Recommendations for identifying pathogenic Vibrio spp. as part of disease surveillance programmes in recirculating aquaculture systems for Pacific white shrimps (Litopenaeus vannamei)

Abstract

Due to their pathogenic potential, identifying Vibrio species from recirculating aquaculture systems (RAS) for Pacific white shrimp (Litopenaeus vannamei) is of great importance to determine the risk for animal's as well as for the consumer's health. The present study compared identification results for a total of 93 Vibrio isolates, including type strains and isolates from shrimp aquaculture. Results from biochemical identifications, 16S rRNA sequencing, sequencing of the uridylate kinase encoding gene pyrH and analysis of the protein spectra assessed by MALDI‐TOF MS were compared. The results achieved by these different methods were highly divergent for many of the analysed isolates and for several Vibrio spp difficulties in reliably identifying occurred. These difficulties mainly resulted from missing entries in digital databases, a low number of comparable isolates analysed so far, and high interspecific similarities of biochemical traits and nucleotide sequences between the closely related Vibrio species. Due to the presented data, it can be concluded that for identifying Vibrio spp. from samples in routine diagnostics, it is recommended to use MALDI‐TOF MS analysis for a quick and reliable identification of pathogenic Vibrio sp. Nevertheless, editing the database, containing the main spectra of Vibrio is recommended to achieve reliable identification results.

Effect of disinfection with peracetic acid on the microbial community of a seawater aquaculture recirculation system for Pacific white shrimp (Litopenaeus vannamei)

“…The amount of Vibrio sp. within the physiological microflora in marine and brackish habitats can reach up to 40% (Bauer et al., 2018; Jeyasanta, Lilly, & Patterson, 2017; Urakawa & Rivera, 2006). A significant reduction in the abundance of these organisms in a seawater RAS running at 30‰ therefore can be regarded as a sign of destabilization of the system.…”

“…During the past few years, the production of Pacific white shrimp ( Litopenaeus vannamei ) has increased in European countries due to the possibility of keeping these animals, independent from natural sea water, on inland farms in recirculating aquaculture systems (RAS) (Bauer et al., 2018). The primary advantages of keeping shrimps in RAS are a reduced consumption of water, a low environmental impact and the possibility of high stocking densities and therefore high productivity.…”

“…Nevertheless, in intensive shrimp aquaculture, disease outbreaks might occur due to infections with viral, parasitic or bacterial pathogens (Austin & Zhang, 2006; Bauer et al., 2018; LeRoux et al., 2015; Lotz, 1997; Soto‐Rodriguez, Gomez‐Gil, & Lozano, 2010). By choosing specific pathogen‐free post‐larvae for stocking these systems, the infection risk for viral pathogens can be reduced.…”

“…By choosing specific pathogen‐free post‐larvae for stocking these systems, the infection risk for viral pathogens can be reduced. However, due to the high stocking densities and the large amount of organic material in recirculating water from non‐utilized feed and faeces, very high numbers of bacteria in water and on all surfaces of the system might occur (Bauer et al., 2018). Additionally, the accumulation of micro‐particles in the water leads to an increased growth of bacteria on these solids (Wold et al., 2014).…”

“…can be found. Among these bacteria, there are also potential pathogenic species that might induce disease (Bauer et al., 2018).…”