Isolation and Identification of Free Living Amoeba from Patients and Contact Lens Users in Iran

Free-living amoebae (FLA) such as Acanthamoeba spp., are considered as opportunistic and pathogenic protozoans.  Acanthamoeba granulomatous encephalitis (AGE) is a serious threat for immunodeficient patients and Acanthamoeba keratitis (AK) for contact lens users. We aimed to identify the presence of free living amoebae in nasal swabs of patients and contact lens users in Qazvin, Iran.

During 2019, 251 nasal and oral swabs (including the pharynx and mouth) were collected from patients with diabetes, AIDS and those under periodic dialysis in Qazvin, Iran. In addition, 27 soft contact lenses were collected from the participants. Following DNA extraction, PCR and sequencing were conducted to identify the genotypes of the amoeba. Phylogenetic analysis of the identified sequences was performed using MEGA 7 software.

A strain of Acanthamoeba belonging to the T3 genotype was isolated from hemodialysis patients. Two specimens of Acanthamoeba with T3 genotype were isolated from keratitis patients.

The clinicians should pay attention to the possible complication of this organism because this amoeba is potentially pathogenic for immunocompromised patients. Since the amoeba is present in environmental resources, the use of contact lenses should be accompanied by considering proper hygiene.