scholarly journals Distribution of Rotavirus VP4 Genotypes and VP7 Serotypes among Nonhospitalized and Hospitalized Patients with Gastroenteritis and Patients with Nosocomially Acquired Gastroenteritis in Austria

2000 ◽  
Vol 38 (5) ◽  
pp. 1804-1806 ◽  
Author(s):  
M. Frühwirth ◽  
S. Brösl ◽  
H. Ellemunter ◽  
I. Moll-Schüler ◽  
A. Rohwedder ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Reverse Transcription ◽  
Nosocomial Infections ◽  
Acute Gastroenteritis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rotavirus Vaccine ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Potential Benefits ◽  
Stool Specimens

To assess the potential benefits of a reassortant tetravalent rotavirus vaccine, we investigated stool specimens from children in three different groups by reverse transcription-PCR (RT-PCR) for rotavirus G and P types: (i) children not hospitalized with community-acquired rotavirus-acute gastroenteritis (RV-AGE), (ii) children hospitalized for RV-AGE, and (iii) children with nosocomially acquired RV-AGE. From a total of 553 samples investigated, 335 were positive by enzyme-linked immunosorbent assay, of which 294 (88%) were positive by RT-PCR. Among the RT-PCR-positive samples, the predominant types were G1P[8] (84%), followed by G4P[8] (9%) and G3P[8] (2%). No differences between the three groups were observed, suggesting that community vaccination will diminish the most cost-relevant cases of hospitalizations and nosocomial infections.

scholarly journals Rapid and Sensitive Detection of Noroviruses by Using TaqMan-Based One-Step Reverse Transcription-PCR Assays and Application to Naturally Contaminated Shellfish Samples

2005 ◽  
Vol 71 (4) ◽  
pp. 1870-1875 ◽  
Author(s):  
Narayanan Jothikumar ◽  
James A. Lowther ◽  
Kathleen Henshilwood ◽  
David N. Lees ◽  
Vincent R. Hill ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Nested Pcr ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Specificity And Sensitivity ◽  
Routine Monitoring ◽  
The Family ◽  
One Step ◽  
Stool Specimens ◽  
Pcr Assays

ABSTRACT Noroviruses (NoV), which are members of the family Caliciviridae, are the most important cause of outbreaks of acute gastroenteritis worldwide and are commonly found in shellfish grown in polluted waters. In the present study, we developed broadly reactive one-step TaqMan reverse transcription (RT)-PCR assays for the detection of genogroup I (GI) and GII NoV in fecal samples, as well as shellfish samples. The specificity and sensitivity of all steps of the assays were systematically evaluated, and in the final format, the monoplex assays were validated by using RNA extracted from a panel of 84 stool specimens, which included NoV strains representing 19 different genotypes (7 GI, 11 GII, and 1 GIV strains). The assays were further validated with 38 shellfish cDNA extracts previously tested by nested PCR. Comparison with a recently described real-time assay showed that our assay had significantly higher sensitivity and was at least as sensitive as the nested PCR. For stool specimens, a one-step duplex TaqMan RT-PCR assay performed as well as individual genogroup-specific monoplex assays. All other enteric viruses examined were negative, and no cross-reaction between genogroups was observed. These TaqMan RT-PCR assays provide rapid (less than 90 min), sensitive, and reliable detection of NoV and should prove to be useful for routine monitoring of both clinical and shellfish samples.

Evaluation of a Sensitive Reverse Transcription PCR–Enzyme-Linked Immunosorbent Assay for Detection of Hepatitis A Virus in Oysters (Saccostrea glomerata) on the East Coast of the Gulf of Thailand

2014 ◽  
Vol 77 (5) ◽  
pp. 859-863 ◽  
Author(s):  
URAIWAN INTAMASO ◽  
SITTHISAK KETKHUNTHOD
Keyword(s):  
Immunosorbent Assay ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
East Coast ◽  
Hepatitis A Virus ◽  
Detection Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gulf Of Thailand ◽  
Rt Pcr ◽  
The Gulf Of Thailand

Hepatitis A virus (HAV) contamination in food can lead to major health problems. We developed a combination reverse transcription (RT) PCR method plus enzyme-linked immunosorbent assay (ELISA) to detect HAV in fresh oysters harvested along the east coast of the Gulf of Thailand. Viral nucleic acid was extracted via the glycine–arginine–polyethylene glycol method followed by RT-PCR amplification with specifically designed primers against HAV and an ELISA to detect the digoxigenin-labeled RT-PCR products. The ELISA in concert with the RT-PCR protocol further increased the detection sensitivity by 100-fold for the HAV genome and 10-fold in artificially contaminated oysters. The overall sensitivity of the RT-PCR in combination with the ELISA was 31.88 pg and 16 PFU/g, respectively. The ELISA increases the specificity of the RT-PCR assay for detecting naturally occurring HAV in oysters. This combined RT-PCR-ELISA approach is a practical and sensitive method for HAV detection and can be utilized in routine screening for HAV in shellfish.

scholarly journals Sacbrood Virus of the Honeybee (Apis mellifera): Rapid Identification and Phylogenetic Analysis Using Reverse Transcription-PCR

2001 ◽  
Vol 8 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Elvira Grabensteiner ◽  
Wolfgang Ritter ◽  
Michael J. Carter ◽  
Sean Davison ◽  
Hermann Pechhacker ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Apis Mellifera ◽  
Reverse Transcription ◽  
Direct Detection ◽  
Geographic Origin ◽  
Rapid Identification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Sacbrood Virus ◽  
Reverse Transcription Pcr

ABSTRACT Sacbrood virus (SBV) infects larvae of the honeybee (Apis mellifera), resulting in failure to pupate and death. Until now, identification of viruses in honeybee infections has been based on traditional methods such as electron microscopy, immunodiffusion, and enzyme-linked immunosorbent assay. Culture cannot be used because no honeybee cell lines are available. These techniques are low in sensitivity and specificity. However, the complete nucleotide sequence of SBV has recently been determined, and with these data, we now report a reverse transcription-PCR (RT-PCR) test for the direct, rapid, and sensitive detection of these viruses. RT-PCR was used to target five different areas of the SBV genome using infected honeybees and larvae originating from geographically distinct regions. The RT-PCR assay proved to be a rapid, specific, and sensitive diagnostic tool for the direct detection of SBV nucleic acid in samples of infected honeybees and brood regardless of geographic origin. The amplification products were sequenced, and phylogenetic analysis suggested the existence of at least three distinct genotypes of SBV.

scholarly journals Comparison of Four Serological Methods and Two Reverse Transcription-PCR Assays for Diagnosis and Surveillance of Zika Virus Infection

2018 ◽  
Vol 56 (3) ◽  
Author(s):  
Angel Balmaseda ◽  
José Victor Zambrana ◽  
Damaris Collado ◽  
Nadezna García ◽  
Saira Saborío ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Zika Virus ◽  
Clinical Manifestations ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Emerging Infections ◽  
Rt Pcr ◽  
Convalescent Phase ◽  
Reverse Transcription Pcr ◽  
Pcr Assays

ABSTRACTZika virus (ZIKV) is a mosquito-borne flavivirus that is responsible for recent explosive epidemics in the Americas. Notably, ZIKV infection during pregnancy has been found to cause congenital birth defects, including microcephaly, and ZIKV has been associated with Guillain-Barré syndrome in adults. Diagnosis and surveillance of Zika in the Americas have been challenging due to similar clinical manifestations and extensive antibody cross-reactivity with endemic flaviviral diseases, such as dengue. We evaluated four serological and two reverse transcription-PCR (RT-PCR) methods in acute-phase (mean day, 1.8), early-convalescent-phase (mean day, 16.7), and late-convalescent-phase (mean, ~7 months) samples from the same individuals in a long-term pediatric cohort study in Nicaragua. Well-characterized samples from 301 cases of Zika, dengue, or non-Zika, nondengue febrile illnesses were tested. Compared to a composite reference, an in-house IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the NIAID-Biodefense and Emerging Infections (BEI) MAC-ELISA measuring IgM yielded sensitivities of 94.5% and 70.1% and specificities of 85.6% and 82.8%, respectively. The NS1 blockade-of-binding ELISA measuring anti-ZIKV NS1 antibody levels yielded sensitivities of 85.0% and 96.5% and specificities of 91.4% and 92.6% at early and late convalescence, respectively. An inhibition ELISA detecting total anti-ZIKV antibodies had sensitivity and specificity values of 68.3% and 58.3% for diagnosis and 94.0% and 98.6% for measuring annual infection incidence. Finally, the ZCD and Trioplex real-time RT-PCR assays detecting Zika, chikungunya, and dengue viruses both yielded a sensitivity of 96.1% and specificity of 100%. Together, these assays resolve the urgent need for diagnostic and surveillance tools for countries affected by Zika virus infections.

scholarly journals Development of Reverse Transcription-PCR (Oligonucleotide Probing) Enzyme-Linked Immunosorbent Assays for Diagnosis and Preliminary Typing of Foot-and-Mouth Disease: a New System Using Simple and Aqueous-Phase Hybridization

2000 ◽  
Vol 38 (12) ◽  
pp. 4604-4613 ◽  
Author(s):  
Soren Alexandersen ◽  
Morag A. Forsyth ◽  
Scott M. Reid ◽  
Graham J. Belsham
Keyword(s):  
Reverse Transcription ◽  
Pcr Amplification ◽  
Foot And Mouth Disease ◽  
Variable Region ◽  
Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Mouth Disease Virus ◽  
Foot And Mouth

A reverse transcription-PCR (RT-PCR)–enzyme-linked immunosorbent assay system that detects a relatively conserved region within the RNA genome of all seven serotypes of foot-and-mouth disease virus (FMDV) has been developed. The high specificity of the assay is achieved by including a rapid hybridization step with a biotin-labeled internal oligonucleotide. The assay is highly sensitive, fast, and easy to perform. A similar assay, based on a highly variable region of the FMDV genome and employing a single asymmetric RT-PCR and multiple hybridization oligonucleotides, was developed to demonstrate the method's ability to type FMDV. Based on our theoretical and practical knowledge of the methodology, we predict that similar assays are applicable to diagnosis and strain differentiation in any system amenable to PCR amplification.

scholarly journals Serological Evidence of Human Klassevirus Infection

2010 ◽  
Vol 17 (10) ◽  
pp. 1584-1588 ◽  
Author(s):  
Alexander L. Greninger ◽  
Lori Holtz ◽  
Gagandeep Kang ◽  
Donald Ganem ◽  
David Wang ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Reverse Transcription ◽  
New Genus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serological Evidence ◽  
3C Protease

ABSTRACT Klassevirus is a proposed new genus of picornavirus that has been associated with pediatric diarrhea. In this study, we used recombinant klassevirus 3C protease as the capture antigen for an indirect serological enzyme-linked immunosorbent assay (ELISA). Four of six klassevirus reverse transcription (RT)-PCR-positive individuals demonstrated seroconversion against the 3C protease, suggesting that klassevirus infection and replication occur in humans. Additional screening of 353 samples from an age-banded serological cohort from two St. Louis hospitals indicated a seroprevalence of 6.8%.

scholarly journals Ο ρόλος της παχυσαρκίας στην ανοσολογική απάντηση ασθενών με σύνδρομο σήψης

2015 ◽  
Author(s):  
Αναστασία Κολυβά
Keyword(s):  
Antioxidant Capacity ◽  
Real Time ◽  
Immunosorbent Assay ◽  
Reverse Transcription ◽  
Total Antioxidant Capacity ◽  
Thiobarbituric Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Thiobarbituric Acid Reactive Substances ◽  
Reverse Transcription Pcr ◽  
Total Antioxidant

Σκοπός: Η σήψη αποτελεί μια από τις σημαντικότερες αιτίες νοσηλείας και θνησιμότητας στον ανεπτυγμένο κόσμο, όπου σχεδόν τα δύο - τρίτα του πληθυσμού υποφέρουν από παχυσαρκία. Σαν αποτέλεσμα, η συνύπαρξη των δύο αυτών καταστάσεων έχει γίνει όλο και συχνότερη στην κλινική πράξη και ένας συνεχώς αυξανόμενος αριθμός κλινικών μελετών προσπαθεί να προσεγγίσει την πιθανή επίδραση της παχυσαρκίας στην νοσηρότητα και θνησιμότητα των ασθενών με σήψη, με έως τώρα αντιφατικά αποτελέσματα. Σκοπός της παρούσας μελέτης είναι να διερευνήσει τον τρόπο με τον οποίο η παχυσαρκία επηρεάζει την ανοσιακή απάντηση των σηπτικών ασθενών, εκτιμώντας τον αριθμό και την κατάσταση ενεργοποίησης των μακροφάγων του λιπώδους ιστού, τα επίπεδα του TNFα στον ορό και στον λιπώδη ιστό και δείκτες οξειδωτικού stress στο πλάσμα.Ασθενείς και Μέθοδοι: Μελετήθηκαν 106 ασθενείς, οι οποίοι χωρίστηκαν σε τέσσερις ομάδες (Ελέγχου n=26, Παχυσαρκίας n=27, Σήψης n=27, Σήψης & Παχυσαρκίας n=26). Ο αριθμός των μακροφάγων στο υποδόριο και ενδοκοιλιακό λίπος και οι υπότυποί τους (M1 και M2) αναγνωρίστηκαν με ανοσοϊστοχημική τεχνική υπό μικροσκόπηση. Τα επίπεδα του TNFα mRNA στο υποδόριο και ενδοκοιλιακό λίπος μετρήθηκαν με real-time reverse transcription-PCR. Στον ορό τα επίπεδα του TNFα μετρήθηκαν με sandwich enzyme-linked immunosorbent assay (ELISA). Το οξειδωτικό stress στο πλάσμα εκτιμήθηκε χρησιμοποιώντας επιλεγμένους βιοδείκτες [TBARS (thiobarbituric acid-reactive substances), Πρωτεϊνικά Καρβονύλια, TAC (total antioxidant capacity)].Αποτελέσματα: Παρατηρήθηκε ότι η σήψη αυξάνει τον ολικό αριθμό και τον Μ2 υπότυπο των μακροφάγων στο ενδοκοιλιακό λίπος, ενώ η παχυσαρκία δεν φάνηκε να επηρεάζει τη συγκέντρωση των μακροφάγων στο λίπος. Η παχυσαρκία βρέθηκε ότι αυξάνει τα επίπεδα του TNFα mRNA (P<0.05) στο ενδοκοιλιακό λίπος καθώς επίσης και τα επίπεδα των TBARS (P<0.001) και Πρωτεϊνικών Καρβονυλίων (P<0.001) στο πλάσμα των σηπτικών ασθενών. Τα επίπεδα της TAC στο πλάσμα βρέθηκε ότι μειώνονται και τα επίπεδα TNFα στον ορό ότι αυξάνονται με τη σήψη, ενώ δεν επηρεάζονταν από την παχυσαρκία. Συμπεράσματα: Η παχυσαρκία σχετίζεται με αυξημένη παραγωγή TNFα στον λιπώδη ιστό και αύξηση του οξειδωτικού stress, προάγοντας την προ-φλεγμονώδη απάντηση στους σηπτικούς ασθενείς.

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