DSpace Repository :: Browsing by Author "Muturi, Margaret"

Browsing by Author "Muturi, Margaret"

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Phytochemical Composition and Antibacterial Activities of the Ethyl Acetate Leaf Extract of Ocimum basilicum
(Research square, 2020) Rapando, Japheth Wambani; Ngugi, Mathew Piero; Muturi, Margaret; Ogutu, James Opiyo
Introduction Antibiotic resistance is a serious threat to humankind. There is need for the development of new therapeutic options. Ocimum basilicum has been used traditionally as a medicinal herb against infectious diseases and as a food additive. Objective This study aimed at evaluating the phytochemical composition and in vitro antibacterial activities of the ethyl acetate leaf extract of Ocimum basilicum. Methods Ocimum basilicum leaves were collected from Mbeere, Embu County, Kenya and ethyl acetate extraction done at Kenyatta University. Phytochemical composition was evaluated by Gas chromatograph mass spectrophotometry while antibacterial activities were evaluated by disc diffusion and broth microdilution methods. The test microorganisms were methicillin resistant S. aureus, S. aureus, P. aeruginosa and E. coli. Results The extract exhibited a broad spectrum antibacterial activity. The gram negative bacteria showed more susceptibility to the organic extract compared to the gram positive bacteria. Pseudomonas aeruginosa had the highest zone of inhibition (27.00 ± 2.00 mm), while the S. aureus isolate had the lowest zone of inhibition (24.00 ± 1.00 mm). Escherichia coli, S. aureus and MRSA species had an MIC of 62.5 mg/ml compared to P. aeruginosa with an MIC of 125mg/ml when exposed to the leaf extract. The antibacterial activity could be attributed to the synergistic effects of phytochemicals such as terpenoids, alkaloids, essential oils, fatty acids, avonoids and aldehydes that have been known to have antimicrobial properties. A total of 30 phytochemical compounds were eluted from the extract of O. basilicum. Nootkatone, a sesquiterpenoid had the highest concentration at 20.86mg/g. The compound 1,3-Dimethyl5-isobutylcyclohexane, a fatty acid had the lowest concentration at 0.10mg/g. Conclusion O. basilicum has antibacterial activities on the tested pathogens and can be used to treat infections. Phytochemicals with antibacterial effects in the herb can be used as lead molecules in developing new antibacterial drugs.
The role of nitric oxide in non specific immunity to plasmodium falciparum malaria and Leishmania Donovani infections in residents of endemic areas in Kenya
(2012-04-20) Muturi, Margaret
Nitric oxide is a potent, non-specific molecule that can mediate activated macrophage cytotoxicity against a variety of intracellular and extracellular infectious agents. For example, it plays a role in host defense against Toxoplasma gondii, Leishmania major amastigotes, and Plasmodium species. The aim of this study was to determine whether serum nitric oxide levels in humans are related to the degree fo resistance or susceptibility to Plasmodium falciparum malaria and whether they correlate with the clinical course of Leishmania donavani infections. Nitric oxide levels in plasma were measured by reduction of its serum surrogates, nitrate to nitrite by Pseudomonas oleovarans nitrate reductase followed by a colorimetric quantitative measure of nitrite by the Greiss reaction. Malaria plasma samples were obtained from semi immune adults and non-immune children with cerebral malaria. Absolute parasitaemia in malaria patients was determined. Similarly, plasma samples from patients with kala-azar obtained and the nitric oxide levels obtained were correlated with the clinical course of leishmaniasis. It was found that nitric oxide production in individuals partly immune to malaria did not correlate with protective immunity (n=268; p>0.05). Futhermore serum nitrate levels in patients treated with antimalarial drugs, azithromycin and doxycycline were significantly different (n=25; t=6.964; p<0.001). Nitric oxide levels were significantly higher in individuals with cerebral malaria compared to those with the mild disease (n=9; t=1.8595; p<0.05). A transient elevation in serum nitric oxide correlated with disease with disease regression in Kala-azar.
Seroprevalence of Anti-SARS-CoV-2 IgM and IgG and COVID19 Vaccine Uptake in Healthy Volunteers in Nairobi, Kenya: A Cross-Sectional Study
(Frontiers in Virology, 2024-11) Otindo, Agnes Muhonja; Ndombi, Eric M.; Theuri, Martin; Muturi, Margaret; Thamaini, Peris; Ogutu, James; Onsongo, Lister; Madete, June K.; Ofula, Victor; Gitau, Samuel; Mwangi, Gladys; Okemo, Paul
Introduction: Seroprevalence of anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) antibodies in the postvaccination period in Kenya remains to be elucidated. This study aimed to determine the seroprevalence of anti-SARS-CoV-2 IgM and IgG and evaluate Covid-19 vaccination uptake in a university setting in Nairobi. Methods: This cross-sectional study assayed serum anti-SARS-CoV-2 IgM and IgG levels using enzyme-linked immunosorbent assays. A structured questionnaire was used to determine vaccine uptake, vaccine hesitancy and reasons for hesitancy. Results: A total of 189 participants were enrolled (median age, 21 years; female, 50.8%). The seroprevalence of anti-SARS-CoV-2 was 12.7% for IgM and 87.8% for IgG. Anti-SARS-CoV-2 IgG titers were higher among the vaccinated vs. nonvaccinated individuals (p < 0.001, U = 2817.5), females vs. males (p = 0.024, U = 3616), and those vaccinated ≤ 6 months before the study vs. those vaccinated >1 year earlier (p = 0.002, H = 12.359). The vaccination hesitancy rate was 43.4% and the underlying reasons included mistrust (22.4%), health concerns (19.7%), and lack of information (18.4%). Discussion: The high seroprevalence of anti-SARS-CoV-2 IgG is an indication of high exposure to SARS-CoV-2 either through natural infection or through vaccination. The high vaccine hesitancy noted necessitates community engagement, and public education to dispel myths and misinformation prior to roll out of new vaccines and other health interventions.
Streptococcus pneumoniae serotype epidemiology among PCV-10 vaccinated and unvaccinated children at Gertrude’s Children’s Hospital, Nairobi County: a cross-sectional study
(F1000Research, 2018) Walekhwa, Michael; Muturi, Margaret; Gunturu, Revathi; Kenya, Eucharia; Kabera, Beatrice
Background: Streptococcus pneumoniae (SPn) serotype replacement and emergence of multidrug resistant SPn has exacerbated the need for continuous regional serotype surveillance. We investigated SPn serotypes circulating among children ≤5 years in Nairobi County. Methods: Streptococcus pneumoniae stocks stored at −70°C in brain heart infusion medium were thawed at room temperature for 30 minutes. In total, 10 μl of the stored SPn cells were suspended in 50 μl PBS and gently vortexed. About 10 μl of the suspended cells were added on to a glass slide and mixed with 10 μl pooled antisera. The glass slide was swirled gently while observing for any reaction. The process was repeated with individual groups under various antisera pools. Those serotypes that did not belong to any pool were typed directly until a positive agglutination reaction was observed. The cells/PBS/serotype-specific antisera mixture on the glass slide were covered with a coverslip and observed under a phase contrast microscope at ×100 objective lens with oil emulsion. Results: Out of the 206 subjects sampled, 20.39% (n=42) were found to be carriers of SPn. About 52% (n=22) of the SPn carriers had received the recommended dose of PCV-10, while 48% (n=20) of the carriers had not. Almost all (n=41; 19.90% of subjects) isolates contained non-vaccine type SPn serotypes, while n=1 of the serotypes (in 0.49% of subjects) were untypeable. Serotypes 28F, 6A, 11A, 3 and 7C were prevalent in both vaccinated and unvaccinated children, whereas serotypes 23A, 17F, 35F, 48, 13 and 35B, and 23B, 20, 19B, 21, untypeable, 15B and 39 were found among unvaccinated and vaccinated groups, respectively. Conclusions: All SPn serotypes isolated from the subjects sampled were non PCV-10 vaccine type. Therefore Kenyan children receiving PCV-10 vaccine are not protected.

Browsing by Author "Muturi, Margaret"

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