Lactococcus lactis, causative agent of an endocarditis valvularis and parietalis thromboticans in the allis shad, Alosa alosa (L.)

Abstract

Since the 1940s, the anadromous allis shad, Alosa alosa (L.), has suffered population declines throughout its distribution range in Europe. In context of EU-LIFE projects for the reintroduction of the allis shad in the Rhine system, a comprehensive study was started in 2012 to investigate infectious diseases occurring in allis shad. In course of the study, 217 mature and young-of-the-year allis shad originating from the wild population from the Gironde-Garonne-Dordogne system (GGD-system) and the Rhine system as well as 38 allis shad from the breeding population were examined by use of bacteriological and histological methods. In 2012 and 2014, an endocarditis valvularis thromboticans caused by a coccoid bacterium was detected in 16% and 25% of mature allis shad originating from the GGD-system. Results of microbiologic examinations, including biochemical characteristics, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence analysis, revealed Lactococcus lactis as causative agent of this infection. This is the first report of an endocarditis valvularis and parietalis thromboticans caused by Lactococcus lactis in fish. Possible sources of infection as well as the impact for the reintroduction programme are discussed.

Scientific Opinion on the update of the list of QPS‐recommended biological agents intentionally added to food or feed as notified to EFSA (2017–2019)

“…Of these, two dealt with animal infections; one reported bovine mastitis (Rodrigues et al., ) and the other involved farmed Alosa‐Alosa fish (Wünnemann et al., ). The remaining papers described pathological processes in humans; four related to endocarditis (Mansour et al., ; Chen et al., ; Georgountzos et al., ; Tato Rodriguez et al., ), two to oral lesions (Kabore et al., ; Mussano et al., ) and the other two to liver abscesses (Fragkiadakis et al., ) and cholangitis (Shimizu et al., ).…”

Lactococcosis a Re-Emerging Disease in Aquaculture: Disease Significant and Phytotherapy

“…The third report was from silver carp ( Hypophthalmichthys molitrix ) with extensive skin lesions near the caudal peduncle and musculoskeletal lesion in the USA [ 86 ]. The fourth outbreak of infection by L. lactis has been reported as the cause of endocarditis valvularis, parientalis thromboticans in mature allis shad ( Alosa alosa ) in Europe in 2018 that could be associated with the stressors, such as capturing, transport, breeding, and low oxygen level [ 87 ]. Although, in some cases the disease was reproduced experimentally, the mechanisms of pathogenesis by L. lactis in aquatic animals warranted future research works.…”

Update of the list of QPS‐recommended biological agents intentionally added to food or feed as notified to EFSA 9: suitability of taxonomic units notified to EFSA until September 2018

“…Finally, the fish studied by Wünnemann et al. () had been recently captured from the wild and kept in an overpopulated tank under very low oxygen concentrations, conditions described by the authors as very stressful.…”

“…Analysis of their titles left nine articles for consideration; the rest were discarded because they did not deal with safety concerns. Analysis of the abstracts allowed selection of four papers that raised safety concerns (Georgountzos et al., ; Mussano et al., ; Tato Rodríguez et al., ; Wünnemann et al., ). Three of them described cases of human endocarditis (Georgountzos et al., ; Tato Rodríguez et al., ) and oral lesions (Mussano et al., ) while the fourth described infection of the fish Alosa alosa .…”