title: Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii.
abstract: BACKGROUND
  The level of intra-species genetic variation in Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii populations in a localized geographic area, like Puducherry, India, remains unknown.
  
  
  METHODS
  In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR) amplified region of the 16S-like ribosomal RNA genes of E. histolytica, E. dispar and E. moshkovskii was investigated by riboprinting and single strand conformation polymorphism (SSCP) analysis.
  
  
  RESULTS
  We found that 70 stool specimens were positive for E. histolytica, 171 stool specimens were positive for E. dispar, and 37 stool specimens were positive for E. moshkovskii by NM-PCR. Ninety liver abscess pus specimens, 21 urine specimens, and 8 saliva specimens were positive for E. histolytica by NM-PCR. Riboprinting analysis detected a mutation in the PCR product of only one E. histolytica isolate from a stool specimen. However, SSCP analysis detected mutations in the PCR products of five E. histolytica isolates and three E. moshkovskii isolates from stool specimens, and one E. histolytica isolate from a saliva specimen. The mutations detected by riboprinting and SSCP analysis were confirmed by sequencing. All the nucleotide sequences showing mutations in this study have already been deposited into the NCBI GenBank database under accession numbers [GenBank: EF682200 to GenBank: EF682208].
  
  
  CONCLUSIONS
  The present study has revealed the subsistence of mutations in the ribosomal RNA genes of E. histolytica and E. moshkovskii, which points towards the existence of intra-species genetic variation in E. histolytica and E. moshkovskii isolates infecting humans.
authors.affiliation: Department of Microbiology, Jawaharlal Institute of Postgraduate, Medical Education and Research, Puducherry, 605006, India. subhashparija@yahoo.co.in
authors.forename: Subhash Chandra
authors.initials: SC
authors.lastname: Parija
authors.forename: Krishna
authors.initials: K
authors.lastname: Khairnar
mesh_terms: D000818:Animals; D001483:Base Sequence; D004404:Dysentery, Amebic / Q000469:parasitology; D004747:Entamoeba / Q000145:classification / Q000235:genetics*; D004748:Entamoeba histolytica / Q000145:classification / Q000235:genetics*; D005243:Feces / Q000469:parasitology; D017125:Genes, Protozoan; D020459:Genes, rRNA; D006801:Humans; D007194:India; D008101:Liver Abscess, Amebic / Q000469:parasitology; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D016053:RNA, Protozoan / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D015183:Restriction Mapping; D021521:Ribotyping; D012463:Saliva / Q000469:parasitology; D016415:Sequence Alignment; D013492:Suppuration / Q000469:parasitology; D014556:Urine / Q000469:parasitology
chemical_list: D016053:RNA, Protozoan; D012336:RNA, Ribosomal, 16S