Elucidation of the Metabolic Network of Helicobacter pylori J99 and Malaysian Clinical Strains by Phenotype Microarray.
BACKGROUND
Helicobacter pylori colonizes almost half of the human population worldwide. H. pylori strains are genetically diverse, and the specific genotypes are associated with various clinical manifestations including gastric adenocarcinoma, peptic ulcer disease (PUD), and nonulcer dyspepsia (NUD). However, our current knowledge of the H. pylori metabolism is limited. To understand the metabolic differences among H. pylori strains, we investigated four Malaysian H. pylori clinical strains, which had been previously sequenced, and a standard strain, H. pylori J99, at the phenotypic level.


METHODS
The phenotypes of the H. pylori strains were profiled using the Biolog Phenotype Microarray system to corroborate genomic data. We initiated the analyses by predicting carbon and nitrogen metabolic pathways from the H. pylori genomic data from the KEGG database. Biolog PM aided the validation of the prediction and provided a more intensive analysis of the H. pylori phenomes.


RESULTS
We have identified a core set of metabolic nutrient sources that was utilized by all strains tested and another set that was differentially utilized by only the local strains. Pentose sugars are the preferred carbon nutrients utilized by H. pylori. The amino acids l-aspartic acid, d-alanine, and l-asparagine serve as both carbon and nitrogen sources in the metabolism of the bacterium.


CONCLUSIONS
The phenotypic profile based on this study provides a better understanding on the survival of H. pylori in its natural host. Our data serve as a foundation for future challenges in correlating interstrain metabolic differences in H. pylori.
Faculty of Medicine, Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.
Woon Ching
WC
Lee
Faculty of Medicine, Department of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Khean Lee
KL
Goh
Faculty of Medicine, Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.
Mun Fai
MF
Loke
Faculty of Medicine, Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.
Jamuna
J
Vadivelu
D002244:Carbon / Q000378:metabolism; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D008296:Malaysia; D053858:Metabolic Networks and Pathways; D046228:Microarray Analysis; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype
D002244:Carbon; D009584:Nitrogen
Metabolism; amino acids; carbon sources; phenotype microarray