Antibacterial activity of carbapenems against clinical isolates of respiratory bacterial pathogens in the northeastern region of Japan in 2007.

As the increasing prevalence of resistant strains of respiratory bacterial pathogens has recently been reported, continuous monitoring of the susceptibility of clinical isolates to antibacterial agents is important. We performed a surveillance study focusing on the susceptibility of major respiratory bacterial pathogens in the northeastern region of Japan to carbapenems and control drugs. A total of 168 bacterial strains isolated from patients with respiratory tract infections in 2007 were collected and the minimum inhibitory concentration (MIC) determined.

Diverse mutations in the ftsI gene in ampicillin-resistant Haemophilus influenzae isolates from pediatric patients with acute otitis media.

To clarify molecular changes in beta-lactamase-nonproducing, ampicillin-resistant (BLNAR) Haemophilus influenzae, which is increasing in pediatric patients with acute otitis media (AOM) in Japan, we identified amino acid (aa) substitutions in penicillin-binding protein 3 for the BLNAR strains. Of 191 H. influenzae strains isolated from middle ear fluid of pediatric AOM patients between October 2005 and March 2008, BLNAR strains determined by PCR accounted for 49.

Nonhemolytic Streptococcus pyogenes isolates that lack large regions of the sag operon mediating streptolysin S production.

Among nonhemolytic Streptococcus pyogenes (group A streptococcus) strains (n = 9) isolated from patients with pharyngitis or acute otitis media, we identified three deletions in the region from the epf gene, encoding the extracellular matrix binding protein, to the sag operon, mediating streptolysin S production.

Antibacterial activity of carbapenems against clinically isolated respiratory bacterial pathogens in Japan between 2005 and 2006.

The current status of the susceptibility of the main respiratory bacterial pathogens was evaluated by analysing the antibacterial activity of 21 drugs, including four carbapenems, against five species of the pathogens isolated between January 2005 and January 2006. A total of 157 strains were studied. Carbapenems inhibited the growth of all of the tested strains of Moraxella catarrhalis, Streptococcus pneumoniae and methicillin-susceptible Staphylococcus aureus strains at concentrations that were below the breakpoints set by the Japanese Society of Chemotherapy (2 and 1mug/mL for pneumonia and chronic respiratory tract infection, respectively).