685
With the widespread use of sequencing of the 16S rRNA gene as a primary method of identifi cation/characterisation, phenotypic characters have been downplayed. Consequently, it is not possible to include the data for all the bacterial fi sh pathogens. Also, there are similarities in the profi les of some organisms;
discrimination needing 16S rRNA sequencing data
1
colony pigmentation, 2
presence of microcysts, 3
fi lterability through 0.45
μm pore fi lters, 4
growth only occurs in tissue culture, 5
gliding, 6
motility by
fl agella, 7
oxidative- fermentative metabolism of glucose, 8
arginine dihydrolase production, 9
β-galactosidase production, 10
indole production, 11
oxidase
production, 12
lysine decarboxylase production, 13
methyl red test, 14
Voges Proskauer reaction, 15
degradation of blood, 16
gelatin degradation, 17
starch
degradation, 18
acid production from maltose, 19
growth at 30 °C, 20
growth at 37 °C, 21
growth in 0 % (w/v) NaCl
b, fl , g, p, r, w and y correspond to brown, fl uorescent, green, purple, red/pink, cream/white and yellow pigment, respectively
+, −, v, ?, (+) and (−) correspond to positive (≥80 % of positive responses), negative (≤20 % of positive responses), variable (21–79 % of positive responses),
unstated, weakly positive, and weakly negative result, respectively
O, F, Alc = oxidative or fermentative metabolism, or production of alkali, respectively
Ps. baetica
and Ps. fl uorescens
by the latters ability to utilise a wide range of compounds including D-alanine whereas the former does not
It is diffi cult to distinguish T. dicentrarchi
and T. maritimum
phenotypically. Reliance may need to be placed on sequencing of the 16S rRNA gene
From the original description, it is diffi cult to distinguish T. dicolor
from T. gallaicum
phenotypically. Reliance may need to be placed on sequencing of the
16S rRNA gene
a
T
Phenotypic Tests
With the widespread use of sequencing of the 16S rRNA gene as a primary method of identifi cation/characterisation, phenotypic characters have been downplayed. Consequently, it is not possible to include the data for all the bacterial fi sh pathogens. Also, there are similarities in the profi les of some organisms;
discrimination needing 16S rRNA sequencing data
1
colony pigmentation, 2
presence of microcysts, 3
fi lterability through 0.45
μm pore fi lters, 4
growth only occurs in tissue culture, 5
gliding, 6
motility by
fl agella, 7
oxidative- fermentative metabolism of glucose, 8
arginine dihydrolase production, 9
β-galactosidase production, 10
indole production, 11
oxidase
production, 12
lysine decarboxylase production, 13
methyl red test, 14
Voges Proskauer reaction, 15
degradation of blood, 16
gelatin degradation, 17
starch
degradation, 18
acid production from maltose, 19
growth at 30 °C, 20
growth at 37 °C, 21
growth in 0 % (w/v) NaCl
b, fl , g, p, r, w and y correspond to brown, fl uorescent, green, purple, red/pink, cream/white and yellow pigment, respectively
+, −, v, ?, (+) and (−) correspond to positive (≥80 % of positive responses), negative (≤20 % of positive responses), variable (21–79 % of positive responses),
unstated, weakly positive, and weakly negative result, respectively
O, F, Alc = oxidative or fermentative metabolism, or production of alkali, respectively
Ps. baetica
and Ps. fl uorescens
by the latters ability to utilise a wide range of compounds including D-alanine whereas the former does not
It is diffi cult to distinguish T. dicentrarchi
and T. maritimum
phenotypically. Reliance may need to be placed on sequencing of the 16S rRNA gene
From the original description, it is diffi cult to distinguish T. dicolor
from T. gallaicum
phenotypically. Reliance may need to be placed on sequencing of the
16S rRNA gene
a
T
Phenotypic Tests