Table 2. Distribution of resistance determinants to trimethoprim/sulfamethoxazole resistance in clinical Stenotrophomonas maltophilia isolates.
| year (n) | genes | SXT | MIC(mg/L) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| qacEΔ1-sul1(%) | sul2(%) | dfra1(%) | dfra5(%) | dfra12(%) | dfra17(%) | dfra27(%) | int1(%) | S(%) | R(%) | range | MIC50 | MIC90 | |
| 2005(26) | 11(42.3) | 2(7.7) | 1(3.8) | 11(42.3) | 21(80.8) | 5(19.2) | 0.25/4.75-32/608 | 0.25/4.75 | 8/152 | ||||
| 2006(26) | 12(46.2) | 2(7.7) | 1(3.8) | 2(7.7) | 13(50) | 18(69.2) | 8(30.8) | 0.25/4.75-32/608 | 0.25/4.75 | 16/304 | |||
| 2007(26) | 18(69.2) | 3(11.5) | 1(3.8) | 2(7.7) | 2(7.7) | 17(65.4) | 17(65.4) | 9(34.6) | 0.25/4.75-32/608 | 0.25/4.75 | 16/304 | ||
| 2008(24) | 13(54.2) | 6(25) | 3(12.5) | 3(12.5) | 15(62.5) | 16(66.7) | 8(33.3) | 0.25/4.75-32/608 | 0.25/4.75 | 32/608 | |||
| 2009(43) | 23(53.5) | 5(11.6) | 5(11.6) | 26(60.5) | 30(69.8) | 13(30.2) | 0.25/4.75-32/608 | 0.5/9.5 | 32/608 | ||||
| 2010(43) | 23(53.5) | 15(34.9) | 2(4.7) | 3(7.0) | 2(4.7) | 35(81.4) | 24(55.8) | 19(44.2) | 0.25/4.75-32/608 | 0.5/9.5 | 32/608 | ||
| 2011(20) | 12(60) | 10(50) | 1(5) | 1(5) | 4(20) | 2(10) | 3(15) | 17(85) | 12(60) | 8(40) | 0.25/4.75-32/608 | 1/19 | 32/608 |
| 2012(32) | 17(53.1) | 16(50) | 1(3.1) | 1(3.1) | 4(12.5) | 5(15.6) | 4(12.5) | 30(93.8) | 15(46.9) | 17(53.1) | 0.25/4.75-32/608 | 4/76 | 32/608 |
| 2013(28) | 25(89.3) | 13(46.4) | 1(3.6) | 6(21.4) | 5(17.9) | 1(3.6) | 24(85.7) | 14(50) | 14(50) | 0.25/4.75-32/608 | 4/76 | 32/608 | |
| 2014(32) | 25(78.1) | 7(21.9) | 5(15.6) | 3(9.4) | 30(93.7) | 17(53.1) | 15(46.9) | 0.25/4.75-32/608 | 4/76 | 32/608 | |||
| Total (300) | 179(59.7) | 77(25.7) | 4(1.3) | 4(1.3) | 35(11.7) | 25(8.3) | 8(2.7) | 218(72.7) | 184(61.4) | 116(38.7) | 0.25/4.75-32/608 | 0.5/9.5 | 32/608 |
SXT, trimethoprim-sulfamethoxazole; S, susceptible; R, resistant; MIC, Minimal inhibitory concentration; MIC50, the concentration needed to inhibit 50% of the strains; MIC90, the concentration needed to inhibit 90% of the strains