Table 1.
Drug | MIC breakpoints137 (μg/mL) S, R | Gene (codon/allele) | Mechanism | Year |
---|---|---|---|---|
Sulfonamides | folP (R228)138,139 | TM | 2005 | |
| ||||
Penicillin (PEN) | ≤0.06, ≥2 | penA45,140 | TM | 1975 |
porB (G120K, A121D/N)140,141 | P | 1975 | ||
mtrR (A39T, G45D, 1 bp del in promoter)140,142–144 | E | 1975 | ||
blaTEM61 | I | 1976 | ||
ponA (L421P)87 | TM | 2002 | ||
pilQ (E666K)87,88 | P | 2002 | ||
| ||||
Tetracycline (TET) | ≤0.25, ≥2 | porB (G120K, A121D/N)140,141 | P | 1975 |
mtrR (A39T, G45D, 1 bp del in promoter)140,142–144 | E | 1975 | ||
tetM32 | TM | 1986 | ||
pilQ (E666K)87,88 | P | 2002 | ||
rpsJ (V57M)145,146 | TM | 1974 | ||
| ||||
Ciprofloxacin (CIP) | ≤0.06, ≥1 | gyrA (S91F, D95A/N/G)147,148 | TM | 1994 |
parC (D86N, S87R/N, S88P, E91K)147,149 | TM | 1994 | ||
parE (G410V)148 | TM | 2002 | ||
norM (−35 promoter sequence, RBS)150 | E | 2003 | ||
| ||||
Spectinomycin | ≤32, ≥128 | rpsE (T24P, deletion V27, A82G)151,152 | TM | 2013 |
16S rDNA (C1187)153 | TM | 2000 | ||
| ||||
Azithromycin (AZI) | mtrR (A39T, G45D, 1 bp del in promoter)140,142–144 | E | 1975 | |
mosaic mtr operon47 | E | 2016 | ||
ermBCF57 | I | 1999 | ||
23S rDNA (C2611T, A2059G)154,155 | TM | 2002 | ||
mef156 | E | 2000 | ||
macAB (−10 promoter sequence)150 | E | 2003 | ||
rplV (3′ tandem duplications)22 | TM | 2016 | ||
rplD (G68, G70)22 | TM | 2016 | ||
| ||||
Cefixime (CFX) | ≤0.25, - | mosaic penA46,157 | TM | 2002 |
| ||||
Ceftriaxone (CRO) | ≤0.25*, - | mosaic penA157 | TM | 2005 |
porB158 | P | 2009 | ||
mtrR158 | E | 2009 |
TM = target modification, P = permeability, E = efflux, I = inactivation.
Reduced susceptibility to CRO is also described as ≥0.125 μg/mL