MICROBIAL

Tomatoes (Solanum lycopersicum) are among the most consumed vegetables in Nigeria and constitute a vital component of human diets due to their high nutritional and economic value. This study investigated the microbial profiles of three tomato varieties: Beefsteak, Globe, and Roma sold in a selected market in Benin City, Edo State, Nigeria. Standard microbiological techniques were employed for the isolation, enumeration and identification of both bacterial and fungal contaminants using Nutrient Agar, MacKonkey Agar, Eosin Methylene Blue (EMB) Agar, and Potato Dextrose Agar (PDA). The total viable bacterial counts varied among varieties, with Beefsteak tomatoes exhibiting the highest total aerobic bacterial count (5.0 ± 0.5×10³), Enteric bacterial count (15.0 ± 0.5×10³) and Coliform bacterial count(7.6 ± 0.5 ×10³) followed by Roma and Globe varieties (4.2 ± 0.5×10³, 9.2 ± 0.5×10³, 6.4 ± 0.5 ×10³) and (4.2 ± 0.5 ×10³, 3.2 ± 0.5×10³, 2.6 ± 0.5 ×10³) respectively. Identified bacterial isolates included Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, while fungal isolates comprised Aspergillus niger, Penicillium expansum, Rhizopus stolonifer, and Fusarium oxysporum. The observed differences in microbial load were attributed to varietal characteristics such as texture, water content, and handling conditions. The results also revealed that poor post-harvest handling, unhygienic market environments, and the use of contaminated wash water contributed significantly to microbial contamination. It is recommended that vendors adopt improved hygiene, proper storage, and temperature control to reduce spoilage and ensure consumer safety.

Shigella flexneri, a leading cause of bacillary dysentery, induces severe gastrointestinal inflammation, disrupting gut homeostasis. This study evaluates the potential of Lactobacillus
casei as probiotics to enhance immune responses in Wistar albino rats against Shigella flexneri infection. Forty healthy Wistar rats were divided into five groups: Control, challenged (Shigella flexneri-infected), Probiotic (Lactobacillus casei-treated), Prophylactic (pre-treated with Lactobacillus casei before infection), and Antibiotic (ciprofloxacin-treated). Stool samples were collected from rats prior to induction with shigella flexneri and Lactobacillus casei, after induction with Shigella flexneri, and antibiotic treatment. Approximately 1g of stool was homogenized in 9 mL of sterile PBS using a vortex mixer to ensure thorough dispersion. A tenfold serial dilution was performed by transferring 1 mL of the stool homogenate into 9 mL of sterile PBS, creating dilutions from 10' to 10-6. From the 1 dilution, 0.1 mL was plated onto Nutrient agar plates and incubated at 37°C for 24hrs

Airborne microbial contamination poses a significant public health challenge, particularlyinconfined spaces such as public transport systems where ventilation may be inadequateandpassenger density is high. This study investigates the microbial air quality of municipal busesin Benin City, Nigeria, focusing on bacterial contamination levels and the antimicrobial resistance (AMR) profiles of isolated organisms. Using the settle plate method for microbial isolation, bacterial samples were collected from four major bus routes in Benin City: NewBenin, Ring Road, Mission Road, and Uselu. Identification of the isolates was basedoncultural, morphological, and biochemical characteristics. The findings revealed varyinglevelsof bacterial contamination across the bus routes, with the highest mean viable bacterial count (2.34 x 10³ ± 0.34 CFU/m³) recorded on the Ring Road bus and the lowest (1.25 x 10³ ±0.08cfu/m³) on the Mission Road bus. Bacterial species identified included Escherichiacoli, Bacillus sp., Proteus sp., Micrococcus sp., Pseudomonas aeruginosa, Staphylococcus sp., andEnterococcus faecalis, with Staphylococcus sp. exhibiting the highest frequencyofoccurrence (60%) across all routes. Antibiotic susceptibility testing revealed alarmingmultidrug resistance (MDR) patterns, particularly in Staphylococcus sp., emphasizingthegrowing threat of AMR in public spaces. The bacterial counts observed in this studysurpassed WHO-recommended indoor air quality limits, underscoring the necessityforimproved sanitation and disinfection protocols within municipal abuses. The study providescritical data to inform public hygiene policies and supports initiatives aimed at enhancingmicrobial safety in public transport systems, particularly in resource-limited settings likeBenin City.

Garri is a commonly consumed cassava product in Nigeria. Poorly processed/stored garri could pose serious health risk to consumers. This study seek to investigate the microbial evaluation of garri sold in open markets Benin City. Five garri samples were purchased from eight open markets which are; Egor market, Oba market, Ekiosa market, Oluku market and Adolor market, Ikpoba-Hill market, and Aduwawa market, all in Edo State making a total of 40 samples. 500 mg each for the sample and appropriately labeled. The samples were transported to the Environmental Management and Toxicology Department laboratory, for microbial, pH and moisture content analysis. Different media such as Potato Dextrose agar (PDA), Nutrient Agar (NA) were prepared separately. 1g of each sample (garri) was weighing on a weighing balance, dissolved properly in 10m1 of pepton water which was used to prepare ten folds serial dilution. Using pour plate method. The total number of bacteria, yeast and moulds in the garri samples was determined. The total number of colony forming unit (CFU/g) was calculated, the moisture content and pH of the garri samples were also calculated. Data obtained were analyzed in percentage and mean. Total Heterotrophic bacteria count in garri samples (cfu/g x103) indicated that Egor and Adolor markets had the highest heterotrophic bacteria count of (9.25 x103) respectively while Ikpoba Hill market had the lowest count of (1.00 x103). The highest fungal count was recorded in Ekiosa market (1.75) and the lowest was in New Benin market (0.50). The bacteria identified are; Micrococcus sp., Escherichia coli,: Klebsiella sp.,Lactobacillus sp Enterobacter sp., Staphylococcus aureus, Enterococcus sp., Pseudomonas sp,, Streptococcus sp., Shigella sp., Bacillus sp. the fungi identified are Rhizomucor sp., Aspergillus sp., Trichophyton sp., Geotrichum sp., Mudurella sp and Candida sp. The highest moisture content was noticed in Aduwawa market 16.80% sample C and last was in Oluku market 8.70% sample B. The highest pH was noticed in Oluku sample C (6.76) and the lowest pH was in Egor market sample A (4.11). There is therefore a need to maintain proper sanitary conditions so as to avoid health risks. The moisture content of garri samples analyzed is low and within standard specification, this could have accounted for keeping the microbial load of garri low.