Papers by Martins Adefisoye
Antimicrobial Agents and Chemotherapy, 2003
Fluoroquinolone resistance in Streptococcus pneumoniae isolated from Hong Kong as part of Prospec... more Fluoroquinolone resistance in Streptococcus pneumoniae isolated from Hong Kong as part of Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin 1999/2000 was found to be due to the spread of the Spain23F-1 clone (mainly a Spain23F-1-14 variant). All the isolates were multidrug resistant but were susceptible to quinupristin-dalfopristin, linezolid, and telithromycin. The Spain23F-1 clone also occurred among antimicrobial-susceptible isolates, which suggests that the primary source of this clone may have been Asia rather than Iberia.
Water, Oct 1, 2020
This study assessed the distribution of five heavy metals (Cd, Pb, Cu, Zn, and Fe) across the var... more This study assessed the distribution of five heavy metals (Cd, Pb, Cu, Zn, and Fe) across the various stages of treatment in three selected sewage treatment facilities and their receiving waterbodies in the Eastern Cape Province, South Africa. Aqueous and solid (sludge) samples were collected monthly from September 2015 to February 2016. Quantitation was achieved by atomic absorption spectrometry after necessary sample preparations. Concentrations of heavy metal cations in the sludge generally varied from <DL (below detection limit) to 1.17 mg kg −1 , <DL to 0.14 mg kg −1 , 27.588 to 69.789 mg kg −1 , and <DL to 0.099 mg kg −1 for Cu, Cd, Fe and Pb; while Zn was below detection all through. Similarly, the levels of Cu, Cd, and Fe in the influents, effluents, upstream and downstream across the three plants ranged from <DL-6.588 mg L −1 , <DL-0.636 mg L −1 , <DL-0.878 mg L −1 and <DL-0.711 mg L −1 , respectively; Zn and Pb were less than DL in all the matrices and study locations. All the contaminants were below hazardous levels in all the sludge and aqueous samples except Cd which was higher in effluents and surface waters across the board. Wastewater Treatment Plant (WWTP)-A exhibited better removal capacity for Fe (86.6%), compared to WWTP-B (34.7%) and WWTP-C (56.9%). However, the removal of Cu and Zn was very poor in all the treatment facilities studied. Carcinogenic and non-carcinogenic risks evaluated were sufficiently low. This suggests that the levels of contamination, even with respect to Cd, was minimal. Nevertheless, efforts should be made to keep the concentrations of these contaminants at levels safe for humans and aquatic organisms. Furthermore, the use of the effluents from these facilities for irrigation should be discouraged to prevent unnecessary build-up of metals in the soil and plants grown with such, as well as subsequent bioaccumulation and biomagnification in the food chain.
Background Rising incidences of antimicrobial resistance has become a major public health issue g... more Background Rising incidences of antimicrobial resistance has become a major public health issue globally resulting in increasing health-care costs and severe and lethal diseases. Several reports have documented alarming increases of antimicrobial resistance in the Enterobacteriaceae family, hence, this study evaluated the occurrence and antibiogram signatures of Enterobacteriaceae isolates recovered from vegetables, hospital e uents and river water samples in two district municipalities in the Eastern Cape Province, South Africa. Results Out of 142 presumptive isolates, 105 were con rmed to belong to the Enterobacteriaceae family. From these, 45% were identi ed as E. coli, 24% as Enterobacter spp., 20% as Citrobacter spp. and 11% as Klebsiella spp. All the isolates demonstrated high resistance against ampicillin at a frequency of 91.4%, followed by nalidixic acid (86.7%), tetracycline (82.9%), cefuroxime (81.9%) and doxycycline (81.9%). The beta-lactam resistance gene bla TEM was detected in 77.8% of the E. coli isolates and 33.3% of the Klebsiella isolates. The sul1 gene was detected in 23.1% of the Enterobacter species, while sul2 gene was detected in 70% of the Klebsiella species. All the Enterobacter species were positive for the strB gene. Conclusions We conclude that the vegetables, hospital e uents and river water in the two District Municipalities are reservoirs of multidrug resistant members of the Enterobacteriaceae family and a potential health hazard for consumers.
Journal of Microbial & Biochemical Technology, Sep 11, 2015
His current research interest covers the area of water and wastewater quality monitoring around t... more His current research interest covers the area of water and wastewater quality monitoring around the Eastern Cape Province of South Africa. He has presented some of his findings at different conferences and published some in reputable journals.
Polish Journal of Environmental Studies, Jan 28, 2019
Contamination of water resources by pathogens due to ever increasing anthropogenic activities and... more Contamination of water resources by pathogens due to ever increasing anthropogenic activities and the related disease burden remains a major concern of water quality globally. This study evaluated the physicochemical and microbiological quality indices of Nahoon Beach and its canal waters in South Africa over a period of 12 months (September 2014 to August 2015). Water samples were collected biweekly from 6 sampling points (3 on the beach and 3 on the canal) and analyzed using standard methods. The physicochemical qualities of the beach and canal waters ranged as follows: turbidity 3.3-99.9 NTU, temperature 15-25ºC, pH 7-10, electrical conductivity 30.0-741.7 µS/cm, and total dissolved solids 19-546 mg/l. As for microbial counts of the water samples, Escherichia coli counts ranged in the order of 10 1-10 3 CFU/100 ml while Enterococcus counts varied in the order of 10 1-10 2 CFU/100 ml. This study underscores the need for the protection of recreational water resources to safeguard public health.
bioRxiv (Cold Spring Harbor Laboratory), Aug 11, 2020
The increasing occurrence of multidrug-resistant Enterobacteriaceae in clinical and environmental... more The increasing occurrence of multidrug-resistant Enterobacteriaceae in clinical and environmental settings has been seen globally as a complex public health challenge, mostly in the developing nations where they significantly impact on freshwater used for a variety of domestic purposes and irrigation. In this paper, we give details as regards the occurrence and antibiogram signatures of Enterobacteriaceae community in Tsomo and Tyhume rivers within the Eastern Cape Province, Republic of South Africa using standard methods. Average distribution of the presumptive Enterobacteriaceae in the rivers ranged from 1 × 10 2 CFU/100ml to 1.95 × 10 4 CFU/100ml. We confirmed 56 (70.8%) out of 79 presumptive Enterobacteriaceae isolated being species within the family Enterobacteriaceae through the Matrix-Assisted Laser Desorption Ionization Time of Flight technique. From this, Citrobacter-, Enterobacter-, Klebsiella species and Escherichia coli were selected (n=40) due to their pathogenic potentials for antibiogram profiling. The results of the antibiotic susceptibility testing gave a revelation that all the isolates were phenotypically multidrugresistant while resistance against ampicillin (95%), tetracycline and doxycycline (88%) and trimethoprim-sulfamethoxazole (85%) antibiotics were most prevalent. The Multiple Antibiotic Resistance indices stretched from 0.22 to 0.94, with the highest index observed in a C. freundii isolate. Molecular characterisation using the PCR technique revealed the .
Scientific Reports
The proliferation of antibiotic-resistant bacteria and antimicrobial resistance is a pressing pub... more The proliferation of antibiotic-resistant bacteria and antimicrobial resistance is a pressing public health challenge because of their possible transfer to humans via contact with polluted water sources. In this study, three freshwater resources were assessed for important physicochemical characteristics as well as heterotrophic and coliform bacteria and as potential reservoirs for extended-spectrum beta-lactamase (ESBL) strains. The physicochemical characteristics ranged from 7.0 to 8.3; 25 to 30 °C, 0.4 to 93 mg/L, 0.53 to 8.80 mg/L and 53 to 240 mg/L for pH, temperature, dissolved oxygen (DO), biological oxygen demand (BOD5) and total dissolved solids, respectively. The physicochemical characteristics mostly align with guidelines except for the DO and BOD5 in some instances. Seventy-six (76) Aeromonas hydrophila and 65 Escherichia coli O157: H7 isolates were identified by preliminary biochemical analysis and PCR from the three sites. Among these, A. hydrophila displayed higher fr...
MicrobiologyOpen, Jan 13, 2016
Antimicrobial resistance (AMR) is a global problem impeding the effective prevention/treatment of... more Antimicrobial resistance (AMR) is a global problem impeding the effective prevention/treatment of an ever-growing array of infections caused by pathogens; a huge challenge threatening the achievements of modern medicine. In this paper, we report the occurrence of multidrug resistance (MDR) in Escherichia coli strains isolated from discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. Standard disk diffusion method was employed to determine the antibiotic susceptibility profile of 223 polymerase chain reaction (PCR)-confirmed E. coli isolates against 17 common antibiotics in human therapy and veterinary medicine. Seven virulence associated and fourteen antibiotic resistance genes were also evaluated by molecular methods. Molecular characterization revealed five pathotypes of E. coli in the following proportions: enterotoxigenic ETEC (1.4%), enteropathogenic EPEC (7.6%), enteroaggregative EAEC (7.6%), neonatal meningitis (NMEC) (14.8%), uropathogenic (41.7%), and others (26.9%). Isolates showed varying (1.7-70.6%) degrees of resistance to 15 of the test antibiotics. Multidrug resistance was exhibited by 32.7% of the isolates, with the commonest multiple antibioticresistant phenotype (MARP) being APT -CFX (12 isolates), while multiple antibiotic-resistant indices (MARI) estimated are 0.23 (Site 1) and 0.24 (Site 2). Associated antibiotic resistance genes detected in the isolates include: strA (88.2%), aadA (52.9%), cat I (15%), cmlA1 (4.6%), blaTEM (56.4%), tetA (30.4%), tetB (28.4%), tetC (42.2%), tetD (50%), tetK (11.8%), and tetM (68.6%). We conclude that municipal wastewater effluents are important reservoirs for the dissemination of potentially pathogenic E. coli (and possibly other pathogens) and antibiotic resistance genes in the aquatic milieu of the Eastern Cape and a risk to public health.
Journal of Microbial & Biochemical Technology, Sep 11, 2015
His current research interest covers the area of water and wastewater quality monitoring around t... more His current research interest covers the area of water and wastewater quality monitoring around the Eastern Cape Province of South Africa. He has presented some of his findings at different conferences and published some in reputable journals.
Antibiotics
Chemical agents including chlorine and antibiotics are used extensively to control infectious mic... more Chemical agents including chlorine and antibiotics are used extensively to control infectious microorganisms. While antibiotics are mainly used to treat bacterial infections, chlorine is widely used for microbial inactivation in the post-secondary disinfection steps of water treatment. The extensive use of these agents has been acknowledged as a driving force for the expansion of antimicrobial resistance (AMR) and has prompted discourse on their roles in the evolution and proliferation of resistant pathogens in the aquatic milieus. We live in a possible “post-antibiotic” era when resistant microbes spread at startling levels with dire predictions relating to a potential lack of effective therapeutic antibacterial drugs. There have been reports of enhancement of resistance among some waterborne pathogens due to chlorination. In this context, it is pertinent to investigate the various factors and mechanisms underlying the emergence and spread of resistance and the possible association...
Probiotic Beverages, 2021
Abstract The growing quest for a healthy lifestyle among humans has led to active search for heal... more Abstract The growing quest for a healthy lifestyle among humans has led to active search for healthier alternatives for the prevention or treatment of infectious diseases. Probiotics are an important groups of microorganisms that have been used to stimulate a healthy balance of gastrointestinal tract (GI) bacteria, thus promoting a wide range of health benefits, such as weight loss, digestive health, reduction of metabolic disorders, and boosting of immune functions. Such probiotic microorganisms/strains are used for the development of probiotic beverages. However, in a rapidly growing commercial probiotics market, consumers often encounter challenges in distinguishing between good-quality and poor-quality probiotic products. This difficulty threatens the trust end-users and healthcare providers have in probiotic products. In order to address this problem, proper quality control (QC) of probiotic organisms and subsequent beverages is all-important. This chapter therefore describes the importance of QC in the selection of microorganism strains for use as probiotics and the various criteria to ensure viability and reliability of the probiotic strains/products towards boosting consumer's trust and acceptance of probiotic beverages.
African Journal of Food Science, Sep 15, 2011
Palm wine is an alcoholic beverage identified with various cultures in Africa by different names ... more Palm wine is an alcoholic beverage identified with various cultures in Africa by different names playing an important role in the tradition, religious and cultural beliefs of the people. Often obtained by tapping the cut flower of palm trees, this alcoholic beverage can serve as sources of some vital nutrients. Palm wine samples bought from fifteen (n = 15) different vendors located in different parts of Ibadan, Nigeria were analyzed for glucose, alcohol and salicylate content. Controls were freshly tapped, undiluted palm wine from five different tappers (n = 5). The mean ± SEM glucose concentration (mg per 100 ml) 15.57 ± 4.94 of regularly sold palm wine is significantly lower than 376.40 ± 9.92 mg per 100 ml observed in freshly tapped undiluted palm wine. The mean ± SEM alcohol concentration (mg per 100 ml) 117.71 ± 11.28 of the regularly sold palm wine is significantly higher than 33.72 ± 2.68 (mg per 100 ml) observed in freshly tapped palm wine. Traces of salicylate were found in samples of some of the regularly sold palm wine but absent in the freshly taped. The mean ± SEM salicylate concentration (mg per 100 ml) is 4.5 × 10-2 ± 1.6 × 10-2 for regularly sold palm wine. This value had no significant difference when compared with 0.00 ± 0.00 (mg per 100 ml) observed in freshly tapped palm wine. However, continued consumption of palm wine with salicylate content might lead to exposure to chronic salicylate poisoning.Saccharomyces cerevisiae to which fermentation of palm sap to palm wine is usually attributed was the fungal isolate in both the regularly sold and freshly tapped palm wine. A ripple health effects can ensue from intoxication due to product’s alcoholic content, unguided drinking behaviour and lack of effective monitoring of product quality. Maintaining this symbolic commodity of immense indigenous values in its original unadulterated form for consumption is advocated. Key words: Palm wine, alcohol, salicylate, Saccharomyces cerevisiae, culture, health.
Fermentation, 2022
The aim of this present study was to optimize the fermentation conditions (time and temperature) ... more The aim of this present study was to optimize the fermentation conditions (time and temperature) of amasi (a Southern African fermented dairy product) using response surface methodology (RSM), and to determine the physicochemical properties, as well as the microbial composition, using next generation sequencing. Fermentation time and temperature were optimized to produce different amasi samples and different parameters, including pH, total soluble solids (TSS), total titratable acids (TTA), and consistency. All the variables studied were found to show significant (p ≤ 0.05) changes with increasing fermentation time and temperature. Numerical optimization was used to obtain the optimal fermentation conditions for amasi; based on RSM, it was 32 °C for 140 h, while with k-means clustering, it was 25 °C for 120 h. Under both conditions for the optimal samples, the pH reduced from 6.64 to 3.99, TTA increased from 0.02 to 0.11 (% lactic acid), TSS decreased from 9.47 to 6.67 °Brix, and th...
This study analysed 330 environmental substrates from three dairy farms for the occurrence, drug ... more This study analysed 330 environmental substrates from three dairy farms for the occurrence, drug resistance and the genetic mutations of MTBC (<i>Mycobacterium tuberculosis</i> complex) in Eastern Cape, South Africa using PCR, while the Genotype MTBDR<i>plus</i> assay was used for drug susceptibility and genetic mutations analyses. About 17% (55/330) of the samples were positive for MTBC at 16.7% (water), 13.3% (soil) and 20% (hayfeed). Isoniazid resistance was detected in 47.3% (26/55) of the samples while 16.4% (9/55) were multidrug-resistant. Genetic mutations were detected on the <i>rpoB</i> gene (resistance to rifampicin) with frequencies ranging from 53.6% (D516V) to 21.4% (H526D), while mutations on the <i>katG</i> and <i>inhA</i> genes (resistance to isoniazid) ranged between 14.3% and 80%. Incidents of diverse genetic mutations in the environmental matrices suggest possible resistance to other anti-TB drugs not ass...
Background Rising incidences of antimicrobial resistance has become a major public health issue g... more Background Rising incidences of antimicrobial resistance has become a major public health issue globally resulting in increasing health-care costs and severe and lethal diseases. Several reports have documented alarming increases of antimicrobial resistance in the Enterobacteriaceae family, hence, this study evaluated the occurrence and antibiogram signatures of Enterobacteriaceae isolates recovered from vegetables, hospital effluents and river water samples in two district municipalities in the Eastern Cape Province, South Africa. Results Out of 142 presumptive isolates, 105 were confirmed to belong to the Enterobacteriaceae family. From these, 45% were identified as E. coli, 24% as Enterobacter spp., 20% as Citrobacter spp. and 11% as Klebsiella spp. All the isolates demonstrated high resistance against ampicillin at a frequency of 91.4%, followed by nalidixic acid (86.7%), tetracycline (82.9%), cefuroxime (81.9%) and doxycycline (81.9%). The beta-lactam resistance gene blaTEM was...
Background: People’s behavior and compliance with COVID-19 control measures is associated with th... more Background: People’s behavior and compliance with COVID-19 control measures is associated with their knowledge, attitude and perceptions (KAP). To this end, we investigated the KAP among people from diverse populations towards the COVID-19 pandemic. We also examined the impact of the outbreak on their livelihoods. Methods: A cross sectional study with the adoption of a 31-item questionnaire divided into five sections namely demographics, knowledge, attitudes, perception and effect on livelihood. Six countries were considered with Australia, United Kingdom and USA in developed countries category; India, Nigeria and South Africa were considered in developing countries category. Reponses were compared by development status. Results: A total of 577 responses were received with 55.5% female and 49% below the age of 35 years. Respondents from developed countries had significantly better knowledge than their counterparts from developing countries on majority (67%) of the items including sy...
Scientific African, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Cereal Science, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Food Research International, 2021
Metabolomics is a high precision analytical approach to obtaining detailed information of varieti... more Metabolomics is a high precision analytical approach to obtaining detailed information of varieties of metabolites produced in biological systems, including foods. This study reviews the use of metabolomic approaches such as liquid chromatography mass spectrometry (LCMS), gas chromatography mass spectrometry (GC-MS), matrix assisted laser desorption /ionization tandem time of flight mass spectrometry (MALDI-TOF-MS) and nuclear magnetic resonance (NMR) for investigating the presence of foodborne pathogens and their metabolites. Pathogenic fungi and their notable metabolites (mycotoxins) have been studied more extensively using metabolomics as compared to bacteria, necessitating further studies in this regard. Nevertheless, such identified fungal and bacteria metabolites could be used as biomarkers for a more rapid detection of these pathogens in food. Other important compounds detected through metabolomics could also be correlated to functionality of these pathogenic strains, determined by the composition of the foods in which they exist, thereby providing insights into their metabolism. Considering the prevalence of these food pathogens, metabolomics still has potentials in the determination of food-borne pathogenic microorganisms especially for the determination of pathogenic bacteria toxins and is expected to generate research interests for further studies and applications.
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Papers by Martins Adefisoye