Omics-based monitoring of microbial dynamics across the food chain for the improvement of food safety and quality

The diffusion of high-throughput sequencing has dramatically changed the study of food microbial ecology. Amplicon-based description of the microbial community may be routinary implemented in the food industry to understand how the processing parameters and the raw material quality may affect the microbial community of the final product, as well as how the community changes during the shelf-life. In addition, application of shotgun metagenomics may represent an invaluable resource to understand the functional potential of the microbial community, identifying the presence of spoilage-associated activities or genes related to pathogenesis. Finally, retrieving Metagenome-Assembled Genomes (MAGs) of relevant species may be useful for strain-tracking along the food chain and in case of food poisoning outbreaks. This review gives an overview of the possible applications of sequencing-based approaches in the study of food microbial ecology, highlighting limitations that still prevent the spreading of these techniques to the food industry

Specific Microbial Communities Are Selected in Minimally-Processed Fruit and Vegetables according to the Type of Product

Fruits and vegetables (F&V) products are recommended for the daily diet due to their low caloric content, high amount of vitamins, minerals and fiber. Furthermore, these foods are a source of various phytochemical compounds, such as polyphenols, flavonoids and sterols, exerting antioxidant activity. Despite the benefits derived from eating raw F&V, the quality and safety of these products may represent a source of concern, since they can be quickly spoiled and have a very short shelf-life. Moreover, they may be a vehicle of pathogenic microorganisms. This study aims to evaluate the bacterial and fungal populations in F&V products (i.e., iceberg lettuces, arugula, spinaches, fennels, tomatoes and pears) by using culture-dependent microbiological analysis and high-throughput sequencing (HTS), in order to decipher the microbial populations that characterize minimally-processed F&V. Our results show that F&V harbor diverse and product-specific bacterial and fungal communities, with vegetables leaf morphology and type of edible fraction of fruits exerting the highest influence. In addition, we observed that several alterative (e.g., Pseudomonas and Aspergillus) and potentially pathogenic taxa (such as Staphylococcus and Cladosporium) are present, thus emphasizing the need for novel product-specific strategies to control the microbial composition of F&V and extend their shelf-life

Design of bioactive biopolymer coating based on Latilactobacillus curvatus 54M16 producer of bacteriocins to preserve the safety of minimally processed fennel

In this study Latilactobacillus curvatus 54M16 (LAB) producing bacteriocins has been incorporated into a sodium caseinate (SC)/guar gum (GG)/beeswax (BW) blend to develop a bioactive film/coating. Moreover, the coating capacity of preserving the safety and quality of minimally processed fennel has been investigated. Results showed significant antimicrobial activity of the bioactive film against L. innocua C6 during 28 days of storage at 4 ◦C, 10 ◦C, 20 ◦C and 30 ◦C. The presence of LAB did not affect the moisture content, thickness, color, and solubility of the SC/GG/BW films, whereas caused a reduction of the film’s stiffness and water vapor permeability. Counts of L. innocua on fennels processed with the active coating showed a significant reduction of about 2 log cycles at the end of storage with respect to the control samples for which L. innocua ranged from 3.42 to 4.13 log CFU/cm2 . Moreover, microbial diversity dramatically decreased in samples coated with antimicrobial film, that were dominated by Lactobacillus sp. In conclusion, the developed bioactive coating can be used as an antimicrobial coating to improve minimally processed fennel safet

Evidence of virulence and antibiotic resistance genes from the microbiome mapping in minimally processed vegetables producing facilities

Daily consumption of fresh vegetables is highly recommended by international health organizations, because of their high content of nutrients. However, fresh vegetables might harbour several pathogenic microorganisms or contribute to spread antibiotic resistance, thus representing a hazard for consumers. In addition, little is known about the transmission routes of the residential microbiome from the food handling environment to vegetables. Therefore, we collected environmental and food samples from three manufactures producing fresh vegetables to estimate the relevance of the built environment microbiome on that of the finished products. Our results show that food contact surfaces sampled after routine cleaning and disinfection procedures host a highly diverse microbiome, including pathogens such as the enterotoxigenic Bacillus cereus sensu stricto. In addition, we provide evidence of the presence of a wide range of antibiotic resistance and virulence genes on food contact surfaces associated with multiple taxa, thus supporting the hypothesis that selection of resistant and pathogenic taxa might occur on sanitized surfaces. This study also highlights the potential of microbiome mapping routinely applied in food industries monitoring programs to ensure food safety

Therapeutic effects elicited by the probiotic Lacticaseibacillus rhamnosus GG in children with atopic dermatitis. The results of the ProPAD trial

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 20% of the pediatric population associated with alteration of skin and gut microbiome. Probiotics have been proposed for AD treatment. The ProPAD study aimed to investigate the therapeutic effects of the probiotic Lacticaseibacillus rhamnosus GG (LGG) in children with AD

Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)

This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands

Psychrotrophic Bacteria Equipped with Virulence and Colonization Traits Populate the Ice Cream Manufacturing Environment

Several microbial taxa have been associated with food processing facilities, and they might resist by attaching on tools and equipment even after sanitation procedures, producing biofilms that adhere to the surfaces and might embed other microorganisms, including spoilers and pathogens. There is increasing evidence that these communities can be transferred to the final product. To explore the microbial contamination routes in a facility producing ice creams, we collected foods and environmental swabs from industrial surfaces of equipment and tools and performed taxonomic and functional analyses of the microbial DNA extracted from the environmental samples. Our results suggest that complex communities dominated by psychrotrophic bacteria (e.g., Pseudomonas and Acinetobacter spp.) inhabit the food processing environment, and we demonstrate that these communities might be transferred from the surfaces to the products. Functional analysis performed on environmental samples highlighted the presence of several genes linked to antimicrobial resistance and adherence on abiotic surfaces; such genes were more abundant on food contact (FC) than on other surfaces. Metagenome-assembled genomes (MAGs) of Pseudomonas stutzeri showed genes linked with biofilm formation and motility, which are surely linked to colonizing capabilities in the processing lines. The study highlights clear potential advantages of applying microbiome mapping in the food industry for source tracking of microbial contamination and for planning appropriate ad hoc sanitization strategies. IMPORTANCE Several microbial species might permanently establish in food processing facilities, thus contributing to food loss. In fact, food contact surfaces might transfer microorganisms to intermediates and products, potentially representing a hazard to human health. In this work, we provide evidence of the existence of complex microbial communities overcoming sanitation in an ice cream-producing facility. These communities harbored several genes that could potentially lead to attachment to surfaces and antimicrobial resistance. Also, prediction of routes of contamination showed that several potential spoilage taxa might end up in the final product. Importantly, in this work, we show that mapping the environmental microbiome is a high-resolution technique that might help food business operators ensure food quality and safety through detection of potentially hazardous microorganisms

Stuck or sluggish fermentations in home-made beers: Beyond the surface

In the last several years, the popularity of homebrewed beers has skyrocketed. However, this type of product is extremely vulnerable to microbial deterioration. Twelve homemade beers, some characterized by defects or stuck fermentation, were analysed by using a polyphasic approach encompassing culturomics and culture-independent techniques to better understand mechanisms that drive microbiota evolution throughout production and to highlight determinants responsible for crowning with success. Two sour beers, one apple-flavoured ale, two Italian grape ales, and seven standard ales were sampled. Microbiological characterization was obtained by plating on nine different media coupled with High- throughput sequencing analysis of fungal and bacterial communities by targeting ITS1–2 and the V3–V4 re- gions of the 16S rRNA, respectively. 2 7 TotalmicrofloraonPCAlargelyvariedamongsamples,rangingfrom<10 CFU/mLuptoaround10 CFU/mL often reflecting yeast counts on WL and LM. LAB population's levels on MRS and SDBm did not overlap, with the counts on the latter being even 5 Log CFU/mL greater. Acetic Acid bacteria were retrieved in Sour beers, as well as in one IGA, even though acetic acid was not detectable by HPLC in this last sample. Brettanomyces spp. were only found in sour beers, as expected, whereas Enterobacteriaceae were never counted. A total of 63 yeasts were randomly isolated from countable plates. Saccharomyces cerevisiae and Wick- erhamomyces anomalus were the most frequently isolated species. In many cases, Interdelta analysis biotyping of S. cerevisiae isolates consistently allowed the detection of the starter strain. By HST S. cerevisiae dominated the mycobiota in four samples, even if in one of them residual maltose and ethanol contents suggested a stuck fermentation. W. anomalus was found to be the dominant species in two beers. Fifty-five LAB cultures were isolated and identified. Pediococcus damnosus was the only species retrieved in sour beers and two Ales, while Levilactobacillus brevis was found in two Ale samples. HTS did not confirm this result in one Ale sample since the genus Panotea spp. accounted for over 90 % of the microbiota. Enterobac- teriaceae which were never counted dominated the microbiome of two Ale beers. Biogenic amines content largely varied with three Ale samples greatly contaminated. Based on chemical and microbiological outcomes only one beer ASAle out of 12 could be considered acceptable. Furthermore, the widespread presence of LAB by culturomics and Enterobacteriaceae by HTS raises concerns about the final products' safety

Effect of Anesthetic Drugs on Vestibular Evoked Myogenic PotentialRecording

The human saccule has preserved the ancestral ability to respond to high-intensity acoustic stimulations, generating a contraction reflex of the cervical tract muscles. Recording the muscular bioelectric potentials following saccular stimulation allows the evidence of the vestibular-evoked myogenic potentials (VEMPs). The aim of this study was to record VEMPs in alert and anesthetized guinea pigs to evaluate the possible different impacts of some anesthetic drugs on VEMP recording. Sixteen guinea pigs, divided into four groups, were employed for the study. Each group underwent general anesthesia induced using different pharmacological regimens; auditory and vestibular functions were examined with Auditory Brain Response (ABR) and VEMP methods. The analysis of the results showed that the VEMPs recording performance was strictly related to the alert status of the guinea pigs: VEMPs were not recordable during anesthesia while reappeared at awakening, with the same temporal and morphological characteristics of pre-anesthesia. ABR was instead normally present during anesthesia without showing any differences with all the various anesthetic drugs employed. These results prompted us to conclude that anesthetic drugs cause the disappearance of saccular reflex in guinea pigs, not minding the specific type of drugs employed. This evidence, in agreement with the data available in literature for humans, induces and encourages future studies about sacculocollic reflex and its possible application in clinical practice