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Papers by Michael Osungunna

Journal of Pharmacy & Bioresources

Vancomycin resistance commonly occurs with Staphylococcus aureus, a pathogen that exhibits intrin... more Vancomycin resistance commonly occurs with Staphylococcus aureus, a pathogen that exhibits intrinsic virulence. Sixty isolates of Staphylococcus aureus tested positive as vancomycin possessive isolates on Brain Heart Infusion Agar medium fortified with 6 μg/mL vancomycin from 100 clinical samples of urine from patients with cases of UTIs via agar diffusion method. Standard 30 μg vancomycin disc served as control. Increase in zones of growth inhibition in relation to vancomycin concentrations was noticed in some of the isolates while it was reversed in others, despite the increase in concentration. Typed strain was susceptible to six concentrations of vancomycin exposed and to the control. Thirty one of the sixty isolates were resistant to vancomycin control. Resistant isolates from standard vancomycin discs were then subjected to molecular investigation. Of the 31 isolates exposed to gel electrophoresis, 14 (47%)elicited plasmids of varied molecular weights ranging from 0.79-23.13 k...

AFRICAN JOURNAL OF INFECTIOUS DISEASES

Biofilm formation, especially on indwelling medical devices such as catheters, can result in infe... more Biofilm formation, especially on indwelling medical devices such as catheters, can result in infections and substantially affect patients' quality of life. Biofilm-associated infections have led to increased morbidity and mortality, increased cost of treatment, and length of hospital stay. However, all of the identified consequences of the biofilm-associated infections had been attributed to the reduced susceptibility of biofilm to conventional antimicrobial agents which has necessitated the development of a new strategy for biofilm infections control, thereby making a search for more effective antimicrobial agents from plant source inevitable. So far, some antimicrobial agents (crude or isolated compounds) from plant sources affect a specific stage of biofilm development while a few of them have been developed into a suitable dosage form for biofilm control. In this review, an attempt is made to look into some definitions of biofilm by "biofilmologists", stages in bio...

Bacterial Empire

The health hazards associated with the handling of contaminated money have been attributed to the... more The health hazards associated with the handling of contaminated money have been attributed to the ability of contaminated money to act as a vehicle by which pathogens can be transmitted among human beings as well as the capacity of the associated organisms to form biofilm. The consequences of biofilm formation are increased rate of mortality and morbidity, increased cost of treatment and prolonged hospital stay, among others. This study, therefore, aimed at evaluating the bacterial isolates from contaminated money for their ability to form biofilm and determining the susceptibility profiles to selected antibiotics A total of 100 pieces Nigerian currency notes were aseptically withdrawn from the Automated Teller Machine (ATM) of five different banks located within Obafemi Awolowo University campus. The bacteria associated with their surfaces were isolated and characterized using conventional biochemical tests. The ability of the isolated bacteria to form biofilm was determined using ...

Journal of Pharmacy & Pharmacognosy Research, 2016

Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) h... more Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue culture plate ...

Asymptomatic bacteriuria, a form of urinary tract infections that involves isolation of a specifi... more Asymptomatic bacteriuria, a form of urinary tract infections that involves isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection is common, but the prevalence in population varies widely with age, sex and the presence of genitourinary abnormalities. This study therefore aimed at investigating the prevalence of asymptomatic bacteriuria among selected students of Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife Nigeria as well as the antibiotic resistance patterns of the bacterial isolates associated with the condition. Urine samples were collected from one hundred apparently healthy students and processed within two hours of collection. The isolates were identified by conventional biochemical tests while antibiotic susceptibility of the isolates were carried out according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. Results rev...

British Microbiology Research Journal, 2016

Aims: Toothbrush has been universally accepted as the most effective tool for removing harmful pl... more Aims: Toothbrush has been universally accepted as the most effective tool for removing harmful plaque and bacteria from mouth. On average, colonization of bacteria is reduced by 88.8% as a result of brushing. Toothbrush if not properly taken care of before, during and after use may serve as a vector for the re-introduction of potential pathogens into the oral cavity. This study therefore aimed at investigating the microbial quality of used toothbrushes among selected students of a Tertiary Institution in Ile-Ife, Nigeria as well as the antibiotic susceptibility profiles and adherence property of the associated bacteria. Methodology: Fifty used toothbrushes were collected from students in sterile nylon and transported to Laboratory for processing within an hour of collection. The bacteria were isolated and characterized by conventional biochemical techniques. Antibiotic susceptibility test was carried out using the disk diffusion test according to the Clinical and Standard Laboratory Institute guidelines. Phenotypic adherence property of the isolates was investigated using the Congo Red Agar (CRA) method. Results: These revealed the presence of six genera of bacteria namely: Bacillus spp, Staphylococcal spp, Klebsiella spp, Enterobacter spp, Citrobacter spp and Serratia spp. Bacillus flexus was the predominant Gram-positive species accounting for 30.9% while Klebsiella oxytoca accounts for 26.5% as the predominant Gram-negative species. All the isolates were multidrug resistant. However, 22% of the isolates were adherent as they produced black crystalline colonies in Congo Red agar. Conclusion: The study concluded that toothbrush should be adequately taken care of to prevent it from serving as vector for infection and re-infection of mouth.

African Journal of Clinical and Experimental Microbiology, 2016

Ten brands of blister-packed paracetamol tablet and twenty brands of paracetamol syrup marketed i... more Ten brands of blister-packed paracetamol tablet and twenty brands of paracetamol syrup marketed in Nigeria were evaluated for their microbial quality. While no microbial contaminant was isolated from all blistered-packed paracetamol tablets, ten of syrups were contaminated with organisms such as Escherichia coli, Klebsiellas spp, Pseudomonas aeruginosa and Staphylococcus aureus at 14.3, 21.4, 21.4 and 42.9% occurrence respectively. Penicillium spp was isolated from two brands. Antibiotic susceptibility profile revealed all bacterial isolates to be multidrug resistant with Escherichia coli resistant to all antibiotics tested, while Staphylococcus aureus isolates were sensitive to Oxacillin, Cefuroxime and vancomycin. Pseudomonas aeruginosa isolates were sensitive to ofloxacin and gentamycin while Klebsiella isolates were sensitive to ofloxacin and nitrofurantoin. The study concluded that compliance with the provisions of good manufacturing practice as well as good quality control play role in determining the microbial bioburden of pharmaceutical products while isolation of multi-drug resistant organisms calls for establishment and adherence to antibiotics use policy in Nigeria.

Journal of Pharmacy & Pharmacognosy Research, 2016

Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) h... more Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue culture plate ...

African Journal of Microbiology Research, 2016

Resumen Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections ... more Resumen Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue cultur...

Journal of Microbiology, Biotechnology and Food Sciences

Southern African Journal of Infectious Diseases

Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antim... more Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antimicrobial resistance profiles. In natural settings, bacterial cells are most often found in close association with surfaces and interfaces, in the form of multicellular aggregates commonly called biofilms. Given their ubiquity and importance in the microbial world, it is hardly surprising that biofilms have attracted the attention of the scientific community. Biofilm formation on medical implant devices such as catheters is also a major problem that is closely tied to the adhesion and resistance-related abilities of the biofilm.Methodology: The ability of 216 bacterial isolates from mid-stream urine (100), catheter-stream urine (52) and catheter tips (64) to form biofilms was investigated using the tissue culture plate method, the tube and Congo red agar methods as well as their antibiotic resistance profiles using the agar disc diffusion method.Results: These revealed that Klebsiella spp...

Journal of Microbiology, Biotechnology and Food Sciences

Journal of Pharmacy & Bioresources

Vancomycin resistance commonly occurs with Staphylococcus aureus, a pathogen that exhibits intrin... more Vancomycin resistance commonly occurs with Staphylococcus aureus, a pathogen that exhibits intrinsic virulence. Sixty isolates of Staphylococcus aureus tested positive as vancomycin possessive isolates on Brain Heart Infusion Agar medium fortified with 6 μg/mL vancomycin from 100 clinical samples of urine from patients with cases of UTIs via agar diffusion method. Standard 30 μg vancomycin disc served as control. Increase in zones of growth inhibition in relation to vancomycin concentrations was noticed in some of the isolates while it was reversed in others, despite the increase in concentration. Typed strain was susceptible to six concentrations of vancomycin exposed and to the control. Thirty one of the sixty isolates were resistant to vancomycin control. Resistant isolates from standard vancomycin discs were then subjected to molecular investigation. Of the 31 isolates exposed to gel electrophoresis, 14 (47%)elicited plasmids of varied molecular weights ranging from 0.79-23.13 k...

AFRICAN JOURNAL OF INFECTIOUS DISEASES

Biofilm formation, especially on indwelling medical devices such as catheters, can result in infe... more Biofilm formation, especially on indwelling medical devices such as catheters, can result in infections and substantially affect patients' quality of life. Biofilm-associated infections have led to increased morbidity and mortality, increased cost of treatment, and length of hospital stay. However, all of the identified consequences of the biofilm-associated infections had been attributed to the reduced susceptibility of biofilm to conventional antimicrobial agents which has necessitated the development of a new strategy for biofilm infections control, thereby making a search for more effective antimicrobial agents from plant source inevitable. So far, some antimicrobial agents (crude or isolated compounds) from plant sources affect a specific stage of biofilm development while a few of them have been developed into a suitable dosage form for biofilm control. In this review, an attempt is made to look into some definitions of biofilm by "biofilmologists", stages in bio...

Bacterial Empire

The health hazards associated with the handling of contaminated money have been attributed to the... more The health hazards associated with the handling of contaminated money have been attributed to the ability of contaminated money to act as a vehicle by which pathogens can be transmitted among human beings as well as the capacity of the associated organisms to form biofilm. The consequences of biofilm formation are increased rate of mortality and morbidity, increased cost of treatment and prolonged hospital stay, among others. This study, therefore, aimed at evaluating the bacterial isolates from contaminated money for their ability to form biofilm and determining the susceptibility profiles to selected antibiotics A total of 100 pieces Nigerian currency notes were aseptically withdrawn from the Automated Teller Machine (ATM) of five different banks located within Obafemi Awolowo University campus. The bacteria associated with their surfaces were isolated and characterized using conventional biochemical tests. The ability of the isolated bacteria to form biofilm was determined using ...

Journal of Pharmacy & Pharmacognosy Research, 2016

Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) h... more Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue culture plate ...

Asymptomatic bacteriuria, a form of urinary tract infections that involves isolation of a specifi... more Asymptomatic bacteriuria, a form of urinary tract infections that involves isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection is common, but the prevalence in population varies widely with age, sex and the presence of genitourinary abnormalities. This study therefore aimed at investigating the prevalence of asymptomatic bacteriuria among selected students of Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife Nigeria as well as the antibiotic resistance patterns of the bacterial isolates associated with the condition. Urine samples were collected from one hundred apparently healthy students and processed within two hours of collection. The isolates were identified by conventional biochemical tests while antibiotic susceptibility of the isolates were carried out according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. Results rev...

British Microbiology Research Journal, 2016

Aims: Toothbrush has been universally accepted as the most effective tool for removing harmful pl... more Aims: Toothbrush has been universally accepted as the most effective tool for removing harmful plaque and bacteria from mouth. On average, colonization of bacteria is reduced by 88.8% as a result of brushing. Toothbrush if not properly taken care of before, during and after use may serve as a vector for the re-introduction of potential pathogens into the oral cavity. This study therefore aimed at investigating the microbial quality of used toothbrushes among selected students of a Tertiary Institution in Ile-Ife, Nigeria as well as the antibiotic susceptibility profiles and adherence property of the associated bacteria. Methodology: Fifty used toothbrushes were collected from students in sterile nylon and transported to Laboratory for processing within an hour of collection. The bacteria were isolated and characterized by conventional biochemical techniques. Antibiotic susceptibility test was carried out using the disk diffusion test according to the Clinical and Standard Laboratory Institute guidelines. Phenotypic adherence property of the isolates was investigated using the Congo Red Agar (CRA) method. Results: These revealed the presence of six genera of bacteria namely: Bacillus spp, Staphylococcal spp, Klebsiella spp, Enterobacter spp, Citrobacter spp and Serratia spp. Bacillus flexus was the predominant Gram-positive species accounting for 30.9% while Klebsiella oxytoca accounts for 26.5% as the predominant Gram-negative species. All the isolates were multidrug resistant. However, 22% of the isolates were adherent as they produced black crystalline colonies in Congo Red agar. Conclusion: The study concluded that toothbrush should be adequately taken care of to prevent it from serving as vector for infection and re-infection of mouth.

African Journal of Clinical and Experimental Microbiology, 2016

Ten brands of blister-packed paracetamol tablet and twenty brands of paracetamol syrup marketed i... more Ten brands of blister-packed paracetamol tablet and twenty brands of paracetamol syrup marketed in Nigeria were evaluated for their microbial quality. While no microbial contaminant was isolated from all blistered-packed paracetamol tablets, ten of syrups were contaminated with organisms such as Escherichia coli, Klebsiellas spp, Pseudomonas aeruginosa and Staphylococcus aureus at 14.3, 21.4, 21.4 and 42.9% occurrence respectively. Penicillium spp was isolated from two brands. Antibiotic susceptibility profile revealed all bacterial isolates to be multidrug resistant with Escherichia coli resistant to all antibiotics tested, while Staphylococcus aureus isolates were sensitive to Oxacillin, Cefuroxime and vancomycin. Pseudomonas aeruginosa isolates were sensitive to ofloxacin and gentamycin while Klebsiella isolates were sensitive to ofloxacin and nitrofurantoin. The study concluded that compliance with the provisions of good manufacturing practice as well as good quality control play role in determining the microbial bioburden of pharmaceutical products while isolation of multi-drug resistant organisms calls for establishment and adherence to antibiotics use policy in Nigeria.

Journal of Pharmacy & Pharmacognosy Research, 2016

Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) h... more Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue culture plate ...

African Journal of Microbiology Research, 2016

Resumen Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections ... more Resumen Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs) has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU) (100), catheter-stream urine (CSU) (14) and catheter tips (CT) (13) using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23) moderately adherent bacterial isolates from MSU (10), CSU (7) and CT (6) using the tissue cultur...

Journal of Microbiology, Biotechnology and Food Sciences

Southern African Journal of Infectious Diseases

Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antim... more Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antimicrobial resistance profiles. In natural settings, bacterial cells are most often found in close association with surfaces and interfaces, in the form of multicellular aggregates commonly called biofilms. Given their ubiquity and importance in the microbial world, it is hardly surprising that biofilms have attracted the attention of the scientific community. Biofilm formation on medical implant devices such as catheters is also a major problem that is closely tied to the adhesion and resistance-related abilities of the biofilm.Methodology: The ability of 216 bacterial isolates from mid-stream urine (100), catheter-stream urine (52) and catheter tips (64) to form biofilms was investigated using the tissue culture plate method, the tube and Congo red agar methods as well as their antibiotic resistance profiles using the agar disc diffusion method.Results: These revealed that Klebsiella spp...

Journal of Microbiology, Biotechnology and Food Sciences