Table 2. Distribution of antimicrobial resistance across group B streptococcal serotypes, Portugal (24 hospitals), 2009–2015 (n = 555a).
| Serotype | Macrolides | Tetracycline | Streptomycin | Other (n) | |
|---|---|---|---|---|---|
| Phenotype (n) | Genotype (n) | Genotype (n) | Genotype (n) | ||
| Ia | cMLSB (9), iMLSB (2), M (6) | ermB (7), ermTR (3), ermB+lsaC (1), mefE (6) | tetM (155), tetO (2), tetM+tetO (2) | aph(3’)-III+ant (6)-Ia (1) | CHL (1), LEV (2) |
| Ib | cMLSB (110), iMLSB (4) | ermB (105), ermTR (5), ermT (1), ermB+ermTR (1), ermB+lsaC (1), ermB+mefE (1) | tetM (122), tetM+tetO (4) | ND | CHL (4) |
| II | iMLSB (2) | ermTR (1), ermT (1) | tetM (31) | None | |
| III | cMLSB (6), iMLSB (10) | ermB (4), ermTR (11), ermB+mefE (1) | tetM (56), tetM+tetO (3), tetO (2) | aph(3’)-III+ant (6)-Ia (3) | CHL (3) |
| IV | None | ND | tetM (6), tetM+tetO (1) | ND | None |
| V | cMLSB (25), iMLSB (10) | ermB (24), ermTR (11) | tetM (67), tetM+tetO (4), tetM+tetL (1), tetO (2) | ND | CHL (1) |
| VI | None | ND | ND | ND | LEV (1) |
| VIII | None | ND | tetM (2) | ND | None |
| IX | M (1) | mefE (1) | ND | ND | CHL (1) |
| NT | cMLSB (8), iMLSB (2) | ermB (8), ermTR (2) | tetM (18) | ND | None |
CHL: chloramphenicol; LEV: levofloxacin; M: resistance to macrolides; MLSB: resistance to macrolides, lincosamides and streptogramins B with the prefix letter referring to the constitutive (cMLSB) or inducible (iMLSB) expression of this phenotype; ND: not determined (resistance genotypes were not determined for the susceptible isolates); NT: non-typeable.
a Only the isolates resistant to tested antimicrobial drugs are listed (n = 490).