Rapid Detection of Mycobacterium tuberculosis Complex by Loop-Mediated Isothermal Amplification Combined with Chemosensor

2013 ◽  
Vol 749 ◽  
pp. 449-452
Author(s):  
De Guo Wang

Loop-mediated isothermal amplification (LAMP) allowed rapid amplification of nucleic acids under isothermal conditions. It can be combined with a chemosensor for much more efficient, field-friendly detection of Mycobacterium tuberculosis complex. In this report, LAMP was performed at 65 °C for 10 min, followed by a rapid reaction of DNA amplification by-product, pyrophosphate ion, with chemosensor resulted in red disappearance. The detection limit of Mycobacterium tuberculosis complex by LAMP-Chemosensor was 3-5 copies, and the total assay time including 10 min for rapid DNA extraction was approximately 30 min. Data on naturally contaminated raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 100% concordance with Real-time PCR. The results showed that the LAMP-Chemosensor method had the advantages of better sensitivity and speed and less dependence on equipment than the standard (PCR) for specifically detecting low levels of Mycobacterium tuberculosis complex DNA, and this can be useful in the field as a routine diagnostic tool.

2013 ◽  
Vol 647 ◽  
pp. 577-582 ◽  
Author(s):  
Yong Zhen Wang ◽  
De Guo Wang

In present study, we reported the performance of a Loop-mediated isothermal amplification (LAMP) assay detecting food-borne pathogen Salmonella. Three pairs of primers were specially designed for recognizing eight distinct sequences on the target invA gene. Time and temperature conditions for amplification of Salmonella were optimized to be 40 min at 61°C. The LAMP assay gave with artificially contaminated raw milk samples detection limit level of 142 CFU/ml which corresponds to 6-9 cells per reaction tube, while the detection level of conventional PCR was 103 CFU/ml. Data on naturally contaminated raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 89.58% concordance with the ISO 6579 reference method for the samples without enrichment and 100% concordance for the samples after enrichment.


2008 ◽  
Vol 57 (4) ◽  
pp. 439-443 ◽  
Author(s):  
Basu Dev Pandey ◽  
Ajay Poudel ◽  
Tomoko Yoda ◽  
Aki Tamaru ◽  
Naozumi Oda ◽  
...  

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.


2003 ◽  
Vol 69 (8) ◽  
pp. 5023-5028 ◽  
Author(s):  
Fumito Maruyama ◽  
Takehiko Kenzaka ◽  
Nobuyasu Yamaguchi ◽  
Katsuji Tani ◽  
Masao Nasu

ABSTRACT A new in situ DNA amplification technique for microscopic detection of bacteria carrying a specific gene is described. Loop-mediated isothermal amplification (LAMP) was used to detect stxA 2 in Escherichia coli O157:H7 cells. The mild permeabilization conditions and low isothermal temperature used in the in situ LAMP method caused less cell damage than in situ PCR. It allowed use of fluorescent antibody labeling in the bacterial mixture after the DNA amplification for identification of E. coli O157:H7 cells with an stxA 2 gene. Higher-contrast images were obtained with this method than with in situ PCR.


2004 ◽  
Vol 28 (6) ◽  
pp. 445-450 ◽  
Author(s):  
Taketoshi Wakabayashi ◽  
Ryoko Yamashita ◽  
Tetsuhiko Kakita ◽  
Mito Kakita ◽  
Tetsuro Oshika

2016 ◽  
Vol 5 (2) ◽  
pp. 105
Author(s):  
Heba Hussien ◽  
Eman Mahrous

<p>This study was conducted to detect <em>Mycobacterium tuberculosis</em> complex in milk in three Egyptian Governorates; El-Sharkia, El-Menoufia and El-Behera Governorates. 300 milk samples were collected from tuberculin positive cases, 18 (6.0%) were shedding <em>Mycobacterium tuberculosis</em> complex in their milk which detected by real time PCR. On another hand, 170 milk samples were collected from tuberculin negative cases, 5 (2.9%) were shedding <em>Mycobacterium tuberculosis</em> complex in their milk which detected by real time PCR. All milk samples were examined by three techniques including Microscopic examination, culture and real time PCR. Real time PCR is more rapid and accurate method than microscopic and culture method. The isolated colonies from culture were examined by Multiplex PCR to demonstrate the source of infection either human or animal source.</p>


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