This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hopkins, K. L.
Right arrow Articles by Carattoli, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hopkins, K. L.
Right arrow Articles by Carattoli, A.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, September 2006, p. 3203-3206, Vol. 50, No. 9
0066-4804/06/$08.00+0     doi:10.1128/AAC.00149-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Replicon Typing of Plasmids Carrying CTX-M or CMY ß-Lactamases Circulating among Salmonella and Escherichia coli Isolates{dagger}

Katie L. Hopkins,1 Ernesto Liebana,2 Laura Villa,3 Miranda Batchelor,2 E. John Threlfall,1 and Alessandra Carattoli3*

Laboratory of Enteric Pathogens, Health Protection Agency Centre of Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom,1 Department of Food and Environmental Safety, Veterinary Laboratories Agency, Weybridge New Haw, Addlestone Surrey KT15 3NB, United Kingdom,2 Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy3

Received 4 February 2006/ Returned for modification 15 April 2006/ Accepted 6 July 2006


arrow
ABSTRACT
 
Replicon typing of plasmids carrying blaCTX-M or blaCMY ß-lactamase genes indicates a predominance of I1 and A/C replicons among blaCMY-carrying plasmids and five different plasmid scaffolds associated with the different types of blaCTX-M genes (I1, FII, HI2, K, and N). These results demonstrate the association of certain ß-lactamase genes with specific plasmid backbones.


arrow
TEXT
 
Understanding the molecular epidemiology of resistance plasmids has proven to be a complex task due to the diversity and promiscuity of these elements. The relatedness of plasmids can be demonstrated either by restriction fragment pattern analysis or by classification into incompatibility groups (Inc) and replicon (rep) typing (8). These analyses require laborious hands-on work, multiple conjugation or transformation assays, or hybridization experiments (8). A PCR-based replicon typing (PBRT) method has been recently developed and can be easily applied to a larger number of strains (6).

The aim of this work was to investigate phylogenetic relatedness among plasmids carrying extended-spectrum cephalosporin (ESC) resistance that are emerging in the United Kingdom and tracing, by PBRT, the diffusion of prevalent plasmids in association with specific ESC resistance gene variants.

The PBRT was applied to transformants or transconjugants obtained from 29 Salmonella enterica and 38 Escherichia coli isolates, representing a collection of plasmid-mediated CTX-M or AmpC producers isolated in the United Kingdom between 1995 and 2003. Strains were received from different laboratories in the country or were isolated at the Health Protection Agency Centre for Infections, London, United Kingdom, or at the Veterinary Laboratory Agency, Addlestone, Surrey, United Kingdom, and archived with antimicrobial susceptibility tests, ß-lactamase gene identification, pulsed-field gel electrophoresis (PFGE), and plasmid profiling, as previously described (1, 2, 3, 10, 11). These strains were not repetitive (one from each patient), and only one strain for each cluster (100% identity by PFGE) was included in the study. Sixty strains were isolated from human urine, blood, feces, sputum, and surgical wounds, and seven strains were from animals (poultry, turkey, horse, and cattle). The ESC resistance genes in this collection were the following: blaCTX-M-9, blaCTX-M-15, blaCTX-M-2, blaCTX-M-14, blaCTX-M-3, blaCTX-M-40, blaCMY-2, blaCMY-4, blaCMY-7, and blaCMY-21 (Tables 1 and 2). Salmonella strains were genetically unrelated by PFGE and belonged to several different serotypes or were isolated in different years. Using a ≥85% similarity cutoff point, PFGE of the E. coli strains identified 14 and 12 different XbaI digest profiles among the 20 blaCTX-M- and 18 blaCMY-producing isolates, respectively, thus indicating that these strains, with the exception of a few clusters of two to three strains each, were genetically unrelated.


View this table:
[in this window]
[in a new window]
  		TABLE 1. Characteristics of the AmpC-carrying plasmids analyzed in this study


View this table:
[in this window]
[in a new window]
  		TABLE 2. Characteristics of the CTX-M-carrying plasmids analyzed in this study

Thirty-one transformants/transconjugants carried plasmid-located AmpC-derivative ß-lactamases. All plasmids were from epidemiologically unrelated isolates: 27 were from human cases, and 7 of these strains were isolated in other countries or were from patients who had recently traveled abroad; the remaining 4 were from animals (Table 1). All the transformants/transconjugants except for two were successfully typed by PBRT, and four strains showed positive results for two different replicons (Table 1). The latter strains were further examined by Southern blot hybridization experiments performed on purified undigested plasmid DNA using the two amplified replicons as probes (data not shown). This experiment indicated that strains A2-VLA and E108137-HPA carried multireplicon plasmids positive for both the FII-FIA and FIA-FIB replicons, respectively, while the E134708-HPA and E115837-HPA strains carried an IncI1 plasmid plus an IncN or IncA/C plasmid, respectively, cotransferred by conjugation. By Southern blot hybridization, the blaCMY-2 gene was associated with the IncI1 plasmid in both strains (data not shown) (Table 1). Thus, with the exception of three IncF plasmids (two of them carrying the blaDHA-1 gene) and two untypeable plasmids, all the blaCMY-positive plasmids of this collection were located on repI1 or repA/C plasmids.

Among the nine blaCMY-2 repA/C plasmids, seven of them were from Salmonella of different serotypes and two were from E. coli showing 53% genetic similarity index by PFGE (10). The DNA sequence of the repA gene obtained by sequencing the entire repA/C amplicon (465 bp) from these nine plasmids showed 100% identity to the repA gene of the previously characterized 2039 plasmid (EMBL accession no. AM087198), originating from the ceftriaxone-resistant S. enterica serovar Typhimurium strain isolated in the United States in 1997 (7). This repA gene is slightly different (94% identity, 26 nucleotide substitutions) from the repA gene of the RA1 IncA/C reference plasmid (GenBank accession no. X73674). The detection of the same resistance gene (blaCMY-2) on an IncA/C plasmid carrying the same repA gene variant strongly indicates that the blaCMY-A/C plasmid could be a successful and widely distributed plasmid circulating on different continents.

The 11 plasmids carrying the blaCMY-7 gene were all associated with the repI1 replicon as well as 4 plasmids carrying the blaCMY-2 and 1 plasmid carrying the blaCMY-21 variant. Thirteen of these plasmids were from E. coli isolated in the United Kingdom. Two clusters, of two and three strains, respectively, showed a genetic similarity index of 90% by PFGE (Table 1), but the other strains showed an index lower than 68%, indicating that they were genetically unrelated (10). These results suggest the circulation of a prevalent IncI1 plasmid carrying the different blaCMY gene variants. It is interesting to note that the IncI1 plasmids carrying the blaCMY gene show some difference with respect to the additional plasmid-located resistance (mainly sulfonamide or trimethoprim resistance; Table 1) or to a capability of self transferability. This observation suggests interesting clues on the evolution of related plasmids that can gain additional resistance determinants and/or lose the transferability gene-associated functions, evolving in different plasmid variants. Furthermore, since the blaCMY-2, blaCMY-4, and blaCMY-21 genes differ from each other by only one or a few nucleotide substitutions, they could therefore simply be variants of one another, and this evolution could have occurred within the same IncI1 or IncA/C plasmid scaffold by accumulation of single point mutations.

In contrast with the previous situation, a very diverse picture was observed for the blaCTX-M-carrying plasmids. We analyzed 36 plasmids: 22 carried blaCTX-M-15, 5 carried blaCTX-M-9, 4 carried blaCTX-M-14, 2 carried blaCTX-M-2, 2 carried blaCTX-M-3, and 1 carried blaCTX-M-40. All plasmids were from epidemiologically unrelated isolates: 33 were from human cases (6 of these had reported traveling abroad), and 3 were from animals (Table 2). CTX-M-15 was the most common CTX-M subtype identified, and the previously analyzed PFGE patterns for the E. coli producers indicated that the spread of CTX-M-15 was not due to a single clone expansion (10). This result is in agreement with other previous studies performed on CTX-M-15 E. coli producers from the United Kingdom, which demonstrated that this extended-spectrum ß-lactamase is prevalent and carried by different E. coli lineages (14).

In this study, two different replicons were associated with the blaCTX-M-15-positive plasmids. Nine of 22 plasmids were self conjugative and positive for the repI1 replicon; the majority was associated with no additional resistance. Twelve of 22 plasmids were positive for repFII, in some strains associated with FIA and/or FIB replicons. In the latter cases the FII, FIA, and FIB replicons were always colocated on the same plasmid by Southern blot hybridization experiments, indicating the presence of multireplicon plasmids carrying the blaCTX-M-15 gene. To further discern these IncF plasmids, HpaI restriction patterns and the nucleotide sequence of the regulatory antisense CopA RNA were analyzed (12). Nucleotide substitutions in the CopA sequence were considered in the classification of FII plasmids, since the antisense RNA has been demonstrated to participate in the control of replication as well as in the incompatibility behavior of the FII plasmids by sequence divergence (4, 12, 13). The sequence of the 270-bp repF amplicon (6) was determined and aligned to the region between nucleotides 392 to 661 in the IncFII NR1 reference plasmid sequence (EMBL accession no. X02302), corresponding to the CopA antisense RNA. These analyses further discriminated the CTX-M-15-carrying plasmids into two FII subgroups (Fig. S1 in the supplemental material). One group showed a CopA sequence 100% identical to that of the FII reference plasmid (indicated as FII-1) NR1 and also identical to that of the pC15-1a plasmid (EMBL accession no. NC_005327), identified in E. coli associated with an outbreak occurring in Canada (5). The pC15-1a plasmid is described as containing a 28.4-kb multidrug resistance region with the blaCTX-M-15, blaOXA-1, blaTEM-1, tetA, aac(6')-Ib, and aac(3)-II genes inserted into the IncFII plasmid backbone (5). The presence of the same gene variant (blaCTX-M-15) associated with the same IncFII type of plasmid in the United Kingdom strongly supports the evidence of a wide distribution of this plasmid in different countries. Restriction pattern analysis also confirmed the presence of related but divergent FII plasmids carrying the blaCTX-M-15 gene (Fig. S2 in the supplemental material). The second subgroup of plasmids, also composed of the two blaDHA-1-carrying plasmids (Table 1; Fig. S1 in the supplemental material), showed a different CopA sequence [indicated as FII (2) in Table 2]. These data demonstrated that blaCTX-M-15 can be located on a largely diffused plasmid (IncI1) or can spread associated with a family of related IncFII plasmids also reported from other continents.

The other blaCTX-M variants were associated with plasmids belonging to different Inc groups. Interestingly, the plasmids carrying the blaCTX-M-9 gene were from United Kingdom strains or were associated with travel to Spain, where this gene variant is largely prevalent (9), and were invariably associated with repHI2. These plasmids were all from S. enterica serovar Virchow, thus suggesting a recurrent association of HI2 plasmids with this Salmonella serotype. Interestingly, the blaCTX-M-14 variant, although closely related to the blaCTX-M-9 variant, was associated with different plasmid types, while blaCTX-M-3 from two S. enterica serovar Virchow strains and blaCTX-M-40 from an E. coli strain were both identified on IncN plasmids, despite these genes being more distantly related. These results indicate a great heterogeneity among the CTX-M plasmids with respect to the CMY plasmids that probably correlates with the higher variability of the blaCTX-M gene family.

The general overview of the results obtained by PBRT indicate the high prevalence of some replicons, such as repI1, repA/C, and repFII, in association with relevant ESC resistance genes, such as the blaCMY-2 and blaCTX-M-15 genes, suggesting a large diffusion of particular plasmids prevailing in the United Kingdom but also identified in other studies in bacterial populations from other continents. These epidemic plasmids seem to prevail in different environments and might spread across different bacterial species in humans as well in animals.

PBRT was demonstrated to be a good method for detecting the replicons in large collections of plasmids. The origin of replication can be considered an additional marker for the constant backbone of the plasmid. The association of replicons with specific plasmid-borne resistance genes opens the possibility of easily detecting and tracing the diffusion of successful plasmids as well as detecting the mobilization capability of a resistance gene among different plasmids.


arrow
ACKNOWLEDGMENTS
 
We are grateful to the Scottish Salmonella Reference Laboratory for supplying strains ESBL3, ESBL7, and ESBL10. This work was supported by the MED-NET-VET Contract with the European Commission (FOOD-CT-2004-506122, WP09), the Specific Targeted Research Project "Role of mobile genetic element in the spread of antimicrobial drug resistance" (contract no. LSHM-CT-2005-018705), and the Department for Environment, Food and Rural Affairs, United Kingdom, project numbers VM02136 and VM02205.


arrow
FOOTNOTES
 
* Corresponding author. Mailing address: Department Infectious, Parasitic, Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Viale Regina Elena 299, 00161 Rome, Italy. Phone: 39-06-4990-3128. Fax: 39-06-4938-7112. E-mail: alecara{at}iss.it. Back

{dagger} Supplemental material for this article may be found at http://aac.asm.org/. Back


arrow
REFERENCES
 
    1
  1. Batchelor, M., F. A. Clifton-Hadley, A. D. Stallwood, G. A. Paiba, R. H. Davies, and E. Liebana. 2005. Detection of multiple cephalosporin-resistant Escherichia coli from a cattle fecal sample in Great Britain. Microb. Drug Resist. 11:58-61.[CrossRef][Medline]
    2. 2
  2. Batchelor, M., K. Hopkins, E. J. Threlfall, F. A. Clifton-Hadley, A. D. Stallwood, R. H. Davies, and E. Liebana. 2005. blaCTX-M genes in clinical Salmonella isolates recovered from humans in England and Wales from 1992 to 2003. Antimicrob. Agents Chemother. 49:1319-1322.[Abstract/Free Full Text]
    3. 3
  3. Batchelor, M., K. Hopkins, E. J. Threlfall, F. A. Clifton-Hadley, A. D. Stallwood, R. H. Davies, and E. Liebana. 2005. Characterization of AmpC-mediated resistance in clinical Salmonella isolates recovered from humans during the period 1992 to 2003 in England and Wales. J. Clin. Microbiol. 43:2261-2265.[Abstract/Free Full Text]
    4. 4
  4. Blomberg, P., K. Nordstrom, and E. G. H. Wagner. 1992. Replication control of plasmid R1: RepA synthesis is regulated by CopA RNA through inhibition of leader peptide translation. EMBO J. 1:2675-2683.
    5. 5
  5. Boyd, D. A., S. Tyler, S. Christianson, A. McGeer, M. P. Muller, B. M. Willey, E. Bryce, M. Gardam, P. Nordmann, and M. R. Mulvey. 2004. Complete nucleotide sequence of a 92-kilobase plasmid harboring the CTX-M-15 extended-spectrum beta-lactamase involved in an outbreak in long-term-care facilities in Toronto, Canada. Antimicrob. Agents Chemother 48:3758-3764.[Abstract/Free Full Text]
    6. 6
  6. Carattoli, A., A. Bertini, L. Villa, V. Falbo, K. L. Hopkins, and E. J. Threlfall. 2005. Identification of plasmids by PCR-based replicon typing. J. Microbiol. Methods 63:219-228.[CrossRef][Medline]
    7. 7
  7. Carattoli, A., F. Tosini, W. P. Giles, M. E. Rupp, S. H. Hinrichs, F. J. Angulo, T. J. Barrett, and P. D. Fey. 2002. Characterization of plasmids carrying CMY-2 from expanded-spectrum cephalosporin-resistant Salmonella isolated in the United States between 1996 and 1998. Antimicrob. Agents Chemother. 46:1269-1272.[Abstract/Free Full Text]
    8. 8
  8. Couturier, M., F. Bex, P. L. Bergquist, and W. K. Maas. 1988. Identification and classification of bacterial plasmids. Microbiol. Rev. 52:375-395.[Free Full Text]
    9. 9
  9. Hernandez, J. R., L. Martinez-Martinez, R. Canton, T. M. Coque, A. Pascual, and the Spanish Group for Nosocomial Infections (GEIH). 2005. Nationwide study of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum beta-lactamases in Spain. Antimicrob. Agents Chemother. 49:2122-2125.[Abstract/Free Full Text]
    10. 10
  10. Hopkins, K. L., M. J. Batchelor, E. Liebana, A. P. Deheer-Graham, and E. J. Threlfall. Characterisation of CTX-M and AmpC genes in human isolates of Escherichia coli identified between 1995 and 2003 in England and Wales. Int. J. Antimicrob. Agents, in press.
    11. 11
  11. Liebana, E., M. Gibbs, C. Clouting, L. Barker, F. A. Clifton-Hadley, E. Pleydell, B. Abdalhamid, N. D. Hanson, L. Martin, C. Poppe, and R. H. Davies. 2004. Characterization of ß-lactamases responsible for resistance to extended-spectrum cephalosporins in Escherichia coli and Salmonella enterica strains from food-producing animals in the United Kingdom. Microb. Drug Resist. 10:1-9.[CrossRef][Medline]
    12. 12
  12. Osborn, A. M., F. M. da Silva Tatleyqq, L. M. Steyn, R. W. Pickup, and J. R. Saunders. 2000. Mosaic plasmids and mosaic replicons: evolutionary lessons from the analysis of genetic diversity in IncFII-related replicons. Microbiology 146:2267-2275.[Abstract/Free Full Text]
    13. 13
  13. Persson, C., E. Gerhart, H. Wagner, and K. Nordstrom. 1990. Control of replication of plasmid Rl: structures and sequences of the antisense RNA, CopA, required for its binding to the target RNA, CopT. EMBO J. 9:3767-3775.[Medline]
    14. 14
  14. Woodford, N., M. E. Ward, M. E. Kaufmann, et al. 2004. Community and hospital spread of Escherichia coli producing CTX-M extended-spectrum b-lactamases in the UK. J. Antimicrob. Chemother. 54:735-743.[Abstract/Free Full Text]

Antimicrobial Agents and Chemotherapy, September 2006, p. 3203-3206, Vol. 50, No. 9
0066-4804/06/$08.00+0     doi:10.1128/AAC.00149-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Mataseje, L. F., Xiao, J., Kost, S., Ng, L.-K., Dore, K., Mulvey, M. R., on behalf of the Canadian Public Health Laboratory, (2009). Characterization of Canadian cefoxitin-resistant non-typhoidal Salmonella isolates, 2005-06. J Antimicrob Chemother 64: 723-730 [Abstract] [Full Text]  
  • Hrabak, J., Empel, J., Bergerova, T., Fajfrlik, K., Urbaskova, P., Kern-Zdanowicz, I., Hryniewicz, W., Gniadkowski, M. (2009). International Clones of Klebsiella pneumoniae and Escherichia coli with Extended-Spectrum {beta}-Lactamases in a Czech Hospital. J. Clin. Microbiol. 47: 3353-3357 [Abstract] [Full Text]  
  • Verdet, C., Gautier, V., Chachaty, E., Ronco, E., Hidri, N., Decre, D., Arlet, G. (2009). Genetic Context of Plasmid-Carried blaCMY-2-Like Genes in Enterobacteriaceae. Antimicrob. Agents Chemother. 53: 4002-4006 [Abstract] [Full Text]  
  • Rodriguez, I., Barownick, W., Helmuth, R., Mendoza, M. C., Rodicio, M. R., Schroeter, A., Guerra, B. (2009). Extended-spectrum {beta}-lactamases and AmpC {beta}-lactamases in ceftiofur-resistant Salmonella enterica isolates from food and livestock obtained in Germany during 2003-07. J Antimicrob Chemother 64: 301-309 [Abstract] [Full Text]  
  • Mataseje, L. F., Neumann, N., Crago, B., Baudry, P., Zhanel, G. G., Louie, M., Mulvey, M. R., and the ARO Water Study Group, (2009). Characterization of Cefoxitin-Resistant Escherichia coli Isolates from Recreational Beaches and Private Drinking Water in Canada between 2004 and 2006. Antimicrob. Agents Chemother. 53: 3126-3130 [Abstract] [Full Text]  
  • Smet, A., Martel, A., Persoons, D., Dewulf, J., Heyndrickx, M., Cloeckaert, A., Praud, K., Claeys, G., Catry, B., Herman, L., Haesebrouck, F., Butaye, P. (2009). Comparative analysis of extended-spectrum-{beta}-lactamase-carrying plasmids from different members of Enterobacteriaceae isolated from poultry, pigs and humans: evidence for a shared {beta}-lactam resistance gene pool?. J Antimicrob Chemother 63: 1286-1288 [Full Text]  
  • Carattoli, A. (2009). Resistance Plasmid Families in Enterobacteriaceae. Antimicrob. Agents Chemother. 53: 2227-2238 [Full Text]  
  • Evershed, N. J., Levings, R. S., Wilson, N. L., Djordjevic, S. P., Hall, R. M. (2009). Unusual Class 1 Integron-Associated Gene Cassette Configuration Found in IncA/C Plasmids from Salmonella enterica. Antimicrob. Agents Chemother. 53: 2640-2642 [Abstract] [Full Text]  
  • Blanco, M., Alonso, M. P., Nicolas-Chanoine, M.-H., Dahbi, G., Mora, A., Blanco, J. E., Lopez, C., Cortes, P., Llagostera, M., Leflon-Guibout, V., Puentes, B., Mamani, R., Herrera, A., Coira, M. A., Garcia-Garrote, F., Pita, J. M., Blanco, J. (2009). Molecular epidemiology of Escherichia coli producing extended-spectrum {beta}-lactamases in Lugo (Spain): dissemination of clone O25b:H4-ST131 producing CTX-M-15. J Antimicrob Chemother 63: 1135-1141 [Abstract] [Full Text]  
  • Fabre, L., Delaune, A., Espie, E., Nygard, K., Pardos, M., Polomack, L., Guesnier, F., Galimand, M., Lassen, J., Weill, F.-X. (2009). Chromosomal Integration of the Extended-Spectrum {beta}-Lactamase Gene blaCTX-M-15 in Salmonella enterica Serotype Concord Isolates from Internationally Adopted Children. Antimicrob. Agents Chemother. 53: 1808-1816 [Abstract] [Full Text]  
  • Lindsey, R. L., Fedorka-Cray, P. J., Frye, J. G., Meinersmann, R. J. (2009). Inc A/C Plasmids Are Prevalent in Multidrug-Resistant Salmonella enterica Isolates. Appl. Environ. Microbiol. 75: 1908-1915 [Abstract] [Full Text]  
  • Literacka, E., Bedenic, B., Baraniak, A., Fiett, J., Tonkic, M., Jajic-Bencic, I., Gniadkowski, M. (2009). blaCTX-M Genes in Escherichia coli Strains from Croatian Hospitals Are Located in New (blaCTX-M-3a) and Widely Spread (blaCTX-M-3a and blaCTX-M-15) Genetic Structures. Antimicrob. Agents Chemother. 53: 1630-1635 [Abstract] [Full Text]  
  • Zioga, A., Whichard, J. M., Kotsakis, S. D., Tzouvelekis, L. S., Tzelepi, E., Miriagou, V. (2009). CMY-31 and CMY-36 Cephalosporinases Encoded by ColE1-Like Plasmids. Antimicrob. Agents Chemother. 53: 1256-1259 [Abstract] [Full Text]  
  • Marcade, G., Deschamps, C., Boyd, A., Gautier, V., Picard, B., Branger, C., Denamur, E., Arlet, G. (2009). Replicon typing of plasmids in Escherichia coli producing extended-spectrum {beta}-lactamases. J Antimicrob Chemother 63: 67-71 [Abstract] [Full Text]  
  • Diestra, K., Juan, C., Curiao, T., Moya, B., Miro, E., Oteo, J., Coque, T. M., Perez-Vazquez, M., Campos, J., Canton, R., Oliver, A., Navarro, F., on behalf of Red Espanola de Investigacion en Pato, (2009). Characterization of plasmids encoding blaESBL and surrounding genes in Spanish clinical isolates of Escherichia coli and Klebsiella pneumoniae. J Antimicrob Chemother 63: 60-66 [Abstract] [Full Text]  
  • Hradecka, H., Karasova, D., Rychlik, I. (2008). Characterization of Salmonella enterica serovar Typhimurium conjugative plasmids transferring resistance to antibiotics and their interaction with the virulence plasmid. J Antimicrob Chemother 62: 938-941 [Abstract] [Full Text]  
  • Zong, Z., Partridge, S. R., Thomas, L., Iredell, J. R. (2008). Dominance of blaCTX-M within an Australian Extended-Spectrum {beta}-Lactamase Gene Pool. Antimicrob. Agents Chemother. 52: 4198-4202 [Abstract] [Full Text]  
  • Lascols, C., Podglajen, I., Verdet, C., Gautier, V., Gutmann, L., Soussy, C.-J., Collatz, E., Cambau, E. (2008). A Plasmid-Borne Shewanella algae Gene, qnrA3, and Its Possible Transfer In Vivo between Kluyvera ascorbata and Klebsiella pneumoniae. J. Bacteriol. 190: 5217-5223 [Abstract] [Full Text]  
  • Garcia-Fernandez, A., Chiaretto, G., Bertini, A., Villa, L., Fortini, D., Ricci, A., Carattoli, A. (2008). Multilocus sequence typing of IncI1 plasmids carrying extended-spectrum {beta}-lactamases in Escherichia coli and Salmonella of human and animal origin. J Antimicrob Chemother 61: 1229-1233 [Abstract] [Full Text]  
  • Hrabak, J., Empel, J., Gniadkowski, M., Halbhuber, Z., Rebl, K., Urbaskova, P. (2008). CTX-M-15-Producing Shigella sonnei Strain from a Czech Patient Who Traveled in Asia. J. Clin. Microbiol. 46: 2147-2148 [Full Text]  
  • Mammeri, H., Eb, F., Berkani, A., Nordmann, P. (2008). Molecular characterization of AmpC-producing Escherichia coli clinical isolates recovered in a French hospital. J Antimicrob Chemother 61: 498-503 [Abstract] [Full Text]  
  • Gonullu, N., Aktas, Z., Kayacan, C. B., Salcioglu, M., Carattoli, A., Yong, D. E., Walsh, T. R. (2008). Dissemination of CTX-M-15 {beta}-Lactamase Genes Carried on Inc FI and FII Plasmids among Clinical Isolates of Escherichia coli in a University Hospital in Istanbul, Turkey. J. Clin. Microbiol. 46: 1110-1112 [Abstract] [Full Text]  
  • Carattoli, A., Garcia-Fernandez, A., Varesi, P., Fortini, D., Gerardi, S., Penni, A., Mancini, C., Giordano, A. (2008). Molecular Epidemiology of Escherichia coli Producing Extended-Spectrum -Lactamases Isolated in Rome, Italy. J. Clin. Microbiol. 46: 103-108 [Abstract] [Full Text]  
  • Pallecchi, L., Bartoloni, A., Fiorelli, C., Mantella, A., Di Maggio, T., Gamboa, H., Gotuzzo, E., Kronvall, G., Paradisi, F., Rossolini, G. M. (2007). Rapid Dissemination and Diversity of CTX-M Extended-Spectrum {beta}-Lactamase Genes in Commensal Escherichia coli Isolates from Healthy Children from Low-Resource Settings in Latin America. Antimicrob. Agents Chemother. 51: 2720-2725 [Abstract] [Full Text]  
  • Cloeckaert, A., Praud, K., Doublet, B., Bertini, A., Carattoli, A., Butaye, P., Imberechts, H., Bertrand, S., Collard, J.-M., Arlet, G., Weill, F.-X. (2007). Dissemination of an Extended-Spectrum-{beta}-Lactamase blaTEM-52 Gene-Carrying IncI1 Plasmid in Various Salmonella enterica Serovars Isolated from Poultry and Humans in Belgium and France between 2001 and 2005. Antimicrob. Agents Chemother. 51: 1872-1875 [Abstract] [Full Text]  
  • Johnson, T. J., Wannemuehler, Y. M., Johnson, S. J., Logue, C. M., White, D. G., Doetkott, C., Nolan, L. K. (2007). Plasmid Replicon Typing of Commensal and Pathogenic Escherichia coli Isolates. Appl. Environ. Microbiol. 73: 1976-1983 [Abstract] [Full Text]  
  • Novais, A., Canton, R., Moreira, R., Peixe, L., Baquero, F., Coque, T. M. (2007). Emergence and Dissemination of Enterobacteriaceae Isolates Producing CTX-M-1-Like Enzymes in Spain Are Associated with IncFII (CTX-M-15) and Broad-Host-Range (CTX-M-1, -3, and -32) Plasmids. Antimicrob. Agents Chemother. 51: 796-799 [Abstract] [Full Text]  

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hopkins, K. L.
Right arrow Articles by Carattoli, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hopkins, K. L.
Right arrow Articles by Carattoli, A.

Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»