Main Article Content
Abstract
Helicobacter pylori has several virulence factors, including the ability to produce urease, which allows it to colonize the stomach and survive for long periods of time. As a results of those virulence factors of H. Pylori causes gastritis. This study aimed to detect H. pylori using of real-time PCR amplification of VacA and CagA genes, and compare between both genes and detection by urease and creatine. For this purpose, a total of 50 patients were selected and have been clinically diagnosed with gastritis. Biopsy samples were collected from all the patients. Rapid urease test (RUT) was applied to all gastric samples to detect the presence of H. Pylori. DNA was extracted and the RT-PCR was perform to detect the VacA and CagA genes. The results of RUT showed 20 samples were positive of H. Pylori, after the Real Time-PCR test were done the results showed 27 (54%) to VacA and 25 (50%) to CagA genes were positives.
Keywords
Helicobactor pylori
Biopsies
Gastritis
Real-time PCR.
Article Details
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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The authors transfer the copyrights of their papers to the Iranian Society of Ichthyology. However, the information could be used in accordance with the Creative Commons licence (Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
How to Cite
JABER, A. S., & ABBAS, F. N. (2021). Molecular detection of the virulence gene’s VacA and CagA of Helicobacter pylori by PCR. Iranian Journal of Ichthyology, 8, 341–347. https://doi.org/10.22034/iji.v8i0.708
References
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Abu-Taleb, A.M.; Abdelattef, R.S.; Abdel-Hady, A.A.; Omran, F.H.; El-Korashi, L.A.; El-hady, A.A. & El-Gebaly, A.M. 2018. Prevalence of Helicobacter pylori cagA and iceA genes and their association with gastrointestinal diseases. International journal of microbiology, 2018.
Abu-Zekry, M.A.; Hashem, M.; Ali, A.A.; Mohamed, I.S. 2013. Frequency of H. pylori infection among Egyptian children presenting with gastrointestinal manifestations. Journal of the Egyptian Public Health Association 8: 74-78.
Alazmi, W.M., Siddique, I.; Alateeqi, N. & Al-Nakib, B. 2010 Prevalence of H. pylori infection among new outpatients with dyspepsia in Kuwait. BMC Gastroenterol 10 (1): 1-4.
Ali A.S. & Borei M.B. 2013. H. pylori and Egyptian infantile colic. Journal of the Egyptian Society of Parasitology 43: 327-332.
Al-Sabary, A.H.; Razzaq, M.S.A. & Wtwt, M. A. 2017. Genotyping of Helicobacter pylori isolated from Iraqi patient with upper gastrointestinal disease. Journal of Global Pharma Technology 9(9): 121-127.
Aydogan, T.; Ulas, T.; Selcoki, Y.; Alkan, R.; Yılmaz, O.C.; Yalcın, K.S. & Turkay, C. 2012. Effects of Helicobacter pylori eradication on proteinuria: a prospective study. Wiener Klinische Wochenschrift 124(7): 241-244.
Balat, M.N.; Fahmy Zanaty, M.A.; EL-Antouny, N.G. & Ahmed, H.K. 2019. Association between proteinuria and active Helicobacter pylori infection in non-diabetic patients. Zagazig University Medical Journal 25(1): 79-84.
Blanchard, T.G. & Nedrud, J.G. 2012, Laboratory maintenance of Helicobacter species. Current Protocols in Microbiology (1): 8B-1.
Bridge, D.R. & Merrell, D.S. 2013. Polymorphism in the Helicobacter pylori CagA and VacA toxins and disease. Gut Microbes 4: 101–17.
Eghbali, Z.; Mojtahedi, A.; Ansar, M.M.; Fakhrieh, S. & Keyvan Aminian, K. 2016. Detection of 23SrRNA Mutations Strongly Related to Clarithromycin Resistance in Helicobacter pylori Strains Isolated from Patients in the North of Iran. Jundishapur Journal of Microbiology 9(2): e29694.
FAO. 2013. Milk and dairy products in human nutrition. Rome.
Feliciano, O.; O. Gutierrez, L.; Valdés, T.; Fragoso, A.M.; Calderin, A.E. & Llanes, R. 2015. Prevalence of Helicobacter pylori vacA, cagA, and iceA Genotypes in Cuban patients with upper gastrointestinal diseases. BioMed Research International.
Gebert, B.; Fischer, W.; Weiss, E.; Hoffmann, R. & Haas, R. 2003; Helicobacter pylori vacuolating cytotoxin inhibits T lymphocyte activation. Science 301: 1099-1102.
Goh, K.L. 1997. Prevalence of and risk factors for H. pylori infection in a multi-racial dyspeptic Malaysian population undergoing endoscopy. Journal of Gastroenterology and Hepatology 12: 29-35.
Haddadi, M-H.; Negahdari, B.; Asadolahi, R. & Bazargani, A. 2020. Helicobacter pylori antibiotic resistance and correlation with cagA motifs and homB gene. Postgrad Medicine 132(6): 512-520.
Hamidi, S.; Badmasti, F.; Heravi, F.S.; Safapoor, M.H.; Tabrizi, A.M.A. & Ghorbani, M. 2020. Antibiotic resistance and clonal relatedness of Helicobacter pylori strains isolated from stomach biopsy specimens in northeast of Iran. Helicobacter 25(2): e12684.
Hasosah, M.; Satti, M.; Shehzad, A.; Alsahafi, A.; Sukkar, G. & Alzaben, A. 2015 Prevalence and risk factors of H. pylori infection in Saudi children: a three-year prospective controlled study. Helicobacter 20: 56-63.
Havaei, A.; Mohajeri, P.; R. Khashei, R.; Salehi, H. & Tavakoli, 2014. Prevalence of Helicobacter Pylori VacA different genotypes in Isfahan. Advanced Biomedical Research, 3.
Hussein, R.N.; Mohammadi, M.; Talebkhan, Y.; Doraghi, M.P.; Letley, D.K.; Muhammad, M.; Argent, H.R. & Atherton, C.J. 2008. Differences in virulence markers between Helicobacter pylori strains from Iraq and those from Iran: potential importance of regional differences in H. pylori-associated disease. Journal of Clinical Microbiology 46: 1774-1779.
Idowu, A.; Mzukwa, A. & Harrison, U. 2019. Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa. BMC Gastroenterol 19: 73.
Isomoto, H.; Moss, J. & Hirayama, T. 2010. Pleiotropic actions of Helicobacter pylori vacuolating cytotoxin, VacA. The Tohoku Journal of Experimental Medicine 220: 3-14.
Kadi, R.H.; Halawani, E.M. & Abdelkader, H.S. 2014 Prevalence of H. pylori strains harbouring cagA and iceA virulence genes in Saudi patients with gastritis and peptic ulcer disease. Microbiology Discovery 2: 2.
Kamangar, F.; Sheikhattari, P. & Mohebtash, M. 2011. Helicobacter pylori and its Effects on Human Health and Disease. H. pylori and Health, Archives of Iranian Medicine 14(3): 192-199
Kao, C.; Sheu, B. & Wu, J. 2016. Helicobacter pylori infection: an overview of bacterial virulence factors and pathogenesis Bioomedine Journal 39: 14-23.
Kong, X.; Xu, D.; Li, F.; Ma, X.; Su, H. & Xu, D. 2017. Association of H. pylori infection with chronic kidney disease among Chinese adults. International Urology and Nephrology 49(5): 845-850.
Lin, S.Y.; Lin, C.L.; Liu, J.H.; Yang, Y.F.; Huang, C.C. & Kao, C.H. 2015. Association between Helicobacter pylori infection and the subsequent risk of end‐stage renal disease: a nationwide population‐based cohort study. International Journal of Clinical Practice 69(5): 604-610.
Marie, MA. 2012. Relationship between Helicobacter pylori virulence genes and clinical outcomes in Saudi patients. Journal of Korean Medical Science 27: 190-193.
Momenah, A.M. & Tayeb, M.T. 2007. Helicobacter pylori cagA and iceA genotypes status and risk of peptic ulcer in Saudi patients. Saudi Medical Journal 28(3): 382-385.
Nahaei, M.R.; Sharifi, Y.; Akhi, M.T., Asgharzadeh, M.; Nahaei, M. & Fatahi, E. 2008. Helicobacter pylori cagA and vacA genotypes and their relationships to peptic ulcer disease and non-ulcer dyspepsia. Research Journal of Microbiology 3(5): 386-394.
Rasheed, F.; Campbell, B.J.; Alfizah, H.; Varro, A.; Zahra, R. & Yamaoka, Y. 2014. Analysis of clinical isolates of H. pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance Helicobacter 19: 387-399.
Sallas, M.; Melchiades, J.; Zabaglia, L. & Moreno, J. 2017. Prevalence of Helicobacter pylori vacA, cagA, dupA and oipA genotypes in patients with Gastric Disease. Advance in Microbiology 7(1): 1-9.
Saribasak, H.; Salih, B.A.; Yamaoka, Y. & Sander, E. 2004. Analysis of Helicobacter pylori genotypes and correlation with clinical outcome in Turkey. Journal of Clinical Microbiology 42(4): 1648-1651.
Sasaki, T.; Hirai, I. & Yamamoto, Y. 2009. Analysis of Helicobacter pylori infection in a healthy Panamanian population. Kansenshogaku Zasshi 83: 127-132.
Smith, S.; Fowora, M. & Pellicano, R. 2019. Infections with Helicobacter pylori and challenges encountered in Africa. World Journal of Gastroenterology 25(25): 3183-3195.
Subhani, M.; Kagolanu, D.; Shah, M.; Rizvon, K. & Mustacchia, P. 2017. Assessing the Link Between 2 Inflammatory Markers: Helicobacter pylori and Microalbuminuria: 1237. American Journal of Gastroenterology 112: S675.
Suzuki, H.; Warren, R. & Marshal, B. 2013. Helicobacter pylori. (Springer Nature, 2016).
Van Doorn, L.J.; Figueiredo, C.; Sanna, R.; Blaser, M.J. & Quint W.G. 1999; Distinct variants of Helicobacter pylori cagA are associated with vacA subtypes. Journal of Clinical Microbiology 37: 2306-2311.
Vazirzadeh, J.; Falahi, J.; Moghim, S.; Narimani, T.; Rafiei, R. & Karbasizadeh, V. 2020. Molecular assessment of resistance to clarithromycin in Helicobacter pylori strains isolated from patients with dyspepsia by fluorescent in situ hybridization in the center of Iran. BioMedcine Research International 2304173: 1-7.
Wijarnpreecha, K.; Thongprayoon, C., Nissaisorakarn, P.; Jaruvongvanich, V.; Nakkala, K., Rajapakse, R. & Cheungpasitporn, W. 2017. Association of Helicobacter pylori with chronic kidney diseases: a meta-analysis. Digestive Diseases and Sciences 62(8): 2045-2052.
References
Abu-Taleb, A.M.; Abdelattef, R.S.; Abdel-Hady, A.A.; Omran, F.H.; El-Korashi, L.A.; El-hady, A.A. & El-Gebaly, A.M. 2018. Prevalence of Helicobacter pylori cagA and iceA genes and their association with gastrointestinal diseases. International journal of microbiology, 2018.
Abu-Zekry, M.A.; Hashem, M.; Ali, A.A.; Mohamed, I.S. 2013. Frequency of H. pylori infection among Egyptian children presenting with gastrointestinal manifestations. Journal of the Egyptian Public Health Association 8: 74-78.
Alazmi, W.M., Siddique, I.; Alateeqi, N. & Al-Nakib, B. 2010 Prevalence of H. pylori infection among new outpatients with dyspepsia in Kuwait. BMC Gastroenterol 10 (1): 1-4.
Ali A.S. & Borei M.B. 2013. H. pylori and Egyptian infantile colic. Journal of the Egyptian Society of Parasitology 43: 327-332.
Al-Sabary, A.H.; Razzaq, M.S.A. & Wtwt, M. A. 2017. Genotyping of Helicobacter pylori isolated from Iraqi patient with upper gastrointestinal disease. Journal of Global Pharma Technology 9(9): 121-127.
Aydogan, T.; Ulas, T.; Selcoki, Y.; Alkan, R.; Yılmaz, O.C.; Yalcın, K.S. & Turkay, C. 2012. Effects of Helicobacter pylori eradication on proteinuria: a prospective study. Wiener Klinische Wochenschrift 124(7): 241-244.
Balat, M.N.; Fahmy Zanaty, M.A.; EL-Antouny, N.G. & Ahmed, H.K. 2019. Association between proteinuria and active Helicobacter pylori infection in non-diabetic patients. Zagazig University Medical Journal 25(1): 79-84.
Blanchard, T.G. & Nedrud, J.G. 2012, Laboratory maintenance of Helicobacter species. Current Protocols in Microbiology (1): 8B-1.
Bridge, D.R. & Merrell, D.S. 2013. Polymorphism in the Helicobacter pylori CagA and VacA toxins and disease. Gut Microbes 4: 101–17.
Eghbali, Z.; Mojtahedi, A.; Ansar, M.M.; Fakhrieh, S. & Keyvan Aminian, K. 2016. Detection of 23SrRNA Mutations Strongly Related to Clarithromycin Resistance in Helicobacter pylori Strains Isolated from Patients in the North of Iran. Jundishapur Journal of Microbiology 9(2): e29694.
FAO. 2013. Milk and dairy products in human nutrition. Rome.
Feliciano, O.; O. Gutierrez, L.; Valdés, T.; Fragoso, A.M.; Calderin, A.E. & Llanes, R. 2015. Prevalence of Helicobacter pylori vacA, cagA, and iceA Genotypes in Cuban patients with upper gastrointestinal diseases. BioMed Research International.
Gebert, B.; Fischer, W.; Weiss, E.; Hoffmann, R. & Haas, R. 2003; Helicobacter pylori vacuolating cytotoxin inhibits T lymphocyte activation. Science 301: 1099-1102.
Goh, K.L. 1997. Prevalence of and risk factors for H. pylori infection in a multi-racial dyspeptic Malaysian population undergoing endoscopy. Journal of Gastroenterology and Hepatology 12: 29-35.
Haddadi, M-H.; Negahdari, B.; Asadolahi, R. & Bazargani, A. 2020. Helicobacter pylori antibiotic resistance and correlation with cagA motifs and homB gene. Postgrad Medicine 132(6): 512-520.
Hamidi, S.; Badmasti, F.; Heravi, F.S.; Safapoor, M.H.; Tabrizi, A.M.A. & Ghorbani, M. 2020. Antibiotic resistance and clonal relatedness of Helicobacter pylori strains isolated from stomach biopsy specimens in northeast of Iran. Helicobacter 25(2): e12684.
Hasosah, M.; Satti, M.; Shehzad, A.; Alsahafi, A.; Sukkar, G. & Alzaben, A. 2015 Prevalence and risk factors of H. pylori infection in Saudi children: a three-year prospective controlled study. Helicobacter 20: 56-63.
Havaei, A.; Mohajeri, P.; R. Khashei, R.; Salehi, H. & Tavakoli, 2014. Prevalence of Helicobacter Pylori VacA different genotypes in Isfahan. Advanced Biomedical Research, 3.
Hussein, R.N.; Mohammadi, M.; Talebkhan, Y.; Doraghi, M.P.; Letley, D.K.; Muhammad, M.; Argent, H.R. & Atherton, C.J. 2008. Differences in virulence markers between Helicobacter pylori strains from Iraq and those from Iran: potential importance of regional differences in H. pylori-associated disease. Journal of Clinical Microbiology 46: 1774-1779.
Idowu, A.; Mzukwa, A. & Harrison, U. 2019. Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa. BMC Gastroenterol 19: 73.
Isomoto, H.; Moss, J. & Hirayama, T. 2010. Pleiotropic actions of Helicobacter pylori vacuolating cytotoxin, VacA. The Tohoku Journal of Experimental Medicine 220: 3-14.
Kadi, R.H.; Halawani, E.M. & Abdelkader, H.S. 2014 Prevalence of H. pylori strains harbouring cagA and iceA virulence genes in Saudi patients with gastritis and peptic ulcer disease. Microbiology Discovery 2: 2.
Kamangar, F.; Sheikhattari, P. & Mohebtash, M. 2011. Helicobacter pylori and its Effects on Human Health and Disease. H. pylori and Health, Archives of Iranian Medicine 14(3): 192-199
Kao, C.; Sheu, B. & Wu, J. 2016. Helicobacter pylori infection: an overview of bacterial virulence factors and pathogenesis Bioomedine Journal 39: 14-23.
Kong, X.; Xu, D.; Li, F.; Ma, X.; Su, H. & Xu, D. 2017. Association of H. pylori infection with chronic kidney disease among Chinese adults. International Urology and Nephrology 49(5): 845-850.
Lin, S.Y.; Lin, C.L.; Liu, J.H.; Yang, Y.F.; Huang, C.C. & Kao, C.H. 2015. Association between Helicobacter pylori infection and the subsequent risk of end‐stage renal disease: a nationwide population‐based cohort study. International Journal of Clinical Practice 69(5): 604-610.
Marie, MA. 2012. Relationship between Helicobacter pylori virulence genes and clinical outcomes in Saudi patients. Journal of Korean Medical Science 27: 190-193.
Momenah, A.M. & Tayeb, M.T. 2007. Helicobacter pylori cagA and iceA genotypes status and risk of peptic ulcer in Saudi patients. Saudi Medical Journal 28(3): 382-385.
Nahaei, M.R.; Sharifi, Y.; Akhi, M.T., Asgharzadeh, M.; Nahaei, M. & Fatahi, E. 2008. Helicobacter pylori cagA and vacA genotypes and their relationships to peptic ulcer disease and non-ulcer dyspepsia. Research Journal of Microbiology 3(5): 386-394.
Rasheed, F.; Campbell, B.J.; Alfizah, H.; Varro, A.; Zahra, R. & Yamaoka, Y. 2014. Analysis of clinical isolates of H. pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance Helicobacter 19: 387-399.
Sallas, M.; Melchiades, J.; Zabaglia, L. & Moreno, J. 2017. Prevalence of Helicobacter pylori vacA, cagA, dupA and oipA genotypes in patients with Gastric Disease. Advance in Microbiology 7(1): 1-9.
Saribasak, H.; Salih, B.A.; Yamaoka, Y. & Sander, E. 2004. Analysis of Helicobacter pylori genotypes and correlation with clinical outcome in Turkey. Journal of Clinical Microbiology 42(4): 1648-1651.
Sasaki, T.; Hirai, I. & Yamamoto, Y. 2009. Analysis of Helicobacter pylori infection in a healthy Panamanian population. Kansenshogaku Zasshi 83: 127-132.
Smith, S.; Fowora, M. & Pellicano, R. 2019. Infections with Helicobacter pylori and challenges encountered in Africa. World Journal of Gastroenterology 25(25): 3183-3195.
Subhani, M.; Kagolanu, D.; Shah, M.; Rizvon, K. & Mustacchia, P. 2017. Assessing the Link Between 2 Inflammatory Markers: Helicobacter pylori and Microalbuminuria: 1237. American Journal of Gastroenterology 112: S675.
Suzuki, H.; Warren, R. & Marshal, B. 2013. Helicobacter pylori. (Springer Nature, 2016).
Van Doorn, L.J.; Figueiredo, C.; Sanna, R.; Blaser, M.J. & Quint W.G. 1999; Distinct variants of Helicobacter pylori cagA are associated with vacA subtypes. Journal of Clinical Microbiology 37: 2306-2311.
Vazirzadeh, J.; Falahi, J.; Moghim, S.; Narimani, T.; Rafiei, R. & Karbasizadeh, V. 2020. Molecular assessment of resistance to clarithromycin in Helicobacter pylori strains isolated from patients with dyspepsia by fluorescent in situ hybridization in the center of Iran. BioMedcine Research International 2304173: 1-7.
Wijarnpreecha, K.; Thongprayoon, C., Nissaisorakarn, P.; Jaruvongvanich, V.; Nakkala, K., Rajapakse, R. & Cheungpasitporn, W. 2017. Association of Helicobacter pylori with chronic kidney diseases: a meta-analysis. Digestive Diseases and Sciences 62(8): 2045-2052.
Abu-Zekry, M.A.; Hashem, M.; Ali, A.A.; Mohamed, I.S. 2013. Frequency of H. pylori infection among Egyptian children presenting with gastrointestinal manifestations. Journal of the Egyptian Public Health Association 8: 74-78.
Alazmi, W.M., Siddique, I.; Alateeqi, N. & Al-Nakib, B. 2010 Prevalence of H. pylori infection among new outpatients with dyspepsia in Kuwait. BMC Gastroenterol 10 (1): 1-4.
Ali A.S. & Borei M.B. 2013. H. pylori and Egyptian infantile colic. Journal of the Egyptian Society of Parasitology 43: 327-332.
Al-Sabary, A.H.; Razzaq, M.S.A. & Wtwt, M. A. 2017. Genotyping of Helicobacter pylori isolated from Iraqi patient with upper gastrointestinal disease. Journal of Global Pharma Technology 9(9): 121-127.
Aydogan, T.; Ulas, T.; Selcoki, Y.; Alkan, R.; Yılmaz, O.C.; Yalcın, K.S. & Turkay, C. 2012. Effects of Helicobacter pylori eradication on proteinuria: a prospective study. Wiener Klinische Wochenschrift 124(7): 241-244.
Balat, M.N.; Fahmy Zanaty, M.A.; EL-Antouny, N.G. & Ahmed, H.K. 2019. Association between proteinuria and active Helicobacter pylori infection in non-diabetic patients. Zagazig University Medical Journal 25(1): 79-84.
Blanchard, T.G. & Nedrud, J.G. 2012, Laboratory maintenance of Helicobacter species. Current Protocols in Microbiology (1): 8B-1.
Bridge, D.R. & Merrell, D.S. 2013. Polymorphism in the Helicobacter pylori CagA and VacA toxins and disease. Gut Microbes 4: 101–17.
Eghbali, Z.; Mojtahedi, A.; Ansar, M.M.; Fakhrieh, S. & Keyvan Aminian, K. 2016. Detection of 23SrRNA Mutations Strongly Related to Clarithromycin Resistance in Helicobacter pylori Strains Isolated from Patients in the North of Iran. Jundishapur Journal of Microbiology 9(2): e29694.
FAO. 2013. Milk and dairy products in human nutrition. Rome.
Feliciano, O.; O. Gutierrez, L.; Valdés, T.; Fragoso, A.M.; Calderin, A.E. & Llanes, R. 2015. Prevalence of Helicobacter pylori vacA, cagA, and iceA Genotypes in Cuban patients with upper gastrointestinal diseases. BioMed Research International.
Gebert, B.; Fischer, W.; Weiss, E.; Hoffmann, R. & Haas, R. 2003; Helicobacter pylori vacuolating cytotoxin inhibits T lymphocyte activation. Science 301: 1099-1102.
Goh, K.L. 1997. Prevalence of and risk factors for H. pylori infection in a multi-racial dyspeptic Malaysian population undergoing endoscopy. Journal of Gastroenterology and Hepatology 12: 29-35.
Haddadi, M-H.; Negahdari, B.; Asadolahi, R. & Bazargani, A. 2020. Helicobacter pylori antibiotic resistance and correlation with cagA motifs and homB gene. Postgrad Medicine 132(6): 512-520.
Hamidi, S.; Badmasti, F.; Heravi, F.S.; Safapoor, M.H.; Tabrizi, A.M.A. & Ghorbani, M. 2020. Antibiotic resistance and clonal relatedness of Helicobacter pylori strains isolated from stomach biopsy specimens in northeast of Iran. Helicobacter 25(2): e12684.
Hasosah, M.; Satti, M.; Shehzad, A.; Alsahafi, A.; Sukkar, G. & Alzaben, A. 2015 Prevalence and risk factors of H. pylori infection in Saudi children: a three-year prospective controlled study. Helicobacter 20: 56-63.
Havaei, A.; Mohajeri, P.; R. Khashei, R.; Salehi, H. & Tavakoli, 2014. Prevalence of Helicobacter Pylori VacA different genotypes in Isfahan. Advanced Biomedical Research, 3.
Hussein, R.N.; Mohammadi, M.; Talebkhan, Y.; Doraghi, M.P.; Letley, D.K.; Muhammad, M.; Argent, H.R. & Atherton, C.J. 2008. Differences in virulence markers between Helicobacter pylori strains from Iraq and those from Iran: potential importance of regional differences in H. pylori-associated disease. Journal of Clinical Microbiology 46: 1774-1779.
Idowu, A.; Mzukwa, A. & Harrison, U. 2019. Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa. BMC Gastroenterol 19: 73.
Isomoto, H.; Moss, J. & Hirayama, T. 2010. Pleiotropic actions of Helicobacter pylori vacuolating cytotoxin, VacA. The Tohoku Journal of Experimental Medicine 220: 3-14.
Kadi, R.H.; Halawani, E.M. & Abdelkader, H.S. 2014 Prevalence of H. pylori strains harbouring cagA and iceA virulence genes in Saudi patients with gastritis and peptic ulcer disease. Microbiology Discovery 2: 2.
Kamangar, F.; Sheikhattari, P. & Mohebtash, M. 2011. Helicobacter pylori and its Effects on Human Health and Disease. H. pylori and Health, Archives of Iranian Medicine 14(3): 192-199
Kao, C.; Sheu, B. & Wu, J. 2016. Helicobacter pylori infection: an overview of bacterial virulence factors and pathogenesis Bioomedine Journal 39: 14-23.
Kong, X.; Xu, D.; Li, F.; Ma, X.; Su, H. & Xu, D. 2017. Association of H. pylori infection with chronic kidney disease among Chinese adults. International Urology and Nephrology 49(5): 845-850.
Lin, S.Y.; Lin, C.L.; Liu, J.H.; Yang, Y.F.; Huang, C.C. & Kao, C.H. 2015. Association between Helicobacter pylori infection and the subsequent risk of end‐stage renal disease: a nationwide population‐based cohort study. International Journal of Clinical Practice 69(5): 604-610.
Marie, MA. 2012. Relationship between Helicobacter pylori virulence genes and clinical outcomes in Saudi patients. Journal of Korean Medical Science 27: 190-193.
Momenah, A.M. & Tayeb, M.T. 2007. Helicobacter pylori cagA and iceA genotypes status and risk of peptic ulcer in Saudi patients. Saudi Medical Journal 28(3): 382-385.
Nahaei, M.R.; Sharifi, Y.; Akhi, M.T., Asgharzadeh, M.; Nahaei, M. & Fatahi, E. 2008. Helicobacter pylori cagA and vacA genotypes and their relationships to peptic ulcer disease and non-ulcer dyspepsia. Research Journal of Microbiology 3(5): 386-394.
Rasheed, F.; Campbell, B.J.; Alfizah, H.; Varro, A.; Zahra, R. & Yamaoka, Y. 2014. Analysis of clinical isolates of H. pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance Helicobacter 19: 387-399.
Sallas, M.; Melchiades, J.; Zabaglia, L. & Moreno, J. 2017. Prevalence of Helicobacter pylori vacA, cagA, dupA and oipA genotypes in patients with Gastric Disease. Advance in Microbiology 7(1): 1-9.
Saribasak, H.; Salih, B.A.; Yamaoka, Y. & Sander, E. 2004. Analysis of Helicobacter pylori genotypes and correlation with clinical outcome in Turkey. Journal of Clinical Microbiology 42(4): 1648-1651.
Sasaki, T.; Hirai, I. & Yamamoto, Y. 2009. Analysis of Helicobacter pylori infection in a healthy Panamanian population. Kansenshogaku Zasshi 83: 127-132.
Smith, S.; Fowora, M. & Pellicano, R. 2019. Infections with Helicobacter pylori and challenges encountered in Africa. World Journal of Gastroenterology 25(25): 3183-3195.
Subhani, M.; Kagolanu, D.; Shah, M.; Rizvon, K. & Mustacchia, P. 2017. Assessing the Link Between 2 Inflammatory Markers: Helicobacter pylori and Microalbuminuria: 1237. American Journal of Gastroenterology 112: S675.
Suzuki, H.; Warren, R. & Marshal, B. 2013. Helicobacter pylori. (Springer Nature, 2016).
Van Doorn, L.J.; Figueiredo, C.; Sanna, R.; Blaser, M.J. & Quint W.G. 1999; Distinct variants of Helicobacter pylori cagA are associated with vacA subtypes. Journal of Clinical Microbiology 37: 2306-2311.
Vazirzadeh, J.; Falahi, J.; Moghim, S.; Narimani, T.; Rafiei, R. & Karbasizadeh, V. 2020. Molecular assessment of resistance to clarithromycin in Helicobacter pylori strains isolated from patients with dyspepsia by fluorescent in situ hybridization in the center of Iran. BioMedcine Research International 2304173: 1-7.
Wijarnpreecha, K.; Thongprayoon, C., Nissaisorakarn, P.; Jaruvongvanich, V.; Nakkala, K., Rajapakse, R. & Cheungpasitporn, W. 2017. Association of Helicobacter pylori with chronic kidney diseases: a meta-analysis. Digestive Diseases and Sciences 62(8): 2045-2052.