Abstract INTRODUCTION Blastocystis is an intestinal protozoan that may play a role in the pathogenicity of humans. This study aimed to (i) genetically characterize Blastocystis isolates obtained from human fecal samples and the water supply of the city of Uberaba, Minas Gerais, Brazil, and (ii) to verify the phylogenetic relationship between these isolates. METHODS Blastocystis species present in 26 fecal samples obtained from humans and animals from Uberaba were genetically characterized by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-sequence-tagged sites. All amplicons were partially sequenced and/or defined according to the GenBank classification. RESULTS Polymerase chain reaction amplicons were generated from 21 human isolates and 18 water samples. The subtypes defined were ST1 (53.3%), ST3 (40.0%), and ST2 (6.7%) for human isolates; ST10 (100%) for bovine isolates; and ST5 (50.0%), ST1 (25%), and ST3 (25%) for pigs. Sequencing of polymerase chain reaction products showed a 98%-99% identity for the Blastocystis sequences deposited in GenBank, except for sequences from water samples that showed the identity of algae sequences. Phylogenetic analysis of Blastocystis sequences showed two distinct groups, one of which was principally formed by ST1, ST5, and ST10, and the other by isolates characterized as ST3 and ST7. Both clades showed human and animal sequences, reinforcing the notion that Blastocystis subtypes are not host-specific. CONCLUSIONS The data showed that Blastocystis subtypes circulating in Uberaba are ST1-ST3, ST5, and ST10, present in both humans and animals, demonstrating that the Blastocystis subtypes are not host-specific; that is, zoonotic transmission is possible.

Abstract INTRODUCTION: Currently, there are few studies regarding Blastocystis epidemiology. This study aimed to evaluate the occurrence of Blastocystis in animals in Uberaba, Brazil. METHODS: Fecal samples were examined by parasitological methods and screened for Blastocystis by polymerase chain reaction. RESULTS: Blastocystis spp. were observed in pigs, sheep, cattle, and dogs. Blastocystis polymerase chain reaction was positive in 14/22 samples positive by parasitological methods. CONCLUSIONS: The occurrence of Blastocystis in animals is high, with a predominance of subtype 1 in the region. This is the first study conducted in Brazil showing the genetic profile of Blastocystis isolated from animals.

Parasitos intestinais são um problema de saúde pública no mundo e a infecção por Blastocystis, protozoário de patogenicidade controversa, é uma das mais frequentes. Nesse estudo foi investigada a ocorrência de parasitos intestinais em pacientes atendidos na Universidade Federal do Triângulo Mineiro, em Uberaba (MG), com ênfase em Blastocystis, pelos métodos parasitológicos direto e de Ritchie. Foram examinadas fezes de 1.323 pacientes de abril/2011 a maio/2012. Em 28,7% deles foi identificado um parasito intestinal, sendo Blastocystis spp. (17,8%) e Giardia intestinalis(7,4%) os mais frequentes. A ocorrência de parasitismo foi maior em crianças de 6-10 anos e a infecção por Blastocystis spp. foi maior acima de seis anos (p < 0,001). Presença exclusiva de G. intestinalis e de Blastocystis spp. foi observada em 5,4% e 12,2% dos pacientes, respectivamente, sendo que dos pacientes com fezes diarreicas, 8% apresentavam parasitismo exclusivo por Blastocystisspp. Outros parasitos intestinais observados em crianças foram Ascaris lumbricoides (0,3%) e Entamoeba histolytica/dispar/moshkovskii (1,4%). O método de Ritchie foi mais sensível (92,8%) que o direto (89,8%), com alta concordância entre eles (97,7%, kappa = 0,92). Em conclusão, a ocorrência de Blastocystis spp. em Uberaba é elevada e foi observada a presença de fezes diarreicas com parasitismo exclusivo por Blastocystis spp.

Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie’s method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides(0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie’s method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed.

Pacientes com AIDS são particularmente susceptíveis a infecção por coccídios intestinais e nesse estudo foi avaliada a freqüência de Cryptosporidium sp. e Cystoisospora belli entre pacientes HIV/AIDS na região do Triângulo Mineiro, Brasil. No período de julho de 1993 a junho de 2003, amostras de fezes de 359 pacientes foram submetidas à coloração pelo método de Ziehl-Neelsen modificado, sendo detectada a presença de coccídios em 19,7% destas (8,6% de Cryptosporidium sp, 10,3% de Cystoisospora belli e 0,8% de ambos coccídios). Pacientes com diarréia e níveis de linfócitos T CD4+ < 200 células/mm3 apresentaram maior frequência destes protozoários, demonstrando o perfil oportunista destas infecções e a relação com o status imunológico do indivíduo. Não foi possível determinar a influência da HARRT, pois apenas 8,5% dos pacientes positivos para coccídios fazriam uso regular desta terapia. Parasitismo por Cryptosporidium sp foi mais freqüente no período compreendido de dezembro a fevereiro caracterizando padrão sazonal desta infecção, fato não observado com Cystoisospora belli.

Patients with AIDS are particularly susceptible to infection with intestinal coccidia. In this study the prevalence of infections with Cryptosporidium sp and Cystoisospora belli were evaluated among HIV/AIDS patients in the Triângulo Mineiro region, Brazil. Between July 1993 and June 2003 faecal samples from 359 patients were collected and stained by a modified Ziehl-Neelsen method, resulting in 19.7% of positivity for coccidian (8.6% with Cryptosporidium sp, 10.3% with Cystoisospora belli and 0.8% with both coccidian). Patients with diarrhoea and T CD4+ lymphocyte levels < 200 cells/mm3 presented higher frequency of these protozoans, demonstrating the opportunistic profile of these infections and its relationship with the immunological status of the individual. It was not possible to determine the influence of HAART, since only 8.5% of the patients positive for coccidian received this therapy regularly. Parasitism by Cryptosporidium sp was more frequent between December and February and thus was characterised by a seasonal pattern of infection, which was not observed with Cystoisospora belli.