scholarly journals Effect of Glycine on Helicobacter pylori In Vitro

2004 ◽  
Vol 48 (10) ◽  
pp. 3782-3788 ◽  
Author(s):  
Masaaki Minami ◽  
Takafumi Ando ◽  
Shin-nosuke Hashikawa ◽  
Keizo Torii ◽  
Tadao Hasegawa ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Eradication Therapy ◽  
Resistant Mutant ◽  
Synergistic Activity ◽  
Wild Type ◽  
Mutant Strains ◽  
The Difference ◽  
H Pylori ◽  
Isogenic Mutants

ABSTRACT Glycine is the simplest amino acid and is used as a metabolic product in some bacteria. However, an excess of glycine inhibits the growth of many bacteria, and it is used as a nonspecific antiseptic agent due to its low level of toxicity in animals. The effect of glycine on Helicobacter pylori is not precisely known. The present study was conducted to investigate (i) the effect of glycine on clarithromycin (CLR)-resistant and -susceptible strains of H. pylori, (ii) the effect of glycine in combination with amoxicillin (AMX), and (iii) the postantibiotic effect (PAE). The MIC at which 90% of strains are inhibited for glycine was almost 2.5 mg/ml for 31 strains of H. pylori, including CLR-resistant strains. We constructed isogenic CLR-resistant mutant strains by natural transformation and investigated the difference between clinical wild-type strains and isogenic mutants. There were no differences in the MICs between CLR-resistant and -susceptible strains or between clinical wild-type and mutant strains. The combination of AMX and glycine showed synergistic activity, with the minimum bactericidal concentration of AMX with glycine decreasing to 1/10 that of AMX alone. Glycine showed no PAE against H. pylori. These results suggest that glycine may be a useful antimicrobial agent against H. pylori not only alone but also in combination with antibacterial drugs for the treatment of H. pylori-associated diseases. Glycine may represent a component of a new type of eradication therapy for CLR-resistant H. pylori.

Enhanced fitness of a Helicobacter pylori babA mutant in a murine model

2021 ◽  
Author(s):  
M. Lorena Harvey ◽  
Aung Soe Lin ◽  
Lili Sun ◽  
Tatsuki Koyama ◽  
Jennifer H. B. Shuman ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane Proteins ◽  
Population Diversity ◽  
Fitness Advantage ◽  
Neutral Locus ◽  
Mutant Strains ◽  
Bacterial Fitness ◽  
H Pylori

Helicobacter pylori genomes encode >60 predicted outer membrane proteins (OMPs). Several OMPs in the Hop family act as adhesins, but the functions of most Hop proteins are unknown. To identify hop mutant strains that exhibit altered fitness in vivo compared to fitness in vitro , we used a genetic barcoding method that allowed us to track changes in the proportional abundance of H. pylori strains within a mixed population. We generated a library of hop mutant strains, each containing a unique nucleotide barcode, as well as a library of control strains, each containing a nucleotide barcode in an intergenic region predicted to be a neutral locus unrelated to bacterial fitness. We orogastrically inoculated each of the libraries into mice and analyzed compositional changes in the populations over time in vivo compared to changes detected in the populations during library passage in vitro . The control library proliferated as a relatively stable community in vitro, but there was a reduction in the population diversity of this library in vivo and marked variation in the dominant strains recovered from individual animals, consistent with the existence of a non-selective bottleneck in vivo . We did not identify any OMP mutants exhibiting fitness defects exclusively in vivo without corresponding fitness defects in vitro . Conversely, a babA mutant exhibited a strong fitness advantage in vivo but not in vitro . These findings, when taken together with results of other studies, suggest that production of BabA may have differential effects on H. pylori fitness depending on the environmental conditions.

scholarly journals Can probiotics improve efficiency and safety profile of triple Helicobacter pylori eradication therapy? A prospective randomized study

2016 ◽  
Vol 73 (11) ◽  
pp. 1044-1049 ◽  
Author(s):  
Sasa Grgov ◽  
Tomislav Tasic ◽  
Biljana Radovanovic-Dinic ◽  
Daniela Benedeto-Stojanov
Keyword(s):  
Helicobacter Pylori ◽  
Randomized Study ◽  
Eradication Therapy ◽  
Saccharomyces Boulardii ◽  
Rapid Urease Test ◽  
Group I ◽  
Urease Test ◽  
Probiotic Strains ◽  
The Difference ◽  
H Pylori

Background/Aim. Some studies suggest the benefit of applying different probiotic strains in combination with antibiotics in the eradication of Helicobacter pylori (H. pylori) infection. The aim of this study was to evaluate the effect of co-administration of multiple probiotic strains with triple H. pylori eradication therapy. Methods. This prospective study included 167 patients with dyspeptic symptoms and chronic gastritis who were diagnosed with H. pylori infection and randomized into two groups. The group I of 77 patients underwent triple eradication therapy, for 7 days, with lansoprazole, 2 ? 30 mg half an hour before the meal, amoxicillin 2 ? 1.000 mg per 12 hours and clarithromycin 2 ? 500 mg per 12 hours. After the 7th day of the therapy, lansoprazole continued at a dose of 30 mg for half an hour before breakfast for 4 weeks. The group II of 90 patients received the same treatment as the patients of the group I, with the addition of the probiotic cultures in the form of a capsule comprising Lactobacillus Rosell-52, Lactobacillus Rosell-11, Bifidobacterium Rosell-1755 and Saccharomyces boulardii, since the beginning of eradication for 4 weeks. Eradication of H. pylori infection control was performed 8 weeks after the therapy by rapid urease test and histopathologic evaluation of endoscopic biopsies or by stool antigen test for H. pylori. Results. Eradication of H. pylori infection was achieved in 93.3% of the patients who received probiotics with eradication therapy and in 81.8% of patients who were only on eradication therapy without probiotics. The difference in eradication success was statistically significant, (p < 0.05). The incidence of adverse effects of eradication therapy was higher in the group of patients who were not on probiotic (28.6%) than in the group that received probiotic (17.7%), but the difference was not statistically significant. Conclusion. Multiple probiotic strains addition to triple eradication therapy of H. pylori achieves a significantly better eradication success, with fewer side effects of antibiotics.

scholarly journals The Entner-Doudoroff Pathway Has Little Effect on Helicobacter pylori Colonization of Mice

2003 ◽  
Vol 71 (5) ◽  
pp. 2920-2923 ◽  
Author(s):  
Amy E. Wanken ◽  
Tyrrell Conway ◽  
Kathryn A. Eaton
Keyword(s):  
Helicobacter Pylori ◽  
Wild Type ◽  
Mutant Strains ◽  
H Pylori ◽  
Type Strains

ABSTRACT Helicobacter pylori mutants deficient in 6-phosphogluconate dehydratase (6PGD) were constructed. Colonization densities were lower and minimum infectious doses were higher for mutant strains than for wild-type strains. In spite of better colonization, however, wild-type strains did not displace the mutant in cocolonization experiments. Loss of 6PGD diminishes the fitness of H. pylori in vivo, but the pathway is nonessential for colonization.

scholarly journals Nitazoxanide in Treatment of Helicobacter pylori: a Clinical and In Vitro Study

2003 ◽  
Vol 47 (12) ◽  
pp. 3780-3783 ◽  
Author(s):  
Yvonne Guttner ◽  
Helen M. Windsor ◽  
Charlie H. Viiala ◽  
Leon Dusci ◽  
Barry J. Marshall
Keyword(s):  
Helicobacter Pylori ◽  
Clinical Laboratory ◽  
Single Agent ◽  
Eradication Therapy ◽  
In Vitro Study ◽  
Laboratory Evaluation ◽  
Microbiological Characteristics ◽  
String Test ◽  
H Pylori

ABSTRACT Nitazoxanide (NTZ) is an antibiotic with microbiological characteristics similar to those of metronidazole but without an apparent problem of resistance. The aim of this study was the prospective evaluation of NTZ given as a single agent in the treatment of Helicobacter pylori infection. Twenty culture-positive patients with dyspepsia who had previously failed at least one course of H. pylori eradication therapy were enrolled. Subjects received 1 g of NTZ twice daily for 10 days. The safety and tolerability of the drug were assessed by physical examination, monitoring of adverse events, and clinical laboratory evaluation. Urea breath tests (UBTs) were performed 6 weeks posttreatment. H. pylori was isolated from UBT-positive patients by the string test or endoscopy with biopsy, and the MICs for these isolates were compared to those for isolates obtained pretherapy. The levels of tizoxanide, the active deacylated derivative of NTZ, were measured in blood, saliva, and tissue from two patients during treatment. The UBT results were positive for all 20 patients after completion of NTZ therapy. The MIC results demonstrated that the NTZ susceptibilities of none of the strains isolated from the patients posttherapy had changed significantly. No major adverse reactions were observed, but frequent minor side effects were observed. In conclusion, NTZ did not eradicate H. pylori when it was given as a single agent.

scholarly journals Novel Functions for Glycosyltransferases Jhp0562 and GalT in Lewis Antigen Synthesis and Variation in Helicobacter pylori

2012 ◽  
Vol 80 (4) ◽  
pp. 1593-1605 ◽  
Author(s):  
Mary Ann Pohl ◽  
Sabine Kienesberger ◽  
Martin J. Blaser
Keyword(s):  
Helicobacter Pylori ◽  
Wild Type ◽  
Sequence Analyses ◽  
Upstream Gene ◽  
Content Type ◽  
Lewis Antigen ◽  
Mutant Strains ◽  
H Pylori

ABSTRACTLewis (Le) antigens are fucosylated oligosaccharides present in theHelicobacter pylorilipopolysaccharide. Expression of these antigens is believed to be important forH. pyloricolonization, since Le antigens also are expressed on the gastric epithelia in humans. A galactosyltransferase encoded by β-(1,3)galTis essential for production of type 1 (Leaand Leb) antigens. The upstream genejhp0562, which is present in many but not allH. pyloristrains, is homologous to β-(1,3)galTbut is of unknown function. BecauseH. pyloridemonstrates extensive intragenomic recombination, we hypothesized that these two genes could undergo DNA rearrangement. A PCR screen and subsequent sequence analyses revealed that the two genes can recombine at both the 5′ and 3′ ends. Chimeric β-(1,3)galT-like alleles can restore function in a β-(1,3)galTnull mutant, but neither native nor recombinantjhp0562can. Mutagenesis ofjhp0562revealed that it is essential for synthesis of both type 1 and type 2 Le antigens. Transcriptional analyses of both loci showed β-(1,3)galTexpression in all wild-type (WT) and mutant strains tested, whereasjhp0562was not expressed injhp0562null mutants, as expected. Sincejhp0562unexpectedly displayed functions in both type 1 and type 2 Le synthesis, we asked whethergalT, part of the type 2 synthesis pathway, had analogous functions in type 1 synthesis. Mutagenesis and complementation analysis confirmed thatgalTis essential for Lebproduction. In total, these results demonstrate thatgalTandjhp0562have functions that cross the expected Le synthesis pathways and thatjhp0562provides a substrate for intragenomic recombination to generate diverse Le synthesis enzymes.

RAPID CHARACTERIZATION AND SEPARATION OF ISOGENIC MUTANTS OF H. PYLORI BY DIELECTROPHORESIS

2009 ◽  
Vol 21 (06) ◽  
pp. 433-436
Author(s):  
Chi-Chang Lin ◽  
Sheng-Kai Li ◽  
Bor-Shyang Sheu ◽  
Hsien-Chang Chang
Keyword(s):  
Helicobacter Pylori ◽  
Individual Cell ◽  
Outer Membrane Proteins ◽  
Cell Types ◽  
Wild Type ◽  
Nondestructive Analysis ◽  
Isogenic Mutant ◽  
Rapid Characterization ◽  
H Pylori ◽  
Isogenic Mutants

A simple, fast, real-time, and nondestructive analysis of protein expression in biological samples, such as membranes, based on dielectrophoresis is described. On the basis of the distinct differences in the dielectrophoretic properties of individual cell types, the wild-type BabA-positive Helicobacter pylori isolates and its BabA-negative isogenic mutant can be identified and separated. The herein-presented approach of using microelectrodes should be an easy-to-use, cheap, and rapid alternative to separate and distinguish the presence or absence of important outer-membrane proteins.

scholarly journals Colonization and Inflammation Deficiencies in Mongolian Gerbils Infected by Helicobacter pylori Chemotaxis Mutants

2005 ◽  
Vol 73 (3) ◽  
pp. 1820-1827 ◽  
Author(s):  
David J. McGee ◽  
Melanie L. Langford ◽  
Emily L. Watson ◽  
J. Elliot Carter ◽  
Yu-Ting Chen ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Immune Cell ◽  
Response Regulator ◽  
Critical Role ◽  
Mongolian Gerbils ◽  
Wild Type ◽  
In The Wild ◽  
H Pylori

ABSTRACT Helicobacter pylori causes disease in the human stomach and in mouse and gerbil stomach models. Previous results have shown that motility is critical for H. pylori to colonize mice, gerbils, and other animal models. The role of chemotaxis, however, in colonization and disease is less well understood. Two genes in the H. pylori chemotaxis pathway, cheY and tlpB, which encode the chemotaxis response regulator and a methyl-accepting chemoreceptor, respectively, were disrupted. The cheY mutation was complemented with a wild-type copy of cheY inserted into the chromosomal rdxA gene. The cheY mutant lost chemotaxis but retained motility, while all other strains were motile and chemotactic in vitro. These strains were inoculated into gerbils either alone or in combination with the wild-type strain, and colonization and inflammation were assessed. While the cheY mutant completely failed to colonize gerbil stomachs, the tlpB mutant colonized at levels similar to those of the wild type. With the tlpB mutant, there was a substantial decrease in inflammation in the gerbil stomach compared to that with the wild type. Furthermore, there were differences in the numbers of each immune cell in the tlpB-mutant-infected stomach: the ratio of lymphocytes to neutrophils was about 8 to 1 in the wild type but only about 1 to 1 in the mutant. These results suggest that the TlpB chemoreceptor plays an important role in the inflammatory response while the CheY chemotaxis regulator plays a critical role in initial colonization. Chemotaxis mutants may provide new insights into the steps involved in H. pylori pathogenesis.

scholarly journals Functional Analysis of the M.HpyAIV DNA Methyltransferase of Helicobacter pylori

2007 ◽  
Vol 189 (24) ◽  
pp. 8914-8921 ◽  
Author(s):  
Anna Skoglund ◽  
Britta Björkholm ◽  
Christina Nilsson ◽  
Anders F. Andersson ◽  
Cecilia Jernberg ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Restriction Enzyme ◽  
Dna Methyltransferase ◽  
Insertional Mutagenesis ◽  
Phase Variation ◽  
Restriction Enzyme Digestion ◽  
Wild Type ◽  
Gene Mutant ◽  
H Pylori

ABSTRACT A large number of genes encoding restriction-modification (R-M) systems are found in the genome of the human pathogen Helicobacter pylori. R-M genes comprise approximately 10% of the strain-specific genes, but the relevance of having such an abundance of these genes is not clear. The type II methyltransferase (MTase) M.HpyAIV, which recognizes GANTC sites, was present in 60% of the H. pylori strains analyzed, whereof 69% were resistant to restriction enzyme digestion, which indicated the presence of an active MTase. H. pylori strains with an inactive M.HpyAIV phenotype contained deletions in regions of homopolymers within the gene, which resulted in premature translational stops, suggesting that M.HpyAIV may be subjected to phase variation by a slipped-strand mechanism. An M.HpyAIV gene mutant was constructed by insertional mutagenesis, and this mutant showed the same viability and ability to induce interleukin-8 in epithelial cells as the wild type in vitro but had, as expected, lost the ability to protect its self-DNA from digestion by a cognate restriction enzyme. The M.HpyAIV from H. pylori strain 26695 was overexpressed in Escherichia coli, and the protein was purified and was able to bind to DNA and protect GANTC sites from digestion in vitro. A bioinformatic analysis of the number of GANTC sites located in predicted regulatory regions of H. pylori strains 26695 and J99 resulted in a number of candidate genes. katA, a selected candidate gene, was further analyzed by quantitative real-time reverse transcription-PCR and shown to be significantly down-regulated in the M.HpyAIV gene mutant compared to the wild-type strain. This demonstrates the influence of M.HpyAIV methylation in gene expression.

scholarly journals In Vitro Probiotic Potential of Lactic Acid Bacteria Isolated from Aguamiel and Pulque and Antibacterial Activity Against Pathogens

2019 ◽  
Vol 9 (3) ◽  
pp. 601 ◽  
Author(s):  
Alicia Cervantes-Elizarrarás ◽  
Nelly Cruz-Cansino ◽  
Esther Ramírez-Moreno ◽  
Vicente Vega-Sánchez ◽  
Norma Velázquez-Guadarrama ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Helicobacter Pylori ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Eradication Therapy ◽  
Antimicrobial Effect ◽  
E Coli ◽  
Probiotic Potential ◽  
H Pylori

Probiotics can act as a natural barrier against several pathogens, such Helicobacter pylori, a bacterium linked to stomach cancer. The aim of the present study was to isolate and identify lactic acid bacteria (LAB) from pulque and aguamiel, and evaluate their probiotic potential and antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. Ten isolates were selected and evaluated for in vitro resistance to antibiotics and gastrointestinal conditions, and antimicrobial activity against E. coli and S. aureus and the effect on H. pylori strains. 16S rRNA identification was performed. Ten potential probiotic isolates were confirmed as belonging to the genera Lactobacillus and Pediococcus. All the strains were susceptible to clinical antibiotics, except to vancomycin. Sixty percent of the isolates exhibited antimicrobial activity against E. coli and S. aureus. The growth of H. pylori ATCC 43504 was suppressed by all the LAB, and the urease activity from all the H. pylori strains was inhibited, which may decrease its chances for survival in the stomach. The results suggest that LAB isolated from pulque and aguamiel could be an option to establish a harmless relationship between the host and H. pylori, helping in their eradication therapy.

scholarly journals Two Predicted Chemoreceptors of Helicobacter pylori Promote Stomach Infection

2002 ◽  
Vol 70 (10) ◽  
pp. 5877-5881 ◽  
Author(s):  
Tessa M. Andermann ◽  
Yu-Ting Chen ◽  
Karen M. Ottemann
Keyword(s):  
Helicobacter Pylori ◽  
Growth Defect ◽  
In Vitro Growth ◽  
Wild Type ◽  
Encoded Proteins ◽  
Genes Encoding ◽  
H Pylori

ABSTRACT Helicobacter pylori must be motile or display chemotaxis to be able to fully infect mammals, but it is not known how this chemotaxis is directed. We disrupted two genes encoding predicted chemoreceptors, tlpA and tlpC. H. pylori mutants lacking either of these genes are fully motile and chemotactic in vitro and are as able as the wild type to infect mice when they are the sole infecting strains. In contrast, when mice are coinfected with the H. pylori SS1 tlpA or tlpC mutant and the wild type, we find more wild type than mutant after 2 weeks of colonization. Neither strain has an in vitro growth defect. These results suggest that the tlpA- and tlpC-encoded proteins assist colonization of the stomach environment.

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