Journal of Advances in Biology & Biotechnology

Aims: The health risk assessment of some toxic metals in groundwater in four selected towns of Delta State, Nigeria was confirmed by this study.

Methodology: Ninety six groundwater samples were obtained from sixty four hand-dug wells and thirty two boreholes between December 2016 and May 2017. Samples were analyzed for heavy metals using standard procedures. Data collected was subjected to descriptive and inferential statistics using the Statistical Package for Social Sciences (SPSS) for Windows version 22.0. Health Risk Assessment for Non cancer hazard and carcinogenic effects were determined.

Results: The HQ of Cr, Mn and Ni were below 1.0 indicating no threat to the water consumers while the HQ values for Pb, Cd and Cu were above 1.0 indicating risk to human health. The HI value was found to be greater than 1.0, indicating noncarcinogenic adverse effects. The estimated Lifetime of Carcinogenic Risks (LTCR) for Pb, Cr, Cd and Ni exceeded the predicted lifetime risk for carcinogens of 10⁻⁶ from ingestion pathway. The groundwater had higher risks of Cr and Cd as LTCR value in most sites were >10⁻⁴_. The high LTCR should be given high priority as public health is concerned.

Conclusions: This study indicated possible non-carcinogenic and carcinogenic human health hazard from groundwater consumption in study area through oral consumption.

Oil/lipid was extracted from a primary sewage sludge by soxhlet extraction using n-hexane as the solvent. The extracted oil was then converted to biodiesel using transesterification process. The physicochemical properties of the oil/lipids and biodiesel were then determined and compared with literature for lipids and biodiesel parameters, whether they are consistent.

A percentage yield of 18.27 % was obtained for lipids extraction from primary sewage sludge, while for biodiesel production from the extracted lipids, a 66.7% was obtained.

Physicochemical parameters of both lipids and biodiesel obtained, gave values consistent with ASTM standardize, thereby suggesting that primary sludge of human excreta is a veritable/good source for the production of biodiesel, as an alternative source of fuel/energy.

The persistent resistance of micro-organisms necessitates the need to intensify studies on the use of possible strategies for proper control of pathogens using extracts from natural products. The stem bark of Lannea acida was extracted by two methods of extraction: Cold and Soxhlet (continuous) extraction. The extract of the stem bark was screened to confirm the presence of alkaloids, flavonoids, saponins, tannins and cardiac glycosides in all the samples of ethanol and hexane/acetone/methanol mixture extracts. The phytochemicals examined varied among the stem bark extracts of other solvents (hexane, chloroform, acetone, and methanol). The result of the antimicrobial test shows that the stem bark extracts exhibited efficacy against some microbes (Bacillus cereus, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa Staphylococcus aureus and Streptococcus pyogenes) that were employed for the study by exhibiting clear inhibition/clearance zones against these microbes which ranges from 06 mm -21 mm. The plant stem bark could therefore be seen as a potential natural source for useful antimicrobial drugs.

The impact of Lactobacillus plantarum 1KMT on the survival rate, growth performance, innate immunity and disease resistance of Oreochromis niloticus challenged with pathogenic Vibrio parahaemolyticus 1T1 was investigated. This study was conducted in the Fisheries Department of National Agriculture Research Centre (NARC), and Department of Biosciences of Comsats University Islamabad, Pakistan between August 2018 and August 2019. Sixty healthy fish (10.99 ± 1.1 g body weight) were acclimatised to laboratory conditions in 1000 L tank for 14 days. After, they were randomly divided equally into two groups G1 and G2 with one replication: G1 fed with the basal diet (BD) without probiotic (control), and group G2 was fed with 1x10⁸ CFU.g^-1 Lactobacillus plantarum 1KMT supplemented diet. The trial was conducted for a period of 60 days. The intestinal microflora, survival rate (SR), weight gain (WG), specific growth rate (SGR) and food conversion ratio (FCR) were checked after every ten days. After 60 days, the innate immune parameter levels were evaluated. For challenge study against Vibrio parahaemolyticus 1T1, eighteen fish from G2 were randomly selected and divided in two subgroups: G2A, with 1KMT continuous treatment and G2B in which treatment was stopped. After 21 days, the mortalities were recorded. The results showed that the intestinal microflora was significantly improved in G2 compared to G1. The survival rate was 96.5% and 86.0% in G2 and G1, respectively. The WG was not significantly affected, while the SGR and innate immunity parameters were significantly improved (p < 0.05) in G2 compared to G1. The mortality rate was 77.7% and 66.6% in G1 and subgroup G2B, respectively, while no mortality was observed in G2A after the challenge test. The Lactobacillus plantarum 1KMT improves the growth performance, survival rate, innate immunity and disease resistance of Nile tilapia.

Background: Antibiotic resistance has remained a global concern. Food pathogens that carry resistance genes will cause public health threat irrespective of their pathogenicity, as this pool of resistance genes are disseminated via food chain. The antibiotic susceptibility of E. coli isolates to different antibiotics were investigated and resistance genes were genetically identified by multiplex Polymerase Chain Reaction (PCR). The study aimed to determine the phenotypic antibiotic resistance pattern of the E. coli isolates and characterize the antibiotics resistance genes in the E. coli isolates from the Cow milk and milk products.

Results: The study showed that the E. coli isolates were Multidrug resistant (MDR) to several antibiotics with resistance pattern of four to ten combinations of antibiotics and the antibiotics resistance occurred mostly in three classes of antibiotics, namely: β-lactams, Amphenicol and Tetracycline.   The antibiotics resistance genes  expressed in the multidrug resistant E. coli isolates were tetA 22(78.6%), dfrA1 9(32.1%), blaCITM and blaSHV 3(10.7%), tetB and blaTEM 1(3.6%), qnr 0(0%) and aac (3)-iv 0(0%).

Conclusion: The study showed that the cow milk and its products sold on the streets of Abuja are contaminated with resistant E. coli that can pose health risk to the consumers.  Monitoring and screening for resistant food pathogens in food especially of animal origin is vital to mitigate the prevalence of antibiotics resistance.