: N2339-98 ND – [19] JF2793 CIP 7433; ATCC 43979 sobria – Type Neuronal Signaling inhibitor strain NENT Nr.2352 ND – [19] JF2929 Fi 179a sobria – Perch, Switzerland ascV + SacrD+ – [22] JF2788 NCMB 74; ATCC 23309 eucrenophila – Type strain NENT Nr. N2348-98 ND – [19] JF3069 ATCC 49904 T ichthiosmia – Type strain Antonella Demarta ND – - JF2790 ATCC 49568 jandaei – Type strain NENT Nr. 2355-98 ND – [19] JF3067 CIP 107763 T culicicola – Type strain ND – [19] JF3068 ATCC 49803 T enteropelogenes – Type strain ND – - ND: not determined. HCN-IS630-RFLP profiles

and stability of IS630 insertions A high degree of IS630 polymorphism, both in a numerical and positional sense, was observed between the various A. salmonicida subspecies (Figure 1). However, the patterns revealed that IS630 copy numbers and positions are well conserved within the given subspecies (Figure 1). The dendogram in Figure 2 is a RFLP tree that reveals the evolutionary relationship between strains analyzed. Strains of the subspecies salmonicida, smithia, Captisol molecular weight achromogenes and masoucida each grouped

together showing a similar banding pattern. The number of IS630-positive bands varied TPCA-1 order from 27 to 35 in A. salmonicida subsp. salmonicida, 23 to 33 in achromogenes and 19 to 21 in smithia. Within a subspecies, several bands were conserved: 21 in salmonicida, 20 in achromogenes and 13 in smithia subspecies. About 15 distinct patterns were observed in A. salmonicida subsp. salmonicida without showing geographical association. The IS630 pattern of A. salmonicida subsp. salmonicida strain A449 as calculated from the genome sequence data closely clusters with these Interleukin-3 receptor 15 patterns. In contrast, each pattern in the achromogenes cluster was different. In A. salmonicida subsp. masoucida 15 to 21 positive bands were detected and only 8 in the subspecies pectinolytica. Even though the copy numbers vary within the subspecies, the patterns form clusters for each subspecies. The most remarkable tight clustering was found for A. salmonicida subsp. salmonicida. This latter presents IS630 patterns that only show minute differences among strains that were isolated from various continents and

over a period of half a century. No pattern was specific of a given geographical region. The results showed also that strains JF3121 and JF3123, formerly classified as A. salmonicida atypical, clustered with A. salmonicida subsp. salmonicida (JF3121) and subsp. achromogenes (JF3123) (Figures 1 and 2) showing that they were misclassified previously. The IS630 pattern of A. salmonicida subsp. salmonicida strain JF 2267 that was subcultured for 4 days at 18°C and 25°C (in stressing conditions) to reach approximately 20 generations remained unchanged (results not shown) indicating a good stability of IS630 under experimental growth conditions. Figure 2 Dendogram generated from the IS 630 -RFLP patterns of the 87 Aeromonas strains used in this study.