TABLE 3.
Mutations identified in co-trimoxazole-resistant S maltophilia strains
| Co-trimoxazole conc. (mg/liter)a | Strain | Phenotypeb | Mutationc |
|
|---|---|---|---|---|
| SmeRv | SmeT | |||
| 2 | MBS509d | Q | GCC→ACC (Ala265Thr) | |
| 2 | MBS510e | Q/CHL/ERY | CTG→CAG (Leu166Gln) | |
| 2 | MBS512 | Q/CHL | IS3 insertion | |
| 2 | MBS513 | Q/CHL | GAC→GGC (Asp302Gly) | |
| 2 | MBS514 | Q/CHL | TGC→TGG (Cys310Trp) | |
| 2 | MBS515 | Q/CHL | GGC→AGC (Gly266Ser) | |
| 2 | MBS516 | Q/CHL | GAC→AAC (Asp302Asn) | |
| 2 | MBS517e | Q/ERY | CTG→CAG (Leu166Gln) | |
| 2 | MBS518e | Q/ERY | CTG→CAG (Leu166Gln) | |
| 2 | MBS520 | Q/CHL/ERY | Lys160_Ile161insLys | |
| 2 | MBS522e | Q/CHL/ERY | Lys160_Ile161insLys | |
| 2 | MBS523 | Q | TGC→TTC (Cys310Phe) | |
| 4 | MBS530 | Q/CHL | GGC→GAC (Gly266Asp) | |
| 4 | MBS534d | Q | GGC→GAC (Gly266Cys) | |
| 4 | MBS540 | Q/CHL | GCG→CCG (Ala308Pro) | |
| 8 | MBS560d | Q/CHL | GGC→AGC (Gly266Ser) | |
| 8 | MBS563 | Q/CHL | GGC→AGC (Gly266Ser) | |
| 8 | MBS567 | Q/CHL | GGC→GAC (Gly266Asp) | |
| 16 | MBS571d | Q/CHL | GGC→GAC (Gly266Asp) | |
| 16 | MBS572 | Q | GCC→GAC (Ala265Asp) | |
| 16 | MBS580 | Q/CHL | GGC→AGC (Gly266Ser) | |
| 32 | MBS583 | Q/CHL | GGC→GAC (Gly266Asp) | |
| 32 | MBS584 | Q/CHL | GGC→GAC (Gly266Asp) | |
| 16 | MBS593 | Q/CHL | GGC→AGC (Gly266Ser) | |
a
Co-trimoxazole concentration used to isolate the mutant (data refer to trimethoprim concentration, as the ratio of trimethoprim to sulfamethoxazole is 1:5).
b
Antibiotic phenotype. Q, quinolone resistance; Q/CHL/ERY, quinolone, chloramphenicol, and erythromycin resistance; Q/CH, quinolone and chloramphenicol resistance; Q/ERY, quinolone and erythromycin resistance.
c
Mutations identified in smeRv or smeT gene in each mutant.
d
Overexpression of smeV confirmed by real time RT-PCR (see Table 2).
e
Overexpression of smeD confirmed by real time RT-PCR (see Table 2).