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

Targeted gene expression study of Salmonella enterica during biofilm formation on rocket leaves

In the present study, the ability of Salmonella Typhimurium to form biofilm community on rocket leaves and rocket extract at 10 C and 20 C was investigated. This goal was achieved with the study of expression of genes associated with biofilm formation and other functional roles. The obtained results showed that Salmonella growth was inhibited when cultured in rocket extract (liquid and solid state) and when grew directly to rocket leaves. The observed inhibition might be attributed to nutrient starvation to the specific growth media because of plant leaves's variability, cell physiology and antimicrobial compounds of rocket. In addition, gene expression study using Real-Time PCR showed that biofilm was formatted on solid media, while the entrance and adhesion of the microorganism within the plant held more strongly through the stomata of the plant leaves. Furthermore, genes associated with managing stress situations were overexpressed at 20 C. From these results, it is indicated that further studies are needed to better determine the survival and/or growth of the pathogen as “real” biofilm cells on plants. In addition, the study on development and gene expression of biofilm cells is necessary in order to eliminate the specific pathogen and reduce the food-borne diseases it causes

Metabolomic analysis of salmonella enterica cells in vitro and in situ

In the present study a comparison of metabolomics, on laboratory medium, on rocket extract, of S. Tymphimurium (ST) CDC 6516-60, as well as on the developed biofilm on rocket tissue was investigated

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

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

Corrigendum: Editorial: Biofilm formation and quorum sensing of foodborne microorganism

: [This corrects the article DOI: 10.3389/fmicb.2022.1107603.]

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)

Characterization of indigenous lactic acid bacteria in cow milk of the Maltese Islands : a geographical and seasonal assessment

A geographical and seasonal assessment of indigenous lactic acid bacteria (LAB) in Maltese cow milk was conducted in this study. To investigate this, milk was collected from different regions of Malta during winter and summer seasons. Total viable counts (TVC) and LAB population were enumerated. Afterwards, LAB were isolated and identified by molecular methods. According to the results, similar TVC were enumerated on winter and summer samples, while highest LAB population was detected on summer samples. LAB isolates were grouped in seven different clusters which were assigned to Lactobacillus casei, Pediococcus pentosaceus, Lactobacillus plantarum, Weissella paramesenteroides, Lactobacillus rhamnosus, Lactococcus lactis, and Lactococcus garvieae. In addition, Enterococcus and Streptococcus species were also isolated. Season seemed to affect the genus / species of LAB since Lactobacillus were mainly isolated from winter samples, while Lactococcus and Enterococcus species were the main genera identified in summer samples. Regarding the geographical distribution, the majority of the Lactobacillus spp. were isolated from the South-eastern region in both seasons. In conclusion, through this study the diversity of indigenous LAB in the Maltese cow milk was monitored for the first time and highlighted that the microbial communities are affected by seasonality and geographical distribution of the farms.peer-reviewe

Identification of meat spoilage gene biomarkers in Pseudomonas putida using gene profiling

While current food science research mainly focuses on microbial changes in food products that lead to foodborne illnesses, meat spoilage remains as an unsolved problem for the meat industry. This can result in important economic losses, food waste and loss of consumer confidence in the meat market. Gram-negative bacteria involved in meat spoilage are aerobes or facultative anaerobes. These represent the group with the greatest meat spoilage potential, where Pseudomonas tend to dominate the microbial consortium under refrigeration and aerobic conditions. Identifying stress response genes under different environmental conditions can help researchers gain an understanding of how Pseudomonas adapts to current packaging and storage conditions. We examined the gene expression profile of Pseudomonas putida KT2440, which plays an important role in the spoilage of meat products. Gene expression profiles were evaluated to select the most differentially expressed genes at different temperatures (30 °C and 10 °C) and decreasing glucose concentrations, in order to identify key genes actively involved with the spoilage process. A total of 739 and 1269 were found to be differentially expressed at 30 °C and 10 °C respectively; of which 430 and 568 genes were overexpressed, and 309 and 701 genes were repressed at 30 °C and 10 °C respectively

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