Table 1 Antibiotic-resistance spectra of LsaA, OptrA and PoxtA ARE–ABCFs.

From: Structural basis for PoxtA-mediated resistance to phenicol and oxazolidinone antibiotics

 

Minimum inhibitory concentration (MIC, μg/mL)

 

pCIEspec vector

LsaA

OptrA ST16

OptrA 35048

PoxtA EF9F6

PoxtA AOUC-0915

Chloramphenicol

2–4

2–4

8–16

4–8

4–8

4–8

Thiamphenicol

4

4

32–64

16–32

8–16

32–64

Florfenicol

1–2

1–2

16–32

8

2–4

16–32

Linezolid

1

1

8

2–4

2–4

4–8

Erythromycin

0.5–1

0.5

0.5

0.5

0.5

0.5

Azithromycin

0.5

0.5

0.5

0.5

0.5

0.5

Leucomycin

0.5

0.5

0.5

0.5

0.5

0.5

Lincomycin

0.125

16–32

0.125

0.125

0.125

0.125

Clindamycin

0.0156

16

0.0156

0.0156

0.0156

0.0156

Tiamulin

0.0625

128

0.0156

0.0156

0.031

0.031

Retapamulin

0.0156

>64

0.0156

0.0156

0.0156

0.0156

Virginiamycin M1

4

>128

4

4

4

4

Virginiamycin S1

8

8

8

8

8

8

Tetracycline

0.25

0.25

0.25

0.25

0.25

0.25

  1. BHI media supplemented with 2 mg/mL kanamycin (to prevent lsa revertants), 0.1 mg/mL spectinomycin (to maintain the pCIEspec plasmid), 100 ng/mL of cCF10 peptide (to induce expression of ABCF proteins) as well as increasing concentrations of antibiotics were inoculated with 5 × 105 CFU/mL (≈OD600 0.0005) of E. faecalis ΔlsaA (lsa::Kan) strain TX5332 transformed either with empty pCIEspec plasmid, or with pCIEspec derivatives for expression of ARE–ABCF proteins. After 16–20 h at 37 °C without shaking, the presence or absence of bacterial growth was scored by eye. The MIC values that are higher than the empty vector control are shown in bold. The experiments were performed in triplicates.
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