The family Dactylogyridae, known for its role as a frequent pathogen in Cyprinids, was identified in a case of mass mortality involving
Catla catla
fingerlings (measuring 6.5 ± 2.0 cm and weighing ...40.5 ± 10 g) in West Bengal, India. Microscopic examination revealed the presence of two co-existing parasites,
Dactylogyrus formosus
and
Paradactylogyrus catlaius
, attached to different sections of the gill filament. Despite their coexistence, these parasites exhibited marked differences in their haptoral hard parts, genital organs, and preferred habitats. Molecular analysis of the Internal Transcribed Spacer 1 and 4 genes indicated more than 90% similarity between the detected parasite and
D. formosus
previously reported in China. Histopathological observations illustrated the parasites' specific attachment to the distal end of the primary gill lamellae, gradually causing destruction to a maximum number of secondary lamellae. Internally, infiltration of eosinophilic granular cells was observed in gill and kidney blood vessels, while the liver exhibited hepatocytes filled with hemosiderin. The infected fish were treated for 24 h with a safe dose of common salt (5.6 ppt) and albendazole (62 ppm). The survivability rate was significantly higher (
p
< 0.05) in both treated groups compared to the control. Interestingly, the group treated with common salt showed superior results compared to the albendazole-treated fish. This study presents the sympatric speciation of
D. formosus
in a new host (
C. catla
) and explores its host specificity, histopathology, and treatment methods. This case marks the first report of
D. formosus
causing substantial mortality in cultured Catla in India, alongside the coexistence with
Paradactylogyrus catlaius
.
Myxozoan parasites pose huge threat to wild and cultured fishes and reported to cause heavy mortality, retarded growth and post-harvest quality degradation. It is one of the highly divergent groups ...of parasites which infects skin, gill, muscle, cartilage and internal organs of host fish and the severity of pathology varies depending on the water temperature, species of fish, site of tissue infection and immune resistance of the individual host. Most infections are difficult to treat, as they can easily evade host cellular and humoral defence mechanisms by proliferating or migrating through immune compromised sites of the host and forming large plasmodia encapsulated by the host cellular elements. This spore-forming parasite is harmless to humans but often detected in faecal samples of immunosuppressed humans. The incidences are mostly associated with the consumption of infected fish having a high concentration of spores which causes diarrhea and stomach pain. Currently, there are no immunostimulants or vaccines available for controlling these parasites, however, fumagillin is the drug of choice in fish for controlling this parasitic infection. Excessive usage of fumagillin causes tissue damage and retarded growth in fish, hence feed incorporation of this antibiotic in proper dose is essential for effective treatment. In this review detailed information on the diseases caused by myxozoan parasites in fishes and their zoonotic potential is discussed.
Intensification and diversification of the aquaculture practices made an opening to the emergence of new viral diseases daunting the farmers to achieve a sustained production. Viruses are obligatory ...parasites abundant in the aquatic environments and are being introduced in the sector directly or indirectly. Infectious Myonecrosis Virus (IMNV) is an emerging shrimp RNA virus causing the disease, infectious myonecrosis (IMN). The disease was reported first from Brazil and currently the geographical locations of infection span in Brazil and Indonesia. Research are centered on the viral pathogenesis, viral entry, disease prevention and epidemiology, diagnostics and molecular pathology. The recent developments in the synthetic and molecular biology techniques have paved way to explore IMNV at its molecular levels, yet further research has to be conducted to fully understand the virus as well as diagnostics of the disease with cause. This review covers all the aspects of the virus, IMNV and the disease IMN, research developments and emphasizes on the current progress and the future prospects of the research in control and prevention strategies.
•Infectious myonecrosis virus (IMNV) is an emerging penaeid shrimp virus belongs to the family Totiviridae•The virus is endemic to Brazil and Indonesia with a potential chance to spread transboundary.•OIE is listed IMNV as one of major viral pathogen to crustaceans and initiated the active surveillance•The infection is characterized by whitish muscles along the abdomen and tail region•Good Management Practices can prevent the virus and diagnostics are under research phase
The outer membrane protein, encoded by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, of Edwardsiella tarda is a highly conserved immunogenic protein. The GAPDH was cloned and expressed in ...Escherichia coli. The purified protein was used to produce mouse monoclonal antibodies (MAbs). Four stable hybridomas producing MAbs (3G12, 4E9, 5A11 and 9G1) against rGAPDH were obtained. The heavy chains of antibodies produced by the hybridomas were of the isotypes IgG1 and IgM. Cross reactivity of MAbs (3G12 and 9G1) was observed with GAPDH of Aeromonas hydrophila and Micrococcus luteus. MAbs 3G12 and 4E9 reacted with Vibrio cholerae, Salmonella enterica and Penaeus monodon tissues but not with vertebrate GAPDH. None of the MAbs reacted with Staphylococcus aureus. The results indicate that the level of conservation of GAPDH is high among evolutionarily close species. The MAbs developed will be a useful tool to study the evolutionarily conserved and functionally diverse GAPDH.
PDF
