JAC Advance Access originally published online on March 26, 2008
Journal of Antimicrobial Chemotherapy 2008 61(6):1229-1233; doi:10.1093/jac/dkn131
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Original research |
Multilocus sequence typing of IncI1 plasmids carrying extended-spectrum β-lactamases in Escherichia coli and Salmonella of human and animal origin
1 Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy 2 Istituto Zooprofilattico Sperimentale delle Venezie, Padua, Italy
Received 17 January 2008; returned 11 February 2008; revised 28 February 2008; accepted 29 February 2008
* Corresponding author. Tel: +39-06-49903128; Fax: +39-06-49387112; E-mail: alecara{at}iss.it
Objectives: Plasmids belonging to incompatibility group I1 (IncI1) are widespread in Enterobacteriaceae and are characterized by the presence of a cluster of genes encoding the type IV pili, contributing to the virulence of Shiga-toxigenic Escherichia coli. Recently, IncI1 plasmids were identified in E. coli and Salmonella strains of animal origin as responsible for the dissemination of β-lactamase genes. Plasmid multilocus sequence typing (pMLST) was developed to discern naturally occurring IncI1 plasmids in homogeneous groups according to their allele assortment.
Methods: pMLST was developed by selecting multiple target genes on the available complete IncI1 plasmid DNA sequences. Sixteen plasmids, all assigned to the IncI1 group by the PCR-based replicon typing method, were included in this study. They were analysed for β-lactamase genes and typed by restriction fragment length polymorphism (RFLP) and pMLST.
Results: Sixteen plasmids identified in E. coli and Salmonella isolated from animals and humans in different countries carried blaCMY-2, blaCTX-M-15, blaCTX-M-1, blaCTX-M-14, blaTEM-52, blaSHV-12 or blaTEM-1 β-lactamase genes. These plasmids were classified by RFLP in nine different groups corresponding to the nine sequence types determined by pMLST.
Conclusions: The pMLST method was suitable for rapid and easy subtyping of IncI1 plasmids. This study demonstrates that the pMLST method can contribute to the epidemiological description of circulation of specific resistance plasmids among β-lactamase producers isolated from animals and humans.
Keywords: pMLST , incompatibility group , CTX-M , CMY , SHV
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Carattoli Resistance Plasmid Families in Enterobacteriaceae Antimicrob. Agents Chemother., June 1, 2009; 53(6): 2227 - 2238. [Full Text] [PDF]
|
|
|
|
 |
|
 R. L. Lindsey, P. J. Fedorka-Cray, J. G. Frye, and R. J. Meinersmann Inc A/C Plasmids Are Prevalent in Multidrug-Resistant Salmonella enterica Isolates Appl. Envir. Microbiol., April 1, 2009; 75(7): 1908 - 1915. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Sunde, H. Tharaldsen, J. S. Slettemeas, M. Norstrom, A. Carattoli, and J. Bjorland Escherichia coli of animal origin in Norway contains a blaTEM-20-carrying plasmid closely related to blaTEM-20 and blaTEM-52 plasmids from other European countries J. Antimicrob. Chemother., January 1, 2009; 63(1): 215 - 216. [Full Text] [PDF]
|
|