Antibiotic resistance profile and phenotypic detection of beta-lactamase-producers among gram-negative bacteria isolated from the gut of household cockroaches in and around University Of Ibadan

Background: Cockroaches are carriers of numerous microorganisms. However, there is paucity of information on their role as potential reservoir for beta-lactamase  producers.Objectives: This research determined the antibiotics susceptibility profile of Beta-lactamase producing Gram-negative bacteria isolated from the gut of  household cockroaches in selected locations in and around University of Ibadan, Oyo state.Materials and Methods: Thirty Cockroaches from different locations in and around University of Ibadan were collected between June 2015 and March, 2016, and their intestinal homogenates cultured on different selective media for the isolation of  bacteria. The isolates were identified using a combination of biochemical tests and 16S rRNA sequencing. Antibiotic susceptibility testing was done using the  disc-diffusion technique and phenotypic detection of extended-spectrum  beta-lactamase (ESBL), AmpC-beta-lactamase (AmpC) and Metallo- beta-lactamase (MBL) production was done using double-disc synergy,  cefoxitin/cloxacillin and imipenem/EDTA double-disc methods respectively.Results: A total number of 58 bacteria belonging to nine genera; Pseudomonas, Proteus, Klebsiella, Salmonella, Enterobacter, Escherichia, Serratia, Shigella and Raoultella were isolated. Higher percentage of the isolates exhibited resistance to  erythromycin (90%), azithromycin (87.5%), amoxicillin (84.5%), ampicillin  (74.1%), amoxicillin-clavulanic acid (74.1%), cefoxitin (67.2%) and  chloramphenicol (54%), while lower percentage showed resistance to aztreonam (25%), ertapenem (13%), cefotaxime (8.6%), ceftazidime (10.3%), cefepime (5.2%), ciprofloxacin (3.5%), gentamicin (5.2%) and imipenem (0%). MDR  phenotype was recorded among 82% of the isolates, 17.2% were positive for ESBL, 12% for AmpC and 13.8% for MBL production.Conclusion: This study identified household cockroaches Periplaneta americana, as a potential reservoir for MDR and beta-lactamase-producing isolates.Keywords: Susceptibility testing, ESBL, AmpC, MBL, Beta-Lactamase, MDR, Household cockroache

Seasonal variations of physicochemical characteristics of brewery industry effluent and receiving water of Ikpoba-Oha Rivers, Benin City, Nigeria

The impact of the effluents from a Brewery industry on the water quality of Ikpoba-Oha River was carried out during wet and dry seasons, 2016. Water samples from three selected points in the river were analyzed for pH, temperature, total solids, total dissolved solids, Hardness, BOD, COD, DO, Chlorides, phosphates, sulphates. Samples were collected at three points designated as: point 1 (effluent), point 2 (upstream), and point 3 (downstream). The results of the analysis of the effluent obtained on both seasons were: pH (5.90-8.38), temperature (25.20oC-33.15oC), chlorides (12.0-129.2mg/l), phosphates (0.9-20.48mg/l), sulphates (3.30-53.0mg/l), nitrates (3.8-17.20mg/l), DO (2.3- 4.15mg/l), Total Hardness (12.10-425.6mg/l), Ca hardness (6.0-296.4mg/l), Total Solids (44.0-513mg/l), TSS (20- 159mg/l) and TDS (24-354mg/l).The levels of most of the parameters monitored are generally higher at the point of effluent discharged into water bodies and dispersed to less malign conditions downstream due to water dilution effect.Keywords: Physicochemical properties, Ikpoba River, Effluent, pH, Hardnes

Optimization of in-situ Biodiesel Production from Raw Castor Oil-Bean Seed

Optimization of in-situ biodiesel production from raw castor oil-bean seed was carried out from raw castor bean oil seed (37.9% oil content) by alkaline catalyzed in-situ trans-esterification with Sodium hydroxide as catalyst and ethanol as the solvent in a laboratory batch processor.  Response surface methodology and central composite experimental design was applied to evaluate effects of reaction time (30 -120 min), alcohol/seed weight ratio (0.5 – 2.0), Catalyst amount (0.3 – 1.5%) and reaction temperature (40 – 70OC).  Catalyst amount, reaction temperature and time all had significant main effects (p < 0.05) while Alcohol-seed ratio had only slight effects on yield of castor biodiesel as a main effect but was significantly involved in interactions with other factors.  A modified statistical model comprised of all significant factors and interactions (p < 0.05) obtained by multiple regressions predicted that the highest yield of castor ethyl-ester was 99.5% of expressible oil at the following optimized reaction values; alcohol/seed weight ratio of 0.5, a catalyst./seed weight ratio of 1.31, reaction temperature of 60.33oC, and reaction time of 81.7minutes.  A Taguchi L9(3^4)  optimization experimental design used to confirm the modified model at optimum point and two other points within experimental region produced yield that was significantly comparable to model predictions at 95% confidence level using  a paired t-test. Measured properties of the castor ethyl-ester such as viscosity(5.78mm2/s), pour point (-21.5 oC), flash point (177.12 oC), calorific value (47.76MJ/kg), acid value (0.34 mg KOH/g) and cetane number (48.73) were within the ASTM standard D6751-02 but specific gravity. Keywords: Castor oil-bean seed, biodiesel, in-situ trans-esterification, response surface methodology, optimization, Castor ethyl-este

Production of Bio-Diesel from Jatropha Curcas Seed Using In-Situ Technique: Effect of Catalyst Amount and Alcohol-Seed Ratio

The effects of alcohol seed ratio (0.5, 1.5 & 2.0) and initial catalyst amount (0.5, 1.0 & 1.5%) on the in-situ production of biodiesel from raw Jatropha Curcas seed were studied and evaluated at a reaction temperature of 600C and reaction time of 120min using the Central Composite experimental Design. Initial catalyst amount and alcohol seed ratio were found to have significant (P<0.05) effects on the yield of biodiesel produced. Initial catalyst amount was the more important factor and had a positive influence on the yield than alcohol seed ratio which does not significantly affect the yield as a single factor. Due to formation of by-products (soaps) caused by excessive amount of catalyst and excess alcohol leading to difficult ester separation from glycerol, there was a general reduction in Jatropha Curcas ethyl-ester as levels of catalyst and alcohol seed ratio increased. A second-order quadratic model was obtained to predict the yield as a function of both factors. The model predicted well the observed data with a R 2 value of 0.985 and a non-significant Lack-of-Fit (P<0.05). The biodiesel obtained, compared favorably with the ASTM D6751-02 standard for biodiesel. Keywords: in-situ, trans-esterification, Jatropha Curcas seed, biodiesel, response surface, biomas

High prevalence of Plasmodium malariae and Plasmodium ovale in co-infections with Plasmodium falciparum in asymptomatic malaria parasite carriers in southwestern Nigeria

Asymptomatic malaria parasite carriers do not seek anti-malarial treatment and may constitute a silent infectious reservoir. In order to assess the level of asymptomatic and symptomatic carriage amongst adolescents in a highly endemic area, and to identify the risk factors associated with such carriage, we conducted a cross-sectional survey of 1032 adolescents (ages 10-19 years) from eight schools located in Ibadan, southwestern Nigeria in 2016. Blood films and blood spot filter paper samples were prepared for microscopy and DNA analysis. The prevalence of asymptomatic malaria was determined using microscopy, rapid diagnostic tests (RDTs) and PCR for 658 randomly selected samples. Of these, we found that 80% of asymptomatic schoolchildren were positive for malaria parasites by PCR, compared with 47% and 9%, determined by RDT and microscopy, respectively. Malaria parasite species typing was performed using PCR targeting the mitochondrial CoxIII gene, and revealed high rates of carriage of Plasmodium malariae (53%) and Plasmodium ovale (24%). Most asymptomatic infections were co-infections of two or more species (62%), with Plasmodium falciparum + P. malariae the most common (35%), followed by P. falciparum + P. malariae + P. ovale (21%) and P. falciparum + P. ovale (6%). Single infections of P. falciparum, P. malariae and P. ovale accounted for 24%, 10% and 4% of all asymptomatic infections, respectively. To compare the species composition of asymptomatic and symptomatic infections, further sample collection was carried out in 2017 at one of the previously sampled schools, and at a nearby hospital. Whilst the species composition of the asymptomatic infections was similar to that observed in 2016, the symptomatic infections were markedly different, with single infections of P. falciparum observed in 91% of patients, P. falciparum + P. malariae in 5% and P. falciparum + P. ovale in 4%