Molecular epidemiology of plasmid patterns in Shigella flexneri types 1–6

• Published in: Epidemiology and infection 1991-10, Vol.107 (2), p.321-334
• Main Authors: Gebre-Yohannes, A., Drasar, B. S.
• Format: Article
• Language: English
• Subjects: Abbreviations; Anti-Bacterial Agents - pharmacology; Bacillary dysentery; DNA, Bacterial - analysis; DNA, Bacterial - chemistry; Drug resistance; Drug Resistance, Microbial; Dysentery, Bacillary - epidemiology; Dysentery, Bacillary - microbiology; Electrophoresis, Agar Gel; Escherichia coli K12; Ethiopia - epidemiology; Humans; Molecular Weight; Plasmids; R Factors; Serotyping; Shigella; Shigella flexneri; Shigella flexneri - classification; Shigella flexneri - drug effects; Shigella flexneri - genetics; Uniformity
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268800048962

A total of 123 drug-resistant and drug-sensitive Shigella flexneri types 1–6, and their Escherichia coli K12 transconjugants were used for plasmid profile analysis by agarose gel electrophoresis. Resistance factors (R-factors) were further characterized by incompatibility testing. The overall distribution of small plasmids in S. flexneri showed that a cryptic plasmid of about 4·6 Kb was found in all serotypes, and a plasmid of about 4·2 Kb was found in serotypes 1–4. Shigella flexneri types 2, 4 and 6 showed a 6·5 Kb plasmid which correlated with SSu-resistance. All S. flexneri serotypes harboured large plasmids of about 217 Kb. Plasmid profile analysis of S. flexneri in Ethiopia showed a high degree of uniformity within individual serotypes. However, there was a limited variability which, at times, could be useful for epidemiological investigation. Shigella flexneri serotypes 1–6 harboured resistance plasmids with diverse molecular weights but mostly belonging to incompatibility groups N and X.