Autor(es):
Azevedo, N. F. 
; Gião, M. S. ; Almeida, C. ; Fernandes, I. ; Keevil, C. W. ; Vieira, M. J.
Data: 2007
Identificador Persistente: http://hdl.handle.net/1822/27326
Origem: RepositóriUM - Universidade do Minho
Descrição
The role of water and water-associated biofilms on the
transmission of Helicobacter pylori has been under debate for the
last 10 years. We have previously shown that the ability of this
bacterium to form monospecies biofilms when exposed to water
is quite limited. However, molecular detection methods have
been used to demonstrate that H. pylori is present in water
microenvironments. Here, we have tested the cultivability and
viability of several strains of H. pylori in water under different
conditions to check whether a large increase in cultivability could
be observed. Interestingly, the absence of light during water
exposure appeared to be highly beneficial for a longer cultivability
of the bacterium, with the ability of some strains to form colonies
increasing from 24 to 96 hours. Nevertheless, recovering the
bacterium from heterotrophic environments continues to pose a
challenge, even when using selective culture media. Hence, we
have applied specific PNA fluorescent in situ hybridization probes
to detect the presence of the bacterium on heterotrophic biofilms.
Results show that H. pylori is able to form aggregates within biofilm
structures under several conditions (high and low shear stress,
15 °C and 20 °C, addition of carbon source). Addition of chlorine,
however, inhibited the formation of these H. pylori agglomerates, and
the bacterium was found to be more evenly dispersed along the
support. This work suggests that the implementation of chlorine
as a disinfection method has hindered the transmission of the
pathogen and hence is partly responsible for the decreased
prevalence observed in the more developed countries.
