Molecular characterization of clinical varicella-zoster strains from India and differentiation from the oka vaccine strain.
With the introduction of varicella vaccination in India, surveillance of circulating varicella-zoster strains has gained significance. The aim of the present study was to achieve molecular characterization of circulating varicella-zoster virus (VZV) strains and differentiation from the Oka vaccine strain. In this study, the genotype of 100 clinical VZV strains was analyzed. Vesicle fluid was collected from patients with VZV infections (92 cases of varicella and 8 cases of herpes zoster). The PCR-RFLP analysis of two polymorphic loci--a PstI restriction site in ORF 38 and a BglI restriction site in ORF 54 was used to characterize and differentiate them from the vaccine strain. All the wild-type strains were positive for the PstI restriction site in ORF 38. This differentiated them from the Oka vaccine strain, which is PstI negative. The wild-type strains as well as the Oka vaccine strain were positive for the BglI restriction site in ORF 54. Thus, the genotype of all the VZV strains examined had the wild-type pattern represented as PstI(+) BglI(+). None of the strains had the PstI(-) BglI(+) genotype characteristic of the Oka strain or the PstI(+) BglI(-) wild-type pattern. To conclude, PstI and BglI serve as good reference markers in the genotyping of circulating varicella strains in India and serve to differentiate them from the vaccine strain as well as other wild-type strains.
Kaushik
Karishma S
KS
Department of Microbiology, Armed Forces Medical College, Pune, India. mahakaroo@yahoo.com
Lahiri
Kunak K
KK
Chumber
Sushil K
SK
Gupta
Rajiv M
RM
Kumar
Satish
S
Kapila
Ketoki
K
Karade
Santosh
S
D002644:Chickenpox / Q000821:virology*; D019433:Chickenpox Vaccine; D005838:Genotype; D006562:Herpes Zoster / Q000821:virology*; D014645:Herpesvirus 3, Human / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D007194:India; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length
D019433:Chickenpox Vaccine