背景:以前的研究表明,非达霉素,一种大环内酯类抗生素,用于治疗复发性艰难梭菌相关性腹泻,还对分离自人的产气荚膜梭菌菌株显示出有效的体外杀菌活性。然而,到目前为止,没有关于动物来源的产气荚膜梭菌菌株对非达霉素的敏感性的数据。另一方面,尽管联合疗法在人类和兽医学中变得流行,关于抗生素组合对产气荚膜梭菌的影响的数据有限。我们研究了从狗和猫获得的21产气荚膜杆菌菌株对非达霉素和非达霉素与六种其他抗生素的组合的体外反应。
结果:用琼脂稀释法测试时,非达霉素最低抑制浓度(MIC)在0.004和0.032µg/ml之间。此外,以Etest为基础的组合试验结果表明,将非达霉素以相当于MIC一半的浓度掺入试验培养基中,显著增加了71.4%和61.9%菌株对甲硝唑和红霉素的敏感性,分别,以及对克林霉素的易感性,亚胺培南,左氧氟沙星,和万古霉素在42.9-52.4%的菌株中。相比之下,?×MIC浓度的非达霉素对左氧氟沙星和万古霉素MIC没有任何影响,仅增强了克林霉素的作用,红霉素,亚胺培南,和甲硝唑在≤23.8%的被测菌株中。
结论:本研究的结果表明,非达霉素对犬科动物和猫科动物来源的产气荚膜梭菌菌株高度有效。尽管非达霉素目前被认为是一种至关重要的抗菌药物,但尚未获得兽医使用许可,我们认为,本文报道的结果提供了有用的基线数据,以追踪产气荚膜梭菌非达霉素耐药菌株在兽医环境中的可能出现。
BACKGROUND: Previous studies have demonstrated that fidaxomicin, a macrocyclic lactone antibiotic used to treat recurrent Clostridioides difficile-associated diarrhea, also displays potent in vitro bactericidal activity against Clostridium perfringens strains isolated from humans. However, to date, there is no data on the susceptibility to fidaxomicin of C. perfringens strains of animal origin. On the other hand, although combination therapy has become popular in human and veterinary medicine, limited data are available on the effects of antibiotic combinations on C. perfringens. We studied the in vitro response of 21 C. perfringens strains obtained from dogs and cats to fidaxomicin and combinations of fidaxomicin with six other antibiotics.
RESULTS: When tested by an agar dilution method, fidaxomicin minimum inhibitory concentrations (MICs) ranged between 0.004 and 0.032 µg/ml. Moreover, the results of Etest-based combination assays revealed that the incorporation of fidaxomicin into the test medium at a concentration equivalent to half the MIC significantly increased the susceptibility of isolates to metronidazole and erythromycin in 71.4% and 61.9% of the strains, respectively, and the susceptibility to clindamycin, imipenem, levofloxacin, and vancomycin in 42.9-52.4% of the strains. In contrast, ¼ × MIC concentrations of fidaxomicin did not have any effect on levofloxacin and vancomycin MICs and only enhanced the effects of clindamycin, erythromycin, imipenem, and metronidazole in ≤ 23.8% of the tested strains.
CONCLUSIONS: The results of this study demonstrate that fidaxomicin is highly effective against C. perfringens strains of canine and feline origin. Although fidaxomicin is currently considered a critically important antimicrobial that has not yet been licensed for veterinary use, we consider that the results reported in this paper provide useful baseline data to track the possible emergence of fidaxomicin resistant strains of C. perfringens in the veterinary setting.