TABLE 5.
Distribution of ciprofloxacin MICs for N. gonorrhoeae isolates with different genotypes
| Genotypea | No. (%) of isolates | No. of isolates with MIC (μg/ml)
|
No. (%) of isolates by susceptibility levelb
|
P valuec | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.002 | 0.004 | 0.008 | 0.015 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | S | I | R | |||
| wt | 150 (32.2) | 76 | 42 | 21 | 6 | 4 | 1 | 149 (99.3) | 1 (0.7) | 0 | <0.001 | ||||||||||
| mtrRmut | 85 (18.3) | 40 | 12 | 16 | 10 | 4 | 1 | 1 | 1 | 82 (96.5) | 0 | 3 (3.5) | <0.001 | ||||||||
| gyrAmut | 17 (3.7) | 2 | 1 | 2 | 4 | 6 | 1 | 1 | 2 (11.8) | 1 (5.9) | 14 (82.3) | <0.001 | |||||||||
| parCmut | 4 (0.1) | 1 | 1 | 2 | 1 (25.0) | 0 | 3 (72.0) | >0.05 | |||||||||||||
| gyrAmutmtrRmut | 6 (1.3) | 2 | 1 | 2 | 1 | 2 (33.3) | 0 | 4 (66.7) | >0.05 | ||||||||||||
| parCmutmtrRmut | 13 (2.8) | 1 | 1 | 2 | 2 | 1 | 4 | 2 | 1 | 2 (15.4) | 0 | 11 (84.6) | <0.001 | ||||||||
| gyrAmutparCmut | 70 (15.1) | 1 | 6 | 3 | 28 | 16 | 11 | 5 | 1 (1.4) | 0 | 69 (98.6) | <0.001 | |||||||||
| gyrAmutparCmutmtrRmut | 119 (25.6) | 5 | 1 | 1 | 4 | 1 | 3 | 12 | 10 | 20 | 29 | 21 | 11 | 12 (10.1) | 0 | 107 (89.9) | <0.001 | ||||
| Total | 464 | 128 | 55 | 38 | 21 | 9 | 0 | 1 | 1 | 0 | 9 | 25 | 24 | 52 | 50 | 35 | 16 | 251 (54.1) | 2 (0.4) | 211 (45.5) | |
a
Pattern of known genetic markers selected for analysis of antimicrobial resistance to fluoroquinolones. wt, wild-type(native) sequence in loci associated with resistance to fluoroquinolones; mtrRmut, nucleotide substitutions are found in either the mtrR gene or its promoter.
b
S, susceptible strains; I, intermediately resistant strains; R, resistant strains (in accordance with CLSI criteria [3] for certain antibiotics). Nonsusceptible categories are shown in bold.
c
Significance of distinctions between isolates from different phenotypes for the particular genotype examined (two-tailed Fisher's exact test was used).