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. 2016 Dec 5:6:38511.
doi: 10.1038/srep38511.

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Xing-Ping Li  1   2 , Liang-Xing Fang  1   2 , Jia-Qi Song  1   2 , Jing Xia  1   2 , Wei Huo  1   2 , Jin-Tao Fang  1   2 , Xiao-Ping Liao  1   2 , Ya-Hong Liu  1   2 , Youjun Feng  3 , Jian Sun  1   2
Affiliations

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Xing-Ping Li et al. Sci Rep. .

Abstract

Since initial identification in China, the widespread geographical occurrence of plasmid-mediated colistin resistance gene mcr-1 in Enterobacteriaceae has been of great concern. In this study, a total of 22 Salmonella enterica were resistant to colistin, while only five isolates which belonged to ST34 Salmonella enterica serovar Typhimurium (S. Typhimurium) were mcr-1 positive. Four of them shared nearly identical PFGE type, although they were from different host species and diverse geographical locations. All the mcr-1-positive S. Typhimurium exhibited multi-resistant phenotypes including ampicillin, streptomycin, gentamicin, florfenicol, nalidixic acid, tetracycline, trimethoprim-sulfamethox, in addition to colistin. The oqxAB and aac(6')-Ib-cr genes were present alone or in combination in four (80.0%) and five (100%) isolates, respectively. The mcr-1 gene was located on a transferable IncI2 plasmid in the four genetically related strains. In the other one strain, mcr-1 was located on an approximately 190 kb IncHI2 plasmid. In conclusion, we report five mcr-1-positive S. Typhimurium/ST34 isolates. Both clonal expansion and horizontal transmission of IncI2-type plasmids were involved in the spread of the mcr-1 gene in Salmonella enterica from food-producing animals in China. There is a great need to monitor the potential dissemination of the mcr-1 gene.

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Conflict of interest statement

The authors declare no competing financial interests.

Figures

Figure 1
Figure 1. Distribution of the mcr-1 colistin resistance gene in China by 30 Aug, 2016.
(Created by ArcGIS 10.3 software, ESRI Inc., Redlands, CA, USA, available at: https://www.arcgis.com/home/).
Figure 2
Figure 2
(A) Pulsed field gels of S1 digested genomic DNA and Southern blot in gel hybridization with probe mcr-1. (B) ApaLI restriction digestion profiles of mcr-1-carrying plasmids of the three transconjugants.
Figure 3
Figure 3
(A) The genetic context surrounding the mcr-1 gene and structural comparison with plasmids pHNSHP45-2 (KU341381), pMR0516mcr (KX276657), pHNSHP45 (KP347127) and pmcr1_IncI2 (KU761326). The arrows indicate the positions and directions of transcription for each gene. Regions of >99% homology are marked by grey shading. The names of plasmids in this study are highlighted in bold. DR, direct repeats; IRL, terminal inverted repeats at the left; IRR, terminal inverted repeats at the right. (B) Sequence feature of the insertion site.
Figure 4
Figure 4. Pulsed-field gel electrophoresis fingerprinting patterns of XbaI-digested total DNA preparations from Salmonella strains harbouring mcr-1.
See this image and copyright information in PMC

References

    1. National Center for Emerging and Zoonotic Infectious Diseases. Pathogens causing US foodborne illnesses, hospitalizations, and deaths, 2000–2008. Available at: http://www.cdc.gov/salmonella/index.html (2012).
    1. Wu H. et al.. Prevalence of extended-spectrum β-lactamase-producing Salmonella on retail chicken in six provinces and two national cities in the People’s Republic of China. J Food Prot 76, 2040–2044 (2013). - PubMed
    1. Zhang W. H. et al.. CTX-M-27 producing Salmonella enterica serotypes Typhimurium and Indiana are prevalent among food-producing animals in China. Front Microbiol 7, 436 (2016). - PMC - PubMed
    1. Liang Z. et al.. Serotypes, seasonal trends, and antibiotic resistance of non-typhoidal Salmonella from human patients in Guangdong Province, China, 2009–2012. BMC Infect Dis 15, 53 (2015). - PMC - PubMed
    1. Foley S. L. & Lynne A. M. Food animal-associated Salmonella challenges: pathogenicity and antimicrobial resistance. J Anim Sci 86, E173–187 (2008). - PubMed

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