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Applied and Environmental Microbiology, July 2007, p. 4681-4685, Vol. 73, No. 14
0099-2240/07/$08.00+0 doi:10.1128/AEM.02491-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Extended-Spectrum ß-Lactamase CTX-M-1 in Escherichia coli Isolates from Healthy Poultry in France
Delphine Girlich,1
Laurent Poirel,1
Alessandra Carattoli,2
Isabelle Kempf,3
Marie-Frédérique Lartigue,1
Alessia Bertini,2 and
Patrice Nordmann1*
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, and Faculté de Médecine Paris-Sud, Université Paris-Sud, Paris XI, Le Kremlin-Bicêtre, France,1
Istituto Superiore di Sanita, Rome, Italy,2
Agence Française de Sécurité Sanitaire des Aliments, Unité de Mycoplasmologie Bactériologie, BP53, 22440 Ploufragan, France3
Received 25 October 2006/
Accepted 12 May 2007

ABSTRACT
Genes encoding extended-spectrum ß-lactamase CTX-M-1
were detected in 12
Escherichia coli isolates recovered over
a 7-month period from the ceca of healthy poultry in seven districts
in France in 2005. Eleven of those strains were not clonally
related and had a
blaCTX-M-1 gene located on transferable plasmids
of different sizes and structures.

INTRODUCTION
Most of the clavulanic acid-inhibited extended-spectrum ß-lactamases
(ESBL) are either derivatives of narrow-spectrum TEM- and SHV-type
ß-lactamases or CTX-M, PER, VEB, and GES/IBC-type
ß-lactamases (
1,
35,
37). The CTX-M-type ß-lactamases
confer resistance to expanded-spectrum cephalosporins, such
as cefotaxime, ceftazidime, and cefepime (
3).
Escherichia coli strains harboring CTX-M-type ESBL genes have been detected increasingly
in humans since the beginning of the 1990s (
3,
4,
5,
23-
26,
46) and represent a real threat mostly in community-acquired
infections (
37). There are now more than 60 CTX-M ß-lactamases
(
www.lahey.org/studies/other.asp), and they may be classified
according to subgroups CTX-M-1, CTX-M-3, CTX-M-8, CTX-M-9, and
CTX-M-25 (
3).
Whereas plasmid-mediated cephalosporinases (CMY type) have been extensively reported in animal isolates (15, 42, 47), the aim of the present study was to search for CTX-M producers in healthy animals recovered in slaughterhouses of several districts located in the western part of France, which is the main region for broiler production.
From April to November 2005, 112 samples were collected from the ceca from healthy poultry in 10 slaughterhouses located in seven districts in France (i.e., Côtes-d'Armor, Finistère, Landes, Maine-et-Loire, Mayenne, Morbihan, and Vendée). These samples were plated on MacConkey agar plates containing ceftazidime (1 µg/ml) or cefotaxime (1 µg/ml). MICs of ß-lactams were determined by an agar dilution technique (12). Out of the 112 samples, 32 nonduplicate E. coli isolates were resistant or intermediate to ceftazidime and/or to cefotaxime. Two isolates were resistant to amoxicillin and ticarcillin and susceptible to ticarcillin and clavulanate, suggesting the production of a penicillinase (PC) (Table 1). Eighteen isolates had a phenotype consistent with the expression of a cephalosporinase (CS), since they were resistant to amoxicillin, amoxicillin-clavulanate, and cephalothin and had reduced susceptibility to cefuroxime (Table 1). A double-disk synergy test for detection of ESBL carried out as described previously (29) revealed synergy between clavulanate and cefotaxime or ceftazidime-containing disks for 12 isolates, suggesting production of an ESBL in 10.7% of the samples (Table 1). The MICs of ß-lactams for those isolates evidenced decreased susceptibility or resistance to expanded-spectrum cephalosporins, including ceftiofur that has been approved in France in 2003 for treatment of animals, including cattle, horses, and pigs (Table 1).
Detection of several ß-lactamase genes, including
blaTEM,
blaSHV,
blaCTX-M,
blaCMY-2,
blaFOX,
blaOXA-1, and amplification
of the entire
ampC gene and its promoter regions were carried
out by PCR as described previously (
17,
24,
36). The PCR products
were sequenced on both strands on an Applied Biosystems sequencer
(ABI 377). Mutations in the
ampC gene and promoter region were
compared to those of
E. coli K-12 strain. A TEM-1 ß-lactamase
gene was detected in the two PC-producing
E. coli isolates (Table
1). Amplification and sequencing of the promoter region of the
ampC gene were carried out on 5 isolates among the 18 CS-producing
E. coli isolates and the PC-producing
E. coli isolates. Mutations
were detected at positions 42 (C

T), 18 (G

A), 1
(C

T), and +58 (C

T) of the
ampC gene. Mutations at these locations
could be associated with AmpC hyperproduction and thus explain
the ß-lactam resistance phenotype made of resistance
to inhibitors (
11,
22). Hyperproduction of the AmpC enzyme was
confirmed by quantitative determination of cephalothin hydrolysis
in culture extracts of the PC- and CS-producing and
E. coli K-12 isolates as described previously (
39). A 40-fold-higher
(ca. 320 versus 8 mU/mg of protein) ß-lactamase activity
was noticed in the PC and CS culture extracts compared to that
of
E. coli K-12. Sequencing of the
ampC structural gene did
not identify specific mutations responsible for the extension
of the hydrolysis spectrum towards expanded-spectrum cephalosporins
as described by Mammeri and Nordmann (
30). All ESBL-producing
E. coli isolates had the same
blaCTX-M-1 gene, and three out
of these isolates had an additional
blaCTX-M-1 ß-lactamase
gene.
The surrounding genetic structures of the blaCTX-M-1 gene were characterized by PCR as reported previously (26). ISEcp1 sequence was identified 80 bp upstream of the start codon of the blaCTX-M-1 gene in all cases (16, 43). ISEcp1 is an insertion sequence frequently associated with any of the blaCTX-M genes belonging to three out of the five known clusters (CTX-M-1, -M-2, and -M-9 clusters) (2, 20, 25, 38, 43) and may contribute to expression of genes located in its right-hand extremity, including blaCTX-M genes. ISEcp1 possesses peculiar transposition properties (23, 40) and may explain mobilization of the plasmid-located blaCTX-M-1 gene from its chromosomal origin in Kluyvera cryocrescens (14).
Pulsed-field gel electrophoresis (PFGE) analysis, performed as described previously with XbaI endonuclease (18), showed that 11 out of the 12 blaCTX-M-1-positive E. coli isolates belonged to distinct genotypes (Fig. 1). Despite several attempts, isolates 21 and 34 could not be typed by PFGE due to DNA self-denaturation. However, these strains had different enterobacterial repetitive intergenic consensus-PCR patterns from those of the other E. coli isolates (data not shown) (17). Only E. coli isolates 12 and 16 had very similar patterns. Thus, spread of the blaCTX-M-1 gene did not result from the spread of a single clone. The characteristics of the blaCTX-M-1-positive E. coli strains are shown in Table 1 and 2. The number of coresistance markers were limited compared to those identified in most CTX-M-producing E. coli human isolates (37).
Since
blaCTX-M-1 genes are usually located on large plasmids
(
20), plasmid DNA was extracted (
21) and used for transformation
into
E. coli TOP10 (Invitrogen) (
20). Large plasmids of ca.
100, 80, and 55 kb (Table
2) were identified (Fig.
2). PCR-based
replicon typing of the major plasmid incompatibility groups
(
9) showed that the
blaCTX-M-1-positive plasmids belonged to
the same IncI1 incompatibility group, with one exception (
E. coli isolate 47) (data not shown). The plasmid of
E. coli isolate
47 gave negative results with all the Inc/rep primers tested
(
9) and cannot be classified in a major plasmid incompatibility
group as several other replicons as described previously (
9).
MICs of ß-lactams for the
E. coli transformants showed
susceptibility profiles that mirrored those observed for clinical
strains (Table
1). Then, plasmid DNA from transformants was
digested with the EcoRI restriction enzyme and subjected to
electrophoresis in a 1% agarose gel as described previously
(
44). Plasmids with similar sizes and structures were detected
in 5 out of the 11 nonrelated isolates withdrawn from four different
slaughterhouses (Fig.
3). This result suggests a possible spread
of similar plasmids between different slaughterhouses. Direct
transfer of these plasmids into rifampin-resistant
E. coli C600
was attempted by liquid mating-out assays as described previously
(
23). Transconjugants resistant to amoxicillin (100 µg/ml)
and rifampin (200 µg/ml) were selected at a frequency
of 2.5 to 4
x 10
5 per donor cell. All transconjugants
were CTX-M-1 positive, demonstrating self-transferability of
these plasmids.
Several reports identified CTX-M-s also from animal isolates
(
2,
6,
7,
8,
13,
19,
45,
46) including the very first CTX-M
enzyme that was from an
E. coli isolate of a Japanese dog (
31).
The
blaCTX-M-1 gene was identified in a single
E. coli isolate
(from milk cattle) out of 10 ESBL-producing
E. coli isolates
from sick animals in Spain in 2003 with CTX-M-14 being predominantly
found in that case (
6). Spread of
E. coli carrying ESBL CMY-2,
SHV-12 and CTX-M-1 has been identified in companion animals
in Italy (
10). Our work identified CTX-M-1 in 12 (10.7%) of
112 poultry fecal samples corresponding to a 10-fold-higher
rate than that of the nation-based surveys performed in Japan
for CTX-M-2
E. coli producers in cattle (
22,
45). This rate
mirrors the increasing and high percentage of CTX-M carriers
reported in humans (
32,
33) that may be related in part to contamination
during abattoir slaughtering and food processing (
15,
27). As
described recently,
E. coli strains of food-producing animal
farms may be a reservoir for ESBL-producing organisms (
2). Recent
studies report
blaCTX-M genes on self-transferable plasmids
in nontyphoid
Salmonella in poultry in Spain, Greece, and France
(
6,
41,
46), suggesting a possible transfer of antibiotic resistance
conjugative plasmids in
E. coli in feces. Interestingly, we
have shown that culture at 40°C may increase IS
Ecp1-mediated
transfer of
blaCTX-M genes (
23), a temperature that corresponds
to the internal temperature of poultry. In addition, we identified
here the
blaCTX-M-1 gene mostly located on IncI1 plasmids, whereas
this ESBL gene was recently identified on IncN plasmids in human
isolates in Italy (
34).
Our study reports a widespread diffusion of CTX-M-1 in E. coli in food-producing poultry in France, although the most important resistance mechanism to extended-spectrum cephalosporins was overexpression of the nontransferable cephalosporinase. Noteworthy, CTX-M-1 belongs to the CTX-M group (including CTX-M-1, CTX-M-3, and CTX-M-15) that is predominantly identified in human isolates in France as well as worldwide (16, 17, 26, 28, 37; P. Nordmann, personal data). This study suggests a possible reservoir for ESBL genes on transferable plasmids in poultry.

ACKNOWLEDGMENTS
This work was funded by a grant from the Ministère de
l'Education Nationale et de la Recherche (UPRES-EA 3539), Université
Paris-Sud, and the Ministère de l'Agriculture et de la
Pêche, Paris, France, and by the European Community (6th
PCRD, LSHM-CT-2005-018705). L.P. is a researcher from INSERM
(Paris, France).
We are grateful to G. Hellard for technical help.

FOOTNOTES
* Corresponding author. Mailing address: Service de Bactériologie-Virologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, 94275 Le Kremlin-Bicêtre Cédex, France. Phone: 33-1-45-21-36-32. Fax: 33-1-45-21-63-40. E-mail:
nordmann.patrice{at}bct.aphp.fr 
Published ahead of print on 18 May 2007. 

REFERENCES
1 - Bauernfeind, A., I. Stemplinger, R. Jungwirth, S. Ernst, and J. M. Casellas. 1996. Sequences of ß-lactamase genes encoding CTX-M-1 (MEN-1) and CTX-M-2 and relationship of their amino acid sequences with those of other ß-lactamases. Antimicrob. Agents Chemother. 40:509-513.[Abstract]
2 - Blanc, V., R. Mesa, M. Saco, S. Lavilla, G. Prats, E. Miro, F. Navarro, P. Cortes, and M. Llagostera. 2006. ESBL- and plasmidic class C beta-lactamase-producing E. coli strains isolated from poultry, pig and rabbit farms. Vet. Microbiol. 118:299-304.[CrossRef][Medline]
3 - Bonnet, R. 2004. Growing group of extended-spectrum ß-lactamases: the CTX-M enzymes. Antimicrob. Agents Chemother. 48:1-14.[Free Full Text]
4 - Bradford, P. A. 2001. Extended-spectrum beta-lactamases in the 21st century: characterization, epidemiology, and detection of this important resistance threat. Clin. Microbiol. Rev. 14:933-951.[Abstract/Free Full Text]
5 - Brigante, G., F. Luzzaro, M. Perilli, G. Lombardi, A. Coli, G. M. Rossolini, G. Amicosante, and A. Toniolo. 2005. Evolution of CTX-M-type ß-lactamases in isolates of Escherichia coli infecting hospital and community patients. Int. J. Antimicrob. Agents 25:157-162.[CrossRef][Medline]
6 - Briñas, L., M. A. Moreno, T. Teshager, Y. Saenz, M. C. Porrero, L. Dominguez, and C. Torres. 2005. Monitoring and characterization of extended-spectrum beta-lactamases in Escherichia coli strains from healthy and sick animals in Spain in 2003. Antimicrob. Agents Chemother. 49:1262-1264.[Abstract/Free Full Text]
7 - Briñas, L., M. A. Moreno, T. Teshager, M. Zarazaga, Y. Saenz, C. Porrero, L. Dominguez, and C. Torres. 2003. Beta-lactamase characterization in Escherichia coli isolates with diminished susceptibility or resistance to extended-spectrum cephalosporins recovered from sick animals in Spain. Microb. Drug Resist. 9:201-209.[CrossRef][Medline]
8 - Briñas, L., M. A. Moreno, M. Zarazaga, C. Porrero, Y. Saenz, M. Garcia, L. Dominguez, and C. Torres. 2003. Detection of CMY-2, CTX-M-14, and SHV-12 ß-lactamases in Escherichia coli fecal-sample isolates from healthy chickens. Antimicrob. Agents Chemother. 47:2056-2058.[Abstract/Free Full Text]
9 - 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]
10 - Carattoli, A., S. Lovari, A. Franco, G. Cordaro, P. Di Matteo, and A. Battisti. 2005. Extended-spectrum ß-lactamases in Escherichia coli isolated from dogs and cats in Rome, Italy, from 2001 to 2003. Antimicrob. Agents Chemother. 49:833-835.[Abstract/Free Full Text]
11 - Caroff, N., E. Espaze, D. Gautreau, H. Richet, and A. Reynaud. 2000. Analysis of the effects of 42 and 32 ampC promoter mutations in clinical isolates of Escherichia coli hyperproducing ampC. J. Antimicrob. Chemother. 45:783-788.[Abstract/Free Full Text]
12 - Clinical and Laboratory Standards Institute. 2005. Performance standards for antimicrobial susceptibility testing; 15th informational supplement. M100-S15. Clinical and Laboratory Standards Institute, Wayne, PA.
13 - Costa, D., P. Poeta, L. Brinas, Y. Saenz, J. Rodrigues, and C. Torres. 2004. Detection of CTX-M-1 and TEM-52 ß-lactamases in Escherichia coli strains from healthy pets in Portugal. J. Antimicrob. Chemother. 54:960-961.[Free Full Text]
14 - Decousser, J.-W., L. Poirel, and P. Nordmann. 2001. Characterization of a chromosomally encoded extended-spectrum class A ß-lactamase from Kluyvera cryocrescens. Antimicrob. Agents Chemother. 45:3595-3598.[Abstract/Free Full Text]
15 - Donaldson, S. C., B. A. Straley, N. V. Hegde, A. A. Sawant, C. Debroy, and B. M. Jayarao. 2006. Molecular epidemiology of ceftiofur-resistant Escherichia coli isolates from dairy calves. Appl. Environ. Microbiol. 72:3940-3948.[Abstract/Free Full Text]
16 - Eckert, C., V. Gautier, and G. Arlet. 2006. DNA sequence analysis of the genetic environment of various blaCTX-M genes. J. Antimicrob. Chemother. 57:14-23.[Abstract/Free Full Text]
17 - Eckert, C., V. Gautier, M. Saladin-Allard, N. Hidri, C. Verdet, Z. Ould-Hocine, G. Barnaud, F. Delisle, A. Rossier, T. Lambert, A. Philippon, and G. Arlet. 2004. Dissemination of CTX-M-type ß-lactamases among clinical isolates of Enterobacteriaceae in Paris, France. Antimicrob. Agents Chemother. 48:1249-1255.[Abstract/Free Full Text]
18 - Girlich, D., T. Naas, A. Leelaporn, L. Poirel, M. Fennewald, and P. Nordmann. 2002. Nosocomial spread of the integron-located veb-1-like cassette encoding an extended-spectrum ß-lactamase in Pseudomonas aeruginosa in Thailand. Clin. Infect. Dis. 34:603-611.[CrossRef][Medline]
19 - Hasman, H., D. Mevius, K. Veldman, I. Olesen, and F. M. Aarestrup. 2005. ß-Lactamases among extended-spectrum ß-lactamase (ESBL)-resistant Salmonella from poultry, poultry products and human patients in The Netherlands. J. Antimicrob. Chemother. 56:115-121.[Abstract/Free Full Text]
20 - Karim, A., L. Poirel, S. Nagarajan, and P. Nordmann. 2001. Plasmid-mediated extended-spectrum beta-lactamase (CTX-M-3 like) from India and gene association with insertion sequence ISEcp1. FEMS Microbiol. Lett. 201:237-241.[Medline]
21 - Kieser, T. 1984. Factors affecting the isolation of CCC DNA from Streptomyces lividans and Escherichia coli. Plasmid 12:19-36.[CrossRef][Medline]
22 - Kojima, A., Y. Ishii, K. Ishihara, H. Esaki, T. Asai, C. Oda, Y. Tamura, T. Takahashi, and K. Yamaguchi. 2005. Extended-spectrum ß-lactamase-producing Escherichia coli strains isolated from farm animals from 1999 to 2002: report from the Japanese Veterinary Antimicrobial Resistance Monitoring Program. Antimicrob. Agents Chemother. 49:3533-3537.[Abstract/Free Full Text]
23 - Lartigue, M. F., L. Poirel, D. Aubert, and P. Nordmann. 2006. In vitro analysis of ISEcp1B-mediated mobilization of naturally occurring ß-lactamase gene blaCTX-M of Kluyvera ascorbata. Antimicrob. Agents Chemother. 50:1282-1286.[Abstract/Free Full Text]
24 - Lartigue, M. F., L. Poirel, J. W. Decousser, and P. Nordmann. 2005. Multidrug-resistant Shigella sonnei and Salmonella enterica serotype Typhimurium isolates producing CTX-M ß-lactamases as causes of community-acquired infection in France. Clin. Infect. Dis. 40:1069-1070.[CrossRef][Medline]
25 - Lartigue, M. F., L. Poirel, C. Héritier, V. Tolün, and P. Nordmann. 2003. First description of CTX-M-15-producing Klebsiella pneumoniae in Turkey. J. Antimicrob. Chemother. 52:315-316.[Free Full Text]
26 - Lartigue, M. F., L. Poirel, and P. Nordmann. 2004. Diversity of genetic environment of blaCTX-M genes. FEMS Microbiol. Lett. 234:201-207.[CrossRef][Medline]
27 - Liebana, E., M. Batchelor, K. L. Hopkins, F. A. Clifton-Hadley, C. J. Teale, A. Foster, L. Barker, E. J. Threlfall, and R. H. Davies. 2006. Longitudinal farm study of extended-spectrum ß-lactamase-mediated resistance. J. Clin. Microbiol. 44:1630-1634.[Abstract/Free Full Text]
28 - Livermore, D. M., and P. M. Hawkey. 2005. CTX-M: changing the face of ESBLs in the UK. J. Antimicrob. Chemother. 56:451-454.[Abstract/Free Full Text]
29 - Luzzaro, F., E. Mantengoli, M. Perilli, G. Lombardi, V. Orlandi, A. Orsatti, G. Amicosante, G. M. Rossolini, and A. Toniolo. 2001. Dynamics of a nosocomial outbreak of multidrug-resistant Pseudomonas aeruginosa producing the PER-1 extended-spectrum ß-lactamase. J. Clin. Microbiol. 39:1865-1870.[Abstract/Free Full Text]
30 - Mammeri, H., and P. Nordmann. 2006. Extended-spectrum cephalosporinases in Enterobacteriaceae. Anti-Infect. Agents Med. Chem. 6:71-82.
31 - Matsumoto, Y., F. Ikeda, T. Kamimura, Y. Yokota, and Y. Mine. 1988. Novel plasmid-mediated ß-lactamase from Escherichia coli that inactivates oxyimino-cephalosporins. Antimicrob. Agents Chemother. 32:1243-1246.[Abstract/Free Full Text]
32 - Mesa, R. J., V. Blanc, A. R. Blanch, P. Cortes, J. J. Gonzalez, S. Lavilla, E. Miro, M. Muniesa, M. Saco, M. Tortola, B. Mirelis, P. Coll, M. Llagostera, G. Prats, and F. Navarro. 2006. Extended-spectrum ß-lactamase-producing Enterobacteriaceae in different environments (humans, food, animal farms and sewage). J. Antimicrob. Chemother. 58:211-215.[Abstract/Free Full Text]
33 - Miro, E., B. Mirelis, F. Navarro, R. A. Rivera, R. J. Mesa, M. C. Roig, L. Gomez, and P. Coll. 2005. Surveillance of extended-spectrum ß-lactamases from clinical samples and faecal carriers in Barcelona, Spain. J. Antimicrob. Chemother. 56:1152-1156.[Abstract/Free Full Text]
34 - Mugnaioli, C., F. De Luca, A. Carattoli, and G. M. Rossolini. 2006. Characterisation of conjugative plasmids encoding CTX-M-type extended-spectrum beta-lactamases in Italian clinical isolates of Escherichia coli, abstr. p506. 16th Eur. Cong. Clin. Microbiol. Infect. Dis., Nice, France.
35 - Nordmann, P. 1998. Trends in ß-lactam resistance among Enterobacteriaceae. Clin. Infect. Dis. 27:S100-S106.[Medline]
36 - Odeh, R., S. Kelkar, A. M. Hujer, R. A. Bonomo, P. C. Schreckenberger, and J. P. Quinn. 2002. Broad resistance due to plasmid-mediated AmpC ß-lactamases in clinical isolates of Escherichia coli. Clin. Infect. Dis. 35:140-145.[CrossRef][Medline]
37 - Pitout, J. D., P. Nordmann, K. B. Laupland, and L. Poirel. 2005. Emergence of extended-spectrum ß-lactamases (ESBLs) in the community. J. Antimicrob. Chemother. 56:52-59.[Abstract/Free Full Text]
38 - Poirel, L., J. W. Decousser, and P. Nordmann. 2003. Insertion sequence ISEcp1B is involved in the expression and mobilization of a blaCTX-M ß-lactamase gene. Antimicrob. Agents Chemother. 47:2938-2945.[Abstract/Free Full Text]
39 - Poirel, L., M. Guibert, D. Girlich, T. Naas, and P. Nordmann. 1999. Cloning, sequence analyses, expression, and distribution of ampC-ampR from Morganella morganii clinical isolates. Antimicrob. Agents Chemother. 43:769-776.[Abstract/Free Full Text]
40 - Poirel, L., M. F. Lartigue, J. W. Decousser, and P. Nordmann. 2005. ISEcp1B-mediated transposition of blaCTX-M in Escherichia coli. Antimicrob. Agents Chemother. 49:447-450.[Abstract/Free Full Text]
41 - Politi, L., P. T. Tassios, M. Lambiri, A. Kansouzidou, M. Pasiotou, A. C. Vatopoulos, K. Mellou, N. J. Legakis, and L. S. Tzouvelekis. 2005. Repeated occurrence of diverse extended-spectrum ß-lactamases in minor serotypes of food-borne Salmonella enterica subsp. enterica. J. Clin. Microbiol. 43:3453-3456.[Abstract/Free Full Text]
42 - Poppe, C., L. C. Martin, C. L. Gyles, R. Reid-Smith, P. Boerlin, S. A. McEwen, J. F. Prescott, and K. R. Forward. 2005. Acquisition of resistance to extended-spectrum cephalosporins by Salmonella enterica subsp. enterica serovar Newport and Escherichia coli in the turkey poult intestinal tract. Appl. Environ. Microbiol. 71:1184-1192.[Abstract/Free Full Text]
43 - Saladin, M., V. T. Cao, T. Lambert, J. L. Donay, J. L. Herrmann, Z. Ould-Hocine, C. Verdet, F. Delisle, A. Philippon, and G. Arlet. 2002. Diversity of CTX-M beta-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals. FEMS Microbiol. Lett. 209:161-168.[Medline]
44 - Sambrook, J., and D. W. Russell. 2001. Molecular cloning: a laboratory manual, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY.
45 - Shiraki, Y., N. Shibata, Y. Doi, and Y. Arakawa. 2004. Escherichia coli producing CTX-M-2 ß-lactamase in cattle, Japan. Emerg. Infect. Dis. 10:69-75.[Medline]
46 - Weill, F. X., R. Lailler, K. Praud, A. Kerouanton, L. Fabre, A. Brisabois, P. A. Grimont, and A. Cloeckaert. 2004. Emergence of extended-spectrum-ß-lactamase (CTX-M-9)-producing multiresistant strains of Salmonella enterica serotype Virchow in poultry and humans in France. J. Clin. Microbiol. 42:5767-5773.[Abstract/Free Full Text]
47 - Zhao, S., D. G. White, P. F. McDermott, S. Friedman, L. English, S. Ayers, J. Meng, J. J. Maurer, R. Holland, and R. D. Walker. 2001. Identification and expression of blaCMY genes in Escherichia coli and Salmonella isolates from food animals and ground meat. Antimicrob. Agents Chemother. 45:3647-3650.[Abstract/Free Full Text]
Applied and Environmental Microbiology, July 2007, p. 4681-4685, Vol. 73, No. 14
0099-2240/07/$08.00+0 doi:10.1128/AEM.02491-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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-
Leflon-Guibout, V., Blanco, J., Amaqdouf, K., Mora, A., Guize, L., Nicolas-Chanoine, M.-H.
(2008). Absence of CTX-M Enzymes but High Prevalence of Clones, Including Clone ST131, among Fecal Escherichia coli Isolates from Healthy Subjects Living in the Area of Paris, France. J. Clin. Microbiol.
46: 3900-3905
[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]