Plasmid profile analysis and restriction enzyme analysis in characterizing Shigella flexneri isolates from an...

Shigella flexneri strains which are multiply resistant to antimicrobial agents were isolated from 11 children from an orphanage in Cluj-Napoca during an epidemiological investigation initiated by the Department of Epidemiology. Plasmid profile analysis and restriction endonuclease analysis were used in conjunction with biotyping, serotyping and antimicrobial susceptibility testing for identifying epidemiological related isolates. All strains were serotype 2a and with one exception all of them showed the same resistotype. Plasmid profile analysis differentiated S. flexneri isolate into four patterns, with two common plasmids of 3.5 and 1.9 kb. This study indicates that this outbreak was caused by at least two different strains of S. flexneri which were not differentiated by the classical technique-biotyping, serotyping and antimicrobial susceptibility pattern.