Daptomycin In Vitro Susceptibility Methodology: a Review of Methods, Including Determination of Calcium in Testing Media

Koeth, Laura; Thorne, Grace M.

doi:10.1016/j.clinmicnews.2010.10.001

Cited by 8 publications

(10 citation statements)

References 25 publications

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“…A subsequent study demonstrated that DPT MICs are generally twofold to fourfold lower when tested in broth containing 50 µg mL -1 of calcium (Fuchs, Barry, Brown, 2000). Another more recent study also confirms the results obtained in previous studies, suggesting the important presence of calcium in susceptible assays using culture medium containing or supplemented with 50 µg mL -1 of calcium (Koeth, Thorne, 2010). Tests with and without calcium were performed by the two methods studied in order to verify the need for calcium in the microbiological assay.…”

Section: Calcium Concentrationsupporting

confidence: 76%

“…These results show the method's inability to detect differences in drug content, since only small changes were observed in the inhibition zones, in spite of the wide concentration range used. Similar responses are reported for other drugs with a high molecular weight, such as vancomycin, teicoplanin, and polymyxins and are attributed to their difficulty in diffusing in solid media (Koeth, Thorne, 2010). Considering these results, we gave up on the agar diffusion assay and started to develop the turbidimetric assay.…”

Section: Preliminary Studiesmentioning

confidence: 90%

“…The molecule is obtained from a strain of Streptomyces roseosporus and was originally known as LY 146032 (Debono et al, 1987;Eliopoulos et al, 1986). The action mechanism is physiologic calcium dependent and possibly involves the disruption of amino acid transport by the cell membrane and changes in the cytoplasmic membrane potential (Debono et al, 1987;Koeth, Thorne, 2010;Lu et al, 2011). Some LC methods have been reported in the literature in order to determine DPT in some biological fluids, such as serum (Deryke et al, 2006;Rybak et al, 1992;Tobin et al, 2008), blood (Gikas et al, 2009;Olszowy et al, 2010), and plasma (Baietto et al, 2010;Dvorchik et al, 2003;Martens-Lobenhofer et al, 2008;Verdier et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…The focus of this study is DPT (Figure 1), which is a cyclic lipopeptide with activity limited to gram-positive bacteria, such as Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pneumoneae, including multidrug-resistant and susceptible strains (Koeth, Thorne, 2010;Lu et al, 2011;Steenbergen et al, 2005). The molecule is obtained from a strain of Streptomyces roseosporus and was originally known as LY 146032 (Debono et al, 1987;Eliopoulos et al, 1986).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A fully validated microbiological assay for daptomycin injection and comparison to HPLC method

Christ

Machado

Ribas

et al. 2015

Braz. J. Pharm. Sci.

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Daptomycin (DPT) was the first lipopeptide antibiotic available for commercialization. It is active against gram-positive bacteria, including resistant strains. This work aimed to develop and validate a turbidimetric microbiologic assay to determine daptomycin in an injectable form. A 3x3 design was employed, at concentrations of 1, 2 and 4.0 µg/mL. The microorganism test used was Staphylococcus aureus ATCC 6538p, and Antibiotic Medium 3 was used as the culture medium. Method validation demonstrated that the bioassay was linear (r=0.9995), precise (RSD=2.58%), accurate (recovery 100.48± 2.11%), and robust. Degradation kinetics was also performed in an alkaline medium, indicating that daptomycin degradation follows first order kinetics under these conditions. The analyses of degraded solutions showed that daptomycin degradation products do not possess bactericidal activity. The bioassay was compared to HPLC method that was previously developed and no significant difference was found between them (p>0.05). The method proved to be appropriate for daptomycin injection quality control.Uniterms: Daptomycin/determination. Daptomycin injection/quality control. Turbidimetric microbiological assay/quantitative analysis.A daptomicina (DPT) é o primeiro lipopeptídeo cíclico disponível para comercialização. Possui atividade frente a bactérias gram-positivas, incluindo cepas resistentes. O objetivo deste trabalho foi desenvolver e validar um ensaio microbiológico turbidimétrico para quantificar a daptomicina na forma injetável. Empregou-se delineamento 3x3, nas concentrações de 1,0; 2,0 e 4,0 µg/mL. Como micro-organismo teste foi usado Staphylococcus aureus ATCC 6538p, e Meio para Antibióticos nº 3 foi empregado como meio de cultura. A validação do método demonstrou que o ensaio foi linear (r=0,9995), preciso (RSD=2,55%), exato (recuperação de 100,48 ± 2,11%) e robusto. A cinética de degradação em meio alcalino foi avaliada, indicando que a daptomicina segue cinética de primeira ordem nessa condição. A análise das soluções degradadas mostrou que os produtos de degradação da daptomicina não possuem atividade antimicrobiana. O bioensaio foi comparado com o método por CLAE previamente desenvolvido e não houve diferença significativa entre ambos (p<0,05). O método mostrou-se apropriado para o controle de qualidade da daptomicina injetável.Unitermos: Daptomicina/determinação. Daptomicina injetável/controle de qualidade. Ensaio microbiológico turbidimétrico/análise quantitativa.

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Section: Calcium Concentrationsupporting

confidence: 76%

Section: Preliminary Studiesmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A fully validated microbiological assay for daptomycin injection and comparison to HPLC method

Christ

Machado

Ribas

et al. 2015

Braz. J. Pharm. Sci.

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“…Optimal performance of broth microdilution (BMD) methods is achieved by supplementing Mueller-Hinton broth with calcium chloride salt to a final concentration of 50 mg/liter Ca 2ϩ (70), which must be confirmed prior to use of each lot of prepared medium by atomic absorption or a similar method. The addition of lysed horse blood or pyridoxal, supplements used for testing fastidious bacteria, does not appear to affect the calcium concentration or daptomycin MICs (179). In contrast, the control of calcium content in agar-based media is more problematic.…”

Section: Susceptibility Testing Broth Microdilution Disk Diffusion mentioning

confidence: 99%

A Current Perspective on Daptomycin for the Clinical Microbiologist

2013

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SUMMARY Daptomycin is a lipopeptide antimicrobial with in vitro bactericidal activity against Gram-positive bacteria that was first approved for clinical use in 2004 in the United States. Since this time, significant data have emerged regarding the use of daptomycin for the treatment of serious infections, such as bacteremia and endocarditis, caused by Gram-positive pathogens. However, there are also increasing reports of daptomycin nonsusceptibility, in Staphylococcus aureus and, in particular, Enterococcus faecium and Enterococcus faecalis . Such nonsusceptibility is largely in the context of prolonged treatment courses and infections with high bacterial burdens, but it may occur in the absence of prior daptomycin exposure. Nonsusceptibility in both S. aureus and Enterococcus is mediated by adaptations to cell wall homeostasis and membrane phospholipid metabolism. This review summarizes the data on daptomycin, including daptomycin's unique mode of action and spectrum of activity and mechanisms for nonsusceptibility in key pathogens, including S. aureus , E. faecium , and E. faecalis . The challenges faced by the clinical laboratory in obtaining accurate susceptibility results and reporting daptomycin MICs are also discussed.

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Daptomycin Etest MICs for methicillin-resistant Staphylococcus aureus vary among different media

Nakashima

Takahashi

Kameko

et al. 2012

Journal of Infection and Chemotherapy

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Daptomycin In Vitro Susceptibility Methodology: a Review of Methods, Including Determination of Calcium in Testing Media

Cited by 8 publications

References 25 publications

A fully validated microbiological assay for daptomycin injection and comparison to HPLC method

A fully validated microbiological assay for daptomycin injection and comparison to HPLC method

A Current Perspective on Daptomycin for the Clinical Microbiologist

Daptomycin Etest MICs for methicillin-resistant Staphylococcus aureus vary among different media

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