Original Article
Development and evaluation of loop-mediated isothermal amplification assay for the rapid detection of Escherichia coli and its microbial toxin
Yukui Zhong, Lisi Deng, Qiulian Deng, Huamin Zhong, Mingyong Luo, Zhenwen Zhou, Muxia Yan, Yongqiang Xie
Published 2018-06-20
Cite as J Chin Physician, 2018, 20(6): 826-831. DOI: 10.3760/cma.j.issn.1008-1372.2018.06.007
Abstract
ObjectiveTo establish and optimize a loop-mediated isothermal amplification (LAMP) method for the rapid detection of Escherichia coli and its microbial toxin.
MethodsThe LAMP reaction system and reaction conditions were determined by optimizing LAMP reaction, and the optimized LAMP system was used for the detection.
ResultsPrimers targeting shiga toxin (stx) gene and O157 antigen gene rfbe were designed. The established and optimized LAMP amplification system contained 1.2 mmol/L dNTPs, 10 mmol/L MgSO4, 0.4 mol/L betaine, 1 μl 10×Bst DNA polymerase Buffer, 8 U Bst DNA polymerase fragment, 2 μl DNA template, and the ratio of inner-primer (FIP and BIP) and outer-primer (F3 and B3) were 8∶1. Time and temperature for LAMP was 60 min, 60 ℃. The sensitivity was 103 times higher than polymerase chain reaction (PCR), reached 5×101 CFU/ml. When LAMP was applied to 19 reference strains, 102 EHEC strains, the specification was 100% while identification rate of rfbe, stx1 and stx2 gene reached 100%, 95.2%, 92.9%.
ConclusionsThe LAMP method showed a promising prospect for the rapid detection of common nosocomial pathogens microbial toxin.
Key words:
Enterohemorrhagic escherichia coli/MI; Nucleic acid amplification techniques; Shiga toxin/GE; Bacterial proteins/GE
Contributor Information
Yukui Zhong
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China
Lisi Deng
Department of Emergency, Guangzhou Huadu District People′s Hospital, Guangzhou 510800, China
Qiulian Deng
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China
Huamin Zhong
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China
Mingyong Luo
Medical Genetic Centre, Guangdong Women and Children Hospital, Guangzhou 511400, China
Zhenwen Zhou
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China
Muxia Yan
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China
Yongqiang Xie
Department of Clinical Laboratory, Guangzhou Women and Children′s Medical Ceter, Guangzhou 510120 , China