Marinkovic, Danijela (2025) A longitudinal study of the microbial colonisation patterns in a hospital water distribution system and its impact on health. Masters thesis, York St John University.

Text (MSc by Research thesis) A longitudinal study of the microbial colonisation patterns in a hospital water distribution system and its impact on health.pdf - Published Version Restricted to Repository staff only until 25 August 2026. Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (3MB) Request a copy

Abstract

Water delivered to taps is not sterile and harbours many microbial species necessitating prior treatments. Water companies use different methods to eliminate and control microbes prior to the point-of-use and hospitals have further requirements for water safety and infection control purposes. Despite these measures, pathogens still find their way into water and represent a threat to vulnerable patients. Thirteen opportunistic premise plumbing pathogens (OPPPs) found in water have been proposed but only two are routinely tested for by current methods (i.e., HTM 04-01).

A total of 345 water samples were collected from a new hospital building opening to patients in 2025 and analysed using traditional microbiological methods (TMM) to identify bacterial species. This included culture techniques and polymerase chain reaction (PCR) amplification to confirm bacterial identity at the genus-species level. The most commonly identified species recovered across 11 sampling occasions were various Pseudomonas genera (P. stutzeri (most frequently isolated)), P. alcaligenes, P. luteola, and P. oryzihabitans), Burkholderia cepacia, Alcaligene faecalis, Aeromonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia.

To investigate if more time-efficient and accurate methodology was available, next generation sequencing was performed using the Oxford Nanopore MinION long-read sequencing technology. Analysis was performed on an additional sampling occasion and directly compared using filtration, DNA extraction, and PCR on 16S rRNA gene regions. Results indicate that MinION identified more bacterial species present in extracted DNA from sampled water than TMM. MinION sequencing identified eight additional bacterial genera, including Sphingomonas spp., Cupriavidus spp., and Elizabethkingia spp., with all classified as potential opportunistic pathogens. This demonstrates limitations in TMM which restricts isolation and identification due to unmet growth conditions.

Overall, there was a good match between both methodologies and coupling nucleotide sequencing with existing TMM could enhance microbiology detection processes, facilitating earlier interventions and limiting the impact of microbial contamination on healthcare systems.

Item Type:	Thesis (Masters)
Status:	Published
Subjects:	Q Science > Q Science (General) Q Science > QR Microbiology
School/Department:	School of Science, Technology and Health
URI:	https://ray.yorksj.ac.uk/id/eprint/14039

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