DNA-level diversity and relatedness of Helicobacter pylori strains in shantytown families in Peru and transmission in a developing-country setting.
The efficiency of transmission of a pathogen within families compared with that between unrelated persons can affect both the strategies needed to control or eradicate infection and how the pathogen evolves. In industrialized countries, most cases of transmission of the gastric pathogen Helicobacter pylori seems to be from mother to child. An alternative model, potentially applicable among the very poor in developing countries, where infection is more common and the sanitary infrastructure is often deficient, invokes frequent transmission among unrelated persons, often via environmental sources. In the present study, we compared the genotypes of H. pylori from members of shantytown households in Peru to better understand the transmission of H. pylori in developing-country settings. H. pylori cultures and/or DNAs were obtained with informed consent by the string test (a minimally invasive alternative to endoscopy) from at least one child and one parent from each of 62 families. The random amplified polymorphic DNA fingerprints of 57 of 81 (70%) child-mother strain pairs did not match, nor did the diagnostic gene sequences (>1% DNA sequence difference), independent of the child's age (range, 1 to 39 years). Most strains from siblings or other paired family members were also unrelated. These results suggest that H. pylori infections are often community acquired in the society studied. Transmission between unrelated persons should facilitate the formation of novel recombinant genotypes by interstrain DNA transfer and selection for genotypes that are well suited for individual hosts. It also implies that the effective prevention of H. pylori infection and associated gastroduodenal disease will require anti-H. pylori measures to be applied communitywide.
Laboratorios de Investigación y Desarrollo, Facultad de Ciencias, Universidad Peruana Cayetano Heredia, Lima, Peru.
Phabiola M
PM
Herrera
Melissa
M
Mendez
Billie
B
Velapatiño
Billie
B
Velapatiõ
Livia
L
Santivañez
Livia
L
Santivaez
Jacqueline
J
Balqui
S Alison
SA
Finger
Jonathan
J
Sherman
Mirko
M
Zimic
Lilia
L
Cabrera
Jose
J
Watanabe
Carlos
C
Rodríguez
Robert H
RH
Gilman
Douglas E
DE
Berg
D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D003906:Developing Countries; D005192:Family Health; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000635:transmission; D016480:Helicobacter pylori / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010568:Peru / Q000453:epidemiology; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial