Dual-species biofilm of Listeria monocytogenes and Escherichia coli on stainless steel surface
Listeria monocytogenes is a Gram-positive bacterium commonly associated with foodborne diseases. Due its ability to survive under adverse environmental conditions and to form biofilm, this bacterium is a major concern for the food industry, since it can compromise sanitation procedures and increase the risk of post-processing contamination. Little is known about the interaction between L. monocytogenes and Gram-negative bacteria on biofilm formation. Thus, in order to evaluate this interaction, Escherichia coli and L. monocytogenes were tested for their ability to form biofilms together or in monoculture. We also aimed to evaluate the ability of L. monocytogenes 1/2a and its isogenic mutant strain (ΔprfA ΔsigB) to form biofilm in the presence of E. coli. We assessed the importance of the virulence regulators, PrfA and σB, in this process since they are involved in many aspects of L. monocytogenes pathogenicity. Biofilm formation was assessed using stainless steel AISI 304 #4 slides immersed into brain heart infusion broth, reconstituted powder milk and E. coli preconditioned medium at 25 °C. Our results indicated that a higher amount of biofilm was formed by the wild type strain of L. monocytogenes than by its isogenic mutant, indicating that prfA and sigB are important for biofilm development, especially maturation under our experimental conditions. The presence of E. coli or its metabolites in preconditioned medium did not influence biofilm formation by L. monocytogenes. Our results confirm the possibility of concomitant biofilm formation by L. monocytogenes and E. coli, two bacteria of major significance in the food industry.
KeywordsBiofilms Listeria monocytogenes Escherichia coli Coculture PrfA SigB
UMP acknowledges a grand support for this project from CNPq-Brazil (Process 457794/2014-3) and the Food Research Center (FAPESP 2013/07914-8); AZG acknowledges CAPES for the fellowship and MTD FAPESP for grant support (Process 2011/18033-7).
AZG designed and performed experiments. MTD advised the study and revised the manuscript. UMP analyzed and interpreted the results and wrote the manuscript.
- Abram F, Starr E, Karatzas KA, Matlawska-Wasowska K, Boyd A, Wiedmann M, Boor KJ, Connally D, O’Byrne CP (2008) Identification of components of the sigma B regulon in Listeria monocytogenes that contribute to acid and salt tolerance. Appl Environ Microbiol 74:6848–6858CrossRefPubMedPubMedCentralGoogle Scholar
- Alavi HED, Hansen LT (2013) Kinetics of biofilm formation and desiccation survival of Listeria monocytogenes in single and dual species biofilms with Pseudomonas fluorescens, Serratia proteamaculans or Shewanella baltica on food-grade stainless steel surfaces. Biofouling 29(10):1253–1268CrossRefGoogle Scholar
- Aragon-Alegro LC (2007) Influência dos coliformes no comportamento de Listeria monocytogenes em queijo Minas Frescal. São Paulo, 2007. Dissertation, Universidade de São PauloGoogle Scholar
- Giaouris E et al (2015) Intra- and inter-species interactions within biofilms of important foodborne bacterial pathogens. Front Microbiol 6(841):1–26Google Scholar
- Kostaki M, Chorianopoulos N, Braxou E, Nychas G-J, Glaoris E (2012) Differential biofilm formation and chemical disinfection resistance of sessile cells of Listeria monocytogenes strains under monospecies and dual-species (with Salmonella enterica) conditions. Appl Environ Microbiol 78(8):2586–2595CrossRefPubMedPubMedCentralGoogle Scholar
- Lou Y, Yousef AH (1999) Characteristics of Listeria monocytogenes important to food processors. In: Ryser ET, Marth EH (eds) Listeria, listeriosis and food safety. Marcel Dekker, New York, pp 134–224Google Scholar
- Midelet G, Kobilinsky A, Carpentier B (2006) Construction and analysis of fractional multifactorial designs to study attachment strength and transfer of Listeria monocytogenes from pure or mixed biofilms after contactwith a solid model food. Appl Environ Microbiol 72:2313–2321CrossRefPubMedPubMedCentralGoogle Scholar