Sunday, August 6, 2017

07/08/2017: Prevent disease outbreaks through effective bacterial pathogen control

by Antonia Tacconi, PhD – Product Manager Acids, and Benedict Standen, PhD – Product Manager Microbials, Biomin, Austria

Aquaculture is the fastest growing food-producing industry and is currently playing a major role in global protein production 

Image credit: Mathias Pastwa on Flickr under CC BY-ND 2.0
The rising demand for aquatic protein has resulted in intensification of production, which is directly linked with an increased incidence of diseases. Major pathogens affecting the aquaculture industry include fungi, viruses, parasites and bacteria.

Bacterial threats

Bacteria can survive very well in aquatic environments, especially when water temperature rises, and can cause significant economic losses. Bacteria such as Aeromonas, Edwardsiella, Pseudomonas, Streptococcus, Vibrio and Yersinia can all be pathogenic to aquatic animals.

Outbreaks of bacterial diseases are usually contained using antibiotics. However, due to growing consumer sentiment opposing the use of sub-therapeutic antibiotics, their use can effectively block producers from selling their product to export markets.

Also, extensive use of such antimicrobials is linked to the development of antibiotic resistant strains and the transfer of resistant genes between different bacterial species. The emergence of pathogenic resistant bacteria has negative impacts, not only in aquaculture, but also on human health and effects consumer perception more negatively. Therefore, the demand for more environmentally friendly alternatives is higher than ever.

Organic acids for pathogen control

Organic acids and blends of such acids are an efficient tool to improve growth performance and pathogen control in aquaculture. Recently, researchers have focused on the role of organic acids and their salts in disease prevention and control with great success.

While the effects of organic acids on pathogenic bacteria are not yet fully clear, it is commonly understood that they can exert either bacteriostatic or bactericidal effects depending on the physiological status of the organism and the physicochemical characteristics of the environment.

Undissociated organic acids are lipophilic and can bypass the plasma membrane of bacteria easily. Once inside the cells, where usually pH levels are more neutral than in the outer environment, organic acids dissociate in their anions and protons.

Traditionally, it has been assumed that the cytoplasmic pH drop caused by this mechanism is the main toxic efficacy of organic acids. Recently, other toxicity mechanisms have been proposed like the capability of these acids to interfere with cytoplasmic membranes structure and functionality as well as interference with nutrient transport, electron transport and macromolecular synthesis inside the cells. 

Figure 1: Growth inhibition of aquatic pathogens by Biotronic® Top3
Image credit: BIOMIN
Choosing a science-backed solution

The organic acid market in aquaculture is vast, and choosing the correct solution can be a minefield. It is important that products are assessed using both in vitro and in vivo models. A recent peer-reviewed publication demonstrated how Biotronic® Top3 (BIOMIN GmbH), an enhanced acidifier, can be used to reduce pathogens and improve disease resistance in aquaculture (Menanteau-Ledouble et al. 2017).

In vitro pathogen control
Scientists cultured a number of pathogens in growth medium, with and without Biotronic® Top3. The pathogens were chosen based on their ability to cause widespread disease and high economic losses in aquaculture and included Aeromonas spp., Edwardsiella sp., Pseudomonas sp., Streptococcus sp., Vibrio spp. and Yersinia sp. Researchers observed that Biotronic® Top3 effectively reduced the growth of all pathogens (Figure 1).

Biotronic® Top3 was most effective against Gram-negative pathogens, although inhibition of Streptococcus was also observed. This is not surprising, since the formulation contains a unique Biomin® Permeabilising Complex, specifically designed to weaken the outer membrane in Gram-negative bacteria.

Read the full article, HERE.

Visit the BIOMIN website, HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
magazine International Aquafeed which is published by
Perendale Publishers Ltd

For additional daily news from aquaculture around the world: aquaculture-news

No comments:

Post a Comment

See our data and privacy policy Click here