scholarly journals Detection of enterovirus in mussels from Morocco by cell culture and real-time PCR

2017 ◽  
Vol 16 (34) ◽  
pp. 1791-1799 ◽  
Author(s):  
Meryem Idrissi Azzouzi Lalla ◽  
Senouci Samira ◽  
El Qazoui Maria ◽  
Oumzil Hicham ◽  
Naciri Mariam
Keyword(s):  
2007 ◽  
Vol 191 (1-4) ◽  
pp. 83-93 ◽  
Author(s):  
M. Muscillo ◽  
M. Pourshaban ◽  
M. Iaconelli ◽  
S. Fontana ◽  
A. Di Grazia ◽  
...  

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Christian Shema Mugisha ◽  
Hung R. Vuong ◽  
Maritza Puray-Chavez ◽  
Adam L. Bailey ◽  
Julie M. Fox ◽  
...  

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions within just a few months, causing severe respiratory disease and mortality. Assays to monitor SARS-CoV-2 growth in vitro depend on time-consuming and costly RNA extraction steps, hampering progress in basic research and drug development efforts. Here, we developed a simplified quantitative real-time PCR assay that bypasses viral RNA extraction steps and can monitor SARS-CoV-2 growth from a small amount of cell culture supernatants. In addition, we show that this approach is easily adaptable to numerous other RNA and DNA viruses. Using this assay, we screened the activities of a number of compounds that were predicted to alter SARS-CoV-2 entry and replication as well as HIV-1-specific drugs in a proof-of-concept study. We found that E64D (inhibitor of endosomal proteases cathepsin B and L) and apilimod (endosomal trafficking inhibitor) potently decreased the amount of SARS-CoV-2 RNA in cell culture supernatants with minimal cytotoxicity. Surprisingly, we found that the macropinocytosis inhibitor ethylisopropylamiloride (EIPA) similarly decreased SARS-CoV-2 RNA levels in supernatants, suggesting that entry may additionally be mediated by an alternative pathway. HIV-1-specific inhibitors nevirapine (a nonnucleoside reverse transcriptase inhibitor [NNRTI]), amprenavir (a protease inhibitor), and allosteric integrase inhibitor 2 (ALLINI-2) modestly inhibited SARS-CoV-2 replication, albeit the 50% inhibitory concentration (IC50) values were much higher than that required for HIV-1. Taking the data together, this simplified assay will expedite basic SARS-CoV-2 research, be amenable to mid-throughput screening assays (i.e., drug, CRISPR, small interfering RNA [siRNA], etc.), and be applicable to a broad number of RNA and DNA viruses. IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of the coronavirus disease 2019 (COVID-19) pandemic, is continuing to cause immense respiratory disease and social and economic disruptions. Conventional assays that monitor SARS-CoV-2 growth in cell culture rely on costly and time-consuming RNA extraction procedures, hampering progress in basic SARS-CoV-2 research and development of effective therapeutics. Here, we developed a simple quantitative real-time PCR assay to monitor SARS-CoV-2 growth in cell culture supernatants that does not necessitate RNA extraction and that is as accurate and sensitive as existing methods. In a proof-of-concept screen, we found that E64D, apilimod, EIPA, and remdesivir can substantially impede SARS-Cov-2 replication, providing novel insight into viral entry and replication mechanisms. In addition, we show that this approach is easily adaptable to numerous other RNA and DNA viruses. This simplified assay will undoubtedly expedite basic SARS-CoV-2 and virology research and be amenable to use in drug screening platforms to identify therapeutics against SARS-CoV-2.


2005 ◽  
Vol 71 (7) ◽  
pp. 3433-3441 ◽  
Author(s):  
M. A. Yáñez ◽  
C. Carrasco-Serrano ◽  
V. M. Barberá ◽  
V. Catalán

ABSTRACT A new real-time PCR assay was developed and validated in combination with an immunomagnetic separation system for the quantitative determination of Legionella pneumophila in water samples. Primers that amplify simultaneously an 80-bp fragment of the dotA gene from L. pneumophila and a recombinant fragment including a specific sequence of the gyrB gene from Aeromonas hydrophila, added as an internal positive control, were used. The specificity, limit of detection, limit of quantification, repetitivity, reproducibility, and accuracy of the method were calculated, and the values obtained confirmed the applicability of the method for the quantitative detection of L. pneumophila. Moreover, the efficiency of immunomagnetic separation in the recovery of L. pneumophila from different kinds of water was evaluated. The recovery rates decreased as the water contamination increased (ranging from 59.9% for distilled water to 36% for cooling tower water), and the reproducibility also decreased in parallel to water complexity. The feasibility of the method was evaluated by cell culture and real-time PCR analysis of 60 samples in parallel. All the samples found to be positive by cell culture were also positive by real-time PCR, while only eight samples were found to be positive only by PCR. Finally, the correlation of both methods showed that the number of cells calculated by PCR was 20-fold higher than the culture values. In conclusion, the real-time PCR method combined with immunomagnetic separation provides a sensitive, specific, and accurate method for the rapid quantification of L. pneumophila in water samples. However, the recovery efficiency of immunomagnetic separation should be considered in complex samples.


2009 ◽  
Vol 72 (6) ◽  
pp. 1156-1164 ◽  
Author(s):  
J. B. DAY ◽  
R. C. WHITING

Francisella tularensis is a gram-negative bacterium that can cause gastrointestinal or oropharyngeal tularemia in humans from ingestion of contaminated food or water. Despite the potential for accidental or intentional contamination of foods with F. tularensis, there are no techniques currently available to detect this organism in specific food matrices. In this study, a macrophage cell culture system is combined with real-time PCR to identify F. tularensis in food matrices. The method utilizes a mouse macrophage cell line (RAW 264.7) as host for the isolation and intracellular replication of F. tularensis. Exposure of macrophages to F. tularensis–contaminated food matrices results in uptake and intracellular replication of the bacteria, which can be subsequently detected by real-time PCR analysis of the DNA released from infected macrophage cell lysates. Macrophage monolayers were exposed to infant formula, liquid egg whites, and lettuce contaminated with varying quantities of F. tularensis. As few as 10 CFU/ml (or CFU per gram) F. tularensis was detected in infant formula and lettuce after 5 h postinfection. As few as 10 CFU/ml F. tularensis was detected in liquid egg whites after 18 h postinfection. Intracellular F. tularensis could also be isolated on Mueller-Hinton medium from lysates of macrophages infected with the bacteria in infant formula, liquid egg whites, and lettuce for subsequent confirmatory identification. This method is the first to successfully identify F. tularensis from select food matrices.


2018 ◽  
Vol 30 (4) ◽  
pp. 554-559 ◽  
Author(s):  
Shaomin Qin ◽  
Darren Underwood ◽  
Luke Driver ◽  
Carol Kistler ◽  
Ibrahim Diallo ◽  
...  

We evaluated a fluorogenic probe–based assay for the detection of encephalomyocarditis virus (EMCV) by comparing a set of published primers and probe to a new set of primers and probe. The published reagents failed to amplify a range of Australian isolates and an Italian reference strain of EMCV. In contrast, an assay based on 2 new sets of primers and probes that were run in a duplex reverse-transcription real-time PCR (RT-rtPCR) worked well, with high amplification efficiency. The analytical sensitivity was ~100-fold higher than virus isolation in cell culture. The intra-assay variation was 0.21–4.90%. No cross-reactivity was observed with a range of other porcine viruses. One hundred and twenty-two clinical specimens were tested simultaneously by RT-rtPCR and virus isolation in cell culture; 72 specimens gave positive results by RT-rtPCR, and 63 of these were also positive by virus isolation. Of 245 archived cell culture isolates of EMCV that were tested in the RT-rtPCR, 242 samples were positive. The new duplex RT-rtPCR assay is a reliable tool for the detection of EMCV in clinical specimens and for use in epidemiologic investigations.


2017 ◽  
Vol 54 (11) ◽  
pp. 1025-1029 ◽  
Author(s):  
Enagnon Kazali Alidjinou ◽  
Famara Sane ◽  
Christine Lefevre ◽  
Agathe Baras ◽  
Ilham Moumna ◽  
...  

2009 ◽  
Vol 75 (16) ◽  
pp. 5321-5327 ◽  
Author(s):  
J. B. Day ◽  
U. Basavanna ◽  
S. K. Sharma

ABSTRACT Salmonella enterica serotype Enteritidis is a major cause of nontyphoidal salmonellosis from ingestion of contaminated raw or undercooked shell eggs. Current techniques used to identify Salmonella serotype Enteritidis in eggs are extremely laborious and time-consuming. In this study, a novel eukaryotic cell culture system was combined with real-time PCR analysis to rapidly identify Salmonella serotype Enteritidis in raw shell eggs. The system was compared to the standard microbiological method of the International Organization for Standardization (Anonymous, Microbiology of food and animal feeding stuffs—horizontal method for the detection of Salmonella, 2002). The novel technique utilizes a mouse macrophage cell line (RAW 264.7) as the host for the isolation and intracellular replication of Salmonella serotype Enteritidis. Exposure of macrophages to Salmonella serotype Enteritidis-contaminated eggs results in uptake and intracellular replication of the bacterium, which can subsequently be detected by real-time PCR analysis of the DNA released after disruption of infected macrophages. Macrophage monolayers were exposed to eggs contaminated with various quantities of Salmonella serotype Enteritidis. As few as 10 CFU/ml was detected in cell lysates from infected macrophages after 10 h by real-time PCR using primer and probe sets specific for DNA segments located on the Salmonella serotype Enteritidis genes sefA and orgC. Salmonella serotype Enteritidis could also be distinguished from other non-serogroup D Salmonella serotypes by using the sefA- and orgC-specific primer and probe sets. Confirmatory identification of Salmonella serotype Enteritidis in eggs was also achieved by isolation of intracellular bacteria from lysates of infected macrophages on xylose lysine deoxycholate medium. This method identifies Salmonella serotype Enteritidis from eggs in less than 10 h compared to the more than 5 days required for the standard reference microbiological method of the International Organization for Standardization (Microbiology of food and animal feeding stuffs—horizontal method for the detection of Salmonella, 2002).


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