Journal Article

Molecular characterization of intestinal protozoa in two poor communities in the State of São Paulo, Brazil

Nogueira Bittencourt, Gabriela, David, Érica Boarato, Branco, Nilson, Pozio, Edoardo, de Oliveira, Ana Paula, Goulart de Oliveira-Sequeira, Teresa Cristina, Bueno Franco, Regina Maura, Guimarães, Semíramis, Cacciò, Simone M, Moraes Nardi, Ana Rita, Bella, Antonino, Tosini, Fabio, Martins Ribolla, Paulo Eduardo

2015

Overview

BACKGROUND: Several species of protozoa cause acute or chronic gastroenteritis in humans, worldwide. The burden of disease is particularly high among children living in developing areas of the world, where transmission is favored by lower hygienic standards and scarce availability of safe water. However, asymptomatic infection and polyparasitism are also commonly observed in poor settings. Here, we investigated the prevalence of intestinal protozoa in two small fishing villages, Porto Said (PS) and Santa Maria da Serra (SM), situated along the river Tietê in the State of São Paolo, Brazil. The villages lack basic public infrastructure and services, such as roads, public water supply, electricity and public health services. METHODS: Multiple fecal samples were collected from 88 individuals in PS and from 38 individuals in SM, who were asymptomatic at the time of sampling and had no recent history of diarrheal disease. To gain insights into potential transmission routes, 49 dog fecal samples (38 from PS and 11 from SM) and 28 river water samples were also collected. All samples were tested by microscopy and PCR was used to genotype Giardia duodenalis, Blastocystis sp., Dientamoeba fragilis and Cryptosporidium spp. RESULTS: By molecular methods, the most common human parasite was Blastocystis sp. (prevalence, 45% in PS and 71% in SM), followed by D. fragilis (13.6% in PS, and 18.4% in SM) and G. duodenalis (18.2% in PS and 7.9% in SM); Cryptosporidium spp. were not detected. Sequence analysis revealed large genetic variation among Blastocystis samples, with subtypes (STs) 1 and 3 being predominant, and with the notable absence of ST4. Among G. duodenalis samples, assemblages A and B were detected in humans, whereas assemblages A, C and D were found in dogs. Finally, all D. fragilis samples from humans were genotype 1. A single dog was found infected with Cryptosporidium canis. River water samples were negative for the investigated parasites. CONCLUSIONS: This study showed a high carriage of intestinal parasites in asymptomatic individuals from two poor Brazilian villages, and highlighted a large genetic variability of Blastocystis spp. and G. duodenalis.

• Publisher: Springer-Verlag,BioMed Central,BMC
• Subject: Animals / Asymptomatic Diseases - epidemiology / Biomedical and Life Sciences / Biomedicine / Blastocystis / Brazil / Brazil - epidemiology / burden of disease / Carrier State - epidemiology / Carrier State - parasitology / children / Cryptosporidium / Dogs / electricity / Entomology / feces / Feces - parasitology / gastroenteritis / genetic variation / genotype / Giardia lamblia / health services / Humans / Infectious Diseases / Intestinal Diseases, Parasitic - epidemiology / Intestinal Diseases, Parasitic - parasitology / Intestinal Diseases, Parasitic - veterinary / Intestinal protozoa / Microscopy / Molecular typing / parasites / Parasitology / Polymerase Chain Reaction / Poverty Areas / Prevalence / Protozoan Infections - epidemiology / Protozoan Infections - parasitology / Protozoan Infections, Animal - parasitology / public health / public water supply / River water / rivers / Rivers - parasitology / roads / sequence analysis / Tropical Medicine / Veterinary Medicine/Veterinary Science / villages / Virology