Adhesion of Selected Bifidobacterium Strains to Human Intestinal Mucus and the Role of Adhesion in Enteropathogen Exclusion

2005 ◽  
Vol 68 (12) ◽  
pp. 2672-2678 ◽  
Author(s):  
M. CARMEN COLLADO ◽  
MIGUEL GUEIMONDE ◽  
MANUEL HERNÁNDEZ ◽  
YOLANDA SANZ ◽  
SEPPO SALMINEN
Keyword(s):  
Bacterial Adhesion ◽  
Pathogenic Bacteria ◽  
Animal Origin ◽  
Enterobacter Sakazakii ◽  
Intestinal Mucus ◽  
Probiotic Strains ◽  
Strain Dependent ◽  
Better Than

The ability of potential probiotic strains to adhere to the intestinal mucosa and exclude and displace pathogens is of utmost importance for therapeutic manipulation of the enteric microbiota. The ability of seven selected human bifidobacterial strains and five human enteropathogenic strains to adhere to human intestinal mucus was analyzed and compared with that of four strains isolated from chicken intestines. The adhesion of the bifidobacterial strains ranged from 3 to 16% depending on the strain. Bifidobacterium strains of animal origin adhered significantly better than did strains of human origin. Of the pathogenic bacteria, Escherichia coli NCTC 8603 had the highest adhesion value (20%), Salmonella Typhimurium ATCC 29631, Enterobacter sakazakii ATCC 29544, and Clostridium difficile ATCC 9689 had adhesion values ranging from 10 to 15%, and Listeria monocytogenes ATCC 15313 had the lowest adhesive value (3%). The ability of these bifidobacteria to inhibit pathogen adhesion and to displace pathogens previously adhering to mucus was also tested. The inhibition of pathogens adhesion by these bifidobacterial strains was variable and clearly strain dependent. In general, bifidobacterial strains of animal origin were better able to inhibit and displace pathogens than were human strains. Preliminary characterization of bacterial adhesion was accomplished using different pretreatments to explore adhesion mechanisms. The results indicate that different molecules are implicated in the adhesion of bifidobacteria to the human intestinal mucus, constituting a multifactorial process.

scholarly journals Characterization of the Opp Peptide Transporter ofCorynebacterium pseudotuberculosisand Its Role in Virulence and Pathogenicity

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Pablo M. R. O. Moraes ◽  
Nubia Seyffert ◽  
Wanderson M. Silva ◽  
Thiago L. P. Castro ◽  
Renata F. Silva ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Etiologic Agent ◽  
Peptide Transporter ◽  
Intercellular Signaling ◽  
Wild Type ◽  
Cell Nutrition ◽  
Oligopeptide Permease ◽  
Extracellular Environment

Despite the economic importance of caseous lymphadenitis (CLA), a chronic disease caused byCorynebacterium pseudotuberculosis, few genes related to the virulence of its etiologic agent have been characterized. The oligopeptide permease (Opp) transporters are located in the plasma membrane and have functions generally related to the uptake of peptides from the extracellular environment. These peptide transporters, in addition to having an important role in cell nutrition, also participate in the regulation of various processes involving intercellular signaling, including the control of the expression of virulence genes in pathogenic bacteria. To study the role of Opp inC. pseudotuberculosis, an OppD deficient strain was constructed via simple crossover with a nonreplicative plasmid carrying part of theoppDgene sequence. As occurred to the wild-type, the ΔoppDstrain showed impaired growth when exposed to the toxic glutathione peptide (GSH), indicating two possible scenarios: (i) that this component can be internalized by the bacterium through an Opp-independent pathway or (ii) that there is toxicity while the peptide is extracellular. Additionally, the ΔoppDmutant presented a reduced ability to adhere to and infect macrophages compared to the wild-type, although both strains exhibit the same potential to colonize spleens and cause injury and death to infected mice.

scholarly journals Characterization of the Erwinia chrysanthemi gan Locus, Involved in Galactan Catabolism

2007 ◽  
Vol 189 (19) ◽  
pp. 7053-7061 ◽  
Author(s):  
Aurélie Delangle ◽  
Anne-France Prouvost ◽  
Virginie Cogez ◽  
Jean-Pierre Bohin ◽  
Jean-Marie Lacroix ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Transport System ◽  
Pathogenic Bacteria ◽  
Erwinia Chrysanthemi ◽  
Potato Tubers ◽  
Inner Membrane ◽  
Saintpaulia Ionantha ◽  
Genes Encoding

ABSTRACT β-1,4-Galactan is a major component of the ramified regions of pectin. Analysis of the genome of the plant pathogenic bacteria Erwinia chrysanthemi revealed the presence of a cluster of eight genes encoding proteins potentially involved in galactan utilization. The predicted transport system would comprise a specific porin GanL and an ABC transporter made of four proteins, GanFGK2. Degradation of galactans would be catalyzed by the periplasmic 1,4-β-endogalactanase GanA, which released oligogalactans from trimer to hexamer. After their transport through the inner membrane, oligogalactans would be degraded into galactose by the cytoplasmic 1,4-β-exogalactanase GanB. Mutants affected for the porin or endogalactanase were unable to grow on galactans, but they grew on galactose and on a mixture of galactotriose, galactotetraose, galactopentaose, and galactohexaose. Mutants affected for the periplasmic galactan binding protein, the transporter ATPase, or the exogalactanase were only able to grow on galactose. Thus, the phenotypes of these mutants confirmed the functionality of the gan locus in transport and catabolism of galactans. These mutations did not affect the virulence of E. chrysanthemi on chicory leaves, potato tubers, or Saintpaulia ionantha, suggesting an accessory role of galactan utilization in the bacterial pathogeny.

scholarly journals Phenotypic and genetic characterization of differential galacto-oligosaccharide utilization in Lactobacillus plantarum

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jori Fuhren ◽  
Markus Schwalbe ◽  
Lucía Peralta-Marzal ◽  
Christiane Rösch ◽  
Henk A. Schols ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Phenotypic Diversity ◽  
Degree Of Polymerization ◽  
Carbohydrate Utilization ◽  
Potential Health ◽  
Probiotic Strains ◽  
Health Promoting ◽  
Phenotypic And Genetic Characterization

AbstractSeveral Lactobacillus plantarum strains are marketed as probiotics for their potential health benefits. Prebiotics, e.g., galacto-oligosaccharides (GOS), have the potential to selectively stimulate the growth of L. plantarum probiotic strains based on their phenotypic diversity in carbohydrate utilization, and thereby enhance their health promoting effects in the host in a strain-specific manner. Previously, we have shown that GOS variably promotes the strain-specific growth of L. plantarum. In this study we investigated this variation by molecular analysis of GOS utilization by L. plantarum. HPAEC-PAD analysis revealed two distinct GOS utilization phenotypes in L. plantarum. Linking these phenotypes to the strain-specific genotypes led to the identification of a lac operon encoding a β-galactosidase (lacA), a permease (lacS), and a divergently oriented regulator (lacR), that are predicted to be involved in the utilization of higher degree of polymerization (DP) constituents present in GOS (specifically DP of 3–4). Mutation of lacA and lacS in L. plantarum NC8 resulted in reduced growth on GOS, and HPAEC analysis confirmed the role of these genes in the import and utilization of higher-DP GOS constituents. Overall, the results enable the design of highly-selective synbiotic combinations of L. plantarum strain-specific probiotics and specific GOS-prebiotic fractions.

scholarly journals Contribution of the ATP-Dependent Protease ClpCP to the Autolysis and Virulence of Streptococcus pneumoniae

2005 ◽  
Vol 73 (2) ◽  
pp. 730-740 ◽  
Author(s):  
Yasser Musa Ibrahim ◽  
Alison R. Kerr ◽  
Nuno A. Silva ◽  
Tim J. Mitchell
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Pneumoniae ◽  
Elevated Temperature ◽  
Stress Resistance ◽  
Pneumococcal Disease ◽  
Pathogenic Bacteria ◽  
Strain Dependent ◽  
Is Strain

ABSTRACT The ATP-dependent caseinolytic proteases (Clp) are fundamental for stress tolerance and virulence in many pathogenic bacteria. The role of ClpC in the autolysis and virulence of Streptococcus pneumoniae is controversial. In this study, we tested the role of ClpC in a number of S. pneumoniae strains and found that the contribution of ClpC to autolysis is strain dependent. ClpC is required for the release of autolysin A and pneumolysin in serotype 2 S. pneumoniae strain D39. In vivo, ClpC is required for the growth of the pneumococcus in the lungs and blood in a murine model of disease, but it does not affect the overall outcome of pneumococcal disease. We also report the requirement of ClpP for the growth at elevated temperature and virulence of serotype 4 strain TIGR4 and confirm its contribution to the thermotolerance, oxidative stress resistance, and virulence of D39.

scholarly journals Function-Based Selection and Characterization of Base-Pair Polymorphisms in a Promoter of Escherichia coli RNA Polymerase-ς70

2001 ◽  
Vol 183 (9) ◽  
pp. 2866-2873 ◽  
Author(s):  
Jian Xu ◽  
Barbara C. McCabe ◽  
Gerald B. Koudelka
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Promoter Sequence ◽  
Kinetic Properties ◽  
Optimal Sequence ◽  
Sequence Requirements ◽  
Better Than

ABSTRACT We performed two sets of in vitro selections to dissect the role of the −10 base sequence in determining the rate and efficiency with which Escherichia coli RNA polymerase-ς70forms stable complexes with a promoter. We identified sequences that (i) rapidly form heparin-resistant complexes with RNA polymerase or (ii) form heparin-resistant complexes at very low RNA polymerase concentrations. The sequences selected under the two conditions differ from each other and from the consensus −10 sequence. The selected promoters have the expected enhanced binding and kinetic properties and are functionally better than the consensus promoter sequence in directing RNA synthesis in vitro. Detailed analysis of the selected promoter functions shows that each step in this multistep pathway may have different sequence requirements, meaning that the sequence of a strong promoter does not contain the optimal sequence for each step but instead is a compromise sequence that allows all steps to proceed with minimal constraint.

scholarly journals The PhlA Hemolysin from the Entomopathogenic Bacterium Photorhabdusluminescens Belongs to the Two-Partner Secretion Family of Hemolysins

2002 ◽  
Vol 184 (14) ◽  
pp. 3871-3878 ◽  
Author(s):  
Julien Brillard ◽  
Eric Duchaud ◽  
Noël Boemare ◽  
Frank Kunst ◽  
Alain Givaudan
Keyword(s):  
Hemolytic Activity ◽  
Pathogenic Bacteria ◽  
Fluorescent Protein ◽  
Gene Encoding ◽  
Rich Media ◽  
The Family ◽  
Insect Interactions ◽  
Green Fluorescent

ABSTRACT Photorhabdus is an entomopathogenic bacterium symbiotically associated with nematodes of the family Heterorhabditidae. Bacterial hemolysins found in numerous pathogenic bacteria are often virulence factors. We describe here the nucleotide sequence and the molecular characterization of the Photorhabdus luminescens phlBA operon, a locus encoding a hemolysin which shows similarities to the Serratia type of hemolysins. It belongs to the two-partner secretion (TPS) family of proteins. In low-iron conditions, a transcriptional induction of the phlBA operon was observed by using the chloramphenicol acetyltransferase reporter gene, causing an increase in PhlA hemolytic activity compared to iron-rich media. A spontaneous phase variant of P. luminescens was deregulated in phlBA transcription. The phlA mutant constructed by allelic exchange remained highly pathogenic after injection in the lepidopteran Spodoptera littoralis, indicating that PhlA hemolysin is not a major virulence determinant. Using the gene encoding green fluorescent protein as a reporter, phlBA transcription was observed in hemolymph before insect death. We therefore discuss the possible role of PhlA hemolytic activity in the bacterium-nematode-insect interactions.

scholarly journals Characterization of fermentation liquid from mangrove leaves Avicennia marina and its inhibitory potential for bacterium causing ice-ice disease

2020 ◽  
Vol 19 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Samsu Adi Rahman ◽  
Sukenda ◽  
Widanarni ◽  
Alimuddin ◽  
Julie Ekasari
Keyword(s):  
Pathogenic Bacteria ◽  
Avicennia Marina ◽  
Rrna Gene ◽  
Bacillus Sp ◽  
Fermentation Liquid ◽  
Inhibitory Power ◽  
Inhibitory Potential ◽  
The 16S Rrna Gene ◽  
Better Than

ABSTRACT   Fermentation liquid from mangrove leaves Avicennia marina contains microorganisms, nutrients, and secondary metabolites. This study aimed to identify bacteria and the compounds in fermentation liquid of mangrove leaves A. marina and measured their inhibitory capacity against pathogenic bacteria Stenotrophomonas maltophilia which causes ice-ice disease in seaweed. Molecular analysis which aimed the 16S rRNA gene showed that the bacteria in fermentation liquid consisted of eight types of Bacillus, Bacillus subtilis MSAR-01, Bacillus megaterium MSAR-02, Bacillus firmus MSAR-03, Bacillus thuringiensis MSAR-04, Bacillus subterranerus MSAR-05, Bacillus vietnamensis MSAR-06, Bacillus sp. MSAR-07, Bacillus circulans MSAR-08, with the best inhibitory power indicated by B. subtilis MSAR-01, B. vietnamensis MSAR-06, and Bacillus sp. MSAR-07. The administration of lactic acid, bacteriocin, total fermentation liquid, and supernatant as much as 15 mL produce inhibition to S. maltophilia indicated better result  than using one or a combination of several types of bacterial isolates. The inhibition of single bacterial enriched fermentation and supernatant liquids was better than bacterial combination enrichment.   Keywords: Avicennia marina, fermentation, ice-ice, mangrove

Emerging role of carbonic anhydrase inhibitors

2021 ◽  
Vol 135 (10) ◽  
pp. 1233-1249
Author(s):  
Claudiu T. Supuran
Keyword(s):  
Carbonic Anhydrase ◽  
Pathogenic Bacteria ◽  
Acute Mountain Sickness ◽  
Proof Of Concept ◽  
Mountain Sickness ◽  
Antiobesity Agents ◽  
New Applications ◽  
Human Isoforms

Abstract Inhibition of carbonic anhydrase (CA, EC 4.2.1.1) was clinically exploited for decades, as most modern diuretics were obtained considering as lead molecule acetazolamide, the prototypical CA inhibitor (CAI). The discovery and characterization of multiple human CA (hCA) isoforms, 15 of which being known today, led to new applications of their inhibitors. They include widely clinically used antiglaucoma, antiepileptic and antiobesity agents, antitumor drugs in clinical development, as well as drugs for the management of acute mountain sickness and idiopathic intracranial hypertension (IIH). Emerging roles of several CA isoforms in areas not generally connected to these enzymes were recently documented, such as in neuropathic pain, cerebral ischemia, rheumatoid arthritis, oxidative stress and Alzheimer’s disease. Proof-of-concept studies thus emerged by using isoform-selective inhibitors, which may lead to new clinical applications in such areas. Relevant preclinical models are available for these pathologies due to the availability of isoform-selective CAIs for all human isoforms, belonging to novel classes of compounds, such as coumarins, sulfocoumarins, dithiocarbamates, benzoxaboroles, apart the classical sulfonamide inhibitors. The inhibition of CAs from pathogenic bacteria, fungi, protozoans or nematodes started recently to be considered for obtaining anti-infectives with a new mechanism of action.

scholarly journals Molecular Characterization of Staphylococcus sciuriStrains Isolated from Humans

2000 ◽  
Vol 38 (3) ◽  
pp. 1136-1143 ◽  
Author(s):  
Isabel Couto ◽  
Ilda Santos Sanches ◽  
Raquel Sá-Leão ◽  
Hermínia de Lencastre
Keyword(s):  
Animal Origin ◽  
Beta Lactams ◽  
Previous Proposal ◽  
Gentamicin Resistance ◽  
Resistance Markers ◽  
Mrsa Strains ◽  
Free Environment ◽  
Different Sources

We previously characterized over 100 Staphylococcus sciuri isolates, mainly of animal origin, and found that they all carried a genetic element (S. sciuri mecA) closely related to the mecA gene of methicillin-resistantStaphylococcus aureus (MRSA) strains. We also found a few isolates that carried a second copy of the gene, identical to MRSAmecA. In this work, we analyzed a collection of 28 S. sciuri strains isolated from both healthy and hospitalized individuals. This was a relatively heterogeneous group, as inferred from the different sources, places, and dates of isolation and as confirmed by pulsed-field gel electrophoresis analysis. All strains carried the S. sciuri mecA copy, sustaining our previous proposal that this element belongs to the genetic background ofS. sciuri. Moreover, 46% of the strains also carried the MRSA mecA copy. Only these strains showed significant levels of resistance to beta-lactams. Strikingly, the majority of the strains carrying the additional MRSA mecA copy were obtained from healthy individuals in an antibiotic-free environment. Most of the 28 strains were resistant to penicillin, intermediately resistant to clindamycin, and susceptible to tetracycline, erythromycin, and gentamicin. Resistance to these last three antibiotics was found in some strains only. The findings reported in this work confirmed the role of S. sciuri in the evolution of the mechanism of resistance to methicillin in staphylococci and suggested that this species (like the pathogenic staphylococci) may accumulate resistance markers for several classes of antibiotics.

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