CC BY
35
GENETIC VARIANTS OF H.pylori IN DIFFERENT FORMS OF CHRONIC GASTRITIS
N. V. Neumoina1, E.I. Efimov1, K.M. Perfilova1, I.V. Shutova1, M.V. Neumoina1, T.A. Troshina1, T.Yu. Butina1, I.V. Kuznetsova1, M.A. Semaka1'2
1 Academician I.N. Blokhina Nizhny Novgorod Scientific Research Institute of Epidemiology and Microbiology, 71 Malaya Yamskaya Street, Nizhny Novgorod, 603950, Russia
2 Federal State Budgetary Educational Institution of Higher Education «Privolzhsky Research Medical University» of the Ministry of Health of the Russian Federation (FSBEI HE PRMU MOH Russia)
Abstract. The development of clinical forms of infection and endoscopic changes in the gastric mucosa depends on the H.pylori genetic diversity in a given region. The aim of this work was to study the relationship of the genetic profile of H.pylori pathogenicity factors with clinical and endoscopic features of Helicobacter-associated gastritis in Nizhny Novgorod. A number of H.pylori pathogenicity genes of DNA isolates obtained by endoscopy from 151 patients with chronic H.pylori-associated gastritis (non-destructive, erosive, and atrophic) were studied by PCR. Results. In destructive processes in the gastric mucosa, the detection frequency of cagA, vacA si ml genes and a combination of several pathogenicity factors, including ice A A1 and bab A was higher than in other forms of gastritis. Atrophic gastritis is characterized by the genetic profile cagA and vacA s2 m2. Infection with several H.pylori strains is determined more often in erosive gastritis and atrophy of the gastric mucosa. Conclusions. In chronic gastritis in Nizhny Novgorod, a predominantly "European" character of the pathogen population structure was revealed - with a moderate content of the most pathogenic cagA, vacA s1-positive strains. Colonization of the gastric mucosa by H.pylori with a genetic structure containing pathogenicity factors cagA, vacA, babA, ice A2, in chronic H.pylori-associated diseases, it is a factor in increasing the severity, activity and prevalence of the inflammatory process, the appearance of signs of atrophy of the gastric mucosa. The greatest influence on these indicators is exerted by the presence of cagA and vacA s1 in the microorganism genome, as well as a combination of several pathogenicity factors.
Keywords: Helicobacter pylori, genes of pathogenicity, genetic structure, chronic gastritis
List of abbreviations
Helicobacter pylori - H.pylori Polymerase chain reaction - PCR Pathogenicity island - PAI Cytotoxin-associated gene - cag Vacuolating associated cytotoxin - vac Blood group associated binding gene - bab Induced by contact with epithelium gene - ice
Introduction
H. pylori infection is one of the most common chronic human infections. According to various data, this infection ranges between 85% and 95% in developing countries in Asia and Africa, between 40% and 80% in Eastern Europe and South America, and between 25% and 40% in developed countries in Europe and North America (Maev et al., 2016; Hooi et al., 2017; Mahachai et al., 2018). H. pylori can persist in the stomach and areas of gastric metaplasia in the human duodenum, causing various forms of infection from asymptomatic infection
up to type B gastritis and peptic ulcer disease, provoking the development of adenocarcinoma or gastric lymphoma (Maev et al., 2016; Hooi et al., 2017; Mahachai et al., 2018; Kpoghomou et al., 2020).
In recent decades, changes in the structure of H. pylori-associated pathology have been detected all over the world, and in Russia, there was a significant reduction in both general and primary incidence of gastric and duodenal ulcers (Baranovsky et al., 2019; Malfertheiner et al., 2018). According to the Federal state statistics service of Russia in 2017, the peptic ulcers among Russians decreased from 1047.0 per 100,000 population in 2010 to 848.3 in 2016 (Health in Russia, 2017). 90-95% of stomach ulcer cases and at least 70-75% of duodenal ulcer cases continue to be associated with H. pylori. So, according to D. S. Borodin et al., in Moscow by 2016, compared with 1994, the incidence of peptic ulcer disease decreased by 77%, and its prevalence-by 64% (Bordin et al., 2018). At the same time, there was an increase
N. V. Neumoina,
in the incidence of gastritis and duodenitis (1.2 times), including those associated with H. pylori infection (Konovalov & Varenova, 2015; Lazareva & Gordeeva, 2017). In addition, the proportion of more severe and prognostically unfavorable forms (erosive, subatrophic, and atrophific) increased by 2.5 times (Avdeeva et al., 2009; Lazareva & Gordeeva, 2017). Long -term H. pylori infection is a risk factor for disruption of regenerative processes in the gastric mucosa, with the development of atrophy manifested in the early stages: 2 years after infec-tion-in 6% of patients, and 10 years later - in 43% of patients (Evsyutina, 2016; Okuda et al., 2016; Nimish et al., 2017).
It is known that the H. pylori infection is not always associated with clinical manifestations. The development variant of any form of H. pylori infection depends on a number of factors, including, first of all, virulent and pathogenic properties of the bacteria strain, immunogenetic characteristics of the host, as well as social and living (Yokota et al., 2015; Mamishi et al., 2016; Hooi, 2017; Bordin et al., 2018; Ofori et al., 2019; Hong-Ming Zhu et al., 2020).
The development, course features, frequency and severity of relapses and success of etiotropic therapy of chronic H. pylori-associated pathology may be due to the presence of certain Helicobacter genotypes in humans. For a number of years, intensive studies of H. pylori genetic diversity have been conducted abroad, and attempts have been made to identify correlations between infection with certain genotypes of this microorganism and human health indicators (Sedaghat et al., 2014; Dadashzadeh K. et al., 2015; Mamishi, 2016).
The greatest interest is the study of a number of genes encoding the production of toxins -virulence factors of the microorganism. These include cagA, vacA, babA, iceA genes and some others.
In the genome of any strain, there is a vac A gene responsible for the production of vacuolat-ing cytotoxin VacA. This toxin increases the production of pepsinogen, reduces the secretion of hydrochloric acid in the stomach and cell proliferation, damages lysosomes and mitochondria, and disrupts the cytoskeleton of gas
tric epithelial cells. The toxin VacA contributes to the nutrition of the bacterial cell, damaging the intercellular contacts in the stomach epithelium and facilitating the transport of small molecules through the cell membranes. Vacuolating cytotoxin A acts on type 5 ATP-ase and acidifies the internal environment of gastric epithelial cells, which ensures the flow of ammonia and other substances from the extracellular space into the epithelial cells, which attract water. As a result, vacuoles swell, which leads to rupture of the cell membrane and cell death. The formation of a cytotoxin protein depends on the composition of the vacA. This gene has three regions: s -signal, i - intermediate and m -middle. Each region includes 2 alleles: the signal s-region - s1 and s2, intermediate i-region -i1 and i2, middle m-region - m1 and m2. The activity of the vacuolating toxin production is determined by the composition of the vacA gene and causes differences in cytotoxic activity between strains (Isaeva & Valieva, 2018). H. pylori strains containing the region s1 vacA, depending on the presence of the region m1 and m2, produce the largest and average amount of cytotoxin and have the ability to colonize the gastric mucosa at a high density. The development of peptic ulcer disease, as well as stomach cancer is associated with the infection with H.pyroli strains containing vacAs1m1 variant (Sedaghat et al., 2014; Dadashzadeh, 2015; Maev et al., 2016; Isaeva & Valieva, 2018; Venneman et al., 2018).
The cagA gene is found only in H. pylori, but is not present in all strains. This gene is one of the main factors of pathogenicity, and indicates the presence of the PAI pathogenicity in this strain. It encodes the CagA protein responsible for the production of pro-inflammatory cytokines, the induction of inflammation and disruption of gastric mucosal epithelium integrity, the induction of uncontrolled proliferation of epithelial and lymphoid cells. The gene has allelic variations that occur in different countries of the world, and depending on the gene subtypes, H.pylori pathogenic properties and resistance to gastric acid, and according to some data, to a number of antibiotics vary (Kusters et al., 2006; Sedaghat et al., 2014; Da-
dashzadeh et al., 2015; Isaeva & Valieva, 2018).
The babA gene encodes the formation of a protein in the blood (the blood group antigen binding adhesion). Sialic acids, glycolipids, sulfogroups of glycoproteins, phospholipids, and fucose Lewis-like antigens are used as adhesion receptors. Due to the interaction of the ligands of the microorganism with the corresponding receptors of the gastric epithelium, adhesion occurs. In addition, microbes can also bind to connective tissue collagen. The babA gene induces the production of interleukin-8, the formation of which increases in proportion to the density of colonization. 3 alleles of the babA gene (babA1, babA2, babA3) were detected. The presence of babA1 and babA2 in the genome of H.pylori is associated with a higher incidence of duodenal ulcer, and the detection of babA2 - as well as with gastric ade-nocarcinoma (Sedaghat et al., 2014; Miftahus-surur et al., 2015; Dadashzadeh et al., 2015; Isaeva & Valieva, 2018).
The expression of the iceA gene (induced by contact with epithelium) was upregulated on contact between H. pylori and human epithelial cells. There are at least two alleles of ice A: iceA1, and iceA2. IceA1 gene is more commonly detected in Asian countries, and iceA2 gene - in Western countries. The role of this gene in the pathogenesis of gastric diseases is not fully understood. Some studies have shown that regardless of cagA status in the presence of iceA1 neutrophil infiltration of the lamina propria of gastric mucosa and the inter-leukin-8 expression enhance, acute inflammation up to the gastric ulcer occurs (Sedaghat et al., 2014; Dadashzadeh, 2015; Isaeva & Valieva, 2018).
To determine the virulence genes is important both for deciphering the mechanism for the development of an infectious process, and for studying the ways of spread of H.pylori in the population (Ivashkin et al., 2013; Zhebrun et al., 2014). The study of the virulence genes of H.pylori isolates from patients living in different regions, their prognostic significance, and the genotypic map creation are regarded as determining directions in epidemiology and the
development of indications for the treatment of
H.pylori infection.
The aim of this work was to study the relationship of the genetic profile of H. pylori pathogenicity factors with clinical and endoscopic features of Helicobacter-associated gastritis in Nizhny Novgorod.
Methods
The work was performed on the basis of the infectious diseases clinic of the Academician
I.N. Blokhina Nizhny Novgorod Scientific Research Institute of Epidemiology and Microbiology: including selection, clinical and laboratory instrumental examination and treatment of patients, interpretation and analysis of results. All patients gave informed voluntary consent to the examination and inclusion of the obtained data in scientific work.
The basic comprehensive examination of patients included clinical diagnostics, instrumental and laboratory tests in accordance with the Standards (protocols) for the diagnosis and treatment of patients with digestive diseases (Standard, 2004; Standard, 2012) and clinical recommendations (Ivashkin et al., 2018; Lazeb-nik et al., 2017).
Instrumental diagnostics included esoph-agogastroduodenoscopy using Olympus Video endoscopes Gif-E150 and H-180, sampling of biopsy material and gastric juice.
For molecular genetic identification of H.pylori (H.pylori DNA and cagA, vacA, babA, iceA genes), the PCR method was used, as described earlier (Perfilova et al., 2016). DNA isolates were obtained from the primary biological material. Commercial and experimental test systems (manufactures «LITECH» - Moscow and «Vector-best») were used in the work. In the structure of the vacA gene, allelic types were determined: allelic types s1 and s2, as well as m1 and m2, in the structure of the ice A gene - allelic types A1 and A2.
In this work, the genetic profile of H.pylori DNA isolates obtained from 151 patients (70 men and 81 women aged 18 to 60 years) with different types of diseases of the stomach and duodenum was investigated. Endoscopic examination revealed active gastritis in 76 patients
without violating the gastric mucosa integrity, in 28 patients with single or multiple erosions of the gastric mucosa and / or duodenal ulcer and non-atrophic gastritis, in 11 - duodenal ulcer and non-atrophic gastritis.
Statistical processing of research results was performed using the program «Statistica» version 6.0 and statistical functions of the Exel program according to standard formulas (Glantz, 1998). The significance of differences was evaluated using nonparametric methods of Pearson (x2) and Fisher. Differences were considered significant at p < 0.05.
The methodology and results were approved by the ethics Committee of the Academician I.N. Blokhina Nizhny Novgorod Scientific Research Institute of Epidemiology and Microbiology.
Results
The study found 22 different combinations of genetic markers of H.pylori virulence factors. The proportion of patients from whom cagA-positive isolates were obtained was 47.7±4.0%. The vacA gene was revealed in different allelic variants in all the examined patients. The proportion of patients with vac As1 strains was accounted for 62.2±3.9%, with va-cAs2 strains - for 39.7±3.9%. The frequency of detection of strains with the vac Am1 genotype was 29.8±3.7%, the vacAml genotype was found in 55.6±4.0% of cases. 42.4±3.9% of isolates DNA were iceAl positive, 28.5±3.7% -iceA2 positive. The babA-positive genotype was detected in 4.6% of patients, mainly with destructive pathology. The genetic profile of virulence factors in patients with peptic ulcer disease and erosive gastritis and duodenitis was similar, which allowed combining these groups. The results of identifying individual genes and their alleles are shown in table 1.
Only one copy of the vacA gene can be present in the genome, so the registration of genotypes containing alleles m1 and m2 or s1 and s2 at the same time in one patient indicates the presence of more than one strain in the clinical sample.
In the examined patients, mixed vacA genotypes of H.pylori were detected quite often -
24.8 ± 3.3% in DNA isolates. Of these, 13.2 ± 2.7% were vacA m1 + m2 variants, and
11.9 + 2.6% were vacA s1 + s2 variants. In general, the vacAm2 and vacAs1 genes were most frequently detected in the group, and cagA and iceA1 were slightly less frequently detected. All 4 allelic variants of the vacA gene were found in 5 patients (4.8%). The detection frequency of cagA, vacA s1 and vacA m2, in peptic ulcer disease and erosive gastritis was higher than in non-destructive gastritis. The vacA m1 and iceA2 genes were detected almost 2 times more often in patients with erosive and ulcerative pathology. However, there were no statistically significant differences in the frequency of detection of certain genes in the examined groups of patients at the present stage of research.
In most cases of destructive gastroduodenal pathology, the cagA vacA s1 m1 genotype was detected, as well as high frequency of infection with at least two strains, and a combination of more than two virulence factor genes. According to the literature, H.pylori with the cagA vacA s1 m1 genome is considered highly pathogenic and has the greatest ability to produce toxins (Sedaghat et al., 2014; Dadashzadeh et al., 2015; Maev et al., 2016; Isaeva & Valieva, 2018). In this study, clinical and endoscopic manifestations of the disease were compared in 2 groups of patients: the first group (main group)-32 patients with gastroduodenal diseases associated with highly pathogenic H. pylori, the second group - 35 patients with H. pylori associated gastroduodenitis, in the genome of which only virulence factors vacA s2 and m2 were found. Statistically significant intergroup differences in the endoscopic picture of the gastric and duodenal mucosa were obtained (table 2).
It was found that colonization of the gastric mucosa by highly pathogenic H. pylori strains leads to the damage area extension. Chronic inflammation in the subcardia was registered in 25% of the main group against 8.6% in the comparison group (p < 0.05), and pangastritis was detected in them more than 4 times more often (34.4% against 8.6%, p < 0.01). Macroscopi-cally, inflammation in the gastric mucosa
Table 2
Comparative characteristics of the clinical and endoscopic picture in patients with the identification of highly pathogenic and weakly pathogenic H.pylori
Table 1
Genetic profile of H.pylori in examined groups (%)
Genes and alleles Total n = 151 Ulcer disease/erosive gastritis n = 39 Non-destrictive antral gastritis/duodenitis n = 76 Atrophic gastritis n = 36
Cag A 47,7 ± 4,0 66,7 ± 7,5 38,2 ± 5,6 47,2 ± 8,3
vacA si 62,2 ± 3,9 71,8 ± 7,2 63,1 ± 5,5 50,0 ± 8,3
s2 39,7 ± 3,9 43,6 ± 6,2 31,6 ± 5,3 52,8 ± 8,3
si + s2 11,9 ± 2,6 20,5 ± 6,4 5,3 ± 2,5 i6,7 ± 6,2
mi 29,8 ± 3,7 53,8 ± 7,9 21,1 ± 4,6 25,0 ± 7,2
m2 55,6 ± 4,0 46,1 ± 8,0 61,8 ± 5,6 52,8 ± 8,3
mi + m2 13,2 ± 2,7 15,4 ± 5,7 9,2 ± 3,3 19,4 ± 6,6
ice Ai 42,4 ± 3,9 48,7 ± 8,0 36,8 ± 5,5 47,2 ± 8,3
A2 28,5 ± 3,7 41,0 ± 7,8 25,0 ± 4,9 22,2 ± 6,9
bab A 4,6 ± i,7 10,3 ± 4,8 3,4 ± 2,0 0
Severity of chronic inflammation of the gastric mucosa 1st group (H.pylori cag A, vacA s1m1, iceA) n = 32 2nd group (H.pylori vac A s2 m2) n = 35 Criterion /2 as amended by Yeats Normalized value of Pearson's coefficient (C')
Inflammation degree in the body of the stomach Absolute value % Absolute value %
Initial i2 37,5 28 80,0 2,571 0,243**
Pronouced ii 34,4 i 2,9 6,238 0,427*
Inflammation degree in the antrum
Medium 2 6,2 i6 45,7 6.487 0.413*
Pronounced 2i 65,6 8 22,8 4,027 0,314**
Phenomena of hyperplasia i6 50,0 3 8,5 5,832 0,374**
Erosions of the mucous membrane i8 56,2 i 2,9 6,512 0,445*
Lymphoid duodenitis ii 34,4 3 8,5 2,841 0,256**
Connection strength: * - strong; ** - medium; *** - weak; **** - insignificant
caused by highly pathogenic H. pylori strains is characterized by the following features: almost every second patient (46.9%) has a pronounced process: in most cases (78.1%) hyperplastic, 25.0% of them show visual signs of atrophy. In patients of group 2, on the contrary, moderate
or minor inflammation prevails (82.9%), more often superficial (54.3%), manifestations of the atrophic process are recorded in isolated cases (5.7%, p < 0.05). Macroscopic signs of severe duodenitis were significantly more often recorded in the main group (68.7% vs. 25.7%,
p < 0.005); lymphoid follicular bulbitis (21.9% vs. 5.7%, p < 0.05). The high severity and activity of the inflammatory process in patients of the main group was confirmed by a high frequency of detection of erosions in them (34.4% vs. 14.3%, p<0.05) and duodenal lymphoid follicles (37.5% vs. 12.5%, p<0.01). Correlation analysis showed that the presence of the cagA gene has the strongest effect on the inflammation severity in the mucous membrane of both the stomach body and the antrum. The presence of this virulence factor positively correlates with all indicators of the inflammatory process: severity (R=+0.42, p< 0.001), activity (R=0.35, p<0.01), signs of atrophy (R=+0.35, p< 0.001), erosions (R =+0.34, p<0.001) and lymphoid follicles (R= +0.32, p<0.01). The presence of other virulence factors in the H.pylori genome also directly correlates with the degree of chronic inflammation in the gastric mucosa. Simultaneously, the presence of several virulence factors increases the closeness of this relationship: the value of the Pearson's correlation coefficient increases to +0.45.
Thus, in destructive processes in the gastric mucosa, the detection frequency of H.pylori genes cagA, vacA s1 m1 is higher, and the presence of more than two genes of pathogenicity. The detection of mixed vacA genotypes indicates the infection with several H.pylori strains is more common in destructive gastritis and atrophy of the gastric mucosa, which suggests an increase in the pathogenic potential of the microorganism and the possibility of its genetic changes with prolonged persistence of infection.
Discussion
Research aimed at studying the H.pylori pathogenesis has shown that the degree of risk of disease is due to specific interactions between the pathogen itself (H.pylori) and the host organism. These interactions, in turn, are directly dependent on strain-specific bacterial factors and effects induced in the host (Chatto-padhyay et al., 2015; Zhebrun, 2015; Maev et al., 2016; Venneman et al., 2018; Khan et al,2019; Bakhti, 2020). The H.pylori genome contains about 1600 genes and 62 of them are
classified as "virulence genes" (Tkachenko & Suvorov, 2009; Maev et al., 2016).
Numerous studies conducted worldwide show a significant diversity in the frequency of H.pylori pathogenicity genes in people in different countries and ethnic groups, depending, in addition, on the diagnosis in the examined groups. So, cag genes in Central Europe are detected in 80.0% of those surveyed, in the Russian Federation in 81.5%, and in a number of countries in Asia and Latin America - only in 50.0% (Leanza et al., 2004; Cellini et al., 2006; Dharne et al., 2007; Basso et al., 2008; Daribi et al., 2009; Chattopadhyay et al., 2015; Orlov et al., 2015; Lucero et al., 2017). Belarusian researchers found a high incidence of cagA in diseases of the stomach and duodenum, which was 93.7% in duodenal ulcer and 78.8% in chronic gastritis (Yanovich et al., 2019). In Japan and Korea, the proportion of cagA-positive H.pylori strains is more than 90.0% (Kim et al., 2009). The prevalence of this gene is associated with a high incidence of stomach cancer in the population. Infection with cagA-positive strains other than distal gastric cancer is associated with an increased risk of severe atrophic gastritis. A variety of genetic variants of the bacterium is observed in various ethnic populations of the Russian Federation. Thus, cagA-positive H.pylori strains were diagnosed in 60.1% of Tuvans, in 59.8% of East Siberian Caucasians, in 43.8% of Evenks, and in 36.5% of the indigenous population of the Republic of Khakassia (Polivanova &Vshivkov, 2017; Gri-shchenko E.G. et al., 2017). However, there is evidence that each ethnic group has a specific type of H.pylori cag gene (Ageyeva et al., 2009; Muraviova, 2014).
VacA gene in the Asian population occurs only in 40.0-65.0% of cases, while in Latin America - in 75.0%. Detection of the vacAs1 allele varies slightly from 63.3% (in Asian countries) and 64.0% (in the Russian Federation) to 73.6% (in Latin America). In Northern and southern America, Central Europe and Australia, dominates H.pylori with the vacAs1, iceA genotype. The iceA1 genotype is found more often in the Russian Federation (71.5%), Europe (67.6%), and Asia (52.0%) than in Latin
America (36.5%). The iceA genotype, on the contrary, is almost 2 times more often detected in the Latin American population than in residents of Asian and European countries (52.0% and 67.6% respectively) (Leanza et al., 2004; Erzin et al., 2006; Basso et al., 2008; Homan M. Et al., 2009; Zhou et al., 2010; Vega et al., 2010; Chattopadhyay et al., 2015; Orlov et al., 2015). H.pylori strains predominate in Cuba -vac Asl-positive (73.5%), ice A2-positive (53.3%), cagA-positive (55.9%) (Feliciano et al., 2015). Studies conducted in China have shown that there is a relationship between duodenal ulcer disease and the iceA gene, but no significant relationship was found between iceA2 and the clinical manifestations of the disease (Chung et al., 2010). In Russia, the distribution of vac Am1 is fairly uniform across all regions and varies from 20.0% in Kazan to 33.0% in Krasnoyarsk and Ufa (Orlov et al., 2015). The most common H.pylori genotype in Russia is vacAs1m1. The association of infection with peptic ulcer disease was registered in the populations of Khakassia: it was found that in Caucasians the peptic ulcer disease is associated with s1 and s2 subtypes of vacA-positive H.pylori strains, and in khakasians with-cagA-positive H.pylori strains (Ageyeva et al., 2009).
The results of a study conducted in children in the Republic of Bashkortostan showed that the majority of patients with chronic gastritis were positive for the iceA gene, and the development of ulcers in childhood was associated with the cagA gene. The combination of cagA+vacAs1+babA2 genes was obligate for duodenal ulcer (Nijevitch et al., 2013).
The babA2 gene is more common in patients with peptic ulcer disease and stomach cancer. According to a meta-analysis summarizing the results of 38 studies, it turned out that in Western countries, babA2 may contribute to an increased risk of developing duodenal ulcers. In contrast, in the Asian population, the presence of babA2 has a slight association with the risk of stomach cancer, which requires further study (Chen et al., 2013; Kpoghomou et al., 2020). In Bulgaria and Turkey, the babA gene was detected in the same percentage, while in Brazilian end Mexico, the detection rate of this gene
is low (Erzin et al., 2006; Gatti et al., 2006; Bo-yanova et al., 2010; Román-Román, et al., 2017). In Russia, the babA2 genotype was detected in 51.5% of clinical H.pylori isolates in the Rostov region, slightly less frequently in Ufa and Kazan (33.0%), and in Krasnoyarsk -in 100.0% of isolates (Orlov et al., 2015; Berez-nyak et al., 2013; Akhtereeva et al, 2017; So-rokin et al., 2018). In our study, the bab A gene was detected in isolated cases and was associated with the most pronounced phenomena of inflammation of the gastric mucosa.
It should be noted that the outcomes of pathology depend not only on the pathogenicity factors of the bacterium, but also on the population-geographical zones, as well as the genetic features of macroorganism. However, despite the available data, the question of what factors or their combination induce H.pylori pathogenicity is still open.
Our study established certain features of the H.pylori genetic composition have been established in different forms of gastroduodenal pathology. The cagA vacAs1m1 or m2 genotypes were more often associated with erosive and ul-cerative pathology, and for non-erosive gastro-duodenitis, the H.pylori vacAs1 or s2 genotype in conjunction with m2 was characteristic. In atrophic gastritis, vac As1 m2 variants and the mixed vacA s1/s2 genotype in conjunction with m2 are more often found. Probably, several H.pylori strains existed in patients with an atrophic process for many years. In the absence of visual signs of mucosal inflammation, H.pylori cagA vac A s2 m1 variants were found. Mixed H.pylori vacAs1/s2 and vacAm1/m2 genotypes were more often identified in the older age (45-60 years).
Assessment of the relationship between the detection frequency of H.pylori genes responsible for the development of virulence factors with the clinical and endoscopic manifestations of the disease can contribute to understanding the mechanisms of pathogenesis of helicobac-teriosis and help optimize the treatment of H.pylori - infection. The study of the genetic H.pylori variant will make it possible to identify persons infected with a microorganism with the highest pathogenic cytotoxic potential, who
need mandatory eradication therapy, regardless of clinical manifestations and endoscopic picture.
The results of this work serve as the basis for further research on epidemiological features and clinical variants of the H.pylori - infection.
Conclusions
Thus, in patients of a large city of Central Russia - Nizhny Novgorod, a predominantly "European" character of the pathogen population structure with a moderate content of the most pathogenic cagA, vacAsl-positive strains was detected. Colonization of the gastric mucosa by H.pylori strains with a genetic structure containing pathogenicity factors cagA, vacA,
babA, iceA in chronic H.pylori-associated diseases is a factor in increasing the severity, activity and prevalence of the inflammatory process, the appearance of signs of atrophy of the gastric mucosa. The greatest influence on these indicators is exerted by the presence of cagA and vac As1 in the genome of the microorganism, as well as a combination of several pathogenicity factors.
Conflict of interest statement: the authors declare no conflict of interest regarding the manuscript.
The work was carried out in accordance with the plan of scientific research of the institute and had no sponsorship.
References
AGEYEVA YE.S., SHTYGASHEVA O.V., RYAZANTSEVA N.V. (2009): Features of the pathogenesis of Helicobacter pilory infection in the KHakass population. Byulleten sibirskoy meditsiny 4, 5-9. (In Russ).
AKHTEREEVA AR., DAVIDYUK YU.N., FAIZULLINA RA., IVANOVSKAYA K.A., SAFIN A G., SAFINA D.D., ABDULKHAKOV S R. (2017): Prevalence of Helicobacter pylori genotypes in patients with gastroduodenal pathology in Kazan. Kazanskiy meditsinskiy zhurnal, 98 (5), 723-728. (In Russ.).
AMIEVA M. & PEEK R.M. (2016): Pathobiology of Helicobacter pylori-Induced Gastric Cancer: Gastroenterology 150 (1): 64-78. https://doi.org/10.10537j.gastro.2015.09.004.
AVDEEVA T. G., RYABUKHIN YU.V., PARMENOVA L. P., KRUTIKOVA N. YU., ZHLOB-NITSKAYA L. A. (2011): Pediatric gastroenterology: a guide, 192 pp. (In Russ.) https://www.rosmed-lib.ru/book/ISBN9785970417225.html.
BAKHTI S.Z., LATIFI-NAVID S., SAFARALIZADEH R., BAKHTI S.Z. (2020): Helicobacter pylori-related risk predictors of gastric cancer: the latest models, challenges, and future prospects. Cancer Med. 9(13), 4808-4822. Doi: 10.1002 / cam4. 3068.
BARANOVSKY A.YU., BELYAEV A.M., KONDRASHINA E.A. (2019): Morbidity and Mortality Rates from Digestive Diseases in the RF Northwestern Federal District (NWFD) and Measures to Reduce Them. Russian Journal of Gastroenterology, Hepatology, Coloproctology 29(1), 36-46. (In Russ.) https://doi.org/10.22416/1382-4376-2019-29-1-36-46.
BASSO D, ZAMBON C., LETLEY D. (2008): Clinical relevance of Helicobacter pylori cagA and vacA gene polymorphisms. Gastroenterology 135(1), 91-99.
BEREZNYAK E.A., SOROKIN V. M., KARPOVA I. O., STUPINA N. A., TERENTYEV A. N. (2013): Features of genotypes of Helicobacter pylori strains circulating in the Rostov region. Epidemiology and vaccinoprophylaxis 4, 30-38. (In Russ.).
BORDIN D.S., VOYNOVAN I.N., KOLBASNIKOV S.V., EMBUTNIEKS YU.V. (2018): Diagnosis of Helicobacter pylori infection in clinical practice. Terapevticheskij arhiv 12, 133-139. (In Russ.).
BOYANOVA L., YORDANOV D., GERGOVA G. (2010): Association of iceA and babA genotypes in Helicobacter pylori strains with patient and strain characteristics. Antonie Van Leeuwenhoek: Epub 98(3). P. 343-350.
CELLINI L., GRANDE R., DI CAMPLI E. (2006): Analysis of genetic variability, antimicrobial susceptibility and virulence markers in Helicobacter pylori identified in Central Italy. Scand J Gastroenterol. 41(3), 280-287.
CHATTOPADHYAY S., MUKHOPADHYAY A., NAIR G. (2015): The vacA and the cagA of Helicobacter pylori: two multitasking proteins of a multitasking bacterium. Journal of Gastrointestinal Disorders and Liver function 06, 19-28. https://doi.org/10.15436/2471-0601.15.002.
CHEN M.Y., HE C.Y., MENG X., YUAN Y. (2013): Association of Helicobacter pylori babA2 with peptic ulcer disease and gastric cancer. World J Gastroenterol. 19(26), 4242-4251. doi: 10.3748/wjg.v19.i26.4242.
CHUNG C., OLIVARES, A., TORRES, E. (2010): Diversity of VacA intermediate region among Helicobacter pylori strains from several regions of the world. J Clin Microbiol. 48(3), 690-696. doi: 10.1128/JCM.01815-09.
DADASHZADEH K., ORTEZAMILANI M., SOMI M. H. (2015): The prevalence of Helicobacter pylori CagA and IceA genotypes and possible clinical outcomes. Acta medica mediterranea 31, 1345-1349.
DARIBI H., MALENKNEJAD P., YAMAOKA Y. (2009): Distribution of Helicobacter pylori cagA, cagE, opiA and vacA in different major ethnic groups in Tehran, Iran. J. Gastroenterol. Hepatol. 20(8), 13801386.
DHARNE M.S., MUNOT H., PUJARI R. (2007): Helicobacter pylori cagA, vacA and iceA genotypes in western Indian population of Maharashtra with varied gastroduodenal diseases. Indian J. Pathol. Microbiol. 50(4), 740-748.
ERZIN Y., KOKSAL V., ALTUN S. (2006): Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA, babA2 genotypes and correlation with clinical outcome in Turkish patients with dyspepsia. Helicobacter 11(6), 574-580.
EVSYUTINA YU. V. (2016): Eradication of H. pylori: a modern view of the old problem. Rmj (Russian medical journal) 11, 673-677. (In Russ.) https://www.rmj.ru/articles/gastroenterologiya
GATTI L.L., MODENA J.L., PAYÄO S.L. (2006): Prevalence of Helicobacter pylori cagA, iceA and babA2 alleles in Brazilian patients with upper gastrointestinal diseases. Acta Trop., Epub 100(3), 232-240. doi: 10.1016 / j. actatropica.2006.08.014
GLANTZ S.A. (1998): Medico-biological statistics M. Practica, 459 p. (In Russ.).
GRAHAM D.Y., OPEKUN AR., OSATO M.S., EL-ZIMAITY H.M., LEE C.K., YAMAOKA Y. (2004): Challenge model for Helicobacter pylori infection in human volunteers. Gut 53, 1235-1243. https://doi.org/10.1136/gut.2003.037499
GRISHCHENKO E.G., PETROVA M M., GILYUK A V., NIKOLAEVA N N. (2017): Genetic variability of Helicobacter pylori and features of gastroduodenal pathology. Zabaykalskiy meditsinskiy vestnik 4, 245-257. (In Russ.).
HEALTH IN RUSSIA (2017): Statistical collection edited by G. K. Oxenoit. Moscow: Rosstat, P. 29. (In Russ.) http://www.gks.ru
HOMAN M., LUZAR B., KOCJAN B.J. (2009): Prevalence and clinical relevance of cagA, vacA, and iceA genotypes of Helicobacter pylori isolated from Slovenian children. J. Pediatr. Gastroenterol. Nutr. 49(3), 289-296.
HOOI J.K.Y., LAI W.Y., NG W.K., SUEN M.M.Y., UNDERWOOD FE., TANYINGOH D., MAL-FERTHEINER P., GRAHAM D.Y., WONG V.W.S., WU J.C.Y., CHAN F.K.L., SUNG J.J.Y., KAPLAN G.G., NG S.C. (2017): Global prevalence of Helicobacter pylori infection: systematic review and meta-analysis. Gastroenterology 153, 420-429.
ISAEVA G.SH., VALIEVA R.I. (2018): Biological characteristics and virulence of Helicobacter pylori. Klinicheskaya mikrobiologiya i antimikrobnaya himioterapiya 20 (1), 14-23. (in Russ.)
IVASHKIN V.T., LAPINA TL., SHEPTULIN A.A., TRUKHMANOV AS., MAEV I.V., DRAPKINA O.M., ABDULHAKOV RA., ALEKSEEVA O.P., ALEKSEENKO S.A., ZAJCEV S.V., KORO-CHANSKAJA N.V., KURILOVICH S.A., OSIPENKO MF., SAJFUTDINOV R.G., SARSENBAEVA A.S. (2013): Practical steps on stomach cancer prevention in the Russian Federation: H. pylori-associated gastritis management algorithm (Advisory board position statement, December, 9, 2013). Russian Journal of Gastroenterology, Hepatology, Coloproctology 2, 102-103. (In Russ.)
IVASHKIN V.T., MAYEV I.V., LAPINA TL., SHEPTULIN A.A., TRUKHMANOV A S., BARANSKAYA Y.K., ABDULKHAKOV RA., ALEKSEYEVA O.P., ALEKSEYENKO S.A., DEKHNICH N.N., KOZLOV R S., KLYARITSKAYA I L., KOROCHANSKAYA N.V., KURILOVICH S.A., OSIPENKO M F., SIMANENKOV V.I., TKACHEV A.V., KHLYNOV I B., TSUKANOV V.V. (2018): Diagnostics and treatment of Helicobacter pylori infection in adults: Clinical guidelines of the Russian gastroenterological association. Russian Journal of Gastroenterology, Hepatology, Colo-proctology 28(1), 55-70. (In Russ.) https://doi.org/10.22416/1382-4376-2018-28-1-55-70.
KHAN F., KHAN Z., REHMAN I. (2019): The virulence of Helicobacter pylori through CagA on gastric mucosa: a review. Journal of pharmacy practice and community medicine 5(1), 03-12. http:// www.jppcm.org DOI: 10.5530 / jppcm.2019.1.2
KIM Y.S., KIM N., KIM J.M. (2009): Helicobacter pylori genotyping findings from multiple cultured isolates and mucosal biopsy specimens: strain diversities of Helicobacter pylori isolates in individual hosts. Eur. J. gastroenterol. hepatol. 21(5), 522-528.
KONOVALOV A. A. &VARENOVA L. E. (2015): The main indicators of public health and the activities of the state medical organizations of the Nizhny Novgorod region in 2014. Collector. Nizhny Novgorod. p. 232. (In Russ.)
KPOGHOMOU M.A., WANG J., WANG T., JIN G. (2020): Association of Helicobacter pylori babA2 gene and gastric cancer risk: a meta-analysis. BMC Cancer 20 (1), 465-478. doi: 10.1186/s12885-020-06962-7.
KUSTERS J.G., VAN VLIET A.H., KUIPERS E.J. (2006): Pathogenesis of Helicobacter pylori infection. Clin. microbiol. rev. 19 (3), 449-490. doi: 10.1128/CMR.00054-05.
LAZAREVA L A. & GORDEEVA E.V. (2017): Analysis of the incidence of children and adolescents with diseases of the digestive system. Mezhdunarodnyy nauchno-issledovatelskiy zhurnal (International scientific research journal) 1, 133-135. (In Russ.) doi: https://doi.org/10.23670/IRJ.2017.55.104.
LAZEBNIK LB., TKACHENKO E.I., ABDULGANIEV D.I., ABDULHAKOV RA., ABDULHAKOV S R., VALUEVA E.B., ARDATSKAYA MD., AKHMEDOV V.A., BORDIN D.S., BURKOV S.G., BUTOV M.A. (2017): VI national recommendations for the diagnosis and treatment of acid-dependent diseases and diseases associated with Helicobacter pylori (VI Moscow agreements). Eksperimental'naya i Klinicheskaya Gastroenterologiya 2 (138), 3-21. (In Russ.).
LEANZA A G., MATTEO M.J. & CRESPO O. (2004): Genetic characterisation of Helicobacter pylori isolates from an Argentinean adult population based on cag pathogenicity island right-end motifs, lspA-glmM polymorphism and iceA and vacA genotypes. Clin. microbiol. infect. 10(9), 811-819.
LUCERO Y., OYARZÜN A. & O'RYAN M. (2017): Corrigendum: Helicobacter pylori cagA+ is associated with milder duodenal histological changes in Chilean celiac patients. Front. cell. infect. microbiol. 7, 376-384. https://doi.org/10.3389/fcimb.2017.00427
MAEV I.V., SAMSONOV A.A., ANDREEV D.N. (2016): Infection of Helicobacter pylori. Moscow: GE-OTAR-Media, 256 pp. (In Russ.) https://www.rosmedlib.ru/book/ISBN9785970436325.html
MAHACHAI V., VILAICHONE R., PITTAYANON R. (2018): Helicobacter pylori management in ASEAN: the Bangkok consensus report. Focus on clinical aspects of H. pylori infection in Asia and recommendations for clinical management. J Gastroenterol Hepatol. 33(1), 37-56. https://doi.org/10.1111/jgh.13911
MALFERTHEINER P., VENERITO M., SCHULZ C. (2018): Helicobacter pylori infection: new facts in clinical management. Current treatment options in gastroenterology 16 (4), 605-615.
MAMISHI S., ESHAGHI H., MAHMOUDI S., BAHADOR A., HOSSEINPOUR SADEGHI R., NAJAFI M., FARAHMAND F., KHODADAD A., POURAKBARI B. (2016): Intrafamilial transmission of Helicobacter pylori: genotyping of faecal samples. Br J Biomed Sci 73(1), 38-43. doi: 10.1080/09674845.2016.1150666.
MIFTAHUSSURUR M., SHARMA R. P., SHRESTHA P. K., SUZUKI R., UCHIDA T., YAMAOKA Y. (2015): Molecular epidemiology of Helicobacter pylori infection in Nepal: specific ancestor root // PLOS ONE 7(10), 1-16. https://doi.org/10.1371/journal.pone.0134216.
MURAVIOVA N.G. (2014): Ethnic aspects of Helicobacter pylori infection in adults and children. Byulleten VSNTs SO RAN 97 (3), 122-127. (In Russ.).
NIJEVITCH A.A., AKHMADEEVA E.N., KUCHINA E S., TUYGUNOV M M., SATAEV V.U. (2013): Regional genotypes of Helicobacter pylori in children with gastroduodenal pathology in the republic of Bashkortostan. Medical Herald of the South of Russia 2, 94-97. (In Russ.) https://doi.org/10.21886/2219-8075-2013-2-94-97. (In Russ.).
NIMISH B., COLIN W., MOAYYEDI P., TACK G. (2017): White paper AGA: functional dyspepsia. Clinical gastrenterology and hepatology 8 (15), 1191-1194.
OFORI E.G., EDENORTE S.I., BOCKARIE A.S. (2019): Helicobacter pylori infection, virulence genes' distribution and accompanying clinical outcomes: the West Africa situation. Biomed. Res. Int. Dec 10: 7312908. doi: 10.1155/2019/7312908
OKUDA M., MABE K., RIKUCH S. (2016): Diagnostic accuracy of urine Helicobacter pylori antibody test in junior and senior high school students in Japan. Helicobacter 21, 78-89.
ORLOV S.V., KALASHNIKOVA V.A., BARYSHNIKOVA N.V., USPENSKIY YU.P. (2015): Genetic features of Helicobacter pylori infection in primates and humans. Dnevnik kazanskoy meditsinskoy shkoly 1(7), 15-20. (In Russ.) https://readera.ru/140126018.
PERFILOVA K., NEUMOINA N., BUTINA T., KUZNETSOVA I., SHUTOVA I., LARIONOVA T., EFIMOVA E. (2016): Experience of application of polymerase chain rection methods for the study of Helicobacter pylori markers. Medalmanac 2, 52-56. (In Russ.). https://socionet.ru/publica-tion.xml.spz:neicon:medalmanac:y:2016:i:2:p:52-56. (In Russ.).
POLIVANOVA T. V. & VSHIVKOV V. A. (2017): Prevalence of CagA strain of Helicobacter pylori and characteristics of associated gastritis in schoolchildren of the Republic of Tyva. Russian pediatric journal 20(1), 19-23. (In Russ.). doi: http://dx.doi.org/10. 18821/1560 9561 2017 20 1 19 23.
ROMÁN-ROMÁN A., MARTÍNEZ-CARRILLO D.N., ATRISCO-MORALES J., AZÚCAR-HEZIQUIO J.C., CUEVAS-CABALLERO AS., CASTAÑÓN-SÁNCHEZ C.A., REYES-RÍOS R., BETANCOURT-LINARES R., REYES-NAVARRETE S., CRUZ-DEL CARMEN I., CA-MORLINGA-PONCE M., CORTÉS-MALAGÓN E.M., FERNÁNDEZ-TILAPA G. (2017): Helico-bacter pylori vacA s1m1 genotype but not cagA or babA2 increase the risk of ulcer and gastric cancer in patients from Southern Mexico. Gut Pathog. Apr 13;9: 18-32. doi: 10.1186/s13099-017-0167-z.
SEDAGHAT H., MONIRI R., JAMALI R., ARJ A., ZADEH M.R., MOOSAVI S.G.A. (2014): Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA, babA2, and oipA genotypes in patients with upper gastrointestinal diseases. Iranian J. Microbiology 6(1), 14-21.
SOROKIN V.M., PISANOV R.V., VODOPIANOV A S., GOLUBKINA E.V., BEREZNYAK E.A. (2018): Comparative analysis of the genotypes of Helicobacter pylori strains in the Rostov and Astrakhan regions. Meditsinskiy vestnik Yuga Rossii 9(4), 81-86. (In Russ.).
STANDARD OF MEDICAL CARE FOR PATIENTS WITH CHRONIC GASTRITIS, DUODENITIS, DYSPEPSIA (2004): Order of the Ministry of health and social development of Russian Federation of 22.11.2004 N. 248. (In Russ.).
STANDARD OF SPECIALIZED MEDICAL CARE FOR GASTRIC AND DUODENAL ULCERS (2012): Order of the Ministry of health of Russian Federation of 09.11.2012 N 773n. (In Russ.).
TKACHENKO E.I. & SUVOROV A.N. (2009): Intestinal dysbiosis. S-Petersburg: InformMed, 276 pp. (In Russ).
VENNEMAN K., HUYBRECHTS I., GUNTER M.J., VANDENDAELE L., HERRERO R., VAN HERCK K. (2018): The epidemiology of Helicobacter pylori infection in Europe and the impact of lifestyle on its natural evolution toward stomach cancer after infection: a systematic review. Helicobacter. 23(3), e12483. https://doi.org/10.1111/hel.12483.
YANOVICH O., DOROSHKO M., TITOV L. (2019): Helicobacter pylori genotypes among Belarus patients with gastroduodenal disorders and their association with clinical outcome. Acta microbiologica et im-munologica Hungarica 66, 399-411.
YOKOTA S.I., KONNO M., FUJIWARA S.I. (2015): Intrafamilial, preferentially mother-to-child and intra-spousal, Helicobacter pylori infection in Japan determined by mutilocus sequence typing and random amplified polymorphic DNA fingerprinting. Helicobacter 20 (5), 334-342.
ZHEBRUN A.B., Svarval A.V., Ferman R.S., Goncharova L.B. (2014): Methods of laboratory diagnostics of infection caused by Helicobacter pylori. S-Petersburg, 60pp. (In Russ.)
ZHEBRUN A.B. (2015): Helicobacter pyliri infection is a global health problem. Biosfera 7 (2), 227-237. (In Russ.).
ZHOU Y., HUANG Y., SHAO C.H. (2010): CagA, vacA and iceA genotypes of Helicobacter pylori isolated from children in Shanghai. Zhongguo dang dai er ke za zhi 12 (4), 267-271.
ZHU H-M., LI B.Y., TANG Z., SHE J., LIANG X.Y., DONG L.K., ZHANG M. (2020): Epidemiological investigation of Helicobacter pylori infection in elderly people in Beijing. World J. Clin. Cases. Jun 6;8( 11), 2173-2180. doi: 10.12998/wjcc.v8.i11.2173.
