André Camille, Wu Kelvin J Y, Myers Andrew G, Bispo Paulo J M
Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston MA, USA.
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
J Glob Antimicrob Resist. 2024 Dec;39:144-148. doi: 10.1016/j.jgar.2024.09.001. Epub 2024 Sep 16.
Antimicrobial resistance is a global pandemic that poses a major threat to vision health as ocular bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), are becoming increasingly resistant to first-line therapies. Here we evaluated the antimicrobial activity of new synthetic lincosamides in comparison to currently used antibiotics against clinical ocular MRSA isolates.
Antimicrobial susceptibility testing was performed by broth microdilution for two novel synthetic lincosamides (iboxamycin and cresomycin) and eight comparator antibiotics against a collection of 50 genomically characterised ocular MRSA isolates, including isolates harbouring erm genes (n = 25).
Both drugs were active against widespread MRSA clonal complexes CC8 and CC5. The MIC and MIC of iboxamycin were 0.06 and 2 mg/L, respectively. Cresomycin (MIC = 0.06 mg/L) also displayed good activity with an in vitro potency four-fold higher (MIC = 0.5 mg/L) than iboxamycin. In isolates harbouring erm genes, MIC were >16, 2, and 0.5 mg/L for clindamycin, iboxamycin, and cresomycin, respectively. The in vitro potencies of iboxamycin and cresomycin were similar or higher than that of comparator agents and were not impacted by multidrug-resistance phenotypes or by the presence of erm genes when compared with clindamycin.
Our results demonstrate that iboxamycin and cresomycin display potent in vitro activity against ocular MRSA isolates, including multidrug-resistant isolates harbouring erm genes.
抗菌药物耐药性是一场全球大流行，对视力健康构成重大威胁，因为眼部细菌，尤其是耐甲氧西林金黄色葡萄球菌（MRSA），对一线治疗的耐药性越来越强。在此，我们评估了新型合成林可酰胺类药物与目前使用的抗生素相比，对临床眼部MRSA分离株的抗菌活性。
采用肉汤微量稀释法，对两种新型合成林可酰胺类药物（伊博霉素和克雷索霉素）和八种对照抗生素进行抗菌药敏试验，受试菌株为50株经基因组特征分析的眼部MRSA分离株，包括携带erm基因的分离株（n = 25）。
两种药物对广泛流行的MRSA克隆复合体CC8和CC5均有活性。伊博霉素的MIC和MIC分别为0.06和2 mg/L。克雷索霉素（MIC = 0.06 mg/L）也表现出良好的活性，其体外效力比伊博霉素高四倍（MIC = 0.5 mg/L）。在携带erm基因的分离株中，克林霉素、伊博霉素和克雷索霉素的MIC分别>16、2和0.5 mg/L。与克林霉素相比，伊博霉素和克雷索霉素的体外效力与对照药物相似或更高，且不受多重耐药表型或erm基因存在的影响。
我们的结果表明，伊博霉素和克雷索霉素对眼部MRSA分离株，包括携带erm基因的多重耐药分离株，具有强大的体外活性。
