Architecture and Viability of the Biofilms Formed by Nine Listeria Strains on Various Hydrophobic and Hydrophilic Materials

Abstract

Biofilms are a key factor in the persistence of Listeria in food processing plants, representing a potential source of foodstuff contamination. Nine Listeria strains (eight Listeria monocytogenes and one Listeria ivanovii) were studied by confocal laser scanning microscopy (CLSM) for their ability to form biofilm on glass, polystyrene, graphene and resin after 120 h of incubation at 12 °C. The relationship between cell surface hydrophobicity and biofilm formation was also investigated. On comparing the data for all the strains, similar (P > 0.05) biovolume values were obtained on glass (average 3.39 ± 1.69 µm3/µm2) and graphene (2.93 ± 1.14 µm3/µm2), while higher (P < 0.05) values were observed for polystyrene (4.39 ± 4.14 µm3/µm2). The highest (P < 0.01) biovolume levels were found in the biofilms formed on resin (7.35 ± 1.45 µm3/µm2), which also had the smallest biomass of inactivated cells (0.38 ± 0.37 µm3/µm2 vs. 1.20 ± 1.12 µm3/µm2 on the remaining surfaces; P < 0.001). No relationship was noted between cell surface hydrophobicity and biofilm-forming ability.

Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for Twelve Antimicrobials (Biocides and Antibiotics) in Eight Strains of Listeria monocytogenes

“…The values for hydrophobicity obtained for the various strains of L. monocytogenes (10.04 ± 2.17% to 29.11 ± 2.36%) fall in the range of previous studies (4.84 ± 1.11% to 31.82 ± 5.98%) using xylene as the hydrocarbon phase [ 70 ]. The negative correlations found between the hydrophobicity and the MICs or MBCs of the biocides should be noted.…”

Antibiotic Resistance and Biofilm-Forming Ability in Enterococcal Isolates from Red Meat and Poultry Preparations

“…In nature, microorganisms by preference grow in the form of biofilms, complex communities of microbes embedded in an extracellular polymer matrix synthesized by the organisms themselves, with an ability to adhere to a variety of different biotic or abiotic surfaces [8,9]. Sessile cells that form part of a biofilm have a much-enhanced resistance to different stress factors, such as disinfectants and antibiotics, when compared with planktonic, or free-living, cells.…”

Rapid-Response Magnetic Enrichment Strategy for Significantly Improving Sensitivity of Multiplex PCR Analysis of Pathogenic Listeria Species

“…Foodborne pathogens contamination is one of the main sources of food safety problems [1]. Among the genus Listeria, Listeria monocytogenes and Listeria ivanovii have been classified as important human and animal pathogens and are widely distributed in food [2]. Human infections are caused by L. monocytogenes and L. ivanovii mainly through eating contaminated food [3], such as meat products [4], vegetables [5], dairy products [6], and seafood [7], while animal infections are caused by the ingestion of organisms through contaminated vegetation.…”