TABLE 1.
MIC of erythromycin, clindamycin, pristinamycin Ia, and virginiamycin S1 for different Staphylococcus strains, as determined by broth microdilution
| Strain | Characteristic(s) or origin | Reference or source | Antibiotic resistance gene(s)a | MIC (μg/ml)b |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| ERY | CLI | iCLI | PIA | iPIA | VS1 | iVS1 | ||||
| S. saprophyticus | ||||||||||
| N041 | Human nose skin sample | This study | erm(44)v | 128 | >256 | >256 | 32 | 32 | 32 | 32 |
| S. aureus | ||||||||||
| RN4220 | Recipient strain for electrotransformation, plasmid free | 18 | <0.5 | <0.25 | NA | 4 | NA | 8 | NA | |
| RN4220/pBUS1-HC | RN4220 with cloning vector pBUS1-HC | 12 | tet(L) | <0.5 | <0.25 | NA | 4 | NA | 8 | NA |
| RN4220/pBUS1-Pcap-HCc | RN4220 with pBUS1-HC containing cap promoter | 12 | tet(L) | <0.5 | <0.25 | NA | 2 | NA | 8 | NA |
| RN4220/pBJW13 | RN4220 with erm(44) from S. xylosus JW4341 cloned into pBUS1-Pcap | 4 | tet(L), erm(44) | >256 | >256 | >256 | 8 | 8 | 16 | 32 |
| RN4220/pLI50-erm(44) | RN4220 with erm(44) from S. saprophyticus A ER Ab-7 cloned into pLI50 | 5 | blaTEM-1, catpC194, erm(44) | >256 | <0.25 | 256 | 4 | 64 | 32 | 128 |
| RN4220/pBCS0714 | RN4220 with erm(44)v from S. saprophyticus N041 and its regulatory region cloned into pBUS1-HC | This study | tet(L), erm(44)v | 16 | >256 | >256 | 2 | 1 | 8 | 4 |
| RN4220/pBCS0814 | RN4220 with erm(44)v from S. saprophyticus N041 cloned into pBUS1-Pcap-HC | This study | tet(L), erm(44)v | 16 | >256 | >256 | 2 | 1 | 8 | 4 |
Antibiotic resistance genes and functions: blaTEM-1, β-lactamase; catpC194, chloramphenicol acetyltransferase; tet(L), tetracycline efflux; erm(44) and erm(44)v, 23S rRNA methylase.
Abbreviations: ERY, erythromycin; CLI, clindamycin; PIA, pristinamycin IA; VS1, virginiamycin S1; iCLI, iPIA, and iVS1, 2 μg/ml erythromycin added to the broth for the detection of inducible resistance to clindamycin (iCLI), pristinamycin IA (iPIA), and virginiamycin S1 (iVS1); NA, not applicable.
Vector pBUS1-Pcap-HC is a pBUS1-HC derivate that harbors the cap promoter of the S. aureus type 1 capsular polysaccharide biosynthesis gene cluster.