Background Giardia duodenalis is a common flagellated protozoan parasite that
infects the small intestine of a wide range of vertebrate hosts. This study
aimed to determine whether tracing of G. duodenalis isolates by current
genetic typing tools is possible using an exemplary set of samples from
infected cattle, buffalo and children from the Ismailia province, Egypt.
Method A total of 804 fecal samples from ruminant animals was collected from
191 herds and 165 samples from diarrheal children below the age of 10 years.
Parasites were detected in these samples using the copro-antigen RIDA®QUICK
test and by real-time PCR. Samples were then genetically characterized based
on the triosephosphate isomerase, glutamate dehydrogenase and β-giardin genes.
Results The prevalence of G. duodenalis was 53% in ruminants and 21% in
symptomatic children and infection was not positively correlated with
diarrheal symptoms. Sequence typing analysis confirmed predominance of B-type
sequences (>67%) in humans and E-type sequences (>81%) in ruminants over
A-type sequences. For 39 samples the complete sequence information of the
three marker gene fragments could be derived. Integration of the concatenated
sequence information of the three marker gene fragments with the spatial data
of the respective sample revealed that identical or near identical (only up to
1 out of 1358 bp different) concatenated sequencing types were spatially
related in 4 out of 5 cases. Conclusion The risk of zoonotic infection
emanating from ruminants even in high prevalence areas is negligible. Genetic
characterization indicated a predominant anthropogenic cycle of infection
within the pediatric population studied. Integration of sequence typing data
with information on geographic origins of samples allows parasite sub-
population tracing using current typing tools.
600 Technik, Medizin, angewandte Wissenschaften::630 Landwirtschaft
Epidemiology of Giardia duodenalis infection in ruminant livestock and
children in the Ismailia province of Egypt
Parasites & Vectors 7 (2014), 1, Artikel Nr. 321
insights by genetic characterization