In vitro activities of cellulase and ceftazidime, alone and in combination against Pseudomonas aeruginosa biofilms

Abstract

Background Biofilms are a main pathogenicity feature of Pseudomonas aeruginosa and has a significant role in antibiotic resistance and persistent infections in humans. We investigated the in vitro activities of antibiotic ceftazidime and enzyme cellulase, either alone or in combination against biofilms of P. aeruginosa. Results Both ceftazidime and cellulase significantly decreased biofilm formation in all strains in a dose-dependent manner. Combination of enzyme at concentrations of 1.25, 2.5, 5, and 10 U/mL tested with 1/16× MIC of antibiotic led to a significant reduction in biofilm biomass. Cellulase showed a significant detachment effect on biofilms at three concentrations of 10 U/mL, 5 U/mL, and 2.5 U/mL. The MIC, MBC, and MBEC values of ceftazidime were 2 to 4 µg/mL, 4 to 8 µg/mL, and 2048 to 8192 µg/mL. When combined with cellulase, the MBECs of antibiotic showed a significant decrease from 32- to 128-fold. Conclusions Combination of the ceftazidime and the cellulase had significant anti-biofilm effects, including inhibition of biofilm formation and biofilm eradication in P. aeruginosa. These data suggest that glycoside hydrolase therapy as a novel strategy has the potential to enhance the efficacy of antibiotics and helps to resolve biofilm-associated wound infections caused by this pathogen.

Fungal Glycoside Hydrolases Display Unique Specificities for Polysaccharides and Staphylococcus aureus Biofilms

“…Enzymatic debridement is another option if we can identify appropriate enzymes. Toward this end, glycoside hydrolases (GHs) are effective for the dispersion of some biofilms, most notably commercial cellulase and amylase preparations [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. While encouraging, commercial enzyme preparations appear to be effective at high concentrations, and we have confirmed that their purity is sometimes questionable.…”

“…Enzymes known as glycoside hydrolases (GHs) have shown promise in degrading the polysaccharides in the EPS to disperse bacteria. Amylase, cellulase, dispersin B, alginate lyase, and other GHs can disperse biofilms both in vitro and in vivo [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Even so, the great diversity of EPS polysaccharides in any single biofilm represents a significant challenge to the therapeutic application of GHs to aid in the clearance of biofilms.…”

Synergistic effects of silybin and curcumin on virulence and carbapenemase genes expression in multidrug resistant Klebsiella oxytoca

“…The biofilm formation was defined compared to the control wells. There were four categories of isolates: non-biofilm producers (OD T < ODc), weak-biofilm producers (ODc < OD T < 2 × ODc), moderate-biofilm producers (2×ODc < OD T < 4 × ODc), and strong-biofilm producers (4 × ODc < OD T ) [ 25 ].…”

Antibacterial and antibiofilm activities of fosfomycin combined with rifampin against carbapenem-resistant Pseudomonas aeruginosa

“…2019; Kamali et al . 2021). Previously, our research group confirmed that PA 11 has a strong ability to produce biofilms, so, we chose PA 11 as the representative strain in this experiment.…”

“…For the reason biofilms-related drug resistance in PA occurred with high frequency, we assayed the inhibition of biofilm formation using crystal violet in 96-well flatbottom polystyrene plates, as previously described with minor modification (Dosler and Karaaslan 2014;Chanda et al 2017;Martinez et al 2019;Vipin et al 2019;Kamali et al 2021). Previously, our research group confirmed that PA11 has a strong ability to produce biofilms, so, we chose PA11 as the representative strain in this experiment.…”