Molecular characterization of invasive and non-invasive Streptococcus pyogenes isolates from Romania.

In 2002, the Romanian National Reference Laboratory was invited to join the Strep-EURO project to study invasive Streptococcus pyogenes infections. During 2003 and 2004, a total of 33 isolates recovered from invasive disease were received from eight Romanian counties. For comparison, 102 isolates from non-invasive disease, as well as a collection of 12 old invasive strains (isolated between 1967 and 1980) were included. All isolates were characterized by several methods: T and emm typing, presence of the fibronectin-binding protein F1 gene (prtF1), serum opacity factor (sof), and superantigen (SAg) genes (speA, speB, speC, speF, speG, speH, ssa and smeZ). The recent invasive isolates exhibited 19 emm-types, of which emm1, emm81, emm76, emm49 and emm78 covered 57 % of the strains. Furthermore, multilocus sequence typing analysis revealed nine new sequence types, corresponding to emm types 1, 12, 49, 81, 92, 100, 106 and 119. The non-invasive isolates comprised 24 different emm types with a predominance of emm1 and 12; the old invasive strains were of eight emm types, of which four were unique for this group. All isolates harboured speB and speF; smeZ was detected in all invasive strains, except for the emm49 and emm81 isolates. The majority of isolates from carriers, and patients with pharyngitis were prtF1 positive, most of these (14 strains) being emm12. High tetracycline resistance rates were noted among both invasive and control isolates (54 % and 35 %, respectively), whereas macrolide resistance rates were low (3 % and 5 %, respectively). Active and continuing surveillance is required to provide an accurate assessment of the disease burden and to provide epidemiological data on the character of isolates in Romania.

A quantitative approach to the effectiveness of ozone against microbiota organisms colonizing toothbrushes.

OBJECTIVES: Toothbrushes are rapidly contaminated with different microorganisms, which colonize the oral cavity and interdental spaces. This can represent a possible cause of infection or reinfection. In this study, the ozone experimental effect upon toothbrushes microflora was estimated microbiologically before and after saturation with ozone gas. METHODS: Fifty used toothbrushes coming from children and adults were entered our study. Microorganisms were enumerated and identified. Bristles from each brush were soaked in ozone saturated PBS solution for 5, 10, 15, 20 and 30 min and the total microbial population was reassessed. RESULTS: Counts of microorganisms isolated per brush varied between 10(2) and 10(7) CFU. Candida albicans was present in used toothbrushes. No obligate anaerobes were isolated. Members of Streptococcaceae family were regularly found (65.2%) belonging to the following species: Streptococcus pyogenes, S. mutans, S. mitis, S. oralis, S. sobrinus, S. viridans, S. salivarius, S. sanguis, Aerococcus viridans. A. viridans and S. mutans were more frequently isolated on children toothbrushes while Staphylococcus aureus and S. epidermidis were found on adults brushes. Escherichia coli, Pseudomonas sp. and Enterococcus sp., were also recovered. We found that the ozone treatment decreased gradually the microbial load. However, a bacterial re-growth was effective following short ozonation period. Decontamination was complete after an extended exposure to ozone for 30 min. CONCLUSIONS: Ozone application was found to remove the toothbrushes bristles microbiota following conventional brushing. Maximum decontamination efficacy of ozone treatment was observed after 30 min while exposure for short time periods seems to be inefficient which probably reflect the low dose of ozone used in this study.