Microbial Composition and Antibiotic Resistance of Biofilms Recovered from Endotracheal Tubes of Mechanically Ventilated Patients

Abstract

In critically ill patients, breathing is impaired and mechanical ventilation, using an endotracheal tube (ET) connected to a ventilator, is necessary. Although mechanical ventilation is a life-saving procedure, it is not without risk. Because of several reasons, a biofilm often forms at the distal end of the ET and this biofilm is a persistent source of bacteria which can infect the lungs, causing ventilator-associated pneumonia (VAP). There is a link between the microbial flora of ET biofilms and the microorganisms involved in the onset of VAP. Culture dependent and independent techniques were already used to identify the microbial flora of ET biofilms and also, the antibiotic resistance of microorganisms obtained from ET biofilms was determined. The ESKAPE pathogens play a dominant role in the onset of VAP and these organisms were frequently identified in ET biofilms. Also, antibiotic resistant microorganisms were frequently present in ET biofilms. Members of the normal oral flora were also identified in ET biofilms but it is thought that these organisms initiate ET biofilm formation and are not directly involved in the development of VAP.

The dynamics of the pulmonary microbiome during mechanical ventilation in the intensive care unit and the association with occurrence of pneumonia

“…ETTs are known to provide a mechanical barrier between bacteria and host circulatory system and as a consequence may limit the access of antibiotics 26. In addition, bacteria recovered from ETTs show increased antibiotic resistance 27. Another explanation is that some classes of antibiotics impact the respiratory microbiome, while others do not.…”

Healthcare-associated infections, medical devices and biofilms: risk, tolerance and control

“…Vandecandelaere and colleagues identified micro-organisms in biofilm form on ETTs using a combination of traditional culture techniques and 16S rRNA sequencing. The results revealed the presence of a diverse range of micro-organisms, from the common oral-associated microflora to more clinically relevant isolates, including Acinetobacter spp., P. aeruginosa, S. aureus and S. epidermidis (Vandecandelaere et al, 2012;Vandecandelaere & Coenye, 2015). These authors not only highlighted the importance of utilizing multiple techniques for the identification of biofilms but also emphasized the microbial diversity within biofilms in ETTs.…”

Recent Nanotechnology Approaches for Prevention and Treatment of Biofilm-Associated Infections on Medical Devices

“…These organisms include methicillin-resistant S. aureus (MRSA) and Gram-negative bacilli, such as E. coli , K. pneumoniae , P. aeruginosa and Acinetobacter spp ., which are key factors of ventilator-associated pneumonia development [90]. Reports indicate diverse microorganisms, from orally associated microflora to clinically specific isolates, can form biofilms in endotracheal tubes [91, 92]. …”