Influence of a nanoscale coating on plucking fingers and stainless steel on attachment and detachment of Salmonella Enteritidis, Escherichia coli and Campylobacter jejuni

Gastroenteritis caused by Campylobacter represents the most common reported foodborne bacterial illness worldwide, followed by salmonellosis. Both diseases are often caused by the consumption of contaminated, insufficiently heated poultry meat. This can result from contamination of the meat during the slaughtering processes. Food contact surfaces like stainless steel or plucking fingers contribute significantly to cross-contamination of poultry carcasses. Modification of these surfaces could lead to a reduction of the bacterial burden, as already proven by successful application in various food industry sectors, such as packaging.In this study, nanoscale silica-coated and uncoated stainless-steel surfaces and plucking fingers were compared on a pilot scale regarding attachment and detachment of Campylobacter jejuni, Salmonella Enteritidis and Escherichia coli.The bacteria did not adhere less to the coated plucking fingers or stainless-steel sections than to the uncoated ones. The coating also did not lead to a significant difference in detachment of Campylobacter jejuni, Salmonella Enteritidis and Escherichia coli from the investigated surfaces compared to the uncoated ones.Our study did not reveal any differences between the coated and uncoated surfaces with regard to the investigated bacteria. In order to achieve a better adaptation of the coating to slaughterhouse conditions, future studies should focus on its further development based on the investigation of specific coating parameters.

Impact of nanoscale silicon dioxide coating of stainless-steel surfaces on Listeria monocytogenes

High resistance to environmental factors as well as the ability to form biofilms allow Listeria monocytogenes to persist for a long time in difficult-to-reach places in food-producing plants. L. monocytogenes enters final products from contaminated surfaces in different areas of plants and poses a health risk to consumer. Modified surfaces are already used in the food industry to prevent cross-contamination. In this study, stainless-steel surfaces were coated with nanoscale silicon dioxide and the effects on attachment, bacterial growth and detachment of L. monocytogenes were evaluated. Attachment was considered for three different ways of application to simulate different scenarios of contamination. Bacterial growth of L. monocytogenes on the surface was recorded over a period of up to 8 h. Detachment was tested after cleaning inoculated stainless-steel surfaces with heated distilled water or detergent. Coating stainless-steel surfaces with nanoscale silica tends to reduce adherence and increased detachment and does not influence the bacterial growth of L. monocytogenes. Further modifications of the coating are necessary for a targeted use in the reduction of L. monocytogenes in food-processing plants.

Clinical longevity of intracoronal restorations made of gold, lithium disilicate, leucite, and indirect resin composite: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials.

MATERIAL AND METHODS

This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I2 statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p < 0.05).

RESULTS

A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference =  - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I2 = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies.

CONCLUSIONS

According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations.

CLINICAL SIGNIFICANCE

Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.

Evaluation of a Harmonized Undergraduate Catalog for Veterinary Public Health and Food Hygiene Pedagogy in Europe

Current and emerging veterinary public health (VPH) challenges raised by globalization, climate change, and industrialization of food production require the veterinarian's role to evolve in parallel and veterinary education to adapt to reflect these changes. The European Food Hygiene catalog was developed to provide a list of topics relevant to Day One Competencies in VPH. A study was undertaken to ensure that the catalog and teaching practices were pertinent to the work of public health veterinarians. Relevant stakeholders were consulted using questionnaires and semi-structured interviews. A long questionnaire was distributed to 49 academics teaching VPH in European veterinary schools to review topics listed in the catalog. Eighteen responses were received (36.7%), representing 12 European countries. There was general agreement that most topics were appropriate for the undergraduate VPH curriculum. A short questionnaire was distributed to 348 European veterinarians working in the industry. Twenty-four questionnaires (6.7%) were received, representing eight European countries. Despite the low participation rate, topics needing greater emphasis in the undergraduate curriculum included Hazard Analysis Critical Control Points (HACCP), food microbiology, and audits. Seven semi-structured interviews with public health veterinarians working in the UK identified the need for curricular changes including greater practical experience and a shift from a focus on meat inspection to risk management. This may be partly achieved by replacing traditional lectures with authentic case-based scenarios. The study findings can be used to inform the future direction to VPH education for veterinary students across Europe.

Pulsed-Light Treatment of Dried Parsley: Reduction of Artificially Inoculated Salmonella and Impact in Given Quality Parameters

ABSTRACT

Dried parsley is regularly contaminated with foodborne pathogens, especially Salmonella. Application of contaminated ingredients in ready-to-eat dishes without further thermal treatment represents a considerable health risk. This study examined the suitability of pulsed light as a novel decontamination method of Salmonella in dried parsley, along with the impact on selected quality parameters (chlorophyll content, phenolic compounds, color, and odor) and product characters (temperature and water activity value). Samples were inoculated with one of three Salmonella isolates (Salmonella Cerro or one of two isolates of Salmonella Agona) at two contamination levels of 103 or 107 CFU/g and treated under various experimental factors, including distance to the light source and exposure time, resulting in fluences in the range of 1.8 to 19.9 J/cm2. At selected parameter settings (9.8 and 13.3 J/cm2), the effect of prolonged storage time (48 h) of inoculated samples before treatment on the reduction of Salmonella Cerro was examined. Samples treated at the same fluences were also stored for 35 days at 22 to 25°C. The three Salmonella isolates were significantly reduced by pulsed light (P < 0.05). Reduction factors ranged between 0.3 and 5.2 log CFU with varying sensitivities of the isolates. In general, increasing fluences (depending on exposure time and distance to the light source) resulted in increasing reductions of Salmonella. However, on closer examination, exposure time and distance to the light source had a varying influence on the reduction of the different Salmonella isolates. Decreasing reduction factors were observed by increasing the contamination level and prolonging the storage time of inoculated samples before treatment. No undesirable changes in quality parameters and sensory analysis were detectable at fluences of 9.8 and 13.3 J/cm2, indicating that pulsed light may be a suitable alternative for the decontamination of dried parsley.

HIGHLIGHTS

Inactivation of Vibrio sp. in pure cultures and mussel homogenates using high hydrostatic pressure

The objective of this study was to determine the effect of high hydrostatic pressure (HHP) on the inactivation of Vibrio sp. in pure cultures and mussel homogenates. Four Vibrio strains including V. alginolyticus, V. cholerae, V. parahaemolyticus and V. vulnificus were used. HHP treatments were performed with both pure Vibrio sp. cultures in alkaline peptone water (2% NaCl) and artificially inoculated mussel homogenates at pressure levels of 250, 350 and 450 MPa for 1 and 3 min at 25°C. Counts of Vibrio were determined before and after treatment using drop plating method. The effect of high pressure on the reduction level significantly differed among the respective Vibrio species. Vibrio vulnificus was the most susceptible species to HHP. To achieve a >5 log reduction in mussel homogenates, pressure treatment needs to be (i) 350-450 MPa for ≥1 min at 25°C for both V. alginolyticus and V. cholerae, (ii) 250 MPa for ≥3 min or 350-450 MPa for ≥1 min for V. vulnificus and (iii) 350 MPa for ≥3 min or 450 MPa for ≥1 min for V. parahaemolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

High hydrostatic pressure (HHP) has been applied to inactivate spoilage and pathogenic micro-organisms in a variety of food products, including seafood. Vibrio sp. are frequently reported as the main cause of foodborne illness associated with consumption of raw or undercooked seafood particularly shellfish worldwide. To date, data on the inactivation of Vibrio sp. via HHP are still limited and most of the trials only investigated HHP application in oysters and clams. This study demonstrates the efficacy of HHP inactivating Vibrio sp. in both pure culture and mussel homogenates.

Eat healthy? Attitudes of the German population towards industrially produced cardioprotective food

BACKGROUND AND AIM

Cardiovascular disease (CVD) is likely to increase in incidence. Foods with cardioprotective functions, e.g. specific functional food, could reduce CVD risk factors and hence CVD incidence. Little is known about industrially modified foods with cardioprotective functions.

METHODS AND RESULTS

In a large German sample (n = 1007), attitudes of consumers in Germany towards industrially produced cardioprotective food were assessed using Cluster analyses. Consumers were contacted via telephone and interviewed using questionnaires. Overall, about 25% knew about industrially produced food with cardioprotective function. Our analysis revealed a small but determined group of consumers who think very skeptical about cardioprotective products, but we also identified a favorable group. These two groups only differed in age, with the skeptical group being ten years older.

CONCLUSIONS

The rising number of industrially modified products with potential cardioprotective benefit is met by skepticism and a lack of knowledge by German costumers. If large scale studies show health benefits of these products, these will need to be better communicated to German customers in order to address possible doubts or concerns and to encourage healthy eating habits in consumer eating behavior.

Antiviral Potential of Selected Starter Cultures, Bacteriocins and D,L-Lactic Acid

The antiviral potential of selected bacteria species [lactic acid bacteria (LAB) and micrococcaceae] was examined. By this, the effect of their cell-free supernatants as well as of certain species-related metabolites (sakacin A, nisin, and lactic acid) was investigated on different viruses after exposure at 24 °C for 3 days. Viruses were incubated with supernatants and metabolites in a dilution ratio of 1:10. Data for antiviral effects towards murine norovirus S99 (MNV), influenza A virus A/WSN/33 (H1N1), Newcastle disease virus Montana (NDV) and feline herpesvirus KS 285 (FHV) were generated in vitro simulating pH and temperature conditions according to raw sausage fermentations. Investigations showed no antiviral effect of sakacin A and nisin on MNV, H1N1, FHV and NDV. Furthermore, the antiviral potential of D,L-lactic acid was determined for MNV and H1N1. At raw sausage-related pH values (5.0-6.2) it could be shown that the virus titre for MNV and H1N1 was reduced by a maximum of 3.25 log and 2.5 log units, respectively. In addition, 29 culture supernatants of different bacteria species, mainly LAB and staphylococci, were tested for their antiviral activity against MNV. Only the cell-free supernatant of a Lb. curvatus strain showed a higher virus titre reduction of MNV by 1.25 log units compared to the control. Further studies on the characterisation of this cell-free supernatant were carried out, however, the antiviral substance could not be identified so far.

Evidence for the transmission of Salmonella from reptiles to children in Germany, July 2010 to October 2011

Binary file ES_Abstracts_Final_ECDC.txt matches

Impact of Sodium Chloride, Sucrose and Milk on Heat Stability of the Murine Norovirus and the MS2 Phage

Until now, little is known about the influence of food additives on heat inactivation of noroviruses. Only a few studies have shown a protective or inhibiting effect on virus infectivity caused by the food matrix. Therefore, the aim of this study was to examine the influence of sodium chloride, sucrose and milk on heat stability of the surrogates murine norovirus (MNV) and MS2 phage at 60 °C for 1-5 min in PBS for MNV and for 5-120 min in suspension medium buffer for MS2 phage. Different concentrations of sodium chloride (5, 10 %) and sucrose (5, 50 %) were added to the respective buffers. In addition, commercially available milk with different fat concentrations (0.3, 1.5, 3.5 %) was investigated in this study. In general, a linear titre reduction for MNV and MS2 phage could be observed, except for the heat treatment of MNV in PBS with 50 % sucrose. A protective effect of PBS with 50 % sucrose and of the matrix milk on MNV could be concluded. All other tested conditions did not show any influence on virus inactivation. However, MS2 phage did show a higher heat resistance throughout the experiments compared to MNV. In future investigations, it should be tested, whether the achieved data may be considered in risk assessments of heat-treated food products with high concentrations of sugar. Furthermore, it should be clarified, whether these results can also be referred to complex food matrices.

Low temperature and anhydrous electron microscopy techniques to observe the infection process of the bacterial pathogen Xanthomonas fragariae on strawberry leaves

Preserving the structural arrangement of the components of a bacterial infection process within a plant for microscopy study is a technical challenge because of the different requirements of each component for optimal preservation and visualization. We used low temperature scanning electron microscopy (cryo-SEM), anhydrous fixation at ambient temperature and freeze-substitution for transmission electron microscopy to examine fractured and sectioned strawberry leaves infected with Xanthomonas fragariae. Cryo-SEM images of fractured samples showed the bacterial colonization of mesophyll air spaces in the leaf, limited by the vascular bundles and the orientation and packing of bacteria in extracellular polysaccharide. Transmission electron microscopy of samples fixed using osmium tetroxide dissolved in FC-72 solvent at ambient temperature showed that the entire plant/bacteria/extracellular polysaccharide system was preserved in situ, and showed plasmolysis of mesophyll cells and disruption of organelles. In freeze-substitution samples, osmium tetroxide in FC-72 solvent gave superior preservation of the extracellular polysaccharide as compared to a conventional cocktail. In addition, strands believed to be xanthan were preferentially contrasted to show their density and orientation around the bacterial cells. We conclude that anhydrous fixation using osmium tetroxide in FC-72 at ambient temperature gave the best preservation of the entire system, and freeze-substitution using this same fixative enhanced the visualization of strands in the biofilm.

Evidence and characterization of a gene cluster required for the production of viscosin, a lipopeptide biosurfactant, by a strain ofPseudomonas fluorescens

The genetic control of viscosin production was examined in a strain of Pseudomonas fluorescens (PfA7B) that causes broccoli head rot. Viscosin is a potent lipopeptide biosurfactant that enables the bacteria to come into intimate contact with the difficult-to-wet waxy heads of broccoli. Tn5 mutagenesis completely disrupted viscosin production as shown by HPLC analysis of the mutagenized cell lysates. The Vis–mutants retained their pectolytic capability and were able to decay potato slices. On broccoli, however, the Vis–mutants caused decay of wounded florets, but the decay failed to spread to adjacent nonwounded florets as had occurred with the wild-type PfA7B. Triparental matings of the Vis–mutants with their corresponding wild-type clones and the helper Escherichia coli HB101 carrying the mobilization plasmid pPK2013 resulted in three stable viscosin-producing transconjugants that caused typical decay of broccoli tissue. Linkage maps of clones and protein profiles showed that a 25-kb chromosomal DNA region of PfA7B affected the production of three high molecular mass proteins required for viscosin synthesis. These proteins, approximately 218, 215, and 137 kDa in size, likely compose a synthetase complex that assembles the nine amino acid peptide of viscosin and subsequently attaches this to the hydrophobic fatty acid component of the molecule. A probe made from this DNA region hybridized with DNA fragments of other phytopathogenic pseudomonads to varying degrees.Key words: virulence factor, head rot, broccoli.

Detection and Quantification of Resistance of Venturia inaequalis Populations to Sterol Demethylation Inhibitors

ABSTRACT Monoconidial isolates of Venturia inaequalis were collected in 1990 and 1991 from orchards in New York, Michigan, and Nova Scotia that had never or only sporadically been treated with fungicides acting as sterol demethylation inhibitors (DMIs). Sensitivities of isolates to two representative DMIs (fenarimol and myclobutanil) were determined by a sensitivity test based on the relative growth (RG) of mycelial colonies at one discriminatory dose. Mean isolate sensitivities were not significantly different (P > 0.2) for the majority of the populations tested, and all sensitivity data obtained from these sites were combined to provide a baseline distribution of isolate sensitivities for both fenarimol and myclobutanil. The baseline distributions were compared with isolate sensitivities determined for an experimental orchard in Nova Scotia with a documented case of DMI resistance and for a commercial orchard in Michigan with a long history of DMI use and first evidence of practical DMI resistance. For both DMIs tested and in both treated orchards, frequencies of isolates with RG values <80 had decreased or only slightly increased compared to the baseline population. In contrast, frequencies of isolates with RG values >80 had increased more than 20-fold over baseline levels. Thus, isolates with RG values >80 were rated DMI resistant. The validity of a qualitative isolate classification was tested in controlled infection studies. At doses of fenarimol and myclobutanil recommended for commercial control of apple scab, reproduction of a typical sensitive isolate on treated apple leaves was suppressed completely. Lesions caused by a resistant isolate continued to expand and produced abundant conidia. Statistical analysis of orchard sensitivities revealed that the analysis of isolate counts grouped into the categories DMI sensitive or resistant was most indicative in comparisons of orchard sensitivities aimed at detection of practical DMI resistance. A high degree of cross-resistance between fenarimol and myclobutanil indicated that sensitivity tests with one of the DMIs employed as the diagnostic tool in this study can serve as a test for other DMIs.

Bacillus subtilis can modulate its capacity and specificity for protein secretion through temporally controlled expression of the sipS gene for signal peptidase I

Bacillus subtilis contains three chromosomally encoded type I signal peptidases (SipS, SipT and SipU), which remove signal peptides from secretory precursor proteins. In the present study the biological function of SipS and the regulation of its synthesis were analysed. Unlike the type I signal peptidase of Escherichia coli, SipS was essential neither for protein secretion nor viability of the cell. However, in the absence of SipS the rate of processing of several preproteins was reduced, and four of the seven major secreted proteins of B. subtilis were hardly detectable in the growth medium. Surprisingly, the processing of Bacillus amyloliquefaciens alpha-amylase and the secretion of at least two endogenous B. subtilis proteins was improved in the absence of SipS. These findings indicate that the substrate preference of SipS differs from that of SipT and SipU, and that SipS is an important factor determining the efficiency of protein secretion in B. subtilis. SipS is transcribed in a growth phase- and medium-dependent manner. In minimal medium, the growth phase-dependent transcription of sipS is controlled by the DegS-DegU two-component regulatory system, indicating that the expression of sipS is regulated by the same factors that control the expression of most genes for secreted degradative enzymes. Our observations suggest that B. subtilis can modulate its capacity and specificity for protein secretion through the controlled expression of sipS.