ABSTRACT
Aim: This study was aimed at identifying bacterial and fungal contaminations in used face masks from different secondary schools in Port Harcourt during COVID-19 EraStudy Design: The study employs statistical analysis of the data and interpretation.Place and Duration of Study: Five Secondary Schools–Three public schools: Federal Government College Rumuokoro; Rumueme and Rumuokuta Girls’ Secondary Schools; Two Private Schools: Solid Steps and Istan Secondary Schools; all located in the city of Port-Harcourt, Nigeria. Sample collection lasted for a week and the analysis lasted for six months.Methodology: The research study was facilitated through Laboratory analysis and the use of questionnaire to get the age and sex from the school children. A total of 25 used face masks samples were collected from school children between ages of 12-18years and they were examined microbiologically. Sterile swab sticks soaked in sterile nutrient broth were employed to swab the inner surface area of the used face mask of circular diameter 10 cm. The swabbed samples were dipped and shaken in 9ml of sterile saline water for 1-3 minutes to dislodge the organisms; the mixture was then diluted through a ten-fold serial dilution, after which an aliquot of 0.1ml were inoculated unto Nutrient Agar (dilution used 10-6, incubated at 370C for 24h), Mac Conkey Agar (dilution used 10-3, incubated at 44±0.20C for 24-48h) and Sabouraud Dextrose Agar (dilution used 10-3; incubated at 370C for 5-7 days). Frequency evaluation and identification of isolates were carried out using standard microbiological techniques.Results: The entire face masks sampled were found contaminated with microorganisms. The Microbial load (Log10 CFU/cm2;) and Percentage (%) occurrence of bacterial isolates from used facemask were; Bacillus spp (6.10±2.13)(30.81) > Staphylococcus auerus (3.89±3.01)(19.57%) > Proteus spp (2.25±2.45)(11.35) > Paenibacillus spp (1.55±2.52)(7.82) > Escherichia coli (0.36±0.81)(1.82) while fungal isolates were Aspergillus spp (2.20±0.55)(11.09) > Mucor spp (2.19±0.96)(11.04) > Penicillum spp (1.29±0.61)(6.51). The contaminated used face masks with microorganism were highest in school children of ages 16-18years (72%) and the lowest occurred in children of 12-14years of age (12%).Conclusion: The presence of potential pathogen such as Staphylococcus auerus, Bacillus spp etc. are of public health significance. It is therefore recommended that crowd should be controlled in such environments with high bacterial and fungal load such as schools and COVID-19 protocols duly observed.
ABSTRACT
Aim: This study was carried out to investigate the antibacterial properties and efficacy of mango (Mangifera indica) leaf extracts on some clinical isolates as test rganisms. Study Design: The study employed statistical analysis of the data and interpretationPlace and Duration of Study: Young and mature mango leaves were collected from the Botanical Garden, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Nigeria, and taken to the laboratory for analyses. Methodology: The samples were dried in an oven at 80oC for 3 days. Thereafter, 50 g of each ground mango leaf (young and mature leaves) were soaked separately in 500 ml of water, ethanol (95% v/v), and acetic acid (99.9% v/v) respectively for another 3 days. The soaked materials were filtered through Whatman No. 1 filter paper into sterile beakers and evaporated to dryness in a water bath at 80oC. The dried extracts obtained were reconstituted with water at concentrations of 100, 75, 50, and 25 mg/ml. Test organisms, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Proteus mirabilis, Bacillus cereus, and Pseudomonas aeruginosa were obtained after proper laboratory screening of isolates from the diagnostic laboratory of the Rivers State University Teaching Hospital, Port Harcourt, Nigeria, for confirmation of identity and storage in universal bottles in a refrigerator. Sensitivity tests were carried out with the agar well diffusion method against the test organisms, using tetracycline as the standard control drug, with cultures incubated accordingly. The measured zones of inhibition were compared with the controls and interpreted as resistant, intermediate, or susceptible to mango extracts in accordance with the interpretive guidelines published by the National Committee for Clinical Laboratory Standards (NCCLS). Assay for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was also carried out. Results: Results obtained showed that acetic acid young leaf extract at 100mg/ml produced 50 % susceptibility and 50 % intermediate response of test bacterial species. Generally, at 100 mg/ml, acetic acid young leaf extracts yielded 50% susceptibility and 50% intermediate response among both Gram-positive and Gram-negative bacteria. Ethanolic extracts gave 100% intermediate sensitivity of Gram-negative species and 50% each of resistant and intermediate response in Gram-positive forms. Aqueous extracts also produced no susceptibility among the test organisms as there was 100% resistance. Extracts of mature mango leaves of all solvents and at all concentrations used yielded no susceptibility response among the test bacterial species on the NCCLS scale. Minimum inhibitory and bactericidal concentrations were found to range from 25 mg/ml to 50 mg/ml. Additionally, it was observed that the sensitivity of organisms to mango extracts increased with concentration.Conclusion: In conclusion, acetic acid has a better extracting potential than ethanol and water as a solvent for the extraction of mango parts. More so, young mango leaves extracted with acetic acid possess higher broad-spectrum antibacterial properties than the mature mango leaves extracted from the same plant. It is therefore recommended that young mango leaves, extracted with acetic acid, be used for the treatment of microbial infections at concentrations not below 50 mg/ml.
ABSTRACT
Aim: To assess the effect of the hydrocarbon discharges from the artisanal refineries on the community structure of microbial mats in an aquatic environment Study Design: The study employs experimental design, statistical analysis of the data and interpretation. Place and Duration of Study: The microbial mats, surface water and sediments samples were collected from four hydrocarbon polluted stations (A, B, C and D) and a control sampling station in Yellow island (Iyalla kiri) in Degema Local Government Area, in Rivers state Nigeria. The samples were immediately transported with ice packs to the Microbiology Laboratory of Rivers State University, Port Harcourt. The study lasted from March 2020 to February 2021, covering both wet and dry seasons. Methodology: Different concentrations of fresh effluent (0, 1.625, 3.25, 6.5, 12.5, 25, 50 and 75%) were prepared in test tubes to final volume of 10ml. Each of the test tubes was inoculated with one milliliter (1ml) of the test organism. Five sets of concentrations were prepared for the five test organisms (Bacillus subtillis MW808817, Enterobacter ludwigiiMW767009, Amorphotheca resinae EU040230, Cladosporium cladosporioides MW793722 and Penicillium chrysogenum MN184857). The organisms were exposed to the pollutant for duration of 0, 4, 8, 12 and 24 hours and plated out using spread plate technique. The cultures were incubated for 24 hours for bacteria and five days for fungi. Median lethal concentration (LC50) was determined using SPSS version 20. Results: The results showed that the percentage logarithm survival of the test organisms decreased with increase in exposure time and concentration. The LC50 of Bacillus subtillis MW808817 was 30.93%, Enterobacter ludwigii MW767009 was 29.74%, Amorphotheca resinae EU040230 was 19.65%,Cladosporium cladosporioides MW793722 was 20.08% and Penicillium chrysogenum MN184857 was 17.77%, (noting; the lower the LC50 the more toxic the pollutant). Conclusion: The effluent discharge was more toxic on Penicillium chrysogenum MN184857 than the other test organisms. Also, the ecotoxicological evaluation of the effluents on the test organisms isolated from the study area showed that LC50 of the effluent was slightly toxic on the microbial population when the results obtained were compared to GESAMP Standard for Toxicity Ranking of Chemicals/Effluents in Marine Environment.