Marine fish parasite, Lernanthropus kroyeri (Copepoda) is a repository of Vibrio anguillarum as evidenced by Loop-Mediated Isothermal Amplification method

Abstract

Fish parasites act as a vector of other pathogenic diseases such as bacteria and virus in fish. Although it has been long known that fish parasites can act as a vector for bacterial pathogens, their role in the transmission of specific bacterial pathogens via particular parasites in the off-host stage has been neglected. The aim of the present study was to disclose that if the copepod parasite, Lernanthropus kroyeri in the off-host stage, can store up the aquatic bacterial pathogens: Aeromonas hydrophila, Photobacterium damsela subsp. piscicida, Vibrio (Listonella) anguillarum, V. harveyi, V. vulnificus, and V. alginolyticus. Our results using the Loop-mediated Isothermal Amplification (LAMP) method demonstrated that the bacteria, V. anguillarum is internally present in the off-host copepod parasites, L. kroyeri. It was also found that the parasite, L. kroyeri could survive in the off-host stage for a given time with its potential of vectoring ability in terms of transmission of the bacterium to the fish. This study demonstrates evidence that the copepod parasite in the off-host stage on the gills of sea bass is a reservoir of pathogen bacteria, Vibrio anguillarum.

Keywords

• Lernanthropus
• parasitic copepod
• vector
• Vibrio anguillarum.

References

1. Aartse A, Scholtens IMJ., van der AHJG, et al (2017): Evaluation of a loop-mediated isothermal amplification (LAMP) method for rapid on-site detection of horse meat. Food Control, 81, 9-15.
2. Bandilla M, Valtonen ET, Suomalainen LR, et al (2006): A link between ectoparasite infection and susceptibility to bacterial disease in rainbow trout. Int J Parasitol, 36, 987-991.
3. Barker DE, Braden LM, Coombs MP, et al (2008): Little bugs with smaller bugs: preliminary studies on the role of sea lice as a vector of bacterial pathogens. Aquaculture Canada 2008. Proceedings of the contributed papers of the 25th Annual Meeting of the Aquaculture Association of Canada, Saint John, NB, 11-14 May 2008.
4. Cusack R, Cone DK (1986): A review of parasites as vectors of viral and bacterial diseases of fish. J Fish Diseases, 9, 169-171.
5. Er A, Kayiş Ş (2015): Intensity and prevalence of some crustacean fish parasites in Turkey and their molecular identification. Turkish J Zool, 39, 1142-1150.
6. Gunimaladevi I, Kono T, LaPatra SE, et al (2005): A loop mediated isothermal amplification (LAMP) method for detection of infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss). Arch Virology, 150, 899-909.
7. Frans I, Michiels CW, Bossier P, et al (2011): Vibrio anguillarum as a fish pathogen: virulence factors, diagnosis and prevention. J Fish Diseases, 34, 643-661.
8. He J, Shi X, Yu L, et al (2013): Development and evaluation of a loop-mediated isothermal amplification assay for diagnosis of Cyprinid herpesvirus 2. J Virol Methods, 194, 206-210.

9. Kotob MH, Menanteau-Ledouble S, Kumar G, et al (2016): The impact of co-infections on fish: a review. Veterinary Research, 47, 1-12.
10. Pylkkö P, Suomalainen LR, Tiirola M, et al (2016): Evidence of enhanced bacterial invasion during Diplostomum spathaceum infection in European grayling, Thymallus thymallus (L.). J Fish Diseases, 29, 79-86.
11. Toksen E (2007): Lernanthropus kroyeri van Beneden, 1851 (Crustacea: Copepoda) infections of cultured sea bass (Dicentrarchus labrax L.). Bull Eur Assoc Fish Pathol, 27, 49-53.
12. Tsai MA, Wang PC, Yoshida S, et al (2019): Establishment of loop-mediated isothermal amplification for rapid and convenient detection of Mycobacterium marinum complex. J Microbiol Methods, 164, 105671.
13. Tully O, Nolan DT (2002): A review of the population biology and host–parasite interactions of the sea louse Lepeophtheirus salmonis (Copepoda:Caligidae). Parasitology, 124, 165-182.
14. Walker PD, Russon IJ, Duijf R, et al (2011): The off-host survival and viability of a native and non-native fish louse (Argulus, Crustacea: Branchiura). Curr Zool, 57, 828-835.
15. Xu DH, Shoemaker CA, Klesius PH (2012): Ichthyophthirius multifiliis as a potential vector of Edwardsiella ictaluri in channel catfish. FEMS Microbiol Lett, 329, 160-167.
16. Yardımci B, Pekmezci G (2012): Gill histopathology in cultured sea bass (Dicentrarchus labrax (L.) co- infected by Diplectanum aequans (Wagener, 1857) and Lernanthropus. Ankara Univ Vet Fak Derg, 59, 61-64.