Disinfection of teleost eggs: a review

Abstract

In aquaculture hatcheries, egg disinfection is commonly employed as a mortality mitigation and disease management tool. In addition, disinfection protocols are utilized in research facilities, as a means to create axenic and gnotobiotic larval models. For the latter, a complete sterilization of the eggs is warranted. Multiple research groups have tested various disinfectants in fish eggs adopting different protocols and a range of parameters to evaluate their efficacy and safety. However, there is a clear lack of a critical review listing these different studies and stressing the advantages and shortcomings of the protocols and adopted disinfectants. This review provides a commented survey of the findings/experiments on the most frequently used and upcoming disinfecting products, the protocols in which they are included and their purposes with emphasis on decreasing bacterial and/or fungal load, underscoring the benefits and the limitations of each product. Supplemented with a critical note, this review assists both aquaculturists and researchers in making an informed choice. Moreover, it will help stakeholders to identify the gaps in knowledge where future research on egg disinfection is needed.

Germ-free sea bass Dicentrarchus labrax larval model: a valuable tool in the study of host-microbe interactions

“…The disinfectants glutaraldehyde, hydrogen peroxide and ozone were included in our experiments, because these were referred to in most other studies as valuable disinfectants for living tissue (De Swaef et al 2015). In addition, non-thermal plas ma, acknowledged as a promising disinfectant tool, was included (Moreau et al 2008, Dobrynin et al 2009).…”

“…The use of antimicrobial agents may elicit unwanted and unknown interactions with the target organism (Marques et al 2006). Furthermore, the envisaged microorganisms need to be made resistant to the antimicrobial agent by multiple in vitro passages, which may have an impact on pathophysiological traits of the micro organism under study (Fux et al 2005, De Swaef et al 2015.…”

“…Despite the significant increase in the use of fish as experimental animals during the last decades (Marques et al 2005, Schaeck et al 2013) and the stressed importance of raising aquatic organisms gnotobiotically (Bates et al 2006), the current know-how of rearing gnotobiotic aquatic organisms is much more limited compared to the more traditional mammalian laboratory animals. To our know ledge, only a handful of studies have reported the successful derivation of gnotobiotic marine fish species (Baker et al 1942, Munro et al 1995, Rawls et al 2004, Forberg et al 2011; for a review, see De Swaef et al 2015). However, not all of these models included a system for axenically feeding the larvae, and some used only culture-based techniques to verify microbial status, with the potential of falsely claiming a germfree status.…”

“…The use of antimicrobial agents may elicit unwanted and unknown interactions with the target organism (Marques et al 2006). Furthermore, the envisaged microorganisms need to be made resistant to the antimicrobial agent by multiple in vitro passages, which may have an impact on pathophysiological traits of the micro organism under study (Fux et al 2005, De Swaef et al 2015.In this respect, the aim of our study was to develop a standardized germ-free sea bass larval model system, independent of the continuous addition of antibiotics and allowing germ-free feeding, which will facilitate the study of host−microbe interactions. …”

Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus Batrachochytrium salamandrivorans

“…Disinfectants with H 2 O 2 and/or peracetic acid as main active ingredient were included as these might provide a more environmentally friendly alternative (see e.g. [16]) for bleach and Virkon S ® [17,18]. For various disinfectants, concentrations and contact times required for 100% killing of Bsal were determined in vitro and compared to data available for Bd .…”