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Virus Detection (virus + detection)
Selected AbstractsMonoclonal Antibodies against the Recombinant Nucleocapsid Protein of Tomato spotted wilt virus and its Application in Virus DetectionJOURNAL OF PHYTOPATHOLOGY, Issue 6 2009Jianxiang Wu Abstract Tomato spotted wilt virus (TSWV) is the type member of the tospovirus genus and causes significant losses in a wide range of economically important ornamental and vegetable crops worldwide. The nucleocapsid gene, located on the ambisense S RNA segment of TSWV was expressed in Escherichia coli using pET-32a as vector and correct expression of recombinant protein was confirmed by Western blot using an anti-TSWV monoclonal antibody (MAb). The recombinant protein was purified using Ni-NTA agarose and the purified protein was used for the production of MAbs. Three murine MAbs against the recombinant nucleocapsid protein were produced. Triple antibody sandwich enzyme-linked immunosorbent assay and immunocapture RT-PCR methods were then established for reliable and efficient detection of TSWV using the produced MAbs. [source] Cytology of high-grade squamous intraepithelial lesion in Japanese-Brazilian women with HIV infection with polymerase chain reaction-assisted human papilloma virus detectionDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2002C.F.I.A.C., Tadao K. Kobayashi Ph.D. First page of article [source] Epidemiology of tomato yellow leaf curl begomovirus in the Fayium area, EgyptEPPO BULLETIN, Issue 2 2000A. E. Aboul-Ata Tomato yellow leaf curl begomovirus (TYLCV) severely invaded tomato plantations in Egypt (Lower and Middle Egypt) in 1989. This study aimed to discover the relationship between TYLCV and other epidemic-associated factors in the Fayium area. The rate of TYLCV infection was inspected visually for three successive years (1994/1996) in the Fayium area. During the same period, whiteflies were collected for virus detection using bait-plant and DNA hybridization techniques. DAS-ELISA was used to detect mixed virus infections in tomato plants. TYLCV infection was prevalent (60,68%) and severe (2.1,3.0) in the Fayium fields. Cucumber mosaic cucumovirus (CMV) was found in some fields (5,28%) with moderate severity (1.0,20). Potato Y potyvirus (PVY) and potato leaf roll polerovirus (PLRV) were found in few fields (5,19% and 5% respectively) at very low severity. There was a negative correlation between TYLCV occurrence and distance from the source of infection, and a positive correlation (98%) between TYLCV intensity and percentage of viruliferous whiteflies in 1994 and 1995. There was no positive correlation between TYLCV and the total population of whiteflies caught during the same period. Five percent of viruliferous whiteflies, as proved by cDNA hybridization, led to 46% TYLCV infection. The same percentage of whiteflies, as shown by bioassay, led to 68% TYLCV infection. Monitoring of viruliferous whiteflies could be used for early prediction of TYLCV infection. [source] Influenza virus assays based on virus-inducible reporter cell linesINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 5 2009Yunsheng Li Background, Virus-inducible reporter genes have been used as the basis of virus detection and quantitation assays for a number of viruses. A strategy for influenza A virus-induction of a reporter gene was recently described. In this report, we describe the extension of this strategy to influenza B virus, the generation of stable cell lines with influenza A and B virus-inducible reporter genes, and the use of these cells in various clinically relevant viral assays. Each of the cell lines described herein constitutively express an RNA transcript that contains a reporter gene coding region flanked by viral 5,- and 3,-untranslated regions (UTR) and therefore mimics an influenza virus genomic segment. Upon infection of the cells with influenza virus the virus-inducible reporter gene segment (VIRGS) is replicated and transcribed by the viral polymerase complex resulting in reporter gene expression. Findings, Reporter gene induction occurs after infection with a number of laboratory strains and clinical isolates of influenza virus including several H5N1 strains. The induction is dose-dependent and highly specific for influenza A or influenza B viruses. Conclusions, These cell lines provide the basis of simple, rapid, and objective assays that involve virus quantitation such as determination of viral titer, assessment of antiviral susceptibility, and determination of antibody neutralization titer. These cell lines could be very useful for influenza virus researchers and vaccine manufacturers. [source] Molecular epidemiology of molluscum contagiosum virus and analysis of the host-serum antibody response in Spanish HIV-negative patientsJOURNAL OF MEDICAL VIROLOGY, Issue 2 2002Monica Agromayor Abstract Molluscum contagiosum virus (MCV) lesions from Spanish human immunodeficiency virus (HIV)-negative patients were clinically examined and analyzed for virus detection and typing. In a study of 147 patients, 97 (66%) were children under 10 years, of whom 49% had atopic dermatitis. MCV lesions were morphologically indistinguishable among the different age groups, but atopic patients presented larger lesions compared with patients without the disorder. In adults, lesions were observed mainly on the genitals. MCVI was the predominant subtype. The deduced MCVI/MCVII ratio (146:1) was much higher than that found in other geographical areas. Protein preparations of the virus-induced lesions were immunoblotted with sera from 25 MCVI patients. The host-serum antibody response was weak and variable, although no significant differences were found between atopic and nonatopic patients. Three immunoreactive proteins of 74/80, 60, and 35 kDa were detected in almost all the analyzed sera. The 35 and 74/80-kDa proteins were virus specific, whereas the 60-kDa protein band was composed of a mix of human keratins. Immunoblotting of MCV lesions and vaccinia virus-infected cell extracts with either MCV patient serum or a rabbit antiserum against vaccinia virus showed no cross-reactivity of these two human poxviruses at the antigenic level. J. Med. Virol. 66:151,158, 2002. © 2002 Wiley-Liss, Inc. [source] Detection of human bocavirus in hospitalised childrenJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2009Julia Dina Aim: The objectives of this study are to assess the frequency of human bocavirus (HBoV) infection in hospitalised children and to study the clinical symptoms associated with the detection of HBoV. Methods: Two groups of hospitalised children were included in this study: group 1 consisted of 1946 children hospitalised from 1st September 2004 to 30th May 2005, and group 2 consisted of 448 children hospitalised from 1st November 2003 to 30th March 2004. The respiratory specimens were tested by polymerase chain reaction. Results: In the first group, HBoV was detected by polymerise chain reaction in 11/828 (1.3%) of nasal specimens that tested negative for other respiratory viruses. One child tested positive for HBoV in both a nasal aspirate and stool sample. In the second group, nasal specimens were tested for all respiratory viruses, including HBoV. The presence of HBoV infection was detected in seven children (1.6%). Detection of a mixed viral population was observed in four of these children. The main symptoms in children infected with HBoV were rhinitis (50%), cough (45%), dyspnoea (28%), wheezing (28%), fever (23%) and diarrhoea (22%). The final clinical diagnoses were bronchiolitis (seven children), rhinopharyngitis (five children), the exacerbation of asthma (two children) and pneumonia (one child). Moreover, four children have associated gastroenteritis. Conclusion: These results contribute to the interest in the HBoV detection in children. HBoV detection in hospitalised children with or without any other respiratory virus detection was essentially associated with lower respiratory tract infection and in a lower score with upper respiratory tract infection and gastroenteritis. [source] Real-time polymerase chain reaction as a rapid and efficient alternative to estimation of picornavirus titers by tissue culture infectious dose 50% or plaque forming unitsMICROBIOLOGY AND IMMUNOLOGY, Issue 3 2009Nina Jonsson ABSTRACT Quantification of viral infectious units is traditionally measured by methods based on forming plaques in semisolid media (PFU) or endpoint dilution of a virus-containing solution (TCID50), methods that are laborious, time-consuming and take on average 3,7 days to carry out. Quantitative real-time PCR is an established method to quantify nucleic acids at high accuracy and reproducibility, routinely used for virus detection and identification. In the present study, a procedure was developed using a two-step real-time PCR and the SYBR Green detection method to study whether there are correlations between TCID50/ml, PFU/ml and Ct values generated by real-time PCR enabling rapid and efficient calculation of titer equivalents when working with viruses in the research laboratory. In addition, an external standard with known concentrations was included using in vitro transcribed viral RNA, thus allowing the calculation of the amount of RNA copies needed for various applications (i.e. per plaque or TCID50). The results show that there is a correlation between the three quantification methods covering a wide range of concentration of viruses. Furthermore, a general regression line between TCID50 and Ct values was obtained for all viruses included in the study, which enabled recording titer equivalents using real-time PCR. Finally, by including an external standard, the amount of RNA genomes generating one TCID50 or PFU for each enterovirus serotype included was determined. [source] Adenovirus Infection in Pediatric Liver and Intestinal Transplant Recipients: Utility of DNA Detection by PCRAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2003Gwenn E. McLaughlin To evaluate the incidence of adenovirus (AdV) infection in pediatric liver and intestinal transplant recipients, the records of patients with possible AdV infection were reviewed for demographic data, symptomatology, methods of diagnosis, treatment and outcome. To evaluate the impact of polymerase chain reaction (PCR) amplification and identification of AdV DNA as a diagnostic test, the incidence and outcome of AdV before and after the introduction of PCR were compared. Adenovirus infection was identified in 4.1% of liver recipients and 20.8% of intestinal transplant recipients. The overall incidence of AdV did not increase over time, even following the introduction of PCR for virus detection. The higher incidence of AdV in the pediatric intestinal transplant recipients may be attributed to the frequent application of PCR methodology to intestinal biopsy material. Detection of AdV by PCR was associated with reduced mortality compared with detection by culture, either because of earlier detection of invasive disease or because PCR detects the presence of latent as well as active AdV. [source] Newly identified respiratory viruses in children with asthma exacerbation not requiring admission to hospitalJOURNAL OF MEDICAL VIROLOGY, Issue 8 2010Katherine E. Arden Abstract There are few data describing the comprehensive identification in and influence of newly identified respiratory viruses on asthma exacerbations. Most studies focus on inpatients. In this preliminary study, the point prevalence and the associations of picornavirus species described recently and human bocavirus (HBoV) with the recovery from exacerbations in non-hospitalized asthmatic children (median age 5.1 years) were examined. Human rhinoviruses (HRVs) were present in 52.6% of specimens, HBoV-1 was in 7.7%. Viral co-detections occurred in 25.6% of children and were associated (P,=,0.04) with lower asthma quality of life scores upon presentation than were single viral detections. The undifferentiated presence or absence of virus did not influence the severity of asthma or recovery however when virus species were examined individually, specific clinical associations emerged. HRV species C (HRV-Cs) were the viruses most frequently detected as single virus detections. Among 41 genotyped HRVs, more HRV-Cs (n,=,23) were identified than HRV-As (n,=,16) however HRV-A detection was associated (P,=,0.01) with worse asthma symptoms and cough for longer than was HRV-C detection. Larger, PCR-based studies are required to elucidate further the true impact of HRV species in childhood asthma exacerbations of both hospitalized and non-hospitalized cohorts. J. Med. Virol. 82:1458,1461, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||