Newly defined in vitro quality control ranges for oritavancin broth microdilution testing and impact of variation in testing parameters

Arhin, Francis F.; Tomfohrde, K. M.; Draghi, Deborah C.; Aranza, M.K.; Parr, Thomas; Sahm, Daniel F.; Moeck, Greg

doi:10.1016/j.diagmicrobio.2008.05.009

Cited by 13 publications

(12 citation statements)

References 5 publications

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“…Subsequent investigations for oritavancin (another lipoglycopeptide) demonstrated that the addition of P-80 to MIC testing broth was also necessary for test performance reliability via minimizing the drug binding to plastic 96-well panels (5), similar to dalbavancin. The antimicrobial susceptibility testing for these lipoglycopeptide agents was revised (6,7), and updated quality control (QC) ranges for dalbavancin and oritavancin were established and published by the Clinical and Laboratory Standards Institute (CLSI), in M100-S24 and previous documents (8). Surfactants, such as P-80, act as wetting agents and are commonly used in commercially prepared antimicrobial agent susceptibility testing panels or as part of the inoculum for broth microdilution assays to aid in the homogenous dispersal of reagents or to ensure their quantitative recovery from solution (4,5).…”

mentioning

confidence: 99%

Revised Reference Broth Microdilution Method for Testing Telavancin: Effect on MIC Results and Correlation with Other Testing Methodologies

Farrell

Mendes

Rhomberg

et al. 2014

Antimicrob Agents Chemother

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The reference broth microdilution (BMD) antimicrobial susceptibility testing method for telavancin was revised to include dimethyl sulfoxide (DMSO) as a solvent and diluent for frozen-form panel preparation, following the CLSI recommendations for water-insoluble agents. Polysorbate 80 (P-80) was also added to the test medium to minimize proven drug losses associated with binding to plastic surfaces. Four hundred sixty-two Gram-positive isolates, including a challenge set of organisms with reduced susceptibilities to comparator agents, were selected and tested using the revised method for telavancin, and the MIC results were compared with those tested by the previously established method and several Sensititre dry-form BMD panel formulations. The revised method provided MIC results 2-to 8-fold lower than the previous method when tested against staphylococci and enterococci, resulting in MIC 50 values of 0.03 to 0.06 g/ml for staphylococci and 0.03 and 0.12 g/ml for Enterococcus faecium and Enterococcus faecalis, respectively. Less-significant MIC decreases (1 to 2 log 2 dilution steps) were observed when testing streptococci in broth supplemented with blood, which showed similar MIC 50 values for both methods. However, Streptococcus pneumoniae had MIC 50 results of 0.008 and 0.03 g/ml when tested by the revised and previous methods, respectively. Highest essential agreement rates (>94.0%) were noted for one candidate dry-form panel formulation compared to the revised test. The revised BMD method provides lower MIC results for telavancin, especially when tested against staphylococci and enterococci. This is secondary to the use of DMSO for panel production and the presence of P-80, which ensure the proper telavancin testing concentration and result in a more accurate MIC determination. Moreover, earlier studies where the previous method was applied underestimated the in vitro drug potency.T elavancin is a lipoglycopeptide antibiotic with potent in vitro bactericidal activity when tested against Gram-positive bacteria, including methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), vancomycin-intermediate S. aureus (VISA), heterogeneous VISA (hVISA), and multidrug-resistant (MDR) streptococci and enterococci (1, 2). Telavancin is approved in the United States and Canada for the treatment of patients with complicated skin and skin structure infections due to susceptible Gram-positive pathogens and in the United States and Europe for the treatment of hospital-acquired bacterial pneumonia, including ventilator-associated bacterial pneumonia (HABP/VABP) due to susceptible isolates of S. aureus (MRSA strains only in Europe), when alternative medicines are unsuitable (3).During the development of dalbavancin, also a lipoglycopeptide, the use of polysorbate 80 (P-80) (0.002%, final testing concentration) was shown to be essential for accurate MIC susceptibility testing determinations (4). Subsequent investigations for oritavancin (another lipoglycopeptide) demonstrated that the addi...

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mentioning

confidence: 99%

Revised Reference Broth Microdilution Method for Testing Telavancin: Effect on MIC Results and Correlation with Other Testing Methodologies

Farrell

Mendes

Rhomberg

et al. 2014

Antimicrob Agents Chemother

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“…The present lack of in vitro susceptibility testing devices for oritavancin, owing to suboptimal disk/agar diffusion tests, is compounded by projected delays in availability of automated antimicrobial susceptibility testing devices containing oritavancin. These limitations can be initially overcome by the application of a validated surrogate susceptibility marker testing strategy (7,8,12,13), as demonstrated here with vancomycin. To this end, oritavancin susceptibility could be inferred with a high degree of confidence when the tested strain is vancomycin susceptible based on the currently utilized laboratory susceptibility testing method and when both peptides are influenced by common resistance mechanisms.…”

Section: Resultsmentioning

confidence: 99%

“…Initial global surveillance study results (11) across 12 countries demonstrated potent oritavancin activity in vitro against staphylococci (including methicillin-resistant Staphylococcus aureus strains [MRSA]), Streptococcus pneumoniae, and enterococci (including vancomycin-resistant enterococci [VRE]), a level of activity clarified by the subsequent understanding that a surfactant (polysorbate 80) was required in testing media for accurate MIC determinations in the plastic trays used for the broth microdilution MIC method (12,13). Furthermore, the concentration-dependent bactericidal activity of oritavancin is based on the two sites of oritavancin action (the cell wall and membrane) and has led to pharmacokinetic/pharmacodynamic (PK/PD) investigations suggesting an optimal single 1,200-mg dosing regimen for acute bacterial skin and skin structure infections (ABSSSI) (14)(15)(16)(17).…”

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confidence: 99%

Use of In Vitro Vancomycin Testing Results To Predict Susceptibility to Oritavancin, a New Long-Acting Lipoglycopeptide

Jones

Turnidge

Moeck³

et al. 2015

Antimicrob Agents Chemother

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Oritavancin is a recently approved lipoglycopeptide antimicrobial agent with activity against Gram-positive pathogens. Its extended serum elimination half-life and concentration-dependent killing enable single-dose treatment of acute bacterial skin and skin structure infections. At the time of regulatory approval, new agents, including oritavancin, are not offered in the most widely used susceptibility testing devices and therefore may require application of surrogate testing using a related antimicrobial to infer susceptibility. To evaluate vancomycin as a predictive susceptibility marker for oritavancin, 26,993 recent Gram-positive organisms from U.S. and European hospitals were tested using reference MIC methods. Organisms included Staphylococcus aureus, coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci (BHS), viridans group streptococci (VGS), and enterococci (ENT). These five major pathogen groups were analyzed by comparing results with FDA-approved susceptible breakpoints for both drugs, as well as those suggested by epidemiological cutoff values and supported by pharmacokinetic/ pharmacodynamic analyses. Vancomycin susceptibility was highly accurate (98.1 to 100.0%) as a surrogate for oritavancin susceptibility among the indicated pathogen species. Furthermore, direct MIC comparisons showed high oritavancin potencies, with vancomycin/oritavancin MIC 90 results of 1/0.06, 2/0.06, 0.5/0.12,1/0.06, and >16/0.06 g/ml for S. aureus, CoNS, BHS, VGS, and ENT, respectively. In conclusion, vancomycin demonstrated acceptable accuracy as a surrogate marker for predicting oritavancin susceptibility when tested against the indicated pathogens. In contrast, 93.3% of vancomycin-nonsusceptible enterococci had oritavancin MIC values of <0.12 g/ml, indicating a poor predictive value of vancomycin for oritavancin resistance against these organisms. Until commercial oritavancin susceptibility testing devices are readily available, isolates that when tested show vancomycin susceptibility can be inferred to be susceptible to oritavancin by using FDA-approved breakpoints. N ewly approved (by the U.S. Food and Drug Administration [FDA] or European Medicines Agency [EMA]) antimicrobial agents rarely have validated commercial susceptibility testing products/systems available at the time of commercialization. In fact, the recent histories of such products demonstrate delays of years, even for those drugs possessing qualities that would favorably impact patient care. To support susceptibility assessments of these approved antimicrobial agents for treatment of indicated infections, clinical microbiology laboratories have resorted to "surrogate" susceptibility testing of a similar (class representative) currently tested agent to predict susceptibility of organisms to the new antimicrobial agent (1-6). This option has been successfully applied to several antimicrobial classes since the first standardization of susceptibility testing methods (7,8).Oritavancin, formerly LY333328 (9, 10), is a recently approved lipogly...

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“…34 This included incubation time, frozen panel storage, pH and inoculum size. Incubation in carbon dioxide as well as the presence of calcium ions were also evaluated.…”

Section: -33mentioning

confidence: 99%

“…In contrast, such changes increased MICs against S .aureus by up to 2 twofold dilutions. 34 Because oritavancin is highly protein-bound (80%), albumin is another factor that must be considered. 35 When tested in bovine serum albumin, oritavancin showed reduced activity (99.9% verses 5% killing of S. aureus with oritavancin for control and bovine serum albumin media, respectively) as well as a shorter post-antibiotic effect (65 minutes vs 5 minutes, respectively).…”

Section: -33mentioning

confidence: 99%

Emerging Treatment Options for Complicated Skin and Skin Structure Infections: Oritavancin

Townsend

Wilson

Pound

et al. 2010

Clinical Medicine Insights: Therapeutics

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Abstract:Oritavancin is a semisynthetic lipoglycopeptide with in vitro activity against a variety of aerobic Gram-positive pathogens (including drug-resistant forms of staphylococci, streptococci, and enterococci) and select anaerobic organisms. Available published clinical efficacy and safety studies in humans to date focus primarily in the treatment of complicated skin and skin structure infections. While oritavancin doses in these studies varied, single daily doses of 200 mg (300 mg in patients 100 kg) for 3-7 days have demonstrated efficacy similar to comparators (such as vancomycin followed by cephalexin). The most frequent adverse events reported to date include gastrointestinal complaints, insomnia, dizziness, itching, and rash. Further safety and efficacy data are needed to better define its potential place in therapy.

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Newly defined in vitro quality control ranges for oritavancin broth microdilution testing and impact of variation in testing parameters

Cited by 13 publications

References 5 publications

Revised Reference Broth Microdilution Method for Testing Telavancin: Effect on MIC Results and Correlation with Other Testing Methodologies

Revised Reference Broth Microdilution Method for Testing Telavancin: Effect on MIC Results and Correlation with Other Testing Methodologies

Use of In Vitro Vancomycin Testing Results To Predict Susceptibility to Oritavancin, a New Long-Acting Lipoglycopeptide

Emerging Treatment Options for Complicated Skin and Skin Structure Infections: Oritavancin

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