Screening of Strongyloides infection using an ELISA test in transplant candidates

OBJECTIVES: Hyperinfection or disseminated strongyloidiasis has been frequently reported after transplants and is related to high mortality. This study aimed to screen for strongyloidiasis using serological diagnoses in transplant candidates. METHODS: An ELISA test was performed with filariform larvae of Strongyloides venezuelensis as a source of antigen. RESULTS: In the serum from transplant candidates, anti-Strongyloides IgG antibodies were detected in 35/150 (23.3%) samples by soluble fractions in phosphate buffered saline (PBS), 31/150 (20.7%) samples by soluble fractions in Tris-HCl, 27/150 (18.0%) samples by membrane fractions in PBS and 22/150 (14.7%) samples by membrane fractions in Tris-HCl. CONCLUSIONS: The present results suggest the ELISA test, ideally using soluble fractions of filariform larvae S. venezuelensis in PBS, as an additional strategy for the diagnosis of strongyloidiasis in transplant candidates.

Protocol for DNA extraction of Cryptosporidium spp. oocysts in fecal samples / Protocolo para extração de DNA de oocistos de Cryptosporidium spp. em amostras fecais

Molecular characterization of Cryptosporidium spp.oocysts in clinical samples is useful for public health since it allows the study of sources of contamination as well as the transmission in different geographical regions. Although widely used in developed countries, in Brazil it is restricted to academic studies, mostly using commercial kits for the extraction of genomic DNA, or in collaboration with external reference centers, rendering the method expensive and limited. The study proposes the application of the modifications recently introduced in the method improving feasibility with lower cost. This method was efficient for clinical samples preserved at -20 °C for up to six years and the low number of oocysts may be overcomed by repetitions of extraction.

A caracterização molecular de oocistos de Cryptosporidium spp. em amostras clínicas é útil à saúde pública, pois permite estudo das fontes de contaminação e a transmissão em determinadas regiões geográficas. Apesar de largamente utilizada em países desenvolvidos, no Brasil está restrita aos estudos acadêmicos, na maioria utilizando kits comerciais para extração do DNA genômico, ou em colaborações com centros de referência externos, o que torna o método caro e limitado. Este estudo propõe a introdução de modificações nos métodos existentes para melhorar a viabilidade e baixar custos. O método proposto foi eficiente em amostras clínicas preservadas a -20 °C por até seis anos e o baixo número de oocistos pode ser contornado por replicadas extrações de DNA.