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Table 1 Biochemical characteristics of Yersinia ruckeri isolates from fish in aquaculture in north west Germany

From: Biochemical and molecular heterogeneity among isolates of Yersinia ruckeri from rainbow trout (Oncorhynchus mykiss, Walbaum) in north west Germany

Test Reference strain (DSM 18,506) Number of the field isolates tested positive (%)
Total Isolates from rainbow trouts in H Isolates from rainbow trouts in N Isolates from rainbow trouts in L Isolates from other fish in L
   (n = 82) (n = 8) (n = 49) (n = 19) (n = 6)
Motility + 16 (19.5) 1 (12.5) 4 (8.2) 6 (31.6) 5 (83.3)
Nitrate reduction + 77 (93.9) 8 (100.0) 47 (95.9) 17 (89.5) 5 (83.3)
Nitrate reduction * - 72 (87.8) 8 (100) 45 (91.8) 14 (73.7) 5 (83.3)
Citrate utilization + 59 (72.0) 6 (75.0) 32 (65.3) 15 (78.9) 6 (100)
Citrate utilization * + 50 (61.7) 6 (75.0) 29 (59.2) 10 (52.6) 5 (83.3)
Voges-Proskauer - 48 (58.5) 5 (62.5) 29 (59.2) 10 (52.6) 4 (66.7)
Voges-Proskauer* - 52 (63.4) 4 (50.0) 37 (75.5) 7 (36.8) 4 (66.7)
Gelatine hydrolysis - 81 (98.8) 8 (100.0) 49 (100.0) 19 (100.0) 5 (83.3)
Gelatine hydrolysis* - 77 (93.9) 8 (100.0) 48 (98.0) 16 (84.2) 5 (83.3)
Methyl-red + 76 (92.7) 7 (87.5) 48 (98.0) 18 (94.7) 3 (50.0)
Tween 20 hydrolysis + 16 (19.5) 1 (12.5) 4 (8.2) 6 (31.6) 5 (83.3)
Tween 80 hydrolysis + 16 (19.5) 1 (12.5) 4 (8.2) 6 (31.6) 5 (83.3)
Acid from sorbitol - 5 (6.1) 1 (12.5) 1 (2.0) 0 (0.0) 3 (50.0)
  1. * API 20E test system.
  2. L: Lower Saxony, H: Hessen, N: North Rhine-Westphalia.