Commensal bacteria from crayfish cuticle and their potential significance in biocontrol of causative agent of crayfish plague

Abstract

Patogeni iz razreda Oomycetes sve su veća prijetnja za biljne i životinjske vrste. Među njima je patogen Aphanomyces astaci (Schikora, 1906), uzročnik bolesti račje kuge, koji je uvršten na popis 100 najopasnijih invazivnih vrsta svijeta. Upravo zbog te bolesti, kao i samim unosom invazivnih vrsta rakova, došlo je do pada u brojnosti populacija autohtonih vrsta rakova u Europi. Jedina poznata efikasna rješenja za tu bolest su toksični kemijski spojevi, koji su zabranjeni za korištenje. Upravo zbog toga se javlja potreba za prirodnim sredstvima kontrole tog patogena. Već je ranije poznato da mikrobni simbionti mogu zaštiti svoje domaćine od raznih patogena te su provedena istraživanja za oomicete iz roda Saprolgnia. Za taj rod se već zna da postoje bakterije na površinama domaćina koje mogu zaštiti domaćina od zaraze. Međutim, za rod Aphanomyces takva istraživanja nisu ranije provedena. Cilj ovoga rada bio je sistematski prikazati rezultate istraživanja na području interakcije domaćina-simbionta za deseteronožne rakove i ukazati na potrebu za detaljnijim istraživanja interakcije A. astaci i bakterija s površine rakova radi boljeg razumijevanja odnosa između patogena, domaćina i simbionata te pronalaska načina kako tu interakciju iskoristiti u korist zaštite samog domaćina – autohtonih europskih vrsta slatkovodnih deseteronožnih rakova.Pathogens belonging to class Oomycetes are increasingly recognized as a threat for animal and plant species. One of such pathogens is Aphanomyces astaci (Schikora, 1906), a causative agent of crayfish plague disease. A. astaci is listed among 100 worst invasive species in the world. Due to crayfish plague disease and spread of non-indigenous crayfish species, declines in populations of indigenous European crayfish species have occurred throughout Europe. The only known effective methods for control of this pathogen are toxic chemical substances that are banned for use due to detrimental effects of freshwater ecosystems. Thus, there is a need for identification of natural resources for control of this pathogen. Microbial symbionts have a demonstrated ability to protect their host from a variety of pathogens, however most of research has been conducted for Oomycetes from genus Saprolegnia. For that genus it is known that there are bacteria on surface of the host that can protect the host from infection. However, for genus Aphanomyces, such research is lacking. The aim of this paper is to systematically analyze results of research in the field of host- symbionts interaction for decapod crayfish species. Furthermore, the paper indicates the need for further research of interaction between A. astaci and bacteria present on the crayfish cuticle for better understanding the host-pathogen-symbionts interaction which can bring novel pathogen control methods and enhance conservation of native European crayfish