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Global concerns over folate deficiency, the risks of excessive synthetic folic acid consumption, and food loss implications for environmental sustainability and food security drive needs of innovative approaches that align food by-product valorisation with folate bio-enrichment. This study explored the use of three fruit by-products extracts (grape, passion fruit, and pitaya) and whey to develop a folate bio-enriched fermented whey-based beverage. Three strains (Lacticaseibacillus rhamnosus LGG, Bifidobacterium infantis BB-02, and Streptococcus thermophilus TH-4) were tested for folate production in different fermentation conditions in modified MRS medium and in a whey-based matrix prepared with water extracts of these fruit by-products. B. infantis BB-02 and S. thermophilus TH-4, alone and in co-culture, were the best folate producers. The selection of cultivation conditions, including the presence of different substrates and pH, with grape by-product water extract demonstrating the most substantial effect on folate production among the tested extracts, was crucial for successfully producing a biofortified fermented whey-based beverage (FWBB). The resulting FWBB provided 40.7 μg of folate per 100 mL after 24 h of fermentation at 37 °C, effectively leveraging food by-products. Moreover, the beverage showed no cytotoxicity in mouse fibroblast cells tests. This study highlights the potential for valorising fruit by-products and whey for the design of novel bioenriched foods, promoting health benefits and contributing to reduced environmental impact from improper disposal., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a total of 248 ground beef samples were analyzed for the presence of Shiga toxin-producing Escherichia coli (STEC). Out of these samples, only one (0.4%) tested positive for STEC. Further analysis using PCR confirmed the presence of all tested genes associated with STEC, including stx1, stx2, eae, ehx, uid, rfbO157, and fliCH7 in this isolate. Interestingly, no STEC strains were detected in the remaining 100 beef cut samples or the 100 chicken cut samples, indicating the absence of detectable STEC contamination in those specific samples. The isolated strain exhibited significant cytotoxic activity in Vero cells, indicating its ability to produce cytotoxic Shiga toxins. To further investigate the strain, whole-genome sequencing (WGS) analyses were performed. The resistome analysis revealed the absence of acquired antimicrobial resistance genes, indicating a pan-susceptible phenotype. However, this strain presented chromosomal mutations in gyrA, gyrB, parC, parE, pmrA, pmrB, and folP. Plasmid analysis identified the presence of two plasmids, namely IncFIB(AP001918) and IncFII. The multi-locus sequence typing (MLST) identified the strain as belonging to sequence type (ST) 11, which is associated with E. coli O157:H7 strains. The virulome analysis confirmed the presence of several canonical virulence markers, including stx1, stx2, eae-g01-gamma, ehxA, stx1a-O157, and stx2a-O157. Overall, this study identified for the first time a rare occurrence of STEC contamination in ground beef, with the isolated strain belonging to the highly virulent O157:H7 serotype. These findings contribute to our understanding of STEC prevalence and characteristics in food samples, highlighting the importance of effective food safety measures to prevent potential health risks associated with STEC contamination., Competing Interests: Declarations. Conflict of interest: The authors have no conflict of interest to declare., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Alicyclobacillus spp. is the cause of great concern for the food industry due to their spores' resistance (thermal and chemical) and the spoilage potential of some species. Despite this, not all Alicyclobacillus strains can spoil fruit juices. Thus, this study aimed to identify Alicyclobacillus spp. strains isolated from fruit-based products produced in Argentina, Brazil, and Italy by DNA sequencing. All Alicyclobacillus isolates were tested for guaiacol production by the peroxidase method. Positive strains for guaiacol production were individually inoculated at concentration of 10 3  CFU/mL in 10 mL of orange (pH 3.90) and apple (pH 3.50) juices adjusted to 11°Brix, following incubation at 45 °C for at least 5 days to induce the production of the following spoilage compounds: Guaiacol, 2,6-dichlorophenol (2,6-DCP) and 2,6-dibromophenol (2,6-DBP). The techniques of micro-solid phase extraction by headspace (HS-SPME) and gas-chromatography with mass spectrometry (GC-MS) were used to identify and quantify the spoilage compounds. All GC-MS data was analyzed by principal component analysis (PCA). The effects of different thermal shock conditions on the recovery of Alicyclobacillus spores inoculated in orange and apple juice (11°Brix) were also tested. A total of 484 strains were isolated from 48 brands, and the species A. acidocaldarius and A. acidoterrestris were the most found among all samples analyzed. In some samples from Argentina, the species A. vulcanalis and A. mali were also identified. The incidence of these two main species of Alicyclobacillus in this study was mainly in products from pear (n = 108; 22.3 %), peach (n = 99; 20.5 %), apple (n = 86; 17.8 %), and tomato (n = 63; 13 %). The results indicated that from the total isolates from Argentina (n = 414), Brazil (n = 54) and Italy (n = 16) were able to produce guaiacol: 107 (25.8 %), 33 (61.1 %) and 13 (81.2 %) isolates from each country, respectively. The PCA score plot indicated that the Argentina and Brazil isolates correlate with higher production of guaiacol and 2,6-DCP/2,6-DBP, respectively. Heatmaps of cell survival after heat shock demonstrated that strains with different levels of guaiacol production present different resistances according to spoilage ability. None of the Alicyclobacillus isolates survived heat shocks at 120 °C for 3 min. This work provides insights into the incidence, spoilage potential, and thermal shock resistance of Alicyclobacillus strains isolated from fruit-based products., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To assess the glycaemic response after ingestion of two specialised oral and enteral nutrition formulas for glycaemic control. The participants were sixteen healthy volunteers, aged 21-49 years, with normal glucose tolerance. The volunteers attended the tests fasting for 10 h, for 5 weeks, and consumed the reference food - glucose solution - for 3 weeks, and the two formulas DiamaxO and DiamaxIG in the following weeks, in amounts equivalent to 25 g of available carbohydrates. During the period of 120 min, seven blood samples were taken through capillary blood sampling to determine the glycaemic response. The glycaemic index (GI) was calculated according to the trapezoidal rule, ignoring areas below the fasting line. The glycaemic load (GL) was determined by the formula GL = ((GI(glucose = reference) × 'g' of available carbohydrate per serving]/100. The formulas showed low GI and GL. GI = 37·8 and GL = 6·6 for DiamaxO and GI = 21·5 and GL = 3·5 for DiamaxIG. The peak of the glycaemic response occurred 30 min after ingestion, with a marked difference in blood glucose between the Diamax products in relation to glucose. Differences were also significant at times 15, 45, 60 and 90 min in relation to glucose (ANOVA with post hoc Bonferroni, P < 0·005), but not between the two products. However, the AUC and the GI of DiamaxIG are significantly smaller than that of the DiamaxO second t test ( P = 0·0059). The glycaemic response to the products is quite reduced, presenting a curve with a little accentuated shape, without high peak, especially in the modified product.

Canastra Minas Artisanal Cheese is produced in the Brazilian State of Minas Gerais using raw milk, rennet, and pingo, a natural endogenous starter culture (fermented whey) collected from the previous day's production. Due to the use of raw milk, the product can carry microorganisms that may cause foodborne diseases (FBD), including Staphylococcus aureus. Genomic characterization of S. aureus is an important tool to assess diversity, virulence, antimicrobial resistance, and the potential for causing food poisoning due to enterotoxin production. This study is aimed at exploring the genomic features of S. aureus strains isolated from Canastra Minas Artisanal Cheeses. Multilocus sequence typing (MLST) classified these strains as ST1, ST5, and a new profile ST7849 (assigned to the clonal complex CC97). These strains belonged to four spa types: t008, t127, t359, and t992. We identified antimicrobial resistance genes with phenotypic correlation against methicillin (MRSA) and tetracycline. Virulome analysis revealed genes associated with iron uptake, immune evasion, and potential capacity for adherence and biofilm formation. The toxigenic potential included cyto- and exotoxins genes, and all strains presented the genes that encode for Panton-Valentine toxin and hemolysin, and two strains encoded 4 and 8 Staphylococcal enterotoxin (SE) genes. The results revealed the pathogenic potential of the evaluated S. aureus strains circulating in the Canastra region, representing a potential risk to public health. This study also provides useful information to monitor and guide the application of control measures to the artisanal dairy food production chain., (© 2023. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Candida albicans is an important vaginosis causative agent, affecting several women worldwide each year. This study reports on two strains of lactic acid bacteria ( Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch) expressing bacteriocin-like inhibitor substances (BLIS) active against C. albicans 1281. Both strains were γ-hemolytic and not affected by numerous antibiotics, contraceptives, and commercial drugs, suggesting safety for human use. The recorded antimicrobial activity of semi-purified BLIS was 25,600 AU/mL for E. mundtii CRL35 and 800 AU/mL for E. faecium ST88Ch. Treatment of BLIS with 1 mg/mL proteinase K resulted in complete loss of antimicrobial activity against Listeria monocytogenes ATCC 15313 and partial loss of activity against C. albicans 1281. The killing effect of the semi-purified BLIS on cell suspensions of C. albicans 1281 after 9 h of contact was dose-dependent: for E. mundtii CRL35, 400 AU/mL to 25,600 AU/mL caused 63.61% to 79.35% lysis, while for E. faecium ST88Ch, 200 AU/mL to 800 AU/mL caused 29.32% to 31.25% cell lysis. The effects of temperature, pH, and presence of the contraceptive Nordette-28 on the adsorption levels of the BLIS to C. albicans 1281 were also evaluated. Nordette-28 (10% or 20%) promoted increased adsorption of both studied BLIS to the cells of C. albicans 1281 at pH 5.0, while a minor effect was observed at pH 3.0. Different levels of aggregation between C. albicans 1281 and E. mundtii CRL35 or E. faecium ST88Ch were recorded, and optimal adsorption levels were recorded at 37 °C. Appropriate BLIS-producing strains can effectively contribute to the equilibrium of vaginal microbial status quo and reduce negative consequences from the development of C. albicans infections.

Because of growing urbanization and lack of time to prepare meals at home, eating out or getting food delivered have become common trends for many people. The consumption of food from unknown sources may impose an increased chance of contamination with microbiological hazards, especially if sanitary conditions are not met. We evaluated data from health surveillance agencies and scientific articles on foodborne diseases (FBD) reported internationally according to the exposure sites. We observed that the data are influenced by cultural, political, and socioeconomic differences. For instance, in New Zealand, Australia, United States, Denmark and India, the occurrence of FBD outbreaks was greater from foods prepared in commercial establishments and street vendors than from households. Conversely, in China, countries of the European Union and Brazil, the results are the opposite. Additionally, the pandemic imposed new eating behavior patterns, increasing delivery services and foods prepared in so-called "Dark Kitchens". The underreporting and heterogeneity of data among countries prevented a precise conclusion to the question of whether homemade foods are inherently safer than foods prepared out. Nevertheless, a lower level of development in a country influences its sanitation conditions, as well as the number of street food vendors, the search for cheaper foods, and insufficient knowledge of the population on good hygiene practices, which can all increase the chances of FBD cases.

Aims: To gather data on agricultural practices in organic farms in Sao Paulo, Brazil, and evaluate their relationship with the microbiological characteristics of samples collected along the production chain., Methods and Results: Practices data were based on field observations and interviews with farmers in 10 selected organic lettuce producing farms. Counts of Enterobacteriaceae and surveys for Salmonella were performed in samples of lettuce (before and after washing), fertilizers, irrigation and washing water, all collected in the same farm. Water samples were also tested for total coliforms and generic Escherichia coli. Isolated Enterobacteriaceae were identified by MALDI-TOF MS. Contamination of lettuce was influenced by some agricultural practices: chicken manure-based fertilization resulted in higher Enterobacteriaceae counts in lettuce when compared to other types of manure, whereas pre-washed lettuces presented lower microbial counts than non-pre-washed samples. Salmonella was detected in one lettuce sample by qPCR. Escherichia coli was detected in all irrigation water samples. All sample types contained Enterobacteriaceae species commonly reported as opportunistic human pathogens., Conclusions: The data highlight the need for improvement in the good agricultural practices in the studied farms., Significance and Impact of the Study: This study provides information on agricultural practices and microbiological characteristics of organic lettuce, contributing to the development of more accurate risk assessments., (© 2021 Society for Applied Microbiology.)

Aims: The objective of this study was to isolate multifunctional bacteriocin-producing strains; to characterize the expressed bacteriocin for the control of Listeria monocytogenes and vancomycin-resistant Enterococcus; to evaluate the safety of studied strains; and to explore their antifungal activity., Methods and Results: Two Pediococcus strains were isolated from silage samples obtained from an organic farm in Belogradchik, Bulgaria. The strains were identified by 16S rRNA sequencing analysis and characterized as bacteriocins producers. Strong antimicrobial activity was detected against more than 74 different strains of Listeria monocytogenes, 27 different vancomycin-resistant Enterococcus strains. In addition, studied strains were able to inhibit the growth of strains of Alternaria alternate, Aspergillus flavus, Aspergillus niger, Cladosporium sphaerospermum, Penicillium chrysogenum and Penicillium expansum. Some aspects of the antimicrobial mode of action were evaluated, including killing curves and aggregation properties. Both strains generated positive PCR results for the presence of pediocin PA-1, but not for other bacteriocins evaluated in this screening process. Metabolomic analysis of the cell-free supernatants from both strains was performed in order to explain the observed antifungal activity against different moulds. According to PCA and PLS-DA score plot, P. acidilactici ST3522BG and P. pentosaceus ST3633BG were clearly clustered from control (MRS). Increases in the production of benzoic acid, 2-hydroxyisocaproic acid, β-phenyl-lactic acid, α-hydroxybutyric acid and 1,3-butanediol were recorded, these metabolites were previously described as antifungal., Conclusions: Pediococcus acidilactici ST3522BG and P. pentosaceus ST3633BG were evaluated as producing bacteriocin strains with high specificity against Listeria and vancomycin-resistant Enterococcus species. In addition, both investigated Pediococcus strains were evaluated as producer of effective antifungal metabolites with potential for the inhibition of mycotoxin-producing moulds., Significance and Impact of the Study: To the best of our knowledge, this report is a pioneer in the evaluation of Pediococcus strains isolated from silage with highly specific bacteriocinogenic antimicrobial activity against Listeria spp. and vancomycin-resistant Enterococcus spp., and antifungal activity against mycotoxin-producing moulds., (© 2021 The Society for Applied Microbiology.)

Objectives: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19)., Methods: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed., Results: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for >12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11% versus 0%, p=0.030), lymphopenia (42% versus 18%, p=0.020), C-reactive protein level of >30 mg/L (35% versus 0%, p=0.0001), and D-dimer level of >1000 ng/mL (43% versus 6%, p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11% versus 2%, p=0.178) and cardiac alterations on echocardiogram (33% versus 22%, p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100] versus 81 [34-100], p=0.012), and school score (60 [15-100] versus 70 [15-95], p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls., Conclusions: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19.

The emergence of multidrug-resistant bacteria stimulates the search for new substitutes to traditional antimicrobial agents, especially molecules with antivirulence properties, such as those that interfere with quorum sensing (QS). This study aimed to evaluate the potential of phenolic compounds for QS inhibition in a QS biosensor strain ( Chromobacterium violaceum ) and three foodborne bacterial species ( Aeromonas hydrophila , Salmonella enterica serovar Montevideo, and Serratia marcescens ). Initially, an in silico molecular docking study was performed to select the compounds with the greatest potential for QS inhibition, using structural variants of the CviR QS regulator of C. violaceum as target. Curcumin, capsaicin, resveratrol, gallic acid, and phloridizin presented good affinity to at least four CviR structural variants. These phenolic compounds were tested for antimicrobial activity, inhibition of biofilm formation, and anti-QS activity. The antimicrobial activity when combined with kanamycin was also assessed. Curcumin, capsaicin, and resveratrol inhibited up to 50% of violacein production by C. violaceum . Biofilm formation was inhibited by resveratrol up to 80% in A. hydrophila , by capsaicin and curcumin up to 40% in S. Montevideo and by resveratrol and capsaicin up to 60% in S. marcescens . Curcumin completely inhibited swarming motility in S. marcescens . Additionally, curcumin and resveratrol increased the sensitivity of the tested bacteria to kanamycin. These results indicate that curcumin and resveratrol at concentrations as low as 6μM are potential quorum sensing inhibitors besides having antimicrobial properties at higher concentrations, encouraging applications in the food and pharmaceutical industries., (Copyright © 2021 Santos, Lima, Franco and Pinto.)

Background: Several actions in the realm of public policies and programs have been implemented worldwide to prevent and control the spread of COVID-19. As Brazil and many parts of the world are marked by regional, cultural, and social inequalities, risk communication and assimilation of protection recommendations by the public may be erratic, hampering the proper measurement of their effectiveness., Scope and Approach: Even though transmission of SARS-CoV-2 by foods is unlikely, this work aimed to evaluate the population's adherence to the recommended food hygiene and personal protection measures to prevent COVID-19. An online survey containing questions on food hygiene and personal protection was publicly disseminated via internet and social networks. Data from 3000 respondents were collected and discussed herein.Key findings and conclusions: Most respondents adopted the recommended hygienic and personal protection measures to avoid contamination with SARS-CoV-2. However, some important flaws were detected, such as lack of use of face masks when in public places (6%), improper hand washing and sanitizing (10-12%) and use of incorrect products for food or environment cleaning and sanitization (28%), indicating that adequate risk communication and preventive recommendations must continue in order to avoid contamination with the coronavirus. The heighten awareness with food hygiene during the pandemic may have an enduring positive effect on food safety., Competing Interests: The authors declare that they have no conflict of interest., (© 2021 Elsevier Ltd. All rights reserved.)

Artisanal cheeses made with raw milk are highly appreciated products in Brazil. Most of these cheeses are produced in small facilities across different production regions in the country, some of which have been granted a protected designation of origin and are award winners. The most prominent state that manufactures these products is Minas Gerais (MG), but production is also gaining strength in other Brazilian states. The major challenge faced by artisanal cheese production is related to microbial risks associated with foodborne pathogens when the quality of the raw milk is unsatisfactory. Regulations created for the dairy industry are constantly been revised and adapted, considering the small-scale production of Brazilian artisanal cheeses, in order to guarantee safety at all steps of cheese production and commercialization. This text presents a summary of the huge diversity of artisanal cheeses produced in the country, grouped by geographical regions, and reviews the current challenges faced by producers and government considering the safety of these cheeses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Pineda, Campos, Pimentel-Filho, Franco and Pinto.)

Fresh produce has been identified as an important vehicle for the transmission of foodborne pathogens. This study evaluated the behavior of vegetative cells and spores of Bacillus thuringiensis , one of the main biological control agents (BCAs) used in the world, and Salmonella enterica on spinach plants (pre-harvest) and spinach cut leaves (post-harvest) at 12°C, experimentally inoculated as single or co-cultures. The results evidenced that spray-inoculated commercial BCA containing Bacillus thuringiensis subsp. aizawai ABTS-1857 (BTa ABTS-1857) spores persisted well on spinach leaves in both pre- and post-harvest simulations. However, when BTa ABTS-1857 vegetative cells were spray-inoculated, more than 2 log reductions in the counts of B. thuringiensis were observed during 20 days pre- and 5 days post-harvest simulations, respectively. The counts of S. Montevideo on the spinach cut leaves during post-harvest storage at 12°C for 5 days remained unchanged, whereas 1 log reduction was noted during pre-harvest. Moreover, during pre-harvest simulation, when co-inoculated with BTa ABTS-1857 vegetative cells or spores, additional 0.5 or 1.0 log reductions were detected on the counts of S. Montevideo in the spinach leaves on the 10th day. These results were obtained under laboratory conditions, and further findings in longitudinal studies from farm (in the agricultural field) to retail (end of shelf life) will contribute to understanding of the role of B. thuringiensis as a BCA on growth/survival of Salmonella spp. in fresh produce., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhao, Silva, Van der Linden, Franco and Uyttendaele.)

Centralizing chemical composition data for biodiverse foods is an important strategy in promoting their consumption. To support this strategy, a dataset of foods based on Brazilian biodiversity was created. The set was based on data for foods produced or commercialized in Brazil; these data were previously compiled for the Brazilian Food Composition Table (TBCA), according to international guidelines. Inclusion criteria were based on the following indicators: (i) foods with description below species level; (ii) wild foods; and (iii) underutilized foods. The dataset contains 1,305 food entries, and the majority correspond to raw plant foods. Nutrient content in foods identified below species level exhibited a wide range of values. Underutilized foods presented similar or higher selected nutrient contents than commonly consumed foods. For instance, depending on the cultivar of sweet potato (Ipomoea batatas), vitamin A content ranged from a negligible amount to high content (0.33- to 3,637-μg retinol equivalents per 100-g edible portion on a fresh weight basis [EP]). Camu-camu (Myrciaria dubia), a fruit from Amazon, was identified as the richest source of vitamin C (2,300 mg of ascorbic acid per 100-g EP), corresponding to 48-fold the content of orange. The dataset provides evidence to promote nutrient-rich foods that may be integrated into more effective programmes and policies on nutrition and food security in Brazil. It can be accessed online, free of charge on the TBCA platform., (© 2020 The Authors. Maternal & Child Nutrition published by John Wiley & Sons Ltd.)

Aims: This study aimed to gather information on farming practices employed in organic lettuce fields in Sao Paulo, Brazil and associate these practices with the microbiological characteristics of the products., Methods and Results: Practices were surveyed using a questionnaire applied in ten farms, where 200 heads of lettuce were collected and submitted to enumeration of total coliforms and generic Escherichia coli and tested for Salmonella spp. using culture and molecular (qPCR) methods. Based on the responses, the farms could be clustered in two groups: group 1, comprised by six farms, where chicken manure was used as fertilizer in most of them and the composting process was not performed on site; and group 2, comprised by four farms, where other types of fertilizer were used, and the composting process was performed on site. Generic E. coli was detected in 56 (28%) samples, with an average of 1·1 ± 0·7 log MPN per g. Salmonella DNA was detected in two (1%) samples by qPCR., Conclusions: The prevalence and bacterial loads of generic E. coli, and the occurrence of Salmonella, even at low populations undetectable by conventional culture methods, highlight the need for control measures during farming practices to reduce microbial contamination and risks of foodborne illnesses. These measures include the use of properly composted manure and appropriate washing procedures for leafy vegetables before consumption., Significance and Impact of the Study: The obtained data contribute to a better understanding of the farming practices of organically grown lettuces in Sao Paulo, Brazil., (© 2019 The Society for Applied Microbiology.)

Microbiological testing is an important quality management tool in the food industry. In this study, the hygiene status of beef carcasses sampled in eight Brazilian slaughterhouses was assessed by enumeration of different hygiene indicator microorganisms, and a model to establish potential associations among these counts was proposed. The carcasses ( n = 464) were surface sampled at four slaughtering steps (step 1: Hide after bleeding; step 2: Carcass after hide removal; step 3: Carcass after evisceration; step 4: Carcass after end washing) and subjected to a counting of mesophilic aerobes (MA), Enterobacteriaceae (EB), total coliforms (TC), and Escherichia coli (EC) using Petrifilm™ plates. Among the sampled beef carcasses (step 4), 32 (6.9%) and 71 (15.3%) presented counts above the microbiological criteria established by (EC) No. 1441/2007 for MA and EB, respectively. Thus, indicating that improvements in slaughter hygiene and a review of process controls are demanded in some of the studied slaughterhouses. The log count differences of EC, TC, and EB from MA were considered as response variables as a function of the slaughtering steps. Differential log counts changed consistently with the steps. The measurements, including the patterns in their inherently random variability, were fairly predictable from steps 1 and 4. The results indicated that differential log counts for TC and EC are not relevant, as their concentrations and random pattern can be inferred from counts of MA and EB. The proposed model can be used as a valuable tool for the design and adoption of feasible quality control programs in beef industries. The adoption of such a tool should have a positive contribution on consumers' health and enhance product quality.

Aim: The objective was to obtain lactic acid bacteria (LAB) capable of hydrolysing immunoreactive proteins in milk, to optimize the hydrolysis, to determine the proteolysis kinetics and to test the safety of the best hydrolytic strain., Methods and Results: Brazilian cheese was used as source of LAB capable of hydrolysing main milk allergens. Proteolytic isolates were submitted to RAPD-PCR for the characterization of clonal diversity. Optimized hydrolysis was strain and protein fraction dependent. 16S rDNA sequencing identified three proteolytic strains: Enterococcus faecalis VB43, that hydrolysed α S1 -, α S2 - and β-caseins, α-lactalbumin and β-lactoglobulin (partial hydrolysis), and Pediococcus acidilactici VB90 and Weissella viridescens VB111, that caused partial hydrolysis of α S1 - and α S2 -caseins. Enterococcus faecalis VB43 tested negative for virulence genes asa1, agg, efaA, hyl, esp, cylL L and cylL S but positive for genes ace and gelE. Ethylenediamine tetra-acetic acid inhibited the proteolysis, indicating that the main proteases of E. faecalis VB43 are metalloproteases., Conclusion: Brazilian artisanal cheese is a good source of LAB capable of hydrolysing allergenic proteins in milk. One isolate (E. faecalis VB43) presented outstanding activity against these proteins and lacked most of the tested virulence genes., Significance and Impact of the Study: Enterococcus faecalis VB43 presents good potential for the manufacture of hypoallergenic dairy products., (© 2018 The Society for Applied Microbiology.)

As consumption of fish and fish-based foods increases, non-destructive monitoring of fish freshness also becomes more prominent. Fish products are very perishable and prone to microbiological growth, not always easily detected by organoleptic evaluation. The analysis of the headspace of fish specimens through gas sensing is an interesting approach to monitor fish freshness. Here we report a gas sensing method for monitoring Tilapia fish spoilage based on the application of a single gas sensitive gel material coupled to an optical electronic nose. The optical signals of the sensor and the extent of bacterial growth were followed over time, and results indicated good correlation between the two determinations, which suggests the potential application of this simple and low cost system for Tilapia fish freshness monitoring.

Antimicrobial compounds produced by lactic acid bacteria can be explored as natural food biopreservatives. In a previous report, the main antimicrobial compounds produced by the Brazilian meat isolate Lactobacillus sakei subsp. sakei 2a, i.e., bacteriocin sakacin P and two ribosomal peptides (P2 and P3) active against Listeria monocytogenes, were described. In this study, we report the spectrum of activity, molecular mass, structural identity and mechanism of action of additional six antilisterial peptides produced by Lb. sakei 2a, detected in a 24 h-culture in MRS broth submitted to acid treatment (pH 1.5) and proper fractionation and purification steps for obtention of free and cell-bound proteins. The six peptides presented similarity to different ribosomal proteins of Lb. sakei subsp sakei 23K and the molecular masses varied from 4.6 to 11.0 kDa. All peptides were capable to increase the efflux of ATP and decrease the membrane potential in Listeria monocytogenes. The activity of a pool of the obtained antilisterial compounds [enriched active fraction (EAF)] against Listeria monocytogenes in a food model (meat gravy) during refrigerated storage (4 °C) for 10 days was also tested and results indicated that the populations of L. monocytogenes in the food model containing the acid extract remained lower than those at time 0-day, evidencing that the acid extract of a culture of Lb. sakei 2a is a good technological alternative for the control of growth of L. monocytogenes in foods.

Food allergies represent a serious problem affecting human health and soy proteins rank among the most allergenic proteins from food origin. The proteolytic enzymes produced by lactic acid bacteria (LAB) can hydrolyse the major allergens present in soybean, reducing their immunoreactivity. Many studies have reported the ability of LAB to ferment soy-based products; while the majority of them focus on the improvement of the sensory characteristics and functionality of soy proteins, a lack of information about the role of lactic fermentation in the reduction of immunoreactivity of these proteins exists. The aim of the present study was to evaluate the capability of the proteolytic strain Enterococcus faecalis VB43 to hydrolyse the main allergenic proteins present in soymilk and to determine the immunoreactivity of the obtained hydrolysates. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) results of fermented soymilk demonstrated complete hydrolysis of the β-subunit from β-conglycinin and the acidic polypeptide from glycinin. Reversed phase high performance liquid chromatography (RP-HPLC) analysis of the peptides released after hydrolysis revealed the appearance of new peptides and the disappearance of non-hydrolysed proteins, indicating extensive hydrolysis of the substrate. Results from competitive enzyme-linked immunosorbent assay (ELISA) tests clearly indicated a reduction in the immunoreactivity (more than one logarithmic unit) in the fermented sample as compared to the non-fermented control. Our results suggest that the soymilk fermented by E. faecalis VB43 may induce lower allergic responses in sensitive individuals. The strain E. faecalis VB43 may be considered as an excellent candidate to efficiently reduce the immunoreactivity of soymilk proteins.

We present here the draft genome sequences of two colistin-resistant mcr-1 -carrying Escherichia coli strains belonging to sequence type 74 (ST74) and ST1850, isolated from commercial chicken meat in Brazil. Assembly of this draft genome resulted in 5,022,083 and 4,950,681 bp, respectively, revealing the presence of the IncX4 plasmid-mediated mcr-1 gene responsible for resistance to colistin., (Copyright © 2017 Monte et al.)

The detection and rapid spread of colistin-resistant Enterobacteriaceae carrying the mcr-1 gene has created an urgent need to strengthen surveillance. In this study, eight clonally unrelated colistin-resistant Escherichia coli isolates carrying mcr-1 and bla CTX-M or bla CMY-2 genes were isolated from commercial chicken meat in Brazil. Most E. coli strains carried IncX4 plasmids, previously identified in human and animal isolates. These results highlight a new reservoir of mcr-1 -harboring E. coli strains in South America., (Copyright © 2017 American Society for Microbiology.)

With the aim of screening proteolytic strains of lactic acid bacteria to evaluate their potential for the reduction of allergenicity of the major bovine milk proteins, we isolated a new proteolytic strain of Enterococcus faecalis (Ent. faecalis VB63F) from raw bovine milk. The proteases produced by this strain had strong activity against caseins (αS1-, αS2-, and β-casein), in both skim milk and sodium caseinate. However, only partial hydrolysis of whey proteins was observed. Proteolysis of Na-caseinate and whey proteins, observed after sodium dodecyl sulfate-PAGE, was confirmed by analysis of peptide profiles by reversed-phase HPLC. Inhibition of proteolysis with EDTA indicated that the proteases produced by Ent. faecalis VB63F belonged to the group of metalloproteases. The optimal conditions for their activity were 42°C and pH 6.5. The majority of assessed virulence genes were absent in Ent. faecalis VB63F. The obtained results suggest that Ent. faecalis VB63F could be efficient in reducing the immunoreactivity of bovine milk proteins., (Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Incidence of enterotoxigenic Escherichia coli (ETEC) in foods usually consumed in the city of Sao Paulo, Brazil was determined. Raw and cooked foods of animal and vegetable origin were investigated. Enterotoxigenic strains were found in approximately 3.5% of food samples contaminated with E. coli . There was a great predominance of ETEC strains producing only LT enterotoxin. None of the isolated strains produced LT and ST simultaneously. Several serotypes were involved, and none of them was positive for colonization factors CFA-I and CFA-II. One ETEC showed resistance to some antibiotics but most were sensitive to the ones tested.