Microbial investigations in throat swab and tracheal aspirate specimens are beneficial to predict the corresponding endotracheal tube biofilm flora among intubated neonates with ventilator-associated pneumonia

Abstract

Abstract. Ventilator-associated pneumonia (VAP) is a common nosocomial infection in neonatal intensive care units with high morbidity and mortality. Bacterial biofilm in the endotracheal tube (ET) provides a notable and persistent source of pathogens that may cause VAP, and thus is important for VAP detection. However, during intubation microbial investigations in ET, samples are unavailable due to the infeasibility of collecting ET samples during intubation of neonates. It is therefore of great importance to find alternative sources of samples that can help identify the ET biofilm flora. In the present study, the microbial signatures of throat swabs and tracheal aspirates were compared with ET biofilm samples from VAP neonates using 16S ribosomal RNA gene polymerase chain reaction, denaturing gradient gel electrophoresis (DGGE), cloning and sequencing. Sequences were assigned to phylogenetic species using BLAST. Microbial diversity and richness among the three types of specimens were compared based on their DGGE fingerprints, and taxonomic characteristics based on the BLAST results. The microbial richness and diversity of ET biofilms were similar to tracheal aspirate yet significantly different from throat swab samples (P<0.05). Compared with ET biofilms, the overall constituent ratio of microflora was significantly different in throat swab and tracheal aspirate samples (P<0.05). However tracheal aspirate samples were useful for predicting Staphylococcus sp. in ET biofilms with a sensitivity of 85.7% and a specificity of 83.3%. The sensitivity for the combination of tracheal aspirate and throat swab samples to detect Staphylococcus sp. in ET biofilms was 100%. The detection of Pseudomonas sp. in throat swabs assisted its identification in ET biofilms (sensitivity 33.3% and specificity 100%). The results of the present study suggest that microbial investigations in throat swab and tracheal aspirate samples are beneficial for identifying the ET biofilm flora. There may therefore be clinical applications of using substituent samples to identify pathogens in ET biofilms for VAP surveillance among intubated neonates.

Significance of sTREM-1 in early prediction of ventilator-associated pneumonia in neonates: a single-center, prospective, observational study

“…VAP is a frequently seen complication in neonates treated with MV, and it is associated with a high morbidity and mortality [2,18]. Early recognition of VAP permits the timely implementations of treatment strategies [19], but unfortunately, early diagnosis of VAP is difficult mainly due to the lack of specific early clinical manifestations.…”

“…Ventilator-associated complications have increasingly drawn attention in ventilated neonatal patients due to their detrimental impact on prognosis. Ventilator-associated pneumonia (VAP) is one of the most commonly seen complications in neonatal patients [ 1 ], and it usually leads to a difficult ventilator weaning, which increases the duration of intensive care unit (ICU) stay [ 2 ]. The reported mortality rates among neonatal patients with VAP have been as high as 20–75% in both China and western countries [ 3 – 5 ].…”

Endotracheal Tube Biofilm and its Impact on the Pathogenesis of Ventilator-Associated Pneumonia

“…Pan et al . uses 16S ribosomal RNA gene polymerase chain reaction, denaturing gradient gel electrophoresis (DGGE), cloning and sequencing in 15 pediatric VAP to compare throat swabs and tracheal aspirates versus ET biofilm samples [30]. Cairns et al .…”

“…Several mechanisms are responsible for ET biofilm involvement in VAP pathogenesis: biofilm pieces dispersed and passively moved towards the lung, biofilm cells aerosolized and aspirated into the lungs due to gas flow during artificial ventilation and individual cells can be dislodged by liquids and transferred deep into the lungs [24, 30].…”

Autoinducer-2 Facilitates Pseudomonas aeruginosa PAO1 Pathogenicity in Vitro and in Vivo

“…The AI-2 used in this study was chosen as a biological relevant concentration, because 10 nM AI-2 resulted in the greatest response in virulence factor production and biofilm formation ( Li et al, 2015a ). Furthermore, AI-2 producing S. mitis and Klebsiella pneumoniae were the most frequent microbes in the biofilms on the surface of neonatal endotracheal tubes extubated from mechanically ventilated newborns, and the AI-2 concentration secreted by these AI-2 producing bacteria in the biofilms on the surface of neonatal endotracheal tubes was about 10–50 nM ( Li et al, 2015b ; Wang et al, 2016 ; Pan et al, 2017 ).…”