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Microbiology Australia Microbiology Australia
Issue 3

Diseases of Aquaculture

Vertical Transmission

As this is my first communication with you as your new president, I should start by thanking ASM’s Council, and especially the Executive Committee, for honouring me in this way and for putting their faith in me. I must also thank Jon Iredell for the wonderful job he did as ASM President for the past two years, and for the amazing support and guidance he has given me to date (and hopefully in future).

Diseases of aquaculture

The value of production of aquaculture in Australia is around $990 million1 and consists of cultivation of over 40 species, most for food, but others such as pearl oysters and crocodiles are cultured for products for the fashion industry. A number of finfish are grown for food including salmon, barramundi, and silver perch, and other species include prawns, marron, abalone, oysters and mussels, whereas southern bluefin tuna are caught from the wild and farmed until they reach market size. A number of species are being investigated for aquacultu...

Antimicrobial susceptibility testing guidelines as a necessary tool to guide chemotherapeutic interventions in aquaculture

The selection of chemotherapy in aquatic animal medicine is not as straightforward as one might believe. A multitude of factors can impact effectiveness in situ. Some of these factors include the pathogen(s) present and their antimicrobial susceptibility, site(s) of infection, timing of treatment, host health/disease status, dose and regimen, water salinity, and water temperature. This article will focus on the first of these factors, and how susceptibility testing of target pathogen(s) can be used to both inform therapy decisions and as...

Antibiotic resistance associated with aquaculture in Vietnam

The fishery sector is an important source of income, employment and food supply in Vietnam. In 2014, Vietnam was ranked the world's fourth largest exporter and the third largest producer of farmed food fish. Vietnam seafood export has attained the value of over US$6.0 billion since 2011 and reached a peak of US$7.9 billion in 2014. However, many problems and diseases confront sustainable development of the fishery sector and overuse of antibiotics is considered a major challenge. Antibiotics are used in aquaculture for both therapeutic and prop...

Francisellosis in fish: an emerging challenge

Francisellosis is a bacterial disease with increasing economic impacts in the culture of tilapia and Atlantic cod since emerging in 1992. Two main strains – Francisella noatunensis subsp. orientalis (Fno) and F. noatunensis subsp. noatunensis (Fnn), have been identified, causing both acute and chronic granulomatous systemic disease. The piscine host range is increasing and Francisella culture should be included in routine diagnosis. Differentiation from the major zoonotic F. tularensis ...

Providencia rettgeri septicaemia in farmed crocodiles

Bacterial septicaemia is a major cause of morbidity and mortality in farmed saltwater crocodiles (Crocodylus porosus) in the Northern Territory. Providencia rettgeri is the most common aetiological agent. Efficacy of antibiotic treatment is dubious and there are high levels of resistance to antibiotics commonly used by farms, underlining the need for exploration of new approaches to managing the disease.

Vaccination against streptococcal infections in farmed fish

Aquaculture produces more than 50% of fish for human consumption and, in spite of major improvements since the adoption of injectable vaccines in the 1990s, bacterial diseases still account for considerable losses, particularly in tropical and warm temperate species. Streptococcosis, caused predominantly by Streptococcus iniae and S. agalactiae, manifests as a generalised septicaemia and meningitis followed by rapid mortality. Vaccination against streptococcal infections is difficult as a result of multiple, poorly defined serotyp...

Testing the efficacy of probiotics for disease control in aquaculture

Infectious diseases have been estimated to cost the global aquaculture industry billions of dollars annually1,2. With concerns over emerging resistance and residues of antibiotics in food3 many such chemicals are now being banned and environmentally friendly alternatives are being sought. Probiotics influence the composition of the gut microbiota and confer health benefits to their host4,5 and are one of several alternative approaches gaining significant popularity in ...

Aquaculture: exotic diseases and surveillance

Aquaculture is a rapidly growing global industry. Half of all seafood is sourced from aquaculture and Australia is part of the trend. A major emerging threat to this industry is disease.

Pacific oyster mortality syndrome: a marine herpesvirus active in Australia

Genotypes of Ostreid herpesvirus 1 (OsHV-1) known as microvariants cause the disease Pacific oyster mortality syndrome (POMS). Since its appearance in NSW in 2010, OsHV-1 microvariant has prevented the farming of Pacific oysters (Crassostrea gigas) in the affected estuaries near Sydney, following the initial massive outbreaks1,2. The arrival of the disease in southeast Tasmania in January 2016 has put the entire $53M industry in Australia in jeopardy3. The virus is a member of the Family...

Identification of bacteria from aquatic animals

A wide range of aquatic animal species are cultured for human consumption, the fashion industry, research purposes or re-stocking natural populations. Each host species may be colonised by bacterial saprophytes or infected with pathogens that have specific growth requirements encompassing temperature, salinity, trace elements or ions. To ensure successful culture and identification of potential pathogens, the microbiologist must have in-depth knowledge of these growth requirements and access to the appropriate resources. Identification techniqu...

Common pathogens found in yellowtail kingfish Seriola lalandi during aquaculture in Australia

Yellowtail kingfish aquaculture in sea-cages is an emerging industry in Australia. Monogenean, myxozoan and bacterial pathogens sometimes cause health issues that require diagnosis or monitoring.

Pseudomonas anguilliseptica infection as a threat to wild and farmed fish in the Baltic Sea

The transport of live fishes related to the growth of the fish farming industry worldwide may increase the transfer of previously known bacterial pathogens into new geographic areas and new host species, but also facilitate the introduction of completely new bacterial pathogens. Species belonging to the genera Vibrio and Aeromonas are well known in many countries, infecting a large number of fish species. Other bacterial fish pathogens like Pseudomonas anguilliseptica species, up to now considered less harmful, may constitu...

Disease threats to wild and cultured abalone in Australia

Abalone species are important for recreational and commercial fisheries and aquaculture in many jurisdictions in Australia. Clinical infections with viral, bacterial and parasitic pathogens can cause significant losses of wild and cultured stock, and subclinical infections may result in decreased productivity and growth. Infections with abalone herpesviruses (AbHV), Vibrio spp. and parasites of the genus Perkinsus are of particular concern to Australian fisheries. Here we provide a brief overview of these three major pathogen grou...

Amoebic gill disease: a growing threat

The risk of disease outbreaks is predicted to increase due to climate change. For farmed fish an example is amoebic gill disease (AGD). While initially reported only in farmed salmonids in Washington State, USA, and Tasmania, Australia, it has now become an issue for Atlantic salmon farming worldwide and affects a range of other farmed marine fish species. Local high temperature anomalies and a lack of rainfall have been associated with the outbreaks of AGD. This worldwide presence is at least partly due to the cosmopolitan nature of the parasi...

Unprecedented toxic algal blooms impact on Tasmanian seafood industry

While most microscopic algae provide food for filter-feeding shellfish and larvae of crustaceans and finfish, other so-called Harmful Algal Blooms (HABs) can have negative effects, causing severe economic losses to aquaculture, fisheries and tourism. Of greatest concern to human society are blooms of toxic HAB species that cause illness and death of fish, seabirds and mammals via toxins transferred through the food web. Unprecedented Alexandrium (Dinophyceae) blooms along the East Coast of Tasmania in 2012 and 2015, a previously low biot...

Report from ASM 2016: New Frontiers

Chronic rhinosinusitis: a microbiome in dysbiosis and the search for alternative treatment options

Chronic rhinosinusitis (CRS) is a common chronic disease. While CRS is a multifactorial disease, many cases involve an imbalance in the sinus bacterial microbiome. This article reviews the composition of the healthy human sinus microbiome compared to the microbiome of CRS patients. Issues with current treatment options, particularly antibiotics, are discussed. Insights into the future of CRS treatment are also explored, principally with regards to probiotics.

Volume 37 Number 3

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