|YANG, XI - Chinese Center For Disease Control|
|BAI, XIANGNING - Chinese Center For Disease Control|
|ZHANG, JI - Massey University|
|SUN, HUI - Chinese Center For Disease Control|
|FU, SHANSHAN - Chinese Center For Disease Control|
|FAN, RUYUE - Chinese Center For Disease Control|
|SCHEUTZ, FLEMMING - Staten Serum Institute|
|MATUSSEK, ANDREAS - Karolinska University Hospital|
|XIONG, YANWEN - Chinese Center For Disease Control|
Submitted to: International Journal of Medical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2019
Publication Date: 10/29/2020
Citation: Yang, X., Bai, X., Zhang, J., Sun, H., Fu, S., Fan, R., He, X., Scheutz, F., Matussek, A., Xiong, Y. 2020. Escherichia coli strains producing a novel Shiga toxin 2 subtype circulate in China. International Journal of Medical Microbiology. 310(1):151377. https://doi.org/10.1016/j.ijmm.2019.151377.
Interpretive Summary: Shiga toxin-producing Escherichia coli (STEC) is an emergent pathogen that can cause severe human diseases including bloody diarrhea and hemolytic uremic syndrome, a life-threatening disease.Shiga toxin 2 (Stx2) play a key role in the pathogenesis of disease caused by STEC. In this study, we identified a novel Stx2 subtype in E. coli strains widely distributed in a broad range of sources and revealed the potential risk of increasing incidence of STEC-associated diseases due to emerging high virulence strains based on the molecular features and pathogenic capacity of these strains.
Technical Abstract: Shiga toxin (Stx) is the key virulent factor in Shiga toxin-producing Escherichia coli (STEC), which can cause diarrhea and hemorrhagic colitis with life-threatening complications. Here, we report a novel Stx2 subtype, designated Stx2k, in E. coli strains widely detected from diarrheal patients, animals, and raw meats in China. Stx2k exhibits varied cytotoxicity in vitro among strains. The Stx2k-converting prophages are genetically and dimensionally variable. Whole genome analysis revealed that Stx2k producing strains were genetically heterogeneous with diverse serotypes, sequence types, and virulence gene profiles, which formed two major clusters closely with strains belonging to STEC, enterotoxigenic E. coli (ETEC), and STEC/ETEC hybrid. This study enlarges the pool of Stx2 subtypes and highlights the extraordinary genomic plasticity of STEC strains. The wide distribution of the Stx2k-producing strains poses high risk to public health. Stx2k should be considered in epidemiological surveillance of STEC infections and clinical diagnosis.