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Analysis of Genomic Diversity among Helicobacter pylori Strains Isolated from Iranian Children by Pulsed Field Gel Electrophoresis.

Falsafi T, Sotoudeh N, Feizabadi MM, Mahjoub F - Iran J Pediatr (2014)

Bottom Line: Similar conclusion was obtained by Total Lab software.However, more relationship was observed between the strains isolated in the close period (1997-2009, 2001-2003, 2005-2007, and 2007-2009) and more difference was observed among those obtained in the distant periods (1997 and 2009).H. pylori strains isolated from children in Iran are extremely diverse and this diversity is not related to their virulence characteristics.

View Article: PubMed Central - PubMed

Affiliation: Department of Mirobiology, Faculty of Biology, Alzahra University, Tehran.

ABSTRACT

Objective: Presence of genomic diversity among Helicobacter pylori (H. pylori) strains have been suggested by numerous investigators. Little is known about diversity of H. pylori strains isolated from Iranian children and their association with virulence of the strains. Our purpose was to assess the degree of genomic diversity among H. pylori strains isolated from Iranian-children, on the basis of vacA genotype, cagA status of the strains, sex, age as well as the pathological status of the patients.

Methods: Genomic DNA from 44 unrelated H. pylori strains isolated during 1997-2009, was examined by pulse-field gel electrophoresis (PFGE). Pathological status of the patients was performed according to the modified Sydney-system and genotype/status of vacA/cagA genes was determined by PCR. PFGE was performed using XbaI restriction-endonuclease and the field inversion-gel electrophoresis system.

Findings: No significant relationship was observed between the patterns of PFGE and the cagA/vacA status/genotype. Also no relationship was observed between age, sex, and pathological status of the children and the PFGE patterns of their isolates. Similar conclusion was obtained by Total Lab software. However, more relationship was observed between the strains isolated in the close period (1997-2009, 2001-2003, 2005-2007, and 2007-2009) and more difference was observed among those obtained in the distant periods (1997 and 2009).

Conclusion: H. pylori strains isolated from children in Iran are extremely diverse and this diversity is not related to their virulence characteristics. Occurrence of this extreme diversity may be related to adaptation of H. pylori strains to variable living conditions during transmission between various host individuals.

No MeSH data available.


Related in: MedlinePlus

PFGE Profile comparing the cagA-positive with cagA-negative isolatesNumbers above of the fig represent the number of strains according to Table 1. Lanes 1, 2, 4–8, 10, 12–13, and 15–16 represent the cagA-negative isolates. Lanes 3, 9, 11, 14, and 17 represent the cagA-positive isolates. Lane 18: 26695 standard strain (sizes of XbaI digested fragments: 370, 270, 260, 215, 200, 100, 80, and <80 Kb.
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F1a: PFGE Profile comparing the cagA-positive with cagA-negative isolatesNumbers above of the fig represent the number of strains according to Table 1. Lanes 1, 2, 4–8, 10, 12–13, and 15–16 represent the cagA-negative isolates. Lanes 3, 9, 11, 14, and 17 represent the cagA-positive isolates. Lane 18: 26695 standard strain (sizes of XbaI digested fragments: 370, 270, 260, 215, 200, 100, 80, and <80 Kb.

Mentions: The 26695 standard H. pylori strain produced 9 reproducible fragments on Xba1 PFGE gels, whereas 35 (80%) of the isolates showed 8 to 12 fragments, 4 isolates contained 5 to 7 fragments and 5 isolates showed 13–14 fragments. The strains were classified according to the numbers and the size of XbaI fragments on PFGE gels. Their comparison showed a marked genomic diversity. Association between the PFGE patterns of the strains and their cagA status, as well as vacA (s,m) alleles was evaluated. Relationship between the PFGE pattern of the strains and sex, age and pathological status of children was also assessed. No significant relationship was observed between the patterns of PFGE (number and size of the fragments) and the cagA status or vacA/cagA genotype (Fig 1, Table 2). Also, no significant relationship was observed between age, sex, and pathological status of the children and the PFGE patterns of their isolates. The PFGE patterns of the strains were also compared on the basis of isolation date (Fig. 2). To confirm the results of visual analysis, the patterns of PFGE were also analyzed using Total Lab software (Total Lab and Phoenix software, www.totallabs.com). The same conclusion was obtained concerning absence of significant relationship between the PFGE patterns of the isolates and their vacA/cagA genotype/status, and pathological status of the children. Fig 3 represents the relationship between PFGE patterns and vacA/cagA, as well as the pathological status among 12 isolates of group III (Total Lab and Phoenix software).


Analysis of Genomic Diversity among Helicobacter pylori Strains Isolated from Iranian Children by Pulsed Field Gel Electrophoresis.

Falsafi T, Sotoudeh N, Feizabadi MM, Mahjoub F - Iran J Pediatr (2014)

PFGE Profile comparing the cagA-positive with cagA-negative isolatesNumbers above of the fig represent the number of strains according to Table 1. Lanes 1, 2, 4–8, 10, 12–13, and 15–16 represent the cagA-negative isolates. Lanes 3, 9, 11, 14, and 17 represent the cagA-positive isolates. Lane 18: 26695 standard strain (sizes of XbaI digested fragments: 370, 270, 260, 215, 200, 100, 80, and <80 Kb.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4442831&req=5

F1a: PFGE Profile comparing the cagA-positive with cagA-negative isolatesNumbers above of the fig represent the number of strains according to Table 1. Lanes 1, 2, 4–8, 10, 12–13, and 15–16 represent the cagA-negative isolates. Lanes 3, 9, 11, 14, and 17 represent the cagA-positive isolates. Lane 18: 26695 standard strain (sizes of XbaI digested fragments: 370, 270, 260, 215, 200, 100, 80, and <80 Kb.
Mentions: The 26695 standard H. pylori strain produced 9 reproducible fragments on Xba1 PFGE gels, whereas 35 (80%) of the isolates showed 8 to 12 fragments, 4 isolates contained 5 to 7 fragments and 5 isolates showed 13–14 fragments. The strains were classified according to the numbers and the size of XbaI fragments on PFGE gels. Their comparison showed a marked genomic diversity. Association between the PFGE patterns of the strains and their cagA status, as well as vacA (s,m) alleles was evaluated. Relationship between the PFGE pattern of the strains and sex, age and pathological status of children was also assessed. No significant relationship was observed between the patterns of PFGE (number and size of the fragments) and the cagA status or vacA/cagA genotype (Fig 1, Table 2). Also, no significant relationship was observed between age, sex, and pathological status of the children and the PFGE patterns of their isolates. The PFGE patterns of the strains were also compared on the basis of isolation date (Fig. 2). To confirm the results of visual analysis, the patterns of PFGE were also analyzed using Total Lab software (Total Lab and Phoenix software, www.totallabs.com). The same conclusion was obtained concerning absence of significant relationship between the PFGE patterns of the isolates and their vacA/cagA genotype/status, and pathological status of the children. Fig 3 represents the relationship between PFGE patterns and vacA/cagA, as well as the pathological status among 12 isolates of group III (Total Lab and Phoenix software).

Bottom Line: Similar conclusion was obtained by Total Lab software.However, more relationship was observed between the strains isolated in the close period (1997-2009, 2001-2003, 2005-2007, and 2007-2009) and more difference was observed among those obtained in the distant periods (1997 and 2009).H. pylori strains isolated from children in Iran are extremely diverse and this diversity is not related to their virulence characteristics.

View Article: PubMed Central - PubMed

Affiliation: Department of Mirobiology, Faculty of Biology, Alzahra University, Tehran.

ABSTRACT

Objective: Presence of genomic diversity among Helicobacter pylori (H. pylori) strains have been suggested by numerous investigators. Little is known about diversity of H. pylori strains isolated from Iranian children and their association with virulence of the strains. Our purpose was to assess the degree of genomic diversity among H. pylori strains isolated from Iranian-children, on the basis of vacA genotype, cagA status of the strains, sex, age as well as the pathological status of the patients.

Methods: Genomic DNA from 44 unrelated H. pylori strains isolated during 1997-2009, was examined by pulse-field gel electrophoresis (PFGE). Pathological status of the patients was performed according to the modified Sydney-system and genotype/status of vacA/cagA genes was determined by PCR. PFGE was performed using XbaI restriction-endonuclease and the field inversion-gel electrophoresis system.

Findings: No significant relationship was observed between the patterns of PFGE and the cagA/vacA status/genotype. Also no relationship was observed between age, sex, and pathological status of the children and the PFGE patterns of their isolates. Similar conclusion was obtained by Total Lab software. However, more relationship was observed between the strains isolated in the close period (1997-2009, 2001-2003, 2005-2007, and 2007-2009) and more difference was observed among those obtained in the distant periods (1997 and 2009).

Conclusion: H. pylori strains isolated from children in Iran are extremely diverse and this diversity is not related to their virulence characteristics. Occurrence of this extreme diversity may be related to adaptation of H. pylori strains to variable living conditions during transmission between various host individuals.

No MeSH data available.


Related in: MedlinePlus