[Molecular typing of the strains of Bordetella pertussis circulating in St. Petersburg during an outbreak of the disease].

Growth of the whooping-cough morbidity during the last years in Russia and other countries with 40-year-long history of immunization gave rise to significant interest of researchers to variability of the Bordetella pertussis population. Comparative assay of the genomes of the B. pertussis strains circulating in St. Petersburg in 1998-2000 and strains used to produce domestic vaccines AKDS was performed using the pulse-field electrophoresis and sequencing. It was found that most strains of B. pertussis circulating during this period were distinguished from the vaccine strains by the DNA-profile and structure of genes involved in encoding of biosynthesis of the S1 subunit of the whooping-cough toxin (ptxS1) and pertactin (prn). It was shown that 62% of wild-type strains had electrophoretic profiles IV alpha and IV beta, whereas vaccine strains had electrophoretic profiles II and III. Circulation of strains with profiles IV alpha and IV beta was found to correlate with the whooping-cough morbidity rate in vaccinated children. Our results and data of other researchers were compared and analyzed.

[Susceptibility of Corynebacteria isolated in St Petersburg to antibacterial drugs]. / Chuvstvitel'nost' k antibakteral'nym peparatam korinebakteril, vydelennykh v Sankt-Peterburge.

Susceptibility of 150 Corynebacterium isolates (91 strains of C.pseudodiphtheriticum and 59 strains of the ANF group corynebacteria) to 21 antibacterial drugs was determined by the method of serial dilutions in a solid medium. It was shown that the MIC of the drugs for the diphtheroids was within the ranges of < 0.015 to > 32.0 micrograms/ml. 66 per cent of the Corynebacterium strains circulating in St. Petersburg was resistant at least to 1 antibacterial drug. The Corynebacterium isolates with moderate resistance to erythromycin and lincomycin (57.3 per cent) and resistant to trimethoprime (16.7 per cent) were the most frequent. 8.0 per cent of the diphtheroids was resistant at least to 4 antibacterial drugs. No significant difference in the susceptibility of the ANF group corynebacteria and C.pseudodiphtheriticum to the drugs was observed. Gentamicin, rifampicin, tetracycline and doxycycline showed high activity against the corynebacteria at present circulating in St. Petersburg. When antibacterial therapy of the infection due to corynebacteria fails it is necessary to estimate antibioticograms of Corynebacterium pure cultures.