Removal of norovirus from water by coagulation, flocculation and sedimentation processes

2014 ◽  
Vol 15 (1) ◽  
pp. 158-163 ◽  
Author(s):  
Gwy-Am Shin ◽  
Mark D. Sobsey

In this study, we determined the removal of a prototype human norovirus (Norwalk virus, NV) by bench-scale alum coagulation, flocculation and sedimentation processes using reverse transcriptase polymerase chain reaction (RT-PCR) for norovirus assays. After determining optimum conditions for the coagulation, flocculation and sedimentation processes in terms of turbidity reduction, jar tests were performed using the same waters seeded with test viruses. For comparison, two other important health-related viruses, poliovirus 1 (PV1) and coliphage MS2, were included in this study. The removal of NV by coagulation, flocculation and sedimentation processes based on RT-PCR assay in this study was 1.5 log10, which was similar to that of PV1 and a little lower than that of coliphage MS2 (2 log10) based on the same RT-PCR assay. The removal of NV in this study (1.5 log10) is considerably higher than the one in a recent study using recombinant norovirus virus-like particles (∼0.7 log10). Overall, the results of this study suggest that human noroviruses can be appreciably reduced by a properly-operated coagulation, flocculation and sedimentation processes and the contamination of drinking water by noroviruses should be controlled by conventional water treatment processes with conventional physico-chemical processes and disinfection.

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Sungwoo Choi ◽  
Hyo Jeong Choi ◽  
Ho Jung Kim

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.


Plant Disease ◽  
2013 ◽  
Vol 97 (5) ◽  
pp. 641-644 ◽  
Author(s):  
Manphool S. Fageria ◽  
Mathuresh Singh ◽  
Upeksha Nanayakkara ◽  
Yvan Pelletier ◽  
Xianzhou Nie ◽  
...  

The current-season spread of Potato virus Y (PVY) was investigated in New Brunswick, Canada, in 11 potato fields planted with six different cultivars in 2009 and 2010. In all, 100 plants selected from each field were monitored for current-season PVY infections using enzyme-linked immunosorbent assay (ELISA) and real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. Average PVY incidence in fields increased from 0.6% in 2009 and 2% in 2010 in the leaves to 20.3% in 2009 and 21.9% in 2010 in the tubers at the time of harvest. In individual fields, PVY incidence in tubers reached as high as 37% in 2009 and 39% in 2010 at the time of harvest. Real-time RT-PCR assay detected more samples with PVY from leaves than did ELISA. A higher number of positive samples was also detected with real-time RT-PCR from growing tubers compared with the leaves collected from the same plant at the same sampling time. PVY incidence determined from the growing tubers showed a significant positive correlation with the PVY incidence of tubers after harvest. Preharvest testing provides another option to growers to either top-kill the crop immediately to secure the seed market when the PVY incidence is low or leave the tubers to develop further for table or processing purposes when incidence of PVY is high.


2016 ◽  
Vol 4 (2) ◽  
pp. 264-270 ◽  
Author(s):  
Aml Soliman ◽  
Asmaa Abdel Aal ◽  
Reham Afify ◽  
Noha Ibrahim

AIM: Aim was to detect Brain and Acute Leukemia, Cytoplasmic (BAALC) and ETS-related gene (ERG) expression in patients with acute myeloid leukemia (AML) as well as to study their biologic and prognostic impact on the disease outcome and survival.PATIENTS AND METHODS: The current study was carried out on 44 patients with denovo acute myeloid leukemia, as well as 44 age and sex matched controls. The quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was performed for estimation of BAALC and ERG expression.RESULTS: The current study was carried out on 44 patients with denovo acute myeloid leukemia, as well as 44 age and sex matched controls. The quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was performed for estimation of BAALC and ERG expression. BAALC was expressed in 36 (81.82%) of AML cases versus 10 (22.72%) of the control group which was highly statistically significant (P < 0.001). While ERG was positive in 39(88.64%) of cases and 8(18.18 %) of controls and that was also highly statistically significant (P < 0.001).CONCLUSION: Further researches still needed to clarify the role of BAALC and ERG in the pathogenesis of leukemia and their importance as targets for treatment of AML.


Author(s):  
Linda Mueller ◽  
Valentin Scherz ◽  
Gilbert Greub ◽  
Katia Jaton ◽  
Onya Opota

Since the beginning of the COVID-19 pandemic, important health and regulatory decisions relied on SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) results. Our diagnostic laboratory faced a rapid increase in the number of SARS-CoV-2 RT-PCR. To maintain a rapid turnaround time, we moved from a case-by-case validation of RT-PCR results to an automated validation and immediate results transmission to clinicians. A quality-monitoring tool based on a homemade algorithm coded in R was developed, to preserve high quality and to track aberrant results. We present the results of this quality-monitoring tool applied to 35,137 RT-PCR results. Patients tested several times led to 4,939 pairwise comparisons: 88% concordant and 12% discrepant. The algorithm automatically solved 428 out of 573 discrepancies. The most likely explanation for these 573 discrepancies was related for 44.9% of the situations to the clinical evolution of the disease, 27.9% to preanalytical factors, and 25.3% to stochasticity of the assay. Finally, 11 discrepant results could not be explained, including 8 for which clinical data was not available. For patients repeatedly tested on the same day, the second result confirmed a first negative or positive result in 99.2% or 88.9% of cases, respectively. The implemented quality-monitoring strategy allowed to: i) assist the investigation of discrepant results ii) focus the attention of medical microbiologists onto results requiring a specific expertise and iii) maintain an acceptable turnaround time. This work highlights the high RT-PCR consistency for the detection of SARS-CoV-2 and the necessity for automated processes to handle a huge number of microbiological results while preserving quality.


2009 ◽  
Vol 45 (No. 4) ◽  
pp. 140-143 ◽  
Author(s):  
S. Kumari

A one-step reverse transcription-polymerase chain reaction (RT-PCR) protocol was developed and used for the detection of <i>Cherry leaf roll virus</i> (CLRV) and <i>Strawberry latent ring spot virus</i> (SLRSV). The protocol was used to test infected screen house plants and also plants from orchards and vineyards where the vector (<i>Xiphinema diversicaudatum</i>) of SLRSV was detected from the soil. The one-step RT-PCR protocol is rapid and sensitive and has the potential to be used for the diagnosis of CLRV and SLRSV in routine diagnostic laboratories.


Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 694 ◽  
Author(s):  
Weiss ◽  
Klempa ◽  
Tenner ◽  
Kruger ◽  
Hofmann

To screen diagnostic specimens for the presence of hantavirus genomes or to identify new hantaviruses in nature, the pan-hanta L-PCR assay, a broadly reactive nested reverse transcription polymerase chain reaction (RT-PCR) assay targeting the L segment, is highly preferred over other assays because of its universality and high sensitivity. In contrast, the geographic allocation of Puumala virus strains to defined outbreak regions in Germany was previously done based on S segment sequences. We show that the routinely generated partial L segment sequences resulting from the pan-hanta L-PCR assay provide sufficient phylogenetic signal to inform the molecular epidemiology of the Puumala virus. Consequently, an additional S segment analysis seems no longer necessary for the identification of the spatial origin of a virus strain.


2009 ◽  
Vol 6 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Shi Li-Jun ◽  
Lu Mao-Min ◽  
Li Gang ◽  
Li Cheng-Yao ◽  
Zhang Jin-Gang

AbstractA rapid real-time polymerase chain reaction (RT-PCR) for detecting West Nile virus (WNV) was established. Primers were designed according to the sequence of the capsid protein gene of WNV by Primer Premier 5.0. In this way, an inexpensive assay using the intercalating dye SYBR Green I was developed and validated. The amplifying curve showed that this method could successfully amplify 102 copies/μl of the WNV gene, while reference to Japanese encephalitis virus (JEV) and blank control were all negative. Tenfold successive dilutions of positive WNV DNA were used to measure the sensitivity of RT-PCR. The assay system showed high reproducibility with coefficient of variation (CV) <2%. Thus the newly established RT-PCR assay was shown to be a rapid, sensitive and specific test for detecting WNV.


2003 ◽  
Vol 112 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Toshio Ishibashi ◽  
Hiroko Monobe ◽  
Masanobu Shinogami ◽  
Yuka Nomura ◽  
Jun Yano

Because respiratory viruses play an important role in the causation and pathogenesis of acute otitis media (AOM), determining which virus has infected a child is important with respect to vaccines and antiviral drugs. In some instances, this information might be used to prevent the occurrence of AOM. We used a rapid, economical, and sensitive diagnostic system involving a multiplex nested reverse transcription–polymerase chain reaction (RT-PCR) assay to detect various respiratory viruses in clinical specimens of middle ear fluid (MEF) from children with AOM in our hospital. Multiplex RT-PCR was completed on 40 MEF samples from 28 infants and children less than 6 years old with AOM. Viral RNA was detected in 17 MEF samples (43%). Respiratory syncytial virus type A was present in 12 samples, adenovirus in 3, rhinovirus in 2, and influenza A (H3N2) in 1. The multiplex RT-PCR assay is recommended to clinical laboratories that are considering adoption of a molecular technique for viral diagnosis.


2006 ◽  
Vol 89 (5) ◽  
pp. 1335-1340
Author(s):  
Amir Abdulmawjood ◽  
Holger Schnenbrcher ◽  
Michael BÜlte

Abstract A collaborative trial was conducted to evaluate a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay for detection of central nervous system (CNS) tissues in meat products (e.g., sausages). The method is based on the detection of ruminant glial fibrillary acidic protein (GFAP) mRNA by applying real-time RT-PCR. The assay was evaluated through a multicenter trial involving 12 participating laboratories that received coded cDNA obtained from 3 different types of sausages. The participants used 5 different real-time detection systems. The results obtained in this validation revealed that this real-time RT-PCR assay performed well in the different laboratories with a detection limit of at least 0.1% CNS in those test materials that contained strongly heat-treated samples (sausages cooked at 120C) and the medium heat-treated samples (sausages cooked at 80C). The detection limit of liver sausages was determined to be 0.2% of CNS. Neither the samples with no CNS additive nor the bovine DNA and the negative control containing 100% swine brain gave any positive signals. The presented results indicate that the real-time RT-PCR assay was just as reproducible between laboratories, as repeatable within a laboratory, could reliably be used for detection of bovine spongiform encephalopathy risk material in meat and meat products, and signify that it may be used with confidence in any laboratory.


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