scholarly journals Primary and secondary clarithromycin resistance in Helicobacter pylori and mathematical modeling of the role of macrolides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Éva Kocsmár ◽  
György Miklós Buzás ◽  
Ildikó Szirtes ◽  
Ildikó Kocsmár ◽  
Zsófia Kramer ◽  
...  

AbstractClarithromycin is a macrolide antibiotic widely used for eradication of Helicobacter pylori infection, and thus resistance to this antibiotic is a major cause of treatment failure. Here, we present the results of a retrospective observational study of clarithromycin resistance (Cla-res) in 4744 H. pylori-infected patients from Central Hungary. We use immunohistochemistry and fluorescence in situ hybridization on fixed gastric tissue samples to determine H. pylori infection and to infer Cla-res status, respectively. We correlate this information with macrolide dispensing data for the same patients (available through a prescription database) and develop a mathematical model of the population dynamics of Cla-res H. pylori infections. Cla-res is found in 5.5% of macrolide-naive patients (primary Cla-res), with no significant sex difference. The model predicts that this primary Cla-res originates from transmission of resistant bacteria in 98.7% of cases, and derives from spontaneous mutations in the other 1.3%. We find an age-dependent preponderance of female patients among secondary (macrolide-exposed) clarithromycin-resistant infections, predominantly associated with prior use of macrolides for non-eradication purposes. Our results shed light into the sources of primary resistant cases, and indicate that the growth rate of Cla-res prevalence would likely decrease if macrolides were no longer used for purposes other than H. pylori eradication.

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Sameh Mohamed Fahiem Ghaly ◽  
Hany Ali Hussien Abd El-Rahman ◽  
Mohamed Osama Aly Aly ◽  
Ahmed Medhat Youssef Ibrahim Youssef

Abstract Background Antibiotic resistance in Helicobacter pylori is the major cause of eradication failure. Prevalence of H.pylori antibiotic resistance is increasing worldwide, and it is the main factor affecting efficacy of current therapeutic regimens. Our aim is to investigate H.pylori resistant patients toward Levofloxacin and detect the most effective antibiotic in eradication of H.pylori. Objective To investigate H.pylori resistant patients toward Levofloxacin including regimens and to detect the most effective antibiotic in H.pylori eradication. Patients and Methods The present study aimed to investigate the Susceptibility of Levofloxacin Resistant H.pylori in patients who had been diagnosed and received any regimen including Levofloxacin and still signs and symptoms of H.pylori infection not releaved and after proper time of stoppage of PPI and antibiotics H.pylori Ag in stool still positive at the period from January 2019 to February 2020. Results In the present study we found a wide spectrum of resistance to rates of H. pylori, from nearly negligible rates of Rifampicin (0%), Imipenem (0%), Cefotaxime (2%), Tetracycline (6%), Doxycycline(10%), and Amoxicillin(38%). To high rates resistance to Metronidazole (100%), Erythromycin (72%), Clarithromycin (68%), Azithromycin (60%), Ciprofloxacin (52%), and Levofloxacin (48%). Conclusion Helicobacter pylori is the most common chronic bacterial infection in humans. Antibiotic resistance is a major issue nowadays. Prior use of macrolide antibiotics or metronidazole appears to increase the risk of H. pylori resistance. Clarithromycin resistance appears to be an "absolute" condition that can not be overcome by increasing the macrolide dose. Levofloxacin resistance seems to be increasing. Culture and susceptibility should be done before starting second line treatment.


2021 ◽  
Vol 27 ◽  
Author(s):  
Jewel Ju Ea Kim ◽  
Ildikó Kocsmár ◽  
György Miklós Buzás ◽  
Ildikó Szirtes ◽  
Orsolya Rusz ◽  
...  

The global rise in clarithromycin (Cla) resistance is considered to be the main contributor of Helicobacter pylori (Hp) eradication failures. In nearly half of the Cla-resistant Hp infections, Cla-susceptible bacteria are simultaneously present with the Cla-resistant ones (Cla-heteroresistance). The proportion of resistant bacteria in the bacterial population (R-fraction) and its predictive role for the use of Cla-based therapies in Cla-heteroresistant infections has not yet been investigated. Our retrospective study analyzed gastric biopsy samples of 62 Hp-positive patients with Cla-heteroresistant infection. Fluorescence In Situ Hybridization technique was used to visualize the coexistence of resistant and susceptible bacteria within one tissue sample. R-fraction was quantified on multichannel microimages by digital morphometry. Resistant bacteria had a patchy distribution within the whole bacterial population causing high diversity among the investigated areas. Patients were subdivided into two major groups according to whether a Cla-based eradication attempt was conducted before or after the biopsy sampling. R-fraction was significantly lower among cases having only one previous Cla-based eradication attempt vs. those that had multiple previous eradications, including at least one Cla-containing therapy (0.41 vs. 0.89, p = 0.0308). Majority of the patients without previous eradication attempt had successful eradication with Cla-containing regimen (59.26%), verified by a negative 13C-urea breath test or control biopsy. Multivariable model indicated that the therapeutic outcome using Cla-based regimens depended on the bacterial density rather than the R-fraction. Our study raises the potential use of Cla-containing eradication therapies in certain Cla-heteroresistant Hp infections, taking into account the possible predictive role of bacterial density.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Jina Vazirzadeh ◽  
Jamal Falahi ◽  
Sharareh Moghim ◽  
Tahmineh Narimani ◽  
Rahmatollah Rafiei ◽  
...  

Background and Aims. Helicobacter pylori is a common infectious bacterium mostly found in gastroduodenal diseases. The increased prevalence of clarithromycin-resistant H. pylori strains is a major challenge in the successful treatment of infections caused by this organism. The present study is aimed at detecting the clarithromycin resistance pattern of H. pylori strains isolated from gastric biopsies and evaluating point mutations of the 23S rRNA gene. Patients and methods. In the present descriptive cross-sectional study, 165 patients with gastrointestinal disorders, who were referred to the Endoscopy Center of Dr. Shariati Hospital of Isfahan, Iran, were enrolled from April to July 2018. H. pylori infection was diagnosed by culture, and susceptibility of the isolates to clarithromycin was assessed by the E-test. Minimum inhibitory concentration (MIC) values were obtained based on EUCAST recommendations. Also, fluorescence in situ hybridization (FISH) was used to determine point mutations associated with clarithromycin resistance. Results. By using culturing, H. pylori was isolated from 50.3% (83/165) gastric biopsy specimens. The overall frequency of resistance to clarithromycin was 25.3% (21/83) by the E-test. In the resistance genotypic analysis, 19 isolates had mutations. The prevalence of A2143G and A2144G mutations was 68.4% (13/19) and 31.5% (6/19), respectively. A2143C mutation was not tracked in any isolate. Two isolates with MIC>0.5 μg/mL had no mutations that could be related to other mechanisms of resistance. Conclusion. As presented in the study, the high prevalence of clarithromycin-resistant H. pylori due to point mutations of the 23S rRNA gene indicates the necessity of revising the standard treatment regimen based on antibiotic susceptibility pattern of each region.


2003 ◽  
Vol 71 (5) ◽  
pp. 2876-2880 ◽  
Author(s):  
Jafar Mahdavi ◽  
Thomas Borén ◽  
Christina Vandenbroucke-Grauls ◽  
Ben J. Appelmelk

ABSTRACT In vitro and in vivo studies from various groups have suggested that Helicobacter pylori lipopolysaccharide (LPS) Lewis x (Lex) antigens mediate bacterial adhesion. We have now reevaluated this hypothesis by studying the adherence in situ of H. pylori strain 11637 and its corresponding Lex-negative rfbM mutant to human gastric mucosa from patients (n = 22) with various gastric pathologies. Significant binding of the parent strain was observed in only 8 out of 22 sections; in four out of eight patients, the Lex-negative mutant bound less well. One of these four patients displayed no gastric abnormalities, and the other three showed dysplasia, metaplasia, and adenocarcinoma, respectively; hence, we are unable to define the circumstances under which LPS-mediated adhesion takes place. We conclude that H. pylori LPS plays a distinct but minor role in adhesion.


2021 ◽  
Vol 35 ◽  
pp. 205873842110303
Author(s):  
Wenwen Gao ◽  
Xiang Zhang ◽  
Yanhui Yin ◽  
Shuwen Yu ◽  
Lu Wang

The evidence on whether high-dose new generation proton pump inhibitors (PPIs) including rabeprazole and esomeprazole achieve a higher eradication rate of Helicobacter pylori has not been assessed. The primary comparison was eradication and adverse events (AEs) rate of standard (esomeprazole 20 mg bid, rabeprazole 10 mg bid) versus high-dose (esomeprazole 40 mg bid, rabeprazole 20 mg bid) PPIs. Sub-analyses were performed to evaluate the eradication rate between Asians and Caucasians, clarithromycin-resistance (CAM-R) strains, and clarithromycin-sensitivity (CAM-S) strains of different dose PPIs. We conducted a literature search for randomized controlled trials comparing high-with standard-dose esomeprazole and rabeprazole for H. pylori eradication and AEs. A total of 12 trials with 2237 patients were included. The eradication rate of high-dose PPIs was not significantly superior to standard-dose PPIs regimens: 85.3% versus 84.2%, OR 1.09 (0.86–1.37), P = 0.47. The high dose induced more AEs than those of the standard dose, but didn’t reach statistical significance (OR 1.25, 95% CI: 0.99–1.56, P = 0.06). Subgroup analysis showed that the difference in eradication rate of PPIs between high- and standard-dose groups were not statistically significant both in Asians (OR 0.99, 95% CI 0.75–1.32, P = 0.97) and Caucasians (OR 1.27, 95% CI 0.84–1.92, P = 0.26). Furthermore, there were similar eradication rates in CAM-S (OR 1.2; 95% CI 0.58–2.5; P = 0.63) and CAM-R strains (OR 1.08; 95% CI 0.45–2.56; P = 0.87) between the standard-and high-dose groups. High and standard dosages of new generation of the PPIs showed similar H. pylori eradication rates and AEs as well as between Asian versus Caucasian populations, with or without clarithromycin-resistance. However, further studies are needed to confirm.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Montserrat Palau ◽  
Núria Piqué ◽  
M. José Ramírez-Lázaro ◽  
Sergio Lario ◽  
Xavier Calvet ◽  
...  

Helicobacter pylori is a common pathogen associated with several severe digestive diseases. Although multiple virulence factors have been described, it is still unclear the role of virulence factors on H. pylori pathogenesis and disease progression. Whole genome sequencing could help to find genetic markers of virulence strains. In this work, we analyzed three complete genomes from isolates obtained at the same point in time from a stomach of a patient with adenocarcinoma, using multiple available bioinformatics tools. The genome analysis of the strains B508A-S1, B508A-T2A and B508A-T4 revealed that they were cagA, babA and sabB/hopO negative. The differences among the three genomes were mainly related to outer membrane proteins, methylases, restriction modification systems and flagellar biosynthesis proteins. The strain B508A-T2A was the only one presenting the genotype vacA s1, and had the most distinct genome as it exhibited fewer shared genes, higher number of unique genes, and more polymorphisms were found in this genome. With all the accumulated information, no significant differences were found among the isolates regarding virulence and origin of the isolates. Nevertheless, some B508A-T2A genome characteristics could be linked to the pathogenicity of H. pylori.


mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Adria Carbo ◽  
Danyvid Olivares-Villagómez ◽  
Raquel Hontecillas ◽  
Josep Bassaganya-Riera ◽  
Rupesh Chaturvedi ◽  
...  

ABSTRACTThe development of gastritis duringHelicobacter pyloriinfection is dependent on an activated adaptive immune response orchestrated by T helper (Th) cells. However, the relative contributions of the Th1 and Th17 subsets to gastritis and control of infection are still under investigation. To investigate the role of interleukin-21 (IL-21) in the gastric mucosa duringH. pyloriinfection, we combined mathematical modeling of CD4+T cell differentiation within vivomechanistic studies. We infected IL-21-deficient and wild-type mice withH. pyloristrain SS1 and assessed colonization, gastric inflammation, cellular infiltration, and cytokine profiles. ChronicallyH. pylori-infected IL-21-deficient mice had higherH. pyloricolonization, significantly less gastritis, and reduced expression of proinflammatory cytokines and chemokines compared to these parameters in infected wild-type littermates. Thesein vivodata were used to calibrate anH. pyloriinfection-dependent, CD4+T cell-specific computational model, which then described the mechanism by which IL-21 activates the production of interferon gamma (IFN-γ) and IL-17 during chronicH. pyloriinfection. The model predicted activated expression of T-bet and RORγt and the phosphorylation of STAT3 and STAT1 and suggested a potential role of IL-21 in the modulation of IL-10. Driven by our modeling-derived predictions, we found reduced levels of CD4+splenocyte-specifictbx21androrcexpression, reduced phosphorylation of STAT1 and STAT3, and an increase in CD4+T cell-specific IL-10 expression inH. pylori-infected IL-21-deficient mice. Our results indicate that IL-21 regulates Th1 and Th17 effector responses during chronicH. pyloriinfection in a STAT1- and STAT3-dependent manner, therefore playing a major role controllingH. pyloriinfection and gastritis.IMPORTANCEHelicobacter pyloriis the dominant member of the gastric microbiota in more than 50% of the world’s population.H. pyloricolonization has been implicated in gastritis and gastric cancer, as infection withH. pyloriis the single most common risk factor for gastric cancer. Current data suggest that, in addition to bacterial virulence factors, the magnitude and types of immune responses influence the outcome of colonization and chronic infection. This study uses a combined computational and experimental approach to investigate how IL-21, a proinflammatory T cell-derived cytokine, maintains the chronic proinflammatory T cell immune response driving chronic gastritis duringH. pyloriinfection. This research will also provide insight into a myriad of other infectious and immune disorders in which IL-21 is increasingly recognized to play a central role. The use of IL-21-related therapies may provide treatment options for individuals chronically colonized withH. pylorias an alternative to aggressive antibiotics.


2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Asieh Bolandi ◽  
Saam Torkan ◽  
Iman Alavi

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.


2001 ◽  
Vol 45 (1) ◽  
pp. 306-308 ◽  
Author(s):  
Dong H. Kwon ◽  
Miae Lee ◽  
J. J. Kim ◽  
J. G. Kim ◽  
F. A. K. El-Zaatari ◽  
...  

ABSTRACT The prevalence of furazolidone, nitrofurantoin, and metronidazole resistance among Helicobacter pylori strains was assessed with 431 clinical isolates. Fifty-two percent were metronidazole resistant, compared to 2% (7 of 431) with resistance to furazolidone and nitrofurantoin. All seven furazolidone- and nitrofurantoin-resistant isolates were also metronidazole resistant.rdxA, frxA, and fdxB knockouts did not result in furazolidone or nitrofurantoin resistance. These data suggest that furazolidone and nitrofurantoin may be good alternatives to metronidazole for treating H. pylori infection.


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