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Antibiotics have contributed significantly to the improvement of animal health and to the availability of animal-derived foodstuffs. However, the routine use of antimicrobials in animal production has raised concerns not only about the potential presence of residues in foods but, particularly, about the development and spread of antibiotic-resistant bacteria that may compromise the treatment of animal and human infectious diseases. In this context, strategies to reduce antibiotic use and/or mitigate their collateral damage, especially the development of resistance and adverse effects on the host microbiota, must be developed. In this article, different strategies and lines of action or research are proposed to be applied within the framework of the Spanish National Plan for Antibiotic Resistance. [ABSTRACT FROM AUTHOR]

The aims of this study were to estimate the prevalence of familial cases in patients with Meniere's disease ( MD) and to identify clinical differences between sporadic and familial MD. We recruited 1375 patients with definite MD according to the American Academy of Otolaryngology-Head and Neck Surgery criteria, obtaining the familial history of hearing loss or episodic vertigo by direct interview or a postal survey in 1245 cases in a multicenter study. Familial clustering was estimated by the recurrence risk ratio in siblings ( λs) and offspring ( λo) using intermediate and high prevalence values for MD in European population. A total of 431 patients (34%) reported a familial history of hearing loss or recurrent vertigo and 133 patients had a relative with possible MD. After clinical reevaluation, 93 relatives in 76 families were diagnosed of definite MD (8.4%), including three pairs of monozygotic twins. λs and λo were 16-48 and 4-12, respectively. We observed genetic heterogeneity, but most families had an autosomal dominant inheritance with anticipation. No clinical differences were found between sporadic and familial MD, except for an early onset in familial cases. We may conclude that MD has a strong familial aggregation and that sporadic and familial MDs are clinically identical. [ABSTRACT FROM AUTHOR]

This report shows the level of scientific consensus on definition, characteristics and health benefits of probiotics. The content of the report has derived from the scientific meeting: Workshop on Probiotics and Health. Scientific evidence, that congregated several Spanish experts, including gastroenterologists, microbiologists, nutritionists, immunologists and food technologists, among others, who have agreed with the statements shown in this document. Each statement has been sustained with the most relevant scientific aspects that were discussed during the Workshop and the following evaluation of the report by all experts who approved and signed it. [ABSTRACT FROM AUTHOR]

Food polyphenols are able to selectively modify the growth of susceptible micro-organisms. Wine is a good source of polyphenols and thus, the moderate consumption of this beverage can lead to the modulation of both oral and gut microbiota. This review aims to bring together the knowledge acquired concerning the potential effects of wine polyphenols on human microbiota, as well as taking into account the ability of bacteria to metabolize these compounds. Red wine phenolic composition, characterized by the occurrence of flavan-3-ols, flavonols, anthocyanins, hydroxybenzoic and hydroxycinnamic acids, stilbenes and phenolic alcohols as the main phenolic compounds, will determine the microbiota-modulating effects of wine consumption. Moreover, although the same bacterial genera can be found in oral and gut ecosystems, their relative amount is different, which can influence the metabolic transformations of wine polyphenols. Taking all this into account, the potential implications of these studies on human microbiota are finally discussed together with perspective and future research trends in this field. [Copyright &y& Elsevier]

Abstract: The diversity of the cheese microbiota contributes greatly to the complexity of the cheese-ripening process, crucially important for developing the unique sensory characteristics of each traditional cheese variety. Interactions between microorganisms, e.g. microbial co-operation and antagonistic effects, markedly impact on the survival, growth and activity of microorganisms in cheese. Bacteriocins are antimicrobials that are produced by lactic acid bacteria (LAB) and enable them to dominate the cheese ecosystem. Recently, there has been interest in the possible use of bacteriocins to promote the lysis of LAB and hence contribute to cheese proteolysis and flavour development. This review examines some of the strategies proposed for controlling bacteria in the cheese ecosystem as a means of ensuring high-quality production standards. It focuses on approaches such as the selection of adjuncts, especially facultatively heterofermentative lactobacilli, the selection of new wild strains of LAB and strategies based on microbial co-operation and microbial antagonism. [Copyright &y& Elsevier]

An intracellular esterase from Lactobacillus casei subsp. casei IFPL731 was purified 1000-fold by ion exchange chromatography and gel filtration chromatography. The relative molecular mass of the native enzyme was 105 kDa, while the subunit molecular mass was estimated to be 38 kDa. The esterase hydrolysed tributyrin and had a preference for esters of short-chain fatty acids (butyrate, caproate and caprylate), while it did not hydrolyse palmitate and sterate esters. The apparent Michaelis-Menten constant of the enzyme on p -nitrophenyl butyrate was 0·3 mmol l-1 while on p -nitrophenyl caprylate, it was 0·04 mmol l-1 . The esterase was active over a broad range of pH and temperature values, and retained about 50% of maximal activity at pH 5·0 and 12 °C. Activity was strongly inhibited by 5 mmol l-1 phenylmethylsulphonyl fluoride, β-mercaptoethanol and N -ethylmaleimide, and was stimulated by Zn2+ at 1 mmol l-1 . [ABSTRACT FROM AUTHOR]

Cites a study examined the effects of various types of animal milk on the characteristics of cheeses, in an effort to optimize the process for making low fat cheeses using ultrafiltration. Information in the ultrafiltration process; Microbiological analyses of the cheeses; Details on the texture of the cheeses; Results of the study.

Caseinomacropeptide (CMP), isolated from cow’s or combined ewe’s and goat’s sweet cheese whey, and whey protein concentrate (WPC), enhanced growth of Bifidobacterium lactis in milk. Supplementation of milk at 2% CMP increased counts of B. lactis by 1.5 log cycles after 24 h incubation at 37 °C when compared with unsupplemented milk, showing no differences between the two CMPs. The highest bacterial growth (9.1 log cfu ml−1) was obtained when milk was supplemented with 2% WPC. The growth-promoting activity shown by WPC could be due to its CMP and whey protein content. CMP and WPC could be utilised to complement milk in order to increase counts of bifidobacteria in probiotic fermented milks. [Copyright &y& Elsevier]

The colonic microbiota plays an important role in the bioavailibility of dietary polyphenols. This work has evaluated the impact on the gut microbiota of long-term feeding with both a red wine polyphenolic extract and the flavan-3-ol metabolizer strain Lactobacillus plantarum IFPL935. The study was conducted in the dynamic Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The feeding of the gut microbiota model with red wine polyphenols caused an initial decrease in the counts of total bacteria in the ascending colon (AC), with Bacteroides, Clostridium coccoides/ Eubacterium rectale and Bifidobacterium being the most affected bacterial groups. The bacterial counts recovered to initial numbers faster than the overall microbial fermentation and proteolysis, which seemed to be longer affected by polyphenols. Addition of L. plantarum IFPL935 helped to promptly recover total counts, Lactobacillus and Enterobacteriaceae and led to an increase in lactic acid formation in the AC vessel at the start of the polyphenol treatment as well as butyric acid in the transverse (TC) and descending (DC) vessels after 5 days. Moreover, L. plantarum IFPL935 favoured the conversion in the DC vessel of monomeric flavan-3-ols and their intermediate metabolites into phenylpropionic acids and in particular 3-(3′-hydroxyphenyl)propionic acid. The results open the possibilities of using L. plantarum IFPL935 as a food ingredient for helping individuals showing a low polyphenol-fermenting metabotype to increase their colonic microbial capacities of metabolizing dietary polyphenols. [ABSTRACT FROM AUTHOR]

Introduction: Recent scientific studies show that gut microbiota may play an important role in the modulation of the body weight of the host. Objective: The aim of this article is to present an updated review of the scientific literature dealing with the potential roles of the gut microbiota and probiotics on the body weight of the host, including the predisposition to and prevention of overweight and obesity. Results and conclusions: The use of probiotics in different growth stages, both in human and animal hosts, is usually associated to a beneficial effect to the host's health. Admittedly, benefits associated to growth do not necessarily imply an increase in the adipose tissue or a predisposition to overweight or obesity. At present, the data that link the presence of specific gut microbial groups with obesity are controversial since it is unknown if they represent a cause or a consequence of obesity-associated diets and/or any other factor related to the pathogenesis of this condition. Studies dealing with the modulation of the gut microbiota to prevent or control obesity in the host, including the use of probiotics, are promising. In fact, probiotic intake in the mother-infant context might contribute to the control of the adult body weight by modulating the infant gut microbiota. However, well-designed randomized double-blind placebo-controlled trials are required to demonstrate the efficacy of specific probiotic strains for prevention or treatment of overweight and obesity. In the frame of the current obesity pandemics, use of probiotic strains with scientifically-substantiated properties against obesity risk factors may constitute a future approach, complementary to changes in diet and life style, for the modulation of the body weight. [ABSTRACT FROM AUTHOR]

Probiotic administration could prevent antibiotic-associated diarrhoea due to the restoration of an intestinal microbiota imbalance caused by antibiotics. The effect of the probiotics Lactobacillus acidophilus LA-5, Lactobacillus casei subsp. casei LC-01 and Bifidobacterium animalis subsp. lactis BB-12 on the composition and metabolic activities of the intestinal microbiota in human subjects during antibiotic treatment has been analyzed. Subjects that were placed on antibiotic therapy (amoxiciline/clavulanic or levofloxacin) were randomly assigned to receive a multispecies probiotic fermented milk ( n = 122) or a placebo fermented milk ( n = 125). Stool samples were collected at different intervals during the intervention study and analysed for faecal microbiota enumeration, probiotic species detection, enzyme activities and short chain fatty acid (SCFA) concentrations. The most predominant microbiota groups were total anaerobes, bacteroides and total aerobes. Probiotic species in fecal samples were analyzed by real-time PCR and results indicated that prevalence of the probiotic species within the probiotic group was below 50 % during the intervention study. Enzyme activities and SCFA concentrations showed a large inter-individual variability over the time in the placebo and probiotic groups, except to β-galactosidase activity, which was the most abundant in both groups over the time. In conclusion, the combination of L. acidophilus LA-5, L. casei subsp. casei LC-01 and B. animalis subsp. lactis Bb-12 taken in daily doses of 10-10 colony-forming units (CFU) does not significantly influence ( P > 0.05) either the fecal microbiota or its metabolic activity in elderly hospitalized patients taking amoxicillin/clavulanate or levofloxacin. In addition, this combination of probiotic strains did not reduce the rate of occurrence of diarrohea in these patients. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effect of seven wine phenolic compounds and six oenological phenolic extracts on the growth of pathogenic bacteria associated with respiratory diseases ( Pseudomonas aeruginosa, Staphylococcus aureus, Moraxella catarrhalis, Enterococcus faecalis, Streptococcus sp Group F, Streptococcus agalactiae and Streptococcus pneumoniae). Methods and Results: Antimicrobial activity was determined using a microdilution method and quantified as IC50. Mor. catarrhalis was the most susceptible specie to phenolic compounds and extracts. Gallic acid and ethyl gallate were the compounds that showed the greatest antimicrobial activity. Regarding phenolic extracts, GSE (grape seed extract) and GSE-O (oligomeric-rich fraction from GSE) were the ones that displayed the strongest antimicrobial effects. Conclusions: Results highlight the antimicrobial properties of wine phenolic compounds and oenological extracts against potential respiratory pathogens. The antimicrobial activity of wine phenolic compounds was influenced by the type of phenolic compounds. Gram-negative bacteria were more susceptible than Gram-positive bacteria to the action of phenolic compounds and extracts; however, the effect was species-dependent. Significance and Impact of Study: The ability to inhibit the growth of respiratory pathogenic bacteria as shown by several wine phenolic compounds and oenological extracts warrants further investigations to explore the use of grape and wine preparations in oral hygiene. [ABSTRACT FROM AUTHOR]

Abstract: Cheese microbiota and their enzymatic conversion of l-methionine to volatile sulphur compounds (VSCs) play an important role in aroma formation during cheese ripening. Here, lactic acid bacteria (LAB) strains isolated from raw goats'' milk cheeses were screened for the major enzymes critical to the formation of VSCs from l-methionine. A large natural biodiversity in enzyme capabilities and high inter- and intra-species variability was found among the LAB isolates investigated. From those isolates tested, lactococci displayed higher C–S lyase specificities towards the sulphur-containing compounds examined than did Lactobacillus and Leuconostoc, in some cases generating higher levels of VSCs than B. linens, known to be an efficient producer of methanethiol (MTL) and related VSCs. Moreover, these differences in C–S lyase activities (determined spectrophotometrically by measuring the formation of free thiol groups) were shown to correspond with the enzymatic potential of the isolates as determined by visualization of enzymatic activities. This technique could therefore prove valuable for the detection and preliminary characterization of C–S lyase activities among LAB isolates. Lactococci were also found to possess higher aminotransferase activities than lactobacilli and leuconostocs, while glutamate dehydrogenase activities were observed to be highest among Leuconostoc and Lactobacillus spp. Meanwhile, α-keto acid decarboxylase activities were highly variable and were measurable in only a limited number of isolates, mainly lactobacilli. From these data, combining indigenous isolates showing high VSCs-producing capabilities with those that facilitate the completion of the metabolic pathway responsible for degrading l-methionine into volatile compounds may provide an efficient approach to enhance cheese aroma development. [Copyright &y& Elsevier]

Abstract: This study describes selective plating methodologies for enumeration of mixed cultures of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus, L. paracasei subsp. paracasei and Bifidobacterium lactis in fermented milk based on selective antibiotic-free media. Enumeration of S. thermophilus was performed using M17-lactose. MRS-fructose was suitable for enumeration of L. bulgaricus and MRS-maltose for differentiation between L. acidophilus and L. paracasei. The selective enumeration of B. lactis was obtained using MRS-raffinose containing 0.05% LiCl. The bacterial counts obtained using selective methods were equivalent to those under optimum culture conditions at a probability level of 95%. Performance of the methods was verified in fermented milk products where identification of the enumerated species was confirmed by species-specific polymerase chain reaction. This study shows that combination of species-specific polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) analysis has great detection and identification potential for verification of accurate species labelling in fermented milk without prior isolation of the bacteria. [Copyright &y& Elsevier]

Abstract: A hygienized rennet paste (HRP) and a defined strain starter culture, including Lactobacillus casei subsp. casei IFPL as adjunct, were considered for manufacturing Majorero cheese, a Spanish traditional variety made from goat milk. Influence of both factors on physicochemical characteristics, proteolysis, rheological and sensory properties, was evaluated throughout the ripening. Cheeses produced either industrially (IL) or in artisanal manner (AL) were compared with the experimental lot (EL), which included HRP and IFPL starter in its manufacture. Results showed a low level of primary proteolysis, expressed by a low content of non-casein nitrogen (NCN), in experimental cheeses. Despite the slightly poor texture (hard and crumbly) related to the high TS and salt contents, a good general acceptability was attained for EL, with the best scores for aroma and flavour intensities achieved at 30 ripening days. In fact, the sensory panel detected the “piquant” flavour (typical of the artisanal cheese variety) in EL after 15 days of ripening. [Copyright &y& Elsevier]

Aims: The use of randomly amplified polymorphic DNA (RAPD)-PCR fingerprinting and plasmid profiles to determine at the strain level, the similarity of Lactococcus lactis isolates obtained during sampling of traditional cheeses and to verify its correspondence to the selected phenotypic characteristics. Methods and Results: A total of 45 L. lactis isolates were genotypically analysed by RAPD-PCR fingerprinting and plasmid patterns. Phenotypic traits used to compare strains were proteolytic, acidifying, aminotransferase (aromatic and branched chain aminotransferase) and α-ketoisovalerate decarboxylase (Kivd) activities. The results show that 23 isolates could be grouped in clusters that exhibited 100% identity in both their RAPD and plasmid patterns, indicating the probable isolation of dominant strains during the cheese sampling process. However, there were phenotypic differences between isolates within the same cluster that included the loss of relevant technological properties such as proteinase activity and acidifying capacity or high variation in their amino acid converting enzyme activities. Likewise, the analysis of a specific attribute, Kivd activity, indicated that 7 of 15 isolates showed no detectable activity despite the presence of the encoding ( kivd) gene. Conclusion: Phenotypic differences found between genotypically similar strains of L. lactis strains could be linked to differences in enzymatic expression. Significance and Impact of the Study: Phenotypic analysis of L. lactis isolates should be considered when selecting strains with new cheese flavour forming capabilities. [ABSTRACT FROM AUTHOR]

Abstract: Several wild lactococcal strains were tested for their ability to produce aroma compounds during growth in milk. Strains were incubated alone and in combination with Lactococcus lactis IFPL730, which is characterized by showing α-keto acid decarboxylase activity. Volatile compounds from incubated milks were analyzed by means of solid-phase microextraction (SPME) and evaluated by gas chromatography–mass spectrometry (GC–MS). Incubated milks were also sniffed for sensory analysis to describe aroma attributes. The combination of L. lactis IFPL326 that showed the highest branched chain aminotransferase activity with IFPL730 contributed to the highest formation of leucine-derived volatile compounds, such as 3-methylbutanal, 3-methyl-1-butanol and 2-hydroxy-4-methyl pentanoic acid methyl ester. In addition, the milk incubated with this combination of strains was awarded, by the test panellists, the highest scores for “ripened cheese” attribute and aroma intensity. The results indicate that combination of L. lactis strains harbouring complementary catabolic routes can contribute to improved cheese aroma formation, the combined cultures with L. lactis IFPL730 resulting in higher volatile compound formation than isolate strains. [Copyright &y& Elsevier]

Abstract: A total of 156 lactic acid bacteria isolates belonging to the genera Lactococcus, Lactobacillus and Leuconostoc were analysed for the amino acid converting enzymes aminotransferases, glutamate dehydrogenase, and α-ketoisovalerate decarboxylase. All isolates showed aminotransferase activity towards phenylalanine (substrate for the aromatic aminotransferase AraT) and isoleucine (substrate for the branched-chain aminotransferase BcaT). Although there was a high variability inter- and intra-species, the lactococcal strains showed the highest values for both aminotransferase activities. Moreover, α-ketoisovalerate decarboxylase (Kivd) activity was only found in lactococcal isolates, although at low relative numbers (16%). On the other hand, glutamate dehydrogenase (Gdh) activity values were highest in facultative heterofermentative lactobacilli (FHL) and the activity was found at high relative numbers (50%) in leuconostocs. Results showed a high variability in amino acid convertase activities within the wild LAB isolates assayed, therefore the utilisation in the dairy industry of new strains with high flavour-forming abilities could be a powerful tool to enhance cheese aroma development. [Copyright &y& Elsevier]

The proteolytic system of Bifidobacterium animalis subsp. lactis was analyzed, and an intracellular endopeptidase (PepO) was identified and characterized. This work reports the first complete cloning, purification, and characterization of a proteolytic enzyme in Bifidobacterium spp. Aminopeptidase activities (general aminopeptidases, proline iminopeptidase, X-prolyl dipeptidylaminopeptidase) found in cell extracts of B. animalis subsp. lactis were higher for cells that had been grown in a milk-based medium than for those grown in MRS. A high specific proline iminopeptidase activity was observed in B. animalis subsp. lactis. Whole cells and cell wall-bound protein fractions showed no caseinolytic activity; however, the combined action of intracellular proteolytic enzymes could hydrolyze casein fractions rapidly. The endopeptidase activity of B. animalis subsp. lactis was examined in more detail, and the gene encoding an endopeptidase O in B. animalis subsp. lactis was cloned and overexpressed in Escherichia coli. The deduced amino acid sequence for B. animalis subsp. lactis PepO indicated that it is a member of the M13 peptidase family of zinc metallopeptidases and displays 67.4% sequence homology with the predicted PepO protein from Bifidobacterium longum. The recombinant enzyme was shown to be a 74-kDa monomer. Activity of B. animalis subsp. lactis PepO was found with oligopeptide substrates of at least S amino acid residues, such as met-enkephalin, and with larger substrates, such as the 23-amino-acid peptide αs1-casein(f1-23). The predominant peptide bond cleaved by B. animalis subsp. lactis PepO was on the N-terminal side of phenylalanine residues. The enzyme also showed a post-proline secondary cleavage site. [ABSTRACT FROM AUTHOR]

A set-type fermented milk manufactured from goat''s milk was developed. Optimal curd tension was achieved by supplementation of milk with skim milk powder and whey protein concentrate (WPC). Milk was fermented employing a commercial probiotic starter culture (ABT-2), which contained Streptococcus thermophilus ST-20Y, Lactobacillus acidophilus LA-5, and Bifidobacterium BB-12. Supplementation of milk with 3% WPC reduced fermentation time by 2 h due to the increase in viable counts of S. thermophilus and Bifidobacterium by 0.3 and 0.7 log units, respectively. Addition of WPC increased the protein content (1%) as well as potassium and magnesium content (0.3 and 0.02 g kg−1, respectively). Increase of the protein content led to an increase in the apparent viscosity and gel firmness of the product, and at the same time whey syneresis was reduced. As a consequence, the product received a high score for appearance, taste, aroma, texture and overall acceptance. [Copyright &y& Elsevier]

Examines the biological and molecular characterization of a two-peptide lantibiotic produced by Lactococcus lactis IFPL105. Purification of the bacterion; Performance of hybridization experiments; Description of lantibiotics.