Nationwide surveillance of resistance rates of Staphylococcus aureus clinical isolates from Greek hospitals, 2012-2013.

Purpose To evaluate the in vitro efficacy of several anti-staphylococcal agents against a nationwide collection of contemporary Staphylococcus aureus clinical isolates from several healthcare centres in Greece. Methods Thirty hospitals throughout Greece (18 in Attica) provided all clinical isolates of S.aureus from April 2012 to May 2013 to a central lab to be re-submitted to susceptibility testing. The MICs were evaluated by Vitek® 2 with the exception of ceftaroline (OXOID M.I.C. Evaluator™). Vancomycin and daptomycin MICs were also evaluated by Etest®. Heterogeneously vancomycin-intermediate strains (hVISA) were detected by the Etest® GRD. VISA phenotype was confirmed by PAP-AUC. Results A total of 1005 isolates (39% MRSA) were studied. Susceptibility rates were: erythromycin 66.5%, clindamycin 79.2%, SXT 98.9%, rifampicin 97.3%, fusidic acid 67%, moxifloxacin 78.8%, vancomycin 99.9%, ceftaroline 92.9% and linezolid, tigecycline and daptomycin 100%. For mupirocin, high level resistance could be excluded for 98.9% of isolates. Vancomycin Etest® MIC50/90 were 1.5/1.5 mg/L, 58.5% of isolates exhibited a MIC > 1 and 8.7% a MIC of 2 mg/L, while Vitek® MIC50/90 were 1/1 and 3.1% showed MIC > 1 mg/L. One VISA strain was detected. Among the selected 175 isolates that were screened for hVISA phenotype, six (3.4%) were positive. In 315 bloodstream isolates, 64.1% had a vancomycin Etest® MIC > 1 mg/L. Conclusions This multi-centre surveillance study revealed that a significant percentage of contemporary S.aureus isolates from Greek patients have a vancomycin MIC (> 1 mg/L) that may compromise the clinical efficacy of the drug for the treatment of serious infections. The in vitro activity of SXT, rifampicin, mupirocin, linezolid, tigecycline, daptomycin and ceftaroline remains excellent.

Changing figures of antimicrobial susceptibility and serovar distribution in Neisseria gonorrhoeae isolated in Greece.

OBJECTIVES: To update surveillance data on antimicrobial susceptibility of Neisseria gonorrhoeae isolated in Greece with information for the years 2005 to 2008, and analyze changes occurred from the previous 4-year period. METHODS: Annual antimicrobial susceptibility rates, susceptibility patterns, and serovars of 635 gonococci isolated in 2005 to 2008 were determined and compared to respective data concerning the gonococcal sample of 2001 to 2004. Genetic similarity of the isolates in phenotypic clusters was investigated by pulsed field gel electrophoresis. Epidemiologic information was also considered. RESULTS: Despite a reduction in the isolation frequency of penicillinase-producing strains (3.9% vs. 11.6% in the previous period), the rates of resistance and intermediate susceptibility increased for penicillin, as well as for tetracycline, erythromycin, and chloramphenicol, leaving very small proportions of isolates sensitive to these agents (4.3%, 12.8%, 10.2%, and 3.6%, respectively). Resistance to fluoroquinolones increased from 11.3% in 2004 up to 63% in 2008, and strongly correlated with multidrug-resistant isolates of Bropyst serovar, accounting for 72.6% of the quinolone-resistant strains isolated during the last 4 years. All isolates were susceptible to spectinomycin and only 2 exceeded susceptibility breakpoints set for cefotaxime, exhibiting MICs 0.75 to 1 microg/mL. These latter isolates, however, belonged to a cluster of strains with decreased susceptibility to cephalosporins (CDS, cefotaxime MICs >or=0.25 microg/mL) that emerged in late 2006 and increased in frequency up to 20.7% through 2008. Notably, CDS isolates were also quinolone-resistant and multiresistant, further contributing to the increasing rates of quinolone and multidrug resistance in the Greek gonococcal sample. CONCLUSIONS: Antimicrobial susceptibility figures of Neisseria gonorrhoeae in Greece are worsening due to changes in the synthesis of gonococcal population, resulting from high endemicity rates of multidrug-resistant strains.

Antimicrobial susceptibility of Neisseria gonorrhoeae in Greece: data for the years 1994-2004.

OBJECTIVES: Surveillance data concerning antimicrobial susceptibilities of Neisseria gonorrhoeae isolated in Greece during the 11 year period 1994-2004 are presented. METHODS: Antimicrobial susceptibilities of all gonococcal isolates received by the Greek National Reference Center for N. gonorrhoeae during the study period were determined in terms of MICs using Etest. Trends in yearly isolation frequencies by susceptibility category were estimated for defining significant changes in overall susceptibility figures. RESULTS: Cefotaxime and spectinomycin retained undiminished activity against all isolates throughout the study period. High rates of resistance and intermediate susceptibilities were noticed for penicillin, tetracycline and erythromycin, and even for norfloxacin and ciprofloxacin. A substantial portion (16.5%) of the gonococcal samples consisted of multiresistant strains exhibiting resistance to two or more agents of different antibiotic classes. Although annual rates of low-level chromosomal resistance decreased, high-level resistance owing to the presence of penicillin- and tetracycline-resistance plasmids increased. Fluoroquinolone resistance also showed a significant increasing trend after 1996, reaching a peak rate of 11.3% in 2004. CONCLUSION: Third-generation cephalosporins and spectinomycin should be considered as first-choice drugs for the empirical treatment of gonorrhoea in Greece.