DEPARTMENT OF MICROBIOLOGY

Malnutrition among infants and young children remains a major public health challenge in Nigeria and many developing countries due to dependence on traditional cereal-based complementary foods with low protein, energy and micronutrient contents. This study developed and evaluated nutrient-dense complementary food formulations from locally available soybean, groundnut, and crayfish as affordable alternatives to traditional weaning foods. Three formulations were prepared: Sample A (70:20:10), Sample B (60:30:10), and Sample C (50:40:10), alongside a commercial complementary food as control. The formulations were evaluated for microbiological quality, proximate composition, functional properties, and sensory attributes. Microbiological analysis of raw ingredients showed total heterotrophic bacterial counts ranging from 11.00 ± 2.83 ×10⁵ cfu/g in crayfish to 23.50 ± 7.78 ×10⁵ cfu/g in groundnut, while no Enterobacteriaceae were detected before processing. Following processing, heterotrophic bacterial counts decreased to 0.90 ± 0.28 ×10⁵–1.35 ± 0.35 ×10⁵ cfu/g. Bacterial isolates identified included Staphylococcus aureus (26.67%), Escherichia coli (20.00%), Salmonella spp. (16.67%), Enterobacter sp. (16.67%), Bacillus subtilis (13.33%), and Shigella sp. (6.67%). Proximate analysis revealed low moisture content (2.48–4.46%), crude fat ranging from 29.90–32.97%, and protein values of 15.30–22.53%, with Sample A recording the highest protein content. Functional properties showed acceptable bulk density (1.14–1.29 g/ml), dispersibility (58–70%), and water absorption capacity (0.63–0.92). Sensory evaluation indicated that Sample B had the highest acceptability among the formulated blends, although the control sample recorded superior scores across sensory parameters. This findings indicate that soybean– groundnut–crayfish blends are nutritionally improved, affordable, and culturally acceptable complementary foods with potential to reduce protein-energy malnutrition in Nigeria. Further studies on micronutrient composition, shelf-life stability, and growth performance are recommended.

Food preservation is essential for extending the shelf life and maintaining the quality of perishable goods. Neem (Azadirachta indica) has gained attention as a natural preservative due to its bioactive compounds with antimicrobial, antifungal, and antioxidant properties. This study aimed to evaluate the preservative potential of neem extracts (aqueous and ethanolic) on bell pepper, tomato, and banana over a 14-day storage period. Bacterial populations on fresh and neem-coated fruits were enumerated, characterized, and identified, while physical and sensory attributes were assessed. The antibiotic susceptibility patterns of isolated bacteria were also determined using the Kirby-Bauer disc-diffusion method. Results showed that ethanolic neem extracts significantly reduced bacterial loads, particularly in bell pepper (5.30±0.13 cfu/cm² by day 14), while aqueous extracts were moderately effective. Coliform and staphylococcal counts declined across all treated fruits, with ethanol-treated bananas exhibiting minimal contamination (0.04±0.00 cfu/cm² by day 9). Salmonella counts also decreased, with ethanol-coated banana samples showing a reduction from 39.80±0.35 to 2.20±0.01 cfu/cm² by day 14. Bacterial isolates identified include Staphylococcus aureus, Micrococcus spp. and Klebsiella pneumoniae, with control samples exhibiting a higher prevalence of pathogenic strains. Physical and sensory assessments revealed that ethanol-coated fruits retained better texture and color, while control samples deteriorated more rapidly. Antibiotic sensitivity tests indicated that Klebsiella pneumoniae isolated from ethanol-treated samples was most susceptible, while control samples harbored more resistant strains, suggesting a higher spoilage risk. The findings confirm the antimicrobial potential of neem extracts in reducing bacterial loads and preserving fruit quality, with ethanolic extracts demonstrating superior efficacy. However, further research is needed to optimize extract concentrations, explore additional fruit varieties, and compare neem with synthetic preservatives for commercial applications. This study highlights the potential of neem-based coatings as a sustainable alternative to chemical preservatives, aligning with global trends in eco-friendly food preservation

This study investigated the presence of pathogenic and antibiotic-resistant bacteria in wastewater collected from selected environmental hotspots within Ikpoba-Okha Local Government Area, Benin City, Edo State, Nigeria. Wastewater samples were aseptically collected from Ramat Park and Ramat Market, sites characterized by intense commercial activity and poor sanitation. Samples were serially diluted and cultured on selective and differential media including MacConkey and EMB agar. Bacterial isolates were identified based on colony morphology, Gram staining, and biochemical tests. Total heterotrophic bacterial counts ranged from 3 × 10 4 to 9.2 × 10⁵ CFU/mL, indicating high microbial contamination. Predominant isolates included Escherichia coli, Pseudomonas species, and Klebsiella species, suggesting fecal pollution and environmental contamination. Antibiotic susceptibility testing revealed high resistance to β-lactam antibiotics (such as Augmentin, Ceftazidime, Ceftriaxone, and Cefuroxime), while isolates showed greater susceptibility to fluoroquinolones (such as Ofloxacin and Ciprofloxacin) and aminoglycosides (such as Gentamicin and Streptomycin). These findings indicate the presence of opportunistic pathogens and multidrugresistant bacteria in wastewater environments, posing potential public health risks. The study emphasizes the urgent need for improved wastewater management, environmental sanitation, and continuous microbial surveillance to prevent the spread of waterborne diseases and antimicrobial resistance within the community.

Coliform bacteria contamination in river water is a significant public health concern, as it often indicates the presence of fecal pollution, which may harbor pathogenic microorganisms. Coliform bacteria, especially Escherichia coli, are commonly used as indicator organisms for water quality assessment due to their presence in the intestines of warm-blooded animals and, therefore, in their waste. This study was aimed at assessing the physicochemical and coliform bacteria in Ikpoba river in Benin City, Edo state. The physicochemical result obtained in this study showed that pH was at 5.0, as against the WHO limit of 6.5-8.5 thus making the water dangerous for consumption by humans and aquatic lives. The electronic conductivity of the water was recorded at 62, against the WHO limit of 1500, this was below the permissible limit. turbidity was at 6.37. Copper, zinc, chromium and cadmium result in this study were 8.73, 26.45, 3.95, 0.042 respectively. The coliform bacteria count obtained in this study showed that the bacteria count ranged at 4.7 X 10 4± 2.00 cfu/ml -7.7 X 10 4± 1.00 cfu/ml for all sections of the river. Using the standard microbial method which include cultural, morphological and biochemical characterization, the isolates obtained in this study were Escherichia coli, Citrobacter sp, Enterobacter sp, Serratia sp and Klebsiella sp. The presence of coliform bacteria such as Escherichia coli, Citrobacter, Enterobacter, Serratia, and Klebsiella in river water can have serious health and ecological effects. The presence of coliform bacteria, such as Escherichia coli, Citrobacter, Enterobacter, Serratia, and Klebsiella, along with heavy metals in river water, poses a multifaceted threat to both human health and aquatic ecosystems.

The overuse of antibiotics in poultry production has heightened resistance concerns, prompting the search for eco-friendly and plant-based antimicrobial alternatives. Both Chromolaena odorata and Vernonia amygdalina are rich in bioactive phytochemicals, including alkaloids, flavonoids, tannins, terpenoids, and saponins, known to exhibit strong antibacterial and antioxidant properties. Eight (8) poultry droppings samples were aseptically collected from four poultry farms in Ekpoma, Edo State, Nigeria, using sterile universal bottles. Standard microbiological procedures were employed for the isolation and identification of enteric bacteria, including serial dilution, culturing on MacConkey agar, and biochemical characterization based on Standard microbiological techniques. Fresh leaves of C. odorata and V. amygdalina were collected, washed, blended, and filtered to obtain aqueous crude extracts. Antibacterial activity was assessed using the agar well diffusion method, while the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined by broth dilution and sub-culturing methods respectively. Five bacterial isolates—Escherichia coli, Bacillus sp., Proteus sp., Pseudomonas aeruginosa, and Staphylococcus aureus—were identified from the poultry droppings. Both extracts showed varying degrees of antibacterial activity against all isolates, with V. amygdalina producing larger zones of inhibition than C. odorata. The MIC and MBC results confirmed that higher extract concentrations corresponded with greater bacterial inhibition and killing effects, indicating concentration-dependent antibacterial efficacy. The findings demonstrate that Chromolaena odorata and Vernonia amygdalina possess significant antibacterial activity against enteric bacteria isolated from poultry droppings, suggesting their potential as natural, plant-based alternatives to synthetic antibiotics for controlling bacterial infections in poultry and mitigating antimicrobial resistance

Indoor air quality in healthcare environments is an important determinant of patient safety and occupational health. Airborne fungi are among the major biological contaminants in hospitals and primary health centers, where they can cause allergic reactions, opportunistic infections, and surface deterioration. This study was designed to evaluate the airborne fungal load and diversity in selected Primary Health Centers (PHCs) within Egor Local Government Area, Edo State, Nigeria. Air samples were collected weekly for three weeks from Uselu, Evbotubu, and Evhuogida PHCs using the settle plate technique. Fungal colonies were enumerated as colonyforming units per cubic meter (CFU/m³), and isolates were identified based on cultural and morphological characteristics. Antifungal susceptibility testing was conducted using standard disc diffusion methods. Results revealed that fungal load ranged from 2.4 ×10² to 3.5 ×10² CFU/m³, with Uselu PHC recording the highest mean load (3.33 ×10² CFU/m³) and Evbotubu PHC the lowest (2.45 ×10² CFU/m³). Four fungal genera Aspergillus sp., Penicillium sp., Cladosporium sp. and Fusarium sp. were identified, with Aspergillus sp (38%) being the most predominant. Alternaria sp. was the least frequent. Antifungal screening showed that Aspergillus sp. was most sensitive to ketoconazole and amphotericin B, while Penicillium sp. showed resistance to fluconazole and ketoconazole. The findings highlight that primary health centers in Egor LGA harbor airborne fungal contaminants, with variations linked to environmental and infrastructural factors. Regular environmental monitoring, adequate ventilation, and periodic sanitation are recommended to reduce potential exposure to pathogenic fungi within healthcare environments.

Mobile phones are frequently exposed to various environmental contaminants and serve as potential reservoirs for bacterial pathogens, particularly among individuals in high-contact occupations such as market women. This study aimed to isolate and identify bacterial contaminants from mobile phones used by selected market women in Benin City, Edo State, to assess potential public health risks. Total bacterial counts (TBC) ranged from 1.70 ± 0.02 × 10⁴ cfu/m³ to 3.80 ± 0.53 × 10⁴ cfu/m³, indicating significant microbial contamination. Morphological and biochemical characterization identified Salmonella spp., Escherichia coli, Bacillus spp., Klebsiella sp., Streptococcus sp., Staphylococcus sp., and Enterococcus sp. Staphylococcus spp. exhibited the highest occurrence (20%), followed by Streptococcus spp. (16%) and Escherichia coli (13%), while Klebsiella sp. had the lowest occurrence (5%). Antibiotic susceptibility testing revealed varying resistance patterns among isolates. Escherichia coli exhibited resistance to cefotaxime and nitrofurantoin, while Staphylococcus sp. was resistant to cefotaxime and nitrofurantoin but sensitive to ampicillin, levofloxacin, and imipenem. The multiple antibiotic resistance (MAR) index ranged from 0.3 to 0.5, highlighting the presence of antibiotic-resistant strains with potential public health implications. These findings emphasize the need for improved hygiene practices among market women to minimize bacterial contamination and potential disease transmission.

This study investigated the microbial source tracking of faecal bacterial pathogens in Ogba River, Benin City, Nigeria. Water samples collected from different locations were analyzed using standard cultural, morphological, Gram staining, and biochemical techniques. The isolates identified were Escherichia coli, Salmonella spp., Shigella spp., and Staphylococcus aureus. E. coli and other Gram-negative rods indicated fecal contamination while S. aureus reflected anthropogenic input from human activities. Biochemical results confirmed the pathogenic potential of the isolates. The detection of these organisms demonstrates that Ogba River is contaminated with both human and animal wastes, posing serious public health risks. The result highlights the effectiveness of microbial source tracking in identifying contamination origins and emphasizes the need for regular water quality monitoring, improved sanitation, and proper waste management to prevent disease outbreaks and protect community health.

Wastewater drains within university hostels can serve as reservoirs for various microorganisms, including opportunistic pathogens that pose significant health and environmental risks. Among these microbes, Klebsiella species—especially Klebsiella oxytoca—are notable for their ability to survive in damp environments and their resistance to multiple antibiotics. This study aimed to isolate and identify Klebsiella spp. from wastewater drains in male hostels (Hall 3 and Hall 4) at the University of Benin, Edo State, Nigeria. Wastewater samples were aseptically collected from four designated drain points—two each from Hall 3 and Hall 4—using sterile 500 mL bottles. The samples were transported in ice-packed coolers to the Microbiology Laboratory, Faculty of Life Sciences, for bacteriological examination. Standard microbiological methods were used to enumerate, isolate, and identify bacterial species based on their cultural, morphological, and biochemical features. The total heterotrophic bacterial counts ranged from 4.82 to 4.87 Log₁₀ CFU/mL, reflecting high microbial loads in all the sampled drains. Total Klebsiella counts varied between 5.75 to 6.00 Log₁₀ CFU/mL, with the highest found at Hall 4 Point A and the lowest at Hall 3 Point A. The identified bacterial isolates included Escherichia coli, Klebsiella oxytoca, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. Notably, Klebsiella oxytoca appeared consistently across all sampling points, indicating its strong adaptability to wastewater environments. The findings underscore that hostel drainage systems can act as reservoirs and transmission routes for potentially pathogenic and environmentally persistent bacteria. Regular sanitation and effective wastewater management are therefore essential to minimize environmental contamination and associated public health risks.

Antibiotic resistance has emerged as a major global health concern, particularly in bacterial pathogens associated with urine from asymptomatic students. This study investigated bacteria isolates from urine samples of healthy students, focusing on their prevalence, virulence characteristics and antibiotic resistance. Thirty-five (35) isolates were obtained and identified using selective media and biochemical tests, while virulence factors including haemolysis, capsule formation, serum resistance and gelatinase production were assessed by standard laboratory methods. Antibiotic susceptibility was determined using the Kirby-Bauer disc
diffusion method. Results showed that Escherichia coli as the most prevalent bacteria 6 (26 %), followed by Staphylococcus aureus 3 (17 %), Streptococcus sp. 4 (13 %), Salmonella sp.3 (12 %) while Micrococcus sp., Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterococcus faecalis 2 (8 %) respectively. All isolates exhibited haemolytic activity, predominantly β-
haemolysin, except Klebsiella pneumoniae and Enterococcus faecalis. All isolates except Micrococcus sp., Pseudomonas aeruginosa and Enterococcus faecalis produced capsule. Serum resistance assays revealed that E. coli, Streptococcus sp., Klebsiella pneumoniae, Pseudomonasaeruginosa and Micrococcus sp. were resistant, while S. aureus, Enterococcus faecalis and Salmonella sp. were sensitive. Gelatinase activity was confirmed in E. coli, S. aureus, Pseudomonas aeruginosa and Salmonella sp., but absent in Streptococcus sp. Enterococcus faecalis, Klebsiella pneumoniae and Micrococcus sp. Antibiotic testing showed the bacteria
isolates were not resistant to levofloxacin and gentamycin, while resistance was observed against other antibiotics tested. The pathogenic potential of bacterial isolates recovered from healthy individuals emphasized the need for continuous monitoring of antimicrobial resistance to prevent dissemination.