Synergy of Herbal Oil Extracts/Antibiotic Combinations in Drug- Resistant Uropathogenic E. coli

Abstract

Urinary tract infection (UTI) is the second most common infection worldwide and Escherichia coli (E. coli) is the chief causing pathogen. Antimicrobial resistance results into therapeutic failure. This study aimed to incrimination of E. coli as uropathogen harbouring cnf1 gene (necrotoxin virulence)and to detect the in vitro antimicrobial efficacy of several selected essential oil/antibiotic combinations against the isolated uropathogenic E. coli. Well diffusion method was used to determine the minimal inhibitory concentrations (MICs) to essential oils (EOs) individually. Broth micro-dilution method was used to determine the minimal inhibitory concentrations (MICs) to antibiotics and in combinations, to figure out the interactive efficacy of tested combinations. Necrotoxin cnf1 gene was detected by PCR assay. E.coli was detected at a rate of 40.6% of the isolated urinary pathogens and 47.8% showed ESBL production. In-vitro synergistic efficacy was only observed for cinnamon oil/gentamycin combination in 100% of selected 15 tested isolates (P-value <0.001). The cnf1 virulence gene was detected in 40% of tested isolates showing no significant correlation the conferred pattern of resistance among the E. coli isolates. Cinnamon/gentamycin combination against drug-resistant E-coli is promising and can pave the way for further clinical trials to formulate pharmacological combinations.

Keywords

• antibiotics
• essential oils
• necrotoxin gene
• synergistic effect