Morphological and molecular identification of free living amoeba isolated from hospital water in Tunisia

Abstract

Free-living amoebae (FLA) are opportunistic and ubiquitous protozoa that are widely found in various environmental sources. They are known to cause serious human infections. The aim of our study was to detect FLA and Acanthamoeba spp. in hospital water circuits. Eighty-four water samples were collected over a period of 4 months (September-December 2011) from different wards of the Sfax University Hospital (surgical services, intensive care unit, operating theater, and water storage tanks). FLA were detected in 53.5 % of samples as follows: surgical services (80 %), operating theater and surgical intensive care unit (13.3 %), medical intensive care unit (0 %), water storage tanks (6.6 %). The predominant morphotype was the acanthopodial (89 %). The others morphotypes were as follows: monopodial (40 %), dactylopodial (22 %), rugosa (62 %), eruptive (24 %), fan shaped (18 %), and polypodial (18 %). Acanthamoeba was found in 40 samples (47.6 %). 64.2 % of isolates were identified as Acanthamoeba spp. by PCR, using primers to amplify a region of 18S rDNA which showed variation in the product length. Sequence analysis of five PCR products identified Acanthamoeba sp. These isolates belong to T4, T10, and T11 genotypes, and to our knowledge this is the first report of the T10 and T11 genotype in Tunisia.The occurrence of potentially pathogenic FLA in the hospital environment may represent a health risk for patients, since these organisms can cause severe opportunistic illness and also can harbor pathogenic agents. Thus, increased awareness regarding these parasites and recognition of their importance, particularly in immunocompromised patients is crucial.

Isolation and molecular identification of Acanthamoeba spp. from hospital dust and soil of Khomein, Iran, as reservoir for nosocomial infection.

“…Microbial surveillance of the hospital environmental resources, especially in developing countries, does not include analyzing for the presence of FLA. On the other hand, in developing countries conventional tests used in medical laboratories for isolation and characterization of FLA agents are not able to identify the Acanthamoeba spp., hence control of these organisms in the hospital environment and setting are difficult ( Trabelsi et al, 2016 ). However, many studies have showed that contamination of hospital equipment and supplies, traced to the persistence of FLA in dust and soil, and their high resistance to disinfectants, could be responsible for pseudo-outbreaks of infections associated with Acanthamoeba spp.…”

Free-living amoebae and their relationship to air quality in hospital environments: characterization of Acanthamoeba spp. obtained from air-conditioning systems

“…Studies of FLA isolation in hospital environments are scarce, despite the importance of these microorganisms as potential causers of opportunistic infections and as vehicles and reservoirs of pathogens. Some reports of isolation of these amoebas in hospital environments have been described from water systems (Trabelsi et al ., 2016; Muchesa et al ., 2017), dust and biofilm (Silva and Rosa, 2003; Carlesso et al ., 2010; Costa et al ., 2010). Reports of FLA isolation from air conditioners have been described in some countries such as Chile (Astorga et al ., 2011) and Malaysia (Chan et al ., 2011), however, in hospital environments the presence of these amoebae in air conditioners is still poorly investigated.…”

Investigating the frequency of free-living amoeba in water resources with emphasis on Acanthamoeba in Bandar Abbas city, Hormozgan province, Iran in 2019–2020

“…In Turkey, environmental samples (100%), in USA 2454 tap water samples (51%), water supply in Osaka, Japan (19%), and in 40 water and sanitation facilities samples in Tunisia Hospital (47.6%) Acanthamoeba was found [ 4 – 6 ].…”