Microbial load and diversity in the gastro-intestinal tract of cultured Nile tilapia (Oreochromis niloticus) and hybrid catfish (Clarias gariepinus ♀ x Heterobranchus bidorsalis ♂) in Ilorin Metropolis, Nigeria

This study investigated microbial load and diversity of gastro-intestinal tract of the cultured Nile tilapia (Oreochromis niloticus) and hybrid catfish (Clarias gariepinus ♀ x Heterobranchus bidorsalis ♂) in Ilorin metropolis, Nigeria. A set of apparently healthy Nile Tilapia and hybrid catfish were obtained from a fish farm in Ilorin metropolis. After dissecting the fish sample aseptically, the entire alimentary canals of the specimens were divided into foregut, midgut and hindgut. Then bacterial isolates were characterised, following standard operating procedures for gram reaction, morphology, motility, catalase and oxidase reactions, citrate utilization, coagulase production, starch hydrolysis, sugar fermentation, and eventual identification of the resultant colonies. The moulds were examined based on their micro-morphology as well as the colour and micro-morphology of their sporulating structures and conidia. The results of the study revealed that microbes were present in the entire gastro-intestinal tract of cultured hybrid catfish and Nile tilapia with highest microbial load found in the hindgut of the two fish species under study. Also, larger number of bacteria diversity indices were found in the hindgut of cultured Nile tilapia, while the hindgut of cultured clariid catfish had higher fungi diversity indices

Cooked sesame meal in the diet of African catfish Clarias gariepinus (Burchell 1822): Effects on haematology, liver and kidney histology

Haematological and histological alterations are strong pointers to the health status of farmed fish, farm animals and even humans. These provide dependable information on metabolic disorders and deficiency. The haematological and histological changes in African catfish Clarias gariepinus (Burchell 1822) fingerlings fed cooked sesame (Sesamum indicum) seed meal was examined in a 56-day feeding trial. Three batches of sesame seeds were cooked for 10, 20 or 30 min, dried, milled, and mechanically defatted using a screw press. Cooked seed meals (CSM) were substituted for defatted soybean meal in the diets of African catfish at 15, 30, and 45 per cent. The highest haemoglobin content (Hb) was found in catfish fed the control diet (CTR), while the lowest Hb levels were found in catfish fed the CSM345 diet. The haemoglobin content of catfish fed different dietary treatments varied significantly (P<0.05). Hb values of catfish fed CTR diet and test diets CSM115, CSM215, CSM315, and CSM130 were not significantly different (P>0.05). Other haematological parameters of the fish fed various dietary treatments showed a similar trend as RBC. Dietary replacement of soybean meal by differently cooked sesame seed meal in Clarias gariepinus diet did not affect haematology of the fish at lower inclusion levels for the different cooking times employed in the study (15% and 30% inclusion level for 10 min cooked sesame-based diets; 15% inclusion level for 20 and 30 min cooked sesame-based diets). Although, there was marked vacuolation of hepatocytes in catfish subjected to various dietary treatments, however these did not relate to dose-dependent dietary treatments

Aquaculture by-product meal as a fishmeal replacer in African catfish (Clarias gariepinus) diet: Effects on serum biochemistry, innate immune response, and oxidative stress markers

The effect of feeding aquaculture by-product meal (ABP) to African catfish (Clarias gariepinus) was investigated in a 56-day feeding trial using serum biochemistry, innate immune response, and oxidative stress markers as indices of assessment. Fishmeal protein in control diets was replaced at a rate of 15, 30, 45, and 60% by aquaculture by-product meal protein. Each experimental diet was randomly distributed into triplicate tanks containing catfish fingerlings (n = 15 fingerlings/replicate, 5.58±0.05 g). The primary haematological parameters (haemoglobin, packed cell volume, red blood cell count) and secondary haematological parameters (MCH, MCV, and MCHC) were similar with the control. The white blood cell count and its differential of the fish group fed ABP meal was numerically higher than control but not significant, except in fish fed D30T that had high lymphocyte count. The platelet count in all the dietary groups was similar. There was no significant variation in some of the serum biochemistry parameters: total protein, albumin, globulin and albumin/globulin ratio, urea, HDL-C and LDL-C. Creatinine values of the D60T fed group were significantly higher than all other dietary treatment groups including the control. Triglyceride's level was statistically similar with control up to 30% replacement level, while there were no significant variations in the cholesterol levels of the blood of C. gariepinus fed the different dietary treatments. Except for catalase, there were no significant differences in other oxidative stress biomarkers under study, primarily SOD, GSH, and GPx. Catalase enzyme activities of the fish group fed D30T were statistically higher than other fed groups. Some serum electrolytes, such as calcium and chloride ions of the differently fed fish groups, were not significantly different. Lastly, serum potassium ions were significantly higher among D60T fed group though statistically similar to D45T-fed group. No stress conditions were recorded among the dietary groups.  These results showed that the health status and immunity of African catfish were not degraded by feeding aquaculture by-product meal to the fish

Toasted Jatropha curcas seed meal in Nile tilapia (Oreochromis niloticus) diet: Effect on growth, economic performance, haematology, serum biochemistry and liver histology

The effect of dietary inclusion of differently timed dry heat-treated Jatropha curcas on the growth and economic performance of Nile tilapia, Oreochromis niloticus, was evaluated in a 56-day feeding trial. Five isonitrogenous and isolipidic dietary treatments (35% crude protein and 10% crude lipid) were made consisting of soybean meal (control) which was replaced by J. curcas seed meal toasted either 5 min or 10 min at 20 and 40% to make other four test diets. A total of 225 juveniles of O. niloticus were acclimatized for a week, weighed and allotted into five dietary treatments. Each treatment was replicated three times with fifteen fish per replicate. Fish were fed 5% body weight on two equal proportions per day for 56 days. Growth data were collected at two-week intervals. The results from the study indicated that there was significant difference (P0.05) in the different growth and economic performance parameters of fish fed CTR and fish fed D520T (5 min toasted, 20%). There was significant reduction in haematological and biochemical parameters of the blood of O. niloticus fed the different dietary treatments containing J. curcas seed meal. Based on economic and physiologic performance, soybean meal in Nile tilapia diet could be replaced up to 40% by 5-minute toasted J. curcass seed meal

SARS-CoV-2 variants-associated outbreaks of COVID-19 in a tertiary institution, North-Central Nigeria: Implications for epidemic control.

The COVID-19 global pandemic is being driven by evolving SARS-CoV-2 variants with consequential implications on virus transmissibility, host immunity, and disease severity. Continuous molecular and genomic surveillance of the SARS-CoV-2 variants is therefore necessary for public health interventions toward the management of the pandemic. This study is a retrospective analysis of COVID-19 cases reported in a Nigerian tertiary institution from July to December 2021. In total, 705 suspected COVID-19 cases that comprised 547 students and 158 non-students were investigated by real time PCR (RT-PCR); of which 372 (~52.8%) tested positive for COVID-19. Using a set of selection criteria, 74 (~19.9%) COVID-19 positive samples were selected for next generation sequencing. Data showed that there were two outbreaks of COVID-19 within the university community over the study period, during which more females (56.8%) tested positive than males (47.8%) (p<0.05). Clinical data together with phylogenetic analysis suggested community transmission of SARS-CoV-2 through mostly asymptomatic and/or pre-symptomatic individuals. Confirmed COVID-19 cases were mostly mild, however, SARS-CoV-2 delta (77%) and omicron (4.1%) variants were implicated as major drivers of respective waves of infections during the study period. This study highlights the importance of integrated surveillance of communicable disease during outbreaks

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Consumers’ Preference and Behaviour Pattern Towards Fresh and Smoked Catfish in Ilorin Metropolis, Nigeria

Consumers’ preference study allows industries to tailor the supply towards the preference of consumers so that market could be optimized for their turn-over and profits. This study investigated consumers’ preference of fresh and smoked catfish in Ilorin Metropolis. A total of 225 questionnaires were administered adopting multi-stage techniques to elicit information from the respondents. The obtained data were subjected to descriptive and inferential statistics. The results showed that majority of the respondents in this study preferred smoked catfish irrespective of their socio-economic profile. The majority of the respondents agreed with the factors used in this study for the preference of fish (i.e. types) and their frequency of eating as their preferred fish. This study showed that only tribe of the respondents showed significant effect (p&lt;0.05) on the respondents’ preferences for whole or chunk fish; and family size, age and religion had significant effect on the frequency of their preferred fish

EVALUATION OF HETEROCLARIAS QUALITY WITH INCREASED STORAGE TIME USING QUALITY INDEX METHOD (QIM)

The quality of Heteroclarias with increased storage time using Quality Index Method (QIM) was evaluated. 140 live samples of Heteroclarias (average weight 230 + 7g) were used for the study. QIM was used to evaluate the key parameters in fish deterioration, twenty semi-trained assessors was used for the sensory evaluation. Data obtained were subjected to appropriate statistical tools using SPSS 16.0 version. Quality Index (QI) of Heteroclarias increases with increased post slaughter time when the fish was left at ambient temperatures (27 + 3°C) indicating decrease in fish quality with time. High correlation of (r=0.993) with a high coefficient of determination (R2=0.986) was obtained indicating that 98.6% of the variation in post slaughter time was explained by quality attributes; the regression equation was significant F(9, 130)=1080 (p Practical Applications :Fish is highly perishable despite its nutritional value, consumers becoming increasingly interested in the quality of fish they consume and the physical attributes of the fish is very vital for on the spot assessment of fish quality. This study provide quality index that could be used for prediction and estimation of fish quality using sensory evaluation

Effect of dietary cinnamon supplementation on the growth in length, haematology, serum biochemistry, intestinal microbiota and enzymes and histomorphological changes of the intestine, liver and the kidney of Heteroclarias (Clarias gariepinus ♀ × Heterobra

The effect of dietary cinnamon supplementation on the growth, haematology, serum biochemistry, intestinal microbiota and enzymes and histomorphological changes of the intestine, liver and kidney of juvenile heteroclarias (Clarias gariepinus ♀ Heterobranchus bidorsalis ♂) was assessed in a 56-day feeding trial. Five 38% crude protein experimental diets were formulated to contain a cinnamon powder that was included at a rate of 0% (DT1), 0.5% (DT2), 1% (DT3),1,5% (DT4) and 2% (DT5). Each diet was allotted to a triplicate group of fish (n=15 fish/ replicate tank 8.55± 0.12 cm average length) in a completely randomized design. There was a significant increase (p0.05) among the dietary groups. Bacteria counts were heightened significantly (p<0.05) with cinnamon supplementation when compared to the control. The contrast was the results for fungi count with diversity indices in favour of DT4 dietary group. The amylase, cellulase and trypsin activity of the cinnamon-fed group was significantly (p<0.05) elevated when compared to those of the control group. The intestine, liver and kidney microstructures were well preserved with no features of injury recorded