Evaluation antibacterial and antibiofilm activity of the antimicrobial peptide P34 against Staphylococcus aureus and Enterococcus faecalis

Abstract

The adhesion ability of bacteria to abiotic surfaces has important implications in food industries, because these organisms can survive for long periods through the biofilm formation. They can be transferred from one place to another in the industry causing contamination of the food processing environment. In this study, the antibacterial and antibiofilm activities of the antimicrobial peptide P34, characterized as a bacteriocinlike substance (BLS P34) were tested against planktonic and sessile cells of Staphylococcus aureus and Enterococcus faecalis isolated from foods. The BLS P34 showed inhibitory effect against all planktonic cells of E. faecalis. The inhibition of biofilm formation and the eradication of pre-formed biofilm were evaluated with the crystal violet assay and with the reduction of 3-bromide [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium. The BLS P34 promoted a reduction of percentage of adhered microbial cells on the surface, not being able to perform the complete elimination of biofilm formation. The metabolic activity of S. aureus biofilms decreased considerably between 41-95%. However, E. faecalis cells showed up metabolically stimulated. The BLS P34 has the potential antibiofilm for the species S. aureus. Studies suggest more detailed approaches to a better understanding of the interactions between the antimicrobial and bacterial cells within the biofilm structure.

Preparation of PLGA-chitosan based nanocarriers for enhancing antibacterial effect of ciprofloxacin in root canal infection

“…All teeth were removed and dispersed in sterile saline solution by vortexing (ZX3 Advanced Vortex Mixer by Velp Scientifica made in Italy) to ensure that all biofilm fell off the teeth. The solution was cultured using a sterile swab on brain heart infusion agar plates and the bacterial colonies were counted and recorded as CFU (Steiner-Oliveira et al, 2007;Lemos et al, 2010;Costa et al, 2018;Ewell 1890).…”

Antibacterial and Antibiofilm Effects of Synbiotics against Multidrug-Resistant bacteria: Acinetobacter baumannii and Enterococcus faecalis

“…The biofilm was stained with crystal violet assay (discussed above). The biofilm killing effects of each synbiotic were estimated by determining the OD 650 of each well in comparison with control wells (bacterial wells without supernatant) [27]. Gentamicin was used as positive control for both Gram-positive A. baumannii and Gram-negative E. faecalis.…”

Bioprospecting the antimicrobial, antibiofilm and antiproliferative activity of Symplocos racemosa Roxb. Bark phytoconstituents along with their biosafety evaluation and detection of antimicrobial components by GC-MS

“…Stepanovic et al [24] and Costa et al [25], where the organisms were grown in suitable broth for 24 h. The 200 µl aliquot of the activated cultures were dispensed into microtitre plates and further incubated at for 24 h, following which the wells were decanted off and stained with 0.1% crystal violet solution for 15 min. The wells were destained with 150 µl of 95% ethanol and the intensity of biofilm formation was affirmed in terms of Optical density (OD) of stained adherent biofilm by using an ELISA reader (Biorad 680-XR, Japan) at 590 nm.…”

“…It was performed as described earlier [25,27] with slight modifications. One hundred microlitre aliquot of each of the 4h activated cultures were dispensed into a 96-well microtitre plate and were incubated at 37°C/24 h to allow biofilm formation and was treated with equal volume of the phytoconstituents.…”