Presence of a mutation in ponA1 of Neisseria gonorrhoeae in numerous clinical samples resistant to various β-lactams and other, structurally unrelated, antimicrobials

Of the 53 isolates tested, 41 strains showed some resistance to penicillin G. A mutation in the ponA (ponA1) gene was identified in 46 isolates. There was a tendency that ponA mutant (ponA1) in N. gonorrhoeae led to higher antimicrobial MICs of β-lactam antimicrobial agents (including penicillin) than those of non-ponA mutants. However, we found lower than expected MICs of penicillin and β-lactams even in ponA mutants. Therefore, we consider that detailed investigations for the further understanding of the effect of other genes, such as penC (which is reported to be related to ponA1 in achieving high-level penicillin resistance) should be our next step.