Antibacterial and antibiofilm activities of methanolic extract of Indigofera tinctoria L. against catheter-associated urinary tract infection (CAUTI) causing pathogens

Microbial attachment on the surface of the catheters during the insertion of the catheter leads to catheter-associated urinary tract infection (CAUTI) which denotes a very important nosocomial infection mainly associated with the formation of biofilms by the causative microorganisms, resulting in serious socio-economic implications due to treatment challenges leading to higher morbidities and increased mortalities.As these pathogens are resistant to many of the antibiotic drugs available, the scientific community is investigating new antibiotics of natural origin and the phytocompounds gain much attraction owing to their pharmacological benefits.So, in a trial to contribute to this investigation, the present study analyzed the methanolic extract of Indigofera tinctoria L. for its antibacterial, antibiofilm, and antiadhesive properties against Staphylococcus aureus, Candida albicans, Escherichia coli, and Enterococcus faecalis which are among the mainly listed organisms causing CAUTI.The well-diffusion method confirmed the potentials of I. tinctoria extract against S. aureus, C. albicans, E. coli, and E. faecalis, and the minimal inhibitory concentrations (MICs) of I. tinctoria were found to be 0.312 mg/ml against each of them except for S. aureus for which it was 0.156 mg/ml).Moreover, I. tinctoria was also studied for its effect on biofilm formation, and biofilm eradication, and it was found that the extract could inhibit the biofilms at its MIC level.Additionally, I. tinctoria treated with 1X MIC of the extract effectively eradicated the biofilms by the microorganisms, E. coli, C. albicans, S. aureus, and E. faecalis by 76%, 77%, 84%, and 71%, respectively.Further, I. tinctoria coated catheter tube showed antibacterial activity against test organisms.The extract also showed promising antioxidant properties when analyzed using DPPH assay Further, the analyses for cytotoxicity on L 929 cells proved that the extract at that particular concentration did not possess any toxic effects on the eukaryotic cells.Thus, the study recommends further in vivo investigations with purified phytocompounds to explore the possibilities for I. tinctoria extracts to be used in the treatment of the CAUTIs caused by the mentioned pathogens.