title: Genetic characterization of Toxoplasma gondii from autopsy proven cases of AIDS associated cerebral toxoplasmosis in South India.
abstract: Toxoplasma gondii (T.gondii) infection can be devastating in the immunodeficient causing high morbidity and mortality. Due to limited availability of both diagnostic facilities and Highly Active Antiretroviral Therapy (HAART), toxoplasmosis continues to be a significant problem amongst Acquired Immuno Deficiency Syndrome (AIDS) patients in India. While scanty literature is available on T. gondii isolates in animals in India, little is known about the genetic diversity of the parasite in humans. Therefore, the present study investigated the genetic diversity of T. gondii in 25 confirmed cases of cerebral toxoplasmosis developing on the background of human immunodeficiency virus (HIV) infection/AIDS. PCR DNA sequencing was performed at four important genetic loci of T. gondii: BTUB, GRA6, alternative SAG2 (alt SAG2) and SAG3 on DNA from tissues obtained at postmortem. The amplified products from all the cases were successfully sequenced except at one locus for one case. Results of the present study suggest that majority of the patients (22/25; 88%) in South India are infected with strains that are recombinants of type II/III and/or strains representing T. gondii different from the archetypal lineages I, II, and III. In addition, clonal types III, MAS, and MAS variant genotypes were encountered. No clonal type I or II was seen in the present study. In addition, variants were observed at alt SAG2 and SAG3 but BTUB and GRA6 were highly conserved. Single nucleotide polymorphisms were observed mainly at two loci which are coding for surface antigens at alt SAG2 and SAG3. In conclusion, the present study reveals genetic diversity in India amongst strains of T. gondii from clinical cases of toxoplasmosis which is in accordance with other recent studies showing a high rate of genetic diversity in this parasite across the globe. There is a need to genotype T. gondii from different forms of toxoplasmosis in humans in India.
authors.affiliation: Department of Microbiology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: br.vijaykumar@rediffmail.com.
authors.forename: B R
authors.initials: BR
authors.lastname: Vijaykumar
authors.affiliation: Department of Microbiology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: swathiulekshmi@gmail.com.
authors.forename: Swathi U
authors.initials: SU
authors.lastname: Lekshmi
authors.affiliation: Department of Microbiology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: r.saikant@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Sai Kant
authors.affiliation: Department of Cell Biology and Molecular Genetics, Sri Devaraj Urs Academy of Higher Education and Research, Tamaka, Kolar 563101, India. Electronic address: vaigundan@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Vaigundan
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neurosciences, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: anita_mahadevan@yahoo.com.
authors.forename: Anita
authors.initials: A
authors.lastname: Mahadevan
authors.affiliation: Defence Food Research Laboratory, Defence Research & Development Organisation, Siddhartha Nagar, Mysore 570011, India. Electronic address: chellairajendran1@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Rajendran
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neurosciences, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: shankarsk2004@gmail.com.
authors.forename: S K
authors.initials: SK
authors.lastname: Shankar
authors.affiliation: Department of Microbiology, Kidwai Memorial Institute of Oncology, Dr. M. H. Marigowda Road, Bangalore 560029, India. Electronic address: microjayshree@gmail.com.
authors.forename: R S
authors.initials: RS
authors.lastname: Jayshree
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000469:parasitology*; D000328:Adult; D001344:Autopsy; D019143:Evolution, Molecular; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing / Q000379:methods; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014122:Toxoplasma / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016781:Toxoplasmosis, Cerebral / Q000134:cerebrospinal fluid / Q000469:parasitology*
chemical_list: D015800:Protozoan Proteins
keywords: Acquired Immuno Deficiency Syndrome; Cerebral toxoplasmosis; Genotyping; Human immunodeficiency virus; Single nucleotide polymorphisms; Toxoplasma gondii