Advances in Microbiology
Vol.09 No.03(2019), Article ID:91295,9 pages
10.4236/aim.2019.93017

Prevalence of Helicobacter pylori cagA and sabA Genotypes in Patients with Gastric Disease

Jéssica Nunes Pereira1, Wilson A. Orcini1, Rita L. Peruquetti1, Marilia A. C. Smith2, Spencer L. M. Payão1, Lucas T. Rasmussen1*

1Universidade do Sagrado Coração (USC), Bauru, Brasil

2Universidade Federal de São Paulo (UNIFESP), São Paulo, Brasil

Copyright © 2019 by author(s) and Scientific Research Publishing Inc.

This work is licensed under the Creative Commons Attribution International License (CC BY 4.0).

http://creativecommons.org/licenses/by/4.0/

Received: February 22, 2019; Accepted: March 18, 2019; Published: March 21, 2019

ABSTRACT

Gastric cancer is one of the most common types of cancer worldwide. Helicobacter pylori is considered one of the most important causes of this condition specially because of its virulence markers as sabA and cagA. Therefore, we aim to investigate the relation between these markers and the gastric diseases in 400 patients who underwent upper digestive endoscopy. To detect the bacteria and its genes by Polymerase Chain Reaction (PCR), the presence of H. pylori was significant when comparing the groups control vs. cancer (p value < 0.0001) OR [95% CI] 12.73 (5.45 - 29.69) and the groups control vs. chronic gastritis (p value < 0.0001) OR [95% CI] 12.99 (7.44 - 22.66). cagA was statistically significant considering its presence when comparing the chronic gastritis vs. cancer groups (p value = 0.0434) OR [95% CI] 2.44 (1.021 - 5.845). Associating both sabA and cagA, we found a statistically significant result (p value < 0.0001) OR [95% CI] 13.68 (3.95 - 47.33) considering the gastritis vs. cancer groups. Helicobacter pylori is directly associated to gastric diseases such as gastritis and cancer and its virulence markers: sabA and cagA increase the injury process to the gastric epithelium making the host more susceptible to cancer.

Keywords:

Stomach Neoplasms, Helicobacter pylori, sabA, cagA

1. Introduction

Gastric cancer is one of the most common types of cancer worldwide and the third leading cause of cancer death. It is responsible for about 720,000 deaths per year around the world, and its occurrence is very frequently in Asian countries [1] [2]. The onset of cancer usually starts with lesions, which evolve into an inflammation that tends to be followed by chronic gastritis, gastric atrophy, and finally gastric cancer [3]. Its progression is related to genetic characteristics of the host, environmental factors, and the most important parameter: the presence of Helicobacter pylori infection as well as its genotype [4].

H. pylori is a Gram negative, microaerophilic bacterium that colonizes half of the world’s population and whose niche is the stomach [4] [5]. Its infection is highly successful due to the interaction of this bacterium with the gastric epithelial cells, and for that reason; it is considered one of the most important causes of gastric cancer [6] [7] [8].

The sialic acid-binding adhesin (sabA) is an outer membrane protein that plays an important role in the first contact of H. pylori with the gastric tissue [9]. This marker determinates the initial and permanent colonization of the bacteria and directly influences the extent of damages by this pathogen. sabA acts in adhesion of Helicobacter pylori by binding to a specific receptor present in human stomach named sialyl-dimeric-Lewis x (Lex) [10] [11] [12]. This binding characterizes a successful and more aggressive infection making the intense inflammation permanent in which susceptive lesions can eventually evolve into gastric cancer [13].

Another virulence marker of H. pylori is the cytotoxin-associated gene A known as cagA, which is related to gastric inflammation [12]. The genome of H. pylori includes a component called cag-PAI island, which encodes the type IV secretion system. This system perforates the cells of the gastric epithelium, allowing the bacteria to deposit in the host molecules, such as the cagA protein, which regulates the metabolism of these cells [14]. This marker is considered one of the most virulent because its presence is usually associated with the etiology of peptic ulcers and gastric cancer [10].

Considering the high occurrence of H. pylori, the present study aimed to investigate the relation of its genes sabA and cagA with gastric diseases and gastric cancer.

2. Material and Methods

This research was carried out over 2016-2017 at the Universidade do Sagrado Coração in Bauru―SP, Brazil, and counted with the collaboration of Hospital Estadual de Bauru and Faculdade de Medicina de Marília (FAMEMA) in Marília―SP, Brazil for the collection of samples. All the patients involved in this research signed a consent form. This study was approved by the Research Ethics Committee of the Universidade do Sagrado Coração, in Bauru, Brazil (No. 1.215.180.2.1).

3. Patients and Gastric Samples

This study analyzed 400 patients (♂173/♀227, mean age 54 years) with peptic symptoms who underwent to upper digestive endoscopy. Two gastric biopsie samples were taken from each patient, one for detection of H. pylori by polymerase chain reaction (PCR) and the second for histopathological analyses performed according to Sydney and Lauren’s classification [15] [16].

The gastric mucosa biopsy samples were separated into groups according to histopathological analysis: 120 control patients, with normal gastric tissue (♂40/♀80), 241 patients with chronic gastritis (♂111/♀130), and 39 with gastric cancer (♂22/♀17). The control and chronic gastritis samples were obtained from the Departments of Gastroenterology of the State Hospital of Bauru and of Marília Medical School, and the gastric cancer samples were obtained in the Federal University of São Paulo. Patients were excluded from this study who had undergone antimicrobial therapy treatment, received treatment via proton pump inhibitors, or used NSAIDs in the three months prior to the endoscopy.

3.1. DNA Extraction and Helicobacter pylori Diagnostic

DNA extraction was performed using QIAamp® tissue kit (Qiagen, Germany) according to the manufacturer’s instructions. For diagnostic of the H. pylori, PCR assays were performed using one pair of oligonucleotides Hpx1: 5’-CTGGAGARACTAAGYCCTCC-3’ and Hpx2: 5’-GAGGAATACTCATTGCGAAGGCGA-3’ that amplifies a 150 bp fragment corresponding to 16S-rRNA from H. pylori. The reaction conditions were the same as described by Scholte et al. (1997) [17] and Pereira et al., 2014 [18] : 40 cycles: 1 min, 94˚C; 1 min, 59˚C and 1 min, 72˚C. In each experiment, positive (strain 26695) and negative (water) controls were included.

3.2. sabA and cagA Detection

The presence of target genes cagA and sabA was also analyzed through PCR, using one pair of oligonucleotides for each gene fragment. To detect the sabA gene, we used the primers Fm 5’-CCGCTAGTGTCCAGGGTAAC-3’ and Rm 5’-CACCGCGTATTGCGTTGGGTA-3’ to amplified a fragment of 400 bp, and the reaction conditions described by Shao et al. [19] were optimized―35 cycles: 30 sec, 94˚C; 30 sec, 50˚C;30 sec, 72˚C. The detection of a 232 bp fragment cagA gene was performed according to Rasmussen et al. (2012) [20] and van Doorn et al. (1998) [21] : we used the primers Cag1 5’-ATGACTAACGAAACTATTGATC-3’ and Cag2 5’-CAGGATTTTTGATCGCTTTATT-3’ and the conditions 40 cycles: 1 min, 94˚C; 1 min, 53˚C; 1 min, 72˚C.

3.3. Statistical Analysis

Statistical analysis was performed using the two-tailed Chi-square test with Yates’ correction and/or Fischer’s exact test. Differences were considered significant when p value was less than 0.05. All statistical analyses were performed with software GraphPad Prism 5.0.

3.4. Results

In the 400 analyzed gastric mucosa samples, Helicobacter pylori was detected in 222 (55.5%) (Table 1). The result was significant for the presence of H. pylori when compared the control vs. cancer groups (p < 0.0001) OR (95% CI) 12.73 (5.45 - 29.69) and the control vs. chronic gastritis groups (p < 0.0001) OR (95% CI) 12.99 (7.44 - 22.66). These results found a significant relation between H. pylori and gastric diseases considering the effects of this bacterium in gastric mucosa.

The virulence marker sabA was detected in 129 (58.10%) H. pylori positive samples of which 11 were from control group, 106 from chronic gastritis group, and 12 from gastric cancer group (Table 1). Comparing the groups control vs. gastritis (p = 0.63) OR (95% CI) 0.78 (0.30 - 1.99), control vs. cancer (p = 0.55) OR (95% CI) 1.63 (0.51 - 5.17), and gastritis vs. cancer (p = 0.097) OR (95% CI) 2.07 (0.92 - 4.66), we found no significant results in any of the analysis.

The cagA gene was detected in 102 (45.94%) H. pylori positive samples also divided in the control, chronic gastritis, and cancer groups, with 8, 86, and 8 samples, respectively (Table 1). This virulence marker was statistically significant considering its presence when comparing the chronic gastritis vs. cancer groups (p = 0.0434) OR (95% CI) 2.44 (1.021 - 5.84). Table 1 showed the results of H. pylori and virulence markers in each group of patients.

4. Associations between cagA and sabA

Analysis of the association between cagA and sabA found no significant results (Table 2). However, the combination of both markers with the groups of patients produced a statistically significant result (p < 0.0001) OR (95% CI) 13.68 (3.95 - 47.33), considering the gastritis vs. cancer groups (Table 3). This result suggests that when these markers act together they potentiate the action of H. pylori by increasing the inflammatory process that can evolve from chronic gastritis into cancer.

Table 1. Distribution of the Helicobacter pylori, sabA and cagA genotypes, and the risk of developing chronic gastritis and gastric cancer.

*Results statistically significant when compared control vs. cancer group (p< 0.0001) and control vs. chronic gastritis group (p < 0.0001). Results statistically significant when compared chronic gastritis group vs. cancer group (p = 0.0434).

Table 2. Association between the cagA and sabA genes in the studded groups.

Table 3. Distribution of the combination between cagA, and sabA genotypes and the risk of gastric disease. Comparisons among: control vs chronic gastritis(a); control vs gastric cancer(b); and chronic gastritis vs gastric cancer group(c).

*Statistically significant association.

5. Discussion

Our results show that Helicobacter pylori is significantly related to gastric diseases, such as gastritis, and increase the risk of gastric cancer. Considering that this bacterium is capable of establishing an intense inflammatory process in the human gastric epithelium, these results were expected, because since the discovery of H. pylori, other works have concluded the sam [22] [23] [24] [25].

The outer membrane protein sabA, which interacts with a specific receptor present in gastric epithelium, can be responsible for facilitating binding between the bacteria and the host [26]. This gene has been identified in more than a half of the H. pylori positive studied population; however, no statistically significant results were found in this work. Our results are in the line with those published in Pakbaz et al. (2013) [13] , but not in agreement with Oleastro et al. (2013) [27] who found association between this adhesin and gastric cancer in western population.

Although we did not find any significant results for the sabA gene, it is still recognized as a virulence marker for its ability to promote intense recruitment of neutrophils and establishment of a persistent colonization [28] [29].

One of the most aggressive virulence markers expressed for Helicobacter pylori and probably the most studied is cagA [4] [10]. This gene confers to the bacteria the ability to modulate the cell metabolism of the host [30] , and its presence is related to development of ulcer and gastric cancer [31]. Our data indicate that cagA gene is a risk factor for the onset of gastric cancer in patients who have previously injured gastric epithelium. This result is similar to the results found by Yamaoka et al. (2006) [32] and Oldani et al. (2009) [31].

It is known that H. pylori depends on a strong initial bond to the gastric tissue to conclude a successful and permanent infection, and it has developed mechanisms that greatly help this process [27]. Once the infection is established, H. pylori starts to release its toxins that regulate the host cells and assist in its adaption to the stomach niche [12] [33].

Both sabA and cagA are important virulence markers for Helicobacter pylori [11] as they participate in the processes mentioned above. Our results indicate that these genes taken together make the infection process more aggressive and increase the lesion of the gastric epithelium making the host more susceptible to cancer. Our data about this association is consistent with the data presented by Backert et al. (2011) [33].

We were expecting to have positive results correlating sabA only and the gastric cancer. We believe that we haven’t got this result because of the sample size and the target population of this work. In addition, we had difficulty finding in the literature works that approached the questions of this article in a similar way to ours and, therefore, there were few comparisons of results that we were able to accomplish.

6. Conclusion

Taken together, our data confirm that Helicobacter pylori is directly related to the emergence and evolution of gastric diseases, especially chronic gastritis and cancer. Its virulence markers sabA and cagA are responsible for a persistent and very aggressive infection that moves the patient’s situation from an initial injury of the gastric epithelium to a greater susceptibility for gastric cancer.

Conflicts of Interest

The authors declare no conflicts of interest regarding the publication of this paper.

Cite this paper

Pereira, J.N., Orcini, W.A., Peruquetti, R.L., Smith, M.A.C., Payão, S.L.M. and Rasmussen, L.T. (2019) Prevalence of Helicobacter pylori cagA and sabA Genotypes in Patients with Gastric Disease. Advances in Microbiology, 9, 239-247. https://doi.org/10.4236/aim.2019.93017

References

  1. 1. Cheung, K.-S. and Leung, W.K. (2018) Risk of Gastric Cancer Development after Eradication of Helicobacter pylori. World Journal of Gastrointestinal Oncology, 10, 115-123. https://doi.org/10.4251/wjgo.v10.i5.115

  2. 2. Zheng, W., Zhang, S., Zhang, S., Min, L., Wang, Y., Xie, J., et al. (2017) The Relationship between Tumor Necrosis Factor-α Polymorphisms and Gastric Cancer Risk: An Updated Meta-Analysis. Biomedical Reports, 7, 133-142. https://doi.org/10.3892/br.2017.934

  3. 3. Xu, Y., Cao, X., Jiang, J., Chen, Y. and Wang, K. (2016) TNF-308/-238 Polymorphisms Areassociated with Gastric Cancer: A Case-Control Family Study in China. Clinics and Research in Hepatology and Gastroenterology, 41, 103-109. https://doi.org/10.1016/j.clinre.2016.05.014

  4. 4. Backert, S. and Tegtmeyer, N. (2017) Type IV Secretion and Signal Transduction of Helicobacter pylori cagA through Interactions with Host Cell Receptors. Toxins, 9, 115. https://doi.org/10.3390/toxins9040115

  5. 5. Gall, A., Gaudet, R.G., Gray-Owen, S.D. and Salama, N.R. (2017) TIFA Signaling in Gastric Epithelial Cells Initiates the Cag Type 4 Secretion System-Dependent Innate Immune Response to Helicobacter pylori Infection. mBio, 8, e01168-17. https://doi.org/10.1128/mBio.01168-17

  6. 6. álvarez-Arellano, L. and Maldonado-Bernal, C. (2014) Helicobacter pylori and Neurological Diseases: Married by the Laws of Inflammation. World Journal of Gastrointestinal Pathophysiology, 5, 400-404. https://doi.org/10.4291/wjgp.v5.i4.400

  7. 7. Klerk, N., Maudsdotter, L., Gebreegziabher, H., Saroj, S.D., Eriksson, B., Eriksson, O.S., et al. (2016) Lactobacilli Reduce Helicobacter pylori Attachment to Host Gastric Epithelial Cells by Inhibiting Adhesion Gene Expression. Infection and Immunity, 84, 1526-1535. https://doi.org/10.1128/IAI.00163-16

  8. 8. Li, M., Zhou, Q., Yang, K., Brigstock, D.R., Zhang, L., Xiu, M., et al. (2015) Rare Case of Helicobacter pylori-Positive Multiorgan IgG4-Related Disease and Gastric Cancer. World Journal of Gastroenterology, 21, 3429-3434. https://doi.org/10.3748/wjg.v21.i11.3429

  9. 9. Magalhães, A., Pinto, R.M., Nairn, A.V., Rosa, M.D., Ferreira, R.M., Neto, S.J., et al. (2015) Helicobacter pylori Chronic Infection and Mucosal Inflammation Switches the Human Gastric Glycosylation Pathways. Biochim Biophys Acta, 1852, 1928-1939. https://doi.org/10.1016/j.bbadis.2015.07.001

  10. 10. Alzahrani, S., Lina, T.T., Gonzalez, J., Pinchuk, I.V., Beswick, E.J. and Reyes, V.E. (2014) Effect of Helicobacter pylori on Gastric Epithelial Cells. World Journal of Gastroenterology, 20, 12767-12780. https://doi.org/10.3748/wjg.v20.i36.12767

  11. 11. Kalali, B., Mejías-Luque, R., Javaheri, A. and Gerhard, M. (2014) H. pylori Virulence Factors: Influence on Immune System and Pathology. Mediators of Inflammation, 2014, Article ID: 426309. https://doi.org/10.1155/2014/426309

  12. 12. Posselt, G., Backert, S. and Wessler, S. (2013) The Functional Interplay of Helicobacter pylori Factors with Gastric Epithelial Cells Induces a Multi-Step Process in Pathogenesis. Cell Communication and Signaling, 11, 77. https://doi.org/10.1186/1478-811X-11-77

  13. 13. Pakbaz, Z., Shirazi, M.H., Ranjbar, R., Reza Pourmand, M., Gholi, M.K., Aliramezani, A., et al. (2013) Frequency of sabA Gene in Helicobacter pylori Strains Isolated From Patients in Tehran, Iran. Iranian Red Crescent Medical Journal, 15, 767-770. https://doi.org/10.5812/ircmj.5044

  14. 14. Santibáñez, M., Aguirre, E., Belda, S., Aragones, N., Saez, J., Rodríguez, J.C., et al. (2015) Relationship between Tobacco, cagA and vacA i1 Virulence Factors and Bacterial Load in Patients Infected by Helicobacter pylori. PLoS ONE, 10, e0126540. https://doi.org/10.1371/journal.pone.0126540

  15. 15. Stolte, M. and Meining, A. (2001) The Updated Sydney System: Classification and Grading of Gastritis as the Basis of Diagnosis and Treatment. Canadian Journal of Gastroenterology, 15, 591-598. https://doi.org/10.1155/2001/367832

  16. 16. Hu, B., El Hajj, N., Sittler, S., Lammert, N., Barnes, R. and Meloni-Ehrig, A. (2012) Gastric Cancer: Classification, Histology and Application of Molecular Pathology. Journal of Gastrointestinal Oncology, 3, 251-261.

  17. 17. Scholte, G.H., van Doorn, L.J., Quint, W.G. and Lindeman, J. (1997) Polymerase Chain Reaction for the Detection of Helicobacter pylori in Formaldehyde-Sublimate Fixed, Paraffin-Embedded Gastric Biopsies. Diagnostic Molecular Pathology, 6, 238-243. https://doi.org/10.1097/00019606-199708000-00008

  18. 18. Pereira, W.N., Ferraz, M.A., Zabaglia, L.M., Labio, R.W., Orcini, W-A., Ximenez, J-P.B., et al. (2014) Association among H. pylori Virulence Markers dupA, cagA and vacA in Brazilian Patients. Journal of Venomous Animals and Toxins Including Tropical Diseases, 20, 1. https://doi.org/10.1186/1678-9199-20-1

  19. 19. Shao, L., Takeda, H., Fukui, T., Mabe, K., Han, J., Kawata, S., et al. (2010) Genetic Diversity of the Helicobacter pylori Sialic Acid-Binding Adhesin (sabA) Gene. BioScience Trends, 4, 249-253.

  20. 20. Rasmussen, L.T., de Labio, R.W., Neto, A.C., Silva, L.C., Queiroz, V.F., Smith, M.A.C., et al. (2012) Detection of Helicobacter pylori in Gastric Biopsies, Saliva and Dental Plaques of Dyspeptic Patients from Marília, São Paulo, Brazil: Presence of vacA and cagA Genes. Journal of Venomous Animals and Toxins Including Tropical Diseases, 18, 180-187. https://doi.org/10.1590/S1678-91992012000200008

  21. 21. Van Doorn, L.J., Figueiredo, C., Rossau, R., Jannes, G., van Asbroek, M., Sousa, J.C., et al. (1998) Typing of Helicobacter pylori vacA Gene and Detection of cagA Gene by PCR and Reverse Hybridization. Journal of Clinical Microbiology, 36, 1271-1276.

  22. 22. Warren, J.R. and Marshall, B. (1983) Unidentified Curved Bacilli on Gastric Epithelium in Active Chronic Gastritis. The Lancet, 321, 1273-1275. https://doi.org/10.1016/S0140-6736(83)92719-8

  23. 23. Suerbaum, S. and Michetti, P. (2002) Helicobacter Pylori Infection. New England Journal of Medicine, 347, 1597-1604. https://doi.org/10.1056/NEJMra020542

  24. 24. Salim, D.K., Sahin, M., Köksoy, S., Adanir, H. and Süleymanlar, I. (2016) Local Immune Response in Helicobacter pylori Infection. Medicine, 95, e3713.

  25. 25. Venerito, M., Vasapolli, R., Rokkas, T., Delchier, J.-C. and Malfertheiner, P. (2017) Helicobacter pylori, Gastric Cancer and Other Gastrointestinal Malignancies. Helicobacter, 22, e12413. https://doi.org/10.1111/hel.12413

  26. 26. Pang, S.S., Nguyen, S.T., Perry, A.J., Day, C.J., Panjikar, S., Tiralongo, J., et al. (2014) The Three-Dimensional Structure of the Extracelular Adhesion Domain of the Sialic Acid-Binding Adhesin SabA from Helicobacter pylori. Journal of Biological Chemistry, 289, 6332-6340. https://doi.org/10.1074/jbc.M113.513135

  27. 27. Oleastro, M. and Ménard, A. (2013) The Role of Helicobacter pylori Outer Membrane Proteins in Adherence and Pathogenesis. Biology, 2, 1110-1134. https://doi.org/10.3390/biology2031110

  28. 28. Nishioka, M., Takeuchi, H., Com, A.S., Uehara, Y., Nishimori, I., Okumiya, T., et al. (2010) The Mechanical Binding Strengths of Helicobacter pylori BabA and SabA Adhesins Using an Adhesion Binding Assay-ELISA, and Its Clinical Relevance in Japan. Microbiology and Immunology, 54, 442-451. https://doi.org/10.1111/j.1348-0421.2010.00237.x

  29. 29. Kato, S., Osaki, T., Kamiya, S., Zhang, X.-S. and Blaser, M.J. (2017) Helicobacter pylori sabA Gene Is Associated with Iron Deficiency Anemia in Childhood and Adolescence. PLoS ONE, 12, e0184046. https://doi.org/10.1371/journal.pone.0184046

  30. 30. Wang, F., Meng, W., Wang, B. and Qiao, L. (2014) Helicobacter pylori-Induced Gastric Inflammation and Gastric Cancer. Cancer Letters, 345, 196-202. https://doi.org/10.1016/j.canlet.2013.08.016

  31. 31. Oldani, A., Cormont, M., Hofman, V., Chiozzi, V., Oregioni, O., Canonici, A., et al. (2009) Helicobacter pylori Counteracts the Apoptotic Action of Its VacA Toxin by Injecting the CagA Protein into Gastric Epithelial Cells. PLoS Pathogens, 5, e1000603. https://doi.org/10.1371/journal.ppat.1000603

  32. 32. Yamaoka, Y., Ojo, O., Fujimoto, S., Odenbreit, S., Haas, R., Gutierrez, O., et al. (2006) Helicobacter pylori Outer Membrane Proteins and Gastroduodenal Disease. Gut, 55, 775-781. https://doi.org/10.1136/gut.2005.083014

  33. 33. Backert, S., Clyne, M. and Tegtmeyer, N. (2011) Molecular Mechanisms of Gastric Epithelial Cell Adhesion and Injection of CagA by Helicobacter pylori. Cell Communication and Signaling, 9, 28. https://doi.org/10.1186/1478-811X-9-28