title: First evidence of genetic intraspecific variability and occurrence of Entamoeba gingivalis in HIV(+)/AIDS.
abstract: Entamoeba gingivalis is considered an oral commensal but demonstrates a pathogenic potential associated with periodontal disease in immunocompromised individuals. Therefore, this study evaluated the occurrence, opportunistic conditions, and intraspecific genetic variability of E. gingivalis in HIV(+)/AIDS patients. Entamoeba gingivalis was studied using fresh examination (FE), culture, and PCR from bacterial plaque samples collected from 82 HIV(+)/AIDS patients. Genetic characterization of the lower ribosomal subunit of region 18S (18S-SSU rRNA) was conducted in 9 positive samples using low-stringency single specific primer PCR (LSSP-PCR) and sequencing analysis. Entamoeba gingivalis was detected in 63.4% (52/82) of the samples. No association was detected between the presence of E. gingivalis and the CD4(+) lymphocyte count (≤200 cells/mm(3) (p = 0.912) or viral load (p = 0.429). The LSSP-PCR results helped group E. gingivalis populations into 2 polymorphic groups (68.3% similarity): group I, associated with 63.6% (7/11) of the samples, and group II, associated with 36.4% (4/11) of the samples, which shared 74% and 83.7% similarity and association with C and E isolates from HIV(-) individuals, respectively. Sequencing of 4 samples demonstrated 99% identity with the reference strain ATCC 30927 and also showed 2 divergent clusters, similar to those detected by LSSP-PCR. Opportunistic behavior of E. gingivalis was not detected, which may be related to the use of highly active antiretroviral therapy by all HIV(+)/AIDS patients. The high occurrence of E. gingivalis in these patients can be influenced by multifactorial components not directly related to the CD4(+) lymphocyte counts, such as cholesterol and the oral microbiota host, which could mask the potential opportunistic ability of E. gingivalis. The identification of the 18S SSU-rRNA polymorphism by LSSP-PCR and sequencing analysis provides the first evidence of genetic variability in E. gingivalis isolated from HIV patients.
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Sibeli B S
authors.initials: SB
authors.lastname: Cembranelli
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Fernanda O
authors.initials: FO
authors.lastname: Souto
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Kennio
authors.initials: K
authors.lastname: Ferreira-Paim
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Túlio T
authors.initials: TT
authors.lastname: Richinho
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Poliana L
authors.initials: PL
authors.lastname: Nunes
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Gabriel A N
authors.initials: GA
authors.lastname: Nascentes
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Thatiana B
authors.initials: TB
authors.lastname: Ferreira
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Dalmo
authors.initials: D
authors.lastname: Correia
authors.affiliation: Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.
authors.forename: Eliane
authors.initials: E
authors.lastname: Lages-Silva
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000821:virology; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D060085:Coinfection; D004747:Entamoeba / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004749:Entamoebiasis / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D005260:Female; D014644:Genetic Variation; D006678:HIV; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D005810:Multigene Family; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000145:classification* / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D019562:Viral Load
chemical_list: D012337:RNA, Ribosomal, 18S