Shiga toxin-producing Escherichia coli (
STEC) pathotype secretes two types of AB5
cytotoxins (Stx1 and Stx2), responsible for
complications such as hemorrhagic
colitis (HC) and
hemolytic uremic syndrome (HUS) in infected
patients, which could
lead to sequels and
death. Currently, there is no effective
treatment against the cytotoxic effect of these toxins. However, in order to approve any
therapy molecule, an
animal experiment is required in order to evaluate the
efficacy and
safety of
therapeutic approaches. The use of alternative small host models is growing among
human infectious disease studies, particularly the
vertebrate zebrafish model, since relevant results have been described for
pathogen-host interaction. In this sense, the present
work aimed to analyze the toxic effect of
Shiga toxins in
zebrafish embryo model in order to standardize this
method in the
future to be used as a fast, simple, and efficient
methodology for the
screening of
therapeutic molecules. Herein, we demonstrated that the
embryos were sensitive in a
dose-dependent manner to both Stx toxins, with
LD50 of 22 µg/mL for Stx1 and 33 µg/mL for Stx2, and the use of anti-Stx polyclonal antibody abolished the toxic effect. Therefore, this
methodology can be a rapid alternative
method for selecting promising compounds against Stx toxins, such as recombinant
antibodies.