In vitro activity of the orally bioavailable ceftibuten/VNRX-7145 (VNRX-5236 etzadroxil) combination against a challenge set of Enterobacterales pathogens carrying molecularly characterized β-lactamase genes.

Objectives: This study assessed the activity of ceftibuten, ceftibuten combined with the active form (VNRX-5236) of the β-lactamase inhibitor VNRX-7145 and comparators against a challenge set of Gram-negative pathogens.

Methods: Two hundred and five Enterobacterales carrying plasmid AmpC (53 isolates), ESBL (50), KPC (50), OXA-48-like (49) or OXA-48-like with KPC (3) encoding genes were selected. Susceptibility was determined by broth microdilution.

Activity of fosfomycin when tested against US contemporary bacterial isolates.

Fosfomycin and comparators were susceptibility tested against over 2200 contemporary clinical isolates from US medical centers. Fosfomycin was active against Enterobacterales (MIC, 4/16 μg/mL), including multidrug-resistant isolates. Potent activity was exhibited against gram-positive organisms, including Staphylococcus aureus (MIC, 4/8 μg/mL).

Performance of BD Max StaphSR for Screening of Methicillin-Resistant Staphylococcus aureus Isolates among a Contemporary and Diverse Collection from 146 Institutions Located in Nine U.S. Census Regions: Prevalence of mecA Dropout Mutants.

This study determined the performance of BD Max StaphSR and the rate of methicillin-resistant Staphylococcus aureus (MRSA) with an unrecognized staphylococcal cassette chromosome mec (SCCmec) right-extremity junction (MREJ) region among 907 methicillin-resistant S. aureus (MRSA) and 900 methicillin-susceptible S. aureus (MSSA) isolates.

More potency assay results for generic non-USA lots of piperacillin/tazobactam and initial reports for generic meropenem compounds marketed in the USA.

An ongoing program of international generic antimicrobial potency assays for piperacillin/tazobactam has been summarized here through December 2010, and the initial results for meropenem generic lots from the United States are also presented. Fifteen additional piperacillin/tazobactam generic lots revealed an average of -10% activity (range, +3 to -23%) compared to the branded product (Zosyn®; Wyeth-Pfizer), a finding consistent with prior reports (46 lots) of -16%. In contrast, meropenem branded and generic products had equivalent assay results (5 generic lots from 2 manufacturers [Hospira and Sandoz]).

Comparative potencies of contemporary generic vancomycin lot: in vitro assay results from nine products and a reference reagent-grade sample.

Numerous studies of generic vancomycin (GV) lots have emerged since the 1980s, casting some doubt on product quality. Publications question the in vivo activity, even when concurrent in vitro and chemical assays meet regulatory guidelines. This study assessed contemporary GV lots by an in vitro assay capable of measuring small variations from target-benchmark (BM) activity.

Fusidic acid resistance rates and prevalence of resistance mechanisms among Staphylococcus spp. isolated in North America and Australia, 2007-2008.

Among 4,167 Staphylococcus aureus and 790 coagulase-negative Staphylococcus (CoNS; not S. saprophyticus) isolates collected consecutively from North American and Australian hospitals, only 87 (1.7% overall) isolates displayed a fusidic acid (FA; also known as CEM-102) MIC of > or = 2 microg/ml (FA resistance).

Occurrence and molecular characterization of fusidic acid resistance mechanisms among Staphylococcus spp. from European countries (2008).

Objectives: To determine fusidic acid resistance rates (MICs of > or = 2 mg/L) and the prevalence of fusidic acid resistance mechanisms among Staphylococcus spp. collected from European countries (2008).

Methods: Staphylococcal isolates (3134) collected from Europe were tested by CLSI broth microdilution.

Expanded studies of piperacillin/tazobactam formulations: variations among branded product lots and assessment of 46 generic lots.

The experience with analyzing the potency of piperacillin/tazobactam generic formulations by a precise multiorganism in vitro assay was expanded to 46 lots (29 manufacturers, 17 countries). Across all generic lots, the range of activity compared with a reference branded lot (RLOT; Zosyn; Wyeth Pharmaceuticals, Philadelphia, PA) was +10% to -42% (average, -16%). Eight lots of Zosyn were also tested with a range of +7 to -19 (average, only -6%), and the reproducibility (13 replicates) of the RLOT assay was confirmed (+/-3%).

Daptomycin antimicrobial activity tested against methicillin-resistant staphylococci and vancomycin-resistant enterococci isolated in European medical centers (2005).

Background: Daptomycin is a cyclic lipopeptide with potent activity and broad spectrum against Gram-positive bacteria currently used for the treatment of complicated skin and skin structure infections and bacteremia, including right sided endocarditis. We evaluated the in vitro activity of this compound and selected comparator agents tested against clinical strains of staphylococci and enterococci collected in European medical centers in 2005.

Methods: A total of 4,640 strains from 23 medical centers located in 10 European countries, Turkey and Israel (SENTRY Program platform) were tested for susceptibility by reference broth microdilution methods according to Clinical and Laboratory Standards Institute guidelines and interpretative criteria.

Antimicrobial activity of a novel peptide deformylase inhibitor, LBM415, tested against respiratory tract and cutaneous infection pathogens: a global surveillance report (2003-2004).

Objectives: To evaluate the spectrum of activity and potency of LBM415, the first of the peptide deformylase inhibitor (PDFI) class to be developed for treatment of community-acquired respiratory tract infections and uncomplicated skin and soft tissue infections (uSSTI), against a large, contemporary international collection of targeted pathogens collected during 2003-2004.

Methods: A total of 21,636 isolates were tested by reference broth microdilution methods as part of a longitudinal international antimicrobial resistance surveillance study. Characteristics of the organism collection included resistance to oxacillin among 35.