Open Access Original Research Article

Anti-viral Activity Evaluation of Selected Medicinal Plants of Nigeria against Measles Virus

Bolaji Bosede Oluremi, Johnson Adekunle Adeniji

Microbiology Research Journal International, Page 218-225
DOI: 10.9734/BMRJ/2015/16220

This study was carried out as a preliminary investigation into selected medicinal plants of Nigeria with the aim of discovering and developing a drug with anti-measles virus activity as an alternative measure in disease control. Ten parts of seven plants (Diospyros barteri leaf, Xylopia aethiopica leaf and stem bark, Picralima nitida stem, Cajanus cajanArgemone MexicanaMorinda lucidaUvaria chamae leaf, stem and root bark) were dried, powdered and extracted by cold maceration using absolute methanol, and maximum non-toxic dose (MNTD) of each extract to Vero cell was determined. The cytotoxic activity and ability of extracts to inhibit viral-induced cytopathic effect (CPE) in tissue culture were evaluated three days post-inoculation and incubation, by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Cytotoxic concentration at 50% (CC50) and inhibitory concentration at 50% (IC50) were determined using graphpad prism, and selective index (SI) was calculated as ratio of CC50 to IC50. Out of the ten plant extracts screened, Xylopia aethiopica leaf extract with IC50 of 1.248 µg/mL, Uvaria chamae root and stem bark extracts with IC50 1.216 µg/mL and 3.281 µg/mL, respectively demonstrated significant in vitro anti-measles virus activity. Bioassay-guided fractionation and further screening of active extracts showed activity to reside in the hexane and dichloromethane fractions of X. aethiopica leaf and U. chamaeroot and stem barks. These results suggest that these two plants could possibly lead to anti-measles virus drug discovery and development.

Open Access Original Research Article

Assessment of Bacteria and Heavy Metals Contamination in Lettuce at Farm Gate and Market in the Accra Metropolis

Mark O. Akrong, Joseph A. Ampofo, Regina A. Banu, Seth K. A. Danso

Microbiology Research Journal International, Page 226-234
DOI: 10.9734/BMRJ/2015/17287

The bacteria and heavy metals contamination of lettuce from two vegetable growing farms irrigated with either stored municipal, stream or polluted drain water were assessed on farm and in the market. A total of 120 irrigated lettuce samples consisting of sixty samples from each farm and the market were collected. All samples were analysed using standard methods. The total coliform levels of lettuce from the farm ranged from 5.63 to 9.38 log MPN/100 g, 5.32 to 10.38 log MPN/100 g, and 6.38 to 10.38 log MPN/100 g when irrigated with stored municipal water, stream water and drain water, respectively. Irrespective of the irrigation water used on the lettuce, the total and faecal coliform levels were above the ICMSF recommended levels of 1x103 100 g-1. Significant difference (p=0.05) was observed between the lettuce irrigated with municipal water and drain water. Thirteen gram-negative bacteria species were identified for irrigated lettuce both on farm and at the market. One bacterium of pathologenic concern, Klebsiella pneumoniae occurred to a lesser extent, on both farm and market-derived lettuce depending on the source of irrigation water. The heavy metals concentration in all lettuce samples examined were far below FAO/WHO recommended levels for safe vegetables consumption. It is therefore recommended that lettuce bought from farm gates or markets be washed properly to reduce the bacteria contamination before it is consumed.

Open Access Original Research Article

Bacteriological and Physicochemical Analysis of Groundwater in Selected Communities in Obio Akpor, Rivers State, Nigeria

V. C. Ugbaja, T. V. Otokunefor

Microbiology Research Journal International, Page 235-242
DOI: 10.9734/BMRJ/2015/16860

Aim: This research work is aimed at assessing the quality of groundwater in Rumuekini, Rumuosi, Aluu communities in Obio-Akpor, Rivers State, Nigeria.
Methodology: Bacteriological and physicochemical analyses were carried out on selected borehole water in Obio-akpor local government area, Rivers state and its environs. Twenty seven samples were obtained randomly from the following locations/communities namely: Rumuekini (nine samples), Rumuosi (nine samples) and Aluu (nine samples). In the study, total heterotrophic bacteria and coliforms were enumerated using the membrane filtration and multiple tube fermentation methods, respectively. The isolates were identified based on cultural, morphological characteristics and a battery of biochemical tests. Selected samples were also subjected to physicochemical analysis of parameters like pH and electrical conductivity which were measured in situ using the pH meter and the conductivity meter respectively. The temperature of the samples was also measured in situ using a thermometer. The nitrate, sulphate and chloride content of the samples were determined using the spectrophotometric and argentometric methods respectively. Biological Oxygen Demand and Chemical Oxygen Demand were measured using the Winkler (respirometric) and titrimetric methods respectively; while the heavy metals’ content of the samples were determined using the atomic absorption spectrophotometer.
Results: In this study, the total heterotrophic bacteria count for the samples ranged from 0.02 to 2.74 x 102cfu/ml and were quite high compared to E.P.A and W.H.O standards of 1.0 x 102 cfu/ml for total heterotrophic bacteria. The results obtained from this study showed that coliform bacteria were present in forty percent of the samples analysed with counts ranging from 0MPN/100 ml to 9.1 MPN/100 ml. These values were much higher than the W.H.O. standards of zero coliform/100 ml. Enterobacter aerogenes was the most common coliform isolated while Escherichia coli was isolated from only one of samples obtained from Aluu community. Pathogens like Salmonella and Vibrio were not detected in any of the samples. The physicochemical analysis of borehole water samples obtained from the three locations revealed the following range values: pH (5.8-7.5), temperature (25-29ºC), turbidity (0-0.8 NTU), Nitrate (1.32-7.72 mg/l), Sulphate (0.43-14.8 mg/l), B.O.D (1.8-4.4) etc. The concentration of zinc in the sampling locations ranged from 0.01 to 0.34 mg/l while that of lead and iron ranged from 0.01 to 0.06 and 0.03 to 0.25 mg/l respectively.
Conclusion: The investigation in this study suggests that the borehole water samples were within W.H.O specified limits for the physicochemical parameters apart from pH that is below limit (5.8) for one of the samples obtained from Rumuekini; The status of water in some of these locations using microbiological, and physicochemical parameters as indicators can be said to be of acceptable limit for human consumption. However, the results obtained from this study showed that forty percent of the samples analysed had total coliforms (i.e. do not confirm with W.H.O standards); this may be as a result of improper construction/drilling of the boreholes or contamination of the storage tanks. There is need for the treatment of water from some of these boreholes in order to reduce the risk of infection.

Open Access Original Research Article

Evaluation of Antibiotic Biosynthetic Potential of Actinomycete Isolates to Produce Antimicrobial Agents

Mobolaji Felicia Adegboye, Olubukola Oluranti Babalola

Microbiology Research Journal International, Page 243-254
DOI: 10.9734/BMRJ/2015/14627

Aim: To assess the antibiotic biosynthetic potential of actinomycete isolates from rhizospheric soil samples collected from Ngaka Modiri Molema district in North West Province of South Africa.
Study Design: The analysis of biosynthetic gene clusters through PCR-based approach presents a useful foundation for the discovery of bioactive compounds.
Place and Duration of Study: Microbial Biotechnology Laboratory, Department of Biological Sciences, North-West University, Mafikeng Campus, South Africa, between June 2011 and November, 2013.
Methodology: Through PCR-based approach 341 actinomycete isolates were screened for thepolyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) biosynthetic gene clusters. The amplification of the genes from some of the actinomycete isolates is an indication of their potential as antibiotic producers. Phylogenetic analysis using PKS-I, PKS-II and NRPS gene sequences were conducted.
Results: Sixteen isolates (4.69%) were identified as PKS-I gene positive strains, 15.25% for PKS-II and 13.48% for NRPS gene. Through the screening, it was found that Streptomyces have higher prevalence of PKS-I, PKS-II and NRPS genes compared to others genera. Phylogenetic analysis of the nucleotide sequences from the amplified biosynthetic genes confirmed that the isolates formed a close phylogenetic relationship with known antibiotic producers.
Conclusion: PCR-based approach using degenerative primers to screen for the presence of biosynthetic gene clusters responsible for the biosynthesis of bioactive secondary metabolites, is an effective approach for discovering diverse antibiotics from actinomycetes.

Open Access Original Research Article

Optimization of Cultural Parameters for Cost Effective Production of Kojic Acid by Fungal species Isolated from Soil

Kayitha Bala Durga Devi, Payala Vijayalakshmi, Vadlamani Shilpa, Bapatla Veerendra Kumar

Microbiology Research Journal International, Page 255-268
DOI: 10.9734/mrji/2015/v7i56136

Two different species of Aspergillus are able to produce kojic acid at higher concentrations under static conditions in the present study. Various physicochemical parameters which influence the production of kojic acid are optimized by means of One-factor-at-a-time method. The other objective of this research is to examine the prospects of using novel substrates like Cassava, Ipomea batatas, Alocasia macrorrhiza tubers and rice bran, wheat bran for the production of value added products like kojic acid. The kojic acid concentration is quantitatively estimated by Bentley’s colorimetric method. It is observed that the maximum yield of kojic acid crystals, 22.5 g/L is obtained with the substrate Cassava and by the isolate Aspergillus flavus. The optimized physicochemical parameters are initial pH - 6.0, Time - 28d, Temperature - 28ºC, Substrate concentration – 100 g/L, Nitrogen source concentration-2 g/L, MgSO4.7H20-0.5 g/L and KH2PO4-2.0 g/L under static conditions. After the fermentation is completed, the fermented broth samples are subjected to crystallization and the isolated kojic acid crystals are examined by Fourier transform infrared spectroscopy and X-ray crystallographic methods. The FTIR spectrum of the sample kojic acid showed bands at functional groups at 3270.8 cm-1, 3179.43 cm-1 (-OH), 2925.17 cm-1, 2854.05 cm-1 (aliphatic-CH), 1660.59 cm-1 (cyclic-C=O), 1611.11 cm-1 (C=C), 1472.61 cm-1 (deformation of-CH2), 1074.04 cm-1 (cyclic C-O-C), 943.58 cm-1, 863.66 cm-1 and 775.65 cm-1 (1,4 α -disubstituted ring). The X-ray diffraction spectrum of the sample is similar to standard sample and reveals seven distinctive peaks appeared at 2θ angles 8º, 19.27º, 21.71º, 27.73º, 31.15º, 36.13º, 39.09º. The result confirms the presence of kojic acid. Antimicrobial activity of kojic acid is tested on some Gram positive and Gram negative bacteria. The culture Escherichia coli and Staphylococcus aureus show equal susceptibility to the antimicrobial compound kojic acid.

Open Access Review Article

Symbiont Localization and Nature of Effector Molecules Generated in Malaria Vector-symbiont Relationships

Mulambalah Chrispinus Siteti, Siteti Darwin Injete

Microbiology Research Journal International, Page 210-217
DOI: 10.9734/BMRJ/2015/16172

The field of mosquito vector symbiosis is largely unexplored and yet it is likely that in the near future it will provide valuable opportunities for malaria control. Symbiont based malaria control approaches are gaining acceptance worldwide and there is need for detailed review to open up new research frontiers. Malaria vector symbionts localize in different parts of Anopheles mosquitoes and express proteins as effector molecules some with anti-Plasmodial effects. The types of effector molecules, their mode of action and site of action need to be elucidated. Microbial symbiotic species diversity and preferred locations in the malaria vector have not been adequately studied to understand the mode of transmission among vector species and from generation to generation. This is necessary for a better understanding of the behaviour and biology of symbionts before designing and executing symbiotic control strategies. The review highlights important developments in the dynamics of transmission of symbionts in malaria vector populations. The review forms a useful guide in the search and deployment of paratransgenic mosquitoes in symbiotic control of malaria. Aspects that require further elucidation by innovative research and new opportunities to exploit in malaria control are highlighted.