Global Transcriptional Analysis of Spontaneous Sakacin P-Resistant Mutant Strains of Listeria monocytogenes during Growth on Different Sugars

Subclass IIa bacteriocins have strong antilisterial activity and can control the growth of Listeria monocytogenes in food. However, L. monocytogenes may develop resistance towards such bacteriocins. In this follow-up study, the transcriptomes of a high level (L502-1) and a low level (L502-6) spontaneous sakacin P-resistant mutant strain of L. monocytogenes were compared to the wild-type (L502). The growth of the resistant strains was reduced on mannose but not affected on cellobiose and the transcriptomics was performed during growth on these sugars. The mannose phosphotransferase system (PTS) encoded by the mptACD operon (mpt) is known for transporting mannose and also act as a receptor to class IIa bacteriocins. The mpt was repressed in L502-1 and this is in accordance with abolition of the bacteriocin receptor with resistance to class IIa bacteriocins. In contrast, the mpt was induced in L502-6. Despite the induction of the mpt, L502-6 showed 1,000 times more resistance phenotype and reduced growth on mannose suggesting the mannose-PTS may not be functional in L502-6. The microarray data suggests the presence of other transcriptional responses that may be linked to the sakacin P resistance phenotype particularly in L502-6. Most of commonly regulated genes encode proteins involved in transport and energy metabolism. The resistant strains displayed shift in general carbon catabolite control possibly mediated by the mpt. Our data suggest that the resistant strains may have a reduced virulence potential. Growth sugar- and mutant-specific responses were also revealed. The two resistant strains also displayed difference in stability of the sakacin P resistance phenotype, growth in the presence of both the lytic bacteriophage P100 and activated charcoal. Taken together, the present study showed that a single time exposure to the class IIa bacteriocin sakacin P may elicit contrasting phenotypic and transcriptome responses in L. monocytogenes possibly through regulation of the mpt

The Binding of Triclosan to SmeT, the Repressor of the Multidrug Efflux Pump SmeDEF, Induces Antibiotic Resistance in Stenotrophomonas maltophilia

The wide utilization of biocides poses a concern on the impact of these compounds on natural bacterial populations. Furthermore, it has been demonstrated that biocides can select, at least in laboratory experiments, antibiotic resistant bacteria. This situation has raised concerns, not just on scientists and clinicians, but also on regulatory agencies, which are demanding studies on the impact that the utilization of biocides may have on the development on resistance and consequently on the treatment of infectious diseases and on human health. In the present article, we explored the possibility that the widely used biocide triclosan might induce antibiotic resistance using as a model the opportunistic pathogen Stenotrophomonas maltophilia. Biochemical, functional and structural studies were performed, focusing on SmeDEF, the most relevant antibiotic- and triclosan-removing multidrug efflux pump of S. maltophilia. Expression of smeDEF is regulated by the repressor SmeT. Triclosan released SmeT from its operator and induces the expression of smeDEF, thus reducing the susceptibility of S. maltophilia to antibiotics in the presence of the biocide. The structure of SmeT bound to triclosan is described. Two molecules of triclosan were found to bind to one subunit of the SmeT homodimer. The binding of the biocide stabilizes the N terminal domain of both subunits in a conformation unable to bind DNA. To our knowledge this is the first crystal structure obtained for a transcriptional regulator bound to triclosan. This work provides the molecular basis for understanding the mechanisms allowing the induction of phenotypic resistance to antibiotics by triclosan

Microbiological and observational data from 87 European kitchens

The data are microbiological and observational data collected from visits in 87 kitchens/households from six European countries: France, Hungary, Norway, Portugal, Romania and United Kingdom. The data are presented in an Excel spreadsheet. A sheet with more explanation of the data is included in the Excel file. This research was performed within the European Commission H2020 – SFS – 2016 – 2017 Project no. 727580 SafeConsume

Dishwashing sponges and brushes

File drying_survival_cleaning contain data on drying (water content) of new sponges and brushes, survival of Salmonella, Campylobacter and food/kitchen bacteria on new sponges and brushes in a laboratory model system, and reduction of bacteria during different cleaning methods of sponges and brushes. File Bacteriota contains data on relative abundance of bacteria (16SrDNA based) on new sponges and brushes from a seven day laboratoty model experiment File Survey_data...contains data from a webbased survey of 9966 European consumers. The dataset is a subset of data related to usage information of Kitchen brushes and sponge

Data for: Kitchen cloths: Consumer practices, drying properties and bacterial growth and survival

The enclosed excel file contains raw data for the publication:Trond Møretrø, Valérie Lengard Almli, Anette Wold Åsli, Charlotte Kummen, Martina Galler, Solveig Langsrud,Kitchen cloths: Consumer practices, drying properties and bacterial growth and survival,Food Control,2022,109195,ISSN 0956-7135, https://doi.org/10.1016/j.foodcont.2022.109195.The excel file contains sheets with names that refer to figures and tables in the manuscript listed aboveTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Microbiological and observational data from 87 European kitchens

The data are microbiological and observational data collected from visits in 87 kitchens/households from six European countries: France, Hungary, Norway, Portugal, Romania and United Kingdom. The data are presented in an Excel spreadsheet. A sheet with more explanation of the data is included in the Excel file. This research was performed within the European Commission H2020 – SFS – 2016 – 2017 Project no. 727580 SafeConsume

Bacterial levels and diversity in kitchen sponges and dishwashing brushes used by consumers

Data on bacterial levels and bacteriota results from sponges and brushes used by consumers. There are also data on usage information on the brushes and sponges reported by consumers.The Excel file "Brushes and sponges" contains information about usage information on sponges and brushes as well as total bacterial counts and Salmonella counts. These are the data used in Table 2 and Table 4 in the article in Journal of Applied Microbiology by Møretrø et.al. with the same title as this dataset.The Excel files "Run1_Norwegian" and "Run2_Portuguese, contain background data for microbiota analysis for Norwegian sponges and brushes and Portuguese sponges, respectively, and refer to data presented in Figure 1 and 2 and in Table 3 in the article in Journal of Applied Microbiology by Møretrø et.al. with the same title as this dataset.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Atividade antibacteriana de desinfetantes para uso na produção orgânica de aves Antibacterial activity of disinfectants for use in organic poultry keeping

A determinação de produtos eficazes para a desinfecção e que não causem danos ao meio ambiente é um grande desafio para a avicultura orgânica. Neste trabalho foram avaliadas as atividades antibacterianas de quatro desinfetantes: ácido peracético, amônia quaternária, hipoclorito de sódio a 1% e a 0,1% de cloro ativo e do composto de ácidos orgânicos (cítrico, lático e ascórbico), frente às amostras padrão de Escherichia coli, Salmonella enteritidis e Staphylococcus aureus, na presença e ausência de matéria orgânica, sob duas diferentes temperaturas e tempo de contato de 20 minutos. Os ácidos orgânicos mostraram-se menos efetivos na presença de matéria orgânica. No entanto, o ácido peracético, na ausência desta, foi o mais eficaz frente à S. Enteritidis e igualmente efetivo, independente da matéria orgânica, frente ao S. aureus e E. coli, revelando-se uma opção válida para desinfecção na avicultura orgânica, desde que precedida de limpeza criteriosa.<br>Efficient products in the disinfection that do not cause damages to the environment are a challenge for the organic poultry keeping. The antibacterial activity of four disinfectants was evaluated to per acetic acid, quaternary ammonium, sodium hypochlorite at 1% and 0,1% and the composed of organics acids (citric, lactic and ascorbic) against standard samples of Escherichia coli, Salmonella enteritidis and Staphylococcus aureus in the presence and absence of organic matter, at two different temperatures and with 20 minutes of contact. Organic acids were shown less effective in the presence of organic matter. However, the per acetic acid in the absence of this revealed most efficient against S. Enteritidis and equally effective in the presence of organic matter, against S. aureus and E. coli showing a valid option for disinfection in the organic poultry keeping since preceded of careful cleanness