Ocorrência e identificação molecular de Cryptosporidium spp. e Giardia spp. em aves silvestres brasileiras

Abstract

Parasitic infections are among the commonest health problems that affect birds. The identification of Cryptosporidium spp. and Giardia spp. in wild birds is relevant, since these animals can act as disseminators of these parasites to humans through environmental contamination. The aim of this research was to determine the occurrence and to perform the molecular characterization of Cryptosporidium and Giardia species/genotypes in feces from free-living and captive wild birds treated in the Laboratory of Wild Animals Research from the Federal University of Uberlândia (LAPAS) and kept in the Zoo of the Municipal Park of Sabiá, in Uberlândia, Minas Gerais, Brazil. The DNA extracted directly from feces was submitted to nested-PCR and semi-nested PCR analysis for amplification of fragments of the SSU rRNA and gdh genes of Cryptosporidium spp. and Giardia spp., respectively. Results showed that out of 256 samples collected, 10 (3.9%) were positive for Cryptosporidium spp., and 8 (3.1%) for Giardia spp.. Out of 172 samples of captive birds, six (3.49%) were positive for Cryptosporidium spp., and four (2.32%) for Giardia spp.. Out of 84 samples of free-living birds, four (4.76%) for Cryptosporidium spp. and four (4.76%) for Giardia spp. were positive. The occurrence of parasites in waterfowl (n=39) was two (5.13%) for Cryptosporidium spp., and four (10.26%) for Giardia spp.; in non-aquatic birds (n=217), it was eight (3.7%) and four (1.84%), respectively. There was no significant difference in the occurrence of Cryptosporidium spp. and Giardia spp. among captive and free-living birds (p = 0.62 and 0.29, respectively). Although no statistical analysis was performed for the positivity of Cryptosporidium spp. and Giardia spp. between waterfowl and non aquatic birds, the meeting of these parasites in waterfowl may have implications for the transmission of these protozoa to humans and other animals. RFLP and sequencing analysis have identified C. meleagridis in two birds of the Anatidae family, in two Aratinga leucophthalma (White-eyed parakeet), and in two Athene cunicularia (Burrowing Owl). They have also found C. baileyi in three Amazona aestiva (Blue-fronted Parrot) and in one Amazona amazonica (Orange-winged Parrot). Only three positive samples for Giardia spp. - classified as Giardia duodenalis assemblage B - were sequenced, two of them found in Rupornis magnirostris (Roadside Hawk), and one in Theristicus caudatus (Buff-necked Ibis). The essay concluded that Cryptosporidium spp. and Giardia spp. are present in wild birds in the microregion of Uberlândia, MG. The existence of zoonotic C. meleagridis and G. duodenalis assemblage B in the animals of this study may have a negative impact on public health.