Helicobacter pylori: comparison of DNA fingerprints provides evidence for intrafamilial infection.

Abstract

Although a high prevalence of antibodies to Helicobacter pylori has been documented within families, culture and DNA typing of strains from infected children and their parents has not been evaluated. This study aimed to analyse H pylori infection within family groups. Endoscopy, gastric biopsy, and H pylori culture were performed on all eight parents of four children who presented with dyspepsia and who had a positive H pylori culture. All biopsy specimens were cultured on Columbia based blood agar under microaerophilic conditions for four days. The DNA from each strain was extracted and electrophoretic patterns were compared after digestion with restriction endonucleases Hae III or Hind III. Ribotyping using a biotinylated cDNA probe prepared from 16S and 23S rRNA of H pylon NCTC 11638 was also used. Seven of the parents were positive for H pylorn on urease testing, histology, and on culture. DNA typing showed the same or a similar strain to be present in at least two family members in three of the four family groups. In family 1, the mother, father, and child all had an identical strain; in family 2, father and son had a similar related strain; father and mother had the same strain in family 3; and all strains were unique in family 4. These data provide evidence for either intrafamilial cross infection or a common source of infection within family groups. (Gut 1993; 34: 1348-1350 Helicobacter pylon is recognised as a significant cause of chronic antral gastritis and important in the aetiology of peptic ulceration.' There is also evidence to support a role as a risk factor for gastric carcinoma.2 5 It is known that the prevalence increases with age6 and that while the incidence in children is lower than that in adults, intrafamilial clustering has been shown. DNA TYPING H pyloni isolates from four children and their parents, plus two isolates chosen randomly from unrelated individuals were incubated on brain heart infusion agar supplemented with 5% v/v horse blood and 1% v/v isovitalex (Oxoid) for 48 hours at 37%, under microaerophilic conditions (5% 02, 5% C02, 2% H2, 88% N2). Chromosomal DNA was isolated and purified from each isolate using the guanidium thiocyanate reagent method.'0 The purified DNA was incubated with the restriction endonuclease (Hae III) for four hours at 37°C and the digests were electrophoresed at 30 v for 16 hours in a horizontal agarose gel. After electrophoresis the gels were stained with ethidium bromide and photographed. Strain DNAs which did not cut with Hae III were subjected to Hind III digestion. For ribotyping, the gels were then transferred to nylon membranes by means of vacublotting. A biotinylated cDNA probe was prepared from 16S and 23S rRNA of H pylori NCTC 11638 using reverse transcriptase. Biotinylation was achieved by the incorporation of biotin-16-dUPT. The membranes were then hybridized by standard procedures for 16 hours at 42°C, using the biotinylated cDNA probe. Restriction digest patterns and ribopatterns were compared. Details of DNA typing methods have b...

Expression of B7-1 and B7-2 costimulatory molecules by human gastric epithelial cells: potential role in CD4+ T cell activation during Helicobacter pylori infection.

“…pylori is now recognized as an etiopathogenetic cause of chronic gastritis, peptic ulcers, as well as gastric adenocarcinoma and mucosal associated lymphoid tissue lymphoma of the stomach (33)(34)(35). Although microbial factors have been associated with the pathogenesis of the more severe gastric diseases associated with H. pylori (36,37), family members infected with the same strain of H. pylori may experience different disease manifestations (38). This observation suggests that host factors may also contribute to the pathogenesis of gastric disease.…”

Aspectos epidemiológicos do Helicobacter pylori na infância e adolescência

“…No entanto, não se pode descartar a possibilidade de esses elementos terem adquirido a doença por exposição à fonte comum de infecção. 8,44,101 Transmissão por via fecal-oral A curva de prevalência da hepatite A relacionada à idade é considerada marcador para transmissão de agentes infecciosos por contaminação fecal-oral. 108 Existe um paralelismo muito grande entre os perfis das curvas do H. pylori e da hepatite A na maioria das populações estudadas, particularmente nas dos paí-ses em desenvolvimento.…”

“…8,27,30,78,94 Rothenbacher et al 119 estudaram a prevalência do H. pylori em 1.143 crianças e seus respectivos acompanhantes (n=1.074) mediante teste respiratório com C 13 -uréia. Os autores concluíram que pais infectados, especialmente as mães, podem desempenhar importante papel na transmissão do H. pylori entre familiares, à semelhança do que se observa em relação a outras bactérias da cavidade oral, como é o caso do Streptococcus mutans.…”

A Population Genetics Pedigree Perspective on the Transmission of Helicobacter pylori

“…Transmission studies in developed countries suggest a person-to-person mode of transmission (Suerbaum and Michetti 2002). Furthermore, epidemiological and DNA-based studies have suggested that a parent-offspring transmission pathway, mostly mother to child, is responsible for transmission within the family and that infection outside the family rarely occurs (Drumm et al 1990;Bamford et al 1993;Rothenbacher et al 1999;Suerbaum and Michetti 2002;Samir et al 2004).…”