scholarly journals Effects of In Vitro Antibiotic Resistance on Treatment: Bismuth-Containing Regimens

2000 ◽  
Vol 14 (10) ◽  
pp. 885-889 ◽  
Author(s):  
Naoki Chiba
Keyword(s):  
Antibiotic Resistance ◽  
Triple Therapy ◽  
Eradication Therapy ◽  
Colloidal Bismuth Subcitrate ◽  
Bismuth Citrate ◽  
Bismuth Compounds ◽  
Metronidazole Resistance ◽  
H Pylori

Bismuth compounds remain useful forHelicobacter pylorieradication therapy. These include colloidal bismuth subcitrate (CBS), bismuth subsalicylate (BSS) and, most recently, ranitidine bismuth citrate (RBC). CBS appears to prevent the development of imidazole resistance when coadministered with nitroimidazoles. Traditional triple therapy with bismuth, metronidazole and tetracycline or amoxicillin (BMT/A) only partially overcomes metronidazole resistance. However, the addition of a PPI to bismuth triple therapy largely overcomes established metronidazole resistance if treatment is given for at least one week or more. When RBC rather than PPI is used with clarithromycin, this dual regimen appears to be more effective in preventing the development of secondary clarithromycin resistance. The triple combination of RBC, metronidazole and clarithromycin appears to be effective against metronidazole resistant strains ofH pylori. Thus, overall, there is some evidence that bismuth compounds may prevent the development of antibiotic resistance and that existing antibiotic resistance may at least be partially overcome in vitro and in vivo. With the growing emergence ofH pyloriresistance to metronidazole and clarithromycin, further research to clarify the role of bismuth compounds is required.

scholarly journals Differential Normalization of Mucosal Interleukin-8 and Interleukin-6 Activity after Helicobacter pyloriEradication

1998 ◽  
Vol 66 (10) ◽  
pp. 4742-4747 ◽  
Author(s):  
Takafumi Ando ◽  
Kazuo Kusugami ◽  
Masahiro Ohsuga ◽  
Kenji Ina ◽  
Masataka Shinoda ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Eradication Therapy ◽  
Interleukin 8 ◽  
Biopsy Specimens ◽  
Mucosal Tissues ◽  
H Pylori ◽  
Triple Treatment

ABSTRACT There is differential resolution of mucosal infiltration with neutrophils and mononuclear cells following successfulHelicobacter pylori eradication. We investigated the effects of H. pylori eradication on mucosal interleukin-8 (IL-8) and IL-6 activity in relation to the resolution of H. pylori-associated gastritis. Eighty-one duodenal ulcer patients with H. pyloriinfection received dual- or triple-treatment eradication therapy, and mucosal biopsy specimens obtained at the initial and follow-up endoscopic examinations were cultured in vitro for 24 h. The levels of IL-8 and IL-6 were measured by enzyme-linked immunosorbent assays. In the 42 patients in whomH. pylori eradication failed, there was little change in the numbers of neutrophils and mononuclear cells infiltrating the mucosa and in IL-8 and IL-6 activity. In the 39 patients in whom H. pylori was eradicated, there was normalization both in the numbers of infiltrating neutrophils and in mucosal IL-8 activity, which was evident within 1 month following therapy. In contrast, there was a gradual resolution of mononuclear cell infiltration over a 6-month period, accompanied by a gradual normalization in IL-6 levels. Addition of H. pylori to cultures of mucosal tissues induced a significant increase in IL-8 activity in both uninfected control subjects and patients from whom H. pylori was eradicated. However, this introduction yielded a significant increase in IL-6 activity only in the latter group. This study indicates a dichotomy in the changes of mucosal IL-8 and IL-6 activity afterH. pylori eradication. The rapid normalization of IL-8 after H. pylori eradication and the ability of H. pylori cells to stimulate IL-8 in control tissues indicate that IL-8 induction is a part of the innate (nonimmune) responses to this organism. In contrast, the results of experiments analyzing IL-6 activity in cultured mucosal tissues suggest that the gradual resolution of mucosal IL-6 activity and mononuclear infiltration after successful eradication observed in vivo may reflect gradually diminishing residual immune responses against H. pylori.

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 Functional Analysis of the RdxA and RdxB Nitroreductases of Campylobacter jejuni Reveals that Mutations in rdxA Confer Metronidazole Resistance

2010 ◽  
Vol 192 (7) ◽  
pp. 1890-1901 ◽  
Author(s):  
Deborah A. Ribardo ◽  
Lacey K. Bingham-Ramos ◽  
David R. Hendrixson
Keyword(s):  
Campylobacter Jejuni ◽  
Biochemical Analysis ◽  
Normal Growth ◽  
Deletion Mutations ◽  
Replication Errors ◽  
Metronidazole Resistance ◽  
H Pylori ◽  
Dna Replication Errors

ABSTRACT Campylobacter jejuni is a leading cause of gastroenteritis in humans and a commensal bacterium of the intestinal tracts of many wild and agriculturally significant animals. We identified and characterized a locus, which we annotated as rdxAB, encoding two nitroreductases. RdxA was found to be responsible for sensitivity to metronidazole (Mtz), a common therapeutic agent for another epsilonproteobacterium, Helicobacter pylori. Multiple, independently derived mutations in rdxA but not rdxB resulted in resistance to Mtz (Mtzr), suggesting that, unlike the case in H. pylori, Mtzr might not be a polygenic trait. Similarly, Mtzr C. jejuni was isolated after both in vitro and in vivo growth in the absence of selection that contained frameshift, point, insertion, or deletion mutations within rdxA, possibly revealing genetic variability of this trait in C. jejuni due to spontaneous DNA replication errors occurring during normal growth of the bacterium. Similar to previous findings with H. pylori RdxA, biochemical analysis of C. jejuni RdxA showed strong oxidase activity, with reduction of Mtz occurring only under anaerobic conditions. RdxB showed similar characteristics but at levels lower than those for RdxA. Genetic analysis confirmed that rdxA and rdxB are cotranscribed and induced during in vivo growth in the chick intestinal tract, but an absence of these genes did not strongly impair C. jejuni for commensal colonization. Further studies indicate that rdxA is a convenient locus for complementation of mutants in cis. Our work contributes to the growing knowledge of determinants contributing to susceptibility to Mtz (Mtzs) and supports previous observations of the fundamental differences in the activities of nitroreductases from epsilonproteobacteria.

scholarly journals Efficacy and Safety of Wei Bi Mei, a Chinese Herb Compound, as an Alternative to Bismuth for Eradication of Helicobacter pylori

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Lei Li ◽  
FanDong Meng ◽  
Shengtao Zhu ◽  
ShuiLong Guo ◽  
YongJun Wang ◽  
...  
Keyword(s):  
Chinese Herb ◽  
Efficacy And Safety ◽  
Sprague Dawley ◽  
Chinese Medicinal Herb ◽  
Colloidal Bismuth Subcitrate ◽  
Synthetic Drugs ◽  
Bismuth Compounds ◽  
Bismuth Subcitrate ◽  
Metronidazole Resistance ◽  
H Pylori

Bismuth-containing quadruple therapy has been recommended as the first line of treatment in areas of high clarithromycin or metronidazole resistance. However, safety concerns of bismuth agents have long been raised. We first assessed the efficacy and safety of Wei Bi Mei granules, which are bismuth compounds consisting of three synthetic drugs and five medicinal herbs, compared to bismuth aluminate and colloidal bismuth subcitrate (CBS) in H. pylori-infected mouse model. We then used atomic fluorescence spectroscopy and autometallography to measure the accumulation of three bismuth agents in the brain, heart, liver, and kidneys in adult Sprague-Dawley rats. We also evaluated the safety of bismuth agents by conducting clinical biochemistry tests in blood samples of experimental animals. Wei Bi Mei granules exhibited the highest efficacy of anti-H. pylori activity and yielded the lowest bismuth accumulation when compared to CBS and bismuth aluminate. Our findings show that Wei Bi Mei granules are a safe Chinese medicinal herb with potent anti-H. pylori activity and can be considered as an alternative to current bismuth compounds. Thus, Wei Bi Mei granules merit further evaluation, particularly with regard to efficacy and safety when they are combined with other H. pylori eradication medications in the clinical setting.

scholarly journals Resistotype of Helicobacter pylori isolates: the impact on eradication outcome

2014 ◽  
Vol 63 (5) ◽  
pp. 703-709 ◽  
Author(s):  
Hanafiah Alfizah ◽  
Ahmad Norazah ◽  
Razlan Hamizah ◽  
Mohamed Ramelah
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Eradication Therapy ◽  
Fluoroquinolone Resistance ◽  
23S Rrna ◽  
Nonsense Mutations ◽  
Metronidazole Resistance ◽  
Resistant Strains ◽  
H Pylori ◽  
The Impact

Antibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6 % of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2  and 1.9 % of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.

scholarly journals Primary Antimicrobial Susceptibility Changes in Children withHelicobacter pyloriInfection over 13 Years in Northern Italy

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Marco Manfredi ◽  
Pierpacifico Gismondi ◽  
Valentina Maffini ◽  
Barbara Bizzarri ◽  
Fabiola Fornaroli ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Eradication Therapy ◽  
Northern Italy ◽  
Local Distribution ◽  
Clarithromycin Resistance ◽  
Time Period ◽  
Metronidazole Resistance ◽  
H Pylori ◽  
Resistance Rates

The eradication therapy ofHelicobacter pylori(H. pylori) infection is still a challenge for gastroenterologists. One of the main causes of failure inH. pylorieradication is the antibiotic resistance mainly to clarithromycin. Culture from biopsies is maybe the most used method among the antimicrobial susceptibility techniques. In this study, we compared the antimicrobial susceptibility changes in children withH. pyloriinfection over 13 years and we confirmed that clarithromycin resistance has been increased (16% versus 26%) though with no statistically signficant value. Therefore, clarithromycin should not be used in empiric treatment ofH. pylorieradication therapy in children, but its use should be limited only to children with known antimicrobial susceptibility. On the other hand, metronidazole resistance has decreased over this time period in statistically significant manner (56% versus 33%,p=0.014). Furthermore, ampicillin resistance has been confirmed to be very rare (3% versus 0%) in children withH. pyloriinfection. In conclusion, inH. pyloriinfection, if we do not know the antibiotic susceptibility of patients, we should recommend an eradication therapy based on the local distribution of antibiotic resistance rates trying to limit the therapeutic failures.

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