Opportunistic Pathogens Mycobacterium Avium Complex (MAC) and Legionella spp. Colonise Model Shower

Harriet Whiley; Steven Giglio; Richard Bentham

doi:10.3390/pathogens4030590

Opportunistic Pathogens Mycobacterium Avium Complex (MAC) and Legionella spp. Colonise Model Shower

Pathogens. 2015 Jul 24;4(3):590-8. doi: 10.3390/pathogens4030590.

Authors

Harriet Whiley¹, Steven Giglio², Richard Bentham³

Affiliations

¹ School of the Environment, Health and the Environment, Flinders University, GPO BOX 2100, Adelaide 5001, Australia. harriet.whiley@flinders.edu.au.
² Healthscope Pathology SA, 1 Goodwood Rd, Wayville 5034, South Australia. Steven.Giglio@healthscope.com.au.
³ School of the Environment, Health and the Environment, Flinders University, GPO BOX 2100, Adelaide 5001, Australia. richardhbentham@gmail.com.

Abstract

Legionella spp. and Mycobacterium avium complex (MAC) are opportunistic pathogens of public health concern. Hot water systems, including showers, have been identified as a potential source of infection. This paper describes the colonization of Legionella and MAC on the flexible tubing within a model potable shower system, utilizing thermostatic mixing and a flexible shower head. A MAC qPCR method of enumeration was also developed. MAC and Legionella spp. were detected within the biofilm at maximum concentrations of 7.0 × 104 and 2.0 × 103 copies/cm2 PVC tubing respectively. No significant changes were observed between sample of the flexible shower tubing that dried between uses and those that remained filled with water. This suggested the "unhooking" showerheads and allowing them to dry is not an effective method to reduce the risk of Legionella or MAC colonisation.

Keywords: Legionella pneumophila; Legionella spp.; Mycobacterium avium complex (MAC); biofilm; model; non-tuberculous mycobacterium (NTM); potable water; showers.