Dynamic colonization of Helicobacter pylori in human gastric mucosa.
OBJECTIVE
To investigate the dynamic behaviour of Helicobacter pylori in the colonization of the human gastric mucosa in patients previously treated for H. pylori infection.


METHODS
Twenty-one dyspeptic patients were included in the study. Biopsies from each individual were taken and analysed for H. pylori detection using cultural, molecular and ultrastructural methods.


RESULTS
Through culture, H. pylori was isolated in 7 out of 21 patients and the detection of the minimum inhibitory concentration (MIC) against drugs commonly used in H. pylori therapy revealed a susceptibility panel in which only one strain was multidrug resistant. By studying the expression of the H. pylori glmM constitutive gene, viable H. pylori cells were detected in 19 out of 21 analysed biopsies. In these positive cases, the expression of the Quorum-Sensing related gene, luxS, was always detected. The analysis of glmM and luxS sequences confirmed the H. pylori identity. Scanning electron microscopy (SEM) analysis of biopsies from patients harbouring culturable bacteria showed a prevalent "S-shape" H. pylori morphotype co-existent with coccoid aggregated bacteria embedded in an abundant matrix; while samples from patients shown as H. pylori-positive only through the molecular method showed clustered coccoid bacteria arranged in a microbial biofilm.


CONCLUSIONS
In the present work we describe a new scenario in H. pylori mucosa colonization suggesting, in infection recalcitrance, the planning of more efficacious protocols in order also to identify camouflaged and protected clustered bacteria, taking into account this serious microbial problem in medicine in the recommendation of therapeutic regimens.
Cellini
Luigina
L
Department of Biomedical Sciences, University G. d'Annunzio, Chieti-Pescara, Italy. l.cellini@unich.it
Grande
Rossella
R
Di Campli
Emanuela
E
Traini
Tonino
T
Di Giulio
Mara
M
Lannutti
Stefano Nicola
SN
Lattanzio
Roberto
R
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D001706:Biopsy; D013437:Carbon-Sulfur Lyases / Q000235:genetics; D024881:Drug Resistance, Bacterial; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology* / Q000473:pathology* / Q000648:ultrastructure; D005756:Gastritis / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D015964:Gene Expression Regulation, Bacterial; D016481:Helicobacter Infections / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology*; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010733:Phosphoglucomutase / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria; D010733:Phosphoglucomutase