Antioksidativna aktivnost sirutke dobivene iz mlijeka fermentiranog s pomoću vrste Lactobacillus, izolirane iz nigerijske fermentirane hrane

Eight Lactobacillus isolates obtained from five indigenous fermented foods (ogi, ogi baba, wara, kunnu and ugba) were investigated. Wara is a dairy-based food while the others are not dairy-based. The bacteria were isolated on MRS agar and purified by successive streaking on the same medium. The whey fraction of skimmed milk fermented with each isolate was assayed for radical scavenging effects using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. All the whey fractions showed radical scavenging activities. The five isolates with the highest activities were selected. On the basis of Gram stain reaction, cellular morphology, biochemical tests and carbohydrate utilization profiles they were identified as strains of Lactobacillus brevis, L. fermentum, L. plantarum, L. casei and L. delbrueckii. The antioxidant activities of whey fractions from 24-hour fermentations with the selected organisms were investigated using both radical scavenging effects and lipid peroxidation inhibitory activity. The radical scavenging activity was generally higher than the lipid peroxidation inhibition, except in the L. plantarum strain, which did not show any significant difference in both activities. The probiotic potential of the isolates was evaluated by pH and bile tolerance. None of the selected isolates showed any growth at pH=2.0 but L. casei and L. delbrueckii survived at this pH. Four of the five selected isolates were able to grow in 0.5 % dehydrated bile, with L. casei strain showing the highest level of growth, followed by L. delbrueckii. L. plantarum strain was not bile tolerant. The ability of L. casei and L. delbrueckii strains to survive at pH=2 and grow in the presence of bile indicates that the isolates may be able to colonize the gastrointestinal tract. The findings of this study indicate that Lactobacillus strains isolated from indigenous Nigerian fermented foods could be useful as starter cultures to provide antioxidants in food and that fermented milk may serve as a delivery vehicle for antioxidative, probiotic lactobacilli from non-dairy sources.Ispitano je osam izolata vrste Lactobacillus, izdvojenih iz pet autohtonih fermentiranih proizvoda (ogi, ogi baba, wara, kunnu i ugba). Wara je mliječni proizvod, a ostali su nemliječni proizvodi. Bakterije su izolirane na MRS agaru i pročišćene tijekom nekoliko uzastopnih nanošenja na tu podlogu. Pomoću DPPH radikala ispitana je antioksidativna aktivnost frakcija sirutke dobivenih iz obranog mlijeka fermentiranog s pomoću svakog izolata, pa je utvrđeno da sve frakcije imaju sposobnost uklanjanja slobodnih radikala. Odabrano je 5 bakterijskih izolata koji su pokazali najveću aktivnost. Metodom bojenja prema Gramu, ispitivanjem morfologije stanica, provođenjem biokemijskog testa i određivanjem utroška ugljikohidrata utvrđeno je da su to: Lactobacillus brevis, L. fermentum, L. plantarum, L. casei i L. delbrueckii. Ispitana je antioksidativna aktivnost, tj. sposobnost uklanjanja slobodnih radikala i inhibicije peroksidacije lipida, sirutke dobivene fermentacijom mlijeka s pomoću tih izolata tijekom 24 sata. Svi sojevi, osim Lactobacillus plantarum, kod kojega nije utvrđena značajna razlika, lakše su uklanjali slobodne radikale nego inhibirali peroksidaciju lipida. Ispitivanjem mogućnosti preživljavanja u uvjetima manje pH-vrijednosti i prisutnosti žuči u podlozi za rast utvrđen je probiotički učinak izolata. Nijedan izolat nije mogao rasti pri pH=2, osim L. casei i L. delbrueckii, koje mogu preživjeti i pri toj pH-vrijednosti. Od pet izolata njih je četiri moglo rasti kad se podlozi za uzgoj dodalo 0,5 % žuči, pri čemu je najotporniji soj bio L. casei, a zatim L. delbrueckii, dok soj L. plantarum nije bio otporan na žuč. Stoga je zaključeno da bi L. casei i L. delbrueckii mogle naseliti probavni trakt i da se bakterije vrste Lactobacillus, izolirane iz autohtone nigerijske fermentirane hrane, mogu upotrijebiti kao starter-kulture za dobivanje proizvoda s antioksidativnom aktivnošću, te da fermentirano mlijeko može biti izvor laktobacila, izoliranih iz nemliječnih proizvoda, koji imaju antioksidativna i probiotička svojstva

Building needs-based healthcare technology competencies across Africa

Needs-based technology innovation for better health on the African continent requires that African countries develop a strong health technology research and development base, grounded in an understanding of the local context. The discipline of biomedical engineering plays an important developmental role in this regard, through research and training to advance health technology capacity. In recognition of this strategic imperative, the African Biomedical Engineering Consortium (ABEC) was founded in 2012, with the vision of building and nurturing the competencies required to support a robust and dynamic health technology sector

Genetic polymorphisms in malaria vaccine candidate Plasmodium falciparum reticulocyte-binding protein homologue-5 among populations in Lagos, Nigeria

BACKGROUND: Vaccines are the most reliable alternative to elicit sterile immunity against malaria but their development has been hindered by polymorphisms and strain-specificity in previously studied antigens. New vaccine candidates are therefore urgently needed. Highly conserved Plasmodium falciparum reticulocyte-binding protein homologue-5 (PfRH5) has been identified as a potential candidate for anti-disease vaccine development. PfRH5 is essential for erythrocyte invasion by merozoites and crucial for parasite survival. However, there is paucity of data on the extent of genetic variations on PfRH5 in field isolates of Plasmodium falciparum. This study described genetic polymorphisms at the high affinity binding polypeptides (HABPs) 36718, 36727, 36728 of PfRH5 in Nigerian isolates of P. falciparum. This study tested the hypothesis that only specific conserved B and T cell epitopes on PfRH5 HABPs are crucial for vaccine development. METHODS: One hundred and ninety-five microscopically confirmed P. falciparum samples collected in a prospective cross-sectional study of three different populations in Lagos, Nigeria. Genetic diversity and haplotype construct of Pfrh5 gene were determined using bi-directional sequencing approach. Tajima's D and the ratio of nonsynonymous vs synonymous mutations were utilized to estimate the extent of balancing and directional selection in the pfrh5 gene. RESULTS: Sequence analysis revealed three haplotypes of PfRH5 with negative Tajima's D and dN/dS value of - 1.717 and 0.011 ± 0.020, respectively. A single nucleotide polymorphism, SNP (G → A) at position 608 was observed, which resulted in a change of the amino acid cysteine at position 203 to tyrosine. Haplotype and nucleotide diversities were 0.318 ± 0.016 and 0.0046 ± 0.0001 while inter-population genetic differentiation ranged from 0.007 to 0.037. Five polypeptide variants were identified, the most frequent being KTKYH with a frequency of 51.3%. One B-cell epitope, 151 major histocompatibility complex (MHC) class II T-cell epitopes, four intrinsically unstructured regions (IURs) and six MHC class I T-cell epitopes were observed in the study. Phylogenetic analysis of the sequences showed clustering and evidence of evolutionary relationship with 3D7, PAS-2 and FCB-2 RH5 sequences. CONCLUSIONS: This study has revealed low level of genetic polymorphisms in PfRH5 antigen with B- and T-cell epitopes in intrinsically unstructured regions along the PfRH5 gene in Lagos, Nigeria. A broader investigation is however required in other parts of the country to support the possible inclusion of PfRH5 in a cross-protective multi-component vaccine

Antioxidant Activity of Whey from Milk Fermented with Lactobacillus Species Isolated from Nigerian Fermented Foods

Eight Lactobacillus isolates obtained from five indigenous fermented foods (ogi, ogi baba, wara, kunnu and ugba) were investigated. Wara is a dairy-based food while the others are not dairy-based. The bacteria were isolated on MRS agar and purified by successive streaking on the same medium. The whey fraction of skimmed milk fermented with each isolate was assayed for radical scavenging effects using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. All the whey fractions showed radical scavenging activities. The five isolates with the highest activities were selected. On the basis of Gram stain reaction, cellular morphology, biochemical tests and carbohydrate utilization profiles they were identified as strains of Lactobacillus brevis, L. fermentum, L. plantarum, L. casei and L. delbrueckii. The antioxidant activities of whey fractions from 24-hour fermentations with the selected organisms were investigated using both radical scavenging effects and lipid peroxidation inhibitory activity. The radical scavenging activity was generally higher than the lipid peroxidation inhibition, except in the L. plantarum strain, which did not show any significant difference in both activities. The probiotic potential of the isolates was evaluated by pH and bile tolerance. None of the selected isolates showed any growth at pH=2.0 but L. casei and L. delbrueckii survived at this pH. Four of the five selected isolates were able to grow in 0.5 % dehydrated bile, with L. casei strain showing the highest level of growth, followed by L. delbrueckii. L. plantarum strain was not bile tolerant. The ability of L. casei and L. delbrueckii strains to survive at pH=2 and grow in the presence of bile indicates that the isolates may be able to colonize the gastrointestinal tract. The findings of this study indicate that Lactobacillus strains isolated from indigenous Nigerian fermented foods could be useful as starter cultures to provide antioxidants in food and that fermented milk may serve as a delivery vehicle for antioxidative, probiotic lactobacilli from non-dairy sources

Biodegradation of Malachite Green by Extracellular Laccase Producing Bacillus thuringiensis RUN1

A bacteria strain Bacillus thuringiensis RUN1identifiedby 16s RNA gene phylogenetic analysiswas used to decolorize malachite green, a triphenylmethane dye in a simulated wastewater. The ability of the organism to produce extracellular laccase and degrade the dye were also investigated. Results showed that the organism decolorized (84.67 ± 1.19 %) malachite green at 40 mgl-1 within 6 h; and the decolorization was associated to laccase production by the organism experimentally. Laccase activity increased as the decolorization process progressed, with the highest activity value of 0.1043 ± 0.02 U/min/ mg protein recorded after 24 h of incubation using ABTS as substrate. In addition, FTIR analysis showed that the strain actually degraded the dye. It was therefore concluded that this strain of Bacillus thuringiensis will be relevant in the biotreatment of industrial effluent containing malachite green and in the production of laccase, an industrially important enzyme

Association of Dopamine Transporter Gene (DAT1) 40 bp 3′ UTR VNTR Polymorphism (rs28363170) and Cannabis Use Disorder

Introduction: Cannabis remains the most widely used illicit drug among Nigerians, often associated with psychiatric disorders. Since genetic predisposition has been implicated in substance use disorders, we, therefore, aimed at finding out the relationship between dopamine transporter gene (DAT1) polymorphism and cannabis use disorder. Methods: We recruited 104 patients from a tertiary psychiatric facility in Lagos, Nigeria, who were diagnosed with cannabis use disorder according to ICD-10 and 96 non-smokers as a comparative group. The smokers were screened with Cannabis Use Disorder Identification Test (CUDIT), and cannabis dependence was assessed with the Severity of Dependence Scale (SDS). Genotyping was carried out for the 40 bp 3′ UTR VNTR of the DAT1 (rs28363170). Results: The frequencies of 9R/9R, 9R/10R, 10R/10R among non-smokers and smokers were 14 (14.3%), 25 (26.2%), 57 (59.5%) and 17 (16.3%), 54 (51.9%), 33 (31.7%) respectively. The genotype distribution was in Hardy Weinberg equilibrium (HWE) only in the smokers’ population (χ² = 1.896, P  = .166). Individuals with the 10R allele were almost twice as likely as the 9R carriers to smoke cannabis (OR = 1.915, 95% CI: 1.225-2.995). However, this polymorphism was not associated with the quantity of cannabis smoked, age at onset of smoking, CUDIT, and SDS scores. Conclusion: The DAT VNTR polymorphism was associated with cannabis smoking but not cannabis use disorder

Pro-inflammatory Cytokine Response and Genetic Diversity in Merozoite Surface Protein 2 of Plasmodium falciparum Isolates from Nigeria

Background: Polymorphisms in Plasmodium falciparum merozoite surface protein-2 (msp-2) and associated parasite genetic diversity which varies between malaria-endemic regions remain a limitation in malaria vaccine development. Pro-inflammatory cytokines are important in immunity against malaria, understanding the influence of genetic diversity on cytokine response is important for effective vaccine design. Methods: P. falciparum isolates obtained from 300 Nigerians with uncomplicated falciparum malaria at Ijede General Hospital, Ijede (IJE), General Hospital Ajeromi, Ajeromi (AJE) and Saint Kizito Mission Hospital, Lekki, were genotyped by nested polymerase chain reaction of msp-2 block 3 while ELISA was used to determine the pro-inflammatory cytokine response to describe the genetic diversity of P. falciparum. Results: Eighteen alleles were observed for msp-2 loci. Of the 195 isolates, 61 (31.0%) had only FC27-type alleles, 38 (19.7%) had only 3D7-type alleles, and 49.3% had multiple parasite lines with both alleles. Band sizes were 275–625 bp for FC27 and 150–425 bp for 3D7. Four alleles were observed from LEK, 2 (375–425 bp) and 2 (275–325 bp) of FC27-and 3D7-types, respectively; 12 alleles from AJE, 9 (275–625 bp) and 3 (325–425 bp) of FC27-types and 3D7-types, respectively; while IJE had a total of 12 alleles, 9 (275–625 bp) and 3 (325–425 bp) of FC27-types and 3D7-types, respectively. Mean multiplicity of infection (MOI) was 1.54. Heterozygosity (HE) ranged from 0.77 to 0.87 and was highest for IJE (0.87). Cytokine response was higher among 0.05) but with neither parasite density nor infection type. Conclusion: P. falciparum genetic diversity is extensive in Nigeria, protection via pro-inflammatory cytokines have little or no interplay with infection multiplicity