Metazoan Parasites of the Red Rockfish Sebastes capensis off Northern Chile (original) (raw)
Related papers
Applied and Environmental Microbiology, 2007
Numerous studies have documented the presence of Cryptosporidium parvum, an anthropozoonotic enteric parasite, in molluscan shellfish harvested for commercial purposes. Getting accurate estimates of Cryptosporidium contamination levels in molluscan shellfish is difficult because recovery efficiencies are dependent on the isolation method used. Such estimates are important for determining the human health risks posed by consumption of contaminated shellfish. In the present study, oocyst recovery was compared for multiple methods used to isolate Cryptosporidium parvum oocysts from oysters (Crassostrea virginica) after exposure to contaminated water for 24 h. The immunomagnetic separation (IMS) and immunofluorescent antibody procedures from Environmental Protection Agency method 1623 were adapted for these purposes. Recovery efficiencies for the different methods were also determined using oyster tissue homogenate and hemolymph spiked with oocysts. There were significant differences in recovery efficiency among the different treatment groups (P < 0.05). We observed the highest recovery efficiency (i.e., 51%) from spiked samples when hemolymph was kept separate during the homogenization of the whole oyster meat but was then added to the pellet following diethyl ether extraction of the homogenate, prior to IMS. Using this processing method, as few as 10 oocysts could be detected in a spiked homogenate sample by nested PCR. In the absence of water quality indicators that correlate with Cryptosporidium contamination levels, assessment of shellfish safety may rely on accurate quantification of oocyst loads, necessitating the use of processing methods that maximize oocyst recovery. The results from this study have important implications for regulatory agencies charged with determining the safety of molluscan shellfish for human consumption.
Cryptosporidium parvum oocysts in seawater clams (Chamelea gallina) in Italy
Preventive Veterinary Medicine, 2005
Bivalves filter large volumes of water and can concentrate organisms which are pathogenic for humans and animals. Our aim was to evaluate the presence of Cryptosporidium spp. in clams from the Adriatic coast (Abruzzo region) and genetically characterize the oocysts isolated from the clams. From March to July 2003, 960 specimens of clams (Chamelea gallina) present in nature were collected at 500 m from the Tordino, Tronto, Vibrata and Vomano river mouths on the Adriatic sea. The haemolymph and tissues were extracted from the specimens (240 per river mouth) after the specimens had been identified, measured and weighed (live weight). Immunofluorescence tests (IFA) were performed on pools (n = 32) of samples and oocysts of Cryptosporidium spp. were detected in 23 pools of C. gallina. To identify the Cryptosporidium species, all the pools IFA-positive were tested by a PCR assay specific for the Cryptosporidium outer wall protein (COWP) gene. Positive amplicons then were sequenced and analysed. Two pools of clams were positive for Cryptosporidium parvum Genotype 2 (the ''bovine'' i.e. zoonotic genotype). This is the first time that C. parvum was found in clams from the Adriatic sea in Italy and the case might be of public health importance. #
Applied and Environmental Microbiology, 2000
Infective Cryptosporidium parvum oocysts were detected in mussels ( Mytilus galloprovincialis ) and cockles ( Cerastoderma edule ) from a shellfish-producing region (Gallaecia, northwest Spain, bounded by the Atlantic Ocean) that accounts for the majority of European shellfish production. Shellfish were collected from bay sites with different degrees of organic pollution. Shellfish harboring C. parvum oocysts were recovered only from areas located near the mouths of rivers with a high density of grazing ruminants on their banks. An approximation of the parasite load of shellfish collected in positive sites indicated that each shellfish transported more than 10 3 oocysts. Recovered oocysts were infectious for neonatal mice, and PCR-restriction fragment length polymorphism analysis demonstrated a profile similar to that described for genotype C or 2 of the parasite. These results demonstrate that mussels and cockles could act as a reservoir of C. parvum infection for humans. Moreover,...
Parasite, 2009
Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis), the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24) and Samut Prakan (n = 32) a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels' cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA) in 12.5 % of the samples examined. The detection of Cryptosporidium oocysts in green mussels' population of Samut Prakan was higher (15.6 %) than in Bangkok market (8.3 %). These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.
Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil
Parasitology, 2015
The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48·9%), followed by Nematopsis sp. (36·3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters' infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.
Aquaculture, 2008
The haplosporidian Bonamia exitiosa was found infecting the European flat oyster Ostrea edulis in the Galician coast (NW Spain), which represents the first report of this parasite along European waters. Histopathology and molecular characterization of the small subunit ribosomal DNA gene were performed to identify this species. Examination of histological sections showed two microcell types, the smaller one corresponding to Bonamia ostreae and the larger one to B. exitiosa. Phylogenetic analysis places the sequence herein reported in a clade with Bonamia species of the Southern hemisphere, namely B. exitiosa, B. roughleyi and Bonamia sp. from North Carolina and Chile. Subsequent PCR-RFLPs analysis showed a highly-endemiotopic infection by B. exitiosa, demonstrating the success of this haplosporidian to infect the European flat oyster in the Galician marine ecosystem even in concurrent infections with B. ostreae.
The purpose of this study was to compare the parasites of two coexisting bivalves, the edible Puelche oyster (Ostrea puelchana) and the false oyster (Pododesmus rudis) that lives attached to O. puelchana shells, and to investigate their host specificity. Samples from wild populations, 465 O. puelchana and 131 P. rudis, were collected seasonally during two years in the San José Gulf (northern Patagonia, Argentina) and were processed using standard histological techniques. To increase the natural low prevalences of Bonamia spp. and Perkinsus spp. that are present in wild populations, an in situ experiment was performed by maintaining captive sentinel bivalves at high densities inside a plastic mesh bag to enhance parasite transmission. Polymerase chain reaction (PCR) assays were used to test for apparent Bonamia sp. infections among captive sentinel O. puelchana specimens (n = 80), and Ray’s fluid thioglycollate medium (RFTM) assays and histological immunoassays tested for apparent Perkinsus sp. infections among captive sentinel P. rudis specimens (n = 100). Despite histological observations that revealed the presence of microcells resembling Bonamia sp. infecting hemocytes of some Puelche oysters, PCR assays did not confirm that parasite identification. Among captive sentinel P. rudis that showed histological evidence of Perkinsus sp. infections, neither RFTM nor immunoassays confirmed such parasites. Ostrea puelchana from wild populations were occasional hosts for both Rickettsia-like organism (RLOs) and Urastoma-like turbellarians. In contrast, six parasite taxa infected P. rudis from coexisting populations, including RLOs, Urastoma-like turbellarians, an intracellular gregarine species, Nematopsis-like oocysts, an unidentified coccidian and a Perkinsus qugwadi-like protozoan. These results demonstrated specific infection patterns of the d parasites in relation to their hosts.
Bulletin of environmental contamination and toxicology, 2017
Cryptosporidium spp. has been recognized as an important pathogen. As bivalve mollusks are noted as potential sources of several pathogens due to their consumption as foodstuffs, the aim of this study was to investigate the occurrence of Cryptosporidium spp. oocysts in Perna perna mussels and in seawater samples from a mussel farm in Southeastern Brazil, where mussels are grown directly in the sea, attached to ropes. Oocysts were observed by microscopy and confirmed by an enzyme-linked immunosorbent assay. Oocysts were present in mussel gills and GI tracts, as well as in the seawater. Of the 100 females, 10% and 11% showed contaminated GI tracts and gills, respectively, while this rate was lower in males, at 5% and 8.9%. Oocysts were present in higher amounts in the GI tract compared to gills and water. Contamination of the study area is apparent, leading to public health risks. More in-depth studies are needed, including molecular investigations, to identify Cryptosporidium species...