Staff Assessment Report 26 February 2020 Advice to the Decision-making Committee to determine the new organism status of microbial pathogens Application code: APP203966 Application type and sub-type: Determination Applicant: South Pacific Sera Limited Date application received: 31 January 2020 Purpose of the document: Information to support the consideration of the determination of Lactococcus garvieae, Tenacibaculum maritimum and New Zealand Rickettsia-like organisms (NZ-RLOs) 1 and 2. Executive Summary Application APP203966 submitted by South Pacific Sera Limited seeks a determination on the new organism status of Lactococcus garvieae, Tenacibaculum maritimum and New Zealand Rickettsia-like organisms (NZ-RLOs) 1 and 2 in New Zealand. The applicant provided evidence that the microbial species have been isolated from many different locations in New Zealand and based on international evidence, are ubiquitous in the natural environment. After reviewing the information provided by the applicant and information found in scientific literature, EPA staff recommend that Lactococcus garvieae, Tenacibaculum maritimum and NZ-RLOs 1 and 2 are not new organisms for the purpose of the Hazardous Substances and New Organisms Act 1996 (the Act). 1 Table of content Introduction ............................................................................................................................................ 3 Microbial ubiquity .................................................................................................................................. 3 Organism descriptions ......................................................................................................................... 4 Lactococcus garvieae.....................................................................................................................4 Tenacibaculum maritimum .............................................................................................................5 New Zealand Rickettsia-like Organisms 1 and 2 ...........................................................................6 Evidence regarding presence in New Zealand ................................................................................... 7 Historical Background ....................................................................................................................7 Evidence for the presence of the proposed organisms in New Zealand .......................................7 Comments from Agencies .................................................................................................................... 8 Effect on New Zealand’s international obligations ............................................................................ 9 Recommendation .................................................................................................................................. 9 References ........................................................................................................................................... 10 Appendix 1: Revised s26 pathway ..................................................................................................... 13 2 Introduction 1. On 31 January 2020, South Pacific Sera Limited applied to the EPA under section 26 of the HSNO Act seeking a determination on the new organism status of Lactococcus garvieae, Tenacibaculum maritimum and New Zealand Rickettsia-like organisms (NZ-RLOs) 1 and 2. 2. Section 2A(1) of the HSNO Act prescribes that a new organism includes an organism belonging to a species that was not present in New Zealand immediately before 29 July 1998. It is against that criterion that we evaluated the evidence available for the organisms in the application. Organism descriptions Lactococcus garvieae Table 1: Taxonomic description of Lactococcus garvieae. Taxonomic Unit Classification Order Lactobacillales Family Streptococcaceae Genus Lactococcus Species garvieae Collins et al. 1984, Schleifer et al. 1986 3. Lactococcus garvieae is a facultatively anaerobic, non-motile, non-spore forming, Gram-positive ovoid coccus, occurring in pairs and short chains and it produces a-haemolysis on blood agar. It grows at 4–45ºC in media containing 6.5% sodium chloride at pH 9.6 with 40% bile and in 0.1% methylene blue-milk. Its optimal growth temperature is 37ºC for 24 hours while at 4ºC, it needs between 12 and 15 days (Kusuda et al. 1991; Eldar et al. 1996). It also grows rapidly in rich media such as brain-heart infusion agar, trypticase-soy agar, blood agar, trypticase-soy broth and bile- esculin agar (Toranzo et al. 1994). 4. Lactococcus garvieae is typically associated with aquatic species such as fish; however, it may also infect humans with 14 reported cases of human infection (Wilbring, 2011). This species has also been isolated from subclinical intramammary infections in cows, subclinical mastitis in water buffalos, poultry meat, raw cow's milk, meat products, porcine blood from industrial abattoirs and from cat and dog tonsils (Zuily et al. 2011). 5. Historically, L. garvieae was previously described as Streptococcus garvieae and was isolated in the United Kingdom from a mastitic udder (Collins et al. 1983). In 1991, the taxonomic name changed to Enterococcus seriolicida in order to bring together a number of Gram-positive isolates recovered from Streptococcus outbreaks in Japanese yellowtail (Seriola quinqueradiata) over the preceding 20 years. Lactococcosis and relevance to L. garvieae 6. Lactococcosis is a kind of Streptococcosis caused by L. garvieae. The first known outbreak of Lactococcosis in rainbow trout from Spanish farms occurred in 1988 with the causal agent being L. garvieae (Palacios et al. 1993; Prieta et al. 1993). 3 7. Lactococcus garvieae is considered to have a ubiquitous global distribution where outbreaks of Lactococcosis affecting rainbow trout, yellowtail, grey mullet and freshwater prawn have been reported in several countries such as Australia, South Africa, Japan, Taiwan, England and the Mediterranean region (Ghittino & Prearo, 1992; Vendrell et al. 2006; Carson et al. 1993) and the Black Sea region in Turkey (Ozturk et al. 2013). Isolations of L. garvieae have also occurred in saltwater fish in the Far East specifically in European rainbow trout (Onchorynchus mykiss) (Wilbring, 2011). Tenacibaculum maritimum Table 2: Taxonomic description of Tenacibaculum maritimum. Taxonomic Unit Classification Order Flavobacteriales Family Flavobacteriaceae Genus Tenacibaculum Species maritimum Hikida et al. 1979, Yoon et al. 2005 8. Tenacibaculum maritimum, formerly known as Flexibacter maritimus, is a Gram-negative and filamentous bacterium that has a broad host range and a global distribution (Perez-Pascual et al. 2017). It has been described as the etiological agent of tenacibaculosis in marine fish. The pathology of the disease caused by the organism has been associated with characteristic body lesions such as ulcers, necrosis and frayed fins (McVicar & White, 1979; Campbell & Buswell, 1982). 9. Tenacibaculosis is responsible for considerable economic losses in all major areas of marine finfish aquaculture worldwide (i.e. Japan, Europe including the Atlantic, Channel and Mediterranean coasts, North America and the Red Sea) (Perez-Pascual et al. 2017). Tenacibaculum maritimum has also been isolated in Norway from diseased farmed sea lice cleaner fish Cyclopterus lumpus (Smage et al. 2016) and is suspected to be responsible for fish mortalities in Chile (Bernardet, 1998). 10. It has been isolated from farmed Atlantic salmon in Australia. This species is difficult to culture under laboratory conditions and diagnosis is therefore primarily based on the appearance of clinical signs such as lesions (MPI, 2017). Under experimental conditions, peak mortality occurs within one to two weeks of exposure and can range anywhere from 10% to 98% depending on the virulence of the strain as well as other environmental conditions (MPI, 2017). 11. Tenacibaculum maritimum grows optimally in water temperatures ranging from 15ºC to 35ºC. Mortality rates in susceptible fish species increase with higher water temperatures and lower water salinities, which favour pathogen replication. This species is only found in the marine environment (MPI, 2017). 4 Table 3: The geographical distribution of T. maritimum in wild and fish farmed fish (Avendano-Herrera et al. 2006): New Zealand Rickettsia-like Organisms 1 and 2 12. Rickettsia-like organisms (RLOs) are very small bacteria that live inside the cells of fish some of which are harmless, while others may cause disease and death (MPI, 2017). 13. New Zealand Rickettsia-like organisms 1 and 2 (NZ-RLO) are closely related to Piscirickettsia salmonis which has been linked to disease outbreaks in Marlborough Sounds, New Zealand (Brosnahan et al. 2019). 14. These organisms are fastidious, obligate intracellular, coccobacilli and difficult to culture in vitro, making it difficult to classify using phenotypic characterisation. In vivo growth research showed NZ-RLO2 was able to grow in Chinook salmon embryo cell line (CHSE-214) and Epithelioma papulosum cyprini cell line (EPC). 15. New Zealand Rickettsia-like organism 1 appears to be part of an Australasian grouping sharing high similarity with the Tasmanian RLO and NZ-RLO2 was shown to be the same as an Irish strain based on two genes (Brosnahan et al. 2019). Rickettsiosis and relevance to RLOs 16. The globally ubiquitous marine disease Rickettsiosis is due to the causative agents of unidentified species