<i>Helicobacter pylori</i>Populations in Peruvian Patients

Berg, Douglas E.; Gilman, Robert H.; Lelwala‐Guruge, Janaki; Srivastava, Kalpana; Valdez, Yanet; Watanabe, José; Miyagi, Juan; Akopyants, Natalia S.; Ramírez-Ramos, Alberto; T, Yoshiwara; Recavarren, Sixto; León-Barúa, Raúl

doi:10.1086/516081

Cited by 43 publications

(42 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bacterial growth. Standard methods (12) were used for H. pylori growth in a microaerobic atmosphere on Difco brain heart infusion agar supplemented with 10% horse blood.…”

Section: Methodsmentioning

confidence: 99%

“…Some of this may reflect preferential transmission of H. pylori within families and among people in close contact (see, e.g., references 10 and 21). In consequence, no given strain need compete simultaneously against many other strains, despite occasional cases of mixed infection by unrelated strains (12,28,40). There is also a sense that humans differ in traits that could be important to individual strains, such as specificity and strength of immune and inflammatory responses and availability and distribution of receptors to which H. pylori adheres (18,19,27,28,35).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Differences in Genotypes ofHelicobacter pylorifrom Different Human Populations

et al. 2000

Self Cite

View full text Add to dashboard Cite

DNA motifs at several informative loci in more than 500 strains of Helicobacter pylori from five continents were studied by PCR and sequencing to gain insights into the evolution of this gastric pathogen. Five types of deletion, insertion, and substitution motifs were found at the right end of the H. pylori cag pathogenicity island. Of the three most common motifs, type I predominated in Spaniards, native Peruvians, and Guatemalan Ladinos (mixed Amerindian-European ancestry) and also in native Africans and U.S. residents; type II predominated among Japanese and Chinese; and type III predominated in Indians from Calcutta. Sequences in the cagA gene and in vacAm1 type alleles of the vacuolating cytotoxin gene (vacA) of strains from native Peruvians were also more like those from Spaniards than those from Asians. These indications of relatedness of Latin American and Spanish strains, despite the closer genetic relatedness of Amerindian and Asian people themselves, lead us to suggest that H. pylori may have been brought to the New World by European conquerors and colonists about 500 years ago. This thinking, in turn, suggests that H. pylori infection might have become widespread in people quite recently in human evolution.Helicobacter pylori is a microaerophilic bacterium with the extraordinary ability to establish infections in human stomachs that can last for years or decades, despite immune and inflammatory responses and normal turnover of the gastric epithelium and overlying mucin layer in which it resides. It is carried by more than half of all people worldwide and has attracted great attention as a major cause of peptic ulcer disease and an early risk factor for gastric cancer, one of the most frequently lethal of malignancies worldwide (for reviews see references 23, 48, and 60).

show abstract

“…Bacterial growth. Standard methods (12) were used for H. pylori growth in a microaerobic atmosphere on Difco brain heart infusion agar supplemented with 10% horse blood.…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Differences in Genotypes ofHelicobacter pylorifrom Different Human Populations

et al. 2000

Self Cite

View full text Add to dashboard Cite

show abstract

“…Also motivating our study were reports that infections by two or more strains are common in some societies (Berg et al, 1997;Brown et al, 2002;Morales-Espinosa et al, 1999), and interest in the dynamic bacterial-host interplay that may result. In particular, mixed infection should facilitate interstrain gene transfer, which in turn would speed adaptation to new or changing gastric mucosal environments (Achtman et al, 1999;Kersulyte et al, 1999;Suerbaum et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Helicobacter pylori tissue tropism: mouse-colonizing strains can target different gastric niches

et al. 2003

Self Cite

View full text Add to dashboard Cite

Studies with the mouse-adapted Helicobacter pylori strain SS1 had supported an idea that infections by this pathogen start in the gastric antrum and spread to the corpus after extensive mucosal damage. This paper shows that the unrelated strain X47 colonizes the corpus preferentially. Differences between strains in preferred gastric region were detected by co-inoculating mice with a mixture of SS1 and X47, and genotyping H. pylori recovered after 2-8 weeks of infection by vacA s allele PCR and RAPD fingerprinting. Mixed infections were found in each of 59 co-inoculated young C57BL/6J mice. On average, however, SS1 was fourfold more abundant than X47 in the antrum and X47 was threefold more abundant than SS1 in the corpus. Similar results were obtained in mice inoculated first with one strain and then the other strain 2 weeks later. SS1 was even more abundant in the antrum of elderly (>1 year old) mice (97 % of isolates). Qualitatively similar SS1 and X47 tissue distributions were seen using unrelated mouse lines (AKR/J, A/J, DBA/2J, BALB/cJ, LG/J, SM/J), but with significantly different SS1 : X47 ratios in some cases. These results suggest the existence of at least two distinct gastric niches whose characteristics may be affected by host genotype and age (physiology), and indicate that strains differ in how effectively they colonize each niche. Differences among gastric regions and the mixed infections that these allow may contribute to H. pylori diversity and genome evolution.

show abstract

“…Some of this may reflect preferential transmission within families and among people in close contact, not in large epidemics (11,24,50). Such a pattern means that no individual strain would compete simultaneously against many others (12,38,55). H. pylori diversity would also be enhanced if humans differ in traits that are important to individual strains (e.g., specificity or strength of immune and inflammatory responses or availability of receptors used for H. pylori adherence [26,33]).…”

mentioning

confidence: 99%

Distinctiveness of Genotypes ofHelicobacter pyloriin Calcutta, India

et al. 2000

Self Cite

View full text Add to dashboard Cite

The genotypes of 78 strains of Helicobacter pylori from Calcutta, India (55 from ulcer patients and 23 from more-benign infections), were studied, with a focus on putative virulence genes and neutral DNA markers that were likely to be phylogenetically informative. PCR tests indicated that 80 to 90% of Calcutta strains carried the cag pathogenicity island (PAI) and potentially toxigenic vacAs1 alleles of the vacuolating cytotoxin gene (vacA), independent of disease status. This was higher than in the West (where cag PAI ؉ vacAs1 genotypes are disease associated) but lower than in east Asia. The iceA2 gene was weakly disease associated in Calcutta, whereas in the West the alternative but unrelated iceA1 gene at the same locus is weakly disease associated. DNA sequence motifs of vacAm1 (middle region) alleles formed a cluster that was distinct from those of east Asia and the West, whereas the cagA sequences of Calcutta and Western strains were closely related. An internal deletion found in 20% of Calcutta iceA1 genes was not seen in any of ϳ200 strains studied from other geographic regions and thus seemed to be unique to this H. pylori population. Two mobile DNAs that were rare in east Asian strains were also common in Calcutta. About 90% of Calcutta strains were metronidazole resistant. These findings support the idea that H. pylori gene pools differ regionally and emphasize the potential importance of studies of Indian and other non-Western H. pylori populations in developing a global understanding of this gastric pathogen and associated disease.

show abstract

Helicobacter pyloriPopulations in Peruvian Patients

Cited by 43 publications

References 30 publications

Differences in Genotypes ofHelicobacter pylorifrom Different Human Populations

Differences in Genotypes ofHelicobacter pylorifrom Different Human Populations

Helicobacter pylori tissue tropism: mouse-colonizing strains can target different gastric niches

Distinctiveness of Genotypes ofHelicobacter pyloriin Calcutta, India

Contact Info

Product

Resources

About