Sputum Specimens (sputum + specimen)

Distribution by Scientific Domains


Selected Abstracts


High phenotypic diversity in infecting but not in colonizing Staphylococcus aureus populations

ENVIRONMENTAL MICROBIOLOGY, Issue 12 2007
Christiane Goerke
Summary In hostile environments diversity within a bacterial population may be beneficial for the fitness of the microbial community as a whole. Here we analysed the population diversity of Staphylococcus aureus in infecting and colonizing situations. In the study, performed independently in two German centres, the heterogeneity of the S. aureus population was determined by quantifying the occurrence of phenotypic variants (differences in haemolysis, pigmentation, colony morphology) in primary cultures from nose, oropharyngeal and sputum specimens from cystic fibrosis (CF) patients and in nose swabs from healthy S. aureus carriers. The proportion of heterogeneous samples, the number of clearly distinguishable isolates per sample and the qualitative differences between phenotypes was significantly higher in CF sputum specimens than in the other samples. The heterogeneity of the S. aureus population could be correlated with high bacterial densities in the sputum samples. In patients co-infected with Pseudomonas aeruginosa lower S. aureus bacterial loads and less heterogeneity in the S. aureus population were observed. Typing of all S. aureus isolates from heterogeneous samples by pulsed-field gel electrophoresis or spa typing revealed that the bacteria were polyclonal in 30%, monoclonal with minor genetic alterations in 25% or not distinguishable in 69% of the specimens. Some specimens harboured monoclonal and polyclonal variants simultaneously. Importantly, differences in antibiotic susceptibility were detected in phenotypic S. aureus variants within a single specimen. Diversification of a S. aureus population is highly favoured during chronic CF lung infection, supporting the general hypothesis that maintenance of intrahost diversity can be of adaptive value, increasing the fitness of the bacterial community. [source]


Inhaled corticosteroid therapy reduces cytokine levels in sputum from very preterm infants with chronic lung disease

ACTA PAEDIATRICA, Issue 1 2009
Rie Honda
Abstract Aim: To evaluate the effects of inhaled corticosteroid therapy and high-frequency oscillatory ventilation (oscillation) on preterm infants with chronic lung disease (CLD). Methods: Ten infants with CLD who received inhaled corticosteroid therapy were enrolled. Week 1 was defined as the first week of therapy. The concentrations of interleukin (IL)-8, tumour necrosis factor-, (TNF-,), IL-1,, IL-6, IL-10 and IL-12p70 in serial sputum specimens from the infants were determined using a cytometric bead array. Results: The sputum concentrations of IL-8 obtained from the infants during week 3,4 were significantly lower than those obtained before therapy and during week 1,2. The sputum concentrations of TNF-,, IL-6 and IL-10 during week 3,4 were significantly lower than the concetrations during week 1,2. The ratio of IL-8 levels during week 1,2 to those before therapy in infants who received oscillation (n = 4) was significantly lower than in those who received intermittent mandatory ventilation (n = 6). Conclusion: Inhaled corticosteroids may be associated with a decrease in pro-inflammatory cytokine levels in sputum from infants with CLD from 2 weeks after the start of therapy. Our further investigations suggest that therapy with oscillation modulated airway inflammation earlier than therapy with intermittent mandatory ventilation. [source]


Antibiotic-resistant obligate anaerobes during exacerbations of cystic fibrosis patients

CLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2009
D. Worlitzsch
Abstract Pseudomonas aeruginosa and Staphylococcus aureus are thought to cause the majority of lung infections in patients with cystic fibrosis (CF). However, other bacterial pathogens may contribute to the pathophysiology of lung disease. Here, obligate anaerobes were identified in a cross-sectional study, and cell numbers and antibiotic susceptibilities of facultative and obligate anaerobes from 114 sputum samples from nine children and 36 adults with CF were determined. Furthermore, in 12 CF patients, we investigated whether conventional intravenous antibiotic therapy, administered during acute exacerbations, would affect the numbers of obligate anaerobes. Fifteen genera of obligate anaerobes were identified in 91% of the CF patients. Cell numbers (mean: 2.2 × 107 ± standard deviation 6.9 × 107 CFU/mL of sputum sample) were comparable to those of P. aeruginosa and S. aureus. Staphylococcus saccharolyticus and Peptostreptococcus prevotii were most prevalent. Infection with P. aeruginosa did not increase the likelihood that obligate anaerobes are present in sputum specimens. Single obligate anaerobic species persisted for up to 11 months in sputum plugs in vivo. Patients with and without obligate anaerobes in sputum specimens did not differ in lung function. Intravenous therapy directed against P. aeruginosa during acute exacerbations increased lung function, but did not reduce the numbers of obligate anaerobes. Obligate anaerobic species differed widely in their patterns of resistance against meropenem, piperacillin,tazobactam, clindamycin, metronidazole and ceftazidime. In 58% of patients with acute exacerbations, obligate anaerobes were detected that were resistant to the antibiotics used for treatment. Antibiotic therapy, optimized to target anaerobes in addition to P. aeruginosa, may improve the management of CF lung disease. [source]