Bacterial septicaemia in prerecruit edible crabs, Cancer pagurus L (original) (raw)
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A novel bacterial infection of the edible crab, Cancer pagurus
Journal of Invertebrate Pathology, 2016
There are few reports of bacterial diseases in crabs. A juvenile edible crab (Cancer pagurus) with a rickettsial-like infection was found in the intertidal zone at Freshwater East in South West Wales in July, 2012. Large numbers of bacteria-like particles were found in the haemolymph and within fixed phagocytes of the hepatopancreas. Molecular sequencing and subsequent phylogenetic analysis showed that the infectious agent was a member of the order Rhizobiales and therefore distinct to bacteria classified as rickettsia.
Parasitology, 2014
SUMMARY This study reports on the prevalence and severity of infections caused by the parasitic dinoflagellate, Hematodinium in juvenile edible crabs (Cancer pagurus) found in 2 intertidal survey sites (Mumbles Head and Oxwich Bay) in the Bristol Channel, UK. Crabs were assessed for the presence and severity of Hematodinium infections by the histological examination of infected tissues. Such infections were found to exhibit a seasonal trend in the 2 study areas with high numbers of animals (ca. 30%) infected in the spring to summer but with low severity. Conversely, in November only ca. 10% of crabs were infected but these animals had large numbers of parasites in their haemolymph and other tissues. At this time, the carapace and underlying tissues of infected crabs had the chalky, pinkish-orange appearance that is characteristic of this disease. Hematodinium-infected crabs ranged in size from 12 to 74 mm carapace width. Overall, it is concluded that the high prevalence of infection...
Journal of Applied Microbiology, 2014
Aims: To determine the prevalence of total and pathogenic Vibrio parahaemolyticus (Vp) and V. vulnificus (Vv) in blue crabs, water and sediment from the Maryland Coastal Bays (MCBs), USA. Methods and Results: Crab, haemolymph, sediment and seawater samples were collected monthly from four sites in MCBs from February 2012 through October 2012 with environmental parameters recorded. The most-probablenumber (MPN) methodology was used to enumerate Vp and Vv with presumptive colonies and the presence of virulence markers confirmed using polymerase chain reaction (PCR). Results indicate that blue crabs contained both Vp and Vv at densities (7Á28 and 5Á43 log MPN g À1 , respectively) higher than those reported for bivalves. In addition, markers for clinically relevant strains of both species were detected in over 30% of samples. Haemolymph, sediment and seawater samples were also routinely positive for both species and clinically relevant strains, but generally at lower densities than found in crabs (4Á27, 3Á28, and 2Á39 log MPN g À1 per ml À1 Vp, and 4Á28, 2Á49 and 2Á38 log MPN g À1 per ml À1 Vv). Conclusions: Blue crabs concentrate Vp and Vv at levels greater than found in water or sediment. While changes in abundance associated with temperature are apparent, there is little evidence to support differences among sampling locations. Significance and Impact of the Study: These results highlight the potential for blue crab related vibriosis and the importance of proper handling, cooking and care of this popular seafood before consumption.
This study reports on an emerging fungal disease of the edible 21 crab, Cancer pagurus. Juvenile (pre-recruit) crabs were found to be subject to 22 this disease condition during the months of May to September at two intertidal 23 sites in South Wales, U.K. Histopathology revealed that the fungi overwhelm 24 the host response in the tissues, leading to progressive septicaemia. The 25 causative agent of this infection was isolated and grown in pure culture and 26 was identified as a member of the Ophiocordyceps clade by sequencing of the 27 small subunit of the fungal rDNA. Of the crabs naturally infected with the 28 fungus, 94% had a co-infection with the parasitic dinoflagellate, 29 Hematodinium. To determine if there was any interaction between the two 30 disease-causing agents, apparently fungus-free crabs, both with and without 31 natural Hematodinium infections, were challenged with the fungal isolate. The 32 presence of Hematodinium caused a significant reduction in fungal 33 multiplication in the hemocoel of the crabs in comparison to Hematodinium-34 free individuals. Histopathology of co-infected crabs showed a systemic 35 multiplication of Hematodinium within host tissues, leading to a rapid death; 36 whilst Hematodinium-free crabs experimentally infected with the fungal 37 isolate, died due to fungal sepsis (septicemia) with the same characteristic 38 pathology as seen in natural infections.
Journal of Invertebrate Pathology, 2015
The prevalence of disease in edible crabs (Cancer pagurus) was assessed at two sites in South West Wales; one estuarine (Pembroke Ferry) and another facing open water (Freshwater East). Diseases included pink crab disease caused by Hematodinium sp., an infection of the antennal gland caused by Paramikrocytos canceri and an idiopathic inflammatory condition of the connective tissue surrounding the anterior ganglionic masses. This latter condition was only found in crabs from Pembroke Ferry. There was a significantly higher prevalence of pink crab disease at Freshwater East than Pembroke Ferry, although both sites had similar levels of infection by P. canceri.
Applied and Environmental Microbiology, 2012
This study reports on an emerging fungal disease of the edible crab,Cancer pagurus. Juvenile (prerecruit) crabs were found to be subject to this disease condition during the months of May to September at two intertidal sites in South Wales, United Kingdom. Histopathology revealed that the fungi overwhelm the host response in the tissues, leading to progressive septicemia. The causative agent of this infection was isolated and grown in pure culture and was identified as a member of theOphiocordycepsclade by sequencing of the small subunit of the fungal ribosomal DNA (rDNA). Of the crabs naturally infected with the fungus, 94% had a coinfection with the parasitic dinoflagellateHematodiniumspecies. To determine if there was any interaction between the two disease-causing agents, apparently fungus-free crabs, both with and without naturalHematodiniuminfections, were challenged with the fungal isolate. The presence ofHematodiniumcaused a significant reduction in fungal multiplication in ...