A novel compound that has antimicrobial activity against penicillin-resistant Streptococcus pneumoniae, and an anti-penicillin resistant pneumococci agent that includes the compound as an active ingredient are provided. Thus, an anti-penicillin resistant pneumococci agent is provided that includes as an active ingredient a compound represented by the following formula (I) or a pharmacologically acceptable salt thereof, or hydrates thereof:wherein, in the formula (I), R represents any one of a halogen atom, an azido group, Ra-Wa-, Rb-Wb-, Rc-Wc-, and RdRd′N—.
