FACULTY OF LIFE SCIENCES

Laundry wastewater, a category of greywater, contains various chemical constituents such as soap, suspended solids, oils, perfumes, and other pollutants at high concentrations. This study investigated the prevalence of virulence factors in bacterial isolates obtained from laundry wastewater to highlight their potential health risks. Samples were collected from residential and industrial laundry facilities, and the microbial isolates were analyzed using biochemical, molecular, and phenotypic methods. The total heterotrophic bacterial counts were recorded as 82.25 ± 4.7 CFU/mL × 10⁷ in Laundry Wastewater V and 94.50 ± 6.1 CFU/mL × 10⁷ in Laundry Wastewater W. Twenty-five bacterial isolates which include Staphylococcus aureus, Staphylococcus spp., Escherichia coli, and pseudomonas spp. were characterized. The most frequently isolated bacterium was Staphylococcus aureus [11/25 (44.0%)], followed by Escherichia coli [7/25 (28.0%)], Pseudomonas spp. [4/25 (16.0%)], and Staphylococcus spp. [3/25 (12.0%)]. Virulence factors such as DNase activity, lipase activity, and hemolytic activity were assessed. DNase activity was observed in 40% of the isolates, lipase activity in 52%, and hemolytic activity in 92%. Among Staphylococcus aureus isolates, DNase activity was 45.5%, lipase activity was 54.5%, and hemolytic activity was 100%. Similarly, hemolytic activity was prevalent in all Escherichia coli isolates (100%) and 75% of Pseudomonas spp. isolates. This study highlights the high prevalence of virulence factors in bacterial isolates from laundry wastewater and underscores its potential as a reservoir of pathogenic microorganisms. Untreated discharge of such wastewater poses serious public health and environmental risks. Therefore, it
emphasizes the need for enhanced wastewater treatment systems and further research on the
ecological and epidemiological implications of virulence factors in laundry effluents.

This study focused on the isolation and identification of bacteria from environmental hot spots using dumpsites located within Oredo Local Government Area of Benin City, Edo State, Nigeria, as reference points. The investigation aimed to assess the bacterial load, identify predominant microbial species, and evaluate their antibiotic susceptibility patterns. Ten samples were collected from various dumpsite points and analyzed using standard microbiological procedures. Total heterotrophic bacterial counts (THBC) ranged from 5 × 10⁴ to 1.25 × 10⁶ CFU/mL on MacConkey and EMB agars, indicating high microbial activity and organic contamination. Four representative isolates were further characterized biochemically and identified as Escherichia coli (three isolates) and Pseudomonas spp. (one isolate). Antibiotic susceptibility testing using the disk diffusion method revealed that all isolates were highly sensitive to fluoroquinolones (ofloxacin, ciprofloxacin, peflacine) and aminoglycosides (gentamicin, streptomycin) but exhibited strong resistance to β-lactam antibiotics such as ceporex and cefuroxime. The dominance of E. coli reflects fecal contamination of the dumpsites, while the presence of Pseudomonas spp. highlights the persistence of environmental opportunistic pathogens. The results suggest that these dumpsites represent potential reservoirs of antibiotic-resistant bacteria with implications for public health and environmental safety. This study emphasizes the urgent need for improved waste management, microbial monitoring, and enforcement of environmental sanitation standards to mitigate the spread of antimicrobial resistance in Benin City and other urban areas of Nigeria.

This study was carried out to determine the concentrations of some heavy metals, such as nickel, cadmium, mercury, and oxidative stress status of tomatoes sold in local markets in Benin City, Edo State, Nigeria. Fresh tomato samples were brought from Uselu and Ikpoba Hill market in Benin City. The samples were oven-dried at 105°C for 24 hours and grinded to powder. The powdered samples were dissolved in deionized water, filtered through Whatman filter paper, and the volume was made up to 25 ml using 10 ml of 98% nitric acid. The resulting solution was analysed for the presence of heavy metals using an Atomic Absorption Spectrophotometer
(AAS, Perkin Elmer model 2130). The results showed that the nickel concentration present fresh tomato samples obtained from the two markets ranged from 0.13 mg/kg to 0.16 mg/kg, while
the cadmium concentration ranged from 0.11 mg/kg to 0.13 mg/kg. However, when compared to
W.H.O standard, the heavy metal concentration was slightly above the recommended value of
0.10 mg/kg. Also, oxidative stress analysis showed that the superoxide dismutase (SOD) value
ranged from 3.02 U/g to 3.48 U/g, Catalase (CAT) value ranged from 0.08 U/g to 0.10 U/g, the glutathione peroxidase (GPx) value ranged from 4.96 U/g to 5.73 U/g, while the malondialdehyde (MDA) value ranged from 0.50 U/g to 0.64 U/g respectively. These findings were indicative of environmental pollution due to industrial and vehicular emissions and also the mode of handing and processing of the samples. Although the heavy metals detected in this study are not beneficial to man and plant, low concentration can prove detrimental to health.

This study assessed the human health risks associated with heavy metals in groundwater from Oluku, Edo State, Nigeria, with a focus on dermal exposure. Groundwater, a primary domestic water source, is vulnerable to contamination by both natural and anthropogenic activities, including industrial discharge, agricultural runoff, and improper waste disposal. Key heavy metals analyzed included zinc (Zn), cadmium (Cd), manganese (Mn), iron (Fe), and Lead (Pb). Fifteen groundwater samples were collected and analyzed using atomic absorption spectrometry (AAS) following standard procedures. Concentrations were compared against World Health Organization (WHO, 2017) and Nigerian Standard for Drinking Water Quality (NSDWQ, 2007) limits, while potential human health risks were estimated using the United States Environmental Protection Agency (USEPA, 2004) Human Health Risk Assessment (HHRA) framework. Results indicated that zinc (Zn) and iron (Fe) were present at relatively higher levels, with mean concentrations of 3.05 mg/L and 1.53 mg/L, respectively, while lead (Pb) and cadmium (Cd) recorded concentrations of 0.604 mg/L and 0.462 mg/L, exceeding WHO and NSDWQ limits. Chronic Daily Intake (CDI) and Hazard Quotient (HQ) analyses revealed that non-carcinogenic risks from Zn, Fe, and Mn were minimal. However, Pb and Cd posed significant health risks, particularly for children, who exhibited higher exposure levels due to lower body weight and greater dermal contact. Carcinogenic risk assessment further indicated that both Pb and Cd exceeded acceptable USEPA limits, with cadmium presenting the highest lifetime cancer risk. The study concluded that Fe and Zn likely originated from natural geogenic sources within the Benin Formation, while Pb and Cd contamination was predominantly anthropogenic, linked to industrial, domestic, and agricultural activities. The uneven spatial distribution of metals highlighted the influence of proximity to pollution sources. These findings underscore the urgent need for continuous groundwater monitoring, effective waste management, and public health interventions to mitigate exposure risks in Oluku, ensuring the safety of groundwater resources for domestic use.

Polyherbal formulations have long been utilized in traditional medicine for their synergistic therapeutic benefits. This study evaluated the comparative antimicrobial activities of Macedar a polyherbal formulation composed of Carica papaya leaves, Veronica amygdalina leaves, and Croton hirtus leaves and Carica papaya leaves alone. Methanol extracts were prepared using cold maceration and tested against selected Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria through agar well diffusion at varying concentrations (62.5–500 mg/ml). The results revealed that both extracts exhibited significant, dose-dependent antibacterial activity, with Macedar demonstrating stronger inhibitory effects across all test organisms. The highest inhibition zones were observed at 500 mg/ml, with Staphylococcus aureus showing the greatest susceptibility. These findings indicate that the synergistic interaction of the three plants in Macedar enhances antimicrobial potency beyond that of single-plant extracts. The study provides scientific validation for the ethno medicinal use of these plants and highlights the potential of polyherbal formulations Macedar as effective alternatives in combating resistant bacterial infections.

This project focused on checking the microbiological quality of different snacks sold within the University of Benin campus. The study was carried out to find out if the snacks commonly eaten by students are safe and free from harmful microorganisms. Snacks such as meat pie, chicken pie, egg roll, fish roll, doughnut, and puff-puff were selected because these foods are among the most popular foods sold by vendors around the school. Samples were collected from various vending points across the university and analyzed using standard laboratory methods. The total number of bacteria and fungi present in each snack was determined, and the organisms were identified using gram staining and biochemical tests. Antibiotic sensitivity tests were also performed to know how the bacterial isolates responded to common antibiotics. The results showed that all the snacks contained microorganisms, but at different levels. Egg roll and meat pie had the highest bacterial counts, while puff-puff showed the lowest. Common bacteria found included Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis, while fungi such as Aspergillus niger and Candida albicans were also isolated. Some bacteria were resistant to certain antibiotics but remained sensitive to others. This study concludes that while most snacks sold within the University of Benin are within acceptable limits of microbial safety, the presence of some harmful microorganisms shows that hygiene during preparation and handling needs to be improved. Regular health checks for food handlers and proper hygiene education are strongly recommended to prevent foodborne infections among students.

Haemolytic anaemia is characterised by accelerated erythrocyte destruction and is often accompanied by oxidative damage and organ dysfunction. Medicinal plants used in traditional medicine may offer protective and regenerative benefits in anaemic conditions. This study evaluated the regenerative effects of a polyherbal aqueous leaf extract of Ipomoea batatas, Justicia carnea and Ficus sur on selected organs in phenylhydrazine-induced haemolytic anaemic rats. Anaemia was induced in Wistar rats using phenylhydrazine hydrochloride. Animals were treated with graded doses of the polyherbal extract, while control groups included normal and anaemia-induced untreated rats. Liver, spleen and thymus tissues were harvested and processed for histopathological examination using haematoxylin and eosin staining. Phenylhydrazine-induced anaemia caused marked histopathological alterations in the liver, spleen and thymus, including hepatocellular degeneration, splenic architectural distortion and thymic involution. Treatment with the polyherbal extract resulted in varying degrees of tissue protection and structural recovery across the organs examined. The polyherbal aqueous extract of I. batatas, J. carnea and F. sur demonstrated protective and regenerative effects against phenylhydrazine-induced organ damage, supporting its potential role in the management of haemolytic anaemia.

The potential public health risk associated with ready-to-eat (RTE) fruits sold in open markets was investigated through a microbiological assessment of three popular fruits: Apple, Pineapple, and Watermelon. A total of three samples were purchased from a market in Benin City and analyzed using standard microbiological techniques, including serial dilution, plating on selective media, and biochemical analysis. The mean total bacterial count was highest in Pineapple and lowest in Apple, while the mean total fungi count was highest in Apple and lowest in Watermelon. Bacterial isolates included Staphylococcus aureus, Bacillus spp, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterobacter. Fungal isolates included Aspergillus niger, Yeasts, Penicillium species, and Mucor. Antibiotic susceptibility testing revealed isolates with resistance to multiple drugs, including Rocephin, Pefloxacin, and Ampliclox (for Gram-positive bacteria), while showing susceptibility to agents like Ciprofloxacin, Gentamicin, Levofloxacin, Ofloxacin, and Amoxicillin. The presence of these pathogenic and opportunistic micro-organisms confirms the contamination of the RTE fruits, which poses a significant public health hazard. This poor microbiological quality is likely due to unhygienic preparation environments, contaminated water, improper handling, and environmental exposure. Regulatory bodies must enhance surveillance, and vendors should strictly adhere to safe food handling practices. Consumers are advised to ensure proper washing of fruits before consumption.

This study investigated the hydrogeological evaluation of borehole water contamination near a solid waste dumpsite in Iyowa, Benin City, Nigeria. The aim was to assess how dumpsite leachate affects groundwater quality by examining physicochemical, microbiological, and heavy metal parameters. Five borehole samples were collected at varying elevations and distances around the dumpsite (coordinates: 6°27′29″N–6°27′44″N, 5°36′10″E–5°36′37″E) using GPS mapping and WHO-recommended sampling procedures. Laboratory analyses covered pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, nitrate, sulphate, phosphate, and selected metals (Pb, Fe, Cr, Zn) determined by Atomic Absorption Spectrophotometry (AAS), alongside microbial tests for total coliforms and E. coli. The results (Tables 4.1–4.3, Figures 1–2) showed acidic groundwater (pH 5.19–6.14) below WHO limits (6.5–8.5), with low alkalinity (4–6 mg/L) and elevated metal concentrations: Pb (0.106–0.428 mg/L), Fe (2.98–7.51 mg/L), and Cr (0.37–3.87 mg/L), all exceeding the permissible limits of 0.01, 0.3, and 0.05 mg/L respectively. Potassium spiked at 55.8 mg/L in the borehole closest to the dumpsite (Sample 2), indicating direct leachate influence. Microbial tests showed absence of coliforms and E. coli, but minor heterotrophic bacteria (1 CFU/mL). Overall, the acidic and metal-enriched groundwater reveals significant leachate intrusion linked to dumpsite proximity, making the borehole water unsafe for domestic consumption without treatment. The findings highlight the need for controlled waste disposal, borehole siting regulation, and continuous groundwater monitoring in Iyowa.

Food safety remains a critical public health concern globally, with dairy products repeatedly implicated in food-borne illness outbreaks. This study aimed to detect enteric pathogens in dairy products sold in Benin City, Edo State. Dairy product samples comprising of branded (Hollandia, Nana, Cedaa, and Super Yogo) and locally processed (Nono milk, Kindoromo, Wara, and Maishanu) products were purchased for this study. Enumeration and isolation of bacteria was done using serial dilution and pour plate techniques on selective agar. Bacterial isolates were identified based on cultural, morphological and biochemical characteristics. The pH and total titratable acidity of samples were determined using a pH meter and acid/base titration method respectively, while antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. The total heterotrophic bacteria count of the samples ranged from 4.8±0.26 to 8.6±0.26 ×10⁸ CFU/ml, while colony counts on MacConkey agar, Salmonella-Shigella agar, and Eosin methylene blue agar ranged from 0.80±0.485 to 6.67±1.53 ×10⁷ CFU/ml; 1.13±0.31 to 6.87±0.61 ×10⁴ CFU/ml and 5.07±0.64 to 7.0±0.40 ×10³ CFU/ml respectively. Six bacterial isolates were identified in this study, which include: Escherichia coli1 , Escherichia coli 2 , Salmonella sp.1 , Salmonella sp.2 , Enterobacter aerogenes and Serratia marcescens with Escherichia coli1 , Escherichia coli2 , Salmonella sp 1 and Salmonella sp 2. having the highest frequency of occurrence of 33.33% each. The pH values of dairy samples ranged from 3.82±0.01 to 6.96±0.03, while total titratable acidity ranged from 0.17±0.02 to 1.86±0.02 mg/l. Most isolates were resistant to antibiotics used, with resistance indices ranging from 0.1 to 0.8, with Enterobacter aerogenes and Salmonella sp.2 recording the highest resistance index of 0.8, indicating multidrug resistance pattern. This study revealed that dairy products (especially in locally processed dairy products) sold in Benin City showed the enteric bacteria which may possibly be pathogenic with high multidrug resistance profiles, underscoring the need for improved hygiene practices, enforcement of pasteurization standards, and stringent microbiological monitoring in the dairy value chain.