title: Variable resistance of Shigellae to ampicillin within a single community.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D004405:Dysentery, Bacillary / Q000188:drug therapy; D006801:Humans; D008396:Maryland; D010403:Penicillin Resistance; D012621:Seasons; D012760:Shigella / Q000187:drug effects*
chemical_list: D000667:Ampicillin