Detection of assemblages A and B of Giardia duodenalis in water and sewage from São Paulo state, Brazil

Abstract

Giardia duodenalis is a protozoan that parasitizes humans and other mammals and causes giardiasis. Although its isolates have been divided into seven assemblages, named A to G, only A and B have been detected in human faeces. Assemblage A isolates are commonly divided into two genotypes, AI and AII. Even though information about the presence of this protozoan in water and sewage is available in Brazil, it is important to verify the distribution of different assemblages that might be present, which can only be done by genotyping techniques. A total of 24 raw and treated sewage, surface and spring water samples were collected, concentrated and purified.DNA was extracted, and a nested PCR was used to amplify an 890 bp fragment of the gdh gene of G. duodenalis, which codes for glutamate dehydrogenase. Positive samples were cloned and sequenced. Ten out of 24 (41.6%) samples were confirmed to be positive for G. duodenalis by sequencing. Phylogenetic analysis grouped most sequences with G. duodenalis genotype AII from GenBank. Only two raw sewage samples presented sequences assigned to assemblage B. In one of these samples genotype AII was also detected. As these assemblages/genotypes are commonly associated to human giardiasis, the contact with these matrices represents risk for public health.

Detection of Giardia lamblia Cysts in Surface Waters of Rasht City, Iran

“…Using IFA, LAMP, and PCR for the detection of Giardia cysts, Mahmoudi et al (2013) reported 37.5% contamination in two rivers of Guilan province, which is almost similar to our results [32]. In a study in Brazil by Fernandes and colleagues (2011), PCR detected Giardia duodenale in 41.6% of surface waters, agricultural waters, and sewage [33]. Monitoring of hygienic principles to prevent the infiltration of infectious agents into water resources can result in significant reduction of water supplies contamination.…”

Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi Impenetrable National Park, Uganda

“…[65–68]) and water samples (e.g. [69, 70]) from around the world. Samples from a human assigned here to assemblage B, subassemblage BIV, based on sequence data from gdh and SSU (KY658183 and KY658187, respectively), grouped with G. duodenalis genotypes reported from humans from Australia, Brazil, the Netherlands and USA [71–73], and wild and domestic animals (including NHP) [74–77], globally.…”

Predominance of Giardia duodenalis Assemblage AII in Fresh Leafy Vegetables from a Market in Southern Brazil

“…Little is known about the geographical distribution of zoonotic genotypes A and B in Brazil (3,4,11,17,28). In this context, the presence of G. duodenalis and its respective genotypes was investigated in vegetables that are consumed raw and sold in a market known as ''market of the Maringá producer,'' which is distinct from most street markets of Brazil because the producers themselves display and sell their produce, and their business has relied upon technical and sanitary assistance at various levels of production and distribution for at least 20 years.…”