Streptococcus agalactiae macrolide/lincosamide resistance; implications for puerperal antimicrobial therapy

We undertook a retrospective observational study at a central London teaching hospital to investigate GBS antimicrobial resistance and peri-partum prescribing between 1st April 2016 and 31st March 2019.

939 obstetric patients had GBS identified at Chelsea & Westminster Hospital during the study period. 31% (279(263 resistant and 16 intermediate)/900) were erythromycin resistant and 27% (246/911) clindamycin resistant. 5.6% (51/900) had incongruent erythromycin/clindamycin resistance, presumed erm mediated.

390 women received peri-partum antimicrobials for GBS. The majority of patients received benzylpenicillin therapy (70.2%, 274/390), with cefuroxime (23.1%, 90/390), clindamycin (5.6%,22/390) and teicoplanin (1%,4/390) based therapies also used. 40.9% (9/22) were given clindamycin despite known GBS resistance.

Our data support the national guidelines, with high erythromycin/clindamycin resistance reported locally. Updated UK guidelines for GBS colonised patients recommend the use of vancomycin for beta-lactam allergic patients. Yet where sensitivities are known, clindamycin may still be used for 70% of beta-lactam allergic patients. Vancomycin, more challenging to administer and monitor, can be reserved for beta-lactam allergic, clindamycin resistant GBS carriers which account for a minority of the population (2.8%). Developing a working pathway implementation is challenging as evident with the inappropriate clindamycin use in 9 patients locally.