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IntroductionPreviously we have reported a r16S gene next generation sequencing study on the effect of high fat diets in the intestinal microbiota using a murine model. However, many important microbial traits occur at strain level and, in order to detect these population changes, culture-dependent approaches need to be applied. With this goal, we decided to study a very well-known commensal genus, Enterococcus, and therefore, intestinal enterococci methodically isolated during the above-mentioned experiment were analyzed.Materials and methodsA collection of 75 distinct enterococcal strains isolated from feces of mice fed a standard diet or high-fat diets enriched with butter, refined olive oil, or extra virgin olive oil and after 0, 6 or 12 weeks of diet, were genetically and phenotypically characterized in search of virulence factors, biogenic amine production and antibiotic resistance. All strains were tested for the susceptibility in vitro to two virgin olive oil polyphenols, oleuropein (the bitter principle of olives) and hydroxytyrosol (derived from oleuropein by enzymatic hydrolysis and responsible for the high stability of olive oil).ResultsNo drastic polyphenol effect was found except at high concentrations. However, when carrying out a comparative statistical study in the 75 strains of the collection according to the different diets, we have detected significant differences between the strains isolated from mice fed with a diet enriched with virgin olive oil and the rest of the diets. EVOO strains also presented less resistance to antibiotics and a more beneficial profile overall.DiscussionThese results support the prebiotic role of polyphenols, showing how they are able to modulate the set of strains that comprises a genus in the gut, allowing them to adapt to a changing environment in the host’s intestine and possibly exerting effects on its physiology.

The heterogenicity of antimicrobial resistance genes described in clinically significant bacterial isolates and their potential role in reducing the efficacy of classically effective antibiotics pose a major challenge for global healthcare, especially in infections caused by Gram-negative bacteria. We analyzed 112 multidrug-resistant (MDR) isolates from clinical samples in order to detect high resistance profiles, both phenotypically and genotypically, among four Gram-negative genera (Acinetobacter, Escherichia, Klebsiella, and Pseudomonas). We found that 9.8% of the total selected isolates were classified as extensively drug-resistant (XDR) (six isolates identified as A. baumannii and five among P. pneumoniae isolates). All other isolates were classified as MDR. Almost 100% of the isolates showed positive results for blaOXA-23 and blaNDM-1 genes among the A. baumannii samples, one resistance gene (blaCTX-M) among E. coli, and two genetic determinants (blaCTX-M and aac(6′)-Ib) among Klebsiella. In contrast, P. aeruginosa showed just one high-frequency antibiotic resistance gene (dfrA), which was present in 68.42% of the isolates studied. We also describe positive associations between ampicillin and cefotaxime resistance in A. baumannii and the presence of blaVEB and blaGES genes, as well as between the aztreonam resistance phenotype and the presence of blaGES gene in E. coli. These data may be useful in achieving a better control of infection strategies and antibiotic management in clinical scenarios where these multidrug-resistant Gram-negative pathogens cause higher morbidity and mortality.

Paenibacillus dendritiformis UJA2219 isolated from carrot produces broad-spectrum antibacterial activity. The aim of the present study was to determine the impact of partially-purified cell-culture extracts of strain UJA2219 on the microbial load and bacterial diversity of a homemade vegetable puree. The puree was challenged with an overnight culture of strain UJA2219 or with cultured broth extracts partially purified by cation exchange (CE) chromatography or reversed-phase (RP) chromatography and incubated for 7 days at temperatures of 4 °C or 25 °C. The best results were obtained at 25 °C with the RP extract, decreasing counts of the presumptive Enterobacteriaceae below detectable levels. The bacterial diversity of control and treated puree was studied by Illumina paired-end sequencing, using DNA extracted from the puree samples incubated at 25 °C for 24 h. The controls and the puree inoculated with the UJA2219 strain showed an almost-identical bacterial diversity profile, with Pseudomonadota (mainly Fam. Pseudomonadaceae -gen. Pseudomonas- and Enterobacteriace as the most abundant groups). The greatest differences in bacterial diversity were obtained in the puree treated with RP extract, showing a decrease in the relative abundance of Pseudomonadota (especially gen. Pseudomonas) and an increase of Bacillota (mainly of the genera Bacillus, Enterococcus and Lactococcus). Results from the study suggest that the antimicrobial preparations from strain UJA2219 have a potential for application in food biopreservation.

Las bacteriocinas son péptidos sintetizados por bacterias que presentan un amplio potencial como conservador de alimentos. Son una buena alternativa para reemplazar los aditivos químicos y producir alimentos mínimamente procesados. Las bacteriocinas que se han estudiado con mayor interés en la industria alimentaria son las derivadas de bacterias ácido-lácticas (bal) porque tienen el estatus Generally Regarded As Safe (gras). No obstante, se ha determinado que las bacteriocinas tienen ciertas desventajas a la hora de aplicarlas en los alimentos, especialmente en derivados lácteos. Esas desventajas pueden enmendarse al combinar las bacteriocinas con otros tratamientos emergentes en la industria alimentaria. El objetivo de esta revisión fue realizar un análisis sobre las principales bacteriocinas utilizadas y su efecto sinérgico contra bacterias patógenas y/o alteradoras, cuando se aplican de manera combinada con otros tratamientos como sustancias químicas, sistema lactoperoxidasa, altas presiones hidrostáticas, nanopartículas, bacteriófagos y aceites esenciales. Los resultados de esta revisión indican que cuando se aplican las bacteriocinas con otros tratamientos pueden aumentar la actividad antimicrobiana, lo cual mejoraría la seguridad alimentaria. Se concluye que las mejores combinaciones del uso de las bacteriocinas y tecnologías emergentes son bacteriocinas y nanopartículas y bacteriocinas con bacteriófagos, cuyas combinaciones inhiben el crecimiento tanto de bacterias Gram positivas como de Gram negativas, entre las ventajas están, fáciles de aplicar en los alimentos, pueden ser de bajo costo, no cambian las características sensoriales del producto, permiten combatir la resistencia antimicrobiana, y destruyen completamente a los microorganismos sin darles oportunidad de recuperación durante el periodo de maduración o almacenamiento.

High hydrostatic pressure (HP) is a promising method to improve the microbiological quality of sous-vide foods. Monitoring the composition and behavior of the microbial communities in foods is of most importance for the production of high-quality and safe products. High-throughput sequencing (HTS) provides advanced approaches to determine food’s microbial community composition and structure. The aim of the present study was to determine the impact of different HP treatments on the microbial load and bacterial diversity of sous-vide Atlantic cod. Sous-vide cooking at 57.1 °C for 30 min followed by HP treatment at 500 MPa for 8 min reduced viable cell counts (total aerobic mesophiles) in the cod samples below detectable levels for 45 days of storage under refrigeration. In a second trial with cod cooked sous-vide at 52 °C for 20 min followed by HP treatments at 300 or 600 MPa (with HP treatment temperatures of 22 °C or 50 °C for 4 or 8 min, depending on treatment), only the treatments at 600 MPa delayed bacterial growth for at least 30 days under refrigeration. The optimal HP conditions to improve the microbiological quality of sous-vide cod cooked at low temperatures were obtained at 600 MPa for 4 min at a pressurization temperature of 50 °C. Bacterial diversity was studied in cod cooked sous-vide at 52 °C for 20 min by HTS. In the absence of HP treatment, Proteobacteria was the main bacterial group. A succession of Pseudomonadaceae (Pseudomonas) and Enterobacteriaceae was observed during storage. Firmicutes had low relative abundances and were represented mainly by Anoxybacillus (early storage) and Carnobacterium (late storage). The HP-treated sous-vide cod showed the greatest differences from controls during late storage, with Aerococcus and Enterococcus as predominant groups (depending on the HP conditions). The application of HTS provided new insights on the diversity and dynamics of the bacterial communities of sous-vide cod, revealing the presence of bacterial genera not previously described in this food, such as Anoxybacillus. The significance of Anoxybacillus as a contaminant of seafoods should be further investigated.

Butter and virgin olive oil (EVOO) are two fats differing in their degree of saturation and insaponifiable fraction. EVOO, enriched in polyphenols and other minority components, exerts a distinct effect on health. Using next generation sequencing, we have studied early and long-term effects of both types of fats on the intestinal microbiota of mice, finding significant differences between the two diets in the percentage of certain bacterial taxa, correlating with hormonal, physiological and metabolic parameters in the host. These correlations are not only concomitant, but most noticeably some of the changes detected in the microbial percentages at six weeks are correlating with changes in physiological values detected later, at twelve weeks. Desulfovibrionaceae/Desulfovibrio/D. sulfuricans stand out by presenting at six weeks a statistically significant higher percentage in the butter-fed mice with respect to the EVOO group, correlating with systolic blood pressure, food intake, water intake and insulin at twelve weeks. This not only suggests an early implication in the probability of developing altered physiological and biochemical responses later on in the host lifespan, but also opens the possibility of using this genus as a marker in the risk of suffering different pathologies in the future.

Extra virgin olive oil (EVOO) has proven to yield a better health outcome than other saturated fats widely used in the Western diet, including a distinct dysbiosis-preventive modulation of gut microbiota. Besides its high content in unsaturated fatty acids, EVOO also has an unsaponifiable polyphenol-enriched fraction that is lost when undergoing a depurative process that gives place to refined olive oil (ROO). Comparing the effects of both oils on the intestinal microbiota of mice can help us determine which benefits of EVOO are due to the unsaturated fatty acids, which remain the same in both, and which benefits are a consequence of its minority compounds, mainly polyphenols. In this work, we study these variations after only six weeks of diet, when physiological changes are not appreciated yet but intestinal microbial alterations can already be detected. Some of these bacterial deviations correlate in multiple regression models with ulterior physiological values, at twelve weeks of diet, including systolic blood pressure. Comparison between the EVOO and ROO diets reveals that some of these correlations can be explained by the type of fat that is present in the diet, while in other cases, such as the genus Desulfovibrio, can be better understood if the antimicrobial role of the virgin olive oil polyphenols is considered.

Este artículo estudia el reconocimiento al usuario de un derecho de cancelación (contractual, unilateral y ad nutum) de la reserva de un alojamiento turístico. Esta posibilidad se ha convertido en la práctica en un medio idóneo para arbitrar una solución razonable, clara y rápida ante posibles dificultades o nuevos intereses del usuario surgidos con posterioridad al contrato. El ejercicio de este derecho, que producirá la extinción del contrato, puede conllevar el abono/pérdida de una penalización por parte del usuario conforme a lo pactado. Aparte de la regulación contractual, es frecuente encontrar una detallada regulación del derecho de cancelación del usuario y sus consecuencias jurídicas en la normativa autonómica reguladora de la actividad turística, cuya aplicación suele establecerse como supletoria. En este trabajo se analiza el régimen jurídico de las cancelaciones, reservas y penalizaciones en estos contratos y sus relaciones con las reglas generales de las obligaciones contractuales.

The effects of high-hydrostatic pressure (HP) treatments (450 and 600 megapascals, MPa, for 5 min at temperatures of 22 °C and 50 °C) on the microbiota of a coriander and parsley dressing was studied via culture-dependent and culture-independent approaches. Samples were refrigerated for 20 days, with periodic counts of the culture media supplemented with, or without, antimicrobials. HP-treated samples showed significantly lower viable cell counts compared to untreated controls. Only the control samples yielded bacterial growth on media with antimicrobials (imipenem, cefotaxime, benzalkonium chloride), including mostly Pseudomonas and Lactobacillus. Bacillus and Paenibacillus were identified from pressurized samples. Few isolates showed higher tolerance to some of the biocides tested. Pseudomonads showed outstanding resistance to meropenem and ceftazidime. According to high-throughput sequencing analysis, the microbiota of the dressing control samples changes during storage, with a reduction in the relative abundance of Proteobacteria and an increase in Firmicutes. The composition of the residual microbiota detected during storage was highly dependent on the pressure applied, and not on the treatment temperature.

Staphylococcus aureus is a common contaminant in artisanal raw-milk cheeses. Tolerance of S. aureus to biocides is a threat to disinfection in the cheese production environment, while antibiotic resistance and enterotoxin production are additional health concerns. This study aimed to evaluate the tolerance of S. aureus isolated from Minas artisanal cheeses to the biocides benzalkonium chloride, hexadecylpyridinium chloride, cetrimide, triclosan, hexachlorophene, and chlorhexidine, and the simultaneous occurrence of genes coding for antibiotic resistance (mecA, aacA-aphD, and tetK), efflux pumps [qacA/B and smr (qacC/D)], and enterotoxins (sea, seb, sec, sed, see, seg, seh, sei, and sej). Among the tested isolates, 38.2% were resistant to at least one biocide, and 73.1% were positive for one or more antibiotic resistance gene. Most of the biocide-tolerant and antibiotic-resistant isolates harbored efflux pump genes, and were positive for at least one staphylococcal enterotoxin gene. The study highlights the need for correct hygiene monitoring programs to ensure the safety of these products.

Olive paste can be a valuable source of phenolic compounds with antioxidant activity. High hydrostatic pressure (HHP) treatment (600 MPa, 8 min) was tested for the preservation of olive paste obtained from Picual unfermented green olives, a variety known for its high content of phenolic compounds. Microbiological load (total aerobic mesophilic counts, yeasts, and moulds), and antioxidant activity were measured during one-month refrigeration storage. At the end of the storage period, control samples maintained 27% of their initial antioxidant activity, showed browning, and had microbial loads (ca. 105 CFU/g) composed mainly of yeasts and moulds, while samples treated with HHP preserved 79% of their initial antioxidant activity, kept green colour and had no microbial counts. These results showed the potential of HHP treatment at 600 MPa for 8 min for the preservation of olive paste with strong antioxidant activity.

Hybrid models combine physics-based models and data-driven models. This combination is a useful technique to detect fault and predict the current degradation of equipment. This paper proposes a physics-based model, which will be part of a hybrid model, for a heating, ventilation, and air conditioning system installed in the passenger vehicle of a train. The physics-based model is divided into four main parts: heating subsystems, cooling subsystems, ventilation subsystems, and cabin thermal networking subsystems. These subsystems are developed when considering the sensors that are located in the real system, so the model can be linked via the acquired sensor data and virtual sensor data to improve the detectability of failure modes. Thus, the physics-based model can be synchronized with the real system to provide better simulation results. The paper also considers diagnostics and prognostics performance. First, it looks at the current situation of the maintenance strategy for the heating, ventilation, air conditioning system, and the number of failure modes that the maintenance team can detect. Second, it determines the expected improvement using hybrid modelling to maintain the system. This improvement is based on the capabilities of detecting new failure modes. The paper concludes by suggesting the future capabilities of hybrid models.

We aimed to better understand resistome and virulome patterns on animal and process-area surfaces through a pig slaughterhouse to track possible contamination within the food production chain. Culture-dependent methods revealed high levels of microbial contamination, corresponding to mesophilic and pathogenic bacteria on both the animal and process-area surfaces mainly in the anesthesia (AA and AS) zone followed by “scorching and whip” (FA and FS) zone and also in the end products. To evaluate the potential risk of antibiotic resistance and virulence determinants, shotgun metagenomic DNA-sequencing of isolates from selected areas/products uncovered a high diversity and richness of antibiotic resistance genes (ARGs): 55–62 genes in the anesthesia area (AA and AS) and 35–40 in “animal-arrival zone” (MA and MS). The “scorching and whip” (FA and FS) area, however, exhibited lowered abundance of ARGs (1–6), indicating that the scalding and depilating process (an intermediate zone between “anesthesia” and “scorching and whip”) significantly decreased bacterial load by 1–3 log10 but also diminished the resistome. The high prevalence of antibiotic-inactivating enzyme genes in the “animal-arrival zone” (60–65%) and “anesthesia” area (56%) were mainly represented by those for aminoglycoside (46–51%) and lincosamide (14–19%) resistance, which did not reflect selective pressures by antibiotics most commonly used in pig therapy—tetracyclines and beta-lactams. Contrary to ARGs, greater number of virulence resistance genes were detected after evisceration in some products such as kidney, which reflected the poor hygienic practices. More than 19 general virulence features—mainly adherence, secretion system, chemotaxis and motility, invasion and motility were detected in some products. However, immune evasion determinants were detected in almost all samples analyzed from the beginning of the process, with highest amounts found from the anesthesia area. We conclude that there are two main sources of contamination in a pig slaughterhouse: the microorganisms carried on the animals’ hide, and those from the evisceration step. As such, focussing control measures, e.g., enhanced disinfection procedures, on these contamination-source areas may reduce risks to food safety and consumer health, since the antibiotic and virulence determinants may spread to end products and the environment; further, ARG and virulence traits can exacerbate pathogen treatments.

The aim of this study was to determine the impact of activated plastic films with thymol and enterocin AS-48 and high-hydrostatic pressure (HP) treatment on the bacterial load and bacterial diversity of vacuum-packaged sea bream fillets under refrigerated storage for 10 days. The activated film and the HP treatment reduced aerobic mesophiles viable counts by 1.46 and 2.36 log cycles, respectively, while the combined treatment achieved a reduction of 4.13 log cycles. HP and combined treatments resulted in longer delays in bacterial growth. Proteobacteria were the dominant phyla in sea bream fillets. The relative abundance of Firmicutes increased by the end of storage both in controls and in samples treated by HP singly or in combination with the activated films. The predominant operational taxonomic units (OTUs) found at time 0 in control samples (Listeria, Acinetobacter, Pseudomonas, Enterobacteriaceae, Chryseobacterium) rapidly changed during storage (with an increase of Vibrio, Photobacterium, and Shewanella together with Cloacibacterium and Lactobacillales by the end of storage). The activated film and the HP treatment induced drastic changes in bacterial diversity right after treatments (with Comamonadaceae, Methylobacterium, Acidovorax, and Sphingomonas as main OTUs) and also induced further modifications during storage. Bacterial diversity in activated film samples was quite homogeneous during storage (with Vibrio, Photobacterium, and Shewanella as main OTUs) and approached control samples. HP treatments (singly or in combination with activated films) determined a high relative abundance of Acinetobacter (followed by Pseudomonas and Shewanella) during early storage as well as a higher relative abundance of lactic acid bacteria by the end of storage. The results indicate that the complex dynamics of bacterial populations in the refrigerated sea bream fillets are markedly influenced by treatment and antimicrobials applied.

The type of fat in the diet determinates the characteristics of gut microbiota, exerting a major role in the development of metabolic syndrome. We hypothesize that a diet enriched with extra virgin olive oil (EVOO) has a distinctive effect on the intestinal microbiome in comparison with an enriched butter diet (BT) and this effect is related to the physiological benefits exerted by EVOO. Swiss Webster mice were fed standard (SD) or two high fat diets enriched with EVOO or butter. Hormonal, physiological and metabolic parameters were evaluated. At the end of the feeding period, DNA was extracted from faeces and the 16S rRNA genes were pyrosequenced. Among the main significant differences found, BT triggered the highest values of systolic blood pressure, correlating positively with the percentage of Desulfovibrio sequences in faeces, which in turn showed significantly higher values in BT than in EVOO. EVOO had the lowest values of plasmatic insulin, correlating inversely with Desulfovibrio, and had the lowest plasmatic values of leptin which correlated inversely with Sutterellaceae, Marispirillum and Mucilaginibacter dageonensis, the three showing significantly higher percentages in EVOO. The lowest total cholesterol levels in plasma were detected in SD, correlating positively with Prevotella and Fusicatenibacter, both taxa with significantly greater presence in SD. These results may be indicative of a link between specific diets, certain physiological parameters and the prevalence of some taxa, supporting the possibility that in some of the proposed effects of virgin olive oil the modulation of intestinal microbiota could be involved.

Multi-drug resistant bacteria (particularly those producing extended-spectrum β-lactamases) have become a major health concern. The continued exposure to antibiotics, biocides, chemical preservatives, and metals in different settings such as the food chain or in the environment may result in development of multiple resistance or co-resistance. The aim of the present study was to determine multiple resistances (biocides, antibiotics, chemical preservatives, phenolic compounds, and metals) in bacterial isolates from seafoods. A 75.86% of the 87 isolates studied were resistant to at least one antibiotic or one biocide, and 6.90% were multiply resistant to at least three biocides and at least three antibiotics. Significant (P < 0.05) moderate or strong positive correlations were detected between tolerances to biocides, between antibiotics, and between antibiotics with biocides and other antimicrobials. A sub-set of 30 isolates selected according to antimicrobial resistance profile and food type were identified by 16S rDNA sequencing and tested for copper and zinc tolerance. Then, the genetic determinants for biocide and metal tolerance and antibiotic resistance were investigated. The selected isolates were identified as Pseudomonas (63.33%), Acinetobacter (13.33%), Aeromonas (13.33%), Shewanella, Proteus and Listeria (one isolate each). Antibiotic resistance determinants detected included sul1 (43.33% of tested isolates), sul2 (6.66%), blaTEM (16.66%), blaCTX−M (16.66%), blaPSE (10.00%), blaIMP (3.33%), blaNDM−1 (3.33%), floR (16.66%), aadA1 (20.0%), and aac(6′)-Ib (16.66%). The only biocide resistance determinant detected among the selected isolates was qacEΔ1 (10.00%). A 23.30 of the selected isolates were able to grow on media containing 32 mM copper sulfate, and 46.60% on 8 mM zinc chloride. The metal resistance genes pcoA/copA, pcoR, and chrB were detected in 36.66, 6.66, and 13.33% of selected isolates, respectively. Twelve isolates tested positive for both metal and antibiotic resistance genes, including one isolate positive for the carbapenemase gene blaNDM−1 and for pcoA/copA. These results suggest that exposure to metals could co-select for antibiotic resistance and also highlight the potential of bacteria on seafoods to be involved in the transmission of antimicrobial resistance genes.

Lactobacillus pentosus MP-10 is a potential probiotic lactic acid bacterium originally isolated from naturally fermented Aloreña green table olives. The entire genome sequence was annotated to in silico analyze the molecular mechanisms involved in the adaptation of L. pentosus MP-10 to the human gastrointestinal tract (GIT), such as carbohydrate metabolism (related with prebiotic utilization) and the proteins involved in bacteria–host interactions. We predicted an arsenal of genes coding for carbohydrate-modifying enzymes to modify oligo- and polysaccharides, such as glycoside hydrolases, glycoside transferases, and isomerases, and other enzymes involved in complex carbohydrate metabolism especially starch, raffinose, and levan. These enzymes represent key indicators of the bacteria’s adaptation to the GIT environment, since they involve the metabolism and assimilation of complex carbohydrates not digested by human enzymes. We also detected key probiotic ligands (surface proteins, excreted or secreted proteins) involved in the adhesion to host cells such as adhesion to mucus, epithelial cells or extracellular matrix, and plasma components; also, moonlighting proteins or multifunctional proteins were found that could be involved in adhesion to epithelial cells and/or extracellular matrix proteins and also affect host immunomodulation. In silico analysis of the genome sequence of L. pentosus MP-10 is an important initial step to screen for genes encoding for proteins that may provide probiotic features, and thus provides one new routes for screening and studying this potentially probiotic bacterium.

Background: Paipa cheese is a traditional, semi-ripened cheese made from raw cow’s milk in Colombia. The aim of this work was to gain insights on the microbiota of Paipa cheese by using a culture-independent approach. Method: two batches of Paipa cheese from three formal producers were sampled during ripening for 28 days. Total DNA from the cheese samples was used to obtain 16S rRNA gene sequences by using Illumina technology. Results: Firmicutes was the main phylum found in the cheeses (relative abundances: 59.2−82.0%), followed by Proteobacteria, Actinobacteria and Bacteroidetes. Lactococcus was the main genus, but other lactic acid bacteria (Enterococcus, Leuconostoc and Streptococcus) were also detected. Stapylococcus was also relevant in some cheese samples. The most important Proteobacteria were Enterobacteriaceae, Aeromonadaceae and Moraxellaceae. Enterobacter and Enterobacteriaceae (others) were detected in all cheese samples. Serratia and Citrobacter were detected in some samples. Aeromonas and Acinetobacter were also relevant. Other minor genera detected were Marinomonas, Corynebacterium 1 and Chryseobacterium. The principal coordinates analysis suggested that there were producer-dependent differences in the microbiota of Paipa cheeses. Conclusions: lactic acid bacteria are the main bacterial group in Paipa cheeses. However, other bacterial groups, including spoilage bacteria, potentially toxin producers, and bacteria potentially pathogenic to humans and/or prone to carry antimicrobial resistance genes are also relevant in the cheeses.

Lactobacillus pentosus MP-10, isolated from brines of naturally fermented Aloreña green table olives, exhibited high probiotic potential. The genome sequence of L. pentosus MP-10 is currently considered the largest genome among lactobacilli, highlighting the microorganism's ecological flexibility and adaptability. Here, we analyzed the complete genome sequence for the presence of acquired antibiotic resistance and virulence determinants to understand their defense mechanisms and explore its putative safety in food. The annotated genome sequence revealed evidence of diverse mobile genetic elements, such as prophages, transposases and transposons involved in their adaptation to brine-associated niches. In-silico analysis of L. pentosus MP-10 genome sequence identified a CRISPR (clustered regularly interspaced short palindromic repeats)/cas (CRISPR-associated protein genes) as an immune system against foreign genetic elements, which consisted of six arrays (4-12 repeats) and eleven predicted cas genes [CRISPR1 and CRISPR2 consisted of 3 (Type II-C) and 8 (Type I) genes] with high similarity to L. pentosus KCA1. Bioinformatic analyses revealed L. pentosus MP-10 to be absent of acquired antibiotic resistance genes, and most resistance genes were related to efflux mechanisms; no virulence determinants were found in the genome. This suggests that L. pentosus MP-10 could be considered safe and with high-adaptation potential, which could facilitate its application as a starter culture and probiotic in food preparations.

Extra virgin olive oil (EVOO) has been reported to have a distinct influence on gut microbiota in comparison to other fats, with its physiological benefits widely studied. However, a large proportion of the population consumes olive oil after a depurative process that not only mellows its taste, but also deprives it of polyphenols and other minority components. In this study, we compare the influence on the intestinal microbiota of a diet high in this refined olive oil (ROO) with other fat-enriched diets. Swiss Webster mice were fed standard or a high-fat diet enriched with EVOO, ROO, or butter (BT). Physiological parameters were also evaluated. At the end of the feeding period, DNA was extracted from feces and the 16S rRNA was pyrosequenced. The group fed ROO behaved differently to the EVOO group in half the families with statistically significant differences among the diets, with higher comparative levels in three families—Desulfovibrionaceae, Spiroplasmataceae, and Helicobacteraceae—correlating with total cholesterol. These results are again indicative of a link between specific diets, certain physiological parameters and the prevalence of some taxa, but also support the possibility that polyphenols and minor components of EVOO are involved in some of the proposed effects of this fat through the modulation of the intestinal microbiota

Heat-stable enterotoxins are the most notable virulence factors associated with Staphylococcus aureus, a common pathogen associated with serious community and hospital acquired diseases. Staphylococcal enterotoxins (SEs) cause toxic shock-like syndromes and have been implicated in food poisoning. But SEs also act as superantigens that stimulate T-cell proliferation, and a high correlation between these activities has been detected. Most of the nosocomial S. aureus infections are caused by methicillin-resistant S. aureus (MRSA) strains, and those resistant to quinolones or multiresistant to other antibiotics are emerging, leaving a limited choice for their control. This review focuses on these diverse roles of SE, their possible correlations and the influence in disease progression and therapy.

The distribution and quantification of tetracycline, sulfonamide and beta-lactam resistance genes were assessed in slaughterhouse zones throughout meat chain production and the meat products; this study represents the first to report quantitatively monitor antibiotic resistance genes (ARG) in goat and lamb slaughterhouse using a culture independent approach, since most studies focused on individual bacterial species and their specific resistance types. Quantitative PCR (qPCR) revealed a high prevalence of tetracycline resistance genes tetA and tetB in almost all slaughterhouse zones. Sulfonamide resistance genes were largely distributed, while beta-lactam resistance genes were less predominant. Statistical analysis revealed that resistant bacteria, in most cases, were spread by the same route in almost all slaughterhouse zones, except for tetB, blaCTX and blaTEM genes, which occurred in few zones as isolated 'hot spots.' The sum of all analyzed ARG indicated that slaughterhouse surfaces and end products act as reservoirs of ARG, mainly tet genes, which were more prevalent in slaughtering room (SR), cutting room (CR) and commercial meat products (MP). Resistance gene patterns suggest they were disseminated throughout slaughterhouse zones being also detected in commercial meat products, with significant correlations between different sampling zones/end products and total resistance in SR, CR and white room (WR) zones, and also refrigerator 4 (F4) and MP were observed. Strategically controlling key zones in slaughterhouse (SR, CR and WR) by adequate disinfection methods could strategically reduce the risks of ARG transmission and minimize the issues of food safety and environment contamination.

Roselle (Hibiscus sabdariffa L.) calyces have abundant phenolic compounds to which multiple therapeutic benefits are attributed. The study aimed to develop a nutraceutical beverage from Hs extracts of genotypes with different pigmentation and phytochemical composition, with sensory characteristics accepted by the consumer and with a high content of antioxidants. Calyces of three cultivars with intense red, light red, and non-pigmentation were used to prepare aqueous extracts, which were mixed in different proportions to achieve beverages with a standardized anthocyanin content (TAC). Four beverage formulations, denoted as B1, B2, B3, and B4, were obtained, which were subjected to global acceptance tests through different sensory variables. The variables determined in the beverages were color, pH, titratable acidity (TA), total soluble phenols (TSPs), TAC, proanthocyanidins (PAs), and antioxidant capacity (AC). The TAC in the beverages ranged from 23 to 24.9 mg anthocyanin per 240 ml portion. The color and TA of the beverages were statistically different according to the objective measurement, but sensory differences were not detected. Beverages B1 and B4, formulated with mixtures of the three cultivars, had the highest TSP content and AC and had the best aroma and flavor. Incorporating pigment-free calyx extracts in the formulation of roselle beverages improves their sensory characteristics and antioxidant content. [ABSTRACT FROM AUTHOR]

Oaxaca is one of the three main producing states of jamaica sorrel or roselle, Hibiscus sabdariffa L., of Mexico. This crop is affected by various pests such as pseudococcids. In 2022, the mealybug Phenacoccus solenopsis was detected causing damage in an experimental plot. The damage it causes to plants is wilting, drying, and defoliation of some terminal apices of the branches. Infestation levels ranged from 14 to 86%. [ABSTRACT FROM AUTHOR]

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Fresh fruits have been involved in transmission of foodborne pathogens. In the present work, five different batches of blueberries were used. One aliquot from each batch was washed with sterile saline solution (SSS) and the other one with a solution of the circular bacteriocin enterocin AS-48 in SSS. Then, the surface microbiota of controls and bacteriocin-treated samples was recovered and used for microbiota analyses, both using viable counts and high-throughput amplicon sequencing. Total aerobic mesophilic loads ranged from 2.70 to 4.09 log CFU/g in most of the samples. Only two samples yielded detectable viable counts on selective media (Enterobacteriaceae, presumptive Salmonella and coliforms), with values ranging from 2.84 to 3.81 log CFU/g. The bacteriocin treatment reduced viable cell counts of total aerobic mesophiles to a range of 1.40–1.88 log CFU/g. No viable cells were detected on selective media. Amplicon sequencing indicated large batch-to-batch variations in the surface microbiota of blueberries and also an effect of the bacteriocin treatment on microbiota composition.

Abstract  A bacteriocin-producing lactic acid bacterium (strain 2.5) isolated from cow’s milk used in cheese production from Northern Morocco was selected for its strong anti-listerial activity. The producer strain was identified as Enterococcus faecalis by molecular methods. Strain 2.5 carried the genetic determinants for the two-peptide enterococcal bacteriocin enterocin 1071, and the active bacteriocin was purified to homogeneity by reversed-phase chromatography from culture broths of the producer strain. Strain 2.5 carried two plasmids (of ∼7 and 40 kb). Characterization of strain 2.5 at biosafety level indicated that this strain is non-haemolytic, and lacks the genetic determinants for most of the virulence factors described in enterococci (cylB, cylM, gelE, ace and agg) although it carried the genetic determinants cylA, efaAfs as well as determinants for the sex pheromone peptides cpd, cob, and ccf. Strain 2.5 was resistant to tetracycline, rifampicin, and ciprofloxacin, but it was sensitive to penicillin, ampicillin, vancomycin, and teicoplanin. Results from the present study support the potential role of strain 2.5 as an anti-listerial agent to be tested in traditional fermented foods. [ABSTRACT FROM AUTHOR]

The production of antimicrobial substances was studied among 195 bacterial isolates from retail table olives. A total 86 isolates tested positive, and they clustered in 10 groups according to their inhibitory spectra. Many isolates (38.37%) produced strong inhibition against all bacteria tested (Listeria innocua, Lactococcus lactis, Bacillus cereus, B. megaterium, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, and Escherichia coli). The selected bacterial isolates were Gram-positive bacteria with rod morphology (62.67%), short rods (26.65%) or cocci (10.67%). Isolates producing antimicrobial substances may be useful as starters to enhance control of table olive fermentation and improve the safety of retail table olives. [ABSTRACT FROM AUTHOR]

A collection of lactobacilli comprising species of Lactobacillus plantarum (43 isolates), Lactobacillus brevis (9 isolates) and Lactobacillus fermentum (6 isolates) obtained from spontaneous fermentations of capers (the fruits of Capparis spinosa) were investigated for resistance to antimicrobial agents. All isolates were resistant to vancomycin and teicoplanin (MIC  > 16 μg/ml). Resistance to ciprofloxacin (MIC  > 2 μg/ml) was detected in all isolates of L. brevis and L. fermentum as well as in most isolates of L. plantarum, whilst resistance to levofloxacin showed a much lower incidence. Among L. plantarum and L. brevis isolates, low levels of resistance to tetracycline and/or nitrofurantoin were detected. Higher resistance levels were also detected in some isolates. Resistance to penicillin and rifampicin were also detected among L. plantarum isolates. All isolates were sensitive to ampicillin, erythromycin, chloramphenicol, gentamicin, streptomycin, and quinupristin/dalfopristin. [ABSTRACT FROM AUTHOR]

In this paper we study a large class of Weingarten surfaces which includes the constant mean curvature one surfaces and flat surfaces in the hyperbolic 3-space. We show that these surfaces can be parametrized by holomorphic data like minimal surfaces in the Euclidean 3-space and we use it to study their completeness. We also establish some existence and uniqueness theorems by studing the Plateau problem at infinity: when is a given curve on the ideal boundary the asymptotic boundary of a complete surface in our family? and, how many embedded solutions are there? [ABSTRACT FROM AUTHOR]

The incidence and diversity of enterococci in retail food samples of meat, dairy and vegetable origin was investigated. Enterococci were present, at concentrations of 101 to 104 CFU/g. Fifty selected isolates from food samples grouped in two separate clusters by RAPD analysis. Cluster G1 (72% of the isolates) contained the E. faecium CECT 410T type strain, and also showed a high degree of genetic diversity. Cluster G2 (28% of the isolates) contained the E. faecalis CECT 481T type strain and was genetically more homogeneous. Virulence traits (haemolysin, gelatinase or DNAse activities, or the presence of structural genes cylL, ace, asa1 and esp) were not detected. All isolates were sensitive to the antibiotics ampicillin, penicillin, gentamicin, streptomycin and chloramphenicol. A high pecentage of isolates were resistant to erythromycin and rifampicin. Many isolates showed intermediate sensitivity to several antibiotics (tetracycline, ciprofloxacin, levofloxacin, or quinupristin/dalfopristin). Vancomycin and teicoplanin resistance was detected in one strain, but vanA, vanB, vanC1, vanC2 or vanC3 genes were not detected. Many of the isolates showed functional properties of food or health relevance. Production of antimicrobial substances was detected in 17 of the isolates, and 14 of them carried structural genes for enterocins A, B and/or P. [ABSTRACT FROM AUTHOR]

Copper-derived compounds are often used in olive tree farms. In a previous study, a collection of bacterial strains isolated from olive tree farms were identified and tested for phenotypic antimicrobial resistance and heavy metal tolerance. The aim of this work was to study the genetic determinants of resistance and to evaluate the co-occurrence of metal tolerance and antibiotic resistance genes. Both metal tolerance and antibiotic resistance genes (including beta-lactamase genes) were detected in the bacterial strains from Cu-treated soils. A high percentage of the strains positive for metal tolerance genes also carried antibiotic resistance genes, especially for genes involved in resistances to beta-lactams and tetracycline. Significant associations were detected between genes involved in copper tolerance and genes coding for beta-lactamases or tetracycline resistance mechanisms. A significant association was also detected between zntA (coding for a Zn(II)-translocating P-type ATPase) and tetC genes. In conclusion, bacteria from soils of Cu-treated olive farms may carry both metal tolerance and antibiotic resistance genes. The positive associations detected between metal tolerance genes and antibiotic resistance genes suggests co-selection of such genetic traits by exposure to metals.

Breast milk from a single mother was collected during a 28-week lactation period. Bacterial diversity was studied by amplicon sequencing analysis of the V3-V4 variable region of the 16S rRNA gene. Firmicutes and Proteobacteria were the main phyla detected in the milk samples, followed by Actinobacteria and Bacteroidetes. The proportion of Firmicutes to Proteobacteria changed considerably depending on the sampling week. A total of 411 genera or higher taxons were detected in the set of samples. Genus Streptococcus was detected during the 28-week sampling period, at relative abundances between 2.0% and 68.8%, and it was the most abundant group in 14 of the samples. Carnobacterium and Lactobacillus had low relative abundances. At the genus level, bacterial diversity changed considerably at certain weeks within the studied period. The weeks or periods with lowest relative abundance of Streptococcus had more diverse bacterial compositions including genera belonging to Proteobacteria that were poorly represented in the rest of the samples.

Guacamole is an avocado sauce highly appreciated for its pleasant taste and nutritional value. The present study addressed the impact of high-hydrostatic pressure (HP) treatments on the product safety and bacterial diversity. Four HP treatments, 5 min each, were applied: (A) 450 megapascals (MPa) at 22 °C; (B) 450 MPa at 50 °C; (C) 600 MPa at 22 °C; (D) 600 MPa at 50 °C. Controls and treated samples were refrigerated stored for 50 days. The residual surviving fraction was lowest for the 600 MPa treatment at 50 °C. Bacterial growth on media supplemented with antibiotics (cefotaxime and imipenem) or the biocide benzalkonium chloride was detected only from control samples but not from HP-treated samples. High throughput sequencing analysis indicated that the bacterial diversity of control samples was dominated by members of Fam. Enterobacteriaceae, but it changed to a lactic acid microbiota during storage. HP-treated samples showed reduced relative abundances of Enterobacteriaceae and lactic acid bacteria and higher abundances of Pantoea, Ralstonia and Methylobacterium. Results from the study indicate that HP treatments of guacamole at 50 °C show higher microbial inactivation compared to 22 °C. However, all treatments reduced the levels of Enterobacteriaceae and penem-tolerant bacteria and provided product stability against acidification by lactic acid bacteria.

A collection of 31 Lactobacillus pentosus strains isolated from naturally fermented Aloreña green table olives were screened in depth in the present study for their probiotic potential. Several strains could be considered promising probiotic candidates since they showed good growth capacity and survival under simulated gastro-intestinal conditions (acidic pH of 1.5, up to 4% of bile salts and 5 mM of nitrate), good ability to auto-aggregate which may facilitate their adhesion to host cells as multiple aggregates and the subsequent displacement of pathogens. Moreover, co-aggregation of lactobacilli with pathogenic bacteria was shown with Listeria innocua, Staphylococcus aureus, Escherichia coli and Salmonella Enteriditis as good defense strategy against gut and food pathogens. Furthermore, they exhibited adherence to intestinal and vaginal cell lines, such property could be reinforced by their capacity of biofilm formation which is also important in food matrices such as the olive surface. Their antagonistic activity against pathogenic bacteria by means of acids and plantaricins, and also their different functional properties may determine their efficacy not only in the gastro-intestinal tract but also in food matrices. Besides their ability to ferment several prebiotics, the new evidence in the present study was their capacity to ferment lactose which reinforces their use in different food matrices including dairy as a dietary adjunct to improve lactose digestibility. Lactobacillus pentosus CF2-10N was selected to have best probiotic profile being of great interest in further studies. In conclusion, spontaneous fermented Aloreña table olives are considered a natural source of potential probiotic Lb. pentosus to be included as adjunct functional cultures in different fermented foods.

Urban expansion constitutes one of the main activities that modify natural environments worldwide; the most vulnerable areas to these effects are peri-urban areas. An example is 59% of the surface of Mexico City, considered a Conservation Zone (CZ). Within the CZ there are natural ecosystems, agricultural and livestock activities take place, which is why it is considered an area that provides a large number of services, including ecosystem services. This study aimed to analyze the rates of urban expansion in the CZ during two periods (2012-2018, 2018-2023) with contrasting environmental policies. Landsat 7 and 8 images were used to perform a supervised classification with Random Forest algorithm with which the surface of different land use classes was estimated for three years 2012, 2018, and 2023. The dynamics of urban expansion in two administrative periods were evaluated with different approaches and budget priorities in the environmental public policy of the CZ. Supervised classification had adequate accuracy (≥89%). The rate of urban expansion during the studied periods was 31.7% (269 ha/year) from 2012 to 2018 and 16.9% (190.3 ha/year) from 2018 to 2023. A clear deceleration of land use change for urban purposes was observed; three out of the nine municipalities comprising the SC exhibited an urban expansion rate close to 0%. Additionally, a “protective” effect was also exhibited towards the agricultural areas and primary forests of the CZ. The budget increase focused on environmental conservation activities and rural development of the CZ appears to have affected the dynamics of urban expansion in the peri-urban area of one of the most complex cities in the world.

ABSTRACTThe antibacterial activities (ABAC) of white calyces varieties (WCV) of Hibiscus sabdariffa L has not been explored in depth. The aims of the study were to determine the ABAC of WCV and the relationship of phenolic composition with ABAC. Four experimental WCV (W1, W2, W3, and W4), and one with red calyces (RCV) were used. The ABAC of ethanol extracts were tested against Gram (+) and Gram (-) bacteria. WCV showed higher ABAC than RCV, and it was associated to flavonoid content which was 60% higher in WCV with respect to RCV. The free phenolic content of W1, W2, and W4 varieties was 50% higher than that observed in RCV and W3 varieties. The standardized abundance of N-feruloyltiramine and quercetin in the extracts of WCV was related with their highest ABAC. WCV are a promising source of phenolic compounds with high ABAC.

The article presents a reprint of a short story "Monologue for Jutito," by Antonio Gálvez Ronceros, which appeared in the book "Monólogo desde las tinieblas," published in 1975. The story revolves around an Afro-Peruvian boy named Jutito. In the story the author says to Jutito, the things he will have to learn when he grows up to be a man like working on fields to fulfill his life.

The short story "Jutito" by Antonio Gálvez Ronceros, previously published in Monólogo desde las tinieblas is presented.

This article addresses issues related to the management of Intellectual Property from legislation and public policies and the importance it has in the sphere of social development at present, in addition it talks about the little interest paid by the academy Ecuadorian to study mechanisms to optimize the capitalization of intangible assets of Intellectual Property and thus allow the full enjoyment of its fruits by its owner, so that in the following lines some important aspects will be mentioned to be considered so that the management of Intellectual property rights in Ecuador reflect the needs of the fourth industrial revolution and the global market today.

In this article an analysis of the performance of the public defense of Ecuador is carried out with the objective of identifying administrative factors that affect the efficiency of this institution to propose solutions that allow an improvement in its performance since in recent years there has been a lack of productivity In this body, which is pernicious to consider that the exercise of the rights of many people in the country depends on their actions. In this project, through the introduction of the principal-agent model, the importance of the costs of agency in the results of the work of the public defense, as manager, and the damages that the citizenship receives as principal is explained. Some incentives to combat the problem of agency in public institutions are analyzed and finally the conclusion is reached that the inefficient performance of public defense lies in a structural problem of the Ecuadorian public administration.