Abstracts cont

2005 Clinical Microbiology and Infection  
Objectives: Tigecycline (TGC), a new glycylcycline antimicrobial in development has demonstrated excellent in vitro activity against Gram-positive and -negative pathogens. Recent reports suggest that TGC MIC values, against some organisms, may be elevated if broth used in microdilution panels is (>12 hours old (aged). The NCCLS has tentatively recommended that testing of TGC be performed in broth that is (<12 hours old (fresh). This study looks at the difference between panels using fresh
more » ... aged broth and broth with a biocatalytic oxygen-reducing agent (BORA) added to compensate for any potential broth differences. Materials and Methods: Testing was performed on approximately 120 organisms including: E. coli; K. pneumoniae; M. catarrhalis; S. epidermidis; and S. pneumoniae. The BORA used in this study is Oxyrase Ò for Broth at 2% concentration. TIG microdilution panels evaluated in this study include: panels and aged broth without oxyrase (Aged); panels and aged broth with oxyrase (AO); panels and fresh broth without oxyrase (Fresh); and panels and fresh broth with oxyrase (FO). Panels and aged broth were prepared by Microscan. Fresh broth was prepared internally. Each organism was tested on all four panel types. Quality controls were performed using NCCLS approved ATCC strains. Results: Combined test results showed an MIC correlation (with in 1 log2 dilution) as follows: 97.5% between Fresh/AO; 85.6% between Fresh/Aged; 94.3% between FO/AO; and 87.9% between FO/Aged. Quality controls ranges for FO, Fresh and AO were all in compliance, but Aged panels were out of range 29.3% of the time. Conclusion: The addition of a BORA to aged broth produced results equivalent to fresh broth without a BORA. Background: Glucose non-fermenting gram negative rods are known to be highly resistant in hospital settings and have always been a challenge for clinicians and hospital infection control. The degree or type of resistance may be due to several sophisticated mechanisms such as production of broad spectrum beta-lactamases, efflux pumps and altered membrane permeability, inactivating most classes of antimicrobials that are available for treatment (cephalosporins, carbapenems, aminoglycosides, fluoruquinolones). Tigecycline, a member of a new class of antimicrobials (glycylcyclines), has been shown to have potent expanded broad spectrum activity against most species of Enterobacteriaceae and selected species of non-fermenters, as well as Gram positives, atypicals and anaerobes. The TEST program determined the in vitro activity of tigecycline compared to amikacin, ampicillin, imipenem, cefepime, ceftazidime, ceftriaxone, levofloxacin, minocycline and piperacillin/tazobactam against members of Acinetobacter spp. and Pseudomonas aeruginosa collected from hospitals in North America, Europe and Asia. Methods: A total of 2513 non-fermenting clinical isolates were identified to the species level at each participating site and confirmed by the central laboratory. Isolates were collected throughout 2004. Minimum Inhibitory Concentration (MICs) were determined by the local laboratory using supplied broth microdilution panels and interpreted according to NCCLS guidelines. Results: The cephalosporins were ineffective towards A. baumannii (n = 424). Tigecycline showed the lowest MICs against A. baumannii with a MIC50/MIC90 of 0.5/2 mcg/ml, outperforming amikacin, 74.3% inhibition MIC50/MIC90 4/64, imipenem, 79.5% MIC50/MIC90 0.5/16, and minocycline, 85.4% MIC50/MIC90 1/8. Similar findings were found in other species of the Acinetobacter genus. Conclusion: The presented data suggest that tigecycline may be an effective and reliable therapeutic option against strains of Acinetobacter spp., including multi-drug resistant strains regardless of degree or type of resistance. Background: Resistance to glycopeptides in enterococci was first recognized in the late 1980s, and since then has been a major challenge to clinicians and infection control. Tigecycline, a member of a new class of antimicrobials (glycylcyclines), has been shown to have potent expanded broad spectrum activity against most commonly encountered species responsible for community and hospital acquired infections. The TEST program determined the in vitro activity of tigecycline compared to vancomycin, linezolid, ampicillin, imipenem, ceftriaxone, levofloxacin, minocycline, penicillin and piperacillin/tazobactam against members of Enterococcus spp. collected from hospitals in the USA. Methods: A total of 509 clinical isolates were identified to the species level at each participating site and confirmed by the central laboratory. Isolates were collected throughout 2004. Minimum Inhibitory Concentration (MICs) were determined by the local laboratory using broth microdilution panels and interpreted according to NCCLS guidelines. Background: Resistance to glycopeptides in enterococci was first recognized in the late 1980s, and since then has been a major challenge to clinicians and infection control. Tigecycline, a member of a new class of antimicrobials (glycylcyclines), has
doi:10.1111/j.1469-0691.2005.clm_1134_02.x fatcat:ao6lemnsubdebket2q3mmwgrta