Colonization of an acid resistant Kingella denitrificans in the stomach may contribute to gastric dysbiosis by Helicobacter pylori.
In the stomach of a gastric ulcer patient who had been administered an anti-acid, a gram-negative and urease-negative bacillus similar in size to Helicobacter pylori was infected together with H. pylori. According to biochemical test and 16S rRNA gene analysis, the urease-negative bacterium was identified as Kingella denitrificans, a human nasopharyngeal commensal. In contrast to the standard strain of K. denitrificans, the isolate showed catalase activity, did not produce acid from glucose, and exhibited acid tolerance. Acid tolerance of H. pylori was increased by cocultivation with the K. denitrificans isolate, but not with other isolates of K. denitrificans. Disruption of physiological and immunological niche by dysbiotic colonization of bacterium may provide pathological attributes to human stomach. Collectively, a careful administration of anti-acids to the elderly, especially those with atrophic gastritis, is necessary to avoid repression of the gastric barrier to bacteria.
Yamaguchi University, Graduate School of Medicine, Minamikogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
Takeshi
T
Okamoto
Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido 060-0815, Japan.
Yasuhiro
Y
Hayashi
Clinical Laboratory, Yamaguchi University Hospital, Minamikogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
Hidekazu
H
Mizuno
Department of Clinical Research, National Hospital Organization Kanmon Medical Center, 1-1 Sotoura, Chofu, Shimonoseki, Yamaguchi 752-8510, Japan.
Hideo
H
Yanai
Yamaguchi University, Graduate School of Medicine, Minamikogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
Jun
J
Nishikawa
Yamaguchi University, Graduate School of Medicine, Minamikogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
Teruko
T
Nakazawa
Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido 060-0815, Japan.
Hisashi
H
Iizasa
Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido 060-0815, Japan.
Masahisa
M
Jinushi
Yamaguchi University, Graduate School of Medicine, Minamikogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
Isao
I
Sakaida
Institute for Genetic Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido 060-0815, Japan. Electronic address: yosiyama@med.shimane-u.ac.jp.
Hironori
H
Yoshiyama
D000368:Aged; D000897:Anti-Ulcer Agents / Q000009:adverse effects / Q000627:therapeutic use; D001706:Biopsy; D002353:Carrier State / Q000175:diagnosis / Q000382:microbiology*; D005753:Gastric Mucosa / Q000166:cytology / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017881:Kingella / Q000302:isolation & purification* / Q000502:physiology; D008297:Male; D050296:Microbial Viability; D016870:Neisseriaceae Infections / Q000175:diagnosis / Q000382:microbiology*; D011899:Ranitidine / Q000009:adverse effects / Q000627:therapeutic use; D013276:Stomach Ulcer / Q000188:drug therapy / Q000382:microbiology*
D000897:Anti-Ulcer Agents; D011899:Ranitidine
Anti-acid administration; Dysbiosis; Gastric barrier to bacteria; Helicobacter pylori; Kingella denitrificans