Antimicrobial Activities of Piperacillin-Tazobactam against Haemophilus influenzae Isolates, Including -Lactamase-Negative Ampicillin-Resistant and -Lactamase-Positive Amoxicillin- Clavulanate-Resistant Isolates, and Mutations in Their Quinolone Resistance-Determining Regions

Antimicrobial Activities of Piperacillin-Tazobactam against Haemophilus influenzae Isolates, Including -Lactamase-Negative Ampicillin-Resistant and -Lactamase-Positive AmoxicillinClavulanate-Resistant Isolates, and Mutations in Their Quinolone Resistance-Determining Regions Yoichi Hirakata,* Kaori Ohmori, Miwako Mikuriya, Takeshi Saika, Kaoru Matsuzaki, Miyuki Hasegawa, Masumitsu Hatta, Natsuo Yamamoto, Hiroyuki Kunishima, Hisakazu Yano, Miho Kitagawa, Kazuaki Arai, Kazuyoshi Kawakami, Intetsu Kobayashi, Ronald N. Jones, Shigeru Kohno, Keizo Yamaguchi, and Mitsuo Kaku Department of Infection Control and Laboratory Diagnostics, Department of Clinical Microbiology with Epidemiological Research & Management and Analysis of Infectious Diseases (C-MERMAID), and Department of Medical Microbiology, Mycology and Immunology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai 980-8574, Japan; Mitsubishi Chemical Medience Corporation, Itabashi-ku, Tokyo 174-8555, Japan; Department of Infection Control and Prevention, Toho University School of Nursing, Ohtaku, Tokyo 143-0015, Japan; JMI Laboratories, North Liberty, Iowa 52317; Second Department of Internal Medicine, Nagasaki University School of Medicine and Dentistry, Nagasaki 852-8501, Japan; and Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Ohtaku, Tokyo 143-8540, Japan