Relationships between high-resolution computed tomography (HRCT) findings in chronic obstructive pulmonary disease (COPD) and bacterial colonization, airway inflammation, or exacerbation indices are unknown. Fifty-four patients with COPD (mean [SD]: age, 69 [7] years; FEV(1), 0.96 [0.33] L; FEV(1) [percent predicted], 38.1 [13.9]%; FEV(1)/forced vital capacity [percent predicted], 40.9 [11.8]%; arterial partial pressure of oxygen, 8.77 [1.11] kPa; history of smoking, 50.5 [33.5] smoking pack-years) underwent HRCT scans of the chest to quantify the presence and extent of bronchiectasis or emphysema. Exacerbation indices were determined from diary cards over 2 years. Quantitative sputum bacteriology and cytokine measurements were performed. Twenty-seven of 54 patients (50%) had bronchiectasis on HRCT, most frequently in the lower lobes (18 of 54, 33.3%). Patients with bronchiectasis had higher levels of airway inflammatory cytokines (p = 0.001). Lower lobe bronchiectasis was associated with lower airway bacterial colonization (p = 0.004), higher sputum interleukin-8 levels (p = 0.001), and longer symptom recovery time at exacerbation (p = 0.001). No relationship was seen between exacerbation frequency and HRCT changes. Evidence of moderate lower lobe bronchiectasis on HRCT is common in COPD and is associated with more severe COPD exacerbations, lower airway bacterial colonization, and increased sputum inflammatory markers.

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Chronic obstructive pulmonary disease (COPD) is characterized by an accelerated decline in lung function and progressive airway inflammation. Bacteria have been isolated from the lower airway of stable COPD patients, and airway inflammation has been related to bacterial load and type. The relationship between bacterial colonization, airway inflammation, and lung function decline remains uncertain. We studied 30 patients with COPD, mean (SD) FEV1 0.947 (0.329), 34.8% (13.6%) predicted, for 12 months. Sputum collected at recruitment and the end of the study was analyzed for cytokines and for quantitative bacteriology. The decline in FEV1 was 57.6 (137.6) ml year-1. Bacterial growth was identified in all subjects, with an initial count of 107.47(0.91) cfu ml-1 rising to 107.93(0.81) cfu ml-1 at the end of the study (p = 0.019). FEV1 decline was related to this increase in airway bacterial load (r = 0.59, p = 0.001). FEV1 decline was greater in subjects who exhibited a change in the colonizing bacterial type compared with those with persistence of a single bacterial species over the study period (p = 0.017). Higher sputum interleukin (IL-8) was associated with greater declines in FEV1 (p = 0.03). Rising airway bacterial load and species changes are associated with greater airway inflammation and accelerated decline in FEV1. Bacterial colonization in COPD is an important factor in disease progression.

The clinical severity and inflammatory responses in COPD exacerbations are modulated by the nature of the infecting organism: bacterial and viral pathogens interact to cause additional rises in inflammatory markers and greater exacerbation severity.

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Lactobacilli, principally the strains that are hydrogen peroxide (H 2 O 2 ) producing, may have a protective effect against vaginal colonization by pathogenic species such as those that cause bacterial vaginosis. Previous reports have also suggested that H 2 O 2 -producing lactobacilli in the vagina may protect pregnant women against ascending infection of the chorioamniotic membranes and uterine cavity. We report the identification and H 2 O 2 production of lactobacilli isolated from vaginal swabs collected at 20 weeks' gestation from a population of pregnant women at high risk of preterm birth. We also report the correlation between identification and H 2 O 2 production in relation to the outcomes of chorioamnionitis and preterm birth. Lactobacilli were identified by partial 16S rRNA gene sequencing. H 2 O 2 production by isolates was determined by a semiquantitative method. The most commonly isolated species were L. crispatus, L. gasseri, L. vaginalis and L. jensenii. Amounts of H 2 O 2 produced by lactobacilli varied widely. The presence of lactobacilli producing high levels of H 2 O 2 in the vagina of this population of pregnant women was associated with a reduced risk of bacterial vaginosis at 20 weeks' gestation and subsequent chorioamnionitis. L. jensenii and L. vaginalis produced the highest levels of H 2 O 2 . We postulate that H 2 O 2 -producing lactobacilli are able to reduce the incidence of ascending infections of the uterus and the subsequent production of proinflammatory molecules which are important in the pathogenesis of chorioamnionitis and preterm birth.The adult human vagina is a complex ecosystem containing an abundance of microorganisms. In women of childbearing age this system is dominated by Lactobacillus spp., a genus of gram-positive, nonmotile rod-like bacteria, a defining characteristic of which is the ability to grow in acid media and tolerate acid conditions (pH Ͻ 4.5); lactobacilli also ferment carbohydrates to produce lactic acid. In bacterial vaginosis (BV) the balance of flora is changed with reduced numbers of lactobacilli and an increase in numbers of other facultative and anaerobic species such as anaerobic cocci Prevotella spp., Gardnerella vaginalis, and Mobiluncus spp. BV is associated with a number of poor health outcomes, including preterm birth (31). Lactobacilli, principally the strains that are H 2 O 2 producing, may have a protective effect against vaginal colonization by pathogenic species such as those that cause BV (16) and possibly human immunodeficiency virus and gonorrhoea (26). Previous reports have also suggested that H 2 O 2 -producing lactobacilli in the vagina may protect pregnant women against ascending infection of the chorioamniotic membranes and uterine cavity (12, 18). There have been few studies in which lactobacilli have been identified to species level and in which H 2 O 2 production in pregnant women has been determined. We report the identification and H 2 O 2 production of lactobacilli isolated from vaginal swabs collected at 20 weeks' gestatio...

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