Reduction of virulence factor pyocyanin production in multidrug-resistant Pseudomonas aeruginosa.

Nosocomial infections caused by metallo-β-lactamase (MBL)-producing multidrug-resistant (MDR) Pseudomonas aeruginosa have become a worldwide problem. Pyocyanin, a representative pigment produced by P. aeruginosa, is the major virulence factor of this organismThe aim of this study was to investigate the pyocyanin-producing ability of MBL-producing MDR P.

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.

Antibacterial effects of brand-name teicoplanin and generic products against clinical isolates of methicillin-resistant Staphylococcus aureus.

Glycopeptide antibiotics, such as vancomycin and teicoplanin, have been used worldwide to treat infection caused by methicillin-resistant Staphylococcus aureus (MRSA). Generic teicoplanin products were manufactured by many companies in 2009. We investigated the susceptibility of 147 MRSA strains to brand-name teicoplanin (TEIC-1) and seven generic products (TEIC-2 to TEIC-8).

Evaluation of dosing designs of carbapenems for severe respiratory infection using Monte Carlo simulation.

Using the Monte Carlo simulation method, the influence of various doses and dosing frequencies of carbapenems on the antimicrobial activities against Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa, which are the main causative organisms of respiratory infections, was studied with the aim of identifying optimized effectiveness. Based on pharmacokinetic (PK) parameters of individual carbapenems in healthy adults, data on changes in the respective blood concentrations in 2000 cases were simulated by applying a lognormal distribution to probability distributions of their volume of distributions and half-life periods. Based on minimum inhibitory concentration (MIC) distribution data of the individual carbapenems against these strains, MICs in the 2000 cases were also simulated.

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).