Characterization of novel bacteriocin PB2 and comprehensive detection of the pediocin gene ped-A1 from Pediococcus pentosaceus PB2 strain isolated from a sorghum-based fermented beverage in Nigeria.

Lactic acid bacteria (LAB) have been known to possess bacteriocidal activity resulting from ribosomally synthesized antimicrobial peptides called bacteriocin. This study focused on the characterization of the bactericidal activity of bacteriocin PB2 and comprehensive detection of the pediocin ped-A1 from Pediococcus pentosaceus obtained from fermented sorghum beverage, Pito, in Nigeria against Escherichia coli ATCC 25922 and Listeria monocytogenes ATCC 15313. Bacteriocin PB2 was purified in a 2-step purification using 80% NH4 (SO4)2, and Carboxymethyl-Sephadex G-50 column chromatography to achieve a 12.62% purification fold. The physicochemical properties of purified bacteriocin were characterized being treated at different temperatures (20 - 120 °C), pH (2.0 - 10.0), with different detergents and enzymes (sodium dodecyl sulphate (SDS) urea, ox-gall, and proteinase K and RNase A), organic solvents (ethanol, phenol, acetone, chloroform and isoamyl alcohol), and exposure to ultraviolet (UV) radiation (2-12 h) respectively. The molecular weight of the bacteriocin PB2 was determined to be 4.87 kDa. The antibacterial activity of bacteriocin PB2 was optimum at 40 °C and pH 5.0. The bacteriocin PB2 lost its activity on treatment with proteinase K and exposure to UV radiation (after 6 h) but was observed to have stable activity in the presence of organic solvents. Also, P. pentosaceus PB2 harbored two plasmids, 0.9 and 1.2 kb which when cured resulted in the loss of the antimicrobial activity. The mRNA transcript for pedA was detected in P. pentosaceus PB2, but not in the cured derivative, confirming the expression of the plasmid ped-A1 gene in PB2. This study validates our previous study that the PB2 strain of Pediococcus pentosaceus isolated from fermented sorghum, Pito, may be used as a probiotic toward clinically important enteropathogenic bacteria. This peptide is a potential agent for use as an alternative antibacterial agent for the treatment of drug-resistant strains of bacterial infection.

Pigment Produced by Glycine-Stimulated Macrophomina Phaseolina Is a (-)-Botryodiplodin Reaction Product and the Basis for an In-Culture Assay for (-)-Botryodiplodin Production.

An isolate of Macrophomina phaseolina from muskmelons (Cucumis melo)was reported by Dunlap and Bruton to produce red pigment(s) in melons and in culture in the presence of added glycine, alanine, leucine, or asparagine in the medium, but not with some other amino acids and nitrogen-containing compounds. We explored the generality and mechanism of this pigment production response using pathogenic M. phaseolina isolates from soybean plants expressing symptoms of charcoal rot disease. A survey of 42 M. phaseolina isolates growing on Czapek-Dox agar medium supplemented with glycine confirmed pigment production by 71% of isolates at the optimal glycine concentration (10 g/L). Studies in this laboratory have demonstrated that some pathogenic isolates of M. phaseolina produce the mycotoxin (-)-botryodiplodin, which has been reported to react with amino acids, proteins, and other amines to produce red pigments. Time course studies showed a significant positive correlation between pigment and (-)-botryodiplodin production by selected M. phaseolina isolates with maximum production at seven to eight days. Pigments produced in agar culture medium supplemented with glycine, beta-alanine, or other amines exhibited similar UV-vis adsorption spectra as did pigments produced by (±)-botryodiplodin reacting in the same agar medium. In a separate study of 39 M. phaseolina isolates, red pigment production (OD520) on 10 g/L glycine-supplemented Czapek-Dox agar medium correlated significantly with (-)-botryodiplodin production (LC/MS analysis of culture filtrates) in parallel cultures on un-supplemented medium. These results support pigment production on glycine-supplemented agar medium as a simple and inexpensive in-culture method for detecting (-)-botryodiplodin production by M. phaseolina isolates.

Exploiting the CRISPR-Cas9 gene-editing system for human cancers and immunotherapy.

The discovery of clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) technology has brought advances in the genetic manipulation of eukaryotic cells, which has revolutionised cancer research and treatment options. It is increasingly being used in cancer immunotherapy, including adoptive T and natural killer (NK) cell transfer, secretion of antibodies, cytokine stimulation and overcoming immune checkpoints. CRISPR-Cas9 technology is used in autologous T cells and NK cells to express various innovative antigen designs and combinations of chimeric antigen receptors (CARs) targeted at specific antigens for haematological and solid tumors. Additionally, advanced engineering in immune cells to enhance their sensing circuits with sophisticated functionality is now possible. Intensive research on the CRISPR-Cas9 system has provided scientists with the ability to overcome the hostile tumor microenvironment and generate more products for future clinical use, especially off-the-shelf, universal cellular products, bringing exciting milestones for immunotherapy. This review discussed the application and challenges of CRISPR technology in cancer research and immunotherapy, its advances and prospects for promoting new cell-based therapeutic beyond immune oncology.

Polymorphism rs3737787 of Upstream Stimulatory Factor 1 gene is associated with serum lipid phenotype in Nigerian population.

Serum lipid profile which is determined by genotype-phenotype relationship plays a significant role in the development of cardiovascular disease. Upstream stimulatory factor 1 (USF1), has been reported to be associated with serum lipid levels in different population, hence, this study investigated the association of variants in USF1 with serum lipid profile in adults in Lagos state, Nigeria. We genotyped rs3737787 (11235C > T) and rs550376620 (10488G > A) with PCR-RFLP in 384 participants and we used logistic regression to assess the association of these variants with serum lipid levels. The minor allele frequency observed in 10488G > A in both case and control groups was 5% while the minor allele of 11235C > T was observed to be more frequent in the control when compared to the dyslipidemic subjects (24% vs 12%; p = 1.84e-05). Levels of total cholesterol, triglycerides, and LDL-c in dyslipidemic subjects with CC genotype of 11235C > T were significantly higher compared to CT and TT genotypes (p < 0.001; p < 0.0001 and p < 0.0001 respectively). Logistic regression with adjustment for age, gender and BMI, showed that the minor allele carriers of 11235C > T have a reduced risk of dyslipidemia (Odds ratio: 0. 0.043, 95% confidence interval (CI): (0.006-0.331, p = 0.002). Our findings revealed that rs3737787 is associated with lipid phenotype in Nigerian population.

A review on the incidence, interaction, and future perspective on Zika Virus

Zika virus(ZIKV) belongs to the family Flaviviridae and genus Flavivirus. It is a single-stranded positive-sense ribonucleic acid(RNA)virus, has its origin traced to Zika forest in Uganda. Its infection leads to ZIKV fever, characterized by arthralgia, myalgia, rash,conjunctivitis, and asthenia. Clinical presentation of the infection is nonspecific and may often be confused with symptoms of other flaviviral diseases (dengue, West Nile [WN], and chikungunya). Recently, ZIKV has been associated with congenital malformations and neurological complications such as microcephaly and Guillain­Barre' syndrome. The viral tropism revealed an infection of the skin fibroblasts, keratinocytes, and immature dendritic cells through enhanced expression of dendritic cell­specific intracellular adhesion molecule 3­grabbing nonintegrin or anexelecto (Greekword: 'uncontrolled') and tyrosine protein kinase receptor 3 systems. Silencing of T-cell immunoglobulin (Ig) and mucin domain 1(TIM-1) and AXL RNAs has shown blockage of viral entry through their anti-TIM-1 and anti-AXL antibodies, hence serving as a potential target for ZIKV drug development. Biotechnological approaches targeted toward ZIKV vector control include the development of transgenic mosquitoes to disrupt the genome pool of wild strains and use of an endosymbiotic bacterium to prevent replication of arboviruses within its vector. Other approaches include the use of gene drive and exploration of the genetic redundancy to disrupt the receptors used by the virus to gain entry into its host. It is also imperative to explore the modality through which neutralizing antibodies block this viral infection as this may prove as a potential target to arrest the viral life cycle

Antioxidant modulation of nevirapine induced hepatotoxicity in rats.

HIV/AIDS related mortality has been dramatically reduced by the advent of antiretroviral therapy (ART). However, ART presents with associated adverse effects. One of such adverse effects is hepatotoxicity observed with nevirapine (NVP) containing ART. Since previous studies showed that NVP hepatotoxicity may be due to oxidative stress via generation of oxidative radicals, this study sought to evaluate the protective effects of antioxidants in alleviating NVP induced hepatotoxicity. Rats were divided into 6 groups with 8 animals per group and received doses of the antioxidants jobelyn (10.7 mg/kg/day), vitamin C (8 mg/kg/day), vitamin E (5 mg/kg/day) and/or NVP (6 mg/kg/day) for 60 days. The animals were sacrificed on day 61 by cervical dislocation, blood samples were collected for biochemical and hematological examination. The liver of the sacrificed animals was weighed and subjected to histopathological examination. There was a statistically significant (p<0.05) elevation in MDA level observed in the NVP group as compared with control. The results further showed non-significant decreases in the levels of MDA in the NVP plus antioxidant groups, except vitamin C, when compared with the NVP alone group. Vitamin E and Vitamin E plus C treated groups showed significantly (p<0.05) higher levels of SOD, CAT and GSH. The results also showed statistically significantly (p<0.05) lower levels of ALT and AST in the antioxidant treated groups There was an observed significantly (p<0.05) higher level of TP and urea in the antioxidant treated rats. A significantly (p<0.05) higher white blood cell count was observed in the antioxidant groups. Histopathological assessment of the liver extracted from the rats showed no visible pathology across the groups. Observations from this study suggest a potentially positive modulatory effect of antioxidants and may be indicative for the inclusion of antioxidants in nevirapine containing ART.

Prevalence, profile and predictors of malnutrition in children with congenital heart defects: a case-control observational study.

OBJECTIVE: To investigate the prevalence, profile and predictors of severe malnutrition in children with congenital heart defects (CHDs). DESIGN: Case-control, observational study. SETTING: Tertiary teaching hospital in Lagos, Nigeria (March 2006 to March 2008). PARTICIPANTS: Children aged 3-192 months with uncorrected symptomatic CHD and healthy controls, frequency matched for age and sex. MAIN OUTCOME MEASURES: Prevalence of malnutrition based on WHO/National Center for Health Statistics/Centers for Disease Control and Prevention z score ≤-2; weight for age, weight for height/length and height for age; proportions of underweight, wasting and stunting in cases and controls, and in acyanotic and cyanotic CHD; and predictors of malnutrition using multivariate logistic analysis. RESULTS: 90.4% of cases and 21.1% of controls had malnutrition (p=0.0001), and 61.2% and 2.6%, respectively, had severe malnutrition (p=0.0001). Wasting, stunting and underweight were identified in 41.1%, 28.8% and 20.5%, and 2.6%, 3.9% and 14.5% of cases and controls, respectively. Wasting was significantly higher (58.3%) in acyanotic CHD (p=0.0001), and stunting (68.0%) in cyanotic CHD (p=0.0001). Age at weaning was significantly lower in cases than controls (3.24±0.88 and 7.04±3.04 months, respectively; p=0.0001) and in acyanotic than cyanotic CHD (2.14±0.33 and 5.33±1.22 months, respectively; p=0.004). Predictors of malnutrition in CHD were anaemia, moderate to severe congestive heart failure (CHF), poor dietary intake of fat and prolonged unoperated disease. CONCLUSION: Severe malnutrition in association with anaemia and moderate to severe CHF is highly prevalent in CHD preoperatively in these children. Early weaning may be a marker of feeding difficulties in heart failure.