Infections by lactic acid bacteria in marine fish from southern Israel (Red Sea): New records

Abstract

Gram-positive chain-forming bacteria were isolated from the spleen, kidney, and blood of dead wild Red Sea fish (broomtail wrasse Cheilinus lunulatus, grouper Epinephelus fasciatus, goatfish Parupeneus sp.) that washed ashore on the Eilat Nature Reserve beach (Israel, Red Sea). Gram-positive bacteria were similarly isolated from rabbitfish Siganus rivulatus, white grouper Epinephelus aeneus, and grey mullet Mugil cephalus cultured in the Israel Oceanographic and Limnological Research, National Center for Mariculture, Eilat. On the basis of their phenotypical characteristics and 16S rRNA gene partial sequence analyses, the bacteria were identified as Streptococcus parauberis (from C. lunulatus), Lactococcus lactis (from E. aeneus and M. cephalus), Streptococcus iniae (from E. fasciatus, Parupeneus sp. and S. rivulatus), Streptococcus agalactiae (from M. cephalus), and Carnobacterium sp. (from E. aeneus). These lactic acid bacteria, isolated between 2009 and 2011, are added to the growing list of bacterial pathogens detected in wild or farmed marine fish in the Gulf of Eilat in recent years, suggesting a rising trend in areas subjected to intense anthropogenic impact (including aquaculture), where newly emerging pathogens and previously unexposed host populations are brought together.