TY - JOUR
T1 - Unusual abundance of atypical strains associated with human ocular toxoplasmosis
AU - Grigg, Michael E.
AU - Ganatra, Jyotsom
AU - Boothroyd, John C.
AU - Margolis, Todd P.
N1 - Funding Information:
Received 4 April 2000; revised 16 May 2001; electronically published 24 July 2001. The protocol used in this study was approved by the University of California, San Francisco, Committee on Human Research. Financial support: Alameda County District Attorney’s Office (Food Safety Initiative grant); National Institutes of Health (grants AI-21423, AI-41014, EY-10008, and EY-02162); Research to Prevent Blindness Lew Wasserman Merit Award (to T.P.M.). a M.E.G. and J.G. contributed equally to this work. Reprints or correspondence: Dr. Todd P. Margolis, Francis I. Proctor Foundation, Box 0944, UCSF Medical Center, San Francisco, CA 94143-0944 ([email protected]).
PY - 2001/9/1
Y1 - 2001/9/1
N2 - To facilitate genotyping of Toxoplasma gondii in vitreous fluid of patients with severe or atypical ocular toxoplasmosis, polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) assays were developed for SA G3 (p43) and SAG4 (p18), 2 single-copy surface antigen genes. Together with strategies for S A G1, S A G2, and B1, multilocus RFLP analyses were performed on PCR-amplified parasite DNA present in 12 clinical specimens. Most samples (8/12) were not infected by type II or type III mouse-avirulent strains. Only 1 type III and 3 type II strains were identified, all from immunosuppressed patients. In 6 otherwise healthy adults and in 1 immunosuppressed patient, the S A G1 allele associated with mouse virulence was amplified. Of 12 samples, 3 possessed true type I strains; 5 of 12 had new recombinant genotypes with alleles typical of type I or III strains at all loci examined. The unusual bias toward type I and/or recombinant genotypes bearing the SA G1 type I allele associated with mouse virulence in immunocompetent adults has important implications for the epidemiology and efficacious treatment of ocular toxoplasmosis.
AB - To facilitate genotyping of Toxoplasma gondii in vitreous fluid of patients with severe or atypical ocular toxoplasmosis, polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) assays were developed for SA G3 (p43) and SAG4 (p18), 2 single-copy surface antigen genes. Together with strategies for S A G1, S A G2, and B1, multilocus RFLP analyses were performed on PCR-amplified parasite DNA present in 12 clinical specimens. Most samples (8/12) were not infected by type II or type III mouse-avirulent strains. Only 1 type III and 3 type II strains were identified, all from immunosuppressed patients. In 6 otherwise healthy adults and in 1 immunosuppressed patient, the S A G1 allele associated with mouse virulence was amplified. Of 12 samples, 3 possessed true type I strains; 5 of 12 had new recombinant genotypes with alleles typical of type I or III strains at all loci examined. The unusual bias toward type I and/or recombinant genotypes bearing the SA G1 type I allele associated with mouse virulence in immunocompetent adults has important implications for the epidemiology and efficacious treatment of ocular toxoplasmosis.
UR - http://www.scopus.com/inward/record.url?scp=0035450774&partnerID=8YFLogxK
U2 - 10.1086/322800
DO - 10.1086/322800
M3 - Article
C2 - 11474426
AN - SCOPUS:0035450774
SN - 0022-1899
VL - 184
SP - 633
EP - 639
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 5
ER -