Co-production of Tet(X7) conferring high-level tigecycline resistance, fosfomycin FosA4 and colistin Mcr-1.1 in Escherichia coli strains from chickens in Egypt

Authors: SOLIMAN, AHMED - University Of Hiroshima; RAMADAN, HAZEM - Mansoura University; ZARAD, HODA - Sidi Ghazy Hospital; YO, SUGAWARA - National Institute Of Infectious Diseases; LIANSHENG, YU - National Institute Of Infectious Diseases; MOTOYUKI, SUGAI - National Institute Of Infectious Diseases; SHIMAMOTO, TOSHI - University Of Hiroshima; Hiott, Lari; Frye, Jonathan; Jackson, Charlene; SHIMAMOTO, TADASHI - University Of Hiroshima

Submitted to: Antimicrobial Agents and Chemotherapy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2021
Publication Date: 4/5/2021
Citation: Soliman, A., Ramadan, H., Zarad, H.O., Yo, S., Liansheng, Y., Motoyuki, S., Shimamoto, T., Hiott, L.M., Frye, J.G., Jackson, C.R., Shimamoto, T. 2021. Co-production of Tet(X7) conferring high-level tigecycline resistance, fosfomycin FosA4 and colistin Mcr-1.1 in Escherichia coli strains from chickens in Egypt. Antimicrobial Agents and Chemotherapy. 65(6). Article e33820767. https://doi.org/10.1128/AAC.02084-20.
DOI: https://doi.org/10.1128/AAC.02084-20

Interpretive Summary: Tigecycline is a last-resort antibiotic approved to treat multidrug or extensively drug-resistant bacteria including carbapenem-resistant Enterobacteriaceae. As tigecycline-carbapenem resistant Escherichia coli have recently been identified in China, this study examined resistance to these two drugs in E. coli from poultry from Egypt. Of the isolates, five were multidrug resistant containing up to 24 resistance genes including genes conferring resistance to both tigecycline and colistin. These genes were co-located on the same plasmid and were transferred to other E. coli strains using conjugation indicating that resistance can be disseminated via plasmids. The easy access of antibiotics in Egyptian hospitals, the community without prescription, and in the agriculture sector may be responsible for the development of high levels of resistance. Infection control policies, judicious use of the tetracycline class of antibiotics in humans and animals, and continuous surveillance for tigecycline resistance genes in Gram-negative bacteria of animal or human origin are essentially needed to maintain usefulness of these antibiotics.

Technical Abstract: The plasmid-mediated tet(X7) gene conferring high-level tigecycline resistance was identified in five mcr-1.1-positive Escherichia coli strains isolated from chickens, Kafrelsheikh Province, Egypt. Two and three isolates belonged to the epidemic spreading sequence types ST155 and ST10, respectively. Transposase ISCR3 is syntenic with tet(X7) in all E. coli isolates suggesting its role in the acquisition and mobilization of tet(X7). To our knowledge, this is the first global report of E. coli strains co-producing Mcr-1.1 and Tet(X7).