Molecular Characterization of <i>Molluscum Contagiosum</i> Virus: Identification of a Putative New Clade Through <i>MC021L</i> Gene Analysis in Diyala Province, Iraq

This research concentrated on the molecular diagnosis of <i>Molluscum contagiosum</i> (MC) in clinically suspected individuals from Diyala Province, Iraq, through the identification of the <i>MC021L</i> gene in skin tissue samples between October 2020 and April 2021. A total of 101 skin lesion samples were collected from patients suspected of MC infection, ranging in age from 5 months to 60 years and including both males and females. Samples were gathered from Baquba Teaching Hospital, the dermatology clinic, and multiple basic healthcare centers, where a tailored questionnaire was developed to capture sociodemographic and clinical details. All samples were analyzed using conventional PCR to detect the <i>MC021L</i> gene with specific primers, followed by gene sequencing and phylogenetic analysis. Data were analyzed using SPSS Version 27, with statistical significance set at <i>p</i> < 0.05. PCR results showed that 19 samples (18.8%) tested positive, with distinct bands at 979 bp. Sequencing of the <i>MC021L</i> locus uncovered 52 nucleic acid variations that are present in almost all samples (including missense mutations in the <i>MC021L</i>-encoded glycoprotein). These variations were uniformly distributed across the <i>MC021L</i> gene in the viral samples. Phylogenetic analysis revealed that all viral strains belonged to a putative new clade that was located between Subtypes-I and -II. Four isolates were submitted to the NCBI database and assigned the accession numbers LC629162, LC629163, LC629164, and LC629165. The unique genetic sequences of these isolates of the <i>MC021L</i> gene confirmed that they do not match any previously identified subtypes, paving the way for further scientific exploration.