Pretreatment antimicrobial susceptibilities of paired gastric Helicobacter pylori isolates: antrum versus corpus.
BACKGROUND
Antimicrobial susceptibility testing of Helicobacter pylori isolates is the most useful tool for guiding specific therapy, especially when primary resistance is suspected. However, the most informative gastric biopsy site for detection of resistant H. pylori isolates is uncertain. We sought to determine whether susceptibilities to commonly used antimicrobials (amoxicillin, clarithromycin, minocycline, and metronidazole) were related to biopsy site.


METHODS
H. pylori isolates were obtained from patients who had duodenal ulcer and had not received any therapy directed against H. pylori. Agar-dilution minimum inhibitory concentrations of each antimicrobial were compared between paired H. pylori isolates from the antrum and the proximal corpus.


RESULTS
Differences in minimum inhibitory concentrations exceeding twofold were observed within the pairs of H. pylori isolates in 5 of the 40 patients tested. In three patients with clarithromycin-resistant isolates and two with metronidazole-resistant isolates, both antral and corporeal specimens revealed resistance. However, no patient had pairs of isolates categorized as resistant at one site and sensitive at the other.


CONCLUSIONS
While we found that an individual may have a mixed H. pylori infection with respect to differing antimicrobial susceptibility in different parts of the stomach, a single biopsy specimen from either the antrum or the corpus should provide reliable detection of H. pylori isolates with primary resistance.
Ikezawa
K
K
Department of Internal Medicine, Tsukuba Memorial Hospital, Ibaraki, Japan.
Kashimura
H
H
Kojima
M
M
Aikawa
T
T
Nakahara
A
A
Mutoh
H
H
Tanaka
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001706:Biopsy; D004381:Duodenal Ulcer / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011706:Pyloric Antrum / Q000382:microbiology; D013270:Stomach / Q000382:microbiology*
D000900:Anti-Bacterial Agents