In Vitro Resistance of Neisseria gonorrhoeae to Metronidazole

Abstract

Susceptibility of 64 clinical isolates of Neisseria gonorrhoeae to metronidazole was determined by the agar dilution technique using Mueller-Hinton and chocolate agar media. All isolates were resistant to metronidazole at 12.5 jig/ml in either medium. This lack of activity of metronidazole against N. gonorrhoeae would suggest that the ability to recover N. gonorrhoeae in patients being treated with metronidazole for concurrent Trichomonas vaginalis infections should not be hampered. RESULTSMICs of metronidazole in Mueller-Hinton and chocolate agars against 64 gonococcal isolates, and the cumulative percent of organisms inhibited at each concentration, are summarized in Table 1. On either medium, all 64 isolates were resistant to metronidazole at 12.5

Phenotypic and transcriptional profiling in Entamoeba histolytica reveal costs to fitness and adaptive responses associated with metronidazole resistance

“…Coincidentally, clinical and in vitro resistance to the drug in Trichomonas vaginalis (Müller et al, 1980 ; Wright et al, 2010 ), Giardia lamblia (Müller et al, 2007 ; Tejman-Yarden et al, 2011 ), Blastocystis spp. (Mirza et al, 2011a , b ), Neisseria gonorrhoeae (Yoshikawa et al, 1974 ), and several anaerobic bacteria (Pumbwe et al, 2007 ; Peláez et al, 2008 ; Tanih et al, 2011 ) have also been reported since the drug was introduced in 1960 (Figure S1 ) (Durel et al, 1960 ). Based on these findings, it is reasonable to assume that clinical resistance to MTZ might soon be reported in E. histolytica .…”