RP-Department of Biochemistry and Biotechnology

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Validity of Procalcitonin and C-Reactive Protein as Biomarkers in Diagnosis Ofneonatal Sepsis in a Referral Hospital, Kenya
(Alexandria Journal of Medicine, 2024-11) Tum, Florence Chepyegon; Ngeranwa, Joseph J.N.; Maiyoh, Geoffrey K.; Frank G. Onyambu
Background: Neonatal sepsis (NS) is a significant health concern causing high morbidity and mortality among neonates. The clinical symptoms of NS can overlap with other common neonatal conditions. The gold standard diagnostic method, the blood culture test, has numerous limitations including lengthy turnaround time, which delays appropriate management of NS. Acute phase protein; procalcitonin (PCT) and C-reactive protein (CRP) tests have emerged as potential alternatives due to short turnaround times, high sensitivity, and specificity in detecting NS. Nevertheless, there is limited data on their usability in Kenyan public hospitals. This study, therefore, was conducted to validate the performance of PCT and CRP tests in diagnosis of NS locally. Methodology: Blood samples were collected from 196 neonates with suspected sepsis admitted at Moi Teaching and Referral Hospital (MTRH). Blood culture was performed using BacT/ALERT blood culture system. Bacteria growths were identified and antibiotic susceptibility for the isolates determined using Vitek II. Serum PCT levels were determined using the chemiluminescence immunoassay method. Serum CRP levels were measured using Immunoturbidimetry method. Results: Growth of organisms occurred in 45.4% of the sepsis suspected neonates. The sensitivity, specificity, positive predictive value, negative predictive value and area under the curve for PCT were 93.3%, 98.1%, 97.6%, 94.6% and 0.959, whereas for CRP they were 100%, 72.8%, 74.3%, 100%, and 0.953, respectively. Conclusion and Recommendation: The CRP test exhibited superior sensitivity, negative predictive value, but lower specificity, making it a more valuable tool for ruling out NS. Overall, however, PCT emerged as a more robust biomarker, offering a reliable balance between sensitivity and specificity, indicating its ability to identify cases with NS correctly. The area under the ROC curve confirms that CRP and PCT have high accuracy in detecting NS. The study recommends adoption of PCT and CRP biomarkers in the diagnostic protocols for NS.
In Vitro Anti-Prostate Cancer Efficacy and Phytochemical Composition of the Dichloromethane and Ethyl Acetate Leaf Extracts Of Vitex Doniana (Sweet)
(Frontiers in Pharmacology, 2024-11) Moriasi, Gervason; Ngugi, Mathew; Mwitari, Peter
Background: Prostate cancer is a significant global health concern, particularly among ageing male populations, with a disproportionately higher burden in subSaharan Africa. Conventional treatments, though effective, are costly and cause devastating side effects which limit their clinical benefits. Hence, this study evaluated the in vitro antiprostate cancer properties and secondary metabolites of dichloromethane and ethyl acetate lead extracts of Vitex doniana to explore safer and efficacious natural alternatives based on ethnomedicinal claims. Methods: Phytochemical profiling was conducted using gas chromatographymass spectrometry (GC-MS) analysis to identify secondary metabolites in the extracts. The cytotoxic effects of the extracts were determined through the MTT assay using Vero CCL-81 cells and DU-145 cells. The expression profile of the selected genes (ar, bcl2, caspase-3, cdk1, and p53) in DU-145 cells treated with the study extracts was investigated using RT-qPCR. Results: GC-MS analysis revealed 10 secondary metabolites in the dichloromethane extract and 27 secondary metabolites in the ethyl acetate extract of V. doniana leaves, with the majority being sesquiterpenes, diterpenoids, and phytosterols. The dichloromethane and ethyl acetate leaf extracts of V. doniana exhibited low cytotoxicity against normal mammalian epithelial cells (Vero CCL-81), with CC50 values of 1,238.85 μg/mL and 964.81 μg/ mL, respectively. Besides, the ethyl acetate leaf extract of the studied plant demonstrated potent anti-prostate cancer activity against DU-145 cells, with an IC50 of 35.68 μg/mL and a high selectivity index (SI) of 27.04. Likewise, the dichloromethane leaf extract of this plant displayed cytotoxic effects (IC50: 287.01 μg/mL) and a selectivity index of 4.32. The reference drug (Doxorubicin) showed a higher toxicity against Vero CCL-81(IC50: 0.41 μg/mL) and DU-145 (IC50: 0.28 μg/mL) cells and a lower selectivity index of 1.46. The DU145 cells treated with the studied plant extracts exhibited notable upregulation of ar and bcl2, and normalization of caspase 3, cdk1 and p53 expression. Conclusion: The studied plant extracts possess in vitro anti-prostate cancer properties and could be promising candidates for further preclinical studies aimed at developing novel botanical-based therapies for the management of prostate cancer.
Gastrointestinal Carriage of Carbapenemase-Producing Enterobacterales among Inpatient and Outpatient Children in Kenya
(Springer Nature, 2024-12) Githii, Susan; Maingi, John M.; Nyaga, Teresia; Ndungu, Cecilia; Nyongesa, Kelvin Wangira; Musyoki, Abednego Moki
Gastrointestinal carriage of antimicrobial-resistant bacteria, especially carbapenemase-producing Enterobacterales (CPE), presents a critical public health threat globally. However, in many resource-constrained countries, epidemiological data on CPE is limited. Here, we assessed gastrointestinal carriage and associated factors of CPE among inpatient and outpatient children (≤ 5 years). This hospital-based cross-sectional study was conducted at Thika Level 5 Hospital in Kenya from February to June 2023. In total, 540 participants were recruited from outpatient (270) and inpatient (270) children, excluding those admitted for < 48 h and outpatients with ≤ 3 months hospitalization history. Demographic data were collected using a questionnaire, and stool or swab samples were cultured following standard microbiology methods. Automated platforms were used for isolates identification and antimicrobial susceptibility testing. Gastrointestinal carriage rate of CPE was 9.6%, 95% confidence interval (CI): 6.39–13.79% (26/270) among the inpatients and 5.9%, 95% CI: 3.42–9.45% (16/270) among the outpatients. The carbapenemase-producing Enterobacterales were predominated by multidrug-resistant Escherichia coli from inpatients (22/22, 100%) and outpatients (8/10, 80%). The colonization rate was higher among inpatients who were presenting with chills (aOR = 10.57, p = 0.008). We report a high gastrointestinal carriage of CPE among children (≤ 5 years). Strict adherence to colonization screening, and antimicrobial stewardship policies are critical to control CPE dissemination in the current study area and beyond.
The Persistent Challenge of Cholera in Africa: A Complex Interplay of Factors
(RPHB, 2024-12) Siamalube, Beenzu; Ehinmitan, Emmanuel; Runo, Steven; Onguso, Justus; Maina, Ngotho
Cholera remains a formidable public health challenge across Africa, disproportionately impacting marginalized and vulnerable populations [1]. The disease's persistence underscores its multifaceted nature, rooted in more than just the biological characteristics of Vibrio cholerae. Instead, it reflects a complex interplay of environmental, social, economic, and systemic factors, each compounding the difficulty of effective prevention and control [1,2]. Africa continues to bear the highest burden of cholera globally, with recurring outbreaks that cause significant morbidity and mortality, often overwhelming already fragile healthcare systems [3]. The disease frequently strikes regions plagued by inadequate access to clean water, sanitation, and hygiene (WASH) infrastructure [3,4]. These deficiencies create fertile ground for the bacterium's proliferation, particularly in densely populated urban slums and rural areas with limited public health outreach. Climate change further exacerbates the problem, with extreme weather events such as floods and droughts creating conditions conducive to cholera outbreaks [5].
Leveraging the Complex Interplay between Arbuscular Mycorrhizal Fungi, Seasonal Dynamics, and Genotypic Diversity to Optimize Maize Productivity in Semi-Arid Agroecosystems
(Heliyon, 2024-09) Kipkorir, Koech; Koskey, Gilbert; Njeru, Ezekiel Mugendi; Maingi, John
Maize production under low-input agricultural systems in semi-arid areas of Sub-Saharan Africa faces significant challenges, primarily stemming from the synergistic impacts of climate vari ability and suboptimal agronomic practices. Harnessing soil microbiota, particularly arbuscular mycorrhizal fungi (AMF), represents a pivotal strategy for bolstering low-input systems. However, their functional utility is contingent upon their compatibility with the prevailing environmental conditions and biotic interactions. This study examines the influence of two distinct AMF in oculants on the growth and yield attributes of diverse maize genotypes across varying seasons within semi-arid regions of Kenya. We hypothesized that AMF inoculants exhibit differential adaptability to varying environmental sites and seasons, and their interaction will enhance the provision of key ecosystem services important for maize production. Field experiments were conducted in three semi-arid Counties (Tharaka-Nithi, Embu, and Kitui) during the 2019/2020 cropping seasons. A randomized complete block design with three replications and three treat ments was adopted. Treatments consisted of Rhizatech (a commercial AMF inoculant), a con sortium of AMF isolates (Rhizophagus irregularis and Funneliformis mosseae), and a non-inoculated control. In season one, notable interaction effects were observed for both site × maize genotype (p = 0.0007) and site × AMF inoculation (p < 0.0001), whereby Duma 43 genotype had the highest yield in Embu (11.93 t ha− 1 ) and Kitui (11.76 t ha− 1 ) counties, and Rhizatech and con sortium inoculation consistently led to elevated grain yields across all three genotypes in Kitui, surpassing non-inoculated controls. AMF inoculation notably augmented phosphorus (P) uptake, with Rhizatech demonstrating a 79.7 % increase and consortium showing a 38.7 % increase in shoot P content compared to control plants in season 1. These findings highlight the complex interplay between AMF effectiveness, seasonal variations, and maize diversity. Further research is needed to elucidate the underlying mechanisms driving these seasonal shifts, allowing for opti mized AMF inoculation strategies for improved maize performance under diverse conditions.
Isolation of phages against Streptococcus species in the oral cavity for potential control of dental diseases and associated systemic complications
(Archives of Microbiology, 2024) Chepchumba, Beatrice; Asudi, George. O.; Katana, Japhet; Ngayo, Musa. O.; Khayeli, Juliah Akhwale
Dental infections and systemic complications caused by Streptococcus species in the oral cavity are increasingly exhibiting resistance to commonly used antibiotics, posing a potential threat to global public health. Phage therapy may ofer a supe rior alternative, given that bacteriophages can be easily isolated and rapidly replicate in large numbers. In this study, six Streptococcus species from the oral cavity were characterized. Bacteriophages isolated from wastewater using five of these species as hosts produced plaques ranging from 0.2 to 2.4 mm in size. The phages demonstrated stability within a temperature range of 4 ℃ to 37 ℃. However, at temperatures exceeding 45 ℃, a noticeable reduction in bacteriophage titer was observed. Similarly, the phages showed greater stability within a pH range of 5 to 10. The isolated phages exhibited latency periods ranging from 15 to 20 min and had burst sizes varying from 10 to 200 viral particles. This study supports the potential use of bacteriophages in controlling infections caused by Streptococcus species.
Characterization of Anopheles Funestus Larval Habitats in Kenya: Insights into Malaria Vector Ecology and Control
(European Journal of Ecology, 2023) Omondi, Clifton; Nonoh, James; Ntabo, Regina
The breeding of malaria-spreading vectors such as Anopheles funestus is influenced by various environmental factors that contribute indirectly to the transmission of the Plasmodium parasite. However, there is limited knowledge of larval habitat ecology that hinder prevention and control of mosquito-borne diseases. This study aimed to charac terize larval habitats based on physicochemical and habitat characteristics, considering the abundance of A. funestus. A cross-sectional survey method was used to collect data on the established transects. Physical parameters (water temperature, pH, conductivity, and total dissolved solids) were measured using a 5-in-1 meter probe. Levels of chem ical parameters (sulphate, COD, and BOD) were determined in the laboratory using standard methods. Observations were also made on habitat characteristics (including watercolor, habitat size, and canopy). There was significant effect (P<0.05) of conductivity, pH, sulphate, COD, and BOD on the number of A. funestus larvae. Water samples with a high population of A. funestus larvae were found to have higher conductivity (Me of 470.5), TDS (Me = 235), and pH levels (Me of 6.71). Conversely, water samples with a high population of non-Anopheles funestus larvae were found to have higher COD (Me of 843.20), BOD (Me of 367.2), and SO4 levels (Me of 11.3). A significant correlation (p<0.5) existed between A. funestus larvae and physical water parameters. For instance, Anopheles funestus larvae was high (Me of 36.85) in stagnant water and in semi-permanent water (Me of 47.37). The study demonstrates that both physico chemical and habitat parameters significantly influence the abundance of Anopheles funestus larvae in larval habitats. Parameters such as conductivity, pH, total dissolved solids, sulphate, COD, BOD, watercolor, depth, distance from the homestead, and habitat size were found to be important in determining the presence of A. funestus larvae. Therefore, vector control strategies should include larval source management by targeting rivers and other water bodies to prevent the emergence of Anopheles funestus.
In Vivo Antidiarrheal Effect and Phytochemical Characterization of Plectranthus Barbatus Andrews
(JABET, 2024-01) Ajwang, Emmah Clarice; Ngugi, Mathew Piero; Omwenga, George Isanda; Muruthi, Carolyn Wanjira
Diarrheal infections remain a public health problem. The mainstays of pharmacological therapy for infectious diarrhea include probiotics, antibacterials, and intestinal adsorbents. Nevertheless, these clinical treatments are not devoid of shortcomings including prohibitive costs and adverse effects. Medicinal plants including Plectranthus barbatus (P. barbatus) have folkloric remedies against diarrhea. However, there is paucity of knowledge to scientifically validate the efficacy of P. barbatus on diarrheal infections. The study was undertaken to ascertain antidiarrheal efficacy, bioactive composition, and toxicity profiles of P. barbatus extracts. Antidiarrheal activity and acute toxicity were carried out on Swiss albino mice. Quantitative phytocompound analysis was evaluated using liquid chromatographymass spectrometry (LCMS). Results indicated that P. barbatus extract has antidiarrheal activity whereby it prolonged the start of diarrhea, causing a decline in the occurrence of wet feces and intestinal transit significantly. Additionally, the extract reduced the accumulation of intraluminal fluid resulting in decrease in distension, intestinal overload, and water content in the fecal drops. Also, acute toxicity assay on mice showed that P. barbatus extract was non-toxic at the dosage level of 2000mg/kgbw. In addition, LCMS analysis detected presence of phytocompounds associated with antidiarrheal effects including forskolin, gallic, kaempferol, and quercetin. Findings from the current study offer a scientific validation for the folkloric utilization of P. barbatus in the management of diarrhea.
Serotype Diversity of Foot and Mouth Disease Virus and Molecular Characterization of Serotype O Strains from 2019 and 2020 Outbreaks in Kenya
(Benha Veterinary Medical Journal, 2024) Josiah, Judith M.; Nyamache, Anthony K.; Woldemariyam, Fanos T.; Kariuki, Christopher K.; Paeshuyse, Jan; Kamau, Joseph
Foot and mouth disease (FMD) is a viral infection affecting ruminants and leads to great economic losses. Control and prevention have been a challenge despite the availability of vaccines. The causative agent exists in seven serotypes and is endemic in Kenya, with serotypes O, A, SAT (South African Territory) 1, and SAT 2 and having circulated in the recent past. This study was aimed at determining the current serotype diversity and serotype O variants during the study period. A cross-sectional study was conducted and a total of 267 epithelial samples were collected from animals during the disease outbreaks of 2019 and 2020. Antigen detection was performed using ELISA (Enzyme-Linked Immunosorbed Assay). The negative samples were inoculated on LFBK(Line of Fetal Bovine Kidney) monolayer cells followed by a repeat ELISA for CPE(Cytopathic Effect) positive samples. The partial VP1 gene for serotype O samples was amplified and directly sequenced. The generated sequences were analyzed and compared with the vaccine strain. The prevalence of FMDV was 65.9% (176/267) and serotypes SAT 1, O, SAT 2, and A in the order of decreasing prevalence were circulating. Serotype O viruses analyzed belonged to the EA 2 against the EA 1 vaccine strain in use. For better control of the disease, this study recommends close monitoring of the circulating serotypes and topotypes, and, regular vaccine matching to ensure vaccine effectiveness.
Endophytic Bacillus aerophilus from the Leaves of Azadirachta indica as a Potential Biocontrol against Staphylococcus aureus
(Journal of Advances in Microbiology, 2023) Mwendwa, Peter Kasyula; Karanja, Anncarol W.; Maingi, John M.
The study entailed isolation and identification of Bacillus aerophilus in the leaves of young Azadirachta indica plants, establishing the antimicrobial activity of the endophyte against Staphylococcus aureus, and screening for phytochemicals. The study investigated the potential of the endophytic Bacillus aerophilus in pathogen inhibition and phytochemical screening for bioactive compounds produced by the endophyte that can be used in drug development. The research contributes to the wider scientific goal of curbing rising cases of antibiotic resistance. Place and Duration of Study: Sample: collected from Kanyonyoo in Kitui County, between August 2022 and June 2023. Methodology: The bacteria were aseptically isolated and sub-cultured on nutrient agar. For identification, the bacteria underwent biochemical tests and molecular characterization. The 16S rRNA region was amplified and sequenced using universal primers 27F and 1492R. Bacterial isolate K1L003 was identified as Bacillus aerophilus. For antimicrobial testing, the agar disk diffusion method was used against pathogenic Staphylococcus aureus on Mueller Hinton Agar plates (MHA). The controls were doxycycline and vancomycin. Results: The endophytic isolate only inhibited Staphylococcus aureus (P < .001), with an inhibition mean similar to doxycycline (26 mm), against the pathogen. The endophytic isolate produced terpenoids, saponins, alkaloids, and flavonoids. Conclusion: Endophytic Bacillus aerophilus has better antimicrobial inhibition potential than vancomycin, against Staphylococcus aureus and produces diverse bioactive secondary metabolites. The endophyte has the potential to produce compounds that are useful in treating drug-resistant Staphylococcal infections.
Production and Characterization of Cellulolytic Enzymes by Chaetomium Globosum for Biomass Saccharification and Ethanol Production
(Discovery Journals, 2024) Munyasi, Kelvin Masinde; Omwenga, George Isanda; Mwamburi, Fredrick Mjomba
This study aimed to isolate, identify and characterize cellulase-producing fungi from a decaying tree trunk, and determine the effects of incubation time, moisture content and initial medium pH on cellulase production using untreated maize cobs and sugarcane bagasse under solid state fermentation after that, to saccharify for ethanol production. Samples were collected from Ngong Forest, Kenya, and screened for the isolation of cellulase producing fungi. The isolated fungi were grown to obtain pure cultures before DNA extraction, PCR amplification and sequencing. The fungus was cultured on substrates for cellulase production with enzymes obtained after fermentation subjected to cellulase assays; filter paper, exoglucanase and endoglucanase. Molecular data analysis was performed using the NCBI-BLAST algorithm and MEGA 11.0 software to identify the isolated fungus, while enzyme activity analysis was done using one-way ANOVA with R software at the P≤0.05 significance level, and the significant differences were determined via the Tukey post hoc test. The isolated fungus was identified as Chaetomium globosum. For the effect of incubation time on cellulase production, the fungus exhibited high enzyme production on different days within the incubation period, and the highest cellulase activity was recorded at a moisture content ratio of 1:2 and initial medium pH of 5. Saccharification optimization studies showed a 7% (v/v) enzyme concentration, 12% (v/w) substrate concentration and hydrolysis time of 72 hours were optimal for the maximum yield of reducing sugars. The total reducing sugar produced maximum bioethanol yield at 72 hours when Saccharomyces cerevisiae was used as a fermentation agent.
Anti-inflammatory Effects of Carissa spiranum Mediated via Attenuation of Leucocyte Migration
(The Journal of Phytopharmacology (TJP), 2024-05) Jeptoo, N Serem; Wambugu, Stanley N; Mwonjoria, John K.
Inflammation is a physiological process vital for pathogen elimination and tissue repair. However, left untreated, it can cause undesirable effects. There are several methods for management of the condition, including traditional remedies from plant sources that are thought to have few deleterious effects on the body, as is the case with steroids and NSAIDs. One of the plants widely used is Carissa spiranum, though little has been done to determine the effects of purified extracts on the condition and their mode of action. The present study investigated the effects of purified plant extract and its flavonoid-rich fraction on inflammation and leukocyte migration in mice. Formalin and carrageenan were used as the phlogistic substances in inflammation induction and leukocyte migration, respectively. While diclofenac sodium and dexamethasone were used as standard drugs. The diameter of the paw edema induced in the left hind paw of mice was measured and quantified as the edema developed in mice, while the number of leucocytes in peritoneal fluid lavage after pretreatment with carrageenan and determined with improved Neubauer chamber was used in the determination of the extent of leucocyte migration. The extracts exhibited a significant (p < 0.05) reduction in paw edema diameter and delayed leucocyte migration compared to the vehicle. These observations suggest that the plant extracts may contain compounds that exert their anti-inflammatory effects via attenuation of leucocyte migration.
Analysis of Antibiotics in Milk from Smallholder Farmers from Kenya Shows Traces Above the Recommended Maximum Residue Limits
(Science Publishing Group, 2024) Odeny, Bonnita Aluoch; Asudi, George Ochieng’; Omwenga, George; Oduor, Richard Okoth; Karau, Geoffrey Muriira
Antimicrobial resistance (AMR) is rising globally and is likely to cause more deaths because of antibiotic-resistant microbial infections and antibiotic residues in animal foods and products as a result of misuse of antibiotics in dairying. Thus, we determined the presence and quantities of sulfonamide, tetracycline, and beta-lactam drug residues in milk sampled in Nyandarua, Meru, and Kiambu counties in Kenya using the Charm TRIO® test kit and liquid chromatography (LC) coupled to the triple quadrupole mass spectroscopy (MS) (LC-MS/MS). The TRIO® test kit showed dicloxacillin as the most prevalent at 9.3%, followed by penicillin and cloxacillin at 3.7% each, and nafcillin at 0.9% among the beta-lactams. Among the tetracyclines, demeclocycline and tigecycline were the most prevalent at 10.3% each, followed by oxytetracycline at 9.3%, chlortetracycline at 7.5%, and doxycycline at 3.7%, while sulfaquinoxaline was the only sulfonamide drug detected at 4%. The LC-MS/MS detected the presence of all the tested β-lactam and tetracycline antimicrobial traces and all sulfonamide drugs except sulfamerazine in all three counties. All the tetracycline antibiotics recorded between 3 and 10.5% of antibiotic residues above the recommended Maximum Residue Levels (MRLs) in milk across all three counties, with beta-lactam antibiotics recording between 2 and 33.3%, indicating their misuse in the three counties. Sulfaquinoxaline was the only sulfonamide detected in milk samples above the recommended MRLs, indicating sulfonamides are less used in those counties. Therefore, it is important to enforce a regulatory framework to control antibiotic use in livestock to minimize potential health risks related to their traces in the foods.
Epidemiology of multi-drug resistant Tuberculosis in the western region of Kenya
(AIMS, 2024-04) Lugonzo, George O.; Njeru, Ezekiel M.; Songock, William; Okumu, Albert A.; Ndombi, Eric M.
Multidrug-resistant tuberculosis (TB) (MDR-TB), or TB that is simultaneously resistant to both isoniazid (INH) and rifampicin (RIF), is a barrier to successful TB control and treatment. Stratified data on MDR-TB, particularly in the high-burden western Kenya region, remain unknown. This data is important to monitor the efficacy of TB control and treatment efforts. Herein, we determined the molecular epidemiology of drug-resistant TB and associated risk factors in western Kenya. This was a non-experimental, population-based, cross-sectional study conducted between January and August 2018. Morning sputum samples of individuals suspected of pulmonary TB were collected, processed, and screened for Mycobacterium tuberculosis (Mtb) and drug resistance using line probe assay (LPA) and Mycobacterium growth indicator tubes (MGIT) culture. MGIT-positive samples were cultured on brain heart infusion (BHII) agar media, and the presence of Mtb was validated using Immunochromatographic assay (ICA). Drug sensitivity was performed on MGIT and ICA-positive but BHI-negative samples. Statistical significance was set at P < 0.05. Of the 622 Mtb isolates, 536 (86.2%) were susceptible to RIF and INH. The rest, 86 (13.83%), were resistant to either drugs or both. A two-sample proportional equality test revealed that the MDR-TB prevalence in western Kenya (5%) did not vary significantly from the global MDR-TB estimate (3.9%) (P = 0.196). Men comprised the majority of susceptible and resistant TB (75.9% and 77.4%%, respectively). Also, compared with healthy individuals, the prevalence of HIV was significantly higher in MDR-TB patients (35.9% vs 5.6%). Finally, TB prevalence was highest in individuals aged 25–44 years, who accounted for 58.4% of the total TB cases. Evidently, the prevalence of MDRTB in Western Kenya is high. Particular attention should be paid to men, young adults, and those with HIV, who bear the greatest burden of resistant TB. Overall, there is a need to refine TB control and treatment programs in the region to yield better outcomes.
Phytonutrient Screening and In vitro Antibacterial and Antifungal Properties of Polar and Nonpolar Extracts of Albizia gummifera, Prunus africana, and Combretum Molle from Mount Elgon Region, Kenya
(JAMB, 2024) Nguimbous, Simone Pierrette; Muthini, John Maingi; Wafula, Alphonse Wanyonyi; Mutuiri, Shem
Background: Globally, and particularly in less-developed countries, one of the principal factors associated with morbidity and mortality is infectious diseases. Over the years, the abuse and misuse of pharmaceutical products have caused an increase in resistant microbes, and consequently, today, the rate of infectious disease cases continues to increase to dangerously high levels as most medications have lost their efficacy. This indicates that there’s a need for new effective medications and calls for active research in drug discovery to curb this dangerous trend. Results: Obtained data demonstrated the presence of different bioactive compounds in the tested plant extracts such as glycosides, alkaloids, tannins, terpenoids, saponins, and phenols. Using the Kirby-Bauer disc diffusion method, P. africana methanol and ethyl acetate extracts showed significantly bigger inhibition zones compared to the rest against S. aureus (excluding controls). None of the tested extracts, however, were able to inhibit C. albicans and E. coli. The P. africana methanolic extract and the A. gummifera hexane, ethyl acetate, and methanolic extracts all inhibited the growth of S. aureus at the same minimum concentration of 31.25 mg/ml. The methanolic extract of C. molle exhibited the least activity against S. aureus, with an MIC of 250 mg/ml and mean zones of inhibition of 9.33±0.33 mm. Conclusions: This study revealed the presence of various phytoconstituents in crude extracts of the selected medicinal plants, but also highlighted the resistance of E. coli and C. albicans to these phytochemicals. The P. africana methanolic extract showed strongest inhibitory effect against S. aureus compared to the other plant extracts. The highest susceptibility was demonstrated by S. aureus, while E. coli and C. albicans were resistant to all the extracts. These findings support the usage of A. gummifera, P. africana, and C. molle in folk medicine against infections caused by S. aureus and highlight them as potential sources of phytonutrients for the development of new drugs.
Phenotypic and Genotypic Characterization of Extended Spectrum Beta-Lactamase-Producing Clinical Isolates of Escherichia coli and Klebsiella Pneumonia in Two Kenyan Facilities: A National Referral and a Level Five Hospital
(Hindawi, 2024-02) Maveke, Sylvia M.; Aboge, Gabriel O.; Kanja, Laetitia W.; Mainga, Alfred O.; Gachau, Naftaly; Muchira, Beatrice W.; Moriasi, Gervason A.
Prospects of classical biological control of papaya mealybug in Kenya: Performance of its exotic parasitoid, Acerophagus papayae, under laboratory and field conditions
(Elsevier Ltd, 2023) Opisa, Selpha; Makale, Fernadis; Nyasani, Johnson O.; Muvea, Alexander; Kabole, Mellon; Chacha, Duncan; Agboyi, Lakpo Koku; Asudi, George O.; Rehman, Abdul; Luke, Belinda; Rwomushana, Ivan
Papaya mealybug (PMB), Paracoccus marginatus, native to Mexico and Central America, invaded Kenya in 2016 causing severe yield losses of between 57% and 91% and £2224/ha household economic losses annually. A classical biological program for PMB involved the importation of Acerophagus papayae, a koinobiont endoparasitoid, from Ghana into the quarantine facility at Kenya Agricultural and Livestock Research Organization, Muguga. Laboratory bioassays were conducted to evaluate the suitability of A. papayae to parasitize PMB. Parasitism rates, sex ratio and development time of the parasitoid were evaluated under choice and no-choice experimental conditions. High parasitism rates of 72.5 ± 5.9 and 75.0 ± 3.8% were recorded in third instar and adult female PMB, respectively, and lower parasitism rates of 43.8 ± 4.6 % were recorded in second instars, under no-choice test conditions. Significant differences in host choice were noted when A. papayae was offered several host stages, with third instars being preferred over second instars. Adult females were preferred over third instars. Adult parasitoids were released and monitored for their establishment at six papaya farms in the Coastal region of Kenya from December 2021 to November 2022. Parasitoid establishment was recovered within the first month of release. Parasitism levels varied across the sites with the highest parasitism of 72.89 % recorded in Kwale. Findings from this study highlight the potential of A. papayae as a good candidate for biological control of PMB in Kenya and Africa beyond.
Molecular Characterization of Indigenous Rhizobia from Kenyan Soils Nodulating with Common Beans
(mdip, 2023-05) Wekesa, Clabe; Kiprotich, Kelvin; Okoth, Patrick; Asudi, George O.; Muoma, John O.; Furch, Alexandra C. U.; Oelmüller, Ralf
Kenya is the seventh most prominent producer of common beans globally and the second leading producer in East Africa. However, the annual national productivity is low due to insufficient quantities of vital nutrients and nitrogen in the soils. Rhizobia are symbiotic bacteria that fix nitrogen through their interaction with leguminous plants. Nevertheless, inoculating beans with commercial rhizobia inoculants results in sparse nodulation and low nitrogen supply to the host plants because these strains are poorly adapted to the local soils. Several studies describe native rhizobia with much better symbiotic capabilities than commercial strains, but only a few have conducted field studies. This study aimed to test the competence of new rhizobia strains that we isolated from Western Kenya soils and for which the symbiotic efficiency was successfully determined in greenhouse experiments. Furthermore, we present and analyze the whole-genome sequence for a promising candidate for agricultural application, which has high nitrogen fixation features and promotes common bean yields in field studies. Plants inoculated with the rhizobial isolate S3 or with a consortium of local isolates (COMB), including S3, produced a significantly higher number of seeds and seed dry weight when compared to uninoculated control plants at two study sites. The performance of plants inoculated with commercial isolate CIAT899 was not significantly different from uninoculated plants (p > 0.05), indicating tight competition from native rhizobia for nodule occupancy. Pangenome analysis and the overall genome-related indices showed that S3 is a member of R. phaseoli. However, synteny analysis revealed significant differences in the gene order, orientation, and copy numbers between S3 and the reference R. phaseoli. Isolate S3 is phylogenomically similar to R. phaseoli. However, it has undergone significant genome rearrangements (global mutagenesis) to adapt to harsh conditions in Kenyan soils. Its high nitrogen fixation ability shows optimal adaptation to Kenyan soils, and the strain can potentially replace nitrogenous fertilizer application. We recommend that extensive fieldwork in other parts of the country over a period of five years be performed on S3 to check on how the yield changes with varying whether conditions.
Old and New Association of Cotesia icipe (Hymenoptera: Braconidae) with Alien Invasive and Native Spodoptera Species and Key Stemborer Species: Implication for their Management
(John Wiley & Sons Ltd, 2023-08) Obala, Francis; Mohamed, Samira A; Magomere, titus Obidi; Subramanian, Sevgan
BACKGROUND: Maize production in Africa is hindered by a myriad of biotic challenges, key among them being invasive and native lepidopteran stemborers. Recent invasion of the continent by fall armyworm, Spodoptera frugiperda, has further exacerbated the situation. Fortunately, Cotesia icipe was found to be very promising against S. frugiperda. However, the co-occurrence and interaction between S. frugiperda and the stemborers (Busseola fusca, Sesamia calamistis, and Chilo partellus) in maize agroecosystem may jeopardize the efficiency of C. icipe as a biocontrol agent of S. frugiperda. This study investigated the performance of C. icipe on S. frugiperda, Spodoptera littoralis and the stemborers. Specifically, the preference and acceptability of C. icipe to the host insects, the physiological suitability of the hosts for its development, and the effect of these hosts on the fitness parameters of the offspring were assessed. RESULTS: Cotesia icipe accepted all the tested hosts, albeit with higher preference for Spodoptera species than for stemborers under multiple-choice tests. Also, the highest parasitism of up to 97% was recorded on S. frugiperda compared with parasitism on the stemborers of 43% in B. fusca. Moreover, physiological suitability and fitness traits (except for per cent female offspring) varied with host species, again being optimal on Spodoptera species. CONCLUSION: Cotesia icipe demonstrated strong potential to control S. frugiperda in maize due to its high affinity for parasitization and developmental success in this host; and despite its non-specific parasitization, the presence of other hosts may not prevent its maximum control of S. frugiperda
In Vivo Ameliorative Effects of Vitamin E against Hydralazine-Induced Lupus
(BMJ, 2023) Githaiga, Fiona Muthoni; Omwenga, George Isanda; Ngugi, Mathew Piero
ABSTRACT Objective In this study, we investigated the in vivo ameliorative effects of vitamin E in a hydralazine-induced lupus model, which closely resembles SLE in humans. We aim to shed light on its potential as a therapeutic agent for managing SLE. Methods Forty BALB/c mice were used in this study. Hydralazine hydrochloride was orally administered in a concentration of 25mg/kg to the five mice groups once weekly for a period of 5weeks to induce a lupus-like condition. The untreated group was the normal control group. To confirm the development of lupus, an ANA test was conducted. After the mice tested positive for ANA, drug treatments commenced. The negative control group did not receive any drug treatment. The treatments included prednisolone, methotrexate and vitamin E, all administered at a concentration of 25mg/kg, with a higher dose of vitamin E (50mg/kg) also administered. Results Notably, on day 35, after drug treatment, we observed that mice that received vitamin E at a dosage of 50mg/kg (3.01±0.100) had a slight decrease in lymphocyte hydrogen peroxide radicals when compared with the group receiving 25mg/kg of vitamin E (3.30±0.100) (p<0.05). This finding suggests that the scavenging potential of vitamin E is dose dependent. Conclusion This study suggests that vitamin E supplementation, especially at a higher dose (50mg/ kg), holds promise in ameliorating lupus-like conditions. These findings warrant further exploration and may offer a potential avenue for improving the disease status of patients experiencing SLE.

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