Distinct genotypic distribution of cytomegalovirus (CMV) envelope glycoprotein B (gB) in a Cuban cohort of patients with different CMV diseases.

To investigate the association between human CMV glycoprotein B (gB) genotypes and CMV disease, we retrospectively analysed 73 biological samples from 56 Cuban patients with different CMV-related diseases using a multiplex nested PCR for detection of the reported 5 CMV gB genotypes. All 4 main genotypes 1 to 4 were found in the clinical samples while no genotype 5 was detected. Among the individuals analysed, genotype gB-2 was the most prevalent (38%) followed by gB-1 (30%) and mixed infections (16%) being mainly detected among immunosuppressed patients (7 out of 9), although there was no association between mixed infections and CMV rejection in transplant recipients. Genotype gB-4 was the least frequent (5 patients), which was almost exclusively detected in mixed infections (4 out of 5, p<0.0001). Genotype gB-1 was more frequently detected in AIDS patients (47%) although it was not statistically significant, while 68% of transplant patients showed mixed infections (p<0.05). This study represents the first report of human CMV gB genotypes in Cuban patients; however, the study is limited by the small number patients, thus making it difficult to draw firm conclusions about the distribution of CMV genotypes in Cuba. Nevertheless, this preliminary report has allowed us to identify that the main 4 CMV genotypes are present in the Cuban population, with genotypes 2 and 1 being the most frequent strains.