ISOLATION

The study of the fungi associated with leaf spot disease of P. guajava (guava) was conducted in order to compare the radial mycelial growth of the isolated fungi on both potato dextrose agar (PDA) and corn meal agar (CMA). Fungi associated with the diseased guava leaves were isolated using the direct plating method while the radial mycelial growth of the isolated fungi was done using radial mycelial measurement technique. Pestalotia psidii and L. theobromae were identified as the fungi associated with the diseased guava leaves. Cultural description shows P. psidii to form whitish to grey mycelium with sparse black sporulation on PDA but grows very slowly on CMA with rarely visible mycelial growth on the culture plate. Lasiodioplodia theobromae on the other hand developed cottony mycelia that transition from white to black as the colony matures on PDA and produces less whitish to dark, septate mycelia on CMA which barely turns black as the colony matures. The results the radial mycelial growth of P. psidii and L .theobromae on corn meal agar shows an increase in the average mycelial growth of P. psidii from 3.25cm on day 3 to 5.20cm on day 7 while L. theobromae was observed to increase from 3.63cm on day 3 to 5.63cm on day 7. On PDA the average mycelial growth of P. psidii increases from 5.05cm on day 3 to 8.5cm on day 7 while L. theobromae was observed to increase from 3.90cm on day 3 to 7.45cm on day 7. Findings of this study has shown P. psidii and L. theobromae to be the major fungi associated with leaf spot disease of guava leaves and also shown the growth medium PDA to be more suitable for the in vitro radial mycelial growth study of P. psidii and L. theobromae.

Wastewater generated from restaurants often contains a mixture of organic matter and microbial contaminants that may pose environmental and public health risks. This research focuses on the detection and isolation of Escherichia coli (E. coli) from wastewater collected from selected restaurants within the University of Benin, Benin City, Nigeria. For this study, wastewater samples were obtained from three restaurants: Helena’s Kitchen, Home and Away, and Buka— during peak operation hours. The samples were collected aseptically and analysed using standard microbiological methods. The pour plate technique was employed for total heterotrophic bacterial counts, while selective media such as Eosin Methylene Blue (EMB) agar were used for the isolation of E. coli. Biochemical tests including indole, methyl red, citrate, urease, and triple sugar iron (TSI) were used to confirm the isolates. The results showed high microbial loads across all samples, with E. coli being consistently present, indicating faecal contamination of the wastewater. The identification of other bacterial species suggest contamination from multiple sources such as food residues, human handling, and the environment. The findings reveal poor wastewater management and hygiene practices in the studied restaurants. In conclusion, the consistent presence of E. coli in restaurant wastewater signifies potential health and environmental hazards within the University of Benin. It is therefore recommended that wastewater from restaurants be regularly monitored, and that adequate sanitation infrastructure and treatment systems be put in place to prevent contamination and safeguard public health.

The contamination of water sources by untreated wastewater poses a serious public health risk due to the spread of pathogenic bacteria, particularly Gram-positive species. This study examined the microbiological properties of wastewater collected from commercial laundry shops in Benin City, Edo State, Nigeria. The research focused on enumerating total heterotrophic bacteria, isolating Gram-positive bacteria, and identifying their species based on morphological and biochemical characteristics. A total of eight (8) wastewater samples were collected in duplicates from two commercial laundry shops, with the samples divided into two categories: wastewater from washing and wastewater from rinsing. Microbial enumeration was performed using the spread plate technique on nutrient agar, while Mannitol salt agar was used for selective screening of Gram-positive bacteria. The bacterial isolates were characterized based on their morphological and biochemical properties using standard microbiological methods. Results revealed that the total heterotrophic bacterial counts were highest in the laundry washing wastewater samples, with values ranging from 102±2.3 × 10⁶ to 81±0.9 × 10⁶ CFU/mL. In contrast, significantly lower bacterial counts were observed in the rinsing wastewater samples, with counts ranging from 48±1.8 × 10⁶ to 25±2.4 × 10⁶ CFU/mL. Additionally, the bacterial counts varied by location, with Laundry Shop 1 recording 68±1.4 × 10⁶ CFU/mL and Laundry Shop 2 showing slightly lower counts at 57±1.6 × 10⁶ CFU/mL. The microbiological assessment of laundry wastewater revealed the presence of diverse bacterial species, with a total of 17 isolates identified and characterized. Staphylococcus aureus was the most prevalent isolate, accounting for 52.9% (9/17) of the total, followed by Staphylococcus spp. (41.2%) and Micrococcus spp. (5.9%). These findings highlight the potential health and environmental risks associated with untreated laundry wastewater, particularly due to the dominance of pathogenic and opportunistic bacteria. The study emphasizes the need for effective wastewater management practices in commercial laundry facilities to mitigate the spread of microbial contaminants. Future research could focus on advanced treatment technologies and their ability to reduce bacterial load in laundry effluent.

The rapid adoption of cashless transactions in Nigeria, particularly in bustling commercial areas like the Uselu to Textile Mill Junction, Benin City, Edo State, has led to the widespread use of Point-of-Sale (POS) machines. These devices, frequently handled by multiple users with varying hygiene practices, have raised concerns about their potential as fomites for microbial contamination and the spread of infectious diseases. The aim of this study was to isolate and identify bacteria associated with POS machines, determining their total heterotrophic count, assessing their distribution across different locations, and evaluating their susceptibility to commonly used antibiotics. Swab samples were collected from 20 POS machines (designated POS 1 to POS 20) during peak usage hour. The bacterial isolates were purified and identified based on standard cultural, morphological and biochemical characteristics. The results revealed significant bacterial contamination, with total viable counts ranging from 5.0 ×10² to 8.1 × 10⁴cfu/ml. The predominant bacterial genera identified were Micrococcus spp., Pseudomonas spp., Staphylococcus spp., Streptococcus spp., and Bacillus spp. Micrococcus spp. and Pseudomonas spp had the same percentage occurrence of 21.67% being the most frequent bacterial isolates. The antibiotic susceptibility tests showed varying resistance patterns, with many isolates resistant to β-lactam antibiotics like ampicillin and ceftriaxone, raising concerns about the potential spread of antimicrobial resistance. This study highlights the urgent need for regular disinfection of POS machines, improved hygiene practices among users and operators, and public awareness campaigns to promote hand hygiene, the high microbial loads and presence of resistant strains underscore the public health risks posed by POS machines in high-traffic settings. These measures are critical to reducing the risk of fomite-mediated infections and combating the growing threat of antimicrobial resistance in community settings like Uselu to Textile Mill Junction

The main objective of food preservation has been on controlling microbial populations, with a specific emphasis on pathogenic microorganisms. Food preservation implies inhibiting the growth of microorganisms. Hostile environments for microorganisms are an adequate food preservation strategy The application of heat treatments, reduction of storage temperatures, application of good manufacturing practices and the addition of additives define the food shelf-life and safety. The aim of this study was to evaluate the presence of Staphylococcus aureus in frozen food such as chicken turkey and fish and to enumerate Staphylococcus aureus in the frozen foods’ samples. The samples were gotten from various locations in Benin City. The eight (8) samples were carried to the laboratory and analyzed following standard operations and procedures. The results of the microbial assessment of the frozen foods to isolate, identify and enumerate Staphylococcus aureus. The total heterotrophic bacterial counts revealed that the population density of the microorganisms varied from one sample to another. The mean total heterotrophic bacterial count ranged from 7.0×10 3 to 4.2×10 4 cfu/g for the samples. The results revealed the isolates as Serratia marcescens, Proteus mirabilis and Staphylococcus aureus. which indicated a diversity of the microbial species found in the frozen food samples. The results obtained in this study revealed that the bacterial isolates present in the frozen food samples were found to harbor certain enzymes and factors, which contributes to their virulence factors. The microbial assessment of the frozen foods revealed that Staphylococcus aureus had the highest prevalence amongst the isolates found in the frozen food samples with a percentage occurrence of 57.14%. From the study it was ascertained that freezing as a means of preservation can reduce bacteria contamination. Due to contamination of frozen food with the bacteria isolates found in this study to be of public health significance thus the usefulness of proper freezing and preservation cannot be overemphasized.

immunocompromised patients. Cryptococcus neoformans var. neoformans is found mainly in temperate climates and is often isolated from pigeon droppings. It is the causative agent of Cryptococcosis and is believed to arise after inhalation of yeast cells or basidiospores from environmental sources. For the purpose of this research, two strains of Cryptococcus neoformans; one clinical FBC and one environmental NBM5 were selected and confirmed using urease medium, based on their melanin production on Niger seed agar and ability to grow at 37oC. An antifungal susceptibility test was carried out on the clinical and the environmental isolates using Fluconazole as the antibiotic agent. Fluconazole is an antifungal therapeutic agent used in the treatment of Cryptococcosis. Responses of both isolates to Fluconazole showed similar results. Both isolates were also subjected to environmental stressors using sodium nitrate (NaNO2) to induce nitrosative stress and hydrogen peroxide (H2O2) to induce oxidative stress. The response of both isolates to this environmental stressors were similar. The selected isolates; clinical isolates FBC and environmental isolates NBM5 were determined to be of the same mating types based on their responses to antifungal susceptibility test and environmental tressors. DNA was isolated from both strains for detailed genetic analysis in the near future. This study provides new insights into how the mating type can greatly influence responses of Cryptococcus neoformans to genetic and environmental factors. Thus, serve as a possible instrument for further study of the genetics of C. neoformans.

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