POTENTIAL CROSS-CONTAMINATION OF SIMILAR Giardia duodenalis ASSEMBLAGE IN CHILDREN AND PET DOGS IN SOUTHERN BRAZIL, AS DETERMINED BY PCR-RFLP.

Giardia duodenalis is an enteric parasite that has distinct genetic groups. Human infections are mainly caused by assemblages A and B, although sporadic infections by assemblages C and D have also been reported. Animals can be infected by a wide range of assemblages (A to H). The aim of this study is to identify the assemblages and sub-assemblages of G. duodenalis with zoonotic features in fecal samples of school-aged children, and in dogs that coexist in the same households in Lages, Santa Catarina, Brazil. Fecal samples of 91 children and 108 dogs were obtained and G. duodenalis cysts were detected in samples from 11 (12.08%) children and 10 (9.25%) dogs. DNA extracted from the 21 positive samples was analyzed by PCR-RFLP, using the gdh gene. Results showed the presence of sub-assemblages AI (2/11), AII (4/11), BIII (2/11), and BIV(3/11) among children and AI (5/10) and BIV(3/10) in dogs, with zoonotic characteristics, and the carnivore specific assemblage C (2/10). G. duodenalis was found to infect both children and dogs living in the same household, with the same sub-assemblage (BIV) indicating that pet dogs are a potential risk of transmission of G. duodenalis to humans.

OCCURRENCE OF Calodium hepaticum (BANCROFT, 1893) MORAVEC, 1982 EGGS IN FECES OF DOGS AND CATS IN LAGES, SANTA CATARINA, BRAZIL.

This study aims to report the incidence of Calodium hepaticum among dogs and cats, pets or stray animals, captured by the Zoonosis Control Center (CCZ) in Lages, Santa Catarina, Brazil. Fecal samples from 108 pet dogs and eight pet cats, and from 357 stray dogs and 97 stray cats, captured by CCZ, were analyzed within the period from July 2010 to November 2012. Coproparasitological exams were performed by techniques of sedimentation, centrifuge-flotation, and simple flotation. Among 465 fecal samples from dogs and 105 from cats, the overall spurious infections for C. hepaticum eggs were 1.05%. For dogs, this positivity was 0.43% and for cats it was 3.81%. The two positive dogs were stray and out of the four cats, three were stray and one was a pet. Although the occurrence of C. hepaticum eggs was low, these data reveal the existence of infected rodents, especially in public places, since, out of the six infected animals, five (83.33%) were stray. These results are discussed and analyzed with an emphasis on the risk to public health.

OCCURRENCE OF Calodium hepaticum (BANCROFT, 1893) MORAVEC, 1982 EGGS IN FECES OF DOGS AND CATS IN LAGES, SANTA CATARINA, BRAZIL

This study aims to report the incidence of Calodium hepaticum among dogs and cats, pets or stray animals, captured by the Zoonosis Control Center (CCZ) in Lages, Santa Catarina, Brazil. Fecal samples from 108 pet dogs and eight pet cats, and from 357 stray dogs and 97 stray cats, captured by CCZ, were analyzed within the period from July 2010 to November 2012. Coproparasitological exams were performed by techniques of sedimentation, centrifuge-flotation, and simple flotation. Among 465 fecal samples from dogs and 105 from cats, the overall spurious infections for C. hepaticum eggs were 1.05%. For dogs, this positivity was 0.43% and for cats it was 3.81%. The two positive dogs were stray and out of the four cats, three were stray and one was a pet. Although the occurrence of C. hepaticum eggs was low, these data reveal the existence of infected rodents, especially in public places, since, out of the six infected animals, five (83.33%) were stray. These results are discussed and analyzed with an emphasis on the risk to public health.

Comparação de seis métodos de extração de DNA genômico de Giardia duodenalis / Comparison of six methods for genomic DNA extraction from Giardia duodenalis CYSTS

Introdução: Giardia duodenalis é um parasito gastrintestinal que infecta o homem e uma variedade de animais domésticos e silvestres. A G. duodenalis em amostras de origem fecal humana pertence a dois principais grupos genéticos, as assemblages A e B, também encontradas em animais. Amostras fecais foram analisadas e a extração e purificação do DNA foram realizadas para avaliar a eficácia da reação em cadeia da polimerase (PCR) na detecção do gene gdh de cistos de G. duodenalis. Métodos: A obtenção de amostras de DNA adequadas para protocolos de amplificação genotípicas foi feita por meio da PCR, comparando seis métodos de extração de DNA de cistos de G. duodenalis em amostras purificadas e não purificadas. Foram realizados os métodos QIAmp DNA Stool Mini Kit, processo de congelamento e descongelamento, ultrassom, uso de glass beads, desnaturação com formamida e o método convencional (fenol/clorofórmio). Resultados: Os métodos com ultrassom e uso de glass beads foram mais efetivos na extração do DNA. Não houve diferença entre o uso de amostras purificadas e não purificados para extração de DNA do protozoário. Conclusão: Verificou-se que tanto amostras purificadas como não purificadas podem ser usadas para extração de DNA de G. Duodenalis. Embora vários métodos de extração de DNA sejam preconizados na literatura, no presente estudo o uso de ultrassom e glass beads foram mais eficazes.

Introduction: Giardia duodenalis is a gastrointestinal parasite that infects human beings and a wide range of domestic and wild animal species. In humans, G.duodenalis samples belong to two major genetic groups, assemblages A and B, also found in animals. Human fecal samples have been approved to analyze the effects of DNA purification and extraction to assess the effectiveness of Polymerase Chain Reaction (PCR) in detecting the gene gdh from G. duodenalis cysts. Methods: Suitable DNA samples for genotypic amplification protocols were obtained by means of PCR, comparing six methods for DNA extraction from G. duodenalis cysts in purified and unpurified samples: QIAmp DNA Stool Mini kit, freeze-thaw procedure, sonication glass bead disruption, formamide denaturation, and conventional method (phenol/chloroform). Results: The methods of sonication and the use of glass beads were more effective in extracting DNA. There was no difference between the use of purified and unpurified samples for protozoan DNA extraction. Conclusions: In the present study we verified that both purified and unpurified samples can be used to G. duodenalis DNA extraction.Though various DNA extraction methods are recommended in the literature, the use of sonicator and glass beads were more effective in this study.

Kinetic and biochemical characterization of Trypanosoma evansi nucleoside triphosphate diphosphohydrolase.

Nucleoside triphosphate diphospho-hydrolases (NTPDases) catalyze the hydrolysis of several nucleosides tri and diphosphate playing major roles in eukaryotes including purinergic signaling, inflammation, hemostasis, purine salvage and host-pathogen interactions. These enzymes have been recently described in parasites where several evidences indicated their involvement in virulence and infection. Here, we have investigated the presence of NTPDase in the genome of Trypanosoma evansi. Based on the genomic sequence from Trypanosoma brucei, we have amplified an 1812 gene fragment corresponding to the T. evansi NTPDase gene. The protein was expressed in the soluble form and purified to homogeneity and enzymatic assays were performed confirming the enzyme identity. Kinetic parameters and substrate specificity were determined. The dependence of cations on enzymatic activity was investigated indicating the enzyme is stimulated by divalent cations and carbohydrates but inhibited by sodium. Bioinformatic analysis indicates the enzyme is a membrane bound protein facing the extracellular side of the cell with 98% identity to the T. brucei homologous NTPDase gene.