Open Access Original Research Article

Methicillin and Inducible Clindamycin-resistant Staphylococcus aureus Isolates from Clinical Samples in Abia State

A. C. Ifediora, R. N. Nwabueze, E. S. Amadi, C. I. Chikwendu

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/mrji/2019/v29i430167

Staphylococcus aureus is a major bacterial pathogen that causes different community and hospital-acquired infections. S. aureus resistant to methicillin has become a big and expanding problem of concern in many developing countries. Clindamycin has also been discovered to be a preferred therapeutic alternative for the treatment of both methicillin susceptible and resistant staphylococcal infections. This study examined the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples of patients in Abia state, Nigeria using standard recommended procedures. A total of 750 clinical specimens of blood and urine samples, wound, ear, nasal, high vaginal and ear swabs were collected from three major health facilities in Abia state, Nigeria. Each sample was cultured for bacterial isolates and examined for colonial and cellular morphology while biochemical identification was performed. Antimicrobial susceptibility test was performed on Mueller-Hinton agar (MHA) by disc diffusion method and MRSA screening was done using cefoxitin disc.  A total of 265 (35.3%) S. aureus isolates were recovered, out of which 126(47.5%) were from males and 139(52.5%) were from females, however there was no association between the prevalence and gender (p-value = 0.05) and also prevalence and age (p-value = 0.52). Of the 265 S. aureus isolates recovered, 164(61.9%) were MRSA. All 100% of the MRSA were susceptible to vancomycin, 120(73.2%) to clindamycin, 92(56.1%) to gentamycin. All 100% were resistant to ceftazidine, 157(95.7%) to cloxacillin, 146(89.0%) to augmentin, 136(82.9%) to ceftriaxone and 103(61.6%) to erythromycin. The MRSA strains showed much higher resistance rate than their MSSA counterparts to all tested antibiotic except clindamycin. 64(39.0%) of the MRSA were resistant to 4 classes of antibiotics indicating multi drug resistance (MDR). The overall prevalence of inducible clindamycin resistance among methicillin resistant isolates was 29(17.7%). This implies that 17.7% could have been misidentified as clindamycin susceptible by Kirby-Bauer disk diffusion method. In conclusion prevalence of MRSA was high and it is important to routinely carry out the D-test for detection of inducible clindamycin resistance if clindamycin is considered as a treatment option.

Open Access Original Research Article

Evaluation of Pathogenic Microorganisms that Cause Onion Bulb Rots in Selected Markets in Abuja, Nigeria

Ozoude, T. Obiageli, Igbokoyi, R. Oluwaseun, Okey-Ndeche N. Florence, Eleanya, E. Ukachi

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/mrji/2019/v29i430168

Onion bulb rots are caused by microorganisms especially fungi and bacteria leading to economic loss. The research study evaluated the microorganisms associated with the rots of onion bulbs. The microorganisms isolated include fungi species such as Saccaromyces cerevisiae, Aspergillus niger, Rhizopus stolonifera, Fusarium oxysporum and Penicillium digitatum and bacterial species such as Pseudomonas spp., Enterobacter spp., and Escherichia coli. Results from the percentage distribution of the fungi in the spoilt onion bulbs about the markets showed the highest percentage distribution of 42.85% for the samples from Bwari market and the lowest percentage distribution of 28.57% for Dutse and Zuma respectively. It was observed that the percentage distribution of the bacteria about the markets were 42.85% for the samples from Bwari market and 21.42% from Zuma market. Pathogenicity tests for Fungi revealed that all the isolated fungi were pathogenic on onion bulbs, however; Saccaromyces cerevisiae, Aspergillus niger and Penicillium digitatum were the most pathogenic leading to the rapid disintegration of the infected bulbs within 14 days of inoculation while Rhizopus stolonifer was the least pathogenic. Pathogenicity tests for Bacteria revealed that all the isolated bacteria were pathogenic on onion bulbs with Pseudomonas spp. as the highest pathogenic and Escherichia coli the least.

Open Access Original Research Article

Isolation and Molecular Characterization of Biosurfactant-Producing Yeasts from Saps of Elaeis guineensis and Raphia africana

I. V. Nwaguma, C. B. Chikere, G. C. Okpokwasili

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/mrji/2019/v29i430169

Aim: This study investigated the screening and molecular characterization of biosurfactant-producing yeasts from saps of Elaeis guineensis (oil palm) and Raphia Africana (Raphia palm).

Methodology: Physicochemical characteristics (pH, temperature, alcohol contents, and reducing sugars) of the saps of Elaeis guineensis and Raphia africana were determined. The capacity of the yeast isolates from both samples to produce biosurfactant was evaluated using emulsification index (E24), emulsification assay, haemolytic assay, oil displacement test, and tilted glass slide. The yeast isolates were identified based on their phenotypic, microscopic, biochemical, and molecular characteristics.

Results: Chemical analysis of the palm wine saps revealed respective pH, temperature, alcohol, and reducing sugars contents of 5.68, 17.1°C, 0.943% and 1.090 mg/mL for Elaeis guineensis and 5.26, 16.9°C, 0.884% and 2.099 mg/mL for Raphia africana. Six isolates (SA-2, SA-5, SB-3, SB-5, SB-6 and SB-8) out of sixteen isolates (16) distributed within both samples were found to produce biosurfactant. Phylogenetic analysis based on the internally transcribed spacer (ITS) genes classified the six isolates as Candida haemulonis SA2, Pichia kudriavzevii SA5, Pichia kudriavzevii SB3, Pichia kudriavzevii SB5, Pichia kudriavzevii SB6, and Pichia kudriavzevii SB8. The sequences obtained from the study have been deposited in GenBank under the accession numbers MN007219.1-MN007224.1. The result obtained from the study revealed high biosurfactant activity with a maximum E24 of 64.5% compared to E24 of 72% by sodium dodecyl sulphate (SDS).

Conclusion: The study demonstrated that saps from Elaeis guineensis and Raphia africana were suitable sources of biosurfactant-producing yeasts with high capacity for hydrocarbon emulsification. The main six biosurfactant-producing yeasts were found to belong to the genera Candida and Pichia.

Open Access Original Research Article

Production of Invertase from Actinomycetes Isolated from Soils in Eliogbolo and Oyigbo, Rivers State using Submerged Fermentation Technique

T. O. Ozoude, O. K. Agwa, E. C. Wokoma

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/mrji/2019/v29i430170

The use of commercial sources of invertase for the production of High fructose syrup and other pharmaceutical formulations has been a problem due to its high ash content and cost implication, therefore there is a need to explore bacterial species that can produce invertase. In this study, actinomycetes strains were isolated from soils from a botanical garden, sugar cane sites and garden egg at Elogbolo and Oyigbo respectively. Yeast extract agar; Czapeks Dox agar and Arginine glycerol agar were used for the isolation of actinomycetes. The study showed that Czapeks Dox agar gave the highest population count followed by Yeast extract and Arginine glycerol agar. The dominated genus of actinomycetes observed were species of Streptomyces designated as OZMU 1; OZMU 2; OZMU 3 and OZMU 4. The results showed that the reducing sugar content of the Streptomyces sp. had similar reducing sugar liberation and consumption behavior without any lag phase, with OZMU 1 concentration peak at 12 h (0.12 g/l), and OZMU 3 (0.15 g/l).  But OZMU 2 indicated a lag phase from 6-12h, increased from 12-24 h (0.18 g/l), but activity declined dramatically at 36 h and 48 h. The reducing sugar content for Streptomyces sp. OZMU 4 revealed longer lag phase, which was almost constant throughout the investigation period from 6-36 h. But at 48 h (0.06 g/l)  a decline in the reducing sugar content was noticed compared to the other isolates, indicating that all the available reducing sugar were completely consumed by the other strains. The research work revealed the ability of indigenous actinomycetes strains to produce invertase enzyme which has high conversion efficiency and can be used in various pharmaceutical and nutraceutical industries.

Open Access Original Research Article

Bioremediation of Refinery Effluent by Consortium of Bacteria Isolated from Abattoir Waste

Urhibo Voke Owarieta, Odesiri-Eruteyan Eunice Asiboroko, Emecheta Onyeka Kingsley, Nnaji Praise Tochukwu

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/mrji/2019/v29i430171

Aim: This research was conducted to examine the efficacy of bioremediation of refinery effluent by a consortium of bacterial organisms from abattoir waste.

Study Design: The experimental and analytical research designs were adopted for the study.

Place and Duration of Study: The study was conducted in a laboratory in the Department of Environmental Management and toxicology, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria. The research was conducted within three months.

Methodology: Standard methods were adopted for sample collection, microbiological analysis and determination of physicochemical properties.

Results: Out of eight bacterial species isolated from abattoir waste, Pseudomonas, Proteus and Bacillus species recorded high hydrocarbon utilization potential. There was a significant difference between the physicochemical property of the control and the refinery effluents. The effluents had a mean Biochemical Oxygen Demand (BOD) of 19 mg/l, Dissolved Oxygen (DO) of 3 mg/l, Total Dissolved Solids (TDS) of 35 ppm, pH of 6.67, Electrical Conductivity (EC) of 71 µs/cm and temperature of 29.5°C. Samples subjected to 0 – 10 days biodegradation test by Pseudomonas, Proteus and Bacillus species recorded a mean increment in EC, reduction in pH, increase of TDS and reduction in Total Petroleum Hydrocarbon (TPH) with Proteus species being the best. The percentage of degradation by Proteus was 69.7%, Bacillus 61.56% and Pseudomonas 53.19%.

Conclusion: The use of abattoir waste bacteria for bioremediation purposes are very safe, cost-effective and aids the environment from accumulating more burdens of unsafe compounds that render it harmful for living organisms including man.