Tracing clonality of Helicobacter pylori infecting family members from analysis of DNA sequences of three housekeeping genes (ureI, atpA and ahpC), deduced amino acid sequences, and pathogenicity-associated markers (cagA and vacA).
Helicobacter pylori, a Gram-negative bacterium, is a causal agent of peptic ulcers and is estimated to infect the gastric mucosa of at least half of the world's population. As primary infections are acquired mainly by household contact, studies on family clusters provide a model for investigating transmission and the natural history of initial infection. Here, sequence typing exploiting genetic variation in core fragments of three key housekeeping loci (ureI, atpA and ahpC) was used to determine clonal descent amongst isolates of ten members of four families in Northern Ireland and a family with three generations in central England. Phylogenetic analysis of each locus for 73 strains of H. pylori from 11 countries indicated high background intraspecific diversity, apart from identical paired isolates from five unrelated patients and strains with identical sequence types (STs) detected in adult members of two families. In several families carrying strains with different STs, evidence of residual clonal descent was detected at one or two loci by comparison of nucleotide and amino acid sequences. Pathogenicity-associated genotypes were heterogeneous with respect to ST and amino acid type. Analysis of these three housekeeping genes provides unique evidence for precise tracing of clonal descent in isolates of H. pylori in family groups.
Helicobacter Reference Unit, Laboratory of Enteric Pathogens, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK#dReceived 11 June 2002 Accepted 6 January 2003.
Robert J
RJ
Owen
Helicobacter Reference Unit, Laboratory of Enteric Pathogens, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK#dReceived 11 June 2002 Accepted 6 January 2003.
Jacqueline
J
Xerry
D025181:ATP Synthetase Complexes / Q000737:chemistry / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D002648:Child; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry; D004739:England / Q000453:epidemiology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics; D008875:Middle Aged; D008969:Molecular Sequence Data; D009660:Northern Ireland / Q000453:epidemiology; D010544:Peroxidases / Q000737:chemistry / Q000235:genetics; D054464:Peroxiredoxins; D010802:Phylogeny; D016415:Sequence Alignment
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D026901:Membrane Transport Proteins; C114527:UreI protein, Helicobacter pylori; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D010544:Peroxidases; D054464:Peroxiredoxins; D025181:ATP Synthetase Complexes