A seroprevalence study of poliovirus antibody against a collection of recombinant and non-recombinant poliovirus vaccine strains in the population of southern Greece.

In this study, the serological status of the southern Greek population in the 1­10-year, 11­20-year, 21­30-year and 31­40-year age groups with regard to Sabin vaccine strains and a collection of 15 recombinant and four non-recombinant poliovirus vaccine strains was determined. For all three poliovirus types, the highest neutralization test (NT) titres were observed in the 1­10- year age group, indicating a good response to vaccination. In general, the serological status of the population of southern Greece with regard to poliovirus is better for types 1 and 2 than for type 3. The presence of the lowest NT titre in the 21­ 30-year age group against poliovirus type 3 suggests the need for a booster dose of monovalent Sabin3 vaccine to ensure personal and herd immunity.

A new RT-PCR assay for the identification of the predominant recombination types in 2C and 3D genomic regions of vaccine-derived poliovirus strains.

In the post-eradication era of wild polioviruses, the only remaining sources of poliovirus infection worldwide would be the vaccine-derived polioviruses (VDPVs). As the preponderance of countries certified to be polio-free has switched from OPV (oral poliovirus vaccine) to IPV (inactivated poliovirus vaccine), importation of recombinant evolved derivatives of vaccinal strains would have serious implication for public health. To test the robustness of the proposed RT-PCR screening analysis, eleven recombinant vaccine-derived polioviruses that were characterized previously by sequencing by our group, in addition to three recently identified recombinant environmental isolates were assayed. Although the most definitive characterization of VDPVs is by genomic sequencing, in this study we describe a new, inexpensive and broadly applicable RT-PCR assay for the identification of the predominant recombination types S3/Sx in 2C and S2/Sx in 3D genomic regions respectively of VDPVs, that can be readily implemented in laboratories lacking sequencing facilities as a first approach for the early detection of vaccine-derived poliovirus (VDPVs).

In vitro activity of daptomycin against Gram-positive cocci: the first multicentre study in Greece.

A total of 10420 Gram-positive cocci (including staphylococci, enterococci and various groups of streptococci) collected from clinically significant specimens in ten Greek hospitals during 2006--2007 were tested for their susceptibility to daptomycin. The minimum inhibitory concentration (MIC) was determined by the broth microdilution method. Daptomycin demonstrated very high activity against Enterococcus faecalis (MIC at which 50% of the isolates were inhibited (MIC50) = 1mg/L and MIC at which 90% of the isolates were inhibited (MIC90) = 1.36 mg/L), Enterococcus faecium (MIC50 = 1.36 mg/L and MIC90 = 1.90 mg/L), Streptococcus pyogenes (MIC50 = 0.12 mg/L and MIC90 = 0.50mg/L), Streptococcus agalactiae (MIC50 = 0.09 mg/L and MIC90 = 0.12 mg/L), Streptococcus pneumoniae (MIC50 = 0.24 mg/L and MIC90 = 0.5 mg/L) and viridans group streptococci (MIC50 = 0.50 mg/L and MIC90 = 0.89 mg/L). Resistance to linezolid and vancomycin for enterococci and to penicillin for streptococci appears to be independent of reduced susceptibility to daptomycin. On the other hand, daptomycin was also active against meticillin-resistant Staphylococcus aureus (MIC50 = 0.44 mg/L and MIC90 = 0.78 mg/L) and meticillin-resistant coagulase-negative staphylococci (MIC50 = 0.24 mg/L and MIC90 = 0.44 mg/L); however, 0.9% of the staphylococci tested had an MIC > 1mg/L, which is the Clinical and Laboratory Standards Institute breakpoint proposed for susceptibility. For all tested organism groups, resistance to daptomycin was not associated with glycopeptide resistance.

Clinical isolates of macrolide-resistant Streptococcus pyogenes in Central Greece.

A total of 300 Streptococcus pyogenes isolates, collected during 2001 from five hospitals in the Thessalia district (Central Greece), were examined for their resistance to macrolides. Resistance to erythromycin was detected in 58 isolates (19.3%). Of these, 68.9% were susceptible to clindamycin (M-phenotype) and carried the mefA gene. Of the remaining isolates, 18 expressed the MLS(B) phenotype: 12 and six exhibited inducible and constitutive resistance to clindamycin, respectively. All of these strains were found to be ermA(TR) positive, except for four that had the ermB gene. Of the erythromycin-resistant strains, none was found to be resistant to penicillin, tetracycline or quinupristin-dalfopristin. Molecular typing by PFGE showed the presence of a limited number of clones.