Molecular identification of Acanthamoeba genotypes isolated from oral cavity of Heart Transplant Patients in Iran.

OBJECTIVE Heart transplant is one of the accepted treatments for some patients with advanced heart failure. Of note, transplant surgeries may cause different infections and complications for patients during the post-transplant period. A wide variety of opportunistic organisms caused these infections including bacteria, fungi, viruses, and protozoa particularly Free-Living Amaoebae (FLA). This study aims to study the presence of pathogenic free- living amoebae from oral cavity of post heart transplant recipient. METHODS Throat swabs were collected from 80 patients who underwent post heart transplant surgery. All swabs were immediately cultured in non-nutrient agar (2%). PCR and sequencing of 18S rRNA gene (DF3 region) of Acanthamoeba isolates was performed using genus specific primers. Genetic associations among sequenced genotypes inferred by the 18S rRNA gene obtained by MEGAX and phylogenetic tree was constructed using maximum likelihood algorithm and Kimura 2-parameter model. RESULTS Out of 80 samples collected from post heart transplant patients, 6 (7.5%) samples showed positive outgrowth of Acanthamoeba based on the page key and sequencing of DF3 region. Sequence similarity of ASA1 by BLAST(n) showed that five isolates (ANHT1, ANHT2, ANHT3, ANHT4, ANHT5) belonged to Acanthamoeba T5 genotype corresponding to A. lenticulata and one strain (ANHT6) belonged to T4 genotype. CONCLUSION To the best of our knowledge for the first time, a comprehensive study of Acanthamoeba genotypes isolated from throat samples of heart transplant recipients is described. Heart transplantation patients can be colonized by FLA and are therefore at risk of developing invasive infection. Physicians awareness of CNS infections related to FLAs and preventive and control measures of patients with compromised immune status due to heart transplant surgery are of utmost importance. This article is protected by copyright. All rights reserved.