Yu-Zhang He1,2, Teng-Fei Long1,2, Bing He1,2, Xing-Ping Li1,2, Gong Li1,2, Liang Chen3, Xiao-Ping Liao1,2, Ya-Hong Liu1,2, Jian Sun1,2. 1. National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China. 2. Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China. 3. Hackensack Meridian Health Center for Discovery and Innovation, Nutley, NJ, United States.
Abstract
OBJECTIVES: The emergence of mobile colistin resistance genes has compromised the efficacy of the last resort antibiotic, colistin, in clinical treatment. The mcr-2 gene was first identified in Belgium in association with the insertion sequence ISEc69. However, the molecular mechanisms of mcr-2 mobilization are not well understood. METHODS: To further explore the mobilization of mcr-2 gene via ISEc69, we constructed a conjugative plasmid that carries an intact composite transposon Tn7052. Transposition assays were performed by conjugation, the transposition sites were characterized by arbitrary primed PCR and DNA sequencing. RESULTS: In this study, we experimentally demonstrated that mcr-2 could be mobilized as a composite transposon Tn7052 and its transposition generated 8-bp AT-rich duplications in the host genome. CONCLUSION: These results indicate that mcr-2 gene could be mobilized by ISEc69, the current investigations provide mechanistic insights in the transposition of mcr-2.
OBJECTIVES: The emergence of mobile colistin resistance genes has compromised the efficacy of the last resort antibiotic, colistin, in clinical treatment. The mcr-2 gene was first identified in Belgium in association with the insertion sequence ISEc69. However, the molecular mechanisms of mcr-2 mobilization are not well understood. METHODS: To further explore the mobilization of mcr-2 gene via ISEc69, we constructed a conjugative plasmid that carries an intact composite transposon Tn7052. Transposition assays were performed by conjugation, the transposition sites were characterized by arbitrary primed PCR and DNA sequencing. RESULTS: In this study, we experimentally demonstrated that mcr-2 could be mobilized as a composite transposon Tn7052 and its transposition generated 8-bp AT-rich duplications in the host genome. CONCLUSION: These results indicate that mcr-2 gene could be mobilized by ISEc69, the current investigations provide mechanistic insights in the transposition of mcr-2.
Authors: Berthony Deslouches; Jonathan D Steckbeck; Jodi K Craigo; Yohei Doi; Jane L Burns; Ronald C Montelaro Journal: Antimicrob Agents Chemother Date: 2014-11-24 Impact factor: 5.191