In Vitro Activity of the Novel Lactone Ketolide Nafithromycin (WCK 4873) When Tested against Contemporary Clinical Bacteria from a Global Surveillance Program.

In Vitro Activity of the Novel Lactone Ketolide Nafithromycin (WCK 4873) When Tested against Contemporary Clinical Bacteria from a Global Surveillance Program. Antimicrob Agents Chemother. 2017 Oct 02;: Authors: Flamm RK, Rhomberg PR, Sader HS Abstract Nafithromycin (WCK 4873), a novel antimicrobial agent of the lactone ketolide class, is currently in Phase 2 development for treatment of community-acquired bacterial pneumonia (CABP): A total of 4,739 non-duplicate isolates were selected from a 2014 global surveillance program from medical institutions located in 43 countries within the United States, Europe, Latin America, and Asia-Pacific. Nafithromycin and comparator agents were susceptibility tested by reference broth microdilution methods. Nafithromycin was active against Staphylococcus aureus (MIC50/90, 0.06/>2 μg/mL), including erythromycin-resistant strains exhibiting an inducible clindamycin-resistance phenotype (MIC50/90, 0.06/0.06 μg/mL) and telithromycin-susceptible strains (MIC50/90, 0.06/0.06 μg/mL), but exhibited limited activity against most telithromycin-resistant and clindamycin-resistant isolates that were constitutively resistant to macrolides (MIC50/90, >2/>2 μg/mL). Nafithromycin was very active (MIC50/90, 0.015/0.06 μg/mL) against 1,911 Streptococcus pneumoniae, inhibiting all strains at MIC values ≤0.25 μg/mL. Telithromycin susceptibility was 99.9% against Streptococcus pneumoniae, and nafithro...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research