Urinary tract infections are among the most prevalent extra-intestinal infections, with high prevalence globally. This cross-sectional study established prevalence of bacterial aetiology causing urinary tract infection (UTI) and their antimicrobial susceptibility profiles. A questionnaire was used to capture socio-demographic data and possible UTI risk factors among the 206 consented adults seeking medicare at Kiambu Level 5 Hospital. The collected midstream urine samples were subjected to dipstick analysis, microscopy and culture for UTI diagnosis. Results: The overall prevalence rate of UTIs was 27.6%, with women's prevalence rate being significantly higher at 80.7% compared to men 19.2%. Pregnant women had UTI prevalence at 34% which was higher than other sets of participants. Women who did not frequently change their underpants daily had a higher UTI cases at 34.8%. Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae were the most prevalent bacterial pathogens at 38.5%, 21% and 19.3%, respectively. Antimicrobial sensitivity analysis revealed high resistances towards Sulfamethoxazole and Ampicillin at range between 50% -85%, suggesting that these drugs are no longer effective for UTI empirical treatment. The resistance patterns towards Cefotaxime, Cefepime and Ciprofloxacin were below 40%. However, more resistance patterns at a range between 14% -40% revealed towards Amoxicillin-clavulanic and Nitrofurantoin imply that these are drugs remain potent but there is the need to revise the current UTI management guidelines.

Productions of various bacterial traits like production of virulence factors (e.g. toxins, enzymes), biofilm formation, luminescence among others, have been known to be controlled by quorum sensing (QS), a process that is dependent on chemical signals or autoinducers (AIs). Bacteria known to rely on such AIs are known to be virulent and tend to be resistant against various antimicrobial agents. Therefore, strategies aimed at the inhibition of QS pathways, are regarded as potential novel therapies in managing bacterial virulence hence reducing their ability to induce infections in humans. In the present study, a portfolio of 25 medicinal plant extracts (ethanol 50% v/v) used in southwestern Kenya were assayed against a transformed E. coli Top 10 reporter QS strain. This biosensor responds to the exogenous addition of 3-oxo-N-hexanoyl homoserine lactone (3OC6HSL) expressing green fluorescent protein (GFP). The large majority of the screened medicinal plants seemed to exhibit toxic effects and almost none of them induced antiquorum sensing (AQS) activity. This could be the consequence of the presence of mixed compounds in the extracts. Elaeodendron buchananii Loes and Acacia gerrardii Benth extracts that seemed to show AQS activity were further proved found to possess mild AQS but with defined antimicrobial activities, and no antibiofilm formation inhibition. As a control, an E. coli pBCA9145_jtk2828::sfGFP strain that produces constitutively GFP was used and confirmed that none of the two extracts quenched the fluorescence of sfGFP. Cytotoxicity assays with mammalian MDCK cells also did indicate that the selected extracts with putative AQS activity, also reduced the cell viability. Therefore, further studies will be needed to separate and re-test the individual compounds especially from the selected two promising plants.

Phytochemicals have been found to be promising alternatives to conventional antibiotic therapies for the control of bacterial infections, as they may entail less selective pressure and hence reduce the development of resistance. This study involved examining the inhibition of biofilm formation and of quorum sensing (QS), and the cytotoxicity on mammalian cells of two flavonoids, quercetin and baicalein, in free form and associated into chitosan-based nanocapsules. This was done by use of a transformed E. coli Top 10 biosensor strain, while the cytotoxicity was evaluated on MDCK-C7 cells. In free form, application both flavonoids exhibited slight inhibitory activity on the QS response and biofilm formation, a scenario that was improved positively upon encapsulation with chitosan (Mw ∼115,000 g/mol and DA ∼42%). The association efficiency of 99% (quercetin) and 87% (baicalein) was determined, and each formulation had an average diameter of 190 ± 4 and 187 ± 2 nm, and zeta (ζ) potential of +48.1 ± 2.03 and +48.4 ± 3.46 mV, respectively. Both types of systems were stable against aggregation in M9 and MEM media. The in vitro release kinetics data of both flavonoids seemed to be similar with only ∼20% released over the first 5 h, or ∼10% over the first 4 h, respectively, with subsequent sudden release increase up to ∼40% in both cases. The free phytochemicals seemed to be cytotoxic to MDCK-C7 cells at higher doses, however, upon nanoencapsulation, a cytoprotective effect was evidenced. We have gained proof-of-principle of the advantages of encapsulation of two bioactive flavonoids.