Identification of Free-Living Amoebae and Amoeba-Associated Bacteria from Reservoirs and Water Treatment Plants by Molecular Techniques

Abstract

The occurrence of free-living amoebae (FLA) was investigated in 83 water samples from reservoirs and water treatment plants, with culture positive in 64 of them (77.1%). Polymerase chain reaction (PCR) of partial 18S rRNA gene and ITS region was performed in order to identify amoeba isolates, and the presence of Legionella pneumophila , Mycobacterium spp., Pseudomonas spp., and Microcystis aeruginosa was investigated in 43 isolates of amoebae by multiplex PCR. Of the isolated amoebae, 31 were Acanthamoeba spp., 21 were Hartmannella vermiformis, 13 were Naegleria spp., and one was Vanella spp. T2, T4, and T5 genotypes of Acanthamoeba have been identified, and T4 isolates were grouped into five subgenotypes and graphically represented with a Weblog application. Inside amoebae, L. pneumophila was detected in 13.9% (6/43) of the isolates, and Pseudomonas spp. and Mycobacterium spp. were detected in 32.6% (14/43) and 41.9% (18/43), respectively. No statistical correlation was demonstrated between FLA isolation and seasonality, but the presence of intracellular bacteria was associated with warm water temperatures, and also the intracellular presence of Mycobacterium spp. and Pseudomonas spp. were associated. These results highlight the importance of amoebae in natural waters as reservoirs of potential pathogens and its possible role in the spread of bacterial genera with interest in public and environmental health.

Impact of upstream chlorination on filter performance and microbial community structure of GAC and anthracite biofilters

“…The observed amoebas had diameters of 20-30 μm. Comparison with literature suggests that these viable amoebas exhibit similar morphology to the genus Vannella, which consists of flabellate amoebas found in freshwater, soil, and seawater (typical diameter = 9-80 μm), 42 as well as in swamps, 43 and moist sanitary areas. 44 They have also been identified in drinking water treatment plants, drinking water biofilms, hot water tanks, and residential and hospital tap waters.…”

Current and Emerging Legionella Diagnostics for Laboratory and Outbreak Investigations

“…An extensive collection of case studies and research articles dating back Ͼ30 years demonstrates the adaptability and potential of legionellae to colonize man-made aquatic environments ( Fig. 1), from the initial point of water treatment (69)(70)(71)(72)(73) to private homes (74)(75)(76)(77)(78), hospitals (79)(80)(81)(82)(83), restaurants (84,85), bath houses (86)(87)(88)(89), hotels (90)(91)(92), and, eventually, wastewater facilities (93,94). These studies underscore the resiliency and persistence of legionellae.…”

Isolation and identification of pathogenic free-living amoeba from surface and tap water of Shiraz City using morphological and molecular methods

“…Naegleria is considered the agent of the lethal disease primary amoebic encephalitis (PAM) in young adults who have the history of water activities like diving (Jamerson et al 2009;Visvesvara et al 2007). This parasite can tolerate high temperatures and could live in warm water sources especially in sedentary water deposits (Garcia et al 2013). Recently, mixed infection of Acanthamoeba and Hartmannella (Vermamoeba) in AK patients has led to the increase of attention to other FLA as potentially pathogenic organisms to human (Lorenzo-Morales et al, 2007).…”