In healthy people the acidity of the stomach kills most of microbial agents. However, if gastric acidity is diminished [e.g. in atrophic autoimmune gastritis (AAG) or reflux oesophagitis treated with omeprazole] the stomach can be colonized. This study investigates the gastric microbiota, in particular total anaerobes and Bifidobacteriaceae, in 29 individuals 13 of which treated with omeprazole, 11 affected by AAG and 5 controls. Samples deriving from biopsies and gastric juice were cultivated anaerobically in non selective and Bifidobacteriaceae selective media. Bifidobacteriaceae family identification was carried out by fructose-6-phosphate phosphoketolase (F6PPK) test. Species identification was obtained with fermentation tests, polyacrylamide gel-electrophoresis of soluble proteins and DNA-DNA homology. Differently from normal acid stomach, in achloridric stomach an important growth of anaerobes was detected. In selective medium colonies showed typical Bifidobacteriaceae morphology. However, F6PKK tests of all 127 isolates revealed that only 45 belonged to Bifidobacteriaceae while others were described as “actinomyces-like group” basing on their irregular morphology. All F6PPK positive isolates were found to belong to Bifidobacteriaceae typical of oral cavity (Scardovia inopinata, Parascardovia denticolens and Bifidobacterium dentium). The presence of an “actinomyces-like group”, probably originated from oral cavity too, suggests that colonization of achloridric stomach derived from oral cavity.
BIFIDOBACTERIACEAE IN THE ACHLORIDRIC STOMACH
GRANATA, MARTA;GAGGIA, FRANCESCA;BRANDI, GIOVANNI;DI GIOIA, DIANA;BIAVATI, BRUNO;MATTARELLI, PAOLA
2008
Abstract
In healthy people the acidity of the stomach kills most of microbial agents. However, if gastric acidity is diminished [e.g. in atrophic autoimmune gastritis (AAG) or reflux oesophagitis treated with omeprazole] the stomach can be colonized. This study investigates the gastric microbiota, in particular total anaerobes and Bifidobacteriaceae, in 29 individuals 13 of which treated with omeprazole, 11 affected by AAG and 5 controls. Samples deriving from biopsies and gastric juice were cultivated anaerobically in non selective and Bifidobacteriaceae selective media. Bifidobacteriaceae family identification was carried out by fructose-6-phosphate phosphoketolase (F6PPK) test. Species identification was obtained with fermentation tests, polyacrylamide gel-electrophoresis of soluble proteins and DNA-DNA homology. Differently from normal acid stomach, in achloridric stomach an important growth of anaerobes was detected. In selective medium colonies showed typical Bifidobacteriaceae morphology. However, F6PKK tests of all 127 isolates revealed that only 45 belonged to Bifidobacteriaceae while others were described as “actinomyces-like group” basing on their irregular morphology. All F6PPK positive isolates were found to belong to Bifidobacteriaceae typical of oral cavity (Scardovia inopinata, Parascardovia denticolens and Bifidobacterium dentium). The presence of an “actinomyces-like group”, probably originated from oral cavity too, suggests that colonization of achloridric stomach derived from oral cavity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
