Open Access Original Research Article

Antibacterial Properties of Young and Mature Mango Leaves (Mangifera indica) Extract on Some Clinical Isolates

David N. Ogbonna, Queen Lugbe, Renner R. Nrior

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/mrji/2022/v32i430378

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 interpretation

Place 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.

Open Access Original Research Article

Toxicity of Herbicide, Paraquat Dichloride and Insecticide, Lambda-cyhalothrin on Phosphate Solubilizing Bacteria, Pantoa dispersa in Aquatic Ecosystems

Nrior, Renner Renner, Douglas, Salome Ibietela, Igoni, Yirabari Gote

Microbiology Research Journal International, Page 13-21
DOI: 10.9734/mrji/2022/v32i430380

Aim: The study was aimed to determine the toxicity of paraquat dichloride and lambda-cyhalothrin on phosphate solubilizing bacteria, Pantoa dispersa in aquatic ecosystems.

Study Design: This study employs randomized block design, statistical analysis of the data and interpretation.

Place and Duration of the Study: Soil sample was collected from the root nodules of leguminous plants in a sterile polythene bag from the Elele, in Etche L.G.A, Rivers State. The fresh water sample was collected from Bane town in Khana L.G.A, brackish water sample was collected from Choba river in Obio/Akpor L.G.A while the marine water was collected from Bonny River of Bonny L.G.A., all of Rivers State, Nigeria. The samples were collected aseptically and transported in an ice-pack immediately to the Rivers State University, Microbiology laboratory for analysis. The study lasted for three months.

Methodology: The bacterium, Pantoa dispersa was isolated and identified based on conventional and molecular characterization from water and soil samples. Different concentrations (3.13%, 6.25, 12.50, 25.00%, 50.00% and 75.00%) and the control (0%) of the herbicide (paraquat dichloride) and insecticide, Lambda-cyhalothrin were prepared using fresh, brackish and marine water samples and 10ml of the test organism, Pantoa dispersa was introduced and the survival count was determined at 0, 4hr, 8hr, 12hr and 24hr. The Mean Lethal Concentration (LC50) of the insecticide and herbicide on Pantoa dispersa in the three aquatic ecosystem was determined.

Results: The LC50 of the herbicide (Paraquat dichloride) was recorded as 15.8% in brackish water, 17.37% in fresh water and 27.44% in marine water. While the LC50 of the insecticide, Lambda-cyhalothrin to Pantoa dispersa was 26.84% in fresh water, 27.26% in brackish water and 32.33% in marine water.

Conclusion: From the study, the herbicide, Paraquat dichloride was more toxic in the three aquatic ecosystems compared to the insecticide, Lambda-cyhalothrin. The use of these agrochemicals should be monitored as they result in the mortality of beneficial soil bacteria like Pantoa dispersa which is phosphate solubilizing bacteria in aquatic ecosystems.

Open Access Original Research Article

Microbiological Assessment of Used Face Masks in Port Harcourt Secondary Schools in COVID-19 Era

Renner Renner Nrior, Amadi Egbuchelem, Victory N. Dike

Microbiology Research Journal International, Page 22-30
DOI: 10.9734/mrji/2022/v32i430381

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 Era

Study 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.

Open Access Original Research Article

Physico-chemical and Microbiological Qualities of Abattoir Wastewater in Egbu, Imo State, Nigeria

E. C. Chinakwe, N. U. Nwogwugwu, C. E. Ihejirika, J. C. Ngumah, E. E. Mike-Anosike, G. C. Ajugwo, J. C. Iwuji

Microbiology Research Journal International, Page 31-36
DOI: 10.9734/mrji/2022/v32i430383

Abbattoir waste water is of a complex composition. When discharged without being treated, poses a threat to human health and the environment. This is the practice common in Nigeria, and is worrisome.

Objective: The aim of this study was to assess the physico-chemical and microbiological qualities of waste water from Egbu abattoir discharged into ‘Otamiri’ river in Owerri North local government area, Imo State, Nigeria.

Methods: The microbial quality of abattoir wastewater was studied. The duration of the study was three months, from June to September, 2019. Sample collection was done in the morning (8-10am) and in the evening (4-6pm). A total of thirty samples (30) were collected from two sampling points, at the place of generation of the wastewater (Effluent source) and at the point of discharge into the river (POE). Standard methods were employed to assess the microbiological and physiochemical quality of the effluent. The microorganisms isolated from the samples included Escherichia coli, Salmonella, Staphylococcus, Aspergillus, Mucor, Listeria, Micrococcus and Candida species. The Total Heterotrophic Count (THC) of effluent samples, at source and POE were 8.51log10 cfu/ml and 6.15log10cfu/ml respectively, Total Coliform Count (TCC) for same samples were 6.77log10 cfu/ml and 4.56log10 cfu/ml respectively. The Total Fungal Count (TFC) of the effluent samples at source and at POE was 5.19log10 cfu/ml and 4.18log10 cfu/ml respectively. Results further revealed that the pH of the effluent at source was 6.58 while that at Point of Entry into the river was 7.30. The temperature of both samples was 25oC. The Total Dissolved Solid values of the effluent collected at source was higher, having a value of 1400mg/L against 1000mg/L at Point of Entry. Also the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the effluent at source were 5.10mg/L and 8.58mg/L respectively, while the BOD and COD of the water at the POE were 4.3mg/L and 7.9mg/L respectively.

Conclusion: Abattoir wastes are becoming a major environmental health challenge and being discharged into the Otamiri River indiscriminately is of public health concern. The potential public health implications associated with discharging untreated abattoir wastewater into the environment and thus, the need for adequate treatment to ensure decontamination as well as providing wastewater treatment facility is imperative.

Open Access Original Research Article

Evaluation of Phytochemical and Antibacterial Potential of Vernonia amygdalina and Elaeis guineensis on Some Bacteria Associated with Diarrhea

O. A. Ollor, A. A. Williams, E. G. Nwokah, C. K. Wachukwu, V. N. Agi

Microbiology Research Journal International, Page 37-43
DOI: 10.9734/mrji/2022/v32i430384

Background: Bitter leaf and palm oil combination in treating diarrhoea is common in Africa. The aim of this study is to determine the synergistic and antimicrobial potential of Vernonia amygdalina and Elaeis guineensis on bacteria isolates from diarrheic stool.

Methodology: One hundred and fifty (150) diarrheic stool samples from the Diagnostic Laboratory in Rivers State University Teaching Hospital (RSUTH), Port Harcourt, were inoculated in Selenite F broth, MacConkey, Nutrient and Salmonella-Shigella agar plates using standard methods. Fresh and dry bitter leaf extracts were prepared by mashing, weighing and dissolving 100 grams(g) and 150 g concentrations of each in 100 milliliters(mls) of ethanol and sterile distilled water respectively. Undiluted mixture of bitter leaf and palm oil were prepared by mixing 2 mls of each in a sterile beaker. Zero-point one milliliter (0.1ml) of each undiluted extract, their mixture, ethanol and palm oil were separately dispensed into appropriately labeled wells using sterile pipette for sensitivity test on the isolated bacteria. The pH, temperatures and the phytochemical contents of the bitter extracts and palm oil were determined using pH meter, thermometer and spectrophotometric method.

Results: Escherichia coli, Staphylococcus aureus and Salmonella sp. were isolated. The pH and temperature of bitter leaf extract and palm oil were 7.2 and 26⁰C and 6.7 and 26⁰C respectively while the pH and temperature for bitter leaf and the palm oil mixture was 6.9 and 26⁰C. The bitter leaf and palm oil extracts, their combination, ethanol and distilled water used on the isolates as antibiotics did not show any sensitivity. The phytochemicals identified in the bitter leaf were saponins, alkaloids and tannins while carotene was detected in the palm oil.

Conclusion: It can be concluded that the bitter leaf extract, palm oil and their combination did not inhibit the growth of bacteria as a result of lack of bioactive components from the bitter leaf. The nature of the diluents used for the extraction may not have been the right one as it would have caused the low concentration, dilution and disfiguring of the molecules of the bioactive compounds that prevented the proper reaction between the bacteria and the extracts used.