DEPARTMENT OF MICROBIOLOGY

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.

Door handles are frequently touched surfaces that can serve as reservoirs for bacterial continuation contributing to the spread of infectious diseases, especially in hig-traffic environments such as universities. This study aimed to isolate and identify bacteria from door handles sampled at different faculties within the University of Benin, assesing microbial load and antibiotic resistance patterns. Total bacterial counts(TBC) varied across faculties, with the Faculty of Physical Sciences(FPS) exhibiting the highest count(4.03 = 0.32 * 10 cfu/cm2 ) in 1 week, while the faculty of life sciences(FLC) recorded the highest count(4.50 = 0.25 *10cfu/cm2) in 2 weeks.

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 laundrywastewater 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.

The safety and microbiological quality of ready-to-eat (RTE) foods are essential to ensuring public health, particularly in institutional environments such as universities, where large populations rely on convenient food options. This study evaluated the bacteriological quality of selected RTE foods sold in restaurants within the University of Benin, Edo State, Nigeria. Food samples analyzed over two weeks included Moi Moi (Bean Pudding), Fried Rice, White Rice, Egusi Soup, and Yam and Plantain Sauce. The Total Viable Bacterial Count (TVC) of the food samples ranged from 2.3 ± 0.30 × 10⁵ cfu/g to 5.1 ± 0.28 × 10⁵ cfu/g in Week 1 and 2.1 ± 0.18 × 10⁵ cfu/g to 4.7 ± 0.30 × 10⁵ cfu/g in Week 2, indicating a significant microbial load that could pose potential health risks. Cultural, morphological, and biochemical analyses were conducted to identify the bacterial contaminants in the food samples. The bacterial isolates identified included Escherichia coli, Bacillus sp., Proteus sp., Citrobacter sp., Staphylococcus sp., and Enterobacter sp. Among these, Staphylococcus sp. was the most prevalent, with the highest percentage occurrence across all food samples. Antibiotic susceptibility testing was performed on the isolates using a panel of commonly used antibiotics, including Cefotaxime, Ampicillin, Ofloxacin, Cefixime, Gentamicin, Levofloxacin, Cefuroxime, Imipenem, Nitrofurantoin, and Nalidixic Acid. The results showed varying levels of resistance and susceptibility, with certain isolates exhibiting multidrug resistance.

Despite the presence of different variety of chemical fungicides, the search for new antifungal substances against plant pathogens continues because of the negative effect these fungicides has on both the plants and the environment. This study was aimed at assessing the antifungal activities of Moringa oleifera and Olea europaea oil individually and their synergistic combination against selected phytopathogenic fungi. Two fungi were isolated from agricultural soils obtained from different locations. Antifungal activities of Moringa, Olive oil individually and synergistically were performed using the food poisoning method. Penicillium chrysogenum and Mucor circinelloides used in this study were isolated from the agricultural soil. The phytochemical analysis of Moringa oil revealed a cocktail of phytochemicals while Olive oil showed only the presence of terpenoids. From the results, Moringa oil alone demonstrated strong activity against the pathogens with radial growth inhibition ranging from 2.83±0.04mm (Penicillium chrysogenum, 14%) to 5.83±0.10mm (Mucor circinelloides, 6%) this was significantly different from the controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). For Olive oil alone the radial growth inhibition ranged from 4.90±0.05mm (Penicillium chrysogenum, 14%) to 24±0.30mm (Mucor circinelloides, 2%)
this was significantly different from the controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). The synergistic combination of Moringa oil and Olive oil gave a result ranging from 0.00±0.00mm (Mucor circinelloides, 14%) to 12.33±0.14mm (Penicillium chrysogenum, 14%) compared to their controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). The highest percentage mycelial radial growth inhibiton for Moringa oil on day 7 was 89.79% (Mucor circinelloides) and the lowest was 71.70% (Penicillium chrysogenum).

Zinc oxide nanoparticles (ZnONPs) have been investigated for their great antimicrobial effect against multiple pathogens. Bacterial pathogens used for this research were isolated from African black soap samples and characterized using the phenotypic method. The antibacterial activity of biologically synthesized zinc oxide nanoparticles (ZnONPs) against the isolates; Pseudomonas amygdali 35-1 CP084212, Micrococcus sp. and Staphylococcus aureus was investigated in-vitro. Nanoparticle treatments were applied at different concentrations (25%, 50%, and 100%) and an antibacterial agent Ampicillin was used as a control. The zones of inhibition were measured in millimeters. ZnONPs at all concentrations had insignificant inhibitory effect on Micrococcus sp. and Staphylococcus aureus (p>0.05) compared to the control. However, ZnONPs (100%) demonstrated significantly higher inhibitory activity on Pseudomonas amygdali 35-1 CP084212 (p<0.05) compared to the control. The zones of inhibition ranged from 3.33 ± 0.54 to 18.00 ± 0.94 mm while the zones of inhibition for the control were 6.33 ± 1.09 mm (Pseudomonas amygdali 35-1 CP084212), 18.67 ± 1.09 mm (Micrococcus sp.) and 16.00 ± 4.10 (Staphylococcus aureus). The findings obtained from this investigation demonstrated the antimicrobial efficacy of zinc oxide nanoparticles against the selected bacterial isolates.

Carrot (Daucus carota) is one of the most important economical root vegetable crops worldwide and the largest source of provitamin A and carotenoids in the human diet. Storage is a prerequisite for a year-round supply of Carrot, but longer duration can affect its quality. Essential oils also has diverse and relevant biological activities. This study was aimed towards isolating the bacteria associated with rotted carrot, characterizing and isolating three bacteria isolate and determining the antibacterial properties of selected essential oils against the isolates using Agar well diffusion method. Suspected bacteria pathogens were isolated from a diseased carrot tuber, the isolates were identified using biochemical and cultural characterization. Essential oils were used in the antimicrobial sensitivity treatment using agar well diffusion method against the isolated bacteria to determine the antibacterial property of the essential oils. The results showed that Enterobacter sp., Pseudomonas sp. and Agrobacterium tumenfacienwere the isolated pathogenic bacteria from the carrot tubers. The essential oils which are (Neem oil, Tea tree oil and Bergamot oil), showed no antibacterial activity on the isolated bacteria pathogens. Further investigations can be done using essential oils against bacterial isolates but it should be extracted from the plant source to avoid destroying its potential antimicrobial properties.

Human hands usually harbor microorganisms both as part of normal flora and
microorganisms contacted from the environment. A prospective study was carried out in the University of Benin, Benin City, Nigeria. This study was aimed at identifying the types of bacteria associated with hands of undergraduate students in the University of Benin and to isolate and determine the hemolysin production of bacteria isolates present on the hands of the students. A total of 6 samples were obtained. The samples were analyzed using cultural, morphological and biochemical characteristics (citrate, indole, oxidase, catalase, motility, triple sugar ion and coagulase). The bacteria isolates recovered were S. aureus 3(25%), C. jeikeium 1(8.33), S. epidermidis 4(33.33), S. hominids 2(16.67) and Escherichia coli 2(16.67). All isolates of S. aureus, E. coli and S. hominis showed complete hemolysis (Beta hemolysis) while S. epidemidis and C. jeikeium were non hemolytic (Gamma hemolysis). All Gram positive isolates were resistant to amoxicillin, rifampin and septrin. Gram negative bacteria isolates were highly resistant to nalixidic acid, gentamicin, ciprofloxacin and ampicillin

Antimicrobial resistance (AMR) poses a significant public health threat, enabling bacterial strains to withstand common antimicrobial therapies. This study aimed to determine the prevalence and antibiotic resistance patterns of hospital-acquired Escherichia coli infections among children admitted to a tertiary hospital in Benin City, Nigeria. This was a cross-sectional study conducted from August to October 2025. A total of 80 swab samples were processed using standard culture-based methods. Bacterial isolates were identified via cultural characteristics, Gram staining, and standard biochemical tests (Catalase, Oxidase, Citrate, Indole, VogesProskauer, Hydrogen Sulphide, Methyl red, Urease and Sugar Fermentation). Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disc diffusion method. The antibiotics tested included ceftriaxone, ceftazidime, ciprofloxacin, gentamicin, amoxicillin-clavulanic acid and meropenem. The Patient demographics showed a clear difference, with the highest number recorded among male in-hospital patients (44) and the lowest among female community patients (4). Organism distribution varied by sample site, where Escherichia coli was the dominant isolate in rectal samples (17 isolates). Testing against a panel of 19 antibiotics revealed that most E. coli isolates remained susceptible. The highest resistance was observed against sulfamethoxazole-trimethoprim (7 isolates). Multidrug resistance patterns were diverse, with the combination of ciprofloxacin, piperacillin, and sulfamethoxazole (CIP, PIP, SUL) being the most frequently observed MDR profile (in 2 isolates). These findings align with previous reports from Nigerian hospitals, emphasizing the need for improved antimicrobial stewardship, routine resistance monitoring, and strict infection prevention measures to reduce hospital-acquired infections and ensure effective patient care.

Study was carried out to investigate bacteria in urine contaminated soils within University of Benin Ugbowo campus. Five soil samples were collected and analyzed using soil serial dilution and pour plating techniques. Nutrient agar was used for bacteria isolation and subculture. Urine contaminated soil samples were collected from Hall three, Life science complex and Library extension while control soil samples were collected from Hall two car park and Hall three. Bacteria isolated from these soil samples and their prevalence include Bacillus subtilis (80%), Staphylococcus aureus (40%), Micrococcus luteus (60%), Escherichia coli (20%), Klebsiella pneumonia (40%) and Pseudomonas aeruginosa (60%). Hall three control soil had the highest bacteria count while Life science complex had the lowest bacteria count with the range of 5.5 × 10³ Cfu/ml and 7 × 10³ Cfu/ml. Various biochemical test were carried out which include oxidase test, citrate test, indole test, TSIA test, to identify isolates based on their reaction to these test. Antibactrial susceptibility test was also carried out. Antibiotics used include Gentamycin, Colistin, Carbenicillin, Ciprofloxacin and Tetracyclin. Urine contaminated soils are threats to the public’s health since they can be used as routes for the spread of infection.