Microbial biofilms as oral vaccine and for ameliorating aquatic environment: a future potential for aquafarming

Microbial biofilms have traditionally been viewed as scourges associated with colonization on medical devices and implants leading to drug resistance and persistent infections. In recent few years, antibiotics have been rampantly used to curb the disease outbreaks in animals, leading not only to escalates antibiotic resistant bacteria and genes but also negative impacts on fish and the environment health. Therefore, vaccines are getting prime importance in aquaculture as an alternative to the antibiotics. Biofilm oral vaccine is another exciting avenue of biofilm utilization for improving fish health. Oral deliveries of vaccine preparations have traditionally failed to induce protective immunity in fish, whereas biofilms of pathogenic bacteria grown on a defined substrate were effective in inducing higher antibody titers and protective immunity. Our studies on oral biofilm vaccines in catfish and major carps models have proved an enhanced protective immunity against the pathogenic bacteria. By virtue of the distinct antigenic makeup and adjuvancy of biofilms assemblage, novelty of biofilm oral vaccine has largely been its safe and effective performances in fish species. Here, we review on the state-of-art knowledge of microbial biofilms as fish vaccine and as amelioration of aquatic environment perspective towards enhanced fish production.