Development and evaluation of molecular tools for detecting and differentiating intestinal amoebae in healthy individuals. Issue 6 (14th January 2019)

• Record Type: Journal Article
• Authors: Chihi, Amal; Stensvold, Christen R.; Ben-abda, Imene; Ben-Romdhane, Rania; Aoun, Karim; Siala, Emna; Bouratbine, Aïda
• Is Part Of: Parasitology. Volume 146:Issue 6(2019)
• Page Start: 821
• Page End: 827
• Publication Date: 2019-01-14
• Subjects: Amoeba, -- diagnosis, -- Endolimax, -- Entamoeba, -- human gut, -- Iodamoeba, -- parasite, -- PCR; Parasitology -- Periodicals; Electronic journals; 616.96
• DOI: 10.1017/S0031182018002196
• Languages: English
• ISSNs: 0031-1820

Abstract

Abstract: Amoebae are single-celled parasites frequently colonizing human gut. However, few molecular tools are available for accurate identification. Here, we evaluated a panel of polymerase chain reactions (PCRs) targeting Entamoeba histolytica, Entamoeba dispar, Entamoeba coli, Entamoeba hartmanni, Entamoeba polecki, Endolimax nana and Iodamoeba bütschlii . Thirty-six faecal samples (18 containing at least one amoeba species by microscopy and 18 microscopy negative for amoebae) were tested. Real-time PCRs were used for detection and differentiation of E. histolytica and E. dispar . Conventional PCR with Sanger sequencing were applied for detection and differentiation of E. coli, E. hartmanni, E. polecki, E. nana and I. bütschlii. All microscopy results were confirmed by DNA-based methods. However, more samples were positive for single and mixed amoebic species by DNA-based assays than by microscopy (22 vs 18 and 7 vs 1, respectively). DNA sequencing allowed identification of E. coli subtypes (ST1 and ST2), showed low intra-specific variation within E. hartmanni, identified two phylogenetically distinct groups within E. nana, and identified Iodamoeba at the ribosomal lineage level. Taking into account the high intra-genetic diversity within some of the species at the small subunit (SSU) rRNA gene level, amplification of SSU rRNA genes with subsequent sequencing represents a useful method for detecting, differentiating and subtyping intestinal amoebae.