The potency of AHL-degrader bacteria as alternative to antibiotics to protect Litopenaeus vannamei postlarvae from vibriosis in hatchery level

Oleh : Dr. Pande Gde Sasmita Julyantoro, S.Si., M.Si
dibuat pada : 2019
Fakultas/Jurusan : Fakultas Kelautan dan Perikanan/Sarjana Manajemen Sumber Daya Perairan

Kata Kunci :
Aquaculture, Quorum sensing, Vibriosis

Abstrak :
The frequent use of antibiotics to control vibriosis in hatcheries has led to the development and spread of antibiotic-resistant bacteria. The increasing occurrence of antibiotic-resistant bacteria has created an adverse situation in the aquaculture sector. Although still being the first line therapy in aquaculture, antibiotics are becoming less effective in treating bacterial diseases in some cases. Furthermore, the use of antibiotics is being reduced because of environmental and human health concerns, and consequently, alternative strategies to control bacterial diseases are urgently needed. One of those strategies is termed as antivirulence therapy. Antivirulence therapy aims to prevent the pathogenic bacteria from attacking the host by controlling virulence (regulatory) mechanisms. This strategy requires an understanding of bacterial pathogenicity mechanisms to find suitable targets for novel therapeutics. One strategy has been developed is inhibiting of quorum sensing (QS), the bacterial cell-to-cell communication. The major advantage of this method is that method has no strong pressure on bacterial growth and proliferation, resulting in a lower risk of resistance development. The long-term purpose of this study is to find an alternative method to antibiotics for combating bacterial diseases in aquaculture. Since QS has been known as regulatory virulence mechanism in some pathogenic bacteria, the QS inhibition might be a valid strategy to protect aquaculture animals from bacterial infections. Specifically, in this study we would try to inhibit the QS-signal produced by aquaculture pathogen, especially the most intensively studied QS signal, the Acyl Homoserine Lactone (AHL) by enzymatic inactivation. This method has been applied mostly in vitro, but still scarce on in vivo application, especially scaling up in hatchery level. Based on that fact, we proposed 2 years research activities. The first year will be focused on the in vitro assessment of the AHL-degrader isolates and serial in vivo challenge test on the small scale of some aquaculture organisms which will be conducted in Udayana University and Lab Aquaculture and Artemia Reference Centre, Ghent University, Belgium. The results of the first year will be submitted to the Aquaculture journal. The second year will be focused on the application of the isolates in large scale capacity (step by step up scaling application) in real aquaculture facilities such as shrimp hatcheries. At the certain moments in this second year, researchers from Ghent University will visit Bali and doing research together in Udayana University. Finally, the last 5 months will be focused on the writing, both for making final report and the second draft for international scientific publication.