scholarly journals Effect of Chlorine on Incorporation of Helicobacter pylori into Drinking Water Biofilms

2009 ◽  
Vol 76 (5) ◽  
pp. 1669-1673 ◽  
Author(s):  
M. S. Gi�o ◽  
N. F. Azevedo ◽  
S. A. Wilks ◽  
M. J. Vieira ◽  
C. W. Keevil
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Nucleic Acid ◽  
Pure Culture ◽  
Peptide Nucleic Acid ◽  
Culture Methods ◽  
Low Concentrations ◽  
H Pylori ◽  
Specific Peptide ◽  
Effect Of Chlorine

ABSTRACT The use of a specific peptide nucleic acid (PNA) probe demonstrated that Helicobacter pylori persisted inside biofilms exposed to low concentrations of chlorine (0.2 and 1.2 mg liter−1) for at least 26 days, although no culturable cells were recovered. Coupled with data obtained using viability stains in pure culture, this result suggests that H. pylori can survive chlorination but remain undetectable by culture methods, which can be effectively replaced by PNA hybridization.

scholarly journals Transmission of Helicobacter pylori and the role of water and biofilms

2009 ◽  
Vol 7 (3) ◽  
pp. 469-477 ◽  
Author(s):  
Steven L. Percival ◽  
John G. Thomas
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Human Infection ◽  
Control Measures ◽  
Risk Assessments ◽  
Culture Methods ◽  
Infection Control Measures ◽  
H Pylori ◽  
Primary Transmission

Documented evidence relating to the survival of Helicobacter pylori outside the gastric niche is extremely limited. To date the primary transmission routes of H. pylori have yet to be confirmed and when this is achieved preventive infection control measures can be implemented to reduce and ultimately prevent human infection from this pathogen. There is mounting evidence which suggests that the prevalence of H. pylori infection has a strong correlation with access to clean water, suggesting a transmission route to the host. However, there are no established culture methods for the detection of viable H. pylori in the environment, in particular drinking water supplies, preventing the development of true epidemiological and risk assessments. The aim of this review is to highlight the available data to date that suggests drinking water and possible survival in biofilms as a probable transmission mode for H. pylori.

scholarly journals Therapeutic effects, immunogenicity and cytotoxicity of a cell penetrating peptide-peptide nucleic acid conjugate against cagA of Helicobacter pylori in cell culture and animal model

2021 ◽  
Author(s):  
Narges Nodeh Farahani ◽  
Behrooz Sadeghi Kalani ◽  
Seyed Hamidreza Monavari ◽  
Shiva Mirkalantari ◽  
Fatemeh Montazer ◽  
...  
Keyword(s):  
Cell Culture ◽  
Animal Model ◽  
Helicobacter Pylori ◽  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Cell Penetrating Peptide ◽  
Mrna Levels ◽  
Cell Penetrating ◽  
A Cell ◽  
H Pylori

Background and Objectives: Helicobacter pylori causes several gastrointestinal diseases, including asymptomatic gastritis, chronic peptic ulcer, duodenal ulcer, lymphoma of the mucosa-associated lymphoid tissue (MALT), and gastric adenocarcinoma. In recent years, failure to eradicate H. pylori infections has become an alarming problem for physicians. It is now clear that the current treatment strategies may become ineffective, necessitating the development of innovative antimicrobial compounds as alternative treatments. Materials and Methods: In this experimental study, a cell-penetrating peptide-conjugated peptide nucleic acid (CPP-PNA) was used to target the cagA expression. cagA expression was evaluated using RT-qPCR assay after treatment by the CPPPNA in cell culture and animal model. Additionally, immunogenicity and toxicity of the CPP-PNA were assessed in both cell culture and animal models. Results: Our analysis showed that cagA mRNA levels reduced in H. pylori-infected HT29 cells after treatment with CPPPNA in a dose-dependent manner. Also, cagA expression in bacterial RNA extracted from stomach tissue of mice treated with PNA was reduced compared to that of untreated mice. The expression of inflammatory cytokines also decreased in cells and tissue of H. pylori-infected mice after PNA treatment. The tested CPP-PNA showed no significant adverse effects on cell proliferation of cultured cells and no detectable toxicity and immunogenicity were observed in mice. Conclusion: These results suggest the effectiveness of CPP-PNA in targeting CagA for various research and therapeutic purposes, offering a potential antisense therapy against H. pylori infections.

scholarly journals Development of an Internal Control for Evaluation and Standardization of a Quantitative PCR Assay for Detection of Helicobacter pylori in Drinking Water

2007 ◽  
Vol 73 (22) ◽  
pp. 7380-7387 ◽  
Author(s):  
Keya Sen ◽  
Nancy A. Schable ◽  
Dennis J. Lye
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Quantitative Pcr ◽  
Water Samples ◽  
Sodium Thiosulfate ◽  
Qpcr Assay ◽  
E Coli ◽  
H Pylori ◽  
Labeled Probe ◽  
Treated Drinking Water

ABSTRACT Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

scholarly journals Frequency of H. Pylori infection in children with recurrent abdominal pain at a Tertiary Care Hospital.

2020 ◽  
Vol 27 (02) ◽  
pp. 237-241
Author(s):  
Asim Khurshid ◽  
Shahid Ishaq ◽  
Mushtaq Ahmad
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Disease Duration ◽  
Family Income ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Recurrent Abdominal Pain ◽  
Male Gender ◽  
Care Hospital ◽  
H Pylori

Objectives: Recurrent abdominal pain (RAP) impacts quality of life of the children. RAP also hampers education and physical activity of the children. Current study was aimed to find out the frequency of Helicobacter pylori in children with RAP in our tertiary care hospital. Study Design: Descriptive, cross-sectional study. Setting:  Department of Pediatric Medicine, Nishtar Hospital, Multan, Period: From 27-12-2017 to 26-06-2018. Material & Methods: A total of 185 patients suffering from RAP, aged 2-12 years, with a disease duration > 3 months, were enrolled. Age of the children, gender, duration of illness, number of episodes of pain, maternal literacy, family income, residential status, source of drinking water and h.pylori infection were calculated in these children. Post stratification chi-square test was applied to see its effect on H. Pylori infection. Results: Of these 185 study cases, 101 (54.6 %) were male patients while 84 (45.4%) were female. Mean age of our study cases was 7.57 ± 1.93 years. Of A total of 95 (51.4%) children belonged to rural areas and 90 (48.6 %) to urban areas. Helicobacter pylori infection was noted in 103 (55.7%) of our study cases. When helicobacter pylori  was stratified with regards to study variables, male gender, age < 8 years, monthly family income <Rs. 35000, source of drinking water as Hand Pump and disease duration < 6 months turned out to be statistically significant (P value < 0.05). Conclusion: Frequency of H.pylori was high in children with RAP. Helicobacter pylori was significantly associated with male gender, younger age, poor socioeconomic status, source of drinking water and disease duration.

scholarly journals Mouse-Colonizing Helicobacter pylori SS1 Is Unusually Susceptible to Metronidazole Due to Two Complementary Reductase Activities

2000 ◽  
Vol 44 (11) ◽  
pp. 3127-3132 ◽  
Author(s):  
Jin-Yong Jeong ◽  
Douglas E. Berg
Keyword(s):  
Helicobacter Pylori ◽  
Kanamycin Resistance ◽  
Phenotypic Traits ◽  
Insertion Mutant ◽  
Low Concentrations ◽  
Mutant Strains ◽  
Resistance Markers ◽  
Clinically Significant ◽  
H Pylori ◽  
Derivatives Of

ABSTRACT In most strains of Helicobacter pylori, mutational inactivation of the rdxA (HP0954) gene, which encodes a nitroreductase that converts metronidazole (MTZ) from a harmless prodrug to a mutagenic and bacteriocidal product, is sufficient to make this pathogen resistant to clinically significant levels of MTZ. Here we report that SS1, a strain with the special ability to colonize mice, is unusual in being susceptible to very low concentrations of MTZ (0.5 μg/ml) and in being especially difficult to mutate to MTZ resistance (Mtzr). These phenotypic traits were traced to expression in this strain of the normally quiescent H. pylori frxAgene (HP0642, an rdxA paralog) along with rdxA. Transformation tests using rdxA::camand frxA::kan insertion mutant DNAs, with selection solely for the chloramphenicol and kanamycin resistance markers, and sequence analyses of frxA in spontaneous Mtzr derivatives of rdxA null mutant strains each showed that the development of Mtzr in SS1 required inactivation of both rdxA and frxA. Inactivation of either gene alone left SS1 susceptible to MTZ, although it was readily mutable from an MTZ-susceptible to an Mtzrphenotype. Reverse transcriptase PCR tests showed that frxAmRNA was at least 10-fold more abundant in SS1 than in reference strain 26695. It is proposed that these reductases play primarily nutritional roles during bacterial growth.

scholarly journals 3-Pentylcatechol, a Non-Allergenic Urushiol Derivative, Displays Anti-Helicobacter pylori Activity In Vivo

2020 ◽  
Vol 13 (11) ◽  
pp. 384
Author(s):  
Hang Yeon Jeong ◽  
Tae Ho Lee ◽  
Ju Gyeong Kim ◽  
Sueun Lee ◽  
Changjong Moon ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Triple Therapy ◽  
Inflammatory Cells ◽  
Control Group ◽  
Vitro Assay ◽  
Low Concentrations ◽  
H Pylori ◽  
Stomach Mucous Membrane

We previously reported that 3-pentylcatechol (PC), a synthetic non-allergenic urushiol derivative, inhibited the growth of Helicobacter pylori in an in vitro assay using nutrient agar and broth. In this study, we aimed to investigate the in vivo antimicrobial activity of PC against H. pylori growing in the stomach mucous membrane. Four-week-old male C57BL/6 mice (n = 4) were orally inoculated with H. pylori Sydney Strain-1 (SS-1) for 8 weeks. Thereafter, the mice received PC (1, 5, and 15 mg/kg) and triple therapy (omeprazole, 0.7 mg/kg; metronidazole, 16.7 mg/kg; clarithromycin, 16.7 mg/kg, reference groups) once daily for 10 days. Infiltration of inflammatory cells in gastric tissue was greater in the H. pylori-infected group compared with the control group and lower in both the triple therapy- and PC-treated groups. In addition, upregulation of cytokine mRNA was reversed after infection, upon administration of triple therapy and PC. Interestingly, PC was more effective than triple therapy at all doses, even at 1/15th the dose of triple therapy. In addition, PC demonstrated synergism with triple therapy, even at low concentrations. The results suggest that PC may be more effective against H. pylori than established antibiotics.

scholarly journals Peptide nucleic acid-templated selenocystine–selenoester ligation enables rapid miRNA detection

2018 ◽  
Vol 9 (4) ◽  
pp. 896-903 ◽  
Author(s):  
Jessica Sayers ◽  
Richard J. Payne ◽  
Nicolas Winssinger
Keyword(s):  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Specific Detection ◽  
Ligation Reaction ◽  
Low Concentrations ◽  
Mirna Detection ◽  
Peptide Ligation

A PNA-templated peptide ligation reaction has been developed between selenocystine and selenoesters. The methodology was used for the sequence specific detection of miRNA at low concentrations.

Synthesis and characterization of a specific peptide nucleic acid that inhibits expression of inducible NO synthase

FEBS Letters ◽  
1998 ◽  
Vol 426 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Marco Giovine ◽  
Anna Gasparini ◽  
Sonia Scarfı̀ ◽  
Gianluca Damonte ◽  
Laura Sturla ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
No Synthase ◽  
Synthesis And Characterization ◽  
Inducible No Synthase ◽  
Specific Peptide

scholarly journals Persistence of Helicobacter pylori in Heterotrophic Drinking-Water Biofilms

2008 ◽  
Vol 74 (19) ◽  
pp. 5898-5904 ◽  
Author(s):  
M. S. Gi�o ◽  
N. F. Azevedo ◽  
S. A. Wilks ◽  
M. J. Vieira ◽  
C. W. Keevil
Keyword(s):  
Shear Stress ◽  
Helicobacter Pylori ◽  
Drinking Water ◽  
Cell Number ◽  
Low Carbon ◽  
Grab Sample ◽  
Route Of Transmission ◽  
H Pylori ◽  
Morphological Transformations ◽  
Microbiological Analyses

ABSTRACT Although the route of transmission of Helicobacter pylori remains unknown, drinking water has been considered a possible transmission vector. It has been shown previously that, in water, biofilms are a protective niche for several pathogens, protecting them from stressful conditions, such as low carbon concentration, shear stress, and less-than-optimal temperatures. In this work, the influence of these three parameters on the persistence and cultivability of H. pylori in drinking-water biofilms was studied. Autochthonous biofilm consortia were formed in a two-stage chemostat system and then inoculated with the pathogen. Total numbers of H. pylori cells were determined by microscopy using a specific H. pylori 16S rRNA peptide nucleic acid probe, whereas cultivable cells were assessed by standard plating onto selective H. pylori medium. Cultivable H. pylori could not be detected at any time point, but the ability of H. pylori cells to incorporate, undergo morphological transformations, persist, and even agglomerate in biofilms for at least 31 days without a noticeable decrease in the total cell number (on average, the concentration was between 1.54 � 106 and 2.25 � 106 cells cm−2) or in the intracellular rRNA content may indicate that the loss of cultivability was due to entry into a viable but noncultivable state. Unlike previous results obtained for pure-culture H. pylori biofilms, shear stress did not negatively influence the numbers of H. pylori cells attached, suggesting that the autochthonous aquatic bacteria have an important role in retaining this pathogen in the sessile state, possibly by providing suitable microaerophilic environments or linking biomolecules to which the pathogen adheres. Therefore, biofilms appear to provide not only a safe haven for H. pylori but also a concentration mechanism so that subsequent sloughing releases a concentrated bolus of cells that might be infectious and that could escape routine grab sample microbiological analyses and be a cause of concern for public health.

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