MST-SCHOOL OF SCIENCE

ANTIBACTERIAL EFFICACY OF ETHANOLIC EXTRACTS FROM RHIZOME BARK AND TUBER OF Colocasia esculenta (L) Schott, Cranberry variety (ARROWROOT), PHYTOCHEMICAL ANALYSIS AND MINIMUM INHIBITORY CONCENTRATION DETERMINATION AGAINST Salmonella typhi, Klebsiella pneumoniae and Acinetobacter baumanii

2025-03-21T06:42:35Z

ANTIBACTERIAL EFFICACY OF ETHANOLIC EXTRACTS FROM RHIZOME BARK AND TUBER OF Colocasia esculenta (L) Schott, Cranberry variety (ARROWROOT), PHYTOCHEMICAL ANALYSIS AND MINIMUM INHIBITORY CONCENTRATION DETERMINATION AGAINST Salmonella typhi, Klebsiella pneumoniae and Acinetobacter baumanii MUNANIE, VIBIAH MUVILI Colocasia esculenta (L) Schott is a widely grown plant with edible corms and medicinal properties. While the leaves of this plant have been studied for their potential medicinal uses, research on the tuber and bark has limited exploration of the synergistic effects of specific phytochemicals present in the ethanolic extracts of Colocasia esculenta (L) Schott Cranberry variety and how these interactions contribute to the antibacterial efficacy. Additionally, more comprehensive studies on minimum inhibitory concentration across a broader spectrum of bacterial strains to assess the generalizability of the plant extracts antibacterial properties need research. This study explores the antibacterial efficacy of ethanolic extracts derived from the rhizome bark and tubers of Colocasia esculenta (L) Schott Cranberry variety. The research involved phytochemical analysis and determination of minimum inhibitory concentration against three pathogenic bacteria: Acinetobacter baumanii, Klebsiella pneumoniae and Salmonella typhi that are a WHO priority, and are commonly associated with respiratory infections in Kenya.n. Experimental research design was adopted. Twenty pieces of Colocasia esculenta were obtained from Kaimosi Friends University to prepare rhizome bark and tuber extracts, in triplicates, using ethanol at concentrations of 25%, 50%, 75% and 100%, with sterile distilled water as the negative control and ciprofloxacin as the positive control in botany laboratory of Maseno University. Three bacterial strains were obtained from KEMRI and were cultured using Mueller- Hinton Agar. Standard techniques were used in phytochemical screening and in antibacterial experiments. Minimum inhibitory concentration was determined by the broth dilution method. Statistical analysis was performed using Statistical Analysis System version 9. 1. Descriptive data analysis was used to determine presence of phytochemicals. One way analysis of variance was done to assess significant differences in activity between the ethanol extracts and the bacteria, and to determine means of diameters of zones of inhibition at a confidence interval of 95%, with p-values obtained to give significant differences between the means. Predictive data analysis was performed to determine the minimum inhibitory concentration. Results showed presence of saponins, steroids, tannins, alkaloids, glycosides and phenolic compounds. Ethanolic extracts from the rhizome bark and rhizome tuber exhibited antimicrobial activity against all three bacteria. A concentration of 25% of the bark extract was most effective against Salmonella typhi and Klebsiella pneumoniae, 75% of the bark extract was most effective against Acinetobacter baumannii, 50% of the tuber extract was most effective against Salmonella typhi and Klebsiella pneumoniae while 100% of the tuber extract was most effective against Acinetobacter baumannii. Extracts from the bark were more effective than those from the tuber. The minimum inhibitory concentrations for the bark extract ranged from 100µg/ml to 160µg/ml, while those for the tuber extract ranged from 150µg/ml to 250µg/ml. Results from this study contribute valuable insights into potential natural sources for antibacterial agents and their effectiveness against clinically relevant pathogens. Beneficiaries for this study are Pharmaceutical companies developing new antimicrobial agents, microbiologists, communities affected by bacteria used in the study, and healthcare professionals seeking for alternative treatment of bacterial infections.

MATHEMATICAL MODELLING OF HUMAN PAPILLOMAVIRUS DYNAMICS WITH VACCINATION INCORPORATING OPTIMAL CONTROL ANALYSIS

2025-03-21T06:17:06Z

MATHEMATICAL MODELLING OF HUMAN PAPILLOMAVIRUS DYNAMICS WITH VACCINATION INCORPORATING OPTIMAL CONTROL ANALYSIS OKWARE, FEDNANT OSAMAL Cervical Cancer (CC) is primarily caused by Human Papillomavirus (HPV). If untreated in the early stages the abnormal development of cervical cells can be fatal. CC is clearly a threat with about half a million documented cases worldwide and over 200 000 reported deaths per year. Particularly in Sub-Saharan Africa, cervical cancer prevalence still remains high. Early stages of the disease can be treated and prevented but later stages have very low survival rates. Women, particularly in low-income nations are more likely to die from cervical cancer as it enters its advanced stages. Numerous mathematical models have been formulated in order to better understand the dynamics of how HPV causes cervical cancer. However, optimal control strategies with the lowest potential cost of preventing HPV and CC have been given little attention. The objective of this study was to formulate a deterministic mathematical model of HPV dynamics with vaccination that incorporates optimal control analysis. The methodology used in developing the model involved the use of qualitative theory of ODEs, the basic reproduction number using next generation matrix, optimal control analysis and numerical simulations. The analysis of the model shows that the model is positively invariant and bounded. Both disease free equilibrium point and endemic equilibrium point exists and shown to be asymptotically stable when some conditions are met. The optimal control problem is also shown to exist using the Pontryagin Maximum Principle. The analysis also shows that when the basic reproduction number is less than one, HPV dies out in the population but when the basic reproduction number is greater than one, HPV spreads and becomes endemic. The result shows that, combining the three interventions (effective awareness, screening and treatment of HPV and CC, and vaccination) at the rates (ϕ1 = 0.2, ϕ2 = 0.3, ϕ3 = 0.03 ) the infection begins to reduce significantly and dies out in the community when the interventions are intensified. The findings of this study will help epidemiologists and healthcare professionals in concentrating on necessary parameters when formulating an infectious disease control policy. Additionally, it will provide as a basic framework for future study on HPV and CC dynamics. In the interest of HPV and CC prevention, the relevant authorities should encourage effective awareness, treatment of HPV and CC, and vaccination in order to prevent the disease from spreading.

UTILITY OF HOSPITAL DATA TO CHARACTERIZE DIARRHOEAL BACTERIA AND THEIR SUSCEPTIBILITY TO GUAVA LEAF (Psidium guajava) EXTRACTS IN VIHIGA COUNTY, KENYA

2025-03-20T08:35:38Z

UTILITY OF HOSPITAL DATA TO CHARACTERIZE DIARRHOEAL BACTERIA AND THEIR SUSCEPTIBILITY TO GUAVA LEAF (Psidium guajava) EXTRACTS IN VIHIGA COUNTY, KENYA ISIAHO, ILOTE BRUNO Studies have shown that diarrhoeal diseases are a leading toll on global morbidity and mortality especially among developing countries. Diarrhoeal cases are on the rise in Vihiga County, and residents have embraced the use of herbal medicine for diarrhoea treatment. General objectives of this study was to characterize the diarrhoeal bacteria based on hospital data and to determine their susceptibility to Psidium guajava leaf extracts in Vihiga County, Kenya. The specific objectives were; to determine the prevalence of pathogenic intestinal bacteria causing human diarrhoea, to assess the phytochemical components found in Psidium guajava leaf extracts, to determine the antimicrobial effects of Psidium guajava leaf extracts on Salmonella typhi, Escherichia coli and Shigella dysentriae, and to determine the minimum inhibitory concentration of Psidium guajava leaf extracts against the pure isolates. Primary data on diarrhoeal cases was collected at the sub-county hospitals, and secondary data on etiological agents for human bacterial diarrhoea obtained from each sub county hospital records MOH 706 from 2019-2022. Salmonella typhi with a prevalence of 37.1%, Escherichia coli at 15.4% and Shigella dysentriae at 10.6% were identified as major causative agents. Pure cultures of the identified bacteria were obtained from Friends Jumuia Hospital Kaimosi microbiology laboratory. Psidium guajava leaves were collected randomly from 70 farms across the county. Phytochemical compounds were extracted from Psidium guajava leaf extracts where flavonoids, tannins, saponins and terpenoids were found to be present. Extracts were prepared by weighing 100 g of dried Psidium guajava leaf powder, transferred into 500 mls conical flasks. 500 mls of 95% Ethanol, acetone and aqueous was poured into conical flasks with powder respectively and stirred. The mixtures were allowed to stand for 24 hours, decanted and filtered using Whitman’s filter paper, filtrates ware concentrated with 2 L series rotary evaporator at 79°C and refrigerated at 4°. On susceptibility testing against ethanol extract, Salmonella typhi had the highest zone of inhibition of 21.05 mm, Shigella dysentriae with 20.10 mm and Escherichia coli at 19.10 mm. On aqueous extracts, Escherichia coli had 11.25 mm, Salmonella typhi 8.15 mm and Shigella dysentriae 6.00 mm. On acetone, only Shigella dysentriae showed significant inhibition of 3.20 mm. Psidium guajava leaf extracts did not show any growth inhibition on Salmonella typhi and Shigella dysentriae in all concentrations of acetone extract. Salmonella typhi had the least MIC value of (2.16 mg/ml) at 100 mg/ml, Escherichia coli (7.16 mg/ml) at 100 mg/ml and Shigella dysentriae (3.0 mg/ml) at 75 mg/ml using ethanol extract. Escherichia coli recorded the highest MIC value of 11.34 mg/ml at 25 mg/ml using ethanol extracts. Data was analysed using ANOVA for variance analysis and then run through STATA (Version 16). All the Psidium guajava leaf extracts showed activities against the tested bacteria, with ethanol extracts showing the highest inhibition. The p-value from the study analysis was 0.001, which was smaller than the chosen significance level of 0.05 meaning that the difference in variation was significant. The study will address the community on the importance of diarrhoeal prevention and treatment.

MATHEMATICAL MODELING OF ALCOHOLISM INCORPORATING MEDIA AWARENESS

2023-01-10T08:53:45Z

MATHEMATICAL MODELING OF ALCOHOLISM INCORPORATING MEDIA AWARENESS MUCHIKA, CELESTINE LIHEMA Alcohol addiction is a phenomenon that has attracted the attention of numerous researchers and academics in a variety of professions due to its serious repercussion on all spheres of human life. Alcoholism is a common addiction in adults throughout the globe. To shed light on the causes of this phenomenon and pinpoint efficient preventative and therapeutic measures, a mathematical model that incorporates media awareness and the impact of the exposed class on light and heavy drinkers’ is crucial. The impact of media awareness and treatment on the drinking behavior of various drinker classes is discussed in several mathematical models. Nevertheless, the impact of the exposed class of alcoholics on light and heavy drinkers in the presence of media awareness, has not been addressed. There is correlation between the exposed class and awareness over time, hence it is vital to understand the spread of alcoholism and the need to curb it. The main objective of this study is to formulate and analyze, a mathematical model of alcoholism incorporating media awareness and the influence of the exposed class on light and heavy drinkers. A set of differential equations served as the foundation for the model’s formulation. To perform stability analysis of the model at each equilibrium point, Jacobian matrix method and the next generation matrix approach were employed. This further aided in the computation of the basic reproduction number, R0. By use of MATLAB, numerical simulations on the impact of awareness on alcoholism were performed. Secondary data obtained from NACADA and data from rehabilitation centers in Kenya was used to validate the analytical results of the impact of media awareness on the drinking population. Stability analysis of the model indicated that the Alcohol Free Equilibrium (AFE) point is locally asymptotically stable whenever R0 < 1 and unstable whenever R0 > 1. Additionally, the Alcohol Endemic Point (AEP) exists and is locally asymptotically stable when R0 > 1. Numerical simulations showed that increase in media awareness programs reduces alcohol prevalence in the community. The study concluded that maximum media awareness is an ideal measure in curbing alcohol abuse in the community. The findings of this study will provide useful insight to the government and policy makers in targeting suitable media awareness programs in combating alcoholism.