title: Conventional polymerase chain reaction for the diagnosis of neurotoxoplasmosis: comparison of three sets of primers for the B1 gene using CSF samples.
abstract: Polymerase chain reaction (PCR) has made a significant improvement in the diagnosis of toxoplasmic encephalitis (TE). Nevertheless, a wide variety of targets and primers has been used in different assays, and few comparative studies had been carried out. The aim of the present study was to compare the efficiency of 3 conventional PCR methods by using 3 sets of primers targeting the repetitive B1 gene in the diagnosis of TE. Diagnostic sensitivity and specificity of PCR and nested-PCR protocols were assessed for 207 (nested-PCR/T1-T4), 200 (nested-PCR/S1-AS1), and 206 (PCR/B22-B23) cerebrospinal fluid (CSF) samples, including AIDS and HIV-negative patients. The diagnostic sensitivity of PCR and nested-PCR assays was 50.85%, 68.97%, and 72.41% for T1-T4, S1-AS1, and B22-B23, respectively. The diagnostic specificity was high for all the assays showing values between 95% and 97%. In general, the best results were obtained for the B22-B23 set of primers, suggesting their usefulness compared with 2 nested-PCR protocols and showing that this simple and rapid strategy may be the preferred one for the diagnosis of TE in AIDS patients.
authors.affiliation: Parasitology Department, Institute of Tropical Medicine Pedro Kourí, Havana, Cuba.
authors.forename: Yenisey
authors.initials: Y
authors.lastname: Alfonso
authors.forename: Jorge
authors.initials: J
authors.lastname: Fraga
authors.forename: Raymundo
authors.initials: R
authors.lastname: Cox
authors.forename: Narciso
authors.initials: N
authors.lastname: Jiménez
authors.forename: Virginia
authors.initials: V
authors.lastname: Capó
authors.forename: Olga
authors.initials: O
authors.lastname: Pomier
authors.forename: Carlos
authors.initials: C
authors.lastname: Fonseca
authors.forename: Francisco
authors.initials: F
authors.lastname: Bandera
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Dorta-Contreras
authors.forename: Vianka
authors.initials: V
authors.lastname: Calá
authors.forename: Dora
authors.initials: D
authors.lastname: Ginorio
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D017931:DNA Primers; D016054:DNA, Protozoan / Q000032:analysis / Q000134:cerebrospinal fluid* / Q000302:isolation & purification; D005260:Female; D017125:Genes, Protozoan; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000235:genetics / Q000302:isolation & purification*; D016781:Toxoplasmosis, Cerebral / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D017931:DNA Primers; D016054:DNA, Protozoan