Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates
<p>Abstract</p> <p>Background</p> <p>Clinical isolates of the gastric pathogen <it>Helicobacter pylori </it>display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of <it>H. pylori...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2007-04-01
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| Series: | BMC Microbiology |
| Online Access: | http://www.biomedcentral.com/1471-2180/7/26 |
| _version_ | 1831689129552773120 |
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| author | Spadafora Domenico Bolland Jeffrey R Bathala Sangeetha Hildebrandt Ellen Langford Melanie L Watson Emily L Hovey Justin G Mendz George L McGee David J |
| author_facet | Spadafora Domenico Bolland Jeffrey R Bathala Sangeetha Hildebrandt Ellen Langford Melanie L Watson Emily L Hovey Justin G Mendz George L McGee David J |
| author_sort | Spadafora Domenico |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Clinical isolates of the gastric pathogen <it>Helicobacter pylori </it>display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of <it>H. pylori </it>to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid.</p> <p>Results</p> <p>The degree of variation in arginase was explored at the DNA sequence, enzyme activity and protein expression levels. To this end, arginase activity was measured from 73 minimally-passaged clinical isolates and six laboratory-adapted strains of <it>H. pylori</it>. The <it>rocF </it>gene from 21 of the strains was cloned into genetically stable <it>E. coli </it>and the enzyme activities measured. Arginase activity was found to substantially vary (>100-fold) in both different <it>H. pylori </it>strains and in the <it>E. coli </it>model. Western blot analysis revealed a positive correlation between activity and amount of protein expressed in most <it>H. pylori </it>strains. Several <it>H. pylori </it>strains featured altered arginase activity upon <it>in vitro </it>passage. Pairwise alignments of the 21 <it>rocF </it>genes plus strain J99 revealed extensive microheterogeneity in the promoter region and 3' end of the <it>rocF </it>coding region. Amino acid S232, which was I232 in the arginase-negative clinical strain A2, was critical for arginase activity.</p> <p>Conclusion</p> <p>These studies demonstrated that <it>H. pylori </it>arginase exhibits extensive genotypic and phenotypic variation which may be used to understand mechanisms of microheterogeneity in <it>H. pylori</it>.</p> |
| first_indexed | 2024-12-20T10:43:45Z |
| format | Article |
| id | doaj.art-1dc77cc79d434996ade50070e56a05a5 |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-12-20T10:43:45Z |
| publishDate | 2007-04-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-1dc77cc79d434996ade50070e56a05a52022-12-21T19:43:29ZengBMCBMC Microbiology1471-21802007-04-01712610.1186/1471-2180-7-26Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolatesSpadafora DomenicoBolland Jeffrey RBathala SangeethaHildebrandt EllenLangford Melanie LWatson Emily LHovey Justin GMendz George LMcGee David J<p>Abstract</p> <p>Background</p> <p>Clinical isolates of the gastric pathogen <it>Helicobacter pylori </it>display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of <it>H. pylori </it>to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid.</p> <p>Results</p> <p>The degree of variation in arginase was explored at the DNA sequence, enzyme activity and protein expression levels. To this end, arginase activity was measured from 73 minimally-passaged clinical isolates and six laboratory-adapted strains of <it>H. pylori</it>. The <it>rocF </it>gene from 21 of the strains was cloned into genetically stable <it>E. coli </it>and the enzyme activities measured. Arginase activity was found to substantially vary (>100-fold) in both different <it>H. pylori </it>strains and in the <it>E. coli </it>model. Western blot analysis revealed a positive correlation between activity and amount of protein expressed in most <it>H. pylori </it>strains. Several <it>H. pylori </it>strains featured altered arginase activity upon <it>in vitro </it>passage. Pairwise alignments of the 21 <it>rocF </it>genes plus strain J99 revealed extensive microheterogeneity in the promoter region and 3' end of the <it>rocF </it>coding region. Amino acid S232, which was I232 in the arginase-negative clinical strain A2, was critical for arginase activity.</p> <p>Conclusion</p> <p>These studies demonstrated that <it>H. pylori </it>arginase exhibits extensive genotypic and phenotypic variation which may be used to understand mechanisms of microheterogeneity in <it>H. pylori</it>.</p>http://www.biomedcentral.com/1471-2180/7/26 |
| spellingShingle | Spadafora Domenico Bolland Jeffrey R Bathala Sangeetha Hildebrandt Ellen Langford Melanie L Watson Emily L Hovey Justin G Mendz George L McGee David J Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates BMC Microbiology |
| title | Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates |
| title_full | Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates |
| title_fullStr | Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates |
| title_full_unstemmed | Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates |
| title_short | Genetic microheterogeneity and phenotypic variation of <it>Helicobacter pylori </it>arginase in clinical isolates |
| title_sort | genetic microheterogeneity and phenotypic variation of it helicobacter pylori it arginase in clinical isolates |
| url | http://www.biomedcentral.com/1471-2180/7/26 |
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