Antimicrobial susceptibility among bacterial isolates from ICU and non-ICU setting and different age groups: results from the tigecycline evaluation and Surveillance trial in North America.

As part of the tigecycline evaluation and Surveillance trial (t.e.S.t.), isolates were collected from centers in North America. In vitro activity was assessed for isolates collected in 2006 using ClSi guidelines and ClSi or FDA interpretive criteria. Data were analyzed according to intensive care unit (iCU) or non-iCU location and age group (18-64 years and > 65 years).Rates of mRSA in 2006 were higher among isolates from patients aged >65 years (52.0%) than younger patients (48.4%) and from non-iCU settings (48.0%) than from the iCU (45.3%). Rates of vancomycin-resistant E. faecium, multidrug-resistant Acinetobacter spp. (resistant to levofloxacin and amikacin as well as the carbapenems and/or third generation cephalosporins), and eSbl-producing K. pneumoniae among isolates collected from the iCU were 70.7%, 5.8%, and 16.6%, respectively.Tigecycline, linezolid and vancomycin were active against all isolates of S. aureus, including mRSA, from both settings and the two age groups. Among E. faecium, >95% of isolates were susceptible to linezolid, and tigecycline maintained MIC(90)s of 0.06-0.12 mg/l. Against Acinetobacter spp., the most active antimicrobials were tigecycline and minocycline irrespective of age group or patient setting (MIC(90)s 2 and 8 mg/l, respectively). Percentage susceptibility off K. pneumoniae was >90% against tigecycline, imipenem, meropenem, cefepime and amikacin for isolates from both age groups and settings. Against eSbl-producing K. pneumoniae, imipenem (88.9%-96.4%) and tigecycline (85.1%-100%) demonstrated the highest rates of activity. tigecycline demonstrated excellent activity against clinically relevant resistant organisms.

Comparative analysis of antimicrobial susceptibility among organisms from France, Germany, Italy, Spain and the UK as part of the tigecycline evaluation and surveillance trial.

As part of the tigecycline evaluation and surveillance trial (TEST), bacterial isolates were collected from 39 centres in France, Germany, Italy, Spain and the UK between January 2004 and August 2006. Antimicrobial susceptibilities were determined according to CLSI guidelines. Italy had the highest rate of methicillin-resistant Staphylococcus aureus (36.4%), and was the only country to report vancomycin-resistant Enterococcus faecalis (8.6%). Tigecycline was the only agent to which all Gram-positive isolates were susceptible. For many of the Gram-negative organisms collected, antimicrobial susceptibilities were lowest among isolates from Italy and highest among isolates from Spain. The notable exception was Acinetobacter baumannii, where the poorest susceptibility profile was among isolates from Spain. For A. baumannii, MIC(90)s of imipenem varied from 1 mg/L for isolates in France and Germany to > or =32 mg/L for isolates from Italy and Spain. Tigecycline was the only agent to maintain an MIC(90) of < or =1 mg/L against isolates from all five countries. The in-vitro activity of tigecycline against both Gram-positive and Gram-negative isolates may make it valuable in the treatment of hospital infections, including those caused by otherwise antimicrobial-resistant organisms.

Determining incidence of extended spectrum beta-lactamase producing Enterobacteriaceae, vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus in 38 centres from 17 countries: the PEARLS study 2001-2002.

The PEARLS study prospectively monitored selected nosocomial pathogens from 38 centres in 13 European, three Middle Eastern countries and South Africa during 2001-2002. Extended spectrum beta-lactamase (ESBL) production rates among Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp. were 5.4% (142/2609), 18.2% (401/2,206) and 8.8% (204/2,328), respectively, for all study sites. The overall ESBL production rate for the combined Enterobacteriaceae was 10.5% (747/7,143), highest in Egypt, 38.5%, and Greece, 27.4%, and lowest in The Netherlands, 2.0%, and Germany, 2.6%. IEF, PCR and DNA sequencing determined 10.7% false positives among Enterobacter spp. when using NCCLS guidelines to screen for ESBL production. The prevalence of nosocomial methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium was 32.4% (294/908) and 8.7% (83/949), respectively. PEARLS provides baseline data against which prospective changes in resistant determinants and outcomes can be measured in this ongoing study.

Comparison of sensititre broth microdilution and agar dilution susceptibility testing techniques for meropenem to determine accuracy, reproducibility, and predictive values.

The stability, accuracy, reproducibility, and predictive value of Sensititre MIC panels containing meropenem (Merrem) were evaluated by using National Committee for Clinical Laboratory Standards (NCCLS)-recommended American Type Culture Collection (ATCC) strains and 110 selected strains of rapidly growing and fastidious aerobes and anaerobes with various degrees of susceptibility to meropenem. The NCCLS-recommended agar dilution method was used as a standard reference method. Meropenem-containing Sensititre MIC panels were monitored for their stabilities at room temperature and reproducibilities over 24 months by using six ATCC strains. Ninety-nine percent of the MICs of both meropenem and imipenem obtained for NCCLS-recommended ATCC strains were within the established ranges after 2 years. The overall agreement (+/- 1 twofold dilution) between the Sensititre and the agar dilution meropenem MICs was greater than 93%. The predictive value of meropenem MICs for indicating suspeptibility or resistance obtained by the Sensititre method was greater than 90%. No major or very major interpretive errors were observed, and only 5% of meropenem MICs were associated with minor interpretive errors. Problematic organisms were not observed. The Sensititre MIC panels containing meropenem offer a convenient and valid alternative to the NCCLS reference method for the susceptibility testing of potential pathogens likely to be recovered from mixed infections.