Comparison of mismatch amplification mutation assay with DNA sequencing for characterization of fluoroquinolone resistance in Neisseria gonorrhoeae

A mismatch amplification mutation assay (MAMA) was developed for identification of point mutations in quinolone resistance-determining region (QRDR) of gyrA at codons 91 and 95. MAMA PCR was used to detect mutations at codons 91 and 95 of gyrA in 117 Neisseria gonorrhoeae isolates (with ciprofloxacin MICs of 0.004 to >32 microg/ml) from Bangladesh during 1997 to 2001. The QRDR regions of the gyrA genes from 31 randomly selected isolates were sequenced, and the results were compared with those of MAMA PCR. Using mismatch PCR, a mutation at Ser91 could be detected in all 27 (resistant and intermediate) isolates, and an Asp95-to-Gly95 mutation could be detected in all 15 isolates, as detected by sequencing. MAMA PCR offers a simple, inexpensive, rapid, and easier alternative for detection of point mutations in fluoroquinolone resistance in N. gonorrhoeae.