T helper 17 cells are involved in the local and systemic inflammatory response in community-acquired pneumonia.

BACKGROUND: Recent findings in mouse models suggest that T helper (Th)17 cells, characterised by production of interleukin (IL)-17A and IL-22, are involved in the immunopathogenesis of pneumonia. OBJECTIVE: In this study, we aimed to identify the involvement of Th17 cells in human community-acquired pneumonia (CAP). DESIGN: Within 24 h of admission, T cells from peripheral blood (n=39) and bronchoalveolar lavage (BAL, n=20) of CAP patients and of 10 healthy individuals were analysed by intracellular flow cytometry for the production of various cytokines, including IL-17A and IL-22. Peripheral blood T cells were also analysed 7 and 30 days after admission. Th17 cytokine profiles were correlated with pneumonia severity index and microbial aetiology. RESULTS: In the BAL of CAP patients, proportions of IL-17A and IL-22 single positive, as well as IL-17A/IL-22 double positive CD4 T cells were significantly increased compared with healthy individuals. Significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells in BAL were found in non-severe and severe CAP patients, as well as in pneumococcal and non-pneumococcal CAP. In the peripheral blood of CAP patients upon admission, we found significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells. One week after admission, the proportions of these double positive cells were still significantly increased in CAP patients compared with healthy individuals. CONCLUSIONS: These data indicate that Th17 cells are engaged in the local and systemic immune response in human pneumonia. Especially, IL-17A/IL-22 double positive Th17 cells may be involved in the immunopathogenesis of CAP.

Direct detection of human Staphylococcus aureus carriage in the nose using the Lightcycler Staphylococcus kit.

The Lightcycler Staphylococcus kit is a diagnostic tool for direct real-time detection of Staphylococcus aureus in clinical materials. We show here that detection of S. aureus nasal carriage using this test is hampered by competition of DNA from coagulase-negative staphylococci. However the test is well suited for species identification after culture and the identification of high-load S. aureus carriers.

Macrolide resistance of Staphylococcus aureus and Haemophilus species associated with long-term azithromycin use in cystic fibrosis.

OBJECTIVES: Azithromycin is used to modulate exuberant inflammatory response in patients with cystic fibrosis (CF). The purpose of this study was to determine the association between long-term use of azithromycin in CF patients and change over time in macrolide susceptibility of Staphylococcus aureus and Haemophilus spp. METHODS: The study was performed at the Erasmus MC-Sophia Children's Hospital. CF patients' sputum cultures were obtained at routine visits and at pulmonary exacerbations. All cultures between January 1999 and March 2004 were included. Antibiotic susceptibility of S. aureus and Haemophilus spp. was tested routinely. Susceptibility was compared with isolates from sputum of non-CF patients. Logistic regression was used to analyse the association between azithromycin use and resistance, adjusting for age, Pseudomonas carriage and time-trends. RESULTS: In March 2004 one-third of CF patients were on azithromycin maintenance treatment. S. aureus (715 isolates) and/or Haemophilus (537 isolates) were cultured in 141 of the 155 patients on one or more occasions. The study period was divided into octiles. Erythromycin resistance in S. aureus increased from 6.9 to 53.8% and clarithromycin resistance in Haemophilus spp. from 3.7 to 37.5%. Resistance but also isolation rates were strongly related to azithromycin use. Resistance of 3217 S. aureus control isolates remained stable and resistance of 3257 Haemophilus controls increased, although at a slower rate than CF isolates. CONCLUSIONS: Over a 4 year period, azithromycin maintenance therapy in our CF population was associated with an increase in macrolide resistance in S. aureus and Haemophilus spp.

Anti-enolase antibodies partially protective against systemic candidiasis in mice.

OBJECTIVE: The evaluation of the effect of protective capacities of antibodies directed against the immunodominant enolase antigen of C. albicans on the survival rate of mice with systemic candidiasis. METHODS: Passive transfer of heterologous rabbit antibodies (IRS) directed against a crude Candida albicans extract and homologous mice anti-enolase antibodies (IMS) in a non-acute but lethal systemic Candida model in mice. RESULTS: Protection could only be demonstrated by repeated administration of homologous as well as heterologous immune sera. The protective effect was not due to non-specific, heat-labile, serum factors, since fractionated anti-cytoplasmic rabbit immunoglobulins also gave a decreased mortality rate. These findings could not be ascribed to enhanced opsonization as observed in in vitro opsonization experiments using peritoneal macrophage monolayers. CONCLUSIONS: Anti-enolase antibodies are partially protective against lethal C. albicans infections. The protection was not due to enhanced initial clearance of viable C. albicans from the internal organs, but was presumably the result of as yet unknown effects of antibodies occurring later in the infectious process.

Multilocus sequence typing of Staphylococcus aureus with DNA array technology.

A newly developed oligonucleotide array suited for multilocus sequence typing (MLST) of Staphylococcus aureus strains was analyzed with two strain collections in a two-center study. MLST allele identification for the first strain collection fully agreed with conventional strain typing. Analysis of strains from the second collection revealed that chip-defined MLST was concordant with conventional MLST. Array-mediated MLST data were reproducible, exchangeable, and epidemiologically concordant.