Acquired acid adaptation of Listeria monocytogenes during its planktonic growth enhances subsequent survival of its sessile population to disinfection with natural organic compounds

In this study, the possible influence of acid adaptation of L. (monocytogenes cells during their planktonic growth on their subsequent resistance against some such compounds (i.e. lactic acid, essential oil or hydrosol of Mediterranean spice Satureja( thymbra) nupon their attachment to SS, was evaluated by simultaneously using the bead vortexing technique and a conductance method

P3-21 Comparative Proteomic Analysis of Salmonella enterica serovar Enteritidis PT4 Planktonic and Sessile Cells on Stainless Steel Surface Provides New Insights in Protein Determinants Involved in the Maintenance of a Biofilm community

In order to better understand the cellular mechanisms sustaining a surface-associated lifestyle of S. Enteritidis in food related environments, the differential protein patterns of this bacterium cultivated as biofilm on SS versus planktonic mode were comparatively studied in the present work

Ability of Salmonella enterica and Staphylococcus aureus to develop biofilm community on stainless steel and colonize rocket tissue

Salmonella enterica and Staphylococcus aureus are important human pathogens capable of causing a diverse array of diseases, while international organization (EFSA, FAO/WHO) report that these are among the most related microorganisms for foodborne diseases. The ability of both species to form biofilm, together with the increased number of antibiotic-resistant S. aureus strains, including ones resistant to methicillin (MRSA), are of special interest for researchers. In addition, the consumption of raw plant tissues, have been recently associated with foodborne diseases outbreaks due to cross contamination. Obviously, the ability of pathogenic strains of these species to survive on either abiotic or plant surfaces needs to be further studied

Population and resistance patterns of Salmonella Typhimurium and Staphylococcus aureus biofilms to sublethal chemical disinfection under mono-and dual-species multi-strain conditions

To evaluate the possible influence of bacterial interactions encountered in mono- and dual-species multi-strain biofilms of Salmonella Typhimurium (ST) and Staphylococcus aureus (SA) on: (i) the ability of strains to develop biofilm, and (ii) their subsequent resistance to sublethal chemical disinfection

Ability of Salmonella enterica and Staphylococcus aureus to develop biofilm community on stainless steel and colonize rocket tissue

In the present study, the ability of S. Typhimurium (CDC 6516-60) and S. aureus strain COL (MRSA) to both develop a biofilm community on stainless steel (SS) and colonize rocket tissue was investigated (incubation at 20°C for 144 h). In parallel, the planktonic growth of these pathogens in Brain Heart Infusion (BHI) broth, was followed

A targeted gene expression analysis during biofilm formation by Salmonella enterica on stainless steel surfaces

In the present study, the expression of 14 genes was comparatively evaluated between planktonic and biofilm cells of S. Enteritidis. These genes were selected based on previous knowledge on their putative involvement in stress related mechanisms and other colonization implications. Biofilms were left to be formed on stainless steel coupons incubated under static conditions in brain heart growth medium at either 10 or 20°C for 6 days (144 h). Results revealed significant differential expression for the genes studied between the two growth modes (planktonic, sessile)

Interactions encountered inside dual-species biofilms formed by Salmonella Typhimurium and autochthonous microbiota recovered from leafy salads on stainless steel

In the present study, the ability of bacteria isolated from leafy salads to affect biofilm formation by Salmonella Typhimurium (ST), when all these were cultured together on stainless steel (SS) coupons, was investigated. To achieve this, isolates recovered from either rocket or spinach salads were left to form mixed culture dual-species biofilms with ST on SS coupons immerged in: (i) LB medium, (ii) rocket sterile extract, and (iii) spinach sterile extract, at 20°C

Bacterial coaggregation in aquatic systems

The establishment of a sessile community is believed to occur in a sequence of steps where genetically distinct bacteria can become attached to partner cells via specific molecules, in a process known as coaggregation. The presence of bacteria with the ability to autoaggregate and coaggregate has been described for diverse aquatic systems, particularly freshwater, drinking water, wastewater, and marine water. In these aquatic systems, coaggregation already demonstrated a role in the development of complex multispecies sessile communities, including biofilms. While specific molecular aspects on coaggregation in aquatic systems remain to be understood, clear evidence exist on the impact of this mechanism in multispecies biofilm resilience and homeostasis. The identification of bridging bacteria among coaggregating consortia has potential to improve the performance of wastewater treatment plants and/or to contribute for the development of strategies to control undesirable biofilms. This study provides a comprehensive analysis on the occurrence and role of bacterial coaggregation in diverse aquatic systems. The potential of this mechanism in water-related biotechnology is further described, with particular emphasis on the role of bridging bacteria.This work was financially supported by: Base Funding UIDB/00511/2020 of LEPABE and UIDB/00081/2020 of CIQUP funded by national funds through the FCT/MCTES (PIDDAC); Project Biocide_for_Biofilm-PTDC/BII-BTI/30219/2017-POCI-01-0145-FEDER 030219, ABFISH–PTDC/ASP-PES/28397/2017-POCI-01-0145-FEDER 028397 and ALGAVALOR-POCI-01-0247-FEDER-035234, funded by FEDER funds through COMPETE2020–Programa Operacional Com petitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. This study was further supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also thank to CITAB (Centre for the Research and Technology of Agro-Environmental and Biological Sciences) under the scope of the FCT funds with reference UIDB/AGR/04033/2020. Ana Afonso acknowledges the FCT grant 2020.04773.BD.info:eu-repo/semantics/publishedVersio

Differential protein expression patterns between planktonic and biofilm cells of Salmonella enterica serovar Enteritidis PT4 on stainless steel surface

In the present study, the proteome of a strain of S. enterica serovar Enteritidis PT4, grown either as biofilm on stainless steel surface or as free-floating (planktonic) in Brain Heart (BH) broth, was investigated in order to detect the strong differences in whole-cell protein expression patterns between the two growth styles. The proteins extracted from both types of cells were subjected to 2-D PAGE, followed by in-gel tryptic digestion, extraction, subsequent MALDI-TOF mass spectrometry (MS) analysis and finally database searches for protein identification. Using this approach, 30 proteins were identified as differentially expressed between the two growth modes on an “on-off” basis, that is, proteins that were detected in one case but not in the other. In particular, 20 and 10 proteins were identified in biofilm and planktonic-grown cells, respectively. The group of proteins whose expression was visible only during biofilm growth included proteins involved in global regulation and stress response (ArcA, BtuE, Dps, OsmY, SspA, TrxA, YbbN and YhbO), nutrient transport (Crr, DppA, Fur and SufC), degradation and energy metabolism (GcvT, GpmA, RibB), detoxification (SseA and YibF), DNA metabolism (SSB), curli production (CsgF), and murein synthesis (MipA). To summarize, this study demonstrates that biofilm growth of S. Enteritidis causes distinct changes in protein expression and offers valuable new data regarding some of the proteins presumably involved in this process. The putative role of these proteins in the maintenance of a biofilm community in Salmonella and other bacteria is discussed