Real-time PCR identification of Listeria monocytogenes serotype 4c using primers for novel target genes obtained by comparative genomic analysis

作者：Li, Fan; Ye, Qinghua; Chen, Moutong^*; Shang, Yuting; Zhang, Jumei; Ding, Yu; Xue, Liang; Wu, Shi; Wang, Juan; Pang, Rui; Lei, Tao; Zeng, Haiyan; Wu, Qingping^*

来源：Food Science and Technology, 2021, 138: 110774.

DOI：10.1016/j.lwt.2020.110774

• Listeria monocytogenes serotype 4c
• Comparative genomics
• Novel molecular targets
• Real-time PCR

Detection of the foodborne pathogen Listeria monocytogenes serotype 4c, one of the predominant serotypes in aquatic products, is difficult and time-consuming. Our objective was to identify novel target genes for real-time PCR detection of L. monocytogenes serotype 4c using comparative genomics to facilitate its specific identification in food products. A total of 160 Listeria genome sequences, including those of 12 L. monocytogenes serotypes and 14 other Listeria species, were employed to identify serotype 4c-specific targets. Two serotype 4c-specific genes (SLCC2376_00062 and SLCC2376_00822) were obtained. Using primers for SLCC2376_00822, a real-time PCR assay for the detection of serotype 4c was developed. The specificty of this assay was robustly verified by other serotypes of L. monocytogenes and non-L. monocytogenes strains. In addition, this real-time PCR method could accurately detect serotype 4c even when mixed with different concentrations of serotypes 1/2a and 1/2b. Furthermore, the assay could successfully detect 1.4 x 10(9) -1.4 x 10(3) CFU/g of L. monocytogenes serotype 4c in artificially contaminated grass carp without enrichment. These results demonstrate that the assay, which has high accuracy and sensitivity, comprises a promising approach for the detection and identification of L. monocytogenes serotype 4c strains in foods.

• 单位
  广东省微生物研究所; 华南农业大学