title: Studies on the inactivation of selected viral and bacterial fish pathogens at high pH for waste disposal purposes.
abstract: This study investigated the use of alkaline hydrolysis at ambient temperature for inactivation of selected fish pathogens in fish tissues under conditions approximating those that are likely to be found in the aquaculture industry. Infectious salmon anaemia virus (ISAV) and Lactococcus garvieae have been determined in a previous study to be the most resistant virus and bacteria to pH 12 from a wide range of viruses and bacteria tested. They were spiked at high titres into fish extracts that were then treated with 1 m sodium hydroxide (NaOH). Viable L. garvieae was not detected in the treated fish extract after 1 h, and ISAV was not detected after 24-h exposure. Field mortalities of Atlantic salmon, Salmo salar L., caused by infectious pancreatic necrosis virus were treated by alkaline hydrolysis at ambient temperature. The macerated fish mortalities contained a high titre of virus (3.38 × 10⁸ TCID₅₀ g⁻¹) that was reduced to approximately 2.2 × 10³ TCID₅₀ g⁻¹ after 24-h exposure to NaOH, and virus was not detected after exposure for 48 h. The results suggest that alkaline hydrolysis at ambient temperature has potential as a biosecure treatment method for fish by-products containing fish pathogens.
authors.affiliation: CEFAS Weymouth Laboratory, Weymouth, Dorset, UK. peter.dixon@cefas.co.uk
authors.forename: P F
authors.initials: PF
authors.lastname: Dixon
authors.forename: M
authors.initials: M
authors.lastname: Algoët
authors.forename: A
authors.initials: A
authors.lastname: Bayley
authors.forename: M
authors.initials: M
authors.lastname: Dodge
authors.forename: C
authors.initials: C
authors.lastname: Joiner
authors.forename: E
authors.initials: E
authors.lastname: Roberts
mesh_terms: D000818:Animals; D017756:Aquaculture / Q000379:methods*; D018175:Birnaviridae Infections / Q000662:veterinary / Q000821:virology; D005393:Fish Diseases / Q000382:microbiology* / Q000821:virology*; D005399:Fishes; D006863:Hydrogen-Ion Concentration; D018061:Infectious pancreatic necrosis virus / Q000502:physiology; D017744:Medical Waste Disposal / Q000379:methods* / Q000592:standards; D050296:Microbial Viability; D012487:Salmonidae / Q000821:virology; D038301:Virus Inactivation
chemical_list: D017744:Medical Waste Disposal