Biology subjects

Ochwo, S.

Publications and source records attributed to Ochwo, S..

2 recordsLinked to original sources

bioRxiv2019

Occurrence of Cryptosporidium hominis in cattle bordering the Lake Mburo National Park in Kiruhura district, Western Uganda

BackgroundCryptosporidium is an emerging opportunistic zoonotic pathogen that causes diarrheal illness in a wide range of hosts including livestock and humans. Globally there is exponential increase in livestock production to meet the worlds demand for animal protein as well as for financial reasons. However, there is raised concern of the public health threat due to contamination of the environment by livestock waste carrying zoonotic pathogens such as Cryptosporidium. This study set out to establish the prevalence of Cryptosporidium as well as the circulating genotypes in order to elucidate the potential role of cattle in the spread of human cryptosporidiosis. We collected rectal coprological samples from 363 cattle in 11 households in Kiruhura district, Southwestern Uganda. The samples were screened for presence of Cryptosporidium oocysts using the phenol auramine staining method followed by fluorescent microscopy. DNA was then extracted from the microscopy positive samples and the COWP gene amplified using PCR. Amplified gene products were sequenced and subjected to phylogenetic analysis. ResultsThe overall animal level prevalence of Cryptosporidium was 7.7% (95% CI: 5.1-10.9), and herd level prevalence was 33.3% (95% CI: 18.5-52.2). We found a statistically significant difference (p=0.02) between infection in bulls as compared to cows. There was however no significant difference in the prevalence among the different cattle breeds sampled, with the following prevalences observed in Crosses 9.2%, Ankole 5.7%, Friesian 7.1%, and Boran 2.8% respectively. The COWP gene was successfully amplified from 20 of the 28 microscopy positive samples. All the sequenced DNA amplicons were confirmed to be C. hominis, with 98%-100% identity to sequences in the GenBank. C. hominis was the only genotype isolated from this study, further asserting that cattle could be a potential high risk source of human cryptosporidiosis. ConclusionThis study represents the first time naturally occurring C. hominis has been isolated from cattle in Uganda. This further provides evidence of cattle possibly being biological reservoirs for C. hominis and cattle could be a potential high risk source of human cryptosporidiosis.

microbiology↗

bioRxiv2019

Serodiagnostic potential of synthetic peptides derived from African swine fever virus putative protein pCP312R

African swine fever (ASF) is a hemorrhagic disease of domestic swine, with often high mortality rates registered. To date there is still no vaccine produced against ASF, and disease management in countries including Uganda, where the disease is endemic is dependent on accurate and timely diagnosis programs and quarantine. This study aimed at contributing more knowledge towards ASF diagnosis by investigating the serodiagnostic potential of synthetic peptides of an ASF putative protein pCP312R. Antigenic regions of the pCP312R putative protein were identified using Kolaskar and Tongaonkar antigenicity prediction method and twelve (12) peptides were predicted, out of which four (4) peptides were selected and synthesised. An additional peptide derived from the carboxyl end of the ASFV p54 protein was also synthesised and used as a control. Polyclonal rabbit antibodies raised against each of the five peptides was used in immunohistochemistry, and each demonstrated ability to localize viral antigen in pig tissue albeit with slightly varying intensities, at a dilution of 1:200, with antibodies against peptides cpr1, cpr2, cpr3 and cpr4 all accurately staining infected macrophages. However all the peptides evaluated in this study performed moderately when used in indirect ELISA tests giving the following results; CP1; diagnostic sensitivity of 55% (95% CI, 0.3421-0.7418) and specificity of 96% (95% CI, 0.8046-0.9929), CP2; diagnostic sensitivity of 100% (95% CI, 0.8389-1) and specificity of 52% (95% CI, 0.335-0.6997), CP3; diagnostic sensitivity of 95% (95% CI, 76.39-99.11) and specificity of 88% (95% CI, 70.04-95.83), CP4; diagnostic sensitivity of 90% (95% CI: 0.699-0.9721) and specificity of 76% (95% CI: 0.5657-0.885) and p54; diagnostic sensitivity of 100% (95% CI, 0.8389-1) and specificity of 56% (95% CI, 0.3707-0.7333). This study presents the first time synthetic peptides have been successfully predicted, designed and evaluated for Serodiagnosis of African swine fever in domestic pigs. This study in addition showed that there is potential for use of polyclonal anti-peptide antibodies in the diagnosis of ASF using immunohistochemistry.

immunology↗