scholarly journals Reverse Transcription-PCR Analysis of Bottled and Natural Mineral Waters for the Presence of Noroviruses

2003 ◽  
Vol 69 (11) ◽  
pp. 6541-6549 ◽  
Author(s):  
Gilbert Thierry Lamothe ◽  
Thierry Putallaz ◽  
Han Joosten ◽  
Joey D. Marugg
Keyword(s):  
Reverse Transcription ◽  
Membrane Filtration ◽  
Limit Of Detection ◽  
Mineral Waters ◽  
Pcr Analysis ◽  
Rna Sequences ◽  
Natural Mineral ◽  
Reverse Transcription Pcr ◽  
Viral Particles ◽  
Nonspecific Amplification

ABSTRACT A seminested reverse transcription-PCR method coupled to membrane filtration was optimized to investigate the presence of norovirus (NV) RNA sequences in bottled and natural mineral waters. The recovery of viral particles by filtration varied between 28 and 45%, while the limit of detection of the overall method ranged from 6 to 95 viral particles. The assay was broadly reactive, as shown by the successful detection of 27 different viral strains representing 12 common genotypes of NVs. A total of 718 bottled and natural mineral water samples were investigated, including 640 samples of finished, spring, and line products (mostly 1 to 1.5 liters), collected from 36 different water brands of various types and from diverse geographic origins over a 2-year period. In addition, 78 samples of larger volume (10 and 400 to 500 liters) and environmental swabs were investigated. From the 1,436 analyses that were performed for the detection of NVs belonging to genogroups I and II, 34 samples (2.44%) were presumptively positive by seminested RT-PCR. However, confirmation by DNA sequence analysis revealed that all presumptive positive results were either due to nonspecific amplification or to cross-contamination. In conclusion, these results do not provide any evidence for the presence of NV genome sequences in bottled waters.

Development of a real-time reverse transcription-PCR assay to detect and quantify group A rotavirus equine-like G3 strains

2021 ◽  
Author(s):  
Eric M. Katz ◽  
Mathew D. Esona ◽  
Rashi Gautam ◽  
Michael D. Bowen
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Reverse Transcription ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Human Populations ◽  
Pcr Assay ◽  
Group A Rotavirus ◽  
Reverse Transcription Pcr ◽  
Group A

Since 2013, group A rotavirus strains characterized as novel DS-1-like inter-genogroup reassortant ‘equine-like G3’ strains have emerged and spread across five continents among human populations in at least 14 countries. Here we report a novel one-step TaqMan quantitative real-time reverse transcription-PCR assay developed to genotype and quantify the viral load for samples containing rotavirus equine-like G3 strains. Using a universal G forward primer and a newly designed reverse primer and TaqMan probe, we developed and validated an assay with a linear dynamic range of 2.3 × 10 9 – 227 copies per reaction and a limit of detection of 227 copies. The percent positive agreement, percent negative agreement, and precision of our assay were 100.00%, 99.63%, and 100.00%, respectively. This assay can simultaneously detect and quantify the viral load for samples containing DS-1-like inter-genogroup reassortant equine-like G3 strains with high sensitivity and specificity, faster turnaround time, and decreased cost and will be valuable for high-throughput screening of stool samples collected to monitor equine-like G3 strain prevalence and circulation among human populations throughout the world.

Norovirus Detection at Oualidia Lagoon, a Moroccan Shellfish Harvesting Area, by Reverse Transcription PCR Analysis

2019 ◽  
Vol 11 (3) ◽  
pp. 268-273
Author(s):  
N. El Moqri ◽  
F. El Mellouli ◽  
N. Hassou ◽  
M. Benhafid ◽  
N. Abouchoaib ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Pcr Analysis ◽  
Reverse Transcription Pcr ◽  
Oualidia Lagoon

scholarly journals Arr-cb Is a Rifampin Resistance Determinant Found Active or Cryptic in Clostridiumbolteae Strains

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Jean-Christophe Marvaud ◽  
Thierry Lambert
Keyword(s):  
Escherichia Coli ◽  
Gut Microbiota ◽  
Reverse Transcription ◽  
Recent Analysis ◽  
Pcr Analysis ◽  
Directed Mutagenesis ◽  
Human Gut ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Rifampin Resistance

ABSTRACT Clostridium bolteae, which belongs to the Clostridium clostridioforme complex, is a member of the human gut microbiota. Recent analysis of seven genomes of C. bolteae revealed the presence of an arr-like gene. Among these strains, only 90A7 was found to be resistant to rifampin in the absence of alteration of RpoB. Cloning of arr-cb from 90A7 in Escherichia coli combined with directed mutagenesis demonstrated that Arr-cb was functional but that a Q127→R variant present in 90A9 and 90B3 was inactive. Quantitative reverse transcription-PCR analysis indicated that arr-cb was silent in the four remaining strains because of defective transcription. Thus, two independent mechanisms can make the probably intrinsic arr-cb gene of C. bolteae cryptic.

scholarly journals Dissolved Oxygen Levels Alter Gene Expression and Antigen Profiles in Borrelia burgdorferi

2004 ◽  
Vol 72 (3) ◽  
pp. 1580-1586 ◽  
Author(s):  
J. Seshu ◽  
Julie A. Boylan ◽  
Frank C. Gherardini ◽  
Jonathan T. Skare
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
Dissolved Oxygen ◽  
Reverse Transcription ◽  
Host Factors ◽  
Pcr Analysis ◽  
Transcriptional Level ◽  
Environmental Signals ◽  
Reverse Transcription Pcr ◽  
Genes Encoding

ABSTRACT The Lyme disease spirochete, Borrelia burgdorferi, encounters many environmental signals as it cycles between the arthropod vector and mammalian hosts, including temperature, pH, and other host factors. To test the possibility that dissolved oxygen modulates gene expression in B. burgdorferi, spirochetes were exposed to differential levels of dissolved oxygen, and distinct alterations were observed at both the transcriptional and translational levels. Specifically NapA, a Dps/Dpr homologue involved in the oxidative stress response in other bacteria, was reduced when B. burgdorferi was grown under oxygen-limiting conditions. In contrast, several immunoreactive proteins were altered when tested with infection-derived sera from different hosts. Specifically, OspC, DbpA, and VlsE were synthesized at greater levels when cells were grown in limiting oxygen, whereas VraA was reduced. The levels of oxygen in the medium did not affect OspA production. Real-time reverse transcription-PCR analysis of RNA isolated from infectious isolates of strains B31 and cN40 indicated that the expression of ospC, dbpA, and vlsE increased while napA expression decreased under dissolved-oxygen-limiting conditions, whereas flaB was not affected. The reverse transcription-PCR results corroborated the immunoblot analyses and indicated that the increase in OspC, DbpA, and VlsE was due to regulation at the transcriptional level of the genes encoding these antigens. These results indicate that dissolved oxygen modulates gene expression in B. burgdorferi and imply that the redox environment may be an additional regulatory cue that spirochetes exploit to adapt to the disparate niches that they occupy in nature.

scholarly journals Detection of Human and Animal Rotavirus Sequences in Drinking Water

2000 ◽  
Vol 66 (6) ◽  
pp. 2690-2692 ◽  
Author(s):  
B. Gratacap-Cavallier ◽  
O. Genoulaz ◽  
K. Brengel-Pesce ◽  
H. Soule ◽  
P. Innocenti-Francillard ◽  
...  
Keyword(s):  
Drinking Water ◽  
Reverse Transcription ◽  
Animal Origin ◽  
Pcr Analysis ◽  
Human Origin ◽  
Reverse Transcription Pcr

ABSTRACT Reverse transcription-PCR analysis of drinking water in the homes of 56 children suffering from rotaviral gastroenteritis has shown the presence of the rotavirus genome in four samples. These strains were different from human rotaviruses detected in the children's feces, as determined by sequencing of the VP7-amplified fragments—three of them of animal origin (porcine or bovine) and one of human origin.

High-Resolution Magic Angle Spinning1H NMR Spectroscopy and Reverse Transcription-PCR Analysis of Apoptosis in a Rat Glioma

2006 ◽  
Vol 78 (5) ◽  
pp. 1546-1552 ◽  
Author(s):  
Julian L. Griffin ◽  
Cherie Blenkiron ◽  
Piia K. Valonen ◽  
Carlos Caldas ◽  
Risto A Kauppinen
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Reverse Transcription ◽  
Pcr Analysis ◽  
Magic Angle ◽  
Rat Glioma ◽  
Reverse Transcription Pcr

scholarly journals In Vivo Selection of Reduced Susceptibility to Carbapenems in Acinetobacter baumannii Related to ISAba1-Mediated Overexpression of the Natural blaOXA-66 Oxacillinase Gene

2009 ◽  
Vol 53 (6) ◽  
pp. 2657-2659 ◽  
Author(s):  
Samy Figueiredo ◽  
Laurent Poirel ◽  
Jacques Croize ◽  
Christine Recule ◽  
Patrice Nordmann
Keyword(s):  
Acinetobacter Baumannii ◽  
Reverse Transcription ◽  
Resistance Pattern ◽  
Pcr Analysis ◽  
In Vivo Selection ◽  
Reverse Transcription Pcr ◽  
Naturally Occurring ◽  
Carbapenemase Gene ◽  
Selection Of

ABSTRACT Two clonally related Acinetobacter baumannii isolates, A1 and A2, were obtained from the same patient. Isolate A2, selected after an imipenem-containing treatment, showed reduced susceptibility to carbapenems. This resistance pattern was related to insertion of the ISAba1 element upstream of the naturally occurring bla OXA-66 carbapenemase gene as demonstrated by sequencing, reverse transcription-PCR analysis, and inactivation of the bla OXA-66 gene.

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