Poster Presentation 9th Australasian Virology Society Meeting 2017

FRNA bacteriophages for risk management of Australian oysters (#144)

Kate Hodgson 1 , Ali Turnbull 1 , Valeria Torok 1
  1. SARDI, Urrbrae, SA, Australia

Bivalve molluscan shellfish feed on particulates in the surrounding water, accumulating and concentrating contaminants including pathogenic micro-organisms, in their soft tissue. Traditionally, the coliform bacteria and Escherichia coli have been used as indicators faecal pollution in growing waters and shellfish. Numerous studies have established that they are inadequate as indicators of human enteric viruses, such as Norovirus and Hepatitis A virus. Bacteriophages (phages) have been identified as potential indicators for human enteric viruses and phage enumeration has been approved in the US facilitating early reopening of growing areas after sewage spills but no earlier than seven days after the contamination has stopped. In Australia, the bivalve shellfish industry maintains a conservative risk management approach to adverse sewage events, with an obligatory 21 day closure. The Australian oyster industry has been shown to have a low prevalence of enteric viruses in market ready product as determined by a recent nationwide survey. Despite this there is potential for enteric viral contamination. We are currently undertaking an 18 month baseline survey for FRNA phages in five commercial Australian oyster growing areas, in addition to testing for FRNA phages, E. coli and human enteric viruses following adverse sewage events triggering oyster harvest closures. Results of the study will inform regulators as to whether FRNA phages are suitable for use in the risk management of Australian oysters at production, potentially allowing for earlier re-opening and reducing the cost to producers without compromising public health.