527
et al. ( 1993 ) studied 46 isolates of V. anguillarum- like organisms from diseased fi sh
and shellfi sh and the environment by numerical phenetic methods, and recognised 4
phena. The apparent heterogeneity was reinforced by the results of ribotyping, with
44 ribotypes recognised among isolates of V. anguillarum (Olesen and Larsen
1993 ). Yet, Austin et al. ( 1995a , 1997 ) recognised a single taxon, homogeneous by
ribotyping – isolates were recovered in a single ribotype – and outer membrane
protein patterns, but heterogeneous in terms of LPS profi les, plasmid composition,
serogrouping, and BIOLOG-GN fi ngerprints and API 20E profi les.
The taxon was re-classifi ed to Listonella, as Listonella anguillarum (MacDonell
and Colwell 1985 ). However, the name change was not widely accepted, and it has
been proposed that Listonella is a heterotypic synonym of Vibrio, and that the epithet anguilllarum should be included in Vibrio (Thompson et al. 2011 ). The pathogen has now been fully sequenced, and it is appreciated that there are two
chromosomes on which there are 8 genomic islands on chromosome 1 and two on
chromosome 2 (Naka et al. 2011 ).
It has been observed that some so-called bona fi de isolates of V. anguillarum
possess fascinating micromorphologies, insofar as broth cultures appear to contain
two types of cells. Apart from the typical short, motile rods, we have observed very
small, highly motile cells, some of which are capable of passing through 0.22 μm
porosity fi lters. From transmission electron microscopy, we believe that these cells
comprise extremely small, spherical bodies, each attached to a single polar fl agelBox 10.8: Vibrio anguillarum
Cultures comprise cream-coloured (a water-soluble brown-pigmented culture
has been reported in Japanese fl ounder; Sakai et al. 2006 ), round, raised,
entire, shiny colonies [dissociation into two or three colony types may occur;
Austin et al. 1996 ] comprising short (0.5 × 1.5 μm), fermentative, Gramnegative rods, which are motile by single polar fl agella. Arginine dihydrolase,
catalase, ß-galactosidase, indole and oxidase, but not H 2 S, lysine or ornithine
decarboxylase, phenylalanine deaminase or urease, are produced. Along with
most other vibrios, sensitivity is displayed to the vibriostatic agent, O/129. A
positive result is usually recorded for the Voges Proskauer reaction, but not for
the methyl red test. Chitin, gelatin, DNA, lipids and starch, but not aesculin,
are degraded. Nitrates are reduced. Growth occurs at 15–37 °C, and in 0.3–
3.0 % (w/v) but not 0 % and 7 % (w/v) sodium chloride. Citrate, malonate and
tartrate are utilised. The organisms produce acid from amygdalin, arabinose,
cellobiose, galactose, glycerol, maltose, mannitol, sorbitol, sucrose and trehalose, but not from adonitol, dulcitol, erythritol, inositol, lactose, melibiose,
raffi nose, rhamnose, salicin or xylose. Cultures comprise a single dominant
ribotype. The G + C ratio of the DNA is 45.6–46.3 moles % (Smith 1961 ;
Kiehn and Pacha 1969 ; Evelyn 1971 ; Muroga et al. 1976a , b ; Schiewe et al.
1981 ; Austin et al. 1995a ; Farmer et al. 2005 ).
Vibrio anguillarum
et al. ( 1993 ) studied 46 isolates of V. anguillarum- like organisms from diseased fi sh
and shellfi sh and the environment by numerical phenetic methods, and recognised 4
phena. The apparent heterogeneity was reinforced by the results of ribotyping, with
44 ribotypes recognised among isolates of V. anguillarum (Olesen and Larsen
1993 ). Yet, Austin et al. ( 1995a , 1997 ) recognised a single taxon, homogeneous by
ribotyping – isolates were recovered in a single ribotype – and outer membrane
protein patterns, but heterogeneous in terms of LPS profi les, plasmid composition,
serogrouping, and BIOLOG-GN fi ngerprints and API 20E profi les.
The taxon was re-classifi ed to Listonella, as Listonella anguillarum (MacDonell
and Colwell 1985 ). However, the name change was not widely accepted, and it has
been proposed that Listonella is a heterotypic synonym of Vibrio, and that the epithet anguilllarum should be included in Vibrio (Thompson et al. 2011 ). The pathogen has now been fully sequenced, and it is appreciated that there are two
chromosomes on which there are 8 genomic islands on chromosome 1 and two on
chromosome 2 (Naka et al. 2011 ).
It has been observed that some so-called bona fi de isolates of V. anguillarum
possess fascinating micromorphologies, insofar as broth cultures appear to contain
two types of cells. Apart from the typical short, motile rods, we have observed very
small, highly motile cells, some of which are capable of passing through 0.22 μm
porosity fi lters. From transmission electron microscopy, we believe that these cells
comprise extremely small, spherical bodies, each attached to a single polar fl agelBox 10.8: Vibrio anguillarum
Cultures comprise cream-coloured (a water-soluble brown-pigmented culture
has been reported in Japanese fl ounder; Sakai et al. 2006 ), round, raised,
entire, shiny colonies [dissociation into two or three colony types may occur;
Austin et al. 1996 ] comprising short (0.5 × 1.5 μm), fermentative, Gramnegative rods, which are motile by single polar fl agella. Arginine dihydrolase,
catalase, ß-galactosidase, indole and oxidase, but not H 2 S, lysine or ornithine
decarboxylase, phenylalanine deaminase or urease, are produced. Along with
most other vibrios, sensitivity is displayed to the vibriostatic agent, O/129. A
positive result is usually recorded for the Voges Proskauer reaction, but not for
the methyl red test. Chitin, gelatin, DNA, lipids and starch, but not aesculin,
are degraded. Nitrates are reduced. Growth occurs at 15–37 °C, and in 0.3–
3.0 % (w/v) but not 0 % and 7 % (w/v) sodium chloride. Citrate, malonate and
tartrate are utilised. The organisms produce acid from amygdalin, arabinose,
cellobiose, galactose, glycerol, maltose, mannitol, sorbitol, sucrose and trehalose, but not from adonitol, dulcitol, erythritol, inositol, lactose, melibiose,
raffi nose, rhamnose, salicin or xylose. Cultures comprise a single dominant
ribotype. The G + C ratio of the DNA is 45.6–46.3 moles % (Smith 1961 ;
Kiehn and Pacha 1969 ; Evelyn 1971 ; Muroga et al. 1976a , b ; Schiewe et al.
1981 ; Austin et al. 1995a ; Farmer et al. 2005 ).
Vibrio anguillarum