Browsing by Author "Mwalongo, Optatus"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Comparative evaluation of antimicrobial activity and synergistic effects of selected Tanzanian medicinal plants against urinary tract infection pathogens
    (South African Journal of Botany, 2025-07-30) Mwalongo, Optatus; Kisula, Lydia; Credo, David; Sauli, Elingarami
    The emergence of microbial resistance towards existing drugs for treating UTIs seriously threatens public health worldwide, thus necessitating the search for alternative antimicrobial agents, particularly from medicinal plants. This study determined the standalone in vitro antimicrobial activity of ethanolic extracts from Ocimum gratissi- mum, Sida acuta, Lantana camara, Plectranthus barbatus, Tridax procumbens, and Euphorbia hirta against selected non-antimicrobial-resistant (AMR) and AMR uropathogens (bacterial strains and Candida albicans). Among these, Plectranthus barbatus, Euphorbia hirta, and Lantana camara exhibited the highest antimicrobial efficacy. Subse- quently, their synergistic interactions were determined against the same test microbes. Plant materials were extracted using 80% ethanol via a maceration technique. The antimicrobial efficacy of the individual and combined extracts was evaluated by broth microdilution against standard and clinical isolate microbial strains, namely Escherichia coli ATCC25922, Klebsiella pneumoniae K6 ATCC700603, Staphylococcus aureus ATCC25923, Methicillin-resistant Staphylococcus aureus (MRSA, WHO control), Enterococcus faecalis ATCC29212, Candida albicans NR29341 and clinical isolate Klebsiella pneumoniae, while a checkerboard microdilution assay was employed to assess the combined extracts’ interaction. Results revealed that all the individual plant extracts significantly inhibited the growth of the test microorganisms with varying efficacy [F (5, 36) = 2.48, η² = 0.8, p = 0.002]. The minimum inhibitory concentration (MIC) values ranged from 0.31 to 6.67 mg/mL. Of the six tested plant extracts, P. barbatus and E. hirta were highly effective against all tested microbes. The combined extracts exhibited significantly higher antimicrobial activity than individual extracts against all tested microbes [t (46.74) = -6.49, Cohen’s d = 1.4, p < 0.001]. Furthermore, the analysis of interaction types among combined extracts demonstrated that double and triple crude extract combinations exhibited partial synergy, additive and indifferent effects. Thus, this study demonstrates