Glycoprotein B genotyping in congenital/perinatal Cytomegalovirus infection in symptomatic infants

Distribution of CMV envelope glycoprotein B, H and N genotypes in infants with congenital cytomegalovirus symptomatic infection

Background

Cytomegalovirus (CMV) is the leading cause of congenital infections worldwide and contributes to long-term sequelae in neonates and children. CMV envelope glycoproteins play a vital role in virus entry and cell fusion. The association between CMV polymorphisms and clinical outcomes remains controversial. The present study aims to demonstrate the distribution of glycoprotein B (gB), H (gH) and N (gN) genotypes in congenitally CMV (cCMV) infected symptomatic infants and attempts to figure out the association between viral glycoprotein genotypes and clinical outcomes.

Methods

Genotyping of gB, gH and gN was performed in 42 cCMV symptomatic infants and 149 infants with postnatal CMV (pCMV) infection in Children's hospital of Fudan university. Nested PCR, gene sequencing and phylogenetic analyses were used to identify the genotypes.

Results

Our study demonstrated that: 1. The CMV gB1, gH1 and gN1 were the predominant genotypes among symptomatic cCMV infected infants, while gB1, gH1 and gN3a were more prevalent in pCMV group. gH1 genotype has a significant association with symptomatic cCMV infection (p = 0.006). 2. No significant correlation was found between CMV genotypes and hearing impairment. However, gH1 was more prevalent among cCMV infected infants with moderate/severe hearing loss although without statistical difference (p = 0.130). 3. gB3 was more prevalent among infants with skin petechiae (p = 0.049) and found to be associated with an increased risk of skin petechiae (OR = 6.563). The gN4a subtype was significantly associated with chorioretinitis due to cCMV infection (p = 0.007). 4. Urine viral loads were not significantly associated with different genotypes or hearing impairment among symptomatic cCMV infected infants.

Conclusions

Our findings demonstrated the overall distribution of gB, gH and gN genotypes in infants with symptomatic cCMV infection in Shanghai for the first time. The findings in our study may suggest a possible association between gH1 genotype and early infancy hearing loss. gB3 genotype was associated with a 6.5-fold increased risk of petechiae while gN4a strongly correlated with chorioretinitis due to cCMV infection. No significant correlation was found between urine viral loads and CMV genotypes or hearing impairment in cCMV infected infants.

Molecular Detection and Glycoprotein B (UL55) Genotyping of Cytomegalovirus among Sudanese Renal Transplant Recipients

Background

Cytomegalovirus (CMV) is the most common opportunistic pathogen among renal transplants with significant morbidity and mortality. This study was designed to detect CMV DNA and to determine the frequency of different glycoprotein B (UL55) genotypes among Sudanese renal transplant recipients.

Methods

One hundred and four renal transplant recipients were included in this study. A blood specimen was collected from each recipient. DNA was extracted from plasma using the QIAamp DNA mini kit. CMV amplification and quantification were performed using CMV Real-RT Quant kits. Genotyping of human CMV gB was carried out by nested PCR and sequencing of the highly diverse region of gB.

Results

CMV DNA was detected in 40/104 (38.5%) of renal transplant recipients. The average of the CMV DNA viral load was 358 × 10⁴ copies/ml (6.5 log₁₀) ranging from 62 copies/ml (1.8 log₁₀) to 1.43 × 10⁸ copies/ml (9 log₁₀). CMV viremia was detected in 60% of recipients of less than 1–12 months, 17% of 13–24, 10% of 25–36, 5% of 37–48, and 8% in more than 48 months posttransplantation with no association (p = 0.296) between CMV viremia and postrenal transplantation time. The association between the type of immunosuppressive drugs and high viral loads (>1000 copies/ml) showed a significant difference (p = 0.05). The association between CMV loads of >1000 copies/ml and symptoms of CMV disease was highly significant (p ≤ 0.001). Fever 7 (41%), fever and leucopenia 6 (35%), and gastrointestinal disease 4 (24%) were the most common symptoms of CMV disease. CMV genotyping revealed 8 cases (80%) for gB3 and 2 cases (20%) for gB4 genotypes. The most frequent genotype among Sudanese renal transplant recipients was gB3.

Conclusions

The frequency of CMV DNA is high among Sudanese renal transplant recipients. CMV gB3 is the most predominant glycoprotein B genotype in Sudanese renal transplant recipients.

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

Human cytomegalovirus (HCMV), one of the most prevalent viruses across the globe, is a common cause of morbidity and mortality for immunocompromised individuals. Recent clinical observations have demonstrated that mixed strain infections are common and may lead to more severe disease progression. This clinical observation illustrates the complexity of the HCMV genome and emphasizes the importance of taking a population-level view of genotypic evolution. Here we review frequently sampled polymorphisms in the glycoproteins of HCMV, comparing the variable regions, and summarizing their corresponding geographic distributions observed to date. The related strain-specific immunity, including neutralization activity and antigen-specific cellular immunity, is also discussed. Given that these glycoproteins are common targets for vaccine design and anti-viral therapies, this observed genetic variation represents an important resource for future efforts to combat HCMV infections.

Human cytomegalovirus envelope glycoprotein B, H, and N polymorphisms among infants of Shanghai area in China

Human cytomegalovirus (HCMV) is the leading cause of congenital infection and an opportunistic pathogen capable of establishing lifelong latency. In the present study, we aimed to investigate the distribution of glycoprotein B, H, and N in infants of Shanghai and correlate the genotype with active and latent HCMV infection. A total of 129 urine samples were collected between August 2014 and December 2015 from infants under 3 years with HCMV infection. Nested PCR was used to amplify the regions of UL55 (gB), UL75 (gH), and UL73 (gN). Gene sequencing and phylogenetic analyses were used to classify the genotypes. Overall, regarding gB, gB1 (57.27%) was predominant, followed by gB3 (41.82%) and gB4 (0.91%). gH1 (54.33%) was the most prevalent genotype of gH, followed by gH2 (45.67%). Concerning gN, we detected gN1 (17.44%), gN2 (2.33%), gN3a (29.07%), gN3b (8.14%), gN4a (13.95%), gN4b (15.12%), and gN4c (13.95%), among which gN3a was the dominant genotype. All the expected genotypes were present except gB2 in children with active infection: gB1 (56.25%), gB3 (42.5%), gB4 (1.25%), gH1 (58.70%), gH2 (41.30%), gN1 (19.05%), gN2 (3.17%), gN3a (25.40%), gN3b (6.35%), gN4a (15.87%), gN4b (17.46%), and gN4c (12.70%). However, among latent cases, we detected gB1 (60%), gB3 (40%), gH1 (42.86%), gH2 (57.14%), gN1 (13.04%), gN3a (39.13%), gN3b (13.04%), gN4a (8.70%), gN4b (8.70%), and gN4c (17.39%), respectively. gB2, gB4, and gN2 were absent in this group. The results revealed that gB1, gH1, and gN3a were predominant in the infants of Shanghai. gH showed different trends among children with active and latent infection.

Genotypes of glycoprotein B gene among the Indian symptomatic neonates with congenital CMV infection

BACKGROUND

Cytomegalovirus [CMV] is a causative agent of congenital infection worldwide and often leads to neurological deficits and hearing loss in newborns. Infants born with symptomatic congenital Cytomegalovirus infection [cCMV] are at significant high risk for developing adverse long-term outcomes. In this study, we look into the sequence variability of surface glycoprotein B [gB] encoding region in newborns with symptomatic CMV infection for the first time in Eastern region of India.

METHODS

576 suspected newborns from seropositive mothers were subjected to the study and ELISA was used to confirm CMV infection. Different genotypes and their subtypes were determined using multiplex nested-PCR. Viral load of different glycoprotein B [gB] genotypes was measured using RT-PCR. Sequencing and phylogenetic analysis was then performed using Bayesian interference.

RESULTS

The overall frequency of cCMV infection was 18.4%, where 16.0% neonates were symptomatic. Among the different gB genotypes, gB1 had the highest frequency [23.5%] and gB4 showed the lowest occurrence [5.8%]. 23.5% of symptomatic neonates had mixed genotypes of gB, probably indicating matrenal reinfection with CMV strains in Indian population. Significant genotypic clades [gB1-gB2-gB3-gB5] were grouped closely based on gene sequences, but the gB4 sequence was in the outlier region of the phylogenetic tree indicating the genetic polymorphism.

CONCLUSION

This is the first study on cCMV genotyping and its phylogenetic analysis from Eastern Indian neonatal population. The study holds importance in the assessment of cCMV seroprevalence in global perspective. gB protein can be used as a potential therapeutic target against CMV infection.

Genotyping of Cytomegalovirus from Symptomatic Infected Neonates in Iraq

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.

Cytomegalovirus Genotype Distribution Among Congenitally and Postnatally Infected Patients: Association of Particular Glycoprotein (g)B and gN Types With Symptomatic Disease

Background. Human cytomegalovirus is a leading cause of congenital infection, and there are limited data on prognosis markers in disease development. We aimed to study 3 virology targets (glycoprotein [g]B, gN, and UL144) to assess their correlation with congenital infection and various organ system involvement.

Methods. Forty-eight congenital cases and 58 postnatally infected children were included (2003–2014). Genotyping for the 3 targets and distribution among the cohorts were investigated, and the relationship between the gB, gN, and UL144 types with clinical manifestations in congenital infection was also studied.

Results. All of the genotypes were similarly represented among cohorts, and the most prevalent were the UL144B, gB1, and gN1 genotypes. The gB2 genotype was associated with abnormal image findings by ultrasound and/or magnetic resonance in congenital infection (odds ratio [OR], 6.2; 95% confidence interval [CI], 1.1–34.3; P = .036); the gN1 genotype was associated with an elevated risk of developing neurological disorders (OR, 7.0; 95% CI, 1.1–45.9; P = .043). Both gN1 and gB2 were independent factors for symptomatic infection. Statistical analyses showed no association between any UL144 genotype and disease severity.

Conclusions. All of the genotypes can be involved in congenital infection, although the gB2 and gN1 genotypes might be associated with a more serious illness.

A multifactorial analysis of the pregnancy outcomes in cytomegalovirus-infected women

AIMS

To investigate the impacts of cytomegalovirus (CMV) viral load, TORCH (toxoplasmosis, others, rubella, CMV and herpes) coinfections, CMV glycoprotein B (gB) genotypes and maternal genetic polymorphisms on pregnancy outcomes among CMV-infected women.

METHODS

A total of 731 CMV-infected pregnant women (634 and 97 with normal and adverse pregnancy outcomes, respectively) were recruited. CMV load quantification and screening of TORCH coinfections were performed by using real-time polymerase chain reaction (PCR) and immunodetection techniques, respectively. Genotyping of CMV gB and maternal NFKB1 -94 ins/del, NFKBIA -826C/T and -881A/G polymorphisms was performed by using PCR-restriction fragment length polymorphism.

RESULTS

We found that the mean CMV viral load in women with adverse pregnancy outcomes was significantly higher than that in women with normal outcomes at all pregnancy stages (p < 0.01). We also found that TORCH coinfections resulted in a 1.65-fold (95% CI = 1.00-2.73) increase in the risk of adverse pregnancy outcomes (p = 0.05). Additionally, we noticed no significant difference in the distribution of CMV gB genotypes between women with normal and adverse pregnancy outcomes (p = 0.42). We also observed that the ins/ins variant genotype of the NFKB1 polymorphism could reduce the risk of adverse pregnancy outcomes (OR = 0.38, 95% CI = 0.15-0.98; p = 0.04).

CONCLUSION

CMV viral load, TORCH coinfections and maternal NFKB1 polymorphism could influence pregnancy outcomes among CMV-infected women.

Congenital cytomegalovirus infections and glycoprotein B genotypes in live-born infants: a prevalence study in Turkey

BACKGROUND

Cytomegalovirus (CMV) infections are the leading cause of infectious hearing loss and central nervous system disease among children worldwide. In this study, we aimed to determine the birth prevalence of congenital CMV infection in live-born infants in Turkey.

METHODS

In total, 944 consecutive live-born infants born from 926 pregnant women were included in this study. CMV-DNA was investigated in saliva samples of all newborns within the first 3 days after birth using TaqMan-based real-time PCR.

RESULTS

The birth prevalence of congenital CMV infection in live-born infants was 1.91% (18/944), and all congenitally infected infants were asymptomatic at birth. The prevalence of congenital CMV infection was 16.7% (3/18) in twin pregnancies and 1.32% (12/908) in single pregnancies (p = 0.002). Genotyping analysis showed glycoprotein B-1 (gB1) to be the most frequently detected genotype at 83.3%.

CONCLUSION

The study results suggest that the majority of congenital CMV infection in Turkey occurs following nonprimary maternal infection. We believe that congenital CMV infection and its long-term effects have been underestimated in our country, as infected infants are usually asymptomatic at birth.

Significance of Epstein-Barr virus (HHV-4) and CMV (HHV-5) infection among subtype-C human immunodeficiency virus-infected individuals

PURPOSE

Opportunistic viral infections are one of the major causes of morbidity and mortality in HIV infection and their molecular detection in the whole blood could be a useful diagnostic tool.

OBJECTIVE

The frequency of opportunistic DNA virus infections among HIV-1-infected individuals using multiplex real-time PCR assays was studied.

MATERIALS AND METHODS

The subjects were in two groups; group 1: Having CD4 counts<100 cells/µl (n=118) and the group 2: counts>350 cells/µl (n=173). Individuals were classified by WHO clinical staging system. Samples from 70 healthy individuals were tested as controls. In-house qualitative multiplex real-time PCR was standardised and whole blood samples from 291 were tested, followed by quantitative real-time PCR for positives. In a proportion of samples genotypes of Epstein-Barr virus (EBV) and CMV were determined.

RESULTS

The two major viral infections observed were EBV and CMV. The univariate analysis of CMV load showed significant association with cryptococcal meningitis, oral hairy leukoplakia (OHL), CMV retinitis, CD4 counts and WHO staging (P<0.05) while the multivariate analysis showed an association with OHL (P=0.02) and WHO staging (P=0.05). Univariate analysis showed an association of EBV load with CD4 counts and WHO staging (P<0.05) and multivariate analysis had association only with CD4 counts. The CMV load was significantly associated with elevated SGPT and SGOT level (P<0.05) while the EBV had only with SGOT.

CONCLUSION

This study showed an association of EBV and CMV load with CD4+ T cell counts, WHO staging and elevated liver enzymes. These viral infections can accelerate HIV disease and multiplex real-time PCR can be used for the early detection. Genotype 1 and 2 of EBV and genotype gB1 and gB2 of CMV were the prevalent in the HIV-1 subtype C-infected south Indians.

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

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.