Molecular investigation of bacterial communities on intravascular catheters: no longer just Staphylococcus

• Published in: European journal of clinical microbiology & infectious diseases 2014-07, Vol.33 (7), p.1189-1198
• Main Authors: Zhang, L., Gowardman, J., Morrison, M., Krause, L., Playford, E. G., Rickard, C. M.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Bacteria; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Bacterial diseases; Biofilms; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Biota; Catheters; Cluster Analysis; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Drug resistance; Drug Resistance, Bacterial; Escherichia; Ethics; Female; Human bacterial diseases; Humans; Infectious diseases; Intensive care; Internal Medicine; Laboratories; Male; Medical equipment; Medical instruments; Medical Microbiology; Medical sciences; Microbial activity; Microorganisms; Middle Aged; Molecular Sequence Data; Mortality; Nosocomial infections; Pathogens; Patients; Phylogeny; Propionibacterium; Ralstonia; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus; Streptococcus; Vascular Access Devices - microbiology; Young Adult
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-014-2058-2

Intravascular catheter-related bloodstream infections (IVC-BSIs) are associated with significant morbidity and mortality. Culture-independent molecular approaches can reveal and capture the composition of complex microbial communities, and are now being used to reveal “new” pathogens as well as the polymicrobial nature of some infections. Patients with concurrently sited arterial and central venous catheters who had clinically suspected IVC-BSIs, were examined by the high-throughput sequencing of microbial 16S rRNA. An average of 100 operational taxonomic units (OTUs, phylotypes) was observed on each IVC, indicating that IVCs were colonised by complex and diverse bacterial communities. Ralstonia (53 % of 16S rRNA sequences), Escherichia group (16 %), Propionibacterium (5 %), Staphylococcus (5 %), and Streptococcus (2 %) were the most abundant genera. There was no statistically significant difference in the bacterial communities examined from arterial and central venous catheters; from those with and without systemic antibiotic treatment; or from conventionally colonised and uncolonised IVCs. The genome of the predominant bacteria, R. pickettii AU12-08, was found to encode resistance to antimicrobial drugs of different classes. In addition, many encoded gene products are involved in quorum sensing and biofilm formation that would further contribute to increased antimicrobial drug resistance. Our results highlight the complex diversity of microbial ecosystems on vascular devices. High-throughput sequencing of 16S rRNA offers an insight into the pathogenesis of IVC-related infections, and opens up the scope for improving diagnosis and patient management.