Phytochemical screening and antibacterial activity of Garcinia kola (hackel) and Cola nitida (vent) extracts

This study was designed to evaluate the phytochemical and antibacterial properties of Garcina kola (Orogbo) and Cola nitida (Obi) extracts. Fresh seeds of Cola nitida and Garcinia kola were collected from Ago-Iwoye market, Ogun State. The ethanolic and aqueous extracts of the test plants were used against selected test organisms, Streptococcus pneumonia, Staphylococcus aureus, Salmonella typhi, Pseudomonas euriginosa and Escherichia coli. Disc diffusion method was adopted to test for susceptibility of the selected test bacteria to the extracts. Minimum inhibition concentration (MIC) and Minimum bactericidal concentration (MBC) were determined. Bioassay data were statistically analyzed using two-way ANOVA. The result of the phytochemical screening confirmed the presence of flavonoid, phenol, alkaloid, saponins, tannins and phlobatanins. The result of the antibacterial activity showed that the ethanolic extract of the test plants recorded highest antimicrobial activity against test isolates compared to aqueous extracts. The tested plant seeds of both plants posses reasonable antibacterial activity but to varied zones of inhibition, with Staphylococcus aureus isolate having the highest inhibitory zones (21.33) mm while Pseudomonas aeuruginosa had the least inhibitory zone (6.00) mm. The antibacterial activity were however found to be concentration dependent (Fvalue= 3.996, Pvalue= < 0.05). All tested organisms were found to have definite MIC and MBC activities which ranges between 125 and 1000μg/ml for MIC except for Kola nitida that has no definite MBC below 1000μg/ml. The result confirms the potential of antibacterial activity of Garcinia kola and Cola nitida extracts. Keywords: Antimicrobial, Cola nitida, Garcinia kola, Phytochemical, Plant extract

Transcriptional factor influence on OTA production and the quelling attribute of Sirna on the OTA producing strains of Aspergillus section Nigri

This study determined the influence of some transcriptional factors on ochratoxin A production as well as investigates the quelling attributes of some designed siRNA on the OTA producing Aspergillus section Nigri using standard recommended techniques. Results obtained following comparison of the pks gene promoter sequences from 15 isolates depicts differences in length and homology with the pks gene ranging from 218bp in a strain of the Aspergillus niger to 700bp in Aspergillus carbonarius. The alignment of the pks gene promoter region revealed that six and two of the aligned genes have Aba A binding site corresponding to CATTCT and CATTCC respectively while Brl A binding site was absent in all the isolates. Pac C binding site corresponding to CCTGGC and GCCAAG was also found in two and three of the pks gene promoter region respectively. The three designed siRNA shows significant impact on OTA inhibitions with no significant statistical differences (80.9, 74.4 and 75.3% for pks_Ia, pks_Ib and pks_Ic respectively) (F= 3.830, p>0.05). It can be concluded that Are A and Aba A are potential enhancers for ochratoxin A biosynthesis and none of the investigated transcriptional factors is enough for the activation of ochratoxin A production. However, pks gene was seen as a good target gene for inactivation in order to develop efficient means for ochratoxin A control using RNA silencing technology.Key words: Transcriptional factors, Ochratoxin A, siRNA, Quelling , Aspergillus section Nigr

Optimal time of the day for controlled maize pollination in rain forest agro-ecology of south-eastern Nigeria

Prevailing weather condition dictates the extent of success for controlled pollination in any given location for any crop and therefore is critical to final yield in Maize. A field experiment was conducted at the Centre for Agricultural Research and Extension (CARE) Farm of Federal University of Technology, Owerri (Latitude 050, 30” N, Longitude 070 O2” E) during the 2015 and 2016 planting seasons., to determine the optimal time of the day for controlled hand-pollination on maize performance. The treatments constitute three maize accessions and hand pollination done between 7.30 am to 9.30am; 10.00am to 12.00noon; and 12.30pm to 2.30pm. The 3 x 3 factional experiment was laid out in Randomized complete block design (RCBD) with four (4) replications. Data collected in the two years were pooled as there was no significant difference and thereafter subjected to analysis of variance (ANOVA), and means separated using-least significant difference (LSD) at 5% level of probability. No significant difference was observed in the growth and yield attributes with respect to time of day for hand pollination when averaged across the accessions. However, based on cob weight and number of grains, Nwoba white accession performed better than the other accessions between the pollination time of 7.30am to 9.30am. Therefore controlled hand pollination in maize could be carried out between 7.30am and 2.30pm, but between 7.30am and 9.30am could give a better performance.Keywords: Maize, optimal-time, hand-pollination, rain-forest and accessio

Biochemical and bacteriological profiles of asymptomatic bacteriuria among school children in Ago-Iwoye, Nigeria

Background: Asymptomatic bacteriuria (ASB) in children is a predisposing factor to symptomatic urinary tract infection (UTI) that may be complicated by blood stream infections if not appropriately treated with resultant mortality or morbidity. The objectives of this study are to determine the prevalence of ASB, and evaluate both biochemical and bacteriological characteristics of urine samples of primary school pupils in Ago-Iwoye, Ijebu North Local Government Area (LGA), Ogun State, Nigeria.Methodology: Three hundred and seventy-two (186 males and 186 females) apparently healthy (asymptomatic) pupils aged 2-16 years from four randomly selected primary schools in the LGA were screened for ASB. Clean catch specimen of midstream urine was collected from each subject. Biochemical analysis of the urine was performed with Combi 10 reagent strip. MacConkey and Cysteine Lactose Electrolyte Deficient (CLED) agar plates were inoculated with calibrated wireloop delivering 0.01 ml of urine for aerobic culture at 37oC for 24 hours. Identification of significant bacteria on culture plates was done using conventional biochemical tests.Results: The frequency of clear, slightly turbid and turbid urine were 31 (8.3%), 99 (26.6%) and 56 (15.1%) respectively. All analyzed urine samples were alkaline and negative for ketone, glucose and blood, but contained protein in 230 (61.8%), bilirubin in 184 (49.5%), nitrites in 64 (17.2%) and urobilinogen in 14 (3.7%) subjects. The prevalence of significant bacteriuria was 11.8% (44 of 372) with 7.0% in males and 16.7% in females (p = 0.0063). The frequency of bacteria isolated in descending order were Escherichia coli 61.4%, Staphylococcus saprophyticus 61.4%, Staphylococcus aureus 45.5%, Bacillus subtilis 45.5%, Enterococcus faecalis 43.2%, Enterobacter spp 36.4%, Serratia marscencen 31.8%, Klebsiella pneumoniae 22.7%, Proteus mirabilis 22.7% and Pseudomonas aeruginosa 20.5%.Conclusion: This result highlights the presence of significant bacteriuria among apparently healthy pupils in the study area, with higher prevalence in the female pupils. The apparent risk of developing symptomatic UTI with the attendant complications in these pupils should spur preventive education of parents/guardians and the general populace about this entity.Keywords: Asymptomatic bacteriuria, S. saprophyticus, morbidity, prevalence, primary school pupil