Faculty of Science & Technology (FST)

Fecal Shedding, Antimicrobial Resistance and In Vitro Biofilm formation on Simulated Gallstones by Salmonella Typhi Isolated from Typhoid Cases and Asymptomatic Carriers in Nairobi, Kenya

2024-04-01T00:00:00Z

Fecal Shedding, Antimicrobial Resistance and In Vitro Biofilm formation on Simulated Gallstones by Salmonella Typhi Isolated from Typhoid Cases and Asymptomatic Carriers in Nairobi, Kenya Wachira, Peter; Muturi, Peter; Wagacha, Maina; Mbae, Mbae; Kavai, Susan; Susan, Musa; Gunn, John S; Kariuki, Samuel Typhoid fever, caused by the human restricted pathogen Salmonella Typhi, remains a major global public health concern. Even after successful treatment, approximately 3–5% of patients with typhoid fail to clear the bacteria within one year and become chronic carriers. Most typhoid carriers have gallstones in their gallbladder, and biofilm formation on gallstones is highly correlated with chronic carriage. This study’s goal was to identify asymptomatic typhoid carriers in an endemic setting in Kenya, and to compare acute versus chronic isolates. A cohort of typhoid fever patients identified through blood and/or stool culture, and their household contacts, were followed up after treatment to detect longitudinal S. Typhi stool shedding. An abdominal ultrasound scan was used to identify individuals with gallstones. A total of 32 index patients and 32 household contacts were successfully followed-up. Gallstones were detected in 4 cases and 1 household contact. The duration of S. Typhi shedding was significantly longer in individuals with gallstones compared to those without, P<0.001. Eighty-three (83) S. Typhi strains were tested for susceptibility to commonly used antimicrobials and examined by in vitro biofilm formation assays. Out of 37 infected individuals, 32.4% had infections caused by multidrug resistant (MDR) S. Typhi strains and only 18.9% were infected by susceptible strains. Non-MDR strains formed significantly better biofilms in vitro than the MDR strains (P<0.001). This study provides data on S. Typhi chronic carriage that will influence public health approaches aimed at reducing typhoid transmission and the burden of infection.

Effect of Soil Properties on the Physical and Nutritional Content of Syzygium Fruits

2022-01-01T00:00:00Z

Effect of Soil Properties on the Physical and Nutritional Content of Syzygium Fruits Chiteva, Rose; Onyari, John M; Njenga, Lydia W; Madadi, Vincent O This study was undertaken to determine the effect of Soil pH, porosity, bulk and particle density, magnesium, manganese, sodium, copper, zinc, and titaniumonthe physicochemical and nutritional content of Syzygium cuminifruits. Multistage sampling was used to select the counties, identify, sample and collect fruit trees. Analysis was done using 40 soil andfruitsamples each per countyusing standard methodologies.Fruit parameters were evaluated by measuring juice pH, total soluble solids, titratable acids, vitamin C, crude fat and fiber, proteins, fruit maturity, carbohydrates, energy, sodium, magnesium, manganese, calcium, iron, copper, and zinc. Results showed that, Syzygium fruits preferred asoil pH from 5.3 to 6.9 which was significantly different between the two counties. Titanium was significantlyhigh in Kwale soil samplesgiving 57.53±8.37 mg/kg. Particle density caused an increase in bulk density, which in turn increased fruit weight, pH, and ash content. Proteins had a weak positive correlation with soil magnesium, 0.11 and very strongly correlated with carbohydrates, 0.99. Mature fruits had significantly higher proteinand carbohydrate contents of 2.96 and 36.1 mg/100g respectively. The physicochemical and nutritional content of Syzygiumcuminifruits were highly influenced by soil properties.

Assessment of the Role Played by Housing Conditions in Exacerbating Tungiasis in Kandara Sub-County, Kenya

2022-01-01T00:00:00Z

Assessment of the Role Played by Housing Conditions in Exacerbating Tungiasis in Kandara Sub-County, Kenya Gitau, Anthony K; Oyieke, Florence A Jigger infestation, also referred to as Tungiasis, is a skin health problem usually associated with poor people. It is caused by penetration of female jigger flea, Tunga penetrans into the skin of a disposed host and, the consequent hypertrophy of the parasite. The disease is zoonotic in nature. The objective of this survey was to assess the role that housing conditions play in aggravating tungiasis in Kandara Sub-County of Murang’a County. This was a 50:50 case-control survey involving 776 participants. The participants filled questionnaires with the assistance of community health extension workers. Univariate regression analysis was conducted between case and control variables. Variables showing significant differences were then analyzed in a multivariate regression to identify those that were independent in abetting jigger problem. The results showed that the infested participants were 1.6 times more likely to live in earthen houses while the floors of their houses were 4.2 times more likely to be earthen when compared to the control. About 54% of these house floors were also cracked and dusty while 49 % of them had cracked rough walls. There was no single parameter that stood out as an independent variable. The findings of the study demonstrated a high relationship between dilapidated housing and jigger infestation in Kandara Sub- County. These results will enable efficacious interventional measures to ultimately control jigger infestation.

Benzo[ b]naphtho[2,1- d]furans and 2-Phenylnaphthalenes from Streblus usambarensis

2023-01-01T00:00:00Z

Benzo[ b]naphtho[2,1- d]furans and 2-Phenylnaphthalenes from Streblus usambarensis Chepkirui, Carolyne; Adem, Fozia A; Rudenko, Anastasia; Gütlin, Yukino; Ndakala, Albert; Derese, Solomon; Orthaber, Andreas; Bourgard, Catarina; Yenesew, Abiy; Erdélyi, Máté Three new benzo[b]naphtho[2,1-d]furans, usambarins A-C (1-3), five new 2-phenylnaphthalenes, usambarins D-H (4-8), a new flavan (9), and a new phenyl-1-benzoxepin (10) as well as two known compounds (11 and 12) were isolated from the extract of the stem and roots of Streblus usambarensis (Moraceae). The structures were deduced using NMR spectroscopic and mass spectrometric analyses, and those of compounds 1 and 4 were confirmed by X-ray crystallography. Usambarin D (4) demonstrated moderate antibacterial activity (MIC 9.0 μM) against Bacillus subtilis, while none of the tested compounds were effective against Escherichia coli.