[Show abstract][Hide abstract] ABSTRACT: The gastric pathogen Helicobacter pylori is extraordinary in its genetic diversity, the differences between strains from well-separated human populations, and the range of diseases that infection promotes.
Housekeeping gene sequences from H. pylori from residents of an Amerindian village in the Peruvian Amazon, Shimaa, were related to, but not intermingled with, those from Asia. This suggests descent of Shimaa strains from H. pylori that had infected the people who migrated from Asia into The Americas some 15,000+ years ago. In contrast, European type sequences predominated in strains from Amerindian Lima shantytown residents, but with some 12% Amerindian or East Asian-like admixture, which indicates displacement of ancestral purely Amerindian strains by those of hybrid or European ancestry. The genome of one Shimaa village strain, Shi470, was sequenced completely. Its SNP pattern was more Asian- than European-like genome-wide, indicating a purely Amerind ancestry. Among its unusual features were two cagA virulence genes, each distinct from those known from elsewhere; and a novel allele of gene hp0519, whose encoded protein is postulated to interact with host tissue. More generally, however, the Shi470 genome is similar in gene content and organization to those of strains from industrialized countries.
Our data indicate that Shimaa village H. pylori descend from Asian strains brought to The Americas many millennia ago; and that Amerind strains are less fit than, and were substantially displaced by, hybrid or European strains in less isolated communities. Genome comparisons of H. pylori from Amerindian and other communities should help elucidate evolutionary forces that have shaped pathogen populations in The Americas and worldwide.
PLoS ONE 11/2010; 5(11):e15076. DOI:10.1371/journal.pone.0015076 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The most accepted treatment for infection by Helicobacter pylori is the proton pump inhibitor based therapy with two antibiotics. However, there is no consensus regarding the duration. The purpose here was to compare eradication percentages in the omeprazole+amoxicillin+clarithromycin regimen administered during 7 days versus 10 days and confront the results with a previous 14-day* experience in Peru.
Patients from the Central Military Hospital and Peruvian-Japanese Hospital evidencing chronic upper gastrointestinal tract symptoms were recruited. We excluded patients with peptic ulcer. Biopsies were taken for diagnosis, for urease and PCR tests, culture and coloring with silver. Omeprazole+clarithromycin+amoxicillin was used during 7 days versus 10 days. Control endoscopy was performed one month after treatment had been completed and molecular biology techniques were used to differentiate recurrences from new infections. Susceptibility to clarithromycin was assessed.
36 patients were included in each group. Eradication was the same in both groups: 86.1% (31/36). In several patients in whom the bacteria persisted, the same initial nucleus was found. In a previous study* using this same regimen during 14 days, a 93% eradication was obtained. 91.18% of our samples were susceptible to clarithromycin.
In Peru, the omeprazole+clarithromycin+amoxicillin combination gives results higher than 80% in the eradication of infection by Helicobacter pylori. The 7 and 10 days regimens eradicated the bacteria in 86% of our patients.
Revista de gastroenterologia del Peru: organo oficial de la Sociedad de Gastroenterologia del Peru 01/2003; 23(3):177-83.
[Show abstract][Hide abstract] ABSTRACT: Compiling our observations from the last 15 years in regard to the epidemiology of Helicobacter pylori in Perú, we have analized 3005 cases. Studying and comparing the rates of infection among japanese inmigrants living in Perú for more than 10 years, niseis, japanese visitors and peruvians, we found similar rates. According to these results it seems that at least in japaneses there is not any genetic predisposition to acquire the infection. Studying peruvians of different socioeconomic levels, we observed similar rates of infection with the exception of women of high socioeconomic level. It seems that the last group of people is not exposed to the different mechanisms of infection. We found similar rates of infection in patients of low socioeconomic level living in the coast, sierra and jungle. Our studies in children showed that the infection is acquired during early childhood. Therefore in Perú we have not observed an ascending rate of infection according to age as has been described in industrialized countries. Analizing water from 48 sources we found Helicobacter pylori in 24 samples, 20 of them were taken from the municipal source of water. Water seems to be an important vehicle of infection, according to our studies, in children drinking water from different sources.
Revista de gastroenterologia del Peru : organo oficial de la Sociedad de Gastroenterologia del Peru 02/1999; 19(3):208-215.
[Show abstract][Hide abstract] ABSTRACT: We anaylize in patients from high socio economic level the histologic findings of biopsies from the gastric mucosa taken endoscopically. Patients with upper gastrointestinal symptoms were examined with esophagogastroduodenoscopy. In the histologic study we considered: presence of Helicobacter pylori, mucinous damage, displasia, atrophy and intestinal metaplasia. Patients were divided in two groups: those who endoscocopically did not present gastric or duodenal active ulcer, gastric neoplasia or were not gastrectomized or vagotomized and those in which active gastric or duodenal ulcer was found. The first group was comprised of 1406 patients (647 women and 769 men). 57.33% (806) showed presence of Helicobacter pylori in the histologic study. Males presented higher prevalence of the bacteria (57.32% vs 42.68%, p=0.021873). Atrophys was found in 8.25% and was more frequent in patients with H. pylori (78.45% vs 21.55% p=0.0000026) / Intestinal metaplasla was found in 11.24% being related more with the presence of H.pylori (74.68% vs 25.32%, p=0.0000043). In the second group comprised of 232 patients: 192 males (82.7%) 82.75% showed presence of the bacteria. There was not a statistical difference by comparing sex and age vs presence of ulcer.
Revista de gastroenterologia del Peru : organo oficial de la Sociedad de Gastroenterologia del Peru 02/1999; 19(3):196-201.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to determine if there was any relationship between the socio-economic level of patients and the colonization of the stomach by Campylobacter pyloridis. We have studied 256 patients who underwent esophagogastroduodenoscopy because they had upper gastrointestinal symptoms of this group, 143 from Arzobispo Loayza Hospital (38 males and 105 females) and 122 from the private practice of three of the authors (77 males and 45 females). The ages ranged from 16 to 75 years (media 45.5 years). In each case biopsies of the antrum were taken and stained with hematoxylin-eosin and Warthin-Starry Silver Stein. We classified patients into 3 different groups based on where they lived: nuclear districts, intermediate districts, and peripheral districts. In Lima, the type of district from the patient strongly correlates with their socio-economic status. The hospital and private patients differed significantly in the distribution of which type of district their patients came from. In contrast there was a no marked similarity between these two patient groups in their rate of colonization by Campylobacter pyloridis. It appears that the socio-economic level of peruvian patients, presenting to clinic with symptomatic gastro-intestinal disease is not an important factor with pyloric campylobacter infection.
[Show abstract][Hide abstract] ABSTRACT: We report a study of 127 patients examined with esophago-gastroduodenoscopy and with a diagnosis of chronic gastritis (by biopsy), and gastric peptic ulcer and duodenal peptic ulcer (endoscopically). Brushing samples and biopsies were taken from the esophagus, stomach, and duodenum. Gram stains of brush-collected samples, culture of brush samples and biopsies were performed in order to detect the presence of PC. In cases of chronic active gastritis, PC was found in 91% of patients. It was found in 73% and 84%, respectively, of cases of gastric and duodenal ulcer. PC was found with equal frequency in the cardia and body as in the antrum of infected individuals, but no confirmed cases of colonization of the esophagus or duodenum were found. The most efficient methods for identifying PC colonization were (in descending order of efficiency), silver stain of biopsies, Gram stain of brushings, hematoxylin-eosin stain of biopsies, culture of biopsies, and culture of brushings. In some cases, we have identified PC in the esophagus and duodenum by gram stain and culture, but no not by silver stain or H&E stain of biopsies, suggesting that contamination from other areas of the stomach may be an occasional problem in sampling these areas for PC.