A bacterium isolated from desert tortoises fits the major criteria for inclusion in the genus Pasteurella (gram-negative, nonmotile, pleomorphic rods that are facultatively anaerobic, fermentative in their attack on various carbohydrates, and catalase, nitratase, and oxidase positive). Tests performed for identifying this organism to the species level produced results that fit none of the currently accepted species of Pasteurella. This organism did not hydrolyze urea but did produce indole from tryptophane, hydrolyze 0-nitrophenyl-β-D-galactopyranoside, and lyse sheep erythrocytes in agar. It fermented a variety of carbohydrates, producing acetic, lactic, propionic, and succinic acids as a result of glucose fermentation. All strains were highly susceptible to ampicillin (≤0.5 μg/ml), and most strains were susceptible to penicillin (≤1 μg/ml); the susceptibilities to tetracycline, streptomycin, and sulfonamides were variable. Serological tests revealed antigenic heterogeneity and suggested the presence of heat-extractable surface antigens in some strains. Mice succumbed to intranasal and intraperitoneal inoculations of large numbers of some of the strains. The guanine-plus-cytosine content of the deoxyribonucleic acid was between 46 and 47 mol%. The Analytab Products API 20E bacterial identification system could not identify some strains of this organism. Other strains were identified as Pasteurella multocida or Aeromonas hydrophila at probability levels ranging from 1:69 to 1:>106. Species status is proposed for these isolates under the name Pasteurella testudinis sp. nov. The type strain of this species is strain UCD 90-23-79n (= ATCC 33688).
|Original language||English (US)|
|Number of pages||10|
|Journal||International Journal of Systematic Bacteriology|
|State||Published - 1982|
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