Riemerella
Authors:   The Editorial Board
Published: August 2015

Rie.me.rel'la. N.L. fem. n.
Riemerella
named in honor of O.V. Riemer, who first described
Riemerella anatipestifer
infections in geese in 1 9 0 4 and referred to the disease as
septicemia anserum exsudativa
(Riemer, 1904).

Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Riemerella

The following description is based on those given by Segers et al. (1993a) and Vancanneyt et al. (1999).
Rods
,
0
.
2–0
.
5
×
1
.
0–2
.
5
μ
m
. Nonmotile. No gliding motility. Nonspore‐forming. Gram‐stain‐negative.
All strains grow microaerobically and most of them grow aerobically on blood agar
. Some strains grow anaerobically at 37°C. Colonies are smooth and nonpigmented or grayish‐white to beige. Growth on litmus lactose agar is strain‐dependent. No growth occurs on MacConkey agar. Most strains show a positive Voges–Proskauer reaction. Nitrates are not reduced.
Acid production from glucose is frequently negative in peptone‐containing media
. The following enzymes are present:
oxidase
,
catalase
, gelatinase, α‐glucosidase, α‐maltosidase, alkaline phosphatase, acid phosphatase, esterase lipase C8, esterase C4, naphthol‐AS‐Bl‐phosphohydrolase, leucine arylamidase, valine arylamidase, cystine arylamidase, and
L
‐aspartic acid arylamidase. The following reactions are strain‐dependent: urease, chymotrypsin, trypsin, arginine dihydrolase, indole production, hemolysis on blood, and esculin hydrolysis. Depending on the micro‐test kit used, the following enzyme reactions give variable results: β‐glucosidase, α‐galactosidase, and lipase (these three reactions are positive in the API ID32E and negative in the API ZYM system); and
N
‐acetyl‐β‐glucosaminidase [negative in API ZYM and API ID32E, positive in LRA‐ZYM‐Oxidase (Hinz et al., 1998); only some representative
Riemerella anatipestifer
strains have been tested using the latter system]. The following enzyme activities are absent: chondroitin sulfatase, hyaluronidase, β‐galactosidase, β‐glucuronidase, α‐mannosidase, α‐fucosidase, trypsin, ornithine decarboxylase, and lysine decarboxylase. None of the strains use malonate as a carbon source or assimilate the following compounds (API 20NE system):
D
‐glucose,
L
‐arabinose,
D
‐mannose,
D
‐mannitol,
N
‐acetylglucosamine, maltose,
D
‐gluconate, caprate, adipate,
L
‐malate, citrate, or phenylacetate. No acid production occurs with the following (API ID32E system):
D
‐ and
L
‐arabitol, galacturonate, 5‐ketogluconate, phenol red,
D
‐mannitol, maltose, adonitol, palatinose, sucrose,
L
‐arabinose, trehalose, rhamnose, inositol, sorbitol, and cellobiose. Using the buffered single substrate (BSS) test, however, acidification of the following carbohydrates may be detected:
D
‐glucose, maltose,
D
‐mannose, and dextrin and, to a lesser extent,
D
‐fructose,
L
‐sorbose, and trehalose, but no acid is produced from lactose,
D
‐galactose,
N
‐acetyl‐
D
‐glucosamine, lactulose, trehalose, sucrose,
D
‐mannitol,
L
‐arabinose,
myo
‐inositol,
D
‐sorbitol,
D
‐xylose, dulcitol, salicin, or adonitol. Menaquinone‐6 is the major respiratory quinone detected in the type species. The dominant fatty acids are the branched‐chain fatty acids C
13:0
iso, C
15:0
iso, C
15:0
anteiso, C
15:0
iso 3‐OH, and C
17:0
iso 3‐OH. Isolated mainly from diseased birds and, in a few cases, from pigs.

DNA G
+
C content
(
mol
%): 29–37.

Type species
:
Riemerella anatipestifer
(Hendrickson and Hilbert 1932) Segers, Mannheim, Vancanneyt, De Brandt, Hinz, Kersters and Vandamme 1993a, 775
VP
[
Moraxella anatipestifer
(Hendrickson and Hilbert 1932) Bruner and Fabricant 1954, 461;
Hemophilus anatipestifer
Hauduroy, Ehringer, Urbain, Guillot and Magrou 1937, 247;
Pasteurella anapestifer
(
sic
) Hauduroy, Ehringer, Guillot, Magrou, Prévot, Rosset and Urbain 1953, 367;
Pasteurella anatipestifer
(Hendrickson and Hilbert 1932) Breed, Murray and Smith 1957, 397;
Pfeifferella anatipestifer
Hendrickson and Hilbert 1932, 249].