First isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata (Moreau) J R López 1 , S NfflÇez 2 , B MagariÇos 2 , N Castro 2 , J I Navas 1 , R de la Herran 3 and A E Toranzo 2 1 IFAPA Centro Agua del Pino, Huelva, Spain 2 Departamento de Microbiologı ´a y Parasitologı ´a, Facultad de Biologı ´a e Instituto de Acuicultura, Universidad de Santiago, Santiago de Compostela, Spain 3 Departamento de Gene ´tica, Facultad de Ciencias, Universidad de Granada, Granada, Spain Abstract The first isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata, is reported. The pathogen was recovered from ulcers of cultured fish, from three different outbreaks. The six isolates ob- tained were biochemically and serologically charac- terized and diagnosis was confirmed by polymerase chain reaction using specific primers and partial 16S rRNA gene sequencing. The isolates constituted a homogeneous phenotypic group; however, they be- long to two of the different serotypes described within this species. A virulence evaluation of the isolates using Wedge sole fry was also performed. Keywords: characterization, Dicologoglossa cuneata, Tenacibaculum maritimum, virulence, wedge sole. Introduction Tenacibaculum maritimum, formerly Flexibacter maritimus (Wakabayashi, Hikida & Masumura 1986; Suzuki, Nakagawa, Harayama & Yamamoto 2001), is a Gram-negative filamentous bacterium that is the causative agent of tenacibaculosis, an ulcerative disease, which causes massive mortalities and severe economic losses in cultures of several marine fish species, with a worldwide distribution (Toranzo, Magarin ˜os & Romalde 2005; Avendan ˜o- Herrera, Toranzo & Magarin ˜os 2006b). The main clinical signs of tenacibaculosis are body surface lesions (i.e. ulcers, necrosis), eroded mouth, frayed fins and tail rot. Sometimes infection can lead to septicaemia. Isolation of the bacterium from dis- eased fish is often problematic because of the slow growth of the pathogen and the overgrowth and/or inhibition by other bacterial species present within the lesions. As these lesions favour the entrance of other pathogenic bacteria and saprophytic organ- isms such as ciliated protozoans (McVicar & White 1979; Kimura & Kusuda 1983; Devesa, Barja & Toranzo 1989; Handlinger, Soltani & Percival 1997), T. maritimum often appears in mixed infections. Serological studies demonstrated the existence in T. maritimum of at least three major O-serogroups, seemingly related to the host species (Avendan ˜o-Herrera et al. 2006b). Concerning flat fish, tenacibaculosis has been reported from sole, Solea solea (L.) (McVicar & White 1979; Bernardet, Campbell & Buswell 1990); Senegalese sole, Solea senegalensis (Kaup) (Cepeda & Santos 2002); Japanese flounder, Paralichthys olivaceous (Tem- minck & Schlegel) (Baxa, Kawai & Kusuda 1986); turbot, Psetta maxima (L.) (Devesa et al. 1989; Alsina & Blanch 1993; Avendan ˜o-Herrera, Maga- rin ˜os, Lo ´pez-Romalde, Romalde & Toranzo 2004), and greenback flounder, Rhombosolea tapirina (Gunther) (Soltani, Munday & Burke 1996; Handlinger et al. 1997). Wedge sole, Dicologoglossa cuneata (Moreau), an economically valuable flat fish species belonging to the Family Soleidae, is being cultured in some farms in south-western Spain to diversify marine aqua- culture. However, the production of this species is Journal of Fish Diseases 2009, 32, 603–610 doi:10.1111/j.1365-2761.2009.01029.x Correspondence J R Lo ´ pez, IFAPA Centro Agua del Pino, Junta de Andalucia, Carretera El Portil-El Rompido s/n, 21450 Cartaya, Huelva, Spain (e-mail: lasacias@yahoo.es) 603 Journal compilation Ó 2009 Blackwell Publishing Ltd No claim to original US government works