Genotyping and Descriptive Proteomics of a Potential Zoonotic Canine Strain of Giardia duodenalis, Infective to Mice

Abstract

The zoonotic potential of giardiasis, as proposed by WHO since the late 70's, has been largely confirmed in this century. The genetic assemblages A and B of Giardia duodenalis are frequently isolated from human and canine hosts. Most of the assemblage A strains are not infective to adult mice, which can limit the range of studies regarding to biology of G. duodenalis, including virulence factors and the interaction with host immune system. This study aimed to determine the infectivity in mice of an assemblage A Giardia duodenalis strain (BHFC1) isolated from a dog and to classify the strain in sub-assemblages (AI, AII, AIII) through the phylogenetic analysis of beta-giardin (bg), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes. In addition, the proteomic profile of soluble and insoluble protein fractions of trophozoites was analyzed by 2D-electrophoresis. Accordingly, trophozoites of BHFC1 were highly infective to Swiss mice. The phylogenetic analysis of tpi and gdh revealed that BHFC1 clustered to sub-assemblage AI. The proteomic map of soluble and insoluble protein fractions led to the identification of 187 proteins of G. duodenalis, 27 of them corresponding to hypothetical proteins. Considering both soluble and soluble fractions, the vast majority of the identified proteins (n = 82) were classified as metabolic proteins, mainly associated with carbon and lipid metabolism, including 53 proteins with catalytic activity. Some of the identified proteins correspond to antigens while others can be correlated with virulence. Besides a significant complementation to the proteomic data of G. duodenalis, these data provide an important source of information for future studies on various aspects of the biology of this parasite, such as virulence factors and host and pathogen interactions.

Giardiasis as a neglected disease in Brazil: Systematic review of 20 years of publications

“…Although the epidemiology regarding transmission is highly variable [ 4 ] and remains a contentious issue, giardiasis can be considered a zoonotic disease. [ 5 , 6 ].…”

Application of Proteomics to the Study of the Therapeutics and Pathogenicity of Giardia duodenalis

“…Although genome sequences for assemblages A, B, and E have been published [ 35 , 36 , 37 ], little is known about the specific differences in virulence factors between Giardia strains and assemblages upon infection from a proteomics point of view. To the best of our knowledge, only two proteomics studies have been published that aimed to analyse the virulence proteins in G. duodenalis : one study investigated G. duodenalis in humans and cockatoos [ 11 ], and the other focused on canine isolates to understand giardiasis in dogs [ 38 ].…”

Applied Proteomics in ‘One Health’

“…Most of these proteins (82) were classified as metabolic proteins, mainly associated with carbon and lipid metabolism, including 53 proteins with catalytic activity. Some further proteins corresponded to antigens, while others were related to virulence [ 201 ].…”