Adenovirus serotypes isolated from ocular infections in London

Phylogenetic and Recombination Analysis of Clinical Vitreous Humor-Derived Adenovirus Isolates Reveals Discordance Between Serotype and Phylogeny

Purpose

To sequence, identify, and perform phylogenetic and recombination analysis on three clinical adenovirus samples taken from the vitreous humor at the Bascom Palmer Eye Institute.

Methods

The PacBio Sequel II was used to sequence the genomes of the three clinical adenovirus isolates. To identify the isolates, a full genome-based multiple sequence alignment (MSA) of 722 mastadenoviruses was generated using multiple alignment using fast Fourier transform (MAFFT). MAFFT was also used to generate genome-based human adenovirus B (HAdV-B) MSAs, as well as HAdV-B fiber, hexon, and penton protein-based MSAs. To examine recombination within HAdV-B, RF-Net 2 and Bootscan software programs were used.

Results

In the course of classifying three new atypical ocular adenovirus samples, taken from the vitreous humor, we found that all three isolates were HAdV-B species. The three Bascom Palmer HAdV-B genomes were then combined with over 300 HAdV-B genome sequences, including nine ocular HAdV-B genome sequences. Attempts to categorize the penton, hexon, and fiber serotypes using phylogeny of the three Bascom Palmer samples were inconclusive due to incongruence between serotype and phylogeny in the dataset. Recombination analysis using a subset of HAdV-B strains to generate a hybridization network detected recombination between nonhuman primate and human-derived strains, recombination between one HAdV-B strain and the HAdV-E outgroup, and limited recombination between the B1 and B2 clades.

Conclusions

The discordance between serotype and phylogeny detected in this study suggests that the current classification system does not accurately describe the natural history and phylogenetic relationships among adenoviruses.

Development of a low-seroprevalence, αvβ6 integrin-selective virotherapy based on human adenovirus type 10

Oncolytic virotherapies (OV) hold immense clinical potential. OV based on human adenoviruses (HAdV) derived from HAdV with naturally low rates of pre-existing immunity will be beneficial for future clinical translation. We generated a low-seroprevalence HAdV-D10 serotype vector incorporating an αvβ6 integrin-selective peptide, A20, to target αvβ6-positive tumor cell types. HAdV-D10 has limited natural tropism. Structural and biological studies of HAdV-D10 knob protein highlighted low-affinity engagement with native adenoviral receptors CAR and sialic acid. HAdV-D10 fails to engage blood coagulation factor X, potentially eliminating "off-target" hepatic sequestration in vivo. We engineered an A20 peptide that selectively binds αvβ6 integrin into the DG loop of HAdV-D10 fiber knob. Assays in αvβ6+ cancer cell lines demonstrated significantly increased transduction mediated by αvβ6-targeted variants compared with controls, confirmed microscopically. HAdV-D10.A20 resisted neutralization by neutralizing HAdV-C5 sera. Systemic delivery of HAdV-D10.A20 resulted in significantly increased GFP expression in BT20 tumors. Replication-competent HAdV-D10.A20 demonstrated αvβ6 integrin-selective cell killing in vitro and in vivo. HAdV-D10 possesses characteristics of a promising virotherapy, combining low seroprevalence, weak receptor interactions, and reduced off-target uptake. Incorporation of an αvβ6 integrin-selective peptide resulted in HAdV-D10.A20, with significant potential for clinical translation.

Determinants of Outcomes of Adenoviral Keratoconjunctivitis

PURPOSE

To determine host and pathogen factors predictive of outcomes in a large clinical cohort with keratoconjunctivitis.

DESIGN

Retrospective analyses of the clinical and molecular data from a randomized, controlled, masked trial for auricloscene for keratoconjunctivitis (NVC-422 phase IIB, NovaBay; clinicaltrials.gov identifier, NCT01877694).

PARTICIPANTS

Five hundred participants from United States, India, Brazil, and Sri Lanka with clinical diagnosis of keratoconjunctivitis and positive rapid test results for adenovirus.

METHODS

Clinical signs and symptoms and bilateral conjunctival swabs were obtained on days 1, 3, 6, 11, and 18. Polymerase chain reaction (PCR) analysis was performed to detect and quantify adenovirus in all samples. Regression models were used to evaluate the association of various variables with keratoconjunctivitis outcomes. Time to resolution of each symptom or sign was assessed by adenoviral species with Cox regression.

MAIN OUTCOME MEASURES

The difference in composite scores of clinical signs between days 1 and 18, mean visual acuity change between days 1 and 18, and time to resolution of each symptom or sign.

RESULTS

Of 500 participants, 390 (78%) showed evidence of adenovirus by PCR. Among adenovirus-positive participants, adenovirus D species was most common (63% of total cases), but a total of 4 species and 21 different types of adenovirus were detected. Adenovirus D was associated with more severe signs and symptoms, a higher rate of subepithelial infiltrate development, and a slower decline in viral load compared with all other adenovirus species. The clinical courses of all patients with non-adenovirus D species infection and adenovirus-negative keratoconjunctivitis were similar. Mean change in visual acuity between days 1 and 18 was a gain of 1.9 letters; worse visual outcome was associated with older age.

CONCLUSIONS

A substantial proportion of keratoconjunctivitis is not associated with a detectable adenovirus. The clinical course of those with adenovirus D keratoconjunctivitis is significantly more severe than those with non-adenovirus D species infections or adenovirus-negative keratoconjunctivitis; high viral load at presentation and non-United States origin of participants is associated with poorer clinical outcome.

Human adenovirus type 8: the major agent of epidemic keratoconjunctivitis (EKC)

Human adenovirus type 8 (HAdV-8) is the most common causative agent of a highly contagious eye disease known as epidemic keratoconjunctivitis (EKC). HAdV-8 strains have been classified into genome types HAdV-8A to 8K and HAdV/D1 to D12 according to restriction endonuclease analysis. This review focuses on the significance of HAdV-8 as an agent of EKC. Molecular analysis of HAdV-8 genome types HAdV-53 and HAdV-54 was performed to reveal potential genetic variation in the hexon and fiber, which might affect the antigenicity and tropism of the virus, respectively. On the basis of the published data, three patterns of HAdV-8 genome type distribution were observed worldwide: (1) genome types restricted to a microenvironment, (2) genome types distributed within a country, and (3) globally dispersed genome types. Simplot and zPicture showed that the HAdV-8 genome types were nearly identical to each other. HAdV-54 is very close to the HAdV-8P, B and E genomes, except in the hexon. In a restriction map, HAdV-8P, B, and E share a very high percentage of restriction sites with each other. Hypervariable regions (HVRs) of the hexon were conserved and were 100% identical among the genome types. The fiber knob of HAdV-8P, A, E, J and HAdV-53 were 100% identical. In phylogeny, HVRs of the hexon and fiber knob of the HAdV-8 genome types segregated into monophyletic clusters. Neutralizing antibodies against one genome type will provide protection against other genome types, and the selection of future vaccine strains would be simple due to the stable HVRs. Molecular analysis of whole genomes, particularly of the capsid proteins of the remaining genome types, would be useful to substantiate our observations.

Molecular Epidemiology of Adenovirus Infection among Pediatric Population with Diarrhea in Asia

A total of 3,577 fecal specimens from infants and children with acute gastroenteritis in Japan, Korea and Vietnam during 1998 and 2001 were tested for adenovirus by the ELISA method. Of these, adenovirus was detected in 158 (4.4%). The detection rate of adenovirus was highest in Korea (8.7%, 20/231) followed by 5.0% (100/1,991) in Japan and 2.8% (38/1,355) in Vietnam. All adenoviruses were further serotyped by PCR-RFLP. The diversity of adenovirus serotypes including Ad2, 3, 5, 8, 31, 40 and 41 was demonstrated. Worth of note was a decrease in the rate of isolation of Ad40 (7.6%, 12/158) and a concomitant increase of Ad41 (63.9%, 101/158) to become the predominant serotype. Another interesting feature of the study was the presence of Ad3 (4.0% and 30%) and Ad8 (8.0% and 20%) in Japan and Korea, respectively, which is mainly associated with keratoconjunctivitis worldwide. Our result underscored the importance of adenovirus in association with acute gastroenteritis in Asian countries.

Genotyping of human adenoviruses using a PCR-based reverse line blot hybridisation assay

OBJECTIVES

Human adenoviruses are common pathogens associated with a broad spectrum of disease. There is a growing clinical interest in typing clinical isolates since it is becoming increasingly clear that individual serotypes are associated with different disease spectra, virulence, severity of consequences, and outbreaks. Current methods cannot detect all known adenoviruses simultaneously and rapidly. We designed a practical adenovirus typing method with polymerase chain reaction (PCR)-based reverse line blot hybridisation assay (RLB) using hypervariable region-7 (HVR-7) in the hexon gene.

METHODS

A PCR-RLB assay was developed based on HVR-7 in the hexon region for potentially genotyping 51 adenovirus serotypes by hybridisation of 62 genotype-specific probes using amplicons generated from one genus-specific primer pair. Single PCR and sequencing were performed for confirmation of RLB results. Eighty-seven previously serotyped clinical isolates (representing 28 serotypes) were studied.

RESULTS

Thirty-two different genotypes were detected by RLB from 87 adenovirus isolates, of which 82 isolates showed consistent results with sequencing. Another five isolates revealed evidence by RLB of co-infection, and were confirmed with a combination of genotype-specific single PCR and sequencing.

CONCLUSIONS

In comparison to sequencing and serological methods, the advantages of the RLB assay include: (1) rapid genotyping of multiple samples in a single run; (2) successful detection of co-infection; (3) detection of subgenotype variants. This will allow rapid and inexpensive characterisation of adenovirus infections and outbreaks.

Management strategies for acute infective conjunctivitis in primary care: a systematic review

A systematic review of the literature on all aspects of the management of acute infective conjunctivitis is undertaken. Acute infective conjunctivitis is a common presentation in primary healthcare. It is usually a mild condition and serious complications are rare. Clinical signs are a poor discriminator of bacterial and viral causes. Studies of treatment show that there is a high rate of clinical cure without any treatment (65% within 2-5 days). Treatment with topical antibiotics improves the rate of clinical recovery and this is more marked in the first 2-5 days after presentation (number needed to treat [NNT] = 6), but less by 6-10 days (NNT = 13). Studies comparing treatment with different antibiotics do not demonstrate that any one antibiotic is superior; the choice of antibiotic should be based on consideration of cost and bacterial resistance. The present practice of prescribing antibiotics to most cases is not necessary.

Stampidine: a selective oculo-genital microbicide

Adenoviruses (ADVs) are causative agents of severe and extremely contagious ocular and genital infections associated with conjunctivitis, genital ulcers and urethritis. Yet, no functional antiviral compounds are currently available against adenoviral infections. We discovered halogen-substituted phenyl phosphoramidate derivatives of stavudine (STV/d4T) as a new class of dual-function anti-human immunodeficiency virus (HIV) agents with potent and selective anti-ADV activity. The lead compound, stampidine [5'-(4-bromophenyl methoxyalaninylphosphate)-2',3'-didehydro-3'-deoxythymidine], was the most potent non-toxic dual-function antiviral agent. Stampidine displayed remarkable in vitro and in vivo anti-HIV activity against drug-sensitive and drug-resistant HIV strains. Stampidine was non-cytotoxic and nonirritating to mucosal epithelial cells. Several preclinical studies conducted thus far, suggest that stampidine has clinical potential as a dual-function topical agent for the prevention and/or effective treatment of oculo-genital ADV/HIV infections.

Genome analysis of adenovirus type 3 isolated in Japan

Adenovirus type 3 (Ad3) isolates, isolated from 45 patients with acute conjunctivitis during the year 1990 in Japan, were studied by DNA restriction enzyme analysis with restriction endonucleases recognizing 6-bp sequences (BamHI, SmaI, HindIII, BglII) and endonucleases recognizing 5- or 4-bp sequences (HinfI and TaqI). All 45 isolates of Ad3 were identified as the genome type Ad3f by six endonucleases. They were further classified into three varieties by HinfI, varieties H1 (87.5%), H2 (8.9%), and H3 (2.2%), and into five varieties by TaqI, varieties T1 (75.6%), T2 (13.3%), T3 (2.2%), T4 (4.5%), and T5 (8.9%). The use of HinfI and TaqI was sufficient to distinguish six subgenome types: types Ad3fH1T1, Ad3fH1T2, Ad3fH1T4, Ad3fH1T5, Ad3fH2T1, and Ad3fH3T3. Among them, Ad3fH1T1 was predominant in areas where the virus is epidemic. The study showed that the same Ad3 genome type, genome type Ad3f, caused acute viral conjunctivitis even in different areas in Japan. The source and the route of infection were suggested to be common in areas where the virus is epidemic.

Analysis with restriction endonucleases recognizing 4- or 5-base-pair sequences of human adenovirus type 3 isolated from ocular diseases in Sapporo, Japan

A total of 49 adenovirus type 3 (Ad3) strains from patients with epidemic keratoconjunctivitis at an eye clinic in Sapporo, Japan, from 1983 to 1986 were classified into either genome type Ad3f (26 strains) or Ad3g (23 strains). By the use of Hinf1 and TaqI restriction endonucleases, they were classified into 11 and 3 subgenome types, respectively. During this observation period, two epidemics of Ad3 infection relating to epidemic keratoconjunctivitis occurred. The prevalent Ad3g strains isolated during the epidemic in 1983 belonged to a single subgenome type. However, in the course of the Ad3f epidemic in 1986, alteration of one subgenome type of the prevalent strain to a different subgenome type which was presumed to be a derivative of the former was observed. In the years in which only a few Ad3 strains were isolated, such Ad3f strains were classified into different subgenome types. However, all Ad3g strains except two belonged to the same subgenome type.

Double-label immunofluorescence method for simultaneous detection of adenovirus and herpes simplex virus from the eye

The development and application of a double-label immunofluorescence method which has the potential to screen for single or dual infections from any site, in single shell vial cultures, is described. In this study, a total of 1,141 ocular specimens were inoculated in shell vials, centrifuged at 15,000 X g for 1 h, incubated at 37 degrees C for 48 h, and fixed in methanol at room temperature for 15 min. The virus inclusions were detected by staining with a double-label indirect immunofluorescence procedure using mixtures of appropriate first antibodies, followed by fluorescein- and rhodamine-conjugated second antibodies. Each specimen was also inoculated in parallel by the conventional virus isolation method. The sensitivity and specificity of the double-label shell vial procedure were comparable to those with the conventional method, and the former test took only 48 h to complete. The test offers a rapid and simple single-vial procedure which allows for individual or simultaneous detection of multiple pathogens. It results in savings in time and cost over the conventional virus isolation method and other shell vial procedures.

Management and prevention of ocular viral and chlamydial infections

A majority of cases of preventable and/or curable ocular morbidity and blindness are caused by ocular infections. They may account for 70 to 90% of all ocular morbidity seen by family doctors, general practitioners, health centers, and local ophthalmologists in both developed and developing countries. Unfortunately, most health authorities and doctors, including ophthalmologists, consider these diseases to be of little or no importance because they are not fully aware of the high prevalence of these infections and the blinding sequelae which may occur following incorrect diagnosis and treatment. Also, they are not aware of the social and economic impact of these infections in the absence of proper management and implementation of preventive measures. In this review, we examine present knowledge of chlamydial and common viral ocular infections. We discuss the problems of diagnosis, management, and prevention and propose solutions relevant to developed and developing countries.

Genome typing of adenovirus strains isolated from conjunctivitis in Japan, Australia, and the Philippines

DNA restriction endonuclease analysis for genome typing of adenovirus (Ad) DNA was carried out on a total of 65 Ad isolates including serotypes Ad4, Ad7, Ad8, Ad11, Ad19, and Ad37 from patients with epidemic keratoconjunctivitis and acute conjunctivitis obtained in Japan from 1982 to 1986, Australia from 1973 to 1986, and the Philippines in 1984. All 4 isolates of Ad7 in Australia were Ad7b. Four of 6 Ad11 isolates obtained in Japan were typed as Ad11 prototype (Ad11p), and the remaining were identified to be new genome types, designated tentatively as Ad11c and Ad11d. An isolate of Ad11 obtained in Australia was typed as Ad11c. Nine Ad8 isolates in Australia and in the Philippines were typed as Ad8p, but 11 Ad8 isolates in Japan were Ad8b. Thirteen Ad19 isolates were identified as Ad19a. All 3 isolates of Ad37 in Japan and three isolates in Australia before 1982 were typed as Ad37p, however, 5 isolates in Australia after 1983 were identified as a new genome type, designated as Ad37d. In Japan, 10 isolates of Ad4 were identified as Ad4a.

Genomic comparison of adenovirus type 3 isolates from patients with acute conjunctivitis in Japan, Australia, and the Philippines

A total of 53 Ad3 isolates obtained from patients with acute conjunctivitis in Japan, Australia, and the Philippines during 1973 to 1986 were analyzed for their genome types with 4 restriction endonucleases, BamHI, BglII, HindIII, and SmaI. Two new genome types designated tentatively as Ad3f and Ad3g were identified by combination of BamHI and BglII in the isolates. The changes of restriction sites and sizes of restriction fragments in newly recognized Ad3f and Ad3g were located at the similar regions reported in other Ad3 genome types by O'Donnell et al (1986) on physical maps of the Ad3 prototype strain GB genome. In Japan, 46 Ad3 isolates obtained from 1983 to 1986 were either Ad3f or Ad3g. Yearly alternation of predominance of both genome types were observed in the northern part of Japan during the period. In Australia, two genome types Ad3p and Ad3f were found in 6 isolates, and the former was observed in the 3 isolates obtained before 1981 and the remaining 3 isolates were obtained after 1983. In the Philippines, the only isolate obtained in 1984 was Ad3p.

Detection of adenovirus by rapid 24-well plate centrifugation and conventional cell culture with dexamethasone

Two methods for rapid detection of adenovirus were tested: (i) 24-well plate centrifugation followed by staining with a monoclonal antibody after incubation for 24 h and 48 h, and (ii) pretreatment of A549 cells used in conventional cell culture and 24-well plate centrifugation with 10(-5)M dexamethasone. Twenty-seven clinical isolates of adenovirus and 12 specimens from which adenovirus had been recovered were included in the analysis. Both isolates and specimens had been frozen at -70 degrees C for up to 6 months. By 24-well plate centrifugation both with and without dexamethasone, 21 (78%) and 27 (100%) isolates were positive for adenovirus at 24 h and 48 h, respectively. Of the specimens, 6 (50%) and 8 (67%) were positive by 24-well plate centrifugation without dexamethasone at 24 h and 48 h, respectively, whereas with dexamethasone 3 (25%) were positive at 24 h and 7 (58%) were positive at 48 h. Overall, combining isolates and specimens, the sensitivity of 24-well plate centrifugation for detection of adenovirus at 24 h was 69% without dexamethasone and 62% with dexamethasone, and at 48 h the sensitivity was 90% without dexamethasone and 87% with dexamethasone. The specificity under all conditions tested was 100%. In conventional tissue culture dexamethasone inhibited recovery of adenovirus. Without dexamethasone, adenovirus was recovered from all 39 samples within 7 days after inoculation; however with dexamethasone pretreatment, the virus was detected in only 31 (79%) of the samples tested in the same period of time.

An epidemic of keratoconjunctivitis due to adenovirus type 37

An epidemic of keratoconjunctivitis due to adenovirus type 37 in Liverpool in 1984 is reported. Initially serum neutralisation suggested that isolates were type 10 but further neutralisation studies supported by DNA restriction enzyme analysis showed that they were type 37. Clinical and epidemiological features of this cause of epidemic keratoconjunctivitis, recently recognised in the United Kingdom, are presented and the implications for the laboratory investigation discussed.

Adult follicular conjunctivitis and neonatal ophthalmia in a Liverpool eye hospital, 1980-1984

In the five year period between 1980 and 1984, 2146 adults and 172 neonates suffering from acute conjunctivitis underwent laboratory investigation for Chlamydia trachomatis (CT), Adenoviruses (AV), Herpes Simplex Virus (HSV) and pathogenic bacteria. Epidemiology and clinical features are presented and discussed. CT was detected in 29 per cent of neonates with conjunctivitis. 5.6 per cent of adults and older children investigated for follicular conjunctivitis were CT positive. There was a significant female preponderance among CT positive neonates of 1.9:1 (p less than 0.02). 91 per cent of neonates and 62 per cent of adults in whom CT was detected were receiving some sort of treatment. Serotypes 7, 3, 10, 4 and 8 were responsible in decreasing order of frequency for 96 per cent of AV infections. Serotype 7 was seen for the first time in an adult age distribution. HSV was isolated in 1.3 per cent of cases in the absence of typical lid or corneal lesions. Viral infection was not detected in any neonate. Bacterial infection was a more likely cause than CT in neonates if infection had persisted longer than 5 weeks (p much less than 0.001). Neonates with Staph aureus infection tended to present earlier in the course of disease than those with Haemophilus sp or Pneumococcus (p less than 0.05).

A correlation between the weather and the incidence of ocular adenovirus infections

Cyclical changes in the frequency of adenovirus isolation from patients with non-epidemic conjunctivitis were shown to correlate with monthly total hours of sunshine. Sunlight may predispose to clinical infection eyes already contaminated with adenovirus.

Genome analysis of species 3 adenoviruses isolated during summer outbreaks of conjunctivitis and pharyngoconjunctival fever in the Glasgow and London areas in 1981

Genome analysis was performed on 125 adenovirus isolates from conjunctival swabs of patients with conjunctivitis obtained in Glasgow between 1981 and 1984. A summer outbreak in 1981 was mainly due to species 3 adenoviruses, of which genotype 3GB and five different genotypic variants cocirculated. Three species 3 variants were also observed in 1982. The genome changes of variants were located on physical maps of the Ad3 reference strain and found to be clustered near the ends of the adenovirus DNA (including the fiber area), whereas the hexon coding region was unaltered. In contrast to the genome heterogeneity observed among the species 3 adenoviruses collected in Glasgow in 1981 it was found that all 69 Ad3 isolates obtained from an outbreak of pharyngoconjunctival fever in a boarding school near London during the summer of 1981 possessed the 3GB genotype.

Prevalence of acute conjunctivitis caused by chlamydia, adenovirus, and herpes simplex virus in an ophthalmic casualty department

The causes of acute conjunctivitis in 140 consecutive patients attending an ophthalmic casualty department in London were investigated. Laboratory evidence of infection with Chlamydia trachomatis, adenovirus, or herpes simplex virus was found in 52 (37%) cases. In 70 cases (50%) no evidence of infection with these agents was found. In the remaining 18 cases (13%) laboratory results were inconclusive. The importance of these findings, the role of laboratory investigations in the differential diagnosis of acute conjunctivitis, and their cost-benefit are discussed.