Polymerase chain reaction based restriction fragment length polymorphism for the genotyping of cytomegalovirus (CMV) from patients with CMV disease in Chennai.

BACKGROUND &
OBJECTIVES: Since cytomegalovirus (CMV) is heterogenous and exhibits genomic polymorphism, polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) was applied to identify the glycoprotein B subtypes in patients diagnosed to have CMV disease.
METHODS: CMV standard strain (AD 169) and 55 clinical specimens from 50 patients (35 males; 15 females) positive for CMV by PCR coding for the morphological transforming region II gene were subjected to PCR coding for gp 55 region of CMV gB gene. PCR amplified products were subjected to RFLP using Hinf I.
RESULTS: Of 50 patients, 26 (52.0%) (20 males; 6 females) were positive by PCR (gB gene). Upon RFLP, AD 169 and CMV strains of 14 (53.8%) patients (14 males) were typed as subtype II, and 12 (46.1%) (6 males; 6 females) as subtype III. Of 11 paediatric patients, 7 (63.6%) were infected with CMV subtype II and 4 (36.4%) with subtype III. CMV strains of the dual specimens from 3 PCR positive patients belonged to the same subtype. INTERPRETATION &
CONCLUSION: In this study on CMV genotypes, CMV gB subtypes II and III were found in 53.8 and 46.1 per cent patients studied respectively, while I and IV were not present.