ABSTRACT
A total of 173 Vibrio cholerae O1 isolates from the recent cholera epidemic in Colombia was analysed by the polymerase chain reaction (PCR) for the genes encoding the A subunit of cholera toxin (ctxA) and the zonula occludens toxin (zot), and by ribotyping. All isolates were positive for ctx A and zot, which was confirmed by hybridisation. Ribotyping with restriction endonuclease Bg/I digestion of total DNA revealed three ribotypes: B5a comprising 165 (96.4%) isolates, and two new designated ribotypes B20 and B21a in six (3.5%) isolates and two (1.1%) isolates, respectively. These findings have significant public health implications.
Subject(s)
Cholera Toxin/genetics , Cholera/epidemiology , RNA, Ribosomal/genetics , Vibrio cholerae/genetics , Bacterial Typing Techniques , Cholera/microbiology , Colombia/epidemiology , Disease Outbreaks , Endotoxins , Genes, Bacterial , Humans , Molecular Epidemiology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , RNA, Bacterial/genetics , Vibrio cholerae/classification , Vibrio cholerae/isolation & purification , rRNA OperonABSTRACT
The rRNA gene restriction patterns of 92 isolates of Haemophilus influenzae biogroup aegyptius, associated with conjunctivitis or Brazilian purpuric fever in the State of São Paulo, Brazil, were studied with 16 + 23S rRNA from Escherichia coli as a probe. All strains were classified into 15 patterns. Isolates from Brazilian purpuric fever cases were seen only in patterns 3 (most frequently) and 4 (rarely), whereas isolates from conjunctivitis were found in all 15 patterns. The study demonstrated that rRNA from E. coli can serve as a probe for molecular epidemiology.