Molecular mechanisms of high level tetracycline-resistance in group A streptococcal isolates, T serotypes 4 and 11.

The molecular mechanism of high level tetracycline resistance in T serotypes 4 and 11 group A streptococcal (GAS) isolates was examined in 61 tetracycline-resistant isolates in Japan. PCR and sequencing analyses revealed that the T serotype/emm genotype, T4/4 isolates carried tet(O) genes, which were genetically homogenous. The T11/11 and T11/89 isolates carried different subtypes of tet(M) genes, which were present on transposons Tn916 and Tn1545, respectively.

[Presence of the genes regarding adherence factors of Escherichia coli isolates and a consideration of the procedure for detection of diarrheagenic strain].

Diarrheagenic Escherichia coli are differentiated from non-pathogenic members with enterotoxin production, enteroinvasiveness and serotyping. However, the serotypic members are rarely sufficient to reliably identify a strain as diarrheagenic on E. coli.

[Epidemiological and bacteriological investigation of enterohemorrhagic Escherichia coli infection in the Chugoku-Shikoku area].

We investigated the occurring tendency of enterohemorrhagic Escherichia coli (EHEC) infection in the prefectural and municipal public health institutes in the Chugoku-Shikoku area from 1996 to 1999, and the bacteriological characteristics of EHEC isolated from these cases. Consequently, epidemiological analysis of the EHEC infection in this district was performed. 22 outbreaks in the various facilities showed the tendency occurred in infants and aged groups, and the serotypes of EHEC isolated from these outbreaks were O26, O111 etc.