Unexpected role of pig nostrils in the clonal and plasmidic dissemination of extended-spectrum beta-lactamase-producing Escherichia coli at farm level.

The presence of methicillin-resistant or -susceptible S. aureus in pig nostrils has been known for a long time, but the occurrence of extended-spectrum beta-lactamase (ESBL)-producing E. coli has hardly been investigated. Here, we collected 25 E. coli recovered from nasal samples of 40 pigs/10 farmers of four farms. Nine ESBL-producing isolates belonging to ST48, ST117, ST847, ST5440, ST14914 and ST10 were retrieved from seven pigs. All blaESBL genes (blaCTX-M-32,blaCTX-M-14,blaCTX-M-1,blaCTX-M-65, and blaSHV-12) were horizontally transferable by conjugation through plasmids belonging to IncI1 (n=3), IncX1 (n=3) and IncHI2 (n=1) types. IncI1-plasmids displayed different genetic environments: i) IS26-blaSHV-12-deoR-IS26, ii) wbuC-blaCTX-M-32-ISKpn26 (IS5), and iii) IS930-blaCTX-M-14-IS26. The IncHI2-plasmid contained the genetic environment IS903-blaCTX-M-65-fipA with multiple resistance genes associated either to: a) Tn21-like transposon harbouring genes conferring aminoglycosides/beta-lactams/chloramphenicol/macrolides resistance located on two atypical class 1 integrons with an embedded ΔTn5393; or b) Tn1721-derived transposon displaying an atypical class 1 integron harbouring aadA2-arr3-cmlA5-blaOXA-10-aadA24-dfrA14, preceding the genetic platform IS26-blaTEM-95-tet(A)-lysR-floR-virD2-ISVsa3-IS3075-IS26-qnrS1, as well as the tellurite resistance module. Other plasmids harbouring clinically relevant genes were detected, such as a ColE-type plasmid carrying the mcr-4.5 gene. Chromosomally encoded genes (fosA7) or integrons (intI1-dfrA1-aadA1-qacE-sul1/intI1-IS15-dfrA1-aadA2) were also identified. Finally, an IncY plasmid harbouring a class 2 integron (intI2-dfrA1-sat2-aadA1-qacL-IS406-sul3) was detected but not associated with a blaESBL gene. Our results evidence that pig nostrils might favour the spread of ESBL-E. coli and mcr-mediated colistin-resistance. Therefore, enhanced monitoring should be considered, especially in a sector where close contact between animals in intensive farming increases the risk of spreading antimicrobial resistance.

Comparative genomics of Staphylococcus aureus strains from wild birds and pig farms elucidates levels of mobilomes, antibiotic pressure and host adaptation.

OBJECTIVES: This study characterized the resistome, mobilome and phylogenomic relatedness of Staphylococcus aureus strains previously obtained from healthy nestling storks (HNS), pigs (HP) and pig farmers (HPF) to analyse possible transmission pathways of S. aureus with implications for the spread of antimicrobial resistance. METHODS: The genomic contents of 52 S. aureus strains obtained from the nasal cavity of HNS, HP and HPF in Spain were sequenced using the Illumina NextSeq platform to characterize their resistome, virulome and mobile genetic elements. The relatedness of strains was assessed by core-genome single nucleotide polymorphisms (SNPs). RESULTS: The frequencies of multidrug-resistance phenotype and transposons were significantly lower in strains from HNS than in those from HP and HPF (P < 0.005). However, the presence of human immune evasion cluster genes in S. aureus strains from HNS was significantly higher than in those from HP and HPF (P < 0.005). Interestingly, the frequencies of plasmids and phages were not significantly associated with the host (P > 0.05). The phylogenetic analysis identified a cluster of all the MSSA-CC398 strains carrying φSa3 and ermT on rep13 separately from the two MRSA-CC398 strains (carrying ermT on repUS18). Highly related MRSA-CC398 strains were detected in some pigs and related farmers (<10 SNPs). CONCLUSION: This study confirms high-level antibiotic selection in S. aureus in HP and HPF in comparison to HNS. Furthermore, our findings highlight the continuous transmission of MRSA-CC398 in the pig-to-human interface and MSSA-CC398 with human adaptation markers in HNS. Molecular surveillance of S. aureus using the One Health model is required to establish appropriate control strategies.

Self-Renewal Inhibition in Breast Cancer Stem Cells: Moonlight Role of PEDF in Breast Cancer.

Breast cancer is the leading cause of death among females in developed countries. Although the implementation of screening tests and the development of new therapies have increased the probability of remission, relapse rates remain high. Numerous studies have indicated the connection between cancer-initiating cells and slow cellular cycle cells, identified by their capacity to retain long labeling (LT+). In this study, we perform new assays showing how stem cell self-renewal modulating proteins, such as PEDF, can modify the properties, percentage of biomarker-expressing cells, and carcinogenicity of cancer stem cells. The PEDF signaling pathway could be a useful tool for controlling cancer stem cells' self-renewal and therefore control patient relapse, as PEDF enhances resistance in breast cancer patient cells' in vitro culture. We have designed a peptide consisting of the C-terminal part of this protein, which acts by blocking endogenous PEDF in cell culture assays. We demonstrate that it is possible to interfere with the self-renewal capacity of cancer stem cells, induce anoikis in vivo, and reduce resistance against docetaxel treatment in cancer patient cells in in vitro culture. We have also demonstrated that this modified PEDF protein produces a significant decrease in the percentage of expressed cancer stem cell markers.

Within-Host Diversity of Coagulase-Negative Staphylococci Resistome from Healthy Pigs and Pig Farmers, with the Detection of cfr-Carrying Strains and MDR-S. borealis.

The ecology and diversity of resistome in coagulase-negative staphylococci (CoNS) from healthy pigs and pig farmers are rarely available as most studies focused on the livestock-associated methicillin-resistant S. aureus. This study aims to characterize the antimicrobial resistance (AMR) mechanisms, intra-host species diversity (more than one species in a host), and intra-species AMR diversity (same species with more than one AMR profile) in CoNS recovered from the nasal cavities of healthy pigs and pig farmers. One-hundred-and-one CoNS strains previously recovered from 40 pigs and 10 pig farmers from four Spanish pig farms were tested to determine their AMR profiles. Non-repetitive strains were selected (n = 75) and their AMR genes, SCCmec types, and genetic lineages were analyzed by PCR/sequencing. Of the non-repetitive strains, 92% showed a multidrug resistance (MDR) phenotype, and 52% were mecA-positive, which were associated with SCCmec types V (46.2%), IVb (20.5%), and IVc (5.1%). A total of 28% of the pigs and pig farmers had intra-host species diversity, while 26% had intra-species AMR diversity. High repertoires of AMR genes were detected, including unusual ones such as tetO, ermT, erm43, and cfr. Most important was the detection of cfr (in S. saprophyticus and S. epidermidis-ST16) in pigs and pig farmers; whereas MDR-S. borealis strains were identified in pig farmers. Pig-to-pig transmission of CoNS with similar AMR genes and SCCmec types was detected in 42.5% of pigs. The high level of multidrug, within-host, and intra-species resistome diversity in the nasal CoNS highlights their ability to be AMR gene reservoirs in healthy pigs and pig farmers. The detection of MDR-S. borealis and linezolid-resistant strains underscore the need for comprehensive and continuous surveillance of MDR-CoNS at the pig farm level.

Nasal staphylococci community of healthy pigs and pig-farmers in Aragon (Spain). Predominance and within-host resistome diversity in MRSA-CC398 and MSSA-CC9 lineages.

This study investigated the diversity and carriage rate of nasal Staphylococcus spp., and within-host variability of antimicrobial resistance (AMR), virulence determinants, immune evasion cluster (IEC) types and genetic lineages of S. aureus isolates. Also, the co-carriage rate of CoNS with S. aureus in the same nasal niche of healthy pigs and pig-farmers were studied in four pig-farms (A-D) in Aragon (Spain). Nasal samples of 40 pigs (10 pigs/farm) and 10 pig-farmers (2-3/farm) were collected for staphylococci recovery and isolates (up to 9 per sample) were identified by MALDI-TOF-MS. The virulence and AMR genes and spa-types of S. aureus isolates were investigated by PCR/sequencing. Of the 243 staphylococci identified (10 different species), 142 were S. aureus and 51 distinct isolates were selected for further characterization (that corresponded to one S. aureus/sample or more than one if they showed different AMR phenotypes). The highest carriage rate in pigs was S. aureus (65%) and S. chromogenes (22.5%), whereas in the pig-farmers, S. aureus (80%) and S. epidermidis (40%). Methicillin-resistant S. aureus (MRSA) were detected in 60% of pigs and 70% of pig-farmers. Only six S. aureus isolates were methicillin-susceptible (MSSA), all from farm-C. A multidrug resistance (MDR) phenotype was detected in all MRSA and in 83.3% of the MSSA isolates. All MRSA isolates were CC398 with spa-type t011 being the predominant (92.7%), while t034, t1451 (only in pig-farmers) and t4571 (in pigs) were also found. MSSA-CC9 isolates (t191, t1430) were detected in farm-C. All S. aureus isolates were negative for luk-S/F-PV, tst, and scn genes, except one MSSA-CC45-t065-IEC-type C isolate from a pig-farmer. About 34.6% and 75.0% of the pigs and pig-farmers S. aureus carriers, respectively, harboured within-host varied spa-types or resistomes. Moreover, 40% of pigs and pig-farmers with MRSA-CC398 had no CoNS nasal co-carriage, and 23.3% had ≥2 CoNS carriage. Conversely, only 16.7% of MSSA carriers had no CoNS co-carriage, whereas 50% had ≥2 CoNS carriages. The very high MRSA level and within-host resistome diversities highlight the need for multiple samplings to account for the dynamics of AMR crisis and control of inter-host transmission of S. aureus in pig-farms using "One Health" approach.

Nasotracheal enterococcal carriage and resistomes: detection of optrA-, poxtA- and cfrD-carrying strains in migratory birds, livestock, pets, and in-contact humans in Spain.

This study determined the carriage rates and antimicrobial resistance (AMR) genes of enterococci from nasotracheal samples of three healthy animal species and in-contact humans. Nasal samples were collected from 27 dog-owning households (34 dogs, 41 humans) and 4 pig-farms (40 pigs, 10 pig-farmers), and they were processed for enterococci recovery (MALDI-TOF-MS identification). Also, a collection of 144 enterococci previously recovered of tracheal/nasal samples from 87 white stork nestlings were characterized. The AMR phenotypes were determined in all enterococci and AMR genes were studied by PCR/sequencing. MultiLocus-Sequence-Typing was performed for selected isolates. About 72.5% and 60% of the pigs and pig-farmers, and 29.4% and 4.9%, of healthy dogs and owners were enterococci nasal carriers, respectively. In storks, 43.5% of tracheal and 69.2% of nasal samples had enterococci carriages. Enterococci carrying multidrug-resistance phenotype was identified in 72.5%/40.0%/50.0%/23.5%/1.1% of pigs/pig-farmers/dogs/dogs' owners/storks, respectively. Of special relevance was the detection of linezolid-resistant enterococci (LRE) in (a) 33.3% of pigs (E. faecalis-carrying optrA and/or cfrD of ST59, ST330 or ST474 lineages; E. casseliflavus-carrying optrA and cfrD); (b) 10% of pig farmers (E. faecalis-ST330-carrying optrA); (c) 2.9% of dogs (E. faecalis-ST585-carrying optrA); and (d) 1.7% of storks (E. faecium-ST1736-carrying poxtA). The fexA gene was found in all optrA-positive E. faecalis and E. casseliflavus isolates, while fexB was detected in the poxtA-positive E. faecium isolate. The enterococci diversity and AMR rates from the four hosts reflect differences in antimicrobial selection pressure. The detection of LRE carrying acquired and transferable genes in all the hosts emphasizes the need to monitor LRE using a One-Health approach.

Experimental rice seed aging under elevated oxygen pressure: Methodology and mechanism.

Seed aging during storage results in loss of vigor and germination ability due to the accumulation of damage by oxidation reactions. Experimental aging tests, for instance to study genetic variation, aim to mimic natural aging in a shorter timeframe. As the oxidation rate is increased by elevating the temperature, moisture, and oxygen levels, this study aimed to (1) investigate the effect of experimental rice seed aging by an elevated partial pressure of oxygen (EPPO), (2) elucidate the mechanism of dry-EPPO aging and (3) compare aging under dry-EPPO conditions to aging under traditional moist-controlled deterioration (CD) conditions and to long-term ambient storage. Dry seeds from 20 diverse rice accessions were experimentally aged under EPPO (200 times higher oxygen levels), at 50% relative humidity (RH), along with storage under high-pressure nitrogen gas and ambient conditions as controls. While no decline in germination was observed with ambient storage, there was significant aging of the rice seeds under EPPO storage, with considerable variation in the aging rate among the accessions, with an average decline toward 50% survival obtained after around 21 days in EPPO storage and total loss of germination after 56 days. Storage under high-pressure nitrogen gas resulted in a small but significant decline, by an average of 5% germination after 56 days. In a second experiment, seven rice seed lots were stored under EPPO as compared to a moist-CD test and two different long-term ambient storage conditions, i.e., conditioned warehouse seed storage (CWSS) and traditional rice seed storage (TRSS). Untargeted metabolomics (with identification of lipid and volatile compounds profiles) showed a relatively high increase in levels of oxidized lipids and related volatiles under all four storage conditions. These compounds had a high negative correlation with seed viability, indicating oxidation as a main deteriorating process during seed aging. Correlation analysis indicated that EPPO storage at 50% RH is more related to aging under TRSS at 60% and CD-aging at 75% ERH rather than CWSS at 40% ERH. In conclusion, aging rice seeds under EPPO conditions is a suitable experimental aging method for analyzing variation among seed lots or genotypes for longevity under storage.

Flavor Profiling Using Comprehensive Mass Spectrometry Analysis of Metabolites in Tomato Soups.

Trained sensory panels are regularly used to rate food products but do not allow for data-driven approaches to steer food product development. This study evaluated the potential of a molecular-based strategy by analyzing 27 tomato soups that were enhanced with yeast-derived flavor products using a sensory panel as well as LC-MS and GC-MS profiling. These data sets were used to build prediction models for 26 different sensory attributes using partial least squares analysis. We found driving separation factors between the tomato soups and metabolites predicting different flavors. Many metabolites were putatively identified as dipeptides and sulfur-containing modified amino acids, which are scientifically described as related to umami or having "garlic-like" and "onion-like" attributes. Proposed identities of high-impact sensory markers (methionyl-proline and asparagine-leucine) were verified using MS/MS. The overall results highlighted the strength of combining sensory data and metabolomics platforms to find new information related to flavor perception in a complex food matrix.

Systematic selection of competing metabolomics methods in a metabolite-sensory relationship study.

INTRODUCTION: The relationship between the chemical composition of food products and their sensory profile is a complex association confronting many challenges. However, new untargeted methodologies are helping correlate metabolites with sensory characteristics in a simpler manner. Nevertheless, in the pilot phase of a project, where only a small set of products are used to explore the relationships, choices have to be made about the most appropriate untargeted metabolomics methodology. OBJECTIVE: To provide a framework for selecting a metabolite-sensory methodology based on: the quality of measurements, the relevance of the detected metabolites in terms of distinguishing between products or in terms of whether they can be related to the sensory attributes of the products. METHODS: In this paper we introduce a systematic approach to explore all these different aspects driving the choice for the most appropriate metabolomics method. RESULTS: As an example we have used a tomato soup project where the choice between two sampling methods (SPME and SBSE) had to be made. The results are not always consistently pointing to the same method as being the best. SPME was able to detect metabolites with a better precision, SBSE seemed to be able to provide a better distinction between the soups. CONCLUSION: The three levels of comparison provide information on how the methods could perform in a follow up study and will help the researcher to make a final selection for the most appropriate method based on their strengths and weaknesses.

Stir bar sorptive extraction of aroma compounds in soy sauce: Revealing the chemical diversity.

Fermented soy sauce is used worldwide to enhance the flavour of many dishes. Many types of soy sauce are on the market, and their differences are mostly related to the country of origin, the production process applied and the ratio of ingredients used. Consequently, several aromas, tastes, colours, and textures are obtained. Nowadays, soy sauce can also be produced without microorganisms making the process shorter and cheaper. However, flavour may be lost. We have carried out a comprehensive metabolomics analysis of volatile compounds using stir bar sorptive extraction (SBSE)-GC-MS to relate differences in volatile content to production history and origin. The results revealed major differences between fermented and non-fermented soy sauces, and a list of volatile compounds is reported as being characteristic of each type. This study was able to relate volatiles to the production process using SBSE-GC-MS and to aroma characteristics using GC-O-MS.

End of Life Intervention Program During COVID-19 in Vall d'Hebron University Hospital.

Introduction: The coronavirus disease 19 (COVID-19) and its consequences have placed our societies and healthcare systems under pressure. Also, a major impact on the individual and societal experience of death, dying, and bereavement has been observed. Factors such as social distancing, unexpected death or not being able to say goodbye, which might predict Prolonged Grief Disorder (PGD), are taking place. Moreover, hospitals have become a habitual place for End of Life (EOL) situations but not in the usual conditions because, for example, mitigation measures prevent families from being together with hospitalized relatives. Therefore, we implemented an EOL program with a multidisciplinary team involving health social workers (HSW) and clinical psychologists (CP) in coordination with the medical teams and nursing staff. Objectives: We aim to describe an EOL intervention program implemented during COVID-19 in the Vall d'Hebron University Hospital (HUVH). We present its structure, circuit, and functions. Descriptive analyses of the sample and the interventions that required psychological and social attention are reported. Material and methods: The total sample consists of 359 relatives of 219 EOL patients. Inclusion criteria were families cared for during the COVID-19 pandemic with family patients admitted to the HUVH in an EOL situation regardless of whether or not the patient was diagnosed with COVID-19. Results: Our program is based on family EOL care perceptions and the COVID-19 context features that hinder EOL situations. The program attended 219 families, of which 55.3% were COVID-19 patients and 44.7% had other pathologies. The EOL intervention program was activated in most of the EOL situations, specifically, in 85% of cases, and 78% of relatives were able to come and say goodbye to their loved ones. An emotional impact on the EOL team was reported. It is necessary to dignify the EOL situation in the COVID-19 pandemic, and appropriate psychosocial attention is needed to try to minimize future complications in grief processes and mitigate PGD.

S. pseudintermedius and S. aureus lineages with transmission ability circulate as causative agents of infections in pets for years.

BACKGROUND: Staphylococcus pseudintermedius (SP) and Staphylococcus aureus (SA) are common colonizers of companion animals, but they are also considered opportunistic pathogens, causing diseases of diverse severity. This study focused on the identification and characterization of 33 coagulase-positive staphylococci isolated from diseased pets (28 dogs and five cats) during 2009-2011 in a veterinary hospital in Spain in order to stablish the circulating lineages and their antimicrobial resistance profile. RESULTS: Twenty-eight isolates were identified as SP and five as SA. Nine methicillin-resistant (MR) isolates (27%) carrying the mecA gene were detected (eight MRSP and one MRSA). The 55% of SP and SA isolates were multidrug-resistant (MDR). MRSP strains were typed as ST71-agrIII-SCCmecII/III-(PFGE) A (n=5), ST68-agrIV-SCCmecV-B1/B2 (n=2), and ST258-agrII-SCCmecIV-C (n=1). SP isolates showed resistance to the following antimicrobials [percentage of resistant isolates/resistance genes]: penicillin [82/blaZ], oxacillin [29/mecA] erythromycin/clindamycin [43/erm(B)], aminoglycosides [18-46/aacA-aphD, aphA3, aadE], tetracycline [71/tet(M), tet(K)], ciprofloxacin [29], chloramphenicol [29/catpC221], and trimethoprim-sulfamethoxazole [50/dfrG, dfrK]. The dfrK gene was revealed as part of the radC-integrated Tn559 in two SP isolates. Virulence genes detected among SP isolates were as follow [percentage of isolates]: siet [100], se-int [100], lukS/F-I [100], seccanine [7], and expB [7]. The single MRSA-mecA detected was typed as t011-ST398/CC398-agrI-SCCmecV and was MDR. The methicillin-susceptible SA isolates were typed as t045-ST5/CC5 (n=2), t10576-ST1660 (n=1), and t005-ST22/CC22 (n=1); the t005-ST22 feline isolate was PVL-positive and the two t045-ST45 isolates were ascribed to Immune Evasion Cluster (IEC) type F. Moreover, the t10576-ST1660 isolate, of potential equine origin, harbored the lukPQ and scneq genes. According to animal clinical history and data records, several strains seem to have been acquired from different sources of the hospital environment, while some SA strains appeared to have a human origin. CONCLUSIONS: The frequent detection of MR and MDR isolates among clinical SP and SA strains with noticeable virulence traits is of veterinary concern, implying limited treatment options available. This is the first description of MRSA-ST398 and MRSP-ST68 in pets in Spain, as well the first report of the dfrK-carrying Tn559 in SP. This evidences that current transmissible lineages with mobilizable resistomes have been circulating as causative agents of infections among pets for years.

Chemical and Sensory Characteristics of Soy Sauce: A Review.

Soy sauce is a fermented product, and its flavor is a complex mixture of individual senses which, in combination, create a strong palatable condiment for many Eastern and Western dishes. This Review focuses on our existing knowledge of the chemical compounds present in soy sauce and their potential relevance to the flavor profile. Taste is dominated by umami and salty sensations. Free amino acids, nucleotides, and small peptides are among the most important taste-active compounds. Aroma is characterized by caramel-like, floral, smoky, malty, and cooked potato-like odors. Aroma-active volatiles are chemically diverse including acids, alcohols, aldehydes, esters, furanones, pyrazines, and S-compounds. The origin of all compounds relates to both the raw ingredients and starter cultures used as well as the parameters applied during production. We are only just starting to help develop innovative studies where we can combine different analytical platforms and chemometric analysis to link flavor attributes to chemical composition.

Comparison of volatile trapping techniques for the comprehensive analysis of food flavourings by Gas Chromatography-Mass Spectrometry.

Trapping volatiles is a convenient way to study aroma compounds but it is important to determine which volatile trapping method is most comprehensive in extracting the most relevant aroma components when investigating complex food products. Awareness of their limitations is also crucial. (Un)targeted metabolomic approaches were used to determine the volatile profiles of two commercial flavourings. Four trapping techniques were tested as was the addition of salt to the mixture. Comprehensiveness and repeatability were compared and SBSE proved particularly suitable for extracting components such as polysulfides, pyrazines and terpene alcohols, and provided an overall broader chemical spectrum. SPME proved to be more suitable in extracting sesquiterpenes and DHS in extracting monoterpenes. Adding salt to the sample had only quantitative effects on volatiles as detected by SPME. These results help clarify the advantages and limitations of different trapping techniques and hence deliver a valuable decision tool for food matrix analysis.

Pedf derived peptides affect colorectal cancer cell lines resistance and tumour re-growth capacity.

Relapse after chemotherapy treatment depends on the cancer initiating cells (CICs). PEDF (Pigmented Epithelium Derived Factor) is an anti-angiogenic, neurotrophic and self-renewal regulator molecule, also involved in CICs biology. Acute and chronic exposition of colon cancer cell lines to CT/CTE PEDF-derived peptides decreased drug-resistance to conventional colorectal cancer treatments, such as oxaliplatin or irinotecan. We confirmed a reduction in the irinotecan and oxaliplatin IC50 doses for all tested tumour cell lines. After xenograft transplantation, CT/CTE treatments also produced a reduction in resistance to conventional chemotherapy treatments as in culture-assays. Metastatic capacity of these treated cell lines was also depleted. The PEDF signaling pathway could be a future therapeutic tool for use as an adjuvant therapy that decreases IC50 dosis, adverse effects and treatment costs. This pathway could also be involved in an increase of the time relapse in patients, decreased tumourigenicity, and decreased capacity to produce metastasis.

Mass spectrometry-based metabolomics of volatiles as a new tool for understanding aroma and flavour chemistry in processed food products.

BACKGROUND: When foods are processed or cooked, many chemical reactions occur involving a wide range of metabolites including sugars, amino acids and lipids. These chemical processes often lead to the formation of volatile aroma compounds that can make food tastier or may introduce off-flavours. Metabolomics tools are only now being used to study the formation of these flavour compounds in order to understand better the beneficial and less beneficial aspects of food processing. AIM OF REVIEW: To provide a critical overview of the diverse MS-based studies carried out in recent years in food metabolomics and to review some biochemical properties and flavour characteristics of the different groups of aroma-related metabolites. A description of volatiles from processed foods, and their relevant chemical and sensorial characteristics is provided. In addition, this review also summarizes the formation of the flavour compounds from their precursors, and the interconnections between Maillard reactions and the amino acid, lipid, and carbohydrate degradation pathways. KEY SCIENTIFIC CONCEPTS OF REVIEW: This review provides new insights into processed ingredients and describes how metabolomics will help to enable us to produce, preserve, design and distribute higher-quality foods for health promotion and better flavour.

Laser Ablation Electrospray Ionization-Mass Spectrometry Imaging (LAESI-MS) for Spatially Resolved Plant Metabolomics.

There is increasing demand to bring the level of metabolomics analyses down to the tissue or cell level. Significant progress has been made involving the use of in situ metabolomics imaging techniques where no tissue collection or extraction is needed prior to analysis. In this chapter we describe a relatively new method which is simple and easy to use. No ectopic matrix or vacuum is required, and analyses are performed with living plant materials directly from (or even still attached to) the plant. Although relatively straightforward, there are still a few caveats as regards this method which are described at the end of the chapter.

The tomato MAX1 homolog, SlMAX1, is involved in the biosynthesis of tomato strigolactones from carlactone.

Strigolactones (SLs) are rhizosphere signalling molecules exuded by plants that induce seed germination of root parasitic weeds and hyphal branching of arbuscular mycorrhiza. They are also phytohormones regulating plant architecture. MORE AXILLARY GROWTH 1 (MAX1) and its homologs encode cytochrome P450 (CYP) enzymes that catalyse the conversion of the strigolactone precursor carlactone to canonical strigolactones in rice (Oryza sativa), and to an SL-like compound in Arabidopsis. Here, we characterized the tomato (Solanum lycopersicum) MAX1 homolog, SlMAX1. The targeting induced local lesions in genomes method was used to obtain Slmax1 mutants that exhibit strongly reduced production of orobanchol, solanacol and didehydro-orobanchol (DDH) isomers. This results in a severe strigolactone mutant phenotype in vegetative and reproductive development. Transient expression of SlMAX1 - together with SlD27, SlCCD7 and SlCCD8 - in Nicotiana benthamiana showed that SlMAX1 catalyses the formation of carlactonoic acid from carlactone. Plant feeding assays showed that carlactone, but not 4-deoxy-orobanchol, is the precursor of orobanchol, which in turn is the precursor of solanacol and two of the three DDH isomers. Inhibitor studies suggest that a 2-oxoglutarate-dependent dioxygenase is involved in orobanchol biosynthesis from carlactone and that the formation of solanacol and DDH isomers from orobanchol is catalysed by CYPs.

Effect of dietary fiber (inulin) addition on phenolics and in vitro bioaccessibility of tomato sauce.

The effect of the addition of inulin (5 and 10%) on the phenolic content and in vitro gastrointestinal digestion of tomato sauces has been investigated. Results have shown that the addition of inulin to tomato sauce significantly decreased the total phenolic content (57-68%), total flavonoid content (48-60%), and total antioxidant capacity (49-61%). Similarly, all assays of the sauce containing both 5% and 10% inulin, showed a slight decrease during in vitro gastrointestinal digestion of tomato sauces. Higher levels of inulin added to tomato sauce resulted in the greatest decrease in phenolic content, probably because of the interaction between inulin and phenolic compounds. To address the effects of inulin on the global metabolite profile of tomato sauce, an untargeted metabolomics approach was followed. Changes related to the presence of inulin suggest that inulin quenches a subset of unidentified compounds which are present in sauce but not in fruit, suggesting that inulin can contribute to the conservation of fruit properties in tomato sauce.