Sequential changes of Legionella antigens and bacterial load in the lungs and urines of a mouse model of pneumonia.

Legionella pneumophila is an important cause of community- and hospital-acquired pneumonia. In spite of the introduction of the urinary antigen detection method, Legionella pneumonia may be still underdiagnosed. We performed kinetic and quantitative analysis of diagnostic markers, such as bacterial loads, DNA assays, and antigen titers, in a 28-day time course murine model of L.

Comparison of clinical and radiological features of pneumocystis pneumonia between malignancy cases and acquired immunodeficiency syndrome cases: a multicenter study.

Background: The clinical features of pneumocystis pneumonia (PCP) differ according to the predisposing factors responsible for immunosuppression. Although PCP in patients with acquired immunodeficiency syndrome (AIDS) has been extensively described, its characteristics in non-AIDS patients, such as those with malignancies, are not thoroughly documented.

Study Objective: To characterize and compare the clinical and imaging features of PCP in patients with malignancies with those in AIDS patients.

[In vitro susceptibilities to levofloxacin and various antibacterial agents of 12,919 clinical isolates obtained from 72 centers in 2007].

We have reported in this journal in vitro susceptibilities of clinical isolates to antibiotics every year since 1992. In this paper, we report the results of an analysis of in vitro susceptibilities of 12,919 clinical isolates from 72 centers in Japan to selected antibiotics in 2007 compared with the results from previous years. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae maintained a high susceptibility to fluoroquinolones (FQs).

Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip.

Total hip replacement for high dislocation of the hip joint remains technically difficult in terms of preparation of the true acetabulum and restoration of leg length. We describe our experience of cementless total hip replacement combined with a subtrochanteric femoral shortening osteotomy in 20 hips with Crowe grade IV dislocation with a mean follow-up of 8.1 years (4 to 11.

Interleukin-1 deficiency in combination with macrophage depletion increases susceptibility to Pseudomonas aeruginosa bacteremia.

We evaluated the role of IL-1 during Pseudomonas aeruginosa bacteremia by intravenously injecting P. aeruginosa strain D4 into IL-1-deficient and WT mice. The two strains showed equivalent mortality rates.

A low concentration of azithromycin inhibits the mRNA expression of N-acyl homoserine lactone synthesis enzymes, upstream of lasI or rhlI, in Pseudomonas aeruginosa.

Low-dose macrolides are effective therapy in patients with chronic lung infections, but the mechanisms of action are unclear. In this study, we performed DNA microarray analysis of Pseudomonas aeruginosa after treatment with a low concentration of azithromycin. We found that a sub-MIC of azithromycin didn't change mRNA expression of quorum-sensing related genes (lasI, lasR, rhlI, rhlR, vft, rsaL), but lowered expression of most N-acyl homoserine lactone (AHL) synthesis enzymes upstream of lasI and rhlI.

Pseudomonas aeruginosa Las quorum sensing autoinducer suppresses growth and biofilm production in Legionella species.

Bacteria commonly communicate with each other by a cell-to-cell signalling mechanism known as quorum sensing (QS). Recent studies have shown that the Las QS autoinducer N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C(12)-HSL) of Pseudomonas aeruginosa performs a variety of functions not only in intraspecies communication, but also in interspecies and interkingdom interactions. In this study, we report the effects of Pseudomonas 3-oxo-C(12)-HSL on the growth and suppression of virulence factors in other bacterial species that frequently co-exist with Ps.

Hyperoxia exaggerates bacterial dissemination and lethality in Pseudomonas aeruginosa pneumonia.

Effects of hyperoxia on lethality in mice with Pseudomonas aeruginosa pneumonia were defined, and protective roles of macrolides were examined both in vitro and in vivo. Sub-lethal hyperoxia accelerated lethality of mice with P. aeruginosa pneumonia.

Efficacy of colistin combination therapy in a mouse model of pneumonia caused by multidrug-resistant Pseudomonas aeruginosa.

Objectives: Multidrug-resistant Pseudomonas aeruginosa (MDRP) is becoming a serious problem in hospitals, especially in patients on ventilators. Recent data demonstrate that colistin may be effective for these patients, although limited in vitro and in vivo data are available. Our aim was to identify further characteristics of colistin for the therapy of pneumonia caused by MDRP.

Paradoxically high resistance of natural killer T (NKT) cell-deficient mice to Legionella pneumophila: another aspect of NKT cells for modulation of host responses.

In the present study, we examined the roles of natural killer T (NKT) cells in host defence against Legionella pneumophila in a mouse model. The survival rate of NKT cell-deficient Jalpha281 knock-out (KO) mice was significantly higher than that of wild-type mice. There was no bacterial overgrowth in the lungs, but Jalpha281 KO mice showed enhanced pulmonary clearance at a later stage of infection, compared with their wild-type counterparts.

Clinical and radiological features of Pneumocystis pneumonia in patients with rheumatoid arthritis, in comparison with methotrexate pneumonitis and Pneumocystis pneumonia in acquired immunodeficiency syndrome: a multicenter study.

Objective: To elucidate the clinical and radiological features of Pneumocystis pneumonia (PCP) in patients with rheumatoid arthritis (RA), compared with methotrexate (MTX) pneumonitis in RA and Pneumocystis pneumonia in acquired immunodeficiency syndrome (AIDS).

Subjects And Methods: Retrospective analysis of 14 PCP cases in RA (RA-PCP), 10 MTX pneumonitis cases in RA (MTX-P) and 11 PCP cases in AIDS (AIDS-PCP) from 9 centers in the Kanto area in the last 6 years.

Results: Compared with AIDS-PCP, both RA-PCP and MTX-P developed more rapidly, showing higher serum CRP and lower plasma beta-D-glucan levels, and more severe oxygenation impairment.

[Evaluation of the usefulness of a rapid immunochromatographic membrane test to detect Streptococcus pneumoniae antigen in the early diagnosis of pneumococcal respiratory tract infections and the relationship to the severity of pneumonia].

We evaluated the usefulness of a rapid immunochromatographic membrane test (Binax NOW Streptococcus pneumoniae kit; ICT) to detect Streptococcus pneumoniae antigen in early diagnosis of pneumococcal respiratory tract infections and the relationship to the severity of pneumonia. We diagnosed 155 of 592 samples, which were performed by ICT, as S. pneumoniae respiratory tract infections.

Diagnosis of peri-prosthetic infection at the hip using triple-phase bone scintigraphy.

We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81).

[Evaluation of ImmnoCard mycoplasma for diagnosis of Mycoplasma pneumoniae infection].

We compared the differences of two tests, for the diagnosis of Mycoplasma pneumoniae infection a rapid detection kit for Mycoplasma pneumoniae-specific IgM antibody, ImmunoCard (IC) Mycoplasma test (Meridian Bioscience-USA), and a particle agglutination (PA) test in a retrospective study among 57 patients. They were all suspected to be suffering from atypical bacterial respiratory infection and were checked by the IC test at the Fukuroi Municipal Hospital from January 2004 to January 2006. In this study, the concordance of IC and PA results showed a great difference in children and adults.

Suppression of Pseudomonas aeruginosa quorum-sensing systems by macrolides: a promising strategy or an oriental mystery?

A breakthrough in antibiotic chemotherapy for patients with chronic Pseudomonas aeruginosa pulmonary infections was brought about by findings in a patient with diffuse panbronchiolitis (DPB), who had been treated with erythromycin over a period of years. Recent clinical trials have demonstrated that long-term macrolide therapy can be used not only for DPB patients but also for those with other chronic infections, including patients with cystic fibrosis (CF). The pathogenesis of chronic P.

Evaluation of antimicrobial susceptibility for beta-lactams using the Etest method against clinical isolates from 100 medical centers in Japan (2006).

This antimicrobial resistance surveillance study was performed in 100 medical centers. Susceptibility testing (Etest; AB BIODISK, Solna, Sweden) of 9152 strains including Escherichia coli (991 strains), Klebsiella spp. (1000 strains), Enterobacter spp.

Oral administration of Bifidobacterium longum prevents gut-derived Pseudomonas aeruginosa sepsis in mice.

Aims: The aim of the study was to evaluate the efficacy of probiotics on gut-derived sepsis caused by Pseudomonas aeruginosa in immunocompromised mice.

Methods And Results: After oral inoculation of P. aeruginosa, mice were treated with cyclophosphamide to induce leucopenia and translocation of the intestinal P.

Stability of FR264205 against AmpC beta-lactamase of Pseudomonas aeruginosa.

FR264205 is a novel parenteral 3'-aminopyrazolium cephalosporin. Here, we compared the stability of FR264205 against AmpC beta-lactamase of Pseudomonas aeruginosa with that of ceftazidime. The effect of ampD inactivation, which causes a moderate degree of hyperinducible AmpC expression, on the minimum inhibitory concentration (MIC) of FR264205 was eight-fold less than that on the MIC of ceftazidime.

Multicenter study to evaluate bloodstream infection by Helicobacter cinaedi in Japan.

Helicobacter cinaedi has being recognized as an important human pathogen which causes bloodstream infections. Although the first case of bacteremia with this pathogen in Japan was reported in 2003, the true prevalence of H. cinaedi as a pathogen of bloodstream infections in this country is not yet known.