scholarly journals Helicobacter pylori. The survival strategy of a commensal symbiont in the Homo sapiens population

2021 ◽  
pp. 102-108
Author(s):  
E. B. Avalueva ◽  
M. Yu. Serkova ◽  
S. I. Sitkin
Keyword(s):  
Helicobacter Pylori ◽  
Homo Sapiens ◽  
Survival Strategy ◽  
H Pylori

Несмотря на крайне высокую степень инфицированности Helicobacter pylori в популяции Homo sapiens, подавляющее большинство инфицированных являются бессимптомными носителями. Широкое распространение инфекции H. pylori среди лиц без признаков патологии и низкая заболеваемость при хронической колонизации слизистой оболочки желудка указывают на то, что H. pylori с большей вероятностью является условно-патогенным микроорганизмом или патобионтом. Популяционная ликвидация инфекции H. pylori существенно снизила заболеваемость инфекцией H. pylori, однако появление устойчивости к противомикробным препаратам привело к их неэффективности.

scholarly journals Shedding Light on the African Enigma: In Vitro Testing of Homo sapiens-Helicobacter pylori Coevolution

2021 ◽  
Vol 9 (2) ◽  
pp. 240
Author(s):  
Bruno Cavadas ◽  
Marina Leite ◽  
Nicole Pedro ◽  
Ana C. Magalhães ◽  
Joana Melo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Host Response ◽  
Homo Sapiens ◽  
European Ancestry ◽  
Genome Wide ◽  
Expression Host ◽  
H Pylori ◽  
Human Ancestry

The continuous characterization of genome-wide diversity in population and case–cohort samples, allied to the development of new algorithms, are shedding light on host ancestry impact and selection events on various infectious diseases. Especially interesting are the long-standing associations between humans and certain bacteria, such as the case of Helicobacter pylori, which could have been strong drivers of adaptation leading to coevolution. Some evidence on admixed gastric cancer cohorts have been suggested as supporting Homo-Helicobacter coevolution, but reliable experimental data that control both the bacterium and the host ancestries are lacking. Here, we conducted the first in vitro coinfection assays with dual human- and bacterium-matched and -mismatched ancestries, in African and European backgrounds, to evaluate the genome wide gene expression host response to H. pylori. Our results showed that: (1) the host response to H. pylori infection was greatly shaped by the human ancestry, with variability on innate immune system and metabolism; (2) African human ancestry showed signs of coevolution with H. pylori while European ancestry appeared to be maladapted; and (3) mismatched ancestry did not seem to be an important differentiator of gene expression at the initial stages of infection as assayed here.

scholarly journals A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas

2020 ◽  
Vol 15 (1) ◽  
pp. 78-92 ◽  
Author(s):  
Zilia Y. Muñoz-Ramirez ◽  
Ben Pascoe ◽  
Alfonso Mendez-Tenorio ◽  
Evangelos Mourkas ◽  
Santiago Sandoval-Motta ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Genes ◽  
Homo Sapiens ◽  
Gene Families ◽  
Human Populations ◽  
Common Component ◽  
Network Analyses ◽  
The Face ◽  
H Pylori ◽  
Genome Analyses

AbstractHelicobacter pylori is a common component of the human stomach microbiota, possibly dating back to the speciation of Homo sapiens. A history of pathogen evolution in allopatry has led to the development of genetically distinct H. pylori subpopulations, associated with different human populations, and more recent admixture among H. pylori subpopulations can provide information about human migrations. However, little is known about the degree to which some H. pylori genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed H. pylori genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723 H. pylori strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from H. pylori populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American H. pylori subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.

scholarly journals Coevolución genética Homo sapiens-Helicobacter pylori y sus implicaciones en el desarrollo del cáncer gástrico: una revisión sistemática

2017 ◽  
Vol 31 (4) ◽  
pp. 376 ◽  
Author(s):  
Alix Andrea Guevara ◽  
John Jairo Suárez ◽  
Angel Criollo ◽  
Mabel Elena Bohórquez ◽  
María Magdalena Echeverry de Polanco
Keyword(s):  
Helicobacter Pylori ◽  
Critical Appraisal ◽  
Homo Sapiens ◽  
H Pylori ◽  
Critical Appraisal Skills

Helicobacter pylori (H. pylori), clasificada como carcinógeno tipo I para cáncer gástrico (CG), ha acompañado al hombre al menos desde hace 116 000 años. Los conocimientos de las fuerzas evolutivas que modulan el rol de esta bacteria en el desarrollo del espectro de enfermedades gástricas son aún escasos. Esta revisión sistemática recopila artículos que reportan un proceso de coevolución, relacionan los componentes ances- trales huésped-hospedero y describen mecanismos adaptativos de H. pylori al entorno gástrico humano, con el fin de comprender si el proceso de coevolución modula la patogenicidad de la bacteria y el desarrollo de enfermedades gástricas. Se realizó una búsqueda sistemática en las bases de datos electrónicas: MEDLINE (OvidSP), Scopus (ScienceDirect), Scielo y Tree of Science (ToS); términos de búsqueda: “stomach”, “can- cer”, “neoplasms”, “ethinicity”, “evolution”, “genetics”, “ancestry” y “Helicobacter pylori”. Idiomas: inglés y es- pañol. Los datos fueron filtrados por un revisor utilizando un formulario estándar de extracción y ulteriormente revisados por otro. El riesgo de sesgo y la calidad metodológica de los estudios fueron evaluadas con el programa: Critical Appraisal Skills Programme (CASP). Del total de 1584 estudios, 36 cumplieron los criterios de inclusión. Los factores más relevantes en el desarrollo del espectro de enfermedades asociadas con la infección por H. pylori son: la disrupción en el proceso de coevolución entre la bacteria y su huésped humano –por la transferencia horizontal de segmentos de genes que no han evolucionado con sus anfitriones–; las sustituciones de aminoácidos; la fijación y la selección positiva principalmente en las regiones hipervariables. 

The rod-to-coccoid body transformation in cultures of Helicobacter pylori

1990 ◽  
Vol 48 (3) ◽  
pp. 626-627
Author(s):  
A. R. Crooker ◽  
W. G. Kraft ◽  
T. L. Beard ◽  
M. C. Myers
Keyword(s):  
Helicobacter Pylori ◽  
Growth Cycle ◽  
Negative Bacterium ◽  
Body Formation ◽  
Coccoid Form ◽  
Spiral Form ◽  
Prolonged Culture ◽  
H Pylori ◽  
Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

Peptische Ulzera und Helicobacter pylori: Wie wir wissen, was wir wissen

2015 ◽  
Vol 72 (7) ◽  
pp. 475-480
Author(s):  
Raphael Scholl
Keyword(s):  
Helicobacter Pylori ◽  
Kontrollierte Studie ◽  
H Pylori ◽  
Peptische Ulzera

Zusammenfassung. Zu den wichtigsten Ursachen peptischer Ulzera gehört das Bakterium Helicobacter pylori. Aber wie wurde dieser ursächliche Zusammenhang nachgewiesen? Aufschluss darüber gibt die Geschichte und Theorie einer Reihe einschlägiger Studien, die in den 1980er Jahren durchgeführt wurden. Am Anfang stand die Entdeckung einer blossen Korrelation zwischen dem neu entdeckten Bakterium und peptischen Ulzera in Magenbiopsien. Unklar blieb, ob das Bakterium die Krankheit verursachte, oder ob es bloss eine opportunistische bakterielle Besiedlung darstellte. Ohne Tiermodell war der experimentelle Nachweis der Richtung der Verursachung jedoch schwierig: Zwar wurde in einem couragierten Selbstversuch mit einer geschluckten Bakterienkultur eine Gastritis beobachtet – aber der Einzelfall war wenig aussagekräftig. Die Schwächen des Selbstversuchs liessen sich durch eine randomisierte, Plazebo-kontrollierte Studie beheben, die den Anforderungen des dritten Koch’schen Postulats gerecht wurde. Darüber hinaus war es notwendig, erste Aufschlüsse über den Mechanismus der ursächlichen Verbindung zwischen H. pylori und peptischen Ulzera zu gewinnen: Wie zum Beispiel kann das Bakterium im sauren Milieu des Magens überleben? Die wissenschaftshistorische und wissenschaftstheoretische Betrachtung des Falls illustriert, wie medizinisches Wissen schrittweise aufgebaut wird.

Helicobacter-pylori-Infektion

2011 ◽  
Vol 11 (05) ◽  
pp. 271-276
Author(s):  
G. Flemming
Keyword(s):  
Helicobacter Pylori ◽  
H Pylori

ZusammenfassungInfektionen mit Helicobacter pylori zählen zu den häufigsten chronischen bakteriellen Infektionen bei Menschen. Es zeigen sich deutliche geografische Unterschiede in der Prävalenz. In den westlichen Industrienationen nimmt die Infektionsrate seit den letzten Jahrzehnten ab. Die Infektion mit H. pylori erfolgt meist in der ersten Lebensdekade. Die Infektion kann lebenslang persistieren, wenn keine antibiotische Eradikation erfolgt. H.-pylori-Infektionen können diverse Erkrankungen hervorrufen, dazu gehören das Ulkus ventrikuli, Ulkus duodeni, das Magenkarzinom und das Lymphom des Mukosa-assoziierten lymphatischen Gewebes (MALT-Lymphom). Die Gefahr der malignen Entartung ist bei Kindern wesentlich geringer als bei Erwachsenen. Ein großes Problem stellen die zunehmenden Antibiotikaresistenzen dar. Daher sollte die Therapie möglichst immer nach Sensibilitätstestung erfolgen. Eine Eradikationskontrolle mittels non-invasiver Testung empfiehlt sich binnen vier bis acht Wochen nach Therapieende.

Роль лекарственных взаимодействий в эффективности и безопасности кларитромицина при эрадикации Helicobacter pylori

2019 ◽  
Vol 53 (8) ◽  
pp. 8-10
Author(s):  
Светлана Юрьевна Сереброва ◽  
Елена Николаевна Карева ◽  
Наталия Николаевна Еременко ◽  
Алексей Борисович Прокофьев ◽  
Дарья Олеговна Кургузова ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
H Pylori

В обзорной статье описаны современные риски резистентности, нежелательных лекарственных реакций и лекарственных взаимодействий кларитромицина при его применении в качестве компонента терапевтических схем эрадикации H. pylori. Кислотонеустойчивость кларитромицина в кислой среде определяет зависимость фармакологических свойств препарата от эффективности ингибиторов протонной помпы, что может быть одной из причин резистентности возбудителя к макролиду. Потенциал лекарственных взаимодействий кларитромицина связан c его способностью метаболизироваться с помощью CYP3A4 и мощно ингибировать этот фермент.

Increased Production of Matrix Metalloproteinases in Helicobacter pylori Infection that Stimulates Gastric Cancer Stem Cells

2020 ◽  
Keyword(s):  
Gastric Cancer ◽  
Stem Cells ◽  
Helicobacter Pylori ◽  
Cancer Stem Cells ◽  
Histopathological Examination ◽  
Physiological Saline ◽  
Rrna Gene ◽  
Peptic Ulcers ◽  
Gastric Cancer Stem Cells ◽  
H Pylori

Background and aim: Helicobacter pylori (H. pylori) is an incriminated pathogen causing diseases in both animals and humans and considered a zoonotic pathogen. H. pylori infection is considered a cause of gastric cancer, which rests a significant health care challenge. This study analyzes the expression pattern of matrix metalloprotein 2 (MMP-2) in patients with Helicobacter pylori-associated gastritis and the effect of H. pylori on gastric cancer stem cells, as well as study the role of helicon bacteriosis in dog in transmission of H. pylori infection to human. Materials and methods: Fifty-five of each sample (gastric biopsy, blood and stool) were collected from patients suffering from dyspepsia, chronic vomiting and perforated peptic ulcers and also from apparent healthy dogs. The investigation detected H. pylori by serological and histopathological examination. Biopsies were stored in physiological saline for identification of H. pylori by conventional time PCR. MMP-2 and Gastric cancer stem cells were then identified by immunohistochemistry. Results: Serological identification for H. pylori Antigen and Antibodies revealed (63% human, 50% dogs) and (87% human, 90% dogs) respectively were positive. Genotyping of H. pylori based on 16S rRNA gene showed 54.5% of human and 35% of dogs were positive. Immunohistochemistry revealed strong expression of CD44 in H. pylori- associated gastric cancer cases, MMP-2 expression was observed in all neoplastic lesions associated with H. pylori infection. Conclusion: H. pylori infection affects gastric mucosa and induces changes in gastric stem cells altering their differentiation and increased expression of MMP’s and CD44with a resultant potentiation of oncogenic alteration. In addition the up-regulation of both markers could be an instrumental to interpret the origination of gastric cancer.

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