small, Gram-negative cocobacilli
Differential characters of the subspecies:
Legend: + positive 90-100%, - negative 90-100%, [+] positive 75-89%,
[-] negative 75-89%, d positive 25-74%
|P. multocida rising and twisting deposit when shaked
|Pasteurella multocida subsp. septica
colonies on Sheep Blood Agar
Phylum Proteobacteria, Class Gammaproteobacteria, Order Pasteurellales, Family Pasteurellaceae, Genus Pasteurella, Pasteurella
multocida (Lehmann and Neumann 1899) Rosenbusch and Merchant 1939.
- P. multocida subsp. multocida (Lehmann and Neumann 1899) Rosenbusch and Merchant 1939
- P. multocida subsp. gallicida Mutters, Ihm, Pohl, Frederiksen and Mannheim 1985
- P. multocida subsp. septica Mutters, Ihm, Pohl, Frederiksen and Mannheim 1985.
Old synonyms: Bacterium mutocidum multocidum Lehmann and Neumann 1899, Pasteurella gallicida (Burrill 1883) Buchanan 1925.
Coccoid cells, short rods, pleomorphic rods and short filaments, 0.3-1.0/1.0-2.0 µm,
Gram-negative, usually bipolar, nonmotile. Many strains produce capsule. Type 4
fimbriae and pili of rigid and curly types have been observed.
Can grow on usual media but grow better on blood or serum-containing media
(sheep or bovine), especially at first isolation. Regular, smooth, nontransparent, gray
colonies; 0.5-2.0 mm. diameter after 24 hours incubations at 37 ºC on agar media;
nonhemolytic. Isolates from the respiratory tract of ruminants, pigs and rabbits may
form large, mucoid colonies agar. Variable growth on MacConkey medium (different
formulations of medium may explain different test result). In broth usually causes
turbidity, but granular growth may occur; a thick pellicle may appear by aging.
Can survive 30 days in cultures at room temperature. Wide mesophilic range from
25-42 ºC; optimal growth for avian strains might be as high as 42 ºC, and 36 ºC for
Wide distribution among terrestrial and aquatic mammals and birds; it is usually an
opportunistic pathogen that may colonize and form part of the indigenous flora of the
mucous membranes of the upper respiratory and lower genital tracts.
Some strains are encapsulated, and four capsular group -A,B,D,E- have been
described. Capsule type A serotypes 1,3, and 4 are the cause of fowl cholera in poultry
and wild birds. P. multocida capsule types B and E are associated with hemorrhagic
septicemia of cattle, water buffaloes & occasionally other species. Bronchopneumonia
in feedlot cattle and enzootic pneumonia of calves less than 6 months old, are mainly
associated with capsule type A.
Atrophic rhinitis and bronchopneumonia in pigs are caused by capsular types A and D.
Strains of P. multocida that cause atrophic rhinitis in pigs produce a 145-kDa
dermonecrotic toxin that is an essential virulence factor for this infection.
Clinical isolates of P. multocida also produce lipases, which may also be potential
It was recovered from a wide range of sporadic infections in many other species,
including laboratory animals, rabbits, dogs, cats, and other mammals.
Mice, pigeons and rabbits are the most sensitive to experimental infection. Guinea pigs
It is a zoonotic pathogen, most human infections result from animal bites; can be
associated with necrotizing fasciitis, lung abscesses, endocarditis, meningitis,
pneumonia, peritonitis, septicemia, tubo-ovarian abscesses.
Admin note: one P. multocida subsp. septica strain was isolated from a dead rabbit
with pleuritis and fibrinous pneumonia.
- R. Mutters, H. Christensen, M. Bisgaard, 2004. Genus I. Pasteurella. In: Bergey’s Manual of Systematic Bacteriology, Second
edition,Vol two, part B, George M. Garrity (Editor-in-Chief), pp. 857-866.
- W.M. Janda, R. Mutters, 2006. Pasteurella, Mannheimia, Actinobacillus, Eikenella, Kingella, Capnocytophaga, and other
miscellaneous Gram-negative rods. In: Topley & Wilson’s Microbiology and Microbial Infections, 10 edition, Vol. 2, Bacteriology,
Edward Arnold Ltd.
- H. Raducanescu, R. Dorobantu, 1985. Genul Pasteurella. In: Bacteriologie medicala, vol II, v. Bilbiie, N. Pozsgi (sub redactia), Ed.
- H. Raducanescu, V. Bica-Popii,1986. Bacteriologie veterinara, Ed. Ceres, Bucuresti, 225-232.
- Mihancea si colab., 1999. Identificarea bacililor Gram-negativi aerobi sau facultativ anaerobi pretentiosi nutritiv. In: Tratat de
microbiologie clinica, D. Buiuc, M. Negut, Ed. Medicala, Bucuresti, 840-849.
- J. G. Holt et al., 1994. Facultatively Anaerobic Gram-Negative Rods. Subgroup 3. Family Pasteurellaceae. In: Begey’s Manual of
Determinative Bacteriology, 9th-edition, Williams & Wilkins, pp 194-196.
Positive results for alkaline phosphatase, catalase, indole production, nitrate
reduction, ornithine decarboxylase, oxidase, acid production from: D(-) fructose, D(+)
glucose (without gas), D(+) galactose, D(+) mannose, mannitol & sucrose. Glucose
fermentation is usually negative in API 20 NE (admin note).
Negative results for gelatinase, ONPG, Voges-Proskauer, arginine dehydrolase,
lysine decarboxylase, citrate (Simmons), urease, acid production from: arabinose,
cellobiose, dextrin, esculin, L(+) meso-inositol, inulin, lactose, maltose, D(+)
melibiose, raffinose, salicin, L(+) rhamnose, L(-) sorbose & xylitol,
H2S production is variable (negative on TSI, positive on other media);
Glycerol & D(+)arabinose fermentation is variable.
(c) Costin Stoica