eastern Africa particularly in Uganda where outbreaks regularly occur. Sequence analysis of variable genome regions have been extensively used for molecular epidemiological studies of African swine fever virus (ASFV) isolates. By combining p72, P54 and pB602L (CVR), a high level resolution approach is achieved for viral discrimination. The major aim of this study therefore, was to investigate the genetic relatedness of ASF outbreaks that occurred between 2010 and 2013 in Uganda to contribute to the clarification of the epidemiological situation over a four year period. Methods: Tissue samples from infected domestic pigs associated with an ASF outbreak from 15 districts in Uganda were confirmed as being infected with ASFV using a p72 gene-based polymerase chain reaction amplification (PCR) assay recommended by OIE. The analysis was conducted by genotyping based on sequence data from three single copy ASFV genes. The E183L gene encoding the structural protein P54 and part of the gene encoding the p72 protein was used to delineate genotypes. Intra-genotypic resolution of viral relationships was achieved by analysis of tetramer amino acid repeats within the hypervariable CVR of the B602L gene. Results: Twenty one (21) ASF outbreaks were confirmed by the p72 ASF diagnostic PCR, however; only 17 isolates were successfully aligned after sequencing. Our entire isolates cluster with previous ASF viruses in genotype IX isolated in Uganda and Kenya using p72 and P54 genes. Analysis of the CVR gene generated three sub-groups one with 23 tetrameric amino acid repeats (TRS) with an additional CAST sequence, the second with 22 TRS while one isolate Ug13. Kampala1 had 13 TRS. Conclusion: We identified two new CVR subgroups different from previous studies. This study constitutes the first detailed assessment of the molecular epidemiology of ASFV in domestic pigs in the different regions of Uganda.
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    Molecular characterization of African swine fever virus in apparently healthy domestic pigs in Uganda
    (African Journal of Biotechnology,, 2014) Kalenzi Atuhaire, David; Ochwo, Sylvester; Afayoa, Mathias; Mwesigwa, Savannah; Mwiine, Frank Norbert; Okuni, Julius Boniface; Olaho-Mukani, William; Ojok, Lonzy
    African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Uganda where outbreaks regularly occur. There is neither a vaccine nor treatment available for ASF control. Twenty two African swine fever virus (ASFV) genotypes (I - XXII) have been identified based on partial sequencing of the C-terminus of the major capsid protein p72 encoded by the B646L gene. The majority of previously characterized Ugandan ASFV strains belong to genotype IX. The major aim of the current study was to determine the ASFV genotypes among asymptomatic slaughter pigs at Wambizi slaughterhouse and in some parts of the country where surveillance was done. Three discrete regions of the ASFV were analysed in the genomes of viruses detected in asymptomatic domestic pigs. The analysis was conducted by genotyping based on sequence data from three single copy ASFV genes. The E183L gene encoding the structural protein P54 and part of the gene encoding the p72 protein were used to delineate genotypes, before intra-genotypic resolution of viral relationships by analysis of tetramer amino acid repeats within the hypervariable central variable region (CVR) of the B602L gene. All the ASF viruses obtained from this study clustered with previous viruses in genotype IX based on analysis of the p72 and P54 genes. Analysis of the CVR gene grouped the viruses in three different subgroups; 13, 23 and 25. Only one genotype is circulating in Uganda among asymptomatic domestic pigs and it is the same virus causing outbreaks in the country and parts of neighbouring Kenya.
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    Prevalence of African swine fever virus in apparently healthy domestic pigs in Uganda
    (BMC veterinary research, 2013) Atuhaire, David Kalenzi; Afayoa, Mathias; Ochwo, Sylvester; Mwesigwa, Savannah; Mwiine, Frank Norbert; Okuni, Julius Boniface; Mukani, William Olaho; Ojok, Lonzy
    African swine fever (ASF) is a contagious viral disease which can cause up to 100% mortality among domestic pigs leading to serious socio-economic impact on people’s livelihoods. ASF is endemic in Uganda and there is paucity of information on the epidemiology of the disease. The major aim of this study was to determine the seroprevalence and prevalence of African swine fever virus (ASFV) in apparently healthy slaughter pigs at Wambizi slaughterhouse in Kampala city, Uganda. We also estimated the presence of ASFV antibodies and circulating viral antigens in pigs from selected districts of Uganda during targeted surveillance. We analysed 540 and 181 blood samples collected from slaughter pigs and pigs from targeted surveillance districts respectively.The prevalence of ASFV in slaughter pigs was 52.96% (95% CI, 48.75-57.14) and 11.5% (95% CI, 9.06-14.45) by ELISA and PCR respectively. In surveillance districts, the proportion of ASFV positive pigs was 53.59% (95% CI, 46.33-60.71) and 0.55% (95% CI, 0.1-3.06) by ELISA and PCR respectively.The study has found out a high seroprevalence of ASFV antibodies in apparently healthy slaughter pigs and also a high proportion of ASFV antibody seropositive pigs in surveyed districts in Uganda indicating exposure to ASFV. However, there was a lower prevalence of ASFV infection implying that there could be low virulent strains of ASFV circulating in domestic pigs in Uganda which requires further investigation.