First case of penicillin-resistant Streptococcus agalactiae (group B Streptococcus) isolated from an adult patient in Italy, February 2026.

A penicillin-resistant group B streptococcal (GBS) strain was identified in Italy, after isolation from the blood culture of a patient in their 80s with comorbidities. The isolate was multidrug-resistant and demonstrated by genome sequencing to be of serotype Ia, sequence type 23, and to possess the alp1 gene. Known and new point mutations were detected in the penicillin-binding-protein genes 2a and 2x. Although sporadic, penicillin-resistance in GBS is a serious concern for prophylaxis and therapy, so continued GBS surveillance remains important.