Synergistic Effect of Propolis and Antibiotics on Uropathogenic Escherichia coli

Abstract

Urinary tract infections (UTIs) are the most common bacterial infections around the world. Uropathogenic Escherichia coli (UPEC) is among the main pathogens isolated in UTIs. The rate of UPEC with high resistance towards antibiotics and multidrug-resistant bacteria have increased dramatically and conduct to the difficulty to treat UTIs. Due to the rarefaction of new antibiotics molecules, new alternative strategies must be evaluated. Since many years, propolis has demonstrated an interesting antibacterial activity against E. coli. Here, we evaluated its activity added to antibiotics on a panel of UPEC with different resistance mechanisms. Minimal inhibitory concentrations (MICs) and time–kill curves of fosfomycin, ceftriaxone, ertapenem and ofloxacin, with and without propolis, were determined. Significant diminution of the MICs was observed using ceftriaxone or ofloxacin + propolis. Propolis alone had a bacteriostatic activity with time-dependent effect against UPEC. The addition of this nutraceutical improved the effect of all the antibiotics evaluated (except fosfomycin) and showed a synergistic bactericidal effect (fractional inhibitory concentrations index ≤ 0.5 and a decrease ≥ 2 log CFU/mL for the combination of propolis plus antibiotics compared with the antibiotic alone). Propolis is able to restore in vitro antibiotic susceptibility when added to antibiotics against UPEC. This study showed that propolis could enhance the efficiency of antibiotics used in UTIs and could represent an alternative solution.

An Overview of the Evidence and Mechanism of Drug–Herb Interactions Between Propolis and Pharmaceutical Drugs

“…Despite the various extraction methods and sources of propolis, a number of microbiological studies have shown the enhanced combinatory effect of propolis extracts with different classes of antibiotics in both gram-positive and gram-negative bacteria . In particular, a confirmed synergy by fractional inhibitory concentration (FIC) values was demonstrated in propolis ethanolic extracts with ceftriaxone, ertapenem, and ofloxacin on Escherichia coli ( Lavigne, Ranfaing, 2020 ), oxacillin, and vancomycin on various bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA) ( Al-Ani, Issam, Zimmermann, Stefan, 2018 ), macrolides on Streptococcus pyogenes and Haemophilus influenzae ( Speciale, Costanzo, 2006 ), and clarithromycin on Helicobacter pylori ( Nostro, Cellini, 2006 ). Remarkably, these above-mentioned antibiotics can be classified into two types based on their mechanistic actions: 1) antibiotics that interrupt the bacterial cell wall (ceftriaxone, ertapenem, oxacillin, and vancomycin) and 2) antibiotics that inhibit bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit (i.e., clarithromycin and macrolides).…”

Antioxidant and Antibacterial Effects of Pollen Extracts on Human Multidrug-Resistant Pathogenic Bacteria

“…Nowadays, the incurable infections caused by multidrug-resistant bacteria remain among the leading causes of mortality in both developed and developing countries. For this, it is essential to find solutions and to develop new strategies to overcome this phenomenon [39,40]. In this context, pollens could represent an appropriate matrix to search for new, safer, and effective antibacterial molecules that can replace or boost the efficiency of conventional antibacterial drugs.…”

Potential Effects of Romanian Propolis Extracts against Pathogen Strains

“…Bee honey and propolis have been used since antiquity due to their health properties. Numerous studies conducted in recent years in various parts of the world highlighted the health benefits of these natural bee products [ 6 , 12 , 13 , 14 , 15 , 16 ].…”