Assessment of stability and fluctuations of cultured lower airway bacterial communities in people with cystic fibrosis.

BACKGROUND: Routine clinical culture detects a subset of the cystic fibrosis (CF) airways microbiota based on culture-independent (molecular) methods. This study aimed to determine how extended sputum culture of viable bacteria changes over time in relation to clinical status and predicts exacerbations. METHODS: Sputa from patients at a baseline stable and up to three subsequent time-points were analysed by extended-quantitative culture; aerobe/anaerobe densities, ecological indexes and community structure were assessed together with clinical outcomes. RESULTS: Eighty patients were prospectively recruited. Sputa were successfully collected and cultured at 199/267 (74.5%) study visits. Eighty-two sputa from 25 patients comprised a complete sample-set for longitudinal analyses. Bacterial density, ecological indexes and clinical outcomes were unchanged in 18 patients with three sequential stable visits. Conversely, in 7 patients who had an exacerbation, total bacterial and aerobe densities differed over four study visits (P < .001) with this difference particularly apparent between the baseline visit and completion of acute antibiotic treatment where a decrease in density was observed. Bacterial communities were more similar within than between patients but stable patients had the least variation in community structure over time. Using logistic regression in a further analysis, baseline features in 37 patients without compared to 15 patients with a subsequent exacerbation showed that clinical measures rather than bacterial density or ecological indexes were independent predictors of an exacerbation. CONCLUSIONS: Greater fluctuation in the viable bacterial community during treatment of an exacerbation than between stable visits was observed. Extended-quantitative culture did not provide prognostic information of a future exacerbation.

A school nurse-delivered adolescent smoking cessation intervention: a randomized controlled trial.

BACKGROUND: The aim of the present study was to evaluate the efficacy of a school nurse-delivered smoking cessation intervention to improve abstinence rates among adolescents interested in quitting. METHODS: Seventy-one high schools in Massachusetts were randomized to either a four-session one-on-one school nurse-delivered smoking cessation intervention (37 schools, n = 571) or usual smoking cessation care control condition (34 schools, n = 577). Adolescents in grades 9-12 who smoked in the past 30 days completed surveys at baseline, 6 weeks and 3 months. The study was conducted during the 2002-2003 school year. RESULTS: Thirty-day self-reported abstinence rates were significantly greater in students in the intervention compared to control condition at 6 weeks (18% vs. 2%, respectively) and 3 months (24% vs. 5%, respectively). After adjusting for school and potential confounders, students in the intervention schools had odds of quitting 8 times greater than students in the control schools at 6 weeks (OR = 8.4; 95% CI 3.7, 20.6) and 6 times greater at 3 months (OR = 6.4; 95% CI 3.4, 11.4). School nurses delivered intervention with a high degree of fidelity. CONCLUSIONS: A four-session smoking cessation intervention can feasibly be delivered by school nurses and increase self-reported short-term abstinence rates among students interested in quitting smoking.