Emergence of clarithromycin-resistant Helicobacter pylori (CRHP) with a high prevalence in children compared with their parents.
BACKGROUND
Clarithromycin-resistant Helicobacter pylori (CRHP) is increasing worldwide. Clarithromycin resistance in H. pylori from familial members has not been investigated.


METHODS
Biopsy specimens were taken from 13 families living in Tokyo, Yokohama, and Niigata between 1998 and 2001. Drug resistance was tested with the replica plating method. The minimum inhibitory concentrations of antimicrobial agents for H. pylori strains were determined by the agar dilution method. Molecular analyses of H. pylori strains were performed by ribosomal RNA gene restriction pattern analysis. The DNA region, associated with clarithromycin resistance, was analyzed by PCR and sequencing.


RESULTS
Helicobacter pylori strains isolated from a 5-year-old-son displayed clarithromycin resistance with a mutation (A --> G at position 2143) in the 23S ribosomal RNA, whereas H. pylori strains from his parents did not. DNA analyses revealed that the boy was infected with his father's strain. The boy had repeatedly developed otitis media and received clarithromycin since the age of 2 years. Studies on an additional 12 families demonstrated that clarithromycin resistance in the children's strains reached 42.9% and was significantly higher than those of H. pylori strains from their parents (0%) or from adult patients (11.1%) (p <.05).


CONCLUSIONS
The rate of clarithromycin resistance in H. pylori strains from Japanese children was extremely high, in contrast to those from their parents or adult patients. Prior history of clarithromycin usage in a child suggested development of clarithromycin resistance in resident H. pylori, which was originated from a parent.
Taneike
Ikue
I
Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori, Niigata, Japan.
Goshi
Satoshi
S
Tamura
Yukiko
Y
Wakisaka-Saito
Noriko
N
Matsumori
Noriko
N
Yanase
Azusa
A
Shimizu
Toshiaki
T
Yamashiro
Yuichiro
Y
Toyoda
Shigeru
S
Yamamoto
Tatsuo
T
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000494:pharmacology*; D004275:DNA, Ribosomal / Q000032:analysis; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005190:Family; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D010290:Parents; D015995:Prevalence; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA
D000900:Anti-Bacterial Agents; D004275:DNA, Ribosomal; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin