In vitro interactions between rainbow trout (Oncorhynchus mykiss) macrophages and Vibrio anguillarum serogroup O2a

Antibody increases phagocytosis and killing of Lactococcus garvieae by rainbow trout (Oncorhynchus mykiss, L.) macrophages

“…In the present study no killing of MT2291 was observed at MOI=1 while 50% killing was observed at MOI=0·1. A similar observation has been reported for Vibrio anguillarum serogroup 02a [10]. Boesen and colleagues observed that the macrophages were lysed at high MOIs and suggested that this lysis may have resulted from a toxic e#ect of the bacteria similar to that observed with A. salmonicida on macrophages of Atlantic salmon [11].…”

Acidophilic granulocytes of the marine fish gilthead seabream ( Sparus aurata L.) produce interleukin-1� following infection with Vibrio anguillarum

“…Activation of the complement system by the classical pathway has been suggested as the protection mechanism induced by vaccination against V. anguillarum serogroup 01, since sub-agglutinating antibody levels in the presence of complement have been shown to kill this serogroup in vitro (Boesen et al 1999a). However, this seems to be unlikely in the case of V. anguillarum serogroup 02, since this serogroup is resistant to in vitro serum killing even in the presence of antibodies (Boesen et al 1999b) and neither antibodies nor complement are able to play an opsonising effect (Boesen et al 2001). The authors of these studies suggest that antibodies may prevent the attachment of the pathogen to the host's tissues and/or that neutrophils may play a role either by the direct phagocytosis of bacteria or by transferring toxic components to the macrophages (Afonso et al 1998).…”

“…Although several commercial vaccines against V. anguillarum are widely used and provide some protection against infection, little is know about the mechanisms underlying this immune protection. Previous studies have demonstrated that antibodies contribute to protection against V. anguillarum serogroups 01 (Akhlaghi 1999) and 02 (Boesen et al 2001) in rainbow trout passively immunised with V. anguillarum antiserum. Activation of the complement system by the classical pathway has been suggested as the protection mechanism induced by vaccination against V. anguillarum serogroup 01, since sub-agglutinating antibody levels in the presence of complement have been shown to kill this serogroup in vitro (Boesen et al 1999a).…”

Defensive response of European sea bass (Dicentrarchus labrax) against Listonella anguillarum or Photobacterium damselae subsp. piscicida experimental infection

“…The ability to evade the host immune response and to spread throughout the organism also contributes to their pathogenicity. In particular, L. anguillarum can persist inside fish professional phagocytes by inhibition of their respiratory burst (Boesen et al, 2001;Sepulcre et al, 2007a) and downregulation of apoptosis (Sepulcre et al, 2007a). Moreover, numerous strains of this species appear to be resistant to the direct killing activity of serum complement, even in the presence of specific antibodies (Boesen et al, 1999).…”