Table 4.
Summary of Alterations Found in L4, L22, and 23s rRNA, Among ERY-Resistant (erm - /mef -, n = 37) and Q/D Nonsusceptible Isolates (n = 18)
| Gene | Mutationa | Observed phenotypeb | Reported phenotypeb | Reference |
|---|---|---|---|---|
| rplD/L4 | E13Q, E30Q, V88I, G98A, A128S, S130E | See notes c and d | No resistance | 56 |
| E30K | Q-D | M | 54 | |
| S112L | See note d | This study | ||
| Q67R + R72G | Q-D LZD | LZD | 14 | |
| 69GTG71 to TPS | MSB | ML, M, MSB | 17, 50, 56 | |
| 63KPWRQKTGTGRAR74 | M | This study | ||
| 63KPWRQKGKGTGRAR74 | Q-D | ERY-I AZI-R | 37 e | |
| 63KPWRQKGSQKGTGRAR74 | M Q-D | This study | ||
| 63KPWRPWRQKGTGRAR74 | Q-D | This study | ||
| rplV/L22 | R103C | M Q-D | This study | |
| 102KRTAHITRTAHIVA110 | M Q-D | M Q-D | 29 | |
| 102KRTAHITRTAHITVA110 | M Q-D | ML, M, M Q-D | 17, 40 | |
| 102KRTAHITKRTAHIVA110 | M Q-D | M Q-D | 6 | |
| 102KRTAHITKRTAHITVA110 | M Q-D | This study | ||
| 102KRTAHITVRTAHITVA110 | M Q-D | This study | ||
| T85P | See note 4 | This study | ||
| 85PMKRFRPPMKRFRPRAK94 | M Q-D | This study | ||
| 85TMKRFRPRASFRPRAK94 | M Q-D | This study | ||
| 76SEAFANEGPTIAFANEGPTM86 | M Q-D | This study | ||
| 23s d. V | A2061G (2059 in Escherichia coli) | M, MLSB | ML, MLSB, MSB | 16, 49, 50, 54 |
| C2613G (2611 in E. coli) | M Q-D | M, M Q-D | 16, 49, 52 | |
| A2060C (2058 in E. coli) | MLSB | ML, M | 33, 42, 52e |
a
Insertions are underlined.
b
“Observed phenotype” refers to this study, while “Reported phenotype” refers to phenotypes observed in previous reports.
c
These changes were found in combination with the 69GTG71 to TPS substitution.
d
Only found in combination with other changes, its role in resistance is unclear.
e
These reports pertain to other bacterial species. Our study is the first to report these changes in Streptococcus pneumoniae.
AZI, azithromycin; ERY, erythromycin; LZD, linezolid; L, lincosamides; M, macrolides; SB, streptogramin B; Q-D, quinupristin–dalfopristin (Synercid).