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ABSTRACT: In this study, a loop-mediated isothermal amplification (LAMP) method to rapidly detect Staphylococcus aureus strains was developed and evaluated by extensively applying a large number of S. aureus isolates from clinical and food samples. Six primers were specially designed for recognizing eight distinct sequences on the species-specific femA gene of S. aureus. The detection limits were 100 fg DNA/tube and 10(4) CFU/ml. The LAMP assay was applied to 432 S. aureus strains isolated from 118 clinical and 314 food samples. Total detection rates for the LAMP and polymerase chain reaction assays were 98.4% (306/311) and 89.4% (278/311), respectively.
Journal of Microbiology and Biotechnology 02/2013; 23(2):246-50. · 1.38 Impact Factor
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Xihong Zhao,
Xiaoping Chen,
Youhong Zhang, Xiaowei He,
Wenmei Li,
Lei Shi,
Xingzhou Chen,
Zhenbo Xu,
Nanjing Zhong,
Guiyuan Ji,
Liansheng Yang,
Jihua Wang
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ABSTRACT: Purpose: The objective of this study was to establish a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) method for rapid detection of human immunodeficiency virus type 1 (HIV-1). Materials and Methods: The HIV-1 integrase gene region was selected because it was a conserved part of the HIV-1 genome. Six primers specific to eight regions of the HIV-1 integrase gene were designed. A total of 171 samples (18 HIV-1 confirmed positive samples and 153 serum specimens were collected in this study) were tested by RT-LAMP and reverse-transcription polymerase chain reaction (RT-PCR). After amplification in an isothermal water bath for 45 min, samples containing HIV-1 generated the expected ladder-like products while other viruses generated no product. Results: The sensitivity and specificity of the RT-LAMP assay were evaluated by comparison with RT-PCR. The assay was significantly more sensitive than normal gel-based RT-PCR. Conclusion: Because it is specific and simple, the RT-LAMP assay can be widely applied in clinical laboratories for rapid detection of HIV-1.
Indian journal of medical microbiology 10/2012; 30(4):391-6.
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ABSTRACT: We developed and evaluated the specificity and sensitivity of a simple loop-mediated isothermal amplification (LAMP) method
for rapid detection of P. aeruginosa strains. The optimal reaction condition was found to be 65°C for 45min, with the detection limit as 100fg DNA/tube and
10CFU/reaction. Application of LAMP assays were performed 426 clinical samples (including 252 P. aeruginosa and 174 non- P. aeruginosa isolates) using a rapid procedure and easy result confirmation. Sensitivity of LAMP and PCR assays was found to be 97.6%
(246/252) and 90.5% (228/252), respectively; with a 100% specificity for both assays.
KeywordsLoop-mediated isothermal amplification (LAMP)–
P. aeruginosa
–Rapid detection
World Journal of Microbiology and Biotechnology 04/2012; 27(1):181-184. · 1.53 Impact Factor
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Xihong Zhao,
Li Wang,
Jin Chu,
Yanmei Li,
Yanyan Li,
Zhenbo Xu,
Lin Li,
Mark E. Shirtliff, Xiaowei He,
Yao Liu,
Jihua Wang,
Liansheng Yang
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ABSTRACT: A loop-mediated isothermal amplification (LAMP) method for rapid detection of the food-borne Salmonella strains had been developed and evaluated in this study. The optimal reaction condition was found to be 65°C for 45 min, with
the detection limit as 1 pg DNA/tube and 100 CFU/reaction. Application of LAMP assays was performed on 214 food-borne Salmonella strains using a rapid procedure and easy result confirmation, where the specificity of LAMP and polymerase chain reaction
(PCR) assays was 97.7% (209/214) and 91.6% (196/214), respectively; with a 100% specificity for both assays.
Keywordsloop-mediated isothermal amplification (LAMP)–
Salmonella
–rapid detection–food-borne pathogen–
invA
Food science and biotechnology 04/2012; 19(6):1655-1659. · 0.49 Impact Factor
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Xihong Zhao,
Li Wang,
Jin Chu,
Yanyan Li,
Yanmei Li,
Zhenbo Xu,
Lin Li,
Mark E. Shirtliff, Xiaowei He,
Yao Liu,
Jihua Wang,
Liansheng Yang
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ABSTRACT: A loop-mediated isothermal amplification (LAMP) method for rapid detection of the foodborne Vibrio parahaemolyticus strains and related virulent factors had been developed and evaluated in this study. Six primers, including outer primers,
inner primers, and loop primers, were specially designed for recognizing 8 distinct sequences on 3 target genes, which were
tlh, tdh, and trh. The detection limits were found to be 100, 100 fg, and 1 pg DNA/tube for tlh, tdh, and trh, respectively. Application of LAMP assays were performed on 368 foodborne V. parahaemolyticus strains, the sensitivities
of LAMP assays for the tlh, tdh, and trh were 100, 95.6, and 96.4%, and the negative predictive values (NPV) were 100, 84.7,
and 93.1%, respectively; with a 100% specificity and positive predictive value (PPV) for all 3 target genes.
Keywordsloop-mediated isothermal amplification (LAMP)-
Vibrio parahaemolyticus
-rapid detection
Food science and biotechnology 04/2012; 19(5):1191-1197. · 0.49 Impact Factor
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ABSTRACT: We developed and evaluated the specificity and sensitivity of a loop-mediated isothermal amplification (LAMP) method for rapid detection of the food-borne Escherichia coli O157 strains. Six primers, including outer primers, inner primers and loop primers, were specially designed for recognizing eight distinct sequences on three targets, which were rfbE, stx1 and stx2. The detection limits were found to be 100, 100 and 10 fg DNA/tube for rfbE, stx1 and stx2, respectively. Application of LAMP assays were performed on 417 food-borne E. coli strains, the sensitivity of LAMP assays for the rfbE, stx1 and stx2 was 100, 95.3 and 96.3%, and the negative predictive value was 100, 96.7 and 97.1%, respectively; with a 100% specificity and positive predictive value for all three targets.
Molecular Biology Reports 09/2009; 37(5):2183-8. · 2.93 Impact Factor
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ABSTRACT: Ractopamine belongs to a group of beta-agonist compounds. It is a forbidden food additive in most countries because of the many reported collective intoxication outbreaks in humans. Because the drug can be rapidly metabolized and eliminated from animal body, the objective of this study was to develop an efficient and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) analytical method for the detection of ractopamine with cutoff below 1 ng/mL to extend the detection window after withdrawal of the drug and at the same time to meet the requirements of zero-tolerance policy set by most countries. After solid-phase cleanup of the non-hydrolyzed and hydrolyzed urine samples, the residues were dissolved in methanol and analyzed directly by LC-MS-MS. Two transitions were monitored and one ratio determined. Samples reported as positive were required to have the ratio of the transitions within 20% of that determined from known calibration standards. The monitoring of the qualifying transition and requirement for its presence within a specific ratio to the primary ion has the potential of limiting the sensitivity of the assay. The limits of detection and quantitation of the assay were 0.1 and 0.25 ng/mL, respectively. The intraday precisions at 0.25 and 35 ng/mL were 4.88% and 0.95%, respectively. Interday precisions were 5.64% and 0.9% at the same concentrations. The percentage recoveries at 0.25 and 0.5 ng/mL were 117.8% and 108.4%, respectively.
Journal of analytical toxicology 08/2009; 33(6):289-93. · 2.02 Impact Factor
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ABSTRACT: In this work, the forward and back extraction of soybean protein by reverse micelles was studied. The reverse micellar systems were formed by anionic surfactant sodium bis(2-ethyl hexyl) sulfosuccinate (AOT), isooctane and KCl solution. The effects of AOT concentration, aqueous pH, KCl concentration and phase volume ratio on the extraction efficiency of soybean protein were tested. Suitability of reverse micelles of AOT and Triton-X-100/AOT mixture in organic solvent toluene for soybean protein extraction was also investigated. The experimental results lead to complete forward extraction at the AOT concentration 120 mmol l(-1), aqueous pH 5.5 and KCl concentration 0.8 mol l(-1). The backward extraction with aqueous phase (pH 5.5) resulted in 100% extraction of soybean protein from the organic phase.
Molecular Biology Reports 04/2009; 37(2):669-75. · 2.93 Impact Factor
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ABSTRACT: The conventional rapid detection method for AIDS is testing HIV-1 antibody in blood. Urine HIV-1 antibody testing is a new means with great potential for development because of its safe, convenient and low cost. In this paper, HIV-1 antibody in urine, the merits of urine HIV-1 testing and factors that effect the result of test were reviewed, the application and product actuality of urine testing production were briefly introduced, and the development prospect of urine HIV-1 testing was viewed.
Wei sheng yan jiu = Journal of hygiene research 08/2008; 37(4):511-4.
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ABSTRACT: Microcystins (MCs) may be group of closely related toxic cyclic heptapeptides produced by common cyanobacteria (blue-green algae). Their toxicity could be associated with specific inhibition of intracellular protein phosphatases type-1 and type-2A (PP1 and PP2A, respectively). There are some methods for analyzing and detecting MCs in aquatic environment, such as HPLC, LC-MS, PPIA, and ELISA. This review introduces advances on MCs determined by enzyme-linked immunosorbent assay (ELISA), and estimates the prospective development of ELISA for monitoring MCs in natural waters.
Wei sheng yan jiu = Journal of hygiene research 06/2007; 36(3):388-90.
