ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
·
2020
·Vol. 64
·期 3
·
IF 4.904
Zhiwei Lin,Zhangya Pu,Guangjian Xu,Bing Bai,Zhong Chen,Xiang Sun,Jinxin Zheng,Peiyu Li,Di Qu,Qiwen Deng,Zhijian Yu
This study aimed to evaluate the in vitro antimicrobial activity, heteroresistance emergence, and resistance mechanism of omadacycline (OMC) in clinical Enterococcus faecalis isolates from China. A total of 276 isolates were collected retrospectively in China from 2011 to 2015. The MICs of OMC, doxycycline (DOX), and minocycline (MIN) against E. faecalis were determined by broth microdilution. Tetracycline (TET)-specific resistance genes and multilocus sequence typing (MLST) of the isolates were investigated using PCR. The detection frequency of OMC heteroresistance in E. faecalis was evaluated with population analysis profiling (PAP). The mechanism of OMC heteroresistance and resistance in E. faecalis was examined by amplifying 30S ribosomal subunit genes, RNA sequencing (RNA-Seq), and in vitro recombination experiments. The OMC MICs of clinical E. faecalis isolates ranged from ≤0.06 to 1.0 mg/liter, and 42% of the E. faecalis isolates with an OMC MIC of 1.0 mg/liter were found to be sequence type 16 (ST16). Six OMC-heteroresistant isolates with MIC values of ≤0.5 mg/liter were detected among 238 E. faecalis isolates. The resistant subpopulations of heteroresistant isolates showed OMC MICs in the range of 2 to 4 mg/liter and were found without 30S ribosomal subunit gene mutations. Moreover, RNA sequencing and in vitro recombination experiments demonstrated that overexpression of a bone morphogenetic protein (BMP) family ATP-binding cassette (ABC) transporter substrate-binding protein, OG1RF_RS00630, facilitated OMC heteroresistance in E. faecalis. In conclusion, OMC exhibited better activity against clinical E. faecalis isolates from China than that of DOX or MIN, and overexpression of OG1RF_RS00630 in E. faecalis facilitated the development of OMC heteroresistance.
研究领域:
微生物学
·
感染病学
·
药理学
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DOI
PubMed
高影响因子
Computational Intelligence and Neuroscience
·
2022
·
IF 3.12
Guiqiu Li,Ying Wei,Yan Guo,Hui Gong,Jie Lian,Guangjian Xu,Bing Bai,Zhijian Yu,Qiwen Deng
This study aimed to evaluate the activity, resistance, clonality of MIC distribution, and the correlation between virulence and resistance genes and biofilm formation of omadacycline (OMC) in clinics for Streptococcus agalactiae isolates from China. 162 isolates were collected retrospectively in China. The S. agalactiae were collected from the body’s cervical secretions, wound secretions, ear swabs, secretions, semen, venous blood, cerebrospinal fluid, pee, etc. The MIC of OMC against S. agalactiae was determined by broth microdilution. The inhibition zone diameters of OMC and other common antibiotics were measured using filter paper. D-test was performed to determine the phenotype of cross resistance between erythromycin and clindamycin. In Multilocus sequence typing (MLST), some commonly-detected resistance genes and virulence gene of these S. agalactiae isolates were investigated using polymerase chain reaction (PCR). Biofilms were detected by crystal violet staining. Our data demonstrated the correalation of the biofilm formation and OMA antimicrobial susceptibility of S.agalactiae clinical isolates with the carrier of virulence gene scpB. Conclusively, OMC exhibits the robust antimcirobial activity against clinical S. agalactiae isolates from China compared with DOX or MIN, and the carrier of the virulence gene scpB might correlate with the biofilm formation in OMC-resistant S. agalactiae.
研究领域:
微生物学
·
感染病学
·
临床医学
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产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2025
·Vol. 15
·期 1
·1-8
·
IF 3.9
Wang Yueyuan,Diao Zhipeng,Qu Yuchen,Fan Kai,Feng Chen,Lv Bo,Yu Yunli,Geng Zhou
Omadacycline, a third-generation tetracycline antibiotic, exhibits time-dependent pharmacokinetics. The ratio of the 24-hour area under the concentration-time curve to minimum inhibitory concentration (AUC 0−24 /MIC) serves as the primary pharmacokinetic/pharmacodynamic (PK/PD) index for omadacycline, demonstrating strong correlation with therapeutic efficacy, particularly in critically ill patient populations. To facilitate routine therapeutic drug monitoring (TDM) in clinical practice, a high-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) method was developed for quantification of omadacycline in human plasma. An Agilent 1260 series liquid chromatograph and an API 4000 triple tandem quadrupole mass spectrometer were used for the determination of omadacycline and endocannabinoids. The separation was performed on a Phenomenex KINETEX XB-C18 column (2.6 μm, 3 × 50 mm) with 0.1% formic acid-water and pure acetonitrile as the mobile phases. The LC-MS/MS separation was carried out using a gradient elution procedure at a flow rate of 0.4 mL/ min, and the total run time was 5 min. An electrospray ionization (ESI) was selected, and the detection ions of omadacycline and the internal standard (fexofenadine-d6) were determined by mass spectrometry scanning with multiple reaction monitoring (MRM) in positive ion mode as follows: m/z 557.4→453.4 and m/z 508.4→472.8, respectively. The established linear range (20-2000 ng/mL) effectively covers the plasma concentration range encountered in > 98% of clinical samples, making it suitable for routine therapeutic drug monitoring. The method demonstrated acceptable selectivity, recovery, and matrix effect. The results of intra-day precision and inter-day precision show that the relative standard deviation (RSD) is less than 10%, while the relative error (RE) is within ± 10.00%. In this study, we developed and validated a simple, sensitive and accurate method to quantify the concentration of omadacycline in human plasma using LC-MS/MS. This offers essential technical support for the rational clinical application of omadacycline.
研究领域:
药理学
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分析化学
·
临床药理学
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质谱分析
·
治疗药物监测
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DOI
PubMed
高影响因子
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