Anti-Biofilm Effect of Bacteriophages and Antibiotics against Uropathogenic Escherichia coli

Abstract

Escherichia coli is a common cause of biofilm-associated urinary tract infections. Bacteria inside the biofilm are more resistant to antibiotics. Six E. coli strains isolated from patients with urinary tract infections were screened for biofilm-forming capability and antimicrobial susceptibility. Two of the most significant biofilm-producing strains were selected for minimal inhibitory concentration and minimal biofilm eradication concentration in vitro testing using amoxicillin–clavulanic acid, ciprofloxacin, and three commercial bacteriophage cocktails (Pyobacteriophag, Ses, and Intesti). In case of a low phage effect, an adaptation procedure was performed. Although the biofilms formed by strain 021UR were resistant to amoxicillin–clavulanic acid and ciprofloxacin, the three phage cocktails were able to reduce biofilm formation. In contrast, phages did not affect the 01206UR strain against planktonic and biofilm-forming cells. After Pyobacteriophag adaptation, the effect improved, and, regardless of the concentration, the adapted phage cocktail could destroy both planktonic cells and the biofilm of strain 01206UR. Bacteriophages capable of killing bacteria in biofilms can be used as an alternative to antibiotics. However, each case should be considered individually due to the lack of clinical trials for phage therapy. Antimicrobial and phage susceptibility should be determined in biofilm models before treatment to achieve the desired anti-biofilm effect.

Correlation between antimicrobial resistance, biofilm formation, and virulence determinants in uropathogenic Escherichia coli from Egyptian hospital

“…The impaired antimicrobial diffusion due to biofilms means that embedded cells are exposed to sub-lethal concentrations of these agents, which promotes biofilm formation, this is called adaptive tolerance and occurs through metabolic or transcriptional adaptation without genetically acquired resistance [ 74 , 78 – 80 ]. Because this tolerance is not expressed in the planktonic state, it cannot be detected by conventional AST, leading to a major difference in the susceptibility of biofilm-associated cells and planktonic cells of the same strain.…”

Effect of Bacteriophages against Biofilms of Escherichia coli on Food Processing Surfaces

“…The biofilm formation on plastic or stainless steel was performed in a 96-well plate or bars (2 cm × 1 cm), respectively, based on the methods previously described by Mukane et al (2022), Park and Park (2021) and Sadekuzzaman et al (2017) [ 55 , 56 , 57 ] with some modifications. Briefly, 200 µL of grown E. coli culture were transferred to each well of a 96-well plate, or 5 mL were transferred to sterilized tubes, depending on the assays on plastic or stainless steel, respectively.…”

“…This procedure was carried out for E. coli ATCC 13706 and E. coli ATCC 25922. Biofilm formation was evaluated by crystal violet assay according to Mangieri et al (2021), Mukane et al (2022), and Coffey and Anderson (2014), with some modifications [ 56 , 58 , 59 ]. Briefly, the wells were stained with 0.1% crystal violet for 15 min, washed three times with PBS, and allowed to dry overnight at room temperature.…”

“…The OD values allowed us to assess not only the ability to form biofilm but also the amount of biofilm produced by each bacterial strain. The biofilm formation capacity parameter was evaluated according to the method by Mukane et al (2022) [ 56 ]. This is based on comparing the absorbance value at OD 540 nm of the negative control (OD C ) with the absorbance value at OD 540 nm of the wells containing the bacteria (OD B ).…”

Effect of Bacteriophages against Biofilms of <em>Escherichia coli</em> on Food Handling Surfaces

“…The biofilm formation on plastic or stainless steel was performed in a 96-well plate or bars (2 cm × 1 cm), respectively, based on the methods previously described by Mukane et al (2022), and Sadekuzzaman et al (2017) [55][56][57] with some modifications. Briefly, 200 µL of grown E. coli culture were transferred to each well of a 96-well plate, or 5 mL were transferred to sterilized tubes, depending on the assays on plastic or stainless steel, respectively.…”