Comparison of Conventional PCR and Multiplex Real-Time PCR Assay for Detection of Staphylococcus aureus and Bacillus cereus in Ready-to-Eat Foods

2021 ◽  
Vol 36 (2) ◽  
pp. 141-147
Author(s):  
Yu-Si Lee ◽  
Seokhwan Kim ◽  
Migyeong Kim ◽  
Soon Han Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Conventional Pcr ◽  
Pcr Assay

Development of Rapid Real-Time PCR and Most-Probable-Number Real-Time PCR Assays To Quantify Enterotoxigenic Strains of the Species in the Bacillus cereus Group

2007 ◽  
Vol 70 (12) ◽  
pp. 2774-2781 ◽  
Author(s):  
I-CHEN YANG ◽  
DANIEL YANG-CHIH SHIH ◽  
JAN-YI WANG ◽  
TZU-MING PAN
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Food Samples ◽  
Most Probable Number ◽  
Pcr Assay ◽  
Bacillus Cereus Group ◽  
Probable Number ◽  
Cooked Rice ◽  
Group Detection

Members of the Bacillus cereus group may produce diarrheal enterotoxins and could be potential hazards if they enter the food chain. Therefore, a method capable of detecting all the species in the B. cereus group rather than B. cereus alone is important. We selected nhe as the target and developed a real-time PCR assay to quantify enterotoxigenic strains of the B. cereus group. The real-time PCR assay was evaluated with 60 B. cereus group strains and 28 others. The assay was also used to construct calibration curves for different food matrices and feces. The assay has an excellent quantification capacity, as proved by its linearity (R2 > 0.993), wide dynamic quantification range (102 to 107 CFU/g for cooked rice and chicken, 103 to 107 CFU/ml for milk, and 104 to 107 CFU/g for feces), and adequate relative accuracy (85.5 to 101.1%). For the low-level contaminations, a most-probable-number real-time PCR assay was developed that could detect as low as 100 CFU/ml. Both assays were tested with real food samples and shown to be considerably appropriate for B. cereus group detection and quantification.

scholarly journals Development and application of a triplex real-time PCR assay for simultaneous detection of avian influenza virus, Newcastle disease virus, and duck Tembusu virus

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiyu Zhang ◽  
Ming Yao ◽  
Zhihui Tang ◽  
Daning Xu ◽  
Yan Luo ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Standard Deviation ◽  
Real Time ◽  
Real Time Pcr ◽  
Virus Isolation ◽  
Simultaneous Detection ◽  
Conventional Pcr ◽  
Pcr Assay ◽  
Duck Tembusu Virus ◽  
Relative Standard

Abstract Background Pathogens including duck-origin avian influenza virus (AIV), duck-origin Newcastle disease virus (NDV) and duck Tembusu virus (DTMUV) posed great harm to ducks and caused great economic losses to the duck industry. In this study, we aim to develop a triplex real-time polymerase chain reaction (PCR) assay to detect these three viruses as early as possible in the suspicious duck flocks. Results The detection limit of the triplex real-time PCR for AIV, NDV, and DTMUV was 1 × 101 copies/μL, which was at least 10 times higher than the conventional PCR. In addition, the triplex assay was highly specific, and won’t cross-react with other duck pathogens. Besides, the intra-day relative standard deviation and inter-day relative standard deviation were lower than 4.44% for these viruses at three different concentrations. Finally, a total of 120 clinical samples were evaluated by the triplex real-time PCR, the conventional PCR and virus isolation, and the positive rates for these three methods were 20.83, 21.67, 19.17%, respectively. Taking virus isolation as the gold standard, the diagnostic specificity and positive predictive value of the three viruses were all above 85%, while the diagnostic sensitivity and negative predictive value of the three viruses were all 100%. Conclusion The developed triplex real-time PCR is fast, specific and sensitive, and is feasible and effective for the simultaneous detection of AIV, NDV, and DTMUV in ducks.

scholarly journals Quantification by Real-Time PCR Assay of Staphylococcus aureus Load: a Useful Tool for Rapidly Identifying Persistent Nasal Carriers

2012 ◽  
Vol 50 (6) ◽  
pp. 2063-2065 ◽  
Author(s):  
Paul O. Verhoeven ◽  
Florence Grattard ◽  
Anne Carricajo ◽  
Frédéric Lucht ◽  
Céline Cazorla ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Pcr Assay

scholarly journals Real-Time PCR Assay for Detection of blaZ Genes in Staphylococcus aureus Clinical Isolates

2014 ◽  
Vol 52 (4) ◽  
pp. 1259-1261 ◽  
Author(s):  
L. A. Pereira ◽  
G. B. Harnett ◽  
M. M. Hodge ◽  
J. A. Cattell ◽  
D. J. Speers
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Clinical Isolates ◽  
Pcr Assay

scholarly journals Real-Time PCR Assay for Detection of Fluoroquinolone Resistance Associated with grlA Mutations in Staphylococcus aureus

2003 ◽  
Vol 41 (7) ◽  
pp. 3246-3251 ◽  
Author(s):  
P. Lapierre ◽  
A. Huletsky ◽  
V. Fortin ◽  
F. J. Picard ◽  
P. H. Roy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Fluoroquinolone Resistance ◽  
Pcr Assay

scholarly journals Real-time evaluation of an optimized real-time PCR assay versus Brilliance chromogenic MRSA agar for the detection of meticillin-resistant Staphylococcus aureus from clinical specimens

2011 ◽  
Vol 60 (3) ◽  
pp. 323-328 ◽  
Author(s):  
J. Danial ◽  
M. Noel ◽  
K. E. Templeton ◽  
F. Cameron ◽  
F. Mathewson ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Test Performance ◽  
High Sensitivity ◽  
Turnaround Time ◽  
Homology Search ◽  
Pcr Assay ◽  
Indirect Measure ◽  
The Mean

A total of 1204 meticillin-resistant Staphylococcus aureus (MRSA) screens (3340 individual swabs) were tested to evaluate a staphylococcal cassette chromosome mec (SCCmec) real-time PCR. In total, 148 (12.3 %) of the screens were MRSA-positive, where 146 (12.1 %) were MRSA-positive by the SCCmec real-time PCR assay. In contrast, 128 (10.6 %) screens were MRSA-positive by culture. One hundred and twenty-six (10.5 %) of the screens were positive by both culture and PCR. Twenty of the 1204 screens (1.66 %) were negative by culture but positive by PCR; these samples were sequenced. In 14 of the cases, a homology search confirmed the sequence as SCCmec, indicating that these samples could be considered true positives. Two of the 1204 (0.2 %) screens were positive by culture and negative by PCR. The mean turnaround time (TAT) for PCR-negative swabs was 6 h 12 min and for PCR-positive swabs was 6 h 48 min. In comparison, for culture-negative swabs the mean TAT was 29 h 30 min and for culture-positive swabs was 69 h. The cost per swab for routine culture was £0.41 (€0.48) and that of the real-time PCR assay was £2.35 (€2.75). This optimized, in-house, inexpensive, real-time PCR test maintained a very high sensitivity and specificity when evaluated under real-time laboratory conditions. The TAT of this real-time PCR assay was substantially lower than that of chromogenic culture. It was also maintained throughout the entire process, which can be taken as an indirect measure of test performance. This study showed that implementation of a molecular test can be achieved with limited resources in a standard microbiology laboratory.

Prevalence of Emetic Bacillus cereus in Different Ice Creams in Bavaria

2010 ◽  
Vol 73 (2) ◽  
pp. 395-399 ◽  
Author(s):  
U. MESSELHÄUSSER ◽  
P. KÄMPF ◽  
M. FRICKER ◽  
M. EHLING-SCHULZ ◽  
R. ZUCKER ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Genetic Background ◽  
Ice Cream ◽  
Toxin Production ◽  
Pcr Assay ◽  
Cultural Methods ◽  
Different Sources ◽  
Culture Positive

In this study, 809 samples of ice cream from different sources were investigated by using cultural methods for the presence of presumptive Bacillus cereus. Isolates from culture-positive samples were examined with a real-time PCR assay targeting a region of the cereulide synthetase gene (ces) that is highly specific for emetic B. cereus strains. The samples were collected from ice cream parlors and restaurants that produced their own ice cream and from international commercial ice cream companies in different regions of Bavaria during the summer of 2008. Presumptive B. cereus was found in 508 (62.7%) ice cream samples investigated, and 24 (4.7%) of the isolates had the genetic background for cereulide toxin production. The level of emetic B. cereus in the positive samples ranged from 0.1 to 20 CFU/g of ice cream.

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