Rapid culture-amplified immunofluorescent test for the detection of human rhinoviruses in clinical samples: evidence of a common epitope in culture

Ohio HeLa cells in multichamber slides were inoculated with nasal samples from patients presenting with common cold symptoms and incubated at 33 degrees C with gentle shaking for 48 hours. The cultures were fixed with cold acetone, and viral antigens were detected by immunofluorescence using an antirhinovirus type 2 (HRV-2) polyclonal serum. Of 158 samples, 58 (36.7%) and 57 (36%) were positive for HRV by virus isolation (confirmed by acid lability test) and by culture-amplified immunofluorescent (CAIF) test, respectively. The correlation between the two tests was highly significant (P = 0.0001). Nasal washings or nasal/throat swabs were equally suitable for detecting virus by isolation but not by CAIF. On the other hand, nasal washings were better than nasal/throat swabs for detecting HRV by CAIF. In an ELISA system, the polyclonal anti-HRV-2 serum recognized a rhinovirus antigen expressed in situ within 48 hr postinfection by all the 11 HRV serotypes investigated. However, 60 hr postinfection, the anti-HRV-2 serum recognized only homologous and closely related HRV antigens. These results suggest that a rhinovirus "common" antigen may be expressed some 48 hr after infection of Ohio HeLa cells with rhinoviruses. The CAIF test provides a sensitive, rapid and reliable procedure to detect wild-type rhinovirus infection as well as a clear alternative to detection by isolation.

Detection of rhinovirus RNA in nasal epithelial cells by in situ hybridization

This paper describes the development and evaluation of in situ hybridization (ISH) for the detection of rhinovirus in cells obtained from nasal washings of volunteers infected with human rhinovirus 14 (HRV-14). Twenty-five (66%) and 27 (71%) of 38 volunteers inoculated with HRV-14 had evidence of infection by virus isolation and ISH, respectively, on at least one of 4 days investigated after virus challenge. In contrast, only 14 of 38 (37%) volunteers had significant antibody rises as detected by the neutralization test. Of the 38 volunteers inoculated with HRV-14, only 13 (34%) had symptoms of colds. Of these, 12 (92%) and 10 (77%) were positive by virus isolation or ISH, respectively, on at least one day. Six (46%) had significant antibody rises by neutralization. Similarly, of the 38 volunteers challenged, 22 (58%) were asymptomatic and of these 10 (45.5%) and 12 (54.5%) were positive by virus isolation and ISH, respectively, on at least one day. Only 8 (36.4%) of these asymptomatic volunteers showed significant antibody rises by neutralization. There were significant associations between the detection of rhinoviruses by ISH and virus isolation on the third day (P less than 0.025) after virus challenge in the group as a whole and in the symptomatic group. These results show that generally rhinovirus detection by ISH compares well with virus isolation and both tests are clearly more sensitive than the neutralization test in detecting evidence of infection. It is concluded that ISH is an interesting new technique that may play an important role in the study of rhinovirus infection and pathogenesis.

Pathogenicity for humans of human rhinovirus type 2 mutants resistant to or dependent on chalcone Ro 09-0410

Mutants of human rhinovirus type 2 (HRV-2) resistant to and dependent on the antirhinoviral compound chalcone Ro 09-0410 were selected in cell culture under clean laboratory conditions. A total of 42 volunteers were challenged with either the drug-resistant mutant [SR2-410(r)] (15 volunteers), the drug-dependent mutant [SR2-410(d)] (15 volunteers), or a wild-type HRV-2 which had a similar passage level in vitro as the mutants but without the drug (12 volunteers). Of volunteers challenged with the wild-type HRV-2, 33, 67, and 82% developed cold symptoms, shed virus, and showed serological evidence of infection, respectively. In contrast, only 13, 27, and 23% of volunteers challenged with the drug-resistant mutant developed colds, shed virus, and showed serological evidence of infection, respectively. None of the volunteers challenged with the drug-dependent virus became infected or had symptoms of colds. These results demonstrate that a drug-resistant rhinovirus was capable of infecting humans and producing disease, although its infectivity was reduced when compared with that of the wild type. In contrast, a drug-dependent virus had lost its ability to infect humans.

The human cytomegalovirus immediate early enhancer-promoter is responsive to activation by the adenovirus-5 13S E1A gene

The stimulatory effects of the 13S adenovirus E1A gene product on the human cytomegalovirus (HCMV) major immediate early (IE) enhancer were examined. Chimeric plasmids containing cloned portions of the HCMV major IE enhancer-promoter positioned upstream of the chloramphenicol acetyltransferase gene (cat) were cotransfected into HeLa cells with the plasmid p13S-wt which contained a cDNA encoding the adenovirus 13S E1A gene product. CAT expression from chimeric plasmids containing at least one copy of the HCMV 19 base pair (bp) repetitive motif was stimulated 10-fold in the presence of p13S-wt. The 19-bp motif contains a potential binding site for the cellular transcription factor ATF/CREB. Deletion analysis indicated that the ATF/CREB site was crucial for E1A-mediated stimulation. Insertion of a synthetic oligonucleotide homologous to a 19-bp motif and containing an ATF/CREB binding site into an HCMV chimera lacking ATF/CREB motifs conferred E1A responsivity on HCMV promoter-mediated CAT expression whereas insertion of a similar oligonucleotide containing a change of two bases in the sequence of the ATF/CREB site did not. Measurement of CAT-specific RNA verified the results of the CAT enzyme experiments. The ATF/CREB motif may be a target for stimulation of HCMV gene expression through either viral or cellular transcription factors.

A host-cell-selected variant of influenza B virus with a single nucleotide substitution in HA affecting a potential glycosylation site was attenuated in virulence for volunteers

An influenza B virus was passaged in man (virus A) and then in human embryo trachea (C) and into embryonated eggs (D) or directly into eggs (B). Virus A, B, and C had the same (cell-like) haemagglutinin phenotype on reaction with selected monoclonal antibodies while D had an "egg-like" phenotype. The viruses were administered at a dose of 1,000 TCD50 (for MDCK cells) by intranasal inoculation to groups of 27 or 28 volunteers. Viruses A, B, and C all produced disease in six to eight volunteers, whereas D produced no illness and only four volunteers were infected. The viruses shed by the volunteers were indistinguishable from those with which they were inoculated. The haemagglutinin genes of the viruses were sequenced and changes were detected indicating amino acid substitutions at position 196-198 in the attenuated egg-grown virus D whereby a potential glycosylation site present in the other viruses was lost.

The effect of intranasal nedocromil sodium on viral upper respiratory tract infections in human volunteers

Two studies involving double-blind group comparative trials in human volunteers compared the effects of intranasal nedocromil sodium (2.6 mg active drug per nostril, q.i.d.) with placebo on clinical symptoms and performance impairment associated with the common cold. In the first study volunteers were challenged with rhinoviruses (RV9 and RV14), and in the second study with respiratory coronavirus. In both studies, active and placebo groups of volunteers were demographically similar. Infection rates in both groups were also similar. There were no withdrawals resulting from unusual symptoms related to either treatment. In the rhinovirus study (19, placebo; 20, nedocromil sodium) daily symptom scores and daily mean nasal secretion weights were significantly lower in the nedocromil sodium-treated group. In the coronavirus study (26, placebo; 27, nedocromil sodium) there was little difference in the severity of colds between the active and placebo-treated groups, but trends favoured nedocromil sodium. In both studies the impairment of performance in volunteers who developed a cold was significantly less in those treated with nedocromil sodium than in those treated with placebo.

The time course of the humoral immune response to rhinovirus infection

The specific humoral immune response of 17 volunteers to infection with human rhinovirus type 2 (HRV-2) has been measured both by neutralization and by ELISA. Six volunteers who had HRV-2-specific antibodies in either serum or nasal secretions before HRV-2 inoculation were resistant to infection and illness. Of the remaining 11 volunteers who had little pre-existing HRV-2-specific antibody, one was immune but 10 became infected and displayed increases in HRV-2-specific antibodies. These antibodies first increased 1-2 weeks after infection and reached a maximum at 5 weeks. All six resistant volunteers who had high pre-existing antibody and eight of the volunteers who became infected maintained their HRV-2-specific antibody for at least 1 year. At this time they were protected against reinfection. Two volunteers showed decreases in HRV-2-specific antibodies from either serum or nasal secretions. They became infected but not ill after HRV-2 inoculation 1 year later.

Evaluation of a new enzyme-linked immunosorbent assay (ELISA) in the diagnosis of rhinovirus infection

This study describes the evaluation of a newly developed ELISA for the direct detection of rhinovirus antigens in nasal washings. Of 54 volunteers inoculated with 100 TCID50 of human rhinovirus type 2 (HRV-2), 50 (96.6%) and 32 (59%) excreted antigen and virus on at least 1 of 3 days investigated, respectively. Thirty-three (61%) had significant rises in rhinovirus-specific IgA by ELISA. Twelve (22%) developed symptoms of colds. Generally the ELISA detected antigen more frequently in volunteers later in the course of infection and provided evidence of infection in a higher proportion of asymptomatic compared with symptomatic volunteers. On the other hand, virus isolation detected virus more frequently earlier in the course of infection and in a higher proportion of symptomatic compared with asymptomatic volunteers. We conclude that rhinovirus antigen detection by ELISA is a simple, rapid, sensitive, and practical test to diagnose a rhinovirus infection and potentially a viable alternative to virus isolation.

Microbial etiology of acute gastroenteritis in hospitalized children in Kuwait

During a period of 15 months 621 hospitalized children with acute gastroenteritis and 152 control children were investigated for etiologic agents of the disease. Putative enteropathogens were identified in 86% of the patients and 10% of the controls. Common viral agents associated with gastroenteritis among children included rotaviruses (45%) and enteric adenoviruses (4%). Bacterial pathogens infecting children were Salmonella serotypes (24%), enterotoxigenic Escherichia coli (9%), Campylobacter jejuni (7%), enteropathogenic E. coli (7%), Shigella (4%) and enterotoxigenic Aeromonas sp. (1%). The highest incidence of infections was observed in the 3- to 25-month age group. Mixed infections were observed in 12% of the patients. Viral gastroenteritis was clinically mild and of short duration. Upper respiratory tract infections, vomiting and watery stools were common features. In contrast bacterial gastroenteritis was more severe; stools were frequently bloody and abdominal pain, cramps, shock, convulsions and milk intolerance were predominant clinical features. Comparative analysis revealed differential features of bacterial and viral gastroenteritis which should help clinicians to make a tentative diagnosis and to start treatment early.

Detection of enteroviruses using cDNA and synthetic oligonucleotide probes

This study compares the detection of enterovirus RNA by cDNA probes prepared from both the 5' and 3' end of the genome of coxsackie A21 and B4 with the use of synthetic oligonucleotides prepared from short but highly conserved sequences in the 5' end non-coding region of the picornavirus genome. The cDNA probes detected enteroviruses with a variable level of sensitivity which presumably depended on the degree of genomic homology with the detecting probes. Generally probes from coxsackievirus A21 detected more enteroviruses than did similar probes from coxsackievirus B4. Probes from the 5' end of the genome of both viruses were more sensitive than 3' end probes. In contrast, synthetic oligonucleotides detected all enteroviruses efficiently suggesting that these probes could be useful as 'universal' probes to detect any enterovirus. This paper discusses the application of these probes in the diagnosis and differentiation of enteroviruses.

Amplification of rhinovirus specific nucleic acids from clinical samples using the polymerase chain reaction

We describe a novel method for the detection of human rhinoviruses in clinical samples, using the polymerase chain reaction. Two synthetic oligonucleotide primers were produced that bind in the 5' noncoding region of all rhinovirus serotypes tested, about 350 nucleotides apart, and were used to prime polymerase chain reaction amplification of the intervening stretch of DNA. The product of this reaction, which can be clearly visualized by gel electrophoresis, is a discrete 380 bp band, the occurrence of which is diagnostic of the presence of a rhinovirus in the clinical sample analysed. The technique, which is rapid, sensitive, and reliable, has been used successfully for all the different rhinovirus serotypes tested to date in our laboratory. However, the sensitivity of detection is greatly dependent on the inclusion of both tRNA and vanadyl complexes during the viral RNA extraction process. Using this technique, under optimal conditions, we were able to detect virus in clinical samples with titres as low as TCID50 10(2.5).

Suppression of colds in human volunteers challenged with rhinovirus by a new synthetic drug (R61837)

This report describes double-blind placebo-controlled trials of a new synthetic antirhinovirus drug, R61837, which showed it to be effective in suppressing colds in human volunteers challenged with rhinovirus type 9. In one trial, R61837 was given by intranasal spray six times a day, commencing 28 h before virus challenge; treatment continued for 4 days and one dose (total dose, 25 mg). This regimen suppressed symptoms until 48 h after medication ceased, at which time colds developed. In another trial, medication with R61837 commenced at 4 h before virus challenge and continued for a total of 6 days (total dose, 36 mg). The drug produced substantial reductions in both the mean daily clinical score and the mean daily nasal secretion weight compared with patients given the placebo. These differences reached statistical significance for 2 and 4 days, respectively. In a further trial, intranasal R61837 was not effective in treating colds even when given shortly after the onset of symptoms and in doses of up to 15 mg/day.

Drug resistant rhinoviruses from the nose of experimentally treated volunteers

Viruses were isolated from nasal washings of volunteers receiving experimental therapy for rhinovirus type 9 infection with intranasal sprays of a new synthetic antiviral R61837. On a screening test nine subjects yielded drug sensitive virus and four resistant virus. In four others the virus was sensitive at first but became resistant later, while in one the reverse occurred. Evidence is given that at least some of the resistant viruses were present in the respiratory tract and were not selected during virus isolation. Of six viruses studied in detail, five had a low degree of resistance and one was highly resistant. The degree of resistance of the five was similar for an antiviral chalcone, dichloroflavan and disoxaril. The sixth was different in that the resistance to disoxaril was relatively less than to the other drugs. The significance of these results is discussed--these are the first experiments in man to show the selection of drug resistant rhinovirus.

Use of synthetic oligonucleotide probes to detect rhinovirus RNA

Current methods of detecting a human rhinovirus (HRV) infection are either based on isolation of virus in appropriate susceptible cell lines, which is time-consuming and requires considerable expertise, or are dependent on knowing the serotype. The existence of over 100 immunologically distinct serotypes makes serotype specific assays, such as ELISA, unsuitable for general diagnostic assays. In this study a general rhinovirus assay is described which utilises synthetic oligonucleotides as probes in a filter hybridization assay. The probes are designed to bind to short but highly conserved regions of the rhinovirus genome. Indeed, the probes successfully detected all 57 rhinovirus serotypes tested. Furthermore, the test was used to demonstrate rhinovirus infection in clinical samples from 57 volunteers, inoculated with HRV, collected on six consecutive days. Clinical samples were taken prior to inoculation and on days 2-7 after inoculation. The filter hybridization assay gave results comparable to virus culture on days 2 and 3 post-inoculation, but was more sensitive on subsequent days.

Effects and after-effects of the common cold and influenza on human performance

Volunteers who develop a cold following virus challenge were significantly slower on choice reaction time tasks than those with no illness. This effect was still observed after the clinical symptoms had gone. In contrast to this, influenza illnesses only impaired performance in tasks in which subjects were uncertain where the target stimulus would appear. These results demonstrate that the CNS effects of respiratory virus infections depend on the type of virus, and that performance impairments may remain even after the symptoms of a cold have gone.

Rhinovirus detection using probes from the 5' and 3' end of the genome

This study investigated the abilities of cDNA probes from the 5' and 3' ends of the genome of human rhinoviruses (HRV-) 14, 9, and 1B to detect RNA from 59 rhinovirus serotypes. The results show that probes from the 5' end of the genomes of HRV-14, 9, and 1 B detected a large number of serotypes but the detection rate was variable and depended on the degree of homology with the particular probe. In contrast, all the 3' end probes were specific for the homologous virus. However, a long HRV-9 probe detected a large number of serotypes. It was concluded that such cDNA probes would not detect all serotypes with equal efficiency. Synthetic oligonucleotides corresponding to short but highly conserved regions in the 5' non coding region may overcome this problem.

Specific and non-specific serological markers in the screening for congenital CMV infection

IgM antibodies specific for cytomegalovirus (CMV) were demonstrated in 15 (2.6%) of 575 umbilical cord sera obtained from newborns in Kuwait. Some 93% and 50% of these CMV-IgM positive cord sera displayed markedly raised (more than normal mean +2 S.D.) content of total IgM and IgA respectively. In contrast, only 0.2 and 1.8% of the CMV-IgM negative cord sera had elevated total IgM and IgA, respectively. Rheumatoid factor (RF) was demonstrable, at concentrations of 30 IU/ml or more, in 67% of the CMV-IgM positive as compared with 3.2% of the CMV-IgM negative sera whereas interferon alpha was found in the serum of only one of these infants. These results indicate that raised total immunoglobulin, in particular IgM, concentrations and the detection of RF in cord blood are useful non-specific markers for the identification of congenital CMV infection.

Fulminant viral hepatitis in Kuwait

This study describes the aetiology and clinical course of fulminant viral hepatitis in 34 patients. Sixteen of 34 (47%) patients presented with serological evidence that indicated that hepatitis B virus (HBV) was the cause of fulminant hepatitis, while in 13 of 34 (38%) non-A, non-B (NANB) virus was implicated as the cause. Further, in three cases (9%) and two cases (6%) the patients' serological data indicated that hepatitis A (HAV) and the delta agent superinfection, respectively, were the cause. Forty-seven per cent of cases with fulminant viral hepatitis were among those aged between 21 and 40 years. Fulminant hepatitis due to HAV was confined to children less than five years of age, while the two patients who had delta infection were 40 years or older. Fulminant hepatitis occurred with equal frequency among males and females, and with the exception of one case, who had a NANB virus infection, the outcome of fulminant viral hepatitis in this study was invariably fatal.

Molecular epidemiology of human rotavirus infections based on genome segment variations in viral strains

Molecular epidemiology of rotavirus infections in 621 hospitalized children was investigated by analysis of migration patterns of viral genomic ribonucleic acid (RNA) segments by electrophoresis in polyacrylamide gels. Based on migration patterns of RNA segments of 184 rotavirus strains, seven different electropherotypes were identified: 146 (79.3%) strains were "long," and 38 (20.7%) were "short" electropherotypes; 61% belonged to a single dominant "long" electropherotype, which persisted throughout the 15-month period of study, whereas six other cocirculating types appeared at varying intervals. Electrophoretic migration patterns of RNA from viral isolates of two patients suggested mixed infections with different rotaviruses. There was a lack of correlation between the electrophoretic migration of segments 10 and 11 and serologically defined subgroup specificity in three of the rotavirus strains. Rotavirus infections and different electropherotypes were observed throughout the year.

Failure to demonstrate synergy between interferon-alpha and a synthetic antiviral, enviroxime, in rhinovirus infections in volunteers

Marked synergy between the antirhinoviral effect of rHuIFN alpha and enviroxime has been observed in vitro but an attempt to demonstrate it in volunteers was unsuccessful. The sub-optimal intranasal dose of rHuIFN alpha (0.18 Mu four times daily for 4 1/4 days) used prophylactically in the trial did reduce the severity of colds induced by RV9 and 14, but the difference did not reach statistical significance and was not enhanced by the administration of enviroxime (0.28 mg six times daily for six days). The main reason for failure is thought to be the rapid removal of enviroxime from the nose when given intranasally.

Recombinant human interferon-gamma as prophylaxis against rhinovirus colds in volunteers

The first evaluation of intranasal (i.n.) recombinant human interferon-gamma (rHuIFN-gamma) as prophylaxis against experimental rhinovirus (RV) infection and illness in volunteers is reported. In two studies, 7 of 27 (26%) of the volunteers who received rHuIFN-gamma (2 Mu i.n. 3 x /day) had either blood stained nasal secretions or nose bleeding which was not observed in any of the 26 placebo recipients. Some volunteers given rHuIFN-gamma showed increased nasal secretion and the majority complained of slight nasal stuffiness, whereas only a few of those receiving placebo complained of these symptoms. In the prophylactic study, 17 volunteers were given the above regimen of rHuIFN-gamma and 17 placebo; after the fourth dose all were challenged with RV9, followed 1 h later with RV14 (100 TCID50 of each virus). Compared with the placebo-treated controls, interferon recipients showed no significant reduction in the proportion who developed colds or became infected, and there was an increase in both their mean clinical scores and mean nasal secretion weights. Thus i.n. rHuIFN-gamma did not prevent rhinovirus infection or illness and may enhance the symptoms.

Evaluation of an enzyme-linked immunosorbent assay that measures rhinovirus-specific antibodies in human sera and nasal secretions

Rhinovirus-specific antibodies have traditionally been detected by their ability to neutralise the homologous rhinovirus serotype in tissue culture. Recently, however, we have described an enzyme-linked immunosorbent assay that detects rhinovirus-specific antibodies in sera and nasal secretions [Barclay and Al-Nakib, 1987]. Here we describe an evaluation of the ELISA in a study involving 71 adult volunteers inoculated intranasally with human rhinovirus type 2 (HRV-2). Pre- and post-inoculation serum samples and pre-inoculation nasal washings were tested for the presence of HRV-2-specific antibodies by ELISA. Such antibodies were associated with protection against infection when present locally in nasal secretions, but when also present in the serum they were associated with protection against both infection and the development of illness. The antibody concentrations showed strong correlation with each other and with that of antibodies detected by the neutralisation test. Following HRV-2 infection, rises in HRV-2-specific IgA in sera detected by ELISA occurred more frequently than rises in neutralising antibody. These results suggest that the ELISA is a sensitive and reliable indicator of recent infection, as well as a predictor of homologous immune status.