Dual-Species Model Biofilm Consisting of Listeria monocytogenes and Salmonella Typhimurium: Development and Inactivation With Cold Atmospheric Plasma (CAP)

Most environmental biofilms contain a variety of species. These species can establish cooperative and competitive interactions, possibly resulting in an increase or a decrease in antimicrobial resistance. Therefore, results obtained following inactivation of single-species biofilms by means of different technologies (e.g., Cold Atmospheric Plasma, CAP) should be validated for multi-species biofilms. First, a strongly adherent and mature Listeria monocytogenes and S. Typhimurium dual-species biofilm was developed by altering different incubation conditions, i.e., growth medium, incubation temperature, inoculum ratio of L. monocytogenes and S. Typhimurium cells, and incubation time. Adherence and maturity were quantified by means of optical density measurements and viable plate counts, respectively. Secondly, both the (1 day old) reference biofilm and a more mature 7 days old biofilm were treated for different CAP treatment times (0–30 min). Viable plate counts were again used to determine the (remaining) cell density. For both the biofilm development and inactivation, predictive models were applied to describe the growth/inactivation kinetics. Finally, the kinetics of the [1 and 7 day(s) old] dual-species biofilms were compared with those obtained for the corresponding single-species biofilms. Results implied that a strongly adherent and mature reference dual-species biofilm was obtained following 24 h of incubation at 25°C using 20-fold diluted TSB and an inoculum r...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

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koh Disease outbreaks caused by the ingestion of contaminated vegetables and fruits pose a significant problem to human health. The sources of contamination of these food products at the preharvest level of agricultural production, most importantly, agricultural soil and irrigation water, serve as potential reservoirs of some clinically significant foodborne pathogenic bacteria. These clinically important bacteria include: Klebsiella spp., Salmonella spp., Citrobacter spp., Shigella spp., Enterobacter spp., Listeria monocytogenes and pathogenic E. coli (and E. coli O157:H7) all of which have the potential to cause dise...
Source: International Journal of Environmental Research and Public Health - Category: Environmental Health Authors: Tags: Review Source Type: research
Foodborne diseases (FBDs) are infections of the gastrointestinal tract caused by foodborne pathogens (FBPs) such as bacteria (Salmonella, Listeria monocytogenes and Shiga toxin-producing E. coli (STEC)) and several viruses, but also parasites and some fungi. Artificial intelligence (AI) and its sub-discipline machine learning (ML) are re-emerging and gaining an ever increasing popularity in the scientific community and industry, and could lead to actionable knowledge in diverse ranges of sectors including epidemiological investigations of FBD outbreaks and antimicrobial resistance (AMR). As genotyping using whole-genome se...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In this study, a systematic approach was used for the improved identification of novel LAB strains able to exert antagonistic effect against important foodborne pathogens. Our findings suggest that the selected panel of LAB probiotic strains can be used as biocontrol cultures to inhibit and/or reduce the growth of L. monocytogenes, Salmonella, and E. coli O157:H7 in different matrices, and environments.
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion This study confirms the in vitro antibacterial activity of BIOCITRO® against Gram-negative and Gram-positive bacteria. For most of the strains, the product reached the bactericidal effect at the same concentration of the bacteriostatic effect and maximum difference between MIC and MBC was two dilution steps. The less susceptible species of the study were S. enterica ssp. enterica and E. coli with MBC90 values of 256 and 128 μg/mL, respectively, while the most susceptible was C. perfringens with MBC90 of 16 μg/mL. After short exposition time to the product, the significant effect over the viability of ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion Genomic analyses herein performed allowed us to confirm the recently (Pérez-Cataluña et al., 2018a,b) suggested amendment of A. butzleri as Al. butzlerii, comb. nov. Antimicrobial susceptibility tests defined Ab 55 and Ab 6V strains as resistant to vancomycin, tetracyclin, nalidixic acid (only Ab 55 whereas Ab 6V is intermediate resistant), erythromycin, and β-lactam antibiotics. Moreover, in our strains isolated from shellfish, we identified numerous virulence, antibiotic, and heavy metal resistance determinants, also additional to those previously found in the genome sequenced A. butzleri ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Publication date: Available online 12 December 2018Source: The Veterinary JournalAuthor(s): Wiebke Jansen, Anja Müller, Nils Grabowski, Corinna Kehrenberg, Benoît Muylkens, Sascha Al DahoukAbstractGlobalisation, international trade and the ever-growing flow of goods and people enable animal diseases and zoonotic pathogens to travel worldwide. The risk of reintroducing previously eradicated animal diseases into the European Union is omnipresent as considerable amounts of food products of animal origin (POAO) from endemic countries are continuously imported legally and illegally into the EU. Additionally, these pr...
Source: The Veterinary Journal - Category: Veterinary Research Source Type: research
In this study, we have determined microbiological quality of informally retailed fresh milk products and characterized the genomic diversity and antimicrobial resistance (AMR) patterns of non-typhoidal Salmonella (NTS) in implicated products. A total of 159 common dairy products were purchased from five traditional milk markets in Accra. Samples were analysed for concentrations of aerobic bacteria, total and fecal coliforms, Escherichia coli, staphylococci, lactic acid bacteria and yeast and moulds. The presence of Salmonella, E. coli O157:H7, Listeria monocytogenes and Staphylococcus aureus were determined. AMR of Salmone...
Source: International Journal of Food Microbiology - Category: Food Science Authors: Tags: Int J Food Microbiol Source Type: research
Abstract Gram-negative bacteria utilize glutathione (GSH) as their major LMW thiol. However, most Gram-positive bacteria do not encode enzymes for GSH biosynthesis and produce instead alternative LMW thiols, such as bacillithiol (BSH) and mycothiol (MSH). BSH is utilized by Firmicutes and MSH is the major LMW thiol of Actinomycetes. LMW thiols are required to maintain the reduced state of the cytoplasm, but are also involved in virulence mechanisms in human pathogens, such as Staphylococcus aureus, Mycobacterium tuberculosis, Streptococcus pneumoniae, Salmonella enterica subsp. Typhimurium and Listeria monocytogen...
Source: Free Radical Biology and Medicine - Category: Biology Authors: Tags: Free Radic Biol Med Source Type: research
Abstract Whole genome sequencing (WGS) has been broadly used to provide detailed characterization of foodborne pathogens. These genomes for diverse species including Salmonella, Escherichia coli, Listeria, Campylobacter and Vibrio have provided great insight into the genetic make-up of these pathogens. Numerous government agencies, industry and academia have developed new applications in food safety using WGS approaches such as outbreak detection and characterization, source tracking, determining the root cause of a contamination event, profiling of virulence and pathogenicity attributes, antimicrobial resistance ...
Source: Current Opinion in Biotechnology - Category: Biotechnology Authors: Tags: Curr Opin Biotechnol Source Type: research
Accelerating emergence of antimicrobial resistance among food pathogens and consumers ’ increasing demands for preservative-free foods are two contemporary challenging aspects within the food industry. Antimicrobial packaging and the use of natural preservatives are promising solutions. In the present study, we used beta-casein—one of the primary self-assembly proteins in milk wi th a high polymeric film production capability—as a fusion partner for the recombinant expression of E 50-52 antimicrobial peptide in Escherichia coli. The pET21a-BCN-E 50-52 construct was transformed to E. coli BL21 (DE3), and p...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
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