Papers by KELECHI M UKAEGBU-OBI
Bacterial community dynamics of diesel-polluted soil was carried out using the vapour phase trans... more Bacterial community dynamics of diesel-polluted soil was carried out using the vapour phase transfer technique. The highest mean log of total heterotrophic count was 9.19 ± 0.04 log 10 cfu/g from pristine soil (control) and least mean log count was 5.32 ± 0.09 log 10 cfu/g from a diesel contaminated soil. There was no statistical difference (P>0.05) in the total heterotrophic count of soil samples. The highest mean log count of diesel degrading bacteria was 8.86 ± 0.07 log 10 cfu/g while the least mean log count was 4.83 ± 0.03Log 10 cfu/g for the control. There was a significant difference in the mean count of diesel degrading bacteria (P<0.05). The bacteria isolated from diesel chronically polluted soil were of the genera These organisms were screened for their ability to degrade diesel. All the organisms were able to grow in diesel at different rates with Pseudomonas sp., Bacillus sp. and Micrococcus sp. showing heavy growths. These bacteria screened for their ability to degrade diesel can be employed as seeds for bioremediation of diesel polluted soil.
This article was published in an CASRP journal. The attached copy is furnished to the author for ... more This article was published in an CASRP journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the authors institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copied, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding CASRP΄s archiving and manuscript policies encouraged to visit: http://www.casrp.co.uk/journals Abstract Tuberculosis (TB) remains a major public health problem. The disease affects people in both developed and developing countries. M. tuberculosis, the causative agent of TB, were initially found in soil. TB was thought to have been introduced in Assyria by the migration of Indo-European cattle herders who were carrying M. tuberculosis by virtue of their exposure to cattle infected with the tubercle bacillus in fifth century BC. Europe, become the epicenter for TB epidemics starting in the 16th and 17th centuries. The famous presentations and postulates of Koch changed dramatically the history of tuberculosis in 1882. In the 20th century, TB steadily dropped in the developed world due to better public health practices and widespread use of the M. bovis BCG vaccine, as well as the development of antibiotics in the 1950s. Unfortunately, the developing world is still suffering heavily from TB. This global crisis is compounded by the emergence of multidrug resistance. The HIV infection and AIDS stand out as the most significant among all the risk-factors for TB and has succeeded in consistently and significantly altering the incidence rate of TB over the last three decades. The recent advances in diagnostics, drugs, and vaccines and enhanced implementation of existing interventions have increased the prospects for improved clinical care and global tuberculosis control.
Objective: This study was carried out to isolate and identify the pathogenic bacteria associated ... more Objective: This study was carried out to isolate and identify the pathogenic bacteria associated with the finger nails
(natural and artificial nails) of students in Michael Okpara University of Agriculture, Umudike as well as to ascertain
the antimicrobial profile these isolates. Materials and methods: A total of hundred nail swabs were collected from
artificial and natural finger nails of both male and female students of Michael Okpara University of Agriculture,
Umudike, Abia State. The finger nails were swabbed in two batches in the morning before lectures and later in the
evening after lectures of the same participants respectively and analyzed for bacterial contamination. Antimicrobial
susceptibility test was carried out on all isolates. Results and conclusion: Proteus spp (5.06%), Klebsiella spp
(11.4%) and Staphylococcus aureus (10.1%) were the most common bacteria isolated from artificial nails while
Pseudomonas aeruginosa (2.5%), Shigella spp (2.5%) was common bacterial isolated from natural nails. Analysis of
the antibiotic susceptibility pattern of the bacterial isolates revealed that those from artificial fingernails were
resistant to a good number of the antibiotics used. Staphylococcus aureus isolates were mostly resistant to all the
antibiotics except Ofloxacin. This result indicated that finger nails are a possible reservoir of several bacteria and
could be implicated in the spread of multiple drug resistant organisms.
Keywords: Antimicrobial susceptibility, Artificial nails, Bacterial profile, Antibiotics
The antibacterial effects in vitro of crude ethanol and aqueous extracts of Turmeric (Curcuma lon... more The antibacterial effects in vitro of crude ethanol and aqueous extracts of Turmeric (Curcuma longa), Ginger (Zingiber officinale) and Turmeric and Ginger combined were assayed against E. coli, S. aureus, P. aeruginosa and S. enterica Type typhi. The antibacterial activity was determined using the well diffusion method. Turmeric (C. longa) showed least antibacterial activity against the test organisms. The combined extracts of C. longa and Z. officinale exhibited higher antibacterial activity than C. longa alone. Ginger (Z. officinale) extracts were most effective. Ethanolic extracts were found to be more potent than the aqueous extracts. The plants' extracts were least active against S. enterica Type typhi and most active against P. aeruginosa. Chloramphenicol which served as the control had higher activity than the spices singly and combined. The Minimum Inhibitory Concentration (MIC) of the ethanolic extracts of plants was 50-150 mg/ml for C. longa, 50-100 mg/ml Z. officinale and 50-150 mg/ml in synergy. Results of this kind exhibit an interesting promise of designing a potentially active antibacterial combined agents of plant origin.
Sensitivity of microorganisms isolated from jewelries and wristwatches worn by students of Michae... more Sensitivity of microorganisms isolated from jewelries and wristwatches worn by students of Michael Okpara University of Agriculture, Umudike to some detergents: Omo, Aerial and Klin were investigated using agar well diffusion method. A total number of 40 jewelries were examined for the presence of bacteria and fungi using standard microbiological methods. The microorganisms isolated were Staphylococus aureus, Proteus, Pseudomonas sp., Streptococcus sp., Escherichia coli and Bacillus sp., for bacteria and Aspergillus sp., Trichophyton sp., Pencillium sp., Microsporum sp. and Yeast for fungi. Staphylococcus aureus had the highest percentage occurrence in wristwatches, bracelets and jewelries. This was attributed to it being a normal flora of the human skin, while Proteus had the least occurrence. The percentage occurrences of the fungal isolates were generally low, with Yeast having the highest percentage occurrence and Penicillium sp. having the least percentage occurrence. Amongst the three test detergents, Omo showed highest antibacterial activity while Klin gave the least antibacterial activity on the test bacterial isolates. Staphylococcus aureus showed the highest sensitivity to Omo while Bacillus sp. showed the least sensitivity to Omo. Escherichia coli showed the highest sensitivity to Aerial while Streptococcus sp. gave the least sensitivity. Proteus showed the highest sensitivity to Klin while Staphylococcus aureus gave the least sensitivity. Minimum Inhibitory Concentrations ranged from 25mg/ml to 50mg/ml and 100mg/ml. Yeast showed the highest sensitivity to Omo. Microsporum sp. gave the highest sensitivity to Aerial. Yeast showed the highest sensitivity to Klin. Penicillium sp. gave the least sensitivity to the three detergents. Inhibitory activity demonstrated by these detergents indicates that they can be employed as sanitizing agents for jewelries.
The increase in human population, death from starvation, civil unrest, malnutrition and related d... more The increase in human population, death from starvation, civil unrest, malnutrition and related diseases in countries of the world call for serious remedy. Agriculture alone cannot meet with the high demands of protein required worldwide. Single cell protein production, therefore, can be seen as a promising technology in combating this global challenge of food protein shortage. Microorganisms like bacteria, yeast, fungi and algae have been used as sources of single cell protein. Single cell protein not only produces protein, but can also employ the technology of waste management in converting agricultural wastes to food and feed for man and animal consumption.
The anti-bacterial effects of the methanol, ethanol and aqueous extracts of A. melegueta seeds we... more The anti-bacterial effects of the methanol, ethanol and aqueous extracts of A. melegueta seeds were investigated on some enterobacteriaceae organisms (Escherichia coli, Klebsiella pneumoniae, Salmonella tyhi and Shigella spp). The organisms tested showed varying degrees of sensitivity to the various extracts with the aqueous extract having the least activity when compared to the ethanol and methanol extracts which had closely inhibitory effects. The ethanol extract had higher zones of inhibition on the organisms than the methanol extract in the decreasing order: E. coli (21.5 mm), Shigella spp (17.0 mm), S. tyhi (11.5 mm) and K. pneumoniae (9.0 mm). The zones of inhibition exerted on the organisms by the methanol extract were in the decreasing order: S. tyhi (15.0 mm), E. coli (13.5 mm), Shigella spp (12.0 mm) and K. pneumoniae (0.0 mm). This study shows that the seeds of A. melegueta possess active ingredients that may be exploited for the development of anti-microbials and alternative remedies for infections and diseases caused by the tested organisms.
Objective: To assess the antimicrobial activity of Monodora myristica seeds on four selected huma... more Objective: To assess the antimicrobial activity of Monodora myristica seeds on four selected human pathogens, Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Pseudomonas aeruginosa. Methods: Disc diffusion technique was used for in vitro antibacterial screening. Results: The most susceptible bacterium were E. coli (17mm) while the most resistant bacterium was P. aeruginosa. The minimum inhibitory concentration result showed that the seed extracts of M. myristica was bacteriostatic. M. myristica extracts when compared with some conventional antibiotics had less sensitivity action against the test organisms. Conclusion: Our findings show that the seed extracts of M. myristica possess some antimicrobial activities which can be employed in the development of novel therapeutic agents against the test organisms.
The synergistic bio-preservative effects of leaves and stem bark of Vernonia amygdalina and Sacog... more The synergistic bio-preservative effects of leaves and stem bark of Vernonia amygdalina and Sacoglottis gabonensis respectively on two (2) palm wine types namely, Elaeis guineensis and Raphia hookeri from Uturu-Nigeria was evaluated. The microbiological and biochemical changes of the palm wine brands were determined. R. hookeri brands were found to support more heterotrophic and coliform populations than the E. guineensis, while the later contained more yeast species. Identification of isolated species revealed the presence of Bacillus sp., Micrococcus sp., Lactobacillus sp., Brevibacterium sp. and Saccharomyces sp. from E. guineensis and R. hookeri. Moreso, heterotrophic counts and pH were observed to decrease as the fermentation time progressed. The combination of both V. amygdalina and S. gabonensis as preservatives lowered the bacterial and fungal load compared to the control and individual plant preservatives and reduced the rate of CO 2 emission as well as keeping the pH fairly constant.
The synergistic approach of plants and rhizobacteria in crude oil contaminated soil in three diff... more The synergistic approach of plants and rhizobacteria in crude oil contaminated soil in three different locations were carried out. The presence of heterotrophic bacteria and hydrocarbon-utilizing bacteria isolated from the polluted and pristine rhizosphere and non-rhizosphere soils of the plants were compared. The polluted rhizosphere of total culturable heterotrophic bacterial count gave a range of 0.98x10 6 cfu/g to 1.37x10 6 cfu/g. The pristine rhizosphere count ranged from 4.11x10 5 cfu/g to 7.55x10 5 cfu/g. The polluted non-rhizosphere gave ranged from 2.39x10 5 cfu/g to 3.28x10 5 cfu/g. The pristine non-rhizosphere had a range of 2.90x10 5 cfu/g to 3.97x10 5 cfu/g. The polluted rhizosphere counts for hydrocarbon-utilizing bacteria ranged from 1.60x10 5 cfu/g to 6.91x10 5 cfu/g. The pristine rhizosphere gave a range of 1.85x10 5 cfu/g to 3.38x10 5 cfu/g. In the polluted non-rhizosphere, the range was from 1.02x10 5 cfu/g to 1.42x10 5 cfu/g. A range of 6.05x10 4 cfu/g to 9.75x10 4 cfu/g was obtained from the pristine non-rhizosphere. There was no significant difference (P>0.05) between the rhizosphere and non-rhizosphere of total heterotrophic and hydrocarbon-utilizing bacterial counts in both polluted and pristine soils. All the plants exhibited positive rhizosphere effects on the rhizobacteria. Hydrocarbon-utilizers were identified as Acinetobacter,
Analysis of the bacterial genera associated with the rhizosphere of Cyperussp., Parkiasp., Panicu... more Analysis of the bacterial genera associated with the rhizosphere of Cyperussp., Parkiasp., Panicumpariflorium, Zea mays, Elaeisguineensis inpetroleum hydrocarbon contaminated soil in Ugada, Imo State, Nigeria was done. The study shows that densities of total culturable heterotrophic and hydrocarbon-utilizing bacteria varied with the type of plant and were higher in the contaminated rhizosphere than in the contaminated bulk soil (non-rhizosphere) of all the plants. Unlike the result of total culturable heterotrophic counts in the bulk soil, the mean counts of the hydrocarbon-utilizing bacteria were higher in the contaminated bulk soil for all plants. Elaeisguineensis, gave the lowest mean counts for both total culturable heterotrophic and hydrocarbon-utilizing bacteria of all the plants studied, this may be as a result of some of the plant's exudates not stimulating all the bacterial community. Statistical analysis showed no significant difference (P>0.05) between the rhizosphere and bulk of total culturable heterotrophic and hydrocarbon-utilizing bacterial counts in both contaminated and uncontaminated soils. The hydrocarbon-utilizing bacterial genera isolated and identified were Acinetobacter, Arthrobacter, Alcaligenes, Bacillus, Flavobacterium, Micrococcus, Pseudomonas spp. These isolates were able to grow on petroleum hydrocarbon at different growth rates indicating that they can be used as seeds for bioaugmentation during remediation of petroleum contaminated soil.
The antibacterial activities of Eucalyptus officinalis extracts were studied. The antibacterial e... more The antibacterial activities of Eucalyptus officinalis extracts were studied. The antibacterial efficiency of the above mentioned plant was evaluated according to agar diffusion and broth dilution methods by using Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, Proteus mirabilis and Pseuomonas aeruginosa clinical isolates and typed cultures. The most susceptible bacteria were E. coli followed by S. aureus while the most resistant bacteria were Pseud. aeruginosa followed by P. mirabilis and Strept. Pneumoniae. From the screening experiment, the hot water extract produced the highest inhibitory effect 17.22+0.14 and 17.63+0.06 against the clinical isolated and typed culture respectively, hence this plant can be further subjected to isolation of the therapeutic antimicrobials and pharmacological evaluation.
Keywords: antibacterial activity, bacterial strains, crude leaf extract, Eucalyptus officinalis, pathogenic,
The rhizo-bacterial genera associated with these plants Cyperus amabalis, Desmodium triflorum, Ph... more The rhizo-bacterial genera associated with these plants Cyperus amabalis, Desmodium triflorum, Phaseolus sp., Solenstemon sp., Mariscus sp were isolated, enumerated and studied. Statistical analysis showed no significant difference (P>0.05) between the rhizosphere and non-rhizosphere of total culturable heterotrophic and hydrocarbon-utilizing bacterial counts in both polluted and unpolluted soils. The rhizosphere effect values of the above named plants were determined. All the plants exhibited positive rhizosphere effects on the rhizo-bacteria. The rhizosphere effect ratio of the hydrocarbon-utilizing bacteria showed significant difference between the polluted and unpolluted soils of Phaseolus sp. (P=0.022), Solenstemon sp. (P=0.012). The hydrocarbon utilizing bacteria isolated were identified as Acinetobacter, Alcaligenes, Arthrobacter, Corynebacterium, Flavobacterium, Pseudomonas and Serratia spp. All the isolates grew on petroleum hydrocarbon at different growth rates. Based on these results, the hydrocarbon utilisers isolated can serve as seeds for bioaugmentation during remediation of crude oil polluted soil while the plants may be employed in rhizoremediation of oil polluted soil.
Keywords: Rhizosphere effect, Bacterial genera, Oil spill, Soil ecosystem, Bioremediation, Hydrocarbons.
Ethanolic and aqueous extracts of Ficus asperifolia and Terminalis catappa were studied for their... more Ethanolic and aqueous extracts of Ficus asperifolia and Terminalis catappa were studied for their in-vitro antibacterial activity against both Gram positive and Gram negative bacteria. The phytochemical screening of the extracts showed the presence of phenolic compounds such as tannins, saponins, flavonoids, alkaloids and glycosides. Both the ethanolic and hot water extracts had broad spectrum antibacterial effect against all the tested bacteria except Pseudomonas aeruginosa that was resistant to the extract of F. asperifolia. The observed activity of the investigated plants may be due to the presence of bioactive components.
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Papers by KELECHI M UKAEGBU-OBI
(natural and artificial nails) of students in Michael Okpara University of Agriculture, Umudike as well as to ascertain
the antimicrobial profile these isolates. Materials and methods: A total of hundred nail swabs were collected from
artificial and natural finger nails of both male and female students of Michael Okpara University of Agriculture,
Umudike, Abia State. The finger nails were swabbed in two batches in the morning before lectures and later in the
evening after lectures of the same participants respectively and analyzed for bacterial contamination. Antimicrobial
susceptibility test was carried out on all isolates. Results and conclusion: Proteus spp (5.06%), Klebsiella spp
(11.4%) and Staphylococcus aureus (10.1%) were the most common bacteria isolated from artificial nails while
Pseudomonas aeruginosa (2.5%), Shigella spp (2.5%) was common bacterial isolated from natural nails. Analysis of
the antibiotic susceptibility pattern of the bacterial isolates revealed that those from artificial fingernails were
resistant to a good number of the antibiotics used. Staphylococcus aureus isolates were mostly resistant to all the
antibiotics except Ofloxacin. This result indicated that finger nails are a possible reservoir of several bacteria and
could be implicated in the spread of multiple drug resistant organisms.
Keywords: Antimicrobial susceptibility, Artificial nails, Bacterial profile, Antibiotics
Keywords: antibacterial activity, bacterial strains, crude leaf extract, Eucalyptus officinalis, pathogenic,
Keywords: Rhizosphere effect, Bacterial genera, Oil spill, Soil ecosystem, Bioremediation, Hydrocarbons.
(natural and artificial nails) of students in Michael Okpara University of Agriculture, Umudike as well as to ascertain
the antimicrobial profile these isolates. Materials and methods: A total of hundred nail swabs were collected from
artificial and natural finger nails of both male and female students of Michael Okpara University of Agriculture,
Umudike, Abia State. The finger nails were swabbed in two batches in the morning before lectures and later in the
evening after lectures of the same participants respectively and analyzed for bacterial contamination. Antimicrobial
susceptibility test was carried out on all isolates. Results and conclusion: Proteus spp (5.06%), Klebsiella spp
(11.4%) and Staphylococcus aureus (10.1%) were the most common bacteria isolated from artificial nails while
Pseudomonas aeruginosa (2.5%), Shigella spp (2.5%) was common bacterial isolated from natural nails. Analysis of
the antibiotic susceptibility pattern of the bacterial isolates revealed that those from artificial fingernails were
resistant to a good number of the antibiotics used. Staphylococcus aureus isolates were mostly resistant to all the
antibiotics except Ofloxacin. This result indicated that finger nails are a possible reservoir of several bacteria and
could be implicated in the spread of multiple drug resistant organisms.
Keywords: Antimicrobial susceptibility, Artificial nails, Bacterial profile, Antibiotics
Keywords: antibacterial activity, bacterial strains, crude leaf extract, Eucalyptus officinalis, pathogenic,
Keywords: Rhizosphere effect, Bacterial genera, Oil spill, Soil ecosystem, Bioremediation, Hydrocarbons.