Two epizootic Perkinsus spp. events in commercial oyster farms at Santa Catarina, Brazil

Abstract

Perkinsus spp. have been detected in various bivalve species from north‐east Brazil. Santa Catarina is a South Brasil state with the highest national oyster production. Considering the pathogenicity of some Perkinsus spp., a study was carried out to survey perkinsosis in two oyster species cultured in this State, the mangrove oyster Crassostrea gasar and the Pacific oyster Crassostrea gigas. Sampling involved eight sites along the state coast, and oyster sampling was collected during the period between January 2013 and December 2014. For the detection of Perkinsus, Ray's fluid thioglycollate medium (RFTM) and histology were used, and for the identification of the species, PCR and DNA sequencing were used. Perkinsus spp. was found by RFTM in C. gigas and C. gasar from São Francisco do Sul. This pathology was also detected in C. gasar from Balneário Barra do Sul both, by RFTM and histology. Perkinsus marinus was identified in C. gigas and C. gasar from São Francisco do Sul and Perkinsus beihaiensis in C. gasar from Balneário Barra do Sul. This is the first report of P. marinus in C. gigas from South America. Results of this preliminary study suggest that both oyster species tolerate the species of Perkinsus identified, without suffering heavy lesions.

Perkinsus sp. infecting three important mollusks from Jaguaribe River estuary, Ceará, Brazil

“…The result of product sequencing of the PCR-positive sample reached the coverage of 616bp of the gene region of the ribosomal RNA, including the ITS1 partial region, the full region 5.8S rRNA, and the ITS2 partial region. These sequences presented homologies of 99% identity with the sequences of P. beihaiensis from Brazil (Cunha et al, 2019;Ferreira et al, 2015;Queiroga et al, 2015;Sabry et al, 2009), from China (Moss et al, 2008) The neighbor-joining tree grouped the sequence of this study (MK880351) into a clade including all sequences classified as P. beihaiensis (Figure 3), indicating a close phylogenetic relationship between the sequences of Perkinsus sp. from Brazil (identified in previous studies), China, and Panama.…”

“…Over the years, with the intensification of the studies, P. marinus was found infecting oysters from estuaries of the states of Paraíba , Sergipe (Silva et al, 2014), Ceará and Bahia (Pinto et al, 2016) and, recently, in C. gigas from cultivation and C. gasar (native) from the State of Santa Catarina, southern Brazil (Cunha et al, 2019), while P. olseni was detected in C. gasar from the São Francisco River estuary, Sergipe (Silva et al, 2014). Despite advances of the research in the region, knowledge about the impact of this protozoan on the host is still little understood.…”

Effects of the toxic dinoflagellates Prorocentrum lima and Ostreopsis cf. ovata on immune responses of cultured oysters Crassostrea gasar

“…(Villalba et al, 2011). These parasites were reported in several states of Northeast Brazil (Dantas-Neto et al, 2015;Luz et al, 2018;Queiroga et al, 2015;Sabry et al, 2013;Silva et al, 2018) and recently in Santa Catarina state in Southern Brazil (Luz Cunha et al, 2019).…”

Diversity and distribution of Perkinsus spp. along the coast of China: Implications for widespread transmission of Perkinsus spp. in mollusks

“…We found that China had the greatest haplotype diversity of P. beihaiensis (86%) and P. olseni (67%) in the world, which suggests that these two species may originate from China, and have been widely transmitted and dispersed among molluscan species along the coast of China. Recent studies have demonstrated the higher tendency of Perkinsus infection with broader geographic range, lower prevalence, more diversified molluscan hosts, and more diversified Perkinsus haplotypes (Pagenkopp Lohan et al, 2016;Pagenkopp Lohan et al, 2018;Luz et al, 2018;Wu et al, 2018;Itoh et al, 2019;Luz Cunha et al, 2019). In the 21st century, molluscan mass mortality events caused by Perkinsus infection seldom occurred anywhere in the world.…”