Evaluation of a silver-amplified immunochromatography kit for adenoviral conjunctivitis.

OBJECTIVE: To compare and evaluate the sensitivity of a newly developed silver-amplified immunochromatography (SAI) kit with various immunochromatography (IC) kits for adenoviruses based on the detection limit (copies/test). METHODS: An SAI kit and four ophthalmic IC kits were evaluated. The detection limits of the five kits were determined using the limiting dilution method for 15 conjunctivitis-associated adenoviruses (adenoviruses 1, 2, 3, 4, 5, 7, 8, 11, 37, 53, 54, 56, 64, 81, and 85). The detection limits were presented as numerical values as determined by real-time polymerase chain reaction (PCR). RESULTS: The detection limit of the SAI kit for the adenovirus types ranged from 1.0 × 103 -5.0 × 10 4 copies/test (geometric mean, 4.7 × 10 3 ). SAI had a 10-250-fold lower detection limit than the four IC kits for all adenoviruses studied. There were also differences in detection limits among the adenovirus types for each kit. DISCUSSION: The detection limit of the SAI kit was drastically reduced because the silver-amplification reaction increased the color development sensitivity. The results revealed the high sensitivity of SAI for detecting adenoviruses and suggested its usefulness for conjunctivitis examination.

Intertypic modular exchanges of genomic segments by homologous recombination at universally conserved segments in human adenovirus species D.

Human adenovirus species D (HAdV-D), which is composed of clinically and epidemiologically important pathogens worldwide, contains more taxonomic "types" than any other species of the genus Mastadenovirus, although the mechanisms accounting for the high level of diversity remain to be disclosed. Recent studies of known and new types of HAdV-D have indicated that intertypic recombination between distant types contributes to the increasing diversity of the species. However, such findings raise the question as to how homologous recombination events occur between diversified types since homologous recombination is suppressed as nucleotide sequences diverge. In order to address this question, we investigated the distribution of the recombination boundaries in comparison with the landscape of intergenomic sequence conservation assessed according to the synonymous substitution rate (dS). The results revealed that specific genomic segments are conserved between even the most distantly related genomes; we call these segments "universally conserved segments" (UCSs). These findings suggest that UCSs facilitate homologous recombination, resulting in intergenomic segmental exchanges of UCS-flanking genomic regions as recombination modules. With the aid of such a mechanism, the haploid genomes of HAdV-Ds may have been reshuffled, resulting in chimeric genomes out of diversified repertoires in the HAdV-D population analogous to the MHC region reshuffled via crossing over in vertebrates. In addition, some HAdVs with chimeric genomes may have had the opportunity to avoid host immune responses thereby causing epidemics.

[Bioinformatics on new human adenoviruses causing nosocomial infection].

Human adenovirus (HAdV) causing epidemic keratoconjunctivitis is limited to D and E species. Recent progress in bioinformatics revealed that these viruses attach to the host with fibers, infiltrate the host cells via RGD (Arg-Gly-Asp) motif of penton base, and reveal their serological reaction by hexons. Loops 1 and 2 are the variable regions of each hexon. The possibility that a novel adenovirus later named HAdV-52 was transmitted over the wall of species' from monkeys to humans was reported. The recombination of the above three hot spots introduces novel types such as HAdV-53, -54, and -56. Boinformatics may provide rapid genotyping in nosocomial infection, predicting future epidemics, and an estimate of the therapeutic target molecules in the near future.

Herpes simplex virus type 1 virion-derived US11 inhibits type 1 interferon-induced protein kinase R phosphorylation.

The herpes simplex virus type 1 (HSV-1) VRTK(-) strain that was previously isolated in our laboratory as an acyclovir-resistant thymidine kinase (TK)-deficient mutant, is more sensitive to type 1 interferon than is the parent strain VR3. The properties of this mutant were investigated to clarify the mechanism for its hyper-sensitivity to interferon (IFN). It was found that: (i) IFN-pretreated cells, but not those treated with IFN after adsorption, are hyper-sensitive to IFN; (ii) the mutant cannot inhibit protein kinase R phosphorylation efficiently during the early stage of replication (2 hrs post-infection); (iii) expression of US11 in infected cells and its incorporation into the virion is reduced in the mutant compared to the wild type, despite the fact that a similar degree of DNA synthesis occurs during replication of both strains and; (iv) over-expression of wild-type viral TK has no effect on the phenotype of the VRTK(-) strain, indicating that the phenotype is induced by a mutation(s) that does not involve the TK gene. These results suggested that the presence of US11 in the virion, but not that expressed after infection, plays an important role in the escape function of HSV-1 from the antiviral activity of type 1 IFN.

Anti-viral and anti-bacterial activities of an extract of blackcurrants (Ribes nigrum L.).

The inhibitory effects of an extract of the blackcurrant (Ribes nigrum L.) against pathogens associated with oral, nasopharyngeal and upper respiratory infectious diseases; namely respiratory syncytial virus (RSV), influenza virus A and B (IFV-A and IFV-B), adenovirus (AdV), herpes simplex virus type 1, Haemophilus influenzae type B, Streptococcus pneumoniae and Streptococcus mutans, were investigated. Less than 1% concentration of extract of blackcurrant inhibited replication of RSV, IFV-A and -B and HSV-1 by over 50% and a 10% extract inhibited adsorption of these viruses onto the cell surface by over 95%. The effects on AdV were much less pronounced; the half minimal inhibitory concentration of AdV replication was 2.54 ± 0.26, and a 10% concentration of the extract inhibited AdV adsorption on the cell surface by 72.9 ± 3.4%. The antibacterial activities of the blackcurrant were evaluated based on its efficacy as a disinfectant. A 10% extract disinfected 99.8% of H. Influenzae type B and 78.9% of S. pneumoniae in 10 min, but had no demonstrable effect against S. mutans. The blackcurrant extract still showed antiviral and antibacterial activities after the pH had been made neutral with sodium hydroxide, suggesting that these activities are not the result of acidic reactions or of components precipitated at a neutral pH. These findings demonstrate the potential of blackcurrant extract as a functional food for oral care.

Recombination analysis of intermediate human adenovirus type 53 in Japan by complete genome sequence.

Human adenovirus type 53 (HAdV-53) has commonly been detected in samples from epidemic keratoconjunctivitis (EKC) patients in Japan since 1996. HAdV-53 is an intermediate virus, containing hexon-chimeric, penton base and fiber structures similar to HAdV-22 and -37, HAdV-37 and HAdV-8, respectively. HAdV-53-like intermediate strains were first isolated from EKC samples in Japan in the 1980s. Here, the complete genome sequences of three such HAdV-53-like intermediate strains (870006C, 880249C and 890357C) and four HAdV-53 strains were determined, and their relationships were analysed. The seven HAdV strains were classified into three groups, 870006C/880249C, 890357C and the four HAdV-53 strains, on the basis of phylogenetic analyses of the partial and complete genome sequences. HAdV strains within the same group showed the highest nucleotide identities (99.87-100.00 %). Like HAdV-53, the hexon loop 1 and 2 regions of 870006C, 880249C and 890357C showed the highest identity with HAdV-22. However, these strains did not show a hexon-chimeric structure similar to HAdV-22 and -37, or a penton base similar to HAdV-37. The fiber genes of 870006C and 880249C were identical to that of HAdV-37, but not HAdV-8. Thus, the three intermediate HAdVs isolated in the 1980s were similar to each other but not to HAdV-53. The recombination breakpoints were inferred by the Recombination Detection Program (rdp) using whole-genome sequences of these seven HAdV and of 12 HAdV-D strains from GenBank. HAdV-53 may have evolved from intermediate HAdVs circulating in the 1980s, and from HAdV-8, -22 and -37, by recombination of sections cut at the putative breakpoints.

Clinical features of adenoviral conjunctivitis at the early stage of infection.

PURPOSE: Because adenoviral conjunctivitis is a contagious disease, prompt and accurate diagnosis in the early stage of infection is necessary to prevent epidemics. We evaluated and compared the clinical features of adenoviral conjunctivitis at the first medical examination with those of nonadenoviral follicular conjunctivitis. METHODS: The clinical features of 102 patients with suspected adenoviral conjunctivitis at the first medical examination were retrospectively reviewed. Human adenovirus (HAdV) DNA in samples from the patients was detected by polymerase chain reaction, and HAdV DNA-positive and HAdV DNA-negative patients were respectively assigned to adenoviral and nonadenoviral follicular conjunctivitis groups. The two groups were compared for bilaterality, intrafamilial infection, multiple subepithelial corneal infiltrates (MSI), preauricular lymphadenopathy, and severity of conjunctivitis. RESULTS: Adenoviral conjunctivitis and nonadenoviral conjunctivitis were diagnosed in 68 and 34 patients, respectively. Bilaterality, intrafamilial infection, and MSI showed significant intergroup differences. Remarkably, MSI was observed in 42.6% of the patients in the early stage of infection. There were no significant intergroup differences in preauricular lymphadenopathy or severity of conjunctivitis at any stage. CONCLUSIONS: To accurately diagnose adenoviral conjunctivitis in the early stage, bilateral conjunctival conditions, history of intrafamilial infection, and MSI should be checked, even in cases of mild or moderate follicular conjunctivitis.

Complete genome analysis of a novel intertypic recombinant human adenovirus causing epidemic keratoconjunctivitis in Japan.

For 4 months from September 2008, 102 conjunctival swab specimens were collected for surveillance purposes from patients across Japan suspected of having epidemic keratoconjunctivitis (EKC). Human adenovirus (HAdV) DNA was detected in 61 samples by PCR, though the HAdV type for 6 of the PCR-positive samples could not be determined by phylogenetic analysis using a partial hexon gene sequence. Moreover, for 2 months from January 2009, HAdV strains with identical sequences were isolated from five conjunctival swab samples obtained from EKC patients in five different regions of Japan. For the analyses of the 11 samples mentioned above, we determined the nucleotide sequences of the entire penton base, hexon, and fiber genes and early 3 (E3) region, which are variable regions among HAdV types, and compared them to those of other HAdV species D strains. The nucleotide sequences of loops 1 and 2 in the hexons of all 11 samples showed high degrees of identity with those of the HAdV type 15 (HAdV-15) and HAdV-29 prototype strains. However, the fiber gene and E3 region sequences showed high degrees of identity with those of HAdV-9, and the penton base gene sequence showed a high degree of identity with the penton base gene sequences of HAdV-9 and -26. Moreover, the complete genome sequence of the 2307-S strain, which was isolated by viral culture from 1 of the 11 samples, was determined. The 2307-S strain was a recombinant HAdV between HAdV-9, -15, -26, -29, and/or another HAdV type; however, the recombination sites in the genome were not obvious. We propose that this virus is a novel intertypic recombinant, HAdV-15/29/H9, and may be an etiological agent of EKC.

Epidemiological and virological features of epidemic keratoconjunctivitis due to new human adenovirus type 54 in Japan.

BACKGROUND/AIMS: New human adenovirus (HAdV)-54 causes epidemic keratoconjunctivitis (EKC) and is virologically close to and has occasionally been detected as HAdV-8. Taking HAdV-54 into account, we re-determined HAdV type in EKC samples to determine its epidemiology in Japan, and examined the virological features of HAdV-54. METHODS: HAdV type was re-determined in 776 conjunctival swabs from Japan and 174 from six other countries, obtained between 2000 and 2009. Using 115 HAdV strains obtained before 1999, trends regarding HAdV-8 and HAdV-54 were also determined. In addition, immunochromatography (IC) kit features, DNA copy numbers and viral isolation of HAdV-54 in samples were evaluated. RESULTS: Recently, HAdV-37 and HAdV-54 have been the major causative types of EKC in Japan. HAdV-54 has been isolated each year since 1995, whereas HAdV-8 has become less common since 1997, although it remains the most common cause of EKC in the six other countries investigated where HAdV-54 is yet to be detected. HAdV-54 is comparable to other EKC-related HAdV types in terms of IC kit sensitivity and DNA copy numbers, although HAdV-54 grows more slowly on viral isolation. CONCLUSIONS: EKC due to HAdV-54 can result in epidemics; therefore, it should be accurately diagnosed and monitored as an emerging infection worldwide.

The quantitative detection of herpes simplex virus, varicella zoster virus, and cytomegalovirus DNAs in recipient corneal buttons.

PURPOSE: We detected herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV) DNAs in recipient corneal buttons taken at the time of penetrating keratoplasty. METHODS: Twenty-seven corneal buttons were obtained from 27 patients (10 men and 17 women), 7 of whom had a history of HSV keratitis. Excised corneal buttons were immediately frozen in liquid nitrogen in the operating theater and then stored at -80°C until DNA extraction. The detection of HSV-1, HSV-2, VZV, and CMV DNAs was carried out by a nested polymerase chain reaction (PCR) method. The genome copy numbers for the nested PCR-positive samples were subsequently quantified by real-time PCR. RESULTS: HSV-1, HSV-2, VZV, and CMV DNAs were detected in 10, 1, 9, and 2 of the 27 recipient corneal buttons, respectively. HSV-1 or HSV-2 DNAs were also detected in 5 of 7 patients with a history of HSV keratitis. Both CMV-positive patients (patients 2 and 3) had ocular pemphigoid. Among the nested PCR-positive samples, 2 HSV-1, 1 HSV-2, 1 VZV, and 1 CMV sample could be quantified by real-time PCR. Copy numbers ranged from 19 to 928 copies. CONCLUSIONS: All 4 herpesviruses, including CMV, were detected in the corneal buttons. The relationship between CMV in the cornea and ocular diseases of the anterior segment should be further evaluated.

[Three cases of acute conjunctivitis caused by human adenovirus in medical workers].

We report three cases of acute conjunctivitis due to different types of human adenovirus (HAdV) in medical workers. Case 1: A 37-year-old man had epidemic keratoconjunctivitis and urethritis caused by human adenovirus type 37 (HAdV-37). Case 2: A 27-year-old woman had acute conjunctivitis due to human adenovirus type 15 (HAdV-15), Case 3:A 32-year-old woman had acute follicular conjunctivitis leading to a serotype of human adenovirus-53 serotype (HAdV-53). Note that HAdV-37 infection may cause keratoconjunctrivitis and urethritis. HAdV-15, -37, and -53 are important causative agents of nosocomial outbreak, and the application of a rapid diagnostic kit or PCR to a rapid diagnosis and proper infection-control measures can significantly reduce infection spread.

An improved rapid quantitative detection and identification method for a wide range of fungi.

To develop a rapid and quantitative diagnostic technique for the detection and identification of a wide range of fungi, an improved molecular method based on real-time PCR and the analysis of its products that targets the internal transcribed spacer (ITS) 2 region was established. The real-time PCR could quantitatively and specifically detect the ITS2 region from all 24 tested pathogenic fungal species at between 10(1) and 10(7) copies per test without amplification of bacterial or human DNA. The sequences of the primer-binding sites are conserved in the registered sequences of 34 other pathogenic fungal species, suggesting that the PCR would also detect these species. The hyperpolymorphic nature of the ITS2 region between fungal species in terms of length and nucleotide sequence provided valuable information for the determination of species. By labelling the 5' end of the reverse primer with NED fluorescent dye, the fragment lengths of the real-time PCR products and their 3'-terminal fragments, derived using restriction enzyme ScrFI digestion, were easily evaluated by capillary electrophoresis. Using this analysis, the number and species of fungi present in samples could be estimated. Moreover, sequence analysis of the real-time PCR products could accurately determine species in samples containing a single species. This diagnostic technique can estimate a wide range of fungi from various clinical samples within 1 day and accurately identify them in 2 days. Quantitative results for fungal titre in samples can also provide useful information for understanding the progression of disease and the efficacy of antifungal chemotherapy.

Nucleotide sequence variation in the hexon gene of human adenovirus type 8 and 37 strains from epidemic keratoconjunctivitis patients in Japan.

Human adenovirus type 8 (HAdV-8) and 37 (HAdV-37) cause epidemic keratoconjunctivitis (EKC) associated with community-acquired and nosocomial infections. The nucleotide sequences of the entire hexon and fiber genes of eight HAdV-8 and 26 HAdV-37 strains were analysed and the transition mutations in each gene were compared among strains. Compared with prototype strains, the hexon gene of HAdV-8 and -37 strains showed between two and seven and one and twelve variations at nine and 21 different positions, respectively. All of these, except one position in HAdV-37, were located in the conserved region 4 (C4). There were only three polymorphisms in the fiber gene of both HAdV-8 and HAdV-37, fewer than those in C4. The nucleotide sequence of HAdV-8 and -37 C4 might be readily modified during EKC epidemics.

Analysis of the complete genome sequence of epidemic keratoconjunctivitis-related human adenovirus type 8, 19, 37 and a novel serotype.

We determined the complete genome sequence of epidemic keratoconjunctivitis (EKC)-related human adenoviruses (HAdVs). We analysed a total of 12 HAdV strains; three prototype strains and two HAdV-8, three HAdV-19 and three HAdV-37 clinical isolates from EKC patients in Japan, and one novel serotype of HAdV. Genome organization of these serotypes was identical to those of the recently determined HAdV-19 and HAdV-37. The identities of the whole genome were over 99 % among strains from the same serotype, except for HAdV-19p, which is not associated with conjunctivitis, resulting in the formation of a distinct cluster in the phylogenetic analysis. The penton, loop 1 and loop 2 of hexon, early region 3 (E3) and fiber were hypervariable regions between serotypes. Results suggest that the HAdV-19 clinical strain is a recombinant of HAdV-19p-like and HAdV-37-like strains, and that the acquisition of the penton, E3 or fiber may be related to ocular tropism.

DSCG reduces RSV-induced illness in RSV-infected mice.

Respiratory syncytial virus (RSV) is one of the pathogens generally associated with the common cold, lower respiratory infection, and exacerbation of asthma. Disodium cromoglycate (DSCG) is a safe and widely used drug for the prevention of bronchial asthma and allergic rhinitis attacks. The effect of DSCG on acute upper respiratory tract viral infections remains controversial. The purpose of the study was to investigate the effects of DSCG on parameters of RSV induced-illness. Using a well-characterized murine model of RSV infection, the effect of DSCG on RSV-induced illness was evaluated by body weight, respiratory function, viral replication, level of IFN-gamma in lungs, serology, and histopathology. Mice treated with DSCG were protected against RSV-induced weight loss. The baseline Penh in RSV-infected mice treated with DSCG was less than that in mice treated with saline. In methacholine challenge, the increase in Penh in RSV-infected mice treated with DSCG was suppressed to the same level as that in the mock-infected group. Further, there were no differences in viral replication between the mice treated with DSCG and those treated with saline, and the level of inflammation observed in the lungs in RSV-infected mice treated with DSCG was not as severe as that in mice treated with saline. These findings indicate that DSCG may be an effective agent for the prevention of RSV induced disease and the relief of symptoms of RSV infection.