Molecular variation in population structure of Xanthomonas axonopodis pv manihotis in the south eastern Nigeria

Xanthomonas axonopodis  pv manihotis (Xam) is the causal agent of cassava bacterial blight (CBB) in all cassava growing areas of the world. To develop an efficient disease management strategy, the genetic diversity of the pathogens population ought to be known. Information is scarce on the genetic diversity of Xam population in Nigeria. Random amplified polymorphic DNA (RAPD) was used to characterize Xam isolates from the southeastern parts of Nigeria. Seventeen Xam strains and two reference strains were analyzed with four RAPD primers. RAPD fragment data showed five major clusters at 80% similarity coefficient level. Four strains were not clustered by this analysis (Del5A, Imo38B, Ebon28A and Ebon27A) and were not grouped with the others in the dendrogram. Principal component analysis (PCA) assembly grouped the bacterial strains into three. One of the strains that was separated in the dendrogram was also clustered separately from the others in the major cluster in the PCA. The results showed a high level of genetic diversity in the pathogen

Microbiological, proximate analysis and sensory evaluation of processed Irish potato fermented in brine solution

The microflora, proximate analysis and sensory evaluation of Irish Potato (Solanum tuberosum) slices fermented in 2.0% brine solution under micro-aerophilic condition for five days at room temperature were studied. The Nutritive qualities of the brined- fermented samples were analyzed and organoleptic parameters were accessed through trained panelist. There was an increase in microbial load of the brined-fermented samples especially within the first three days of fermentation as a result of hydrolysis of carbohydrate and subsequent conversion to sugars and minerals by the fermenting microorganisms. The organisms isolated from the fermentation set up include Bacillus, Flavobacterium, Micrococcus, Lactobacillus and Staphylococcus species. Decrease in microbial counts at the latter stages of fermentation was attributed to the high total acidity of the medium with reduction in pH from 7.50 to 5.03, while the lactic acid bacteria increased continuously throughout the period of fermentation. The results of the proximate analysis showed that there was a reduction in the crude fiber content from 28.96 to 20.04 mg/g, reducing sugar from 127 to 72 mg/g and ash content from 8.01 to 4.08 mg/g. The fried fermented chips were more desirable and preferred to the unfermented control

Detection of fungi and aflatoxin in shelved bush mango seeds (

A survey of the fungi and aflatoxin contamination of bush mango seeds (Irvingia spp.) was conducted in Akwa lbom State, Nigeria. Bush mango seeds sold at four major markets, located at Abak, Uyo, IkotEkpene and Itam in Akwa Ibom State were heavily contaminated with moulds. Eight different fungi were found associated with the bush mango seeds; Aspergillus carbonarius, Aspergillus tereus, Aspergillusflavus, Aspergillus candidus, Penicillium expansum, Aspergillus niger, Candida tropicalis and Aspergillus glaucus. A. niger have the highest rate of occurrence with high colony counts (1.0 x 103 –4.3 x 103 colonies/g). The aflatoxins B1 and G1 concentrations ranged from 0.2 – 4.0 and 0.3 – 4.2 ìg/kg, respectively. The result showed that bush mango seeds sold in Akwa lbom markets require quality control and proper preservation

Growth performance and survival rate of Clarias gariepinus juveniles fed different levels of aflatoxin – contaminated feeds

This experiment was conducted to evaluate the effects of different levels of aflatoxin- contaminated feed (0% toxigenic maize, 25% toxigenic maize +75% good maize, 50% toxigenic maize+50%good maize, 75% toxigenic maize +25% good maize and 100% toxigenic maize) on growth, survival, haematology and histology of Clarias gariepinus juveniles. Ten Clarias gariepinus juveniles with average weight of 42.81±0.01g were subjected to five treatments, with two replicates for each. The fish were fed twice daily at 5% body weight of 40% crude protein for six weeks. Growth performance indices such as Mean Weight Gain (MWG), Specific Growth Rate (SGR), Survival Rate (SR) and Feed Conversion Ratio (FCR) were determined. Haematological parameters such as Packed Cell Volume (PCV), Red Blood Cell (RBC), Haemoglobin (Hb) content and lymphocytes were evaluated. Data resulting from the experiment were subjected to descriptive statistics and ANOVA at P = 0.05. Results showed that highest mean weight gain (107.00± 10g), specific growth rate (0.03±00g), survival rate (60.00%) and feed conversion ratio (0.68±0.05) were observed with control diet. MWG, SGR, SR and FCR were significantly (p<0.05) higher in control diet compared with the other treatments. Also, packed cell volume, red blood cell (count) were higher in the control compared with other treatments, red blood cell counts were significantly different (p< 0.05) in control than other treatments. Lymphocytes were better in control and treatment 1 (25% toxigenic maize + 75% good maize) while decreased value were observed in the other treatments which indicate reduction in immune response of the fish. The control diet and treatment 1 were significantly (p<0.05) higher than other treatments but no significant difference (p>0.05) were recorded between control and treatment 1 (25% toxigenic maize + 75% good maize). Histology analyses of the liver and intestine of aflatoxin – contaminated feeds revealed severe degeneration and diffuse necrosis and mucosal erosion respectively. This study concludes that presence of aflatoxin contaminated feed affect the survival and growth performance of Clarias gariepinus juvenilesKeywords: Growth, Aflatoxin- contaminated feeds, Clarias gariepinus, Haematology Surviva

Comparative studies and microbial risk assessment of different Ready-to-Eat (RTE) frozen sea-foods processed in Ijora-olopa, Lagos State, Nigeria

This study reports the comparative studies and microbial risk assessment of different frozen seasfoods processed in Ijora-olopa, Lagos State, Nigeria. Different varieties of popularly consumed frozensea-foods bought from different processing shops in Ijora-olopa, Lagos were microbiologically analyzed for the presence of microorganisms. Total plate counts, enterobacteriaceae counts and Salmonella-Shigella (SS) counts were enumerated using Plate Count Agar (PCA), Eosin Methylene Blue (EMB) Agar and Salmonella-Shigella Agar (SSA), respectively. The total counts for all the processed frozen seafood products ranged between 1.08 x 102 to 2.86 x 104 CFU/ml. These were generally high exceeding the limit of 1.0 x 102 CFU/ml. The coliform count ranged between 0.76 x 102 and 1.36 x 104cells. The Salmonella-Shigella (SS) count ranged between 0.26 x 102 and 0.96 x 104 cells. Seventeen (17) isolates were characterized from the samples on PCA with percentage of occurrence of differentmicroorganisms characterized as follows: Bacillus cereus (29.4%), Enterobacter aerogenes (29.4%), Salmonella sp. (17.6%), Flavobacterium sp. (11.8%), Micrococcus sp. (5.9%), and Staphylococcus auerus (5.9%). Consumption of some of this water and the seafood product processed with these water samples available in the market should be discouraged