Bovicin HC5 and nisin reduce Staphylococcus aureus adhesion to polystyrene and change the hydrophobicity profile and Gibbs free energy of adhesion

Abstract

Staphylococcus aureus is an opportunistic pathogen often multidrug-resistant that not only causes a variety of human diseases, but also is able to survive on biotic and abiotic surfaces through biofilm communities. The best way to inhibit biofilm establishment is to prevent cell adhesion. In the present study, subinhibitory concentrations of the bacteriocins bovicin HC5 and nisin were tested for their capability to interfere with the adhesion of S. aureus to polystyrene. Subinhibitory dosages of the bacteriocins reduced cell adhesion and this occurred probably due to changes in the hydrophobicity of the bacterial cell and polystyrene surfaces. After treatment with bovicin HC5 and nisin, the surfaces became more hydrophilic and the free energy of adhesion (∆G(adhesion)) between bacteria and the polystyrene surface was unfavorable. The transcriptional level of selected genes was assessed by RT-qPCR approach, revealing that the bacteriocins affected the expression of some important biofilm associated genes (icaD, fnbA, and clfB) and rnaIII, which is involved in the quorum sensing mechanism. The conditioning of food-contact surfaces with bacteriocins can be an innovative and powerful strategy to prevent biofilms in the food industry. The results are relevant for food safety as they indicate that bovicin HC5 and nisin can inhibit bacterial adhesion and consequent biofilm establishment, since cell adhesion precedes biofilm formation.

Effects of nisin on Staphylococcus aureus count and physicochemical properties of Minas Frescal cheese

“…This bacteriocin mix was able to reduce only 1 log cycle until 15 d of storage at 4°C. After this period, bacteria was grown again (Pimentel-Filho et al, 2014).…”

“…(Hamama et al, 2002;Pinto et al, 2011;Pimentel-Filho et al, 2014;Zhao et al, 2014;Liu et al, 2015). However, to the best of our knowledge, few data are available regarding the effect of nisin against S. aureus in Minas Frescal cheese, which is a fresh, highly manipulated product and, thus, an important vehicle for the staphylococcal enterotoxin.…”

Synergistic interactions of nisin in combination with cinnamaldehyde against Staphylococcus aureus in pasteurized milk

“…Lactis (Kindrachuk et al, 2012). Nisin was permitted and widely used in the food industry as a safe and natural food preservative in over 50 countries around the world (Pimentel-Filho, Martins, Nogueira, Mantovani, & Vanetti, 2014). In addition, nisin is highly active against a wide range of Gram-positive bacteria such as S. aureus, Listeria monocytogenes, Lactobacillus spp., Microcococcus spp., Bacillus spp., and Clostrdium spp.…”

Biofilm formation by Staphylococcus aureus strains and their control by selected phytochemicals

“…Microtiter plate (MtP) and test tube assays were also used to compare biofilm formations of S. aureus isolates on polystyrene (hydrophobic) and glass surfaces (hydrophilic) to represent model surface materials used in the food industry (Pimentel-Filho et al 2014).…”