Molecular fingerprinting of Helicobacter pylori strains from duodenal ulcer patients

Abstract

Aims: To characterize the molecular fingerprinting of Helicobacter pylori population isolated in duodenal ulcer patients treated with triple therapy. Methods and Results: Gastric biopsy specimens from corpus and antrum, were cultured for H. pylori isolation. Helicobacter pylori eradication was evaluated after 4 and 16 weeks. DNAs of all isolates were characterized by random amplified polymorphic DNA typing and cagA gene was also detected. After the therapy, five patients harboured the microorganism at 4 weeks and two of them remained H. pylori positive at 16 weeks. The analysis of DNA fingerprinting of strains isolated from antrum and corpus of patients susceptible to treatment, showed similar patterns. Instead, when the therapy was not effective, strains isolated from sequential biopsies from initial and after 4 and 16 weeks, showed distinct fingerprintings and retained the cagA status, over time. Conclusions: The drugs used for therapy could exercise an effect in genotypical rearrangement among H. pylori cells. Significance and Impact of the Study: The variableness among H. pylori strains represents a way to challenge environmental stress.

Detection of Helicobacter pylori associated with zooplankton

“…In particular, the H. pylori isolate vacA showed a deletion of 85 bp with respect to H. pylori ATCC 43629. The difference in the amplified fragment size obtained in the present study confirms the high genetic variability in H. pylori cells (Suerbaum 2000, Cellini et al 2003). In the aquatic environment, H. pylori isolate retains the cagA gene, emphasizing the role of seawater in the diffusion of virulence genes representing a serious public health risk.…”

“…The natural habitat for the microorganism is the human stomach, but it also needs to survive in other environments to become a life-long infection threat (Sasaki et al 1999). H. pylori has been detected in dental plaque, in houseflies and in human and animal faeces (Grubel et al 1997, Parsonnet et al 1999, Kabir 2003, and a large number of studies report its presence in aquatic environments (Hulten et al 1996, Baker & Hegarty 2001, Mazari-Hiriart et al 2001, Park et al 2001, Lu et al 2002, Cellini et al 2003. Water supplies contaminated by sewage containing fluids or faeces from infected people have therefore been considered as a potential source for H. pylori transmission (McKeown et al 1999, Mazari-Hiriart et al 2001, Park et al 2001, Lu et al 2002, Cellini et al 2004.…”

The Prevalence of Mixed Helicobacter pylori Infections in Symptomatic and Asymptomatic Subjects in Dhaka, Bangladesh

“…It was also demonstrated that recombination had occurred between both the strains on at least six occasions, thus accounting for the observed heterogeneity . The high degree of genomic diversity among H. pylori strains in one individual, which can be due to mechanisms such as free recombination or coinfection with mixed H. pylori strains , has been confirmed by AFLP analysis . In the present study, we found that some of the subjects are infected with mixed strains, have similar band pattern with either emergence of new bands or lack of some bands.…”

Coccoid Form of Helicobacter pylori as a Morphological Manifestation of Cell Adaptation to the Environment

“…(iv) Transformation to the coccoid form always appears to occur in what are thought to be the most adverse environments when the cells have no chance of survival. On the other hand, several reports have argued that coccoid cells might constitute a survival strategy in adverse environmental conditions (4,10,11,22). The main argument for this is the existence of a state named viable but nonculturable (18,27,29).…”