Mixed infections with distinct cytomegalovirus glycoprotein B genotypes in Polish pregnant women, fetuses, and newborns

Abstract

The purpose of this investigation was to describe a distribution of cytomegalovirus (CMV) single and multiple genotypes among infected pregnant women, their fetuses, and newborns coming from Central Poland, as well as congenital cytomegaly outcome. The study involved 278 CMV-seropositive pregnant women, of whom 192 were tested for viral DNAemia. Human cytomegalovirus (HCMV) genotyping was performed for 18 of 34 pregnant women carrying the viral DNA and for 12 of their 15 offspring with confirmed HCMV infections. Anti-HCMV antibodies levels were assessed by chemiluminescence immunoassay (CLIA) and enzyme-linked fluorescence assay (ELFA) tests. Viral DNA loads and genotypes were determined by real-time polymerase chain reaction (PCR) assays for the UL55 gene. In the pregnant women, we identified HCMV gB1, gB2, gB3, and gB4 genotypes. Single gB2, gB3, or gB4 genotypes were observed in 14 (77.8 %) women, while multiple gB1–gB2 or gB2–gB3 genotypes were observed in four (22.2 %). Maternal HCMV genotypes determined the genotypes identified in their fetuses and newborns (p ≤ 0.050). Half of them were infected with single HCMV gB1, gB2, or gB3 genotypes and the other half with multiple gB1–gB2 or gB2–gB3 genotypes. Single and multiple genotypes were observed in both asymptomatic and symptomatic congenital cytomegaly, although no gB3 genotype was identified among asymptomatic cases. In Central Poland, infections with single and multiple HCMV strains occur in pregnant women, as well as in their fetuses and neonates, with both asymptomatic and symptomatic infections. HCMV infections identified in mothers seem to be associated with the viral genotypes in their children.

Diagnosis, gB genotype distribution and viral load of symptomatic congenitally infected CMV patients in Cuba

“…In other studies, gB-1 has been detected as the predominant genotype (46% of all infants). 24,25 Rycel et al 23 argued that the genotypic variability of CMV seems to be geographically related, because rates of mixed infections varied from low frequency (2% in Chinese) to high frequency (45% in American infants). Furthermore, despite genotypic variability of CMV seems to be geographically related, different genotypification methodologies have proven different sensitivities for mixed infection detection.…”

Cytomegalovirus in pregnancy and the neonate

“…In CMV seropositive women, the risk factors for congenital infection are less well defined, although in a recent study of pregnant Polish women, around 22% of seropositive women who transmitted to their neonate were infected with multiple CMV strains as judged by glycoprotein B genotyping 20 . Additional studies by targeted sequencing demonstrated that other genes of CMV have highly variable regions including proteins gN, gO, gH, and UL144 2 , 3 .…”

Is the mixture of human cytomegalovirus genotypes frequent in infants with congenital infection at birth in a high seroprevalence population?

“…On the other hand, there is evidence proposing that coinfection with more than 1 HCMV strain may be a frequent event at birth in children with congenital infection . Ross et al analyzed samples of saliva, urine, and blood from 28 children with HCMV congenital infection using PCR, followed by cloning and Sanger sequencing for the gN, gB, and gH genes.…”

“…Although there are studies in low HCMV seroprevalence populations showing the occurrence of multiple HCMV strains in the urine, saliva, and blood of children with congenital infection by this virus, there are no studies in populations with high seroprevalence . It is not known whether women with nonprimary infection, even if they are carriers of more than 1 viral strain, transmit 1 or more strains with which they had contact during or before gestation.…”