{'fraction_non_alphanumeric': 0.03854482459939368, 'fraction_numerical': 0.021654395842355997, 'mean_word_length': 5.875, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Linezolid limits burden of methicillin-resistant Staphylococcus aureus in biofilm of tracheal tubes

Objective: To evaluate the effects of systemic treatment with linezolid compared with vancomycin on biofilm formation in mechanically ventilated pigs with severe methicillin-resistant Staphylococcus aureus–induced pneumonia. Design: Prospective randomized animal study. Setting: Departments of Pneumology, Microbiology, and Pharmacy of the Hospital Clínic, Barcelona, and Scientific and Technological Services of the University of Barcelona. Subjects: We prospectively analyzed 70 endotracheal tube samples. Endotracheal tubes were obtained from pigs either untreated (controls, n = 20), or treated with vancomycin (n = 32) or linezolid (n = 18). Interventions: The endotracheal tubes were obtained from a previous randomized study in tracheally intubated pigs with methicillin-resistant Staphylococcus aureus severe pneumonia, and mechanically ventilated for 69 ± 16 hrs. Measurements and Main Results: Distal and medial hemisections of the endotracheal tube were assessed to quantify methicillin-resistant Staphylococcus aureus burden, antibiotic biofilm concentration by high-performance liquid chromatography or bioassay, and biofilm thickness through scanning electron microscopy. We found a trend toward a significant variation in biofilm methicillin-resistant Staphylococcus aureus burden (log colony-forming unit/mL) among groups (p = .057), and the lowest bacterial burden was found in endotracheal tubes treated with linezolid (1.98 ± 1.68) in comparison with untreated endotracheal tubes (3.72 ± 2.20, p = .045) or those treated with vancomycin (2.97 ± 2.43, p = .286). Biofilm linezolid concentration was 19-fold above the linezolid minimum inhibitory concentration, whereas biofilm vancomycin concentration (1.60 ± 0.91 µg/mL) was consistently below or close to the vancomycin minimum inhibitory concentration. Biofilm was thicker in the vancomycin group (p = .077). Conclusions: Systemic treatment with linezolid limits endotracheal tube biofilm development and methicillin-resistant Staphylococcus aureus burden. The potential clinical usefulness of linezolid in decreasing the risk of biofilm-related respiratory infections during prolonged tracheal intubation requires further investigation.