title: High prevalence of subtype 4 among isolates of Blastocystis hominis from symptomatic patients of a health district of Valencia (Spain).
abstract: In order to know the genetic diversity of Blastocystis hominis from a health district of Valencia (Spain) 51 clinical isolates from symptomatic patients, 31 axenic and 20 monoxenic, were ribotyped by analysing the restriction fragment length polymorphism (RFLP) of amplicons obtained by polymerase chain reaction (PCR) of small-subunit of ribosomal DNA genes (SSU-rDNA). For this purpose, DNA was subjected to two independent PCR (RD3-RD5, F1-R1) and to three independent treatments with restrictases (AluI, HinfI and RsaI). The digested DNA was separated electrophoretically, the isolates were clustered into ribotypes (ribodemes, RD3-RD5; subgroups, F1-R1) according to their profiles and the results were translated into genetic subtypes (ST) proposed by a consensus terminology. The results show that the isolates studied are an heterogeneous population and that both PCR-RFLP SSU-rDNA protocols have a similar discriminative power, since it allowed the ribotyping of all isolates and their clustering into four demes: ribodemes 1, 3 and 3-r and 6, which include isolates belonging to subgroup III, IV, V and V-r, respectively; which were assigned to ST1 (2%), ST2 (3.9%) and ST4 (94.1%). The most common of which is a zoonotic subtype (Blastocystis ratti) which includes, according to recent studies, non-pathogenic and pathogenic variants.
authors.affiliation: Servicio de Microbiología, Hospital Universitario de La Ribera, Alzira 46600, Spain.
authors.forename: M Victoria
authors.initials: MV
authors.lastname: Domínguez-Márquez
authors.forename: Remedios
authors.initials: R
authors.lastname: Guna
authors.forename: Carlos
authors.initials: C
authors.lastname: Muñoz
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Gómez-Muñoz
authors.forename: Rafael
authors.initials: R
authors.lastname: Borrás
mesh_terms: D000328:Adult; D000818:Animals; D016776:Blastocystis Infections / Q000453:epidemiology* / Q000469:parasitology*; D016845:Blastocystis hominis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D015995:Prevalence; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D021521:Ribotyping; D013030:Spain / Q000453:epidemiology; D055815:Young Adult
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S