scholarly journals Repeated out-of-Africa expansions of Helicobacter pylori driven by replacement of deleterious mutations

2021 ◽  
Author(s):  
Harry Thorpe ◽  
Elise Tourrette ◽  
Koji Yahara ◽  
Filipa Vale ◽  
Siqi Liu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
African Ancestry ◽  
Deleterious Mutations ◽  
Bacterial Populations ◽  
Synonymous Mutations ◽  
Anatomically Modern Humans ◽  
Population Sizes ◽  
Out Of Africa ◽  
H Pylori

All genomes mutate but the consequences of the resulting deleterious mutational load are poorly understood. Helicobacter pylori lives in the human stomach, has a higher mutation rate than most bacteria and has accompanied anatomically modern humans in migrations including the out-of-Africa expansion more than 50,000 years ago. H. pylori from East Asia have accumulated at least 500 more non-synonymous mutations than African strains, which we propose is due to reduced efficacy of selection during the out-of-Africa bottleneck. H. pylori from Europe and the Middle East trace a substantially higher fraction of ancestry from modern African populations than the humans that carry them, which we find is due to at least three separate admixture events. African ancestry is elevated at positions in the genome where non-synonymous mutations are at high frequency in Asia. We propose that this is due to replacement of deleterious mutations that accumulated during the bottleneck, with the high overall African ancestry proportion due to clonal expansion of strains of African origin. We use simulations to show that a Muller's ratchet like effect can lead to long-term segregation of deleterious mutations within bacterial populations after a bottleneck, despite high rates of homologous recombination, but that population fitness can be restored by migration of small numbers of bacteria from non-bottlenecked populations. Our results demonstrate that population bottlenecks can have long-term genomic and demographic consequences, even in species with enormous population sizes.

scholarly journals MALT lymphoma: epidemiology, clinical diagnosis and treatment

2018 ◽  
Vol 11 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Petruta Violeta Filip ◽  
◽  
Denisa Cuciureanu ◽  
Laura Sorina Diaconu ◽  
Ana Maria Vladareanu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
B Cell ◽  
Malt Lymphoma ◽  
Cell Lymphoma ◽  
Gastric Lymphoma ◽  
Eradication Therapy ◽  
B Cell Lymphoma ◽  
Gastric Malt Lymphoma ◽  
H Pylori

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

scholarly journals Identification of Markers for Helicobacter pylori Strains Isolated from Children with Peptic Ulcer Disease by Suppressive Subtractive Hybridization

2006 ◽  
Vol 74 (7) ◽  
pp. 4064-4074 ◽  
Author(s):  
Mónica Oleastro ◽  
Lurdes Monteiro ◽  
Philippe Lehours ◽  
Francis Mégraud ◽  
Armelle Ménard
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Subtractive Hybridization ◽  
Suppressive Subtractive Hybridization ◽  
Ulcer Disease ◽  
Lipopolysaccharide Biosynthesis ◽  
The Difference ◽  
H Pylori

ABSTRACT Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent. We used suppressive subtractive hybridization for comparative genomics between H. pylori strains isolated from a 5-year-old child with duodenal ulcer and from a sex- and age-matched child with gastritis only. The prevalence of the 30 tester-specific subtracted sequences was determined on a collection of H. pylori strains from children (15 ulcers and 30 gastritis) and from adults (46 ulcers and 44 gastritis). Two of these sequences, jhp0562 (80.0% versus 33.3%, P = 0.008) and jhp0870 (80.0% versus 36.7%, P = 0.015), were highly associated with PUD in children and a third sequence, jhp0828, was less associated (40.0% versus 10.0%, P = 0.048). Among adult strains, none of the 30 sequences was associated with PUD. However, both jhp0562 and jhp0870 were less prevalent in adenocarcinoma strains than in PUD strains from children and adults, the difference being statistically significant for jhp0870. In conclusion, two H. pylori genes were identified as being strongly associated with PUD in children, and their putative roles as an outer membrane protein for jhp0870 and in lipopolysaccharide biosynthesis for jhp0562, suggest that they may be novel virulence factors of H. pylori.

scholarly journals RECURRENCE RATE OF HELICOBACTER PYLORI IN PATIENTS WITH PEPTIC ULCER FIVE YEARS OR MORE AFTER SUCCESSFUL ERADICATION

2016 ◽  
Vol 53 (3) ◽  
pp. 152-155 ◽  
Author(s):  
Yuri Costa Farago FERNANDES ◽  
Gabriel da Rocha BONATTO ◽  
Mauro Willeman BONATTO
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Recurrence Rate ◽  
Early Recurrence ◽  
Peptic Ulcers ◽  
Ulcer Disease ◽  
Gastroduodenal Mucosa ◽  
H Pylori

ABSTRACT Background Infection with Helicobacter pylori is highly prevalent worldwide, especially in developing countries. Its presence in the gastroduodenal mucosa is related with development of peptic ulcer and other illnesses. The eradication of H. pylori improves mucosal histology in patients with peptic ulcers. Objective This study was aimed to verify if H. pylori recurrence occurs five years or more after confirmed eradication in patients with peptic ulcer. Moreover, we sought to determine the recurrence rate. Methods Retrospective and longitudinal, this study was based on a sample of 201 patients from western Paraná, Brazil. The patients were diagnosed with peptic ulcer disease, in the period of 1990-2000, and followed for five years or more after successful H. pylori eradication. Patients with early recurrence - prior to five years after eradication - were excluded from the sample. Results During an average follow-up of 8 years, 180 patients (89.55%) remained negative, and 21 (10.45%) became positive for H. pylori infection. New ulcers appeared in two-thirds of the patients with H. pylori recurrence. Conclusion The recurrence of H. pylori in patients with peptic ulcer can occur in the long-term - even if the infection had been successfully eradicated and the patients had remained free of recurrence in the first years of follow-up.

scholarly journals Effects of eradication of Helicobacter pylori on oral malodor and the oral environment: a single-center observational study

2020 ◽  
Author(s):  
Nao Suzuki ◽  
Richiko Beppu ◽  
Masahiro Yoneda ◽  
Toru Takeshita ◽  
Mikari Asakawa ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Test Score ◽  
Dimethyl Sulfide ◽  
Oral Microbiota ◽  
Clinical Parameters ◽  
Oral Malodor ◽  
Bacterial Composition ◽  
Bacterial Populations ◽  
Organoleptic Test ◽  
H Pylori

Abstract Objective: Although a relationship between Helicobacter pylori and oral malodor has been suggested, it remains to be confirmed. One reason for this is that many studies assess oral malodor subjectively. Another reason for the uncertainty is that the reduction in oral malodor may be due to the effect of antibiotics on the oral microbiota. In this study, changes in oral malodor after eradication of H. pylori were investigated by organoleptic test and gas chromatography. In addition, the salivary bacterial composition and clinical parameters were analyzed.Results: The organoleptic test score, hydrogen sulfide and dimethyl sulfide concentrations, and all clinical parameters except for tongue-coating score were significantly decreased at 1 week compared with baseline. On the date that H. pylori was determined to have been eradicated from all of the subjects (7 weeks after treatment), only the organoleptic test score was significantly lower compared with baseline. Although the overall composition of the salivary bacterial populations was altered by antibiotic treatment, they had recovered at 7 weeks. Therefore, it is possible that the levels of odorous components other than volatile sulfur compounds related to oral malodor were decreased by H. pylori eradication.

scholarly journals Eradication of Helicobacter pylori may improve dyspepsia in the elderly for the long term

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ikko Tanaka ◽  
Shoko Ono ◽  
Yoshihiko Shimoda ◽  
Masaki Inoue ◽  
Sayoko Kinowaki ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Elderly Patients ◽  
Epigastric Pain ◽  
Eradication Therapy ◽  
The Elderly ◽  
Long Term Effects ◽  
Postprandial Fullness ◽  
Abdominal Symptoms ◽  
H Pylori

Abstract Background Therapy for eradication of Helicobacter pylori (H. pylori) improves symptoms of H. pylori-associated dyspepsia (HPD), but the effects of eradication in elderly patients are unclear. The aim of our study was to investigate dyspepsia symptoms and long-term effects of eradication in elderly patients. Methods This retrospective study included 496 patients who received H. pylori eradication therapy. The patients were divided into a group of elderly patients (group E: ≧ 65 years old) and a group of non-elderly patients (group N: < 65 years old). Abdominal symptoms were evaluated using a questionnaire about abdominal symptoms before eradication and after eradication (1–2 months and more than one year). Dyspepsia was defined as a score of 4 points or more for at least one of 4 items (postprandial fullness, early satiety, epigastric pain, and hunger pain). Improvement of symptoms was defined on the basis of changes in Global Overall Systems scores. Results There were no differences in abdominal symptoms before eradication between the two groups. Successful eradication improved symptoms in patients with dyspepsia within 2 months (in 75.6% (56/74) of the patients in group N and in 64.5% (20/31) of the patients in group E). The questionnaire showed that 80% (32/40) of the patients in group N and 60% (12/20) of the patients in group E had long-term relief of dyspepsia. The scores for abdominal symptoms in group E continued to improve for a mean period of 54.8 months after eradication. Conclusions Eradication of H. pylori age-independently improved dyspepsia symptoms for the long term.

scholarly journals Mass eradication of Helicobacter pylori to reduce gastric cancer incidence and mortality: a long-term cohort study on Matsu Islands

Gut ◽  
2020 ◽  
pp. gutjnl-2020-322200 ◽  
Author(s):  
Tsung-Hsien Chiang ◽  
Wei-Jung Chang ◽  
Sam Li-Sheng Chen ◽  
Amy Ming-Fang Yen ◽  
Jean Ching-Yuan Fann ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Cancer Incidence ◽  
Control Period ◽  
Eradication Therapy ◽  
Incidence Rates ◽  
Long Term Effects ◽  
Incidence And Mortality ◽  
H Pylori

ObjectiveAlthough mass eradication of Helicobacter pylori has been proposed as a means to eliminate gastric cancer, its long-term effects remain unclear.DesignMass eradication of H. pylori infection was launched in 2004 and continued until 2018 for a high-risk Taiwanese population aged 30 years or older dwelling on Matsu Islands with prevalent H. pylori infection. Test positives for the 13C-urea breath test underwent eradication therapy. We evaluated the effectiveness of the mass eradication in reducing two main outcomes, incidence and mortality rates of gastric cancer, until the end of 2016 and 2018, respectively.ResultsAfter six rounds of mass screening and eradication, the coverage rate reached 85.5% (6512/7616). The referral rate for treatment was 93.5% (4286/4584). The prevalence rates of H. pylori fell from 64.2% to 15.0% with reinfection rates of less than 1% per person-year. The presence and severity of atrophic gastritis and intestinal metaplasia also decreased with time. Compared with the historical control period from 1995 to 2003, the effectiveness in reducing gastric cancer incidence and mortality during the chemoprevention period was 53% (95% CI 30% to 69%, p<0.001) and 25% (95% CI −14% to 51%, p=0.18), respectively. No significant changes were noted in the incidence rates of other digestive tract cancers or the antibiotic resistance rate of H. pylori.ConclusionPopulation-based eradication of H. pylori has significantly reduced gastric cancer incidence with no increase in the likelihood of adverse consequences. A significant reduction in mortality is likely to be achieved with a longer follow-up period.Trial registration numberNCT00155389

scholarly journals Dynamics of Helicobacter pylori infection as a determinant of progression of gastric precancerous lesions: 16-year follow-up of an eradication trial

Gut ◽  
2017 ◽  
Vol 67 (7) ◽  
pp. 1239-1246 ◽  
Author(s):  
Robertino M Mera ◽  
Luis E Bravo ◽  
M Constanza Camargo ◽  
Juan C Bravo ◽  
Alberto G Delgado ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Linear Models ◽  
Precancerous Lesions ◽  
Gastric Lesions ◽  
Logistic Regression Models ◽  
Risk Of Progression ◽  
H Pylori ◽  
Cumulative Time

ObjectiveTo evaluate the long-term effect of cumulative time exposed to Helicobacter pylori infection on the progression of gastric lesions.Design795 adults with precancerous gastric lesions were randomised to receive anti-H. pylori treatment at baseline. Gastric biopsies were obtained at baseline and at 3, 6, 12 and 16 years. A total of 456 individuals attended the 16-year visit. Cumulative time of H. pylori exposure was calculated as the number of years infected during follow-up. Multivariable logistic regression models were used to estimate the risk of progression to a more advanced diagnosis (versus no change/regression) as well as gastric cancer risk by intestinal metaplasia (IM) subtype. For a more detailed analysis of progression, we also used a histopathology score assessing both severity and extension of the gastric lesions (range 1–6). The score difference between baseline and 16 years was modelled by generalised linear models.ResultsIndividuals who were continuously infected with H. pylori for 16 years had a higher probability of progression to a more advanced diagnosis than those who cleared the infection and remained negative after baseline (p=0.001). Incomplete-type IM was associated with higher risk of progression to cancer than complete-type (OR, 11.3; 95% CI 1.4 to 91.4). The average histopathology score increased by 0.20 units/year (95% CI 0.12 to 0.28) among individuals continuously infected with H. pylori. The effect of cumulative time of infection on progression in the histopathology score was significantly higher for individuals with atrophy (without IM) than for individuals with IM (p<0.001).ConclusionsLong-term exposure to H. pylori infection was associated with progression of precancerous lesions. Individuals infected with H. pylori with these lesions may benefit from eradication, particularly those with atrophic gastritis without IM. Incomplete-type IM may be a useful marker for the identification of individuals at higher risk for cancer.

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