Genotyping of Cytomegalovirus from Symptomatic Infected Neonates in Iraq

Abstract

. Among all other viruses, human cytomegalovirus (HCMV) is the most frequent cause of congenital infection worldwide. Strain variation in HCMV may predict severity or outcome of congenital HCMV disease. Previous studies have associated a particular genotype with specific sequelae or more severe illness, but the results were contradictory. There are no previous studies addressing the genotype of HCMV in Iraq. Therefore, the present study is aimed at molecular detection and genotyping of HCMV isolated from symptomatic congenitally/perinatally infected neonates. This prospective study comprised 24 serum samples from symptomatic neonates with congenital/perinatal infection. Viral DNA was extracted from these serum samples; nested polymerase chain reaction was used to amplify the HCMV gB ( UL55 ) gene. Polymerase chain reaction products of the second round of amplification were subjected to direct Sanger sequencing. Bioedit and MEGA5 software (EMBL-EBI, Hinxton, Cambridgeshire, UK) were used for alignment and construction of a phylogenetic tree. Human cytomegalovirus DNA was detected in 23 of 24 samples (95.8%). According to the phylogenetic analysis, three genotypes of the virus were identified; gB1, gB2, and gB3 genotypes. However, the gB4 genotype was not detected. Human cytomegalovirus gB3 was the most frequent genotype: 14 of 24 (58.33%) among symptomatic infected infants, followed by gB1 (6/24; 25%) and gB2 (4/24; 16.67%). A mixed HCMV infection with gB3/gB1 was detected in only one case. Human cytomegalovirus gB3 was the most predominant genotype among symptomatic congenitally/perinatally HCMV-infected neonates. No association was found between B3 genotype and specific clinical presentation. Jaundice was the most common clinical feature among symptomatically infected neonates, followed by hepatosplenomegaly.

Common Polymorphisms in the Glycoproteins of Human Cytomegalovirus and Associated Strain-Specific Immunity

“…Compared to a single gB genotype infection, mixed gB genotype infections are frequently reported in organ/bone marrow transplant recipients and AIDS patients [105,118,125,128,129,152]. Multiple studies have also demonstrated that mixed infections are able to be transmitted in utero [63,68,[74][75][76][77]109,122,134,137,138,141]. Although there is no established association between single genotype infections and disease outcomes, patients with mixed gB genotype infections have been reported to have faster disease progression or higher viral loads [83,97,102,144].…”

Clinical Features, Treatment Courses, and Distribution of Cytomegalovirus Genotypes among Thrombocytopenia Patients Aged Younger than 12 Months

“…The potential significant differences in genotype distribution found in different studies may be based on geographical distribution, patient population, and CMV tissue tropism 25 26 Ignoring these factors to investigate the possible relationship between genotype and clinical features may lead to wrong conclusions. We systematically reviewed some literature concerning the distributions of gB genotype among Chinese populations.…”

Analysis of the relationship between human cytomegalovirus DNA and gB-1 genotype in the saliva of HIV/AIDS patients with xerostomia and salivary flow rate

“…33 However, other studies confirmed that gB3 and gB2 were the most prevalent genotypes in the sera of AIDS patients and HCMV-infected neonates and a high incidence of mixed infection with the gB1 and gB3 genotypes. 34,35 HCMV is known to be responsible for a variety of diseases, for example, in the oral cavity; persistent and atypical mucosal ulcers and xerostomia potentially accompanied by salivary gland dysfunction. 36 The prevalence of xerostomia among HIV-infected patients, has been estimated to range from 1.2 to 40% 22 and reduced salivary flow rate occurs in 2-30% of subjects.…”