Biofilms on Hospital Shower Hoses: Characterization and Implications for Nosocomial Infections

Abstract

e Although the source of drinking water (DW) used in hospitals is commonly disinfected, biofilms forming on water pipelines are a refuge for bacteria, including possible pathogens that survive different disinfection strategies. These biofilm communities are only beginning to be explored by culture-independent techniques that circumvent the limitations of conventional monitoring efforts. Hence, theories regarding the frequency of opportunistic pathogens in DW biofilms and how biofilm members withstand high doses of disinfectants and/or chlorine residuals in the water supply remain speculative. The aim of this study was to characterize the composition of microbial communities growing on five hospital shower hoses using both 16S rRNA gene sequencing of bacterial isolates and whole-genome shotgun metagenome sequencing. The resulting data revealed a Mycobacterium-like population, closely related to Mycobacterium rhodesiae and Mycobacterium tusciae, to be the predominant taxon in all five samples, and its nearly complete draft genome sequence was recovered. In contrast, the fraction recovered by culture was mostly affiliated with Proteobacteria, including members of the genera Sphingomonas, Blastomonas, and Porphyrobacter. The biofilm community harbored genes related to disinfectant tolerance (2.34% of the total annotated proteins) and a lower abundance of virulence determinants related to colonization and evasion of the host immune system. Additionally, genes potentially conferring resistance to ␤-lactam, aminoglycoside, amphenicol, and quinolone antibiotics were detected. Collectively, our results underscore the need to understand the microbiome of DW biofilms using metagenomic approaches. This information might lead to more robust management practices that minimize the risks associated with exposure to opportunistic pathogens in hospitals.

Ecological analyses of mycobacteria in showerhead biofilms and their relevance to human health

“…Mycobacterium accounting for >10% of 16S rRNA gene reads in 238 of the total 652 samples. The observed ubiquity of mycobacteria is comparable to other studies that have used cultivation-independent methods to assess mycobacterial abundances in water 150 distribution systems (4,14,15,31).…”

The role of hospital environment in transmissions of multidrug-resistant gram-negative organisms

“…However, the aqueous environment presents unique challenges to infection prevention and control (IPC), with wet surfaces providing the solid-liquid interface that predisposes to biofilm formation [8]. These biofilms have been proven to harbour multidrugresistant Gram-negative organisms (MDRO) [2,9] which were genetically related to clinical isolates suggesting that aqueous environment can serve as a reservoir for human infections. Furthermore, waste material disposed into the sinks and drains potentially provide the nutrients necessary for the formation and maintenance of biofilms which function as a reservoir for MDRO [10].…”

Transitory Change of Bacterial Community Structure in Hot Water Biofilm: Effects of Anti‐Legionella Treatments

“…Three genera dominated the bacteria in the biofilm during anti‐ Legionella treatments period; Aquabacterium , Novosphingobium , and Burkholderiales . Aside from Aquabacterium , which is naturally found in water environment, Novosphingobium is frequently detected in water distribution systems due to its known resistance to water disinfectants …”