Nationwide surveillance of bacterial respiratory pathogens conducted by the Surveillance Committee of Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Clinical Microbiology in 2009: General view of the pathogens' antibacterial susceptibility

For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis, 78 Klebsiella pneumoniae, and 103 Pseudomonas aeruginosa). A maximum of 45 antibacterial agents including 26 b-lactams (four penicillins, three penicillins in combination with b-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), four 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 Standard Institute (CLSI). Incidence of methicillin-resistant S. aureus (MRSA) was as high as 58.5 %, and that of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) was 6.3 % and 0.0 %, respectively. Among H. influenzae, 21.1 % of them were found to be b-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 18.7 % to be b-lactamasenon- producing ABPC-resistant (BLNAR), and 5.7 % to be b-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5 %) of b-lactamase-producing strains has been suspected in Moraxella catarrhalis isolates. Four (3.2 %) extended-spectrum b-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5 %) of P. aeruginosa were found to be metallob- lactamase-producing strains, including three (1.9 %) suspected multi-drug resistant strains showing resistance against imipenem, amikacin, and ciprofloxacin. Continuous national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.