Direct analysis of bacterial viability in endotracheal tube biofilm from a pig model of methicillin-resistant Staphylococcus aureus pneumonia following antimicrobial therapy.

Abstract

Confocal laser scanning microscopy (CLSM) helps to observe the biofilms formed in the endotracheal tube (ETT) of ventilated subjects and to determine its structure and bacterial viability using specific dyes. We compared the effect of three different treatments (placebo, linezolid, and vancomycin) on the bacterial biofilm viability captured by CLSM. Eight pigs with pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) were ventilated up to 96 h and treated with linezolid, vancomycin, or placebo (controls). ETT images were microscopically examined after staining with the live/dead(®) BacLight(™) Kit (Invitrogen, Barcelona, Spain) with a confocal laser scanning microscope. We analyzed 127 images obtained by CLSM. The median ratio of live/dead bacteria was 0.51, 0.74, and 1 for the linezolid, vancomycin, and control groups, respectively (P = 0.002 for the three groups); this ratio was significantly lower for the linezolid group, compared with the control group (P = 0.001). Images showed bacterial biofilm attached and non-attached to the ETT surface but growing within secretions accumulated inside ETT. Systemic treatment with linezolid is associated with a higher proportion of dead bacteria in the ETT biofilm of animals with MRSA pneumonia. Biofilm clusters not necessarily attach to the ETT surface.

• Authors: Laia Fernández-Barat, Gianluigi Li Bassi, Miquel Ferrer, Anna Bosch, Maria Calvo, Jordi Vila, Albert Gabarrús, Pilar Martínez-Olondris, Montse Rigol, Mariano Esperatti, Néstor Luque, Antoni Torres
• Journal: FEMS immunology and medical microbiology (FEMS Immunol Med Microbiol) Vol. 65 Issue 2 Pg. 309-17 (Jul 2012) ISSN: 1574-695X [Electronic] England
• PMID: 22444646 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Chemical References

• Acetamides
• Anti-Bacterial Agents
• Oxazolidinones
• Placebos
• Vancomycin
• Linezolid

Topics

• Acetamides (administration & dosage)
• Animals
• Anti-Bacterial Agents (administration & dosage)
• Biofilms (drug effects, growth & development)
• Disease Models, Animal
• Equipment and Supplies (microbiology)
• Intubation, Intratracheal
• Linezolid
• Methicillin-Resistant Staphylococcus aureus (drug effects, physiology)
• Microbial Viability (drug effects)
• Microscopy, Confocal
• Oxazolidinones (administration & dosage)
• Placebos (administration & dosage)
• Pneumonia, Staphylococcal (drug therapy, microbiology)
• Spain
• Staining and Labeling (methods)
• Swine
• Vancomycin (administration & dosage)