Variation in Biofilm Formation among Strains of Listeriamonocytogenes

Abstract

Contamination of food by Listeria monocytogenes is thought to occur most frequently in food-processing environments where cells persist due to their ability to attach to stainless steel and other surfaces. Once attached these cells may produce multicellular biofilms that are resistant to disinfection and from which cells can become detached and contaminate food products. Because there is a correlation between virulence and serotype (and thus phylogenetic division) of L. monocytogenes, it is important to determine if there is a link between biofilm formation and disease incidence for L. monocytogenes. Eighty L. monocytogenes isolates were screened for biofilm formation to determine if there is a robust relationship between biofilm formation, phylogenic division, and persistence in the environment. Statistically significant differences were detected between phylogenetic divisions. Increased biofilm formation was observed in Division II strains (serotypes 1/2a and 1/2c), which are not normally associated with food-borne outbreaks. Differences in biofilm formation were also detected between persistent and nonpersistent strains isolated from bulk milk samples, with persistent strains showing increased biofilm formation relative to nonpersistent strains. There were no significant differences detected among serotypes. Exopolysaccharide production correlated with cell adherence for highbiofilm-producing strains. Scanning electron microscopy showed that a high-biofilm-forming strain produced a dense, three-dimensional structure, whereas a low-biofilm-forming strain produced a thin, patchy biofilm. These data are consistent with data on persistent strains forming biofilms but do not support a consistent relationship between enhanced biofilm formation and disease incidence.

Effect of peracetic acid on biofilms formed by Listeria monocytogenes strains isolated from a Brazilian cheese processing plant

“…BFI values of the three isolates decreased (P<0.05) after 60 s treatment, although there were no differences (P>0.05) between the treatment times for isolate A. Isolates B and C had lower BFI at 180 s, which was consistent with their higher percentage reductions (P<0.05) at this time when compared with values obtained at 60 or 120 s. The isolate A belonged to serotype 4b, which is of great public health importance since this serotype is frequently involved in outbreaks of human listeriosis (Graves, Swaminathan, Hunter, 2007). Although in the present study the BFI values for isolate A (serotype 4b) were lower than for isolates B or C (serotype 1/2b) at all treatment times, the available data relating phylogenetic division, serotype, and biofilm formation remained inconclusive (Djordjevic, Wiedmann, Mclandsborough, 2002;Borucki et al, 2003). In a recent report by Wang et al (2016), the biofilm-formation ability of serotype 1/2b was higher than serotype 1/2a, which is consistent with data presented in this study.…”

Evaluating the Effect of Copper Nanoparticles in Inhibiting Pseudomonas aeruginosa and Listeria monocytogenes Biofilm Formation

“…Many bacteria have the potency to colonize and adhere to surfaces by producing a three-dimensional matrix of extracellular polymeric substances called the biofilm (1). Biofilms permit bacteria to persist in the environment and resist treatment with antibacterial agents, rendering their elimination very problematic (2)(3)(4).…”

Biossurfactantes: propriedades anticorrosivas, antibiofilmes e antimicrobianas

“…15 Outro trabalho também correlacionou a maior produção de exopolissacarídeos com as linhagens de L. monocytogenes capazes de ter maior adesão a superfícies. 32 …”