TABLE 1.
Characterization of mecI mutations and quantitation of specific mecA mRNA
| Mutation class | Strain | Mutation in mecI gene
|
Amt of specific mecA mRNA/16S mRNA | |
|---|---|---|---|---|
| Nucleotide position (change) | Amino acid changea | |||
| Nonsense | SA41 | 202 (C→T) | Gln 68→stop codon | 330 |
| SA35 | 202 (C→T) | Gln 68→stop codon | 285 | |
| SA7 | 202 (C→T) | Gln 68→stop codon | 179, 129b | |
| SA33 | 202 (C→T) | Gln 68→stop codon | 176 | |
| SA18 | 202 (C→T) | Gln 68→stop codon | 145, 83 | |
| SA12 | 202 (C→T) | Gln 68→stop codon | 142, 139 | |
| SA20 | 202 (C→T) | Gln 68→stop codon | 117 | |
| SA9 | 202 (C→T) | Gln 68→stop codon | 116 | |
| SA16 | 202 (C→T) | Gln 68→stop codon | 102 | |
| SA19 | 202 (C→T) | Gln 68→stop codon | 141 | |
| SA2 | 202 (C→T) | Gln 68→stop codon | 90 | |
| SA11 | 202 (C→T) | Gln 68→stop codon | 43 | |
| SA57 | 343 (G→T) | Glu 115→stop codon | 226, 301 | |
| Frameshift | SA10 | 193 (extra A) | Lys 65→12 aa to stop | 306 |
| SA13 | 64 (extra A) | Lys 22→7 aa to stop | 1,172 | |
| SA42 | 250 (extra A) | Lys 84→5 aa to stop | 834, 801 | |
| SA56 | 91 (extra T) | Ile 30→8 aa to stop | 330, 219 | |
| Missense | SA5 | 32 (C→T) | Ala 11→Val | 21, 28 |
| SA15 | 35, 32 | |||
| SA24 | 261, 256 | |||
| SA14 | 347 (T→C) | Leu 116→Ser | 202, 193 | |
| SA36 | 1,907, 940 | |||
| SA46 | 22 (A→G) | Iso 8→Val | 21, 35 | |
| SA78 | 125 (C→T) | Pro 42→Leu | 64, 75 | |
| SA30 | 116 (A→G) | Asp 39→Gly | 40, 52 | |
| SA54 | 152 (G→T) | Arg 51→Ile | 1,101, 1,227 | |
| SA47 | 370 (T→A) | +18 aa to stop | 66, 79 | |
| SA27 | 142 (C→T) | Leu 48→Phe | 66, 49 | |
a
aa, amino acids.
b
For some isolates two independent RNA samples, prepared on different days, were analyzed to assess reproducibility of RT-PCR values for mecA-specific mRNA.