A swab of the lachrymal secretions is taken from the deep canthus of the eye. Ideally BTA plates should be inoculated immediately after collection. If this is not possible, each swab is placed in about 1– 2 ml of sterile distilled water, to prevent desiccation, and the specimens taken to the laboratory within two hours after collection. Table 9.6: Summary of the disease and sites of isolation of some the Moraxella species Species Host Natural habitat Disease Cattle Conjunctiva or nasopharynx of Infectious bovine keratoconjunctivitis M. bovis cattle older than 2 years Conjunctivitis Horses Opportunistic pathogen: septicaemia, Many animal species Mucous membranes of abortions M. lacunata animals Humans Conjunctivitis M. ovis Sheep Mucous membranes Not pathogenic Sheep & cattle Urogenital tract Psychrobacter Pigs Urogenital tract Pathogenicity for animals is unknown phenylpyruvica Goats Intestinal tract Table 9.7: Differentiation of the Moraxella/Brahamnella species Characteristic M. bovis B. ovis M. lacunata P. phenylpyruvica Other Moraxella + (not Beta-haemolysis (blood) equine + - - - strains) Growth on MacConkey agar - + - (+) d Oxidase + + + + + Catalase (+) + + + + Nitrate reduction - (+) + (+) d Urease - - - + - DNAse - + - + d Peptonisation of milk + - - Gelatinase or Loeffler serum (+) (-) + - - slope Direct microscopy Gram-stained smears show Gram-negative short, plump diplobacilli. A fluorescent antibody technique will demonstrate and identify M. bovis if sufficient bacterial cells are present. Isolation Inoculate BTA and incubate at 35°C for 48–72 hours. The inoculation of the MacConkey plate is useful to gauge the degree of contamination by other Gram-negative bacteria, as M. bovis does not grow on this agar. Colony identification
A swab of the lachrymal secretions is taken from the deep canthus of the eye. Ideally BTA plates should be inoculated immediately after collection. If this is not possible, each swab is placed in about 1– 2 ml of sterile distilled water, to prevent desiccation, and the specimens taken to the laboratory within two hours after collection. Table 9.6: Summary of the disease and sites of isolation of some the Moraxella species Species Host Natural habitat Disease M. bovis Cattle Horses Conjunctiva or nasopharynx of cattle older than 2 years Infectious bovine keratoconjunctivitis Conjunctivitis M. lacunata Many animal species Humans Mucous membranes of animals Opportunistic pathogen: septicaemia, abortions Conjunctivitis M. ovis Sheep Mucous membranes Not pathogenic Psychrobacter phenylpyruvica Sheep & cattle Pigs Goats Urogenital tract Urogenital tract Intestinal tract Pathogenicity for animals is unknown Table 9.7: Differentiation of the Moraxella/Brahamnella species Characteristic M. bovis B. ovis M. lacunata P. phenylpyruvica Other Moraxella Beta-haemolysis (blood) + (not equine strains) + - - - Growth on MacConkey agar - + - (+) d Oxidase + + + + + Catalase (+) + + + + Nitrate reduction - (+) + (+) d Urease - - - + - DNAse - + - + d Peptonisation of milk + - - Gelatinase or Loeffler serum slope (+) (-) + - - Direct microscopy Gram-stained smears show Gram-negative short, plump diplobacilli. A fluorescent antibody technique will demonstrate and identify M. bovis if sufficient bacterial cells are present. Isolation Inoculate BTA and incubate at 35°C for 48–72 hours. The inoculation of the MacConkey plate is useful to gauge the degree of contamination by other Gram-negative bacteria, as M. bovis does not grow on this agar. Colony identification
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