Phenotypic and genotypic characterization of antimicrobial resistances reveals the effect of the production chain in reducing resistant lactic acid bacteria in an artisanal raw ewe milk PDO cheese.

Antimicrobial resistance (AMR) is a significant public health threat, with the food production chain, and, specifically, fermented products, as a potential vehicle for dissemination. However, information about dairy products, especially raw ewe milk cheeses, is limited. The present study analysed, for the first time, the occurrence of AMRs related to lactic acid bacteria (LAB) along a raw ewe milk cheese production chain for the most common antimicrobial agents used on farms (dihydrostreptomycin, benzylpenicillin, amoxicillin and polymyxin B). More than 200 LAB isolates were obtained and identified by Sanger sequencing (V1-V3 16S rRNA regions); these isolates included 8 LAB genera and 21 species. Significant differences in LAB composition were observed throughout the production chain (P ≤ 0.001), with Enterococcus (e.g., E. hirae and E. faecalis) and Bacillus (e.g., B. thuringiensis and B. cereus) predominating in ovine faeces and raw ewe milk, respectively, along with Lactococcus (L. lactis) in whey and fresh cheeses, while Lactobacillus and Lacticaseibacillus species (e.g., Lactobacillus sp. and L. paracasei) prevailed in ripened cheeses. Phenotypically, by broth microdilution, Lactococcus, Enterococcus and Bacillus species presented the greatest resistance rates (on average, 78.2 %, 56.8 % and 53.4 %, respectively), specifically against polymyxin B, and were more susceptible to dihydrostreptomycin. Conversely, Lacticaseibacillus and Lactobacillus were more susceptible to all antimicrobials tested (31.4 % and 39.1 %, respectively). Thus, resistance patterns and multidrug resistance were reduced along the production chain (P ≤ 0.05). Genotypically, through HT-qPCR, 31 antimicrobial resistance genes (ARGs) and 6 mobile genetic elements (MGEs) were detected, predominating Str, StrB and aadA-01, related to aminoglycoside resistance, and the transposons tnpA-02 and tnpA-01. In general, a significant reduction in ARGs and MGEs abundances was also observed throughout the production chain (P ≤ 0.001). The current findings indicate that LAB dynamics throughout the raw ewe milk cheese production chain facilitated a reduction in AMRs, which has not been reported to date.

Cross-sectional, commercial testing, and chromatographic study of the occurrence of antibiotic residues throughout an artisanal raw milk cheese production chain.

This study investigated antibiotic utilization in artisanal dairies and residue occurrence throughout the raw milk cheese production chain using commercial testing (Charm KIS and Eclipse Farm3G) and UHPLC-QqQ-MS/MS and LC-QqQ-MS/MS. The cross-sectional survey results revealed gaps in the producers' knowledge of antibiotic use. Commercial testing detected antibiotic levels close to the LOD in 12.5 % of the samples, mainly in raw milk and whey, with 10.0 % testing positive, specifically in fresh and ripened cheeses, indicating that antibiotics are concentrated during cheese-making. Chromatographically, several antibiotics were identified in the faeces of healthy animals, with chlortetracycline (15.7 ± 34.5 µg/kg) and sulfamethazine (7.69 ± 16.5 µg/kg) predominating. However, only tylosin was identified in raw milk (3.28 ± 7.44 µg/kg) and whey (2.91 ± 6.55 µg/kg), and none were found in fresh or ripened cheeses. The discrepancy between commercial and analytical approaches is attributed to compounds or metabolites not covered chromatographically.

Normal-Fat vs. High-Fat Diets and Olive Oil vs. CLA-Rich Dairy Fat: A Comparative Study of Their Effects on Atherosclerosis in Male Golden Syrian Hamsters.

The relationship between milk fat intake (because of its high saturated fatty acid content) and the risk of suffering from cardiovascular diseases remains controversial. Thus, Golden Syrian hamsters were fed two types of fat-sheep milk fat that was rich in rumenic (cis9,trans11-18:2) and vaccenic (trans11-18:1) acids and olive oil-and two doses (a high- or normal-fat diet) for 14 weeks, and markers of lipid metabolism and atherosclerosis evolution were analyzed. The results revealed that the type and percentage of fat affected most plasma biochemical parameters related to lipid metabolism, while only the expression of five (CD36, SR-B1, ACAT, LDLR, and HMG-CoAR) of the studied lipid-metabolism-related genes was affected by these factors. According to aortic histology, when ingested in excess, both fats caused a similar increase in the thickness of fatty streaks, but the high-milk-fat-based diet caused a more atherogenic plasma profile. The compositions of the fats that were used, the results that were obtained, and the scientific literature indicated that the rumenic acid present in milk fat would regulate the expression of genes involved in ROS generation and, thus, protect against LDL oxidation, causing an effect similar to that of olive oil.

Relationship between the dynamics of volatile aroma compounds and microbial succession during the ripening of raw ewe milk-derived Idiazabal cheese.

Cheese microbiota contributes to various biochemical processes that lead to the formation of volatile compounds and the development of flavour during ripening. Nonetheless, the role of these microorganisms in volatile aroma compounds production is little understood. This work reports for the first time the dynamics and odour impact of volatile compounds, and their relationship to microbial shifts during the ripening of a raw ewe milk-derived cheese (Idiazabal). By means of SPME-GC-MS, 81 volatile compounds were identified, among which acids predominated, followed by esters, ketones and alcohols. The ripening time influenced the abundance of most volatile compounds, thus the moments of greatest abundance were determined (such as 30-60 days for acids). Through Odour Impact Ratio (OIR) values, esters and acids were reported as the predominant odour-active chemical families, while individually, ethyl hexanoate, ethyl 3-methyl butanoate, ethyl butanoate, butanoic acid or 3-methyl butanal were notable odorants, which would provide fruity, rancid, cheesy or malt odour notes. Using a bidirectional orthogonal partial least squares (O2PLS) approach with Spearman's correlations, 12 bacterial genera were reported as key bacteria for the volatile and aromatic composition of Idiazabal cheese, namely Psychrobacter, Enterococcus, Brevibacterium, Streptococcus, Leuconostoc, Chromohalobacter, Chryseobacterium, Carnobacterium, Lactococcus, Obesumbacterium, Stenotrophomonas and Flavobacterium. Non-starter lactic acid bacteria (NSLAB) were highly related to the formation of certain acids, esters and alcohols, such as 3-hexenoic acid, ethyl butanoate or 1-butanol. On the other hand, the starter LAB (SLAB) was related to particular ketones production, specifically 3-hydroxy-2-butanone; and environmental and/or non-desirable bacteria to certain ketones, hydrocarbons and sulphur compounds formation, such as 2-propanone, t-3-octene and dimethyl sulphone. Additionally, the SLAB Lactococcus and Psychrobacter, Brevibacterium and Chromohalobacter were described as having a negative effect on aroma development caused by NSLAB and vice versa. These results provide novel knowledge to help understand the aroma formation in a raw ewe milk-derived cheese.

Relationship between the Dynamics of Gross Composition, Free Fatty Acids and Biogenic Amines, and Microbial Shifts during the Ripening of Raw Ewe Milk-Derived Idiazabal Cheese.

This study reports for the first time the relationship between bacterial succession, characterized by high-throughput sequencing (sequencing of V3-V4 16S rRNA regions), and the evolution of gross composition, free fatty acids (FFAs) and biogenic amines (BAs) during cheese ripening. Specifically, Idiazabal PDO cheese, a raw ewe milk-derived semi-hard o hard cheese, was analysed. Altogether, 8 gross parameters were monitored (pH, dry matter, protein, fat, Ca, Mg, P and NaCl) and 21 FFAs and 8 BAs were detected. The ripening time influenced the concentration of most physico-chemical parameters, whereas the producer mainly affected the gross composition and FFAs. Through an O2PLS approach, the non-starter lactic acid bacteria Lactobacillus, Enterococcus and Streptococcus were reported as positively related to the evolution of gross composition and FFAs release, while only Lactobacillus was positively related to BAs production. Several environmental or non-desirable bacteria showed negative correlations, which could indicate the negative impact of gross composition on their growth, the antimicrobial effect of FFAs and/or the metabolic use of FFAs by these genera, and their ability to degrade BAs. Nonetheless, Obesumbacterium and Chromohalobacter were positively associated with the synthesis of FFAs and BAs, respectively. This research work provides novel information that may contribute to the understanding of possible functional relationships between bacterial communities and the evolution of several cheese quality and safety parameters.

Characterization of Microbial Shifts during the Production and Ripening of Raw Ewe Milk-Derived Idiazabal Cheese by High-Throughput Sequencing.

In this study, we used high-throughput sequencing technologies (sequencing of V3-V4 hypervariable regions of 16S rRNA gene) to investigate for the first time the microbiota of Latxa ewe raw milk and the bacterial shifts that occur during the production and ripening of Idiazabal cheese. Results revealed several bacterial genera not reported previously in raw ewe milk and cheese, such as Buttiauxella and Obesumbacterium. Both the cheese making and ripening processes had a significant impact on bacterial communities. Overall, the growth of lactic acid bacteria (LAB) (Lactococcus, Lactobacillus, Leuconostoc, Enterococcus, Streptococcus and Carnobacterium) was promoted, whereas that of non-desirable and environmental bacteria was inhibited (such as Pseudomonas and Clostridium). However, considerable differences were observed among producers. It is noteworthy that the starter LAB (Lactococcus) predominated up to 30 or 60 days of ripening and then, the growth of non-starter LAB (Lactobacillus, Leuconostoc, Enterococcus and Streptococcus) was promoted. Moreover, in some cases, bacteria related to the production of volatile compounds (such as Hafnia, Brevibacterium and Psychrobacter) also showed notable abundance during the first few weeks of ripening. Overall, the results of this study enhance our understanding of microbial shifts that occur during the production and ripening of a raw ewe milk-derived cheese (Idiazabal), and could indicate that the practices adopted by producers have a great impact on the microbiota and final quality of this cheese.

Valorisation of fruit and vegetable discards by fungal submerged and solid-state fermentation for alternative feed ingredients production.

The present research describes an integral strategy for valorisation of fruit and vegetable discards (FVd) in feeding application, using solid-state fermentation (SSF) and submerged fermentation (SmF), for both solid and liquid fractions obtained during these by-products handle and processing, using a strain of Rhizopus sp. After SSF, fermented biomass had 1.9 times higher protein content (up to 20.2 ± 1.7% DM) than the original mass and an improved amino acid (AA) profile (45.7 ± 1.8% essential AAs). Fatty acid (FA) profile was also modified during fermentation process, with higher monounsaturated (MUFA) and lower polyunsaturated fatty acid (PUFA) percentage in the final product compared with initial substrate. Phenolic compound concentration was double in final biomass than in initial substrate (up to 8.9 ± 1.5 mg GAE/g DM) and fermented product had higher antioxidant activity (DPPH reduction of 81.3 ± 7.7% and TEAC of 3.6 ± 0.3 mg/g DM). Compared with previously reported results, fruit complementation with vegetables increased the available nitrogen and resulted in higher biomass production. The fruit and vegetable leachate (FVL) obtained by centrifugation was treated by SmF and led, per liter of substrate, to 10.6 ± 1.4 g of fungal biomass and 3.3 g protein after 7 days of fermentation. Obtained fungal biomass was rich in PUFAs (27.1 ± 7.2% of total FA) and had an AA profile comparable to soybean meal, with 45.3 ± 1.5% of essential amino acids (EAA). In conclusion, results demonstrate that combined solid and liquid fermentation is a successful strategy for FVd valorisation to produce valuable alternative feed ingredient due to their high protein and the well-balanced lipid content and amino acid profile.

Novel Vibrio spp. Strains Producing Omega-3 Fatty Acids Isolated from Coastal Seawater.

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA) (20:5n-3) and docosahexaenoic acid (DHA) (22:6n-3), are considered essential for human health. Microorganisms are the primary producers of omega-3 fatty acids in marine ecosystems, representing a sustainable source of these lipids, as an alternative to the fish industry. Some marine bacteria can produce LC-PUFAs de novo via the Polyunsaturated Fatty Acid (Pfa) synthase/ Polyketide Synthase (PKS) pathway, which does not require desaturation and elongation of saturated fatty acids. Cultivation-independent surveys have revealed that the diversity of microorganisms harboring a molecular marker of the pfa gene cluster (i.e., pfaA-KS domain) is high and their potential distribution in marine systems is widespread, from surface seawater to sediments. However, the isolation of PUFA producers from marine waters has been typically restricted to deep or cold environments. Here, we report a phenotypic and genotypic screening for the identification of omega-3 fatty acid producers in free-living bacterial strains isolated from 5, 500, and 1000 m deep coastal seawater from the Bay of Biscay (Spain). We further measured EPA production in pelagic Vibrio sp. strains collected at the three different depths. Vibrio sp. EPA-producers and non-producers were simultaneously isolated from the same water samples and shared a high percentage of identity in their 16S rRNA genes, supporting the view that the pfa gene cluster can be horizontally transferred. Within a cluster of EPA-producers, we found intraspecific variation in the levels of EPA synthesis for isolates harboring different genetic variants of the pfaA-KS domain. The maximum production of EPA was found in a Vibrio sp. strain isolated from a 1000 m depth (average 4.29% ± 1.07 of total fatty acids at 10 °C, without any optimization of culturing conditions).

Valorization of cheese whey and orange molasses for fungal biomass production by submerged fermentation with Rhizopus sp.

Submerged fermentation (SmF) is an attractive biotechnological option for waste treatment, generating fungal bioprotein from food industry by-products. Using different Rhizopus sp. strains as fermentation agents, this paper describes a global strategy to identify interactions between cultivation parameters (pH 4.75-7.75, 7.5-82.5 g/l glucose, 0.75-3.75 g/l nitrogen, incubation time up to 5 days) for valorization of food industry by-products. Selected parameters and/or their interactions are critical for most of the proposed resulting values, giving the opportunity to optimize the process depending on the objective and making an "in silico" pre-evaluation of the process conditions. SmF of orange molasses leads to a high biomass and protein yield (11.9 g biomass/l and 4.0 g protein/l), with 43.1 ± 0.1% of essential amino acids and chemical oxygen demand (COD) reduction of almost 50%. Experiments with cheese whey result in 76.3 ± 1.1% of glucose consumption and a biomass production of 5.6 ± 2.2 g/l with 48.9 ± 5.1% of essential amino acids. SmF of orange molasses and cheese whey could contribute to promoting a sustainable feed industry while reducing by-product treatment.

Dermatitis seborreica como manifestación cutánea de sífilis primaria en paciente con SIDA / Seborrheic dermatitis as a cutaneous manifestation of syphilis in patient a with AIDS

Existe una asociación epidemiológica entre sífilis e infección por VIH; las úlceras genitales favorecen la transmisión de Treponema pallidum y éste a su vez, la transmisión del VIH. La dermatitis seborreica (DS) se presenta en 2 a 4% de la población general; sin embargo, en los pacientes con infección por VIH/SIDA y SIFILIS es significativamente mayor, llegando a 85% en algunas series. Se presenta el caso de un paciente masculino de 22 años de edad, natural y procedente del Distrito Capital, Venezuela, sin otras patologías conocidas, quien acude a la emergencia por presentar periodos de hetero agresividad y desorientación témporo ­ espacial., El familiar refiere aparición de lesiones descamativas de fondo eritematoso en región facial desde hace 6 meses, no pruriginosas y a la exploración física se evidencia parafasia y pupila de Argyll- Robertson. Se reportan serologías Positivas para HIV por ELISA de 4ta Generación, VDRL Reactivo a 4 diluciones y FTA-ABS Reactivo, La punción Lumbar evidenció pleocitosis, hiperproteinorraquia, hipoglucorraquia y VDRL REACTIVO. La biopsia cutánea con coloración argéntica de Fontana fué positiva para Treponema pallidum, con mejoría clínica significativa posterior al cumplimiento del esquema de Penicilina Cristalina. La dermatitis seborreica puede ser uno de los primeros indicadores de infección por VIH, por lo cual en toda dermatitis seborreica atípica, extensa o que no responda a tratamiento debe solicitarse serología para VIH y VDRL(AU)

There is an epidemiological association between syphilis and HIV infection; genital ulcers facilitatethe transmission of Treponema pallidum and this in turn, the transmission of HIV. Seborrheic dermatitis (SD) occurs in 2 to 4% of the general population; however, in patients with HIV / AIDS and SIFILIS infection it is significantly higher, reaching 85% in some series. We present the case of a male patient, of a 22 years-old , natural from the Caracas, Venezuela, without other known pathologies, who came to the emergency ward due to periods of aggressiveness and temporo - spatial disorientation. Desquamative lesions with an erythematous background in in his face appeared 6 months earlier.The neurological examination showeds paraphasia and Argyll-Robertson´ pupil. Positive serologies for HIV by 4th Generation ELISA and VDRL reactive at 4 dilutions as well as positive FTA-ABS were reported, Lumbar tab evidenced pleocytosis, hyperproteinorrachia, hypoglucorraquia and reagent VDRL . The skin biopsy with Fontana silver coloration was positive for Treponema pallidum and he improved clinically after treatment with a Crystalline Penicillin scheme. Seborrheic dermatitis may be one of the first indicators of HIV infection, so in all atypical seborrheic dermatitis, extensive or unresponsive to treatment, serology for HIV and VDRL should be determined(AU)

Bacteriophages against Serratia as Fish Spoilage Control Technology.

Bacteria of the genus Serratia, mainly S. proteamaculans and S. fonticola, are important spoilage agents in Atlantic horse mackerel (Trachurus trachurus). In order to evaluate whether bacteriophages against Serratia could delay the spoilage process, 11 viral strains active against this genus were isolated from food and best candidate was applied to fresh mackerel filets. All the phages belong to the Siphoviridae and Podoviridae families and were active at multiplicity of infection (MOI) levels below 1:1 in Long & Hammer broth. The ability of phage AZT6 to control Serratia populations in real food was tested in Atlantic horse mackerel extract and applied to fresh mackerel filets. Treatment with high phage concentration (MOI 350:1, initial Serratia population 3.9 ± 0.3 Log cfu/g) can reduce the Serratia populations up to 90% during fish storage (a maximum of 6 days) at low temperatures (6°C). Bacterial inhibition was dependent on the bacteriophage dosage, and MOI of 10:1 or lower did not significantly affect the Serratia populations.

Phage therapy as an approach to prevent Vibrio anguillarum infections in fish larvae production.

Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL-1) and one was later treated with a phage lysate (∼108 PFU mL-1). A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control). Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture.

Evolution of the indigenous microbiota in modified atmosphere packaged Atlantic horse mackerel (Trachurus trachurus) identified by conventional and molecular methods.

A combination of conventional methods and genetic identification (PCR sequencing) was used to study the dynamics of the bacterial population during the spoilage of modified atmosphere packaged (MAP) Atlantic horse mackerel (Trachurus trachurus) fillets. The cultivable microflora in Atlantic horse mackerel samples packaged in a modified atmosphere (48% CO2, 50% N2 and 2% O2) at refrigeration temperature (6 °C) was measured on days 1, 5 and 7 using non-selective (Long and Hammer agar) and selective media (Kligler's iron agar, STAA and MRS). The microflora was genetically characterised using partial amplification of 16S rRNA gene sequences from 309 bacterial isolates obtained from Long and Hammer agar. At the end of the shelf life (5 days), the total viable counts (TVC) on Long and Hammer agar were not significantly different to the LAB counts on MRS agar (p>0.05). The molecular approach showed that Photobacterium, Arthrobacter, Chryseobacterium and Pseudoclavibacter (44.5% of total) dominated the microbial composition of the fish at the beginning of storage. However, Serratia, Shewanella and Yersinia dominated at the late spoilage stages (over 57.2% of the total). Carnobacterium was the most important species of the lactic acid bacteria (LAB) and was identified at the beginning and end of the storage period. Vibrio spp. was only found at the end of the shelf life. This research demonstrates that the microbial biodiversity in MAP Atlantic horse mackerel is enormous and the dominant species change over the storage time. The results presented here on the dominant communities in fish products will make it possible to accurately select the best preservation practices.

Quality changes of Atlantic horse mackerel fillets (Trachurus trachurus) packed in a modified atmosphere at different storage temperatures.

BACKGROUND: Atlantic horse mackerel (Trachurus trachurus) is an important commercial fish in Europe. Changes in microbial growth, sensory quality and chemical evolution of modified atmosphere packed (MAP) horse mackerel fillets (48% CO2/50% N2/2% O2) were monitored at different storage temperatures (2, 4, 6 and 10 °C). RESULTS: The observed sensory shelf life of MAP fish fillets was found to be approximately 7 days at 2 °C, 6 days at 4 °C, 5 at 6 °C and 3 days at 10 °C. A significant correlation was observed between all sensory attributes and two groups of bacteria [total viable count (TVC) and psychrotrophic bacteria], with sensorial rejection when the bacteria approached 106 CFU g⁻¹ at 4, 6 and 10 °C. A level of 30-50 mg total volatile basic nitrogen 100 g⁻¹ of mackerel muscle was well correlated with sensory shelf life determination at all temperatures, except for 2 °C. During the storage time, lipid oxidation did not increase at any temperature and could not be related to quality decay. The presence of acetaldehyde and butyraldehyde in the packing atmosphere was only found in fillets stored at the highest temperature studied (10 °C). CONCLUSION: In this study, key quality parameters were established to monitor the spoilage and shelf life of MAP Trachurus trachurus stored at different temperatures. In addition, these results confirm the use of modified atmosphere packaging as a mild preservation method for fillets of Atlantic horse mackerel.

Tumor-stromal interactions of the bone microenvironment: in vitro findings and potential in vivo relevance in metastatic lung cancer models.

Lung cancer comprises a large variety of histological subtypes with a frequent proclivity to form bone metastasis; a condition associated with dismal prognosis. To identify common mechanisms in the development of osteolytic metastasis, we systematically screened a battery of lung cancer cell lines and developed three models of non-small cell lung cancer (NSCLC) with a common proclivity to form osseous lesions, which represented different histological subtypes. Comparative analysis revealed different incidences and latency times. These differences were correlated with cell-type-specific secretion of osteoclastogenic factors, including macrophage inflammatory protein-1α, interleukin-8 and parathyroid hormone-related protein, some of which were exacerbated in conditions that mimicked tumor-stroma interactions. In addition, a distinct signature of matrix metalloproteinase (MMP) activity derived from reciprocal tumor-stroma interactions was detected for each tumor cell line. Thus, these results suggest subtle differences in the mechanisms of bone colonization for each lung cancer subtype, but share, although each to a different degree, dual MMP and osteoclastogenic activities that are differentially enhanced upon tumor-stromal interactions.

Hemorragia digestiva superior en el Hospital Vargas de Caracas

La HDS constituye una causa común de consulta en las emergencias y hospitalización. Objetivo: Presentar la experiencia de la Unidad de Sangrantes Digestivos del Hospital Vargas de Caracas en los últimos 4 años, haciendo énfasis en el diagnóstico y eficacia del tratamiento endoscópico en pacientes con HDS. Pacientes y Métodos: Se incluyeron todos los pacientes con HDS atendidos. Se realizó la EDS en las primeras 24 horas del evento. Se registraron los hallazgos así como la terapéutica endoscópica utilizada, resangrados y número de muertes. Resultados: Se incluyeron en el estudio 832 pacientes, de estos 663 con lesiones no variceales, 148 variceales y en 21 no se precisó la causa de sangrado. Las lesiones ulcero pépticas fueron las más frecuentes, seguidas de las várices esofágicas y la gastroduodenopatía erosiva. La terapéutica endoscópica mas utilizada en lesiones no variceales fue inyección con Adrenalina y en las lesiones variceales la ligadura con bandas elásticas. Se presentó resangrado en 5.16% de los pacientes y la mortalidad general fue de 0.72%. Conclusión: La realización precoz del diagnóstico y terapéutica endoscópica constituyen herramientas fundamentales en el manejo de pacientes con HDS.

Upper Gastrointestinal Bleeding (UGIB) remains a common cause in emergency consultation and patient hospitalization. Objectives: This study reviews the experience of the Bleeding Digestive Unit at the "Hospital Vargas" in Caracas during the last four years, emphasizing the diagnosis and efficiency of endoscopic therapies in the control of acute upper GI bleeding. Patients and methods: All treated patients with Upper GI bleeding were included. Early endoscopy was performed in the first 24 hours. All the findings were recorded as well as the endoscopic therapeutic procedure performed, rebleedings and fatalities were also recorded. Results: 832 patients were included; 663 with non variceal lesions, 148 variceal and 21 without a precise cause of bleeding. Peptic ulcers were the most frequent lesions found, followed by esophagueal varices and gastroduodenal erosions. The endoscopic treatment most frecuently performed in non variceal lesions was adrenaline injection and banding for variceal lesions. Rebleeding was reported in 5.16% of patients and general mortality was 0.72%. Conclusions: Early diagnosis and endoscopic treatment constitute the most successful tools for handling patients with upper GI bleeding.

Expression of plant flavor genes in Lactococcus lactis.

Lactic acid bacteria, such as Lactococcus lactis, are attractive hosts for the production of plant-bioactive compounds because of their food grade status, efficient expression, and metabolic engineering tools. Two genes from strawberry (Fragaria x ananassa), encoding an alcohol acyltransferase (SAAT) and a linalool/nerolidol synthase (FaNES), were cloned in L. lactis and actively expressed using the nisin-induced expression system. The specific activity of SAAT could be improved threefold (up to 564 pmol octyl acetate h-1 mg protein-1) by increasing the concentration of tRNA1Arg, which is a rare tRNA molecule in L. lactis. Fermentation tests with GM17 medium and milk with recombinant L. lactis strains expressing SAAT or FaNES resulted in the production of octyl acetate (1.9 microM) and linalool (85 nM) to levels above their odor thresholds in water. The results illustrate the potential of the application of L. lactis as a food grade expression platform for the recombinant production of proteins and bioactive compounds from plants.

Changes in lipid fractions and sensory properties of Idiazabal cheese induced by lipase addition.

This work studied the addition of an adequate lipase to enhance lipolysis reactions and the development of piquant flavour and sharp odour in Idiazabal cheese, as an alternative to the use of lamb rennet paste. Cheeses were manufactured from bulk raw ewes' milk in 50 l vats with commercial bovine rennet and 80 lipase units of pregastric or 180 lipase units of fungal lipase and ripened for 180 days. A higher lipolytic activity was induced by lipase addition promoting strong changes in odour and flavour attributes. Both fungal and pregastric lipases increased the content of total free fatty acids (FFA), but the fungal lipase released mainly medium- and long-chain FFA. In contrast, the pregastric lipase preferably released short-chain FFA. Diglyceride (DG) content was considerably higher in cheeses made with added pregastric lipase compared with those made with fungal lipase or with no lipase. Monoglycerides (MG) were detected only in cheeses made with either lipase added, reaching comparable concentrations after ripening for 180 days. The cheeses made with pregastric lipase had the highest scores for odour and flavour intensity, and sharp and rennet odours, desirable attributes for the Idiazabal cheese made with lamb rennet paste. None of the texture attributes were significantly influenced by the concentrations of MG and DG in the cheeses made with either lipase. Thus, the pregastric lipase was more appropriate than the fungal lipase to develop a more traditionally-flavoured Idiazabal cheese.