Detection of amoeba-associated Legionella pneumophila in hospital water networks of Johannesburg

Abstract

The prevalence of free-living amoeba and associated Legionella spp. in hospital water systems may pose a risk of Legionnaires’ disease to immuno-compromised patients. This study investigated the occurrence of amoeba-associated Legionella pneumophila in three South African hospital water systems. A total of 98 water and/or biofilm samples were collected from the sterilisation unit, theatres, neonatal ward and intensive care units. Amoebae were isolated from 71 (72.4%) samples. Isolated amoebae were analysed using qPCR and culture methods to test for the presence of Legionella. L. pneumophila did not grow on selective media in any of the samples. A total of 7 out of the 71 (9.9%) amoeba-positive samples showed a positive reaction for L. pneumophila using qPCR. Although relatively few samples were positive for Legionella in this preliminary study, the association with amoeba still presents a potential public health risk to immuno-compromised patients when exposed to contaminated water.

Monitoring Water Quality Parameters in Egyptian Tap Water

“…Free-living amoebae that were found in all sampling districts might be due to its wide ecological distribution in the environment [3]. They have been frequently found in humans and have been isolated from drinking water plants [6,25], hospital water networks [8,[26][27] and domestic water networks [2,16,28]. Several studies were conducted in Egypt and recorded FLAs in tap water: 4% in samples collected from different Egyptian governorates [29] and 60.4% in Giza governorate [16].…”

“…Biofilm formation attracts more predatory FLAs, which engulf and feed on bacterial colonies [5,12]. Therefore, high contamination of the piped water network with FLAs would definitely result in nosocomial infections due to the survival and persistence of these pathogens in the biofilms inside the storage tanks of hospitals [8,[26][27].…”

“…Free-living amoebae pose a potential health risk in water systems as they may be pathogenic and harbor potential pathogenic bacteria known as amoebaeresistant bacteria such as methicillin-resistant Staphylococcus aureus, Vibrio cholerae and Legionella species, including Legionella pneumophila and environmental Mycobacterium species [13]. Therefore, FLAs are reservoirs of various bacteria and other microorganisms, among which some are pathogenic, thus being of particular importance for human health [8,14]. FLAs have been described as biological by-passes of water treatment because they can protect intracellular bacteria as well as improving their virulence and antimicrobial resistance [15].…”

Abstracts of the 78th Scientific Conference of the University of Latvia

“…FLP is able to create biofilms in water pipes and can protect pathogenic bacteria from high temperatures, disinfectants, can serve as a reservoir for bacterial populations. The interaction of bacteria and protozoa can increase the resistance of microorganisms to antibiotics and their virulence (Muchesa et al 2018).…”

The traditional use of southern African medicinal plants for the treatment of bacterial respiratory diseases: A review of the ethnobotany and scientific evaluations

“…This review concentrates on the use of southern African plants to treat these four diseases due to their relevance to southern African health. Whilst other bacteria such as Legionella pneumophila (Legionaires disease) may also cause respiratory diseases, they make relatively minor contributions to southern African health ( Muchesa et al, 2018 ) and thus are not a focus of this review.…”