DEPARTMENT OF MICROBIOLOGY

Lecture theatre tables serve as potential reservoirs for bacterial contamination, posing a risk of microbial transmission among students and staff. This study aimed to isolate and identify bacterial species from tables in lecture theatres within the Faculty of Life Sciences, University of Benin. Total heterotrophic bacterial counts were determined over two weeks, with values ranging from 1.88 ± 1.00 × 10⁴ cfu/cm² to 3.80 ± 0.53 × 10⁴ cfu/cm². The highest bacterial load was recorded in the Microbiology Lecture Theatre (3.80 ± 0.53 × 10⁴ cfu/cm² in Week 2), while the lowest was observed in the Optometry Lecture Theatre (1.88 ± 1.00 × 10⁴ cfu/cm² in Week 1). Biochemical characterization and standard taxonomic references identified six bacterial genera: Staphylococcus, Streptococcus, Pseudomonas, Enterobacter, Escherichia coli, and Bacillus. Among these, Staphylococcus spp. (31%) exhibited the highest occurrence, while Pseudomonas spp. (10%) had the lowest. Antibiotic susceptibility testing revealed varying resistance patterns, with Bacillus spp. being the most sensitive, whereas Pseudomonas spp. and Escherichia coli displayed resistance to multiple antibiotics. The multiple antibiotic resistance (MAR) index ranged from 0.2 to 0.4, with Pseudomonas spp. and Escherichia coli exhibiting the highest resistance. The findings underscore the need for regular sanitation of lecture theatre surfaces to mitigate the risk of bacterial transmission and potential health implications.

Soy milk, sometimes referred to as soybean milk, a staple of the Asian diet is a plant-based beverage made by crushing, boiling, and soaking soybeans, the leftovers are then filtered to create a smooth liquid. However, because of its affordability, growing awareness of its health advantages, and improved public acceptance particularly among those who wish to reduce their intake of animal products its consumption ratio has been rising in other areas. It is also a component of other goods such dressing, soy cheese, and soy yoghurt. Among those who are lactose intolerant or allergic to cow’s milk proteins, it is one of the most popular dairy substitutes consumed globally. Soymilk samples were collected from five major locations; Boundary, Newton, Edo Street, JB, and Backgate and analyzed using standard microbiological methods for total heterotrophic and coliform counts, as well as for the isolation and identification of bacterial species. The total bacterial counts ranged from 1.095 × 10⁷ to 9.5 × 10⁷ CFU/ml, while total coliform counts ranged from 1.0 × 10⁶ to 2.3 × 10⁷ CFU/ml, indicating a high microbial load exceeding recommended limits for ready-to-drink beverages. Three bacterial species were consistently isolated across all samples: Bacillus subtilis, Staphylococcus epidermidis, and Klebsiella pneumoniae. Antimicrobial testing showed that chitosan exhibited broad-spectrum antibacterial activity, with inhibition zones ranging from 21 mm to 50.5 mm. Klebsiella pneumoniae was the most susceptible (MIC = 6.25 µg/ml; MBC = 12.5 µg/ml), while Bacillus subtilis showed the least sensitivity (MIC = 12.5 µg/ml; MBC = 25 µg/ml). These findings reveal significant microbial contamination of locally sold soymilk due to poor hygiene and handling practices and demonstrate the potential of chitosan as a natural biopreservative to enhance the microbial safety and shelf life of soy-based beverages. The study emphasizes the need for Good Manufacturing Practices (GMP) and Hazard Analysis and Critical Control Points (HACCP) systems among local soymilk producers to safeguard public health.

With the poultry sector being among the fastest growing agro-based industries world-wide, the poultry farms have emerged as a perspective and widely distributed business industry in Nigeria. However the global increase in the incidence of food borne illnesses with poultry and its products being a major contributor to these infections has become a major challenge to poultry farming. The aim of this study is to isolate and identify different enteric bacteria, find the antimicrobial sensitivity profile against the pathogens isolated from selected poultry farms in Benin city, Edo state. A total of fifteen (15) freshly voided fecal sample were collected aseptically from different poultry farms. The samples were cultured on selective and differential media including Eosin Methylene Blue (EMB) agar, MacConkey agar, Salmonella shigella (SS) agar and bacterial isolate were identified based on cultural, morphological and biochemical properties. Antibiotic sensitivity test was carried using Kirby-Buer disk diffusion method. The total heterotrophic bacterial counts obtained from the fecal sample ranged from 1.00 × 106 CFU/g to 65.00 × 106 CFU/g. Five bacterial species were identified: Escherichia coli, Salmonella sp., Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis. Among the identified bacterial isolate Escherichia coli had the highest frequency of (53.33%), followed by Klebsiella pneumoniae and Klebsiella oxytoca with a total frequency of (66.67%), Salmonella sp. with a frequency of (26.67%) while Proteus miribilis had the lowest frequency of (4.35%). E. coli and Klebsiella spp. demonstrated resistance to most βlactams, while Salmonella spp. were resistant to β-lactams and gentamicin (aminoglycoside) but showed low susceptibility to fluoroquinolones (ciprofloxacin, ofloxacin). Proteus mirabilis was resistant to all antibiotics tested. Overall, over 80.00% of isolates exhibited resistance to at least two antibiotic classes. These findings underscore the presence of multidrug-resistant enteric bacteria in poultry environments and highlight the need for improved antibiotic stewardship, surveillance, and farm biosecurity.

With the poultry sector being among the fastest growing agro-based industries world-wide, the poultry farms have emerged as a perspective and widely distributed business industry in Nigeria. However the global increase in the incidence of food borne illnesses with poultry and its products being a major contributor to these infections has become a major challenge to poultry farming. The aim of this study is to isolate and identify different enteric bacteria, find the antimicrobial sensitivity profile against the pathogens isolated from selected poultry farms in Benin city, Edo state. A total of fifteen (15) freshly voided fecal sample were collected aseptically from different poultry farms. The samples were cultured on selective and differential media including Eosin Methylene Blue (EMB) agar, MacConkey agar, Salmonella shigella (SS) agar and bacterial isolate were identified based on cultural, morphological and biochemical properties. Antibiotic sensitivity test was carried using Kirby-Buer disk diffusion method. The total heterotrophic bacterial counts obtained from the fecal sample ranged from 1.00 × 106 CFU/g to 65.00 × 106 CFU/g. Five bacterial species were identified: Escherichia coli, Salmonella sp., Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis. Among the identified bacterial isolate Escherichia coli had the highest frequency of (53.33%), followed by Klebsiella pneumoniae and Klebsiella oxytoca with a total frequency of (66.67%), Salmonella sp. with a frequency of (26.67%) while Proteus miribilis had the lowest frequency of (4.35%). E. coli and Klebsiella spp. demonstrated resistance to most βlactams, while Salmonella spp. were resistant to β-lactams and gentamicin (aminoglycoside) but showed low susceptibility to fluoroquinolones (ciprofloxacin, ofloxacin). Proteus mirabilis was resistant to all antibiotics tested. Overall, over 80.00% of isolates exhibited resistance to at least two antibiotic classes. These findings underscore the presence of multidrug-resistant enteric bacteria in poultry environments and highlight the need for improved antibiotic stewardship, surveillance, and farm biosecurity.

Airborne bacterial contamination in student residential areas poses significant public health risks, particularly in densely populated university settings. This study evaluated the microbial quality of air in two student hostels, Ekosodin and Osasogie, at the University of Benin, Edo State, Nigeria, over a three-week period. Air samples were collected and analyzed for total bacterial counts, cultural and biochemical characteristics, distribution patterns, frequency of occurrence, and antibiotic susceptibility profiles. The results revealed that Ekosodin generally exhibited higher bacterial loads, peaking at 5.4 ± 0.35 ×10³ CFU/m³ during Week 2, whereas Osasogie recorded the lowest load of 2.1 ± 0.20 ×10³ CFU/m³ in Week 3. Six bacterial species were isolated: Staphylococcus aureus, Escherichia coli, Klebsiella sp., Proteus sp., Pseudomonas aeruginosa and Bacillus sp. E. coli (25%) and S. aureus (20%) were the most frequently occurring isolates. Antibiotic susceptibility testing revealed that fluoroquinolones (ciprofloxacin and pefloxacin) and aminoglycosides (gentamicin and streptomycin) were the most effective against the isolates, while beta-lactams (ampicillin and amoxicillin) and cotrimoxazole showed widespread resistance. The Multiple Antibiotic Resistance (MAR) indices ranged from 0.00 (Bacillus sp.) to 0.40 (Pseudomonas aeruginosa), highlighting the presence of multidrugresistant bacteria in the residential air. These findings underscore the need for improved ventilation, hygiene, and routine microbial monitoring in student residential facilities to mitigate the risks of airborne bacterial infections.

The growing resistance of pathogenic bacteria to commonly used antibiotics has stimulated renewed global interest in medicinal plants as alternative sources of antimicrobial agents. One such plant, Ocimum gratissimum (commonly known as scent leaf), has long been utilized in traditional medicine due to its therapeutic properties. This study investigated the antibacterial activity of scent leaf extracts against selected bacterial pathogens. Fresh leaves of Ocimum gratissimum were procured, air-dried, and ground into powder. The powdered material was extracted using ethanol and distilled water to obtain ethanolic and aqueous extracts, respectively. The antibacterial effects of these extracts were evaluated against clinical isolates of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, obtained from the University of Benin Teaching Hospital, using the agar well diffusion technique in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phytochemical analysis of both extracts confirmed the presence of alkaloids, flavonoids, tannins, and saponins in varying concentrations, with the ethanolic extract exhibiting a higher abundance of these bioactive compounds. Antibacterial testing revealed a concentration-dependent inhibitory effect for both extracts, with reduced activity observed at lower concentrations. However, the ethanolic extract demonstrated superior antibacterial efficacy, producing inhibition zones of up to 15 mm against Staphylococcus aureus and 12 mm against Pseudomonas species at a concentration of 100 mg/mL. In contrast, the aqueous extract showed moderate activity, with inhibition zones ranging between 10 mm and 12 mm. The minimum inhibitory concentration (MIC) of the ethanolic extract was determined to be 50 mg/mL for S. aureus, E. coli, and Pseudomonas, while Klebsiella species required 100 mg/mL for inhibition. For the aqueous extract, MIC values were only observed at 100 mg/mL for E. coli and Pseudomonas. Furthermore, the minimum bactericidal concentration (MBC) of the ethanolic extract was 50 mg/mL for Staphylococcus aureus and Pseudomonas, and 100 mg/mL for E. coli, whereas Klebsiella species exhibited only bacteriostatic response. The aqueous extract showed bactericidal activity only against Pseudomonas at 100 mg/mL. Overall, the results indicate that Ocimum gratissimum possesses notable antibacterial properties, particularly when extracted with ethanol. These findings validate its traditional medicinal use and suggest its potential application in the development of plant-based antimicrobial agents.

Door handles in public spaces serve as potential reservoirs for microbial contamination, posing risks for the transmission of pathogenic bacteria. This study aimed to isolate, identify, and assess the antibiotic susceptibility of bacterial contaminants on door handles of selected banks within the University of Benin, Benin City, Edo State, Nigeria. The research was conducted across five banks within the university campus, selected due to their high patronage, which increases the likelihood of microbial contamination. Sterile swab samples were collected from both entrance and interior door handles of each bank over a two-week period, during peak business hours (10:00 AM – 12:00 PM). The collected swabs were transferred into sterile peptone water and transported to the microbiology laboratory within one hour for bacterial analysis. The total heterotrophic bacterial count (THBC) was determined using standard culture techniques, with counts ranging from 2.03 ± 0.03 × 10⁴ CFU/ml (Bank D) to 4.72 ± 0.31 × 10⁴ CFU/ml (Bank E). Biochemical and morphological characterization of isolates identified seven bacterial species, including Staphylococcus sp., Bacillus sp., Streptococcus sp., Pseudomonas sp., Enterobacter sp., Escherichia coli, and Klebsiella sp. The frequency of occurrence varied, with Escherichia coli having the highest prevalence (28%), followed by Staphylococcus sp. (20%), while Pseudomonas sp. had the lowest occurrence (12%). Antibiotic susceptibility testing against ten commonly used antibiotics revealed varying resistance patterns among isolates. The multiple antibiotic resistance (MAR) index ranged from 0.3 to 0.5, with the highest recorded for Escherichia coli, Pseudomonas sp., and Micrococcus sp. The results highlight significant bacterial contamination on frequently touched surfaces, emphasizing the need for regular disinfection and improved hygiene practices in high-contact public spaces.

Lemongrass (Cymbopogon citratus) is widely known for its medicinal and antimicrobial properties, with its extracts being used in traditional and modern medicine. Due to the increasing resistance of bacteria to conventional antibiotics, plant-based antimicrobials have gained attention as alternative therapeutic agents. This study investigated the phytochemical composition and antibacterial activity of hot and cold water extracts of Lemongrass leaves against Staphylococcus aureus, Escherichia coli, and Pseudomonas sp. Phytochemical analysis revealed the presence of flavonoids, tannins, and glycosides in both extracts, with glycosides being more prominent in the hot extract. Saponins, steroids, and terpenoids were absent. Antibacterial activity was assessed using the agar well diffusion method, where the hot extract showed higher zones of inhibition at 100% concentration: S. aureus (13.00 ± 0.00 mm), E. coli (16.00 ± 0.00 mm), and Pseudomonas sp. (18.20 ± 0.00 mm), compared to the cold extract: S. aureus (9.0 ± 0.50 mm), E. coli (11.20 ± 0.20 mm), and Pseudomonas sp. (12.00 ± 0.00 mm). The Minimum Inhibitory Concentration (MIC) revealed that the hot extract inhibited E. coli at 25 mg/ml, Pseudomonas sp. at 50 mg/ml, and S. aureus at 25 mg/ml, while the cold extract only inhibited Pseudomonas sp. at 100 mg/ml and S. aureus at 25 mg/ml. Minimum Bactericidal Concentration (MBC) results showed that the hot extract was bactericidal against S. aureus and bacteriostatic against E. coli and Pseudomonas sp., while the cold extract was bactericidal against Pseudomonas sp. and bacteriostatic against the other isolates. Antibiotic susceptibility testing indicated that Gram-positive bacteria were highly susceptible to ciprofloxacin, while Gram-negative bacteria were sensitive to azithromycin. These results highlight the potential application of Cymbopogon citratus as an alternative treatment for bacterial infections, particularly in combating antibiotic-resistant pathogens

The consumption of ready-to-eat vended fruits has become increasingly popular in urban areas, particularly in developing countries. These fruits, often sold by street vendors, are convenient and accessible, providing a quick source of nutrition for many consumers. However, this convenience comes with significant health risks due to potential microbial contamination. Fresh fruits are rich in essential nutrients, including vitamins, minerals, and phytochemicals, making them an integral part of a balanced diet. Fruits can become contaminated with pathogenic microorganisms at various stages, including during harvesting, processing, and selling. Common sources of contamination include unsanitary water used for washing, improper handling by vendors, and exposure to environmental contaminants. Research has identified several bacterial pathogens associated with vended fruits, including Escherichia coli, Salmonella spp., Shigella spp., and Staphylococcus aureus. These pathogens pose a significant risk of foodborne illnesses, which can lead to severe gastrointestinal diseases in consumers. In Nigeria, the rising trend of consuming ready-to-eat fruits has been noted, particularly in markets where hygiene standards are often overlooked. The primary issue is the high prevalence of pathogenic microorganisms such as Escherichia coli, Salmonella spp., Shigella spp., and Staphylococcus aureus on these fruits. These pathogens can easily contaminate fruits through contact with sewage, contaminated utensils, and water, increasing the risk of foodborne illnesses among consumers. The presence of these microbial contaminants not only compromises the safety of ready-to-eat vended fruits but also poses a significant public health risk. The high bacterial and fungal loads observed in these fruits suggest that they are unfit for human consumption, necessitating urgent intervention to improve hygiene standards and food safety practices among vendors. The microbial contamination of ready-to-eat vended fruits is a significant concern. Studies have shown that these fruits can harbour a variety of microorganisms due to exposure to soil, dust, water, and mishandling during harvest and post-harvest processing. The microbial load in the vended fruits was assessed by determining the colony-forming units (CFU) per gram of fruit. The results indicate varying levels of microbial contamination across different fruits. The findings from this study reveal significant microbial contamination in ready-to-eat vended fruits from Ekosodin Community and the environs of the University of Benin. The results indicate a high microbial load across all fruit samples, with both bacterial and fungal contaminants identified. The presence of these bacteria and fungi suggests potential health risks, as they can cause foodborne illnesses if consumed

The scalp hair is composed of soft tissue layers that cover the cranium. This study focused on isolation, identification and antibiogram of bacteria isolates from scalp hair. With the aid of a sterile swab sticks, nine scalp hair of undergraduates’ students were swabbed and transported to the laboratory for bacteriological analysis. All the samples were analyzed within 24hrs of collection. Collected swabbed stick was submerged in a sterile test tubes label A – I contained Nutrient broth and incubated for 2hrs. 1ml was plated from each test tube. It was then incubated at 37 0 C for 24hours. The result of the bacteria isolated include; Staphylococcus epidermis 6 (15%), Staphylococcus aureus 6 (15%), Pseudomonas sp. 2(5%), Bacillus sp. 18(45%), Streptococcus spp. 5(12.5%) and Micrococcus spp. 3(7.5%). Haemolysin test on the strains of Staphylococcus auraeus Streptococcus sp. Staphylococcus epidermis, Micrococcus spp. and Psuedomonas sp. revealed they had β hemolytic activity and only strains of Bacillus spp. showed α hemolytic activity. While the gelatin test showed that all isolates produce gelatinase enzyme which breakdown gelatin. The antibiogram results revealed that All isolates were highly sensitive to ciprofloxacin, Ofloxacin and clindamycin 40(100%). Ciprofloxacin, Ofloxacin and clindamycin was proved to be the most effective against Gram positive and Gram-negative isolates studied in this work. Contamination of scalp hair from this research, could be from poor hand hygiene and environmental hygiene.