Anaerobes in nosocomial and community acquired pleural infections

Abstract

Anaerobes are important causes of pleural space infections. The aim of the study is to evaluate the role of the anaerobic bacteria in pleural infections. The study involved 278 consecutive clinical samples sent to the Clinical Microbiology Laboratory of Tertiary Chest Hospital. Anaerobes were isolated in 39 community acquired and five nosocomial cases out of 278 anaerobic cultivations (15.8%). Total of 56 anaerobe strains were identified and 21 aerobes were accompanied to anaerobic isolates. Aerobe isolates were associated with anaerobic microorganisms in 19 cases (43.2%). Bacteroides species (21.4%) and Pseudomonas aeruginosa (33.3%) were the most common anaerobic and aerobic isolates.

Analysis of antibiotic use and clinical outcomes in adults with known and suspected pleural empyema

“…The population of culpable organisms is thought to partially overlap with but to be distinct from the population of organisms that causes bacterial pneumonia, given that pneumonia is not always the cause of empyema and that the relatively hypoxic pleural space is a distinct host environment from the lung parenchyma [5,6,10,11]. Anaerobes are widely agreed to be clinically significant players in cases of lung abscess, necrotizing pneumonia, and bronchopleural fistulas, but some historical and more recent studies have also implicated anaerobes as relatively frequent isolates in cultures of empyema specimens [4,8,[12][13][14], and more than 25% of the pleural cultures from empyema patients in Bulgaria in a 2004 investigation grew only anaerobes [14]. In fact, reported rates of isolation of anaerobes may be underestimates of their actual presence given that anaerobes do not always grow reliably in culture, especially in mixed infections and in patients who have already received antibiotics by the time a specimen is obtained for culture.…”

“…None of the independent variables was associated with mortality. Longer total antibiotic duration was associated with lower readmission rate for empyema (median 17 [interquartile range 11-28] antibiotic days in non-readmission group vs. 13 [6][7][8][9][10][11][12][13][14][15] days in readmission group), with a non-significant trend for all-cause readmission rate (17 [11-28] days vs. 14 [9-21] days). IV antibiotic duration was not associated with a difference in any of the defined outcomes.…”