Figure 2. Repetitive sequence–based, PCR–generated dendrogram for 43 Shigella sonnei isolates obtained from sporadic or outbreak cases during 1996–2007 in the Paris area. Isolates with >97% similarity were considered to be closely genetically related. Profile 1) representative of the 32 isolates of the 2007outbreak with azithromycin (MIC >256 mg/L by Etest) . Profile 2) 1 of 6 isolates from sporadic cases (2003–2006) with azithromycin MIC <16 mg/L. Profile 3) representative isolate Shi 03-3580 from 2003 outbreak with azithromycin MIC <16 mg/L by Etest. Profile 4) representative isolate Shi 02-9633 from 2002 outbreak with azithromycin MIC <16 mg/L by Etest. Profile 5) representative isolate Shi 96 1420 from 1996 outbreak with azithromycin MIC <16 mg/L by Etest. Profile 6) isolate from 2007 with azithromycin MIC <16 mg/L by Etest; another AZM S 2007 isolate had an identical profile. AZM, azithromycin; R, resistant; S, sensitive; Rep, repetitive sequence-based PCR.