Cercenado Emilia, Loras Cristina, Cobos Alejandro, Sanz Juan Carlos
Servicio de Microbiología y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Departamento de Medicina, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Laboratorio de Microbiología, Hospital Santa Bárbara, Puertollano (Ciudad Real), Spain.
Enferm Infecc Microbiol Clin (Engl Ed). 2020 Nov 12. doi: 10.1016/j.eimc.2020.09.016.
We report the activity of delafloxacin, a new fluoroquinolone with high affinity for both topoisomerase IV and DNA gyrase, against highly-levofloxacin-resistant invasive strains of Streptococcus pneumoniae.
A total of 173 highly-levofloxacin-resistant (MIC>32mg/L) S. pneumoniae invasive isolates were studied. The strains were isolated from blood (n=162) and other sterile fluids (n=11). Serotyping was performed by the Pneumotest-Latex and Quellung reaction. Delafloxacin, levofloxacin, penicillin, cefotaxime, erythromycin and vancomycin MICs were determined by the gradient diffusion method following EUCAST guidelines and breakpoints.
Among the isolates, 32.9% were penicillin non-susceptible, 19.7% cefotaxime non-susceptible, and 76.9% erythromycin resistant. All were susceptible to vancomycin. Delafloxacin MIC and MIC (mg/L) values were 0.064 and 0.12, respectively; 60% (15/25) of serotype 9V isolates showed delafloxacin MICs≥0.12mg/L.
Delafloxacin was very active against highly-levofloxacin-resistant invasive isolates of S. pneumoniae. Isolates belonging to serotype 9V showed higher delafloxacin MIC values.
我们报告了新型氟喹诺酮类药物德拉沙星对拓扑异构酶IV和DNA旋转酶均具有高亲和力，对高度耐左氧氟沙星的侵袭性肺炎链球菌菌株的活性。
共研究了173株高度耐左氧氟沙星（MIC>32mg/L）的侵袭性肺炎链球菌分离株。这些菌株从血液（n=162）和其他无菌体液（n=11）中分离得到。通过肺炎球菌乳胶凝集试验和荚膜肿胀反应进行血清分型。按照欧洲药敏试验委员会（EUCAST）的指南和断点，采用梯度扩散法测定德拉沙星、左氧氟沙星、青霉素、头孢噻肟、红霉素和万古霉素的MIC。
在分离株中，32.9%对青霉素不敏感，19.7%对头孢噻肟不敏感，76.9%对红霉素耐药。所有菌株对万古霉素敏感。德拉沙星的MIC和MIC（mg/L）值分别为0.064和0.12；9V血清型分离株中有60%（15/25）的德拉沙星MIC≥0.12mg/L。
德拉沙星对高度耐左氧氟沙星的侵袭性肺炎链球菌分离株具有很强的活性。9V血清型的分离株显示出较高的德拉沙星MIC值。
