Daniel K Olukoya

Daniel K Olukoya
The National Institute for Medical Research, Yaba | NIMR

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70
Publications
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1,246
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Publications

Publications (70)
Article
Full-text available
We examined clinical samples from Nigerian patients with acute watery diarrhea for Vibrio cholerae during the 2010 cholera outbreak. A total of 109 suspected isolates were characterized, but only 57 V. cholerae strains could be confirmed using multiplex real-time PCR as well as rpoB sequencing and typed as V. cholerae O:1 Ogawa biotype El Tor. This...
Article
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Nigeria has been plagued with seasonal epidemics of cholera with high mortality impact since 2007. Data to understand the molecular epidemiology of strains for developing country-specific control measures are either not available or incomplete in most of the epidemic states. To bridge this information gap, this study determined the phage type profi...
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Objective: To investigate the possibility of isolating indigenous probiotic strains from faecal specimens of breastfed infants. Method: One hundred and sixty four Lactobacillus strains [Lb. reuteri 72 (43.9%), Lb. casei 40 (24.4%), Lb. acidophilus 35 (21.3%), Lb. bifidus 11 (6.71 %), Lb. brevis 3 (1.83 %) and Lb. plantarum 3 (1.83 %] isolated from...
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This study scientifically examined the phytochemistry, antioxidant and antimicrobial potencies of two organic extracts of Pleurotus ostreatus . Generally, both extracts were effective against 89.8% of the isolates tested with Bacillus subtilis (7.6 – 7.8 mm), Escherichia coli (7.6 – 8.2 mm) and Saccharomycee cerevisae (10.5 – 10.8 mm) exhibiting hi...
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This study scientifically examined the phytochemistry, antioxidant and antimicrobial potencies of two organic extracts of Pleurotus ostreatus. Generally, both extracts were effective against 89.8% of the isolates tested with Bacillus subtilis (7.6 – 7.8 mm), Escherichia coli (7.6 – 8.2 mm) and Saccharomycee cerevisae (10.5 – 10.8 mm) exhibiting hig...
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Fourteen strains isolated from vegetable sources and identified as belonging to Lactobacillus plantarum presented an atypical pattern of amplification with a species-specific multiplex-PCR assay. Phylogenetic analysis of two protein-encoding genes, recA (encoding the recombinase A protein) and cpn60 (encoding the GroEL chaperonin), as well as pheno...
Article
The genetic basis of the fungicidal activity of strains of Lactobacillus brevis and L. fermentum isolated from indigenous fermented foods was determined. A 5.5-kb plasmid was isolated from L. brevis while L. Fermentum was found to harbor no plasmid. Plasmid curing indicated no correlation between the plasmid and the fungicidal activity of the Lacto...
Article
A cry2 gene encoding a larvicidal crystal protein was isolated from a strain of Bacillus thuringiensis found in soil samples in Nigeria. This gene was cloned into plasmid pUC19 and subcloned into both pBluescript (sk(+/-)) and pPICZ alpha B placed under a T7/AOXI (alcohol oxidase I) promoter respectively and transformed into Escherichia coli and Pi...
Article
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The study examined a possible association between HIV infection and conventional sexually transmitted diseases (STDS) in a population of 700 patients seen in some hospitals and clinics in Lagos State between November 1997 and December 1999. The patients were drawn mainly from LUTH and Jolad hospitals in Lagos State. In these hospitals, patients who...
Article
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A total of 635 clinically diagnosed typhoid fever patients were bled from three different health institutions in the metropolis of Lagos, Nigeria over a period of 15 months, May 1997 to July 1998. Out of the total blood cultured, 101 (15.9% ) isolates of Salmonella species were isolated of which 68 (67.3% ) were S. typhi, 17 (16.8% ) and 16 (15.8%...
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Six isolates of Bacillus thuringiensis isolated from soil samples confirmed to be toxic to mosquito larvae were differentiated using a PCR-Based technique. Three of these isolates initially identified using a serological technique were further differentiated with the PCR amplification of the delta-endotoxin target sequences. Using the total DNA of...
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Genomic DNA from 58 strains of Campylobacter made up of 48 Campylobacter jejuni and ten Campylobacter coli were digested with Sma I and analysed by pulsed-field gel electrophoresis (PFGE). The cleavage of DNA by Sma I gave 22 distinct hybridization patterns. The two Campylobacter species were subtyped by PFGE. The average genomic size for C. jejuni...
Article
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Diversity, based on restriction fragment length polymorphism (RFLP) analysis, was studied in 48 strains of Campylobacter, comprising 27 chicken and 21 human strains of C. jejuni and C. coli, using genomic Southern hybridisation. Restriction digests of chromosomal DNA were prepared by treating with HaeIII and probed using a C. jejuni DNA probe. Nine...
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Flagellin gene sequence polymorphisms were used to discrimate amongst 53 strains of Campylobacter jejuni and C. coli. The Campylobacter strains were made up of forty-three strains of Campylobacter jejuni and 10 strains of Campylobacter coli. The results were analysed in relation to Penner serotyping. Twenty DNA PCR -RFLP patterns (genotypes) were i...
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The pH values of both cooked and uncooked ogi and koko samples were determined and the survival rate of four diarrhoeagenic agents, enteroinvasive Escherichia coli, Salmonella typhi, Shigella flexneri, and Vibrio cholerae were studied after they were seeded into cooked ogi and koko. Analysis of the pH of the cooked inoculated samples showed that th...
Article
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Lactobacillus species (28 in toto) were isolated from fifty pig faeces, including Lactobacillus acidophilus (21.44%), L. fermentum (17.86%), L. salivarius (14.29%), L. plantarum (10.71%), L. buchneri (10.71%), L. delbrueckii (7.14%), L. brevis (7.14%) and L. bulgaricus (10.71%). The predominant species was L. acidophilus (21.44%). The isolates were...
Article
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Diversity based on ribosomal RNA gene-restriction endonuclease digest patterns was detected amongst forty-seven strains of Campylobacter made up of 38 strains of Campylobacter jejuni and 9 strains of Campylobacter coli. Restriction digests of chromosomal DNA prepared by treating with Hae III were probed with an oligonucleotide specific for Campylob...
Article
Objective: To compare genotyping of leucocyte DNA by PCR and Dde I with the conventional genotyping of haemoglobin of the same subject. Design: Comparative study. Subjects: 25 adults, 16 males and nine females. Main outcome measures: Predictability. Results: In all cases the results were comparable. Conclusions: The technology can be app...
Article
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Fifty-eight Compylobacter strains were isolated from children with diarrhoea at various health centres in Lagos and from healthy chicken. Twenty-nine strains of Campylobacter were isolated from humans, while the same number were isolated from chicken. The strains were biotyped using the modified Preston biotype scheme. The Preston biotyping results...
Article
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A total of 228 bacteria with an ability to resist toxic heavy metals were isolated from 8 selected sites of the Lagos Lagoon. The bacteria isolated were Staphylococcus sp., Bacillus sp., Pseudomonas sp., Streptococcus sp., Moraxella sp., Escherichia coli, Proteus sp., Klebsiella sp. and Salmonella sp. The heavy metals to which resistance was record...
Article
As a part of a program to develop starter cultures aiding in the spoilage control and sanitation of African fermented foods, a cereal-based food ('ogi' and its solid form 'agidi' or 'eko') was prepared using a bacteriocin-producing Lactobacillus strain as the starter culture. The survival of an enterotoxigenic Escherichia coli strain was investigat...
Article
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Two hundred isolates of Lactobacillus were obtained from seven indigenous fermented foods namely: 'fufu' (fermented cassava), 'iru' (fermented African locust bean), 'kenkey' and 'ogi' (fermented maize), 'kunu zarki' (fermented millet), 'ugba' (fermented African oil bean) and 'wara' (fermented skimmed cow milk). Lactobacillus species identified were...
Article
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A total of sixty Campylobacter strains were tested for their ability to produce β-lactamase. The isolates were from chicken (30) and human (30) sources. The starch paper technique was employed in the detection of β-lactamase, while ampicillin resistance was tested using the disc diffusion method. Out of the sixty strains analysed, three (5%) showed...
Article
To ascertain the antibiotic resistance patterns and plasmids of Staphyl coccus aureus and coagulae negative staphylococci isolated from different clinical specimens in Lagos, Nigeria. Prospective study involving the screening of specimens of blood, urine, skin and soft tissue infections, vagina, urethra, eye, ear, nose, pleural fluid and seminal fl...
Article
To determine the prevalence, antimicrobial properties and beta-lactamase production of haemolytic enterobacteria in patients with diarrhoea and urinary tract infections in Lagos, Nigeria. Hospital based prospective study. Total of 324 patients comprising 194 diarrhoeal and 130 urinary tract infection (UTI) cases. Production of haemolysms. beta-lact...
Article
In an investigation into the problems of infections due to Staphylococcus aureus in Nigeria, 100 strains were isolated from various hospitals in Lagos. The strains were screened for the presence of plasmids and for susceptibility to antimicrobial agents. Plasmids were extracted by modification of the method of Takahashi and Nagono[1]. The plasmids...
Article
In a study on the outbreak of cholera in Nigeria in 1992, 86 strains of Vibrio cholerae O1 (79 Ogawa serotype and 7 Inaba serotype) were isolated. Antimicrobial susceptibility testing and plasmid profile analysis of the strains were done. Most isolates were highly sensitive to ciprofloxacin, cefotaxime, chloramphenicol, gentamicin, erythromycin, na...
Article
Four of the seven tested medicinal plants exhibited antimicrobial activity against Vibrio cholerae. These 7 plants are: Ficus capensis, Mitragyna stipulosa, Entada africana, Piliostigma reticulatum, Terminalia avicennoides, Mimosa pudica, and Lannea acida. Of them Terminalia avicennoides showed higher antimocrobial activity than others. Potentials...
Article
Genetic analysis of antibiotic-resistant plasmids from 102 serologically defined strains of enteropathogenic Escherichia coli from Nigeria was carried out. All the isolates were screened for susceptibility to antibiotics, and 47 were found resistant to tetracycline. A total of 138 plasmids was isolated by agarose gel electrophoresis. Transformation...
Article
Ten bacteriocin-producing (bacteriocinogenic) Lactobacillus isolates obtained from three Nigerian fermented foods namely: kenkey, ogi and wara were tested against the following indicator organisms: Lactobacillus plantarum and food borne pathogens comprising enterotoxigenic Escherichia coli, enterohaemorrhagic Escherichia coli, Serratia, Pseudomonas...
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A total of 150 stool samples obtained from different medical centers in Lagos were screened for the presence of Salmonella and Shigella using standard microbiological procedures. Of the 150 stool samples screened, 14 (8.70%) and 15 (10.0%) were positive for Salmonella and Shigella respectively. Antimicrobial sensitivity results showed that both iso...
Article
As part of a programme to formulate foods to aid the control of diarrhoeal diseases, an improved ogi (the commonest weaning food in Nigeria) named DogiK has been developed. DogiK was produced by using Lactobacillus starter cultures with antimicrobial activity against diarrhoeagenic bacteria and also possessing amylolytic activity. The survival of d...
Article
Fourteen of 200 Lactobacillus isolates from African fermented foods, viz. 'wara', 'kenkey', 'ugba', 'ogi', 'kunuzarki', 'fufu' and 'iru' were found to produce bacteriocins against L. plantarum and only three bacteriocinogenic isolates inhibited some of the food pathogens. Plasmid analysis of the 14 bacteriocin-producing lactobacilli showed that onl...
Article
About 30% of clinical isolates of Escherichia coli tested utilized L-sorbose as a carbon and energy source. Escherichia coli K-12 is naturally sorbose negative. The genes for L-sorbose utilization (sor+) is being used as a prototype for studying variable genes amongst bacterial pathogens. The sor+ genes from seven isolates were transferable to E. c...
Article
A total of 1239 normal donors from the Lagos University Teaching Hospital (LUTH) and 111 staff of the National Institute for Medical Research (NIMR) Yaba were screened for ABO antibodies. Of the number from LUTH, 220 (17.8%) were found to be in group A, 282 (22.8%) in group B, 85 (6.9%) in group AB and 652 (52.6%) in group O. The number from NIMR c...
Article
As part of an investigation into the genetics of lactobacilli isolated from Nigerian fermented foods, Lactobacillus species isolates were obtained from nine locally fermented foods. The food items were ogi, fufu, burukutu, pito, nono, kunu zarki, wara, iru and ugba.In order to evaluate the plasmid-encoded genes involved in the fermentation of Niger...
Article
In an epidemiological survey of antibiotic resistance in this environment, Bacillus bacteria were isolated from commonly consumed fermented foods. The fifty strains isolated were tested for susceptibility to antibiotics and screened for the presence of plasmids. Majority (72%) were resistant to Cloxacillin and Penicillin (70%) while 40% harbour pla...
Article
As part of an epidemiological study, R plasmids coding for tetracycline resistance were isolated from enteropathogenic Escherichia coli. A 1.4kb Pst 1 fragment of one of them p1479 (size 5.7kb) has been cloned into plasmid pGL101. This recombinant plasmid containing the tetracycline gene was then transformed into E. coli DHI where the tetracycline...
Article
In an epidemiological investigation on the genetic determinants responsible for tetracycline resistance in Nigeria, 518 isolates of enteric bacteria from hospitals and clinics were screened for susceptibility to antibiotics. 305 (58.8%) were resistant to tetracycline. The commonest resistance pattern that involved tetracycline resistance was tetr a...
Article
Antibiotic susceptibility testing and plasmid screening of 50 local isolates of Campylobacter coli and Campylobacter jejuni were done. All isolates were sensitive to ofloxacin but were resistant to ampicillin, cloxacillin, penicillin, streptomycin and aztreonam. A large number of isolates were sensitive to nalidixic acid (96%), ceftriaxone (96%) an...
Article
Full-text available
In an epidemiological survey, plasmid profiles and antimicrobial susceptibility testing of 100 shigella isolates in Lagos, Nigeria was done. All the isolates were sensitive to nalidixic acid, nitrofurantoin and ciprofloxacin. The commonest antimicrobial susceptibility pattern was resistance to ampicillin, colistin sulphate, co-trimoxazole, streptom...
Article
Biochemical and sensory changes of Nigerian melon seeds fermented with fourBacillus strains isolated from African locust beans were studied. In all fermentations, the reducing sugar content doubled from a starting value of 45 mg/g. The total free amino acid content decreased for the first 40 h and then increased. WithB. licheniformis, B. subtilis a...
Article
In an epidemiological study of enteropathogenic Escherichia coli, 102 strains were isolated from patients seen at the University Teaching Hospital in Lagos. The most common serotype encountered was 055 followed by 026. Antimicrobial susceptibility testing and plasmid profiling of the strains were done. All the strains were sensitive to colistin, na...
Article
Clinical isolates of Neisseria gonorrhoeae, Campylobacter jejuni, Escherichia coli, Shigella dysenteriae, Shigella boydii, Yersinia spp. and Salmonella spp. were screened for the presence of plasmids. Approximately 80% of these strains harboured plasmids ranging in molecular weight from 1.0 to 45 x 10(6) daltons.
Article
Genes for citrate utilization were transferred by transduction into Escherichia coli from Salmonella and Klebsiella strains. The genes appear to take chromosomal positions at 6-10 min on the K12 linkage map. Growth on citrate medium by Cit+ K12 hybrids was poor. Incorporate of glycine or L-serine into citrate minimal media improved growth of K12 Ci...
Article
Full-text available
Nutritional tests were carried out on 62 strains of Escherichia coli as part of a study on the genetic basis of natural nutritional variation. The ability of these strains to utilize 84 compounds as carbon, nitrogen and carbon plus nitrogen sources was tested using an auxanographic method. The tests revealed polymorphic characters which are suitabl...

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Project
Due to the rising spread of third-generation cephalosporin resistant non-Enterobacteriaceae among hospitalised patients in Nigeria, there has been an increasing use of carbapenems orally and intravenously. To monitor and evaluate the impact of antibiotic stewardship programme, my Lab in now screening hospital isolates for carbapenemase production using phenotypic methods then genotypic methods (PCR-based) for the detection of class A, B and C carbapenemase genes. This will eb followed by the use RAPD, AFLP and MLST for genetic diversity determination and clonal structure. the first phase of this project has been completed.