Mann.hei' mi.a. L. n. fem.
Mannheimia
named in tribute to the German microbiologist Walter Mannheim.
Proteobacteria / Gammaproteobacteria / Pasteurellales / Pasteurellaceae / Mannheimia
Gram‐negative, nonmotile rods or coccobacilli. Cell sizes of ∼0.5 × 1.2 μm are similar to those of
Pasteurella
species. Some species exhibit bipolar staining. Endospores are not formed. Growth is mesophilic and facultatively anaerobic or microaerophilic. Neither X nor V factor is required for growth. Glucose is fermented without gas production. Oxidase reaction is normally positive, but may be variable. Alkaline phosphatase and catalase test is positive, and nitrate is reduced. Simmon's citrate, arginine dihydrolase, and Voges–Proskauer tests are negative, and there is no fermentation of
d
‐adonitol or
l
‐sorbose. All strains ferment
d
‐mannitol. Urease reaction is negative. Trehalose and
d
‐mannose are not fermented. Cultural characteristics are typical of those of the family
Pasteurellaceae
. A zone of β‐hemolysis is commonly observed, depending on media, type of blood, and pH.
DNA G
+
C content (mol%)
: 39.2–43.9.
Type species
:
Mannheimia haemolytica
Angen et al. 1999
VP
(basonym:
Pasteurella haemolytica
Newsom and Cross 1932
AL
).