Chitosan improves the efficacy of gentamicin against MDR and biofilm-forming URO pathogenic E. coli

Abstract

Uropathogenic E. coli is the most common cause of urinary tract infections (UTIs), accounting for 80-90% of community-acquired UTIs and 30-50% of hospital-acquired UTIs. Uropathogenic E. coli that form biofilms are linked to chronic and persistent inflammation, resulting in severe and recurring UTIs. Biofilms promote antibiotic resistance and the horizontal transfer of virulence genes, promoting the formation of multidrug-resistant organisms. This study aimed to combine low-molecular-weight chitosan with aminoglycoside gentamicin to improve its efficacy against biofilm formation and MDR E. coli. Different strains of bacteria were isolated from urine samples of different patients at the Ayub Teaching Hospital, Abbottabad, out of which 16 were identified as E. coli by API (Analytical Profile Index) 20E. The antibiotic sensitivity profile was determined using the disk diffusion method, and the results showed that a total of 10 isolates were found to be multidrug-resistant MDR (N=62.5%). Biofilm formation was tested using the TCP method, a total of 7 isolates were found to be strong biofilm producers (N=44%). Gentamicin exhibited the highest inhibitory activity against 10 isolates of E.coli, with MIC-p ranges of 4 and 2 µg/ml, respectively, while 6 isolates showed resistance to gentamicin with MIC-p ranges >512 µg/ml.