Perna perna mussels as bioindicators of aquatic contamination by Cryptosporidium spp

ABSTRACT

Background: Bivalve mollusks, such as the Perna perna mussels, are used as bioindicators of aquatic contamination by heavy metals, pesticides, bacteria, viruses and protozoa. The protozoan Cryptosporidium spp. has species capable of infecting several hosts, including humans, with ingestion being the only form of transmission of oocysts, through water and/or contaminated food. The objective of this study was to use Perna perna mussels as bioindicators of aquatic contamination through the genetic characterization of species and/or genotypes of Cryptosporidium, associating the sources of environmental contamination by faeces and correlating the possible presence of the protozoan with precipitation indexes in the region of Mangaratiba, Rio de Janeiro.Materials, Methods & Results: The mussels were obtained from two sites, both formed by rocks bathed in natural sea water. Site A is called Lage Black and site B is called beach Bag. Samples were taken monthly from March 2009 to February 2010, totaling 12 collections. For the analyzes, the DNA extracted from tissues of mussels was used in the amplification of 18 SSU rDNA sequences, through the Nested-PCR technique. During all months of the study, we diagnosed Cryptosporidium-positive Perna perna mussels samples from, at least, one of the sites studied. We could identify the species C. andersoni, C. meleagridis and C. parvum...(AU)