P. multocida strain Amounts of hyaluronic acid (10-8 µg/CFU)a Viabilityb P-1059 12.2 ± 0.9 0.2 ± 0.1 ∆hexB 2.3 ± 0.3 0.4 ± 0.3 P-1059C 11.4 ± 0.6 0.1 ± 0.2 a The levels of hyaluronic acid produced by strains P-1059 and P-1059C compared to that of ΔhexB were significantly different (P<0.01), bViability is expressed as the ratio of bacterial number (CFU/ml) after treatment at 42°C to that before treatment at 42°C.

Table 3: Extracellular hyaluronic acid produced by P. multocida strains.