A Potential Treatment Option for Multidrug-Resistant Gonorrhea

Nano-mupirocin may be a potential treatment option for multidrug-resistant (MDR) gonorrhea, according to a new study, which demonstrated strong in vitro activity.

Typically used to treat staphylococci skin infections, mupirocin in its standard form has high protein binding and has traditionally been limited to topical applications. But by loading the antibiotic into PEGylated nano‐liposomes, investigators in Israel sought to evaluate whether nano-mupirocin could be a viable treatment for MDR gonorrhea.

According to findings presented at the American Society for Microbiology (ASM) and the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) Conference on Drug Development to Meet the Challenge of Antimicrobial Resistance, the research team used the agar dilution method to test mupirocin minimum inhibitory concentrations (MIC) against clinical isolates of Neisseria gonorrhoeae.

Investigators evaluated the distribution of nano-mupirocin in the vaginal mucus of mice via swabs collected at various time points after administration. Nano-mupirocin labeled fluorescently was also injected into the lipidic membrane to be observed via fluorescent microscopy. Resistance assays comprising serial passages and spontaneous mutation frequency (SMF) experiments were also performed.

The research team recorded a MIC₉₀ value of 0.031 µg/ml with mupirocin and noted no cross-resistance between mupirocin and isolates with resistance to either of the comparator antibiotics. Eight isolates demonstrated increased MIC in the resistance passaging experiments, and 1 isolate demonstrated minor elevated MIC.

“In the SMF experiment, no mutants were obtained,” investigators concluded. “Nano‐mupirocin was found in the vaginal mucus of mice at concentrations > MIC. High fluorescence intensity was observed in the mucus of mice injected with labeled [nano-mupirocin]…The in vitro activity of [nano-mupirocin], as well as its distribution to vaginal mucus, strongly support the development of [nano-mupirocin] for the treatment of MDR gonorrhea.”

The poster, “Nano‐mupirocin Characterization as a Potential Candidate for MDR Gonorrhea Treatment,” was presented Wednesday, September 4, 2019, at the 2019 ASM/ESCMID Conference in Boston, Massachusetts.