Biology subjects

Machuka, E.

Publications and source records attributed to Machuka, E..

2 recordsLinked to original sources

bioRxiv2024

Analysis of spatial and temporal risk of Peste des Petits Ruminants Virus (PPRV) outbreaks in endemic settings: A scoping review

BackgroundSustained Peste des petits ruminants (PPR) circulation, as evidenced by surveillance, shows PPR endemicity in Africa and Asia. Regional transmission of PPR is enabled by joining numerous epidemiological factors. Spatial, spatiotemporal and transmission dynamics analytical methods have been used to explore the risk of PPR transmission. The dearth of information on the risk factors associated with spatiotemporal distribution and transmission dynamics of PPR at a regional scale is high. Through a thorough analysis of peer-reviewed literature, this study sought to evaluate the risks of Peste des Petit ruminant virus (PPRV) epidemics by noting distinctions of geographical and spatial-temporal approaches applied in endemic settings. MethodsA scoping literature review of PPR research publications that used spatial and spatiotemporal approaches to assess PPR risks in endemic areas was carried out using PubMed and Google Scholar data base. ResultsOut of 42 papers selected 19 focused on Asia, 15 on Africa, and 8 had a global view. 61.9% used clustering analysis while 35.7% used spatial autocorrelation. Temporal trends were described by most studies at about 71.2% while modeling approaches were used by 13 articles (30%). Five risk factors evaluated include demographics and livestock-wildlife interactions (n = 20), spatial accessibility (n = 19), trade and commerce (n = 17), environment and ecology (n = 12), and socioeconomic aspects (n=9). Transmission dynamics of PPR was covered in almost all articles except 2 articles but it has linked all the risk factors. ConclusionsThe review has contributed to the shifting and improvement of our understanding on PPR outbreaks in endemic settings and support evidence-based decision-making to mitigate the impact of the virus on small ruminant populations. Linkage of other risk factors to livestock trade which is the major driver of livestock movement has been shown to pose a significant risk of PPR epidemics in endemic settings. With many studies being found in Asia compared to Africa, future development of predictive models to evaluate possible eradication strategies at national and regional levels should also consider Africa.

scientific communication and education↗

bioRxiv2022

Diversity and functional analysis of rumen and fecal microbial communities associated with dietary changes in crossbreed dairy cattle

The objective of this study was to investigate the effect of varying roughage and concentrate proportions, in diet of crossbreed dairy cattle, on the composition and associated functional genes of rumen and fecal microbiota. We also explored fecal samples as a proxy for rumen liquor samples. Six crossbred dairy cattle were reared on three diets with an increasing concentrate and reducing roughage amount in three consecutive 10-day periods. After each period, individual rumen liquor and fecal samples were collected and analyzed through shotgun metagenomic sequencing. Average relative abundance of identified Operational Taxonomic Units (OTU) and microbial functional roles from all animals were compared between diets and sample types (fecal and rumen liquor). Results indicated that dietary modifications significantly affected several rumen and fecal microbial OTUs. In the rumen, an increase in dietary concentrate resulted in an upsurge in the abundance of Proteobacteria, while reducing the proportions of Bacteroidetes and Firmicutes. Conversely, changes in microbial composition in fecal samples were not consistent with dietary modification patterns. Microbial functional pathway classification identified that carbohydrate metabolism and protein metabolism pathways dominated microbial roles. Assessment of dietary effects on the predicted functional roles of these microbiota revealed that a high amount of dietary concentrate resulted in an increase in central carbohydrate metabolism and a corresponding reduction in protein synthesis. Moreover, we identified several microbial stress-related responses linked to dietary changes. Bacteroides and Clostridium genera were the principal hosts of these microbial functions. Therefore, the roughage to concentrate proportion has more influence on the microbial composition and microbial functional genes in rumen samples than fecal samples. As such, we did not establish a significant relationship between the rumen and fecal metagenome profiles, and the rumen and fecal microbiota from one animal did not correlate more than those from different animals.

microbiology↗