Antimicrobial, cytotoxicity and preliminary phytochemical determination of commonly used medicinal plants to treat oral cavity, urinary tract and gut infections by inhabitants of Borabu sub-county, Nyamira County, Kenya

Aims@#The study aimed at determining the antimicrobial activities and cytotoxicity properties of medicinal plants collected from southwestern Kenya. @*Methods and results@#A total of 23 ethanol extracts of selected medicinal plants were bio-assayed against Gramnegative bacterial strains (Escherichia coli NU14, Helicobacter pylori ATCC 700824, and Porphyromonas gingivalis ATCC 33277). Cytotoxicity tests were also carried out on mammalian cell lines (AGS, KB, and TR146). Preliminary type of phytochemical compounds present in the extracts was determined by thin-layer chromatography. Cassia didymobotrya plant extract (1 mg/mL) had strong antimicrobial activity against P. gingivalis (average zone of inhibition of 21.70 ± 0.88 mm, MIC 0.13 ± 0.00 mg/mL and MBC 0.50 ± 0.00 mg/mL). Escherichia coli was resistant to all the extracts bioassayed. Leonotis nepetifolia (15.80 ± 0.20 mm) and Clerodendrum myriacoides (14.20 ± 0.44 mm) showed only moderate activity against H. pylori. Cell cytotoxicity results indicated a dose-dependent response against KB, TR146 and AGS cell lines with C. didymobotrya having IC50 values of 47.64 and 704.00 µg/mL on KB and TR146 cell lines, respectively. L. nepetifolia and C. myriacoides did produce IC50 of 0.1883 mg/mL and 0.1061 mg/mL against the AGS cell line respectively. @*Conclusion, significance and impact of the study@#Most of the extracts had no or weak activity against test isolates, but C. didymobotrya leaves extracts showed strong activity against P. gingivalis. C. didymobotrya can offer alternative medicare to P. gingivalis conditions.

Effect of mastitis on raw milk compositional quality

In this study, we investigated the impact of mastitisinfection on the quality of milk composition in small-scaledairy bovine herds. The purpose of this study was to finda milk quality somatic cell count (SCC) standard thatcould be used as an integral component of a controlprogram. In all, 396 quarter milk samples from lactatingcross-bred cows (Holstein & Zebu) were analyzed; 56% ofthese quarters were experiencing intramammary infection,with an overall mean SCC of 5.46x10(5)+/-2.30x10(4)cells/ml. Infected quarters had significantly (p<0.05) highermean SCC levels (6.19x10(5)+/-4.40x10(4)cells/ml) comparedto healthy quarters (2.65x10(5)+/- 2.40x10(4)cells/ml). Inhigh SCC milk and infected quarters, the concentrationsof non-casein fractions, sodium, chloride, and free fattyacid were higher (p<0.05), while the casein content,lactose, casein-to-total protein, potassium, and calciumwere lower (p<0.05) compared to normal quarters. Thesefindings suggest a mean SCC threshold limit of 5.46x10(5)cells/ml for the region. It was concluded that the resultscould be used to propose a milk quality SCC standard thatcan be used as an integral component of a control program.

Evaluation of a Bacillus stearothermophilus tube test as a screening tool for anticoccidial residues in poultry

A Bacillus stearothermophilus var. calidolactis C953 tube test was evaluated for its ability in detecting the residue of selected anticoccidial drugs in poultry, specically sulfamethazine, furazolidone, and amprolium. Various concentrations of each drug were injected into chicken liver and kidney tissues and these tissues were tested to determine the drug detection limits for each drug. The detection limit was defined as the drug concentration at which 95% of the test results were interpreted as positive. The limits of detection in liver tissue were 0.35 microgram/ml for furazolidone, 0.70 microgram/ml for sulfamethazine and 7.80 microgram/ ml for amprolium. In kidney tissues, they were 0.30 microgram/ml for furazolidone, 0.54 microgram/ml for sulfamethazine, and 7.6 microgram/ml for amprolium. It was concluded that this tube test could be used to screen for the residue of these three drugs in poultry.

Assessment of the California mastitis test usage in smallholder dairy herds and risk of violative antimicrobial residues

This study evaluated how predictive the California Mastitis Test (CMT) is for sub-clinical mastitis under tropical smallholder dairy production conditions in Kenya. It intended to establish whether the CMT usage could be contributing to misdiagnosis and consequent mistreatment with animal drugs resulting in residue problems. Milk samples (n = 239) were aseptically collected from lactating cows in the Rift Valley of Kenya and tested using the CMT, somatic cell counts (SCC) and bacterial culture. The samples were also screened for violative drug residues using the commercial delvo test and compared to the milks mastitic status for possible association. There was a numerical but non-significant (p > 0.05) difference evident in the frequencies observed using the three different mastitis indicators. The prevalent bacterial species isolated from mammary glands with subclinical mastitis were Staphylococcus aureus (45.6%), coagulase-negative Staphylococci (13.0%), Streptococci (11.7%) and Escherichia coli 5.9%. There was an overall poor but significant (p < 0.05) correlation between the CMT and the violative antimicrobial residues in samples from all quarters, infected and non-infected respectively. The results suggest that the CMT use amongst the smallholder dairy sector as a mastitic indicator may not be a risk factor in violative antimicrobial residues problems in milk.