470
Control
Susceptibility was reported to fl orfenicol, fl umequine, oxolinic acid and rifampin,
and less so to ciprofl oxacin, erythromycin, oxytetracycline, streptomycin and trimethoprim/sulphadiazine (Isachsen et al. 2012 ).
Francisella noatunensis subsp. orientalis
Characteristics of the Disease
Francisella was found in diseased [granulomatous] tilapia fry in an English recirculation site, with sequence homology confi rming the pathogen (Jeffrey et al. 2010 ).
The fry were lethargic, displayed exophthalmia, pale gills and petechial haemorrhaging in and around the pectoral fi ns. The spleens were enlarged and granular;
some kidneys were enlarged, and the intestines were empty. The gall bladders were
large (Jeffrey et al. 2010 ). Furthermore, the organism was recovered from granulomatous disease in Nile tilapia farmed in Brazil (Leal et al. 2014 ) and Mozambique
tilapia, Koilapia ( Oreochromis hornorum ), blue tilapia ( Oreochromis aureus ) and
Nile tilapia hybrids from Oahu, Hawaii (Soto et al. 2013 ).
The organism has been associated with disease in wild caught French grunt
( Haemulon fl avolineatum ) and Caesar grunt (Haemulon carbonarium) from the
Florida Keys, USA. Dead fi sh revealed the presence of granulomas particularly in
the kidney and spleen (Soto et al. 2014 ). Also, Malawi ornamental cichlids from
Austria displayed disease, i.e. anorexia, dyspnea, and abdominal distension, leading
to mortalities (Lewisch et al. 2014 ).
Characteristics of the Pathogen
Although the organisms were fi rst recognised in tilapia in Taiwan, it is thought that
they may have been introduced on imports from South America, and identifi ed initially as Rickettsia -like organisms (Chern and Chao, 1994 ).
Box 8.2: Francisella noatunensis subsp. orientalis
Small (1 mm diameter) colonies develop after 3 days incubation at 22 °C, and
comprise non-motile, weakly catalase positive, oxidase negative, strictly aerobic weakly Gram-negative cocco-bacilli, that produce H 2 S on cysteine containing media. Growth occurs at 10–30 °C but not at 37 °C. Acid is not
produced from carbohydrates in phenol red broth base. Alkaline and acid
phosphate, esterase C4, esterase lipase C8 and naphthol-AS-BIphosphohydrolase are produced (Mikalsen and Colquhoun 2010 ).
8 Francisellaceae Representatives
Control
Susceptibility was reported to fl orfenicol, fl umequine, oxolinic acid and rifampin,
and less so to ciprofl oxacin, erythromycin, oxytetracycline, streptomycin and trimethoprim/sulphadiazine (Isachsen et al. 2012 ).
Francisella noatunensis subsp. orientalis
Characteristics of the Disease
Francisella was found in diseased [granulomatous] tilapia fry in an English recirculation site, with sequence homology confi rming the pathogen (Jeffrey et al. 2010 ).
The fry were lethargic, displayed exophthalmia, pale gills and petechial haemorrhaging in and around the pectoral fi ns. The spleens were enlarged and granular;
some kidneys were enlarged, and the intestines were empty. The gall bladders were
large (Jeffrey et al. 2010 ). Furthermore, the organism was recovered from granulomatous disease in Nile tilapia farmed in Brazil (Leal et al. 2014 ) and Mozambique
tilapia, Koilapia ( Oreochromis hornorum ), blue tilapia ( Oreochromis aureus ) and
Nile tilapia hybrids from Oahu, Hawaii (Soto et al. 2013 ).
The organism has been associated with disease in wild caught French grunt
( Haemulon fl avolineatum ) and Caesar grunt (Haemulon carbonarium) from the
Florida Keys, USA. Dead fi sh revealed the presence of granulomas particularly in
the kidney and spleen (Soto et al. 2014 ). Also, Malawi ornamental cichlids from
Austria displayed disease, i.e. anorexia, dyspnea, and abdominal distension, leading
to mortalities (Lewisch et al. 2014 ).
Characteristics of the Pathogen
Although the organisms were fi rst recognised in tilapia in Taiwan, it is thought that
they may have been introduced on imports from South America, and identifi ed initially as Rickettsia -like organisms (Chern and Chao, 1994 ).
Box 8.2: Francisella noatunensis subsp. orientalis
Small (1 mm diameter) colonies develop after 3 days incubation at 22 °C, and
comprise non-motile, weakly catalase positive, oxidase negative, strictly aerobic weakly Gram-negative cocco-bacilli, that produce H 2 S on cysteine containing media. Growth occurs at 10–30 °C but not at 37 °C. Acid is not
produced from carbohydrates in phenol red broth base. Alkaline and acid
phosphate, esterase C4, esterase lipase C8 and naphthol-AS-BIphosphohydrolase are produced (Mikalsen and Colquhoun 2010 ).
8 Francisellaceae Representatives