LARVICIDAL ACTIVITY OF Picralima nitida, AN ENVIRONMENTAL APPROACH IN MALARIA VECTOR CONTROL

Abstract Insecticide resistance and high incidence of malaria prompt the search for alternative strategies for malaria vector control. This study evaluated the larvicidal efficacy of Picralima nitida on 3rd and early 4th instar larvae of Anopheles gambiae. Laboratory Reared Larvae of Anopheles gambiae were exposed to varying concentrations of the Picralima nitida extracts ranging from 0.5 to 5.0mg/ml, according to WHO Bioassay Methods for susceptibility. Probit analysis using SPSS version 16.0, at (P<0.05) gave LC 50 and LC 95 values of 3.141mg/ml and 42.154mg/ml, 0.352mg/ml and 4.730mg/ml and 0.164mg/ml and 2.201mg/ml for aqueous leaf extracts at 24, 48 and 72h. LC 50 values for methanolic leaf extract were 48.383mg/ml, 15.817mg/ml and 0.333mg/ml at 24h, 48h and 72 h. Methanolic seed extract gave LC 50 value of 0.87mg/ml, 0.21mg/ml and 0.15mg/ml at 24, 48 and 72 h and an LC 95 value of 0.739mg/ml, 0.182mg/ml and 0.124mg/ml at same time interval. The 24 h Relative Potency estimate revealed that aqueous leaf extract had 5.479 times the potency of aqueous seed, while the methanolic seed extract had 269.763 times the potency of the methanolic leaf extracts. The potential use of the methanolic seed and aqueous leaf extracts of P. nitida as an eco-friendly alternative in malaria vector larviciding is demonstrated

Value-added materials recovered from waste bone biomass: technologies and applications.

As the world population increases, the generation of waste bones will multiply exponentially, increasing landfill usage and posing health risks. This review aims to shed light on technologies for recovering valuable materials (e.g., alkaline earth material oxide such as CaO, hydroxyapatite, beta tri-calcium phosphate, phosphate and bone char) from waste bones, and discuss their potential applications as an adsorbent, catalyst and catalyst support, hydroxyapatite for tissue engineering, electrodes for energy storage, and phosphate source for soil remediation. Waste bone derived hydroxyapatite and bone char have found applications as a catalyst or catalyst support in organic synthesis, selective oxidation, biodiesel production, hydrocracking of heavy oil, selective hydrogenation and synthesis of bioactive compounds. With the help of this study, researchers can gather comprehensive data on studies regarding the recycling of waste bones, which will help them identify material recovery technologies and their applications in a single document. Furthermore, this work identifies areas for further research and development as well as areas for scaling-up, which will lead to reduced manufacturing costs and environmental impact. The idea behind this is to promote a sustainable environment and a circular economy concept in which waste bones are used as raw materials to produce new materials or for energy recovery

Pulp Extracts of Picralima nitida: a Larvicidal Agent in Malaria Vector Control

The methanolic and aqueous pulp extracts of Picralima nitida as an eco-friendly alternative in malaria vector control were investigated. The sample yielded a 3.93% extract with methanol and 0.89% with aqueous. The phytochemicals constitutes of crude methanolic and aqueous extracts of P. nitida pulp include the alkaloids, cardiac glycosides, saponins, tannins, flavonoids, terpenes and steroids. Laboratory reared larvae of Anopheles gambiae 4th instar were exposed to varying concentrations of the P. nitida pulp extracts ranging from 0.5 to 5.0mg/ml, according to WHO Bioassay Methods for susceptibility. Probit analysis using statistical package for social sciences version 16.0, at (P<0.05) gave time dependent LC50 and LC95 values of 4.979 mg/ml and 18.541mg/ml, 4.299 mg/ml and 16.008 mg/ml and 2.792 mg/ml and 10.397 mg/ml for aqueous pulp extracts at 24, 48 and 72 hours while methanolic extract values were 12.285 and 96.993 mg/ml, 9.700 and 76.584 mg/ml and 6.490 and 51.236 mg/ml at 24h, 48h and 72 h respectively. The Relative Potency estimate revealed that methanolic extract has 1.525, 1.554 and 1.880 times the potency of aqueous extract at 24 h, 48 h and 72 h respectively. Keywords: Picralima nitida, Eco-friendly, Insecticides, Resistance, Larvicidal

An Investigation of the Lethality of Picralima Nitida, Family Apocynaceae in Malaria Vector Control

Insecticides resistance and the corresponding health and environmental challenges that arises as a result of the use of synthetic chemical based insecticides prompts the search for better alternative control measures which are more effective, specific in action and less toxic. The 4th instar larvae of Anopheles spp, the vector of the deadly plasmodium were evaluated in this research against aqueous and methanolic leaf extracts of the plant Picralima nitida. Results revealed that aqueous leaf extract of the test plant had a mean mortality of 11 at 24hrs exposure and concentration of 5.0mg/ml. 95% mortality was also recorded at 5.0mg/ml after 48hrs exposure. Methanolic leaf extract had a mean mortality of 7.7 at 48hrs exposure time and same concentration of 5.0mg/ml. however, at 72hrs exposure, (concentration 5.0mg/ml), the mean mortality increased to 19.3 (97% mortality). The Median Lethal Time evaluated using probit analysis at 95% Confidence Limit showed the average lethal time of the test organism Anopheles larvae to the methanolic extract to be 55hrs and 29hrs for the aqueous leaf extract. This result hence supports the fact that leaf extracts of P. nitida can be used as a source of eco-friendly alternatives in the control of mosquito vectors, if developed. Keywords: Resistance, Insecticides, Anopheles spp, Eco-friendly, Larvicidin

Ascorbic Acid Supplementation: Effects on the Growth and Packed Cell Volume of Broiler Chickens

This study was conducted to observe the effect of natural and artificial ascorbic acid supplementation on the growth and packed cell volume using broiler chicks. The chicks were divided into groups A, B, C and D. They were fed with the same quantity of feed but different type of ascorbic acid in a litre of water were also administered to groups B to D. Group A which served as the control group received no ascorbic acid and groups B was given 150 g of natural and 150 g of artificial ascorbic acid per litre of water, C received 300 g of natural and 300 g artificial ascorbic acid while D was given 300 g of artificial ascorbic acid per litre of water. The result of the supplement effects on the birds showed that birds feed with natural ascorbic acid recorded the highest weight gain 1.22 kg followed by those feed with mixture of natural and artificial ascorbic acid 1.09kg. Birds that were feed artificial ascorbic acid recorded a weight gain of 0.89 kg while the control group produced the least weight gain of 0.79 kg. The mixture of natural and artificial ascorbic acid proved to be most effective on PCV 21.23, followed by that of artificial ascorbic acid 18.1. Whereas control group recorded a PCV level of 12.84 natural ascorbic acid recorded the least PCV level of 9.93. The result of the experiment indicated that natural ascorbic acid elevated body weight while mixture of natural and artificial ascorbic acid boosted PCV in broiler when given in the right proportion. Keywords: ascorbic acid; packed cell volume; supplementation; natural; artifici

Potential Applications of Eucalyptus camaldulensis in Food Preservation and Biofilm Inhibition on Food Contact Surfaces

Thesis (Ph.D., Microbiology)--Prince of Songkla University, 202

Rifampicin Enhanced Carbapenem Activity with Improved Antibacterial Effects and Eradicates Established <i>Acinetobacter baumannii</i> Biofilms

Biofilm-mediated infections are critical to public health and a leading cause of resistance among pathogens, amounting to a prolonged hospital stay and increased mortality rate in the intensive care unit. In this study, the antibacterial and antibiofilm activities of rifampicin or carbapenem monotherapies were compared with rifampicin and carbapenem combination therapies against rifampicin-resistant and carbapenem-resistant Acinetobacter baumannii isolates. Among 29 CRAB isolates, 24/29 (83%) were resistant to rifampicin, with MIC values between 2–256 µg/mL. Checkerboard assays disclosed that combination therapies at FICIs between 1/8 and 1/4 improved the activity of carbapenems at subinhibitory concentrations. Time-kill kinetics indicated a 2- to 4-log reduction at 1/2 MIC rifampicin + 1/4 MIC carbapenem and 1/4 MIC rifampicin + 1/4 MIC carbapenem against the isolates, with the MIC values ranging from 2–8 µg/mL. The MTT assay revealed a dose-dependent decrease of the cell viability of established bacterial biofilm at 4 MIC rifampicin + 2 MIC carbapenems, with a percentage reduction of 44–75%, compared with monotherapies at 16 MIC. Scanning electron microscopy further confirmed bacterial cell membrane disruption, suggesting a synergism between carbapenem and rifampicin against a representative isolate. The findings demonstrated that the combination of rifampicin with carbapenems could improve antibacterial activities and eradicate established Acinetobacter baumannii biofilm

Characteristics, Influencing Factors, Predictive Scoring System, and Outcomes of the Patients with Nephrotoxicity Associated with Administration of Intravenous Colistin

Multidrug-resistant Gram-negative infection is a major global public health threat. Currently, colistin is considered the last-resort treatment despite its nephrotoxicity. The purpose of this study was to estimate the incidence, characteristics, and influencing factors and to develop a prediction model for colistin-associated nephrotoxicity. A retrospective study was conducted in the university hospital in the South of Thailand from December 2015 to June 2019. A total of 381 patients (median age (IQR) of 64 (51&ndash;62) years) were analyzed. Overall, 282 (74%) had nephrotoxicity according to the Kidney Disease: Improving Global Outcomes (KDIGO) classification. In-hospital, 30-day mortality rates and cost of hospital admission were significantly higher among those with nephrotoxicity. Age &gt; 60 years, comorbidities, serum albumin less than 3.5 g/dL, and concomitant nephrotoxic use were significantly associated with colistin-associated nephrotoxicity with adjusted OR (95% CI) 2.01 (1.23&ndash;2.45), 1.85 (1.18&ndash;3.6), 1.68 (1.09&ndash;2.99), and 1.77 (1.10&ndash;2.97), respectively. The prediction model for high-risk colistin-associated nephrotoxicity was identified with good overall performance (specificity of 79.6% (95% CI 70.3&ndash;87.1) and positive predictive value of 92.1% (95% CI 88.0&ndash;95.1)). In conclusion, the incidence of colistin-associated nephrotoxicity was high and incurred significant morbidity, mortality, and economic burden. Our predictive scoring system is relatively simple and useful for optimizing colistin therapy