Detecting drug-resistant human cytomegalovirus mutations in liver transplant recipients: A study of the UL97 gene

Human cytomegalovirus (HCMV or HHV-5) is a member of the beta herpesvirus family and remains dormant for life after the initial infection. However, if conditions such as immunosuppression occur, the virus can become active again and lead to severe diseases. The incidence of disease in solid organ transplant (SOT) recipients is reduced by prophylactic use of ganciclovir (either intravenously or orally). This study aimed to determine the pattern of clinical mutations associated with the cytomegalovirus UL97 gene after treatment with ganciclovir and the effect of these mutations on disease progression in liver transplant recipients infected with Iranian HCMV strains. Six HCMV-positive liver transplant recipients were enrolled, comprising 3 (50.0 %) males and 3 (50.0 %) females. Sequence analysis and mutation detection were performed using Finch software (version 1.4.0) and the NCBI Nucleotide Blast database, whereas phylogenetic analysis was performed using MEGA X (version 10.0.5). Mann-Whitney U nonparametric test, Chi-square test, Spearman's correlation coefficient analysis, were employed for statistical analysis. The results of the study showed that two samples from two patients had mutations in the UL97 gene, and the viral load of the mutated samples decreased after administering antiviral medications. Furthermore, the phylogenetic tree demonstrated a close relationship between the Iranian HCMV strains and global reference sequences.