Giuseppe
Emeritus
[Source: PLoS ONE, full text: (LINK). Abstract, edited.]
Identification of New Delhi Metallo-β-lactamase 1 in Acinetobacter lwoffii of Food Animal Origin
Yang Wang<SUP>1</SUP><SUP>#</SUP>, Congming Wu<SUP>1</SUP><SUP>#</SUP>, Qijing Zhang<SUP>2</SUP>, Jing Qi<SUP>3</SUP>, Hebing Liu<SUP>1</SUP>, Yu Wang<SUP>1</SUP>, Tao He<SUP>1</SUP>, Licai Ma<SUP>1</SUP>, Jing Lai<SUP>1</SUP>, Zhangqi Shen<SUP>2</SUP>, Yuqing Liu<SUP>3</SUP>, Jianzhong Shen<SUP>1</SUP><SUP>*</SUP>
1 Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China, 2 Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America, 3 Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, People's Republic of China
Abstract
Background
To investigate the presence of metallo-β-lactamase (MBL) genes and the genetic environment of the New Delhi metallo-β-lactamase gene bla<SUB>NDM-1</SUB> in bacteria of food animal origin.
Methodology/Principal Findings
Gram-negative bacteria with low susceptibility to imipenem (MIC>8 ?g/mL) were isolated from swab samples collected from 15 animal farms and one slaughterhouse in eastern China. These bacteria were selected for phenotypic and molecular detection of known MBL genes and antimicrobial susceptibility testing. For the bla<SUB>NDM-1</SUB> positive isolate, conjugation and transformation experiments were carried out to assess plasmid transfer. Southern blotting was conducted to localize the bla<SUB>NDM-1</SUB> genes, and DNA sequencing was performed to determine the sequences of bla<SUB>NDM-1</SUB> and the flanking genes. In total, nine Gram-negative bacteria of four different species presented a MBL phenotype. bla<SUB>NDM-1</SUB> was identified on a mobile plasmid named pAL-01 in an Acinetobacter lwoffii isolate of chicken origin. Transfer of pAL-01 from this isolate to E. coli J53 and JM109 resulted in resistance to multiple β-lactams. Sequence analysis revealed that the bla<SUB>NDM-1</SUB> gene is attached to an intact insertion element ISAba125, whose right inverted repeat (IR-R) overlaps with the promoter sequence of bla<SUB>NDM-1</SUB>. Thus, insertion of ISAba125 likely enhances the expression of bla<SUB>NDM-1</SUB>.
Conclusion
The identification of a bla<SUB>NDM-1</SUB>- carrying strain of A. lwoffii in chickens suggests the potential for zoonotic transmission of bla<SUB>NDM-1</SUB> and has important implications for food safety.
Citation: Wang Y, Wu C, Zhang Q, Qi J, Liu H, et al. (2012) Identification of New Delhi Metallo-β-lactamase 1 in Acinetobacter lwoffii of Food Animal Origin. PLoS ONE 7(5): e37152. doi:10.1371/journal.pone.0037152
Editor: Axel Cloeckaert, Institut National de la Recherche Agronomique, France
Received: February 21, 2012; Accepted: April 14, 2012; Published: May 18, 2012
Copyright: ? 2012 Wang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by grants from the National Natural Science Foundation of China (No. U0631006) and the program for Chang Jiang Scholars and the Innovative Research Team at the University of China (No. IRT0866). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: sjz@cau.edu.cn
# These authors contributed equally to this work.
- ------Yang Wang<SUP>1</SUP><SUP>#</SUP>, Congming Wu<SUP>1</SUP><SUP>#</SUP>, Qijing Zhang<SUP>2</SUP>, Jing Qi<SUP>3</SUP>, Hebing Liu<SUP>1</SUP>, Yu Wang<SUP>1</SUP>, Tao He<SUP>1</SUP>, Licai Ma<SUP>1</SUP>, Jing Lai<SUP>1</SUP>, Zhangqi Shen<SUP>2</SUP>, Yuqing Liu<SUP>3</SUP>, Jianzhong Shen<SUP>1</SUP><SUP>*</SUP>
1 Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China, 2 Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America, 3 Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, People's Republic of China
Abstract
Background
To investigate the presence of metallo-β-lactamase (MBL) genes and the genetic environment of the New Delhi metallo-β-lactamase gene bla<SUB>NDM-1</SUB> in bacteria of food animal origin.
Methodology/Principal Findings
Gram-negative bacteria with low susceptibility to imipenem (MIC>8 ?g/mL) were isolated from swab samples collected from 15 animal farms and one slaughterhouse in eastern China. These bacteria were selected for phenotypic and molecular detection of known MBL genes and antimicrobial susceptibility testing. For the bla<SUB>NDM-1</SUB> positive isolate, conjugation and transformation experiments were carried out to assess plasmid transfer. Southern blotting was conducted to localize the bla<SUB>NDM-1</SUB> genes, and DNA sequencing was performed to determine the sequences of bla<SUB>NDM-1</SUB> and the flanking genes. In total, nine Gram-negative bacteria of four different species presented a MBL phenotype. bla<SUB>NDM-1</SUB> was identified on a mobile plasmid named pAL-01 in an Acinetobacter lwoffii isolate of chicken origin. Transfer of pAL-01 from this isolate to E. coli J53 and JM109 resulted in resistance to multiple β-lactams. Sequence analysis revealed that the bla<SUB>NDM-1</SUB> gene is attached to an intact insertion element ISAba125, whose right inverted repeat (IR-R) overlaps with the promoter sequence of bla<SUB>NDM-1</SUB>. Thus, insertion of ISAba125 likely enhances the expression of bla<SUB>NDM-1</SUB>.
Conclusion
The identification of a bla<SUB>NDM-1</SUB>- carrying strain of A. lwoffii in chickens suggests the potential for zoonotic transmission of bla<SUB>NDM-1</SUB> and has important implications for food safety.
Citation: Wang Y, Wu C, Zhang Q, Qi J, Liu H, et al. (2012) Identification of New Delhi Metallo-β-lactamase 1 in Acinetobacter lwoffii of Food Animal Origin. PLoS ONE 7(5): e37152. doi:10.1371/journal.pone.0037152
Editor: Axel Cloeckaert, Institut National de la Recherche Agronomique, France
Received: February 21, 2012; Accepted: April 14, 2012; Published: May 18, 2012
Copyright: ? 2012 Wang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by grants from the National Natural Science Foundation of China (No. U0631006) and the program for Chang Jiang Scholars and the Innovative Research Team at the University of China (No. IRT0866). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: sjz@cau.edu.cn
# These authors contributed equally to this work.