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Sample records for lactobacilli inhibit gonococci

  1. Screening of probiotic lactobacilli for inhibition of Shigella sonnei and the macromolecules involved in inhibition.

    PubMed

    Zhang, Ying-Chun; Zhang, Lan-Wei; Ma, Wei; Yi, Hua-Xi; Yang, Xin; Du, Ming; Shan, Yu-Juan; Han, Xue; Zhang, Li-Li

    2012-10-01

    A total of 91 lactobacilli were screened for antimicrobial activity against Shigella sonnei. Agar-well assay showed that 16 lactobacilli displayed strong antibacterial activity against S. sonnei. The nature of these antimicrobial agents were investigated and shown to be dependent on their production of organic acids. Adhesion tests showed that 6 lactobacilli demonstrated good adherence to HT-29 cells, of these Lactobacillus johnsonii F0421 were selected for acid and bile salt tolerance properties. We further research on L. johnsonii F0421 inhibition of S. sonnei adhesion to HT-29 cells. The result showed that L. johnsonii F0421 exhibited significant inhibitory activity and excluded, competed and displaced adhered S. sonnei by 48%, 38% and 33%, respectively. In order to elucidate the inhibitory functions of macromolecules involved in L. johnsonii F0421, the cells were treated with 5 M LiCl, 0.05 M sodium metaperiodate and heating and assayed for inhibition activity. The results suggested a role of S-layer proteins on L. johnsonii F0421 cells in inhibition of the adhesion process, but carbohydrates do not seem to be involved. SDS-PAGE analysis confirmed the presence of S-layer proteins with dominant bands of approximately 40 kDa. In addition, 100 μg/well of S-layer proteins from L. johnsonii F0421 cells were effective in inhibiting adhesion of S. sonnei to HT-29 cells. These findings suggest that L. johnsonii F0421 possesses the capacity for inhibition of S. sonnei activity as well as probiotic properties, which could serve as a potential novel and effective probiotic strain for use in the food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Lactobacilli Reduce Helicobacter pylori Attachment to Host Gastric Epithelial Cells by Inhibiting Adhesion Gene Expression

    PubMed Central

    de Klerk, Nele; Maudsdotter, Lisa; Gebreegziabher, Hanna; Saroj, Sunil D.; Eriksson, Beatrice; Eriksson, Olaspers Sara; Roos, Stefan; Lindén, Sara; Sjölinder, Hong

    2016-01-01

    The human gastrointestinal tract, including the harsh environment of the stomach, harbors a large variety of bacteria, of which Lactobacillus species are prominent members. The molecular mechanisms by which species of lactobacilli interfere with pathogen colonization are not fully characterized. In this study, we aimed to study the effect of lactobacillus strains upon the initial attachment of Helicobacter pylori to host cells. Here we report a novel mechanism by which lactobacilli inhibit adherence of the gastric pathogen H. pylori. In a screen with Lactobacillus isolates, we found that only a few could reduce adherence of H. pylori to gastric epithelial cells. Decreased attachment was not due to competition for space or to lactobacillus-mediated killing of the pathogen. Instead, we show that lactobacilli act on H. pylori directly by an effector molecule that is released into the medium. This effector molecule acts on H. pylori by inhibiting expression of the adhesin-encoding gene sabA. Finally, we verified that inhibitory lactobacilli reduced H. pylori colonization in an in vivo model. In conclusion, certain Lactobacillus strains affect pathogen adherence by inhibiting sabA expression and thereby reducing H. pylori binding capacity. PMID:26930708

  3. Lactobacilli Reduce Helicobacter pylori Attachment to Host Gastric Epithelial Cells by Inhibiting Adhesion Gene Expression.

    PubMed

    de Klerk, Nele; Maudsdotter, Lisa; Gebreegziabher, Hanna; Saroj, Sunil D; Eriksson, Beatrice; Eriksson, Olaspers Sara; Roos, Stefan; Lindén, Sara; Sjölinder, Hong; Jonsson, Ann-Beth

    2016-05-01

    The human gastrointestinal tract, including the harsh environment of the stomach, harbors a large variety of bacteria, of which Lactobacillus species are prominent members. The molecular mechanisms by which species of lactobacilli interfere with pathogen colonization are not fully characterized. In this study, we aimed to study the effect of lactobacillus strains upon the initial attachment of Helicobacter pylori to host cells. Here we report a novel mechanism by which lactobacilli inhibit adherence of the gastric pathogen H. pylori In a screen with Lactobacillus isolates, we found that only a few could reduce adherence of H. pylori to gastric epithelial cells. Decreased attachment was not due to competition for space or to lactobacillus-mediated killing of the pathogen. Instead, we show that lactobacilli act on H. pylori directly by an effector molecule that is released into the medium. This effector molecule acts on H. pylori by inhibiting expression of the adhesin-encoding gene sabA Finally, we verified that inhibitory lactobacilli reduced H. pylori colonization in an in vivo model. In conclusion, certain Lactobacillus strains affect pathogen adherence by inhibiting sabA expression and thereby reducing H. pylori binding capacity.

  4. Attachment and ingestion of gonococci human neutrophils.

    PubMed

    Dilworth, J A; Hendley, J O; Mandell, G L

    1975-03-01

    Previous studies have indirectly shown that type 1 gonococci are more resistant to phagocytosis by human neutrophils (PMN) than type 3 gonococci. Using phase contrast, fluorescent, and light microscopy, we directly quantitated PMN-gonococcal interaction, with emphasis on separating ingestion from attachment. PMN monolayers were incubated on slides with type 1 or type 3 gonococcal fluorescent antibody (FA). After methanol fixation, the FA-stained gonococci associated with PMN were cointed. Since the live PMN excludes FA, the FA-stained gonococci represent only extracellular gonococci. Methylene blue was then added to the smae slide to stain both ingested and surface attached gonococci. Using these methods, intracellular and extracellular cell-associated gonococci were quantitated under varying conditions. The numbers of methylene blue-stained cell-associated gonococci that were ingested were: with normal serum, 3.7 plus or minus 4.1 per cent for type 1 and 56.2 plus or minus 3.7 percent for type 3 (P smaller than 0.001); with heat-inactivated serum, 1.0 plus or minus 3.0 per cent for type 1 and 52.6 plus or minus 3.7 per cent for type 3 (P smaller than 0.001); with higher-titer anti-gonococcal antibody serum, 4.8 plus or minus 4.3 percent for type 1 and 64.0 plus or minus 1.6 per cent for type 3 (P smaller than 0.001). Thus, most type 3 organisms were ingested, but most type 1 gonococci were bound on the PMN surface.

  5. Attachment and ingestion of gonococci human neutrophils.

    PubMed Central

    Dilworth, J A; Hendley, J O; Mandell, G L

    1975-01-01

    Previous studies have indirectly shown that type 1 gonococci are more resistant to phagocytosis by human neutrophils (PMN) than type 3 gonococci. Using phase contrast, fluorescent, and light microscopy, we directly quantitated PMN-gonococcal interaction, with emphasis on separating ingestion from attachment. PMN monolayers were incubated on slides with type 1 or type 3 gonococcal fluorescent antibody (FA). After methanol fixation, the FA-stained gonococci associated with PMN were cointed. Since the live PMN excludes FA, the FA-stained gonococci represent only extracellular gonococci. Methylene blue was then added to the smae slide to stain both ingested and surface attached gonococci. Using these methods, intracellular and extracellular cell-associated gonococci were quantitated under varying conditions. The numbers of methylene blue-stained cell-associated gonococci that were ingested were: with normal serum, 3.7 plus or minus 4.1 per cent for type 1 and 56.2 plus or minus 3.7 percent for type 3 (P smaller than 0.001); with heat-inactivated serum, 1.0 plus or minus 3.0 per cent for type 1 and 52.6 plus or minus 3.7 per cent for type 3 (P smaller than 0.001); with higher-titer anti-gonococcal antibody serum, 4.8 plus or minus 4.3 percent for type 1 and 64.0 plus or minus 1.6 per cent for type 3 (P smaller than 0.001). Thus, most type 3 organisms were ingested, but most type 1 gonococci were bound on the PMN surface. Images PMID:46842

  6. Inhibition of Giardia intestinalis by Extracellular Factors from Lactobacilli: an In Vitro Study

    PubMed Central

    Pérez, Pablo F.; Minnaard, Jessica; Rouvet, Martine; Knabenhans, Christian; Brassart, Dominique; De Antoni, Graciela L.; Schiffrin, Eduardo J.

    2001-01-01

    The aim of the present work was to evaluate the effect of spent culture supernatants of different strains of lactobacilli on giardia trophozoites. The growth of Giardia intestinalis strain WB, as well as the attachment to the human intestinal epithelial cell line Caco-2, was evaluated by using proliferation and adhesion assays with radiolabeled parasites. In addition, scanning electron microscopy and flow cytometric analysis were performed. The effect of spent culture supernatants from lactobacilli was strain dependent. Lactobacillus johnsonii La1 significantly inhibited the proliferation of G. intestinalis trophozoites. Although the effect was strongly pH dependent, it was not simply due to lactic acid. According to flow cytometric analysis, trophozoites were arrested in G1 phase but neither significant necrosis nor apoptosis could be detected. Bacterial cells or their spent culture supernatants were unable to modify trophozoite attachment to Caco-2 cells. However, trophozoites treated with spent culture supernatants had little, if any, proliferative capacity. These results suggest that La1 produces some substance(s) able to inhibit proliferation of Giardia trophozoites. Partial characterization of the factors involved in the antigiardiasic action showed that they have a low molecular mass and are inactivated by heating. On this basis, it seems worthwhile to explore how colonization of the proximal small bowel with these lactic acid bacteria could interfere with giardiasis in vivo. PMID:11679323

  7. [Preliminary examination of a LB-H2O2 substance that inhibit Neisseria gonorrhea growth].

    PubMed

    Zheng, H; Cao, J; Jin, H; Wang, J

    1999-10-01

    To study the possible mechanism of H2O2-producing lactobacilli inhibited neisseria gonorrhoeae growth. H2O2-producing lactobacilli were coincubated with neisseria gonorrhoeae in vitro, LB+ cell were disrupted by sonication, the protein in the lactobacilli lysate was separated by filtration through different MW sizes membranes and was examined for the ability to inhibit N. gonorrhoeae catalase activity. When coincubation medium was at pH 5.0, there was a significant decrease in the gonococcal catalase activity, the lysates of LB+ also effectively inhibited gonococcal catalase activity. This inhibition was retained upon heating of lysate to 100 degrees C for 15 minutes but was lost with proteinase K treatment. The LB+ may inhibit growth of gonococci by production of catalase inhibitors.

  8. Bacteriocins and other bioactive substances of probiotic lactobacilli as biological weapons against Neisseria gonorrhoeae.

    PubMed

    Ruíz, Francisco O; Pascual, Liliana; Giordano, Walter; Barberis, Lucila

    2015-04-01

    In the search of new antimicrobial agents against Neisseria gonorrhoeae, the bacteriocins-producing probiotic lactobacilli deserve special attention. The inhibitory effects of biosubstances such as organic acids, hydrogen peroxide and each bacteriocin-like inhibitory substance (BLIS) L23 and L60 on the growth of different gonococcal strains were investigated. Different non-treated and treated cell-free supernatants of two probiotic lactobacilli containing these metabolites were used. The aims of this work were (i) to evaluate the antimicrobial activity of the biosubstances produced by two probiotic lactobacilli, estimating the proportion in which each of them is responsible for the inhibitory effect, (ii) to define their minimum inhibitory concentrations (MICs) and, (iii) to determine the potential interactions between these biosubstances against N. gonorrhoeae. The main antimicrobial metabolites were the BLIS-es L23 and L60 in comparison with other biosubstances. Proportionally, their contributions to the inhibition on the gonococcal growth were 87.28% and 80.66%, respectively. The MIC values of bacteriocins were promising since these substances, when diluted, showed considerable inhibitory activity for all gonococci. In the interaction between bacteriocins, 100% of synergism was found on the gonococcal growth. In summary, this study indicates that both L23 and L60 could potentially serve to design new bioproducts against N. gonorrhoeae.

  9. [Lactobacilli and colon carcinoma--A review].

    PubMed

    Wang, Shumei; Zhang, Lanwei; Shan, Yujuan

    2015-06-04

    Epidemiological studies showed that incidence of colon carcinoma is increased in the world. There are many difficulties to inhibit colon carcinoma because the causes of inducing colon carcinoma were various and interactive each other. Previous evidence supported the balance of the colonic microflora was critical in inhibiting colon carcinoma and the protection by colonic microflora could be improved by ingesting lactobacilli. Therefore, the biological functions and anticancer effects of lactobacilli attract attention of researchers. In this review we discussed the causes of colon carcinoma; the anticancer mechanisms of lactobacilli on the basis of our own studies. Eventually, we summarized the effects of anticancer of different components and metabolic products extracted from lactobacilli.

  10. Determining the suitability of Lactobacilli antifungal metabolites for inhibiting mould growth

    Treesearch

    Vina W. Yang; Carol A. Clausen

    2005-01-01

    In recent years, public concern about indoor mould growth has increased dramatically in the United States. In this study, lactic acid bacteria (LAB), which are known to produce antimicrobial compounds important in the biopreservation of food, were evaluated to determine if the same antimicrobial properties can be used to inhibit mould fungi that typically colonize wood...

  11. Probiotic lactobacilli inhibit early stages of Candida albicans biofilm development by reducing their growth, cell adhesion, and filamentation.

    PubMed

    Matsubara, Victor Haruo; Wang, Yi; Bandara, H M H N; Mayer, Marcia Pinto Alves; Samaranayake, Lakshman P

    2016-07-01

    We evaluated the inhibitory effects of the probiotic Lactobacillus species on different phases of Candida albicans biofilm development. Quantification of biofilm growth and ultrastructural analyses were performed on C. albicans biofilms treated with Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus acidophilus planktonic cell suspensions as well as their supernatants. Planktonic lactobacilli induced a significant reduction (p < 0.05) in the number of biofilm cells (25.5-61.8 %) depending on the probiotic strain and the biofilm phase. L. rhamnosus supernatants had no significant effect on the mature biofilm (p > 0.05), but significantly reduced the early stages of Candida biofilm formation (p < 0.01). Microscopic analyses revealed that L. rhamnosus suspensions reduced Candida hyphal differentiation, leading to a predominance of budding growth. All lactobacilli negatively impacted C. albicans yeast-to-hyphae differentiation and biofilm formation. The inhibitory effects of the probiotic Lactobacillus on C. albicans entailed both cell-cell interactions and secretion of exometabolites that may impact on pathogenic attributes associated with C. albicans colonization on host surfaces and yeast filamentation. This study clarifies, for the first time, the mechanics of how Lactobacillus species may antagonize C. albicans host colonization. Our data elucidate the inhibitory mechanisms that define the probiotic candicidal activity of lactobacilli, thus supporting their utility as an adjunctive therapeutic mode against mucosal candidal infections.

  12. Porin polypeptide contributes to surface charge of gonococci.

    PubMed Central

    Swanson, J; Dorward, D; Lubke, L; Kao, D

    1997-01-01

    Each strain of Neisseria gonorrhoeae elaborates a single porin polypeptide, with the porins expressed by different strains comprising two general classes, Por1A and Por1B. In the outer membrane, each porin molecule folds into 16 membrane-spanning beta-strands joined by top- and bottom-loop domains. Por1A and Por1B have similar membrane-spanning regions, but the eight surface-exposed top loops (I to VIII) differ in length and sequence. To determine whether porins, and especially their top loop domains, contribute to bacterial cell surface charge, strain MS11 gonococci that were identical except for expressing a recombinant Por1A, Por1B, or mosaic Por1A-1B polypeptide were compared by whole-cell electrophoresis. These porin variants displayed different electrophoretic mobilities that correlated with the net numbers of charged amino acids within surface-exposed loops of their respective porin polypeptides. The susceptibilities of porin variants to polyanionic sulfated polymers correlated roughly with gonococcal surface charge; those porin variants with diminished surface negativity showed increased sensitivity to the polyanionic sulfated compounds. These observations indicate that porin polypeptides in situ contribute to the surface charge of gonococci, and they suggest that the bacterium's interactions with large sulfated compounds are thereby affected. PMID:9171398

  13. Relationship between lactobacilli and opportunistic bacterial pathogens associated with vaginitis

    PubMed Central

    Razzak, Mohammad Sabri A.; Al-Charrakh, Alaa H.; AL-Greitty, Bara Hamid

    2011-01-01

    Background: Vaginitis, is an infectious inflammation of the vaginal mucosa, which sometimes involves the vulva. The balance of the vaginal flora is maintained by the Lactobacilli and its protective and probiotic role in treating and preventing vaginal infection by producing antagonizing compounds which are regarded as safe for humans. Aim: The aim of this study was to evaluate the protective role of Lactobacilli against common bacterial opportunistic pathogens in vaginitis and study the effects of some antibiotics on Lactobacilli isolates. Materials and Methods: In this study (110) vaginal swabs were obtained from women suffering from vaginitis who admitted to Babylon Hospital of Maternity and Paediatrics in Babylon province, Iraq. The study involved the role of intrauterine device among married women with vaginitis and also involved isolation of opportunistic bacterial isolates among pregnant and non pregnant women. This study also involved studying probiotic role of Lactobacilli by production of some defense factors like hydrogen peroxide, bacteriocin, and lactic acid. Results: Results revealed that a total of 130 bacterial isolates were obtained. Intrauterine device was a predisposing factor for vaginitis. The most common opportunistic bacterial isolates were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae, and Klebsiella pneumoniae. All Lactobacilli were hydrogen peroxide producers while some isolates were bacteriocin producers that inhibited some of opportunistic pathogens (S. aureus, E. coli). Lactobacilli were sensitive to erythromycin while 93.3% of them were resistant to ciprofloxacin and (40%, 53.3%) of them were resistant to amoxicillin and gentamycin respectively. Results revealed that there was an inverse relationship between Lactobacilli presence and organisms causing vaginitis. This may be attributed to the production of defense factors by Lactobacilli. Conclusion: The types of antibiotics used to treat vaginitis must be very

  14. Relationship between lactobacilli and opportunistic bacterial pathogens associated with vaginitis.

    PubMed

    Razzak, Mohammad Sabri A; Al-Charrakh, Alaa H; Al-Greitty, Bara Hamid

    2011-04-01

    Vaginitis, is an infectious inflammation of the vaginal mucosa, which sometimes involves the vulva. The balance of the vaginal flora is maintained by the Lactobacilli and its protective and probiotic role in treating and preventing vaginal infection by producing antagonizing compounds which are regarded as safe for humans. The aim of this study was to evaluate the protective role of Lactobacilli against common bacterial opportunistic pathogens in vaginitis and study the effects of some antibiotics on Lactobacilli isolates. In this study (110) vaginal swabs were obtained from women suffering from vaginitis who admitted to Babylon Hospital of Maternity and Paediatrics in Babylon province, Iraq. The study involved the role of intrauterine device among married women with vaginitis and also involved isolation of opportunistic bacterial isolates among pregnant and non pregnant women. This study also involved studying probiotic role of Lactobacilli by production of some defense factors like hydrogen peroxide, bacteriocin, and lactic acid. Results revealed that a total of 130 bacterial isolates were obtained. Intrauterine device was a predisposing factor for vaginitis. The most common opportunistic bacterial isolates were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae, and Klebsiella pneumoniae. All Lactobacilli were hydrogen peroxide producers while some isolates were bacteriocin producers that inhibited some of opportunistic pathogens (S. aureus, E. coli). Lactobacilli were sensitive to erythromycin while 93.3% of them were resistant to ciprofloxacin and (40%, 53.3%) of them were resistant to amoxicillin and gentamycin respectively. Results revealed that there was an inverse relationship between Lactobacilli presence and organisms causing vaginitis. This may be attributed to the production of defense factors by Lactobacilli. The types of antibiotics used to treat vaginitis must be very selective in order not to kill the beneficial bacteria

  15. Fimbriae and lipopolysaccharides are necessary for co-aggregation between Lactobacilli and Escherichia coli.

    PubMed

    Mizuno, Kouhei; Furukawa, Soichi; Usui, Yumi; Ishiba, Madoka; Ogihara, Hirokazu; Morinaga, Yasushi

    2014-01-01

    Cells of Lactobacilli co-aggregated with Escherichia coli K-12 cells to form co-aggregates under mixed-culture conditions at 37 °C for 24 h. Co-aggregation was inhibited by sodium dodecyl sulfate but not by protease. E. coli deletion mutants of fimbriae formation and lipopolysaccharide (LPS) formation did not co-aggregate with Lactobacilli. These results showed that fimbriae and LPS are necessary for co-aggregation between Lactobacilli and E. coli.

  16. Oral Lactobacilli and Dental Caries

    PubMed Central

    Caufield, P.W.; Schön, C.N.; Saraithong, P.; Li, Y.; Argimón, S.

    2015-01-01

    Lactobacilli have been associated with dental caries for over a century. Here, we review the pertinent literature along with findings from our own study to formulate a working hypothesis about the natural history and role of lactobacilli. Unlike most indigenous microbes that stably colonize a host, lactobacilli appear to be planktonic, opportunistic settlers that can gather and multiply only in certain restrictive niches of the host, at least within the oral cavity. We postulate that the following essential requirements are necessary for sustained colonization of lactobacilli in humans: 1) a stagnant, retentive niche that is mostly anaerobic; 2) a low pH milieu; and 3) ready access to carbohydrates. Three sites on the human body meet these specifications: caries lesions, the stomach, and the vagina. Only a handful of Lactobacillus species is found in caries lesions, but they are largely absent in caries-free children. Lactobacilli present in caries lesions represent both a major contributor to caries progression and a major reservoir to the gastrointestinal (GI) tract. We extend the assertion from other investigators that lactobacilli found in the GI tract originate in the oral cavity by proposing that lactobacilli in the oral cavity arise from caries lesions. This, in turn, leads us to reflect on the health implications of the lactobacilli in the mouth and downstream GI and to ponder whether these or any of the Lactobacillus species are truly indigenous to the human GI tract or the oral cavity. PMID:25758458

  17. Lactobacilli as multifaceted probiotics with poorly disclosed molecular mechanisms.

    PubMed

    Turpin, Williams; Humblot, Christèle; Thomas, Muriel; Guyot, Jean-Pierre

    2010-10-15

    inhibited by probiotics. They can reinforce the intestinal barrier, simply occupying the ecological niche, or they can have an active role by synthesizing various metabolites inhibiting pathogen development. Lactobacilli have a long standing history with foods and humans but comparatively, their history as probiotics is recent. Their effects are investigated in in vitro and in vivo models leading sometimes to contradictory or controversial results that make necessary final demonstrations through clinical trials. Researches on molecular mechanisms involved in the beneficial effects reviewed here are necessary for a better understanding of these effects, but could also lead to the development of molecular tools to help the screening of the probiotic potential of lactobacilli that are common inhabitants of numerous fermented foods around the world.

  18. Nutritional requirements and penicillin susceptibilities of gonococci from pharyngeal and anogenital sites.

    PubMed Central

    Catlin, B W; Pace, P J

    1977-01-01

    Neisseria gonorrhoeae was isolated from 5.9% of oropharyngeal specimens obtained from patients attending a clinic for sexually transmitted diseases. Oropharyngeal isolates from 69 patients and anogenital isolated from 97 other patients attending the same clinic were compared. Many of the gonococci could be differentiated by the compounds required for growth in chemically defined media or by differences in the minimum inhibitory concentration (MIC) of penicillin G. Strains with requirements for either proline (Pro-) or arginine (Arg-) or for none of the compounds that are used for differentiation (zero phenotype) were more common in the oropharynx (91.3% of patients) than in anogenital sites (73.2% of patients). On the other hand, gonococci with multiple requirements that include arginine, hypoxanthine, and uracil (AHU strains) were present in oropharyngeal specimens from only three patients (4.4%), but were isolated from anogenital specimens from 18 patients (18.6%). A high susceptibility to penicillin characterised the AHU strains from all sites, as others have reported. The penicillin MIC ranged from 0.003-0.72 microgram/ml for strains with Pro-, Arg-, and zero phenotypes. However, a penicillin MIC greater than or equal to 0.42 microgram/ml was found for 17.6% of oropharyngeal isolates of these types, but for only 4.1% of Pro-, Arg-, and zero isolates from anogenital sites. None of these moderately resistant strains produced beta-lactamase. Our findings indicate that gonococci differ in their ability to colonise the oropharynx successfully. PMID:412557

  19. Genetic Resistance Determinants for Cefixime and Molecular Analysis of Gonococci Isolated in Italy.

    PubMed

    Carannante, Anna; Vacca, Paola; Ghisetti, Valeria; Latino, Maria Agnese; Cusini, Marco; Matteelli, Alberto; Vocale, Caterina; Prignano, Grazia; Leli, Christian; Ober, Patrizia; Antonetti, Raffaele; Poletti, Federica; Stefanelli, Paola

    2017-03-01

    A strictly defined subset of gonococci (n = 65) isolated in Italy from 2011 to 2014 was characterized by antimicrobial susceptibility for cefixime (CFM) and ceftriaxone (CRO) and by sequencing of resistance determinant genes (penA, mtrR, porB1b, ponA) for extended-spectrum cephalosporins and Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST). The penA mosaic alleles XXXIV and XXXV were found in all resistant (R) and decreased susceptibility (DS) gonococci to CFM, except for one. They were associated with an adenine deletion in the mtrR promoter plus amino acid substitutions, H105Y or G45D, in the coding region and ponA L421P. The penA mosaic allele XXXIV, and one variant, was found exclusively among genogroup (G) 1407 and its closely related sequence types (STs), as in CFM-DS as well as in CFM-R isolates. Single or combined mutation patterns in penA, mtrR, porB1b, and ponA genes were associated with different CFM susceptibility patterns and NG-MAST STs. Genotyping and antimicrobial resistance (AMR) determinant analyses can be valuable to enhance the gonococcal AMR surveillance.

  20. Genomic analysis of urogenital and rectal Neisseria meningitidis isolates reveals encapsulated hyperinvasive meningococci and coincident multidrug-resistant gonococci.

    PubMed

    Harrison, Odile B; Cole, Kevin; Peters, Joanna; Cresswell, Fiona; Dean, Gillian; Eyre, David W; Paul, John; Maiden, Martin Cj

    2017-09-01

    Invasive meningococcal disease (IMD) outbreaks in men who have sex with men (MSM) have been associated with meningococcal colonisation of the urethra and rectum, but little is known about this colonisation or co-colonisation with the closely related gonococcus. Whole genome sequencing (WGS) was employed to explore these phenomena. Meningococci isolated from the urogenital tract and rectum (n=23) and coincident gonococci (n=14) were analysed by WGS along with contemporary meningococci from IMD (n=11). All isolates were obtained from hospital admissions in Brighton, UK, 2011-2013. Assembled WGS were deposited in the PubMLST/neisseria database (http://pubmlst.org/neisseria) and compared at genomic loci common to gonococci or meningococci. As expected, most meningococci from IMD were encapsulated and belonged to hyperinvasive lineages. So too were meningococci found in the urogenital tract and rectum, contrasting to those asymptomatically carried in the nasopharynx where such meningococci are rare. Five hyperinvasive meningococcal lineages and four distinct gonococcal genotypes were recovered, including multiresistant ST-1901 (NG MAST-1407) gonococci. These data were consistent with a predisposition for potentially virulent encapsulated hyperinvasive meningococci to colonise the urethra and rectum, which suggests their involvement in MSM IMD outbreaks. The coincidence of multiresistant gonococci raises wider public health concerns. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. Lactobacilli Reduce Chemokine IL-8 Production in Response to TNF-α and Salmonella Challenge of Caco-2 Cells

    PubMed Central

    Ren, Da-Yong; Li, Chang; Qin, Yan-Qing; Yin, Rong-Lan; Du, Shou-Wen; Ye, Fei; Liu, Hong-Feng; Wang, Mao-Peng; Sun, Yang; Li, Xiao; Tian, Ming-Yao; Jin, Ning-Yi

    2013-01-01

    The probiotic properties of two selected lactobacilli strains were assessed. L. salivarius and L. plantarum displayed higher hydrophobicity (48% and 54%, resp.) and coaggregation ability with four pathogens (from 7.9% to 57.5%). L. salivarius and L. plantarum had good inhibitory effects on S. aureus (38.2% and 49.5%, resp.) attachment to Caco-2 cells. Live lactobacilli strains and their conditioned media effectively inhibited IL-8 production (<14.6 pg/mL) in TNF-α-induced Caco-2 cells. Antibiotic-treated and the sonicated lactobacilli also maintained inhibitory effects (IL-8 production from 5.0 to 36.3 pg/mL); however, the heat-treated lactobacilli lost their inhibitory effects (IL-8 production from 130.2 to 161.0 pg/mL). These results suggest that both the structural components and the soluble cellular content of lactobacilli have anti-inflammatory effects. We also found that pretreatment of Caco-2 cells with lactobacilli inhibited S. typhimurium-induced IL-8 production (<27.3 pg/mL). However, lactobacilli did not inhibit IL-8 production in Caco-2 cells pretreated with S. typhimurium. These results suggest that the tested lactobacilli strains are appropriate for preventing inflammatory diseases caused by enteric pathogens but not for therapy. In short, L. salivarius and L. plantarum are potential candidates for the development of microbial ecological agents and functional foods. PMID:24455739

  2. Gene conversion accounts for pilin structural changes and for reversible piliation "phase" changes in gonococci.

    PubMed

    Swanson, J; Bergstrom, S; Boslego, J; Koomey, M

    1987-01-01

    Pilus+ "wild-type" gonococci (Gc) frequently display gene conversion of their expressed complete pilin gene (CPG); a copy of DNA derived from one of the Gc genome's multiple silent partial pilin genes (PPG) is recombinationally-inserted into the CPG's central and 3' portions with formation of a new, chimeric CPG. Expression of that new CPG leads to either 1) retention of pilus+ phenotype but change in pilin primary structure/antigenicity, or 2) phase change to pilus- phenotype capable of reverting. This study utilizes pilus revertants of P-rp +/- Gc and P+ colony morphotype variants spawned by P++ Gc to examine pilin gene conversion in strain MS11mk Gc in greater detail. Each revertant's and variant's expressed pilin gene's sequence (as pilin mRNA) was defined to learn whether their differences are due to gene conversion by different PPGs, or by varying stretches from the same PPG, or both. Gene conversion by PPG pilS1 copy 2 has been documented in Gc recovered from a human volunteer's urethra previously inoculated with pilus Gc (strain MS11). The pilus+ Gc isolated expressed structurally/antigenically distinct pilins.

  3. Vaginal lactobacilli, probiotics, and IVF.

    PubMed

    Verstraelen, Hans; Senok, Abiola C

    2005-12-01

    Perturbation of the normal lactobacilli-dominated vaginal microflora is associated with reproductive failure and adverse pregnancy outcomes, ranging from early pregnancy loss to late miscarriage and preterm birth. As high rates of bacterial vaginosis are observed with IVF patients, abnormal vaginal microflora presumably explain, at least to some extent, reproductive failure as well as the increased risk of adverse pregnancy outcome seen in these patients. Accordingly, there may be a window of opportunity for improving IVF success rates and outcomes. At present, a screen-and-treat procedure to restore the normal vaginal microflora is not a routine part of the infertility work-up and treatment. While Gram staining of vaginal smears would offer an inexpensive and validated means for screening and diagnosis, probiotics that contain live lactobacilli capable of re-colonizing the vagina may offer an elegant and safe choice of treatment. Carefully designed trials using well characterized probiotic strains and treatment regimens are still required to evaluate the effect of probiotics on IVF-embryo transfer pregnancy rates.

  4. Exogenous lactobacilli mitigate microbial changes associated with grain fermentation (corn, oats, and wheat) by equine fecal microflora ex vivo

    PubMed Central

    Harlow, Brittany E.; Lawrence, Laurie M.; Harris, Patricia A.; Aiken, Glen E.

    2017-01-01

    Cereal grains are often included in equine diets. When starch intake exceeds foregut digestion starch will reach the hindgut, impacting microbial ecology. Probiotics (e.g., lactobacilli) are reported to mitigate GI dysbioses in other species. This study was conducted to determine the effect of exogenous lactobacilli on pH and the growth of amylolytic and lactate-utilizing bacteria. Feces were collected from 3 mature geldings fed grass hay with access to pasture. Fecal microbes were harvested by differential centrifugation, washed, and re-suspended in anaerobic media containing ground corn, wheat, or oats at 1.6% (w/v) starch and one of five treatments: Control (substrate only), L. acidophilus, L. buchneri, L. reuteri, or an equal mixture of all three (107 cells/mL, final concentration). After 24 h of incubation (37°C, 160 rpm), samples were collected for pH and enumerations of total amylolytics, Group D Gram-positive cocci (GPC; Enterococci, Streptococci), lactobacilli, and lactate-utilizing bacteria. Enumeration data were log transformed prior to ANOVA (SAS, v. 9.3). Lactobacilli inhibited pH decline in corn and wheat fermentations (P < 0.0001). Specifically, addition of either L. reuteri or L. acidophilus was most effective at mitigating pH decline with both corn and wheat fermentation, in which the greatest acidification occurred (P < 0.05). Exogenous lactobacilli decreased amylolytics, while increasing lactate-utilizers in corn and wheat fermentations (P < 0.0001). In oat fermentations, L. acidophilus and L. reuteri inhibited pH decline and increased lactate-utilizers while decreasing amylolytics (P < 0.0001). For all substrates, L. reuteri additions (regardless of viability) had the lowest number of GPC and the highest number of lactobacilli and lactate-utilizers (P < 0.05). There were no additive effects when lactobacilli were mixed. Exogenous lactobacilli decreased the initial (first 8 h) rate of starch catalysis when wheat was the substrate, but did not

  5. Normal and tumour cervical cells respond differently to vaginal lactobacilli, independent of pH and lactate.

    PubMed

    Motevaseli, Elahe; Shirzad, Mahdieh; Akrami, Seyed Mohammad; Mousavi, Azam-Sadat; Mirsalehian, Akbar; Modarressi, Mohammad Hossein

    2013-07-01

    Cervical cancer is a human papilloma virus (HPV)-related cancer, but most HPV infections are transient or intermittent and resolve spontaneously. Thus, other factors, such as cervical microflora, which are dominated by lactobacilli, must be involved in invasive cervical carcinoma development after HPV infection. Previous studies have demonstrated that lactobacilli have antitumour effects, and it is possible that vaginal lactobacilli prevent cervical cancer. Here we examined the proliferative and apoptotic responses of normal and tumour cervical cells to common vaginal lactobacilli components by investigating human normal fibroblast-like cervical (normal cervical) and HeLa (cervical tumour) cell responses to Lactobacillus gasseri and Lactobacillus crispatus. The effects of different lactobacilli components, such as culture supernatants, cytoplasmic extracts, cell-wall extracts and live cells, were determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, trypan blue staining, lactate dehydrogenase assay and colorimetric caspase-3 activity assay. Changes in caspase-3 and human chorionic gonadotropin β (hCGβ) expression were analysed by quantitative RT-PCR. Tumour cell growth inhibition by culture supernatants was higher than that by pH- and lactate-adjusted controls. However, the effects of the supernatants on normal cells were similar to those of lactate-adjusted controls. Apoptosis was inhibited by supernatants, which was consistent with higher hCGβ expression since hCG inhibits apoptosis. Our study demonstrated that common vaginal lactobacilli exert cytotoxic effects on cervical tumour cells, but not on normal cells, and that this cytotoxicity is independent of pH and lactate. Our results encourage further studies on the interaction between lactobacilli and cervical cells, and administration of common vaginal lactobacilli as probiotics.

  6. Antibiotic Susceptibility of Potentially Probiotic Vaginal Lactobacilli

    PubMed Central

    Ocaña, Virginia; Silva, Clara; Nader-Macías, María Elena

    2006-01-01

    Objective. To study the antimicrobial susceptibility of six vaginal probiotic lactobacilli. Methods. The disc diffusion method in Müeller Hinton, LAPTg and MRS agars by the NCCLS (National Committee for Clinical Laboratory Standards) procedure was performed. Due to the absence of a Lactobacillus reference strains, the results were compared to those of Staphylococcus aureus ATCC29213. Minimal Inhibitory Concentration (MIC) with 21 different antibiotics in LAPTg agar and broth was also determined. Results. LAPTg and MRS agars are suitable media to study antimicrobial susceptibility of lactobacilli. However, the NCCLS procedure needs to be standardized for this genus. The MICs have shown that all Lactobacillus strains grew at concentrations above 10 μg/mL of chloramphenicol, aztreonam, norfloxacin, ciprofloxacin, ceftazidime, ceftriaxone, streptomycin and kanamycin. Four lactobacilli were sensitive to 1 μg/mL vancomycin and all of them were resistant to 1000 μg/mL of metronidazole. Sensitivity to other antibiotics depended on each particular strain. Conclusions. The NCCLS method needs to be standardized in an appropriate medium to determine the antimicrobial susceptibility of Lactobacillus. Vaginal probiotic lactobacilli do not display uniform susceptibility to antibiotics. Resistance to high concentrations of metronidazole suggests that lactobacilli could be simultaneously used with a bacterial vaginosis treatment to restore the vaginal normal flora. PMID:17485797

  7. Mechanisms and therapeutic effectiveness of lactobacilli

    PubMed Central

    Di Cerbo, Alessandro; Palmieri, Beniamino; Aponte, Maria; Morales-Medina, Julio Cesar; Iannitti, Tommaso

    2016-01-01

    The gut microbiome is not a silent ecosystem but exerts several physiological and immunological functions. For many decades, lactobacilli have been used as an effective therapy for treatment of several pathological conditions displaying an overall positive safety profile. This review summarises the mechanisms and clinical evidence supporting therapeutic efficacy of lactobacilli. We searched Pubmed/Medline using the keyword ‘Lactobacillus’. Selected papers from 1950 to 2015 were chosen on the basis of their content. Relevant clinical and experimental articles using lactobacilli as therapeutic agents have been included. Applications of lactobacilli include kidney support for renal insufficiency, pancreas health, management of metabolic imbalance, and cancer treatment and prevention. In vitro and in vivo investigations have shown that prolonged lactobacilli administration induces qualitative and quantitative modifications in the human gastrointestinal microbial ecosystem with encouraging perspectives in counteracting pathology-associated physiological and immunological changes. Few studies have highlighted the risk of translocation with subsequent sepsis and bacteraemia following probiotic administration but there is still a lack of investigations on the dose effect of these compounds. Great care is thus required in the choice of the proper Lactobacillus species, their genetic stability and the translocation risk, mainly related to inflammatory disease-induced gut mucosa enhanced permeability. Finally, we need to determine the adequate amount of bacteria to be delivered in order to achieve the best clinical efficacy decreasing the risk of side effects. PMID:26578541

  8. Studies on gonococcus infection. VIII. 125Iodine labeling of gonococci and studies on their in vitro interactions with eukaryotic cells.

    PubMed Central

    Swanson, J; King, G; Zeligs, B

    1975-01-01

    Intact gonococci (GC) have been labeled with 125iodine by the lactoperoxidase plus hydrogen peroxide procedure. The specific activities of types 2, 4, and 4 GC have been determined and are found to show small differences as follows: T4 greater than T2 greater than T4. 125I-labeled GC have been studied for their associations with both leukocytes and tissue culture cells. 125I-labeled GCshow the following relative order of association with the leukocytes: T2 equals T4* greater than T4. This contrasts with the relative degree of interaction between the GC and tissue culture cells, which follows the relative order: T2 greater than T4 equals T4*. Trypsin pretreatment of GC markedly reduces the association of all three types (T2, T4 AND T4*) with leukocytes but does not alter the level of attachment of any of the gonococcal types with tissue culture cells. PMID:803927

  9. Characterization of homofermentative lactobacilli isolated from kefir grains: potential use as probiotic.

    PubMed

    Golowczyc, Marina A; Gugliada, Maria J; Hollmann, Axel; Delfederico, Lucrecia; Garrote, Graciela L; Abraham, Analía G; Semorile, Liliana; De Antoni, Graciela

    2008-05-01

    Considering that several health promoting properties are associated with kefir consumption and a reliable probiotic product requires a complete identification of the bacterial species, the present work evaluates several proved markers of probiotic potential of eleven isolates of homofermentative lactobacilli isolated from kefir grains and molecular identification and genotypic diversity. Using restriction analysis of amplified ribosomal DNA (ARDRA) and analysis of the 16S-23S rRNA internal spacer region we confirmed that all homofermentative lactobacilli belong to the species Lactobacillus plantarum. RAPD-PCR analysis allowed the discrimination of lactobacilli in five clusters. All isolates exhibited high resistance to bile salt. High survival after one hour of exposure to pH 2.5 was observed in Lb. plantarum CIDCA 8313, 83210, 8327 and 8338. All isolates were hydrophilic and non autoaggregative. Isolate CIDCA 8337 showed the highest percentage of adhesion among strains. All tested lactobacilli had strong inhibitory power against Salmonella typhimurium and Escherichia coli. Seven out of eleven isolates showed inhibition against Sal. enterica and five isolates were effective against Sal. gallinarum. Only CIDCA 8323 and CIDCA 8327 were able to inhibit Sal. sonnei. We did not find any correlation between the five clusters based on RAPD-PCR and the probiotic properties, suggesting that these isolates have unique characteristics.

  10. Uptake of metabolites by gonococci grown with lactate in a medium containing glucose: evidence for a surface location of the sialyltransferase.

    PubMed

    Gao, L; Linden, L; Parsons, N J; Cole, J A; Smith, H

    2000-05-01

    Promotion of uptake of essential metabolites is a possible reason for the general stimulation of gonococcal metabolism which is caused by lactate (1 mM) in a defined medium containing glucose (5 mM). However, although uptake of(14)C adenine by gonococci [strain BS4(agar)] held for 4 or 7 min at 37 degrees C in Hanks balanced salt solution was increased for lactate treated gonococci compared with control organisms, uptake of(14)C glucose and(14)C proline under these conditions was unaffected. Hence, there is no evidence that lactate produces general stimulation of metabolite uptake. Unlike the other metabolites, cytidine 5'-monophospho-(14)CN-acetyl neuraminic acid (CMP-(14)CNANA), the substrate for sialylation of gonococcal lipopolysaccharide (LPS), was adsorbed in substantial quantities by gonococci held on ice for 6 min. Also, the increase in uptake of CMP-(14)CNANA at 37 degrees C over that adsorbed at 0 degrees C was much smaller (less than two-fold) than for the other compounds (4-30-fold). The substantial adsorption at 0 degrees C suggested a surface receptor for CMP-(14)CNANA. It is probably the sialyltransferase because a sialyltransferase deficient mutant, JB1, did not absorb CMP-(14)CNANA at 0 degrees C or take it up at 37 degrees C, in contrast to its parent strain, F62, which behaved similarly to strain BS4 (agar). This supports previous evidence for a surface location of the sialyltransferase. There was a small increase in adsorption of CMP-(14)CNANA in lactate treated gonococci indicating a slight increase in the surface enzyme. This could enhance LPS sialylation and hence affect pathogenicity.

  11. Estimation of vaginal probiotic lactobacilli growth parameters with the application of the Gompertz model.

    PubMed

    Juárez, TomásMaríaSilvina; de, LabandaElenaBru; de, RuizHolgadoAidaPesce; Nader-Macías, María Elena

    2002-01-01

    Lactobacilli are widely described as probiotic microorganisms used to restore the ecological balance of different animal or human tracts. For their use as probiotics, bacteria must show certain characteristics or properties related to the ability of adherence to mucosae or epithelia or show inhibition against pathogenic microorganisms. It is of primary interest to obtain the highest biomass and viability of the selected microorganisms. In this report, the growth of seven vaginal lactobacilli strains in four different growth media and at several inoculum percentages was compared, and the values of growth parameters (lag phase time, maximum growth rate, maximum optical density) were obtained by applying the Gompertz model to the experimental data. The application and estimation of this model is discussed, and the evaluation of the growth parameters is analyzed to compare the growth conditions of lactobacilli. Thus, these results in lab experiments provide a basis for testing different culture conditions to determine the best conditions in which to grow the probiotic lactobacilli for technological applications.

  12. Combining ultrasound and lactobacilli treatment for high-fat-diet-induced obesity in mice.

    PubMed

    Liao, A-H; Jiang, C-B; Li, C-C; Chuang, H-C; Chiang Chiau, J-S; Chan, W-T; Yeung, C-Y; Cheng, M-L; Lee, H-C

    2017-08-01

    Chronic systemic lipopolysaccharide-induced inflammation can cause obesity. In animal experiments, lactobacilli have been shown to inhibit obesity by modifying the gut microbiota, controlling inflammation and influencing the associated gene expression. A previous study found that high-fat-diet-induced (HFD) obesity was suppressed by lactobacilli ingestion in rats via the inhibition of parasympathetic nerve activity. This study explored the combined use of lactobacilli ingestion and ultrasound (US) to control body weight and body fat deposition in HFD mice over an 8-week experimental period. Male C57BL/6J mice received an HFD during treatment and were randomly divided into four groups: (i) control group (H), (ii) lactobacilli alone (HB), (iii) US alone (HU) and (iv) lactobacilli combined with US (HUB). The US was targeted at the inguinal portion of the epididymal fat pad on the right side. At the 8th week, body weight had decreased significantly in the HUB group (15.56 ± 1.18%, mean ± SD) group compared with the HU (26.63 ± 0.96%) and H (32.62 ± 5.03%) groups (p < 0.05). High-resolution microcomputed tomography (micro-CT) scans revealed that the reduction in total body fat volume was significantly greater in the HUB group (69%) than in the other two experimental groups (HB, 52%; HU, 37%; p < 0.05). The reductions in the thickness of the subcutaneous epididymal fat pads were significantly greater in the HUB group (final thickness: 340 ± 7 μm) than in the H (final thickness: 1150 ± 21 μm), HB (final thickness: 1060 ± 18 μm) and HU (final thickness: 370 ± 5 μm) groups (all p < 0.05). Combination therapy with lactobacilli and US appears to enhance the reduction in body weight, total and local body fat deposition, adipocyte size and plasma lipid levels over an 8-week period over that achieved with lactobacilli or US alone in HFD mice. These results indicate that US treatment alone can reduce hyperlipidemia in HFD mice. Journal of

  13. Catabolic flexibility of mammalian-associated lactobacilli

    PubMed Central

    2013-01-01

    Metabolic flexibility may be generally defined as “the capacity for the organism to adapt fuel oxidation to fuel availability”. The metabolic diversification strategies used by individual bacteria vary greatly from the use of novel or acquired enzymes to the use of plasmid-localised genes and transporters. In this review, we describe the ability of lactobacilli to utilise a variety of carbon sources from their current or new environments in order to grow and survive. The genus Lactobacillus now includes more than 150 species, many with adaptive capabilities, broad metabolic capacity and species/strain variance. They are therefore, an informative example of a cell factory capable of adapting to new niches with differing nutritional landscapes. Indeed, lactobacilli naturally colonise and grow in a wide variety of environmental niches which include the roots and foliage of plants, silage, various fermented foods and beverages, the human vagina and the mammalian gastrointestinal tract (GIT; including the mouth, stomach, small intestine and large intestine). Here we primarily describe the metabolic flexibility of some lactobacilli isolated from the mammalian gastrointestinal tract, and we also describe some of the food-associated species with a proven ability to adapt to the GIT. As examples this review concentrates on the following species - Lb. plantarum, Lb. acidophilus, Lb. ruminis, Lb. salivarius, Lb. reuteri and Lb. sakei, to highlight the diversity and inter-relationships between the catabolic nature of species within the genus. PMID:23680304

  14. Divergent signaling pathways regulate IL-12 production induced by different species of Lactobacilli in human dendritic cells.

    PubMed

    Amar, Yacine; Rizzello, Valeria; Cavaliere, Riccardo; Campana, Stefania; De Pasquale, Claudia; Barberi, Chiara; Oliveri, Daniela; Pezzino, Gaetana; Costa, Gregorio; Meddah, Aicha Tirtouil; Ferlazzo, Guido; Bonaccorsi, Irene

    2015-07-01

    Recent studies have indicated that different strains of Lactobacilli differ in their ability to regulate IL-12 production by dendritic cells (DCs), as some strains are stronger inducer of IL-12 while other are not and can even inhibit IL-12 production stimulated by IL-12-inducer Lactobacilli. In this report we demonstrate that Lactobacillus reuteri 5289, as previously described for other strains of L. reuteri, can inhibit DC production of IL-12 induced by Lactobacilllus acidophilus NCFM. Remarkably, L. reuteri 5289 was able to inhibit IL-12 production induced not only by Lactobacilli, as so far reported, but also by bacteria of different genera, including pathogens. We investigated in human DCs the signal transduction pathways involved in the inhibition of IL-12 production induced by L. reuteri 5289, showing that this potential anti-inflammatory activity, which is also accompanied by an elevated IL-10 production, is associated to a prolonged phosphorilation of ERK1/2 MAP kinase pathway. Improved understanding of the immune regulatory mechanisms exerted by Lactobacilli is crucial for a more precise employment of these commensal bacteria as probiotics in human immune-mediated pathologies, such as allergies or inflammatory bowel diseases.

  15. Development of gemifloxacin in vitro susceptibility test methods for gonococci including quality control guidelines. The Quality Control Study Group.

    PubMed

    Jones, R N; Erwin, M E

    2000-07-01

    Gemifloxacin (formerly SB-265805 or LB20304a) is a new fluoronapthyridone with documented activity against Gram-positive and -negative organisms. The activity of gemifloxacin was tested against 150 Neisseria gonorrhoeae strains, using reference agar dilution, standardized disk diffusion, and Etest (AB BIODISK, Solna, Sweden) methods. Gemifloxacin was very potent against ciprofloxacin (CIPRO)-susceptible strains (MIC(90,) 0.008 microg/ml) but was significantly less active against the CIPRO-resistant gonococci (MIC(90,) 0.12 microg/ml). Etest and reference agar dilution MIC results showed excellent correlation (r = 0.96), and 98.7% MICs were within +/- one log(2) dilution. Agar dilution MICs were also compared to zone diameters obtained using gemifloxacin 5-microg disks; and complete intermethod categorical agreement (100%) was achieved applying breakpoints proposed as follows: < or =0.25 microg/ml (zone, > or =25 mm) for susceptible and > or =1 microg/ml (zone, < or =21 mm) for resistant. Gemifloxacin MIC and disk diffusion te quality control (QC) ranges were established for N. gonorrhoeae ATCC 49226. Data were collected from > or = seven laboratories, three GC agar medium lots for both agar MICs and disk methods, and two lots each of the 5- and 10-microg disks. The proposed MIC QC range was 0.002 to 0.016 microg/ml and the calculated mm zone ranges (median +/- 0.5x average mm range) for both disks were similar, but contained only 88.1 to 91.9% of participant results. To achieve the acceptable > or = 95% of all study results within range, a 43 to 54 mm limits (5-microg disks) were necessary. The excellent broad-spectrum activity and a low reported adverse effects profile of gemifloxacin shows a potential for treatment of fluoroquinolone-resistant gonorrhea.

  16. Anti-Helicobacter pylori activity of non-living, heat-killed form of lactobacilli including Lactobacillus johnsonii No.1088.

    PubMed

    Aiba, Yuji; Ishikawa, Hiroki; Tokunaga, Masayoshi; Komatsu, Yasuhiko

    2017-06-15

    Some strains of lactic acid bacteria are reported to inhibit the growth of Helicobacter pylori and proposed to be useful to support so-called triple therapy for H. pylori. Although most strains must be alive to exert their anti-H. pylori activity, some lactobacilli strains are effective even when dead. One possible underlying mechanism of such an activity of non-living lactobacilli is reportedly co-aggregation with H. pylori. In this study, we found that a non-living heat-killed form of Lactobacillus johnsonii No.1088 (HK-LJ88) and also that of some other lactobacilli inhibited the growth of H. pylori in vitro. Furthermore, the number of H. pylori in the infected stomach of germ-free mice was significantly decreased by the repeated oral administration of HK-LJ88. Observation by scanning electron microscopy revealed that no co-aggregation had occurred between H. pylori and HK-LJ88; instead, deformations of H. pylori (e.g. disappearance of spiral, bending of cell body, coccoid formation, degradations, etc.) appeared after incubation for 24 h with HK-LJ88. These results suggest that HK-LJ88 inhibited H. pylori activity probably not by co-aggregation but by some unknown mechanism involving HK-LJ88's cell surface molecules and that even non-living lactobacilli are possibly useful to support H. pylori eradication therapy. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Prevention of Helicobacter pylori infection by lactobacilli in a gnotobiotic murine model.

    PubMed Central

    Kabir, A M; Aiba, Y; Takagi, A; Kamiya, S; Miwa, T; Koga, Y

    1997-01-01

    BACKGROUND: Helicobacter pylori is a bacterium which causes gastric inflammatory diseases. Oral inoculation of H pylori usually results in only a temporary colonisation without a successful infection in the stomach of conventional mice in which lactobacilli are the predominant indigenous bacteria. AIM: To determine whether lactobacilli exert an inhibitory effect on colonisation by H pylori in the stomach. METHODS: The effects of H pylori on attachment to murine and human gastric epithelial cells and the H pylori mediated release of interleukin-8 (IL-8) by these cells were examined in vitro. Lactobacillus salivarius infected gnotobiotic BALB/c mice and control germ free mice were inoculated orally with H pylori to examine whether L salivarius can inhibit colonisation by H pylori. RESULTS: L salivarius inhibited both the attachment and IL-8 release in vitro. H pylori could not colonise the stomach of L salivarius infected gnotobiotic BALB/c mice, but colonised in large numbers and subsequently caused active gastritis in germ free mice. In addition, L salivarius given after H pylori implantation could eliminate colonisation by H pylori. CONCLUSION: These findings suggest the possibility of lactobacilli being used as probiotic agents against H pylori. Images PMID:9274471

  18. Effect of Probiotic Lactobacilli on the Growth of Streptococcus Mutans and Multispecies Biofilms Isolated from Children with Active Caries

    PubMed Central

    Lin, Xiaolong; Chen, Xi; Tu, Yan; Wang, Sa; Chen, Hui

    2017-01-01

    Background The purpose of this investigation was to evaluate the effect of probiotic lactobacilli on Streptococcus mutans (MS) and multispecies biofilms isolated from children with severe caries. Material/Methods Twenty children with active caries (DMFS ≥6) were selected as the experimental group and Streptococcus mutans (MS) were isolated from their saliva. After identification the MS strains were mixed with lactobacilli at 37°C, following which viable MS colonies were counted. At the same time dental plaques from the children were mixed with lactobacilli in vitro to form biofilms, and the population of nine common strains in the biofilms was enumerated after 24 hours of growth. Results Lactobacillus casei Shirota, L. casei LC01, L. plantarum ST-III and L. paracasei LPC37 all had strong inhibitory effects on the majority the MS isolated from children with active caries, with the inhibition rate reaching approximately 70–90% (p<0.05). L. casei Shirota, L. casei LC01, L. plantarum ST-III, L. paracasei LPC37 also significantly reduced the numbers of MS, Streptococcus spp., S. sanguinis and total bacteria in mixed biofilms compared with the control group (p<0.05). Conclusions The four strains of lactobacilli were able to inhibit the growth of Streptococcus mutans and had effects on the composition of bacterial biofilms in vitro. Ingestion of probiotics may be a promising method of caries prevention. PMID:28851857

  19. The effect of five probiotic lactobacilli strains on the growth and biofilm formation of Streptococcus mutans.

    PubMed

    Lin, X; Chen, X; Chen, Y; Jiang, W; Chen, H

    2015-01-01

    To compare the effects of five probiotic lactobacilli strains on the growth and biofilm formation of Streptococcus mutans (MS). Five probiotic lactobacilli bacteria (LB), Lactobacillus casei Shirota, Lactobacillus casei LC01, Lactobacillus plantarum ST-III, Lactobacillus paracasei Lpc-37, and Lactobacillus rhamnosus HN001, were used as test strains effecting on the Streptococci strain S. mutans UA159 in this study. The effect of LB strains and their supernatants on the viability of the MS was evaluated. Then, the effect of LB strains on the growth of MS biofilm formation was observed by fluorescence microscope. All of the LB strains inhibited the growth of MS at concentrations of 1 × 10(8) and 3 × 10(8) CFU ml(-1) (P < 0.05). Untreated (without pH adjustment and ultrafiltration) LB supernatants from all of the LB strains inhibited the growth of MS (P < 0.05) as well. After pH adjustment and ultrafiltration (treated), only supernatants from L. casei Shirota and L. rhamnosus HN001 inhibited the growth of MS (P < 0.05). MS biofilm formation was also inhibited by all untreated supernatants and by the treated supernatants of L. casei Shirota and L. rhamnosus HN001 (P < 0.05). All five probiotic lactobacilli strains inhibited the growth and biofilm formation of MS, likely through the production of an acid environment, bacteriocin-like poly peptides, or both, and the effects on MS were dependent on the LB strains used. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Use of lactobacilli and their pheromone-based regulatory mechanism in gene expression and drug delivery.

    PubMed

    Diep, D B; Mathiesen, G; Eijsink, V G H; Nes, I F

    2009-01-01

    Lactobacilli are common microorganisms in diverse vegetables and meat products and several of these are also indigenous inhabitants in the gastro-intestinal (GI) tract of humans and animals where they are believed to have health promoting effects on the host. One of the highly appreciated probiotic effects is their ability to inhibit the growth of pathogens by producing antimicrobial peptides, so-called bacteriocins. Production of some bacteriocins has been shown to be strictly regulated through a quorum-sensing based mechanism mediated by a secreted peptide-pheromone (also called induction peptide; IP), a membrane-located sensor (histidine protein kinase; HPK) and a cytoplasmic response regulator (RR). The interaction between an IP and its sensor, which is highly specific, leads to activation of the cognate RR which in turn binds to regulated promoters and activates gene expression. The HPKs and RRs are built up by conserved modules, and the signalling between them within a network is efficient and directional, and can easily be activated by exogenously added synthetic IPs. Consequently, components from such regulatory networks have successfully been exploited in construction of a number of inducible gene expression systems. In this review, we discuss some well-characterised quorum sensing networks involved in bacteriocin production in lactobacilli, with special focus on the use of the regulatory components in gene expression and on lactobacilli as potential delivery vehicle for therapeutic and vaccine purposes.

  1. Diversity in proteinase specificity of thermophilic lactobacilli as revealed by hydrolysis of dairy and vegetable proteins.

    PubMed

    Pescuma, Micaela; Espeche Turbay, María Beatriz; Mozzi, Fernanda; Font de Valdez, Graciela; Savoy de Giori, Graciela; Hebert, Elvira María

    2013-09-01

    Ability of industrially relevant species of thermophilic lactobacilli strains to hydrolyze proteins from animal (caseins and β-lactoglobulin) and vegetable (soybean and wheat) sources, as well as influence of peptide content of growth medium on cell envelope-associated proteinase (CEP) activity, was evaluated. Lactobacillus delbrueckii subsp. lactis (CRL 581 and 654), L. delbrueckii subsp. bulgaricus (CRL 454 and 656), Lactobacillus acidophilus (CRL 636 and 1063), and Lactobacillus helveticus (CRL 1062 and 1177) were grown in a chemically defined medium supplemented or not with 1 % Casitone. All strains hydrolyzed mainly β-casein, while degradation of αs-caseins was strain dependent. Contrariwise, κ-Casein was poorly degraded by the studied lactobacilli. β-Lactoglobulin was mainly hydrolyzed by CRL 656, CRL 636, and CRL 1062 strains. The L. delbrueckii subsp. lactis strains, L. delbrueckii subsp. bulgaricus CRL 656, and L. helveticus CRL 1177 degraded gliadins in high extent, while the L. acidophilus and L. helveticus strains highly hydrolyzed soy proteins. Proteinase production was inhibited by Casitone, the most affected being the L. delbrueckii subsp. lactis species. This study highlights the importance of proteolytic diversity of lactobacilli for rational strain selection when formulating hydrolyzed dairy or vegetable food products.

  2. Cross-talk between probiotic lactobacilli and host immune system.

    PubMed

    Kemgang, T S; Kapila, S; Shanmugam, V P; Kapila, R

    2014-08-01

    The mechanism by which probiotic lactobacilli affect the immune system is strain specific. As the immune system is a multicompartmental system, each strain has its way to interact with it and induce a visible and quantifiable effect. This review summarizes the interplay existing between the host immune system and probiotic lactobacilli, that is, with emphasis on lactobacilli as a prototype probiotic genus. Several aspects including the bacterial-host cross-talk with the mucosal and systemic immune system are presented, as well as short sections on the competing effect towards pathogenic bacteria and their uses as delivery vehicle for antigens. © 2014 The Society for Applied Microbiology.

  3. Postbiotic activities of lactobacilli-derived factors.

    PubMed

    Cicenia, Alessia; Scirocco, Annunziata; Carabotti, Marilia; Pallotta, Lucia; Marignani, Massimo; Severi, Carola

    2014-01-01

    Probiotics are alive nonpathogenic microorganisms present in the gut microbiota that confer benefits to the host for his health. They act through molecular and cellular mechanisms that contrast pathogen bacteria adhesion, enhance innate immunity, decrease pathogen-induced inflammation, and promote intestinal epithelial cell survival, barrier function, and protective responses. Some of these beneficial effects result to be determined by secreted probiotic-derived factors that recently have been identified as "postbiotic" mediators. They have been reported for several probiotic strains but most available literature concerns Lactobacilli. In this review, we focus on the reported actions of several secretory products of different Lactobacillus species highlighting the available mechanistic data. The identification of soluble factors mediating the beneficial effects of probiotics may present an opportunity not only to understand their fine mechanisms of action, but also to develop effective pharmacological strategies that could integrate the action of treatments with live bacteria.

  4. Impact of lactobacilli on orally acquired listeriosis

    PubMed Central

    Archambaud, Cristel; Nahori, Marie-Anne; Soubigou, Guillaume; Bécavin, Christophe; Laval, Laure; Lechat, Pierre; Smokvina, Tamara; Langella, Philippe; Lecuit, Marc; Cossart, Pascale

    2012-01-01

    Listeria monocytogenes is a foodborne pathogen that crosses the intestinal barrier and disseminates within the host. Here, we report a unique comprehensive analysis of the impact of two Lactobacillus species, Lactobacillus paracasei CNCM I-3689 and Lactobacillus casei BL23, on L. monocytogenes and orally acquired listeriosis in a gnotobiotic humanized mouse model. We first assessed the effect of treatment with each Lactobacillus on L. monocytogenes counts in host tissues and showed that each decreases L. monocytogenes systemic dissemination in orally inoculated mice. A whole genome intestinal transcriptomic analysis revealed that each Lactobacillus changes expression of a specific subset of genes during infection, with IFN-stimulated genes (ISGs) being the most affected by both lactobacilli. We also examined microRNA (miR) expression and showed that three miRs (miR-192, miR-200b, and miR-215) are repressed during L. monocytogenes infection. Treatment with each Lactobacillus increased miR-192 expression, whereas only L. casei association increased miR-200b and miR-215 expression. Finally, we showed that treatment with each Lactobacillus significantly reshaped the L. monocytogenes transcriptome and up-regulated transcription of L. monocytogenes genes encoding enzymes allowing utilization of intestinal carbon and nitrogen sources in particular genes involved in propanediol and ethanolamine catabolism and cobalamin biosynthesis. Altogether, these data reveal that the modulation of L. monocytogenes infection by treatment with lactobacilli correlates with a decrease in host gene expression, in particular ISGs, miR regulation, and a dramatic reshaping of L. monocytogenes transcriptome. PMID:23012479

  5. Isolation of Vaginal Lactobacilli and Characterization of Anti-Candida Activity

    PubMed Central

    Parolin, Carola; Marangoni, Antonella; Laghi, Luca; Foschi, Claudio; Ñahui Palomino, Rogers Alberto; Calonghi, Natalia; Cevenini, Roberto; Vitali, Beatrice

    2015-01-01

    Healthy vaginal microbiota is dominated by Lactobacillus spp., which form a critical line of defence against pathogens, including Candida spp. The present study aims to identify vaginal lactobacilli exerting in vitro activity against Candida spp. and to characterize their antifungal mechanisms of action. Lactobacillus strains were isolated from vaginal swabs of healthy premenopausal women. The isolates were taxonomically identified to species level (L. crispatus B1-BC8, L. gasseri BC9-BC14 and L. vaginalis BC15-BC17) by sequencing the 16S rRNA genes. All strains produced hydrogen peroxide and lactate. Fungistatic and fungicidal activities against C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis and C. lusitaniae were evaluated by broth micro-dilution method. The broadest spectrum of activity was observed for L. crispatus BC1, BC4, BC5 and L. vaginalis BC15, demonstrating fungicidal activity against all isolates of C. albicans and C. lusitaniae. Metabolic profiles of lactobacilli supernatants were studied by 1H-NMR analysis. Metabolome was found to be correlated with both taxonomy and activity score. Exclusion, competition and displacement experiments were carried out to investigate the interference exerted by lactobacilli toward the yeast adhesion to HeLa cells. Most Lactobacillus strains significantly reduced C. albicans adhesion through all mechanisms. In particular, L. crispatus BC2, L. gasseri BC10 and L. gasseri BC11 appeared to be the most active strains in reducing pathogen adhesion, as their effects were mediated by both cells and supernatants. Inhibition of histone deacetylases was hypothesised to support the antifungal activity of vaginal lactobacilli. Our results are prerequisites for the development of new therapeutic agents based on probiotics for prophylaxis and adjuvant therapy of Candida infection. PMID:26098675

  6. Inhibitory effects of arabitol on caries-associated microbiologic parameters of oral Streptococci and Lactobacilli.

    PubMed

    Loman, Abdullah Al; Ju, Lu-Kwang

    2015-12-01

    The aim of this study was to compare arabitol with its better studied isomer xylitol for their inhibitory effects on cell growth and acid production of oral bacteria. Streptococcus mutans, Streptococcus salivarius and Streptococcus sobrinus were used as representatives of oral streptococci and Lactobacillus acidophilus and Lactobacillus fermentum were used for oral lactobacilli. Growth was followed by measuring the absorbance at 660nm, acid production by pH change. Sensitivity of these oral bacteria to arabitol and xylitol was first compared at 1% (65mM) additive concentration with glucose as sugar substrate. For all bacteria tested, the inhibitory effects of the two polyols were comparable; both were significantly stronger on streptococci (with 20-60% inhibition) than on lactobacilli (with 5-10% inhibition). Effects of arabitol and xylitol were also compared for S. mutans and S. salivarius in media with 1% of different sugar substrates: glucose (55mM), fructose (55mM), galactose (55mM) and sucrose (30mM). Inhibition occurred for all sugars: stronger on glucose and galactose (60-65%) than on fructose and sucrose (40-45%). Inhibition dependency on the arabitol/xylitol concentration from 0.01% (0.65mM) to 2% (130mM) was further determined for S. mutans and S. salivarius. Regardless of the concentration, sugar substrate and bacterial species tested, arabitol showed very similar inhibition effects to its isomer xylitol. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. The Role of Cell Surface Architecture of Lactobacilli in Host-Microbe Interactions in the Gastrointestinal Tract

    PubMed Central

    Altermann, Eric; Anderson, Rachel C.; McNabb, Warren C.; Moughan, Paul J.; Roy, Nicole C.

    2013-01-01

    Lactobacillus species can exert health promoting effects in the gastrointestinal tract (GIT) through many mechanisms, which include pathogen inhibition, maintenance of microbial balance, immunomodulation, and enhancement of the epithelial barrier function. Different species of the genus Lactobacillus can evoke different responses in the host, and not all strains of the same species can be considered beneficial. Strain variations may be related to diversity of the cell surface architecture of lactobacilli and the bacteria's ability to express certain surface components or secrete specific compounds in response to the host environment. Lactobacilli are known to modify their surface structures in response to stress factors such as bile and low pH, and these adaptations may help their survival in the face of harsh environmental conditions encountered in the GIT. In recent years, multiple cell surface-associated molecules have been implicated in the adherence of lactobacilli to the GIT lining, immunomodulation, and protective effects on intestinal epithelial barrier function. Identification of the relevant bacterial ligands and their host receptors is imperative for a better understanding of the mechanisms through which lactobacilli exert their beneficial effects on human health. PMID:23576850

  8. Lactobacilli Interfere with Streptococcus pyogenes Hemolytic Activity and Adherence to Host Epithelial Cells

    PubMed Central

    Saroj, Sunil D.; Maudsdotter, Lisa; Tavares, Raquel; Jonsson, Ann-Beth

    2016-01-01

    Streptococcus pyogenes [Group A streptococcus (GAS)], a frequent colonizer of the respiratory tract mucosal surface, causes a variety of human diseases, ranging from pharyngitis to the life-threatening streptococcal toxic shock-like syndrome. Lactobacilli have been demonstrated to colonize the respiratory tract. In this study, we investigated the interference of lactobacilli with the virulence phenotypes of GAS. The Lactobacillus strains L. rhamnosus Kx151A1 and L. reuteri PTA-5289, but not L. salivarius LMG9477, inhibited the hemolytic activity of S. pyogenes S165. The inhibition of hemolytic activity was attributed to a decrease in the production of streptolysin S (SLS). Conditioned medium (CM) from the growth of L. rhamnosus Kx151A1 and L. reuteri PTA-5289 was sufficient to down-regulate the expression of the sag operon, encoding SLS. The Lactobacillus strains L. rhamnosus Kx151A1, L. reuteri PTA-5289, and L. salivarius LMG9477 inhibited the initial adherence of GAS to host epithelial cells. Intriguingly, competition with a combination of Lactobacillus species reduced GAS adherence to host cells most efficiently. The data suggest that an effector molecule released from certain Lactobacillus strains attenuates the production of SLS at the transcriptional level and that combinations of Lactobacillus strains may protect the pharyngeal mucosa more efficiently from the initial colonization of GAS. The effector molecules released from Lactobacillus strains affecting the virulence phenotypes of pathogens hold potential in the development of a new generation of therapeutics. PMID:27524981

  9. Molecular identification and typing of lactobacilli isolated from kefir grains.

    PubMed

    Delfederico, Lucrecia; Hollmann, Axel; Martínez, Mariano; Iglesias, N Gabriel; De Antoni, Graciela; Semorile, Liliana

    2006-02-01

    Seventeen heterofermentative lactobacilli isolated from kefir grains were characterized by molecular methods. Bacterial isolates were identified by amplification of 16S rRNA gene and analysis by Amplified Ribosomal DNA Restriction Analysis (ARDRA), using the restriction enzymes Hae III, Dde I, and Hinf I. ARDRA analysis of lactobacilli isolates showed, for each enzyme used, a same banding pattern between the heterofermentative lactobacilli and the reference strains Lactobacillus kefir JCM 5818 and Lb. kefir ATCC 8007. Other reference lactobacilli and one homofermentative isolate showed differences in at least one of these patterns. The 16S-23S rRNA spacer region was also used to discriminate the bacterial isolates at the species level. The data obtained from the analysis of spacer region confirmed that sequencing of this genome region is a good tool for a reliable identification of members of Lb. kefir species. Genotyping of isolates was performed by Random Amplified Polymorphic DNA (RAPD-PCR) analysis using M13, Coc, ERIC-2 and 1254 primers. Patterns obtained allowed the differentiation of isolates in three groups. The three clusters showed by RAPD-PCR analysis could be correlated with at least three different strains of Lb. kefir species in the group of heterofermentative lactobacilli isolates obtained from Argentinian kefir grains.

  10. Adhesion Forces and Coaggregation between Vaginal Staphylococci and Lactobacilli

    PubMed Central

    Younes, Jessica A.; van der Mei, Henny C.; van den Heuvel, Edwin; Busscher, Henk J.; Reid, Gregor

    2012-01-01

    Urogenital infections are the most common ailments afflicting women. They are treated with dated antimicrobials whose efficacy is diminishing. The process of infection involves pathogen adhesion and displacement of indigenous Lactobacillus crispatus and Lactobacillus jensenii. An alternative therapeutic approach to antimicrobial therapy is to reestablish lactobacilli in this microbiome through probiotic administration. We hypothesized that lactobacilli displaying strong adhesion forces with pathogens would facilitate coaggregation between the two strains, ultimately explaining the elimination of pathogens seen in vivo. Using atomic force microscopy, we found that adhesion forces between lactobacilli and three virulent toxic shock syndrome toxin 1-producing Staphylococcus aureus strains, were significantly stronger (2.2–6.4 nN) than between staphylococcal pairs (2.2–3.4 nN), especially for the probiotic Lactobacillus reuteri RC-14 (4.0–6.4 nN) after 120 s of bond-strengthening. Moreover, stronger adhesion forces resulted in significantly larger coaggregates. Adhesion between the bacteria occurred instantly upon contact and matured within one to two minutes, demonstrating the potential for rapid anti-pathogen effects using a probiotic. Coaggregation is one of the recognized mechanisms through which lactobacilli can exert their probiotic effects to create a hostile micro-environment around a pathogen. With antimicrobial options fading, it therewith becomes increasingly important to identify lactobacilli that bind strongly with pathogens. PMID:22629342

  11. Importance of lactobacilli in food and feed biotechnology.

    PubMed

    Giraffa, Giorgio; Chanishvili, Nina; Widyastuti, Yantyati

    2010-01-01

    The genus Lactobacillus is a heterogeneous group of lactic acid bacteria (LAB) with important implications in food fermentation. The ability to colonize a variety of habitats is a direct consequence of the wide metabolic versatility of this group of LAB. Consequently, lactobacilli have been used for decades in food preservation, as starters for dairy products, fermented vegetables, fish and sausages as well as silage inoculants. Lactobacilli have also been proposed as probiotics and microbial cell factories for the production of nutraceuticals. However, a wide range of applications of lactobacilli in food biotechnology remains potential, whereas a number of important strains still need to be discovered and characterized. This article provides an overview of the taxonomy of lactobacilli and describes four of the most significant case studies on the application of this group of LAB in food and feed biotechnology, including their use as probiotics, dairy starters, silage inoculants, and microbial cell factories. The importance of access to and exchange of biological material within and between different strain collections as a crucial step in expanding the range of different biotechnological applications of lactobacilli is also emphasized. (c) 2010 Elsevier Masson SAS. All rights reserved.

  12. Isolation and characterization of faecal bifidobacteria and lactobacilli isolated from dogs and primates.

    PubMed

    Strompfová, Viola; Lauková, Andrea

    2014-10-01

    Although bifidobacteria and lactobacilli have been suggested beneficial for the host and are components of many probiotics and competitive exclusion mixtures, the knowledge on abundance, metabolic and probiotic characteristics in isolates from dogs and monkeys is still limited. The present study was aimed to isolate Bifidobacterium and Lactobacillus strains (faeces of 22 dogs and of 5 primates: Cebus apella, Eulemur fulvus, Erythrocebus patas, Macaca fascicularis, Papio hamadryas) with the MALDI-TOF identification system Lactobacillus murinus, Bifidobacterium animalis and Pediococcus acidilactici were more frequently isolated species in dogs while Lactobacillus plantarum was isolated in several species of primates. Ten strains of 6 species were assayed for enzymatic activities (only Lactobacillus reuteri strains showed no undesirable enzymatic activity), antimicrobial susceptibility (detected higher minimum inhibitory concentration levels for tetracycline and gentamicin), and inhibitory activity against 15 indicator bacteria. All strains inhibited Gram-negative indicators while lactobacilli showed larger inhibition zones than bifidobacteria. L. reuteri II/3b/a (isolate from M. fascicularis) showed the best antimicrobial properties. Resistance to bile (0.3% w/v) was observed in all tested strains (no decrease of CFU/ml) whereas the decrease of 68.4-94.4% (after 90 min exposition) and 78.4-99.9% CFU/ml (after 180 min) depending on the strain was detected in the artificial gastric juice.

  13. Characterization of vaginal lactobacilli in women after kidney transplantation.

    PubMed

    Martirosian, G; Radosz-Komoniewska, H; Pietrzak, B; Ekiel, A; Kamiński, P; Aptekorz, M; Doleżych, H; Samulska, E; Jóźwiak, J

    2012-04-01

    Limited number of publications described vaginal microflora after kidney transplantation. Our PubMed search revealed only 18 publications including words "vaginal bacteria & kidney transplant" in the period of 1978-2011. The aim of this study was to characterize lactobacilli isolated from vaginal swabs of women after kidney transplantation, compared with healthy women. Eighteen renal transplant recipients (mean age 36.1) and 20 healthy women (mean age 36.0) were evaluated. Lactobacilli were cultured on MRS and Columbia blood agars. Biochemical identification with API 50 CHL (bioMerieux, Marcy L'Etoile, France) and multiplex PCR according to Song et al. was performed. Lactobacilli were tested for production of H(2)O(2). Minimal inhibitory concentrations (MICs) of selected antimicrobial agents were determined with E-tests (bioMerieux, Marcy L'Etoile, France) and interpreted with CLSI and EUCAST criteria. No bacterial vaginosis was found among studied women. Two strains of group I were identified as Lactobacillus delbrueckii; 18 strains as Lactobacillus gasseri and 15 strains as Lactobacillus crispatus. Only 3 strains from group II were not identified by species-specific mPCR. Group IV was represented with 2 unidentified strains. Vaginal lactobacilli isolated from healthy women represented more homogenous group compared with heterogenous renal transplant recipients. Biochemical identification of lactobacilli by API 50 CHL kits was concordant with mPCR results only in 7 cases (17.5%), all 7 strains were identified as L. crispatus. Majority (93%) of lactobacilli were H(2)O(2) producers. All isolated lactobacilli (100%) demonstrated high resistance to metronidazole (MIC > 256 μg/ml). Only 2 strains resistant to vancomycin (MICs: 32 and 256 μg/ml respectively), in the study and control group, and one to moxifloxacin (MIC = 32 μg/ml), were found. Resistance to metronidazole and vancomycin was concordant in CLSI and EUCAST (2010) criteria. Although significant

  14. Lactobacilli Inactivate Chlamydia trachomatis through Lactic Acid but Not H2O2

    PubMed Central

    Gong, Zheng; Luna, Yesmin; Yu, Ping; Fan, Huizhou

    2014-01-01

    Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C. trachomatis infection. PMID

  15. Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

    PubMed

    Gong, Zheng; Luna, Yesmin; Yu, Ping; Fan, Huizhou

    2014-01-01

    Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C. trachomatis infection.

  16. Colonization by lactobacilli of piglet small intestinal mucus.

    PubMed

    Rojas, M; Conway, P L

    1996-11-01

    The colonization potential of lactobacilli was investigated using small intestinal mucus extracts from 35-d-old pigs. Mucus-secreting tissue from the small intestine of piglets was gently rinsed to remove contents and then shaken in buffer to release mucus from the surface. Numbers of lactobacilli in different portions of the small intestine of 35-d-old pigs were enumerated. Also, mucus isolated from the small intestine of pigs was investigated for its capacity to support the growth of lactobacilli. Results indicated that Lactobacillus spp. inhabit the mucus layer of the small intestine and can grow and adhere to ileal mucus. From adhesion studies of Lactobacillus fermentum 104R to mucus analysed by Scatchard plot, it is suggested that an associating system showing positive cooperativity is involved. Proteinaceous compounds(s) involved in the adhesion to mucus were detected in the spent culture fluid from the growth of strain 104R. Studies are continuing in order to identify and characterize the adhesion-promoting protein(s). From the data, it is proposed that lactobacilli colonize the mucus layer of the small intestine of pigs.

  17. Acid production by oral strains of Candida albicans and lactobacilli.

    PubMed

    Klinke, T; Kneist, S; de Soet, J J; Kuhlisch, E; Mauersberger, S; Forster, A; Klimm, W

    2009-01-01

    Both Candida albicans and lactobacilli are common colonizers of carious lesions in children and adolescents. The purpose of this study is to compare the velocity of acid production between C. albicans and several Lactobacillus species at different pH levels and concentrations of glucose. Washed, pure resting-cell suspensions were obtained by culturing a total of 28 oral isolates comprising the species C. albicans, Lactobacillus rhamnosus, Lactobacillus paracasei paracasei, Lactobacillus paracasei tolerans and Lactobacillus delbrueckii lactis. Acid production from glucose was determined at a constant pH of 7.0, 5.5, 5.0 and 4.0 by repeated titrations with NaOH in an automated pH-stat system. Acid formation rates of yeast and lactobacilli proved to be similar at both neutral and low pH, while in a moderately acidic environment C. albicans produced less acid than the lactobacilli. Ion chromatographic analysis of the cell-free medium after titration revealed pyruvate to be the predominant organic acid anion secreted by C. albicans. The proportion of organic acids to overall acid production by the yeast was below 10% at neutral conditions, in contrast to 42-66% at pH 4.0. Compared to lactobacilli, yeast required a concentration of glucose that was about 50 times higher to allow acid production at half the maximum speed. Considering the clinical data in the literature about the frequency and proportions of microorganisms present in early childhood caries lesions, the contribution of oral lactobacilli as well as C. albicans to overall microbial acid formation appears to be important.

  18. Adhesive Properties and Acid-Forming Activity of Lactobacilli and Streptococci Under Inhibitory Substances, Such as Nitrates.

    PubMed

    Hakobyan, L; Harutyunyan, K; Harutyunyan, N; Melik-Andreasyan, G; Trchounian, A

    2016-06-01

    One of the main requirements for probiotics is their ability to survive during passage through gastrointestinal tract and to maintain their activity at different adverse conditions. The aim of the study was to look for the strains of lactobacilli and streptococci with high adhesive properties even affected by inhibitory substances, such as nitrates (NO3 (-)). To study the adhesion properties hemagglutination reaction of bacterial cells with red blood cells of different animals and humans was used. The acid formation ability of bacteria was determined by the method of titration after 7 days of incubation in the sterile milk. These properties were investigated at different concentrations of NO3 (-). The high concentration (mostly ≥2.0 %) NO3 (-) inhibited the growth of both lactobacilli and streptococci, but compared with streptococcal cultures lactobacilli, especially Lactobacillus acidophilus Ep 317/402, have shown more stability and higher adhesive properties. In addition, the concentrations of NO3 (-) of 0.5-2.0 % decreased the acid-forming activity of the strains, but even under these conditions they coagulated milk and, in comparison to control, formed low acidity in milk. Thus, the L. acidophilus Ep 317/402 with high adhesive properties has demonstrated a higher activity of NO3 (-) transformation.

  19. Influence of lactobacilli on the adhesion of Staphylococcus aureus and Candida albicans to fibers and epithelial cells.

    PubMed

    Reid, G; Tieszer, C; Lam, D

    1995-09-01

    The ability of organisms to adhere to and form biofilms on fibrous materials is believed to be an important initiating step in the induction of several diseases, such as toxic shock syndrome. Using an in vitro assay, a moderately hydrophobic strain of Staphylococcus aureus (water contact angle 35 degrees) and a hydrophilic Candida albicans (shown by a hexadecane test) were highly adherent to commercial diaper fibers. The lumen side of the diaper was porous and the fibers were very hydrophobic (> 140 degrees), but the internal section was very hydrophilic (0 degrees), presumably for lus strains was present. Surfaces precoated with lactobacilli inhibited staphylococcal adhesion by 26-97%, and candida by 0-67%. When the lactobacilli were used to challenge adherent pathogens, there was 99% displacement of the S. aureus and up to 91% displacement of C. albicans. Hydrophobic L. acidophilus 76 (54 degrees) and T-13 (80 degrees) were the most effective of five Lactobacillus isolates tested at interference by precoating. The moderately hydrophilic L. casei var rhamnosus GR-1 (33 degrees) was the most effective at displacing the yeast. Experiments with uroepithelial cells also showed that the lactobacilli could significantly interfere with the adhesion of both pathogens to the cells. The results demonstrate the rapidity with which two pathogens adhered to fibers and epithelial cells, and raised the possibility that members of the normal female urogenital flora might interfere with infections caused by these organisms.

  20. Lactobacilli Differentially Modulate mTOR and Wnt/ β-Catenin Pathways in Different Cancer Cell Lines

    PubMed Central

    Taherian-Esfahani, Zahra; Abedin-Do, Atieh; Nouri, Zahra; Mirfakhraie, Reza; Ghafouri-Fard, Soudeh; Motevaseli, Elahe

    2016-01-01

    Background Lactobacilli are a group of beneficial bacteria whose anti cancer effects have been evaluated in different cancer cell lines as well as animal models and human subjects. Such anti cancer effects can be exerted via different mechanisms such as modulation of immune response as well as inhibition of pathogens colonization. In addition, lactobacilli have direct cytotoxic effects against cancer cells which may be exerted through modulation of expression cancer related pathways. Objectives The aim of this study is to find the mechanism of anti cancer effects of two lactobacilli strains, Lactobacillus. crispatus (LC) and Lactobacillus. rhamnosus (LR). Materials and Methods We analyzed expression of some mTOR and Wnt/ β-catenin pathways genes in three cancer cell lines (HeLa, MDA-MB-231 and HT-29) following treatment with LC and LR culture supernatants. Results Of note, the expression of CCND1 as a marker of cell proliferation, survival, and angiogenesis, has been decreased following LR treatment in all cell lines. In addition, the expression of SFRP2, an antagonist of Wnt pathway, has been increased in HT-29 following LR treatment and in HeLa cells following LR and LC treatments. Furthermore, we have demonstrated the downregulation of S6K1 expression, a marker of poor prognosis, following LR treatment in HT-29 and following LR and LC treatments in MDA-MB-231 cell line. Conclusions Consequently, lactobacilli can modulate expression of mTOR and Wnt/ β-catenin pathways genes in cancer cell lines in a strain specific as well as cell type specific manner. PMID:27703648

  1. Characterization and in vitro properties of oral lactobacilli in breastfed infants

    PubMed Central

    2013-01-01

    Background Lactobacillus species can contribute positively to general and oral health and are frequently acquired by breastfeeding in infancy. The present study aimed to identify oral lactobacilli in breast and formula-fed 4 month-old infants and to evaluate potential probiotic properties of the dominant Lactobacillus species detected. Saliva and oral swab samples were collected from 133 infants who were enrolled in a longitudinal study (n=240) examining the effect of a new infant formula on child growth and development. Saliva was cultured and Lactobacillus isolates were identified from 16S rRNA gene sequences. Five L. gasseri isolates that differed in 16S rRNA sequence were tested for their ability to inhibit growth of selected oral bacteria and for adhesion to oral tissues. Oral swab samples were analyzed by qPCR for Lactobacillus gasseri. Results 43 (32.3%) infants were breastfed and 90 (67.7%) were formula-fed with either a standard formula (43 out of 90) or formula supplemented with a milk fat globule membrane (MFGM) fraction (47 out of 90). Lactobacilli were cultured from saliva of 34.1% breastfed infants, but only in 4.7% of the standard and 9.3% of the MFGM supplemented formula-fed infants. L. gasseri was the most prevalent (88% of Lactobacillus positive infants) of six Lactobacillus species detected. L. gasseri isolates inhibited Streptococcus mutans binding to saliva-coated hydroxyapatite, and inhibited growth of S. mutans, Streptococcus sobrinus, Actinomyces naeslundii, Actinomyces oris, Candida albicans and Fusobacterium nucleatum in a concentration dependent fashion. L. gasseri isolates bound to parotid and submandibular saliva, salivary gp340 and MUC7, and purified MFGM, and adhered to epithelial cells. L. gasseri was detected by qPCR in 29.7% of the oral swabs. Breastfed infants had significantly higher mean DNA levels of L. gasseri (2.14 pg/uL) than infants fed the standard (0.363 pg/uL) or MFGM (0.697 pg/uL) formula. Conclusions Lactobacilli

  2. Development of Recombinant Vaccines in Lactobacilli for Elimination of Salmonella

    PubMed Central

    KAJIKAWA, Akinobu; IGIMI, Shizunobu

    2011-01-01

    Many Lactobacillus and Lactococcus strains are generally regarded as safe for consumption because they are utilized for food fermentation or inhabit the intestinal mucosa as commensals. Recently, vaccine delivery systems using lactic acid bacteria (LAB) have been under development. Our research group has been investigating the development of oral mucosal vaccines against Salmonella enterica serovar Enteritidis (SE) using Lactobacillus casei IGM393 as an antigen delivery vehicle. Recombinant lactobacilli expressing SE antigens, FliC, SipC, and OmpC, have been constructed and orally administered to mice. Antigen specific immune responses and protective immunity were elicited after the immunization. For adjuvant-delivery, IL-1β-secreting L. casei was also engineered and its effects evaluated in vitro and in vivo. This article reviews a novel approach to the elimination of Salmonella via the development of a vaccine in lactobacilli. PMID:25045314

  3. Studies on the removal of Cd ions by gastrointestinal lactobacilli.

    PubMed

    Polak-Berecka, Magdalena; Boguta, Patrycja; Cieśla, Jolanta; Bieganowski, Andrzej; Skrzypek, Tomasz; Czernecki, Tomasz; Waśko, Adam

    2017-04-01

    Accumulation of toxic metal ions in food and water is nowadays a growing health-related problem. One detoxification method involves the use of microorganisms naturally inhabiting the gastrointestinal tract (GIT). The purpose of this study was to prove that lactic acid bacteria derived from the GIT are able to effectively remove Cd(2+) from water solution. Seven strains of lactobacilli, out of 11 examined, showed tolerance to high concentrations of cadmium ions. The metal-removal efficiencies of these seven lactobacilli ranged from 6 to 138.4 μg/h mg. Among these bacteria, Lactobacillus gallinarum and Lactobacillus crispatus belonged to the highest (85%) Cd-removal efficiency class. An analysis of the zeta potential (ζ) indicated that the bacterial cell surface had a negative charge at the pH ranging from 3 to 10. The presence of carboxyl, amide, and phosphate groups was favorable for Cd(2+) binding to the cell surface, which found confirmation in FTIR-ATR spectra. Elemental SEM/EDS analysis and TEM imaging not only confirmed the adsorption of Cd(2+) on the cell envelope but also gave us a reason to suppose that Lb. crispatus accumulates metal ions inside the cell. Our findings open perspectives for further research on the new biological function of GIT lactobacilli as natural biosorbents.

  4. Molecular characterization of lactobacilli isolated from fermented idli batter.

    PubMed

    Agaliya, Perumal Jayaprabha; Jeevaratnam, Kadirvelu

    2013-12-01

    Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis.

  5. Molecular characterization of lactobacilli isolated from fermented idli batter

    PubMed Central

    Agaliya, Perumal Jayaprabha; Jeevaratnam, Kadirvelu

    2013-01-01

    Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis. PMID:24688512

  6. Enhanced growth of lactobacilli in soymilk upon immobilization on agrowastes.

    PubMed

    Teh, Sue-Siang; Ahmad, Rosma; Wan-Abdullah, Wan-Nadiah; Liong, Min-Tze

    2010-04-01

    Cell immobilization is an alternative to microencapsulation for the maintenance of cells in a liquid medium. The objective of this study was to evaluate the effects of agrowastes from durian (Durio zibethinus), cempedak (Artocarpus champeden), and mangosteen (Garcinia mangostana) as immobilizers for lactobacilli grown in soymilk. Rinds from the agrowastes were separated from the skin, dried, and ground (150 microm) to form powders and used as immobilizers. Scanning electron microscopy revealed that lactobacilli cells were attached and bound to the surface of the immobilizers. Immobilized cells of Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and L. bulgaricus FTCC 0411 were inoculated into soymilk, stored at room temperature (25 degrees C) and growth properties were evaluated over 168 h. Soymilk inoculated with nonimmobilized cells was used as the control. Utilization of substrates, concentrations of lactic and acetic acids, and changes in pH were evaluated in soymilk over 186 h. Immobilized lactobacilli showed significantly better growth (P < 0.05) compared to the control, accompanied by higher production of lactic and acetic acids in soymilk. Soymilk containing immobilized cells showed greater reduction of soy sugars such as stachyose, raffinose, sucrose, fructose, and glucose compared to the control (P < 0.05).

  7. Prevalence of lactobacilli in normal women and women with bacterial vaginosis.

    PubMed

    Chooruk, Aksorntong; Utto, Parada; Teanpaisan, Rawee; Piwat, Supatcharin; Chandeying, Nutthaporn; Chandeying, Verapol

    2013-05-01

    To study the prevalence and the number of lactobacilli in normal subjects and in women with bacterial vaginosis (BV). The studied subjects consisted of 60 normal and 60 BV women. The diagnosis of BV was based on at least three of five indicators of Chandeying criteria. The vaginal specimens were collected and cultured on MRS plates for determination of lactobacilli counts. The number of lactobacilli was highly significant (p < 0.001) in the women with diagnosis of BK and the mean count of lactobacilli in BV was markedly decreased (5.3 +/- 1.8 log colony-forming unit--CFU/ml), compared with normal women (8.8 +/- 2.9 log CFU/ml). Among the treated BV group, follow-up vaginal specimen was encountered in 47 of 60 cases (78.3%). The proportion of lactobacilli isolation was slightly increased from 12 (25.5%) to 15 (31.9%) in 47 cases. Concordance with quantitative settlement of lactobacilli in BV was increased from 1.4 +/- 2.6 log CFU/ml, to 1.8 +/- 2.9 log CFU/ml in treated BV. Treated BV the lactobacilli had not restored significance (p = 0.5831), as well as the total bacteria. Lactobacilli dominantly occur in healthy women, and markedly decline in BV. However, the vaginal ecosystem is dynamically changed in the lactobacilli of either normal or BV women.

  8. A Genomic View of Lactobacilli and Pediococci Demonstrates that Phylogeny Matches Ecology and Physiology

    PubMed Central

    Zheng, Jinshui; Ruan, Lifang; Sun, Ming

    2015-01-01

    Lactobacilli are used widely in food, feed, and health applications. The taxonomy of the genus Lactobacillus, however, is confounded by the apparent lack of physiological markers for phylogenetic groups of lactobacilli and the unclear relationships between the diverse phylogenetic groups. This study used the core and pan-genomes of 174 type strains of Lactobacillus and Pediococcus to establish phylogenetic relationships and to identify metabolic properties differentiating phylogenetic groups. The core genome phylogenetic tree separated homofermentative lactobacilli and pediococci from heterofermentative lactobacilli. Aldolase and phosphofructokinase were generally present in homofermentative but not in heterofermentative lactobacilli; a two-domain alcohol dehydrogenase and mannitol dehydrogenase were present in most heterofermentative lactobacilli but absent in most homofermentative organisms. Other genes were predominantly present in homofermentative lactobacilli (pyruvate formate lyase) or heterofermentative lactobacilli (lactaldehyde dehydrogenase and glycerol dehydratase). Cluster analysis of the phylogenomic tree and the average nucleotide identity grouped the genus Lactobacillus sensu lato into 24 phylogenetic groups, including pediococci, with stable intra- and intergroup relationships. Individual groups may be differentiated by characteristic metabolic properties. The link between phylogeny and physiology that is proposed in this study facilitates future studies on the ecology, physiology, and industrial applications of lactobacilli. PMID:26253671

  9. A Genomic View of Lactobacilli and Pediococci Demonstrates that Phylogeny Matches Ecology and Physiology.

    PubMed

    Zheng, Jinshui; Ruan, Lifang; Sun, Ming; Gänzle, Michael

    2015-10-01

    Lactobacilli are used widely in food, feed, and health applications. The taxonomy of the genus Lactobacillus, however, is confounded by the apparent lack of physiological markers for phylogenetic groups of lactobacilli and the unclear relationships between the diverse phylogenetic groups. This study used the core and pan-genomes of 174 type strains of Lactobacillus and Pediococcus to establish phylogenetic relationships and to identify metabolic properties differentiating phylogenetic groups. The core genome phylogenetic tree separated homofermentative lactobacilli and pediococci from heterofermentative lactobacilli. Aldolase and phosphofructokinase were generally present in homofermentative but not in heterofermentative lactobacilli; a two-domain alcohol dehydrogenase and mannitol dehydrogenase were present in most heterofermentative lactobacilli but absent in most homofermentative organisms. Other genes were predominantly present in homofermentative lactobacilli (pyruvate formate lyase) or heterofermentative lactobacilli (lactaldehyde dehydrogenase and glycerol dehydratase). Cluster analysis of the phylogenomic tree and the average nucleotide identity grouped the genus Lactobacillus sensu lato into 24 phylogenetic groups, including pediococci, with stable intra- and intergroup relationships. Individual groups may be differentiated by characteristic metabolic properties. The link between phylogeny and physiology that is proposed in this study facilitates future studies on the ecology, physiology, and industrial applications of lactobacilli.

  10. Properties of porcine and yogurt lactobacilli in relation to lactose intolerance.

    PubMed

    Burton, J P; Tannock, G W

    1997-10-01

    Lactobacilli that had been isolated from the stomach of piglets were tested for properties relevant to the production of fermented milk products for consumption by lactose-intolerant humans. The strains were characterized for beta-galactosidase activity, the ability to reduce the lactose concentration of milk, viability, and pH of the fermented milk over a 30-d period. Strains that had favorable attributes were studied further, and the optimal pH for beta-galactosidase activity, ability to grow in the presence of bile salts, and ability to deconjugate bile salts were determined. Commercial yogurts were also examined to determine whether products varied in characteristics that might affect tolerance of milk products by lactose-intolerant subjects. The Lactobacillus sp. isolated from pigs had lower beta-galactosidase activity than did Lactobacillus delbrueckii ssp. bulgaricus strains ATCC 11842 and NCDO 1489 and strains of lactobacilli isolated from yogurt. The beta-galactosidase activity of all strains decreased rapidly once the fermented milk was stored at 4 degrees C. Strain JB10, originating in the stomach contents of the piglets, had properties that were useful for the manufacture of fermented milk products for lactose-intolerant humans. Milk fermented by this strain had a lactose concentration of about 4.0% and contained 6.6 x 10(6) cfu/ml after storage at 4 degrees C for 20 d. Strain JB10 produced a beta-galactosidase that was active at pH 5.5 (35% of the activity at pH 7.0) and was not inhibited by the presence of bile acids in the culture medium. Beta-Galactosidase activity and lactose concentration varied among yogurts.

  11. Potential of Microalgae and Lactobacilli in Biosynthesis of Silver Nanoparticles

    PubMed Central

    Mohseniazar, Mahdi; Barin, Mohsen; Zarredar, Habib; Alizadeh, Siamak; Shanehbandi, Dariush

    2011-01-01

    Introduction Application of nanoparticles has been extensively increased in last decades. Nanoparticles of noble metals such as gold, platinum and especially silver are widely applied in medical and pharmaceutical applications. Although, variety of physical and chemical methods has been developed for production of metal nanoparticles, because of destructive effects of them on environment, biosynthetic methods have been suggested as a novel alternative. Some bacteria and microalgae have different ranges of potentiality to uptake metal ions and produce nanoparticles during detoxification process. In the present work, we study the potential of three Lactobacilli and three algal species in production of AgNPs in different concentrations of silver nitrate. Methods Utilizing AAS, XRD and TEM methods, Nannochloropsis oculata, Dunaliella salina and Chlorella vulgaris as three algal species in addition to three Lactobacilli including L. acidophilus, L. casei, L. reuteri were monitored for production of silver nanoparticles. Three concentrations of AgNO3 (0.001, 0.002, 0.005 M) and two incubation times (24h and 48h) were included in this study. Results Our findings demonstrated that C. vulgaris, N. oculata and L. acidophilus have the potential of nanosilver production in a culture medium containing 0.001 M of AgNO3 within 24 hours. Also L. casei and L. reuteri species exhibited their potential for production of silver nanoparticles in 0.002 M concentration of AgNO3 in 24 hours. The size range of particles was approximately less than 15 nm. The uptake rate of silver in the five species was between 1.0 to 2.7 mg/g of dry weight. Nanoparticle production was not detected in other treatments and the algae Dunaliella. Conclusion The biosynthesis of silver nanoparticles in all of three Lactobacilli and two algal species including N. oculata and C. vulgaris was confirmed. PMID:23678420

  12. Factors Which Increase Acid Production in Milk by Lactobacilli

    PubMed Central

    Huhtanen, C. N.; Williams, W. L.

    1963-01-01

    The stimulation by yeast extract of acid production in milk by various lactobacilli was studied. It was found that supplementing milk with purine and pyrimidine bases and amino acids allowed nearly maximal acid production by Lactobacillus bulgaricus strain 7994, L. acidophilus 4796, 4356, and 4357, and L. leichmannii 326 and 327. Further supplementation with deoxyribotides allowed maximal acid production by L. acidophilus 204, but L. acidophilus 207 required adenosine or adenylic acid. L. casei strain 7469 showed no appreciable response to the amino acids or purine and pyrimidine bases, and is presumed to require an unidentified factor in corn steep liquor. PMID:13955610

  13. Life in the littoral zone: lactobacilli losing the plot.

    PubMed

    Hay, P

    2005-04-01

    Recurrent bacterial vaginosis is a challenge for those affected by it, and their physicians. Our inability to prevent relapse after treatment, may be because of the flawed approach of using antibiotics to treat a condition that is an imbalance rather than an infection. The maintenance of a healthy lactobacillus population offers an approach to preventing relapse: the problem is how best to do this. Physiological approaches such as the use of hydrogen peroxide, lactic acid, and exogenous lactobacilli need to be explored further. The role of bacterial vaginosis as a risk factor for acquisition of HIV and other STIs is a further impetus to attempting to prevent bacterial vaginosis from recurring.

  14. Characterisation of probiotic properties in human vaginal lactobacilli strains

    PubMed Central

    Hütt, Pirje; Lapp, Eleri; Štšepetova, Jelena; Smidt, Imbi; Taelma, Heleri; Borovkova, Natalja; Oopkaup, Helen; Ahelik, Ave; Rööp, Tiiu; Hoidmets, Dagmar; Samuel, Külli; Salumets, Andres; Mändar, Reet

    2016-01-01

    Background Vaginal lactobacilli offer protection against recurrent urinary infections, bacterial vaginosis, and vaginal candidiasis. Objective To characterise the isolated vaginal lactobacilli strains for their probiotic properties and to compare their probiotic potential. Methods The Lactobacillus strains were isolated from vaginal samples by conventional culturing and identified by sequencing of the 16S rDNA fragment. Several functional properties were detected (production of hydrogen peroxide and lactic acid; antagonistic activity against Escherichia coli, Candida albicans, Candida glabrata, and Gardnerella vaginalis; auto-aggregation and adhesiveness) as well as safety (haemolytic activity, antibiotic susceptibility, presence of transferrable resistance genes). Results A total of 135 vaginal lactobacilli strains of three species, Lactobacillus crispatus (56%), Lactobacillus jensenii (26%), and Lactobacillus gasseri (18%) were characterised using several functional and safety tests. Most of L. crispatus (89%) and L. jensenii (86%) strains produced H2O2. The best lactic acid producers were L. gasseri (18.2±2.2 mg/ml) compared to L. crispatus (15.6±2.8 mg/ml) and L. jensenii (11.6±2.6 mg/ml) (p<0.0001; p<0.0001, respectively). L. crispatus strains showed significantly higher anti-E. coli activity compared to L. jensenii. L. gasseri strains expressed significantly lower anticandidal activity compared to L. crispatus and L. jensenii (p<0.0001). There was no significant difference between the species in antagonistic activity against G. vaginalis. Nearly a third of the strains were able to auto-aggregate while all the tested strains showed a good ability to adhere to HeLa cells. None of the tested lactobacilli caused haemolysis. Although phenotypical resistance was not found to ampicillin, chloramphenicol, erythromycin, gentamycin, tetracycline, and vancomycin, the erm(B), tet(M), and tet(K) were detected in some strains. All strains were resistant to metronidazole

  15. Lactobacilli and dairy propionibacterium with potential as biopreservatives against food fungi and yeast contamination.

    PubMed

    Ho, P H; Luo, J B; Adams, M C

    2009-01-01

    Naturally fermented and raw foods contain a range of organisms that may have benefit as additives in some foods and food processing. In particular, potential anti-fungal properties of these organisms may be potentially utilised as natural alternatives to chemical additives used to delay and prevent spoilage by fungi and yeast. This study examined 12 novel bacteria previously isolated from food as possible biopreservatives. The bacteria from the lactobacilli and dairy propionibacterium groups were tested by agar overlay method for their ability to inhibit the growth of 10 fungi and one yeast commonly associated with food contamination. Eight among eleven tested lactic acid bacteria demonstrated broad spectrum of antifungal activity. Strong fungi inhibition was also demonstrated by the dairy propionibacterium, but efficacy was growth medium dependant. Only one fungi, Geotrichum candidum was highly resistant to the bacteria. Variation between the inhibition results for different bacteria identifies the importance of careful strain selection, and the benefits of strain combinations when selecting biopreservatives for foods.

  16. Characterization of the beneficial properties of lactobacilli isolated from bullfrog (Rana catesbeiana) hatchery.

    PubMed

    Pasteris, Sergio E; Vera Pingitore, Esteban; Roig Babot, Germán; Otero, María C; Bühler, Marta I; Nader-Macías, María E

    2009-05-01

    The present work addresses the isolation and partial identification of the microbial population of a R. catesbeiana hatchery in spring and summer as well as some beneficial properties of Lactobacillus strains isolated in different seasons and hatchery areas. The bacterial population was grouped into the following taxa: Lactobacillus spp., Pediococcus spp., Enterococcus faecalis and Ent. faecium, and Enterobacteriaceae (Enterobacter spp., Escherichia coli) while Pseudomonas aeruginosa and Staphylococcus epidermidis were isolated from frogs displaying red-leg syndrome. The Lactobacillus plantarum and L. curvatus strains isolated showed to inhibit the growth of red-leg syndrome associated pathogens and food-borne bacteria by organic acids. While L. plantarum CRL 1606 also inhibited red-leg syndrome related pathogens by hydrogen peroxide, meat spoilage bacteria were only inhibited by acidity. However, by using a MRS medium added with tetramethyl-benzidine and peroxidase, a high percentage of H(2)O(2)-producing lactobacilli were detected. The surface properties of Lactobacillus strains showed that a few strains were able to agglutinate ABO human erythrocytes, while the highest number of strains had a low to medium degree of hydrophobicity. This paper constitute the first study related to the beneficial properties of Lactobacillus isolated from a bullfrog hatchery, as well as the selection criteria applied to a group of strains, which could help to control or prevent bacterial infectious diseases in raniculture.

  17. Oral Lactobacilli and Dental Caries: A Model for Niche Adaptation in Humans.

    PubMed

    Caufield, P W; Schön, C N; Saraithong, P; Li, Y; Argimón, S

    2015-09-01

    Lactobacilli have been associated with dental caries for over a century. Here, we review the pertinent literature along with findings from our own study to formulate a working hypothesis about the natural history and role of lactobacilli. Unlike most indigenous microbes that stably colonize a host, lactobacilli appear to be planktonic, opportunistic settlers that can gather and multiply only in certain restrictive niches of the host, at least within the oral cavity. We postulate that the following essential requirements are necessary for sustained colonization of lactobacilli in humans: 1) a stagnant, retentive niche that is mostly anaerobic; 2) a low pH milieu; and 3) ready access to carbohydrates. Three sites on the human body meet these specifications: caries lesions, the stomach, and the vagina. Only a handful of Lactobacillus species is found in caries lesions, but they are largely absent in caries-free children. Lactobacilli present in caries lesions represent both a major contributor to caries progression and a major reservoir to the gastrointestinal (GI) tract. We extend the assertion from other investigators that lactobacilli found in the GI tract originate in the oral cavity by proposing that lactobacilli in the oral cavity arise from caries lesions. This, in turn, leads us to reflect on the health implications of the lactobacilli in the mouth and downstream GI and to ponder whether these or any of the Lactobacillus species are truly indigenous to the human GI tract or the oral cavity. © International & American Associations for Dental Research.

  18. β-Glucuronidase and β-glucosidase activity and human fecal water genotoxicity in the presence of probiotic lactobacilli and the heterocyclic aromatic amine IQ in vitro.

    PubMed

    Nowak, Adriana; Śliżewska, Katarzyna

    2014-01-01

    The aim of the study was to assess the genotoxicity of fecal water (FW) and the activity of fecal enzymes (β-glucuronidase and β-glucosidase) after incubation with 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) and probiotic lactobacilli: Lb. casei 0900, Lb. casei 0908, and Lb. paracasei 0919. Our results show that the carcinogen IQ greatly increased FW genotoxicity (up to 16.92 ± 3.03 U/mg) and the activity of fecal enzymes (up to even 1.4 ± 0.16 U/mg) in 15 individuals (children, adults and elderly). After incubation with IQ, the activity of β-glucuronidase was reduced by Lactobacillus bacteria by 76.0% (Lb. paracasei 0908) in the FW of children, and by 82.0% (Lb. paracasei 0919) in the elderly; while that of β-glucosidase was reduced by 55.0% in children (Lb. casei 0908) and 90.0% (Lb. paracasei 0919) in elderly subjects. Lactobacilli decreased the genotoxicity of FW after incubation with IQ to the greatest extent in adults (by 64.5%). Probiotic lactobacilli, in the presence of IQ, efficiently inhibits activity of fecal enzymes to the level of control. Genotoxicity inhibition depends on the person's age, its individual microbiota and diet. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Glycerol Monolaurate Does Not Alter Rhesus Macaque (Macaca mulatta) Vaginal Lactobacilli and Is Safe for Chronic Use▿

    PubMed Central

    Schlievert, Patrick M.; Strandberg, Kristi L.; Brosnahan, Amanda J.; Peterson, Marnie L.; Pambuccian, Stefan E.; Nephew, Karla R.; Brunner, Kevin G.; Schultz-Darken, Nancy J.; Haase, Ashley T.

    2008-01-01

    Glycerol monolaurate (GML) is a fatty acid monoester that inhibits growth and exotoxin production of vaginal pathogens and cytokine production by vaginal epithelial cells. Because of these activities, and because of the importance of cytokine-mediated immune activation in human immunodeficiency virus type 1 (HIV-1) transmission to women, our laboratories are performing studies on the potential efficacy of GML as a topical microbicide to interfere with HIV-1 transmission in the simian immunodeficiency virus-rhesus macaque model. While GML is generally recognized as safe by the FDA for topical use, its safety for chronic use and effects on normal vaginal microflora in this animal model have not been evaluated. GML was therefore tested both in vitro for its effects on vaginal flora lactobacilli and in vivo as a 5% gel administered vaginally to monkeys. In vitro studies demonstrated that lactobacilli are not killed by GML; GML blocks the loss of their viability in stationary phase and does not interfere with lactic acid production. GML (5% gel) does not quantitatively alter monkey aerobic vaginal microflora compared to vehicle control gel. Lactobacilli and coagulase-negative staphylococci are the dominant vaginal aerobic microflora, with beta-hemolytic streptococci, Staphylococcus aureus, and yeasts sporadically present; gram-negative rods are not part of their vaginal flora. Colposcopy and biopsy studies indicate that GML does not alter normal mucosal integrity and does not induce inflammation; instead, GML reduces epithelial cell production of interleukin 8. The studies suggest that GML is safe for chronic use in monkeys when applied vaginally; it does not alter either mucosal microflora or integrity. PMID:18838587

  20. Glycerol monolaurate does not alter rhesus macaque (Macaca mulatta) vaginal lactobacilli and is safe for chronic use.

    PubMed

    Schlievert, Patrick M; Strandberg, Kristi L; Brosnahan, Amanda J; Peterson, Marnie L; Pambuccian, Stefan E; Nephew, Karla R; Brunner, Kevin G; Schultz-Darken, Nancy J; Haase, Ashley T

    2008-12-01

    Glycerol monolaurate (GML) is a fatty acid monoester that inhibits growth and exotoxin production of vaginal pathogens and cytokine production by vaginal epithelial cells. Because of these activities, and because of the importance of cytokine-mediated immune activation in human immunodeficiency virus type 1 (HIV-1) transmission to women, our laboratories are performing studies on the potential efficacy of GML as a topical microbicide to interfere with HIV-1 transmission in the simian immunodeficiency virus-rhesus macaque model. While GML is generally recognized as safe by the FDA for topical use, its safety for chronic use and effects on normal vaginal microflora in this animal model have not been evaluated. GML was therefore tested both in vitro for its effects on vaginal flora lactobacilli and in vivo as a 5% gel administered vaginally to monkeys. In vitro studies demonstrated that lactobacilli are not killed by GML; GML blocks the loss of their viability in stationary phase and does not interfere with lactic acid production. GML (5% gel) does not quantitatively alter monkey aerobic vaginal microflora compared to vehicle control gel. Lactobacilli and coagulase-negative staphylococci are the dominant vaginal aerobic microflora, with beta-hemolytic streptococci, Staphylococcus aureus, and yeasts sporadically present; gram-negative rods are not part of their vaginal flora. Colposcopy and biopsy studies indicate that GML does not alter normal mucosal integrity and does not induce inflammation; instead, GML reduces epithelial cell production of interleukin 8. The studies suggest that GML is safe for chronic use in monkeys when applied vaginally; it does not alter either mucosal microflora or integrity.

  1. High Doses of Halotolerant Gut-Indigenous Lactobacillus plantarum Reduce Cultivable Lactobacilli in Newborn Calves without Increasing Its Species Abundance

    PubMed Central

    Staempfli, Henry R.; Weese, J. Scott

    2017-01-01

    To elucidate the ecological effect of high oral doses of halotolerant (resistant to table salt) indigenous-gut bacteria on other commensals early in life, we conducted a culture-based study to quantify the effect of intestinal Lactobacillus plantarum strain of bovine origin (with remarkable aerobic growth capabilities and inhibitory activity against Escherichia coli O157:H7 and F5) on clinical health and gut lactobacilli/coliforms in newborn calves. In a double-blind placebo-randomized trial twelve colostrum-fed calves, consecutively born at a farm, were fed L. plantarum within 12 hours from birth at low (107-8 CFU/day) or high concentrations (1010-11) or placebo (q24 h, 5 d; 10 d follow-up). We developed a 2.5% NaCl-selective culture strategy to facilitate the enumeration of L. plantarum-strain-B80, and tested 384 samples (>1,152 cultures). L. plantarum-B80-like colonies were detected in a large proportion of calves (58%) even before their first 24 hours of life indicating endemic presence of the strain in the farm. In contrast to studies where human-derived Lactobacillus LGG or rhamnosus had notoriously high, but short-lived, colonization, we found that L. plantarum colonized stably with fecal shedding of 6 ± 1 log10·g−1 (irrespective of dose, P > 0.2). High doses significantly reduced other fecal lactic acid bacteria (e.g., lactobacilli, P < 0.01) and slightly reduced body weight gain in calves after treatment. For the first time, a halotolerant strain of L. plantarum with inhibitory activity against a human pathogen has the ability to inhibit other lactobacilli in vivo without changing its species abundance, causing transintestinal translocation, or inducing clinical disease. The future selection of probiotics based on halotolerance may expand therapeutic product applicability. PMID:28596790

  2. Reduction of Campylobacter jejuni in a simulated chicken digestive tract by Lactobacilli cultures.

    PubMed

    Chang, M H; Chen, T C

    2000-11-01

    Studies were conducted to investigate the impact of a selected lactobacilli mixed culture on Campylobacter jejuni in simulated chicken digestive tract models. Veronal buffer solutions corresponding to the pH of successive segments of the chicken digestive tract were prepared. The lactobacilli mixtures were prepared by mixing four fresh lactobacilli cultures, including Lactobacillus acidophilus, Lactobacillus fermenentum, Lactobacillus crispatus, and Lactobacillus brevis. The C. jejuni and lactobacilli mixture were mixed with sterile poultry feed, and the previously prepared veronal buffer solutions were then added separately. The mixture was incubated at 41.1 degrees C for various lengths of time with periodic agitation. The feed passage time for five segments of the digestive tract were adopted: crop (pH 4.5), 30 min; proventriculus (pH 4.4), 15 min; gizzard (pH 2.6), 90 min; small intestine (pH 6.2), 90 min; and large intestine (pH 6.3), 15 min. The Campylobacter and lactobacilli were enumerated. An antagonistic effect on C. jejuni by the tested lactobacilli spp. was found in individual sections and the complete simulated digestive tract models. In the simulated complete chicken digestion system, no C. jejuni were found during the final incubation period when a lactobacilli mixture was present. The results of this in vitro study indicate the potential value of future in vivo studies.

  3. Determining the Genetic Diversity of Lactobacilli from the Oral Cavity

    PubMed Central

    Yang, R.; Argimon, S.; Li, Y.; Zhou, X.; Caufield, P. W.

    2010-01-01

    Summary Several methods for determining the diversity of Lactobacillus spp were evaluated with the purpose of developing a realistic approach for further studies. The patient population was comprised of young children with an oral disease called severe early childhood caries. The ultimate goal of these studies was to ascertain the role of lactobacilli in the caries process. To accomplish that goal, we evaluated several methods and approaches for determining diversity including AP-PCR, chromosomal DNA fingerprinting, denaturing gradient gel electrophoresis, and 16S rRNA gene sequencing. Central to these methods was the gathering and screening of isolates from cultivation medium. Using various estimates of diversity, we addressed the question as to how many isolates represent the overall diversity and how cultivation compares to non-cultivation techniques. Finally, we proposed a working approach for achieving the goals outlined framed by both practical constraints in terms of time, effort and efficacy while yielding a reliable outcome. PMID:20573585

  4. Determining the genetic diversity of lactobacilli from the oral cavity.

    PubMed

    Yang, R; Argimon, S; Li, Y; Gu, H; Zhou, X; Caufield, P W

    2010-08-01

    Several methods for determining the diversity of Lactobacillus spp were evaluated with the purpose of developing a realistic approach for further studies. The patient population was comprised of young children with an oral disease called severe early childhood caries. The ultimate goal of these studies was to ascertain the role of lactobacilli in the caries process. To accomplish that goal, we evaluated several methods and approaches for determining diversity including AP-PCR, chromosomal DNA fingerprinting, denaturing gradient gel electrophoresis, and 16S rRNA gene sequencing. Central to these methods was the gathering and screening of isolates from cultivation medium. Using various estimates of diversity, we addressed the question as to how many isolates represent the overall diversity and how cultivation compares to non-cultivation techniques. Finally, we proposed a working approach for achieving the goals outlined framed by both practical constraints in terms of time, effort and efficacy while yielding a reliable outcome.

  5. Impact of chymosin- and plasmin-mediated primary proteolysis on the growth and biochemical activities of lactobacilli in miniature Cheddar-type cheeses.

    PubMed

    Milesi, M M; McSweeney, P L H; Hynes, E R

    2008-09-01

    Strongly proteolytic starters seem to improve the growth of nonstarter lactobacilli during cheese ripening, but no information is available on the impact of the nonmicrobial proteases usually active in cheese on their development. In the current study, the influence of chymosin- and plasmin-mediated proteolysis on the growth and biochemical activities of lactobacilli during ripening of miniature Cheddar-type cheeses, manufactured under controlled microbiological conditions, was studied. Two experiments were performed; in the first, residual chymosin activity was inhibited by the addition of pepstatin, and in the second, plasmin activity was increased by adding more enzyme, obtained in vitro through the activation of plasminogen induced by urokinase. Cheeses with or without a Lactobacillus plantarum I91 adjunct culture and with or without added pepstatin or plasmin solution were manufactured and ripened for 60 d. The addition of the adjunct culture resulted in enhancement of secondary proteolysis, evidenced by an increase in the total content of free amino acids (FAA) and modifications of the individual FAA profiles. Reduction in residual chymosin activity caused a decrease in primary and secondary proteolysis, characterized by the absence of alpha(s1)-casein hydrolysis and reduced production of peptides and FAA, respectively. The increase in plasmin activity accelerated primary proteolysis but no enhancement of secondary proteolysis was observed. Chymosin- and plasmin-mediated proteolysis did not influence the growth and biochemical activities of adventitious or adjunct lactobacilli, indicating that it is not a limiting factor for the development and proteolytic-peptidolytic activities of lactobacilli in the cheese model studied.

  6. In vitro inhibition of growth of Neisseria gonorrhoeae by Neisseria meningitidis isolated from the pharynx of homosexual men.

    PubMed

    Bisaillon, J G; Turgeon, P; Dubreuil, D; Beaudet, R; Sylvestre, M; Ashton, F E

    1984-01-01

    Despite the high prevalence of pharyngeal gonorrhea and of meningococcal carriage among homosexual men, Neisseria gonorrhoeae and Neisseria meningitidis are rarely co-isolated from the throat. Forty-seven meningococcal isolates from the pharynx of homosexual men were examined, by a lawn-spotting method, for their ability to inhibit N. gonorrhoeae in vitro. Eight (17%) of the meningococcal isolates were inhibitory when tested against gonococci from the same patient, while 31 (66%) were inhibitory when tested against N. gonorrhoeae strain 650 (T1). The colonial type T1 of a given strain was, in all cases tested, more sensitive to the inhibitory activities than the corresponding T4 type. Since the meningococci co-isolated from the throat with gonococci were at least as inhibitory in vitro as those isolated without gonococci, the natural resistance to gonococcal pharyngitis cannot be explained on the basis of the inhibitory activities produced by the meningococci in vitro. The inhibitory strains of N. meningitidis were identified in decreasing importance as: nonserogroupable, W135, C, B, 29E, and X. The addition of trypsin to the solid medium removed the inhibition produced by the meningococci, an observation suggesting the involvement of protein inhibitors.

  7. Expanding the biotechnology potential of lactobacilli through comparative genomics of 213 strains and associated genera

    PubMed Central

    Sun, Zhihong; Harris, Hugh M. B.; McCann, Angela; Guo, Chenyi; Argimón, Silvia; Zhang, Wenyi; Yang, Xianwei; Jeffery, Ian B; Cooney, Jakki C.; Kagawa, Todd F.; Liu, Wenjun; Song, Yuqin; Salvetti, Elisa; Wrobel, Agnieszka; Rasinkangas, Pia; Parkhill, Julian; Rea, Mary C.; O'Sullivan, Orla; Ritari, Jarmo; Douillard, François P.; Paul Ross, R.; Yang, Ruifu; Briner, Alexandra E.; Felis, Giovanna E.; de Vos, Willem M.; Barrangou, Rodolphe; Klaenhammer, Todd R.; Caufield, Page W.; Cui, Yujun; Zhang, Heping; O'Toole, Paul W.

    2015-01-01

    Lactobacilli are a diverse group of species that occupy diverse nutrient-rich niches associated with humans, animals, plants and food. They are used widely in biotechnology and food preservation, and are being explored as therapeutics. Exploiting lactobacilli has been complicated by metabolic diversity, unclear species identity and uncertain relationships between them and other commercially important lactic acid bacteria. The capacity for biotransformations catalysed by lactobacilli is an untapped biotechnology resource. Here we report the genome sequences of 213 Lactobacillus strains and associated genera, and their encoded genetic catalogue for modifying carbohydrates and proteins. In addition, we describe broad and diverse presence of novel CRISPR-Cas immune systems in lactobacilli that may be exploited for genome editing. We rationalize the phylogenomic distribution of host interaction factors and bacteriocins that affect their natural and industrial environments, and mechanisms to withstand stress during technological processes. We present a robust phylogenomic framework of existing species and for classifying new species. PMID:26415554

  8. Expanding the biotechnology potential of lactobacilli through comparative genomics of 213 strains and associated genera.

    PubMed

    Sun, Zhihong; Harris, Hugh M B; McCann, Angela; Guo, Chenyi; Argimón, Silvia; Zhang, Wenyi; Yang, Xianwei; Jeffery, Ian B; Cooney, Jakki C; Kagawa, Todd F; Liu, Wenjun; Song, Yuqin; Salvetti, Elisa; Wrobel, Agnieszka; Rasinkangas, Pia; Parkhill, Julian; Rea, Mary C; O'Sullivan, Orla; Ritari, Jarmo; Douillard, François P; Paul Ross, R; Yang, Ruifu; Briner, Alexandra E; Felis, Giovanna E; de Vos, Willem M; Barrangou, Rodolphe; Klaenhammer, Todd R; Caufield, Page W; Cui, Yujun; Zhang, Heping; O'Toole, Paul W

    2015-09-29

    Lactobacilli are a diverse group of species that occupy diverse nutrient-rich niches associated with humans, animals, plants and food. They are used widely in biotechnology and food preservation, and are being explored as therapeutics. Exploiting lactobacilli has been complicated by metabolic diversity, unclear species identity and uncertain relationships between them and other commercially important lactic acid bacteria. The capacity for biotransformations catalysed by lactobacilli is an untapped biotechnology resource. Here we report the genome sequences of 213 Lactobacillus strains and associated genera, and their encoded genetic catalogue for modifying carbohydrates and proteins. In addition, we describe broad and diverse presence of novel CRISPR-Cas immune systems in lactobacilli that may be exploited for genome editing. We rationalize the phylogenomic distribution of host interaction factors and bacteriocins that affect their natural and industrial environments, and mechanisms to withstand stress during technological processes. We present a robust phylogenomic framework of existing species and for classifying new species.

  9. Production of Organic Acids by Probiotic Lactobacilli Can Be Used to Reduce Pathogen Load in Poultry

    PubMed Central

    Neal-McKinney, Jason M.; Lu, Xiaonan; Duong, Tri; Larson, Charles L.; Call, Douglas R.; Shah, Devendra H.; Konkel, Michael E.

    2012-01-01

    Probiotic Lactobacillus can be used to reduce the colonization of pathogenic bacteria in food animals, and therefore reduce the risk of foodborne illness to consumers. As a model system, we examined the mechanism of protection conferred by Lactobacillus species to inhibit C. jejuni growth in vitro and reduce colonization in broiler chickens. Possible mechanisms for the reduction of pathogens by lactobacilli include: 1) stimulation of adaptive immunity; 2) alteration of the cecal microbiome; and, 3) production of inhibitory metabolites, such as organic acids. The Lactobacillus species produced lactic acid at concentrations sufficient to kill C. jejuni in vitro. We determined that lactic acid produced by Lactobacillus disrupted the membrane of C. jejuni, as judged by biophotonics. The spectral features obtained using Fourier-transform infrared (FT-IR) and Raman spectroscopy techniques were used to accurately predict bacterial viability and differentiate C. jejuni samples according to lactic acid treatment. FT-IR spectral features of C. jejuni and Lactobacillus grown in co-culture revealed that the metabolism was dominated by Lactobacillus prior to the killing of C. jejuni. Based on our results, the development of future competitive exclusion strategies should include the evaluation of organic acid production. PMID:22962594

  10. Production of organic acids by probiotic lactobacilli can be used to reduce pathogen load in poultry.

    PubMed

    Neal-McKinney, Jason M; Lu, Xiaonan; Duong, Tri; Larson, Charles L; Call, Douglas R; Shah, Devendra H; Konkel, Michael E

    2012-01-01

    Probiotic Lactobacillus can be used to reduce the colonization of pathogenic bacteria in food animals, and therefore reduce the risk of foodborne illness to consumers. As a model system, we examined the mechanism of protection conferred by Lactobacillus species to inhibit C. jejuni growth in vitro and reduce colonization in broiler chickens. Possible mechanisms for the reduction of pathogens by lactobacilli include: 1) stimulation of adaptive immunity; 2) alteration of the cecal microbiome; and, 3) production of inhibitory metabolites, such as organic acids. The Lactobacillus species produced lactic acid at concentrations sufficient to kill C. jejuni in vitro. We determined that lactic acid produced by Lactobacillus disrupted the membrane of C. jejuni, as judged by biophotonics. The spectral features obtained using Fourier-transform infrared (FT-IR) and Raman spectroscopy techniques were used to accurately predict bacterial viability and differentiate C. jejuni samples according to lactic acid treatment. FT-IR spectral features of C. jejuni and Lactobacillus grown in co-culture revealed that the metabolism was dominated by Lactobacillus prior to the killing of C. jejuni. Based on our results, the development of future competitive exclusion strategies should include the evaluation of organic acid production.

  11. Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

    PubMed Central

    CHEN, Chih-YU; CHUNG, Ying-CHIEN

    2012-01-01

    Dental caries is still a major oral health problem in most industrialized countries. The development of dental caries primarily involves Lactobacilli spp. and Streptococcus mutans. Although antibacterial ingredients are used against oral bacteria to reduce dental caries, some reports that show partial antibacterial ingredients could result in side effects. Objectives The main objective is to test the antibacterial effect of water-soluble chitosan while the evaluation of the mouthwash appears as a secondary aim. Material and Methods The chitosan was obtained from the Application Chemistry Company (Taiwan). The authors investigated the antibacterial effects of water-soluble chitosan against oral bacteria at different temperatures (25-37ºC) and pH values (pH 5-8), and evaluated the antibacterial activities of a self-made water-soluble chitosan-containing mouthwash by in vitro and in vivo experiments, and analyzed the acute toxicity of the mouthwashes. The acute toxicity was analyzed with the pollen tube growth (PTG) test. The growth inhibition values against the logarithmic scale of the test concentrations produced a concentrationresponse curve. The IC50 value was calculated by interpolation from the data. Results The effect of the pH variation (5-8) on the antibacterial activity of water-soluble chitosan against tested oral bacteria was not significant. The maximal antibacterial activity of water-soluble chitosan occurred at 37ºC. The minimum bactericidal concentration (MBC) of water-soluble chitosan on Streptococcus mutans and Lactobacilli brevis were 400 µg/mL and 500 µg/mL, respectively. Only 5 s of contact between water-soluble chitosan and oral bacteria attained at least 99.60% antibacterial activity at a concentration of 500 µg/mL. The water-soluble chitosan-containin g mouthwash significantly demonstrated antibacterial activity that was similar to that of commercial mouthwashes (>99.91%) in both in vitro and in vivo experiments. In addition, the alcohol

  12. Effects of lactobacilli on yeast-catalyzed ethanol fermentations.

    PubMed Central

    Narendranath, N V; Hynes, S H; Thomas, K C; Ingledew, W M

    1997-01-01

    Normal-gravity (22 to 24 degrees Plato) wheat mashes were inoculated with five industrially important strains of lactobacilli at approximately 10(5), approximately 10(6), approximately 10(7), approximately 10(8), and approximately 10(9) CFU/ml in order to study the effects of the lactobacilli on yeast growth and ethanol productivity. Lactobacillus plantarum, Lactobacillus paracasei, Lactobacillus #3, Lactobacillus rhamnosus, and Lactobacillus fermentum were used. Controls with yeast cells but no bacterial inoculation and additional treatments with bacteria alone inoculated at approximately 10(7) CFU/ml of mash were included. Decreased ethanol yields were due to the diversion of carbohydrates for bacterial growth and the production of lactic acid. As higher numbers of the bacteria were produced (depending on the strain), 1 to 1.5% (wt/vol) lactic acid resulted in the case of homofermentative organisms. L. fermentum, a heterofermentative organism, produced only 0.5% (wt/vol) lactic acid. When L. plantarum, L. rhamnosus, and L. fermentum were inoculated at approximately 10(6) CFU/ml, an approximately 2% decrease in the final ethanol concentration was observed. Smaller initial numbers (only 10(5) CFU/ml) of L. paracasei or Lactobacillus #3 were sufficient to cause more than 2% decreases in the final ethanol concentrations measured compared to the control. Such effects after an inoculation of only 10(5) CFU/ml may have been due to the higher tolerance to ethanol of the latter two bacteria, to the more rapid adaptation (shorter lag phase) of these two industrial organisms to fermentation conditions, and/or to their more rapid growth and metabolism. When up to 10(9) CFU of bacteria/ml was present in mash, approximately 3.8 to 7.6% reductions in ethanol concentration occurred depending on the strain. Production of lactic acid and a suspected competition with yeast cells for essential growth factors in the fermenting medium were the major reasons for reductions in yeast

  13. Use of lactobacilli and estriol combination in the treatment of disturbed vaginal ecosystem: a review

    PubMed Central

    Ünlü, Cihat; Donders, Gilbert

    2011-01-01

    To maintain a healthy vaginal ecosystem or to restore any disturbance, sufficient estrogen levels, an intact mature vaginal epithelium, and physiological lactobacillary microflora are essential. Thus, a combination of beneficial lactobacilli and estrogen is an appealing treatment option. This article reviews the published data on the use of viable Lactobacillus acidophilus KS400 and a low dose of estriol (0.03 mg E3) in the form of vaginal tablets (Gynoflor®). In vitro studies demonstrated that L. acidophilus KS400 produces lactic acid and hydrogen peroxide (H2O2), inhibits the growth of relevant vaginal pathogens, and inhibits adherence of pathogens to epithelial cells. Topical administration of E3 for treatment of vaginal diseases is generally preferred, as this route of application of hormones produces a more significant local proliferative response and has no stimulating effect on the endometrium. Overall, 16 clinical studies have been published with the combination of L. acidophilus KS400 and 0.03 mg E3. The results of these trials have demonstrated that the combination improves the vaginal epithelium and the restoration of the lactobacillary microflora with an excellent safety profile, even during pregnancy. The combination can be used in pre- and postmenopausal women for the restoration of the vaginal flora after anti-infective therapy, for treatment of symptomatic vaginal atrophy, and for abnormal vaginal flora therapy. It can be also considered in repetitive therapy courses for the long-term prevention of recurrences of bacterial vaginosis, even though further clinical studies are needed to substantiate the benefit of this application. PMID:24592002

  14. Carbohydrate catabolic diversity of bifidobacteria and lactobacilli of human origin.

    PubMed

    McLaughlin, Heather P; Motherway, Mary O'Connell; Lakshminarayanan, Bhuvaneswari; Stanton, Catherine; Paul Ross, R; Brulc, Jennifer; Menon, Ravi; O'Toole, Paul W; van Sinderen, Douwe

    2015-06-16

    Because increased proportions of particular commensal bacteria such as bifidobacteria and lactobacilli have been linked to human health through a variety of mechanisms, there is corresponding interest in identifying carbohydrates that promote growth and metabolic activity of these bacteria. We evaluated the ability of 20 carbohydrates, including several commercially available carbohydrates that are sold as prebiotic ingredients, to support growth of 32 human-derived isolates belonging to the genera Bifidobacterium and Lactobacillus, including those isolated from healthy elderly subjects. In general, bifidobacterial strains were shown to display more diverse carbohydrate utilization profiles compared to the tested Lactobacillus species, with several bifidobacterial strains capable of metabolizing xylo-oligosaccharide (XOS), arabinoxylan, maltodextrin, galactan and carbohydrates containing fructo-oligosaccharide (FOS) components. In contrast, maltodextrin, galactan, arabinogalactan and galactomannan did not support robust growth (≥0.8 OD600 nm) of any of the Lactobacillus strains assessed. Carbohydrate fermentation was variable among strains tested of the same species for both genera. This study advances our knowledge of polysaccharide utilization by human gut commensals, and provides information for the rational design of selective prebiotic food ingredients.

  15. Antioxidative activity of lactobacilli measured by oxygen radical absorbance capacity.

    PubMed

    Saide, J A O; Gilliland, S E

    2005-04-01

    The reducing ability and antioxidative activity of some species of Lactobacillus were compared under in vitro conditions. Cultures of Lactobacillus delbrueckii ssp. lactis, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and Lactobacillus casei were grown at 37 degrees C in de Man, Rogosa, Sharpe (MRS) broth supplemented with 0.5% 2,3,5 triphenyl tetrazolium chloride (TTC) to evaluate reducing activity. Reduced TTC was extracted from the cultures with acetone, and the intensity of the red color measured colorimetrically at 485 nm was an indication of reducing activity. The lactobacilli varied significantly in relative ability to reduce TTC when grown in MRS broth for 15 h. The relative amounts of growth as indicated by pH values at 18 h appeared to influence the amount of reduction. Antioxidative activity was evaluated by the ability of the whole cells or the cell-free extracts from cultures to protect a protein from being attacked by free radicals. These analyses were performed using the oxygen radical absorbance capacity method. All cultures tested exhibited some degree of antioxidative activity. Among the treatments, the cell-free extracts from cells grown in MRS broth exhibited significantly higher values than did whole cells. There was no apparent relationship between the reducing and antioxidative activities of the cultures evaluated. The results from this study show that these cultures can provide a source of dietary antioxidants. Furthermore, selection of cultures that produce antioxidants as starters could provide yet another health or nutritional benefit from cultured or culture-containing dairy products.

  16. Sugar-glycerol cofermentations in lactobacilli: the fate of lactate.

    PubMed

    Veiga da Cunha, M; Foster, M A

    1992-02-01

    The simultaneous fermentation of glycerol and sugar by lactobacillus brevis B22 and Lactobacillus buchneri B190 increases both the growth rate and total growth. The reduction of glycerol to 1,3-propanediol by the lactobacilli was found to influence the metabolism of the sugar cofermented by channelling some of the intermediate metabolites (e.g., pyruvate) towards NADH-producing (rather than NADH-consuming) reactions. Ultimately, the absolute requirement for NADH to prevent the accumulation of 3-hydroxypropionaldehyde leads to a novel lactate-glycerol cofermentation. As a result, additional ATP can be made not only by (i) converting pyruvate to acetate via acetyl phosphate rather than to the ethanol usually found and (ii) oxidizing part of the intermediate pyruvate to acetate instead of the usual reduction to lactate but also by (iii) reoxidation of accumulated lactate to acetate via pyruvate. The conversion of lactate to pyruvate is probably catalyzed by NAD-independent lactate dehydrogenases that are found only in the cultures oxidizing lactate and producing 1,3-propanediol, suggesting a correlation between the expression of these enzymes and a raised intracellular NAD/NADH ratio. The enzymes metabolizing glycerol (glycerol dehydratase and 1,3-propanediol dehydrogenase) were expressed in concert without necessary induction by added glycerol, although their expression may also be influenced by the intracellular NAD/NADH ratio set by the different carbohydrates fermented.

  17. Lack of correlation between in vitro antibiosis and in vivo protection against enteropathogenic bacteria by probiotic lactobacilli.

    PubMed

    Bujalance, Carmen; Jiménez-Valera, María; Moreno, Encarnación; Ruiz-López, María-Dolores; Lasserrot, Agustín; Ruiz-Bravo, Alfonso

    2014-01-01

    Increased resistance to infection is one of the beneficial effects attributed to probiotic microorganisms. This effect may be due to several mechanisms: production of inhibitory substances, blocking of adhesion sites on the intestinal surface, competition for nutrients and stimulation of mucosal and systemic immunity. The present study aimed to investigate the correlation between in vitro and in vivo antimicrobial activity of probiotic lactobacilli. The agar spot test was used to show that twenty Lactobacillus strains were able to inhibit the enteropathogenic bacterium Yersinia enterocolitica. This inhibition was mainly attributable to a decrease in pH resulting from dextrose fermentation by lactobacilli. The inhibition of Y. enterocolitica, Salmonella enterica serovar Typhimurium and Listeria monocytogenes by two probiotic strains, Lactobacillus casei C1 and Lactobacillus plantarum C4, was also associated with the pH decrease. However, both strains lacked protective effects in mouse experimental infection models, with the exception of long-lasting pre-treatment with L. plantarum C4, which exerted a partial protective effect against S. Typhimurium that was attributable to an immunostimulatory mechanism. Our results show that in vitro antibiosis tests do not provide useful information on the probiotic potential of Lactobacillus strains.

  18. Impact of oral Lactobacillus acidophilus gavage on rooster seminal and cloacal Lactobacilli concentrations.

    PubMed

    Kiess, A S; Hirai, J H; Triplett, M D; Parker, H M; McDaniel, C D

    2016-08-01

    The use of antibiotics in poultry is being heavily scrutinized, therefore alternatives such as probiotics are being investigated. Lactobacilli spp. are a commonly used bacteria in formulating probiotics, and the addition of Lactobacilli to broiler diets has demonstrated increased growth rates, stimulated immune systems, and reduced pathogen loads in the gastro-intestinal tract ( GI: ) tract. However, previous research has shown that when rooster semen is directly exposed to Lactobacillus acidophilus (L. acidophilus) sperm quality is reduced. Therefore, the objective of the current study was to determine if oral administration of L. acidophilus increases the concentration of Lactobacilli in semen as well as the cloaca. A total of 30 roosters were used: 15 roosters were gavaged with 1X PBS (Control) and 15 roosters were gavaged with 10(7) cfu/mL of L. acidophilus (Treated). All roosters were gavaged for 14 consecutive days. Semen was collected on a 3 d interval, and cloacal swabs were collected on a 2 d interval, beginning on the first day prior to oral administration. Semen and cloacal swabs were serial diluted, and 100 μL of each dilution was then plated on Man, Rogosa, Sharpe ( MRS: ) agar plates. All plates were incubated for 48 h at 37°C under anaerobic conditions and counted. All Lactobacilli counts were first log transformed, then log transformed (day 0) pre-counts were subtracted from the log transformed day counts providing log differences for the analysis. Seminal Lactobacilli counts were not altered by treatments. However, the main effect of treatment (P = 0.026) for cloacal counts indicated that roosters gavaged with Lactobacilli yielded higher counts than the controls. Additionally, cloaca samples also demonstrated a treatment by day interaction trend (P = 0.082), where Lactobacilli was higher in the L. acidophilus gavaged roosters than the controls only on days 3, 5, 13, and 15. In conclusion, the addition of L. acidophilus to the male breeder diet

  19. Role of indigenous lactobacilli in gastrin-mediated acid production in the mouse stomach.

    PubMed

    Takahashi, Hidenori; Nakano, Yasuhiro; Matsuoka, Takashi; Kumaki, Nobue; Asami, Yukio; Koga, Yasuhiro

    2011-10-01

    It is known that the stomach is colonized by indigenous lactobacilli in mice. The aim of this study was to examine the role of such lactobacilli in the development of the stomach. For a DNA microarray analysis, germ-free BALB/c mice were orally inoculated with 10(9) CFU lactobacilli, and their stomachs were excised after 10 days to extract RNA. As a result, lactobacillus-associated gnotobiotic mice showed dramatically decreased expression of the gastrin gene in comparison to germ-free mice. The mean of the log(2) fold change in the gastrin gene was -4.3. Immunohistochemistry also demonstrated the number of gastrin-positive (gastrin(+)) cells to be significantly lower in the lactobacillus-associated gnotobiotic mice than in the germ-free mice. However, there was no significant difference in the number of somatostatin(+) cells in these groups of mice. Consequently, gastric acid secretion also decreased in the mice colonized by lactobacilli. In addition, an increase in the expression of the genes related to muscle system development, such as nebulin and troponin genes, was observed in lactobacillus-associated mice. Moreover, infection of germ-free mice with Helicobacter pylori also showed the down- and upregulation of gastrin and muscle genes, respectively, in the stomach. These results thus suggested that indigenous lactobacilli in the stomach significantly affect the regulation of gastrin-mediated gastric acid secretion without affecting somatostatin secretion in mice, while H. pylori also exerts such an effect on the stomach.

  20. Role of Indigenous Lactobacilli in Gastrin-Mediated Acid Production in the Mouse Stomach ▿

    PubMed Central

    Takahashi, Hidenori; Nakano, Yasuhiro; Matsuoka, Takashi; Kumaki, Nobue; Asami, Yukio; Koga, Yasuhiro

    2011-01-01

    It is known that the stomach is colonized by indigenous lactobacilli in mice. The aim of this study was to examine the role of such lactobacilli in the development of the stomach. For a DNA microarray analysis, germ-free BALB/c mice were orally inoculated with 109 CFU lactobacilli, and their stomachs were excised after 10 days to extract RNA. As a result, lactobacillus-associated gnotobiotic mice showed dramatically decreased expression of the gastrin gene in comparison to germ-free mice. The mean of the log2 fold change in the gastrin gene was −4.3. Immunohistochemistry also demonstrated the number of gastrin-positive (gastrin+) cells to be significantly lower in the lactobacillus-associated gnotobiotic mice than in the germ-free mice. However, there was no significant difference in the number of somatostatin+ cells in these groups of mice. Consequently, gastric acid secretion also decreased in the mice colonized by lactobacilli. In addition, an increase in the expression of the genes related to muscle system development, such as nebulin and troponin genes, was observed in lactobacillus-associated mice. Moreover, infection of germ-free mice with Helicobacter pylori also showed the down- and upregulation of gastrin and muscle genes, respectively, in the stomach. These results thus suggested that indigenous lactobacilli in the stomach significantly affect the regulation of gastrin-mediated gastric acid secretion without affecting somatostatin secretion in mice, while H. pylori also exerts such an effect on the stomach. PMID:21803885

  1. Ecology of Lactobacilli in the Oral Cavity: A Review of Literature

    PubMed Central

    Badet, C; Thebaud, N.B

    2008-01-01

    Lactobacilli appear in the oral cavity during the first years of a child’s life. Their presence depends on numerous factors such as the presence of ecological niches e.g. natural anfractuosities of the teeth. A strong correlation has been established between the saliva Lactobacillus count and dental caries, the higher the DMF index, the higher the number of children harbouring a high Lactobacillus count. Among children, the presence of lactobacilli in coronal caries is incontestable. Among adults, lactobacilli are found in root caries. Since 1999, taxonomical revisions make it difficult to interpret the results obtained in the numerous previous studies carried out on the identification of oral lactobacilli, but whatever the sampling method or the identification technique, the carious site or the age of sampled subjects, most species belong to the Lactobacillus casei group. This is important because if a specific correlation can be found between few species of lactobacilli and caries a better understanding of their properties could allow the development of new tools for prevention. PMID:19088910

  2. Acid and bile tolerance and cholesterol removal ability of lactobacilli strains.

    PubMed

    Liong, M T; Shah, N P

    2005-01-01

    Eleven strains of lactobacilli were studied for their acid and bile tolerance. Possible mechanisms of cholesterol removal by strains of lactobacilli were examined. Cholesterol assimilation as determined by the difference in cholesterol content in the medium before and after the incubation period showed that all lactobacilli strains were able to assimilate cholesterol at varying levels ranging from 12.03 to 32.25 microg/mL. Cholesterol removal was associated with growth of cultures. Binding of cholesterol to lactobacilli cells was determined using growing, heat-killed, and resting cells in phosphate buffer. Cholesterol removed by dead and resting cells ranged from 0.79 to 3.82 mg/g of dry weight compared with growing cells, which ranged from 4.53 to 16.03 mg/g of dry weight. Fatty acid methyl esters, as quantified using gas chromatography, showed changes in lipid profiles in cells grown in the presence of cholesterol compared with those grown without cholesterol. Fatty acid profiles, especially of hexadecanoic, octadecanoic, total saturated, and unsaturated acids suggested that cholesterol from the medium was incorporated into the cellular membrane. These findings suggest that strains of lactobacilli could remove cholesterol via various mechanisms and may be promising candidates for use as a dietary adjunct to lower serum cholesterol in vivo.

  3. Conversion of Methionine to Thiols by Lactococci, Lactobacilli, and Brevibacteria†

    PubMed Central

    Dias, Benjamin; Weimer, Bart

    1998-01-01

    Methanethiol has been strongly associated with desirable Cheddar cheese flavor and can be formed from the degradation of methionine (Met) via a number of microbial enzymes. Methionine γ-lyase is thought to play a major role in the catabolism of Met and generation of methanethiol in several species of bacteria. Other enzymes that have been reported to be capable of producing methanethiol from Met in lactic acid bacteria include cystathionine β-lyase and cystathionine γ-lyase. The objective of this study was to determine the production, stability, and activities of the enzymes involved in methanethiol generation in bacteria associated with cheese making. Lactococci and lactobacilli were observed to contain high levels of enzymes that acted primarily on cystathionine. Enzyme activity was dependent on the concentration of sulfur amino acids in the growth medium. Met aminotransferase activity was detected in all of the lactic acid bacteria tested and α-ketoglutarate was used as the amino group acceptor. In Lactococcus lactis subsp. cremoris S2, Met aminotransferase was repressed with increasing concentrations of Met in the growth medium. While no Met aminotransferase activity was detected in Brevibacterium linens BL2, it possessed high levels of l-methionine γ-lyase that was induced by addition of Met to the growth medium. Met demethiolation activity at pH 5.2 with 4% NaCl was not detected in cell extracts but was detected in whole cells. These data suggest that Met degradation in Cheddar cheese will depend on the organism used in production, the amount of enzyme released during aging, and the amount of Met in the matrix. PMID:9726877

  4. Stability of lactobacilli encapsulated in various microbial polymers.

    PubMed

    Jiménez-Pranteda, María Luján; Poncelet, Denis; Náder-Macías, María Elena; Arcos, Antonio; Aguilera, Margarita; Monteoliva-Sánchez, Mercedes; Ramos-Cormenzana, Alberto

    2012-02-01

    Various microbial polymers, namely xanthan gum, gellan gum, pullulan gum and jamilan, were tested as a suitable encapsulating material for Lactobacillus plantarum CRL 1815 and Lactobacillus rhamnosus ATCC 53103. Resulting capsules were also studied for their pH and simulated gastrointestinal conditions tolerance. The morphology of the microcapsules was studied using scanning electron microscopy. pH tolerance was tested at pH 2.0, 3.5, 5.0 and 6.5 over a 6h incubation period. Simulated gastrointestinal conditions were assayed with simulated gastric and pancreatic juices and simulated bile over a 24h incubation period. Suspensions of probiotic organisms were used as a control. The results from encapsulation with microbial polymers indicate that mixtures of 1% xanthan gum with 0.75% gellan gum and 1% jamilan with 1% gellan gum were the most suitable for microencapsulation. Results for the pH tolerance tests showed no improvement in the viability of cells in relation to the control, except for pH 2.0 where lactobacilli encapsulated in xanthan:gellan gum (1%:0.75%) prolonged their viability by 6h exposure. Xanthan:gellan gum (1%:0.75%) was the most effective of the encapsulating materials tested in protecting L. plantarum and L. rhamnosus against simulated bile, improving its viability in 1-2 logCFU when compared with control. The results of this study suggest that microbial polymers are an interesting source of encapsulating material that should be taken into account for prospective studies of probiotic encapsulation for oral delivery applications. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Effect of lactobacilli on E. coli adhesion to Caco-2 cells in vitro.

    PubMed

    Horosová, K; Bujnáková, D; Kmet, V

    2006-01-01

    Inhibitory effect of various lactobacilli against pathogenic strains of E. coli in model system Caco2 cells was determined by enumerating the number of adhering E. coli after pre-incubation (exclusion), post-incubation (displacement) or co-incubation (competition) with lactobacilli. Porcine E. coli strain F107 (F18ab, Stx2v) in the competition assay with porcine lactobacillus strain P10 gave bacterial counts 7.25 (log CFU per well); in the exclusion test it was only 7.05 while in displacement test it reached 7.29. The lowest E. coli counts adhering to Caco-2 cells were in exclusion assay (pre-incubation, Lactobacillus inoculated as the first). Pre-treatment of E. coli with our lactobacilli strains reduced the cultivable E. coli numbers.

  6. Short term effect of mechanical plaque control on salivary concentration of S. mutans and lactobacilli.

    PubMed

    Wikner, S

    1986-08-01

    All visible plaque was professionally removed from teeth of 40 children who were highly infected with S. mutans and lactobacilli. Shortly before and after the removal of plaque the concentrations of those bacteria were assessed in saliva stimulated by chewing. S. mutans and lactobacilli correlated well at baseline but not after plaque elimination, e.g. more than 80% of children who were heavily infected with S. mutans could be identified by a lactobacillus test at baseline. After the elimination of plaque, the mean concentration of S. mutans dropped by 64% but lactobacilli remained unchanged. The results indicate that oral hygiene measures taken by the patient prior to sampling of saliva may mask the true concentration of salivary S. mutans and complicate the identification of high caries risk patients.

  7. The effects of intravaginal clindamycin and metronidazole therapy on vaginal lactobacilli in patients with bacterial vaginosis.

    PubMed

    Nyirjesy, Paul; McIntosh, Matthew J; Gattermeir, David J; Schumacher, Robert J; Steinmetz, Jana I; Joffrion, James L

    2006-05-01

    The purpose of this study was to determine the effects of 3 intravaginal antibacterial treatments on vaginal lactobacilli in patients with bacterial vaginosis (BV). Retrospective analyses were performed on Lactobacillus scores from 3 similar studies evaluating 2 2% clindamycin vaginal creams and 0.75% metronidazole gel at baseline and at 21 to 30 days in 408 patients with BV. Scores were compared using a 1-way global F test and McNemar's test. All groups had similar mean Lactobacillus scores at baseline (P = 0.37) and at 21 to 30 days (P = .71). The 3 groups were also comparable at both visits with respect to the distributions of scores within each group. In all groups, there was significant improvement in the percentages of patients with no lactobacilli present at 21 to 30 days compared with baseline (P < .0001 for all comparisons). Clindamycin and metronidazole promoted similar levels of restoration of vaginal lactobacilli at 21 to 30 days.

  8. Lactobacilli Dominance and Vaginal pH: Why Is the Human Vaginal Microbiome Unique?

    PubMed

    Miller, Elizabeth A; Beasley, DeAnna E; Dunn, Robert R; Archie, Elizabeth A

    2016-01-01

    The human vaginal microbiome is dominated by bacteria from the genus Lactobacillus, which create an acidic environment thought to protect women against sexually transmitted pathogens and opportunistic infections. Strikingly, lactobacilli dominance appears to be unique to humans; while the relative abundance of lactobacilli in the human vagina is typically >70%, in other mammals lactobacilli rarely comprise more than 1% of vaginal microbiota. Several hypotheses have been proposed to explain humans' unique vaginal microbiota, including humans' distinct reproductive physiology, high risk of STDs, and high risk of microbial complications linked to pregnancy and birth. Here, we test these hypotheses using comparative data on vaginal pH and the relative abundance of lactobacilli in 26 mammalian species and 50 studies (N = 21 mammals for pH and 14 mammals for lactobacilli relative abundance). We found that non-human mammals, like humans, exhibit the lowest vaginal pH during the period of highest estrogen. However, the vaginal pH of non-human mammals is never as low as is typical for humans (median vaginal pH in humans = 4.5; range of pH across all 21 non-human mammals = 5.4-7.8). Contrary to disease and obstetric risk hypotheses, we found no significant relationship between vaginal pH or lactobacilli relative abundance and multiple metrics of STD or birth injury risk (P-values ranged from 0.13 to 0.99). Given the lack of evidence for these hypotheses, we discuss two alternative explanations: the common function hypothesis and a novel hypothesis related to the diet of agricultural humans. Specifically, with regard to diet we propose that high levels of starch in human diets have led to increased levels of glycogen in the vaginal tract, which, in turn, promotes the proliferation of lactobacilli. If true, human diet may have paved the way for a novel, protective microbiome in human vaginal tracts. Overall, our results highlight the need for continuing research on non

  9. Lactobacilli Dominance and Vaginal pH: Why Is the Human Vaginal Microbiome Unique?

    PubMed Central

    Miller, Elizabeth A.; Beasley, DeAnna E.; Dunn, Robert R.; Archie, Elizabeth A.

    2016-01-01

    The human vaginal microbiome is dominated by bacteria from the genus Lactobacillus, which create an acidic environment thought to protect women against sexually transmitted pathogens and opportunistic infections. Strikingly, lactobacilli dominance appears to be unique to humans; while the relative abundance of lactobacilli in the human vagina is typically >70%, in other mammals lactobacilli rarely comprise more than 1% of vaginal microbiota. Several hypotheses have been proposed to explain humans' unique vaginal microbiota, including humans' distinct reproductive physiology, high risk of STDs, and high risk of microbial complications linked to pregnancy and birth. Here, we test these hypotheses using comparative data on vaginal pH and the relative abundance of lactobacilli in 26 mammalian species and 50 studies (N = 21 mammals for pH and 14 mammals for lactobacilli relative abundance). We found that non-human mammals, like humans, exhibit the lowest vaginal pH during the period of highest estrogen. However, the vaginal pH of non-human mammals is never as low as is typical for humans (median vaginal pH in humans = 4.5; range of pH across all 21 non-human mammals = 5.4–7.8). Contrary to disease and obstetric risk hypotheses, we found no significant relationship between vaginal pH or lactobacilli relative abundance and multiple metrics of STD or birth injury risk (P-values ranged from 0.13 to 0.99). Given the lack of evidence for these hypotheses, we discuss two alternative explanations: the common function hypothesis and a novel hypothesis related to the diet of agricultural humans. Specifically, with regard to diet we propose that high levels of starch in human diets have led to increased levels of glycogen in the vaginal tract, which, in turn, promotes the proliferation of lactobacilli. If true, human diet may have paved the way for a novel, protective microbiome in human vaginal tracts. Overall, our results highlight the need for continuing research on non

  10. Enhanced growth of lactobacilli and bioconversion of isoflavones in biotin-supplemented soymilk by electroporation.

    PubMed

    Ewe, Joo-Ann; Wan-Abdullah, Wan-Nadiah; Alias, Abdul Karim; Liong, Min-Tze

    2012-08-01

    This study aimed at utilizing electroporation to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli were treated with different pulsed electric field strength (2.5, 5.0 and 7.5 kV/cm) for 3, 3.5 and 4 ms prior to inoculation and fermentation in biotin-soymilk at 37°C for 24 h. Electroporation triggered structural changes within the cellular membrane of lactobacilli that caused lipid peroxidation (p < 0.05) and alteration of membrane fluidity (p < 0.05). This was due to the application of electric potential difference across membrane that induced pores formation and subsequently increased membrane permeability. Reversible permeabilized cells resumed growth to >9 log CFU/ml after fermentation in biotin-soymilk (p < 0.05). Lactobacilli cells treated at electric field strength of 7.5 kV/cm for 3.5 ms also showed enhanced β-glucosidase activity (p < 0.05) compared to lower doses and control, leading to increased bioconversion of isoflavones glucosides to aglycones in biotin-soymilk (p < 0.05). Results from this study show that electroporation could be used to produce biotin-soymilk with increased bioactive aglycones.

  11. Exogenous lactobacilli mitigate microbial changes associated with grain fermentation in vitro

    USDA-ARS?s Scientific Manuscript database

    Cereal grains are often included in equine diets. Sugars and starch in grains can be digested and absorbed in the small intestine, but a high proportion of grain in the diet can allow starch to reach the hindgut, disturbing the microbial ecology. Streptococci and lactobacilli both catabolize starch ...

  12. Development of a Lactobacillus Specific T-RFLP Method to Determine Lactobacilli Diversity in Complex Samples

    PubMed Central

    Chen, Long; Teasdale, Matt T.; Kaczmarczyk, Melissa M.; Freund, Gregory G.; Miller, Michael J.

    2012-01-01

    Terminal restriction fragment length polymorphism (T-RFLP) analysis has been widely used for studying microbial communities. However, most T-RFLP assays use 16S rDNA as the target and are unable to accurately characterize a microbial subpopulation. In this study, we developed a novel T-RFLP protocol based on Lactobacillus hsp60 to rapidly characterize and compare lactobacilli composition. The theoretical terminal restriction fragment (TRF) profiles were calculated from 769 Lactobacillus hsp60 sequences from online databases. In silico digestion with restriction endonucleases AluI and TacI on hsp60 amplicons generated 83 distinct TRF patterns, of which, 70 were species specific. To validate the assay, five previously sequenced lactobacilli were cultured independently, mixed at known concentrations and subjected to analysis by T-RFLP. All five strains generated the predicted TRFs and a qualitative consistent relationship was revealed. We performed the T-RFLP protocol on fecal samples from mice fed 6 different diets (n=4). Principal component analysis and agglomerative hierarchical clustering revealed that the lactobacilli community was strongly connected to dietary supplementation. Our study demonstrates the potential for using Lactobacillus specific T-RFLP to characterize lactobacilli communities in complex samples. PMID:22981747

  13. Sample handling factors affecting the enumeration of lactobacilli and cellulolytic bacteria in equine feces

    USDA-ARS?s Scientific Manuscript database

    The objectives were to compare media types and evaluate the effects of fecal storage time and temperature on the enumeration of cellulolytic bacteria and lactobacilli from horses. Fecal samples were collected from horses (n = 3) and transported to the lab (CO2, 37 ºC, 0.5 h). The samples were assign...

  14. Improved growth and viability of lactobacilli in the presence of Bacillus subtilis (natto), catalase, or subtilisin.

    PubMed

    Hosoi, T; Ametani, A; Kiuchi, K; Kaminogawa, S

    2000-10-01

    In an effort to demonstrate the potential usefulness of Bacillus subtilis (natto) as a probiotic, we examined the effect of this organism on the growth of three strains of lactobacilli co-cultured aerobically in vitro. Addition of B. subtilis (natto) to the culture medium resulted in an increase in the number of viable cells of all lactobacilli tested. Since B. subtilis (natto) can produce catalase, which has been reported to exhibit a similar growth-promoting effect on lactobacilli, we also examined the effect of bovine catalase on the growth of Lactobacillus reuteri JCM 1112 and L. acidophilus JCM 1132. Both catalase and B. subtilis (natto) enhanced the growth of L. reuteri JCM 1112, whereas B. subtilis (natto) but not catalase enhanced the growth of L. acidophilus JCM 1132. In a medium containing 0.1 mM hydrogen peroxide, its toxic effect on L. reuteri JCM 1112 was abolished by catalase or B. subtilis (natto). In addition, a serine protease from B. licheniformis, subtilisin, improved the growth and viability of L. reuteri JCM 1112 and L. acidophilus JCM 1132 in the absence of hydrogen peroxide. These results indicate that B. subtilis (natto) enhances the growth and (or) viability of lactobacilli, possibly through production of catalase and subtilisin.

  15. Cooperation between Lactococcus lactis and nonstarter lactobacilli in the formation of cheese aroma from amino acids.

    PubMed

    Kieronczyk, Agnieszka; Skeie, Siv; Langsrud, Thor; Yvon, Mireille

    2003-02-01

    In Gouda and Cheddar type cheeses the amino acid conversion to aroma compounds, which is a major process for aroma formation, is essentially due to lactic acid bacteria (LAB). In order to evaluate the respective role of starter and nonstarter LAB and their interactions in cheese flavor formation, we compared the catabolism of phenylalanine, leucine, and methionine by single strains and strain mixtures of Lactococcus lactis subsp. cremoris NCDO763 and three mesophilic lactobacilli. Amino acid catabolism was studied in vitro at pH 5.5, by using radiolabeled amino acids as tracers. In the presence of alpha-ketoglutarate, which is essential for amino acid transamination, the lactobacillus strains degraded less amino acids than L. lactis subsp. cremoris NCDO763, and produced mainly nonaromatic metabolites. L. lactis subsp. cremoris NCDO763 produced mainly the carboxylic acids, which are important compounds for cheese aroma. However, in the reaction mixture containing glutamate, only two lactobacillus strains degraded amino acids significantly. This was due to their glutamate dehydrogenase (GDH) activity, which produced alpha-ketoglutarate from glutamate. The combination of each of the GDH-positive lactobacilli with L. lactis subsp. cremoris NCDO763 had a beneficial effect on the aroma formation. Lactobacilli initiated the conversion of amino acids by transforming them mainly to keto and hydroxy acids, which subsequently were converted to carboxylic acids by the Lactococcus strain. Therefore, we think that such cooperation between starter L. lactis and GDH-positive lactobacilli can stimulate flavor development in cheese.

  16. Cooperation between Lactococcus lactis and Nonstarter Lactobacilli in the Formation of Cheese Aroma from Amino Acids

    PubMed Central

    Kieronczyk, Agnieszka; Skeie, Siv; Langsrud, Thor; Yvon, Mireille

    2003-01-01

    In Gouda and Cheddar type cheeses the amino acid conversion to aroma compounds, which is a major process for aroma formation, is essentially due to lactic acid bacteria (LAB). In order to evaluate the respective role of starter and nonstarter LAB and their interactions in cheese flavor formation, we compared the catabolism of phenylalanine, leucine, and methionine by single strains and strain mixtures of Lactococcus lactis subsp. cremoris NCDO763 and three mesophilic lactobacilli. Amino acid catabolism was studied in vitro at pH 5.5, by using radiolabeled amino acids as tracers. In the presence of α-ketoglutarate, which is essential for amino acid transamination, the lactobacillus strains degraded less amino acids than L. lactis subsp. cremoris NCDO763, and produced mainly nonaromatic metabolites. L. lactis subsp. cremoris NCDO763 produced mainly the carboxylic acids, which are important compounds for cheese aroma. However, in the reaction mixture containing glutamate, only two lactobacillus strains degraded amino acids significantly. This was due to their glutamate dehydrogenase (GDH) activity, which produced α-ketoglutarate from glutamate. The combination of each of the GDH-positive lactobacilli with L. lactis subsp. cremoris NCDO763 had a beneficial effect on the aroma formation. Lactobacilli initiated the conversion of amino acids by transforming them mainly to keto and hydroxy acids, which subsequently were converted to carboxylic acids by the Lactococcus strain. Therefore, we think that such cooperation between starter L. lactis and GDH-positive lactobacilli can stimulate flavor development in cheese. PMID:12570989

  17. Development of a Lactobacillus specific T-RFLP method to determine lactobacilli diversity in complex samples.

    PubMed

    Chen, Long; Teasdale, Matt T; Kaczmarczyk, Melissa M; Freund, Gregory G; Miller, Michael J

    2012-11-01

    Terminal restriction fragment length polymorphism (T-RFLP) analysis has been widely used for studying microbial communities. However, most T-RFLP assays use 16S rDNA as the target and are unable to accurately characterize a microbial subpopulation. In this study, we developed a novel T-RFLP protocol based on Lactobacillus hsp60 to rapidly characterize and compare lactobacilli composition. The theoretical terminal restriction fragment (TRF) profiles were calculated from 769 Lactobacillus hsp60 sequences from online databases. In silico digestion with restriction endonucleases AluI and TacI on hsp60 amplicons generated 83 distinct TRF patterns, of which, 70 were species specific. To validate the assay, five previously sequenced lactobacilli were cultured independently, mixed at known concentrations and subjected to analysis by T-RFLP. All five strains generated the predicted TRFs and a qualitative consistent relationship was revealed. We performed the T-RFLP protocol on fecal samples from mice fed 6 different diets (n=4). Principal component analysis and agglomerative hierarchical clustering revealed that the lactobacilli community was strongly connected to dietary supplementation. Our study demonstrates the potential for using Lactobacillus specific T-RFLP to characterize lactobacilli communities in complex samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Homo- and heterofermentative lactobacilli differently affect sugarcane-based fuel ethanol fermentation

    USDA-ARS?s Scientific Manuscript database

    The antagonism between by yeast and lactobacilli is largely dependent on the initial population of each organism. While homo-fermentative lactobacillus present higher inhibitory effect upon yeast when in equal cell number, in industrial fuel ethanol conditions where high yeast cell densities prevail...

  19. Isolation of Tannin-Degrading Lactobacilli from Humans and Fermented Foods

    PubMed Central

    Osawa, Ro; Kuroiso, Keiko; Goto, Satoshi; Shimizu, Akira

    2000-01-01

    Lactobacilli with tannase activity were isolated from human feces and fermented foods. A PCR-based taxonomic assay revealed that the isolates belong to Lactobacillus plantarum, L. paraplantarum, and L. pentosus. Additional studies on a range of Lactobacillus species from established culture collections confirmed that this enzymatic activity is a phenotypic property common to these three species. PMID:10877812

  20. Comparison of the CLSI guideline and ISO/IDF standard for antimicrobial susceptibility testing of Lactobacilli.

    PubMed

    Mayrhofer, Sigrid; Zitz, Ulrike; Birru, Firew H; Gollan, Dagmar; Gołoś, Aleksandra K; Kneifel, Wolfgang; Domig, Konrad J

    2014-12-01

    Lactobacilli play a crucial role as probiotics and as starter cultures in the production of fermented foods. Although lactobacilli are a technologically useful and beneficial group of bacteria, a few members of them have been rarely correlated with bacterial infections. Correspondingly, clinicians are interested in the antimicrobial susceptibility of lactobacilli. In addition, antimicrobial susceptibility testing (AST) is also relevant for commercially applied lactobacilli as bacterial strains harboring transferable antibiotic resistance genes should not be used in fermented and probiotic foods. Therefore, two methods were developed by different organizations, which were compared within this study. For this purpose, 22 Lactobacillus-type strains were tested for their antimicrobial susceptibility to 16 antibiotics following the procedures of the Clinical and Laboratory Standards Institute (CLSI) and the International Organization of Standardization (ISO)/International Dairy Federation (IDF). Crucial discrepancies between both procedures were detected mainly due to the different AST media. Hence, half of the strains tested did not consistently grow in the CLSI medium, whereas all showed evaluable growth in the ISO/IDF medium. However, some antibiotics were influenced by the latter medium. In particular, low levels of essential agreement between both methods were obtained with seven antibiotics. Accordingly, different interpretative criteria are needed for both procedures to distinguish resistant from susceptible strains.

  1. Two strains of nonstarter lactobacilli increased the production of flavor compounds in soft cheeses.

    PubMed

    Milesi, M M; Wolf, I V; Bergamini, C V; Hynes, E R

    2010-11-01

    The contribution to flavor generation and secondary proteolysis of 2 strains of mesophilic lactobacilli isolated from cheese was studied. Miniature soft cheeses (200 g) were produced with or without the inclusion of a culture of Lactobacillus plantarum I91 or Lactobacillus casei I90 in the starter composed of Streptococcus thermophilus. During ripening, cheeses containing the added lactobacilli showed an increased content of total free amino acids, but this increase was only significant in cheeses with Lb. plantarum I91. In addition, free amino acid profiles were modified by selective increases of some amino acids, such as Asp, Ser, Arg, Leu, and Phe. Cheeses inoculated with Lb. plantarum I91 or Lb. casei I90 were also characterized by a significantly higher concentration of diacetyl, a key flavor compound, and an increased content of acetoin. Results suggest an increase in the catabolism of either citrate or aspartate, with the production of the derived aroma compounds. Overall, aspartate content increased in both lactobacilli-added cheeses, whereas citrate was more or less constant, suggesting that aspartate could be the source of increased diacetyl and acetoin. A triangle aroma test showed that the addition of the lactobacilli strains significantly changed the sensory attributes of cheeses. At least 11 of 12 panelists commented that the aroma of cheeses with adjuncts was more buttery than that of control cheeses, which is desirable in most soft cheeses. Both Lb. plantarum I91 and Lb. casei I90 performed well as adjunct cultures by influencing cheese aroma development and cheese proteolysis.

  2. Effect of oregano essential oil on chicken lactobacilli and E. coli.

    PubMed

    Horosová, K; Bujnáková, D; Kmet, V

    2006-01-01

    The effect of the oregano essential oil (EO) on lactobacilli and E. coli isolated from chicken was showed in the series of in vitro and in vivo experiments. Minimum inhibitory concentrations of amikacin, apramycin, streptomycin, neomycin against E. coli strains increased after oral application of EO.

  3. Cervicovaginal fluid and semen block the microbicidal activity of hydrogen peroxide produced by vaginal lactobacilli

    PubMed Central

    2010-01-01

    Background H2O2 produced by vaginal lactobacilli is believed to protect against infection, and H2O2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution. However, cervicovaginal fluid (CVF) and semen have significant H2O2-blocking activity. Methods We measured the H2O2 concentration of CVF and the H2O2-blocking activity of CVF and semen using fluorescence and in vitro bacterial-exposure experiments. Results The mean H2O2 measured in fully aerobic CVF was 23 ± 5 μM; however, 50 μM H2O2 in salt solution showed no in vitro inactivation of HSV-2, Neisseria gonorrhoeae, Hemophilus ducreyii, or any of six BV-associated bacteria. CVF reduced 1 mM added H2O2 to an undetectable level, while semen reduced 10 mM added H2O2 to undetectable. Moreover, the addition of just 1% CVF supernatant abolished in vitro pathogen-inactivation by H2O2-producing lactobacilli. Conclusions Given the H2O2-blocking activity of CVF and semen, it is implausible that H2O2-production by vaginal lactobacilli is a significant mechanism of protection in vivo. PMID:20482854

  4. [Testing of the potentially probiotic lactobacilli for use in food supplements].

    PubMed

    Bilková, Andrea; Bilka, František; Sepová, Hana Kiňová; Balážová, Andrea

    2013-02-01

    Some lactobacilli strains are used as probiotics in food industry and in dietary supplements. Eight lactobacilli strains, originated from the stomach of the lamb and goatling, are tested for their potential use in human and/or veterinary medicine in our department. Sanguinarine is a major alkaloid of Papaveraceae suspension cultures. For its antimicrobial, antifungal, anti-plaque and anti-inflammatory properties sanguinarine found application in dental preparations. A mixture of sanguinarine with other alkaloids is used for appetite stimulation of livestock. This paper is focused on testing of selected lactobacilli sensitivity to sanguinarine, isolated from the opium poppy suspension cultures. L. reuteri KO5 demonstrated the lowest sensitivity (MIC 0.6 mg.l-1). Other less sensitive strains were L. murinus C, L. mucosae D and L. plantarum KG4 (MIC 0.3 mg.l-1). For a combination of more strains of microorganisms in one preparation it is necessary to know their ability to influence their growth and survival. To test the mutual influence of lactobacilli, the streak line method on agar plates was used. The results show that the strains L. reuteri E, L. plantarum KG1 a L. reuteri KO4m are the most suitable ones for the use in combinations. Lactobacillus spp. probiotics food supplements sanguinarine.

  5. Rapid discrimination of lactobacilli isolated from kefir grains by FT-IR spectroscopy.

    PubMed

    Bosch, Alejandra; Golowczyc, Marina A; Abraham, Analía G; Garrote, Graciela L; De Antoni, Graciela L; Yantorno, Osvaldo

    2006-10-01

    Fourier transform infrared (FT-IR) spectroscopy was used in combination with multivariate statistical analysis for differentiation of lactic bacteria isolated from kefir grains. Twelve reference strains and 42 lactobacilli isolates from four local kefir grains, previously identified by biochemical traditional techniques at species level were included in this study. The spectra were analysed by hierarchical clustering analysis (HCA) using Pearson's product-moment correlation coefficient and Ward's algorithm. The differentiation between homo- and heterofermentative lactobacilli, proposed as a first level in the classification scheme, was performed with vector normalized first derivatives spectra in the windows 1789-1700, 1059-935, 3000-2927 and 896-833 cm(-1). For heterofermentative lactobacilli the windows 1780-1750, 1500-1200, 2950-2930 and 900-700 cm(-1) were found to contribute to the maximal separation among L. kefir, L. parakefir and Lactobacillus brevis. It was also demonstrated that although this model was robust against small variations in growth temperature (+/-5 degrees C) and growth time (+/-5 h), the make of culture medium used (Biokar or Difco) affected the separation of heterofermentative lactobacilli at species level. For homofermentative lactobacilli the spectral regions 1230-900, 1777-1690, 1357-1240 and 2960-2870 cm(-1), were selected for discrimination among 5 different species that are normally present in kefir grains: L. plantarum, L. acidophilus, L. kefirgranum, L. kefiranofaciens and L. cassei. The classification and discrimination schemes proposed in this work completely matched with the identification obtained by classical biochemical techniques at species level.

  6. Synthesis of conjugated linoleic acid by the linoleate isomerase complex in food-derived lactobacilli.

    PubMed

    Yang, B; Chen, H; Gu, Z; Tian, F; Ross, R P; Stanton, C; Chen, Y Q; Chen, W; Zhang, H

    2014-08-01

    To assess strains of lactobacilli for their capacity to produce functional fatty acid-conjugated linoleic acid. To assess the linoleate isomerase for CLA production in the most efficient CLA producer. In this study, strains of food-derived lactobacilli were cultured in media with linoleic acid and CLA production was assessed. Most of the selected strains produced CLA at different levels, with Lactobacillus plantarum ZS2058 being the most efficient CLA producer converting over 50% of linoleic acid to c9, t11-CLA and t9, t11-CLA. Some intermediates 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid were determined via GC-MS. The genes coding the multicomponent linoleate isomerase containing myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase and acetoacetate decarboxylase for CLA production in Lact. plantarum ZS2058 were cloned and expressed in Escherichia coli. With the mixture of recombinant E. coli, c9, t11-CLA and three kinds of intermediates were produced from linoleic acid, which were in line with those in the lactobacilli. The ability for CLA production by lactobacilli exhibited variation. Lactobacillus plantarum and Lact. bulgaricus were the most efficient producers in the selected strains. Lact. plantarum ZS2058 converted linoleic acid to CLAs with 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid as intermediates. The multiple-step reactions for CLA production catalysed by multicomponent linoleate isomerase in Lact. plantarum ZS2058 were confirmed successfully. Multicomponent linoleate isomerase provides important results for the illustration of the mechanism for CLA production in lactic acid bacteria. Food-derived lactobacilli with CLA production ability offers novel opportunities for functional foods development. © 2014 The Society for Applied Microbiology.

  7. Synthesis of conjugated linoleic acid by the linoleate isomerase complex in food-derived lactobacilli

    PubMed Central

    Yang, B.; Chen, H.; Gu, Z.; Tian, F.; Ross, R. P.; Stanton, C.; Chen, Y. Q.; Chen, W.; Zhang, H.

    2015-01-01

    Aims To assess strains of lactobacilli for their capacity to produce functional fatty acid-conjugated linoleic acid. To assess the linoleate isomerase for CLA production in the most efficient CLA producer. Methods and Results In this study, strains of food-derived lactobacilli were cultured in media with linoleic acid and CLA production was assessed. Most of the selected strains produced CLA at different levels, with Lactobacillus plantarum ZS2058 being the most efficient CLA producer converting over 50% of linoleic acid to c9, t11-CLA and t9, t11-CLA. Some intermediates 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid were determined via GC-MS. The genes coding the multicomponent linoleate isomerase containing myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase and acetoacetate decarboxylase for CLA production in Lact. plantarum ZS2058 were cloned and expressed in Escherichia coli. With the mixture of recombinant E. coli, c9, t11-CLA and three kinds of intermediates were produced from linoleic acid, which were in line with those in the lactobacilli. Conclusions The ability for CLA production by lactobacilli exhibited variation. Lactobacillus plantarum and Lact. bulgaricus were the most efficient producers in the selected strains. Lact. plantarum ZS2058 converted linoleic acid to CLAs with 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid as intermediates. The multiple-step reactions for CLA production catalysed by multicomponent linoleate isomerase in Lact. plantarum ZS2058 were confirmed successfully. Significance and Impact of the study Multicomponent linoleate isomerase provides important results for the illustration of the mechanism for CLA production in lactic acid bacteria. Food-derived lactobacilli with CLA production ability offers novel opportunities for functional foods development. PMID:24750362

  8. Presence of drug resistance in intestinal lactobacilli of dairy and human origin in Turkey.

    PubMed

    Cataloluk, Osman; Gogebakan, Bulent

    2004-07-01

    The prevalence of different resistance genes was investigated in lactobacilli of human and dairy origin by PCR. The presence of erm, van, tet, and cat-TC genes were determined in 16 raw milk, 15 cream, 10 yogurt, 50 hand-made cheese, and 20 industrially produced white-cheese samples of dairy origin and 16 mouth, 32 fecal, and 36 vaginal samples from different subjects of human origin. Lactobacilli of dairy and human origin were found to carry only erm(B) and tet(M) genes. The majority of the isolates, Lactobacillus crispatus (61), Lactobacillus gasseri (49), Lactobacillus plantarum (80) studied were found to harbor either erm(B) or tet(M) gene or both. No resistant lactobacilli was found in raw-milk and cream samples. All the human fecal samples and the majority of vaginal (29 of 36) and mouth (10 of 14) samples were found to carry the resistance genes. While a third of the hand-made cheeses carried resistant lactobacilli only one industrially produced cheese was found to carry resistant lactobacilli. Furthermore, the genes were found in the non-starter species, Lactobacillus acidophilus and Lb. plantarum, indicating that industrially produced cheeses in this respect could be considered more favorable. These results indicate that drug resistance seems to be very common in Turkey. Even though the number of dairy samples harboring the resistance genes (17 of 111) is smaller in regards to human samples, 10% of them were still found to carry the resistance genes as well. The presence of the resistance genes in majority of the samples of human origin and in minority of the samples of dairy origin indicates that drug resistance may be acquired in the intestinal tract during passage and spread to dairy products by the hands of workers during production.

  9. Nonstarter lactobacilli isolated from soft and semihard Argentinean cheeses: genetic characterization and resistance to biological barriers.

    PubMed

    Ugarte, Mariana Bude; Guglielmotti, Daniela; Giraffa, Giorgio; Reinheimer, Jorge; Hynes, Erica

    2006-12-01

    Nonstarter lactic acid bacteria isolated from Argentinean cheeses were identified and characterized by focusing on their resistance to biological barriers, along with other physiological features of potential interest, in the search for future probiotic organisms. Lactobacilli were enumerated and isolated from semihard and soft cheeses made with multistrain Streptococcus thermophilus starters. Lactobacilli counts in 1-week-old cheeses were between 10(5) and 10(7) CFU/g and then reached 10(7) CFU/ g in all 1-month samples, while streptococci were always above 10(9) CFU/g. A total number of 22 lactobacilli isolates were retained, identified, and characterized by in vitro tests. Species identity was determined by carbohydrate metabolism and species-specific PCR assays. Genetic diversity was explored by random amplified polymorphic DNA (RAPD) PCR analysis. The Lactobacillus strains were assigned to the species L. casei, L. plantarum, L. rhamnosus, L. curvatus, L. fermentum, and L. perolens. All the strains studied tolerated 25 ppm of lysozyme, and most of them showed resistance to 0.3% bile. After incubation in gastric solution (pH 2.0), counts decreased by several log units, ranging from 3.2 to 7.0. The strains were able to grow in the presence of bile salts, but only three isolates were capable of deconjugation. The nonstarter lactobacilli that were assayed fermented the prebiotic substrates (especially lactulose and inulin). Some strains showed high cell hydrophobicity and beta-galactosidase activity, as well as inhibitory activity against pathogenic bacteria. It was concluded that most of the lactobacilli isolated in this study demonstrated resistance to biological barriers and physiological characteristics compatible with probiotic properties, which make them suitable for further research in in vivo studies aimed at identifying new probiotic organisms.

  10. Determining Antioxidant Activities of Lactobacilli Cell-Free Supernatants by Cellular Antioxidant Assay: A Comparison with Traditional Methods

    PubMed Central

    Xing, Jiali; Wang, Gang; Zhang, Qiuxiang; Liu, Xiaoming; Gu, Zhennan; Zhang, Hao; Chen, Yong Q.; Chen, Wei

    2015-01-01

    Antioxidant activity of lactic acid bacteria is associated with multiple health-protective effects. Traditional indexes of chemical antioxidant activities poorly reflect the antioxidant effects of these bacteria in vivo. Cellular antioxidant activity (CAA) assay was used in this study to determine the antioxidant activity of cell-free supernatants (CFSs) of 10 Lactobacillus strains. The performance of the CAA assay was compared with that of four chemical antioxidant activity assays, namely, DPPH radical scavenging, hydroxyl radical scavenging (HRS), reducing power (RP), and inhibition of linoleic acid peroxidation (ILAP). Results of the CAA assay were associated with those of DPPH and ILAP assays, but not with those of RP and HRS assays. The inter- and intra-specific antioxidant activities of CFS were characterized by chemical and CAA assays. L. rhamnosus CCFM 1107 displayed a high antioxidative effect similar to positive control L. rhamnosus GG ATCC 53103 in all of the assays. The CAA assay is a potential method for the detection of antioxidant activities of lactobacilli CFSs. PMID:25789875

  11. Determining antioxidant activities of lactobacilli cell-free supernatants by cellular antioxidant assay: a comparison with traditional methods.

    PubMed

    Xing, Jiali; Wang, Gang; Zhang, Qiuxiang; Liu, Xiaoming; Gu, Zhennan; Zhang, Hao; Chen, Yong Q; Chen, Wei

    2015-01-01

    Antioxidant activity of lactic acid bacteria is associated with multiple health-protective effects. Traditional indexes of chemical antioxidant activities poorly reflect the antioxidant effects of these bacteria in vivo. Cellular antioxidant activity (CAA) assay was used in this study to determine the antioxidant activity of cell-free supernatants (CFSs) of 10 Lactobacillus strains. The performance of the CAA assay was compared with that of four chemical antioxidant activity assays, namely, DPPH radical scavenging, hydroxyl radical scavenging (HRS), reducing power (RP), and inhibition of linoleic acid peroxidation (ILAP). Results of the CAA assay were associated with those of DPPH and ILAP assays, but not with those of RP and HRS assays. The inter- and intra-specific antioxidant activities of CFS were characterized by chemical and CAA assays. L. rhamnosus CCFM 1107 displayed a high antioxidative effect similar to positive control L. rhamnosus GG ATCC 53103 in all of the assays. The CAA assay is a potential method for the detection of antioxidant activities of lactobacilli CFSs.

  12. Stimulation of indigenous lactobacilli by fermented milk prepared with probiotic bacterium, Lactobacillus delbrueckii subsp. bulgaricus strain 2038, in the pigs.

    PubMed

    Ohashi, Yuji; Tokunaga, Makoto; Taketomo, Naoki; Ushida, Kazunari

    2007-02-01

    The aim of this study was to evaluate the effect of feeding yoghurt, prepared with Lactobacillus delbrueckii subsp. bulgaricus strain 2038, on indigenous lactobacilli in the pig cecum. Three female pigs fistulated at the cecum were fed 250 g of this yoghurt that contained over 10(11) colony-forming units of L. delbrueckii subsp. bulgaricus strain 2038 with their daily meal for 2 wk. The relative abundance and the composition of cecal lactobacilli was monitored by analysis of bacterial 16S rDNA with real time PCR and amplified bacterial rDNA restriction analysis using Lactobacillus-group specific primers, respectively, for 2 wk prior to, at the end of 2 wk of and 2 wk after the administration of this yoghurt. The relative abundance of lactobacilli was significantly increased by feeding yoghurt (p<0.01), although the bacterial 16S rDNA matching L. delbrueckii subsp. bulgaricus strain 2038 was not detected by amplified bacterial rDNA restriction analysis during this study. The number of operational taxonomic units (OTUs) detected was increased with feeding of the yoghurt in all pigs. At the same time, the estimated cell number of each OTU was increased with feeding of the yoghurt. It is demonstrated that continuous consumption of the probiotic lactobacilli will stimulate the growth of some indigenous lactobacilli and alter the composition of the lactobacilli.

  13. Association between salivary level of infection with Streptococcus mutans/Lactobacilli and caries-risk factors in mothers.

    PubMed

    Latifi-Xhemajli, B; Véronneau, J; Begzati, A; Bytyci, A; Kutllovci, T; Rexhepi, A

    2016-03-01

    Understanding factors in mothers associated with high and low salivary levels of Streptococcus mutans and Lactobacilli is an important strategy for early childhood caries prevention. Aim of the study was to identify the association between salivary levels of Streptococcus mutans/Lactobacillus and potential caries risk factors in mothers. Cross-sectional design used a voluntary sample of 300 mothers of young children. Close-ended questions and observations were used to identify mothers' potential caries risk factors. The presence of Streptococcus mutans and Lactobacilli was determined using the CRT bacteria test (Ivoclar Vivadent). All collected information was converted into frequency and proportion describing the prevalence factor in correlation with Streptococcus mutans and Lactobacilli cariogenic bacteria levels of infection. Results Sample participants showed a high caries risk based on socioeconomic, behavioural and clinical factors. also showed high levels (>105) of Streptococcus mutans and Lactobacilli infections among 28% of mothers. Three factors were significantly associated with Streptococcus mutans infection: level of education, past caries experiences, and observable dental plaque, whereas, a fourth factor, frequency of daily tooth brushing, was associated to Lactobacilli infection. This study showed that easily collectible informations such as maternal level of education, frequency of daily tooth brushing and past clinical factors tend to be associated with high level of Streptococcus mutans and Lactobacilli infections in caregivers.

  14. Extensive intra-phylotype diversity in lactobacilli and bifidobacteria from the honeybee gut.

    PubMed

    Ellegaard, Kirsten M; Tamarit, Daniel; Javelind, Emelie; Olofsson, Tobias C; Andersson, Siv G E; Vásquez, Alejandra

    2015-04-11

    In the honeybee Apis mellifera, the bacterial gut community is consistently colonized by eight distinct phylotypes of bacteria. Managed bee colonies are of considerable economic interest and it is therefore important to elucidate the diversity and role of this microbiota in the honeybee. In this study, we have sequenced the genomes of eleven strains of lactobacilli and bifidobacteria isolated from the honey crop of the honeybee A. mellifera. Single gene phylogenies confirmed that the isolated strains represent the diversity of lactobacilli and bifidobacteria in the gut, as previously identified by 16S rRNA gene sequencing. Core genome phylogenies of the lactobacilli and bifidobacteria further indicated extensive divergence between strains classified as the same phylotype. Phylotype-specific protein families included unique surface proteins. Within phylotypes, we found a remarkably high level of gene content diversity. Carbohydrate metabolism and transport functions contributed up to 45% of the accessory genes, with some genomes having a higher content of genes encoding phosphotransferase systems for the uptake of carbohydrates than any previously sequenced genome. These genes were often located in highly variable genomic segments that also contained genes for enzymes involved in the degradation and modification of sugar residues. Strain-specific gene clusters for the biosynthesis of exopolysaccharides were identified in two phylotypes. The dynamics of these segments contrasted with low recombination frequencies and conserved gene order structures for the core genes. Hits for CRISPR spacers were almost exclusively found within phylotypes, suggesting that the phylotypes are associated with distinct phage populations. The honeybee gut microbiota has been described as consisting of a modest number of phylotypes; however, the genomes sequenced in the current study demonstrated a very high level of gene content diversity within all three described phylotypes of

  15. Lactobacilli and Bifidobacteria in Human Breast Milk: Influence of Antibiotherapy and Other Host and Clinical Factors

    PubMed Central

    Soto, Ana; Martín, Virginia; Jiménez, Esther; Mader, Isabelle; Rodríguez, Juan M.; Fernández, Leonides

    2014-01-01

    ABSTRACT Objective: The objective of this work was to study the lactobacilli and bifidobacteria population in human milk of healthy women, and to investigate the influence that several factors (including antibioteraphy during pregnancy and lactation, country and date of birth, delivery mode, or infant age) may exert on such population. Methods: A total of 160 women living in Germany or Austria provided the breast milk samples. Initially, 66 samples were randomly selected and cultured on MRS-Cys agar plates. Then, the presence of DNA from the genera Lactobacillus and Bifidobacterium, and from most of the Lactobacillus and Bifidobacterium species that were isolated, was assessed by qualitative polymerase chain reaction (PCR) using genus- and species-specific primers. Results: Lactobacilli and bifidobacteria could be isolated from the milk of 27 (40.91%) and 7 (10.61%), respectively, of the 66 cultured samples. On the contrary, Lactobacillus and Bifidobacterium sequences were detected by PCR in 108 (67.50%) and 41 (25.62%), respectively, of the 160 samples analyzed. The Lactobacillus species most frequently isolated and detected was L salivarius (35.00%), followed by L fermentum (25.00%) and L gasseri (21.88%), whereas B breve (13.75%) was the bifidobacterial species most commonly recovered and whose DNA was most regularly found. The number of lactobacilli- or bifidobacteria-positive samples was significantly lower in women who had received antibiotherapy during pregnancy or lactation. Conclusions: Our results suggest that either the presence of lactobacilli and/or bifidobacteria or their DNA may constitute good markers of a healthy human milk microbiota that has not been altered by the use of antibiotics. PMID:24590211

  16. Impact of consumption of probiotic lactobacilli-containing yogurt on microbial composition in human feces.

    PubMed

    Uyeno, Yutaka; Sekiguchi, Yuji; Kamagata, Yoichi

    2008-02-29

    An in vivo study was carried out to determine the effect of consuming probiotic lactobacilli-containing yogurt on the composition of microbiota in the human gut. Fifteen healthy adults ingested a daily serving of one of three commercial yogurts (two of the products contained a probiotic lactobacilli strain) for 20 days. Fecal samples at defined time points before, during, and after the period of yogurt ingestion were collected and analyzed. The fecal population of lactobacilli was determined by a culture-based method and subsequent colony PCR for the identification of species. Six predominant bacterial groups in the fecal samples were quantitatively determined based on a sequence-specific SSU rRNA cleavage method coupled with a suite of oligonucleotide probes, which was optimized for the target-specific detection of bacterial groups inhabiting human feces. In the ingestion period, one probiotic strain was detected in the feces of all five subjects who consumed the yogurt containing the strain, while the other strain was detected in three of another five subjects. The population levels of the two major groups (Bacteroides and Prevotella, and the Clostridium coccoides-Eubacterium rectale group) in the fecal samples tended to change in response to the ingestion but the change did not seem to be dependent on the product-specific property of each yogurt. These results suggest that the human fecal bacterial community could be altered by ingesting yogurt, although whether probiotic lactobacilli are present or absent in the yogurt does not seem to be a factor in this change.

  17. Vaginal pH and Microbicidal Lactic Acid When Lactobacilli Dominate the Microbiota

    PubMed Central

    O’Hanlon, Deirdre E.; Moench, Thomas R.; Cone, Richard A.

    2013-01-01

    Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid. PMID:24223212

  18. Effects of a lactobacilli, oligosaccharide and organic germanium intake on the immune responses of mice.

    PubMed

    Nakamura, Takashi; Saito, Miki; Aso, Hisashi

    2012-01-01

    The organic germanium compound, Ge-132, has immune-modulating effects. We evaluated the symbiotic effects of Ge-132 with lactobacilli and oligosaccharide (LB/OS) on the immune responses of mice. The highest fecal IgA levels were observed in the mice receiving a low concentration of Ge-132 with LB/OS for 8 weeks. Our data suggest that LB/OS with a low concentration of Ge-132 stimulated the intestinal immunity.

  19. Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota.

    PubMed

    O'Hanlon, Deirdre E; Moench, Thomas R; Cone, Richard A

    2013-01-01

    Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.

  20. Lactobacilli Activate Human Dendritic Cells that Skew T Cells Toward T Helper 1 Polarization

    DTIC Science & Technology

    2005-01-06

    symbiotic bacteria to perform their critical functions in host nutrition, intestinal permeability, and protection against foreign, pathogenic microbes...memory T cells to Th1 responses, which are proinflammatory and lead to robust im- munity against infections and other diseases (27). Interestingly, IL-12...as safe when ad- ministered as probiotics . Because DCs can naturally or therapeu- tically encounter lactobacilli, we investigated the effects of

  1. Headspace flavour compounds produced by yeasts and lactobacilli during fermentation of preferments and bread doughs.

    PubMed

    Torner, M J; Martínez-Anaya, M A; Antuña, B; Benedito de Barber, C

    1992-01-01

    Production of volatile flavour compounds during fermentation with pure cultures of Saccharomyces cerevisiae and Candida guilliermondii, Lactobacillus brevis and Lactobacillus plantarum have been investigated, using wheat doughs and several preferements as substrates. For yeast, preferments consisted of 10% (w/v) glucose, maltose and sucrose solutions, whereas for lactobacilli they consisted of supplemented and unsupplemented (3% and 10% (w/v)) glucose solutions, and a 10% (w/v) wheat flour slurry. Seven volatile compounds (acetaldehyde, acetone, ethyl acetate, ethanol, hexanal+isobutyl alcohol, and propanol) were detected when using yeasts. All these compounds, except propanol, appeared for all the substrates assayed, with ethanol as the predominant component. Generally, S. cerevisiae produced higher amounts of the different components than C. guilliermondii. Both yeasts produced larger amounts of volatile flavour compounds during fermentation in glucose and sucrose solutions than in maltose or wheat dough. In general the yeasts examined produced more flavour components than the lactobacilli. For the lactobacilli the highest number of volatile flavour compounds were observed for substrates containing flour.

  2. Use of cheese whey for biomass production and spray drying of probiotic lactobacilli.

    PubMed

    Lavari, Luisina; Páez, Roxana; Cuatrin, Alejandra; Reinheimer, Jorge; Vinderola, Gabriel

    2014-08-01

    The double use of cheese whey (culture medium and thermoprotectant for spray drying of lactobacilli) was explored in this study for adding value to this wastewater. In-house formulated broth (similar to MRS) and dairy media (cheese and ricotta whey and whey permeate) were assessed for their capacity to produce biomass of Lactobacillus paracasei JP1, Lb. rhamnosus 64 and Lb. gasseri 37. Simultaneously, spray drying of cheese whey-starch solution (without lactobacilli cells) was optimised using surface response methodology. Cell suspensions of the lactobacilli, produced in in house-formulated broth, were spray-dried in cheese whey-starch solution and viability monitored throughout the storage of powders for 2 months. Lb. rhamnosus 64 was able to grow satisfactorily in at least two of the in-house formulated culture media and in the dairy media assessed. It also performed well in spray drying. The performance of the other strains was less satisfactory. The growth capacity, the resistance to spray drying in cheese whey-starch solution and the negligible lost in viability during the storage (2 months), makes Lb. rhamnosus 64 a promising candidate for further technological studies for developing a probiotic dehydrated culture for foods, utilising wastewaters of the dairy industry (as growth substrate and protectant) and spray drying (a low-cost widely-available technology).

  3. Characterization of tetracycline resistance lactobacilli isolated from swine intestines at western area of Taiwan.

    PubMed

    Chang, Yi-Chih; Tsai, Chen-Yen; Lin, Chuen-Fu; Wang, Yu-Chih; Wang, I-Kuan; Chung, Tung-Ching

    2011-10-01

    To investigate the frequency of tetracycline resistance (Tet-R) lactobacilli in pig intestines, a total of 256 pig colons were analyzed and found to contain typical colonies of Tet-R lactic acid bacteria in every sample, ranging from 3.2 × 10(3) to 6.6 × 10(5) CFU/cm(2). From these samples, a total of 159 isolates of Tet-R lactobacilli were obtained and identified as belonging to 11 species, including Lactobacillus reuteri, Lactobacillus amylovorus, Lactobacillus salivarius, Lactobacillus plantarum, Lactobacillus ruminis, Lactobacillus kefiri, Lactobacillus fermentum, Lactobacillus sakei, Lactobacillus coryniformis, Lactobacillus parabuchneri and Lactobacillus letivazi. Based on the EFSA (2008) breakpoints, all isolates, after MIC analysis, were qualified as Tet-R, from which the significant high Tet-R MIC(50) and MIC(90) values indicated an ecological distribution of Tet-R lactobacilli mostly with high resistance potency in pig colons. PCR-detection identified 5 tet genes in these isolates, the most predominant one being tet (W), followed by tet (M), (L), (K), and (Q). Their detection rates were 82.0%, 22.5%, 14.4%, 8.1% and 0.9%, respectively. Noteworthily, isolates of the same species carrying identical tet gene(s) usually had a wide different MIC values. Furthermore, strain-subtyping of these isolates by REP-PCR demonstrated a notable genotypic biodiversity % (average = 62%).

  4. Not only osmoprotectant: betaine increased lactate dehydrogenase activity and L-lactate production in lactobacilli.

    PubMed

    Zou, Huibin; Wu, Zaiqiang; Xian, Mo; Liu, Hui; Cheng, Tao; Cao, Yujin

    2013-11-01

    Lactobacilli are commonly used for industrial production of polymer-grade L-lactic acid. The present study tested the Tween 80 alternative betaine in L-lactate production by several industrial lactobacilli. In flask fermentation of Lactobacillus casei, Lactobacillus buchneri, Lactobacillus lactis and Lactobacillus rhamnosus, the betaine addition (2g/l) had similar osmoprotectant effect with Tween 80 but had increased the lactate dehydrogenase activities and L-lactate production than Tween 80 control. In fed-batch fermentation of L. casei, betaine supplementation improved the L-lactic acid titer to 190 g/l, the yield to 95.5% (g L-lactic acid/g glucose), the productivity to 2.6g/lh, and the optical purity to 97.0%. The results demonstrated that supplementation of Tween 80 alternative - betaine in the fermentation medium is feasible for industrial l-lactic acid fermentation by lactobacilli, which will improve the lactate production but will not increase the process costs and modify any process conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Enhanced growth of lactobacilli and bioconversion of isoflavones in biotin-supplemented soymilk upon ultrasound-treatment.

    PubMed

    Ewe, Joo-Ann; Wan Abdullah, Wan-Nadiah; Bhat, Rajeev; Karim, A A; Liong, Min-Tze

    2012-01-01

    This study aimed at utilizing ultrasound treatment to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli (Lactobacillus acidophilus BT 1088, L. fermentum BT 8219, L. acidophilus FTDC 8633, L. gasseri FTDC 8131) were treated with ultrasound (30 kHz, 100 W) at different amplitudes (20%, 60% and 100%) for 60, 120 and 180 s prior to inoculation and fermentation in biotin-soymilk. The treatment affected the fatty acids chain of the cellular membrane lipid bilayer, as shown by an increased lipid peroxidation (P<0.05). This led to increased membrane fluidity and subsequently, membrane permeability (P<0.05). The permeabilized cellular membranes had facilitated nutrient internalization and subsequent growth enhancement (P<0.05). Higher amplitudes and longer durations of the treatment promoted growth of lactobacilli in soymilk, with viable counts exceeding 9 log CFU/mL. The intracellular and extracellular β-glucosidase specific activities of lactobacilli were also enhanced (P<0.05) upon ultrasound treatment, leading to increased bioconversion of isoflavones in soymilk, particularly genistin and malonyl genistin to genistein. Results from this study show that ultrasound treatment on lactobacilli cells promotes (P<0.05) the β-glucosidase activity of cells for the benefit of enhanced (P<0.05) isoflavone glucosides bioconversion to bioactive aglycones in soymilk. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Isolation, molecular characterization and screening of indigenous lactobacilli for their abilities to produce bioactive conjugated linoleic acid (CLA).

    PubMed

    Dahiya, Dinesh Kumar; Puniya, Anil Kumar

    2017-03-01

    Ingestion of conjugated linoleic acid poised many health benefits; however, amount of CLA one can get through generalized diet in is inadequate in exerting the desired benefits. Therefore, presence of CLA producing lactobacilli in dairy fermented foods has a tremendous potential to increase the CLA content. Therefore, present study was focused to isolate and characterize CLA producing lactobacilli from different dairy products and human faeces. Arguably, 283 lactobacilli were isolated from various sources and tested for CLA production. Fifty-seven CLA producing (≥20 µg/ml) lactobacilli were selected from screening in de Man, Rogosa and Sharpe (MRS) broth and reconstituted with skim milk (SM), supplemented with 0.5 mg/ml of linoleic acid. Positive strains were classified into-L. plantarum (44%), L. gasseri (30%), L. fermentum (21%) and L. salivarius (5%) species. Nineteen most efficient strains (CLA ≥25 µg/ml) were further assessed in SM for CLA production. Total 08 strains produced significantly higher CLA in SM than MRS and also produced cis 9, trans 11, trans 10, cis 12 and trans 9, trans 11 isomers. Overall, L. plantarum HIF15 was reported as the best producer of CLA and other 08 lactobacilli may be utilized for the formulation of CLA-enriched functional foods to support these bacteria to synthesize CLA in the human gut.

  7. pH gradient and distribution of streptococci, lactobacilli, prevotellae, and fusobacteria in carious dentine

    PubMed Central

    Nguyen, Ky-Anh T.; Browne, Gina V.; Simonian, Mary; Hunter, Neil

    2013-01-01

    Objectives Caries process comprises acidogenic and aciduric bacteria that are responsible for lowering the pH and subsequent destruction of hydroxyapatite matrix in enamel and dentine. The aim of this study was to identify the correlation between the pH gradient of a carious lesion and proportion and distribution of four bacterial genera; lactobacilli, streptococci, prevotellae, and fusobacteria with regard to total load of bacteria. Materials and methods A total of 25 teeth with extensive dentinal caries were sampled in sequential layers. Using quantitative real-time PCR of 16S rRNA gene, we quantified the total load of bacteria as well as the proportion of the abovementioned genera following pH measurement of each sample with a fine microelectrode. Results We demonstrated the presence of a pH gradient across the lesion with a strong association between the quantity of lactobacilli and the lowest pH range (pH 4.5–5.0; p = 0.003). Streptococci had a tendency to occupy the most superficial aspect of the carious lesion but showed no correlation to any pH value. Prevotellae showed clear preference for the pH range 5.5–6.0 (p = 0.042). The total representation of these four genera did not reach more than one quarter of the total bacterial load in most carious samples. Conclusion We revealed differential colonization behavior of bacteria with respect to pH gradient and a lower than expected abundance of lactobacilli and streptococci in established carious lesions. The data indicate the numerical importance of relatively unexplored taxa within the lesion of dentinal caries. Clinical relevance The gradient nature of pH in the lesion as well as colonization difference of examined bacterial taxa with reference to pH provides a new insight in regard to conservative caries management. PMID:23771212

  8. pH gradient and distribution of streptococci, lactobacilli, prevotellae, and fusobacteria in carious dentine.

    PubMed

    Kianoush, Nima; Nguyen, Ky-Anh T; Browne, Gina V; Simonian, Mary; Hunter, Neil

    2014-01-01

    Caries process comprises acidogenic and aciduric bacteria that are responsible for lowering the pH and subsequent destruction of hydroxyapatite matrix in enamel and dentine. The aim of this study was to identify the correlation between the pH gradient of a carious lesion and proportion and distribution of four bacterial genera; lactobacilli, streptococci, prevotellae, and fusobacteria with regard to total load of bacteria. A total of 25 teeth with extensive dentinal caries were sampled in sequential layers. Using quantitative real-time PCR of 16S rRNA gene, we quantified the total load of bacteria as well as the proportion of the above-mentioned genera following pH measurement of each sample with a fine microelectrode. We demonstrated the presence of a pH gradient across the lesion with a strong association between the quantity of lactobacilli and the lowest pH range (pH 4.5-5.0; p = 0.003). Streptococci had a tendency to occupy the most superficial aspect of the carious lesion but showed no correlation to any pH value. Prevotellae showed clear preference for the pH range 5.5-6.0 (p = 0.042). The total representation of these four genera did not reach more than one quarter of the total bacterial load in most carious samples. We revealed differential colonization behavior of bacteria with respect to pH gradient and a lower than expected abundance of lactobacilli and streptococci in established carious lesions. The data indicate the numerical importance of relatively unexplored taxa within the lesion of dentinal caries. The gradient nature of pH in the lesion as well as colonization difference of examined bacterial taxa with reference to pH provides a new insight in regard to conservative caries management.

  9. Dynamics and rRNA transcriptional activity of lactococci and lactobacilli during Cheddar cheese ripening.

    PubMed

    Desfossés-Foucault, Émilie; LaPointe, Gisèle; Roy, Denis

    2013-08-16

    Cheddar cheese is a complex ecosystem where both the bacterial population and the cheese making process contribute to flavor and texture development. The aim of this study was to use molecular methods to evaluate the impact of milk heat treatment and ripening temperature on starter lactococci and non-starter lactic acid bacteria (NSLAB) throughout ripening of Cheddar cheese. Eight Cheddar cheese batches were manufactured (four with thermized and four with pasteurized milk) and ripened at 4, 7 and 12°C to analyze the bacterial composition and rRNA transcriptional activity reflecting the ability of lactococci and lactobacilli to synthesize proteins. Abundance and rRNA transcription of lactococci and lactobacilli were quantified after DNA and RNA extraction by using quantitative PCR (qPCR) and reverse transcription-quantitative PCR (RT-qPCR) targeting the 16S rRNA gene, respectively. Results showed that lactococci remained dominant throughout ripening, although 16S rRNA genome and cDNA copies/g of cheese decreased by four and two log copy numbers, respectively. Abundance and rRNA transcription of Lactobacillus paracasei, Lactobacillus buchneri/parabuchneri, Lactobacillus rhamnosus, Lactobacillus brevis, and Lactobacillus coryniformis as well as total lactobacilli were also estimated using specific 16S rRNA primers. L. paracasei and L. buchneri/parabuchneri concomitantly grew in cheese made from thermized milk at 7 and 12°C, although L. paracasei displayed the most rRNA transcription among Lactobacillus species. This work showed that rRNA transcriptional activity of lactococci decreased throughout ripening and supports the usefulness of RNA analysis to assess which bacterial species have the ability to synthesize proteins during ripening, and could thereby contribute to cheese quality. © 2013.

  10. Effect of enhanced proteolysis on formation of biogenic amines by lactobacilli during Gouda cheese ripening.

    PubMed

    Leuschner, R G; Kurihara, R; Hammes, W P

    1998-10-20

    The effect of enhanced proteolysis on amine formation by amino acid decarboxylase positive Lactobacillus sp. during Gouda cheese ripening was examined. A commercial proteolytic enzyme preparation was added to pasteurized milk prior to cheese preparation. The effect of this manipulation on the formation of putrescine, histamine and tyramine was investigated in the presence and absence of amino acid decarboxylase-positive strains during a 12-week ripening period. Four batches were supplemented with a proteolytic enzyme. Batch I contained the proteolytic enzyme only, whereas batches II-IV were additionally supplemented with Lactobacillus delbrueckii LTH 1260 (batch II), Lactobacillus buchneri LTH 1388 (batch III) or Lactobacillus brevis LTH 2560 (batch IV). In batch I putrescine was detected with 4 mg/kg, in batch II, 42 mg/kg putrescine, 238 mg/kg histamine and 636 mg/kg tyramine were found. Batch III contained 13 mg/kg putrescine and 418 mg/kg histamine, whereas in batch IV, 26 mg/kg putrescine and 776 mg/kg tyramine were present. Batch V was supplemented with all three lactobacilli but did not contain the proteolytic enzyme. In this experiment, 4 mg/kg putrescine, 179 mg/kg histamine and 337 mg/kg tyramine were detected. A control cheese batch (VI) without addition of amine forming lactobacilli or a proteolytic enzyme was produced and only 4 mg/kg putrescine were detected. An increase in amine concentration during cheese ripening under conditions of enhanced proteolysis in the presence of starter and spoilage lactobacilli was evident from the experiments.

  11. Determination of Antibacterial and Technological Properties of Vaginal Lactobacilli for Their Potential Application in Dairy Products

    PubMed Central

    Siroli, Lorenzo; Patrignani, Francesca; Serrazanetti, Diana I.; Parolin, Carola; Ñahui Palomino, Rogers A.; Vitali, Beatrice; Lanciotti, Rosalba

    2017-01-01

    Functional foods could differently affect human health in relation to the gender. Recent studies have highlighted the anti-Candida and anti-Chlamydia activities of some Lactobacillus strains isolated from the vagina of healthy women. Considering these important beneficial activities on women's health, the preparation of functional food containing active vaginal lactobacilli can represent a great scientific challenge for the female gender. In this context, the aim of this work was to study some functional and technological properties of 17 vaginal strains belonging to the species Lactobacillus crispatus, Lactobacillus gasseri, and Lactobacillus vaginalis in the perspective to include them in dairy products. The antagonistic activities against the pathogenic and spoilage species associated to food products and against the principal etiological agents of the genitourinary tract infections were evaluated. Moreover, the vaginal lactobacilli were characterized for their antibiotic resistance, and for their fermentation kinetics and viability during the refrigerated storage in milk. Finally, the volatile molecule profiles of the obtained fermented milks were determined. The results showed that several strains, mainly belonging to the species Lactobacillus crispatus, exhibited a significant antagonistic activity against spoilage and pathogenic microorganisms of food interest, as well as against urogenital pathogens. All the vaginal lactobacilli showed antimicrobial activity against strains belonging to the foodborne pathogenic species Listeria monocytogenes, Listeria innocua, Eenterococcus faecalis and Escherichia coli. In addition, most of the Lactobacillus strains were active toward the main pathogens responsible of vaginal and urinary tract infections including Staphylococcus aureus, Enterococcus faecium, Gardnerella vaginalis, and Proteus mirabilis. The antimicrobial activity can be attributed to the high production of organic acids. The fermentation kinetics in milk

  12. Characterizing Diversity of Lactobacilli Associated with Severe Early Childhood Caries: A Study Protocol.

    PubMed

    Li, Yihong; Argimón, Silvia; Schön, Catherine N; Saraithong, Prakaimuk; Caufield, Page W

    2015-01-01

    Lactobacilli have been consistently associated with dental caries for decades; however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on socio-demographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children's medical history, and a questionnaire survey. Combined non-stimulated saliva and supra-gingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, extraction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species

  13. Characterizing Diversity of Lactobacilli Associated with Severe Early Childhood Caries: A Study Protocol

    PubMed Central

    Argimón, Silvia; Schön, Catherine N.; Saraithong, Prakaimuk; Caufield, Page W.

    2015-01-01

    Lactobacilli have been consistently associated with dental caries for decades; however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on socio-demographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children’s medical history, and a questionnaire survey. Combined non-stimulated saliva and supra-gingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, extraction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species

  14. Lactobacilli, bifidobacteria and E. coli nissle induce pro- and anti-inflammatory cytokines in peripheral blood mononuclear cells

    PubMed Central

    Helwig, Ulf; Lammers, Karen M; Rizzello, Fernando; Brigidi, Patricia; Rohleder, Verena; Caramelli, Elisabetta; Gionchetti, Paolo; Schrezenmeir, Juergen; Foelsch, Ulrich R; Schreiber, Stefan; Campieri, Massimo

    2006-01-01

    AIM: To investigate whether the stimulation of peripheral blood mononuclear cells (PBMNC) with the cell debris and cell extraction of different probiotic strains is similar or species specific. METHODS: Three strains of bifidobacteria, 4 strains of lactobacilli, and E. coli nissle were sonicated and centrifuged in order to divide them into cell extract and cell debris. PBMNC were separated by density gradient and incubated for 36 h with either the cell debris or the cell extract of single strains of probiotic bacteria in doses from 102 to 108 CFU/mL. Cell supernatants were taken and interleukin (IL)-10, IL-1β, and tumor necosis factor (TNF)-α were determined by ELISA. RESULTS: Depending on the species super-family, the strains had different stimulation patterns. Except for both L. casei strains, the cell extract of bifidobacteria and lactobacilli had less stimulating capacity than cell debris, whereas the cell extract of E. coli nissle had similar stimulating properties to that of the cell debris of the strain and significantly more stimulating capacity than that of bifidobacteria and lactobacilli. The cell debris of bifidobacteria stimulated more cytokine release than the cell debris of lactobacilli. The cell debris of lactobacilli did not have a stimulating capacity when lower concentrations were used. Neither cell extraction nor cell debris had an inhibitory effect on the production of the tested cytokines by stimulated PBMNC. CONCLUSION: The incubation of probiotic strains, which have been used in clinical trials for inflammatory diseases, with immunocompetent cells leads to different species specific reactions. High IL-10 response to cell debris of bifidobacteria and E. coli nissle can be found. This corresponds to positive effects of bifidobacteria and E. coli nissle in clinical trials for inflammatory bowel disease compared to negative outcomes obtained with lactobacilli. PMID:17009396

  15. [Comparative study of effects of Escherichia coli M-17 exometabolites and fructooligosaccharides on the growth and antagonistic activity of Lactobacilli].

    PubMed

    Vakkhitov, T Ia; Dobrolezh, O V; Petrov, L N; Verbitskaia, N B; Zadaura, E Iu

    2001-01-01

    Facts concerning the evaluation of the influence of E. coli M17 exometabolites and fructooligosaccharides (FOS) on the growth and antagonistic activity of lactobacilli are presented. As revealed by these facts, preparation "Aktoflor" accelerates the growth of lactobacillary cultures, increases the final yield of biomass and antagonistic activity. E. coli M17 exometabolites contained in "Aktoflor" have been shown to be more active in comparison with FOS. The character of their influence on lactobacilli is discussed and the conclusion is made that the restoration and maintenance of eubiosis is greatly determined by the pool of metabolites excreted by the bacteria.

  16. Sequential fermentation of pearl millet by yeasts and lactobacilli--effect on the antinutrients and in vitro digestibility.

    PubMed

    Khetarpaul, N; Chauhan, B M

    1991-10-01

    Sequential culture fermentation by yeasts (S. diastaticus or S. cerevisiae) at 30 degrees C for 72 hr and then followed by lactobacilli fermentation (L. brevis or L. fermentum) at 30 degrees C for 72 h more resulted in a significant reduction in phytic acid and polyphenol content of pearl millet flour. Fermentation by S. diastaticus and L. brevis combination almost eliminated phytic acid from pearl millet flour. The combinations of S. diastaticus with both the lactobacilli reduced phytic acid more effectively than those of S. cerevisiae. The products fermented by S. cerevisiae and L. brevis and by S. diastaticus and L. brevis combinations had the highest protein and starch digestibility (in vitro).

  17. Utilisation of steviol glycosides from Stevia rebaudiana (Bertoni) by lactobacilli and bifidobacteria in in vitro conditions.

    PubMed

    Kunová, Gabriela; Rada, Vojtěch; Vidaillac, Adrien; Lisova, Ivana

    2014-05-01

    In the current study, eight strains of bifidobacteria and seven strains of lactobacilli were tested for their ability to grow in the presence of rebaudioside A and steviol glycosides from the sweetener Natusweet M001 originating from herb Stevia rebaudiana (Bertoni). Stevia is gaining popularity as a natural, non-caloric sugar substitute, and recently, it was allowed as a food additive by European Union too. Utilisation of steviol glycosides by intestinal microbiota suggests that they might have potential prebiotic effect. Based on the evaluation of bacterial density and pH values in our in vitro study, it was found that lactobacilli and bifidobacteria tested were able to utilise steviol glycosides as a carbon source only to a very limited extent. All strains tested showed significantly lower change in the absorbance A540 (P < 0.05) and pH decrease of the growth media as compared with the positive controls (medium containing glucose as a carbon source and de Man Rogosa Sharpe broth). We concluded that a suggested prebiotic effect was not confirmed either in the case of rebaudioside A or in the case of the sweetener Natusweet M001 containing a mixture of steviol glycosides.

  18. Levansucrase and sucrose phoshorylase contribute to raffinose, stachyose, and verbascose metabolism by lactobacilli.

    PubMed

    Teixeira, Januana S; McNeill, Victoria; Gänzle, Michael G

    2012-09-01

    Raffinose family oligosaccharides (RFOs) in food are considered anti-nutritional factors. This study elucidated the role of α-galactosidase (α-Gal), levansucrase, and sucrose phosphorylase for conversion of RFOs by lactobacilli. Quantification of gene expression by reverse-transcriptase quantitative PCR revealed that expression of levansucrase and sucrose phosphorylase by Lactobacillus reuteri is increased more than 100 fold when sucrose or raffinose are available. Fava bean (Vicia faba) or field pea (Pisum sativum) flours were fermented with α-Gal positive L. reuteri or α-Gal negative Lactobacillus sanfranciscensis. Isogenic strains lacking levansucrase activity, a L. reuteri ftfA mutant and a L. sanfranciscensis levS mutant, were used for comparison. During growth in pulse flours, L. sanfranciscensis accumulated melibiose and α-galactooligosaccharides (α-GOSs); the levansucrase-negative strain did not grow. L. reuteri metabolized raffinose, stachyose, and verbascose by levansucrase activity and accumulated α-GOSs as metabolic intermediates. Oligosaccharide metabolism in the levansucrase-negative mutant was slower, and accumulation of α-GOSs was not observed. The use of sorghum sourdough fermented with L. reuteri LTH5448 and bean flour in gluten-free baking converted RFOs to α-GOSs by levansucrase and invertase activities. In conclusion, the elucidation of the role levansucrase in RFO metabolism by lactobacilli allowed the conversion or hydrolysis of RFOs in food fermentations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Characterization and stability of lactobacilli and yeast microbiota in kefir grains.

    PubMed

    Vardjan, T; Mohar Lorbeg, P; Rogelj, I; Čanžek Majhenič, A

    2013-05-01

    Characterization and stability of lactobacilli and yeasts from kefir grains using culture-dependent and culture-independent methods were investigated in this study. Culture-dependent analysis, followed by sequencing of 16S ribosomal DNA for bacteria and 26S rRNA gene for yeasts, revealed 3 different species of lactobacilli and yeasts, respectively. The most frequently isolated bacterial species were Lactobacillus kefiranofaciens ssp. kefirgranum, Lb. parakefiri, and Lb. kefiri, whereas yeasts belonged to Kluyveromyces marxianus, Kazachstania exigua, and Rhodosporidium kratochvilovae. This study is the first to report on the presence of R. kratochvilovae in kefir grains. On the other hand, PCR-denaturing gradient gel electrophoresis in the culture-independent method showed that the dominant microorganisms were Lb. kefiranofaciens ssp. kefirgranum, Kl. marxianus and Ka. exigua, but did not reveal bands corresponding to Lb. parakefiri, Lb. kefiri, or R. kratochvilovae. Our results support the necessity of combining more techniques for detailed and reliable study of microbial communities in kefir grains. Another interesting finding confirmed that the detected dominant microbiota of kefir grains is very stable and did not change over experimental time. This finding is important to ensure consistent product quality. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Suppression of salivary Streptococcus mutans and lactobacilli by topical caries preventive agents.

    PubMed

    Juric, H; Dukic, W; Jankovic, B; Karlovic, Z; Pavelic, B

    2003-12-01

    Reduction of cariogenic bacteria, especially salivary Streptococcus mutans and lactobacilli is a valuable clinical procedure that in many ways alleviates implementation of targeted caries preventive procedures in the entire population. The aim of this study was to investigate the caries preventive values of certain preventive procedures in in vivo conditions. Four groups of subjects, each with 18 children aged from 4-5 and 10-12 years (n = 72) were treated with different caries preventive agent (aminfluoride solution, Proxyt paste, chewing gum containing xylitol and fluoride and chlorhexidine solution). During a period of two months five control measurements for number of salivary Streptococcus mutans (SM) and lactobacilli (LB) were performed. At the end of the study the best result in the reduction of the bacteria was achieved by the application of Proxyt paste and daily use of chewing gum (p < 0.001). In patients treated with this preventive procedure the number of SM was reduced by 1 class and LB to < 10(4) CFU/ml saliva after two months of study. The results obtained indicate that professional teeth cleaning and use of chewing gum with xylitol and fluorides on daily basis can be very effective protocol for cariogenic bacteria reduction and in the individual caries prevention.

  1. Diversity and dynamics of lactobacilli populations during ripening of RDO Camembert cheese.

    PubMed

    Henri-Dubernet, Ségolène; Desmasures, Nathalie; Guéguen, Micheline

    2008-03-01

    The diversity and dynamics of Lactobacillus populations in traditional raw milk Camembert cheese were monitored throughout the manufacturing process in 3 dairies. Culture-dependent analysis was carried out on isolates grown on acidified de Man - Rogosa - Sharpe agar and Lactobacillus anaerobic de Man Rogosa Sharpe agar supplemented with vancomycin and bromocresol green media. The isolates were identified by polymerase chain reaction - temperature gradient gel electrophoresis (PCR-TGGE) and (or) species-specific PCR and (or) sequencing, and Lactobacillus paracasei and Lactobacillus plantarum isolates were characterized by pulsed field gel electrophoresis (PFGE). Milk and cheese were subjected to culture-independent analysis by PCR-TGGE. Presumed lactobacilli were detected by plate counts throughout the ripening process. However, molecular analysis of total DNA and DNA of isolates failed to detect Lactobacillus spp. in certain cases. The dominant species in the 3 dairies was L. paracasei. PFGE analysis revealed 21 different profiles among 39 L. paracasei isolates. Lactobacillus plantarum was the second most isolated species, but it occurred nearly exclusively in one dairy. The other species isolated were Lactobacillus parabuchneri, Lactobacillus fermentum, Lactobacillus acidophilus, Lactobacillus helveticus, a Lactobacillus psittaci/delbrueckii subsp. bulgaricus/gallinarum/crispatus group, Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, Lactobacillus brevis, Lactobacillus kefiri, and Lactobacillus perolens. Lactobacilli diversity at the strain level was high. Dynamics varied among dairies, and each cheese exhibited a specific picture of species and strains.

  2. Human milk oligosaccharide consumption by probiotic and human-associated bifidobacteria and lactobacilli.

    PubMed

    Thongaram, Taksawan; Hoeflinger, Jennifer L; Chow, JoMay; Miller, Michael J

    2017-10-01

    Human milk contains high concentrations of nondigestible complex oligosaccharides (human milk oligosaccharides; HMO) that reach the colon and are subsequently fermented by the infant gut microbiota. Using a high-throughput, low-volume growth determination, we evaluated the ability of 12 lactobacilli and 12 bifidobacteria strains, including several commercial probiotics, to ferment HMO and their constituent monomers. Of the 24 strains tested, only Bifidobacterium longum ssp. infantis ATCC 15697 and Bifidobacterium infantis M-63 were able to ferment 3'-sialyllactose, 6'-sialyllactose, 2'-fucosyllactose, and 3'-fucosyllactose. Bifidobacterium infantis M-63 degraded almost 90% of the 2'-fucosyllactose but left most of the fucose in the supernatant, as detected by HPLC. Among bifidobacteria, only the B. infantis strains and Bifidobacterium breve ATCC 15700 were able to ferment lacto-N-neotetraose (LNnT). Among lactobacilli, Lactobacillus acidophilus NCFM was found to be the most efficient at utilizing LNnT. The extracellular β-galactosidase (lacL, LBA1467) of L. acidophilus NCFM cleaves the terminal galactose of LNnT for growth, leaving lacto-N-triose II in the media as detected by HPLC. Inactivation of lacL abolishes growth of L. acidophilus NCFM on LNnT. These results contribute to our knowledge of HMO-microbe interactions and demonstrate the potential for synbiotic combinations of pre- and probiotics. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Ureaplasma urealyticum and Mycoplasma hominis sensitivity to bacteriocins produced by two Lactobacilli strains.

    PubMed

    Daniele, M; Ruiz, F; Pascual, L; Barberis, L

    2011-10-01

    The purpose of the present study was to determine the inhibitory activities of two bacteriocins, produced by lactobacilli, against genital mycoplasmas. In this study, infections produced by genital mycoplasmas were studied; of these, 1.3% were caused by Mycoplasma hominis, 10.7% by Ureaplasma urealyticum and 5.6% by U. urealyticum + M. hominis. U. urealyticum was isolated from 75 out of 123 patients with genital mycoplasmas, while M. hominis was isolated from 9 patients (7.3%) and both U. urealyticum and M. hominis from 39 patients (31.7%). Bacteriocins, L23 and L60, produced by Lactobacillus fermentum and L. rhamnosus, respectively, appear to be two novel inhibitors of bacterial infection with potential antibacterial activity. Both bacteriocins proved to be active against 100% of strains tested; MICs of bacteriocin L23 ranged between 320 and 160 UA ml(-1) for 78% of the M. hominis strains and between 320 and 80 UA ml(-1) for 95% of the U. urealyticum strains. In addition, bacteriocin L60 was still active at 160 UA ml(-1) for a high percentage (56%) of M. hominis strains, and at 80 UA ml(-1) for 53% of the U. urealyticum strains. Interestingly, these antimicrobial substances produced by lactobacilli showed an inhibitory activity against genital mycoplasmas even when diluted. Altogether, our study indicates that the bacteriocins, L23 and L60, are good candidates for the treatment or prevention of genital infections in women.

  4. Characterization of the adherence properties of human Lactobacilli strains to be used as vaginal probiotics.

    PubMed

    Martín, Rebeca; Sánchez, Borja; Suárez, Juan Evaristo; Urdaci, María C

    2012-03-01

    In the present work, the adhesion of 43 human lactobacilli isolates to mucin has been studied. The most adherent strains were selected, and their capacities to adhere to three epithelial cell lines were studied. All intestinal strains and one vaginal isolate adhered to HT-29 cells. The latter was the most adherent to Caco-2 cells, although two of the intestinal isolates were also highly adherent. Moreover, five of the eight strains strongly adhered to HeLa cells. The binding of an Actinomyces neuii clinical isolate to HeLa cells was enhanced by two of the lactobacilli and by their secreted proteins, while those of another two strains almost abolished it. None of the strains were able to interfere with the adhesion of Candida albicans to HeLa cells. The components of the extracellular proteome of all strains were identified by MALDI-TOF/MS. Among them, a collagen-binding A precursor and aggregation-promoting factor-like proteins are suggested to participate on adhesion to Caco-2 and HeLa cells, respectively. In this way, several proteins with LysM domains might explain the ability of some bacterial supernatants to block A. neuii adhesion to HeLa cell cultures. Finally, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) could explain the good adhesion of some strains to mucin.

  5. Survival of pathogenic and lactobacilli species of fermented olives during simulated human digestion

    PubMed Central

    Arroyo-López, Francisco N.; Blanquet-Diot, Stéphanie; Denis, Sylvain; Thévenot, Jonathan; Chalancon, Sandrine; Alric, Monique; Rodríguez-Gómez, Francisco; Romero-Gil, Verónica; Jiménez-Díaz, Rufino; Garrido-Fernández, Antonio

    2014-01-01

    The present survey uses a dynamic gastric and small intestinal model to assess the survival of one pathogenic (Escherichia coli O157:H7 EDL 933) and three lactobacilli bacteria with probiotic potential (Lactobacillus rhamnosus GG, L. pentosus TOMC-LAB2, and L. pentosus TOMC-LAB4) during their passage through the human gastrointestinal tract using fermented olives as the food matrix. The data showed that the survival of the E. coli strain in the stomach and duodenum was very low, while its transit through the distal parts (jejunum and ileum) resulted in an increase in the pathogen population. The production of Shiga toxins by this enterohemorrhagic microorganism in the ileal effluents of the in vitro system was too low to be detected by ELISA assays. On the contrary, the three lactobacilli species assayed showed a considerable resistance to the gastric digestion, but not to the intestinal one, which affected their survival, and was especially evident in the case of both L. pentosus strains. In spite of this, high population levels for all assayed microorganisms were recovered at the end of the gastrointestinal passage. The results obtained in the present study show the potential use of table olives as a vehicle of beneficial microorganisms to the human body, as well as the need for good hygienic practices on the part of olive manufacturers in order to avoid the possibility of contamination by food-borne pathogens. PMID:25352842

  6. Formation of biogenic amine in mayonnaise, herring and tuna fish salad by lactobacilli.

    PubMed

    Leuschner, R G; Hammes, W P

    1999-05-01

    The effect of amino acid decarboxylase-positive lactobacilli in mayonnaise, herring and tuna fish salads on formation of biogenic amines (BA) was investigated. Commercial mayonnaise was inoculated with either of five amine-forming lactobacilli which were selected as model contaminants: Lactobacillus curvatus LTH 975 and LTH 1859 (cadaverine, putrescine, tyramine and phenylethylamine producing), L. delbrueckii LTH 1260 (tyramine and phenylethylamine forming) and L. buchneri LTH 1388 and LTH 661 (histamine forming). Low concentrations of tyramine (4.5 ppm) were detected and an addition of precursor amino acids resulted in an increase of amine concentrations to 40 ppm putrescine, 16.5 ppm tyramine and 5.5 ppm cadaverine. Herring and tuna fish salads were inoculated either with L. curvatus LTH 975 or L. Buchneri LTH 1388. In tuna fish salad 1 ppm putrescine, 3 ppm cadaverine, 7 ppm histamine and 28 ppm tyramine were found after 4 days when L. curvatus was added. In the corresponding herring salad putrescine (14 ppm), cadaverine (11.5 ppm), histamine (17 ppm) and tyramine (72 ppm) were detected. Fish salads containing L. buchneri displayed histamine concentrations of 900 ppm in tuna and 670 ppm in herring salad, respectively. Eight lactic acid bacteria and five yeasts, isolates from spoiled delicatessen salads and ingredients, were not able to form putrescine, cadaverine, histamine, tyramine or phenylethylamine.

  7. Exogenous lactobacilli mitigate microbial changes associated with grain fermentation (corn, oats, and wheat) by equine fecal microflora ex vivo

    USDA-ARS?s Scientific Manuscript database

    Cereal grains are often included in equine diets. When starch intake exceeds foregut digestion starch will reach the hindgut, impacting microbial ecology. Probiotics (e.g., lactobacilli) are reported to mitigate GI dysbioses in other species. This study was conducted to determine the effect of star...

  8. Differential targeting of the E-Cadherin/β-Catenin complex by gram-positive probiotic lactobacilli improves epithelial barrier function.

    PubMed

    Hummel, Stephanie; Veltman, Katharina; Cichon, Christoph; Sonnenborn, Ulrich; Schmidt, M Alexander

    2012-02-01

    The intestinal ecosystem is balanced by dynamic interactions between resident and incoming microbes, the gastrointestinal barrier, and the mucosal immune system. However, in the context of inflammatory bowel diseases (IBD), where the integrity of the gastrointestinal barrier is compromised, resident microbes contribute to the development and perpetuation of inflammation and disease. Probiotic bacteria have been shown to exert beneficial effects, e.g., enhancing epithelial barrier integrity. However, the mechanisms underlying these beneficial effects are only poorly understood. Here, we comparatively investigated the effects of four probiotic lactobacilli, namely, Lactobacillus acidophilus, L. fermentum, L. gasseri, and L. rhamnosus, in a T84 cell epithelial barrier model. Results of DNA microarray experiments indicating that lactobacilli modulate the regulation of genes encoding in particular adherence junction proteins such as E-cadherin and β-catenin were confirmed by quantitative reverse transcription-PCR (qRT-PCR). Furthermore, we show that epithelial barrier function is modulated by Gram-positive probiotic lactobacilli via their effect on adherence junction protein expression and complex formation. In addition, incubation with lactobacilli differentially influences the phosphorylation of adherence junction proteins and the abundance of protein kinase C (PKC) isoforms such as PKCδ that thereby positively modulates epithelial barrier function. Further insight into the underlying molecular mechanisms triggered by these probiotics might also foster the development of novel strategies for the treatment of gastrointestinal diseases (e.g., IBD).

  9. Yeast fermentation affected by homo- and hetero-fermentative Lactobacilli isolated from fuel ethanol distilleries with sugarcane products as substrates

    USDA-ARS?s Scientific Manuscript database

    The antagonism between by yeast and lactobacilli is largely dependent on the initial population of each organism. While homo-fermentative lactobacillus present higher inhibitory effect upon yeast when in equal cell number, in industrial fuel ethanol conditions where high yeast cell densities prevail...

  10. Effect of storage time and temperature of equine feces on the subsequent enumeration of lactobacilli and cellulolytic bacteria

    USDA-ARS?s Scientific Manuscript database

    Cellulolytic bacteria and lactobacilli are beneficial microbes in the equine hindgut. There are several existing methodologies for the enumeration of these bacteria, which vary based on selective and differential media and sample handling procedures including storage time and temperature. The object...

  11. Effect of Pomegranate Juice on Dental Plaque Microorganisms (Streptococci and Lactobacilli)

    PubMed Central

    Kote, Sowmya; Kote, Sunder; Nagesh, Lakshminarayan

    2011-01-01

    To study the effect of pomegranate juice on dental plaque microorganisms. A clinical trial was conducted on thirty healthy volunteers aged 25-30 years who visited Out Patient Department (OPD) of Bapuji Dental College and Hospital, Davangere during the month of October 2006. Before conducting the study, thorough oral prophylaxis was done and the subjects were asked to refrain from the oral hygiene procedures for 24 hrs. Dental plaque was collected from each subject, before and after rinsing 30ml of pomegranate juice without sugar. Plaque samples were cultured using Mitis Salivarius Agar and Rogosa SL Agar media. Wilcoxon's signed rank test was used for statistical analysis. Results showed that pomegranate rinse was effective against dental plaque microorganisms. There was a significant reduction in the number of colony forming units of streptococci (23%) and lactobacilli (46%). The ruby red seeds may be a possible alternative for the treatment of dental plaque bacteria. PMID:23284205

  12. Identification and evaluation of the probiotic potential of lactobacilli isolated from canine milk.

    PubMed

    Martín, Rocío; Olivares, Mónica; Pérez, Manuela; Xaus, Jordi; Torre, Celina; Fernández, Leonides; Rodríguez, Juan M

    2010-08-01

    Canine milk protects puppies against infectious diseases through a variety of mechanisms. In this study, the presence of potentially probiotic lactic acid bacteria grown on MRS-Cys agar plates from milk of nine bitches was investigated. The Gram positive catalase negative bacilli identified in this study belonged to four Lactobacillus species (Lactobacillus reuteri, Lactobacillus fermentum, Lactobacillus murinus, Lactobacillus animalis), as well as one isolate that was identified as Weissella viridescens. Random amplified polymorphic DNA profiling revealed 28 different genetic profiles among the lactobacilli isolates. Their probiotic potential was evaluated through different assays, including survival in conditions that resemble those existing in the gastrointestinal tract, production of antimicrobial compounds, adherence to intestinal mucin, degradation of mucin and pattern of antibiotic sensitivity. Some strains showed potential for future applications as canine probiotics.

  13. Adhesion of lactobacilli to urinary catheters and diapers: effect of surface properties.

    PubMed

    Reid, G; Lam, D; Bruce, A W; van der Mei, H C; Busscher, H J

    1994-06-01

    Thirteen strains of lactobacilli were tested for their ability to adhere to commercial devices used in the urinary tract. Although it appeared that the most hydrophilic organisms adhered in highest numbers, there was no significant correlation between water contact angle and adhesiveness to catheters. Five organisms tested were found to be highly adherent to Huggies commercial diapers. Loss in hydrophobicity upon serial culture of Lactobacillus fermentum B-54 was not due to a proteinaceous S layer, although protein involvement per se cannot be ruled out. It was evident that, not only can members of the normal female urogenital flora adhere to commonly used commercial prostheses, but their ability to attach is related to hydrophilic as well as hydrophobic surface components.

  14. Nutritionally enhanced fermented sausages as a vehicle for potential probiotic lactobacilli delivery.

    PubMed

    Rubio, Raquel; Jofré, Anna; Aymerich, Teresa; Guàrdia, Maria Dolors; Garriga, Margarita

    2014-02-01

    The suitability of three potential probiotic lactobacilli strains (Lactobacillus casei CTC1677, L. casei CTC1678 and Lactobacillus rhamnosus CTC1679), previously isolated from infants' faeces and characterized, and three commercial probiotic strains (Lactobacillus plantarum 299v, L. rhamnosus GG and L. casei Shirota) was assessed during the manufacture of low-acid fermented sausages (fuets) with reduced Na(+) and fat content. The inoculated strains were successfully monitored by RAPD-PCR during the process. L. rhamnosus CTC1679 was the only strain able to grow and dominate (levels ca. 10(8)CFU/g) the endogenous lactic acid bacteria population in two independent trials, throughout the ripening process. Thus, fuet containing L. rhamnosus CTC1679 as a starter culture could be a suitable vehicle for putative probiotic bacteria delivery. All the final products recorded a satisfactory overall sensory quality without any noticeable off-flavour, and with the characteristic sensory properties of low-acid fermented sausages.

  15. Detection, growth, and amine-producing capacity of lactobacilli in cheese.

    PubMed

    Joosten, H M; Northolt, M D

    1989-09-01

    A differential plating medium was developed to detect decarboxylating lactobacilli in cheese. With this medium, 15 cheeses made from raw milk were investigated for the presence of these bacteria. Five histidine-decarboxylating strains and one tyrosine-decarboxylating strain were isolated. The isolates were identified with the API 50L system. Accordingly, each of the five histidine-decarboxylating strains was identified as Lactobacillus buchneri, whereas the tyrosine-decarboxylating strain is a representative of Lactobacillus brevis. Cheesemaking experiments using a low inoculum concentration of the histidinedecarboxylating L. buchneri strain St2A (0.2 CFU/ml of milk) showed that, under conditions of accelerated proteolysis, histamine may accumulate rapidly; after 3 months of ripening, 410 mg/kg was found. An inoculum concentration of 5 CFU/ml gave rise to the formation of 1,060 mg/kg.

  16. Effect of Aloe vera juice on growth and activities of Lactobacilli in-vitro.

    PubMed

    Nagpal, Ravinder; Kaur, Varinder; Kumar, Manoj; Marotta, Francesco

    2012-12-01

    In present investigation, different concentrations of Aloe vera juice incorporated into the growth media of Lactobacilli were tested to observe the effect on growth and activities of these bacteria. From the results obtained, it was observed that aloe vera juice at a concentration of 5% v/v was effective in promoting the growth of L. acidophilus, L. plantarum and L. casei, as evident from the fall in pH and increased acidity, as well as from the improved generation time. At 15 to 25% concentration, growth was unaffected as compared to the controls; however, concentration higher than 25%v/v discouraged the growth. Overall, it was concluded that Aloe vera juice or gel at a particular concentration could possibly be used in combination with probiotic Lactobacillus strain(s) as a combinational therapy for gastrointestinal disorders and cardiovascular diseases.

  17. Selection of potential probiotic lactobacilli from pig feces to be used as additives in pelleted feeding.

    PubMed

    De Angelis, Maria; Siragusa, Sonya; Berloco, Mariagrazia; Caputo, Leonardo; Settanni, Luca; Alfonsi, Giuditta; Amerio, Marica; Grandi, Augusto; Ragni, Adriano; Gobbetti, Marco

    2006-10-01

    Thirty-five isolates from pig feces were identified as Lactobacillus reuteri (12 strains), Lactobacillus mucosae (7), Lactobacillus plantarum (6), Lactobacillus kitasatonis (3), Lactobacillus rossiae (2), Lactobacillus ultunensis (2), Lactobacillus crispatus (2), and Lactobacillus intestinalis (1) by partial sequence analysis of the 16S rRNA. All isolates were detected at 8-9 log CFU g(-1). Preliminarily, strains were selected based on resistance to heat treatments (ca. 70 degrees C for 10 s). The decrease in viability for some L. reuteri, L. mucosae, L. plantarum, L. kitasatonis, and L. rossiae strains was lower than 1 log cycle. Selected strains were further characterized for acid and bile salt resistance, and antibacterial activity. Except for L. kitasatonis, tolerance to simulated gastric and intestinal conditions was enhanced for all strains by addition of reconstituted skimmed milk. Antibacterial activity was found against Gram-positive and -negative potential pathogens. L. reuteri 8.1, 3S7, 6.2, and 1.2, L. mucosae 1.1R, L. plantarum 4.1, and L. rossiae 4.4 were freeze-dried and mixed (1%, w/w) into pig feed before pelleting. After pelleting, pig feed contained 10-9 log CFU kg(-1) of lactobacilli. L. plantarum 4.1, and L. reuteri 3S7 were selected based on their bile salt resistance, pH tolerance, antimicrobial activity and heat resistance. The findings in this study provide a strong basis for exploring the potential of porcine lactobacilli isolates to be used in pelleted feeding as probiotic additives.

  18. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge.

    PubMed

    Harlow, Brittany E; Lawrence, Laurie M; Flythe, Michael D

    2013-09-27

    Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 per horse) were taken during dietary adaptation (3 weeks), antibiotic challenge (1 week), and withdrawal (1 week). Bacteria were enumerated by serial dilution and viable count. Cellulolytic bacteria decreased by >99% during administration of either antibiotic (P<0.0001) and were still less than controls at the end of the withdrawal period (P<0.0001). Fecal samples from horses challenged with ceftiofur had 75% fewer lactobacilli than those from control horses at the end of the antibiotic challenge period (P<0.05). Antibiotic challenged horses also shed more salmonella than control horses (P<0.05). Antibiotics had no effect on the number of Clostridium perfringens isolates. There was no detectable Clostridium difficile during adaptation or in any control horse. C. difficile increased (P<0.0001) to approximately 10(4)cfu/g when horses were challenged with antibiotics, and were still detectable 1 week after withdrawal. These results indicate that antibiotics can disrupt the normal gastrointestinal microbiota and allow proliferation of Salmonella spp. and C. difficile.

  19. Ultra-low-dose estriol and lactobacilli in the local treatment of postmenopausal vaginal atrophy.

    PubMed

    Jaisamrarn, U; Triratanachat, S; Chaikittisilpa, S; Grob, P; Prasauskas, V; Taechakraichana, N

    2013-06-01

    The aim of this study was to demonstrate the efficacy of an ultra-low-dose vaginal estriol 0.03 mg in combination with viable Lactobacillus acidophilus KS400 (Gynoflor(®) vaginal tablets) in the short-term therapy and to investigate the long-term maintenance dose in the treatment of vaginal atrophy. This was a double-blind, randomized, placebo-controlled study (Controlled phase--initial therapy) followed by an open-label follow-up (Open phase--test medication initial and maintenance therapy). Included were postmenopausal women with vaginal atrophy symptoms and Vaginal Maturation Index (VMI) of ≤ 40%. The method of treatment was initial therapy with test medication (or placebo in first phase), one vaginal tablet daily for 12 days, followed by maintenance therapy, one tablet on two consecutive days weekly for 12 weeks. A total of 87 women completed the study. The Controlled phase results for a change in VMI demonstrated superiority of the 0.03 mg estriol-lactobacilli combination to placebo (p < 0.001). In the test group, the positive change in VMI was 35.2%, compared to 9.9% in the placebo group. In the Open phase after the initial therapy, the VMI was increased to 55.4% and, during maintenance therapy, it stayed at a comparable level (52.8-49.4%). The maturation of epithelium was followed by improvement of clinical symptoms and normalization of the vaginal ecosystem. The ultra-low-dose, vaginal 0.03 mg estriol-lactobacilli combination (Gynoflor(®)) was superior to placebo with respect to changes in VMI after the 12-day initial therapy, and the maintenance therapy of two tablets weekly was sufficient to prevent the relapse of vaginal atrophy.

  20. Ultra-low-dose estriol and lactobacilli in the local treatment of postmenopausal vaginal atrophy

    PubMed Central

    2013-01-01

    Objective The aim of this study was to demonstrate the efficacy of an ultra-low-dose vaginal estriol 0.03 mg in combination with viable Lactobacillus acidophilus KS400 (Gynoflor® vaginal tablets) in the short-term therapy and to investigate the long-term maintenance dose in the treatment of vaginal atrophy. Methods This was a double-blind, randomized, placebo-controlled study (Controlled phase – initial therapy) followed by an open-label follow-up (Open phase – test medication initial and maintenance therapy). Included were postmenopausal women with vaginal atrophy symptoms and Vaginal Maturation Index (VMI) of ≤ 40%. The method of treatment was initial therapy with test medication (or placebo in first phase), one vaginal tablet daily for 12 days, followed by maintenance therapy, one tablet on two consecutive days weekly for 12 weeks. Results A total of 87 women completed the study. The Controlled phase results for a change in VMI demonstrated superiority of the 0.03 mg estriol–lactobacilli combination to placebo (p < 0.001). In the test group, the positive change in VMI was 35.2%, compared to 9.9% in the placebo group. In the Open phase after the initial therapy, the VMI was increased to 55.4% and, during maintenance therapy, it stayed at a comparable level (52.8–49.4%). The maturation of epithelium was followed by improvement of clinical symptoms and normalization of the vaginal ecosystem. Conclusions The ultra-low-dose, vaginal 0.03 mg estriol–lactobacilli combination (Gynoflor®) was superior to placebo with respect to changes in VMI after the 12-day initial therapy, and the maintenance therapy of two tablets weekly was sufficient to prevent the relapse of vaginal atrophy. PMID:23347400

  1. Probiotic lactobacilli: an innovative tool to correct the malabsorption syndrome of vegetarians?

    PubMed

    Famularo, Giuseppe; De Simone, Claudio; Pandey, Vandana; Sahu, Adita Ranjan; Minisola, Giovanni

    2005-01-01

    Vegetarians may have subtle nutritional deficiencies which have been related to the occurrence of an unrecognized malabsorption syndrome. The excess phytate content in cereals, nuts, legumes and oilseeds which represent the mainstay of their food intake, seems to play a central role in the pathogenesis of this malabsorption syndrome as an inverse relationship has been shown to link the phytate content of the diet with the intestinal absorption of trace minerals and proteins. We postulate that manipulating the endogenous digestive microflora of subjects on a vegetarian diet through administering probiotic lactic bacteria would represent an innovative tool to counteract the occurrence of the malabsorption syndrome dependent on the high phytate content of their diet. Even though there are no data about the composition of endogenous digestive microflora in subjects on a vegetarian diet, we expect that probiotic lactobacilli can interact with or affect distinct yet interrelated components within the intestinal milieu, such as epithelial cells, enteric flora, and/or mucosal immune cells. This would ultimately translate into the correction of the unregulated mechanisms implicated in the altered intestinal absorption of trace metals and proteins commonly seen in vegetarians. Clinical experience with probiotic therapy of patients with inflammatory bowel disease fully agrees with this view. One additional point of interest is that probiotic lactobacilli, and other species of the endogenous digestive microflora as well, are an important source of the enzyme phytase which catalyses the release of phosphate from phytate and hydrolyses the complexes formed by phytate and metal ions or other cations, rendering them more soluble ultimately improving and facilitating their intestinal absorption. The regular intake of probiotic preparation, may represent a cheap and safe tool in order to convert a diet with a low potential for bioavailability of trace minerals and proteins, such as

  2. Technological and probiotic role of adjunct cultures of non-starter lactobacilli in soft cheeses.

    PubMed

    Burns, Patricia; Cuffia, Facundo; Milesi, Mercedes; Vinderola, Gabriel; Meinardi, Carlos; Sabbag, Nora; Hynes, Erica

    2012-05-01

    The influence of two cheese-isolated Lactobacillus strains on cheese composition, acceptability and probiotic capacity was assessed. Soft cheeses with and without the addition of Lactobacillus plantarum I91 or Lactobacillus paracasei I90 were prepared. Gross composition was assessed and secondary proteolysis was described by soluble fractions and free amino acids profiles. Acceptability was determined by a panel of 98 non-trained consumers. Cheeses harboring added Lactobacillus strains were also studied in vivo to evaluate their probiotic capacity. Gross composition of the cheeses was similar for control and treated (Lactobacillus-added) cheeses. Peptidolysis increased in cheeses with added lactobacilli, which was evidenced by a higher free amino acid content. Overall, the acceptability of the cheeses was good: 65%-80% of the consumers said that they "liked very much" or "liked" the cheeses. Cheeses with L. plantarum I91 showed the highest changes in composition and proteolysis and were the most accepted ones. On the contrary, composition of cheeses with L. paracasei I90 was similar to that of the controls, but these samples were less accepted than cheeses without lactobacilli. The oral administration of cheese containing L. plantarum I91 or L. paracasei I90 proved to be safe and able to enhance the number of IgA + cells in the small intestine lamina propria of mice. The use of selected strains of NSLAB exerted a technological and probiotic role: it contributed to the standardization of cheese quality and induced benefic health effects at the gut mucosa in vivo.

  3. Hydrogen-peroxide producing lactobacilli are associated with lower levels of vaginal IL1β, independent of bacterial vaginosis

    PubMed Central

    Mitchell, Caroline; Fredricks, David; Agnew, Kathy; Hitti, Jane

    2015-01-01

    Background The presence of hydrogen peroxide (H2O2)-producing lactobacilli in the vagina is associated with decreased rates of preterm birth and HIV acquisition. We hypothesize that this is due to immunomodulatory effects of these species. Methods Concentrations of IL1β, IL6, IL8, secretory leukocyte protease inhibitor (SLPI) and human beta defensin 2 (HBD2) were quantified from vaginal swabs from 4 groups of women: women with and without bacterial vaginosis (BV) by Nugent score, further stratified by detection of H2O2-producing lactobacilli by semi-quantitative culture. Ten quantitative PCR assays characterized presence and quantity of select Lactobacillus and BV-associated species in each group. Levels of immune markers and bacteria were compared between the four groups using ANOVA, Kruskal-Wallis, Mann Whitney U or chi-square tests. Results Swabs from 110 women from four groups were included: 26 had a normal Nugent score (BV−), and no H2O2-producing lactobacilli detected(H2O2−), 47 were BV−, H2O2+, 27 BV+, H2O2− and 10 BV+, H2O2+. The groups were similar in age, marital status and reproductive history, but not ethnicity: the BV−, H2O2− group had more Caucasian participants(p = 0.02). In women with and without BV, IL1β was lower in the H2O2+ groups. HBD2 was lowest in BV+ H2O2− women and highest in BV−, H2O2−. SLPI was lower in women with BV, and did not differ by the presence of H2O2–producing lactobacilli. In regression analysis higher quantities of L. crispatus were associated with lower quantities of IL1β. Detection and quantity of BV-associated species by qPCR was significantly different between women with and without BV, but not between women with and without H2O2-producing lactobacilli within those groups. Conclusions The presence of H2O2-producing lactobacilli is associated with lower levels of some vaginal pro-inflammatory cytokines, even in women with BV. PMID:26222747

  4. Mechanism of degradation of immunogenic gluten epitopes from Triticum turgidum L. var. durum by sourdough lactobacilli and fungal proteases.

    PubMed

    De Angelis, Maria; Cassone, Angela; Rizzello, Carlo G; Gagliardi, Francesca; Minervini, Fabio; Calasso, Maria; Di Cagno, Raffaella; Francavilla, Ruggero; Gobbetti, Marco

    2010-01-01

    As shown by R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay (ELISA), selected sourdough lactobacilli, in combination with fungal proteases, hydrolyzed gluten (72 h at 37 degrees C) of various cultivars of Triticum turgidum L. var. durum to less than 20 ppm. Complementary electrophoretic, chromatography, and mass spectrometry techniques were used to characterize the gluten and epitope hydrolysis. Nine peptidases were partially purified from the pooled cytoplasmic extract of the sourdough lactobacilli and used to hydrolyze the 33-mer epitope, the most immunogenic peptide generated during digestion of Triticum species. At least three peptidases (general aminopeptidase type N [PepN], X-prolyl dipeptidyl aminopeptidase [PepX], and endopeptidase PepO) were necessary to detoxify the 33-mer without generation of related immunogenic epitopes. After 14 h of incubation, the combination of all or at least six different peptidases totally hydrolyzed the 33-mer (200 mM) into free amino acids. The same results were found for other immunogenic epitopes, such as fragments 57-68 of alpha 9-gliadin, 62-75 of A-gliadin, and 134-153 of gamma-gliadin. When peptidases were used for fermentation of durum wheat semolina, they caused the hydrolysis of gluten to ca. 2 ppm. The in vivo digestion was simulated, and proteins/peptides extracted from pepsin-trypsin (PT) digestion of durum wheat semolina fermented with selected sourdough lactobacilli induced the expression of gamma interferon and interleukin 2 at levels comparable to those of the negative control. Durum wheat semolina fermented with sourdough lactobacilli was freeze-dried and used for making Italian-type pasta. The scores for cooking and sensory properties for this pasta were higher that those of conventional gluten-free pasta.

  5. Mechanism of Degradation of Immunogenic Gluten Epitopes from Triticum turgidum L. var. durum by Sourdough Lactobacilli and Fungal Proteases▿

    PubMed Central

    De Angelis, Maria; Cassone, Angela; Rizzello, Carlo G.; Gagliardi, Francesca; Minervini, Fabio; Calasso, Maria; Di Cagno, Raffaella; Francavilla, Ruggero; Gobbetti, Marco

    2010-01-01

    As shown by R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay (ELISA), selected sourdough lactobacilli, in combination with fungal proteases, hydrolyzed gluten (72 h at 37°C) of various cultivars of Triticum turgidum L. var. durum to less than 20 ppm. Complementary electrophoretic, chromatography, and mass spectrometry techniques were used to characterize the gluten and epitope hydrolysis. Nine peptidases were partially purified from the pooled cytoplasmic extract of the sourdough lactobacilli and used to hydrolyze the 33-mer epitope, the most immunogenic peptide generated during digestion of Triticum species. At least three peptidases (general aminopeptidase type N [PepN], X-prolyl dipeptidyl aminopeptidase [PepX], and endopeptidase PepO) were necessary to detoxify the 33-mer without generation of related immunogenic epitopes. After 14 h of incubation, the combination of all or at least six different peptidases totally hydrolyzed the 33-mer (200 mM) into free amino acids. The same results were found for other immunogenic epitopes, such as fragments 57-68 of α9-gliadin, 62-75 of A-gliadin, and 134-153 of γ-gliadin. When peptidases were used for fermentation of durum wheat semolina, they caused the hydrolysis of gluten to ca. 2 ppm. The in vivo digestion was simulated, and proteins/peptides extracted from pepsin-trypsin (PT) digestion of durum wheat semolina fermented with selected sourdough lactobacilli induced the expression of gamma interferon and interleukin 2 at levels comparable to those of the negative control. Durum wheat semolina fermented with sourdough lactobacilli was freeze-dried and used for making Italian-type pasta. The scores for cooking and sensory properties for this pasta were higher that those of conventional gluten-free pasta. PMID:19948868

  6. The Antibacterial Effect of Ethanol Extract of Polish Propolis on Mutans Streptococci and Lactobacilli Isolated from Saliva

    PubMed Central

    Dziedzic, Arkadiusz; Kubina, Robert; Wojtyczka, Robert D.; Kabała-Dzik, Agata; Tanasiewicz, Marta; Morawiec, Tadeusz

    2013-01-01

    Dental caries occurrence is caused by the colonization of oral microorganisms and accumulation of extracellular polysaccharides synthesized by Streptococcus mutans with the synergistic influence of Lactobacillus spp. bacteria. The aim of this study was to determine ex vivo the antibacterial properties of ethanol extract of propolis (EEP), collected in Poland, against the main cariogenic bacteria: salivary mutans streptococci and lactobacilli. The isolation of mutans streptococci group bacteria (MS) and Lactobacillus spp. (LB) from stimulated saliva was performed by in-office CRT bacteria dip slide test. The broth diffusion method and AlamarBlue assay were used to evaluate the antimicrobial activity of EEP, with the estimation of its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The biochemical composition of propolis components was assessed. The mean MIC and MBC values of EEP, in concentrations ranging from 25 mg/mL to 0.025 mg/mL, for the MS and LB were found to be 1.10 mg/mL versus 0.7 mg/mL and 9.01 mg/mL versus 5.91 mg/mL, respectively. The exposure to an extract of Polish propolis affected mutans streptococci and Lactobacillus spp. viability, exhibiting an antibacterial efficacy on mutans streptococci group bacteria and lactobacilli saliva residents, while lactobacilli were more susceptible to EEP. Antibacterial measures containing propolis could be the local agents acting against cariogenic bacteria. PMID:23606887

  7. Molecular Detection of Two Potential Probiotic Lactobacilli Strains and Evaluation of Their Performance as Starter Adjuncts in Yogurt Production.

    PubMed

    Saxami, Georgia; Papadopoulou, Olga S; Chorianopoulos, Nikos; Kourkoutas, Yiannis; Tassou, Chrysoula C; Galanis, Alex

    2016-05-04

    A molecular method for efficient and accurate detection and identification of two potential probiotic lactobacilli strains isolated from fermented olives, namely Lactobacillus pentosus B281 and Lb. plantarum B282, was developed in the present study. Random Amplified Polymorphic DNA (RAPD) analysis was performed, and strain specific primers were designed and applied in a multiplex polymerase chain reaction (PCR) assay. The specificity of the assay was tested and successfully confirmed in 27 and 22 lactobacilli strains for Lb. pentosus B281 and Lb. plantarum B282, respectively. Moreover, the two strains were used as starter cultures in yogurt production. Cell enumeration followed by multiplex PCR analysis demonstrated that the two strains were present in yogurt samples at levels ≥6 log CFU/g even after 35 days of storage at 4 °C. Microbiological analysis showed that lactobacilli and streptococci were present within usual levels, whereas enterobacteriaceae and yeast/mold counts were not detected as expected. Although the pH values of the novel products were slightly lower than the control ones, the yogurt containing the probiotic cultures scored similar values compared to the control in a series of sensory tests. Overall, these results demonstrated the possible use of the two strains as starter adjuncts in the production of yogurt with potential probiotic properties.

  8. Effect of mesophilic lactobacilli and enterococci adjunct cultures on the final characteristics of a microfiltered milk Swiss-type cheese.

    PubMed

    Bouton, Yvette; Buchin, Solange; Duboz, Gabriel; Pochet, Sylvie; Beuvier, Eric

    2009-04-01

    The effect of four associations of adjunct cultures composed of mesophilic lactobacilli and enterococci, either solely or combined, on the microbiological, biochemical and sensory characteristics of Swiss-type cheese made using microfiltered cows' milk and supplemented with propionibacteria was studied. The global pattern of growth was similar to that generally observed in raw milk cheese and interactions between microflora were highlighted during ripening. Enterococci, which negatively affected the survival of streptococci starters, seemed to play a limited role in the formation of volatile compounds, probably due to their low levels throughout ripening. On the contrary, mesophilic lactobacilli, which affected the evolution of propionibacteria, enterococci and L. delbrueckii subsp. lactis starter counts, modified free amino acid content, production of volatile compounds and organoleptic properties of mature cheese. This population appeared to be of major importance in the formation of cheese flavor as it was positively related to numerous potential flavor compounds such as alcohols and their corresponding esters, acetaldehyde and 4-methyl-4-heptanone. The original mesophilic lactobacilli present in milk could play an important role in the sensorial diversity of raw milk Swiss-type cheeses such as Comte.

  9. Effect of Chocobar Ice Cream Containing Bifidobacterium on Salivary Streptococcus mutans and Lactobacilli: A Randomised Controlled Trial.

    PubMed

    Nagarajappa, Ramesh; Daryani, Hemasha; Sharda, Archana J; Asawa, Kailash; Batra, Mehak; Sanadhya, Sudhanshu; Ramesh, Gayathri

    2015-01-01

    To examine the effect of chocobar ice cream containing bifidobacteria on salivary mutans streptococci and lactobacilli. A double-blind, randomised controlled trial was conducted with 30 subjects (18 to 22 years of age) divided into 2 groups, test (chocobar ice cream with probiotics) and control (chocobar ice cream without probiotics). The subjects were instructed to eat the allotted chocobar ice cream once daily for 18 days. Saliva samples collected at intervals were cultured on Mitis Salivarius agar and Rogosa agar and examined for salivary mutans streptococci and lactobacilli, respectively. The Mann-Whitney U-test, Friedman and Wilcoxon signed-rank tests were used for statistical analysis. Postingestion in the test group, a statistically significant reduction (p < 0.05) of salivary mutans streptococci was recorded, but a non-significant trend was seen for lactobacilli. Significant differences were was also observed between follow-ups. Short-term daily ingestion of ice cream containing probiotic bifidobacteria may reduce salivary levels of mutans streptococci in young adults.

  10. Comparative Functional Genomics of Lactobacillus spp. Reveals Possible Mechanisms for Specialization of Vaginal Lactobacilli to Their Environment

    PubMed Central

    Suzuki, Haruo; Hickey, Roxana J.; Forney, Larry J.

    2014-01-01

    Lactobacilli are found in a wide variety of habitats. Four species, Lactobacillus crispatus, L. gasseri, L. iners, and L. jensenii, are common and abundant in the human vagina and absent from other habitats. These may be adapted to the vagina and possess characteristics enabling them to thrive in that environment. Furthermore, stable codominance of multiple Lactobacillus species in a single community is infrequently observed. Thus, it is possible that individual vaginal Lactobacillus species possess unique characteristics that confer to them host-specific competitive advantages. We performed comparative functional genomic analyses of representatives of 25 species of Lactobacillus, searching for habitat-specific traits in the genomes of the vaginal lactobacilli. We found that the genomes of the vaginal species were significantly smaller and had significantly lower GC content than those of the nonvaginal species. No protein families were found to be specific to the vaginal species analyzed, but some were either over- or underrepresented relative to nonvaginal species. We also found that within the vaginal species, each genome coded for species-specific protein families. Our results suggest that even though the vaginal species show no general signatures of adaptation to the vaginal environment, each species has specific and perhaps unique ways of interacting with its environment, be it the host or other microbes in the community. These findings will serve as a foundation for further exploring the role of lactobacilli in the ecological dynamics of vaginal microbial communities and their ultimate impact on host health. PMID:24488312

  11. Comparison of Microbiological and Probiotic Characteristics of Lactobacilli Isolates from Dairy Food Products and Animal Rumen Contents

    PubMed Central

    Jose, Neethu Maria; Bunt, Craig R.; Hussain, Malik Altaf

    2015-01-01

    Lactobacilli are employed in probiotic food preparations and as feed additives in poultry and livestock, due to health benefits associated with their consumption. The objective of this study was to evaluate and compare the probiotic potential of ten lactobacilli strains isolated from commercial dairy food products and animal rumen contents in New Zealand. Genetic identification of the isolates revealed that all belonged to the genus Lactobacillus, specifically the species L. reuteri, L. rhamnosus and L. plantarum. All isolates did not show any haemolytic behaviour. Isolates of dairy origin showed better tolerance to low pH stress. On the other hand, rumen isolates exhibited a higher tolerance to presence of bile salts. All isolates exhibited resistance to aminoglycoside antibiotics, however most were sensitive to ampicillin. Isolates of rumen origin demonstrated a higher inhibitory effect on Listeria monocytogenes, Enterobacter aerogenes and Salmonella menston. Bacterial adherence of all isolates increased with a decrease in pH. This screening study on lactobacilli isolates has assessed and identified potential probiotic candidates for further evaluation. PMID:27682086

  12. Comparison of Microbiological and Probiotic Characteristics of Lactobacilli Isolates from Dairy Food Products and Animal Rumen Contents.

    PubMed

    Jose, Neethu Maria; Bunt, Craig R; Hussain, Malik Altaf

    2015-04-15

    Lactobacilli are employed in probiotic food preparations and as feed additives in poultry and livestock, due to health benefits associated with their consumption. The objective of this study was to evaluate and compare the probiotic potential of ten lactobacilli strains isolated from commercial dairy food products and animal rumen contents in New Zealand. Genetic identification of the isolates revealed that all belonged to the genus Lactobacillus, specifically the species L. reuteri, L. rhamnosus and L. plantarum. All isolates did not show any haemolytic behaviour. Isolates of dairy origin showed better tolerance to low pH stress. On the other hand, rumen isolates exhibited a higher tolerance to presence of bile salts. All isolates exhibited resistance to aminoglycoside antibiotics, however most were sensitive to ampicillin. Isolates of rumen origin demonstrated a higher inhibitory effect on Listeria monocytogenes, Enterobacter aerogenes and Salmonella menston. Bacterial adherence of all isolates increased with a decrease in pH. This screening study on lactobacilli isolates has assessed and identified potential probiotic candidates for further evaluation.

  13. Effect of electroporation on viability and bioconversion of isoflavones in mannitol-soymilk fermented by lactobacilli and bifidobacteria.

    PubMed

    Yeo, Siok-Koon; Liong, Min-Tze

    2013-01-01

    The aim of this study was to evaluate the effect of electroporation (2.5-7.5 kV cm⁻¹ for 3.0-4.0 ms) on the growth of lactobacilli and bifidobacteria, membrane properties and bioconversion of isoflavones in mannitol-soymilk. The viability of lactobacilli and bifidobacteria decreased immediately after electroporation. This was attributed to lipid peroxidation, which led to alterations in the membrane phospholipid bilayer, specifically at the polar head, interface and apolar tail regions. Such alterations also resulted in decreased membrane fluidity and increased membrane permeability upon electroporation (P < 0.05). However, the effect was reversible and treated cells showed better growth than the control upon fermentation for 24 h at 37 °C (P < 0.05). Additionally, electroporation increased the bioconversion of glucosides to bioactive aglycones in mannitol-soymilk, which was attributed to increased intracellular and extracellular β-glucosidase activities of cells upon treatment (P < 0.05). Application of electroporation on lactobacilli and bifidobacteria could be beneficial for the development of fermented soymilk with enhanced bioactivity. Considering the enhanced bioactive aglycones, this soymilk could be useful for the prevention of hormone-dependent disorders. Copyright © 2012 Society of Chemical Industry.

  14. Comparative functional genomics of Lactobacillus spp. reveals possible mechanisms for specialization of vaginal lactobacilli to their environment.

    PubMed

    Mendes-Soares, Helena; Suzuki, Haruo; Hickey, Roxana J; Forney, Larry J

    2014-04-01

    Lactobacilli are found in a wide variety of habitats. Four species, Lactobacillus crispatus, L. gasseri, L. iners, and L. jensenii, are common and abundant in the human vagina and absent from other habitats. These may be adapted to the vagina and possess characteristics enabling them to thrive in that environment. Furthermore, stable codominance of multiple Lactobacillus species in a single community is infrequently observed. Thus, it is possible that individual vaginal Lactobacillus species possess unique characteristics that confer to them host-specific competitive advantages. We performed comparative functional genomic analyses of representatives of 25 species of Lactobacillus, searching for habitat-specific traits in the genomes of the vaginal lactobacilli. We found that the genomes of the vaginal species were significantly smaller and had significantly lower GC content than those of the nonvaginal species. No protein families were found to be specific to the vaginal species analyzed, but some were either over- or underrepresented relative to nonvaginal species. We also found that within the vaginal species, each genome coded for species-specific protein families. Our results suggest that even though the vaginal species show no general signatures of adaptation to the vaginal environment, each species has specific and perhaps unique ways of interacting with its environment, be it the host or other microbes in the community. These findings will serve as a foundation for further exploring the role of lactobacilli in the ecological dynamics of vaginal microbial communities and their ultimate impact on host health.

  15. Molecular Detection of Two Potential Probiotic Lactobacilli Strains and Evaluation of Their Performance as Starter Adjuncts in Yogurt Production

    PubMed Central

    Saxami, Georgia; Papadopoulou, Olga S.; Chorianopoulos, Nikos; Kourkoutas, Yiannis; Tassou, Chrysoula C.; Galanis, Alex

    2016-01-01

    A molecular method for efficient and accurate detection and identification of two potential probiotic lactobacilli strains isolated from fermented olives, namely Lactobacillus pentosus B281 and Lb. plantarum B282, was developed in the present study. Random Amplified Polymorphic DNA (RAPD) analysis was performed, and strain specific primers were designed and applied in a multiplex polymerase chain reaction (PCR) assay. The specificity of the assay was tested and successfully confirmed in 27 and 22 lactobacilli strains for Lb. pentosus B281 and Lb. plantarum B282, respectively. Moreover, the two strains were used as starter cultures in yogurt production. Cell enumeration followed by multiplex PCR analysis demonstrated that the two strains were present in yogurt samples at levels ≥6 log CFU/g even after 35 days of storage at 4 °C. Microbiological analysis showed that lactobacilli and streptococci were present within usual levels, whereas enterobacteriaceae and yeast/mold counts were not detected as expected. Although the pH values of the novel products were slightly lower than the control ones, the yogurt containing the probiotic cultures scored similar values compared to the control in a series of sensory tests. Overall, these results demonstrated the possible use of the two strains as starter adjuncts in the production of yogurt with potential probiotic properties. PMID:27153065

  16. Douching in relation to bacterial vaginosis, lactobacilli, and facultative bacteria in the vagina.

    PubMed

    Ness, Roberta B; Hillier, Sharon L; Richter, Holly E; Soper, David E; Stamm, Carol; McGregor, James; Bass, Debra C; Sweet, Richard L; Rice, Peter

    2002-10-01

    To study how frequency, recentness, and reason for douching impact bacterial vaginosis-related vaginal microflora and the occurrence of cervical pathogens. Douching has been linked to bacterial vaginosis as well as to chlamydial cervicitis in some, but not all, studies. A total of 1200 women at high risk for sexually transmitted infections were enrolled from five clinical sites around the United States. Cross-sectional, structured interviews were conducted and vaginal swabs were self-obtained for Gram stain, culture, and DNA amplification tests for Neisseria gonorrhoeae and Chlamydia trachomatis. Douching at least once per month was associated with an increased frequency of bacterial vaginosis. Those who douched recently (within 7 days) were at highest risk [odds ratio (OR) 2.1, 95% confidence interval (CI) 1.3, 3.1]. Douching for symptoms (OR 1.7, 95% CI 1.1, 2.6) and for hygiene (OR 1.3, 95% CI 1.0, 1.9) both related to bacterial vaginosis risk. The associations between douching and Gardnerella vaginalis, Mycoplasma hominis, and lack of hydrogen peroxide-producing lactobacilli were similar to those between douching and bacterial vaginosis. Gonococcal or chlamydial cervicitis was not associated with douching. Douching for symptoms or hygiene, particularly frequent or recent douching, was associated with bacterial vaginosis and bacterial vaginosis-associated vaginal microflora, but not with gonococcal or chlamydial cervicitis.

  17. Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment.

    PubMed Central

    Hastings, J W; Holzapfel, W H; Niemand, J G

    1986-01-01

    Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp., one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four references strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO2, and N2). Organisms exhibited the highest death rate (lowest D10 values [doses required to reduce the logarithm of the bacterial population by 1] ) under CO2 packaging conditions, but resistance to irradiation was increased under N2. The D10 values of the isolates were generally greater than those of the reference strains. The D10 values were also higher (approximately two times) in meat than in semisynthetic growth medium. PMID:3096207

  18. Comparison of innate immune activation after prolonged feeding of milk fermented with three species of Lactobacilli.

    PubMed

    Kapila, Rajeev; Sebastian, Renjith; Varma D, Vivek Phani; Sharma, Rohit; Kapasiya, Meena; Salingati, Vamshi; Kapila, Suman; Dang, Ajay K

    2013-11-01

    The present investigation aimed at identifying the abilities of three different species of probiotic lactobacilli to modulate cellular immune responses in mouse neutrophils and macrophages in vivo over a study period of 60 days. Neutrophil respiratory burst enzymes (cytochrome c reductase and MPO) showed remarkable increased activity (P ≤ 0.01) after consumption of milks fermented by different species of probiotics over 30 and 60 days of feeding trials. Enzyme activities (β-galactosidase and β-glucuronidase) and nitric oxide production also increased considerably (P ≤ 0.01) in macrophages, both in peritoneal fluid and in enriched cell cultures. The effects of enhanced enzyme activities were corroborated by simultaneous increases in the phagocytic activities of neutrophils and macrophages. The increases in cellular functions were invariably maximal during the first 30 days of study and were maintained, but did not increase, over the next 30 days. Further, Lactobacillus helveticus-fed groups were most effective at modulating neutrophil functions whereas Lactobacillus paracasei-fed groups were more potent at enhancing macrophage functions. Together, our results indicate that probiotics have strain specific effects on stimulating cellular functions while not causing excessive stimulation of the immune system over longer feeding periods, thereby resulting in maximum and stable health benefits.

  19. Effect of traditional leafy vegetables on the growth of lactobacilli and bifidobacteria.

    PubMed

    Kassim, Muhammad Arshad; Baijnath, Himansu; Odhav, Bharti

    2014-12-01

    Traditional leafy vegetables, apart from being a staple in the diet of most of sub-Saharan Africa, are an essential part of traditional medicine and are used daily by traditional healers in the region to treat a wide variety of ailments. In this study, a batch culture technique was used to investigate whether 25 infusions from 22 traditional leafy vegetables stimulated the growth of Lactobacillus bulgaricus, Lactobacillus lactis, Lactobacillus reuteri and Bifidobacterium longum in pure culture. High performance liquid chromatography was used to determine the inulin content of the infusions. Sonchus oleraceus stimulated all four strains and Taraxacum officinale stimulated three strains. In total, 18 plants stimulated at least one of the four probiotic strains. The inulin content of the infusions varied between 2.5% and 3.6%, with Asparagus sprengeri containing the highest percentage. These results indicate that traditional leafy vegetables do stimulate the growth of the selected lactobacilli and bifidobacteria in pure culture and contain inulin. These infusions can now be tested for prebiotic potential using mixed culture systems or human hosts.

  20. Sweet potatoes as a basic component in developing a medium for the cultivation of lactobacilli.

    PubMed

    Hayek, Saeed A; Shahbazi, Aboghasem; Awaisheh, Saddam S; Shah, Nagendra P; Ibrahim, Salam A

    2013-01-01

    A sweet potato medium (SPM) was formed with extract from baked sweet potatoes supplemented with 0, 4, or 8 g/L of each nitrogen source (beef extract, yeast extract, and proteose peptone #3) to form SPM1, SPM2, and SPM3 respectively. Lactobacilli MRS was used as control medium. Ten Lactobacillus strains containing an average of 2.34 ± 0.29 log CFU/mL were inoculated individually into batches of MRS, SPM1, SPM2, and SPM3. The growth patterns for the tested Lactobacillus strains growing in SPM2 and SPM3 were found to be similar to that in MRS. The average final population after 24 h of incubation in MRS, SPM2, and SPM3 reached 10.41 ± 0.35, 10.59 ± 0.27, and 10.72 ± 0.19 log CFU/mL respectively. SPM2 and SPM3 maintained higher pH values throughout the incubation period than MRS. These findings indicate that SPM2 can be a suitable medium for the growth of Lactobacillus and can provide an alternative at low-cost.

  1. Screening of biofilm formation by beneficial vaginal lactobacilli and influence of culture media components.

    PubMed

    Terraf, M C Leccese; Juárez Tomás, M S; Nader-Macías, M E F; Silva, C

    2012-12-01

    To assess the ability of vaginal lactobacilli to form biofilm under different culture conditions and to determine the relationship between their growth and the capability of biofilm formation by selected strains. Fifteen Lactobacillus strains from human vagina were tested for biofilm formation by crystal violet staining. Only Lactobacillus rhamnosus Centro de Referencia para Lactobacilos Culture Collection (CRL) 1332, Lact. reuteri CRL 1324 and Lact. delbrueckii CRL 1510 were able to grow and form biofilm in culture media without Tween 80. However, Lact. gasseri CRL 1263 (a non-biofilm-forming strain) did not grow in these media. Scanning electron microscopy showed that Lact. rhamnosus CRL 1332 and Lact. reuteri CRL 1324 formed a highly structured biofilm, but only Lact. reuteri CRL 1324 showed a high amount of extracellular material in medium without Tween. Biofilm formation was significantly influenced by the strain, culture medium, inoculum concentration, microbial growth and chemical nature of the support used for the assay. The results allow the selection of biofilm-forming vaginal Lactobacillus strains and the conditions and factors that affect this phenomenon. © 2012 The Society for Applied Microbiology.

  2. Antagonistic activity of probiotic lactobacilli against human enteropathogenic bacteria in homemade tvorog curd cheese from Azerbaijan

    PubMed Central

    Masoumikia, Reza; Ganbarov, Khudaverdi

    2015-01-01

    Introduction: Human health is deemed to be maintained by the crosstalk among the body and probiotic bacteria. Disruptions in this composition are associated with the pathogenesis of numerous diseases. Through modernization, traditional foods consumption has been abandoned and native food starters have been substituted with industrial products. Hence, we aimed to isolate and evaluate probiotic bacteria from traditional fermented foods which can be used as probiotics as well as starter cultures in food industry and in medicine against antibiotic resistant pathogenes. To this end, an intact village was recognized in the Republic of Azerbaijan with traditional dairy products, yielding a variety of potential probiotics. Methods: In this study, tvorog as a traditional dairy product from Dashkasan, Ismailli and khachmaz regions in Azerbaijan was characterized for the isolation of Lactobacilli with probiotic potentiality. The bacteria were tested for the resistance to the acid, bile, and the antagonistic effect of human pathogenic bacteria. The isolates were identified by 16s rDNA sequencing with a blast to the databank. Results: Three species with higher homology to the L. planetarium, L. rhamnosus, and L. casei with high probiotic potentiality and antibacterial effects were isolated. Conclusion: Homemade tvorog curd cheese in Azerbaijan harbor a variety of probiotics with industrial applications as well as potentiality to be preserved in a biobank for the future medicinal applications especially against antibiotic resistant pathogenes. PMID:26457253

  3. Isolation and characterization of lactobacilli from some traditional fermented foods and evaluation of the bacteriocins.

    PubMed

    Jamuna, Marilingappa; Jeevaratnam, Kadirvelu

    2004-04-01

    Lactic acid bacteria (LAB) commonly used in food as starter cultures are known to produce antimicrobial substances such as bacteriocins and have great potential as food biopreservatives. LAB isolated from traditional fermented foods (appam batter and pickles) were screened for bacteriocin production. Two lactobacilli, LABB and LABP (one from each source) producing bacteriocins were characterized. Both the bacilli were homo-fermentative, catalase negative and micro-aerophilic in nature. LABB was found to be a thermobacterium growing at 45 degrees C while LABP was a streptobacterium growing at 15 degrees C. Both were able to grow at pH 4.5-8.6 but were intolerant to high salt concentration. They failed to produce gas from glucose as well as ammonia from arginine. Among the sugars examined they could not ferment arabinose, raffinose, rhamnose or xylose. Additionally, LABB could not ferment esculin, gluconate or mannose. LABB is identified as Lactobacillus acidophilus while LABP as Lb. casei. Their bacteriocins showed a broad inhibitory spectrum against the indicator organisms tested. They were active below pH 8.0 and after autoclaving as well. There was a complete loss of activity when treated with proteolytic enzymes such as trypsin indicating the proteinaceous nature of the active molecules. SDS-PAGE of partially purified bacteriocins indicated the molecular mass of the bacteriocin as 3.8 and 4.5 kDa for LABB and LABP respectively.

  4. Conserved S-Layer-Associated Proteins Revealed by Exoproteomic Survey of S-Layer-Forming Lactobacilli

    PubMed Central

    Johnson, Brant R.; Hymes, Jeffrey; Sanozky-Dawes, Rosemary; Henriksen, Emily DeCrescenzo

    2015-01-01

    The Lactobacillus acidophilus homology group comprises Gram-positive species that include L. acidophilus, L. helveticus, L. crispatus, L. amylovorus, L. gallinarum, L. delbrueckii subsp. bulgaricus, L. gasseri, and L. johnsonii. While these bacteria are closely related, they have varied ecological lifestyles as dairy and food fermenters, allochthonous probiotics, or autochthonous commensals of the host gastrointestinal tract. Bacterial cell surface components play a critical role in the molecular dialogue between bacteria and interaction signaling with the intestinal mucosa. Notably, the L. acidophilus complex is distinguished in two clades by the presence or absence of S-layers, which are semiporous crystalline arrays of self-assembling proteinaceous subunits found as the outermost layer of the bacterial cell wall. In this study, S-layer-associated proteins (SLAPs) in the exoproteomes of various S-layer-forming Lactobacillus species were proteomically identified, genomically compared, and transcriptionally analyzed. Four gene regions encoding six putative SLAPs were conserved in the S-layer-forming Lactobacillus species but not identified in the extracts of the closely related progenitor, L. delbrueckii subsp. bulgaricus, which does not produce an S-layer. Therefore, the presence or absence of an S-layer has a clear impact on the exoproteomic composition of Lactobacillus species. This proteomic complexity and differences in the cell surface properties between S-layer- and non-S-layer-forming lactobacilli reveal the potential for SLAPs to mediate intimate probiotic interactions and signaling with the host intestinal mucosa. PMID:26475115

  5. Conserved S-Layer-Associated Proteins Revealed by Exoproteomic Survey of S-Layer-Forming Lactobacilli.

    PubMed

    Johnson, Brant R; Hymes, Jeffrey; Sanozky-Dawes, Rosemary; Henriksen, Emily DeCrescenzo; Barrangou, Rodolphe; Klaenhammer, Todd R

    2015-10-16

    The Lactobacillus acidophilus homology group comprises Gram-positive species that include L. acidophilus, L. helveticus, L. crispatus, L. amylovorus, L. gallinarum, L. delbrueckii subsp. bulgaricus, L. gasseri, and L. johnsonii. While these bacteria are closely related, they have varied ecological lifestyles as dairy and food fermenters, allochthonous probiotics, or autochthonous commensals of the host gastrointestinal tract. Bacterial cell surface components play a critical role in the molecular dialogue between bacteria and interaction signaling with the intestinal mucosa. Notably, the L. acidophilus complex is distinguished in two clades by the presence or absence of S-layers, which are semiporous crystalline arrays of self-assembling proteinaceous subunits found as the outermost layer of the bacterial cell wall. In this study, S-layer-associated proteins (SLAPs) in the exoproteomes of various S-layer-forming Lactobacillus species were proteomically identified, genomically compared, and transcriptionally analyzed. Four gene regions encoding six putative SLAPs were conserved in the S-layer-forming Lactobacillus species but not identified in the extracts of the closely related progenitor, L. delbrueckii subsp. bulgaricus, which does not produce an S-layer. Therefore, the presence or absence of an S-layer has a clear impact on the exoproteomic composition of Lactobacillus species. This proteomic complexity and differences in the cell surface properties between S-layer- and non-S-layer-forming lactobacilli reveal the potential for SLAPs to mediate intimate probiotic interactions and signaling with the host intestinal mucosa. Copyright © 2015 Johnson et al.

  6. Heterologous Protein Secretion in Lactobacilli with Modified pSIP Vectors

    PubMed Central

    Karlskås, Ingrid Lea; Maudal, Kristina; Axelsson, Lars; Rud, Ida; Eijsink, Vincent G. H.; Mathiesen, Geir

    2014-01-01

    We describe new variants of the modular pSIP-vectors for inducible gene expression and protein secretion in lactobacilli. The basic functionality of the pSIP system was tested in Lactobacillus strains representing 14 species using pSIP411, which harbors the broad-host-range Lactococcus lactis SH71rep replicon and a β-glucuronidase encoding reporter gene. In 10 species, the inducible gene expression system was functional. Based on these results, three pSIP vectors with different signal peptides were modified by replacing their narrow-host-range L. plantarum 256rep replicon with SH71rep and transformed into strains of five different species of Lactobacillus. All recombinant strains secreted the target protein NucA, albeit with varying production levels and secretion efficiencies. The Lp_3050 derived signal peptide generally resulted in the highest levels of secreted NucA. These modified pSIP vectors are useful tools for engineering a wide variety of Lactobacillus species. PMID:24614815

  7. Evidence for the presence of heat-stable protein (HPr) and ATP-dependent HPr kinase in heterofermentative lactobacilli lacking phosphoenolpyruvate:glycose phosphotransferase activity.

    PubMed Central

    Reizer, J; Peterkofsky, A; Romano, A H

    1988-01-01

    An analysis of the biochemical basis for the lack of phosphoenolpyruvate:glycose phosphotransferase activity in heterofermentative lactobacilli was carried out. Extracts of Lactobacillus brevis and Lactobacillus buchneri failed to reconstitute phosphotransferase activity of extracts of Staphylococcus aureus mutants impaired in the phosphotransferase system due to the absence of enzyme I, enzyme IILac, or enzyme IIILac activity, suggesting that these lactobacilli lack those phosphotransferase system components. In contrast, complementation tests with an extract of a S. aureus mutant deficient in heat-stable protein (HPr) indicated the presence of HPr activity in heterofermentative lactobacilli. The HPr of L. brevis was purified and shown to have properties similar to those of a typical HPr. In addition, L. brevis possesses an ATP-dependent protein kinase that phosphorylates a serine residue of the endogenous HPr as well as other HPrs of Gram-positive origin. The kinase activity is markedly stimulated by phosphorylated compounds related to sugar metabolism and is negatively modulated by orthophosphate, pyrophosphate, or arsenate and by a low molecular weight endogenous factor. In keeping with the idea of a regulatory role for the phosphorylation of HPr in lactobacilli, a HPr[Ser(P)] phosphatase activity in L. brevis was also demonstrated. On the basis of the finding of HPr and a system for its reversible covalent modification in an organism devoid of a functional phosphotransferase system we propose that, in lactobacilli, HPr has a role in the regulation of pathways other than the phosphotransferase system. Images PMID:2832843

  8. DETECTION OF LACTOBACILLI IN MONTHLY MAIL-IN STOOL SAMPLES FROM 3-18 MONTHS OLD INFANTS AT GENETIC RISK FOR TYPE 1 DIABETES

    PubMed Central

    Salami, F; Abels, M; Hyöty, H; Vaziri-Sani, F; Aronsson, CA; Vehik, K; Delli, A; Hagopian, WA; Rewers, M; Ziegler, AG; Simell, O; Akolkar, B; Krischer, J; She, J; Lernmark, Å

    2014-01-01

    The feasibility to detect lactobacilli in mail-in infant stools collected monthly from 3-18 months old children was investigated. The aim was to determine total lactobacilli and Lactobacillus plantarum (L. plantarum) content (ng/g feces) in 50 infants each from Colorado (648 samples), Finland (624 samples) and Sweden (685 samples) who participated in the TEDDY (The Environmental Determinants of Diabetes in the Young) study. Total lactobacilli content varied markedly between 5 and 16,800 ng/g feces in the three clinical sites within and between individuals especially in infants. L.plantarum also varied markedly intra- and inter-individually from <0.5 - 736 ng/g feces. A higher variability of total lactobacilli was found before 10 months of age than after in the three different clinical sites. Sweden had the lowest total lactobacilli content compared to Colorado and Finland while the L.plantarum content was higher in Sweden. Mail-in stool samples from infants should prove useful in analyzing probiotics in childhood. PMID:25045339

  9. Selected lactobacilli and bifidobacteria development in solid state fermentation using soybean paste.

    PubMed

    Rodríguez de Olmos, Antonieta; Correa Deza, Maria Alejandra; Garro, Marisa S

    At present, consumers are looking for more natural foods so as to improve health through their active compounds. Within this context, soybean is an excellent substrate due to its beneficial effects on consumers' health. Moreover, lactic cultures are widely used in the food industry to improve the technological, nutritional and functional characteristics of fermented foods. It is interesting to find new matrices in which to transport these starter cultures (potentially probiotic microorganisms). The aim of this research was to obtain a solid state fermentation system from soybean to analyze the behavior of selected lactobacilli and bifidobacteria, with the potential to develop a functional vegetarian food to serve as carrier for the microorganisms. A soybean solid substrate system was optimized by selecting the relationship of the main processing parameters. Homogeneous soybean pastes with different moisture content (60-80%) were obtained and used as substrate and support for solid substrate fermentation. Moisture, inoculum size and temperature were optimized: 80%, 4%, 37°C, respectively. L. rhamnosus CRL 981 was chosen as the best starter to use in this kind of fermentation, showing high acidification and cell counts at 24h of fermentation and increased specific growth rate in tested soybean pastes. It was demonstrated that the selected soybean paste could be used as a carrier of these microorganisms having probiotic potential for the production of vegetarian foods. Moreover, these microorganisms are able to modify the substrate to enhance their nutritional and functional characteristics, which would change the soybean into a more attractive product for consumers. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Vaginal estriol-lactobacilli combination and quality of life in endocrine-treated breast cancer.

    PubMed

    Buchholz, S; Mögele, M; Lintermans, A; Bellen, G; Prasauskas, V; Ortmann, O; Grob, P; Neven, P; Donders, G

    2015-04-01

    We investigated the effect of a combination of vaginal ultra-low-dose estriol with lactobacilli on the sexual functioning domain of quality of life during the treatment of breast cancer survivors on an aromatase inhibitor with vaginal atrophy. This was an open-label, bicentric, exploratory, clinical study in 16 postmenopausal breast cancer survivors on aromatase inhibitors suffering from vaginal atrophy-induced sexual disorders. Atrophy symptoms were assessed by scoring with an 11-point estimation scale (0 = not at all, 10 = worst imaginable feeling). Sexuality parameters of quality of life and medication adherence were recorded in a patient's diary and in the Female Somatic Sexual Experience Instrument (FSSEI) questionnaire. Patients underwent an initial treatment for 4 weeks (one vaginal tablet of Gynoflor(®) containing 0.03 mg estriol daily), followed by maintenance therapy (three vaginal Gynoflor(®) tablets weekly) for 8 weeks. Vaginal dryness continuously improved from a median score of 8 at entry to a score of 4 at the end of initial therapy, and a median score of 2 at the end of maintenance therapy. Normal sexual activity before breast cancer diagnosis was reported by 14 women (88%). At study entry, only three women (19%) were sexually active. At the end of the Gynoflor(®) regimen, ten women (63%) reported sexual activity, of which seven (44%) reported sexual intercourse. The FSSEI demonstrated a non-significant trend of improvement of parameters related to sexuality. Local vaginal therapy with Gynoflor(®) in breast cancer survivors on aromatase inhibitors reporting atrophic vaginitis could be considered as a useful treatment for the quality of sexual life.

  11. Characterization of Pro-Inflammatory Flagellin Proteins Produced by Lactobacillus ruminis and Related Motile Lactobacilli

    PubMed Central

    Neville, B. Anne; Forde, Brian M.; Claesson, Marcus J.; Darby, Trevor; Coghlan, Avril; Nally, Kenneth; Ross, R. Paul; O’Toole, Paul W.

    2012-01-01

    Lactobacillus ruminis is one of at least twelve motile but poorly characterized species found in the genus Lactobacillus. Of these, only L. ruminis has been isolated from mammals, and this species may be considered as an autochthonous member of the gastrointestinal microbiota of humans, pigs and cows. Nine L. ruminis strains were investigated here to elucidate the biochemistry and genetics of Lactobacillus motility. Six strains isolated from humans were non-motile while three bovine isolates were motile. A complete set of flagellum biogenesis genes was annotated in the sequenced genomes of two strains, ATCC25644 (human isolate) and ATCC27782 (bovine isolate), but only the latter strain produced flagella. Comparison of the L. ruminis and L. mali DSM20444T motility loci showed that their genetic content and gene-order were broadly similar, although the L. mali motility locus was interrupted by an 11.8 Kb region encoding rhamnose utilization genes that is absent from the L. ruminis motility locus. Phylogenetic analysis of 39 motile bacteria indicated that Lactobacillus motility genes were most closely related to those of motile carnobacteria and enterococci. Transcriptome analysis revealed that motility genes were transcribed at a significantly higher level in motile L. ruminis ATCC27782 than in non-motile ATCC25644. Flagellin proteins were isolated from L. ruminis ATCC27782 and from three other Lactobacillus species, while recombinant flagellin of aflagellate L. ruminis ATCC25644 was expressed and purified from E. coli. These native and recombinant Lactobacillus flagellins, and also flagellate L. ruminis cells, triggered interleukin-8 production in cultured human intestinal epithelial cells in a manner suppressed by short interfering RNA directed against Toll-Like Receptor 5. This study provides genetic, transcriptomic, phylogenetic and immunological insights into the trait of flagellum-mediated motility in the lactobacilli. PMID:22808200

  12. Differential inflammatory mediator response in vitro from murine macrophages to lactobacilli and pathogenic intestinal bacteria.

    PubMed

    Marcinkiewicz, J; Ciszek, M; Bobek, M; Strus, M; Heczko, P B; Kurnyta, M; Biedroń, R; Chmielarczyk, A

    2007-06-01

    Chronic active colitis (including inflammatory bowel disease - IBD) is maintained by a variety of pro-inflammatory mediators. Certain intestinal bacterial strains may induce colitis, whereas some strains (e.g. Lactobacillus spp.) show a protective effect in colitis owing to their anti-inflammatory activity. In this study, we have examined the production of selected inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO) and the expression of haeme oxygenase-1 (HO-1) by murine peritoneal macrophages stimulated in vitro by the intestinal bacterial strains, isolated from mice with colitis. Lactobacillus strains (Lactobacillus reuteri, L. johnsonii, L. animalis/murinus) and two potentially pathogenic bacteria (Escherichia coli and Enterococcus faecalis) induced the production of substantial amounts of cytokines with a strain specific profile. Despite some interstrain differences, all lactobacilli induced production of anti-inflammatory cytokines (IL-10(high), IL-6(low), IL-12p70(low)). Conversely, E. faecalis and E. coli induced the production of proinflammatory cytokines (TNF-alpha, IL-12p70), the cytokines essential for chronic IBD. Macrophages released comparably substantial amounts of ROS in response to all Lactobacillus strains tested, while E. coli and E. faecalis ability to induce generation of ROS was negligible. In contrast to ROS, the production of NO/NO(2) (-) by macrophages activated with all bacterial strains tested was similar. Moreover, for the first time, it has been shown that intestinal bacteria differed in their ability to induce expression of HO-1, a stress-inducible enzyme with antioxidant and anti-inflammatory properties. The beneficial immunoregulatory properties of candidate probiotic bacteria for the treatment of IBD are discussed.

  13. Differential inflammatory mediator response in vitro from murine macrophages to lactobacilli and pathogenic intestinal bacteria

    PubMed Central

    Marcinkiewicz, J; Ciszek, M; Bobek, M; Strus, M; Heczko, P B; Kurnyta, M; Biedroń, R; Chmielarczyk, A

    2007-01-01

    Chronic active colitis (including inflammatory bowel disease – IBD) is maintained by a variety of pro-inflammatory mediators. Certain intestinal bacterial strains may induce colitis, whereas some strains (e.g. Lactobacillus spp.) show a protective effect in colitis owing to their anti-inflammatory activity. In this study, we have examined the production of selected inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO) and the expression of haeme oxygenase-1 (HO-1) by murine peritoneal macrophages stimulated in vitro by the intestinal bacterial strains, isolated from mice with colitis. Lactobacillus strains (Lactobacillus reuteri, L. johnsonii, L. animalis/murinus) and two potentially pathogenic bacteria (Escherichia coli and Enterococcus faecalis) induced the production of substantial amounts of cytokines with a strain specific profile. Despite some interstrain differences, all lactobacilli induced production of anti-inflammatory cytokines (IL-10high, IL-6low, IL-12p70low). Conversely, E. faecalis and E. coli induced the production of proinflammatory cytokines (TNF-α, IL-12p70), the cytokines essential for chronic IBD. Macrophages released comparably substantial amounts of ROS in response to all Lactobacillus strains tested, while E. coli and E. faecalis ability to induce generation of ROS was negligible. In contrast to ROS, the production of NO/NO2− by macrophages activated with all bacterial strains tested was similar. Moreover, for the first time, it has been shown that intestinal bacteria differed in their ability to induce expression of HO-1, a stress-inducible enzyme with antioxidant and anti-inflammatory properties. The beneficial immunoregulatory properties of candidate probiotic bacteria for the treatment of IBD are discussed. PMID:17504445

  14. Antimicrobial and antibiofilm potential of biosurfactants isolated from lactobacilli against multi-drug-resistant pathogens

    PubMed Central

    2014-01-01

    Background Biosurfactants (BS) are amphiphilic compounds produced by microbes, either on the cell surface or secreted extracellularly. BS exhibit strong antimicrobial and anti-adhesive properties, making them good candidates for applications used to combat infections. In this study, our goal was to assess the in vitro antimicrobial, anti-adhesive and anti-biofilm abilities of BS produced by Lactobacillus jensenii and Lactobacillus rhamnosus against clinical Multidrug Resistant (MDR) strains of Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus (MRSA). Cell-bound BS from both L. jensenii and L. rhamnosus were extracted and isolated. The surface activities of crude BS samples were evaluated using an oil spreading assay. The antimicrobial, anti-adhesive and anti-biofilm activities of both BS against the above mentioned MDR pathogens were determined. Results Surface activities for both BS ranged from 6.25 to 25 mg/ml with clear zones observed between 7 and 11 cm. BS of both L. jensenii and L. rhamnosus showed antimicrobial activities against A. baumannii, E. coli and S. aureus at 25-50 mg/ml. Anti-adhesive and anti-biofilm activities were also observed for the aforementioned pathogens between 25 and 50 mg/ml. Finally, analysis by electron microscope indicated that the BS caused membrane damage for A. baumannii and pronounced cell wall damage in S. aureus. Conclusion Our results indicate that BS isolated from two Lactobacilli strains has antibacterial properties against MDR strains of A. baumannii, E. coli and MRSA. Both BS also displayed anti-adhesive and anti-biofilm abilities against A. baumannii, E. coli and S. aureus. Together, these capabilities may open up possibilities for BS as an alternative therapeutic approach for the prevention and/or treatment of hospital-acquired infections. PMID:25124936

  15. Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial.

    PubMed

    Anauate Netto, Camillo; Marcucci, Maria Cristina; Paulino, Niraldo; Anido-Anido, Andrea; Amore, Ricardo; de Mendonça, Sergio; Borelli Neto, Laurindo; Bretz, Walter Antonio

    2013-04-01

    The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups: 1) PROP-alcohol-free 2% typified propolis rinse (n = 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PL-placebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

  16. Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial

    PubMed Central

    Anauate Netto, Camillo; Marcucci, Maria Cristina; Paulino, Niraldo; Anido-Anido, Andrea; Amore, Ricardo; de Mendonça, Sergio; Borelli Neto, Laurindo; Bretz, Walter Antonio

    2014-01-01

    Objective The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). Methods One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18–55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups: 1) PROP-alcohol-free 2% typified propolis rinse (n = 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PL-placebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. Results PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). Conclusion Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies. PMID:24494174

  17. Growth kinetic models of five species of Lactobacilli and lactose consumption in batch submerged culture.

    PubMed

    Rezvani, Fazlollah; Ardestani, Fatemeh; Najafpour, Ghasem

    Kinetic behaviors of five Lactobacillus strains were investigated with Contois and Exponential models. Awareness of kinetic behavior of microorganisms is essential for their industrial process design and scale up. The consistency of experimental data was evaluated using Excel software. L. bulgaricus was introduced as the most efficient strain with the highest biomass and lactic acid yield of 0.119 and 0.602gg(-1) consumed lactose, respectively. The biomass and carbohydrate yield of L. fermentum and L. lactis were slightly less and close to L. bulgaricus. Biomass and lactic acid production yield of 0.117 and 0.358 for L. fermentum and 0.114 and 0.437gg(-1) for L.actobacillus lactis were obtained. L. casei and L. delbrueckii had the less biomass yield, nearly 11.8 and 22.7% less than L. bulgaricus, respectively. L. bulgaricus (R(2)=0.9500 and 0.9156) and L. casei (R(2)=0.9552 and 0.8401) showed acceptable consistency with both models. The investigation revealed that the above mentioned models are not suitable to describe the kinetic behavior of L. fermentum (R(2)=0.9367 and 0.6991), L. delbrueckii (R(2)=0.9493 and 0.7724) and L. lactis (R(2)=0.8730 and 0.6451). Contois rate equation is a suitable model to describe the kinetic of Lactobacilli. Specific cell growth rate for L. bulgaricus, L. casei, L. fermentum, L. delbrueckii and L. lactis with Contois model in order 3.2, 3.9, 67.6, 10.4 and 9.8-fold of Exponential model.

  18. Salivary levels of mutans streptococci and Lactobacilli among Palestinian school children in East Jerusalem.

    PubMed

    Steinberg, Doron; Eskander, Lana; Zini, Avraham; Sgan-Cohen, Harold; Bajali, Musa

    2014-04-01

    The aim of the present study was to investigate the distribution of oral cariogenic bacteria among 12-year-old Palestinian children attending schools in East Jerusalem. Salivary levels of mutans streptococci (MS) and Lactobacilli (LB) were examined by semi-quantitative commercial kits and then correlated to social-demographic parameters. Overall, 52.1 % of the examined children presented the highest possible ranking score categories for MS bacteria, with only 5.4 % in the lowest category. Only 12.6 % of the school children presented the highest LB score, while 25 % had the lowest ranking score. Salivary MS levels in children attending private schools were lower than those of children in government schools and United Nations Relief and Works Agency (UNRWA) schools. Conversely, levels of LB were lowest in children attending UNRWA schools compared to government and private schools. Girls had significantly higher amounts of MS and LB than boys (p = 0.001). Lower MS levels were significantly related to the following socioeconomic variables: higher father's education level (p = 0.037), higher mother's education level (p = 0.063), mother's employment status (p = 0.012), and lower home density (p = 0.001). For LB, the only significant socioeconomic variable was higher father's employment level, which was related to lower LB level (p = 0.025). Levels of MS and LB were found to be strongly related with socioeconomic status among Palestinian children in East Jerusalem. The relatively high prevalence of cariogenic bacteria suggests that oral care prevention and treatment demands special attention from the health care institutions and authorities.

  19. Metabolites produced by probiotic Lactobacilli rapidly increase glucose uptake by Caco-2 cells

    PubMed Central

    2010-01-01

    Background Although probiotic bacteria and their metabolites alter enterocyte gene expression, rapid, non-genomic responses have not been examined. The present study measured accumulation of tracer (2 μM) glucose by Caco-2 cells after exposure for 10 min or less to a chemically defined medium (CDM) with different monosaccharides before and after anaerobic culture of probiotic Lactobacilli. Results Growth of L. acidophilus was supported by CDM with 110 mM glucose, fructose, and mannose, but not with arabinose, ribose, and xylose or the sugar-free CDM. Glucose accumulation was reduced when Caco-2 cells were exposed for 10 min to sterile CDM with glucose (by 92%), mannose (by 90%), fructose (by 55%), and ribose (by 16%), but not with arabinose and xylose. Exposure of Caco-2 cells for 10 min to bacteria-free supernatants prepared after exponential (48 h) and stationary (72 h) growth phases of L. acidophilus cultured in CDM with 110 mM fructose increased glucose accumulation by 83% and 45%, respectively; exposure to a suspension of the bacteria had no effect. The increase in glucose accumulation was diminished by heat-denaturing the supernatant, indicating the response of Caco-2 cells is triggered by as yet unknown heat labile bacterial metabolites, not by a reduction in CDM components that decrease glucose uptake. Supernatants prepared after anaerobic culture of L. gasseri, L. amylovorus, L. gallinarum, and L. johnsonii in the CDM with fructose increased glucose accumulation by 83%, 32%, 27%, and 14%, respectively. Conclusion The rapid, non-genomic upregulation of SGLT1 by bacterial metabolites is a heretofore unrecognized interaction between probiotics and the intestinal epithelium. PMID:20089192

  20. Metabolites produced by probiotic Lactobacilli rapidly increase glucose uptake by Caco-2 cells.

    PubMed

    Rooj, Arun K; Kimura, Yasuhiro; Buddington, Randal K

    2010-01-20

    Although probiotic bacteria and their metabolites alter enterocyte gene expression, rapid, non-genomic responses have not been examined. The present study measured accumulation of tracer (2 microM) glucose by Caco-2 cells after exposure for 10 min or less to a chemically defined medium (CDM) with different monosaccharides before and after anaerobic culture of probiotic Lactobacilli. Growth of L. acidophilus was supported by CDM with 110 mM glucose, fructose, and mannose, but not with arabinose, ribose, and xylose or the sugar-free CDM. Glucose accumulation was reduced when Caco-2 cells were exposed for 10 min to sterile CDM with glucose (by 92%), mannose (by 90%), fructose (by 55%), and ribose (by 16%), but not with arabinose and xylose. Exposure of Caco-2 cells for 10 min to bacteria-free supernatants prepared after exponential (48 h) and stationary (72 h) growth phases of L. acidophilus cultured in CDM with 110 mM fructose increased glucose accumulation by 83% and 45%, respectively; exposure to a suspension of the bacteria had no effect. The increase in glucose accumulation was diminished by heat-denaturing the supernatant, indicating the response of Caco-2 cells is triggered by as yet unknown heat labile bacterial metabolites, not by a reduction in CDM components that decrease glucose uptake. Supernatants prepared after anaerobic culture of L. gasseri, L. amylovorus, L. gallinarum, and L. johnsonii in the CDM with fructose increased glucose accumulation by 83%, 32%, 27%, and 14%, respectively. The rapid, non-genomic upregulation of SGLT1 by bacterial metabolites is a heretofore unrecognized interaction between probiotics and the intestinal epithelium.

  1. Differential effect on cell-mediated immunity in human volunteers after intake of different lactobacilli

    PubMed Central

    Rask, C; Adlerberth, I; Berggren, A; Ahrén, I L; Wold, A E

    2013-01-01

    Probiotics are live microorganisms which have beneficial effects on the host when ingested in adequate amounts. Probiotic bacteria may stimulate immune effector functions in a strain-specific manner. In this blind placebo-controlled trial, we investigated the effects on the immune system following daily intake of six different strains of lactobacilli or the Gram-negative bacterium Pseudomonas lundensis for 2 or 5 weeks. Blood lymphocyte subsets were quantified by fluorescence activated cell sorter and the expression of activation and memory markers was determined. The bacterial strains were also examined for their capacity to adhere to human intestinal cells and to be phagocytosed by human peripheral blood mononuclear cells. Intake of Lactobacillus plantarum strain 299v increased the expression of the activation marker CD25 (P = 0·01) on CD8+ T cells and the memory cell marker CD45RO on CD4+ T cells (P = 0·03), whereas intake of L. paracasei tended to expand the natural killer T (NK T) cell population (P = 0·06). The phagocytic activity of granulocytes was increased following intake of L. plantarum 299v, L. plantarum HEAL, L. paracasei or L. fermentum. In contrast, ingestion of L. rhamnosus decreased the expression of CD25 and CD45RO significantly within the CD4+ cell population. The observed immune effects after in-vivo administration of the probiotic bacteria could not be predicted by either their adherence capacity or the in-vitro-induced cytokine production. The stimulation of CD8+ T cells and NK T cells suggests that intake of probiotic bacteria may enhance the immune defence against, e.g. viral infections or tumours. PMID:23574328

  2. The effect of polydextrose and probiotic lactobacilli in a Clostridium difficile–infected human colonic model

    PubMed Central

    Forssten, Sofia D.; Röytiö, Henna; Hibberd, Ashley A.; Ouwehand, Arthur C.

    2015-01-01

    Background Clostridium difficile is a natural resident of the intestinal microbiota; however, it becomes harmful when the normal intestinal microbiota is disrupted, and overgrowth and toxin production occurs. The toxins can cause bloating and diarrhoea, which may cause severe disease and have the potential to cause outbreaks in hospitals and other healthcare settings. Normally, antibiotic agents are used for treatment, although for some of the patients, these treatments provide only a temporary relief with a recurrence of C. difficile–associated diarrhoea. Objective The effects of polydextrose (PDX), Lactobacillus acidophilus NCFM, and L. paracasei Lpc-37 on the growth of C. difficile were investigated in an in vitro model of infected human large intestine. Design The semi-continuous colonic model is composed of four connected vessels inoculated with human faecal microbes and spiked with pathogenic C. difficile (DSM 1296). PDX in two concentrations (2 and 4%), NCFM, and Lpc-37 were fed to the system during the 2-day simulation, and the growth of C. difficile and several other microbial groups were monitored using quantitative polymerase chain reaction (qPCR) and 16S rDNA sequencing. Results The microbial community structure of the simulation samples was closely grouped according to treatment, and the largest shifts in the microbial composition were seen with PDX. The microbial diversity decreased significantly with 4% PDX, and the OTU containing C. difficile was significantly (p<0.01) decreased when compared to control and lactobacilli treatments. The mean numbers of C. difficile also decreased as detected by qPCR, although the reduction did not reach statistical significance. Conclusions The treatments influenced the colonic microbiota, and a trend for reduced numbers of C. difficile as well as alterations of several microbial groups could be detected. This suggests that PDX may be able to modulate the composition and/or function of the colonic microbiota in

  3. Lactococci and lactobacilli as mucosal delivery vectors for therapeutic proteins and DNA vaccines

    PubMed Central

    2011-01-01

    Food-grade Lactic Acid Bacteria (LAB) have been safely consumed for centuries by humans in fermented foods. Thus, they are good candidates to develop novel oral vectors, constituting attractive alternatives to attenuated pathogens, for mucosal delivery strategies. Herein, this review summarizes our research, up until now, on the use of LAB as mucosal delivery vectors for therapeutic proteins and DNA vaccines. Most of our work has been based on the model LAB Lactococcus lactis, for which we have developed efficient genetic tools, including expression signals and host strains, for the heterologous expression of therapeutic proteins such as antigens, cytokines and enzymes. Resulting recombinant lactococci strains have been tested successfully for their prophylactic and therapeutic effects in different animal models: i) against human papillomavirus type 16 (HPV-16)-induced tumors in mice, ii) to partially prevent a bovine β-lactoglobulin (BLG)-allergic reaction in mice and iii) to regulate body weight and food consumption in obese mice. Strikingly, all of these tools have been successfully transposed to the Lactobacillus genus, in recent years, within our laboratory. Notably, anti-oxidative Lactobacillus casei strains were constructed and tested in two chemically-induced colitis models. In parallel, we also developed a strategy based on the use of L. lactis to deliver DNA at the mucosal level, and were able to show that L. lactis is able to modulate the host response through DNA delivery. Today, we consider that all of our consistent data, together with those obtained by other groups, demonstrate and reinforce the interest of using LAB, particularly lactococci and lactobacilli strains, to develop novel therapeutic protein mucosal delivery vectors which should be tested now in human clinical trials. PMID:21995317

  4. Comparative mRNA Expression Profiles of Riboflavin Biosynthesis Genes in Lactobacilli Isolated from Human Feces and Fermented Bamboo Shoots.

    PubMed

    Thakur, Kiran; Tomar, Sudhir K; Wei, Zhao-Jun

    2017-01-01

    With the aim to bioprospect potent riboflavin producing lactobacilli, the present study was carried out to evaluate the relative mRNA expression of riboflavin biosynthesis genes namely Rib 1, Rib 2, Rib 3, and Rib 4 from potent riboflavin producers obtained from our previous studies. All the four genes were successfully cloned and sequenced for further analysis by in silico procedures. As studied by non-denaturing Polyacrylamide gel electrophoresis, no difference in size of all the four genes among those of various lactobacilli was observed. The relative fold increase in mRNA expression in Rib 1, Rib 2, Rib 3, and Rib 4 genes has been observed to be 10-, 1-, 0.7-, and 8.5-fold, respectively. Due to increase in relative mRNA expression for all the Rib genes as well as phenotypic production attribute, KTLF1 strain was used further for expression studies in milk and whey. The fold increase in mRNA expression for all the four Rib genes was higher at 12 and 18 h in milk and whey respectively. After exposure to roseoflavin, resistant variant of KTLF1 showed considerable increase in expression of all the targets genes. This is the first ever study to compare the mRNA expression of riboflavin biosynthesis pathway genes in lactobacilli and it also under lines the effect of media and harvesting time which significantly affect the expression of rib genes. The use of roseoflavin-resistant strains capable of synthesizing riboflavin in milk and whey paves a way for an exciting and economically viable biotechnological approach to develop novel riboflavin bio-enriched functional foods.

  5. Comparative mRNA Expression Profiles of Riboflavin Biosynthesis Genes in Lactobacilli Isolated from Human Feces and Fermented Bamboo Shoots

    PubMed Central

    Thakur, Kiran; Tomar, Sudhir K.; Wei, Zhao-Jun

    2017-01-01

    With the aim to bioprospect potent riboflavin producing lactobacilli, the present study was carried out to evaluate the relative mRNA expression of riboflavin biosynthesis genes namely Rib 1, Rib 2, Rib 3, and Rib 4 from potent riboflavin producers obtained from our previous studies. All the four genes were successfully cloned and sequenced for further analysis by in silico procedures. As studied by non-denaturing Polyacrylamide gel electrophoresis, no difference in size of all the four genes among those of various lactobacilli was observed. The relative fold increase in mRNA expression in Rib 1, Rib 2, Rib 3, and Rib 4 genes has been observed to be 10-, 1-, 0.7-, and 8.5-fold, respectively. Due to increase in relative mRNA expression for all the Rib genes as well as phenotypic production attribute, KTLF1 strain was used further for expression studies in milk and whey. The fold increase in mRNA expression for all the four Rib genes was higher at 12 and 18 h in milk and whey respectively. After exposure to roseoflavin, resistant variant of KTLF1 showed considerable increase in expression of all the targets genes. This is the first ever study to compare the mRNA expression of riboflavin biosynthesis pathway genes in lactobacilli and it also under lines the effect of media and harvesting time which significantly affect the expression of rib genes. The use of roseoflavin-resistant strains capable of synthesizing riboflavin in milk and whey paves a way for an exciting and economically viable biotechnological approach to develop novel riboflavin bio-enriched functional foods. PMID:28367143

  6. Highly Efficient Gluten Degradation by Lactobacilli and Fungal Proteases during Food Processing: New Perspectives for Celiac Disease▿

    PubMed Central

    Rizzello, Carlo G.; De Angelis, Maria; Di Cagno, Raffaella; Camarca, Alessandra; Silano, Marco; Losito, Ilario; De Vincenzi, Massimo; De Bari, Maria D.; Palmisano, Francesco; Maurano, Francesco; Gianfrani, Carmen; Gobbetti, Marco

    2007-01-01

    Presently, the only effective treatment for celiac disease is a life-long gluten-free diet. In this work, we used a new mixture of selected sourdough lactobacilli and fungal proteases to eliminate the toxicity of wheat flour during long-time fermentation. Immunological (R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay [ELISA] and R5 antibody-based Western blot), two-dimensional electrophoresis, and mass spectrometry (matrix-assisted laser desorption ionization-time of flight, strong-cation-exchange-liquid chromatography/capillary liquid chromatography-electrospray ionization-quadrupole-time of flight [SCX-LC/CapLC-ESI-Q-TOF], and high-pressure liquid chromatography-electrospray ionization-ion trap mass spectrometry) analyses were used to determine the gluten concentration. Assays based on the proliferation of peripheral blood mononuclear cells (PBMCs) and gamma interferon production by PBMCs and intestinal T-cell lines (iTCLs) from 12 celiac disease patients were used to determine the protein toxicity of the pepsin-trypsin digests from fermented wheat dough (sourdough). As determined by R5-based sandwich and competitive ELISAs, the residual concentration of gluten in sourdough was 12 ppm. Albumins, globulins, and gliadins were completely hydrolyzed, while ca. 20% of glutenins persisted. Low-molecular-weight epitopes were not detectable by SCX-LC/CapLC-ESI-Q-TOF mass spectrometry and R5-based Western blot analyses. The kinetics of the hydrolysis of the 33-mer by lactobacilli were highly efficient. All proteins extracted from sourdough activated PBMCs and induced gamma interferon production at levels comparable to the negative control. None of the iTCLs demonstrated immunoreactivity towards pepsin-trypsin digests. Bread making was standardized to show the suitability of the detoxified wheat flour. Food processing by selected sourdough lactobacilli and fungal proteases may be considered an efficient approach to eliminate gluten toxicity

  7. Regulation of acetic acid production by homo- and heterofermentative lactobacilli in whole-wheat sour-doughs.

    PubMed

    Martínez-Anaya, M A; Llin, M L; Pilar Macías, M; Collar, C

    1994-09-01

    The efficiency of sour-dough as a possible preservative agent of microbial spoilage of bread depends on its acetic acid content. As a secondary metabolite of sugar fermentation by lactic acid bacteria, acetic acid may be promoted in the presence of O2 or H+ acceptors. This paper studies the influence of O2 and high fructose content products (pure sugar, invert sugar, fructose syrup) addition on acetic acid production by hetero- (Lactobacillus brevis 25a, B-21, L-62; L. sanfrancisco L-99) and homofermentative (L. plantarum B-39) lactobacilli in whole-wheat sour-doughs [280 and 250 dough yield (DY)]. The pH and total titratable acidity (TTA) of sour-doughs after 44 h fermentation varied with DY and strain. As expected, the addition of O2 promoted greater increases in TTA with heterofermentative lactobacilli (15-42%) than with L. plantarum (15%). Fructose addition was only effective for heterofermentative strains, but the overall effects were smaller than those observed for oxygenation. The ability of lactobacilli to produce acetic acid in sour-doughs without treatment varied from 0.16 g/100 g flour at 44 h (B-39, 280, 350 DY) to 0.47-0.65% (L-62, 280, 350 DY). The production of acetic acid was positively promoted by all treatments. Oxygenation was again the most effective way of inducing acetic acid production; increases ranged from 54% (B-21) to 269% (L-99, 350 DY). The addition of H+ acceptors had variable effects.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. In Vitro Evaluation of the Probiotic Potential of Halotolerant Lactobacilli Isolated from a Ripened Tropical Mexican Cheese.

    PubMed

    Melgar-Lalanne, Guiomar; Rivera-Espinoza, Yadira; Reyes Méndez, Ana Itzel; Hernández-Sánchez, Humberto

    2013-12-01

    Three halotolerant lactobacilli (Lactobacillus plantarum, L. pentosus, and L. acidipiscis) isolated from a ripened Mexican tropical cheese (double cream Chiapas cheese) were evaluated as potential probiotics and compared with two commercial probiotic strains (L. casei Shirota and L. plantarum 299v) from human origin. All the strains survived the in vitro gastrointestinal simulation from the oral cavity to the ileum. During the stomach simulation, all the strains survived in satiety conditions (60 min, pH 3.0, 3 g/L pepsin, 150 rpm) and only L. pentosus could not survive under fasting conditions (60 min, pH 2.0, 3 g/L pepsin, 150 rpm). All the strains showed a strong hydrophilic character with low n-hexadecane and a variable chloroform affinity. L. plantarum showed a mucin adhesion rate similar to that of L. plantarum 299v and L. casei Shirota, while L. pentosus and L. acidipiscis had a lower mucin adhesion. The isolated halotolerant lactobacilli exhibited similar antimicrobial activity against some gram-positive and gram-negative pathogens in comparison with the two commercial strains. In addition, the proteinaceous character of the antimicrobial agents against the most pathogenic strains was demonstrated. The compounds showed a low molecular weight (less than 10 kDa). Besides, L. plantarum and L. acidipiscis were able to produce the enzyme β-galactosidase. Finally, L. pentosus was able to deconjugate taurocholic, taurodeoxycholic, glycocholic, and glycodeoxycholic acids better than the two commercial strains analyzed. All these results suggest that the halotolerant lactobacilli isolated from this ripened Mexican cheese could be potentially probiotic. This is the first time that halotolerant lactic acid bacteria have been shown to have probiotic properties.

  9. Highly efficient gluten degradation by lactobacilli and fungal proteases during food processing: new perspectives for celiac disease.

    PubMed

    Rizzello, Carlo G; De Angelis, Maria; Di Cagno, Raffaella; Camarca, Alessandra; Silano, Marco; Losito, Ilario; De Vincenzi, Massimo; De Bari, Maria D; Palmisano, Francesco; Maurano, Francesco; Gianfrani, Carmen; Gobbetti, Marco

    2007-07-01

    Presently, the only effective treatment for celiac disease is a life-long gluten-free diet. In this work, we used a new mixture of selected sourdough lactobacilli and fungal proteases to eliminate the toxicity of wheat flour during long-time fermentation. Immunological (R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay [ELISA] and R5 antibody-based Western blot), two-dimensional electrophoresis, and mass spectrometry (matrix-assisted laser desorption ionization-time of flight, strong-cation-exchange-liquid chromatography/capillary liquid chromatography-electrospray ionization-quadrupole-time of flight [SCX-LC/CapLC-ESI-Q-TOF], and high-pressure liquid chromatography-electrospray ionization-ion trap mass spectrometry) analyses were used to determine the gluten concentration. Assays based on the proliferation of peripheral blood mononuclear cells (PBMCs) and gamma interferon production by PBMCs and intestinal T-cell lines (iTCLs) from 12 celiac disease patients were used to determine the protein toxicity of the pepsin-trypsin digests from fermented wheat dough (sourdough). As determined by R5-based sandwich and competitive ELISAs, the residual concentration of gluten in sourdough was 12 ppm. Albumins, globulins, and gliadins were completely hydrolyzed, while ca. 20% of glutenins persisted. Low-molecular-weight epitopes were not detectable by SCX-LC/CapLC-ESI-Q-TOF mass spectrometry and R5-based Western blot analyses. The kinetics of the hydrolysis of the 33-mer by lactobacilli were highly efficient. All proteins extracted from sourdough activated PBMCs and induced gamma interferon production at levels comparable to the negative control. None of the iTCLs demonstrated immunoreactivity towards pepsin-trypsin digests. Bread making was standardized to show the suitability of the detoxified wheat flour. Food processing by selected sourdough lactobacilli and fungal proteases may be considered an efficient approach to eliminate gluten toxicity.

  10. Advanced application of bovine intestinal epithelial cell line for evaluating regulatory effect of lactobacilli against heat-killed enterotoxigenic Escherichia coli-mediated inflammation

    PubMed Central

    2013-01-01

    Background Previously, a bovine intestinal epithelial cell line (BIE cells) was successfully established. This work hypothesized that BIE cells are useful in vitro model system for the study of interactions of microbial- or pathogen-associated molecular patterns (MAMPs or PAMPs) with bovine intestinal epithelial cells and for the selection of immunoregulatory lactic acid bacteria (LAB). Results All toll-like receptor (TLR) genes were expressed in BIE cells, being TLR4 one of the most strongly expressed. We demonstrated that heat-stable PAMPs of enterotoxigenic Escherichia coli (ETEC) significantly enhanced the production of IL-6, IL-8, IL-1α and MCP-1 in BIE cells by activating both NF-κB and MAPK pathways. We evaluated the capacity of several lactobacilli strains to modulate heat-stable ETEC PAMPs-mediated inflammatory response in BIE cells. Among these strains evaluated, Lactobacillus casei OLL2768 attenuated heat-stable ETEC PAMPs-induced pro-inflammatory response by inhibiting NF-κB and p38 signaling pathways in BIE cells. Moreover, L. casei OLL2768 negatively regulated TLR4 signaling in BIE cells by up-regulating Toll interacting protein (Tollip) and B-cell lymphoma 3-encoded protein (Bcl-3). Conclusions BIE cells are suitable for the selection of immunoregulatory LAB and for studying the mechanisms involved in the protective activity of immunobiotics against pathogen-induced inflammatory damage. In addition, we showed that L. casei OLL2768 functionally modulate the bovine intestinal epithelium by attenuating heat-stable ETEC PAMPs-induced inflammation. Therefore L. casei OLL2768 is a good candidate for in vivo studying the protective effect of LAB against intestinal inflammatory damage induced by ETEC infection or heat-stable ETEC PAMPs challenge in the bovine host. PMID:23497067

  11. Comparative evaluation of three Lactobacilli with strain-specific activities for rats when supplied in drinking water.

    PubMed

    Guo, Xiao-Hua; Zhao, Zhi-Dan; Nam, Hyang-Mi; Kim, Jae-Myung

    2012-11-01

    To test the in vivo benefits of three lactobacilli and to compare their different efficacies based on strain-specific activities by using rats as an experimental model, a growth-promotion and a challenge trial were conducted. The three strains, Lactobacillus salivarius G1-1, Lactobacillus reuteri G22-2, and Lactobacillus reuteri G8-5 shared antimicrobial, bile-salt-hydrolase and amylolytic activities in vitro, respectively. In the 17 day growth-promotion trial, 48 rats were allotted to four treatments with 12 replicates per treatment: a control group, which received saline, as well as three experimental groups, which received 10(8) cells/ml of one of the three lactobacilli in saline suspension. The results showed that compared with the control group, L. reuteri G8-5 significantly improved feed efficiency and decreased fecal pH values on days 8 and 17, concomitant with reduced faecal coliform counts on d 17 (p < 0.05). All treatments with lactobacilli caused an increase in the moisture content of the faeces and a decrease in the serum total cholesterol and blood urea nitrogen levels. High-density lipoprotein cholesterol was only elevated for rats which received L. reuteri G22-2. In the Salmonella-challenge trial, 40 rats were allotted to five treatments (8 replicates per treatment) which consisted of a positive control (infected, no Lactobacillus pretreatment), a negative control (uninfected, no Lactobacillus pretreatment) and three Lactobacillus-pretreated groups (10(9) cells/ml in saline). The results showed that rats in all Lactobacillus pretreated groups were protected from infection with significantly higher weight gain, feed intake and feed efficiency compared with positive control rats (p < 0.05). Rats treated with L. salivarius G1-1 and L. reuteri G22-2 tended to exhibit higher weight gains than those pretreated with L. reuteri G8-5. Significantly lower Salmonella shedding in faeces, Salmonella numbers in the spleen and the relative weight of the spleen

  12. Screening of Probiotic Activities of Lactobacilli Strains Isolated from Traditional Tibetan Qula, A Raw Yak Milk Cheese

    PubMed Central

    Zhang, Bei; Wang, Yanping; Tan, Zhongfang; Li, Zongwei; Jiao, Zhen; Huang, Qunce

    2016-01-01

    In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78

  13. Immune-modulating effects in mouse dendritic cells of lactobacilli and bifidobacteria isolated from individuals following omnivorous, vegetarian and vegan diets.

    PubMed

    Luongo, Diomira; Treppiccione, Lucia; Sorrentino, Alida; Ferrocino, Ilario; Turroni, Silvia; Gatti, Monica; Di Cagno, Raffaella; Sanz, Yolanda; Rossi, Mauro

    2017-09-01

    Lactobacilli and bifidobacteria play a primary role in modulation of gut immunity. By considering that microbiota composition depends on various factors, including diet, we asked whether functional differences could characterize faecal populations of lactobacilli and bifidobacteria isolated from individuals with different dietary habits. 155 healthy volunteers who followed omnivorous, ovo-lacto-vegetarian or vegan diets were recruited at four Italian centres (Turin, Parma, Bologna and Bari). Faecal samples were collected; lactobacilli and bifidobacteria were isolated on selective media and their immunomodulatory activity was tested in mouse dendritic cells (DCs). Pre-incubation with lactobacilli increased LPS-induced expression of the maturation markers CD80 and CD86, whereas pre-incubation with bifidobacteria decreased such expression. Analysis of the cytokine profile indicated that strains of both genera induced down-regulation of IL-12 and up-regulation of IL-10, whereas expression of TNF-α was not modulated. Notably, analysis of anti-inflammatory potential (IL-10/IL-12 ratio) showed that lactobacilli evoked a greater anti-inflammatory effect than did bifidobacteria in the omnivorous group (P<0.05). We also found significantly reduced anti-inflammatory potential in the bacterial strains isolated from Bari's volunteers in comparison with those from the cognate groups from the other centres. In conclusion, lactobacilli and bifidobacteria showed a genus-specific ability of modulating in vitro innate immunity associated with a specific dietary habit. Furthermore, the geographical area had a significant impact on the anti-inflammatory potential of some components of faecal microbiota. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Design of novel urogenital pharmabiotic formulations containing lactobacilli, salivaricin CRL 1328 and non-microbial compounds with different functionalities.

    PubMed

    Vera Pingitore, Esteban; Juárez Tomás, María Silvina; Wiese, Birgitt; Nader-Macías, María Elena Fátima

    2015-06-01

    The administration of pharmabiotics is a promising alternative to antimicrobial drugs for the treatment and/or prevention of female urogenital infections. To design pharmabiotic formulations including bioactive ingredients of microbial origin combined with non-microbial substances and then to evaluate the stability of the combinations during freeze-drying and storage. Different formulations including Lactobacillus gasseri CRL 1263, Lactobacillus salivarius CRL 1328, salivaricin CRL 1328 (a bacteriocin) and non-microbial compounds (lactose, inulin and ascorbic acid) were assayed, and the ingredients were freeze-dried together or separately. The formulations were stored in gelatin capsules at 4 °C for 360 d. The viability of lactobacilli was affected to different extents depending on the strains and on the formulations assayed. L. salivarius and ascorbic acid were successfully combined only after the freeze-drying process. Salivaricin activity was not detected in formulations containing L. gasseri. However, when combined with ascorbic acid, lactose, inulin or L. salivarius, the bacteriocin maintained its activity for 360 d. The selected microorganisms proved to be compatible for their inclusion in multi-strain formulations together with lactose, inulin and ascorbic acid. Salivaricin could be included only in a L. salivarius CRL 1328 single-strain formulation together with non-microbial substances. This study provides new insights into the design of urogenital pharmabiotics combining beneficial lactobacilli, salivaricin CRL 1328 and compounds with different functionalities.

  15. Structural and immunomodulatory differences among lactobacilli exopolysaccharides isolated from intestines of mice with experimentally induced inflammatory bowel disease

    PubMed Central

    Górska, Sabina; Sandstrőm, Corine; Wojas-Turek, Justyna; Rossowska, Joanna; Pajtasz-Piasecka, Elżbieta; Brzozowska, Ewa; Gamian, Andrzej

    2016-01-01

    Characteristic changes in the microbiota biostructure and a decreased tolerance to intestinal bacteria have been associated with inflammatory bowel disease (IBD). However, few studies have examined the constituents of the intestinal microbiota, including the surface molecules of the bacteria, in healthy and IBD subsets. Here, we compare the chemical structures and immunomodulatory properties of the exopolysaccharides (EPS) of lactobacilli isolated from mice with induced IBD (IBD “+”) versus those of healthy mice (IBD “−”). Classical structural analyses were performed using nuclear magnetic resonance spectroscopy and mass spectrometry. Immunomodulatory properties were assessed by stimulation of dendritic cells derived from mouse bone marrow or human peripheral mononuclear blood cells. Our results revealed that EPS produced by IBD “+” species are structurally different from those isolated from IBD “−”. Moreover, the structurally different EPS generate different immune responses by dendritic cells. We speculate that resident strains could, upon gut inflammation, switch to producing EPS with specific motifs that are absent from lactobacilli IBD “−”, and/or that bacteria with a particular EPS structure might inhabit the inflamed intestinal mucosa. This study may shed light on the role of EPS in IBD and help the development of a specific probiotic therapy for this disease. PMID:27869188

  16. EFFECT OF DIETARY ANTIBIOTICS UPON COLIFORM BACTERIA AND LACTOBACILLI IN THE INTESTINAL TRACT OF URIC ACID-FED CHICKS1

    PubMed Central

    Bare, L. N.; Wiseman, R. F.; Abbott, O. J.

    1964-01-01

    Bare, L. N. (University of Kentucky, Lexington), R. F. Wiseman, and O. J. Abbott. Effect of dietary antibiotics upon coliform bacteria and lactobacilli in the intestinal tract of uric acid-fed chicks. J. Bacteriol. 87:329–331. 1964.—Male chicks (1-day-old; Vantress X Arbor Acre) were fed a basal glucose-soybean oil meal diet, a 2% uric acid-containing diet with and without 5 mg/lb of zinc bacitracin and 20 mg/lb of procaine penicillin G, and one supplemented with the antibiotics only. After 4 weeks, the chicks receiving the uric acid without antibiotics showed a weight depression. The presence of antibiotics in the ration with the uric acid reversed this growth depression. Bacteriological and chemical analyses of the contents of the small intestine revealed an increase in numbers of uricolytic Aerobacter spp. and an increased degradation of uric acid in the tract of the “uric-antibiotic”-fed chicks. The counts of lactobacilli were always lowest in this group of chicks PMID:14151052

  17. Utilization of physiological and taxonomic fluorescent probes to study Lactobacilli cells and response to pH challenge.

    PubMed

    Olszewska, Magdalena A; Kocot, Aleksandra M; Nynca, Anna; Łaniewska-Trokenheim, Łucja

    2016-11-01

    pH stress is recognized as an important feature for Lactobacillus in relation to lifestyle and commercial utility. Hence, this study aims to investigate the cell function of Lactobacilli cells subjected to pHs between 7.0 and 2.0. For this purpose, the Lactobacilli isolates of vegetable origin were first hybridized with fluorescent oligonucleotide rRNA probes for detecting Lactobacillus species. Then, cells were exposed to pH stress and labelled with fluorescent probes, carboxyfluorescein diacetate (CFDA) and propidium iodine (PI), which provided the insight into esterase activity and membrane integrity of cells. Among isolates, fluorescence in situ hybridization (FISH) enabled us to specifically detect L. plantarum and L. brevis. Interestingly, FCM analysis revealed that at pHs between 7.0 and 4.0 the cell membrane was intact, while after the exposure at pH 3.0, and 2.0 became perturbed or impaired. Finally, L. brevis and L. plantarum differed from each other in fluorescence labeling behaviour and culturability. However, the results showed that the same standard protocol for labeling enables discrimination of subpopulations of tested species. Depending on the species, the substantial culturability loss was observed at pH 3.0 and 2.0. These results suggest that the taxonomic and physiological fluorescent probes could be suitable for in situ detection of specific bacteria and rapid assessment of the physiological status of cells.

  18. Individual strains of Lactobacillus paracasei differentially inhibit human basophil and mouse mast cell activation

    PubMed Central

    Cassard, Lydie; Lalanne, Ana Inés; Garault, Peggy; Cotillard, Aurélie; Chervaux, Christian; Wels, Michiel; Smokvina, Tamara

    2016-01-01

    Abstract Introduction The microbiota controls a variety of biological functions, including immunity, and alterations of the microbiota in early life are associated with a higher risk of developing allergies later in life. Several probiotic bacteria, and particularly lactic acid bacteria, were described to reduce both the induction of allergic responses and allergic manifestations. Although specific probiotic strains were used in these studies, their protective effects on allergic responses also might be common for all lactobacilli. Methods To determine whether allergic effector cells inhibition is a common feature of lactobacilli or whether it varies among lactobacilli strains, we compared the ability of 40 strains of the same Lactobacillus paracasei species to inhibit IgE‐dependent mouse mast cell and human basophil activation. Results We uncovered a marked heterogeneity in the inhibitory properties of the 40 Lactobacillus strains tested. These segregated into three to four clusters depending on the intensity of inhibition. Some strains inhibited both mouse mast cell and human basophil activation, others strains inhibited only one cell type and another group induced no inhibition of activation for either cell type. Conclusions Individual Lactobacillus strains of the same species differentially inhibit IgE‐dependent activation of mouse mast cells and human basophils, two cell types that are critical in the onset of allergic manifestations. Although we failed to identify specific bacterial genes associated with inhibition by gene‐trait matching analysis, our findings demonstrate the complexity of the interactions between the microbiota and the host. These results suggest that some L. paracasei strains might be more beneficial in allergies than others strains and provide the bases for a rational screening of lactic acid bacteria strains as next‐generation probiotics in the field of allergy. PMID:27621812

  19. Use of MRSD medium and the hydrophobic grid membrane filter technique to differentiate between pediococci and lactobacilli in fermented meat and starter cultures.

    PubMed

    Holley, R A; Millard, G E

    1988-10-01

    Modifications of MRS medium were made by incorporation of 0.1 M L-arginine-HCl, 0.0025% phenol red, 100 IU polymyxin B sulfate, by deletion of meat extract, use of only 1.2% (w/v) glucose and increase of Mn2+ to 1000 ppm. In addition, adoption of the hydrophobic grid membrane filter (HGMF) system with 0.025% Fast Green FCF dye and adjustment of the agar medium to pH 5.5 gave MRSD (differential) medium. Incubation at 25 degrees C anaerobically under N2 or CO2 followed by a post-growth staining procedure involving use of 0.4% (w/v) bromocresol purple yielded conditions under which pediococci colonies were blue whereas homo- and heterofermentative lactobacilli were green in color. Under these conditions, 7 pediococci, 16 lactobacilli, and 18 commercial meat starter cultures were successfully analyzed by plate count to yield a differential assessment of the lactobacilli and pediococci present without interference from the 9 other genera tested. Streptococcus lactis and Leuconostoc spp. produced blue and green colonies, respectively, at 25 degrees C which might interference but these organisms are not present in significant numbers in fermented meats. Pediococcus parvulus and Streptococcus faecalis produced green and blue colonies, respectively, but their very poor growth at 25 degrees C prevented their interference. Use of the developed MRSD medium was described for enumeration of both pediococci and lactobacilli in starter cultures and in fermenting dry sausages to enable documentation of starter culture performance.

  20. Vaginal Lactobacillus Inhibits HIV-1 Replication in Human Tissues Ex Vivo

    PubMed Central

    Ñahui Palomino, Rogers A.; Zicari, Sonia; Vanpouille, Christophe; Vitali, Beatrice; Margolis, Leonid

    2017-01-01

    Lactobacillus species, which dominate vaginal microbiota of healthy reproductive-age women, lower the risks of sexually transmitted infections, including the risk of human immunodeficiency virus (HIV) acquisition. The exact mechanisms of this protection remain to be understood. Here, we investigated these mechanisms in the context of human cervico-vaginal and lymphoid tissues ex vivo. We found that all six Lactobacillus strains tested in these systems significantly suppressed HIV type-1 (HIV-1) infection. We identified at least three factors that mediated this suppression: (i) Acidification of the medium. The pH of the undiluted medium conditioned by lactobacilli was between 3.8 and 4.6. Acidification of the culture medium with hydrochloric acid (HCl) to this pH in control experiments was sufficient to abrogate HIV-1 replication. However, the pH of the Lactobacillus-conditioned medium (CM) diluted fivefold, which reached ∼6.9, was also suppressive for HIV-1 infection, while in control experiments HIV-1 infection was not abrogated when the pH of the medium was brought to 6.9 through the use of HCl. This suggested the existence of other factors responsible for HIV-1 inhibition by lactobacilli. (ii) Lactic acid. There was a correlation between the concentration of lactic acid in the Lactobacillus-CM and its ability to suppress HIV-1 infection in human tissues ex vivo. Addition of lactic acid isomers D and L to tissue culture medium at the concentration that corresponded to their amount released by lactobacilli resulted in HIV-1 inhibition. Isomer L was produced in higher quantities than isomer D and was mostly responsible for HIV-1 inhibition. These results indicate that lactic acid, in particular its L-isomer, inhibits HIV-1 independently of lowering of the pH. (iii) Virucidal effect. Incubation of HIV-1 in Lactobacillus-CM significantly suppressed viral infectivity for human tissues ex vivo. Finally, lactobacilli adsorb HIV-1, serving as a sink decreasing the

  1. Transcriptomic Analysis of the Innate Antiviral Immune Response in Porcine Intestinal Epithelial Cells: Influence of Immunobiotic Lactobacilli.

    PubMed

    Albarracin, Leonardo; Kobayashi, Hisakazu; Iida, Hikaru; Sato, Nana; Nochi, Tomonori; Aso, Hisashi; Salva, Susana; Alvarez, Susana; Kitazawa, Haruki; Villena, Julio

    2017-01-01

    Lactobacillus rhamnosus CRL1505 and Lactobacillus plantarum CRL1506 are immunobiotic strains able to increase protection against viral intestinal infections as demonstrated in animal models and humans. To gain insight into the host-immunobiotic interaction, the transcriptomic response of porcine intestinal epithelial (PIE) cells to the challenge with viral molecular associated pattern poly(I:C) and the changes in the transcriptomic profile induced by the immunobiotics strains CRL1505 and CRL1506 were investigated in this work. By using microarray technology and reverse transcription PCR, we obtained a global overview of the immune genes involved in the innate antiviral immune response in PIE cells. Stimulation of PIE cells with poly(I:C) significantly increased the expression of IFN-α and IFN-β, several interferon-stimulated genes, cytokines, chemokines, adhesion molecules, and genes involved in prostaglandin biosynthesis. It was also determined that lactobacilli differently modulated immune gene expression in poly(I:C)-challenged PIE cells. Most notable changes were found in antiviral factors (IFN-α, IFN-β, NPLR3, OAS1, OASL, MX2, and RNASEL) and cytokines/chemokines (IL-1β, IL-6, CCL4, CCL5, and CXCL10) that were significantly increased in lactobacilli-treated PIE cells. Immunobiotics reduced the expression of IL-15 and RAE1 genes that mediate poly(I:C) inflammatory damage. In addition, lactobacilli treatments increased the expression PLA2G4A, PTGES, and PTGS2 that are involved in prostaglandin E2 biosynthesis. L. rhamnosus CRL1505 and L. plantarum CRL1506 showed quantitative and qualitative differences in their capacities to modulate the innate antiviral immune response in PIE cells, which would explain the higher capacity of the CRL1505 strain when compared to CRL1506 to protect against viral infection and inflammatory damage in vivo. These results provided valuable information for the deeper understanding of the host-immunobiotic interaction and their

  2. Transcriptomic Analysis of the Innate Antiviral Immune Response in Porcine Intestinal Epithelial Cells: Influence of Immunobiotic Lactobacilli

    PubMed Central

    Albarracin, Leonardo; Kobayashi, Hisakazu; Iida, Hikaru; Sato, Nana; Nochi, Tomonori; Aso, Hisashi; Salva, Susana; Alvarez, Susana; Kitazawa, Haruki; Villena, Julio

    2017-01-01

    Lactobacillus rhamnosus CRL1505 and Lactobacillus plantarum CRL1506 are immunobiotic strains able to increase protection against viral intestinal infections as demonstrated in animal models and humans. To gain insight into the host–immunobiotic interaction, the transcriptomic response of porcine intestinal epithelial (PIE) cells to the challenge with viral molecular associated pattern poly(I:C) and the changes in the transcriptomic profile induced by the immunobiotics strains CRL1505 and CRL1506 were investigated in this work. By using microarray technology and reverse transcription PCR, we obtained a global overview of the immune genes involved in the innate antiviral immune response in PIE cells. Stimulation of PIE cells with poly(I:C) significantly increased the expression of IFN-α and IFN-β, several interferon-stimulated genes, cytokines, chemokines, adhesion molecules, and genes involved in prostaglandin biosynthesis. It was also determined that lactobacilli differently modulated immune gene expression in poly(I:C)-challenged PIE cells. Most notable changes were found in antiviral factors (IFN-α, IFN-β, NPLR3, OAS1, OASL, MX2, and RNASEL) and cytokines/chemokines (IL-1β, IL-6, CCL4, CCL5, and CXCL10) that were significantly increased in lactobacilli-treated PIE cells. Immunobiotics reduced the expression of IL-15 and RAE1 genes that mediate poly(I:C) inflammatory damage. In addition, lactobacilli treatments increased the expression PLA2G4A, PTGES, and PTGS2 that are involved in prostaglandin E2 biosynthesis. L. rhamnosus CRL1505 and L. plantarum CRL1506 showed quantitative and qualitative differences in their capacities to modulate the innate antiviral immune response in PIE cells, which would explain the higher capacity of the CRL1505 strain when compared to CRL1506 to protect against viral infection and inflammatory damage in vivo. These results provided valuable information for the deeper understanding of the host–immunobiotic interaction and their

  3. Phenotypic and genotypic screening of human-originated lactobacilli for vitamin B12 production potential: process validation by micro-assay and UFLC.

    PubMed

    Bhushan, Bharat; Tomar, S K; Mandal, Surajit

    2016-08-01

    Vitamin B12 (B12) production is a strain specific, rare and hidden functional attribute of lactobacilli and a cogent protocol for selection of such isolates from the herd of lactobacilli is required. The present study included isolation of lactobacilli from human samples (milk and fecal), screening them by a polyphasic (three-phase) methodology for probable B12 production potential and validating the screening protocol by exploring selected strains for in vitro vitamin production (two-phase fermentation) and quantification [micro-assay and ultra fast liquid chromatography (UFLC)]. Fifty-nine Lactobacillus strains were recovered from tested biological samples. Contrary to screening inapplicabilities of first [growth potential (GP) in B12-free medium] and second phases (GP in B12-free and cobalt chloride-supplemented conditions), third phase (cbiK gene detection on genomic DNA) alone was revealed as a validated strategy for selection of two probable B12-producing lactobacilli. Microbiological assay confirmed production and bioavailability of produced vitamin, while UFLC testing validated the results by precisely quantifying the cyanocobalamin (industrially produced bio-available form of B12) in cell extracts of both possible B12 producers [BHM10 (10.91 ± 1.55 μg/l) and BCF20 (23.90 ± 1.73 μg/l)] and positive standard [Lactobacillus reuteri DSM20016 (20.03 ± 4.17 μg/l)]. Moreover, this study generates a novel report for genomic detection, partial amplification and sequencing of cbiK gene in Lactobacillus plantarum species (both BHM10 and BCF20). In conclusion, contrary to first two phases, cbiK gene detection strategy successfully selects B12-producing strains from a group of human-originated lactobacilli and can be used in the future for similar screening studies.

  4. Effectiveness of vaginal tablets containing lactobacilli versus pH tablets on vaginal health and inflammatory cytokines: a randomized, double-blind study.

    PubMed

    Hemalatha, R; Mastromarino, P; Ramalaxmi, B A; Balakrishna, N V; Sesikeran, B

    2012-11-01

    The purpose of this study was to evaluate the effectiveness of lactobacilli on vaginal health and proinflammatory cytokines. Sixty-seven patients with bacterial vaginosis (BV), 50 with intermediate flora and 42 with normal vaginal flora were enrolled in this double-blind study. The subjects were randomized to receive probiotic lactobacilli vaginal tablets (L. brevis CD2, L. salivarius subsp. salicinius, L. plantarum) or the vaginal pH tablet (active comparator). Cervico-vaginal lavage was collected to measure the concentrations of IL-1β, TNFα and IL-6 by ELISA. Neutral sphingomyelinase activity was also quantified in both arms before and after treatment. The probiotic vaginal tablet was well tolerated and no side effects were reported. The study demonstrated a cure rate of nearly 80 %; i.e., 32 % of the women could restore normal vaginal flora and 47 % had improved Nugent score, whereas 20 % of the subjects did not clear BV in the first follow-up (after 8 days treatment). The pH tablet containing pH lowering compounds induced resolution of BV and restoration of normal vaginal flora in 74 % and 26 %, respectively. The lactobacilli tablet was found to be better than the pH tablet in preventing BV in healthy subjects. A significant reduction in IL-1β and IL-6 vaginal cytokines was observed after treatment with lactobacilli, while the active comparator did not have any effect on local proinflammatory cytokines. Vaginal neutral sphingomyelinase activity was not modified in either group. Vaginal tablets containing lactobacilli can cure BV and reduce vaginal inflammatory response.

  5. A mixed culture of Propionibacterium jensenii and Lactobacillus paracasei subsp. paracasei inhibits food spoilage yeasts.

    PubMed

    Schwenninger, Susanne Miescher; Meile, Leo

    2004-03-01

    Screening for antimicrobial features of 197 propionibacteria and tests with several antifungal lactobacilli led to the development of three protective cultures containing Propionibacterium jensenii SM11 and Lactobacillus paracasei subsp. paracasei strain SM20, SM29 or SM63. These cultures showed inhibitory activities (up to 5 orders of magnitude) against yeasts in dairy products such as yoghurt or cheese surface at refrigerator temperatures (6 degrees C) without an influence on the quality properties of the food. Initial cell numbers of 5 x 10(7) cells/g of propionibacteria and 1 x 10(8) cells/g of lactobacilli were the optimal concentrations to yield a total inhibition of the spoilage yeasts (Candida pulcherrima, Candida magnoliae, Candida parapsilosis and Zygosaccharomyces bailii).

  6. Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

    PubMed Central

    Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  7. Novel antimicrobial peptides that inhibit gram positive bacterial exotoxin synthesis.

    PubMed

    Merriman, Joseph A; Nemeth, Kimberly A; Schlievert, Patrick M

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges.

  8. Microbiological characterization of wet wheat distillers' grain, with focus on isolation of lactobacilli with potential as probiotics.

    PubMed

    Pedersen, C; Jonsson, H; Lindberg, J E; Roos, S

    2004-03-01

    Wet wheat distillers' grain (WWDG), a residue from ethanol fermentation, was examined from a microbiological perspective. After storage, WWDG was characterized by a high content of lactobacilli, nondetectable levels of other bacteria, occasional occurrence of yeasts, and a pH of about 3.6 and contained a mixture of lactic acid, acetic acid, and ethanol. The composition of lactobacilli in WWDG was simple, including primarily the species Lactobacillus amylolyticus, Lactobacillus panis, and Lactobacillus pontis, as determined by 16S rRNA gene sequencing. Since the use of WWDG as pig feed has indicated a health-promoting function, some relevant characteristics of three strains of each of these species were examined together with basal physiological parameters, such as carbohydrate utilization and growth temperature. Seven of the strains were isolated from WWDG, and two strains from pig feces were included for comparison. It was clear that all three species could grow at temperatures of 45 to 50 degrees C, with L. amylolyticus being able to grow at temperatures as high as 54 degrees C. This finding could be the explanation for the simple microflora of WWDG, where a low pH together with a high temperature during storage would select for these organisms. Some strains of L. panis and L. pontis showed prolonged survival at pH 2.5 in synthetic stomach juice and good growth in the presence of porcine bile salt. In addition, members of all three species were able to bind to immobilized mucus material in vitro. Especially the isolates from pig feces but, interestingly, some isolates from WWDG as well possessed properties that might be of importance for colonization of the gastrointestinal tracts of pigs.

  9. Supplementation of the Diet with High-Viscosity Beta-Glucan Results in Enrichment for Lactobacilli in the Rat Cecum

    PubMed Central

    Snart, Jennifer; Bibiloni, Rodrigo; Grayson, Teresa; Lay, Christophe; Zhang, Haiyan; Allison, Gwen E.; Laverdiere, Julie K.; Temelli, Feral; Vasanthan, Thavaratnam; Bell, Rhonda; Tannock, Gerald W.

    2006-01-01

    BBn (BioBreeding) rats were fed casein-based diets supplemented with barley flour, oatmeal flour, cellulose, or barley β-glucans of high [HV] or low viscosity [LV] in order to measure the prebiotic effects of these different sources of dietary fiber. The dietary impact on the composition of the cecal microbiota was determined by the generation of denaturing gradient gel electrophoresis (DGGE) profiles of PCR-amplified 16S rRNA gene sequences. The DGGE profiles produced from the cecal microbiota of rats within each dietary group were similar, but consensus profiles generated from pooled bacterial DNAs showed differences between rat groups. Animals fed HV glucans (HV-fed rats) had DGGE consensus profiles that were 30% dissimilar from those of the other rat groups. A 16S rRNA gene fragment that was more conspicuous in the profiles of HV-fed animals than in those of cellulose-fed rats had sequence identity with Lactobacillus acidophilus. Measurements of L. acidophilus rRNA abundance (DNA-RNA hybridization), the preparation of cloned 16S rRNA gene libraries, and the enumeration of Lactobacillus cells (fluorescent in situ hybridization) showed that lactobacilli formed a greater proportion of the cecal microbiota in HV-fed rats. In vitro experiments confirmed that some lactobacilli utilize oligosaccharides (degree of polymerization, 3 or 4) present in β-glucan hydrolysates. The results of this study have relevance to the use of purified β-glucan products as dietary supplements for human consumption. PMID:16517639

  10. The effect of tongue scraper on mutans streptococci and lactobacilli in patients with caries and periodontal disease.

    PubMed

    Almas, Khalid; Al-Sanawi, Essam; Al-Shahrani, Bander

    2005-03-01

    Tongue cleaning is an ancient habit. Recent literature has shown that tongue cleaning leads to healthy oral environment. The aims of this study were to assess the effect of tongue scraper among male adult patients with caries and periodontal disease, on Mutans streptococci (MS) and Lactobacilli (Lb) bacteria and secondly to assess the effect on self perceived oral malodour. Sixty male patients completed the study. The age ranged from 20-55 years (32 +/- 9.53). Fifty percent of the subjects were with university education level. Mean DMFT score was 9.17 (+/-5.46), while 88% of the subjects were with early to moderate periodontitis assessed by CPITN. Thirty one percent of the subjects were smoker, while 86.7% had tea/coffee drinking habit and tooth brushing. Only 28% claimed of using miswak (chewing stick). All patients were advised to use a tongue scraper twice daily for at least 2 minutes per day for 7 days. No effort was made to change tooth brushing or dietary habits of patients. Self perceived oral malodour was reported by 41.7% at baseline and 30% after use of tongue scraper. Salivary count of Mutans Streptococci and Lactobacilli had significant decrease 3.37 (+/- 0.71) to 2.27 (+/- 0.80) and 3.22 (+/- 0.85) to 2.32 (+/- 0.87) respectively (P = 0.000). It was concluded that tongue scraping twice daily for 7 days had significant effect on MS and Lb bacteria and also decreased oral malodour

  11. Vaginal colonisation by probiotic lactobacilli and clinical outcome in women conventionally treated for bacterial vaginosis and yeast infection.

    PubMed

    Pendharkar, Sonal; Brandsborg, Erik; Hammarström, Lennart; Marcotte, Harold; Larsson, Per-Göran

    2015-07-03

    The aim of this study was to investigate the colonisation by lactobacilli and clinical outcome in women with bacterial vaginosis (BV) and recurrent vulvovaginal candidiasis (R-VVC) receiving antibiotic or anti-fungal treatment in combination with the probiotic EcoVag® capsules. A total of 40 Scandinavian women diagnosed with BV or VVC on the basis of Amsel's criteria or clinical symptoms were consecutively recruited in two pilot open label clinical trials. In trial I, women with BV were treated with clindamycin and metronidazole followed by vaginal EcoVag® capsules, containing Lactobacillus rhamnosus DSM 14870 and Lactobacillus gasseri DSM 14869, for 5 consecutive days after each antibiotic treatment. In trial II, women were recruited in three groups as follows: women with BV receiving clindamycin and metronidazole treatment together with a prolonged administration of EcoVag® (10 consecutive days after each antibiotic treatment followed by weekly administration of capsules for next four months), women with R-VVC receiving extended fluconazole and EcoVag® treatment, and women receiving extended fluconazole treatments only. The difference in frequency of isolation of EcoVag® strains or other lactobacilli between groups was compared by Fisher's exact test. The 6-month cure rate for BV was 50 % in trial I while both the 6- and 12-month cure rates were 67 % in trial II. The 6- and 12-month cure rates for VVC were 100 % and 89 % in women receiving fluconazole and EcoVag®, and 100 % and 70 % in women receiving fluconazole only. The frequency of isolation of any Lactobacillus species during the course of the study was associated with cure of BV in trial I and II, whereas the frequency of isolation of EcoVag® strains was significantly associated with the cure of BV in trial II only. As previously observed, a change in sexual partner was associated with relapse of BV with an Odds ratio of 77 (95 % CI: 2.665 to 2225). The study suggests that the treatment with

  12. Urea hydrogen peroxide reduces the numbers of lactobacilli, nourishes yeast, and leaves no residues in the ethanol fermentation.

    PubMed

    Narendranath, N V; Thomas, K C; Ingledew, W M

    2000-10-01

    Urea hydrogen peroxide (UHP) at a concentration of 30 to 32 mmol/liter reduced the numbers of five Lactobacillus spp. (Lactobacillus plantarum, L. paracasei, Lactobacillus sp. strain 3, L. rhamnosus, and L. fermentum) from approximately 10(7) to approximately 10(2) CFU/ml in a 2-h preincubation at 30 degrees C of normal-gravity wheat mash at approximately 21 g of dissolved solids per ml containing normal levels of suspended grain particles. Fermentation was completed 36 h after inoculation of Saccharomyces cerevisiae in the presence of UHP, even when wheat mash was deliberately contaminated (infected) with L. paracasei at approximately 10(7) CFU/ml. There were no significant differences in the maximum ethanol produced between treatments when urea hydrogen peroxide was used to kill the bacteria and controls (in which no bacteria were added). However, the presence of L. paracasei at approximately 10(7) CFU/ml without added agent resulted in a 5.84% reduction in the maximum ethanol produced compared to the control. The bactericidal activity of UHP is greatly affected by the presence of particulate matter. In fact, only 2 mmol of urea hydrogen peroxide per liter was required for disinfection when mashes had little or no particulate matter present. No significant differences were observed in the decomposition of hydrogen peroxide in normal-gravity wheat mash at 30 degrees C whether the bactericidal agent was added as H(2)O(2) or as urea hydrogen peroxide. NADH peroxidase activity (involved in degrading H(2)O(2)) increased significantly (P = 0.05) in the presence of 0.75 mM hydrogen peroxide (sublethal level) in all five strains of lactobacilli tested but did not persist in cells regrown in the absence of H(2)O(2). H(2)O(2)-resistant mutants were not expected or found when lethal levels of H(2)O(2) or UHP were used. Contaminating lactobacilli can be effectively managed by UHP, a compound which when used at ca. 30 mmol/liter happens to provide near-optimum levels of

  13. Urea Hydrogen Peroxide Reduces the Numbers of Lactobacilli, Nourishes Yeast, and Leaves No Residues in the Ethanol Fermentation

    PubMed Central

    Narendranath, N. V.; Thomas, K. C.; Ingledew, W. M.

    2000-01-01

    Urea hydrogen peroxide (UHP) at a concentration of 30 to 32 mmol/liter reduced the numbers of five Lactobacillus spp. (Lactobacillus plantarum, L. paracasei, Lactobacillus sp. strain 3, L. rhamnosus, and L. fermentum) from ∼107 to ∼102 CFU/ml in a 2-h preincubation at 30°C of normal-gravity wheat mash at ∼21 g of dissolved solids per ml containing normal levels of suspended grain particles. Fermentation was completed 36 h after inoculation of Saccharomyces cerevisiae in the presence of UHP, even when wheat mash was deliberately contaminated (infected) with L. paracasei at ∼107 CFU/ml. There were no significant differences in the maximum ethanol produced between treatments when urea hydrogen peroxide was used to kill the bacteria and controls (in which no bacteria were added). However, the presence of L. paracasei at ∼107 CFU/ml without added agent resulted in a 5.84% reduction in the maximum ethanol produced compared to the control. The bactericidal activity of UHP is greatly affected by the presence of particulate matter. In fact, only 2 mmol of urea hydrogen peroxide per liter was required for disinfection when mashes had little or no particulate matter present. No significant differences were observed in the decomposition of hydrogen peroxide in normal-gravity wheat mash at 30°C whether the bactericidal agent was added as H2O2 or as urea hydrogen peroxide. NADH peroxidase activity (involved in degrading H2O2) increased significantly (P = 0.05) in the presence of 0.75 mM hydrogen peroxide (sublethal level) in all five strains of lactobacilli tested but did not persist in cells regrown in the absence of H2O2. H2O2-resistant mutants were not expected or found when lethal levels of H2O2 or UHP were used. Contaminating lactobacilli can be effectively managed by UHP, a compound which when used at ca. 30 mmol/liter happens to provide near-optimum levels of assimilable nitrogen and oxygen that aid in vigorous fermentation performance by yeast. PMID:11010858

  14. Survival of potential probiotic lactobacilli used as adjunct cultures on Pecorino Siciliano cheese ripening and passage through the gastrointestinal tract of healthy volunteers.

    PubMed

    Pino, Alessandra; Van Hoorde, Koenraad; Pitino, Iole; Russo, Nunziatina; Carpino, Stefania; Caggia, Cinzia; Randazzo, Cinzia L

    2017-07-03

    In the present study, two lactobacilli strains, Lactobacillus rhamnosus H25 and Lactobacillus paracasei N24, used as adjunct cultures, were evaluated for their heat resistance both with and without prior heat adaptation and for their survival, at industrial scale, during the production and ripening of the Pecorino Siciliano cheese. In addition, the viability and persistence of the lactobacilli strains after passage through the gastrointestinal tract of healthy volunteers were evaluated by using rep-PCR analysis of viable cells. Both strains exhibited good heat resistance and survival throughout cheese production and ripening, and positively influenced the physico-chemical, the microbiological and the sensorial characteristics of the final product. In addition, the molecular typing of the lactobacilli isolates, retrieved from fecal samples of healthy volunteers during and after 15 days of the experimental cheese administration, revealed a high survival of the strains, highlighting their persistence during passage into the GI tract. In conclusion, this study proposes the two adjunct cultures as potential probiotic candidate deliverable by cheese. Copyright © 2017. Published by Elsevier B.V.

  15. Short-term effect of ice-cream containing Bifidobacterium lactis Bb-12 on the number of salivary mutans streptococci and lactobacilli.

    PubMed

    Caglar, Esber; Kuscu, Ozgur Onder; Selvi Kuvvetli, Senem; Kavaloglu Cildir, Sule; Sandalli, Nuket; Twetman, Svante

    2008-06-01

    Probiotic bacteria are thought to reduce the risk of some infectious diseases. The aim of the present study was to examine whether or not short-term consumption of ice-cream containing bifidobacteria can affect the salivary levels of mutans streptococci and lactobacilli in young adults. A double-blind, randomized crossover study was performed and 24 healthy subjects (mean age 20 years) were followed over 4 periods. During periods 2 and 4 (10 days each), they ingested 100 ml (53 g) ice-cream containing Bifidobacterium lactis Bb-12 once daily or a control ice-cream without viable bacteria. Periods 1 and 3 were run-in and washout periods, respectively. Salivary mutans streptococci and lactobacilli were enumerated with chair-side kits at baseline and immediately after the intervention period. A statistically significant reduction (p<0.05) of salivary mutans streptococci was recorded after consumption of the probiotic ice-cream. A decline of high mutans streptococci counts was also seen after intake of the control ice-cream, but the difference compared to baseline was not statistically significant. The salivary lactobacilli levels were unaltered after both regimes. Daily consumtion of ice-cream containing probiotic bifidobacteria may reduce the salivary levels of mutans streptococci in young adults.

  16. Antifungal activity of lactobacilli and its relationship with 3-phenyllactic acid production.

    PubMed

    Cortés-Zavaleta, O; López-Malo, A; Hernández-Mendoza, A; García, H S

    2014-03-03

    In this study, 13 lactic acid bacteria (LAB) strains (including 5 Lactobacillus casei, 2 Lactobacillus rhamnosus, 2 Lactobacillus fermentum, 1 Lactobacillus acidophilus, 1 Lactobacillus plantarum, 1 Lactobacillus sakei, and 1 Lactobacillus reuteri species) were assessed for both their antifungal activity against four food spoilage molds (Colletotrichum gloeosporioides, Botrytis cinerea, Penicillium expansum, and Aspergillus flavus) and their capability to produce the novel antimicrobial compound 3-phenyllactic acid (PLA). Results demonstrated that all molds were sensitive to varying degrees to the cell-free supernatants (CFS) from LAB fermentations (p<0.05), with growth inhibitions ranging from 2.65% to 66.82%. The inhibition ability of CFS was not affected by a heating treatment (121°C, 20 min); however, it declined markedly when the pH of CFS was adjusted to 6.5. With the exception of L. plantarum NRRL B-4496 and L. acidophilus ATCC-4495, all other LAB strains produced PLA ranging from 0.021 to 0.275 mM. The high minimum inhibitory concentration for commercial PLA (3.01-36.10mM) suggests that it cannot be considered the only compound related with the antifungal potential of studied LAB and that synergistic effects may exist among other metabolism products.

  17. NOD Dendritic Cells Stimulated with Lactobacilli Preferentially Produce IL-10 versus IL-12 and Decrease Diabetes Incidence

    PubMed Central

    Manirarora, Jean N.; Parnell, Sarah A.; Hu, Yoon-Hyeon; Kosiewicz, Michele M.; Alard, Pascale

    2011-01-01

    Dendritic cells (DCs) from NOD mice produced high levels of IL-12 that induce IFNγ-producing T cells involved in diabetes development. We propose to utilize the microorganism ability to induce tolerogenic DCs to abrogate the proinflammatory process and prevent diabetes development. NOD DCs were stimulated with Lactobacilli (nonpathogenic bacteria targeting TLR2) or lipoteichoic acid (LTA) from Staphylococcus aureus (TLR2 agonist). LTA-treated DCs produced much more IL-12 than IL-10 and accelerated diabetes development when transferred into NOD mice. In contrast, stimulation of NOD DCs with L. casei favored the production of IL-10 over IL-12, and their transfer decreased disease incidence which anti-IL-10R antibodies restored. These data indicated that L. casei can induce NOD DCs to develop a more tolerogenic phenotype via production of the anti-inflammatory cytokine, IL-10. Evaluation of the relative production of IL-10 and IL-12 by DCs may be a very useful means of identifying agents that have therapeutic potential. PMID:21716731

  18. Comparison of probiotic lactobacilli and bifidobacteria effects, immune responses and rotavirus vaccines and infection in different host species

    PubMed Central

    Vlasova, Anastasia N.; Kandasamy, Sukumar; Chattha, Kuldeep S.; Rajashekara, Gireesh; Saif, Linda J.

    2016-01-01

    Different probiotic strains of Lactobacillus and Bifidobacterium genera possess significant and widely acknowledged health-promoting and immunomodulatory properties. They also provide an affordable means for prevention and treatment of various infectious, allergic and inflammatory conditions as demonstrated in numerous human and animal studies. Despite the ample evidence of protective effects of these probiotics against rotavirus (RV) infection and disease, the precise immune mechanisms of this protection remain largely undefined, because of limited mechanistic research possible in humans and investigated in the majority of animal models. Additionally, while most human clinical probiotic trials are well-standardized using the same strains, uniform dosages, regimens of the probiotic treatments and similar host age, animal studies often lack standardization, have variable experimental designs, and non-uniform and sometime limited selection of experimental variables or observational parameters. This review presents selected data on different probiotic strains of lactobacilli and bifidobacteria and summarizes the knowledge of their immunomodulatory properties and the associated protection against RV disease in diverse host species including neonates. PMID:26809484

  19. Isolation and identification of new lactobacilli from goatling stomach and investigation of reuterin production in Lactobacillus reuteri strains.

    PubMed

    Kiňová Sepová, Hana; Bilková, Andrea

    2013-01-01

    Five new strains of lactobacilli isolated from goatling's stomach were identified by molecular-biological approaches. Profiles of fermentable saccharides, Gram staining, and cell morphology were also determined. They were identified as Lactobacillus reuteri (strains KO4b, KO4m, KO5) and as Lactobacillus plantarum (strains KG1z, KG4). In DNA samples of all newly isolated L. reuteri strains as well as in L. reuteri E (Lreu E; originated from lamb), the part of gldC gene, coding large subunit of glycerol dehydratase, that is necessary for 3-hydroxypropionaldehyde (3-HPA; reuterin) production, was amplified using two designed primer sets. However, the 3-HPA production was revealed only in the strain Lreu E. It produced five- or ten-fold lower amount of 3-HPA in comparison with probiotic L. reuteri ATCC 55730 in aerobic or anaerobic conditions, respectively. Moreover, Lreu E completely lost its production ability after ca. five passages in MRS medium. The co-incubation of Lreu E, but not other L. reuteri isolates, with Escherichia coli re-induced 3-HPA production. In the case of L. reuteri ATCC 55730, the 3-HPA production increased more than four times after co-incubation with E. coli.

  20. Exploring the relationship between exposure to technological and gastrointestinal stress and probiotic functional properties of lactobacilli and bifidobacteria.

    PubMed

    Amund, O D

    2016-09-01

    Strains of Lactobacillus and Bifidobacterium are considered probiotic because of their associated potential health benefits. Probiotics are commonly administered orally via incorporation into food products. Microorganisms for use as probiotics encounter stress conditions, which include acid, bile, osmotic, oxidative, heat and cold stresses. These can occur during processing and storage and during passage through the gastrointestinal tract, and can affect viability. Probiotic bacteria have to remain viable to confer any health benefits. Therefore, the ability to withstand technological and gastrointestinal stresses is crucial probiotic selection criteria. While the stress tolerance mechanisms of lactobacilli and bifidobacteria are largely understood, the impact of exposure to stressful conditions on the functional properties of surviving probiotic microorganisms is not clear. This review explores the potentially positive and negative relationships between exposure to stress conditions and probiotic functional properties, such as resistance to gastric acid and bile, adhesion and colonization potential, and tolerance to antibiotics. Protective strategies can be employed to combat negative effects of stress on functional properties. However, further research is needed to ascertain synergistic relationships between exposure to stress and probiotic properties.

  1. Quantitative detection and identification of tyramine-producing enterococci and lactobacilli in cheese by multiplex qPCR.

    PubMed

    Ladero, Victor; Fernández, María; Cuesta, Isabel; Alvarez, Miguel A

    2010-10-01

    Tyramine is the most abundant biogenic amine in fermented dairy products, in which it is produced through the microbial enzymatic decarboxylation of tyrosine. This activity has been detected in a variety of lactic acid bacteria mainly belonging to the genera Enterococcus and Lactobacillus. This paper describes a culture-independent qPCR method, based on the specific amplification of the tdc gene, for the detection, quantification and identification of bacteria with the ability to produce tyramine. This method was found to be specific and to show a wide dynamic range, thus allowing the quantification of these tdc+ bacterial groups among the complex microbiota of cheese. tdc qPCR was used to follow the development of tdc+ microbiota during the manufacture of a blue-veined cheese (Cabrales) made from raw milk. In this type of cheese, tdc+ enterococci seem to be responsible for the high concentrations of tyramine detected. The method was also used to identify and quantify tdc+ enterococci and lactobacilli in 18 commercially available cheeses. Different types and numbers of these microorganisms were found. Their relationships with the concentration of tyramine and technological factors are discussed.

  2. Immunomodulatory and antimicrobial efficacy of Lactobacilli against enteropathogenic infection of Salmonella typhi: In-vitro and in-vivo study.

    PubMed

    Mazaya, Basem; Hamzawy, Mohamed A; Khalil, Mahmoud A F; Tawkol, Wael M; Sabit, Hussein

    2015-12-01

    Salmonellosis-induced diarrhea, is one of the commonest cause of childhood mortality in developing countries. Using of probiotics is viewed as a promising means for reducing the pathogenic loads of bacterial infection. The current study aimed to evaluate the potential antimicrobial and immunomodulatory efficacy of isolated lactobacillus strains against the enteropathogenic effect of S. Typhi. Different Lactobacillus strains were isolated from 13 dairy products. Their antimicrobial activities were tested against different bacterial strains. Six groups of CD1 mice were treated for 8 days as follows: group (1) untreated control; group (2) was challenged with single inoculation S. typhi, and groups (3) and (4) were treated with Lactobacillus plantarum (LA5) or Lactobacillus paracsi (LA7) for 7 days, respectively. Groups (5) and (6) were challenged with S. typhi, and then treated with either LA5 or LA 7 for 7 days, respectively. Isolated Lactobacillus showed antimicrobial activity against wide range of bacterial strains. Salmonellosis showed high widal titer, induced significant disturbance of TNF and IL-1β, while sever changes of the histological patterns of the intestinal villi and hepatocytes have been illustrated. LA5 or LA7 succeeded to eradicate typhoid infection, restore the values of inflammatory cytokines to typical levels of control group, and improve histological pictures of intestinal and hepatic tissues. It can be concluded that lactobacilli are promising candidate in protection and eradication against bacterial infection induced by S. Typhi due to its antimicrobial, anti-inflammatory, and immunomodulatory activities.

  3. Roles of Probiotic Lactobacilli Inclusion in Helping Piglets Establish Healthy Intestinal Inter-environment for Pathogen Defense.

    PubMed

    Yang, Jiajun; Qian, Kun; Wang, Chonglong; Wu, Yijing

    2017-03-30

    The gastrointestinal tract of pigs is densely populated with microorganisms that closely interact with the host and with ingested feed. Gut microbiota benefits the host by providing nutrients from dietary substrates and modulating the development and function of the digestive and immune systems. An optimized gastrointestinal microbiome is crucial for pigs' health, and establishment of the microbiome in piglets is especially important for growth and disease resistance. However, the microbiome in the gastrointestinal tract of piglets is immature and easily influenced by the environment. Supplementing the microbiome of piglets with probiotic bacteria such as Lactobacillus could help create an optimized microbiome by improving the abundance and number of lactobacilli and other indigenous probiotic bacteria. Dominant indigenous probiotic bacteria could improve piglets' growth and immunity through certain cascade signal transduction pathways. The piglet body provides a permissive habitat and nutrients for bacterial colonization and growth. In return, probiotic bacteria produce prebiotics such as short-chain fatty acids and bacteriocins that benefit piglets by enhancing their growth and reducing their risk of enteric infection by pathogens. A comprehensive understanding of the interactions between piglets and members of their gut microbiota will help develop new dietary interventions that can enhance piglets' growth, protect piglets from enteric diseases caused by pathogenic bacteria, and maximize host feed utilization.

  4. Comparison of probiotic lactobacilli and bifidobacteria effects, immune responses and rotavirus vaccines and infection in different host species.

    PubMed

    Vlasova, Anastasia N; Kandasamy, Sukumar; Chattha, Kuldeep S; Rajashekara, Gireesh; Saif, Linda J

    2016-04-01

    Different probiotic strains of Lactobacillus and Bifidobacterium genera possess significant and widely acknowledged health-promoting and immunomodulatory properties. They also provide an affordable means for prevention and treatment of various infectious, allergic and inflammatory conditions as demonstrated in numerous human and animal studies. Despite the ample evidence of protective effects of these probiotics against rotavirus (RV) infection and disease, the precise immune mechanisms of this protection remain largely undefined, because of limited mechanistic research possible in humans and investigated in the majority of animal models. Additionally, while most human clinical probiotic trials are well-standardized using the same strains, uniform dosages, regimens of the probiotic treatments and similar host age, animal studies often lack standardization, have variable experimental designs, and non-uniform and sometime limited selection of experimental variables or observational parameters. This review presents selected data on different probiotic strains of lactobacilli and bifidobacteria and summarizes the knowledge of their immunomodulatory properties and the associated protection against RV disease in diverse host species including neonates.

  5. Evaluation of propidium monoazide real-time PCR for enumeration of probiotic lactobacilli microencapsulated in calcium alginate beads.

    PubMed

    Oketič, K; Matijašić, B Bogovič; Obermajer, T; Radulović, Z; Lević, S; Mirković, N; Nedović, V

    2015-01-01

    The aim of the study was to evaluate real-time PCR coupled with propidium monoazide (PMA) treatment for enumeration of microencapsulated probiotic lactobacilli microencapsulated in calcium alginate beads. Lactobacillus gasseri K7 (CCM 7710) and Lactobacillus delbrueckii subsp. bulgaricus (CCM 7712) were analysed by plate counting and PMA real-time PCR during storage at 4 °C for 90 days. PMA was effective in preventing PCR amplification of the target sequences of DNA released from heat-compromised bacteria. The values obtained by real-time PCR of non-treated samples were in general higher than those obtained by real-time PCR of PMA-treated samples or by plate counting, indicating the presence of sub-lethally injured cells. This study shows that plate count could not be completely replaced by culture independent method PMA real-time PCR for enumeration of probiotics, but may rather complement the well-established plate counting, providing useful information about the ratio of compromised bacteria in the samples.

  6. Selection of sourdough lactobacilli with antifungal activity for use as biopreservatives in bakery products.

    PubMed

    Garofalo, Cristiana; Zannini, Emanuele; Aquilanti, Lucia; Silvestri, Gloria; Fierro, Olga; Picariello, Gianluca; Clementi, Francesca

    2012-08-08

    Two hundred and sixteen LAB cultures from sourdoughs and dough for bread and panettone production were screened for in vitro antifungal properties against three indicator cultures ascribed to Aspergillus japonicus , Eurotium repens , and Penicillium roseopurpureum , isolated from bakery environment and moldy panettone. Nineteen preselected isolates were subjected to minimum inhibitory concentration determination against the indicator cultures. Sourdoughs prepared with the two most promising strains, identified as Lactobacillus rossiae LD108 and Lactobacillus paralimentarius PB127, were characterized. The sourdough extracts were subjected to HPLC analysis coupled with a microtiter plate bioassay against A. japonicus to identify the active fractions. MALDI-TOF MS analysis revealed the occurrence of a series of peptides corresponding to wheat α-gliadin proteolysis fragments in the active fraction from L. rossiae LD108 sourdough. The ability to prevent mold growth on bread was demonstrated for both strains, whereas L. rossiae LD108 also inhibited mold growth on panettone.

  7. Antimicrobial and Safety Properties of Lactobacilli Isolated from two Cameroonian Traditional Fermented Foods

    PubMed Central

    Kaktcham, Pierre Marie; Zambou, Ngoufack François; Tchouanguep, Félicité Mbiapo; El-Soda, Morsi; Choudhary, Muhammad Iqbal

    2012-01-01

    Twenty-one Lactobacillus isolates from “Sha’a” (a maize – based fermented beverage) and “Kossam” (traditionally fermented cow milk) were selected in accordance with their antagonistic activities and tested for their bacteriocinogenic potential as well as safety properties. These isolates were preliminarily identified as Lactobacillus plantarum (62%), Lactobacillus rhamnosus (24%), Lactobacillus fermentum (10%) and Lactobacillus coprophilus (4%) based on phenotypic characteristics and rep-PCR genomic fingerprinting. Twelve (57.1%) out of the 21 strains tested were found to be bacteriocin producers, as revealed by the sensitivity of their antimicrobial substances to proteolytic enzymes (Trypsin, Proteinase K) and inhibition of other Lactobacillus spp. These bacteriocinogenic strains showed no positive haemolytic and gelatinase activities and proved to be sensitive to penicillin G, ampicillin, tetracycline, erythromycin, amoxicillin, chloramphenicol, co-trimoxazole and doxycyclin, but resistant to ciprofloxacin and gentamicin. The bacteriocins showed a broad inhibitory activity against Gram-positive and Gram-negative pathogenic bacteria, several of which are classified as especially dangerous by the World Health Organization, as well as Multidrug-resistant strains. These include Staphylococcus aureus, Salmonella enterica subsp. enterica serovare Typhi, Bacillus cereus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Shigella flexneri. These Lactobacillus strains are promising candidates for use as protective cultures in food fermentation. PMID:22396914

  8. Optimizing Production of Two Potential Probiotic Lactobacilli Strains Isolated from Piglet Feces as Feed Additives for Weaned Piglets.

    PubMed

    Chiang, Ming-Lun; Chen, Hsi-Chia; Chen, Kun-Nan; Lin, Yu-Chun; Lin, Ya-Ting; Chen, Ming-Ju

    2015-08-01

    Two probiotic strains, Lactobacillus johnsonii x-1d-2 and Lactobacillus mucosae x-4w-1, originally isolated from piglet feces, have been demonstrated to possess antimicrobial activities, antibiotic resistances and interleukin-6 induction ability in RAW 267.4 macrophages in our previous study. These characteristics make L. johnsonii x-1d-2 and L. mucosae x-4w-1 good candidates for application in feed probiotics. In this study, soybeal meal, molasses and sodium acetate were selected to optimize the growth medium for cultivation of L. johnsonii x-1d-2 and L. mucosae x-4w-1. These two strains were then freeze-dried and mixed into the basal diet to feed the weaned piglets. The effects of L. johnsonii x-1d-2 and L. mucosae x-4w-1 on the growth performance and fecal microflora of weaned piglets were investigated. The results showed that the bacterial numbers of L. johnsonii x-1d-2 and L. mucosae x-4w-1 reached a maximum of 8.90 and 9.30 log CFU/mL, respectively, when growing in optimal medium consisting of 5.5% (wt/vol) soybean meal, 1.0% (wt/vol) molasses and 1.0% (wt/vol) sodium acetate. The medium cost was 96% lower than the commercial de Man, Rogosa and Sharpe medium. In a further feeding study, the weaned piglets fed basal diet supplemented with freeze-dried probiotic cultures exhibited higher (p<0.05) body weight gain, feed intake, and gain/feed ratio than weaned piglets fed basal diet. Probiotic feeding also increased the numbers of lactobacilli and decreased the numbers of E. coli in the feces of weaned piglets. This study demonstrates that L. johnsonii x-1d-2 and L. mucosae x-4w-1 have high potential to be used as feed additives in the pig industry.

  9. Optimizing Production of Two Potential Probiotic Lactobacilli Strains Isolated from Piglet Feces as Feed Additives for Weaned Piglets

    PubMed Central

    Chiang, Ming-Lun; Chen, Hsi-Chia; Chen, Kun-Nan; Lin, Yu-Chun; Lin, Ya-Ting; Chen, Ming-Ju

    2015-01-01

    Two probiotic strains, Lactobacillus johnsonii x-1d-2 and Lactobacillus mucosae x-4w-1, originally isolated from piglet feces, have been demonstrated to possess antimicrobial activities, antibiotic resistances and interleukin-6 induction ability in RAW 267.4 macrophages in our previous study. These characteristics make L. johnsonii x-1d-2 and L. mucosae x-4w-1 good candidates for application in feed probiotics. In this study, soybeal meal, molasses and sodium acetate were selected to optimize the growth medium for cultivation of L. johnsonii x-1d-2 and L. mucosae x-4w-1. These two strains were then freeze-dried and mixed into the basal diet to feed the weaned piglets. The effects of L. johnsonii x-1d-2 and L. mucosae x-4w-1 on the growth performance and fecal microflora of weaned piglets were investigated. The results showed that the bacterial numbers of L. johnsonii x-1d-2 and L. mucosae x-4w-1 reached a maximum of 8.90 and 9.30 log CFU/mL, respectively, when growing in optimal medium consisting of 5.5% (wt/vol) soybean meal, 1.0% (wt/vol) molasses and 1.0% (wt/vol) sodium acetate. The medium cost was 96% lower than the commercial de Man, Rogosa and Sharpe medium. In a further feeding study, the weaned piglets fed basal diet supplemented with freeze-dried probiotic cultures exhibited higher (p<0.05) body weight gain, feed intake, and gain/feed ratio than weaned piglets fed basal diet. Probiotic feeding also increased the numbers of lactobacilli and decreased the numbers of E. coli in the feces of weaned piglets. This study demonstrates that L. johnsonii x-1d-2 and L. mucosae x-4w-1 have high potential to be used as feed additives in the pig industry. PMID:26104525

  10. Effects of Three Mastic Gums on the Number of Mutans Streptococci, Lactobacilli and PH of the Saliva

    PubMed Central

    Biria, Mina; Eslami, Gita; Taghipour, Elaheh; Akbarzadeh Baghban, Alireza

    2014-01-01

    Objective: In the recent years, herbal oral hygiene products have gained increasing attention. The aim of this study was to assess the effects of three types of mastic gums on the level of Mutans streptococci, Lactobacilli and pH of the saliva. Materials and Methods: Forty-two students in the age range of 20–30 years were divided into three parallel groups; each of them separately used pure mastic gum, xylitol mastic gum and probiotic mastic gum for three weeks. Number of microorganisms and pH of the saliva were assessed before and after the intervention. The data were analyzed using Wilcoxon Signed Rank, paired-sample-t, Kruskal-Wallis and Tukey’s post-hoc tests and Oneway ANOVA. Results: Level of Mutans streptococci showed a significant reduction compared to its baseline value in all three groups (P<0001 for all). Salivary Lactobacillus count increased in the groups using pure and xylitol mastic gums but decreased in the group using probiotic type, albeit these changes were only significant in the group using probiotic mastic gum (P<0.001). Use of pure and xylitol mastic gums increased the pH of the saliva but not significantly. In the group using probiotic mastic gum, the pH of the saliva decreased significantly (P=0.029). Conclusion: Three weeks use of all mastic gums resulted in a significant drop in the number of Mutans streptococci in the saliva. However, the drop in the saliva pH due to the use of probiotic mastic gum is not in favor of dental health. PMID:25628697

  11. Impact of adding Saccharomyces strains on fermentation, aerobic stability, nutritive value, and select lactobacilli populations in corn silage.

    PubMed

    Duniere, L; Jin, L; Smiley, B; Qi, M; Rutherford, W; Wang, Y; McAllister, T

    2015-05-01

    Bacterial inoculants can improve the conservation and nutritional quality of silages. Inclusion of the yeast Saccharomyces in the diet of dairy cattle has also been reported to be beneficial. The present study assessed the ability of silage to be used as a means of delivering Saccharomyces strains to ruminants. Two strains of Saccharomyces cerevisiae (strain 1 and 3)and 1 strain of Saccharomyces paradoxus (strain 2) were inoculated (10(3) cfu/g) individually onto corn forage that was ensiled in mini silos for 90 d. Fermentation characteristics, aerobic stability, and nutritive value of silages were determined and real-time quantitative PCR (RT-qPCR) was used to quantify S. cerevisiae, S.paradoxus, total Saccharomyces, fungal, and bacterial populations. Fermentation characteristics of silage inoculated with S1 were similar to control silage. Although strain 3 inoculation increased ash and decreased OM contents of silage (P = 0.017), no differences were observed in nutrient composition or fermentation profiles after 90 d of ensiling. Inoculation with Saccharomyces had no detrimental effect on the aerobic stability of silage. In vitro DM disappearance, gas production, and microbial protein synthesis were not affected by yeast inoculation.Saccharomyces strain 1 was quantified throughout ensiling, whereas strain 2 was detected only immediately after inoculation. Saccharomyces cerevisiae strain 3 was quantified until d 7 and detectable 90 d after ensiling. All inoculants were detected and quantified during aerobic exposure. Inoculation with Saccharomyces did not alter lactobacilli populations. Saccharomycetales were detected by RT-qPCR throughout ensiling in all silages. Both S. cerevisiae and S. paradoxus populations increased during aerobic exposure, demonstrating that the density of these yeast strains would increase between the time that silage was removed from storage and the time it was fed.

  12. Extended antimicrobial treatment of bacterial vaginosis combined with human lactobacilli to find the best treatment and minimize the risk of relapses.

    PubMed

    Larsson, Per-Göran; Brandsborg, Erik; Forsum, Urban; Pendharkar, Sonal; Andersen, Kasper Krogh; Nasic, Salmir; Hammarström, Lennart; Marcotte, Harold

    2011-08-19

    The primary objective of this study was to investigate if extended antibiotic treatment against bacterial vaginosis (BV) together with adjuvant lactobacilli treatment could cure BV and, furthermore, to investigate factors that could cause relapse. In all, 63 consecutive women with bacterial vaginosis diagnosed by Amsel criteria were offered a much more aggressive treatment of BV than used in normal clinical practice with repeated antibiotic treatment with clindamycin and metronidazole together with vaginal gelatine capsules containing different strains of lactobacilli both newly characterised and a commercial one (109 freeze-dried bacteria per capsule). Oral clindamycin treatment was also given to the patient's sexual partner. The cure rate was 74.6% after 6 months. The patients were then followed as long as possible or until a relapse. The cure rate was 65.1% at 12 months and 55.6% after 24 months. There was no significant difference in cure rate depending on which Lactobacillus strains were given to the women or if the women were colonised by lactobacilli. The most striking factor was a new sex partner during the follow up period where the Odds Ratio of having a relapse was 9.3 (2.8-31.2) if the patients had a new sex partner during the observation period. The study shows that aggressive treatment of the patient with antibiotics combined with specific Lactobacillus strain administration and partner treatment can provide long lasting cure. A striking result of our study is that change of partner is strongly associated with relapse of BV. ClinicalTrials.gov: NCT01245322.

  13. Extended antimicrobial treatment of bacterial vaginosis combined with human lactobacilli to find the best treatment and minimize the risk of relapses

    PubMed Central

    2011-01-01

    Background The primary objective of this study was to investigate if extended antibiotic treatment against bacterial vaginosis (BV) together with adjuvant lactobacilli treatment could cure BV and, furthermore, to investigate factors that could cause relapse. Methods In all, 63 consecutive women with bacterial vaginosis diagnosed by Amsel criteria were offered a much more aggressive treatment of BV than used in normal clinical practice with repeated antibiotic treatment with clindamycin and metronidazole together with vaginal gelatine capsules containing different strains of lactobacilli both newly characterised and a commercial one (109 freeze-dried bacteria per capsule). Oral clindamycin treatment was also given to the patient's sexual partner. Results The cure rate was 74.6% after 6 months. The patients were then followed as long as possible or until a relapse. The cure rate was 65.1% at 12 months and 55.6% after 24 months. There was no significant difference in cure rate depending on which Lactobacillus strains were given to the women or if the women were colonised by lactobacilli. The most striking factor was a new sex partner during the follow up period where the Odds Ratio of having a relapse was 9.3 (2.8-31.2) if the patients had a new sex partner during the observation period. Conclusions The study shows that aggressive treatment of the patient with antibiotics combined with specific Lactobacillus strain administration and partner treatment can provide long lasting cure. A striking result of our study is that change of partner is strongly associated with relapse of BV. Trial registration ClinicalTrials.gov: NCT01245322 PMID:21854593

  14. Characterization of growth inhibition of oral bacteria by sophorolipid using a microplate-format assay.

    PubMed

    Solaiman, Daniel K Y; Ashby, Richard D; Uknalis, Joseph

    2017-05-01

    Sophorolipid (SL) is a class of glycolipid biosurfactant produced by yeast and has potent antimicrobial activity against many microorganisms. In this paper, a microplate-based method was developed to characterize the growth inhibition by SL on five representative species of caries-causing oral bacteria. Bacterial growth on microplate in the absence and presence of varying concentrations of SL was continuously monitored by recording the absorbance at 600nm of the cultures using a microplate reader. The results showed that SL completely inhibited the growth of the Lactobacilli at ≥1mg/ml and the Streptococci at much lower concentrations of ≥50μg/ml. More importantly, we further defined the mechanism of antimicrobial activity of SL by analyzing the pattern of the cell growth curves. SL at sublethal concentrations (<1mg/ml) is bactericidal towards the Lactobacilli; it lengthens the apparent cell-doubling time (Td) and decreases the final cell density (as indicated by A600nm) in a concentration-dependent manner. Against the oral Streptococci, on the other hand, SL at sublethal concentrations (<50μg/ml) is bacteriostatic; it delays the onset of cell growth in a concentration-dependent fashion, but once the cell growth is commenced there is no noticeable adverse effect on Td and the final A600nm. Scanning electron microscopic (SEM) study of L. acidophilus grown in sublethal concentration of SL reveals extensive structural damage to the cells. S. mutans grown in sublethal level of SL did not show morphological damage to the cells, but numerous protruding structures could be seen on the cell surface. At the respective lethal levels of SL, L. acidophilus cells were lysed (at 1mg/ml SL) and the cell surface structure of S. mutans (at 130μg/ml SL) was extensively deformed. In summary, this paper presents the first report on a detailed analysis of the effects of SL on Lactobacilli and Streptococci important to oral health and hygiene.

  15. Enumeration of lactobacilli in the fecal flora of infant using two different modified de-Man Rogosa Sharpe media under aerobic and anaerobic incubation.

    PubMed

    Mirlohi, M; Soleimanian-Zad, S; Sheikh-Zeiondin, M; Fazeli, Hossein

    2008-03-15

    Regarding the importance of the presence of intestinal lactobacilli and their population in infants, four different treatments were evaluated for Lactobacillus isolation efficiency via reduction in the growth of other groups of bacteria capable of growing on de-Man Rogosa Sharpe (MRS) medium from fecal samples of 11 Iranian infants. MRS-Vancomycin (1 mg L(-l)) was used as a base medium and application of lactic acid and aerobic incubation of inoculated plates were performed as selective factors. Each fecal sample was cultivated as duplicate on to the base medium with or without lactic acid to reduce the pH to 5.4 +/- 0.2. Half of the plates were incubated aerobically and the rest of them incubated under 10% CO2 concentration. Total count and Lactobacillus count of all samples were recorded according to the age differences of infants. The counts of false positive colonies were recorded with respect to their cell morphology and gram reaction in all treatments. Anaerobic incubation of lactic acid modified MRS-Vancomycin gave the most Lactobacillus percentage coverage, about 93% among the Lactobacillus positive samples. Using this treatment, the median Lactobacillus count yielded 8.29 log10 cfu g(-1) in the younger and 5.70 log10 cfu g(-1) in the elder group. It could be concluded that lactic acid might be a proper pH reducing agent when enumeration of lactobacilli from fecal samples is of interest.

  16. Salivary mutans streptococci and lactobacilli modulations in young children on consumption of probiotic ice-cream containing Bifidobacterium lactis Bb12 and Lactobacillus acidophilus La5.

    PubMed

    Singh, Richa Polka; Damle, Satyawan Gangaram; Chawla, Amrita

    2011-11-01

    To compare the levels of mutans streptococci and lactobacilli in saliva of school children, before and after consumption of probiotic and control ice-cream. A double-blind, cross-over, placebo-controlled trial was carried out in forty, 12-14 year-old children, with no clinically detectable caries. The selected children were randomized equally into two groups I and II. Following an initial run-in period of 1 week, children in group I and II were given ice-creams 'A' and 'B', respectively, for 10 days. Being a cross-over study, the ice-creams were interchanged in the two groups after a 2-week wash-out period. Saliva samples at baseline and follow-up were assessed using Dentocult SM and Dentocult LB kits. On statistical evaluation, it was seen that probiotic ice-cream brought about a statistically significant reduction (p-value = 0.003) in salivary mutans streptococci levels with no significant effect on lactobacilli levels. In conclusion, probiotic ice-cream containing Bifidobacterium lactis Bb-12 ATCC27536 and Lactobacillus acidophilus La-5 can reduce the levels of certain caries-associated micro-organisms in saliva.

  17. Antifungal metabolites of lactobacilli

    Treesearch

    Vina A. Yang; Carol A. Clausen

    2004-01-01

    In recent years, public concern about indoor mold growth has increased dramatically in the United States. In this study, lactic acid bacteria, which are known to produce antimicrobial compounds important in the biopreservation of food, were evaluated to determine if the same antimicrobial properties can be used to protect wood from mold establishment. Based on biomass...

  18. Lactobacillus crispatus inhibits the infectivity of Chlamydia trachomatis elementary bodies, in vitro study.

    PubMed

    Nardini, Paola; Ñahui Palomino, Rogers Alberto; Parolin, Carola; Laghi, Luca; Foschi, Claudio; Cevenini, Roberto; Vitali, Beatrice; Marangoni, Antonella

    2016-06-29

    Lactobacillus species dominate the vaginal microbiota of healthy reproductive-age women and protect the genitourinary tract from the attack of several infectious agents. Chlamydia trachomatis, a leading cause of sexually transmitted disease worldwide, can induce severe sequelae, i.e. pelvic inflammatory disease, infertility and ectopic pregnancy. In the present study we investigated the interference of Lactobacillus crispatus, L. gasseri and L. vaginalis, known to be dominant species in the vaginal microbiome, with the infection process of C. trachomatis. Lactobacilli exerted a strong inhibitory effect on Chlamydia infectivity mainly through the action of secreted metabolites in a concentration/pH dependent mode. Short contact times were the most effective in the inhibition, suggesting a protective role of lactobacilli in the early steps of Chlamydia infection. The best anti-Chlamydia profile was shown by L. crispatus species. In order to delineate metabolic profiles related to anti-Chlamydia activity, Lactobacillus supernatants were analysed by (1)H-NMR. Production of lactate and acidification of the vaginal environment seemed to be crucial for the activity, in addition to the consumption of the carbonate source represented by glucose. The main conclusion of this study is that high concentrations of L. crispatus inhibit infectivity of C. trachomatis in vitro.

  19. Lactobacillus crispatus inhibits the infectivity of Chlamydia trachomatis elementary bodies, in vitro study

    PubMed Central

    Nardini, Paola; Ñahui Palomino, Rogers Alberto; Parolin, Carola; Laghi, Luca; Foschi, Claudio; Cevenini, Roberto; Vitali, Beatrice; Marangoni, Antonella

    2016-01-01

    Lactobacillus species dominate the vaginal microbiota of healthy reproductive-age women and protect the genitourinary tract from the attack of several infectious agents. Chlamydia trachomatis, a leading cause of sexually transmitted disease worldwide, can induce severe sequelae, i.e. pelvic inflammatory disease, infertility and ectopic pregnancy. In the present study we investigated the interference of Lactobacillus crispatus, L. gasseri and L. vaginalis, known to be dominant species in the vaginal microbiome, with the infection process of C. trachomatis. Lactobacilli exerted a strong inhibitory effect on Chlamydia infectivity mainly through the action of secreted metabolites in a concentration/pH dependent mode. Short contact times were the most effective in the inhibition, suggesting a protective role of lactobacilli in the early steps of Chlamydia infection. The best anti-Chlamydia profile was shown by L. crispatus species. In order to delineate metabolic profiles related to anti-Chlamydia activity, Lactobacillus supernatants were analysed by 1H-NMR. Production of lactate and acidification of the vaginal environment seemed to be crucial for the activity, in addition to the consumption of the carbonate source represented by glucose. The main conclusion of this study is that high concentrations of L. crispatus inhibit infectivity of C. trachomatis in vitro. PMID:27354249

  20. The effect of indigenous Neem Azadirachta indica [correction of (Adirachta indica)] mouth wash on Streptococcus mutans and lactobacilli growth.

    PubMed

    Vanka, A; Tandon, S; Rao, S R; Udupa, N; Ramkumar, P

    2001-01-01

    Neem is one of the most widely researched tropical tree, with almost all it's parts being put for a variety of uses. In the present study, the antibacterial effect of Neem mouthwash against salivary levels of streptococcus mutans and lactobacillus has been tested over a period of 2 months. Also it's effect in reversing incipient carious lesions was assessed. While streptococcus mutans was inhibited by Neem mouthwashes, with or without alcohol as well as chlorhexidine, lactobacillus growth was inhibited by chlorhexidine alone. The initial data appears to prove it's effect in inhibiting S. mutans and reversing incipient carious lesions, longer term clinical trials are essential.

  1. Specific vaginal lactobacilli suppress the inflammation induced by lipopolysaccharide stimulation through downregulation of toll-like receptor 4 expression in human embryonic intestinal epithelial cells

    PubMed Central

    TOBITA, Keisuke; WATANABE, Itsuki; SAITO, Masanori

    2016-01-01

    Vaginal lactobacilli (VLB) spread from the mother to the infant during vaginal delivery. However, the effects of VLB on infant intestinal function remain unclear. We investigated the probiotic function and immune effects of VLB on the human embryonic intestinal epithelial cell line INT-407. VLB survived artificial gastric juice and adhered to INT-407 cells. Exposure of INT-407 cells to VLB attenuated both the lipopolysaccharide (LPS)-induced stimulation of interleukin-8 and tumor necrosis factor alpha production and the LPS-stimulated upregulation of TLR4 expression. These results suggest that specific VLB suppresses the inflammation induced by LPS stimulation through downregulation of TLR4 expression in human embryonic intestinal epithelial cells. PMID:28243550

  2. The approximal bone height and intrabony defects in young adults, related to the salivary buffering capacity and counts of Streptococcus mutans and Lactobacilli.

    PubMed

    Wikner, S; Söder, P O; Frithiof, L; Wouters, F

    1990-01-01

    Using a computerized technique the bone height and prevalence of approximal periodontal intrabony defects were assessed on posterior bite-wing radiographs from 151 young adults. The results were related to the buffering capacity and counts of Streptococcus mutans and lactobacilli in whole stimulated saliva. The mean distance from the cement-enamel junction to the alveolar bone crest was greater in the high buffering group than in the low buffering group (p less than 0.05), and particularly in non-smokers (p less than 0.01). Intrabony defects were more common in the low buffering group (p less than 0.05) and in women (p less than 0.001).

  3. Lactate- and acetate-based cross-feeding interactions between selected strains of lactobacilli, bifidobacteria and colon bacteria in the presence of inulin-type fructans.

    PubMed

    Moens, Frédéric; Verce, Marko; De Vuyst, Luc

    2017-01-16

    Cross-feeding interactions were studied between selected strains of lactobacilli and/or bifidobacteria and butyrate-producing colon bacteria that consume lactate but are not able to degrade inulin-type fructans (ITF) in a medium for colon bacteria (supplemented with ITF as energy source and acetate when necessary). Degradation of oligofructose by Lactobacillus acidophilus IBB 801 and inulin by Lactobacillus paracasei 8700:2 and Bifidobacterium longum LMG 11047 resulted in the release of free fructose into the medium and the production of mainly lactate (lactobacilli) and acetate (B. longum LMG 11047). During bicultures of Lb. acidophilus IBB 801 and Anaerostipes caccae DSM 14662(T) on oligofructose, the latter strain converted lactate (produced by the former strain from oligofructose) into butyrate and gases, but only in the presence of acetate. During bicultures of Lb. paracasei 8700:2 and A. caccae DSM 14662(T) or Eubacterium hallii DSM 17630 on inulin, the butyrate-producing strains consumed low concentrations of lactate and acetate generated by inulin degradation by the Lactobacillus strain. As more acetate was produced during tricultures of Lb. paracasei 8700:2 and B. longum LMG 11047, which degraded inulin simultaneously, and A. caccae DSM 14662(T) or E. hallii DSM 17630, a complete conversion of lactate into butyrate and gases by these butyrate-producing strains occurred. Therefore, butyrate production by lactate-consuming, butyrate-producing colon bacterial strains incapable of ITF degradation, resulted from cross-feeding of monosaccharides and lactate by an ITF-degrading Lactobacillus strain and acetate produced by a Bifidobacterium strain.

  4. Anti-inflammatory and Intestinal Barrier-protective Activities of Commensal Lactobacilli and Bifidobacteria in Thoroughbreds: Role of Probiotics in Diarrhea Prevention in Neonatal Thoroughbreds.

    PubMed

    Tanabe, Soichi; Suzuki, Takuya; Wasano, Yuichiro; Nakajima, Fumihiko; Kawasaki, Hiroshi; Tsuda, Tomonori; Nagamine, Natsuko; Tsurumachi, Takashi; Sugaya, Kiyoshi; Akita, Hiroaki; Takagi, Misako; Takagi, Kunihiko; Inoue, Yoshinobu; Asai, Yo; Morita, Hidetoshi

    2014-01-01

    We previously isolated the commensal bacteria lactobacilli and bifidobacteria from the Thoroughbred intestine and prepared the horse probiotics LacFi(TM), consisting of Lactobacillus ruminis KK14, L. equi KK 15, L. reuteri KK18, L. johnsonii KK21, and Bifidobacterium boum HU. Here, we found that the five LacFi(TM) constituent strains remarkably suppressed pro-inflammatory interleukin-17 production in mouse splenocytes stimulated with interleukin-6 and transforming growth factor-β. The protective effects of the probiotic on impaired intestinal barrier function were evaluated in Caco-2 cells treated with tumor necrosis factor-α. Evaluation of transepithelial resistance showed that all the strains exhibited intestinal barrier protective activity, with significant suppression of barrier impairment by L. reuteri KK18. The LacFi(TM) constituent strains were detected in neonatal LacFi(TM)-administered Thoroughbred feces using polymerase chain reaction denaturing gradient gel electrophoresis and culture methods. These five strains were found to be the predominant lactobacilli and bifidobacteria in the intestinal microbiota of LacFi(TM)-administered Thoroughbreds. Administration of LacFi(TM) to neonatal Thoroughbreds decreased diarrhea incidence from 75.9% in the control group (n=29 neonatal Thoroughbreds) to 30.7% in the LacFi(TM)-administered group (n=101 neonatal Thoroughbreds) immediately after birth to 20 weeks after birth. LacFi(TM) treatment also prevented diarrhea especially at and around 4 weeks and from 10 to 16 weeks. The duration of diarrhea was also shorter in the probiotics-administered group (7.4 ± 0.8 days) than in the control group (14.0 ± 3.2 days). These results indicate that the LacFi(TM) probiotics regulates intestinal function and contributes to diarrhea prevention.

  5. Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning.

    PubMed

    Jonecova, Zuzana; Toth, Stefan; Ciccocioppo, Rachele; Rodrigo, Luis; Kruzliak, Peter; Nemcova, Radomira

    2015-06-01

    The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P < 0.05 and 0.001 respectively) on the weaning day. Moreover, the flaxseed addition caused a significant decrease in villus height (P < 0.01) and crypt depth (P < 0.01) 21 days postweaning in comparison with the sunflower group. The proliferative ratio of the epithelial cells in the sunflower group on the weaning day was significantly higher than in both flaxseed groups (P < 0.01). Paradoxically, significantly higher proliferative activity in the mucosal connective tissue in the group with flaxseed supplementation in comparison with the sunflower group was observed on the day of weaning, as well as 3 days later (P < 0.05 both). A combination of flaxseed with lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group.

  6. Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning

    PubMed Central

    Jonecova, Zuzana; Toth, Stefan; Ciccocioppo, Rachele; Rodrigo, Luis; Kruzliak, Peter; Nemcova, Radomira

    2015-01-01

    The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P < 0.05 and 0.001 respectively) on the weaning day. Moreover, the flaxseed addition caused a significant decrease in villus height (P < 0.01) and crypt depth (P < 0.01) 21 days postweaning in comparison with the sunflower group. The proliferative ratio of the epithelial cells in the sunflower group on the weaning day was significantly higher than in both flaxseed groups (P < 0.01). Paradoxically, significantly higher proliferative activity in the mucosal connective tissue in the group with flaxseed supplementation in comparison with the sunflower group was observed on the day of weaning, as well as 3 days later (P < 0.05 both). A combination of flaxseed with lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group. PMID:25929724

  7. Effect of lyophilized lactobacilli and 0.03 mg estriol (Gynoflor®) on vaginitis and vaginosis with disrupted vaginal microflora: a multicenter, randomized, single-blind, active-controlled pilot study.

    PubMed

    Donders, G G G; Van Bulck, B; Van de Walle, P; Kaiser, R R; Pohlig, G; Gonser, S; Graf, F

    2010-01-01

    To evaluate the efficacy of lyophilized lactobacilli in combination with 0.03 mg estriol when compared to metronidazole in the treatment of bacterial vaginal infections. Multicenter, randomized, single-blind, active-controlled pilot study in 3 independent gynecological practices in Belgium. Forty-six, 18- to 50-year-old premenopausal women with a disrupted vaginal flora due to a bacterial vaginal infection (bacterial vaginosis, aerobic vaginitis) were included, provided that fresh phase-contrast microscopy of the vaginal fluid showed lactobacillary flora grade 2B or 3. Patients were given a blinded box with either 12 vaginal tablets of Gynoflor® (study medication) or 6 vaginal suppositories containing 500 mg metronidazole (control medication). Eight efficacy variables were studied to assess the status of the vaginal flora at entry, 3-7 days (control 1), 4-6 (control 2) weeks and 4 months after the end of therapy. At control 1, the combined variables equally improved in the lactobacilli group as in the metronidazole group. At control 2, the lactobacillus preparation showed slightly inferior results when compared to metronidazole. At 4 months, this analysis could not be performed due to low numbers, but analysis of recurrence rate and extra medication needed was not different between both groups. Lyophilized lactobacilli in combination with low-dose estriol are equivalent to metronidazole in the short-term treatment of bacterial vaginal infections, but have less effect after 1 month. Further studies are required to evaluate the long-term efficacy of lactobacilli when applied repeatedly. Copyright © 2010 S. Karger AG, Basel.

  8. Determination of the In Vitro and In Vivo Antimicrobial Activity on Salivary Streptococci and Lactobacilli and Chemical Characterisation of the Phenolic Content of a Plantago lanceolata Infusion

    PubMed Central

    Roberto, Lia; Ingenito, Aniello; Roscetto, Emanuela

    2015-01-01

    Introduction. Plant extracts may be suitable alternative treatments for caries. Aims. To investigate the in vitro and in vivo antimicrobial effects of Plantago lanceolata herbal tea (from flowers and leaves) on cariogenic bacteria and to identify the major constituents of P. lanceolata plant. Materials and Methods. The MIC and MBC against cariogenic bacteria were determined for P. lanceolata tea. Subsequently, a controlled random clinical study was conducted. Group A was instructed to rinse with a P. lanceolata mouth rinse, and Group B received a placebo mouth rinse for seven days. The salivary colonisation by streptococci and lactobacilli was investigated prior to treatment and on the fourth and seventh days. Finally, the P. lanceolata tea was analysed for its polyphenolic content, and major phenolics were identified. Results and Discussion. P. lanceolata teas demonstrate good in vitro antimicrobial activity. The in vivo test showed that Group A subjects presented a significant decrease in streptococci compared to Group B. The phytochemical analysis revealed that flavonoids, coumarins, lipids, cinnamic acids, lignans, and phenolic compounds are present in P. lanceolata infusions. Conclusions. P. lanceolata extract could represent a natural anticariogenic agent via an antimicrobial effect and might be useful as an ancillary measure to control the proliferation of cariogenic flora. PMID:25767805

  9. Probiotic Lactobacillus fermentum UCO-979C biofilm formation on AGS and Caco-2 cells and Helicobacter pylori inhibition.

    PubMed

    Salas-Jara, M J; Sanhueza, E A; Retamal-Díaz, A; González, C; Urrutia, H; García, A

    2016-11-01

    The ability of the human isolate Lactobacillus fermentum UCO-979C to form biofilm and synthesize exopolysaccharide on abiotic and biotic models is described. These properties were compared with the well-known Lactobacillus casei Shirota to better understand their anti-Helicobacter pylori probiotic activities. The two strains of lactobacilli synthesized exopolysaccharide as detected by the Dubois method and formed biofilm on abiotic and biotic surfaces visualized by crystal violet staining and scanning electron microscopy. Concomitantly, these strains inhibited H. pylori urease activity by up to 80.4% (strain UCO-979C) and 66.8% (strain Shirota) in gastric adenocarcinoma (AGS) cells, but the two species showed equal levels of inhibition (~84%) in colorectal adenocarcinoma (Caco-2) cells. The results suggest that L. fermentum UCO-979C has probiotic potential against H. pylori infections. However, further analyses are needed to explain the increased activity observed against the pathogen in AGS cells as compared to L. casei Shirota.

  10. Isolation and characterization of lactobacilli from human faeces and indigenous fermented foods for their potential application as probiotics.

    PubMed

    Mandal, Hemanti; Jariwala, Ruchi; Bagchi, Tamishraha

    2016-04-01

    This study was conducted to select Lactobacillus strains from various sources on the basis of their probiotic attributes, such as acid and bile tolerance, binding to intestinal cells, and antimicrobial activity. Twelve isolates were obtained from human and food sources and were evaluated against standard probiotic Lactobacillus rhamnosus GG (LGG). Isolates were also studied for their antibiotic susceptibility. Isolate Lactobacillus fermentum GPI-6 showed the best survival profile at 0.3% and 1% bile salt, as compared with LGG. Isolates Lactobacillus plantarum GRI-2 and Lactobacillus salivarius GPI-4 showed no reduction in survival rate at pH 2.5. As expected, isolates showed strain-specific differences when comparing various attributes. Isolates GPI-4, GPI-7, and FA-5 showed better adhesion to HT-29, while isolate GPI-4 adhered better to Caco-2 cells than did LGG. However, when studying their ability to compete with Escherichia coli O26:H11, isolates GPI-6 and GPI-7 significantly inhibited E. coli adhesion to both HT-29 and Caco-2 cells compared with LGG. In conclusion, isolates GPI-4, GPI-7, and FA-5 showed excellent binding ability and antagonistic activity and better tolerance to acidic pH (pH 2.5) and to different bile salt concentrations in comparison with LGG, and hence, they could be considered as potential probiotic candidates.

  11. Decrease in lactobacilli in the intestinal microbiota of celiac children with a gluten-free diet, and selection of potentially probiotic strains.

    PubMed

    Lorenzo Pisarello, María J; Vintiñi, Elisa O; González, Silvia N; Pagani, Florencia; Medina, Marcela S

    2015-01-01

    The intestinal microbiota would be implicated in pathology associated with celiac disease caused by an abnormal immune system reaction against gluten present in cereal grains. The objectives of this work were to detect through basic methods the changes in the composition of the most common genera of bacteria from the intestinal microbiota of symptom-free celiac disease children with a gluten-free diet compared with healthy children from Tucumán and to select lactobacilli (Lb) strains with probiotic potential from the feces of healthy children. Results demonstrated that the feces of celiac children with a gluten-free diet showed significantly lower counts of Lb (P < 0.05) compared with healthy children, while enterobacteria tended to increase in celiac children. On the basis of these results, isolation of some Lb from the feces of healthy children was carried out. Thus, 5 Lb strains were selected because of their high resistance percentages to gastrointestinal tract conditions. In addition, their autoaggregation and hydrophobicity properties were evaluated: Lactobacillus rhamnosus (LC4) showed the highest percentage of autoaggregation while Lactobacillus paracasei (LC9) showed high hydrophobicity. Based on these results, LC4 and LC9 were selected, and their use as potential probiotic strains to improve signs and symptoms associated with celiac disease is discussed. This is the first study performed in Argentina concerning the relationship between intestinal microbiota and celiac disease in celiac children with a gluten-free diet. In addition, the development of a probiotic food addressed towards celiac patients and designed with Lb isolated from the feces of healthy children from our province represents a promising alternative to improve the quality of life of celiac patients.

  12. Supplementation of lactobacilli improves growth, regulates microbiota composition and suppresses skeletal anomalies in juvenile pike-perch (Sander lucioperca) reared in recirculating aquaculture system (RAS): A pilot study.

    PubMed

    Ljubobratovic, Uros; Kosanovic, Dejana; Vukotic, Goran; Molnar, Zsuzsanna; Stanisavljevic, Nemanja; Ristovic, Tijana; Peter, Geza; Lukic, Jovanka; Jeney, Galina

    2017-07-24

    This research aimed to test the effects of lactobacilli, applied to cultured pike-perch, either through hydrolyzed OTOHIME fish diet, or through Artemia nauplii, on fish growth, microbiota balance and skeletal development. On the 12th Day Post Hatching (DPH) fish were divided into following treatment groups: two groups received the combination of OTOHIME and nauplii enriched either with Lactobacillus paracasei BGHN14+Lactobacillus rhamnosus BGT10 or with Lactobacillus reuteri BGGO6-55+Lactobacillus salivarius BGHO1, and one group received OTOHIME hydrolyzed by BGHN14+BGT10 and non-enriched nauplii. Control group received non-enriched nauplii and non-hydrolyzed OTOHIME. The treatment lasted 14days and fish were sacrificed on the 26th DPH for the assessment of digestive enzyme activity and microbiota composition. Individual total lengths and individual body weights were recorded at the end of the treatments, on the 26th DPH, and also on the 45th DPH, in parallel with the evaluation of skeletal deformities and fish survival. Our results indicated positive effect of Artemia enriched with BGGO6-55+BGHO1 on fish growth, skeletal development and trypsin to chymotrypsin activity ratio (T/C), as an indicator of protein digestibility. Hydrolysis of OTOHIME was also associated with better skeletal development, higher T/C values and lower levels of Aeromonas and Mycobacterium spp., which are important fish pathogens. Though additional testing in larger cohort studies is needed, these observations are promising in terms of usage of probiotics for improved environmentally friendly production of pike-perch in Recirculating Aquaculture System (RAS). Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Effect of probiotic supplementation on total lactobacilli, bifidobacteria and short chain fatty acids in 2–5-year-old children

    PubMed Central

    Hemalatha, R.; Ouwehand, A. C.; Saarinen, M. T.; Prasad, U. V.; Swetha, K.; Bhaskar, V.

    2017-01-01

    ABSTRACT ​Background: Consumption of Lactobacillus paracasei Lpc-37 or Bifidobacterium lactis HN019 by 2–5-year-old children was found to reduce risk for diarrhoea and fever during the rainy season. Objective: Can changes in faecal short chain fatty acids (SCFAs) or branched chain fatty acids (BCFAs) explain the observed positive influence of probiotics and their role on nutritional status and diarrhoea risk? Design: Faecal samples were analysed for SCFAs and BCFAs and correlated to Bifidobacterium and Lactobacillus levels; both at the start and after nine months’ consumption of either of the two probiotic strains, or placebo. Results: No differences in SCFAs, BCFAs, Lactobacillus or Bifidobacterium levels were found between boys and girls. Severely underweight children were observed to have the highest Lactobacillus levels. Probiotic intervention was found to be associated with higher levels of selected SCFAs and BCFAs in subjects who had experienced diarrhoea. Treatment with either of the probiotics led to changes in SCFAs and BCFAs. SCFAs, acetate, propionate and butyrate, were found to correlate with each other. Likewise, BCFAs isobutyrate, 2-methylbutyrate and isovalerate correlated with each other. After the intervention, L. paracasei Lpc-37 correlated positively with total Bifidobacterium counts and isovalerate levels. B. lactis HN019 counts were found to correlate positively with total bacterial counts and negatively with propionate levels. Conclusions: ​Nutritional status was associated with higher levels of faecal lactobacilli; the meaning of this requires further investigation. The intervention with the two probiotics was observed to influence the levels of faecal SCFAs and BCFAs and there is a differential response in those who developed diarrhoea and those who did not. It is, however, not clear to what extent this is a mechanism that explains the earlier observed effect the strains had on diarrhoea risk. PMID:28572751

  14. Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment. [Lactobacillus sake; Lactobacillus curvatus; Lactobacillus farciminis; Staphylococcus aureus; Salmonella typimurium

    SciTech Connect

    Hastings, J.W.; Holzapfel, W.H.; Niemand, J.G.

    1986-10-01

    Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp. one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four reference strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO/sub 2/, and N/sub 2/). Organisms exhibited the highest death rate (lowest D/sub 10/ values (doses required to reduce the logarithm of the bacterial population by 1) under CO/sub 2/ packaging conditions, but resistance to irradiation was increased under N/sub 2/. The D/sup 10/ values of the isolates were generally greater than those of the reference strains. The D/sup 10/ values were also higher (approximately two times) in meat than in a semisynthetic growth medium.

  15. A multicentre randomised controlled trial evaluating lactobacilli and bifidobacteria in the prevention of antibiotic-associated diarrhoea in older people admitted to hospital: the PLACIDE study protocol

    PubMed Central

    2012-01-01

    Background Antibiotic associated diarrhoea complicates 5–39% of courses of antibiotic treatment. Major risk factors are increased age and admission to hospital. Of particular importance is C. difficile associated diarrhoea which occurs in about 4% of antibiotic courses and may result in severe illness, death and high healthcare costs. The emergence of the more virulent 027 strain of C. difficile has further heightened concerns. Probiotics may prevent antibiotic associated diarrhoea by several mechanisms including colonization resistance through maintaining a healthy gut flora. Methods This study aims to test the hypothesis that administration of a probiotic comprising two strains of lactobacilli and two strains of bifidobacteria alongside antibiotic treatment prevents antibiotic associated diarrhoea. We have designed a prospective, parallel group trial where people aged 65 years or more admitted to hospital and receiving one or more antibiotics are randomly allocated to receive either one capsule of the probiotic or a matching placebo daily for 21 days. The primary outcomes are the frequency of antibiotic associated and C. difficile diarrhoea during 8–12 weeks follow-up. To directly inform routine clinical practice, we will recruit a sufficient number of patients to demonstrate a 50% reduction in the frequency of C. difficile diarrhoea with a power of 80%. To maximize the generalizability of our findings and in view of the well-established safety record of probiotics, we will recruit a broad range of medical and surgical in-patients from two different health regions within the UK. Discussion Antibiotic associated diarrhoea constitutes a significant health burden. In particular, current measures to prevent and control C. difficile diarrhoea are expensive and disrupt clinical care. This trial may have considerable significance for the prevention of antibiotic associated diarrhoea in hospitals. Trial registration International Standard Randomised Controlled

  16. Probiotic cheese containing Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM® modifies subpopulations of fecal lactobacilli and Clostridium difficile in the elderly.

    PubMed

    Lahtinen, Sampo J; Forssten, Sofia; Aakko, Juhani; Granlund, Linda; Rautonen, Nina; Salminen, Seppo; Viitanen, Matti; Ouwehand, Arthur C

    2012-02-01

    Aging is associated with alterations in the intestinal microbiota and with immunosenescence. Probiotics have the potential to modify a selected part of the intestinal microbiota as well as improve immune functions and may, therefore, be particularly beneficial to elderly consumers. In this randomized, controlled cross-over clinical trial, we assessed the effects of a probiotic cheese containing Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM on the intestinal microbiota and fecal immune markers of 31 elderly volunteers and compared these effects with the administration of the same cheese without probiotics. The probiotic cheese was found to increase the number of L. rhamnosus and L. acidophilus NCFM in the feces, suggesting the survival of the strains during the gastrointestinal transit. Importantly, probiotic cheese administration was associated with a trend towards lower counts of Clostridium difficile in the elderly, as compared with the run-in period with the plain cheese. The effect was statistically significant in the subpopulation of the elderly who harbored C. difficile at the start of the study. The probiotic cheese was not found to significantly alter the levels of the major microbial groups, suggesting that the microbial changes conferred by the probiotic cheese were limited to specific bacterial groups. Despite that the administration of the probiotic cheese to the study population has earlier been shown to significantly improve the innate immunity of the elders, we did not observe measurable changes in the fecal immune IgA concentrations. No increase in fecal calprotectin and β-defensin concentrations suggests that the probiotic treatment did not affect intestinal inflammatory markers. In conclusion, the administration of probiotic cheese containing L. rhamnosus HN001 and L. acidophilus NCFM, was associated with specific changes in the intestinal microbiota, mainly affecting specific subpopulations of intestinal lactobacilli and C

  17. Effect of probiotic supplementation on total lactobacilli, bifidobacteria and short chain fatty acids in 2-5-year-old children.

    PubMed

    Hemalatha, R; Ouwehand, A C; Saarinen, M T; Prasad, U V; Swetha, K; Bhaskar, V

    2017-01-01

    ​Background: Consumption of Lactobacillus paracasei Lpc-37 or Bifidobacterium lactis HN019 by 2-5-year-old children was found to reduce risk for diarrhoea and fever during the rainy season. Objective: Can changes in faecal short chain fatty acids (SCFAs) or branched chain fatty acids (BCFAs) explain the observed positive influence of probiotics and their role on nutritional status and diarrhoea risk? Design: Faecal samples were analysed for SCFAs and BCFAs and correlated to Bifidobacterium and Lactobacillus levels; both at the start and after nine months' consumption of either of the two probiotic strains, or placebo. Results: No differences in SCFAs, BCFAs, Lactobacillus or Bifidobacterium levels were found between boys and girls. Severely underweight children were observed to have the highest Lactobacillus levels. Probiotic intervention was found to be associated with higher levels of selected SCFAs and BCFAs in subjects who had experienced diarrhoea. Treatment with either of the probiotics led to changes in SCFAs and BCFAs. SCFAs, acetate, propionate and butyrate, were found to correlate with each other. Likewise, BCFAs isobutyrate, 2-methylbutyrate and isovalerate correlated with each other. After the intervention, L. paracasei Lpc-37 correlated positively with total Bifidobacterium counts and isovalerate levels. B. lactis HN019 counts were found to correlate positively with total bacterial counts and negatively with propionate levels. Conclusions: ​Nutritional status was associated with higher levels of faecal lactobacilli; the meaning of this requires further investigation. The intervention with the two probiotics was observed to influence the levels of faecal SCFAs and BCFAs and there is a differential response in those who developed diarrhoea and those who did not. It is, however, not clear to what extent this is a mechanism that explains the earlier observed effect the strains had on diarrhoea risk.

  18. High dose and low dose Lactobacilli acidophilus exerted differential immune modulating effects on T cell immune responses induced by an oral human rotavirus vaccine in gnotobiotic pigs

    PubMed Central

    Wen, Ke; Li, Guohua; Bui, Tammy; Liu, Fangning; Li, Yanru; Kocher, Jacob; Lin, Lin; Yang, Xingdong; Yuan, Lijuan

    2011-01-01

    Background Strain-specific effects of probiotics in pro- or anti-inflammatory immune responses have been well recognized. Several proinflammatory Lactobacillus strains have been shown to act as adjuvants to enhance the immunogenicity of vaccines. However, dose effects of probiotics in modulating immune responses are not clearly understood. This study examined the dose effects of Lactobacillus acidophilus (LA) NCFM strain on T cell immune responses to rotavirus vaccination in a gnotobiotic (Gn) pig model. Methods Frequencies of IFN-γ producing CD4+ and CD8+ T cell and IL-10 and TGF-β producing CD4+CD25+ and CD4+CD25- regulatory T (Treg) cell responses were determined in the intestinal and systemic lymphoid tissues of Gn pigs vaccinated with an oral human rotavirus vaccine in conjunction with low dose (5 feedings; up to 106 colony forming units [CFU]/dose) or high dose (14 feedings; up to 109 CFU/dose) or without LA feeding. Results Low dose LA significantly promoted IFN-γ producing T cell responses and down-regulated Treg cell responses and their TGF-β and IL-10 productions in all the tissues compared to the high dose LA and control groups. To the contrary, high dose LA increased the frequencies of Treg cells in most of the tissues compared to the control groups. The dose effects of LA on IFN-γ producing T cell and CD4+CD25- Treg cell immune responses were similar in the intestinal and systemic lymphoid tissues and were independent from the vaccination. Conclusion Thus the same probiotic strain in different doses can either promote or suppress IFN-γ producing T cell or Treg cell immune responses. These findings have significant implications in the use of probiotic lactobacilli as immunostimulatory versus immunoregulatory agents. Probiotics can be ineffective or even detrimental if not used at the optimal dosage for the appropriate purposes. PMID:22178726

  19. A combination of a dairy product fermented by lactobacilli and galactooligosaccharides shows additive effects on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor.

    PubMed

    Takasugi, Satoshi; Ashida, Kinya; Maruyama, Suyaka; Matsukiyo, Yukari; Kaneko, Tetsuo; Yamaji, Taketo

    2013-06-01

    This study aimed to investigate the effects of a combination of a dairy product fermented by lactobacilli (DFL) and galactooligosaccharides (GOS) on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor (PPI). Three-week-old male rats were assigned to receive one of six diets: a control diet, control diets containing 1.6 or 5.0 % GOS, a DFL diet and DFL diets containing 1.6 or 5.0 % GOS for 9 days. From day 5 of the feeding period, half of the rats fed with control diets were subcutaneously administered with saline, whereas the remaining rats were administered with PPI for 5 days. Calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe) and zinc (Zn) balances were determined from days 6 to 9. PPI administration significantly decreased the apparent absorption of Ca and Fe and increased urinary P excretion, resulting in decreased Ca, Fe and P retention. GOS dose-dependently increased the apparent absorption of Ca, Mg and Fe and urinary Mg excretion and decreased urinary P excretion. DFL significantly increased the apparent absorption of Ca and Mg and urinary Mg excretion. The combination of DFL and GOS additively affected these parameters, resulting in increased Ca, P and Fe retention, and it further increased the apparent absorption and retention of Zn at 5.0 % GOS. In conclusion, the combination of DFL and GOS improves Ca, P and Fe retention in an additive manner and increases the Zn retention in growing rats with hypochlorhydria induced by PPI.

  20. Anti-microbial efficacy of green tea and chlorhexidine mouth rinses against Streptococcus mutans, Lactobacilli spp. and Candida albicans in children with severe early childhood caries: A randomized clinical study.

    PubMed

    Thomas, Ann; Thakur, Sneha R; Shetty, Sowmya B

    2016-01-01

    Green tea is a beverage which is consumed worldwide and is reported to have anti-cariogenic effect. So, if it was as effective as chlorhexidine (CHX) mouth rinse against cariogenic microbes it could be considered a natural, economical alternative. The purpose of this study was to evaluate and compare the anti-microbial efficacy of 0.5% green tea and 0.2% CHX mouth rinses against Streptococcus Mutans, Lactobacilli spp. and Candida Albicans. 30 children aged 4-6 years with S-ECC (based on defs score) were selected. Children were divided randomly into 2 equal groups and were asked to rinse with the prescribed mouth rinse once daily for 2 weeks after breakfast under supervision. A base-line and post rinsing non-stimulated whole salivary sample (2 ml) was collected and tested for the number of colony forming units. The data was statistically analyzed using SPSS v16.0 software with one-way ANOVA and Tukey's POSTHOC test. A statistically significant fall in colony count was found with both the mouth rinses in Streptococcus Mutans (P < 0.001, P < 0.001) and lactobacilli (P < 0.001, P < 0.001) but not against Candida albicans (P = 0.264, P = 0.264). Against Streptococcus Mutans, green tea mouth rinse was found to be significantly better than CHX mouth rinse (P = 0.005). Against lactobacilli spp, CHX mouth rinse was significantly better than green tea mouth rinse (P < 0.001). Green tea mouth rinse can be considered safe, economical and used without much concern. However, further studies are recommended.

  1. Anti-inflammatory capacity of selected lactobacilli in experimental colitis is driven by NOD2-mediated recognition of a specific peptidoglycan-derived muropeptide.

    PubMed

    Macho Fernandez, Elise; Fernandez, Elise Macho; Valenti, Véronique; Rockel, Christoph; Hermann, Corinna; Pot, Bruno; Boneca, Ivo Gomperts; Grangette, Corinne

    2011-08-01

    Inflammatory bowel disease (IBD) has been linked to a loss of tolerance towards the resident microflora. Therapeutic use of probiotics is known to be strain specific, but precise mechanisms remain unclear. The role of NOD2 signalling and the protective effect of Lactobacillus peptidoglycan (PGN) and derived muropeptides in experimental colitis were evaluated. The anti-inflammatory capacity of lactobacilli and derived bacterial compounds was evaluated using the 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis model. The role of NOD2, MyD88 and interleukin 10 (IL-10) in this protection was studied using Nod2(-/-), MyD88(-/-) and Il10-deficient mice, while induction of regulatory dendritic cells (DCs) was monitored through the expansion of CD103(+) DCs in mesenteric lymph nodes or after adoptive transfer of bone marrow-derived DCs. The development of regulatory T cells was investigated by following the expansion of CD4(+)FoxP3(+) cells. High-performance liquid chromatography and mass spectrometry were used to analyse the PGN structural differences. The protective capacity of strain Lactobacillus salivarius Ls33 was correlated with a local IL-10 production and was abolished in Nod2-deficient mice. PGN purified from Ls33 rescued mice from colitis in an IL-10-dependent manner and favoured the development of CD103(+) DCs and CD4(+)Foxp3(+) regulatory T cells. In vitro Ls33 PGN induced IL-10-producing DCs able to achieve in vivo protection after adoptive transfer in a NOD2-dependent way. This protection was also correlated with an upregulation of the indoleamine 2,3-dioxygenase immunosuppressive pathway. The protective capacity was not obtained with PGN purified from a non-anti-inflammatory strain. Structural analysis of PGNs highlighted in Ls33 the presence of an additional muropeptide, M-tri-Lys. The synthesised ligand protected mice from colitis in a NOD2-dependent but MyD88-independent manner. The results indicated that PGN and derived muropeptides are active

  2. Dietary fructo-oligosaccharides and lactulose inhibit intestinal colonisation but stimulate translocation of salmonella in rats

    PubMed Central

    Bovee-Oudenhoven, I M J; ten Bruggencate, S J M; Lettink-Wissink, M L G; van der Meer, R

    2003-01-01

    Background and aims: It is frequently assumed that dietary non-digestible carbohydrates improve host resistance to intestinal infections by stimulating the protective gut microflora. However, compelling scientific evidence from in vivo infection studies is lacking. Therefore, we studied the effect of several non-digestible carbohydrates on the resistance of rats to Salmonella enteritidis infection. Methods: Rats (n=8 per group) were fed “humanised” purified diets containing 4% lactulose, fructo-oligosaccharides (FOS), resistant starch, wheat fibre, or cellulose. After an adaptation period of 2 weeks the animals were orally infected with S enteritidis. Supplement induced changes in faecal biochemical and microbiological parameters were studied before infection. Colonisation of salmonella was determined by studying the faecal excretion of this pathogen and translocation by analysis of urinary nitric oxide metabolites over time and classical organ cultures. Intestinal mucosal myeloperoxidase activity was determined to quantify intestinal inflammation after infection. Results: Despite stimulation of intestinal lactobacilli and bifidobacteria and inhibition of salmonella colonisation, FOS and lactulose significantly enhanced translocation of this pathogen. These supplements also increased cytotoxicity of faecal water and faecal mucin excretion, which may reflect mucosal irritation. In addition, caecal and colonic, but not ileal, mucosal myeloperoxidase activity was increased in infected rats fed FOS and lactulose. In contrast, cellulose, wheat fibre, and resistant starch did not affect the resistance to salmonella. Conclusions: In contrast to most expectations, FOS and lactulose impair the resistance of rats to intestinal salmonella infection. Obviously, stimulation of the endogenous lactobacilli and bifidobacteria is no guarantee of improved host defence against intestinal infections. PMID:14570725

  3. Systemic Effects of Ingested Lactobacillus Rhamnosus: Inhibition of Mast Cell Membrane Potassium (IKCa) Current and Degranulation

    PubMed Central

    Forsythe, Paul; Wang, Binxiang; Khambati, Ibrahim; Kunze, Wolfgang A.

    2012-01-01

    Exposure of the intestine to certain strains lactobacillus can have systemic immune effects that include the attenuation of allergic responses. Despite the central role of mast cells in allergic disease little is known about the effect of lactobacilli on the function of these cells. To address this we assessed changes in rat mast cell activation following oral treatment with a strain of Lactobacillus known to attenuate allergic responses in animal models. Sprague Dawley rats were fed with L.rhamnosus JB-1 (1×109) or vehicle control for 9 days. Mediator release from peritoneal mast cells (RPMC) was determined in response to a range of stimuli. Passive cutaneous anaphylaxis (PCA) was used to assess mast cell responses in vivo. The Ca2+ activated K+ channel (KCa3.1) current, identified as critical to mast cell degranulation, was monitored by whole cell patch-clamp. L.rhamnosus JB-1 treatment lead to significant inhibition of mast cell mediator release in response to a range of stimuli including IgE mediated activation. Furthermore, the PCA response was significantly reduced in treated rats. Patch-clamp studies revealed that RPMC from treated animals were much less responsive to the KCa3.1 opener, DCEBIO. These studies demonstrate that Ingestion of L.rhamnosus JB-1 leads to mast cell stabilization in rats and identify KCa3.1 as an immunomodulatory target for certain lactobacilli. Thus the systemic effects of certain candidate probiotics may include mast cell stabilization and such actions could contribute to the beneficial effect of these organisms in allergic and other inflammatory disorders. PMID:22815978

  4. Sourdough lactobacilli and celiac disease.

    PubMed

    Gobbetti, Marco; Giuseppe Rizzello, Carlo; Di Cagno, Raffaella; De Angelis, Maria

    2007-04-01

    Celiac disease (CD) is one of the most common food intolerance. The only effective treatment for CD is a strict adherence to a gluten-free diet throughout the patient's lifetime. Gluten-free products are not widely available and are usually more expensive than their gluten-containing counterparts. There is, therefore, an urgent need to develop safe and effective therapeutic alternatives, to develop high-quality gluten-free products and to investigate the potential of the bread making biotechnology following ancient protocols which include long-time fermentation by selected sourdough lactic acid bacteria. This review describes the most relevant results related to biotechnologies that use selected sourdough lactic acid bacteria and probiotics as starters for sourdough fermentation to investigate their potential to decrease the risk of gluten contamination in gluten-free products. As shown by studies in vitro on celiac intestinal tissue and in vivo on CD patients, the bacterial proteolytic activity is rather promising not only as currently demonstrated for eliminating traces of contaminant gluten but probably also in perspective for the manufacture of tolerated baked goods.

  5. Taxonomy of Lactobacilli and Bifidobacteria.

    PubMed

    Felis, Giovanna E; Dellaglio, Franco

    2007-09-01

    Genera Lactobacillus and Bifidobacterium include a large number of species and strains exhibiting important properties in an applied context, especially in the area of food and probiotics. An updated list of species belonging to those two genera, their phylogenetic relationships and other relevant taxonomic information are reviewed in this paper. The conventional nature of taxonomy is explained and some basic concepts and terms will be presented for readers not familiar with this important and fast-evolving area, which importance is often underestimated. The analysis of biodiversity and its cataloguing, i.e. taxonomy, constitute the basis for applications and scientific communication: reliable identification and correct naming of bacterial strains are not only primary aims of taxonomic studies, but also fundamental elements in an applied context, for the tracking of probiotic strains and a non fraudulent labelling of fermented milks and pharmaceutical products containing probiotic microorganisms. A number of resources freely available have been listed and their use is suggested for people concerned with different aspects of taxonomy. Some perspectives in taxonomy have been outlined, in particular considering the role of culture independent analyses to reveal the still unknown and uncultured microorganisms. Finally, the impact of the availability of whole-genome sequences in taxonomy is briefly explained: they have already begun to give insights on bacterial evolution, which will surely have implications on taxonomy, even if the analysis of data for lactic acid bacteria is still limited to few species.

  6. Lectin characterization of gonococci from an outbreak caused by penicillin-resistant Neisseria gonorrhoeae.

    PubMed Central

    Schalla, W O; Rice, R J; Biddle, J W; Jeanlouis, Y; Larsen, S A; Whittington, W L

    1985-01-01

    A total of 40 Neisseria gonorrhoeae isolates, representing 19 penicillin-resistant isolates (from 8 heterosexual patients and 11 homosexual patients) and 21 penicillin-susceptible isolates (from 15 heterosexual patients and 6 homosexual patients) and obtained from the same geographic area, were examined. Lectin agglutination patterns were based on the reactivity of the isolates with the following 14 lectins: concanavalin A, Lens culinaris, Trichosanthes kinlowii, Griffonia simplicifolia I, Arachis hypogeae (peanut agglutinin), Glycine max (soybean agglutinin), Dolichos bifloris, Griffonia simplicifolia II, Solanum tuberosum (potato starch agglutinin), Triticum vulgaris (wheat germ agglutinin), Limax flavus, Phaseolus vulgaris, Ulex europaeus I, and Lotus tetragonolobus. All isolates were serotyped with monoclonal antibodies specific for gonococcal outer membrane protein I and auxotyped, and the plasmid content was determined. Resistant patient isolates were selected for their decreased penicillin susceptibility, and control isolates were selected for their penicillin susceptibility. Even though the patient isolates demonstrated resistance to penicillin, no phenotypic differences in lectin-grouping patterns were demonstrated between the two study groups; i.e., two predominant lectin groups were observed. No resistance-associated plasmids were detected. All patient isolates were serogroup IB (serovars IB-1, IB-2, and IB-4), whereas 12 of 21 control isolates were serogroup IA (P less than 0.05). Isolates obtained from different anatomical sites in the same patient (cervical and rectal) agreed with regard to lectin patterns and serovars but not auxotypes. PMID:3935658

  7. Indigenous lactobacilli strains of food and human sources reverse enteropathogenic E. coli O26:H11-induced damage in intestinal epithelial cell lines: effect on redistribution of tight junction proteins.

    PubMed

    Jariwala, Ruchi; Mandal, Hemanti; Bagchi, Tamishraha

    2017-09-01

    The aim of the study was to investigate the neutralizing effect of lactobacilli isolated from indigenous food and human sources on enteropathogenic Escherichia coli (EPEC) O26 : H11-induced epithelial barrier dysfunction in vitro. This was assessed by transepithelial electrical resistance (TEER) and permeability assays using intestinal cell lines, HT-29 and Caco-2. Furthermore, the expression and distribution of tight junction (TJ) proteins were analysed by qRT-PCR and immunofluorescence assay, respectively. The nine strains used in the study were from different species viz. Lactobacillus fermentum, Lactobacillushelveticus, Lactobacillus salivarius and Lactobacillus plantarum. All strains were able to reverse the decrease in TEER and corresponding increase in permeability across E. coli-infected monolayers. Maximum reversal was observed after 18 h [up to 93.8±2.0 % by L. rhamnosus GG followed by L. fermentum IIs11.2 (92.6±2.2 %) and L. plantarum GRI-2 (91.9±0.9 %)] of lactobacilli exposure following EPEC O26 : H11 infection. All strains were able to redistribute the TJ proteins to the cell periphery either partially or completely. Moreover, L. helveticus FA-7 was also able to significantly increase the mRNA expression of ZO-1 and claudin-1 (2.5-fold and 3.0-fold, respectively; P<0.05). The rapid reversal observed by these strains could be mostly because of the redistribution rather than increased mRNA expression of TJ proteins. In conclusion, L. helveticus FA-7, L. fermentum FA-1 and L. plantarum GRI-2 were good in all the aspects studied, and the other strains were good in some aspects. L. helveticus FA-7, L. fermentum FA-1 and L. plantarum GRI-2 can therefore be used for potential therapeutic purpose against intestinal epithelial dysfunction.

  8. Corrosion inhibiting organic coatings

    SciTech Connect

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  9. The Natural Antimicrobial Peptide Subtilosin Acts Synergistically with Glycerol Monolaurate, Lauric Arginate, and ε-Poly-l-Lysine against Bacterial Vaginosis-Associated Pathogens but Not Human Lactobacilli

    PubMed Central

    Sutyak Noll, Katia; Prichard, Mark N.; Khaykin, Arkady; Sinko, Patrick J.

    2012-01-01

    Subtilosin is a cyclical antimicrobial peptide produced by Bacillus amyloliquefaciens that has antimicrobial activity against the bacterial vaginosis-associated human pathogen Gardnerella vaginalis. The ability of subtilosin to inhibit G. vaginalis alone and in combination with the natural antimicrobial agents glycerol monolaurate (Lauricidin), lauric arginate, and ε-poly-l-lysine was tested using a checkerboard approach. Subtilosin was found to act synergistically with all of the chosen antimicrobials. These promising results indicate that lower concentrations of subtilosin in combination with other compounds could effectively be used to inhibit growth of the pathogen, thereby decreasing the risk of developed antimicrobial resistance. This is the first report on the effects of subtilosin combined with other natural antimicrobials against G. vaginalis. PMID:22252803

  10. The natural antimicrobial peptide subtilosin acts synergistically with glycerol monolaurate, lauric arginate, and ε-poly-L-lysine against bacterial vaginosis-associated pathogens but not human lactobacilli.

    PubMed

    Noll, Katia Sutyak; Prichard, Mark N; Khaykin, Arkady; Sinko, Patrick J; Chikindas, Michael L

    2012-04-01

    Subtilosin is a cyclical antimicrobial peptide produced by Bacillus amyloliquefaciens that has antimicrobial activity against the bacterial vaginosis-associated human pathogen Gardnerella vaginalis. The ability of subtilosin to inhibit G. vaginalis alone and in combination with the natural antimicrobial agents glycerol monolaurate (Lauricidin), lauric arginate, and ε-poly-L-lysine was tested using a checkerboard approach. Subtilosin was found to act synergistically with all of the chosen antimicrobials. These promising results indicate that lower concentrations of subtilosin in combination with other compounds could effectively be used to inhibit growth of the pathogen, thereby decreasing the risk of developed antimicrobial resistance. This is the first report on the effects of subtilosin combined with other natural antimicrobials against G. vaginalis.

  11. Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

    PubMed

    Donders, G; Bellen, G; Neven, P; Grob, P; Prasauskas, V; Buchholz, S; Ortmann, O

    2015-10-01

    This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p < 0.001). Whereas BV was a rare event, AV was frequent and substantially improved during treatment (p < 0.01). While at entry most patients had moderate or severe AV, after maintenance therapy no patient except one had AV. The number of leukocytes dropped dramatically from a score of 1.78 ± 0.70 to 1.06 ± 0.25 which was consistent till the end of the study (p < 0.01). Parabasal cells dropped from a score of 3.4 ± 0.64 at entry to 1.3 ± 0.60 at the final visit (p trend < 0.01). Starting from a low rate of Candida colonisation of 2/14 (14%), a sudden rise to 7/16 (44%) occurred after 2 weeks, to return back to base levels at subsequent visits. The vaginal use of ultra-low dose estriol and lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend

  12. Dendritic spikes veto inhibition.

    PubMed

    Stuart, Greg J

    2012-09-06

    How inhibition regulates dendritic excitability is critical to an understanding of the way neurons integrate the many thousands of synaptic inputs they receive. In this issue of Neuron, Müller et al. (2012) show that inhibition blocks the generation of weak dendritic spikes, leaving strong dendritic spikes intact. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Saccadic Inhibition in Reading

    ERIC Educational Resources Information Center

    Reingold, Eyal M.; Stampe, Dave M.

    2004-01-01

    In 5 experiments, participants read text that was briefly replaced by a transient image for 33 ms at random intervals. A decrease in saccadic frequency, referred to as saccadic inhibition, occurred as early as 60-70 ms following the onset of abrupt changes in visual input. It was demonstrated that the saccadic inhibition was influenced by the…

  14. Synbiotic Lactobacillus acidophilus NCFM and cellobiose does not affect human gut bacterial diversity but increases abundance of lactobacilli, bifidobacteria and branched-chain fatty acids: a randomized, double-blinded cross-over trial.

    PubMed

    van Zanten, Gabriella C; Krych, Lukasz; Röytiö, Henna; Forssten, Sofia; Lahtinen, Sampo J; Abu Al-Soud, Waleed; Sørensen, Søren; Svensson, Birte; Jespersen, Lene; Jakobsen, Mogens

    2014-10-01

    Probiotics, prebiotics, and combinations thereof, that is synbiotics, have been reported to modulate gut microbiota of humans. In this study, effects of a novel synbiotic on the composition and metabolic activity of human gut microbiota were investigated. Healthy volunteers (n = 18) were enrolled in a double-blinded, randomized, and placebo-controlled cross-over study and received synbiotic [Lactobacillus acidophilus NCFM (10(9) CFU) and cellobiose (5 g)] or placebo daily for 3 weeks. Fecal samples were collected and lactobacilli numbers were quantified by qPCR. Furthermore, 454 tag-encoded amplicon pyrosequencing was used to monitor the effect of synbiotic on the composition of the microbiota. The synbiotic increased levels of Lactobacillus spp. and relative abundances of the genera Bifidobacterium, Collinsella, and Eubacterium while the genus Dialister was decreased (P < 0.05). No other effects were found on microbiota composition. Remarkably, however, the synbiotic increased concentrations of branched-chain fatty acids, measured by gas chromatography, while short-chain fatty acids were not affected. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  15. Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation.

    PubMed

    Petrova, Mariya I; Imholz, Nicole C E; Verhoeven, Tine L A; Balzarini, Jan; Van Damme, Els J M; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

    2016-01-01

    Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections.

  16. Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation

    PubMed Central

    Petrova, Mariya I.; Imholz, Nicole C. E.; Verhoeven, Tine L. A.; Balzarini, Jan; Van Damme, Els J. M.; Schols, Dominique; Vanderleyden, Jos; Lebeer, Sarah

    2016-01-01

    Objectives Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties. Methods The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening. Results The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells. Conclusions Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections. PMID:27537843

  17. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Caroline

    1999-01-01

    This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

  18. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Carolyn

    1999-10-05

    This invention provides a system for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, this system can be used to palliate certain inflammatory and immunological conditions.

  19. Inhibition of selectin binding

    DOEpatents

    Nagy, Jon O.; Spevak, Wayne R.; Dasgupta, Falguni; Bertozzi, Caroline

    2001-10-09

    This invention provides compositions for inhibiting the binding between two cells, one expressing P- or L-selectin on the surface and the other expressing the corresponding ligand. A covalently crosslinked lipid composition is prepared having saccharides and acidic group on separate lipids. The composition is then interposed between the cells so as to inhibit binding. Inhibition can be achieved at an effective oligosaccharide concentration as low as 10.sup.6 fold below that of the free saccharide. Since selectins are involved in recruiting cells to sites of injury, these composition scan be used to palliate certain inflammatory and immunological conditions.

  20. AOP description: Acetylcholinesterase inhibition

    EPA Science Inventory

    This adverse outcome pathway (AOP) leverages existing knowledge in the open literature to describe the linkage between inhibition of acetylcholinesterase (AChE) and the subsequent mortality resulting from impacts at cholinergic receptors. The AOP takes a chemical category approa...

  1. Survival and in vivo adhesion of human isolates Lactobacillus gasseri LF221 and K7 in weaned piglets and their effects on coliforms, clostridia and lactobacilli viable counts in faeces and mucosa.

    PubMed

    Matijasic, Bojana Bogovic; Stojkovic, Sasa; Rogelj, Irena

    2006-11-01

    In in vivo study on 24 weaned piglets (8 per group), the survival rates of human isolates Lactobacillus gasseri K7 and LF221 were quantified by selective enumeration on MRS agar with rifampicin, and the presence of both strains in intestinal mucosa was examined. Faeces from individual animals were analysed for the number (cfu/g) of coliforms, lactobacilli, clostridia and both of the two probiotic strains during 2-weeks probiotic application period (5 x 10(10) cfu of individual strain/day) and 1 week after the probiotic treatment was ceased. Samples of duodenum, jejunum and ileum of sacrificed animals (5th or 20th day) were also examined microbiologically. A great variability in the microflora of faeces and mucosa was observed even between equally treated animals. The survival of both Lb. gasseri strains was established by their detection in the faeces (2.5 x 10(5) to 3.3 x 10(5) cfu of K7 strain/g faeces; 4.5 x 10(5) to 5 x 10(5) cfu of LF221 strain/g). In two animals, the LF221 or K7 viable cells were found in the faeces 6 d after ceasing probiotic application. In both animals from the group fed with Lb. gasseri K7 that were sacrificed 5 d after weaning, the presence of K7 strain was found either in the mucosa of duodenum (140 cfu/10 cm2) and jejunum (170 cfu/10 cm2) or in the ileum (1600 cfu/10 cm2). LF221 cells were detected in the ileal mucosa of one piglet (820 cfu/10 cm2). The results demonstrated the capability of both tested strains of in vivo adhesion to intestinal mucosa and of temporary colonisation of the piglets' intestine.

  2. Novel approaches for the taxonomic and metabolic characterization of lactobacilli: Integration of 16S rRNA gene sequencing with MALDI-TOF MS and 1H-NMR

    PubMed Central

    Parolin, Carola; Giordani, Barbara; Compri, Monica; Cevenini, Roberto; Vitali, Beatrice

    2017-01-01

    Lactobacilli represent a wide range of bacterial species with several implications for the human host. They play a crucial role in maintaining the ecological equilibrium of different biological niches and are essential for fermented food production and probiotic formulation. Despite the consensus about the ‘health-promoting’ significance of Lactobacillus genus, its genotypic and phenotypic characterization still poses several difficulties. The aim of this study was to assess the integration of different approaches, genotypic (16S rRNA gene sequencing), proteomic (MALDI-TOF MS) and metabolomic (1H-NMR), for the taxonomic and metabolic characterization of Lactobacillus species. For this purpose we analyzed 40 strains of various origin (intestinal, vaginal, food, probiotics), belonging to different species. The high discriminatory power of MALDI-TOF for species identification was underlined by the excellent agreement with the genotypic analysis. Indeed, MALDI-TOF allowed to correctly identify 39 out of 40 Lactobacillus strains at the species level, with an overall concordance of 97.5%. In the perspective to simplify the MALDI TOF sample preparation, especially for routine practice, we demonstrated the perfect agreement of the colony-picking from agar plates with the protein extraction protocol. 1H-NMR analysis, applied to both culture supernatants and bacterial lysates, identified a panel of metabolites whose variations in concentration were associated with the taxonomy, but also revealed a high intra-species variability that did not allow a species-level identification. Therefore, despite not suitable for mere taxonomic purposes, metabolomics can be useful to correlate particular biological activities with taxonomy and to understand the mechanisms related to the antimicrobial effect shown by some Lactobacillus species. PMID:28207855

  3. The expression of adhesin EF-Tu in response to mucin and its role in Lactobacillus adhesion and competitive inhibition of enteropathogens to mucin.

    PubMed

    Dhanani, A S; Bagchi, T

    2013-08-01

    To analyse the expression of EF-Tu in Lactobacillus strains with response to mucin exposure and its role in interfering with adhesion of enteropathogens to mucin. The Lactobacillus strains were analysed for their ability to adhere to immobilized mucin in microtiter plates. Lactobacillus delbrueckii M and Lactobacillus plantarum CS24.2 showed statistically significant adhesion to mucin, which was similar to Lactobacillus rhamnosus GG, the best binding probiotic strain. Lactobacillus rhamnosus GG, Lact. delbrueckii M, Lact. plantarum CS23 and Lact. plantarum CS24.2 were able to effectively antagonize the adhesion of Escherichia coli and Salmonella enterica serovar Typhi to mucin. In the presence of Lactobacillus adhesin - EF-Tu, the adhesion of Lact. delbrueckii M and the strains of Lact. plantarum to mucin was significantly inhibited. Similarly, EF-Tu also reduced the adhesion of enteropathogens to mucin. Furthermore, the relative fold change in gene expression analysis showed significant up-regulation of EF-Tu gene in the strains of Lact. plantarum and Lact. delbrueckii M when exposed to mucin for 3 h. The study shows the significant role of EF-Tu in lactobacilli adhesion and enteropathogens inhibition. The study suggests EF-Tu as an important factor linked to the Lactobacillus adhesion as well as enteropathogen inhibition. Lactobacillus plantarum CS23 and Lact. plantarum CS24.2 can be used as potential probiotic strains. © 2013 The Society for Applied Microbiology.

  4. Potentiation of latent inhibition.

    PubMed

    Rodriguez, Gabriel; Hall, Geoffrey

    2008-07-01

    Rats were given exposure either to an odor (almond) or a compound of odor plus taste (almond plus saline), prior to training in which the odor served as the conditioned stimulus. It was found, for both appetitive and aversive procedures, that conditioning was retarded by preexposure (a latent inhibition effect), and the extent of the retardation was greater in rats preexposed to the compound (i.e., latent inhibition to the odor was potentiated by the presence of the taste). In contrast, the presence of the taste during conditioning itself overshadowed learning about the odor. We argue that the presence of the salient taste in compound with the odor enhances the rate of associative learning, producing a rapid loss in the associability of the odor. This loss of associability will generate both overshadowing and the potentiation of latent inhibition that is observed after preexposure to the compound.

  5. Chitin deacetylase product inhibition.

    PubMed

    Jaworska, Malgorzata M

    2011-02-01

    Chitin deacetylase is the only known enzyme catalyzing the hydrolysis of the acetamino linkage in the N-acetylglucosamine units of chitin and chitosan. This reaction can play an important role in enzymatic production of chitosan from chitin, or in enzymatic modification of chitosan, which has applications in medicine, pharmacy or plant protection. It was previously shown that acetic acid, a product of the deacetylation process, may act as an inhibitor of chitin deacetylase. Here we show the mechanism of inhibition of chitin deacetylase isolated from Absidia orchidis vel coerulea by acetic acid released during the deacetylation process. The process follows competitive inhibition with respect to acetic acid with an inhibition constant of K(i) = 0.286 mmol/L. These results will help to find the optimal system to carry out the enzymatic deacetylation process for industrial applications.

  6. Inhibition of enteropathogens adhesion to human enterocyte-like HT-29 cells by a dairy strain of Propionibacterium acidipropionici.

    PubMed

    Zárate, G; Palacios, J M; Villena, J; Zúñiga-Hansen, M E

    2016-06-01

    Adhesion to the host intestinal mucosa is considered relevant for orally delivered probiotics as it prolongs their persistence in the gut and their health promoting effects. Classical propionibacteria are microorganisms of interest due to their role as dairy starters as well as for their functions as probiotics. Propionibacterium acidipropionici Q4, is a dairy strain isolated from a Swiss-type cheese made in Argentina that displays probiotic potential. In the present work we assessed the ability of this strain to adhere to the human enterocyte-like HT-29 cell line and to counteract the adhesion of two common human enteropathogens, such as Escherichia coli C3 and Salmonella Enteritidis 90/390. The results were compared with those obtained with the well-known probiotic Lactobacillus rhamnosus GG. P. acidipropionici Q4 showed a high adhesion capacity, even higher than the reference strain L. rhamnosus GG (42.3±4.4% and 36.2±2.3%, respectively), whereas adhesion of enteropathogens was significantly lower (25.2±2.2% for E. coli and 21.0±3.4% for S. Enteritidis). Propionibacteria as well as lactobacilli were able to inhibit by exclusion and competition the adherence of E. coli C3 and S. Enteritidis 90/390 whereas only L. rhamnosus GG displaced S. Enteritidis from HT-29 intestinal cells. Inhibition of pathogens by propionibacteria was not exerted by antimicrobials or coaggregation but was mainly due to exclusion by cell surface components, such as proteins and carbohydrates. The relevance of cell surface proteins (CSP) for preventing pathogens infection was confirmed by their concentration dependent effect observed for both pathogens: 100 µg/ml of CSP inhibited E. coli attachment almost as untreated propionibacteria, whereas it partially inhibited the attachment of S. Enteritidis. Results suggest that P. acidipropionici Q4 could be considered for the development of propionibacteria containing functional foods helpful in counteracting enteropathogen infection.

  7. Reinforcement of inhibition

    PubMed Central

    Anger, Douglas

    1983-01-01

    A differential-reinforcement-of-other-behavior (DRO) schedule with trials and delayed reinforcement was investigated. Periodically a wheel was briefly available to rats, followed six seconds later by brief availability of a bar. Variable-ratio food reinforcement of wheel turns was adjusted to give 95% turns. After variable-ratio-five reinforcement of bar presses produced 100% pressing, then separate ratio schedules were used for presses following turns (turn presses) and presses following nonturns (nonturn presses). Increasing nonturn-press reinforcements decreased turns, even though total reinforcements increased. Reversal by decreasing nonturn-press reinforcements raised turns, though with hysteresis. Thus food reinforcement increased nonturns even though delayed six to ten seconds after nonturns, a delay that greatly reduces response reinforcement. Those and other results indicate that the turn decrease was not due to reinforcement of competing responses. Evidence against other alternatives, and the reduction of responding by increased reinforcement, indicate that the term inhibition is appropriate for the phenomenon reinforced. Response-specific inhibition appears appropriate for this particular kind, since its effects are more specific to particular responses than Pavlovian conditioned-inhibition. Response-specific inhibition seems best considered a behavioral output comparable to responses (e.g., both reinforcible) but with important properties different from responses (e.g., different reinforcement-delay gradients). PMID:16812315

  8. Peptide bioregulators inhibit apoptosis.

    PubMed

    Khavinson, V K; Kvetnoii, I M

    2000-12-01

    The effects of peptide bioregulators epithalon and vilon on the dynamics of irradiation-induced apoptotic death of spleen lymphocytes in rats indicate that these agents inhibit physiologically programmed cell death. The antiapoptotic effect of vilon was more pronounced, which corroborates the concept on tissue-specific effect of peptide bioregulators.

  9. Serine proteases inhibiting cyanopeptides.

    PubMed

    Radau, G

    2000-08-01

    There are many compounds inhibiting serine proteases which play an important role in the human organism. This article reviews publications on the low-molecular weight, serine protease inhibitory cyanopeptides and reports on new developments in establishing structure-activity relationships.

  10. [Non-viral sexually transmitted infections - Epidemiology, clinical manifestations, diagnostics and therapy : Part 1: Gonococci].

    PubMed

    Nenoff, P; Manos, A; Ehrhard, I; Krüger, C; Paasch, U; Helmbold, P; Handrick, W

    2017-01-01

    Approximately 1 million people are infected per day worldwide by one or more sexually transmitted infections (STI) as estimated by the World Health Organization (WHO). Gonorrhoea represents an almost exclusively sexually transmitted infection, which predominantly affects mucous membranes of the genitourinary tract. Extragenital localization of infections is also possible, e. g. in the anorectal region. Currently, only syphilis and human immunodeficiency virus (HIV) are notifiable diseases according to the Infection Protection Act in Germany. In Saxony, an extended registration ordinance according to the German Infection Protection Act is in force, which means that besides syphilis the laboratory detection of Neisseria gonorrhoeae, Chlamydia trachomatis and genital mycoplasms are also notifiable infections. In particular, beginning in 2009 in Saxony a spectacular increase of registered infections due to N. gonorrhoeae was observed and in 2015 altogether 824 infections due to N. gonorrhoeae were reported. Alarming is the increase in resistance of N. gonorrhoeae against penicillin, doxycycline, ciprofloxacin and recently also against azithromycin and third generation cephalosporins. The so-called superbug of N. gonorrhoeae, which originated in Japan with multidrug resistance against most of the currently available oral antibiotics, has now arrived in Europe. Intramuscular or intravenous injection of ceftriaxone plus oral azithromycin, each given as single dose is the standard therapy for gonorrhoea.

  11. Semantic processing and response inhibition.

    PubMed

    Chiang, Hsueh-Sheng; Motes, Michael A; Mudar, Raksha A; Rao, Neena K; Mansinghani, Sethesh; Brier, Matthew R; Maguire, Mandy J; Kraut, Michael A; Hart, John

    2013-11-13

    The present study examined functional MRI (fMRI) BOLD signal changes in response to object categorization during response selection and inhibition. Young adults (N=16) completed a Go/NoGo task with varying object categorization requirements while fMRI data were recorded. Response inhibition elicited increased signal change in various brain regions, including medial frontal areas, compared with response selection. BOLD signal in an area within the right angular gyrus was increased when higher-order categorization was mandated. In addition, signal change during response inhibition varied with categorization requirements in the left inferior temporal gyrus (lIT). lIT-mediated response inhibition when inhibiting the response only required lower-order categorization, but lIT mediated both response selection and inhibition when selecting and inhibiting the response required higher-order categorization. The findings characterized mechanisms mediating response inhibition associated with semantic object categorization in the 'what' visual object memory system.

  12. Inhibition and Brain Work

    PubMed Central

    Buzsáki, György; Kaila, Kai; Raichle, Marcus

    2008-01-01

    The major part of the brain’s energy budget (~60%–80%) is devoted to its communication activities. While inhibition is critical to brain function, relatively little attention has been paid to its metabolic costs. Understanding how inhibitory interneurons contribute to brain energy consumption (brain work) is not only of interest in understanding a fundamental aspect of brain function but also in understanding functional brain imaging techniques which rely on measurements related to blood flow and metabolism. Herein we examine issues relevant to an assessment of the work performed by inhibitory interneurons in the service of brain function. PMID:18054855

  13. Pharmacological inhibition of FTO.

    PubMed

    McMurray, Fiona; Demetriades, Marina; Aik, WeiShen; Merkestein, Myrte; Kramer, Holger; Andrew, Daniel S; Scudamore, Cheryl L; Hough, Tertius A; Wells, Sara; Ashcroft, Frances M; McDonough, Michael A; Schofield, Christopher J; Cox, Roger D

    2015-01-01

    In 2007, a genome wide association study identified a SNP in intron one of the gene encoding human FTO that was associated with increased body mass index. Homozygous risk allele carriers are on average three kg heavier than those homozygous for the protective allele. FTO is a DNA/RNA demethylase, however, how this function affects body weight, if at all, is unknown. Here we aimed to pharmacologically inhibit FTO to examine the effect of its demethylase function in vitro and in vivo as a first step in evaluating the therapeutic potential of FTO. We showed that IOX3, a known inhibitor of the HIF prolyl hydroxylases, decreased protein expression of FTO (in C2C12 cells) and reduced maximal respiration rate in vitro. However, FTO protein levels were not significantly altered by treatment of mice with IOX3 at 60 mg/kg every two days. This treatment did not affect body weight, or RER, but did significantly reduce bone mineral density and content and alter adipose tissue distribution. Future compounds designed to selectively inhibit FTO's demethylase activity could be therapeutically useful for the treatment of obesity.

  14. Beneficial bacteria inhibit cachexia

    PubMed Central

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  15. Pharmacological Inhibition of FTO

    PubMed Central

    McMurray, Fiona; Demetriades, Marina; Aik, WeiShen; Merkestein, Myrte; Kramer, Holger; Andrew, Daniel S.; Scudamore, Cheryl L.; Hough, Tertius A.; Wells, Sara; Ashcroft, Frances M.; McDonough, Michael A.; Schofield, Christopher J.; Cox, Roger D.

    2015-01-01

    In 2007, a genome wide association study identified a SNP in intron one of the gene encoding human FTO that was associated with increased body mass index. Homozygous risk allele carriers are on average three kg heavier than those homozygous for the protective allele. FTO is a DNA/RNA demethylase, however, how this function affects body weight, if at all, is unknown. Here we aimed to pharmacologically inhibit FTO to examine the effect of its demethylase function in vitro and in vivo as a first step in evaluating the therapeutic potential of FTO. We showed that IOX3, a known inhibitor of the HIF prolyl hydroxylases, decreased protein expression of FTO (in C2C12 cells) and reduced maximal respiration rate in vitro. However, FTO protein levels were not significantly altered by treatment of mice with IOX3 at 60 mg/kg every two days. This treatment did not affect body weight, or RER, but did significantly reduce bone mineral density and content and alter adipose tissue distribution. Future compounds designed to selectively inhibit FTO’s demethylase activity could be therapeutically useful for the treatment of obesity. PMID:25830347

  16. Ribotyping of lactobacilli isolated from spoiled beer.

    PubMed

    Yansanjav, Altanzaya; Svec, Pavel; Sedlácek, Ivo; Hollerová, Ida; Nemec, Miroslav

    2003-12-05

    Twenty-nine Lactobacillus strains contaminating beers in different Czech breweries as well as representative type strains obtained from the Czech Collection of Microorganisms were characterized using ribotyping with EcoRI and a probe made complementary to 16S and 23S rRNA genes. Biochemical test results assigned the 29 strains to the species L. brevis, L. plantarum, L. buchneri and L. paracasei subsp. paracasei. Ribotyping separated L. brevis, L. plantarum and L. paracasei subsp. paracasei strains into species-specific ribogroups in full correspondence with biotyping; L. buchneri strains were split into two ribogroups. Characteristic band patterns for each species and even typical bands of certain sizes were observed.

  17. Biodiversity of spoilage lactobacilli: phenotypic characterisation.

    PubMed

    Sanders, J W; Oomes, S J C M; Membré, J-M; Wegkamp, A; Wels, M

    2015-02-01

    Preventing food spoilage is a challenge for the food industry, especially when applying mild preservation methods and when avoiding the use of preservatives. Therefore, it is essential to explore the boundaries of preservation by better understanding the causative microbes, their phenotypic behaviour and their genetic makeup. Traditionally in food microbiology, single strains or small sets of selected strains are studied. Here a collection of 120 strains of 6 different spoilage related Lactobacillus species and a multitude of sources was prepared and their growth characteristics determined in 384-well plates by optical density measurements (OD) over 20 days, for 20 carbon source-related phenotypic parameters and 25 preservation-related phenotypic parameters. Growth under all conditions was highly strain specific and there was no correlation of phenotypes at the species level. On average Lactobacillus brevis strains were amongst the most robust whereas Lactobacillus fructivorans strains had a much narrower growth range. The biodiversity data allowed the definition of preservation boundaries on the basis of the number of Lactobacillus strains that reached a threshold OD, which is different from current methods that are based on growth ability or growth rate of a few selected strains. Genetic information on these microbes and a correlation study will improve the mechanistic understanding of preservation resistance and this will support the future development of superior screening and preservation methods.

  18. Firefly luciferase inhibition.

    PubMed

    Leitão, João M M; Esteves da Silva, Joaquim C G

    2010-10-05

    Firefly luciferase (Luc) is the most studied of the luciferase enzymes and the mechanism and kinetics of the reactions catalyzed by this enzyme have been relatively well characterized. Luc catalyzes the bioluminescent reaction involving firefly luciferin (D-LH(2)), adenosine triphosphate (ATP), magnesium ion and molecular oxygen with the formation of an electronically excited species (oxyluciferin), inorganic pyrophosphate (PPi), carbon dioxide and adenosine monophosphate (AMP). Luc also catalyzes other non-luminescent reactions, which can interfere with the light production mechanism. Following electronic relaxation, the excited oxyluciferin emits radiation in the visible region of the electromagnetic spectrum (550-570 nm). Among the various possible compounds, several classes of inhibitory substances interfere with the activity of this enzyme: here, we consider substrate-related compounds, intermediates or products of the Luc catalyzed reactions, in addition to anesthetics and, fatty acids. This review summarizes the main inhibitors of Luc and the corresponding inhibition kinetic parameters.

  19. Anxiety and retrieval inhibition: support for an enhanced inhibition account.

    PubMed

    Nuñez, Mia; Gregory, Josh; Zinbarg, Richard E

    2017-02-01

    Retrieval inhibition of negative associations is important for exposure therapy for anxiety, but the relationship between memory inhibition and anxiety is not well understood-anxiety could either be associated with enhanced or deficient inhibition. The present study tested these two competing hypotheses by measuring retrieval inhibition of negative stimuli by related neutral stimuli. Non-clinically anxious undergraduates completed measures of trait and state anxiety and completed a retrieval induced forgetting task. Adaptive forgetting varied with state anxiety. Low levels of state anxiety were associated with no evidence for retrieval inhibition for either threatening or non-threatening categories. Participants in the middle tertile of state anxiety scores exhibited retrieval inhibition for non-threatening categories but not for threatening categories. Participants in the highest tertile of state anxiety, however, exhibited retrieval inhibition for both threatening and non-threatening categories with the magnitude of retrieval inhibition being greater for threatening than non-threatening categories. The data are in line with the avoidance aspect of the vigilance-avoidance theory of anxiety and inhibition. Implications for cognitive behavioural therapy practices are discussed.

  20. Anthrax lethal factor inhibition.

    PubMed

    Shoop, W L; Xiong, Y; Wiltsie, J; Woods, A; Guo, J; Pivnichny, J V; Felcetto, T; Michael, B F; Bansal, A; Cummings, R T; Cunningham, B R; Friedlander, A M; Douglas, C M; Patel, S B; Wisniewski, D; Scapin, G; Salowe, S P; Zaller, D M; Chapman, K T; Scolnick, E M; Schmatz, D M; Bartizal, K; MacCoss, M; Hermes, J D

    2005-05-31

    The primary virulence factor of Bacillus anthracis is a secreted zinc-dependent metalloprotease toxin known as lethal factor (LF) that is lethal to the host through disruption of signaling pathways, cell destruction, and circulatory shock. Inhibition of this proteolytic-based LF toxemia could be expected to provide therapeutic value in combination with an antibiotic during and immediately after an active anthrax infection. Herein is shown the crystal structure of an intimate complex between a hydroxamate, (2R)-2-[(4-fluoro-3-methylphenyl)sulfonylamino]-N-hydroxy-2-(tetrahydro-2H-pyran-4-yl)acetamide, and LF at the LF-active site. Most importantly, this molecular interaction between the hydroxamate and the LF active site resulted in (i) inhibited LF protease activity in an enzyme assay and protected macrophages against recombinant LF and protective antigen in a cell-based assay, (ii) 100% protection in a lethal mouse toxemia model against recombinant LF and protective antigen, (iii) approximately 50% survival advantage to mice given a lethal challenge of B. anthracis Sterne vegetative cells and to rabbits given a lethal challenge of B. anthracis Ames spores and doubled the mean time to death in those that died in both species, and (iv) 100% protection against B. anthracis spore challenge when used in combination therapy with ciprofloxacin in a rabbit "point of no return" model for which ciprofloxacin alone provided 50% protection. These results indicate that a small molecule, hydroxamate LF inhibitor, as revealed herein, can ameliorate the toxemia characteristic of an active B. anthracis infection and could be a vital adjunct to our ability to combat anthrax.

  1. Biomarkers for Checkpoint Inhibition.

    PubMed

    Weber, Jeffrey S

    2017-01-01

    The identification of predictive biomarkers for the benefit of cancer immunotherapy is the holy grail of the burgeoning immunotherapy field. Recent work has shown that there are a core of concepts that establish the presence of an immune cell-infiltrate, an inflammatory signature of the tumor microenvironment, and the availability of target antigens defined by mutated neoantigens, as critical for the success of the checkpoint blockade. Genetic analyses have shown that resistance to PD-1 blockade, either innate or adaptive, may be due to existing or de novo mutations in signaling pathways critical for T-cell function in a modest proportion of cases. Major hurdles in the field that remain to be overcome are the difficulty of obtaining tumor biopsies for biomarker assessment, the heterogeneity of biomarker expression within tumors and within different tumors from the same patient, and the inducibility of some biomarkers by disease-related processes. Although assessment of peripheral blood or serum biomarkers would be ideal, few data suggest that they would reliably predict outcome with checkpoint blockade. Ultimately, some amalgamated biomarker that includes tumor and host factors will be required to predict which patients are likely to benefit from, or be resistant to, the effects of checkpoint inhibition.

  2. Checkpoint inhibition in myeloma.

    PubMed

    Benson, Don M

    2016-12-02

    Historically, attempts at cancer immunotherapy have emphasized strategies designed to stimulate or augment the immune system into action. In the past decade, a complementary approach has developed, that of releasing immune cells from inhibitory restraint. Discoveries in the fundamental biology of how immunity is regulated, how the immune system interfaces with malignancy, and how cancer cells may exploit these processes to evade detection have all been translated into the rapidly growing field of therapeutic immune checkpoint inhibition for cancer. Myeloma is a malignancy associated with significant immune dysfunction imparted both by the disease itself as well as by many of the immunosuppressive therapies that have been used in the past. The growing body of preclinical data regarding immunoregulatory mechanisms that appear active in myeloma has begun to be translated to clinical trials targeting these signaling axes. This review will attempt to summarize the current understanding of the basic biology of several immune checkpoint pathways that may be important in myeloma and provide an up-to-date overview of recent and ongoing clinical trials of immune checkpoint inhibitors in myeloma. Finally, several current challenges and possible future directions of immune checkpoint blockade in myeloma will be reviewed. © 2016 by The American Society of Hematology. All rights reserved.

  3. Forcing contact inhibition of locomotion.

    PubMed

    Roycroft, Alice; Mayor, Roberto

    2015-07-01

    Contact inhibition of locomotion drives a variety of biological phenomenon, from cell dispersion to collective cell migration and cancer invasion. New imaging techniques have allowed contact inhibition of locomotion to be visualised in vivo for the first time, helping to elucidate some of the molecules and forces involved in this phenomenon. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Inhibition of Retinoblastoma Protein Inactivation

    DTIC Science & Technology

    2016-09-01

    Retinoblastoma protein, E2F transcription factor, high throughput screen, drug discovery, x - ray crystallography 16. SECURITY CLASSIFICATION OF: 17...developed a method to perform fragment based screening by x - ray crystallography. 2.0 KEYWORDS Retinoblastoma (Rb) pathway, E2F transcription factor...cancer, cell-cycle inhibition, activation, modulation, inhibition, high throughput screening, fragment-based screening, x - ray crystallography

  5. Can Arousal Modulate Response Inhibition?

    ERIC Educational Resources Information Center

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  6. Inhibition of cellulases by phenols

    USDA-ARS?s Scientific Manuscript database

    The inhibition of enzymes by the end products that they make is a well-known phenomenon. Another form of inhibition is manifested by the decrease in hydrolysis of pretreated cellulosic material as the concentration of solid biomass material increases, even though the ratio of enzyme to cellulose is...

  7. Can Arousal Modulate Response Inhibition?

    ERIC Educational Resources Information Center

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  8. Balanced feedforward inhibition and dominant recurrent inhibition in olfactory cortex

    PubMed Central

    Large, Adam M.; Vogler, Nathan W.; Mielo, Samantha; Oswald, Anne-Marie M.

    2016-01-01

    Throughout the brain, the recruitment of feedforward and recurrent inhibition shapes neural responses. However, disentangling the relative contributions of these often-overlapping cortical circuits is challenging. The piriform cortex provides an ideal system to address this issue because the interneurons responsible for feedforward and recurrent inhibition are anatomically segregated in layer (L) 1 and L2/3 respectively. Here we use a combination of optical and electrical activation of interneurons to profile the inhibitory input received by three classes of principal excitatory neuron in the anterior piriform cortex. In all classes, we find that L1 interneurons provide weaker inhibition than L2/3 interneurons. Nonetheless, feedforward inhibitory strength covaries with the amount of afferent excitation received by each class of principal neuron. In contrast, intracortical stimulation of L2/3 evokes strong inhibition that dominates recurrent excitation in all classes. Finally, we find that the relative contributions of feedforward and recurrent pathways differ between principal neuron classes. Specifically, L2 neurons receive more reliable afferent drive and less overall inhibition than L3 neurons. Alternatively, L3 neurons receive substantially more intracortical inhibition. These three features—balanced afferent drive, dominant recurrent inhibition, and differential recruitment by afferent vs. intracortical circuits, dependent on cell class—suggest mechanisms for olfactory processing that may extend to other sensory cortices. PMID:26858458

  9. Biology of TACE inhibition

    PubMed Central

    Newton, R; Solomon, K; Covington, M; Decicco, C; Haley, P; Friedman, S; Vaddi, K

    2001-01-01

    Studies conducted over the past decade have demonstrated a central role for tumour necrosis factor α (TNFα) in inflammatory diseases. As a result of this work, a number of biological agents that neutralise the activity of this cytokine have entered the clinic. The recent clinical data obtained with etanercept and infliximab highlight the relevance of this strategy. TNFα converting enzyme (TACE) is the metalloproteinase that processes the 26 kDa membrane bound precursor of TNFα (proTNFα) to the 17 kDa soluble component. Although a number of proteases have been shown to process proTNFα, none do so with the efficiency of TACE. A series of orally bioavailable, selective, and potent TACE inhibitors are currently in clinical development. These inhibitors effectively block TACE mediated processing of proTNFα and can reduce TNF production by lipopolysaccharide stimulated whole blood by >95%. Through a series of studies it is shown here that >80% of the unprocessed proTNFα is degraded intracellularly. The remainder appears to be transiently expressed on the cell surface. Although, in vitro, TACE inhibition has also been implicated in shedding of p55 and p75 surface TNFα receptors, the in vivo data cast doubt on the consequences of this finding. In a mouse model of collagen-induced arthritis, the inhibitors are efficacious both prophylactically and therapeutically. The efficacy seen is equivalent to strategies that neutralise TNFα. In many studies greater efficacy is observed with the TACE inhibitors, presumably owing to greater penetration to the site of TNFα production.

 PMID:11890648

  10. Behavioral inhibition and childhood stuttering.

    PubMed

    Choi, Dahye; Conture, Edward G; Walden, Tedra A; Lambert, Warren E; Tumanova, Victoria

    2013-06-01

    The purpose of this study was to assess the relation of behavioral inhibition to stuttering and speech/language output in preschool-age children who do (CWS) and do not stutter (CWNS). Participants were preschool-age (ages 36-68 months), including 26 CWS (22 males) and 28 CWNS (13 males). Participants' behavioral inhibition (BI) was assessed by measuring the latency to their sixth spontaneous comment during conversation with an unfamiliar experimenter, using methodology developed by Kagan, Reznick, and Gibbons (1989). In addition to these measures of BI, each participant's stuttered and non-stuttered disfluencies and mean length of utterance (in morphemes) were assessed. Among the more salient findings, it was found that (1) there was no significant difference in BI between preschool-age CWS and CWNS as a group, (2) when extremely high versus low inhibited children were selected, there were more CWS with higher BI and fewer CWS with lower BI when compared to their CWNS peers, and (3) more behaviorally inhibited CWS, when compared to less behaviorally inhibited CWS, exhibited more stuttering. Findings are taken to suggest that one aspect of temperament (i.e., behavioral inhibition) is exhibited by some preschool-age CWS and that these children stutter more than CWS with lower behavioral inhibition. The present results seem to support continued study of the association between young children's temperamental characteristics and stuttering, the diagnostic entity (i.e., CWS versus CWNS), as well as stuttering, the behavior (e.g., frequency of stuttered disfluencies). After reading this article, the reader will be able to: (a) summarize the salient empirical findings in the extant literature with regard to the association between temperament and childhood stuttering; (b) describe the concept of behavioral inhibition (BI) as well as the methods to measure BI; and (c) discuss the association between behavioral inhibition and childhood stuttering in preschool-age children

  11. The expression of heterologous MAM-7 in Lactobacillus rhamnosus reduces its intrinsic capacity to inhibit colonization of pathogen Vibrio parahaemolyticus in vitro.

    PubMed

    Beltran, Sebastian; Munoz-Bergmann, Cristian A; Elola-Lopez, Ana; Quintana, Javiera; Segovia, Cristopher; Trombert, Annette N

    2016-01-07

    Vibrio parahaemolyticus (V. parahaemolyticus) is a Gram-negative, halophilic bacterium recognized as one of the most important foodborne pathogen. When ingested, V. parahaemolyticus causes a self-limiting illness (Vibriosis), characterized mainly by watery diarrhoea. Treatment is usually oral rehydration and/or antibiotics in complicated cases. Since 1996, the pathogenic and pandemic V. parahaemolyticus O3:K6 serotype has spread worldwide, increasing the reported number of vibriosis cases. Thus, the design of new strategies for pathogen control and illness prevention is necessary. Lactobacillus sp. grouped Gram positive innocuous bacteria, part of normal intestinal microbiota and usually used as oral vaccines for several diarrheic diseases. Recombinants strains of Lactobacillus (RL) expressing pathogen antigens can be used as part of an anti-adhesion strategy where RL block the pathogen union sites in host cells. Thus, we aimed to express MAM-7 V. parahaemolyticus adhesion protein in Lactobacillus sp. to generate an RL that prevents pathogen colonization. We cloned the MAM-7 gene from V. parahaemolyticus RIMD 2210633 in Lactobacillus expression vectors. Recombinant strains (Lactobacillus rhamnosus pSEC-MAM7 and L. rhamnosus pCWA-MAM7) adhered to CaCo-2 cells and competed with the pathogen. However, the L. rhamnosus wild type strain showed the best capacity to inhibit pathogen colonization in vitro. In addition, LDH-assay showed that recombinant strains were cytotoxic compared with the wild type isogenic strain. MAM-7 expression in lactobacilli reduces the intrinsic inhibitory capacity of L. rhamnosus against V. parahaemolyticus.

  12. A highly acid-resistant novel strain of Lactobacillus johnsonii No. 1088 has antibacterial activity, including that against Helicobacter pylori, and inhibits gastrin-mediated acid production in mice

    PubMed Central

    Aiba, Yuji; Nakano, Yasuhiro; Koga, Yasuhiro; Takahashi, Kenji; Komatsu, Yasuhiko

    2015-01-01

    A novel strain of Lactobacillus johnsonii No. 1088 was isolated from the gastric juice of a healthy Japanese male volunteer, and characterized for its effectiveness in the stomach environment. Lactobacillus johnsonii No. 1088 was found to have the strongest acid resistance among several lactobacilli examined (>10% of cells survived at pH 1.0 after 2 h), and such a high acid resistance property was a specific characteristic of this strain of L. johnsonii. When cultured with various virulent bacteria, L. johnsonii No. 1088 inhibited the growth of Helicobacter pylori,Escherichia coli O-157, Salmonella Typhimurium, and Clostridium difficile, in which case its effectiveness was more potent than that of a type strain of L. johnsonii,JCM2012. In addition to its effect in vitro, L. johnsonii No. 1088 inhibited the growth of H. pylori in human intestinal microbiota-associated mice in both its live and lyophilized forms. Moreover, L. johnsonii No. 1088 suppressed gastric acid secretion in mice via decreasing the number of gastrin-positive cells in the stomach. These results taken together suggest that L. johnsonii No. 1088 is a unique lactobacillus having properties beneficial for supporting H. pylori eradication by triple therapy including the use of a proton pump inhibitor (PPI) and also for prophylaxis of gastroesophageal reflux disease possibly caused after H. pylori eradication as a side effect of PPI. PMID:25771812

  13. Infrared inhibition of embryonic hearts

    NASA Astrophysics Data System (ADS)

    Wang, Yves T.; Rollins, Andrew M.; Jenkins, Michael W.

    2016-06-01

    Infrared control is a new technique that uses pulsed infrared lasers to thermally alter electrical activity. Originally developed for nerves, we have applied this technology to embryonic hearts using a quail model, previously demonstrating infrared stimulation and, here, infrared inhibition. Infrared inhibition enables repeatable and reversible block, stopping cardiac contractions for several seconds. Normal beating resumes after the laser is turned off. The block can be spatially specific, affecting propagation on the ventricle or initiation on the atrium. Optical mapping showed that the block affects action potentials and not just calcium or contraction. Increased resting intracellular calcium was observed after a 30-s exposure to the inhibition laser, which likely resulted in reduced mechanical function. Further optimization of the laser illumination should reduce potential damage. Stopping cardiac contractions by disrupting electrical activity with infrared inhibition has the potential to be a powerful tool for studying the developing heart.

  14. Inhibition of MMPs by alcohols

    PubMed Central

    Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Hoshika, Tomohiro; Uchiyama, Toshikazu; Tjäderhane, Leo; Breschi, Lorenzo; Mazzoni, Annalisa; Thompson, Jeremy M.; McCracken, Courtney E.; Looney, Stephen W.; Tay, Franklin R.; Pashley, David H.

    2011-01-01

    Objectives While screening the activity of potential inhibitors of matrix metalloproteinases (MMPs), due to the limited water solubility of some of the compounds, they had to be solubilized in ethanol. When ethanol solvent controls were run, they were found to partially inhibit MMPs. Thus, the purpose of this study was to compare the MMP-inhibitory activity of a series of alcohols. Methods The possible inhibitory activity of a series of alcohols was measured against soluble rhMMP-9 and insoluble matrix-bound endogenous MMPs of dentin in completely demineralized dentin. Increasing concentrations (0.17, 0.86, 1.71 and 4.28 moles/L) of a homologous series of alcohols (i.e. methanol, ethanol, propanols, butanols, pentanols, hexanols, the ethanol ester of methacrylic acid, heptanols and octanol) were compared to ethanediol, and propanediol by regression analysis to calculate the molar concentration required to inhibit MMPs by 50% (i.e. the IC50). Results Using two different MMP models, alcohols were shown to inhibit rhMMP-9 and the endogenous proteases of dentin matrix in a dose-dependent manner. The degree of MMP inhibition by alcohols increased with chain length up to 4 methylene groups. Based on the molar concentration required to inhibit rhMMP-9 fifty percent, 2-hydroxyethylmethacrylate (HEMA), 3-hexanol, 3-heptanol and 1-octanol gave the strongest inhibition. Significance The results indicate that alcohols with 4 methylene groups inhibit MMPs more effectively than methanol or ethanol. MMP inhibition was inversely related to the Hoy's solubility parameter for hydrogen bonding forces of the alcohols (i.e. to their hydrophilicity). PMID:21676453

  15. Phosphanilic Acid Inhibits Dihydropteroate Synthase

    DTIC Science & Technology

    1989-11-01

    dihydropteroate synthases of P. aeruginosa and E . coli were about equally susceptible to inhibition by PA. These results suggest that cells of P. aeruginosa...are more permeable to PA than cells of E . coli . Although a weak inhibitor, PA acted on dihydropteroate synthase in the same manner as the sulfonamides...with which PA is structurally related. Inhibition of E . coli by PA in a basal salts-glucose medium was prevented by p-aminobenzoic acid (pABA). However

  16. Differential intracellular efficacies of ciprofloxacin and cefixime against Neisseria gonorrhoeae in human fallopian tube organ culture.

    PubMed

    Phanucharas, J P; Gorby, G L

    1997-07-01

    This study compared the abilities of ciprofloxacin and cefixime to kill intracellular Neisseria gonorrhoeae in a human fallopian tube organ culture assay. When invasion was inhibited by cytochalasin D, 0.996% of the tissue-associated gonococci survived ciprofloxacin exposure compared to 1.70% of gonococci exposed to cefixime (95% confidence interval for the ratio of the means, 0.267 to 1.30), indicating that the two antibiotics did not significantly differ in the ability to kill extracellular attached organisms. In the absence of cytochalasin D, 1.63% survived ciprofloxacin exposure while 9.76% survived cefixime treatment (95% confidence interval for the ratio of the means, 0.067 to 0.418). These results suggest that ciprofloxacin penetrated epithelial cells and killed intracellular gonococci better than did cefixime. Thus, at concentrations achievable in serum, ciprofloxacin was more effective in total gonococcal killing than cefixime in this human fallopian tube organ culture model.

  17. CD66-mediated phagocytosis of Opa52 Neisseria gonorrhoeae requires a Src-like tyrosine kinase- and Rac1-dependent signalling pathway.

    PubMed

    Hauck, C R; Meyer, T F; Lang, F; Gulbins, E

    1998-01-15

    The interaction of Neisseria gonorrhoeae with human phagocytes is a hallmark of gonococcal infections. Recently, CD66 molecules have been characterized as receptors for Opa52-expressing gonococci on human neutrophils. Here we show that Opa52-expressing gonococci or Escherichia coli or F(ab) fragments directed against CD66, respectively, activate a signalling cascade from CD66 via Src-like protein tyrosine kinases, Rac1 and PAK to Jun-N-terminal kinase. The induced signal is distinct from Fcgamma-receptor-mediated signalling and is specific for Opa52, since piliated Opa- gonococci, commensal Neisseria cinerea or E.coli do not stimulate this signalling pathway. Inhibition of Src-like kinases or Rac1 prevents the uptake of Opa52 bacteria, demonstrating the crucial role of this signalling cascade for the opsonin-independent, Opa52/CD66-mediated phagocytosis of pathogenic Neisseria.

  18. Behavioral inhibition and childhood stuttering

    PubMed Central

    Choi, Dahye; Conture, Edward G.; Walden, Tedra A.; Lambert, Warren E.; Tumanova, Victoria

    2013-01-01

    Purpose The purpose of this study was to assess the relation of behavioral inhibition to stuttering and speech/language output in preschool-age children who do (CWS) and do not stutter (CWNS). Method Participants were preschool-age (ages 36 to 68 months), including 26 CWS (22 males) and 28 CWNS (13 males). Participants’ behavioral inhibition (BI) was assessed by measuring the latency to their sixth spontaneous comment during conversation with an unfamiliar experimenter, using methodology developed by Kagan, Reznick, and Gibbons (1989). In addition to these measures of BI, each participant’s stuttered and non-stuttered disfluencies and mean length of utterance (in morphemes) were assessed. Results Among the more salient findings, it was found that (1) there was no significant difference in BI between preschool-age CWS and CWNS as a group, (2) when extremely high versus low inhibited children were selected, there were more CWS with higher BI and fewer CWS with lower BI when compared to their CWNS peers, and (3) more behaviorally inhibited CWS, when compared to less behaviorally inhibited CWS, exhibited more stuttering. Conclusions Findings are taken to suggest that one aspect of temperament (i.e., behavioral inhibition) is exhibited by some preschool-age CWS and that these children stutter more than CWS with lower behavioral inhibition. The present results seem to support continued study of the association between young children’s temperamental characteristics and stuttering, the diagnostic entity (i.e., CWS versus CWNS), as well as stuttering, the behavior (e.g., frequency of stuttered disfluencies). PMID:23773669

  19. Inhibition of Hageman factor activation

    PubMed Central

    Nossel, H. L.; Rubin, H.; Drillings, M.; Hsieh, R.

    1968-01-01

    A method for studying inhibitors of the contact stages of blood coagulation is described. A number of positively charged substances were shown to inhibit the contact stages. The inhibitory substances include spermine, cytochrome c, ribonuclease, and lysozyme. The inhibitory effect of these substances was neutralized by the addition of an activated plasma thromboplastin antecedent, factor XI, (PTA) fraction. Other positively charged substances including protamine, hexadimethrine, polylysine, polyornithine, methylene blue, and ortho-toluidine blue also inhibited the contact stages of coagulation, but the inhibitory effect on coagulation was not neutralized by the activated PTA fraction. Negatively charged substances such as heparin and insulin did not inhibit the contact stages of coagulation. Cytochrome c inhibited Celite adsorption of a partially purified Hageman factor fraction, and cytochrome, ribonuclease, spermine, and lysozome inhibited the adsorption of Hageman factor from PTA-deficient plasma. Very much smaller quantities of Celite completely adsorbed Hageman factor from the fraction rather than from whole plasma, which suggested the possibility that plasma contains an inhibitor or inhibitors of Hageman factor adsorption. Furthermore cytochrome c, spermine, ribonuclease, and lysozyme inhibited the coagulant activity of the following activators of the Hageman and PTA factors: Celite, kaolin, sodium stearate, ellagic acid, and skin. It is suggested that negatively charged sites on these activators are critical for adsorption and activation and that inhibition results from neutralization of the negatively charged sites by the adsorbed inhibtor. Tests with polylysine polymers indicate that inhibitory activity is directly related to molecular size over the molecular weight range of 4000 to 100,000. PMID:5645860

  20. Lateral inhibition during nociceptive processing.

    PubMed

    Quevedo, Alexandre S; Mørch, Carsten Dahl; Andersen, Ole K; Coghill, Robert C

    2017-06-01

    Spatial summation of pain (SSP) is the increase of perceived intensity that occurs as the stimulated area increases. Spatial summation of pain is subadditive in that increasing the stimulus area produces a disproportionately small increase in the perceived intensity of pain. A possible explanation for subadditive summation may be that convergent excitatory information is modulated by lateral inhibition. To test the hypothesis that lateral inhibition may limit SSP, we delivered different patterns of noxious thermal stimuli to the abdomens of 15 subjects using a computer-controlled CO2 laser. Lines (5 mm wide) of variable lengths (4, 8 cm) were compared with 2-point stimuli delivered at the same position/separation as the length of lines. When compared with one-point control stimuli, 2-point stimulus patterns produced statistically significant SSP, while no such summation was detected during line stimulus patterns. Direct comparison of pain intensity evoked by 2-point pattern stimuli with line pattern stimuli revealed that 2-point patterns were perceived as significantly more painful, despite the fact that the 2-point pattern stimulated far smaller areas of skin. Thus, the stimulation of the skin region between the endpoints of the lines appears to produce inhibition. These findings indicate that lateral inhibition limits SSP and is an intrinsic component of nociceptive information processing. Disruption of such lateral inhibition may contribute substantially to the radiation of some types of chronic pain.

  1. Ingested (oral) SST inhibits EAE.

    PubMed

    Brod, Staley A; Hood, Zachary M

    2011-08-01

    Ingested immunoactive proteins type I interferon, soluble immune response suppressor peptide 1-21 and melanocyte-stimulating hormone inhibit clinical attacks and inflammation in acute experimental autoimmune encephalomyelitis (EAE). We examined whether another immunoactive protein, somatostatin (SST), would have similar anti-inflammatory effects on EAE after oral administration. B6 mice were immunized with MOG peptide 35-55 and gavaged with control saline or SST during ongoing disease. Splenocytes from mock-fed or SST-fed mice were adoptively transferred into active MOG peptide 35-55-immunized recipient mice during ongoing disease. In actively fed mice, increased Th2-like cytokines in both the spleen and the central nervous system (CNS) inhibited active disease. In recipients of donor cells from SST-fed donors, reduction of Th1 and Th17 and induction of Th2-like IL-4 cytokines in both the spleen and CNS inhibited disease. T(reg) cells were increased threefold in actively fed spleen cells that are responsible for protection against disease after adoptive transfer. Ingested (orally administered) SST can inhibit clinical disease, inhibit CNS inflammation by decreasing Th17 and Th1-like cytokines and increasing Th2-like cytokines in the CNS via induction of T(reg) cells.

  2. Remote inhibition of polymer degradation.

    SciTech Connect

    Clough, Roger Lee; Celina, Mathias Christopher

    2005-08-01

    Polymer degradation has been explored on the basis of synergistic infectious and inhibitive interaction between separate materials. A dual stage chemiluminescence detection system with individually controlled hot stages was applied to probe for interaction effects during polymer degradation in an oxidizing environment. Experimental confirmation was obtained that volatile antioxidants can be transferred over a relatively large distance. The thermal degradation of a polypropylene (PP) sample receiving traces of inhibitive antioxidants from a remote source is delayed. Similarly, volatiles from two stabilized elastomers were also capable of retarding a degradation process remotely. This observation demonstrates inhibitive cross-talk as a novel interactive phenomenon between different polymers and is consequential for understanding general polymer interactions, fundamental degradation processes and long-term aging effects of multiple materials in a single environment.

  3. Catalase is inhibited by flavonoids.

    PubMed

    Krych, Justyna; Gebicka, Lidia

    2013-07-01

    Catalases, heme enzymes, which catalyze decomposition of hydrogen peroxide to water and molecular oxygen, belong to the antioxidant defense system of the cell. In this work we have shown that catalase from bovine liver is inhibited by flavonoids. The inhibition is, at least partially, due to the formation of hydrogen bonds between catalase and flavonoids. In the presence of some flavonoids the formation of unreactive catalase compound II has been detected. The most potent catalase inhibitors among the tested flavonoids have appeared myricetin, epicatechin gallate and epigallocatechin gallate. The relationship between the degree of enzyme inhibition and molecular structure of flavonoids has been analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Strigolactone inhibition of shoot branching.

    PubMed

    Gomez-Roldan, Victoria; Fermas, Soraya; Brewer, Philip B; Puech-Pagès, Virginie; Dun, Elizabeth A; Pillot, Jean-Paul; Letisse, Fabien; Matusova, Radoslava; Danoun, Saida; Portais, Jean-Charles; Bouwmeester, Harro; Bécard, Guillaume; Beveridge, Christine A; Rameau, Catherine; Rochange, Soizic F

    2008-09-11

    A carotenoid-derived hormonal signal that inhibits shoot branching in plants has long escaped identification. Strigolactones are compounds thought to be derived from carotenoids and are known to trigger the germination of parasitic plant seeds and stimulate symbiotic fungi. Here we present evidence that carotenoid cleavage dioxygenase 8 shoot branching mutants of pea are strigolactone deficient and that strigolactone application restores the wild-type branching phenotype to ccd8 mutants. Moreover, we show that other branching mutants previously characterized as lacking a response to the branching inhibition signal also lack strigolactone response, and are not deficient in strigolactones. These responses are conserved in Arabidopsis. In agreement with the expected properties of the hormonal signal, exogenous strigolactone can be transported in shoots and act at low concentrations. We suggest that endogenous strigolactones or related compounds inhibit shoot branching in plants. Furthermore, ccd8 mutants demonstrate the diverse effects of strigolactones in shoot branching, mycorrhizal symbiosis and parasitic weed interaction.

  5. PHAGOCYTOSIS INHIBITION AND REVERSAL I.

    PubMed Central

    Sbarra, Anthony J.; Shirley, William

    1963-01-01

    Sbarra, Anthony J. (St. Margaret's Hospital, Boston, Mass.) and William Shirley. Phagocytosis inhibition and reversal. I. Effect of glycolytic intermediates and nucleotides on particle uptake. J. Bacteriol. 86:259–265. 1963.—By microscopically monitoring phagocytosis and following the biochemical changes associated with this process, the inhibition of phagocytosis by fluoride or iodoacetate was shown to be partially reversed by pyruvate. This reversal occurred with both inhibitors, either aerobically or anaerobically. Nicotinamide adenine dinucleotide (NAD) apparently increased the degree of pyruvate reversal when fluoride, but not iodoacetate, was the inhibitory agent. Lactate under some conditions was also shown to reverse the inhibition. It is suggested that pyruvate and NAD are key compounds for the phagocytic process. PMID:14058950

  6. Post-Stop-Signal Adjustments: Inhibition Improves Subsequent Inhibition

    ERIC Educational Resources Information Center

    Bissett, Patrick G.; Logan, Gordon D.

    2012-01-01

    Performance in the stop-signal paradigm involves a balance between going and stopping, and one way that this balance is struck is through shifting priority away from the go task, slowing responses after a stop signal, and improving the probability of inhibition. In 6 experiments, the authors tested whether there is a corresponding shift in…

  7. Substrate inhibition competes with halide inhibition in polyphenol oxidase.

    PubMed

    Lim, Giselle Grace Fernando; Imura, Yuki; Yoshimura, Etsuro

    2012-10-01

    Polyphenol oxidase (PPO) is a ubiquitous enzyme important in the food industry. Although PPO activity followed Michaelis-Menten kinetics at catechol concentrations of up to 1 mM, it slowly decreased at catechol concentrations above 2 mM. This result indicated that in addition to the active site (site A), the enzyme possesses a second catechol-binding site (site B) that exerts an inhibitory effect on PPO activity. Halides inhibit PPO activity in such a way that substrate inhibition is lessened when halide concentration is increased. Furthermore, elevated concentrations of catechol diminished the degree of inhibition by halides. These findings suggest that halides also bind to site B to inhibit PPO activity. A steady-state kinetic analysis demonstrated that the dissociation constant between catechol and PPO depended on the binding of halides to site B. The dissociation constants were greatest when chloride bound to the site. Bromide and iodide yielded lower dissociation constants, in that order. These data indicate that the binding of halide to site B modulated the structure of site A, thereby exerting an inhibitory effect.

  8. Post-Stop-Signal Adjustments: Inhibition Improves Subsequent Inhibition

    ERIC Educational Resources Information Center

    Bissett, Patrick G.; Logan, Gordon D.

    2012-01-01

    Performance in the stop-signal paradigm involves a balance between going and stopping, and one way that this balance is struck is through shifting priority away from the go task, slowing responses after a stop signal, and improving the probability of inhibition. In 6 experiments, the authors tested whether there is a corresponding shift in…

  9. Homo economicus belief inhibits trust.

    PubMed

    Xin, Ziqiang; Liu, Guofang

    2013-01-01

    As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners' benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals' homo economicus belief and inhibit their trust. It seems that people's increasing homo economicus belief may serve as one cause of the worldwide decline of trust.

  10. Homo Economicus Belief Inhibits Trust

    PubMed Central

    Xin, Ziqiang; Liu, Guofang

    2013-01-01

    As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners’ benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals’ homo economicus belief and inhibit their trust. It seems that people’s increasing homo economicus belief may serve as one cause of the worldwide decline of trust. PMID:24146907

  11. Action spectra for photosynthetic inhibition

    NASA Technical Reports Server (NTRS)

    Caldwell, M. M.; Flint, S.; Camp, L. B.

    1981-01-01

    The ultraviolet action spectrum for photosynthesis inhibition was determined to fall between that of the general DNA action spectrum and the generalized plant action spectrum. The characteristics of this action spectrum suggest that a combination of pronounced increase in effectiveness with decreasing wavelength, substantial specificity for the UV-B waveband, and very diminished response in the UV-A waveband result in large radiation amplification factors when the action spectra are used as weighting functions. Attempted determination of dose/response relationships for leaf disc inhibition provided inconclusive data from which to deconvolute an action spectrum.

  12. Action spectra for photosynthetic inhibition

    NASA Technical Reports Server (NTRS)

    Caldwell, M. M.; Flint, S.; Camp, L. B.

    1981-01-01

    The ultraviolet action spectrum for photosynthesis inhibition was determined to fall between that of the general DNA action spectrum and the generalized plant action spectrum. The characteristics of this action spectrum suggest that a combination of pronounced increase in effectiveness with decreasing wavelength, substantial specificity for the UV-B waveband, and very diminished response in the UV-A waveband result in large radiation amplification factors when the action spectra are used as weighting functions. Attempted determination of dose/response relationships for leaf disc inhibition provided inconclusive data from which to deconvolute an action spectrum.

  13. Characterization of Lactobacillus salivarius strains B37 and B60 capable of inhibiting IL-8 production in Helicobacter pylori-stimulated gastric epithelial cells.

    PubMed

    Panpetch, Wimonrat; Spinler, Jennifer K; Versalovic, James; Tumwasorn, Somying

    2016-10-18

    Interleukin (IL)-8 is the key agent for initiating an inflammatory response to infection with Helicobacter pylori. Some strains of Lactobacillus spp. are known to colonize the stomach and suppress inflammation caused by H. pylori. In this study, we characterized two gastric-derived lactobacilli, Lactobacillus salivarius (LS) strains B37 and B60, capable of inhibiting H. pylori-induced IL-8 production by gastric epithelial cells. Conditioned media from LS-B37 and LS-B60 suppressed H. pylori-induced IL-8 production and mRNA expression from AGS cells without inhibiting H. pylori growth. These conditioned media suppressed the activation of NF-κB but did not suppress c-Jun activation. IL-8 inhibitory substances in conditioned media of LS-B37 and LS-B60 are heat-stable and larger than 100 kDa in size. The inhibitory activity of LS-B37 was abolished when the conditioned medium was treated with α-amylase but still remained when treated with either proteinase K, trypsin, lipase or lysozyme. The activity of LS-B60 was abolished when the conditioned medium was treated with either amylase or proteinase K but still remained when treated with lysozyme. Treatment with lipase and trypsin also significantly affected the inhibitory activity of LS-B60 although the conditioned medium retained IL-8 suppression statistically different from media control. These results suggest that L. salivarius strains B37 and B60 produce different immunomodulatory factors capable of suppressing H. pylori-induced IL-8 production from gastric epithelial cells. Our results suggest that the large, heat-stable immunomodulatory substance(s) present in the LCM of LS-B37 is a polysaccharide, while the one(s) of LS-B60 is either complex consisting of components of polysaccharide, lipid and protein or includes multiple components such as glycoprotein and lipoprotein.

  14. Azide inhibition of urate oxidase.

    PubMed

    Gabison, Laure; Colloc'h, Nathalie; Prangé, Thierry

    2014-07-01

    The inhibition of urate oxidase (UOX) by azide was investigated by X-ray diffraction techniques and compared with cyanide inhibition. Two well characterized sites for reagents are present in the enzyme: the dioxygen site and the substrate-binding site. To examine the selectivity of these sites towards azide inhibition, several crystallization conditions were developed. UOX was co-crystallized with azide (N3) in the presence or absence of either uric acid (UA, the natural substrate) or 8-azaxanthine (8AZA, a competitive inhibitor). In a second set of experiments, previously grown orthorhombic crystals of the UOX-UA or UOX-8AZA complexes were soaked in sodium azide solutions. In a third set of experiments, orthorhombic crystals of UOX with the exchangeable ligand 8-nitroxanthine (8NXN) were soaked in a solution containing uric acid and azide simultaneously (competitive soaking). In all assays, the soaking periods were either short (a few hours) or long (one or two months). These different experimental conditions showed that one or other of the sites, or the two sites together, could be inhibited. This also demonstrated that azide not only competes with dioxygen as cyanide does but also competes with the substrate for its enzymatic site. A model in agreement with experimental data would be an azide in equilibrium between two sites, kinetically in favour of the dioxygen site and thermodynamically in favour of the substrate-binding site.

  15. Azide inhibition of urate oxidase

    PubMed Central

    Gabison, Laure; Colloc’h, Nathalie; Prangé, Thierry

    2014-01-01

    The inhibition of urate oxidase (UOX) by azide was investigated by X-ray diffraction techniques and compared with cyanide inhibition. Two well characterized sites for reagents are present in the enzyme: the dioxygen site and the substrate-binding site. To examine the selectivity of these sites towards azide inhibition, several crystallization conditions were developed. UOX was co-crystallized with azide (N3) in the presence or absence of either uric acid (UA, the natural substrate) or 8-azaxanthine (8AZA, a competitive inhibitor). In a second set of experiments, previously grown orthorhombic crystals of the UOX–UA or UOX–8AZA complexes were soaked in sodium azide solutions. In a third set of experiments, orthorhombic crystals of UOX with the exchangeable ligand 8-nitroxanthine (8NXN) were soaked in a solution containing uric acid and azide simultaneously (competitive soaking). In all assays, the soaking periods were either short (a few hours) or long (one or two months). These different experimental conditions showed that one or other of the sites, or the two sites together, could be inhibited. This also demonstrated that azide not only competes with dioxygen as cyanide does but also competes with the substrate for its enzymatic site. A model in agreement with experimental data would be an azide in equilibrium between two sites, kinetically in favour of the dioxygen site and thermodynamically in favour of the substrate-binding site. PMID:25005084

  16. Infant Predictors of Behavioural Inhibition

    ERIC Educational Resources Information Center

    Moehler, Eva; Kagan, Jerome; Oelkers-Ax, Rieke; Brunner, Romuald; Poustka, Luise; Haffner, Johann; Resch, Franz

    2008-01-01

    Behavioural inhibition in the second year of life is a hypothesized predictor for shyness, social anxiety and depression in later childhood, adolescence and even adulthood. To search for the earliest indicators of this fundamental temperamental trait, this study examined whether behavioural characteristics in early infancy can predict behavioural…

  17. Behavioral Inhibition: Type or Continuum?

    ERIC Educational Resources Information Center

    Scholmerich, Axel; And Others

    This study investigated whether behavioral inhibition is best conceptualized as a continuous variable or as a distinct typology with two or more subcategories. The following data were gathered on 58 infants at 5, 7, 10, and 13 months of age; physiological functioning (cardiovascular activity and salivary cortisol); emotional expressivity in…

  18. Epigallocatechin gallate inhibits endothelial exocytosis.

    PubMed

    Yamakuchi, Munekazu; Bao, Clare; Ferlito, Marcella; Lowenstein, Charles J

    2008-07-01

    Consumption of green tea is associated with a decrease in cardiovascular mortality. The beneficial health effects of green tea are attributed in part to polyphenols, organic compounds found in tea that lower blood pressure, reduce body fat, decrease LDL cholesterol, and inhibit inflammation. We hypothesized that epigallocatechin gallate (EGCG), the most abundant polyphenol in tea, inhibits endothelial exocytosis, the initial step in leukocyte trafficking and vascular inflammation. To test this hypothesis, we treated human umbilical-vein endothelial cells with EGCG and other polyphenols, and then measured endothelial exocytosis. We found that EGCG decreases endothelial exocytosis in a concentration-dependent manner, with the effects most prominent after 4 h of treatment. Other catechin polyphenols had no effect on endothelial cells. By inhibiting endothelial exocytosis, EGCG decreases leukocyte adherence to endothelial cells. In searching for the mechanism by which EGCG affects endothelial cells, we found that EGCG increases Akt phosphorylation, eNOS phosphorylation, and nitric oxide (NO) production. NOS inhibition revealed that NO mediates the anti-inflammatory effects of EGCG. Our data suggest that polyphenols can decrease vascular inflammation by increasing the synthesis of NO, which blocks endothelial exocytosis.

  19. Inhibition among olfactory receptor neurons

    PubMed Central

    Van der Goes van Naters, Wynand

    2013-01-01

    Often assumed to be epiphenomena of a cell’s activity, extracellular currents and resulting potential changes are increasingly recognized to influence the function of other cells in the vicinity. Experimental evidence shows that even small electric fields can modulate spike timing in neurons. Moreover, when neurons are brought close together experimentally or in pathological conditions, activity in one neuron can excite its neighbors. Inhibitory ephaptic mechanisms, however, may depend on more specialized coupling among cells. Recent studies in the Drosophila olfactory system have shown that excitation of a sensory neuron can inhibit its neighbor, and it was speculated that this interaction was ephaptic. Here we give an overview of ephaptic interactions that effect changes in spike timing, excitation or inhibition in diverse systems with potential relevance to human neuroscience. We examine the mechanism of the inhibitory interaction in the Drosophila system and that of the well-studied ephaptic inhibition of the Mauthner cell in more detail. We note that both current towards and current away from the local extracellular environment of a neuron can inhibit it, but the mechanism depends on the specific architecture of each system. PMID:24167484

  20. Tagetitoxin inhibits chloroplast RNA synthesis

    SciTech Connect

    Mathews, D.E.; Durbin, R.D.

    1987-04-01

    Tagetitoxin is a non-host specific phytotoxin which inhibits chloroplast development. Chloroplast encoded gene products as well as their transcripts are conspicuously depleted in toxin-treated tissue. Intact chloroplasts from 8-9 day old peas were incubated for 60 min. in the presence of tagetitoxin. This treatment reduced RNA synthesis but did not affect protein synthesis as measured by the incorporation of radiolabeled uridine or methionine, respectively. Tagetitoxin also inhibited chloroplast RNA synthesis in vitro. Total UTP incorporation was reduced 50% by 0.5..mu..M tagetitoxin in transcriptionally active chloroplast extracts containing 5mg/ml protein. In vitro transcription with purified E. coli RNA polymerase was also inhibited by tagetitoxin, yet wheat germ RNA polymerase II and several bacteriophage RNA polymerase enzymes were unaffected. Recent evidence suggests that RNA polymerase from chloroplasts and prokaryotes may share extensive homology. In light of this evidence and the authors own data, they propose that tagetitoxin directly inhibits chloroplast RNA polymerase.

  1. Inhibition of carcinogenesis by tea.

    PubMed

    Yang, Chung S; Maliakal, Pius; Meng, Xiaofeng

    2002-01-01

    Tea has received a great deal of attention because tea polyphenols are strong antioxidants, and tea preparations have inhibitory activity against tumorigenesis. The bioavailability and biotransformation of tea polyphenols, however, are key factors limiting these activities in vivo. The inhibition of tumorigenesis by green or black tea preparations has been demonstrated in animal models on different organ sites such as skin, lung, oral cavity, esophagus, forestomach, stomach, small intestine, colon, pancreas, and mammary gland. Epidemiological studies, however, have not yielded clear conclusions concerning the protective effects of tea consumption against cancer formation in humans. The discrepancy between the results from humans and animal models could be due to 1) the much higher doses of tea used in animals in comparison to human consumption, 2) the differences in causative factors between the cancers in humans and animals, and 3) confounding factors limiting the power of epidemiological studies to detect an effect. It is possible that tea may be only effective against specific types of cancer caused by certain etiological factors. Many mechanisms have been proposed for the inhibition of carcinogenesis by tea, including the modulation of signal transduction pathways that leads to the inhibition of cell proliferation and transformation, induction of apoptosis of preneoplastic and neoplastic cells, as well as inhibition of tumor invasion and angiogenesis. These mechanisms need to be evaluated and verified in animal models or humans in order to gain more understanding on the effect of tea consumption on human cancer.

  2. Neuronal Inhibition under the Spotlight.

    PubMed

    Mortensen, Martin; Smart, Trevor G

    2015-12-02

    In this issue of Neuron,Lin et al. (2015) report an optical method to precisely manipulate the activity of GABAA receptors by designing a mutant receptor that binds photosensitive compounds. This allows for studying GABAA receptors in situ and represents a valuable tool to investigate how inhibition affects brain physiology.

  3. Infant Predictors of Behavioural Inhibition

    ERIC Educational Resources Information Center

    Moehler, Eva; Kagan, Jerome; Oelkers-Ax, Rieke; Brunner, Romuald; Poustka, Luise; Haffner, Johann; Resch, Franz

    2008-01-01

    Behavioural inhibition in the second year of life is a hypothesized predictor for shyness, social anxiety and depression in later childhood, adolescence and even adulthood. To search for the earliest indicators of this fundamental temperamental trait, this study examined whether behavioural characteristics in early infancy can predict behavioural…

  4. Prostacyclin analogs inhibit fibroblast migration.

    PubMed

    Kohyama, Tadashi; Liu, Xiangde; Kim, Hui Jung; Kobayashi, Tetsu; Ertl, Ronald F; Wen, Fu-Qiang; Takizawa, Hajime; Rennard, Stephen I

    2002-08-01

    The controlled accumulation of fibroblasts to sites of inflammation is crucial to effective tissue repair after injury. Either inadequate or excessive accumulation of fibroblasts could result in abnormal tissue function. Prostacyclin (PGI(2)) is a potent mediator in the coagulation and inflammatory processes. The aim of this study was to investigate the effect of PGI(2) on chemotaxis of human fetal lung fibroblasts (HFL-1). Using the blind well chamber technique, we found that the PGI(2) analog carbaprostacyclin (10(-6) M) inhibited HFL-1 chemotaxis to human plasma fibronectin (20 microg/ml) 58.0 +/- 13.2% (P < 0.05) and to platelet-derived growth factor (PDGF)-BB (10 ng/ml) 48.7 +/- 4.6% (P < 0.05). Checkerboard analysis demonstrated that carbaprostacyclin inhibits both directed and undirected migration. The inhibitory effect of the carbaprostacyclin was concentration dependent and blocked by the cAMP-dependent protein kinase (PKA) inhibitor KT-5720, suggesting that a cAMP-PKA pathway may be involved in the process. Two other PGI(2) analogs, ciprostene and dehydro-15-cyclohexyl carbaprostacyclin (both 10(-6) M), significantly inhibited fibroblast migration to fibronectin. In summary, PGI(2) appears to inhibit fibroblast chemotaxis to fibronectin and PDGF-BB. Such an effect may contribute to the regulation of fibroblasts in wound healing and could contribute to the pathogenesis of diseases characterized by abnormal tissue repair remodeling.

  5. Inhibition in Prolonged Work Tasks.

    ERIC Educational Resources Information Center

    van der Ven, A. H. G. S.; And Others

    1989-01-01

    A new model is presented that explains reaction time fluctuations in prolonged work tasks. The model extends the so-called Poisson-Erlang model and accounts for long-term trend effects in the reaction time curve. The model is consistent with Spearman's hypothesis that inhibition increases during work and decreases during rest. (TJH)

  6. Acute ethanol administration inhibits Toll-like receptor 4 signaling pathway in rat intestinal epithelia.

    PubMed

    Zhou, Chao; Zhao, Ji; Li, Jing; Wang, Haiying; Tang, Chengwei

    2013-05-01

    Excess alcohol intake, as in binge drinking, increases susceptibility to microbial pathogens. Alcohol impairs macrophage function by suppression of the Toll-like receptor 4 (TLR4) pathway. This study investigated the effects of acute ethanol intake on the TLR4 pathway in rat intestinal epithelia, which usually encounters luminal antigens at first and participates in the development of intestinal immunity. Twenty Wistar rats were randomly assigned to an ethanol group given ethanol as a 25% (v/v) solution in water at 7.5 g/kg, or a control group given saline, by oral gavage daily for 3 days. The epithelial histology and ultrastructure, the intestinal microflora, peripheral and portal venous plasma lipopolysaccharide (LPS) levels, and somatostatin (SST) levels in the peripheral plasma and small intestine were evaluated. Somatostatin receptor 2 (SSTR2), TLR4, TANK binding kinase-1 (TBK1), activated nuclear factor-κB (NF-κB), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in the intestinal mucosa were assayed. LPS responsiveness with or without SST pretreatment was assayed in vitro by quantification of TLR4, TBK1, activated NF-κB, IFN-γ and TNF-α in isolated intestinal epithelia. Mucosal damage was observed in the ethanol group by light and electron microscopy. Escherichia coli cultures were unchanged in rat intestine of the ethanol group compared with controls, but lactobacilli cultures were reduced (p < 0.05). LPS levels increased in peripheral and portal venous plasma (p < 0.05), but mucosal TLR4, TBK1, nuclear NF-κB, IFN-γ and TNF-α were unchanged in the ethanol group. LPS treatment in vitro up-regulated the level of TLR4, TBK1 and nuclear NF-κB as well as the production of IFN-γ and TNF-α in isolated intestinal epithelia in the control (p < 0.05), but not the ethanol group. The stimulatory effects of LPS on intestinal epithelia isolated from the control group were significantly inhibited by SST pretreatment (p < 0.05). The

  7. Effects of the administration of lactobacilli, maltodextrins and fructooligosaccharides upon the adhesion of E. coli O8:K88 to the intestinal mucosa and organic acid levels in the gut contents of piglets.

    PubMed

    Nemcová, R; Bomba, A; Gancarcíková, S; Reiffová, K; Guba, P; Koscová, J; Jonecová, Z; Sciranková, L; Bugarský, A

    2007-10-01

    The influence of the administration of Lactobacillus plantarum, maltodextrin Maldex 150 and Raftifeed IPX fructooligosaccharides on the inhibition of adhesion of E. coli O8:K88 to the mucosa of the jejunum, ileum and colon as well as on the organic acid levels was investigated in 33 conventional piglets. The counts of E. coli K88 adhering to the jejunal mucosa were significantly decreased (p < 0.05) in Lact. plantarum + Maldex 150 and Lact. plantarum + Maldex 150 + Raftifeed IPX groups. The counts of E. coli K88 adhering to the colonic mucosa of Lact. plantarum + Maldex 150 + Raftifeed IPX and Lact. plantarum + Raftifeed IPX groups were significantly lower (p < 0.05) than in Lact. plantarum and Lact. plantarum + Maldex 150 animals. The acetic acid levels in the ileum and colon of the Lact. plantarum + Maldex 150 + Raftifeed IPX group and Lact. plantarum + Raftifeed IPX group were significantly higher (p < 0.05) than in the Lact. plantarum and Lact. plantarum + Maldex 150 group. The combination of Lact. plantarum, maltodextrin Maldex 150 and Raftifeed IPX proved to be the most effective one to inhibit the counts of E. coli O8:K88 adhering to the intestinal mucosa of the jejunum and colon of conventional piglets.

  8. Attentional inhibition mediates inattentional blindness.

    PubMed

    Thakral, Preston P; Slotnick, Scott D

    2010-06-01

    Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle (the critical stimulus) was concurrently presented. Participants were instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location (at the same eccentricity). In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy. 2010 Elsevier Inc. All rights reserved.

  9. Inhibition of Cyclooxygenases by Dipyrone

    PubMed Central

    Pierre, S C; Schmidt, R; Brenneis, C; Michaelis, M; Geisslinger, G; Scholich, K

    2007-01-01

    Background and Purpose: Dipyrone is a potent analgesic drug that has been demonstrated to inhibit cyclooxygenase (COX). In contrast to classical COX-inhibitors, such as aspirin-like drugs, dipyrone has no anti-inflammatory effect and a low gastrointestinal toxicity, indicating a different mode of action. Here, we aimed to investigate the effects of dipyrone on COX. Experimental approach: The four major metabolites of dipyrone, including the two pharmacologically active metabolites, 4-methyl-amino-antipyrine (MAA) and amino-antipyrine (AA), were used to characterise their binding to COX and haem as well as their effects on the biochemical properties of COX. Mass spectrometry, UV and visible photometry were used to study binding and prostaglandin production. Levels of anti-oxidant enzymes were assessed by Western blotting. Key results: The pharmacologically active metabolites of dipyrone, MAA and AA, did not inhibit COX activity in vitro like classical COX inhibitors, but instead redirected the prostaglandin synthesis, ruling out inhibition of COX through binding to its active site. We found that MAA and AA formed stable complexes with haem and reacted with hydrogen peroxide in presence of haem, ferrous ions (Fe2+) or COX. Moreover, MAA reduced Fe3+ to Fe2+ and accordingly increased lipid peroxidation and the expression of anti-oxidant enzymes in cultured cells and in vivo. Conclusions and implications: Our data suggest that the pharmacologically active metabolites of dipyrone inhibit COX activity by sequestering radicals which initiate the catalytic activity of this enzyme or through the reduction of the oxidative states of the COX protein. PMID:17435797

  10. Inhibition of Retinoblastoma Protein Inactivation

    DTIC Science & Technology

    2015-09-01

    phosphorylation, which dissociates the E2F transcription factor from Rb. Our goal is to find and characterize molecules that stabilize the complex between...Retinoblastoma protein, E2F transcription factor, high throughput screen, drug discovery 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER...including breast cancer. Inhibition of cell proliferation by Rb is linked to its direct binding of E2F transcription factors and repression of E2F

  11. Threat interferes with response inhibition.

    PubMed

    Hartikainen, Kaisa M; Siiskonen, Anna R; Ogawa, Keith H

    2012-05-09

    A potential threat, such as a spider, captures attention and engages executive functions to adjust ongoing behavior and avoid danger. We and many others have reported slowed responses to neutral targets in the context of emotional distractors. This behavioral slowing has been explained in the framework of attentional competition for limited resources with emotional stimuli prioritized. Alternatively, slowed performance could reflect the activation of avoidance/freezing-type motor behaviors associated with threat. Although the interaction of attention and emotion has been widely studied, little is known on the interaction between emotion and executive functions. We studied how threat-related stimuli (spiders) interact with executive performance and whether the interaction profile fits with a resource competition model or avoidance/freezing-type motor behaviors. Twenty-one young healthy individuals performed a Go-NoGo visual discrimination reaction time (RT) task engaging several executive functions with threat-related and emotionally neutral distractors. The threat-related distractors had no effect on the RT or the error rate in the Go trials. The NoGo error rate, reflecting failure in response inhibition, increased significantly because of threat-related distractors in contrast to neutral distractors, P less than 0.05. Thus, threat-related distractors temporarily impaired response inhibition. Threat-related distractors associated with increased commission errors and no effect on RT does not suggest engagement of avoidance/freezing-type motor behaviors. The results fit in the framework of the resource competition model. A potential threat calls for evaluation of affective significance as well as inhibition of undue emotional reactivity. We suggest that these functions tax executive resources and may render other executive functions, such as response inhibition, temporarily compromised when the demands for resources exceed availability.

  12. Conditioned inhibition and reinforcement rate.

    PubMed

    Harris, Justin A; Kwok, Dorothy W S; Andrew, Benjamin J

    2014-07-01

    We investigated conditioned inhibition in a magazine approach paradigm. Rats were trained on a feature negative discrimination between an auditory conditioned stimulus (CS) reinforced at one rate versus a compound of that CS and a visual stimulus (L) reinforced at a lower rate. This training established L as a conditioned inhibitor. We then tested the inhibitory strength of L by presenting it in compound with other auditory CSs. L reduced responding when tested with a CS that had been reinforced at a high rate, but had less or even no inhibitory effect when tested with a CS that had been reinforced at a low rate. The inhibitory strength of L was greater if it signaled a decrease in reinforcement from an already low rate than if it signaled an equivalent decrease in reinforcement from a high rate. We conclude that the strength of inhibition is not a linear function of the change in reinforcement that it signals. We discuss the implications of this finding for models of learning (e.g., Rescorla & Wagner, 1972) that identify inhibition with a difference (subtraction) rule.

  13. Serotonin, Inhibition, and Negative Mood

    PubMed Central

    Dayan, Peter; Huys, Quentin J. M

    2008-01-01

    Pavlovian predictions of future aversive outcomes lead to behavioral inhibition, suppression, and withdrawal. There is considerable evidence for the involvement of serotonin in both the learning of these predictions and the inhibitory consequences that ensue, although less for a causal relationship between the two. In the context of a highly simplified model of chains of affectively charged thoughts, we interpret the combined effects of serotonin in terms of pruning a tree of possible decisions, (i.e., eliminating those choices that have low or negative expected outcomes). We show how a drop in behavioral inhibition, putatively resulting from an experimentally or psychiatrically influenced drop in serotonin, could result in unexpectedly large negative prediction errors and a significant aversive shift in reinforcement statistics. We suggest an interpretation of this finding that helps dissolve the apparent contradiction between the fact that inhibition of serotonin reuptake is the first-line treatment of depression, although serotonin itself is most strongly linked with aversive rather than appetitive outcomes and predictions. PMID:18248087

  14. Complement inhibition in cancer therapy.

    PubMed

    Pio, Ruben; Ajona, Daniel; Lambris, John D

    2013-02-01

    For decades, complement has been recognized as an effector arm of the immune system that contributes to the destruction of tumor cells. In fact, many therapeutic strategies have been proposed that are based on the intensification of complement-mediated responses against tumors. However, recent studies have challenged this paradigm by demonstrating a tumor-promoting role for complement. Cancer cells seem to be able to establish a convenient balance between complement activation and inhibition, taking advantage of complement initiation without suffering its deleterious effects. Complement activation may support chronic inflammation, promote an immunosuppressive microenvironment, induce angiogenesis, and activate cancer-related signaling pathways. In this context, inhibition of complement activation would be a therapeutic option for treating cancer. This concept is relatively new and deserves closer attention. In this article, we summarize the mechanisms of complement activation on cancer cells, the cancer-promoting effect of complement initiation, and the rationale behind the use of complement inhibition as a therapeutic strategy against cancer.

  15. Honokiol inhibits lung tumorigenesis through inhibition of mitochondrial function.

    PubMed

    Pan, Jing; Zhang, Qi; Liu, Qian; Komas, Steven M; Kalyanaraman, Balaraman; Lubet, Ronald A; Wang, Yian; You, Ming

    2014-11-01

    Honokiol is an important bioactive compound found in the bark of Magnolia tree. It is a nonadipogenic PPARγ agonist and capable of inhibiting the growth of a variety of tumor types both in vitro and in xenograft models. However, to fully appreciate the potential chemopreventive activity of honokiol, a less artificial model system is required. To that end, this study examined the chemopreventive efficacy of honokiol in an initiation model of lung squamous cell carcinoma (SCC). This model system uses the carcinogen N-nitroso-trischloroethylurea (NTCU), which is applied topically, reliably triggering the development of SCC within 24 to 26 weeks. Administration of honokiol significantly reduced the percentage of bronchial that exhibit abnormal lung SCC histology from 24.4% bronchial in control to 11.0% bronchial in honokiol-treated group (P = 0.01) while protecting normal bronchial histology (present in 20.5% of bronchial in control group and 38.5% of bronchial in honokiol-treated group. P = 0.004). P63 staining at the SCC site confirmed the lung SCCs phenotype. In vitro studies revealed that honokiol inhibited lung SCC cells proliferation, arrested cells at the G1-S cell-cycle checkpoint, while also leading to increased apoptosis. Our study showed that interfering with mitochondrial respiration is a novel mechanism by which honokiol changed redox status in the mitochondria, triggered apoptosis, and finally leads to the inhibition of lung SCC. This novel mechanism of targeting mitochondrial suggests honokiol as a potential lung SCC chemopreventive agent. ©2014 American Association for Cancer Research.

  16. Self-regulation, ego depletion, and inhibition.

    PubMed

    Baumeister, Roy F

    2014-12-01

    Inhibition is a major form of self-regulation. As such, it depends on self-awareness and comparing oneself to standards and is also susceptible to fluctuations in willpower resources. Ego depletion is the state of reduced willpower caused by prior exertion of self-control. Ego depletion undermines inhibition both because restraints are weaker and because urges are felt more intensely than usual. Conscious inhibition of desires is a pervasive feature of everyday life and may be a requirement of life in civilized, cultural society, and in that sense it goes to the evolved core of human nature. Intentional inhibition not only restrains antisocial impulses but can also facilitate optimal performance, such as during test taking. Self-regulation and ego depletion- may also affect less intentional forms of inhibition, even chronic tendencies to inhibit. Broadly stated, inhibition is necessary for human social life and nearly all societies encourage and enforce it. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The ontogeny of learned inhibition

    PubMed Central

    Meyer, Heidi C.; Bucci, David J.

    2014-01-01

    Previous studies have examined the maturation of learning and memory abilities during early stages of development. By comparison, much less is known about the ontogeny of learning and memory during later stages of development, including adolescence. In Experiment 1, we tested the ability of adolescent and adult rats to learn a Pavlovian negative occasion setting task. This procedure involves learning to inhibit a behavioral response when signaled by a cue in the environment. During reinforced trials, a target stimulus (a tone) was presented and immediately followed by a food reward. On nonreinforced trials, a feature stimulus (a light) was presented 5 sec prior to the tone and indicated the absence of reward following presentation of the tone. Both adult and adolescent rats learned to discriminate between two different trial types and withhold responding when the light preceded the tone. However, adolescent rats required more sessions than adults to discriminate between reinforced and nonreinforced trials. The results of Experiment 2 revealed that adolescents could learn the task rules but were specifically impaired in expressing that learning in the form of withholding behavior on nonreinforced trials. In Experiment 3, we found that adolescents were also impaired in learning a different version of the task in which the light and tone were presented simultaneously during the nonreinforced trials. These findings add to existing literature by indicating that impairments in inhibitory behavior during adolescence do not reflect an inability to learn to inhibit a response, but instead reflect a specific deficit in expressing that learning. PMID:24549569

  18. Chrysin Inhibits Lymphangiogenesis in Vitro.

    PubMed

    Prangsaengtong, Orawin; Athikomkulchai, Sirivan; Xu, Jiuxiang; Koizumi, Keiichi; Inujima, Akiko; Shibahara, Naotoshi; Shimada, Yutaka; Tadtong, Sarin; Awale, Suresh

    2016-01-01

    The induction of lymphangiogenesis is an important process to promote cancer growth and cancer metastasis via the lymphatic system. Identifying the compounds that can prevent lymphangiogenesis for cancer therapy is urgently required. Chrysin, 5,7-dihydroxyflavone, a natural flavone extracted from Thai propolis, was used to investigate the effect on the lymphangiogenesis process of TR-LE, rat lymphatic endothelial cells. In this study, maximal nontoxic doses of chrysin on TR-LE cells were selected by performing a proliferation assay. The process of lymphangiogenesis in vitro was determined by cord formation assay, adhesion assay and migration assay. Chrysin at a nontoxic dose (25 μM) significantly inhibited cord formation, cell adhesion and migration of TR-LE cells when compared with the control group. We also found that chrysin significantly induced vascular endothelial growth factor C (VEGF-C) mRNA expression and nitric oxide (NO) production in TR-LE cells which was involved in decreasing the cord formation of TR-LE cells. In conclusion, we report for the first time that chrysin inhibited the process of lymphangiogenesis in an in vitro model. This finding may prove to be a natural compound for anti-lymphangiogenesis that could be developed for use in cancer therapy.

  19. Graphene: corrosion-inhibiting coating.

    PubMed

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  20. Action inhibition in Tourette syndrome.

    PubMed

    Ganos, Christos; Kühn, Simone; Kahl, Ursula; Schunke, Odette; Feldheim, Jan; Gerloff, Christian; Roessner, Veit; Bäumer, Tobias; Thomalla, Götz; Haggard, Patrick; Münchau, Alexander

    2014-10-01

    Tourette syndrome is a neuropsychiatric disorder characterized by tics. Tic generation is often linked to dysfunction of inhibitory brain networks. Some previous behavioral studies found deficiencies in inhibitory motor control in Tourette syndrome, but others suggested normal or even better-than-normal performance. Furthermore, neural correlates of action inhibition in these patients are poorly understood. We performed event-related functional magnetic resonance imaging during a stop-signal reaction-time task in 14 uncomplicated adult Tourette patients and 15 healthy controls. In patients, we correlated activations in stop-signal reaction-time task with their individual motor tic frequency. Task performance was similar in both groups. Activation of dorsal premotor cortex was stronger in the StopSuccess than in the Go condition in healthy controls. This pattern was reversed in Tourette patients. A significant positive correlation was present between motor tic frequency and activations in the supplementary motor area during StopSuccess versus Go in patients. Inhibitory brain networks differ between healthy controls and Tourette patients. In the latter the supplementary motor area is probably a key relay of inhibitory processes mediating both suppression of tics and inhibition of voluntary action. © 2014 International Parkinson and Movement Disorder Society.

  1. Pharmacological inhibition of poly(ADP-ribose) polymerase inhibits angiogenesis

    SciTech Connect

    Rajesh, Mohanraj; Mukhopadhyay, Partha; Batkai, Sandor; Godlewski, Grzegorz; Hasko, Gyoergy; Liaudet, Lucas; Pacher, Pal . E-mail: pacher@mail.nih.gov

    2006-11-17

    Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme which plays an important role in regulating cell death and cellular responses to DNA repair. Pharmacological inhibitors of PARP are being considered as treatment for cancer both in monotherapy as well as in combination with chemotherapeutic agents and radiation, and were also reported to be protective against untoward effects exerted by certain anticancer drugs. Here we show that pharmacological inhibition of PARP with 3-aminobenzamide or PJ-34 dose-dependently reduces VEGF-induced proliferation, migration, and tube formation of human umbilical vein endothelial cells in vitro. These results suggest that treatment with PARP inhibitors may exert additional benefits in various cancers and retinopathies by decreasing angiogenesis.

  2. Mullerian inhibiting substance: an update.

    PubMed

    MacLaughlin, David T; Donahoe, Patricia K

    2002-01-01

    The decades long study of Mullerian Inhibiting Substance by numerous laboratories around the world has been driven, in large part, by pediatric surgeons and pediatric endocrinologists who have a keen interest in the molecular pathophysiology of genital tract defects that are visited upon their patients. A better understanding of the genes involved in the development of the normal reproductive tract in males and females should lead to a more rational analysis of the diseases caused by their abnormal function. Furthermore, a translation of this knowledge from the bench to the bedside may lead to clinically useful advances in the diagnosis and management of intersex patients. The molecular analyses of MIS and MIS receptor gene mutations and persistent Mullerian duct syndrome and the development of MIS ELISAs to evaluate testicular function as well as to follow the progress of gonadal tumors are several clear examples of successes over the years. It will be interesting to see what lies ahead.

  3. Notch Signaling Inhibits Axon Regeneration

    PubMed Central

    Bejjani, Rachid El; Hammarlund, Marc

    2013-01-01

    Summary Many neurons have limited capacity to regenerate their axons after injury. Neurons in the mammalian CNS do not regenerate, and even neurons in the PNS often fail to regenerate to their former targets. This failure is likely due in part to pathways that actively restrict regeneration; however, only a few factors that limit regeneration are known. Here, using single-neuron analysis of regeneration in vivo, we show that Notch/lin-12 signaling inhibits the regeneration of mature C. elegans neurons. Notch signaling suppresses regeneration by acting autonomously in the injured cell to prevent growth cone formation. The metalloprotease and gamma-secretase cleavage events that lead to Notch activation during development are also required for its activity in regeneration. Furthermore, blocking Notch activation immediately after injury improves regeneration. Our results define a novel, post-developmental role for the Notch pathway as a repressor of axon regeneration in vivo. PMID:22284182

  4. Stereotype Activation, Inhibition, and Aging

    PubMed Central

    Radvansky, Gabriel A.; Copeland, David E.; von Hippel, William

    2009-01-01

    This research explored age-related changes in drawing stereotypic inferences during the comprehension of narrative texts. Previous research suggests that declines in inhibitory function can lead older adults to rely more on stereotypes and be more prejudiced than younger adults, even in the face of a desire to be non-prejudiced. In two experiments reported here, younger and older adults read stories that allowed for stereotypic inferences. Older adults were less likely to inhibit stereotypic inferences as measured by recognition measures and lexical decision times. A third control experiment verified that the results of the lexical decision task were not due to a priori response biases for the specific target words. Overall, older adults were more likely to make and maintain stereotypic inferences than younger adults, potentially causing them to be more prejudiced than younger adults. PMID:20161549

  5. Regulating anxiety with extrasynaptic inhibition

    PubMed Central

    Botta, Paolo; Demmou, Lynda; Kasugai, Yu; Markovic, Milica; Xu, Chun; Fadok, Jonathan P.; Lu, Tingjia; Poe, Michael M.; Xu, Li; Cook, James M.; Rudolph, Uwe; Sah, Pankaj; Ferraguti, Francesco; Lüthi, Andreas

    2015-01-01

    Aversive experiences can lead to complex behavioral adaptations including increased levels of anxiety and fear generalization. The neuronal mechanisms underlying such maladaptive behavioral changes, however, are poorly understood. Here, using a combination of behavioral, physiological and optogenetic approaches in mouse, we identify a specific subpopulation of central amygdala neurons expressing protein kinase C δ (PKCδ) as key elements of the neuronal circuitry controlling anxiety. Moreover, we show that aversive experiences induce anxiety and fear generalization by regulating the activity of PKCδ+ neurons via extrasynaptic inhibition mediated by α5 subunit-containing GABAA receptors. Our findings reveal that the neuronal circuits that mediate fear and anxiety overlap at the level of defined subpopulations of central amygdala neurons and demonstrate that persistent changes in the excitability of a single cell type can orchestrate complex behavioral changes. PMID:26322928

  6. Well having inhibited microbial growth

    DOEpatents

    Lee, Brady D.; Dooley, Kirk J.

    2006-08-15

    The invention includes methods of inhibiting microbial growth in a well. A packing material containing a mixture of a first material and an antimicrobial agent is provided to at least partially fill a well bore. One or more access tubes are provided in an annular space around a casing within the well bore. The access tubes have a first terminal opening located at or above a ground surface and have a length that extends from the first terminal opening at least part of the depth of the well bore. The access tubes have a second terminal opening located within the well bore. An antimicrobial material is supplied into the well bore through the first terminal opening of the access tubes. The invention also includes well constructs.

  7. Suramin inhibits EV71 infection.

    PubMed

    Wang, Yaxin; Qing, Jie; Sun, Yuna; Rao, Zihe

    2014-03-01

    Enterovirus-71 (EV71) is one of the major causative reagents for hand-foot-and-mouth disease. In particular, EV71 causes severe central nervous system infections and leads to numerous dead cases. Although several inactivated whole-virus vaccines have entered in clinical trials, no antiviral agent has been provided for clinical therapy. In the present work, we screened our compound library and identified that suramin, which has been clinically used to treat variable diseases, could inhibit EV71 proliferation with an IC50 value of 40 μM. We further revealed that suramin could block the attachment of EV71 to host cells to regulate the early stage of EV71 infection, as well as affected other steps of EV71 life cycle. Our results are helpful to understand the mechanism for EV71 life cycle and provide a potential for the usage of an approved drug, suramin, as the antiviral against EV71 infection.

  8. Behavioral Inhibition: Temperament or Prodrome?

    PubMed Central

    Pérez-Edgar, Koraly E.; Guyer, Amanda E.

    2014-01-01

    Individual differences in temperament emerge in the first months of life. Some infants display a heightened sensitivity to novelty and uncertainty in the world around them, leading a subset to fearfully withdraw from the social environment. Extreme forms of this temperament, Behavioral Inhibition (BI), are associated with increased risk for social anxiety disorder. Indeed, the link is so strong that some suggest that BI is not simply a risk factor for anxiety, but rather a milder form of the disorder. The current overview describes the literature linking BI and anxiety, highlighting the unique biobehavioral profiles evident in each construct. It then highlights specific evidence that may help distinguish the form and function of BI and anxiety. Finally, we briefly discuss unresolved issues that may help inform future work aimed at improving our understanding of individual development and shape therapeutic interventions directed at specific mechanisms of disorder. PMID:25101234

  9. Genetic and biochemical analysis of gonococcal IgA1 protease: cloning in Escherichia coli and construction of mutants of gonococci that fail to produce the activity.

    PubMed Central

    Koomey, J M; Gill, R E; Falkow, S

    1982-01-01

    The biological significance of bacterial extracellular proteases that specifically cleave human IgA1 is unknown. We have prepared a gene bank of gonococcal chromosomal DNA in Escherichia coli K-12 using a cosmid cloning system. Among these clones, we have identified and characterized an E. coli strain that elaborates an extracellular endopeptidase that is indistinguishable from gonococcal IgA1 protease in its substrate specificity and action on human IgA1. Analysis of recombinant plasmids and examination of plasmid-specific peptides in minicells have shown that the IgA1 protease activity in E. coli is associated with expression of a Mr 140,000 peptide. We have isolated IgA1 protease-deficient mutants of Neisseria gonorrhoeae by reintroduction of physically defined deletions of the cloned gene into the gonococcal chromosome by transformation. Images PMID:6818556

  10. Latent inhibition in human adults without masking.

    PubMed

    Escobar, Martha; Arcediano, Francisco; Miller, Ralph R

    2003-09-01

    Latent inhibition refers to attenuated responding to Cue X observed when the X-outcome pairings are preceded by X-alone presentations. It has proven difficult to obtain in human adults unless the preexposure (X-alone) presentations are embedded within a masking (i.e., distracting) task. The authors hypothesized that the difficulty in obtaining latent inhibition with unmasked tasks is related to the usual training procedures, in which the preexposure and conditioning experiences are separated by a set of instructions. Experiment 1 reports latent inhibition without masking in a task in which preexposure and conditioning occur without interruption. Experiments 2 and 3 demonstrate that this attenuation in responding to target Cue X does not pass a summation test for conditioned inhibition and is context specific, thereby confirming that it is latent inhibition. Experiments 3 and 4 confirm that introducing instructions between preexposure and conditioning disrupts latent inhibition.

  11. Phosphate Inhibits Acetotrophic Methanogenesis on Rice Roots

    PubMed Central

    Conrad, Ralf; Klose, Melanie; Claus, Peter

    2000-01-01

    The contribution of acetate- and H2/CO2-dependent methanogenesis to total CH4 production was determined in excised washed rice roots by radiolabeling, methyl fluoride inhibition, and stable carbon isotope fractionation. Addition of ≥20 mM phosphate inhibited methanogenesis, which then was exclusively from H2/CO2. Otherwise, acetate contributed about 50 to 60% of the total methanogenesis, demonstrating that phosphate specifically inhibited acetotrophic methanogens on rice roots. PMID:10653759

  12. Inhibition of the dorsal premotor cortex does not repair surround inhibition in writer's cramp patients.

    PubMed

    Veugen, Lidwien C; Hoffland, Britt S; Stegeman, Dick F; van de Warrenburg, Bart P

    2013-03-01

    Writer's cramp is a task-specific form of focal dystonia, characterized by abnormal movements and postures of the hand and arm during writing. Two consistent abnormalities in its pathophysiology are a loss of surround inhibition and overactivity of the dorsal premotor cortex (PMd). This study aimed to assess a possible link between these two phenomena by investigating whether PMd inhibition leads to an improvement of surround inhibition, in parallel with previously demonstrated writing improvement. Fifteen writer's cramp patients and ten controls performed a simple motor hand task during which surround inhibition was measured using transcranial magnetic stimulation. Motor cortical excitability was measured of the active and surround muscles at three phases of the task. Surround inhibition and writing performance were assessed before and after PMd inhibitory continuous theta burst stimulation. In contrast to healthy controls, patients did not show inhibition of the abductor digiti minimi muscle during movement initiation of the first dorsal interosseus muscle, confirming the loss of surround inhibition. PMd inhibition led to an improvement of writing speed in writer's cramp patients. However, in both groups, no changes in surround inhibition were observed. The results confirm a role for the PMd in the pathophysiology of writer's cramp. We show that PMd inhibition does not lead to restoration of the surround inhibition defect in writer's cramp, despite the improvement in writing. This questions the involvement of the PMd in the loss of surround inhibition, and perhaps also the direct link between surround inhibition and dystonia.

  13. The inhibition of acquired fear.

    PubMed

    Izquierdo, Iván; Cammarota, Martín; Vianna, Mónica M R; Bevilaqua, Lía R M

    2004-01-01

    A conditioned stimulus (CS) associated with a fearsome unconditioned stimulus (US) generates learned fear. Acquired fear is at the root of a variety of mental disorders, among which phobias, generalized anxiety, the posttraumatic stress disorder (PTSD) and some forms of depression. The simplest way to inhibit learned fear is to extinguish it, which is usually done by repeatedly presenting the CS alone, so that a new association, CS-"no US", will eventually overcome the previously acquired CS-US association. Extinction was first described by Pavlov as a form of "internal inhibition" and was recommended by Freud and Ferenczi in the 1920s (who called it "habituation") as the treatment of choice for phobic disorders. It is used with success till this day, often in association with anxiolytic drugs. Extinction has since then been applied, also successfully and also often in association with anxiolytics, to the treatment of panic, generalized anxiety disorders and, more recently, PTSD. Extinction of learned fear involves gene expression, protein synthesis, N-methyl-D-aspartate (NMDA) receptors and signaling pathways in the hippocampus and the amygdala at the time of the first CS-no US association. It can be enhanced by increasing the exposure to the "no US" component at the time of behavioral testing, to the point of causing the complete uninstallment of the original fear response. Some theorists have recently proposed that reiteration of the CS alone may induce a reconsolidation of the learned behavior instead of its extinction. Reconsolidation would preserve the original memory from the labilization induced by its retrieval. If true, this would of course be disastrous for the psychotherapy of fear-motivated disorders. Here we show that neither the CS nor retrieval cause anything remotely like reconsolidation, but just extinction. In fact, our findings indicate that the reconsolidation hypothesis is essentially incorrect, at least for the form of contextual fear most

  14. Dimethylphosphoryl-inhibited human cholinesterases: inhibition, reactivation, and aging kinetics.

    PubMed

    Worek, F; Diepold, C; Eyer, P

    1999-02-01

    Human poisoning by organophosphates bearing two methoxy groups, e.g. by malathion, paraoxon-methyl, dimethoate and oxydemeton-methyl, is generally considered to be rather resistant to oxime therapy. Since the oxime effectiveness is influenced not only by its reactivating potential but also by inhibition, aging and spontaneous reactivation kinetics, experiments were performed with human acetyl- (AChE) and butyrylcholinesterase (BChE) to determine the respective kinetic constants. The efficacy of obidoxime in reactivating dimethylphosphoryl-AChE was 40, 9 and 3 times higher than of HI 6, pralidoxime and HLö 7, respectively. Aging (t1/2 3.7 h) and spontaneous reactivation (t1/2 0.7 h) occurred concomitantly, with the portion of the aged enzyme being dependent on the presence of excess inhibitor. Calculation of steady-state AChE activity in the presence of inhibitor and oxime revealed that obidoxime was superior to pralidoxime. In addition, organophosphate concentrations up to 10(-6) M (paraoxon-methyl) and 10(-4) M (oxydemeton-methyl) could be counteracted at clinically relevant oxime concentrations (10 microM). These data indicate that oximes may effectively reactivate human dimethylphosphoryl-AChE. Failure of oximes may be attributed to megadose intoxications and to prolonged time intervals between poison uptake and oxime administration. The potency of the oximes to reactivate dimethylphosphoryl-BChE was much lower and the spontaneous reactivation slower (t1/2 9 h), while aging proceeded at a comparable rate. Thus, BChE activity determination for diagnosis and therapeutic monitoring may give no reliable information on AChE status.

  15. [Inhibition of premature uterine contractions].

    PubMed

    Troszyński, M; Leibschang, J; Chazan, B; Adamowicz, R; Brankowska, J

    1979-01-01

    Various drugs used to stop premature uterine contractions are discussed in the paper. Particular attention is paid to beta-mimetic drugs. The results of ming Partusisten, one of beta-mimetic drugs, is presented on the material of 104 patients with threatening immature and premature labour. Partusisten was administered in the form of intravenous drip infusion or tablets. During treatment monitoring of the uterine contractility and of foetal heart rate took place. Inhibition of the uterine contraction activity was successful in 100 per cent of cases. In 60,9 per cent in the group of threatening immature labour and in 38,1 per cent in the group threatening premature labour, the delay of delivery was more then 28 days. The delay of delivery by 48 hours was 87 per cent and 84 per cent in both groups respectively. Tachycardia was one of the first side effects observed in 15,2 per cent of cases. There is also presented an example of pregnancy when delivery was delayed by 21 days in spite of premature outflow of amniotic fluid (at a high rupture of membrane). The authors are of the opinion that Partusisten is very effective and gives little side effects, preventing premature uterine contractions. Dosage should be individualized according to the case and labour advancement, and should be based on topographic evaluation of uterine contraction. Negative influence of the drug on foetuses was not observed.

  16. Glutamatergic Inhibition in Sensory Neocortex

    PubMed Central

    Sherman, S. Murray

    2009-01-01

    In the mammalian brain, glutamate and γ-aminobutyric acid are considered major excitatory and inhibitory neurotransmitters, respectively. However, we have found evidence that glutamate can also act as a postsynaptic inhibitory neurotransmitter in layer 4 of the neocortex. Using whole-cell recordings from layer 4 neurons in slice preparations from the mouse visual, auditory, and somatosensory cortices, we found that metabotropic glutamate receptor (mGluR) agonists (ACPD, APDC, and DCG IV) elicit a robust, long-lasting hyperpolarization that is abolished by the group II mGluR antagonist, MCCG. This response largely involves a K+ conductance mediated by G-protein activity and GIRK channels. Furthermore, electrical and photostimulation of the intracortical inputs to layer 4 elicits a similar hyperpolarization that is blocked by group II mGluR antagonists. This novel inhibition mediated by group II mGluRs may be an unappreciated mechanism for refining cortical receptive fields in layer 4 and may enable synaptic gain control during periods of high activity. PMID:19176638

  17. Glutamatergic inhibition in sensory neocortex.

    PubMed

    Lee, Charles C; Sherman, S Murray

    2009-10-01

    In the mammalian brain, glutamate and gamma-aminobutyric acid are considered major excitatory and inhibitory neurotransmitters, respectively. However, we have found evidence that glutamate can also act as a postsynaptic inhibitory neurotransmitter in layer 4 of the neocortex. Using whole-cell recordings from layer 4 neurons in slice preparations from the mouse visual, auditory, and somatosensory cortices, we found that metabotropic glutamate receptor (mGluR) agonists (ACPD, APDC, and DCG IV) elicit a robust, long-lasting hyperpolarization that is abolished by the group II mGluR antagonist, MCCG. This response largely involves a K(+) conductance mediated by G-protein activity and GIRK channels. Furthermore, electrical and photostimulation of the intracortical inputs to layer 4 elicits a similar hyperpolarization that is blocked by group II mGluR antagonists. This novel inhibition mediated by group II mGluRs may be an unappreciated mechanism for refining cortical receptive fields in layer 4 and may enable synaptic gain control during periods of high activity.

  18. Allosteric Inhibition Through Core Disruption

    SciTech Connect

    Horn, James R.; Shoichet, Brian K.

    2010-03-05

    Although inhibitors typically bind pre-formed sites on proteins, it is theoretically possible to inhibit by disrupting the folded structure of a protein or, in the limit, to bind preferentially to the unfolded state. Equilibria defining how such molecules act are well understood, but structural models for such binding are unknown. Two novel inhibitors of {beta}-lactamase were found to destabilize the enzyme at high temperatures, but at lower temperatures showed no preference for destabilized mutant enzymes versus stabilized mutants. X-ray crystal structures showed that both inhibitors bound to a cryptic site in {beta}-lactamase, which the inhibitors themselves created by forcing apart helixes 11 and 12. This opened up a portion of the hydrophobic core of the protein, into which these two inhibitors bind. Although this binding site is 16 {angstrom} from the center of the active site, the conformational changes were transmitted through a sequence of linked motions to a key catalytic residue, Arg244, which in the complex adopts conformations very different from those in catalytically competent enzyme conformations. These structures offer a detailed view of what has heretofore been a theoretical construct, and suggest the possibility for further design against this novel site.

  19. Mood stabilizers inhibit cytomegalovirus infection.

    PubMed

    Ornaghi, Sara; Davis, John N; Gorres, Kelly L; Miller, George; Paidas, Michael J; van den Pol, Anthony N

    2016-12-01

    Cytomegalovirus (CMV) infection can generate debilitating disease in immunocompromised individuals and neonates. It is also the most common infectious cause of congenital birth defects in infected fetuses. Available anti-CMV drugs are partially effective but are limited by some toxicity, potential viral resistance, and are not recommended for fetal exposure. Valproate, valpromide, and valnoctamide have been used for many years to treat epilepsy and mood disorders. We report for the first time that, in contrast to the virus-enhancing actions of valproate, structurally related valpromide and valnoctamide evoke a substantial and specific inhibition of mouse and human CMV in vitro. In vivo, both drugs safely attenuate mouse CMV, improving survival, body weight, and developmental maturation of infected newborns. The compounds appear to act by a novel mechanism that interferes with CMV attachment to the cell. Our work provides a novel potential direction for CMV therapeutics through repositioning of agents already approved for use in psychiatric disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. A Generalized Convective Inhibition Energy

    NASA Astrophysics Data System (ADS)

    Tailleux, R.

    2002-12-01

    The common view about preconvecting soundings is that they possess both CAPE (Convective Available Potential Energy) and CINE (Convective INhibition Energy), the latter preventing the former to be spontaneously released. The two concepts of CAPE and CINE are ambiguous, however, because they depend upon the parcel used to compute the work of buoyancy forces, as well as upon the thermodynamic transformation (adiabatic, pseudo-adiabatic) assumed in lifting the parcel. To remove the ambiguity intrinsically associated with CAPE, Randall and Wang (1992) introduced the concept of GCAPE (Generalized CAPE), defined as the minimum achievable energy difference between the total nonkinetic energy (NKE) of the column of air considered minus the total NKE of a reference soundings obtained by reorganizing the parcels along the vertical by conserving mass. Because the method focuses on how to achieve a global energy minimum without addressing the issue of whether it is achievable or how to achieve it, the concept of CINE is lost. The present work shows how to remedy to this problem, and how to define a Generalized CINE within the same framework serving to define the GCAPE.

  1. Cytokinin inhibition of leaf senescence

    PubMed Central

    Zwack, Paul J.; Rashotte, Aaron M.

    2013-01-01

    The senescence delaying effect of cytokinin is well known, however, the details behind how this process occurs remain unclear. Efforts to improve understanding of this phenomenon have led to the identification in Arabidopsis of specific cytokinin signaling components through which senescence signal responses are regulated. These include the cytokinin receptor (AHK3), the type-B response regulator (ARR2) and the recently identified cytokinin response factor (CRF6). At the mechanistic end of this process, it was found that increased cell-wall invertase activity which occurs in response to cytokinin is both necessary and sufficient for the inhibition of senescence. Yet, a direct link between the signaling and mechanistic steps of a cytokinin regulated senescence process has yet to be demonstrated. This may be in part because the relationship between senescence and primary metabolism implied by the key role of cell-wall invertase is the subject of two apparently opposing bodies of evidence. Here we briefly summarize and propose a model in which cytokinin mediated changes in sink/source relationships leads to delayed senescence which is consistent with existing evidence both for and against sugars as a trigger for developmental senescence. PMID:23656876

  2. Shed syndecan-2 inhibits angiogenesis

    PubMed Central

    De Rossi, Giulia; Evans, Alun R.; Kay, Emma; Woodfin, Abigail; McKay, Tristan R.; Nourshargh, Sussan; Whiteford, James R.

    2014-01-01

    ABSTRACT Angiogenesis is essential for the development of a normal vasculature, tissue repair and reproduction, and also has roles in the progression of diseases such as cancer and rheumatoid arthritis. The heparan sulphate proteoglycan syndecan-2 is expressed on mesenchymal cells in the vasculature and, like the other members of its family, can be shed from the cell surface resulting in the release of its extracellular core protein. The purpose of this study was to establish whether shed syndecan-2 affects angiogenesis. We demonstrate that shed syndecan-2 regulates angiogenesis by inhibiting endothelial cell migration in human and rodent models and, as a result, reduces tumour growth. Furthermore, our findings show that these effects are mediated by the protein tyrosine phosphatase receptor CD148 (also known as PTPRJ) and this interaction corresponds with a decrease in active β1 integrin. Collectively, these data demonstrate an unexplored pathway for the regulation of new blood vessel formation and identify syndecan-2 as a therapeutic target in pathologies characterised by angiogenesis. PMID:25179601

  3. Selenium inhibition of chemical carcinogenesis.

    PubMed

    Ip, C

    1985-06-01

    In this article I review the work of our laboratory concerning the relationship between dietary Se intake and susceptibility to mammary carcinogenesis induced by 7,12-dimethylbenz[a]anthracene in female rats. The effect of graded levels of Se in the diet was investigated, ranging from deficiency to excessive supplementation that produced marginal toxicity in the animals. In addition, the interdependence between Se status and fat intake was also explored. Further experiments were aimed at defining the role of Se in the initiation and promotion phases of chemical carcinogenesis. In view of the biochemical function of Se as an antioxidant, the chemopreventive efficacy of Se was compared to that of vitamin E in conjunction with their ability to inhibit lipid peroxidation. Results of this study indicated that the antitumorigenic activity of Se could not be accounted for by suppression of tissue peroxidation, although an environment with a lower oxidant stress might enhance the potency of Se in protecting against cancer. The possible mechanisms of action of Se based on the observations and characteristics of several tumor models are briefly discussed.

  4. Hydroxyl radical scavengers inhibit lymphocyte mitogenesis.

    PubMed Central

    Novogrodsky, A; Ravid, A; Rubin, A L; Stenzel, K H

    1982-01-01

    Agents that are known to be scavengers of hydroxyl radicals inhibit lymphocyte mitogenesis induced by phorbol myristate acetate (PMA) to a greater extent than they inhibit mitogenesis induced by concanavalin A or phytohemagglutinin. These agents include dimethyl sulfoxide, benzoate, thiourea, dimethylurea, tetramethylurea, L-tryptophan, mannitol, and several other alcohols. Their inhibitory effect is not associated with cytotoxicity. The hydroxyl radical scavengers do not inhibit PMA-dependent amino acid transport in T cells or PMA-induced superoxide production by monocytes. Thus, they do not inhibit the primary interaction of PMA with responding cells. Treatment of peripheral blood mononuclear cells with PMA increased cellular guanylate cyclase in most experiments, and dimethyl sulfoxide tended to inhibit this increase. In addition to inhibition of PMA-induced mitogenesis, hydroxyl radical scavengers markedly inhibited the activity of lymphocyte activating factor (interleukin 1). The differential inhibition of lymphocyte mitogenesis induced by different mitogens appears to be related to the differential macrophage requirements of the mitogens. The data suggest that hydroxyl radicals may be involved in mediating the triggering signal for lymphocyte activation. Some of the hydroxyl radical scavengers are inducers of cellular differentiation,. nd it is possible that their differentiating activity is related to their ability to scavenge free radicals. PMID:6122209

  5. Quorum sensing inhibition, relevance to periodontics.

    PubMed

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored.

  6. Inhibition: Mental Control Process or Mental Resource?

    ERIC Educational Resources Information Center

    Im-Bolter, Nancie; Johnson, Janice; Ling, Daphne; Pascual-Leone, Juan

    2015-01-01

    The current study tested 2 models of inhibition in 45 children with language impairment and 45 children with normally developing language; children were aged 7 to 12 years. Of interest was whether a model of inhibition as a mental-control process (i.e., executive function) or as a mental resource would more accurately reflect the relations among…

  7. Factors Impacting the Child with Behavioral Inhibition

    ERIC Educational Resources Information Center

    Hornbuckle, Suzanne R.

    2010-01-01

    Various factors influence the developmental course of the behaviorally inhibited child. These factors include reciprocating, contextual factors, such as the child's own traits, the environment, the maternal characteristics, and the environment. Behaviorally inhibited children show physiological and behavioral signs of fear and anxiety when…

  8. Optimal Decision Making in Neural Inhibition Models

    ERIC Educational Resources Information Center

    van Ravenzwaaij, Don; van der Maas, Han L. J.; Wagenmakers, Eric-Jan

    2012-01-01

    In their influential "Psychological Review" article, Bogacz, Brown, Moehlis, Holmes, and Cohen (2006) discussed optimal decision making as accomplished by the drift diffusion model (DDM). The authors showed that neural inhibition models, such as the leaky competing accumulator model (LCA) and the feedforward inhibition model (FFI), can mimic the…

  9. A Qualitative Approach to Enzyme Inhibition

    ERIC Educational Resources Information Center

    Waldrop, Grover L.

    2009-01-01

    Most general biochemistry textbooks present enzyme inhibition by showing how the basic Michaelis-Menten parameters K[subscript m] and V[subscript max] are affected mathematically by a particular type of inhibitor. This approach, while mathematically rigorous, does not lend itself to understanding how inhibition patterns are used to determine the…

  10. A Qualitative Approach to Enzyme Inhibition

    ERIC Educational Resources Information Center

    Waldrop, Grover L.

    2009-01-01

    Most general biochemistry textbooks present enzyme inhibition by showing how the basic Michaelis-Menten parameters K[subscript m] and V[subscript max] are affected mathematically by a particular type of inhibitor. This approach, while mathematically rigorous, does not lend itself to understanding how inhibition patterns are used to determine the…

  11. Inhibition: Mental Control Process or Mental Resource?

    ERIC Educational Resources Information Center

    Im-Bolter, Nancie; Johnson, Janice; Ling, Daphne; Pascual-Leone, Juan

    2015-01-01

    The current study tested 2 models of inhibition in 45 children with language impairment and 45 children with normally developing language; children were aged 7 to 12 years. Of interest was whether a model of inhibition as a mental-control process (i.e., executive function) or as a mental resource would more accurately reflect the relations among…

  12. Substrate inhibition kinetics of phenol biodegradation

    SciTech Connect

    Goudar, C.T.; Ganji, S.H.; Pujar, B.G.; Strevett, K.A.

    2000-02-01

    Phenol biodegradation was studied in batch experiments using an acclimated inoculum and initial phenol concentrations ranging from 0.1 to 1.3 g/L. Phenol depletion an associated microbial growth were monitored over time to provide information that was used to estimate the kinetics of phenol biodegradation. Phenol inhibited biodegradation at high concentrations, and a generalized substrate inhibition model based on statistical thermodynamics was used to describe the dynamics of microbial growth in phenol. For experimental data obtained in this study, the generalized substrate inhibition model reduced to a form that is analogous to the Andrews equation, and the biokinetic parameters {micro}{sub max}, maximum specific growth; K{sub s}, saturation constant; and K{sub i}, inhibition constant were estimated as 0.251 h{sup {minus}1}, 0.011 g/L, and 0.348 g/L, respectively, using a nonlinear least squares technique. Given the wide variability in substrate inhibition models used to describe phenol biodegradation, an attempt was made to justify selection of particular model based on theoretical considerations. Phenol biodegradation data from nine previously published studies were used in the generalized substrate inhibition model to determine the appropriate form of the substrate inhibition model. In all nine cases, the generalized substrate inhibition model reduced to a form analogous to the Andrews equation suggesting the suitability of the Andrews equation to describe phenol biodegradation data.

  13. Optimal Decision Making in Neural Inhibition Models

    ERIC Educational Resources Information Center

    van Ravenzwaaij, Don; van der Maas, Han L. J.; Wagenmakers, Eric-Jan

    2012-01-01

    In their influential "Psychological Review" article, Bogacz, Brown, Moehlis, Holmes, and Cohen (2006) discussed optimal decision making as accomplished by the drift diffusion model (DDM). The authors showed that neural inhibition models, such as the leaky competing accumulator model (LCA) and the feedforward inhibition model (FFI), can mimic the…

  14. Evaluation of antibacterial activity of Calotropis gigentica against Streptococcus mutans and Lactobacillus acidophilus: An in vitro comparative study

    PubMed Central

    Sharma, Meenakshi; Tandon, Sandeep; Aggarwal, Vishal; Bhat, Kishore G; Kappadi, Damodhar; Chandrashekhar, Pavitra; Dorwal, Rakesh

    2015-01-01

    Background: This study was conducted to evaluate in vitro antibacterial potential of ethanolic extract of Calotropis gigentica. Materials and Methods: The inhibitory effect of the ethanolic extract was tested against Streptococcus mutans and Lactobacilli casei by using disc diffusion method. Results: Ethanolic extract of Calotropis gigentica showed 16 mm and 14 mm of minimum inhibition zone at 1.25% concentration for S. mutans and lactobacilli, respectively. Conclusion: Calotropis gigentica was found to effective against S. mutans and lactobacilli. PMID:26752839

  15. Lysophospholipase inhibition by organophosphorus toxicants.

    PubMed

    Quistad, Gary B; Casida, John E

    2004-05-01

    Lysophospholipases (LysoPLAs) are a large family of enzymes for removing lysophospholipids from cell membranes. Potent inhibitors are needed to define the importance of LysoPLAs as targets for toxicants and potential therapeutics. This study considers organophosphorus (OP) inhibitors with emphasis on mouse brain total LysoPLA activity relative to the mipafox-sensitive neuropathy target esterase (NTE)-LysoPLA recently established as 17% of the total activity and important in the action of OP delayed toxicants. The most potent inhibitors of total LysoPLA in mouse brain are isopropyl dodecylphosphonofluoridate (also for LysoPLA of Vibrio bacteria), ethyl octylphosphonofluoridate (EOPF), and two alkyl-benzodioxaphosphorin 2-oxides (BDPOs)[(S)-octyl and dodecyl] (IC50 2-8 nM). OP inhibitors acting in vitro and in vivo differentiate a more sensitive portion but not a distinct NTE-LysoPLA compared with total LysoPLA activity. For 10 active inhibitors, NTE-LysoPLA is 17-fold more sensitive than total LysoPLA, but structure-activity comparisons give a good correlation (r(2) = 0.94) of IC50 values, suggesting active site structural similarity or identity. In mice 4 h after intraperitoneal treatment with discriminating doses, EOPF, tribufos (a plant defoliant), and dodecanesulfonyl fluoride inhibit 41-57% of the total brain LysoPLA and 85-99% of the NTE-LysoPLA activity. Total LysoPLA as well as NTE-LysoPLA is decreased in activity in Nte(+/-)-haploinsufficient mice compared to their Nte(+/+) littermates. The lysolecithin level of spinal cord but not brain is elevated significantly following EOPF treatment (3 mg/kg), thereby focusing attention on localized rather than general alterations in lysophospholipid metabolism in OP-induced hyperactivity and toxicity.

  16. Hydrogen Sulfide Inhibits Amyloid Formation

    PubMed Central

    2015-01-01

    Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer’s disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL). HEWL forms typical β-sheet rich fibrils during the course of 70 min at low pH and high temperatures. The addition of H2S completely inhibits the formation of β-sheet and amyloid fibrils, as revealed by deep UV resonance Raman (DUVRR) spectroscopy and ThT fluorescence. Nonresonance Raman spectroscopy shows that disulfide bonds undergo significant rearrangements in the presence of H2S. Raman bands corresponding to disulfide (RSSR) vibrational modes in the 550–500 cm–1 spectral range decrease in intensity and are accompanied by the appearance of a new 490 cm–1 band assigned to the trisulfide group (RSSSR) based on the comparison with model compounds. The formation of RSSSR was proven further using a reaction with TCEP reduction agent and LC-MS analysis of the products. Intrinsic tryptophan fluorescence study shows a strong denaturation of HEWL containing trisulfide bonds. The presented evidence indicates that H2S causes the formation of trisulfide bridges, which destabilizes HEWL structure, preventing protein fibrillation. As a result, small spherical aggregates of unordered protein form, which exhibit no cytotoxicity by contrast with HEWL fibrils. PMID:25545790

  17. Habituation, latent inhibition, and extinction.

    PubMed

    Jordan, Wesley P; Todd, Travis P; Bucci, David J; Leaton, Robert N

    2015-06-01

    In two conditioned suppression experiments with a latent inhibition (LI) design, we measured the habituation of rats in preexposure, their LI during conditioning, and then extinction over days. In the first experiment, lick suppression, the preexposed group (PE) showed a significant initial unconditioned response (UR) to the target stimulus and significant long-term habituation (LTH) of that response over days. The significant difference between the PE and nonpreexposed (NPE) groups on the first conditioning trial was due solely to the difference in their URs to the conditioned stimulus (CS)-a habituated response (PE) and an unhabituated response (NPE). In the second experiment, bar-press suppression, little UR to the target stimulus was apparent during preexposure, and no detectable LTH. Thus, there was no difference between the PE and NPE groups on the first conditioning trial. Whether the UR to the CS confounds the interpretation of LI (Exp. 1) or not (Exp. 2) can only be known if the UR is measured. In both experiments, LI was observed in acquisition. Also in both experiments, rats that were preexposed and then conditioned to asymptote were significantly more resistant to extinction than were the rats not preexposed. This result contrasts with the consistently reported finding that preexposure either produces less resistance to extinction or has no effect on extinction. The effect of stimulus preexposure survived conditioning to asymptote and was reflected directly in extinction. These two experiments provide a cautionary procedural note for LI experiments and have shown an unexpected extinction effect that may provide new insights into the interpretation of LI.

  18. Cardiac remodelling and RAS inhibition

    PubMed Central

    Ferrario, Carlos M.

    2016-01-01

    Risk factors such as hypertension and diabetes are known to augment the activity and tissue expression of angiotensin II (Ang II), the major effector peptide of the renin–angiotensin system (RAS). Overstimulation of the RAS has been implicated in a chain of events that contribute to the pathogenesis of cardiovascular (CV) disease, including the development of cardiac remodelling. This chain of events has been termed the CV continuum. The concept of CV disease existing as a continuum was first proposed in 1991 and it is believed that intervention at any point within the continuum can modify disease progression. Treatment with antihypertensive agents may result in regression of left ventricular hypertrophy, with different drug classes exhibiting different degrees of efficacy. The greatest decrease in left ventricular mass is observed following treatment with angiotensin converting enzyme inhibitors (ACE-Is), which inhibit Ang II formation. Although ACE-Is and angiotensin receptor blockers (ARBs) provide significant benefits in terms of CV events and stroke, mortality remains high. This is partly due to a failure to completely suppress the RAS, and, as our knowledge has increased, an escape phenomenon has been proposed whereby the human sequence of the 12 amino acid substrate angiotensin-(1-12) is converted to Ang II by the mast cell protease, chymase. Angiotensin-(1-12) is abundant in a wide range of organs and has been shown to increase blood pressure in animal models, an effect abolished by the presence of ACE-Is or ARBs. This review explores the CV continuum, in addition to examining the influence of the RAS. We also consider novel pathways within the RAS and how new therapeutic approaches that target this are required to further reduce Ang II formation, and so provide patients with additional benefits from a more complete blockade of the RAS. PMID:27105891

  19. Amiodarone Inhibits Apamin-Sensitive Potassium Currents

    PubMed Central

    Turker, Isik; Yu, Chih-Chieh; Chang, Po-Cheng; Chen, Zhenhui; Sohma, Yoshiro; Lin, Shien-Fong; Chen, Peng-Sheng; Ai, Tomohiko

    2013-01-01

    Background Apamin sensitive potassium current (IKAS), carried by the type 2 small conductance Ca2+-activated potassium (SK2) channels, plays an important role in post-shock action potential duration (APD) shortening and recurrent spontaneous ventricular fibrillation (VF) in failing ventricles. Objective To test the hypothesis that amiodarone inhibits IKAS in human embryonic kidney 293 (HEK-293) cells. Methods We used the patch-clamp technique to study IKAS in HEK-293 cells transiently expressing human SK2 before and after amiodarone administration. Results Amiodarone inhibited IKAS in a dose-dependent manner (IC50, 2.67±0.25 µM with 1 µM intrapipette Ca2+). Maximal inhibition was observed with 50 µM amiodarone which inhibited 85.6±3.1% of IKAS induced with 1 µM intrapipette Ca2+ (n = 3). IKAS inhibition by amiodarone was not voltage-dependent, but was Ca2+-dependent: 30 µM amiodarone inhibited 81.5±1.9% of IKAS induced with 1 µM Ca2+ (n = 4), and 16.4±4.9% with 250 nM Ca2+ (n = 5). Desethylamiodarone, a major metabolite of amiodarone, also exerts voltage-independent but Ca2+ dependent inhibition of IKAS. Conclusion Both amiodarone and desethylamiodarone inhibit IKAS at therapeutic concentrations. The inhibition is independent of time and voltage, but is dependent on the intracellular Ca2+ concentration. SK2 current inhibition may in part underlie amiodarone's effects in preventing electrical storm in failing ventricles. PMID:23922993

  20. Striatal responses to Negative Monetary Outcomes Differ between Temperamentally Inhibited and Non-inhibited Adolescents

    PubMed Central

    Helfinstein, Sarah M.; Benson, Brenda; Perez-Edgar, Koraly; Bar-Haim, Yair; Detloff, Allison; Pine, Daniel S.; Fox, Nathan A.; Ernst, Monique

    2011-01-01

    The present study compared blood oxygen level dependent (BOLD) response in behaviorally inhibited and behaviorally non-inhibited adolescents to positive and negative feedback following their choice in a reward task. Previous data in these same subjects showed enhanced activation in striatal areas in behaviorally inhibited subjects to cues predicting gain or a loss. However, no analyses had examined responses following actual gains or losses. Relative to non-inhibited subjects, behaviorally inhibited subjects in the current study showed enhanced caudate response to negative but not positive feedback, indicating that striatal sensitivity to feedback may be specific to aversive information. In addition, compared to non-inhibited subjects, behaviorally inhibited subjects exhibited reduced differentiation between positive and negative feedback in ventromedial prefrontal cortex (vmPFC). This suggests a perturbed ability to encode reward value. PMID:21167189

  1. Structural and functional bases of inhibited temperament.

    PubMed

    Clauss, Jacqueline A; Seay, April L; VanDerKlok, Ross M; Avery, Suzanne N; Cao, Aize; Cowan, Ronald L; Benningfield, Margaret M; Blackford, Jennifer Urbano

    2014-12-01

    Children born with an inhibited temperament are at heightened risk for developing anxiety, depression and substance use. Inhibited temperament is believed to have a biological basis; however, little is known about the structural brain basis of this vulnerability trait. Structural MRI scans were obtained from 84 (44 inhibited, 40 uninhibited) young adults. Given previous findings of amygdala hyperactivity in inhibited individuals, groups were compared on three measures of amygdala structure. To identify novel substrates of inhibited temperament, a whole brain analysis was performed. Functional activation and connectivity were examined across both groups. Inhibited adults had larger amygdala and caudate volume and larger volume predicted greater activation to neutral faces. In addition, larger amygdala volume predicted greater connectivity with subcortical and higher order visual structures. Larger caudate volume predicted greater connectivity with the basal ganglia, and less connectivity with primary visual and auditory cortex. We propose that larger volume in these salience detection regions may result in increased activation and enhanced connectivity in response to social stimuli. Given the strong link between inhibited temperament and risk for psychiatric illness, novel therapeutics that target these brain regions and related neural circuits have the potential to reduce rates of illness in vulnerable individuals. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  2. Pattern of organotin inhibition of methanogenic bacteria.

    PubMed

    Boopathy, R; Daniels, L

    1991-04-01

    Seven organotin compounds and tin chloride were tested for their effects on the methanogenic bacteria Methanococcus thermolithotrophicus, Methanococcus deltae delta LH, and Methanosarcina barkeri 227. The methanogens were strongly inhibited by triethyltin, tripropyltin, and monophenyltin compounds, generally at concentrations below 0.05 mM. Less inhibition by tributyltin and diphenyltin was observed at levels below 0.1 mM, but complete inhibition was observed at a 1 mM concentration. Tin chloride inhibited all methanogens, with nearly complete inhibition at a 1 mM concentration. There was no inhibition by tetra-n-butyltin and triphenyltin compounds even at 2 mM, the highest concentration tested. The 50 and 100% inhibitory concentrations of all compounds were estimated; these values varied with both the compound tested and the bacterium tested. The 50% inhibitory concentration estimate generally decreased (i.e., giving a higher toxicity) as the total surface area of the alkyltin molecules decreased. These results differ considerably from those reported previously for aerobic microorganisms (G. Eng, E. J. Tierney, J. M. Bellama, and F. E. Brinckman, Appl. Organometallic Chem. 2:171-175, 1988), where a clear correlation between increasing total molecular surface area and increasing toxicity was documented with a variety of organisms. Using the same procedures as for the methanogens, we examined the effects of organotin compounds on Escherichia coli growing aerobically or anaerobically. The E. coli inhibition pattern clearly resembled that seen in the data of Eng et al., under both aerobic and anaerobic conditions.

  3. Use of cannabis enhances attentional inhibition.

    PubMed

    Vivas, Ana B; Estevez, Angeles F; Moreno, Margarita; Panagis, George; Flores, Pilar

    2012-09-01

    Orienting attention to an irrelevant location hampers the response to subsequent targets presented at that location in relation to novel, not previously attended, locations. This inhibitory effect has been named inhibition of return. We conducted an experiment to study the temporal course of inhibition of return in users of cannabis. Twenty-five cannabis users who self-reported a regular frequency of cannabis use in joints per month, and 26 drug-free controls participated in the study. We employed a typical inhibition of return task with a single cue and manipulated the time interval between the onset of the cue and the target (150, 350, 550, 1500, and 2550 ms). Participants were asked to detect the onset of the target regardless of its location. The group of cannabis users showed a significantly greater overall inhibition relative to the group of nonusers. Furthermore, inhibition of return appeared earlier (at the 350 ms cue-target interval) in the user group. This is the first study to show that attentional inhibition is enhanced in cannabis users. More research is needed to determine whether greater inhibition represents an advantage or disadvantage for visual search performance of cannabis users. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Praziquantel inhibits Schistosoma mansoni attachment in vitro.

    PubMed

    da-Silva, S P; Noel, F

    1990-01-01

    Male adult Schistosoma mansoni worms were placed in a glass dish containing Tyrode solution and observed for 15 min after addition of praziquantel (0.01 to 1 microM). Praziquantel promoted a concentration- and time-dependent inhibition of sucker-mediated attachment of the worm. Attachment inhibition was correlated with shortening of the parasite. We propose that the rapid and total inhibition of worm attachment observed in vitro with 1 microM praziquantel indicates that therapeutic concentrations of this drug should promote a rapid hepatic shift, in vivo, which may facilitate host tissue reaction.

  5. Optogenetic inhibition of cocaine seeking in rats.

    PubMed

    Stefanik, Michael T; Moussawi, Khaled; Kupchik, Yonatan M; Smith, Kyle C; Miller, Rachel L; Huff, Mary L; Deisseroth, Karl; Kalivas, Peter W; LaLumiere, Ryan T

    2013-01-01

    Inhibitory optogenetics was used to examine the roles of the prelimbic cortex (PL), the nucleus accumbens core (NAcore) and the PL projections to the NAcore in the reinstatement of cocaine seeking. Rats were microinjected into the PL or NAcore with an adeno-associated virus containing halorhodopsin or archaerhodopsin. After 12 days of cocaine self-administration, followed by extinction training, animals underwent reinstatement testing along with the presence/absence of optically induced inhibition via laser light. Bilateral optical inhibition of the PL, NAcore or the PL fibers in the NAcore inhibited the reinstatement of cocaine seeking. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.

  6. Growth-Inhibiting and morphostructural effects of constituents identified in Asarum heterotropoides root on human intestinal bacteria

    PubMed Central

    2013-01-01

    Background The growth-inhibiting and morphostructural effects of seven constituents identified in Asarum heterotropoides root on 14 intestinal bacteria were compared with those of the fluoroquinolone antibiotic ciprofloxacin. Method A microtiter plate-based bioassay in sterile 96-well plates was used to evaluate the minimal inhibitory concentrations (MICs) of the test materials against the organisms. Results δ-3-Carene (5) exhibited the most potent growth inhibition of Gram-positive bacteria (Clostridium difficile ATCC 9689, Clostridium paraputrificum ATCC 25780, Clostridium perfringens ATCC 13124, and Staphylococcus aureus ATCC 12600) and Gram-negative bacteria (Escherichia coli ATCC 11775 and Bacteroides fragilis ATCC 25285) (minimal inhibitory concentrations (MIC), 0.18–0.70 mg/mL) except for Salmonella enterica serovar Typhimurium ATCC 13311 (MIC, 2.94 mg/mL). The MIC of methyleugenol (2), 1,8-cineole (3), α-asarone (4), (−)-asarinin (6), and pellitorine (7) was between 1.47 and 2.94 mg/mL against all test bacteria (except for compound 2 against C. difficile (0.70 mg/mL); compounds 1 (23.50 mg/mL) and 4 (5.80 mg/mL) against C. paraputricum; compounds 2 (5.80 mg/mL), 4 (12.0 mg/mL), and 7 (0.70 mg/mL) against C. perfringens); compound 1 against E. coli (7.20 mg/mL) and S. enterica serovar Typhimurium (12.0 mg/mL). Overall, all of the constituents were less potent at inhibiting microbial growth than ciprofloxacin (MIC, 0.063–0.25 mg/ mL). The lactic acid-producing bacteria (four bifidobacteria and two lactobacilli) and one acidulating bacterium Clostridium butyricum ATCC 25779 were less sensitive and more susceptible than the five harmful bacteria and two nonpathogenic bacteria (B. fragilis and E. coli) to the constituents and to ciprofloxacin, respectively. Beneficial Gram-positive bacteria and harmful and nonpathogenic Gram-negative bacteria were observed to have different degrees of antimicrobial susceptibility to the constituents, although

  7. Lobelane Inhibits Methamphetamine-Evoked Dopamine Release via Inhibition of the Vesicular Monoamine Transporter-2S⃞

    PubMed Central

    Nickell, Justin R.; Krishnamurthy, Sairam; Norrholm, Seth; Deaciuc, Gabriela; Siripurapu, Kiran B.; Zheng, Guangrong; Crooks, Peter A.

    2010-01-01

    Lobeline is currently being evaluated in clinical trials as a methamphetamine abuse treatment. Lobeline interacts with nicotinic receptor subtypes, dopamine transporters (DATs), and vesicular monoamine transporters (VMAT2s). Methamphetamine inhibits VMAT2 and promotes dopamine (DA) release from synaptic vesicles, resulting ultimately in increased extracellular DA. The present study generated structure-activity relationships by defunctionalizing the lobeline molecule and determining effects on [3H]dihydrotetrabenazine binding, inhibition of [3H]DA uptake into striatal synaptic vesicles and synaptosomes, the mechanism of VMAT2 inhibition, and inhibition of methamphetamine-evoked DA release. Compared with lobeline, the analogs exhibited greater potency inhibiting DA transporter (DAT) function. Saturated analogs, lobelane and nor-lobelane, exhibited high potency (Ki = 45 nM) inhibiting vesicular [3H]DA uptake, and lobelane competitively inhibited VMAT2 function. Lobeline and lobelane exhibited 67- and 35-fold greater potency, respectively, in inhibiting VMAT2 function compared to DAT function. Lobelane potently decreased (IC50 = 0.65 μM; Imax = 73%) methamphetamine-evoked DA overflow, and with a greater maximal effect compared with lobeline (IC50 = 0.42 μM, Imax = 56.1%). These results provide support for VMAT2 as a target for inhibition of methamphetamine effects. Both trans-isomers and demethylated analogs of lobelane had reduced or unaltered potency inhibiting VMAT2 function and lower maximal inhibition of methamphetamine-evoked DA release compared with lobelane. Thus, defunctionalization, cis-stereochemistry of the side chains, and presence of the piperidino N-methyl are structural features that afford greatest inhibition of methamphetamine-evoked DA release and enhancement of selectivity for VMAT2. The current results reveal that lobelane, a selective VMAT2 inhibitor, inhibits methamphetamine-evoked DA release and is a promising lead for the development of a

  8. Lobelane inhibits methamphetamine-evoked dopamine release via inhibition of the vesicular monoamine transporter-2.

    PubMed

    Nickell, Justin R; Krishnamurthy, Sairam; Norrholm, Seth; Deaciuc, Gabriela; Siripurapu, Kiran B; Zheng, Guangrong; Crooks, Peter A; Dwoskin, Linda P

    2010-02-01

    Lobeline is currently being evaluated in clinical trials as a methamphetamine abuse treatment. Lobeline interacts with nicotinic receptor subtypes, dopamine transporters (DATs), and vesicular monoamine transporters (VMAT2s). Methamphetamine inhibits VMAT2 and promotes dopamine (DA) release from synaptic vesicles, resulting ultimately in increased extracellular DA. The present study generated structure-activity relationships by defunctionalizing the lobeline molecule and determining effects on [(3)H]dihydrotetrabenazine binding, inhibition of [(3)H]DA uptake into striatal synaptic vesicles and synaptosomes, the mechanism of VMAT2 inhibition, and inhibition of methamphetamine-evoked DA release. Compared with lobeline, the analogs exhibited greater potency inhibiting DA transporter (DAT) function. Saturated analogs, lobelane and nor-lobelane, exhibited high potency (K(i) = 45 nM) inhibiting vesicular [(3)H]DA uptake, and lobelane competitively inhibited VMAT2 function. Lobeline and lobelane exhibited 67- and 35-fold greater potency, respectively, in inhibiting VMAT2 function compared to DAT function. Lobelane potently decreased (IC(50) = 0.65 microM; I(max) = 73%) methamphetamine-evoked DA overflow, and with a greater maximal effect compared with lobeline (IC(50) = 0.42 microM, I(max) = 56.1%). These results provide support for VMAT2 as a target for inhibition of methamphetamine effects. Both trans-isomers and demethylated analogs of lobelane had reduced or unaltered potency inhibiting VMAT2 function and lower maximal inhibition of methamphetamine-evoked DA release compared with lobelane. Thus, defunctionalization, cis-stereochemistry of the side chains, and presence of the piperidino N-methyl are structural features that afford greatest inhibition of methamphetamine-evoked DA release and enhancement of selectivity for VMAT2. The current results reveal that lobelane, a selective VMAT2 inhibitor, inhibits methamphetamine-evoked DA release and is a promising lead for

  9. Inhibition of urinary calculi -- a spectroscopic study

    NASA Astrophysics Data System (ADS)

    Manciu, Felicia; Govani, Jayesh; Durrer, William; Reza, Layra; Pinales, Luis

    2008-10-01

    Although a considerable number of investigations have already been undertaken and many causes such as life habits, metabolic disorders, and genetic factors have been noted as sources that accelerate calculi depositions and aggregations, there are still plenty of unanswered questions regarding efficient inhibition and treatment mechanisms. Thus, in an attempt to acquire more insights, we propose here a detailed scientific study of kidney stone formation and growth inhibition based on a traditional medicine approach with Rotula Aquatica Lour (RAL) herbal extracts. A simplified single diffusion gel growth technique was used for synthesizing the samples for the present study. The unexpected Zn presence in the sample with RAL inhibitor, as revealed by XPS measurements, explains the inhibition process and the dramatic reflectance of the incident light observed in the infrared transmission studies. Raman data demonstrate potential binding of the inhibitor with the oxygen of the kidney stone. Photoluminescence results corroborate to provide additional evidence of Zn-related inhibition.

  10. Toxicants inhibiting anaerobic digestion: a review.

    PubMed

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion.

  11. Disodium cromoglycate inhibits production of immunoglobulin E.

    PubMed

    Seo, S B; Park, S J; Park, S T; Cho, C C; Park, B H; Lee, S J; Kim, H M; Kajiuchi, T; Shin, T Y

    2001-05-01

    Disodium cromoglycate (DSCG) has been shown to inhibit the release of mediators from mast cells. In the present study, the effect of DSCG on active anaphylactic reaction was studied in mice. DSCG dose-dependently inhibited the active systemic anaphylactic reaction and serum immunoglobulin (Ig)E production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. DSCG strongly inhibited IL-4-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, DSCG also showed an inhibitory effect on the IgE production. These results suggest that DSCG has an anti-anaphylactic activity by inhibition of IgE production from B cells.

  12. TNF inhibition as therapy for rheumatoid arthritis.

    PubMed

    Wollheim, Frank A

    2002-07-01

    The introduction of TNF- alpha -inhibiting biologicals has been a major therapeutic breakthrough in rheumatoid arthritis therapy. Against a background of conventional disease-modifying antirheumatic drug experience, this review focuses on present experiences and possible future developments. TNF inhibition results in profound improvement in the majority of rheumatoid arthritis patients, but non-response and adverse effects need attention. Adalimumab is being filed for approval. Other monoclonal antibodies or receptor constructs are in late development. Small molecule inhibitors of TNF production or signalling are a hot topic. One emerging target is nuclear factor kappa B and selective inhibition has proved effective in animal models of arthritis. Synovial proliferation in rheumatoid arthritis is characterised by diminished apoptosis of fibroblasts, whereas bone marrow precursor cells undergo accelerated apoptosis in active rheumatoid arthritis. Both abnormalities are seemingly ameliorated by TNF inhibition. Anti-apoptotic strategies will soon go into development for control of unresponsive rheumatoid arthritis.

  13. Glycerol inhibition of ruminal lipolysis in vitro

    USDA-ARS?s Scientific Manuscript database

    Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of...

  14. Trypanosoma cruzi: inhibition of metacyclogenesis by mannose.

    PubMed

    Barbieri, M A; Lammel, E M; Isola, E L; Bertini, F

    1992-08-31

    Metacyclogenesis of Trypanosoma cruzi epimastigotes was evaluated in a medium supplemented with Triatoma infestans intestinal homogenate in the presence of sugars and derivates as are mannose, galactose, fucose, N-acetylglucosamine, mannose 6-P, and fructose 1,6-P at a concentration of 25 mM. Only mannose significantly inhibited metacyclogenesis. Sodium metaperiodate and trypsin treatment of the intestinal homogenate also inhibited differentiation. In our opinion there exists a proteinic factor in the intestine of the vector that promotes metacyclogenesis and is incorporated by the parasite. Treatment of the intestinal homogenate with alkaline phosphatase had no effect. Instead, high ionic strength in the medium (0.4 M NaCl) strongly inhibited metacyclogenesis indicating that, in these conditions, the possible binding of the differentiation factor to the parasite surface was inhibited.

  15. Inhibited solid propellant composition containing beryllium hydride

    NASA Technical Reports Server (NTRS)

    Thompson, W. W. (Inventor)

    1978-01-01

    An object of this invention is to provide a composition of beryllium hydride and carboxy-terminated polybutadiene which is stable. Another object of this invention is to provide a method for inhibiting the reactivity of beryllium hydride toward carboxy-terminated polybutadiene. It was found that a small amount of lecithin inhibits the reaction of beryllium hydride with the acid groups in carboxy terminated polybutadiene.

  16. Inhibition of metalloproteinase activity by fruit extracts.

    PubMed

    Tate, Patricia; God, Jason; Bibb, Robert; Lu, Qi; Larcom, Lyndon L

    2004-08-30

    While the metalloproteinase enzymes are essential for development and remodeling of tissues, aberrant over expression of these enzymes contributes to several pathologic conditions. In particular, metalloproteinase over expression in cancer plays a significant role in metastasis by providing a mechanism for invasion and spread. The data presented here indicate that water extracts of raspberries, blackberries and muscadine grapes inhibit the activities of metalloproteinases 2 and 9. This inhibition could contribute to the suppression of carcinogenesis by diets high in fruit content.

  17. Quorum Sensing Inhibition, Relevance to Periodontics

    PubMed Central

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored. PMID:25709373

  18. Aerospace Non Chrome Corrosion Inhibiting Primer Systems

    DTIC Science & Technology

    2009-09-01

    Aerospace Coatings | Title 1 AsetsDefense 2009 Workshop Aerospace Non Chrome Corrosion Inhibiting Primer Systems Roger Brown, Akzonobel Aerospace...DATE SEP 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Aerospace Non Chrome Corrosion Inhibiting Primer...Title 2 Overview comments and a historical perspective on non chrome systems A quick test; Technology development for replacement of chromated

  19. Activin inhibits telomerase activity in cancer

    SciTech Connect

    Katik, Indzi; Mackenzie-Kludas, Charley; Nicholls, Craig; Jiang, Fang-Xu; Zhou, Shufeng; Li, He; Liu, Jun-Ping

    2009-11-27

    Activin is a pleiotropic cytokine with broad tissue distributions. Recent studies demonstrate that activin-A inhibits cancer cell proliferation with unknown mechanisms. In this report, we demonstrate that recombinant activin-A induces telomerase inhibition in cancer cells. In breast and cervical cancer cells, activin-A resulted in telomerase activity in a concentration-dependent manner. Significant inhibition was observed at 10 ng/ml of activin-A, with a near complete inhibition at 80 ng/ml. Consistently, activin-A induced repression of the telomerase reverse transcriptase (hTERT) gene, with the hTERT gene to be suppressed by 60-80% within 24 h. In addition, activin-A induced a concomitant increase in Smad3 signaling and decrease of the hTERT gene promoter activity in a concentration-dependent fashion. These data suggest that activin-A triggered telomerase inhibition by down-regulating hTERT gene expression is involved in activin-A-induced inhibition of cancer cell proliferation.

  20. Piperine, a dietary phytochemical, inhibits angiogenesis

    PubMed Central

    Doucette, Carolyn D.; Hilchie, Ashley L.; Liwski, Robert; Hoskin, David W.

    2012-01-01

    Angiogenesis plays an important role in tumor progression. Piperine, a major alkaloid constituent of black pepper, has diverse physiological actions including killing of cancer cells; however, the effect of piperine on angiogenesis is not known. Here we show that piperine inhibited the proliferation and G1/S transition of human umbilical vein endothelial cells (HUVECs) without causing cell death. Piperine also inhibited HUVEC migration and tubule formation in vitro, as well as collagen-induced angiogenic activity by rat aorta explants and breast cancer cell-induced angiogenesis in chick embryos. Although piperine binds to and activates the cation channel transient receptor potential vanilloid 1 (TRPV1), its effects on endothelial cells did not involve TRPV1 since the antiproliferative effect of piperine was not affected by TRPV1-selective antagonists, nor did HUVECs express detectable TRPV1 mRNA. Importantly, piperine inhibited phosphorylation of Ser 473 and Thr 308 residues of Akt (protein kinase B), which is a key regulator of endothelial cell function and angiogenesis. Consistent with Akt inhibition as the basis of piperine’s action on HUVECs, inhibition of the phosphoinositide-3 kinase/Akt signaling pathway with LY-294002 also inhibited HUVEC proliferation and collagen-induced angiogenesis. Taken together, these data support the further investigation of piperine as an angiogenesis inhibitor for use in cancer treatment. PMID:22902327

  1. Inhibition of lipase activities by citrus pectin.

    PubMed

    Tsujita, Takahiro; Sumiyosh, Maho; Han, Li-Kun; Fujiwara, Tsutomu; Tsujita, Junji; Okuda, Hiromichi

    2003-10-01

    The oral administration of pectin to rats reduced and delayed the peak plasma triacylglycerol concentration. Pectin inhibited the hydrolysis of trioleoylglycerol emulsified with soybean phosphatidylcholine by pancreatic, carboxylester, and lingual lipases in a concentration-dependent manner. However, the effective concentration of pectin for lingual lipase was 100 times lower than that for pancreatic lipase. Pectin did not inhibit the tributyrin- and p-nitrophenylbutyrate-hydrolyzing activities by pancreatic and carboxylester lipase. When low molecular weight pectin was assayed, pectin at a molecular weight of 90,000 (MW 90) most strongly inhibited three lipase activities. When the effect of pH on pectin inhibition was analyzed using pancreatic lipase, strong inhibition was observed at an acidic pH (below pH 7.0). In the assay system, the pancreatic lipase protein levels in the supernatant and fat layer were estimated by Western blotting with an anti-pancreatic lipase antibody. Pectin reduced the amount of pancreatic lipase protein in the fat layer in a concentration-dependent manner and concomitantly increased that in the supernatant. These results suggest that pectin may interact with emulsified substrates and inhibit the adsorption of lipase to the surface of substrate emulsion.

  2. Inhibition of Heme Peroxidases by Melamine

    PubMed Central

    Vanachayangkul, Pattaraporn; Tolleson, William H.

    2012-01-01

    In 2008 melamine-contaminated infant formula and dairy products in China led to over 50,000 hospitalizations of children due to renal injuries. In North America during 2007 and in Asia during 2004, melamine-contaminated pet food products resulted in numerous pet deaths due to renal failure. Animal studies have confirmed the potent renal toxicity of melamine combined with cyanuric acid. We showed previously that the solubility of melamine cyanurate is low at physiologic pH and ionic strength, provoking us to speculate how toxic levels of these compounds could be transported through the circulation without crystallizing until passing into the renal filtrate. We hypothesized that melamine might be sequestered by heme proteins, which could interfere with heme enzyme activity. Four heme peroxidase enzymes were selected for study: horseradish peroxidase (HRP), lactoperoxidase (LPO), and cyclooxygenase-1 and -2 (COX-1 and -2). Melamine exhibited noncompetitive inhibition of HRP (Ki  9.5 ± 0.7 mM), and LPO showed a mixed model of inhibition (Ki  14.5 ± 4.7 mM). The inhibition of HRP and LPO was confirmed using a chemiluminescent peroxidase assay. Melamine also exhibited COX-1 inhibition, but inhibition of COX-2 was not detected. Thus, our results demonstrate that melamine inhibits the activity of three heme peroxidases. PMID:22852071

  3. Inhibition of chymotrypsin by heparin cofactor II.

    PubMed Central

    Church, F C; Noyes, C M; Griffith, M J

    1985-01-01

    Human heparin cofactor II is a plasma protein that is known to inhibit thrombin. The rate of thrombin inhibition by heparin cofactor II is accelerated (greater than or equal to 1000-fold) in the presence of the glycosaminoglycans, heparin and dermatan sulfate. We have found that chymotrypsin A alpha is also inhibited by heparin cofactor II with a second-order rate constant value of 1.8 X 10(6) M-1 X min-1 at pH 8.0 and 25 degrees C. However, there was no measurable effect of heparin or dermatan sulfate on the rate of chymotrypsin inhibition. Arginine-modified heparin cofactor II showed a comparable percentage loss of both antichymotrypsin and antithrombin activities. Heparin cofactor II and chymotrypsin formed a stable complex with a Mr value near 90,000 when analyzed by NaDodSO4/polyacrylamide gel electrophoresis; this suggests a 1:1 reaction stoichiometry. The chymotrypsin cleavage site in heparin cofactor II was the same as that for thrombin, and primary structure analysis of the inhibitor showed a P'1-P'8 sequence of Ser-Thr-Gln-Val-Arg-Phe-Thr-Val ... . The results indicate that, in contrast to alpha 1-antichymotrypsin, which does not inhibit trypsin-like enzymes, including thrombin, heparin cofactor II can effectively inhibit both thrombin and chymotrypsin. PMID:3863104

  4. Inhibition in the Human Auditory Cortex

    PubMed Central

    Inui, Koji; Nakagawa, Kei; Nishihara, Makoto; Motomura, Eishi; Kakigi, Ryusuke

    2016-01-01

    Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI) in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms) prepulse. The time course of the inhibition evaluated by prepulses presented at 10–800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20–60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful. PMID:27219470

  5. Modelling Myc inhibition as a cancer therapy

    PubMed Central

    Soucek, Laura; Whitfield, Jonathan; Martins, Carla P.; Finch, Andrew J.; Murphy, Daniel J.; Sodir, Nicole M.; Karnezis, Anthony N.; Swigart, Lamorna Brown; Nasi, Sergio; Evan, Gerard I.

    2015-01-01

    Myc is a pleiotropic basic helix–loop–helix leucine zipper transcription factor that coordinates expression of the diverse intracellular and extracellular programs that together are necessary for growth and expansion of somatic cells1. In principle, this makes inhibition of Myc an attractive pharmacological approach for treating diverse types of cancer. However, enthusiasm has been muted by lack of direct evidence that Myc inhibition would be therapeutically efficacious, concerns that it would induce serious side effects by inhibiting proliferation of normal tissues, and practical difficulties in designing Myc inhibitory drugs. We have modelled genetically both the therapeutic impact and the side effects of systemic Myc inhibition in a preclinical mouse model of Ras-induced lung adenocarcinoma by reversible, systemic expression of a dominant-interfering Myc mutant. We show that Myc inhibition triggers rapid regression of incipient and established lung tumours, defining an unexpected role for endogenous Myc function in the maintenance of Ras-dependent tumours in vivo. Systemic Myc inhibition also exerts profound effects on normal regenerating tissues. However, these effects are well tolerated over extended periods and rapidly and completely reversible. Our data demonstrate the feasibility of targeting Myc, a common downstream conduit for many oncogenic signals, as an effective, efficient and tumour-specific cancer therapy. PMID:18716624

  6. Impact of Hydroxychloroquine-Loaded Polyurethane Intravaginal Rings on Lactobacilli

    PubMed Central

    Traore, Yannick Leandre; Chen, Yufei; Bernier, Anne-Marie

    2015-01-01

    The use of polymeric devices for controlled sustained delivery of drugs is a promising approach for the prevention of HIV-1 infection. Unfortunately, certain microbicides, when topically applied vaginally, may be cytotoxic to vaginal epithelial cells and the protective microflora present within the female genital tract. In this study, we evaluated the impact of hydroxychloroquine (HCQ)-loaded, reservoir-type, polyurethane intravaginal rings (IVRs) on the growth of Lactobacillus crispatus and Lactobacillus jensenii and on the viability of vaginal and ectocervical epithelial cells. The IVRs were fabricated using hot-melt injection molding and were capable of providing controlled release of HCQ for 24 days, with mean daily release rates of 17.01 ± 3.6 μg/ml in sodium acetate buffer (pH 4) and 29.45 ± 4.84 μg/ml in MRS broth (pH 6.2). Drug-free IVRs and the released HCQ had no significant effects on bacterial growth or the viability of vaginal or ectocervical epithelial cells. Furthermore, there was no significant impact on the integrity of vaginal epithelial cell monolayers, in comparison with controls, as measured by transepithelial electrical resistance. Overall, this is the first study to evaluate the effects of HCQ-loaded IVRs on the growth of vaginal flora and the integrity of vaginal epithelial cell monolayers. PMID:26416871

  7. [Induction of the NO synthesis in lactobacilli under stress conditions].

    PubMed

    Smolentseva, O A; Iarullina, D R; Il'inskaia, O N

    2012-01-01

    An increase in the nitric oxide (NO) biosynthesis in Lactobacillus plantarum 8P-A3 cells takes place under strong stress influence, which leads to a considerable decrease in the microbial cell viability: heating at 70 degrees C and 80 degrees C, prolonged cultivation, toxic effect of hexylresorcinol. The factors, which do not lead to cell death, such as heating at 60 degrees C, 50 microg/ml homoserine lactone, Bacillus intermedius 7P ribonuclease (binase) in concentrations up to 300 microg/ml, do not induce NO synthesis. The activation of the NO biosynthesis in response to stress treatment evidences to universality of key-mechanisms of stress response in cells differing in the level of their organization as well as to important role of nitric oxide in them.

  8. Characterization of Cinnamoyl Esterases from Different Lactobacilli and Bifidobacteria.

    PubMed

    Fritsch, Caroline; Jänsch, André; Ehrmann, Matthias A; Toelstede, Simone; Vogel, Rudi F

    2017-02-01

    A high variety of plants that are used for food production contain esterified hydroxycinnamic acids. As their free forms display several benefits, like an enhanced absorption in human intestinal tract, anti-oxidative and anti-carcinogenic effects, an improved protein solubility and reduced discoloration, the microbial ability to cleave the ester bond is highly desired. In order to examine potential fermentation strains for this purpose, six different lactic acid bacteria and one bifidobacterial strain were screened for their ability to degrade esterified hydroxycinnamic acids because these strains are commonly used for fermentation of plant-based foods. Moreover, their cinnamoyl esterase activity was examined by molecular biological analyses. The enzymes were heterologously expressed in Escherichia coli, purified and biochemically characterized. The purified esterases with a molecular mass around 27-29 kDa had their optimum predominantly between pH 7 and 8 at 20-30 °C. Bifidobacterium animalis subsp. lactis, Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus fermentum displayed activities against a broad substrate range (methyl caffeate, methyl trans-p-coumarate, chlorogenic acid as well as partially ethyl ferulate). Concerning substrate affinity, reaction velocity, thermal and pH stability, Lactobacillus gasseri showed the overall best performance. The herein studied lactic acid- and bifidobacteria are promising for the production of fermented plant-based foods with an increased quality and nutritional value.

  9. Characterization and selection of lactobacilli isolated from Spanish fermented sausages.

    PubMed

    Rovira, A; Nieto, J C; Rodríguez, A; Reguera, J I; González, Z

    1997-06-01

    The use of starter cultures to control and run the fermentative process is a usual way of manufacturing sausages in meat industries. The first stage in the starter culture designing process is to characterize the lactic acid bacteria isolated from these meat products, in order to select the best strains. The strains used for this study were isolated from different dry fermented sausages, obtained during the manufacturing process. The main tests used to identify the isolated bacteria were: microscopic-morphologic characteristics, catalase activity, production of gas, growth at 8, 15 and 45 degrees C, fermentation of carbohydrates and production of lactic acid isomers. A total of 194 strains were identified. Lactobacillus sake and Lactobacillus plantarum were the most frequent species. Other microbiological tests were also performed, and three strains of Lactobacillus sake were found which did not produce dextran from sucrose.

  10. Sortase-deficient lactobacilli: effect on immunomodulation and gut retention

    PubMed Central

    Call, Emma K.; Goh, Yong Jun; Selle, Kurt; Klaenhammer, Todd R.

    2015-01-01

    Surface proteins of probiotic microbes, including Lactobacillus acidophilus and Lactobacillus gasseri, are believed to promote retention in the gut and mediate host–bacterial communications. Sortase, an enzyme that covalently couples a subset of extracellular proteins containing an LPXTG motif to the cell surface, is of particular interest in characterizing bacterial adherence and communication with the mucosal immune system. A sortase gene, srtA, was identified in L. acidophilus NCFM (LBA1244) and L. gasseri ATCC 33323 (LGAS_0825). Additionally, eight and six intact sortase-dependent proteins were predicted in L. acidophilus and L. gasseri, respectively. Due to the role of sortase in coupling these proteins to the cell wall, ΔsrtA deletion mutants of L. acidophilus and L. gasseri were created using the upp-based counterselective gene replacement system. Inactivation of sortase did not cause significant alteration in growth or survival in simulated gastrointestinal juices. Meanwhile, both ΔsrtA mutants showed decreased adhesion to porcine mucin in vitro. Murine dendritic cells exposed to the ΔsrtA mutant of L. acidophilus or L. gasseri induced lower levels of pro-inflammatory cytokines TNF-α and IL-12, respectively, compared with the parent strains. In vivo co-colonization of the L. acidophilus ΔsrtA mutant and its parent strain in germ-free 129S6/SvEv mice resulted in a significant one-log reduction of the ΔsrtA mutant population. Additionally, a similar reduction of the ΔsrtA mutant was observed in the caecum. This study shows for the first time that sortase-dependent proteins contribute to gut retention of probiotic microbes in the gastrointestinal tract. PMID:25500495

  11. Relationships between inhibition constants, inhibitor concentrations for 50% inhibition and types of inhibition: new ways of analysing data.

    PubMed Central

    Cortés, A; Cascante, M; Cárdenas, M L; Cornish-Bowden, A

    2001-01-01

    The concentration of an inhibitor that decreases the rate of an enzyme-catalysed reaction by 50%, symbolized i(0.5), is often used in pharmacological studies to characterize inhibitors. It can be estimated from the common inhibition plots used in biochemistry by means of the fact that the extrapolated inhibitor concentration at which the rate becomes infinite is equal to -i(0.5). This method is, in principle, more accurate than comparing the rates at various different inhibitor concentrations, and inferring the value of i(0.5) by interpolation. Its reciprocal, 1/i(0.5), is linearly dependent on v(0)/V, the uninhibited rate divided by the limiting rate, and the extrapolated value of v(0)/V at which 1/i(0.5) is zero allows the type of inhibition to be characterized: this value is 1 if the inhibition is strictly competitive; greater than 1 if the inhibition is mixed with a predominantly competitive component; infinite (i.e. 1/i(0.5) does not vary with v(0)/V) if the inhibition is pure non-competitive (i.e. mixed with competitive and uncompetitive components equal); negative if the inhibition is mixed with a predominantly uncompetitive component; and zero if it is strictly uncompetitive. The type of analysis proposed has been tested experimentally by examining inhibition of lactate dehydrogenase by oxalate (an uncompetitive inhibitor with respect to pyruvate) and oxamate (a competitive inhibitor with respect to pyruvate), and of cytosolic malate dehydrogenase by hydroxymalonate (a mixed inhibitor with respect to oxaloacetate). In all cases there is excellent agreement between theory and experiment. PMID:11415458

  12. Spatially reciprocal inhibition of inhibition within a stimulus selection network in the avian midbrain.

    PubMed

    Goddard, C Alex; Mysore, Shreesh P; Bryant, Astra S; Huguenard, John R; Knudsen, Eric I

    2014-01-01

    Reciprocal inhibition between inhibitory projection neurons has been proposed as the most efficient circuit motif to achieve the flexible selection of one stimulus among competing alternatives. However, whether such a motif exists in networks that mediate selection is unclear. Here, we study the connectivity within the nucleus isthmi pars magnocellularis (Imc), a GABAergic nucleus that mediates competitive selection in the midbrain stimulus selection network. Using laser photostimulation of caged glutamate, we find that feedback inhibitory connectivity is global within the Imc. Unlike typical lateral inhibition in other circuits, intra-Imc inhibition remains functionally powerful over long distances. Anatomically, we observed long-range axonal projections and retrograde somatic labeling from focal injections of bi-directional tracers in the Imc, consistent with spatial reciprocity of intra-Imc inhibition. Together, the data indicate that spatially reciprocal inhibition of inhibition occurs throughout the Imc. Thus, the midbrain selection circuit possesses the most efficient circuit motif possible for fast, reliable, and flexible selection.

  13. Iminosugars Inhibit Dengue Virus Production via Inhibition of ER Alpha-Glucosidases—Not Glycolipid Processing Enzymes

    PubMed Central

    Sayce, Andrew C.; Alonzi, Dominic S.; Killingbeck, Sarah S.; Tyrrell, Beatrice E.; Hill, Michelle L.; Caputo, Alessandro T.; Iwaki, Ren; Kinami, Kyoko; Ide, Daisuke; Kiappes, J. L.; Beatty, P. Robert; Kato, Atsushi; Harris, Eva; Dwek, Raymond A.; Miller, Joanna L.; Zitzmann, Nicole

    2016-01-01

    It has long been thought that iminosugar antiviral activity is a function of inhibition of endoplasmic reticulum-resident α-glucosidases, and on this basis, many iminosugars have been investigated as therapeutic agents for treatment of infection by