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Bacillus mycoides
Characteristics of the Disease
An epizootic occurred in channel catfi sh in Alabama during 1992. The fi sh were
darker in colour, inappetant, displayed pale areas or ulcers on the dorsal surface,
focal necrosis of the epaxial muscle, and opaque muscle (Goodwin et al. 1994 ).
Histopathological examination revealed the presence of chains of Gram-positive
rods.
Isolation
Material from ulcers, brain, kidney, liver and necrotic muscle were inoculated onto
a range of media, including 5 % (v/v) sheep blood in blood agar base, Mueller
Hinton agar (for example, as supplied by Difco or Oxoid) and BHIA within incubation at an unspecifi ed temperature for an unstated duration (Goodwin et al. 1994 ).
Raised, rhizoidal colonies with fi lamentous swirling patterns developed.
Characteristics of the Pathogen
Cultures were considered to possess the key characteristics of B. mycoides, as
follows:
Diagnosis
Bacillus mycoides could be distinguished from other bacilli, as follows (Goodwin
et al. ( 1994 )):
Box 3.5: Bacillus mycoides
Cultures are rhizoidal, and contain non motile Gram-positive rods with oval
endospores. Parasporal crystals are not observed. Indole is not produced. The
Voges Proskauer reaction is positive. Blood (haemolysis), casein, gelatin,
lecithin and tyrosine are degraded. Acid is produced from D-glucose.
Resistance is recorded to penicillin. Growth does not occur at 45 °C (Goodwin
et al. 1994 ).
Bacillaceae Representatives
Bacillus mycoides
Characteristics of the Disease
An epizootic occurred in channel catfi sh in Alabama during 1992. The fi sh were
darker in colour, inappetant, displayed pale areas or ulcers on the dorsal surface,
focal necrosis of the epaxial muscle, and opaque muscle (Goodwin et al. 1994 ).
Histopathological examination revealed the presence of chains of Gram-positive
rods.
Isolation
Material from ulcers, brain, kidney, liver and necrotic muscle were inoculated onto
a range of media, including 5 % (v/v) sheep blood in blood agar base, Mueller
Hinton agar (for example, as supplied by Difco or Oxoid) and BHIA within incubation at an unspecifi ed temperature for an unstated duration (Goodwin et al. 1994 ).
Raised, rhizoidal colonies with fi lamentous swirling patterns developed.
Characteristics of the Pathogen
Cultures were considered to possess the key characteristics of B. mycoides, as
follows:
Diagnosis
Bacillus mycoides could be distinguished from other bacilli, as follows (Goodwin
et al. ( 1994 )):
Box 3.5: Bacillus mycoides
Cultures are rhizoidal, and contain non motile Gram-positive rods with oval
endospores. Parasporal crystals are not observed. Indole is not produced. The
Voges Proskauer reaction is positive. Blood (haemolysis), casein, gelatin,
lecithin and tyrosine are degraded. Acid is produced from D-glucose.
Resistance is recorded to penicillin. Growth does not occur at 45 °C (Goodwin
et al. 1994 ).
Bacillaceae Representatives