MOLECULAR CHARACTERIZATION AND SEQUENCE PHYLOGENETIC ANALYSIS OF SURFACE ANTIGEN 3 (SAG3) GENE OF LOCAL INDIAN ISOLATES (CHENNAI AND IZATNAGAR) OF Toxoplasma gondii

Context and objective:

The molecular characterization of local isolates of Toxoplasma gondii is considered significant so as to assess the homologous variations between the different loci of various strains of parasites.

Design and setting:

The present communication deals with the molecular cloning and sequence analysis of the 1158 bp entire open reading frame (ORF) of surface antigen 3 (SAG3) of two Indian T. gondii isolates (Chennai and Izatnagar) being maintained as cryostock at the IVRI.

Method:

The surface antigen 3 (SAG3) of two local Indian isolates were cloned and sequenced before being compared with the available published sequences.

Results:

The sequence comparison analysis revealed 99.9% homology with the standard published RH strain sequence of T. gondii. The strains were also compared with other established published sequences and found to be most related to the P-Br strain and CEP strain (both 99.3%), and least with PRU strain (98.4%). However, the two Indian isolates had 100% homology between them.

Conclusion:

Finally, it was concluded that the Indian isolates were closer to the RH strain than to the P-Br strain (Brazilian strain), the CEP strain and the PRU strains (USA), with respect to nucleotide homology. The two Indian isolates used in the present study are known to vary between themselves, as far as homologies related to other genes are concerned, but they were found to be 100% homologous as far as SAG3 locus is concerned. This could be attributed to the fact that this SAG3 might be a conserved locus and thereby, further detailed studies are thereby warranted to exploit the use of this particular molecule in diagnostics and immunoprophylactics. The findings are important from the point of view of molecular phylogeny.     

Disability in Indian patients with haemophilia

Chronic shortage of clotting factor concentrates, exorbitant treatment costs and the poor economic status of patients makes disability an inevitable consequence of haemophilia in India. The prevalence and risk factors for disability were studied in 148 patients with severe haemophilia A registered at five haemophilia clinics in the country. Disability was measured using a scoring method that used a compilation of functional ability, mobility and range-of-motion scores for each patient. Patients ranged in age from 5 to 55 years. Only nine of 148 patients were free of disability. The proportion of disability free patients in the 5-12, 13-24 and 25+ age groups were 14.3%, 4.4% and 0% respectively. The risk factors significantly associated with disability were patients age, socio-economic status, number of persons in the family, family history of haemophilia, frequency of physiotherapy exercises, home use of coagulation factor concentrate and type of blood product(s) used, that is clotting factor concentrate or cryoprecipitate. The study highlights the need to provide coagulation factor concentrates in sufficient amounts to prevent disability, the beneficial role of physiotherapy exercises and the advantage of older patients as peer educators for younger patients. The most important utility of the data is to demonstrate the widespread prevalence of disability amongst patients, its social costs in terms of incomplete education and unemployment, which justifies the need to include haemophilia as one of the conditions under the Disability Act of India.     

Pannus and enthesitis in the atlanto‐axial region in ankylosing spondylitis

A 30‐year‐old man with ankylosing spondylitis (AS) of 7 years duration consulted us for intractable neck pain of 2 months duration. Magnetic resonance imaging cervical spine showed inflammatory pannus around the dens and computed tomography scan showed fluffy periostitis at the attachment of the alar ligament. Cervical spine involvement in AS is reviewed.