title: Free living amoebae in water sources of critical units in a tertiary care hospital in India.
abstract: BACKGROUND
  Isolation of free-living amoebae (FLA) is reported sparsely from water taps, ventilators, air conditioners, haemodialysis units and dental irrigation systems of hospitals worldwide. Their prevalence in hospital environment especially in wards having immunocompromised patients may pose a risk to this group of susceptible population as they may cause disease themselves or may carry pathogens inside them. No study from India has performed such surveillance.
  
  
  OBJECTIVE
  To evaluate extent of FLA contamination in water sources of bone marrow transplant (BMT) intensive care unit (ICU), transplant ICU, haemodialysis unit and high dependency unit in a tertiary care hospital in India.
  
  
  METHODS
  A total of hundred samples including fifty each of tap water samples and swabs from mouth of taps used for drinking, bathing and hand washing purposes in these units were collected according to standard procedure. Samples were inoculated onto non-nutrient agar plates at room temperature followed by morphological confirmation. Molecular identification including polymerase chain reaction (PCR) and sequencing was performed in culture positive samples.
  
  
  RESULTS
  Four tap water samples and ten swab samples showed growth of trophozoites and cyst formation. Morphologically, four amoebae resembled Acanthamoeba spp. which was further confirmed by PCR and sequencing showed them to be of T3 and T4 genotypes.
  
  
  CONCLUSIONS
  The presence of these FLA in hospital water sources emphasises the urgent need of implementing effective preventive measures. Further studies are required to estimate the true prevalence of FLA in Indian hospitals by taking larger number of samples.
authors.affiliation: Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: S
authors.initials: S
authors.lastname: Khurana
authors.forename: M
authors.initials: M
authors.lastname: Biswal
authors.forename: H
authors.initials: H
authors.lastname: Kaur
authors.forename: P
authors.initials: P
authors.lastname: Malhotra
authors.forename: P
authors.initials: P
authors.lastname: Arora
authors.forename: K
authors.initials: K
authors.lastname: Megha
authors.forename: N
authors.initials: N
authors.lastname: Taneja
authors.forename: R
authors.initials: R
authors.lastname: Sehgal
mesh_terms: D000048:Acanthamoeba / Q000302:isolation & purification*; D006748:Hospital Departments; D006801:Humans; D007194:India; D008828:Microbiological Techniques; D010274:Parasitology / Q000379:methods; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D062606:Tertiary Care Centers; D014867:Water / Q000469:parasitology*
chemical_list: D014867:Water