Characteristics and biotypes of Pasteurella multocida isolated from humans

Abstract

Fifty-two isolates of Pasteurella (48 strains of Pasteurella multocida and 4 strains of atypical Pasteurella) were identified by conventional and commercial test systems. All strains fermented glucose, sucrose, and fructose in purple broth base (Difco Laboratories) with bromocresol purple as indicator, although the atypical Pasteurella produced fermentation reactions that were barely perceptible. Eleven different biotypes were identified by fermentation reactions in maltose, mannitol, xylose, sorbitol, and trehalose media. There was a correlation of biotypes to cat bites, with 61% of cat bite isolates falling into biotype A and B. A correlation of biotype and dog bite isolates was not seen. The choice of medium used for fermentation tests was critical as evidenced by the inability of the organisms to grow in a second commercially purchased preparation of purple broth base. The reliability of commercial test systems in identifying Pasteurella was 81% for Oxi/Ferm (Roche Diagnostics, Div. Hoffmann-La Roche, Inc., Nutley, N.J.), 68% for API (Analytab Products, Plainview, N.Y.), and 11% for Minitek (BBL Microbiology Systems, Cockeysville, MD.).

REINVESTIGATION AND RECLASSIFICATION OF A COLLECTION OF 56 HUMAN ISOLATES OF PASTEURELLACEAE

“…Most publications dealing with phenotypic characters of human isolates of Paslurella spp. do not contain sufficient information to allow classification according to present knowledge (6,11,19,24,25). Since different reactions have been reported in urease.…”

Increased indole detection for Pasteurella multocida

“…Indole production was detected in all 96 isolates of P. multocida within 18 to 24 h after inoculation (Table 1), and as early as 12 h for some isolates. In comparison, Oberhofer (5) observed that 87 to 88% of his 48 strains of P. multocida were indole positive after 24 h of incubation with the conventional test, and 100% of 31 strains were indole positive with the spot test.…”

“…Pasteurella multocida isolates from different hosts show a wide variability in physiological characteristics (1)(2)(3)(4)(5). In view of the fulminant course that P. multocida infections can take, rapid and accurate identification is imperative.…”

“…In view of the fulminant course that P. multocida infections can take, rapid and accurate identification is imperative. However, positive identification can be difficult depending on the selection of biochemical media (5). Indole production by P. multocida is an important but variable characteristic of identification (2-5).…”

“…The formulation and preparation of the medium (MRP broth) that we used included: 20 g of peptone (Difco Laboratories, Detroit, Mich.), 5.0 g of yeast autolysate (Sigma Chemical Co., St. Louis, Mo. ), 5.0 g of NaCl, 990 ml of distilled water, and 10 ml of a 100x vitamin concentrate.…”