scholarly journals Efficient and Specific Detection ofSalmonellain Food Samples Using astn-Based Loop-Mediated Isothermal Amplification Method

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mevaree Srisawat ◽  
Watanalai Panbangred
Keyword(s):  
Lamp Assay ◽  
High Sensitivity ◽  
High Specificity ◽  
Culture Method ◽  
Food Samples ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Method ◽  
Pure Cultures

TheSalmonellaenterotoxin (stn) gene exhibits high homology amongS. entericaserovars andS. bongori. A set of 6 specific primers targeting thestngene were designed for detection ofSalmonellaspp. using the loop-mediated isothermal amplification (LAMP) method. The primers amplified target sequences in all 102 strains of 87 serovars ofSalmonellatested and no products were detected in 57 non-Salmonellastrains. The detection limit in pure cultures was 5 fg DNA/reaction when amplified at 65°C for 25 min. The LAMP assay could detectSalmonellain artificially contaminated food samples as low as 220 cells/g of food without a preenrichment step. However, the sensitivity was increased 100-fold (~2 cells/g) following 5 hr preenrichment at 35°C. The LAMP technique, with a preenrichment step for 5 and 16 hr, was shown to give 100% specificity with food samples compared to the reference culture method in which 67 out of 90 food samples gave positive results. Different food matrixes did not interfere with LAMP detection which employed a simple boiling method for DNA template preparation. The results indicate that the LAMP method, targeting thestngene, has great potential for detection ofSalmonellain food samples with both high specificity and high sensitivity.

Loop-Mediated Isothermal Amplification Method for Rapid Detection of Shigella dysenteriae

2011 ◽  
Vol 140 ◽  
pp. 369-373 ◽  
Author(s):  
Qing Ping Zhong ◽  
Li Wang ◽  
Bin Wang ◽  
Hong Yuan Chen
Keyword(s):  
Isothermal Condition ◽  
Lamp Assay ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Shigella Dysenteriae ◽  
Lamp Method ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Method ◽  
Target Dna ◽  
Pcr Method

The study was aimed to develop a loop-mediated isothermal amplification (LAMP) method which amplifies DNA with high specificity and rapidity for the detection of Shigella dysenteriae. A set of four primers was designed for recognizing six distinct sequences on the target ipaH of S. dysenteriae. By the method, the target DNA was amplified within 1h under isothermal condition at 65 °C. The sensitivities of the LAMP for detecting pure culture and genomic DNA were 1.04 CFU/ml and 1.06 fg/μl, while the sensitivities of PCR method were 1.04×102 CFU/ml and 1.06 pg/μl. Furthermore, the LAMP assay was examined for its ability to detect S. dysenteriae in artificially contaminated lettuce sample, the detection limits of this LAMP assay and the PCR method were 4.60 CFU/g and 4.60×102 CFU/g, respectively.

scholarly journals Loop-Mediated Isothermal Amplification for Detection ofStaphylococcus aureusin Dairy Cow Suffering from Mastitis

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Zhang Tie ◽  
Wang Chunguang ◽  
Wei Xiaoyuan ◽  
Zhao Xinghua ◽  
Zhong Xiuhui
Keyword(s):  
Staphylococcus Aureus ◽  
High Sensitivity ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Specific Primers ◽  
Loop Mediated Isothermal Amplification ◽  
Reaction Tube ◽  
Specificity And Sensitivity ◽  
Detectable Concentration

To develop a rapid detection method ofStaphylococcus aureususing loop-mediated isothermal amplification (LAMP), four specific primers were designed according to six distinct sequences of thenucgene. In addition, the specificity and sensitivity of LAMP were verified and compared with those of PCR. Results showed that the LAMP reaction was completed within 45 min at 62.5°C, and ladder bands were appeared in LAMP products analyzed by gel electrophoresis. After adding 1x SYBR Green l, the positive reaction tube showed green color and the negative reaction tube remained orange, indicating that the LAMP has high specificity. The minimal detectable concentration of LAMP was1×102 CFU/mL and that of PCR was1×104 CFU/mL, indicating that the LAMP was 100 times more sensitive than the PCR. The LAMP method for detection ofStaphylococcus aureushas many advantages, such as simple operation, high sensitivity, high specificity, and rapid analysis. Therefore, this method is more suitable for the rapid on-site detection ofStaphylococcus aureus.

scholarly journals Development of an in-house loop-mediated isothermal amplification (LAMP) assay for detection of Mycobacterium tuberculosis and evaluation in sputum samples of Nepalese patients

2008 ◽  
Vol 57 (4) ◽  
pp. 439-443 ◽  
Author(s):  
Basu Dev Pandey ◽  
Ajay Poudel ◽  
Tomoko Yoda ◽  
Aki Tamaru ◽  
Naozumi Oda ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lamp Assay ◽  
High Sensitivity ◽  
Isothermal Amplification ◽  
Nucleic Acid Amplification ◽  
Lamp Method ◽  
Rrna Gene ◽  
Predictive Values ◽  
Loop Mediated Isothermal Amplification ◽  
System A

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal amplification (LAMP) is an NAA possessing superior isothermal reaction characteristics. In the present study, a set of six specific primers targeting the Mycobacterium tuberculosis 16S rRNA gene with high sensitivity was selected and a LAMP system (MTB-LAMP) was developed. Using this system, a total of 200 sputum samples from Nepalese patients were investigated. The sensitivity of MTB-LAMP in culture-positive samples was 100 % (96/96), and the specificity in culture-negative samples was 94.2 % (98/104, 95 % confidence interval 90.5–97.9 %). The positive and negative predictive values of MTB-LAMP were 94.1 and 100 %, respectively. These results indicate that this MTB-LAMP method may prove to be a powerful tool for the early diagnosis of TB.

Rapid Detection of Mycoplasma pneumoniae by Loop-Mediated Isothermal Amplification (LAMP) in Clinical Respiratory Specimens

2019 ◽  
Author(s):  
Maryam ARFAATABAR ◽  
Narjes NOORI GOODARZI ◽  
Davoud AFSHAR ◽  
Hamed MEMARIANI ◽  
Ghasem AZIMI ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Rapid Detection ◽  
Lamp Assay ◽  
Culture Method ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Culture Methods ◽  
Loop Mediated Isothermal Amplification ◽  
Specificity And Sensitivity ◽  
Respiratory Specimens

  Background: Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) worldwide, especially among children and debilitated populations. The present study aimed to investigate a loop-mediated isothermal amplification (LAMP) technique for rapid detection of M. pneumoniae in clini-cal specimens collected from patients with pneumonia. Methods: Throat swabs were collected from 110 outpatients who suffered from pneumonia. Throat swab samples were obtained from patients referred to the hospital outpatient clinics of Tehran University hospitals, Iran in 2017. The presence of M. pneumoniae in the clinical specimens was evaluated by LAMP, PCR and culture methods. Sensitivity and specificity of the LAMP and PCR assays were also determined. Results: Out of 110 specimens, LAMP assay detected M. pneumoniae in 35 specimens. Detection limit of the LAMP assay was determined to be 33fg /μL or ~ 40 genome copies/reaction. Moreover, no cross-reaction with genomic DNA from other bacteria was observed. Only 25 specimens were positive by the culture method. The congruence between LAMP assay and culture method was ‘substantial’ (κ=0.77). Specificity and sensitivity of LAMP assay were 88.2%, 100% in compare with culture. However, the con-gruence between LAMP assay and PCR assay was ‘almost perfect’ (κ=0.86). Specificity and sensitivity of LAMP assay were 92.5%, 100% in compare with PCR. Conclusion: Overall, the LAMP assay is a rapid and cost-efficient laboratory test in comparison to other methods including PCR and culture. Therefore, the LAMP method can be applied in identification of M. pneumoniae isolates in respiratory specimens.

Development and Evaluation of a Loop-Mediated Isothermal Amplification Assay for Rapid and Sensitive Detection of Vibrio parahaemolyticus

2011 ◽  
Vol 74 (9) ◽  
pp. 1462-1467 ◽  
Author(s):  
JIRO NEMOTO ◽  
MASANARI IKEDO ◽  
TADASHI KOJIMA ◽  
TAKAYOSHI MOMODA ◽  
HIROTAKA KONUMA ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Lamp Assay ◽  
Culture Method ◽  
Isothermal Amplification ◽  
Most Probable Number ◽  
Lamp Method ◽  
Probable Number ◽  
Loop Mediated Isothermal Amplification ◽  
Negative Results ◽  
Rpod Gene

Loop-mediated isothermal amplification (LAMP) assays targeting the rpoD and toxR genes were developed to detect Vibrio parahaemolyticus. All 78 tested V. parahaemolyticus strains yielded positive results within 40 min, while negative results were obtained for 69 strains of other organisms even at 60 min. For V. parahaemolyticus ATCC 17802 in pure culture, the detection limits of LAMP assays targeting rpoD and toxR were 3.7 and 450 CFU per test, respectively. Due to the higher sensitivity of rpoD-LAMP, it was further evaluated for the ability to detect V. parahaemolyticus in seafood samples. V. parahaemolyticus populations spiked in short-necked clams were enumerated by the most-probable-number (MPN) method combined with the rpoD-LAMP assay and the MPN method with a culture method using agar medium. The MPN-rpoD-LAMP method had better sensitivity and was more rapid than the conventional method. These results indicate that the MPN-LAMP assay targeting the rpoD gene is a specific, sensitive, and rapid method to enumerate V. parahaemolyticus organisms.

Detection of Enteroaggregative Escherichia coli by Loop-Mediated Isothermal Amplification

2010 ◽  
Vol 73 (6) ◽  
pp. 1064-1072 ◽  
Author(s):  
EIJI YOKOYAMA ◽  
MASAKO UCHIMURA ◽  
KENITIRO ITO
Keyword(s):  
Escherichia Coli ◽  
Food Samples ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Bacterial Strains ◽  
Exact Test ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Method ◽  
Contaminated Food ◽  
Better Than

A novel gene amplification method, loop-mediated isothermal amplification (LAMP), has been recently developed as a rapid, specific diagnostic method for various infectious diseases. We have investigated whether LAMP can be used to detect small numbers of enteroaggregative Escherichia coli (EAEC) cells contaminated in food samples. Primers for LAMP reaction were designed with EAEC aggR gene sequences (available in GenBank). LAMP specificity with these primers was the same as that of PCR in a study of 37 EAEC and 42 non-EAEC bacterial strains. The sensitivity of the LAMP method was better than that of PCR in a study of serially diluted EAEC cells. The LAMP method was significantly more effective than was PCR in detecting EAEC-contaminated food samples (Fisher's exact test, P < 0.05). Therefore, the LAMP method described here should be useful for detecting small numbers of EAEC cells in food samples.

Rapid detection of Betacoronavirus 1 from clinical fecal specimens by a novel reverse transcription loop-mediated isothermal amplification assay

2011 ◽  
Vol 24 (1) ◽  
pp. 174-177 ◽  
Author(s):  
Jun Qiao ◽  
Qingling Meng ◽  
Xuepeng Cai ◽  
Chuangfu Chen ◽  
Zaichao Zhang ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Rapid Detection ◽  
Lamp Assay ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Lamp Method ◽  
Nucleocapsid Gene ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Assay

Betacoronavirus 1 (BCoV-1) is an important pathogen causing diarrhea in calves. In the current study, a novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for rapid detection of BCoV-1 was successfully developed. The primers were designed to target the highly conserved fragment of BCoV-1 nucleocapsid gene. The assay displayed high specificity detecting only BCoV-1 with no cross reaction with other viruses. When 418 clinical samples from 6 different geographical areas of Xinjiang province were tested by the RT-LAMP method, the results indicated that this test is a simple, rapid, accurate, and sensitive method for the detection of BCoV-1.

scholarly journals SARS-CoV-2 Direct Detection Without RNA Isolation With Loop-Mediated Isothermal Amplification (LAMP) and CRISPR-Cas12

2021 ◽  
Vol 8 ◽  
Author(s):  
Alfredo Garcia-Venzor ◽  
Bertha Rueda-Zarazua ◽  
Eduardo Marquez-Garcia ◽  
Vilma Maldonado ◽  
Angelica Moncada-Morales ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Direct Detection ◽  
Direct Method ◽  
Rna Extraction ◽  
Rna Isolation ◽  
High Sensitivity ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Loop Mediated Isothermal Amplification

As to date, more than 49 million confirmed cases of Coronavirus Disease 19 (COVID-19) have been reported worldwide. Current diagnostic protocols use qRT-PCR for viral RNA detection, which is expensive and requires sophisticated equipment, trained personnel and previous RNA extraction. For this reason, we need a faster, direct and more versatile detection method for better epidemiological management of the COVID-19 outbreak. In this work, we propose a direct method without RNA extraction, based on the Loop-mediated isothermal amplification (LAMP) and Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein (CRISPR-Cas12) technique that allows the fast detection of SARS-CoV-2 from patient samples with high sensitivity and specificity. We obtained a limit of detection of 16 copies/μL with high specificity and at an affordable cost. The diagnostic test readout can be done with a real-time PCR thermocycler or with the naked eye in a blue-light transilluminator. Our method has been evaluated on a small set of clinical samples with promising results.

scholarly journals Rapid identification of transgenic cotton (Gossypium hirsutum L.) plants by loop-mediated isothermal amplification

2011 ◽  
Vol 47 (No. 4) ◽  
pp. 140-148 ◽  
Author(s):  
N. Rostamkhani ◽  
A. Haghnazari ◽  
M. Tohidfar ◽  
A. Moradi
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Lamp Assay ◽  
Transgenic Cotton ◽  
Rapid Identification ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Lamp Method ◽  
Loop Mediated Isothermal Amplification ◽  
Leaf Tissues

In an attempt to speed up the process of screening of transgenic cotton (G. hirsutum L.) plants, a visual and rapid loop-mediated isothermal amplification (LAMP) assay was adopted. Genomic DNA was extracted from fresh leaf tissues of T<sub>2</sub> transgenic cotton containing chitinase (chi) and cry1A(b) genes. Detection of genes of interest was performed by polymerase chain reaction (PCR), LAMP and real-time PCR methods. In LAMP assay the amplification was performed after 30 min at 65&deg;C when loop primers were involved in the reaction. The involvement of loop primers decreased the time needed for amplification. By testing serial tenfold dilutions (10<sup>&ndash;1</sup> to 10<sup>&ndash;8</sup>) of the genes of interest, the detection sensitivity of LAMP was found to be 100-fold higher than that of PCR. The rapid DNA extraction method and LAMP assay can be performed within 30 min and the derived LAMP products can be directly observed as visually detectable based on turbidity in the reaction tube. The accuracy of LAMP method in the screening of transgenes was confirmed by PCR and real-time PCR. The developed method was efficient, rapid and sensitive in the screening of cotton transgenic plants. This method can be applied to any other crops.

Loop-mediated isothermal amplification technique: principle, development and wide application in food safety

2020 ◽  
Vol 12 (46) ◽  
pp. 5551-5561
Author(s):  
Tianzeng Huang ◽  
Linzhi Li ◽  
Xing Liu ◽  
Qi Chen ◽  
Xueen Fang ◽  
...  
Keyword(s):  
Food Safety ◽  
Gene Amplification ◽  
Foodborne Pathogens ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Isothermal Conditions ◽  
Loop Mediated Isothermal Amplification ◽  
Novel Gene ◽  
Amplification Method ◽  
Amplification Technique

LAMP is a relatively novel gene amplification method under isothermal conditions with rapidity, and high specificity. It is widely applied in the field of food safety, such as in the detection of foodborne pathogens, GM, OP pesticides and so on

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