Bacterial Peptidoglycans in Relation to the Membrane and the Mechanism of Action of Penicillin

in Vanek, Z.; Hostalek, Z.; Cudlin, J. (Eds.) Genetics of industrial microorganisms. Bacteria (1973)

Bacterial protein synthesis in the pig's large intestine varies according to the fermented non-starch polysaccharides.

in Journal of Animal Science (2007), 85(Suppl. 2), 114-115

Bacterial wall peptidoglycan, DD-peptidases and beta-lactam antibiotics

in Scandinavian Journal of Infectious Diseases (1984), 42

Wall peptidoglycan expansion in bacteria rests upon a cytoplasmic D-Ala: D-Ala ligase (ADP) which catalyses synthesis of a D-Ala-D-Ala dipeptide (with accompanying hydrolysis of one molecule of ATP) and a ... [more ▼]

Wall peptidoglycan expansion in bacteria rests upon a cytoplasmic D-Ala: D-Ala ligase (ADP) which catalyses synthesis of a D-Ala-D-Ala dipeptide (with accompanying hydrolysis of one molecule of ATP) and a set of DD-peptidases which utilize this D-Ala-D-Ala dipeptide--once it has been translocated at the outer face of the plasma membrane as the C-terminal portion of a disaccharide peptide unit--as carbonyl donor for transpeptidation and carboxypeptidation reactions (without additional energy expenditure). Four DD-peptidases have been selected which differ from each other with respect to the effects that amino compounds exert on the fate and rate of consumption of a D-Ala-D-Ala terminated amide carbonyl donor analogue. They serve as models to understand the different mechanisms by which the DD-peptidases perform catalysis and show widely varying responses to the action of beta-lactams, from extreme sensitivity to very high resistance. [less ▲]

Bactericidal activity against Pseudomonas aeruginosa is acquired by cultured human monocyte-derived macrophages after uptake of myeloperoxidase.

in Experientia (1996), 52(2), 167-74

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producing cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules ... [more ▼]

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producing cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules. Pseudomonas aeruginosa (10(6) bacteria per 1ml) are killed within 1 h in vitro by a MPO/H2O2/C1- system (48mU=132ng of MPO). The question arose as to whether human macrophages would acquire cytotoxic activity when loaded with this enzyme. Monocytes were therefore isolated from human blood and cultured for up to ten days to induce maturation to macrophages. These cells lost endogenous MPO within five days while H2O2 production in response to stimulation by phorbol myristate acetate (10(-6)M) decreased to 23% within ten days. On the other hand, their capacity to take up exogenous MPO increased fourfold from day three to day ten. Human macrophages cultured from eight days (when both H2O2 production and MPO uptake were sufficient) were therefore used to study the effects of MPO uptake on cytocidal activity against Pseudomonas aeruginosa. After a 1 h MPO loading period, macrophages (5X10(5) cells per ml) were incubated in the presence of bacteria (0.5 to 2X10(6) bacteria per ml) for 2 h at 37 degrees C. At a bacteria/macrophage ratio of 1, only 34.8+/-7.0% of bacteria survived (compared to killing by non-loaded macrophages), while 74.4+/-9.3% survived at a ratio of 4. From these results, we conclude that loading macrophages with exogenous MPO could enhance their microbicidal activity, suggesting a potentially useful therapeutic application. [less ▲]

Bacteriochlorin a activated oxygen forms production: a ESR and a laser flash photolysis study

Conference (1996)

Bacteriocin producers from traditional food products

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2007), 11(4), 275-281

A total of 220 strains of LAB isolated from 32 samples of traditional fermented food from Senegal were screened for bacteriocin production. Two bacteriocin producers, Lactococcus lactis subsp. lactis and ... [more ▼]

A total of 220 strains of LAB isolated from 32 samples of traditional fermented food from Senegal were screened for bacteriocin production. Two bacteriocin producers, Lactococcus lactis subsp. lactis and Enterococcus faecium, were identifi ed from 12 bacteriocin-producing isolates on the basis of phenotypic analyses and 16S rDNA sequence. Both bacteriocins produced by new isolates show antimicrobial activity against Listeria monocytogenes and Bacillus coagulans whereas only that produced by Lactococcus lactis has an activity against Bacillus cereus. Bacteriocin-producing Lactococcus lactis strains were found in a variety of traditional foods indicating a high potential of growth of this strain in variable ecological complex environment. Partial 16S rDNA of the two bacteriocin producers obtained in this study has been registered to Genbank databases under the accession number AY971748 for Lactococcus lactis subsp. lactis (named CWBI-B1410) and AY971749 for Enterococcus faecium (named CWBI-B1411). The new bacteriocin-producing Lactococcus lactis subsp. lactis strain has been selected for identification and application of the bacteriocin to food preservation. [less ▲]

Les bactériocines des bactéries lactiques : caractéristiques et intérêts pour la bioconservation des produits alimentaires

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2009), 13(1), 349-356

Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity ... [more ▼]

Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in food products to inhibit pathogenic or food-spoilage bacteria has then been suggested. This review focuses on the classification, structure, function, mode of action, biosynthesis and current food applications of bacteriocins from lactic acid bacteria. [less ▲]

Bactériologie comparée des liquides de lavage pulmonaire obtenus par voie transtrachéale ou par voie nasotrachéale chez le veau

in Annales de Médecine Vétérinaire (2000), 144

Bage - A New Gene Encoding An Antigen Recognized On Human Melanomas By Cytolytic T-Lymphocytes

in Immunity (1995), 2(2), 167-75

Several tumor antigens are recognized by autologous cytolytic T lymphocytes (CTL) on human melanoma MZ2-MEL. Some of them are encoded by genes MAGE-1 and MAGE-3, which are not expressed in normal tissues ... [more ▼]

Several tumor antigens are recognized by autologous cytolytic T lymphocytes (CTL) on human melanoma MZ2-MEL. Some of them are encoded by genes MAGE-1 and MAGE-3, which are not expressed in normal tissues except in testis. Here, we report the identification of a new gene that codes for another of these antigens. This gene, named BAGE, codes for a putative protein of 43 aa and seems to belong to a family of several genes. The antigen recognized by the autologous CTL consists of BAGE-encoded peptide AARAVFLAL bound to an HLA-Cw 1601 molecule. Gene BAGE is expressed in 22% of melanomas, 30% of infiltrating bladder carcinomas, 10% of mammary carcinomas, 8% of head and neck squamous cell carcinomas, and 6% of non-small cell lung carcinomas. Like the MAGE genes, it is silent in normal tissues with the exception of testis. Because of its tumor-specific expression, the BAGE-encoded antigen may prove useful for cancer immunotherapy. [less ▲]

La baignade en rivière : comment concilier les divers usages de l'eua en milieu naturel pour garantir la bonne qualité de l'eau de baignade ? Le cas du bassin de la Semois en Région wallonne de Belgique.

in European Journal of Water Quality = Journal Européen d’Hydrologie (2010), 41(1), 15-30

La pratique de la baignade dans les eaux naturelles européennes est permise et soumise à la Directive 2006/7/CE relative à la qualité des eaux de baignade. En Région wallonne de Belgique, 36 sites ... [more ▼]

La pratique de la baignade dans les eaux naturelles européennes est permise et soumise à la Directive 2006/7/CE relative à la qualité des eaux de baignade. En Région wallonne de Belgique, 36 sites aménagés en rivières et en lacs permettent cette activité en pleine nature. Étant donné que les rivières sont partagées par de multiples usagers, la complexité du milieu, les pressions diverses sur les ressources hydriques et la cohabitation avec d’autres usages de l’eau conduisent au risque de ne pouvoir garantir en permanence, durant la saison estivale, une qualité satisfaisante de toutes les eaux de baignade. Le modèle wallon de contrat de rivière offre un espace de rencontre entre tous les usagers de la rivière en prenant en compte les préoccupations de chacun en vue d’une gestion intégrée des cours d’eau. Cette approche basée sur la recherche d’un consensus entre les acteurs est traduite dans un programme d’actions concrètes. Trois actions du contrat de rivière Semois en faveur de la baignade sont présentées. Les deux premières actions conduisent à une amélioration de la qualité bactériologique de l’eau, la troisième permet de garantir un niveau d’eau suffisant pour permettre la baignade. La première action a donc permis d’améliorer la qualité bactériologique de la rivière. Les rivières étant les milieux récepteurs des eaux usées, une source importante de contamination provient du rejet des effluents même après une station d’épuration classique avec traitement biologique. Si le système de désinfection des eaux par UV est régulièrement appliqué en Région wallonne, l’installation pilote d’un taillis de saules à courte rotation en tant que support à un traitement tertiaire d’eaux usées domestiques a permis de constater un excellent abattement de la charge bactérienne. À côté de résultats satisfaisants en termes de réduction des charges en nitrates et phosphates, le taillis de saules permet de répondre aux normes de qualité des eaux de baignade. La seconde réalisation concerne l’abreuvement du bétail en cours d’eau qui constitue un facteur de risque non négligeable en milieu rural. Une nouvelle réglementation oblige la pose de clôtures le long des cours d’eau localisés en zone pâturée par le bétail dans un périmètre de 10 km en amont de la zone de baignade, mais il s’agit aussi de préserver l’usage « abreuvement du bétail ». Une étude comparative, entre un ruisseau protégé par des clôtures avec l’installation de bacs abreuvoirs pour l’alimentation en eau du bétail et un cours d’eau non protégé dans lequel le bétail divague, a permis de noter des abattements de l’ordre de 2 à 3 unités logarithmiques des germes de contamination fécale. La troisième action est relative à la restauration d’un ancien barrage à valeur patrimoniale et paysagère en vue de maintenir un niveau d’eau suffisant pour permettre la baignade dans l’un des huit sites en rivière Semois officiellement reconnus. Ces trois réalisations, qui ont été initiées dans le cadre d’un contrat de rivière, permettent de démontrer l’intérêt et la possibilité de concilier divers usages de l’eau et de répondre aux préoccupations des usagers, notamment des adeptes de la baignade en rivière. Au final, par l’organisation annuelle des journées européennes de la baignade qui se déroulent chaque année en Région wallonne, cette pratique populaire peut constituer un excellent support de sensibilisation du grand public à la bonne qualité des eaux de surface, tout en apportant un soutien citoyen à la mise en œuvre de la directive cadre eau. [less ▲]