Drug-resistant respiratory pathogens in Japan

In order to investigate the trends of antimicrobial susceptibility in respiratory pathogens in Japan, the Japanese Society of Chemotherapy (JSC) established a nationwide surveillance network in 2006. During the period from January to August, 2007, 1,178 strains were collected from clinical specimens obtained from adult patients with well-diagnosed respiratory tract infections. Susceptibility testing was evaluated for 1,108 strains (226 Staphylococcus aureus, 257 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 206 Haemophilus influenzae, 120 Moraxella catarrhalis, 122 Klebsiella pneumoniae, and 171 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 P-lactams (four penicillins, three penicillins in combination with (3-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), three aminoglycosides, four macrolides (including ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standards Institute (CLSI). The incidence of MRSA was high, at 59.7%, and the incidences of PISP and PRSP were 30.4% and 5.1%, respectively. Among H. influenzae strains, 19.9% of them were found to be BLNAI, 29.1% to be BLNAR, and 6.7% to be BLPAR strains. ESBL-producing K pneumoniae was not isolated. Two isolates (1.2%) of P. aeruginosa were found to be metallo-I3lactamase-producing strains, including one (0.6%) multidrug-resistant strain. Through the nationwide surveillance, we obtained fundamental antimicrobial susceptibility data of clinically relevant bacterial pathogens in adult respiratory tract infections to various antibacterial agents. Continued surveillance is required to prevent the further spread of these antimicrobial resistances.