Biology subjects

Misinzo, G.

Publications and source records attributed to Misinzo, G..

4 recordsLinked to original sources

bioRxiv2023

Effect of Soybean and Seaweed-based Diets on Growth Performance, Feed Utilization, and Gut Microbiota of Tilapia: A Systematic Review and Meta-analysis

Tilapia, a significant aquaculture species globally, relies heavily on feed for its production. While numerous studies have investigated the impact of soybean and seaweed-based diets on tilapia, a comprehensive understanding remains elusive. This review aimed at evaluating and synthesizing the existing literature on these diets effects, focusing on growth performance, feed utilization, and gut microbiota. A systematic search of databases was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and a total of 57 studies were included in the qualitative analysis and 24 in the meta-analysis. The results indicated that soybean-based diets, at a 59.4% inclusion level improved the Specific Growth Rate (SGR) of tilapia with an effect size of -2.14 (95% CI: -2.92, -1.37; p < 0.00001; I2= 99%) and did not improve the feed conversion rate (FCR), as the effect size was 1.80 (95% CI: 0.72, 2.89; p = 0.001; I2 = 100%). For seaweed-based diets, at a 15,9% inclusion level did not improve SGR, with an effect size of -0.74 (95% CI: -1.70, 0.22; p = 0.13; I2 = 99%), and the FCR with an effect size of -0.70 (95% CI: -1.94, 0.54; p = 0.27; I2 = 100%). Regarding the gut microbiota, was noted a lack of studies meeting the inclusion criteria for tilapia. However, findings from studies on other farmed fishes suggested that soybean and seaweed-based diets could have diverse effects on gut microbiota composition and promote the growth of beneficial microbiota. This study suggests that incorporating soybean-based diets at 59.4% inclusion can improve the SGR of tilapia. Seaweed-based diets, while not demonstrating improvement in the analyzed parameters with an inclusion level of 15.9%, have the potential to contribute to the sustainability of the aquaculture industry when incorporated at lower levels.

physiology↗

bioRxiv2019

Co-circulation of Dengue Virus Serotypes 1 and 3 during the 2019 epidemic in Dar es Salaam, Tanzania

BackgroundDengue is an important mosquito-borne viral disease in tropical and sub-tropical countries. In this study molecular characterization was carried out to determine dengue viruses circulating among patients at health facilities during 2019 epidemic in Dar es Salaam, Tanzania.\n\nMethodsThe study involved outpatients seeking care for febrile illness at four health facilities in Kinondoni and Ilala Districts of Dar es Salaam City in Tanzania. A total of 45 sera from the outpatients were confirmed dengue-positive for dengue virus (DENV) non-structural protein 1 (NS1) antigen and/or NS1-IgG/IgM antibodies using on-site rapid test. The presence of the virus was detected by reverse-transcription polymerase chain reaction (RT-PCR) method. Of the 45 sera, 20 samples were selected randomly for identification of specific dengue virus serotypes using RT-PCR followed by evaluation of resulting amplicons on agarose gel electrophoresis.\n\nFindings and significanceBoth Dengue virus serotypes 1 (DENV-1) and 3 (DENV-3) were detected in the samples tested with the former being dominant. We present the first evidence of dengue virus co-infection of DENV-1 and DENV-3 serotypes in Tanzania. The emergence of DENV-1 indicates the possibility of importation of the virus to Tanzania from endemic countries. Due to DENV serotype co-circulation, there is an increased risk of severe dengue in future epidemics. Our findings advocate the importance of genomic-based surveillance to provide rapid evidence of dengue virus emergence/re-emergence and spread.\n\nAuthor SummaryDengue viruses are the most important mosquito-borne pathogens that pose a serious global health threat. Tanzania has reported several dengue virus epidemics since 2010 with the majority of the epidemics occurring in Dar-es-Salaam city. Until August 2019, a total of 6,859 dengue cases have been confirmed in the country. We performed molecular characterization of dengue viruses (DENV) circulating during the 2019 epidemic phase. It was found that DENV-1 serotype was dominant during the epidemic and two samples of the tested sera were co-infected by DENV-1 and DENV-3 serotypes. These findings emphasize the importance of genomic-based surveillance of dengue viruses in Tanzania to guide strategies for appropriate interventions.

genomics↗

bioRxiv2019

Molecular characteristics of chronic hepatitis B virus infection among voluntary blood donors in Kinshasa, Democratic Republic of the Congo

BackgroundHepatitis B represents a major global health problem. Despite the high endemicity of hepatitis B in Sub-Saharan Africa, little is known about the molecular characteristics of chronic hepatitis B virus (HBV) infection in Africa, and there are very few published studies that describe the genetic characteristics of HBV in asymptomatic adults in DRC. The present study aimed at determining the molecular diversity of chronic HBV infection in voluntary blood donors in Kinshasa, DRC.\n\nMethodsBlood samples from 582 voluntary blood donors at the National Blood Transfusion Centre in Kinshasa, DRC, were screened for hepatitis B surface antigen (HBsAg) using enzyme-linked immunosorbent assay (ELISA). Partial amplification and sequencing of S gene in HBV-positive samples was conducted.\n\nResultsThe presence of HBsAg was detected in 6.9 % (40/582) blood donors. Phylogenetic analysis based on partial S gene nucleotide sequences of HBV showed that the majority (66.7 %, 10/15) of HBV strains clustered into genotype A, followed by the genotypes E (26.6 %, 4/15) and D (6.7 %, 1/15). Genotype A strains were classified into subgenotype A1, quasi-subgenotype A3, and subgenotype A4, with quasi-subgenotype A3 being predominant. One new genotype A strain did not cluster with any existing HBV/A subgenotype or quasi-subgenotype.\n\nConclusionsThe present study highlights the high genetic variability of chronic HBV infection in DRC, and the possibility of a new HBV/A subgenotype, suggesting that HBV has a long evolutionary history in DRC. Further molecular characterization of complete HBV genomes is needed for a more accurate assessment of HBV genetic variability and its clinical significance in DRC, as partial sequences are not appropriate for determining HBV new subgenotypes.

microbiology↗

bioRxiv2019

Disease driven extinction in the wild of the Kihansi spray toad (Nectophrynoides asperginis)

The Kihansi spray toad, Nectophrynoides asperginis, became extinct in the wild despite population monitoring and conservation management of its habitat in the Kihansi gorge, Tanzania. Anecdotal evidence has indicated human induced habitat modification, predators, pesticides and disease as possible causes of a rapid population decline and the species extirpation. Here, we systematically investigate the role of disease in the extinction event of the wild toad population. The amphibian chytrid fungus, Batrachochytrium dendrobatidis, was detected in spray toads that died during the extinction event and subsequently in other amphibian species in Kihansi Gorge and the adjacent Udagaji Gorge, but not in any toads collected prior to this. Following the population decline, the remnant spray toad population gradually disappeared over a nine-month period. We demonstrate how demographic and behavioral attributes predisposed the spray toads to chytridiomycosis, due to B. dendrobatidis infection, and how epidemic disease could have been exacerbated by altered environmental conditions in the spray wetlands. Our results show that chytridiomycosis was the proximate cause of extinction in the wild of N. asperginis. This represents the first known case of extinction by disease of an amphibian species in Africa. A captive breeding program in the US and Tanzania ensures the survival of the species and a reintroduction program is underway. However, we caution that chytridiomycosis remains an existing threat that requires a comprehensive mitigation strategy before the desired conservation outcome of an established population of repatriated toads can be achieved.

epidemiology↗