This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
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 Naas, T.
Right arrow Articles by Nordmann, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Naas, T.
Right arrow Articles by Nordmann, P.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, May 1999, p. 1281-1284, Vol. 43, No. 5
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

An SHV-Derived Extended-Spectrum beta -Lactamase in Pseudomonas aeruginosa

Thierry Naas,1,2 Laurence Philippon,1 Laurent Poirel,1 Esthel Ronco,3 and Patrice Nordmann1,*

Service de Bactériologie-Virologie, Hôpital de Bicêtre, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre,1 Service de Bactériologie-Virologie, Hôpital Antoine Béclère, Faculté de Médecine Paris-Sud, 92141 Clamart Cedex,2 and Service de Microbiologie, Hôpital Raymond Poincaré, Faculté de Médecine Paris-Ouest, 92380 Garches,3 Assistance Publique/Hôpitaux de Paris, France

Received 12 October 1998/Returned for modification 25 January 1999/Accepted 26 February 1999


    ABSTRACT
Top
Abstract
Text
References

A clinical isolate of Pseudomonas aeruginosa RP-1 produced the extended-spectrum beta -lactamase (ESBL) SHV-2a. Its gene was expressed from a composite promoter made of the -35 region derived from the left inverted repeat of IS26 and the -10 region from the blaSHV-2a promoter itself. The DNA sequences immediately surrounding blaSHV-2a were homologous to plasmid pMPA2a from Klebsiella pneumoniae KpZU-3, while further away and 3' to the blaSHV-2a gene, a sequence corresponding to the left end of Tn1721 was detected, thus indicating a likely enterobacterial origin of this ESBL gene.


    TEXT
Top
Abstract
Text
References

The so-called extended-spectrum beta -lactamases (ESBLs) hydrolyze extended-spectrum cephalosporins such as ceftriaxone, cefotaxime, and ceftazidime and monobactams such as aztreonam, while their activity is inhibited by clavulanic acid. Most of them are penicillinases (Ambler class A beta -lactamases) (2), which are members of the 2be group of the Bush functional classification (3, 10), being mainly point mutation derivatives of TEM-1/TEM-2 or SHV-1 (22). They have been extensively described worldwide and are mostly plasmid mediated in members of the family Enterobacteriaceae (22).

Pseudomonas aeruginosa possesses inducible, naturally occurring cephalosporinases (3) which confer low-level resistance to aminopenicillins, narrow-spectrum cephalosporins such as cephalothin, and cephamycins such as cefoxitin. These Ambler class C beta -lactamases are not inhibited by clavulanic acid (3). The most common mechanism for increased resistance to ceftazidime and other extended-spectrum cephalosporins in P. aeruginosa is derepression of the chromosomal class C enzyme, resulting in its overproduction (4, 5, 26).

However, within the last 4 years, three clavulanic acid-inhibitable ESBLs were found in P. aeruginosa. Among the 2be Bush group enzymes, two ESBLs are known, PER-1 and TEM-42 (16, 19). PER-1 was originally identified as chromosomally located in a P. aeruginosa isolate from the urinary tract of a Turkish patient hospitalized in Paris in 1992 (16). The PER-1 gene was later also identified as plasmid mediated (6). Recently, a Turkish study shows that PER-1 is found in 11% of P. aeruginosa hospital isolates and in 43% of Acinetobacter sp. strains, underlining its wide spread in this country (27). PER-1 is weakly related to the ESBLs of TEM or SHV derivatives (18). TEM-42 is the second ESBL found in a P. aeruginosa isolate in Paris in 1992 and is so far limited to just one isolate (16). It is also plasmid mediated. The only oxacillin-hydrolyzing beta -lactamase (Ambler class D) with clavulanic acid-inhibited extended-spectrum properties is OXA-18, identified in a P. aeruginosa strain from an Italian patient hospitalized in Paris in 1995 (23). blaOXA-18 was chromosomally located.

In this study, we analyzed the beta -lactamase content of a P. aeruginosa clinical strain for which a slight synergy between the ceftazidime and clavulanic acid discs was found in the double-disc diffusion test on a routine antibiogram.

(This work was presented in part at the 37th Interscience Conference on Antimicrobial Agents and Chemotherapy, Toronto, Ontario, Canada, on 26 September 1997.)

P. aeruginosa RP-1 was isolated in 1995 from a bronchoalveolar brush of a 52-year-old patient hospitalized in the intensive care unit at the Raymond Poincaré hospital (Garches, France). This French patient had recently returned from a trip to Tunisia, where he was hospitalized. This laboratory specimen was collected because the patient suffered from pneumonia. The strain was identified by using an API 20NE system (bioMérieux, Marcy l'Etoile, France). According to routine antibiogram results, it was additionally resistant to fluoroquinolones (ciprofloxacin, ofloxacin, and pefloxacin), aminoglycosides (amikacin, isepamicin, netilmicin, and tobramycin), chloramphenicol, and rifampin. The isolated strain showed a slight synergy between ceftazidime and clavulanate discs, which was best evidenced when the discs were put 1 cm from one another, suggesting the presence of an ESBL. Such a synergy test was performed as routine screening for all P. aeruginosa isolates in order to detect any ESBL-possessing strains. To search for any other gastrointestinal carriers of P. aeruginosa strains with the same unusual beta -lactam resistance profile, rectal swab samples were collected from patients in the same hospitalization unit over the same period of time. The negative results ruled out any cross-contamination or any outbreak in this hospitalization unit.

Plasmid DNA extractions from P. aeruginosa RP-1 failed, despite repeated attempts using four different extraction methods (23). Conjugation assays performed as previously described (23), by using as the recipient strain P. aeruginosa PU21 or in vitro-obtained ciprofloxacin-resistant Escherichia coli JM109, also failed. Genomic DNA from P. aeruginosa RP-1 was then prepared as described previously (23). Preliminary dot blot hybridizations were performed with probes consisting of several class A or D beta -lactamase genes, i.e., blaPER-1, blaSHV-3, blaTEM-1, and blaOXA-18 (23). Only the blaSHV-3 probe gave a positive signal with genomic DNA of P. aeruginosa RP-1. Partially Sau3AI-digested genomic DNA from P. aeruginosa RP-1 was then ligated into the BamHI site of a pBK-CMV cloning vector as previously described (23). Ten recombinant plasmids were obtained after selection of the E. coli JM109 electroporants on trypticase soy plates containing amoxicillin (100 µg/ml). The recombinant strains had decreased susceptibility to extended-spectrum cephalosporins such as ceftazidime compared to E. coli JM109 (data not shown). Analysis of their plasmid content revealed insert sizes ranging from 2.9 to 10 kb. One of them, pPL20 harboring the 2.9-kb insert, was retained for further analysis (Fig. 1).


View larger version (15K):
[in this window]
[in a new window]
  		FIG. 1.   Schematic map of recombinant plasmid pPL20 which possesses blaSHV-2a. The thin, solid line represents the cloned insert from P. aeruginosa RP-1, while the dotted lines indicate the pBK-CMV cloning vector. The open boxes represent genes, and the arrow indicates their translational orientation. pMPA2a (20) and Tn1721 (1) homology regions are indicated. Details of the nucleotide sequence of the blaSHV-2a promoter region are shown below. The boxed sequence corresponds to the left inverted repeat (IRL) of IS26, the -35, -10, and +1 promoter sequences of blaSHV2-a are those described by Podbielski et al. (24). RBS, ribosome-binding site.

Susceptibility testing of E. coli JM109 harboring pPL20 and of P. aeruginosa RP-1 was performed by an agar dilution method as previously described (17, 23). Additionally, MICs were determined for reference strain P. aeruginosa ATCC 27853 and its in vitro-obtained, stably derepressed, cephalosporinase-producing mutant. This mutant, obtained after selection on ceftazidime-containing plates, produced an 85-fold increase of cephalosporinase activity determined as described for an Enterobacter cloacae isolate (14). This beta -lactamase level, as well as the beta -lactam MICs (Table 1), corresponded to a P. aeruginosa strain with a high basal level of constitutive cephalosporinase production (4). As shown in Table 1, P. aeruginosa RP-1 had decreased susceptibility to all of the beta -lactams tested except imipenem. The MIC of ceftazidime (32 µg/ml) was reduced to 8 µg/ml in the presence of clavulanic acid. E. coli JM109(pPL20) had decreased susceptibility to all of the beta -lactams tested except cefoxitin and imipenem; the MICs of the extended-spectrum cephalosporins and aztreonam were markedly reduced in the presence of clavulanic acid, indicating the presence of an ESBL (Table 1). Crude extracts from P. aeruginosa RP-1 and from E. coli JM109(pPL20) were analyzed by isoelectric focusing (23) and revealed a beta -lactamase with a pI of 7.6 in both cases and an additional beta -lactamase with a pI of 8.2 (likely corresponding to an AmpC cephalosporinase) found only in P. aeruginosa RP-1 extracts (data not shown).

                              
View this table:
[in this window]
[in a new window]
  		TABLE 1.   MICs of beta -lactams for P. aeruginosa RP-1, E. coli JM109 harboring recombinant plasmid pPL20, reference strain E. coli JM109, reference strain P. aeruginosa ATCC 27853, and its stably derepressed cephalosporinase-producing mutant, Mut

The 2.9-kb cloned fragment from pPL20 was sequenced on both strands with an Applied Biosystems ABI 377 sequencer. Analysis of the sequenced DNA and the deduced protein revealed a sufficiently large open reading frame of 861 bp encoding a 286-amino-acid protein identified as SHV-2a. First described from a Klebsiella pneumoniae isolate in Germany (25), SHV-2a is a point mutation derivative of SHV-2 differing only by a leucine-to-glutamine replacement at the unusual position 35 of the Ambler numbering. Compared to the consensus sequence for SHV-1 (21), SHV-2 and SHV-2a possess a G238S change, explaining their extended-spectrum catalytic properties. Although initially considered insignificant (25), the position 35 mutation in SHV-2a compared to SHV-2 increased its resistance to ceftazidime but reduced the MICs of all other cephalosporins (20). The prevalence of SHV-2a in Enterobacteriaceae in Western Europe or in the United States is not known, although it was recently reported as being widespread among K. pneumoniae strains in Korea (11).

The -35 (5'-TTGCAA-3') and -10 (5'-TATTCT-3') promoter sequences of blaSHV-2a present on the 2.9-kb insert of pPL20 (Fig. 1) corresponded exactly to those previously identified for this beta -lactamase gene in a K. pneumoniae isolate (25). No promoter sequence specific for P. aeruginosa genes was found upstream the blaSHV-2a structural gene. The -35 and -10 boxes showed higher homology to E. coli promoter sequences described by Hawley and McClure (9) than does the promoter belonging to blaSHV-2, thus explaining the blaSHV-2a promoter strength (24). In fact, a detailed analysis of blaSHV2a revealed that the immediate upstream and downstream sequences retained 100% DNA identity with parts of plasmid pMPA2a from K. pneumoniae KpZU-3 (20). Analysis of the promoter sequences of blaSHV2a indicated that they resulted from a fusion of the -35 sequence from IS26 (15) to the -10 sequence of the native blaSHV-2a promoter (Fig. 1). IS26 was, in fact, previously reported as being the promoter for the expression of an aminoglycoside resistance gene within a multidrug resistance operon (12). A similar hybrid promoter was identified for ESBL gene blaTEM-6, for which an IS1-like element provided the -35 sequence, thus allowing high-level expression of TEM-6 (8). From a general point of view, it is known that insertion sequences may act as mobile promoters on prokaryotic gene expression (7). Their inverted repeats contain -35 sequences that, upon insertion next to -10 sequences, may boost gene expression (7).

Although blaSHV2a was not plasmid located, our report indicates that the ESBL SHV derivatives may be identified in P. aeruginosa. The sequences surrounding blaSHV-2a had strong homology with K. pneumoniae plasmid sequences, and the more distantly related downstream sequences from blaSHV2a had homology with Tn1721, a transposon often encountered in Enterobacteriaceae (1) (Fig. 1). Pulsed-field gel electrophoresis of XbaI-restricted genomic DNA of P. aeruginosa RP-1 (13), followed by blaSHV-2a-specific hybridization, revealed that the fragment containing blaSHV-2a was larger than 300 kb, indicating its likely chromosomal origin (data not shown). We therefore believe that a putative plasmid derived from K. pneumoniae (containing blaSHV-2a) became integrated into P. aeruginosa RP-1 chromosomal DNA either by homologous recombination or by insertion sequence- or transposon-mediated specific cointegration (7).

Our report indicates that the ESBL genes are no longer limited to Enterobacteriaceae, from which they may have originated. From a clinical point of view, detection of these ESBLs based on the double-disc synergy test remains difficult in P. aeruginosa. This bacterial species may therefore become a hidden reservoir for such ESBLs, as is the case for oxacillinase extended-spectrum derivatives.

Nucleotide sequence accession number. The nucleotide sequence reported in this work will appear in the GenBank nucleotide sequence database under accession no. AF074950.


    ACKNOWLEDGMENTS

This work was financed in part by a grant from the Ministère de l'Education Nationale et de la Recherche, Faculté de Médecine Paris-Sud (UPRES, JE 2227), Université Paris XI, France.


    FOOTNOTES

* Corresponding author. Service de Bactériologie-Virologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, Le Kremlin-Bicêtre 94275, France. Phone: 33 1 45 21 36 32. Fax: 33 1 45 21 63 40. E-mail: nordmann.patrice{at}bct.ap-hop-paris.fr.


    REFERENCES
Top
Abstract
Text
References

1. Allmeier, H., B. Gesnar, M. Greck, and R. Schmitt. 1992. Complete nucleotide sequence of Tn1721: gene organization and a novel gene product with features of chemotaxis protein. Gene 111:11-20[Medline].
2. Ambler, R. P. 1980. The structure of beta -lactamases. Philos. Trans. R. Soc. Lond. B Biol. Sci. 289:321-331[Abstract/Free Full Text].
3. Bush, K., G. A. Jacoby, and A. A. Medeiros. 1995. A functional classification scheme for beta -lactamases and its correlation with molecular structure. Antimicrob. Agents Chemother. 39:1211-1233[Medline].
4. Campbell, J. I. A., O. Ciofu, and N. Hoiby. 1997. Pseudomonas aeruginosa isolates from patients with cystic fibrosis have different beta -lactamase expression phenotypes but are homogeneous in the ampC-ampR genetic region. Antimicrob. Agents Chemother. 41:1380-1384[Abstract].
5. Chen, H. Y., M. Yuan, and D. M. Livermore. 1995. Mechanisms of resistance to beta -lactam antibiotics amongst Pseudomonas aeruginosa isolates collected in the UK in 1993. J. Med. Microbiol. 43:300-309[Abstract/Free Full Text].
6. Danel, F., L. M. C. Hall, D. Gur, H. E. Akalin, and D. M. Livermore. 1995. Transferable production of PER-1 beta -lactamase in Pseudomonas aeruginosa. J. Antimicrob. Chemother. 35:281-294[Abstract/Free Full Text].
7. Galas, D. J., and M. Chandler. 1989. Bacterial insertion sequences, p. 109-162. In D. E. Berg, and M. M. Howe (ed.), Mobile DNA. American Society for Microbiology, Washington, D.C.
8. Goussard, S., W. Sougakoff, C. Mabilat, A. Bauernfeind, and P. Courvalin. 1991. An IS1-like element is responsible for high-level synthesis of extended-spectrum beta -lactamase TEM-6 in Enterobacteriaceae. J. Gen. Microbiol. 137:2681-2687[Abstract/Free Full Text].
9. Hawley, D. K., and W. R. McClure. 1983. Compilation and analysis of Escherichia coli promoter DNA sequences. Nucleic Acids Res. 11:2237-2255[Abstract/Free Full Text].
10. Jacoby, G. A., and A. A. Medeiros. 1991. More extended-spectrum beta -lactamases. Antimicrob. Agents Chemother. 35:1697-1704[Free Full Text].
11. Kim, J., Y. Kwon, H. Pai, J. W. Kim, and D. T. Cho. 1998. Survey of Klebsiella pneumoniae strains producing extended-spectrum beta -lactamases: prevalence of SHV-12 and SHV-2a in Korea. Antimicrob. Agents Chemother. 36:1446-1449.
12. Lee, K. Y., J. D. Hopkins, and M. Syvanen. 1990. Direct involvement of IS26 in an antibiotic resistance operon. J. Bacteriol. 172:3229-3236[Abstract/Free Full Text].
13. Maslow, J. N., A. M. Slutsky, and R. D. Arbeit. 1993. Application of pulse-field gel electrophoresis to molecular microbiology, p. 563-572. In D. H. Persing, T. F. Smith, F. C. Tenover, and T. J. White (ed.), Diagnostic molecular microbiology: principles and applications. American Society for Microbiology, Washington, D.C.
14. Mimoz, O., A. Jacolot, S. Léotard, N. Hidri, K. Samii, P. Nordmann, and O. Petitjean. 1998. Efficacies of cefepime, ceftazidime, and imipenem alone or in combination with amikacin in rats with experimental pneumonia due to ceftazidime-susceptible or -resistant Enterobacter cloacae strains. Antimicrob. Agents Chemother. 42:3304-3308[Abstract/Free Full Text].
15. Mollet, B., S. Iida, J. Shepherd, and W. Arber. 1983. Nucleotide sequence of IS26, a new prokaryotic mobile genetic element. Nucleic Acids Res. 11:6319-6330[Abstract/Free Full Text].
16. Mugnier, P., S. Dubrous, G. Arlet, and E. Collatz. 1996. A TEM-derived extended-spectrum beta -lactamase in Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 40:2488-2493[Abstract].
17. National Committee for Clinical Laboratory Standards. 1993. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. Approved standard M7-A3. National Committee for Clinical Laboratory Standards, Villanova, Pa.
18. Nordmann, P., and T. Naas. 1994. Sequence analysis of PER-1 extended-spectrum beta -lactamase from Pseudomonas aeruginosa and comparison with class A beta -lactamases. Antimicrob. Agents Chemother. 38:104-114[Abstract/Free Full Text].
19. Nordmann, P., E. Ronco, T. Naas, C. Duport, Y. Michel-Briand, and R. Labia. 1993. Characterization of PER-1, a novel extended-spectrum beta -lactamase from Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 37:962-969[Abstract/Free Full Text].
20. Nüesch-Inderbinen, M. T., H. Hächler, and F. H. Kayser. 1995. New system based on site-directed mutagenesis for highly accurate comparison of resistance levels conferred by SHV beta -lactamases. Antimicrob. Agents Chemother. 39:1726-1730[Abstract].
21. Nüesch-Inderbinen, M. T., F. H. Kayser, and H. Hächler. 1997. Survey and molecular genetics of SHV beta -lactamases in Enterobacteriaceae in Switzerland: two novel enzymes, SHV-11 and SHV-12. Antimicrob. Agents Chemother. 41:943-949[Abstract].
22. Philippon, A., G. Arlet, and P. H. Lagrange. 1994. Origin and impact of plasmid-mediated extended-spectrum beta-lactamases. Eur. J. Clin. Microbiol. Infect. Dis. 13(Suppl. 1):17-29.
23. Philippon, L. N., T. Naas, A. T. Bouthors, V. Barakett, and P. Nordmann. 1997. OXA-18, a class D clavulanic-acid inhibited extended-spectrum beta -lactamase from Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 41:2188-2195[Abstract].
24. Podbielski, A., J. Schönling, B. Melzer, and G. Haase. 1991. Different promoters of SHV-2 and SHV-2a beta -lactamase lead to diverse levels of cefotaxime resistance in their bacterial producers. J. Gen. Microbiol. 137:1667-1675[Abstract/Free Full Text].
25. Podbielski, A., J. Schönling, B. Melzer, K. Warnatz, and H. G. Leusch. 1991. Molecular characterization of a new plasmid-encoded SHV-type beta -lactamase (SHV-2 variant) conferring high level cefotaxime resistance upon K. pneumoniae. J. Gen. Microbiol. 137:569-578[Abstract/Free Full Text].
26. Sanders, C. C., M. L. Gates, and W. E. Sanders, Jr. 1988. Heterogeneity of class I beta -lactamase expression in clinical isolates of Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 32:1893-1895[Abstract/Free Full Text].
27. Vahaboglu, H., R. Ozturk, G. Aygun, F. Coskunkan, A. Yaman, A. Kaygusuz, H. Leblebicioglu, I. Balik, K. Aydin, and M. Otkun. 1997. Widespread detection of PER-type extended-spectrum beta -lactamases among nosocomial Acinetobacter and Pseudomonas aeruginosa isolates in Turkey: a nationwide multicenter study. Antimicrob. Agents Chemother. 41:2265-2269[Abstract].

Antimicrobial Agents and Chemotherapy, May 1999, p. 1281-1284, Vol. 43, No. 5
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Picao, R. C., Poirel, L., Gales, A. C., Nordmann, P. (2009). Diversity of {beta}-Lactamases Produced by Ceftazidime-Resistant Pseudomonas aeruginosa Isolates Causing Bloodstream Infections in Brazil. Antimicrob. Agents Chemother. 53: 3908-3913 [Abstract] [Full Text]  
  • Strateva, T., Yordanov, D. (2009). Pseudomonas aeruginosa - a phenomenon of bacterial resistance. J Med Microbiol 58: 1133-1148 [Abstract] [Full Text]  
  • Brasme, L., Nordmann, P., Fidel, F., Lartigue, M. F., Bajolet, O., Poirel, L., Forte, D., Vernet-Garnier, V., Madoux, J., Reveil, J. C., Alba-Sauviat, C., Baudinat, I., Bineau, P., Bouquigny-Saison, C., Eloy, C., Lafaurie, C., Simeon, D., Verquin, J. P., Noel, F., Strady, C., De Champs, C. (2007). Incidence of class A extended-spectrum {beta}-lactamases in Champagne-Ardenne (France): a 1 year prospective study. J Antimicrob Chemother 60: 956-964 [Abstract] [Full Text]  
  • Naas, T., Namdari, F., Reglier-Poupet, H., Poyart, C., Nordmann, P. (2007). Panresistant extended-spectrum {beta}-lactamase SHV-5-producing Acinetobacter baumannii from New York City. J Antimicrob Chemother 60: 1174-1176 [Full Text]  
  • Depardieu, F., Podglajen, I., Leclercq, R., Collatz, E., Courvalin, P. (2007). Modes and Modulations of Antibiotic Resistance Gene Expression. Clin. Microbiol. Rev. 20: 79-114 [Abstract] [Full Text]  
  • al Naiemi, N., Bart, A., de Jong, M. D., Vandenbroucke-Grauls, C. M., Rietra, P. J. G. M., Debets-Ossenkopp, Y. J., Wever, P. C., Spanjaard, L., Bos, A. J., Duim, B. (2006). Widely Distributed and Predominant CTX-M Extended-Spectrum {beta}-Lactamases in Amsterdam, The Netherlands.. J. Clin. Microbiol. 44: 3012-3014 [Abstract] [Full Text]  
  • Vedel, G. (2005). Simple method to determine {beta}-lactam resistance phenotypes in Pseudomonas aeruginosa using the disc agar diffusion test. J Antimicrob Chemother 56: 657-664 [Abstract] [Full Text]  
  • Dubois, V., Arpin, C., Noury, P., Andre, C., Coulange, L., Quentin, C. (2005). Prolonged Outbreak of Infection Due to TEM-21-Producing Strains of Pseudomonas aeruginosa and Enterobacteria in a Nursing Home. J. Clin. Microbiol. 43: 4129-4138 [Abstract] [Full Text]  
  • Poirel, L., Van De Loo, M., Mammeri, H., Nordmann, P. (2005). Association of Plasmid-Mediated Quinolone Resistance with Extended-Spectrum {beta}-Lactamase VEB-1. Antimicrob. Agents Chemother. 49: 3091-3094 [Abstract] [Full Text]  
  • Jones, L. A., McIver, C. J., Kim, M.-J., Rawlinson, W. D., White, P. A. (2005). The aadB Gene Cassette Is Associated with blaSHV Genes in Klebsiella Species Producing Extended-Spectrum {beta}-Lactamases. Antimicrob. Agents Chemother. 49: 794-797 [Abstract] [Full Text]  
  • Boyd, D. A., Tyler, S., Christianson, S., McGeer, A., Muller, M. P., Willey, B. M., Bryce, E., Gardam, M., Nordmann, P., Mulvey, M. R. (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] [Full Text]  
  • Poirel, L., Lebessi, E., Castro, M., Fevre, C., Foustoukou, M., Nordmann, P. (2004). Nosocomial Outbreak of Extended-Spectrum {beta}-Lactamase SHV-5-Producing Isolates of Pseudomonas aeruginosa in Athens, Greece. Antimicrob. Agents Chemother. 48: 2277-2279 [Abstract] [Full Text]  
  • Poirel, L., Heritier, C., Tolun, V., Nordmann, P. (2004). Emergence of Oxacillinase-Mediated Resistance to Imipenem in Klebsiella pneumoniae. Antimicrob. Agents Chemother. 48: 15-22 [Abstract] [Full Text]  
  • Poirel, L., Decousser, J.-W., Nordmann, P. (2003). Insertion Sequence ISEcp1B Is Involved in Expression and Mobilization of a blaCTX-M {beta}-Lactamase Gene. Antimicrob. Agents Chemother. 47: 2938-2945 [Abstract] [Full Text]  
  • Weldhagen, G. F., Poirel, L., Nordmann, P. (2003). Ambler Class A Extended-Spectrum {beta}-Lactamases in Pseudomonas aeruginosa: Novel Developments and Clinical Impact. Antimicrob. Agents Chemother. 47: 2385-2392 [Full Text]  
  • Bert, F., Ould-Hocine, Z., Juvin, M., Dubois, V., Loncle-Provot, V., Lefranc, V., Quentin, C., Lambert, N., Arlet, G. (2003). Evaluation of the Osiris Expert System for Identification of {beta}-Lactam Phenotypes in Isolates of Pseudomonas aeruginosa. J. Clin. Microbiol. 41: 3712-3718 [Abstract] [Full Text]  
  • Preston, K. E., Graffunder, E. M., Evans, A. M., Venezia, R. A. (2003). Survey of Plasmid-Associated Genetic Markers in Enterobacteriaceae with Reduced Susceptibilities to Cephalosporins. Antimicrob. Agents Chemother. 47: 2179-2185 [Abstract] [Full Text]  
  • Mammeri, H., Poirel, L., Mangeney, N., Nordmann, P. (2003). Chromosomal Integration of a Cephalosporinase Gene from Acinetobacter baumannii into Oligella urethralis as a Source of Acquired Resistance to {beta}-Lactams. Antimicrob. Agents Chemother. 47: 1536-1542 [Abstract] [Full Text]  
  • Naas, T., Zerbib, M., Girlich, D., Nordmann, P. (2003). Integration of a Transposon Tn1-Encoded Inhibitor-Resistant {beta}-Lactamase Gene, blaTEM-67 from Proteus mirabilis, into the Escherichia coli Chromosome. Antimicrob. Agents Chemother. 47: 19-26 [Abstract] [Full Text]  
  • Dubois, V., Arpin, C., Noury, P., Quentin, C. (2002). Clinical Strain of Pseudomonas aeruginosa Carrying a blaTEM-21 Gene Located on a Chromosomal Interrupted TnA Type Transposon. Antimicrob. Agents Chemother. 46: 3624-3626 [Abstract] [Full Text]  
  • Poirel, L., Weldhagen, G. F., De Champs, C., Nordmann, P. (2002). A nosocomial outbreak of Pseudomonas aeruginosa isolates expressing the extended-spectrum {beta}-lactamase GES-2 in South Africa. J Antimicrob Chemother 49: 561-565 [Abstract] [Full Text]  
  • Coque, T. M., Oliver, A., Perez-Diaz, J. C., Baquero, F., Canton, R. (2002). Genes Encoding TEM-4, SHV-2, and CTX-M-10 Extended-Spectrum {beta}-Lactamases Are Carried by Multiple Klebsiella pneumoniae Clones in a Single Hospital (Madrid, 1989 to 2000). Antimicrob. Agents Chemother. 46: 500-510 [Abstract] [Full Text]  
  • Kim, J., Shin, H.-S., Seol, S.-Y., Cho, D.-T. (2002). Relationship between blaSHV-12 and blaSHV-2a in Korea. J Antimicrob Chemother 49: 261-267 [Abstract] [Full Text]  
  • Chanawong, A., M'Zali, F. H., Heritage, J., Lulitanond, A., Hawkey, P. M. (2001). SHV-12, SHV-5, SHV-2a and VEB-1 extended-spectrum {beta}-lactamases in Gram-negative bacteria isolated in a university hospital in Thailand. J Antimicrob Chemother 48: 839-852 [Abstract] [Full Text]  
  • 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] [Full Text]  
  • Randegger, C. C., Hächler, H. (2001). Real-Time PCR and Melting Curve Analysis for Reliable and Rapid Detection of SHV Extended-Spectrum {beta}-Lactamases. Antimicrob. Agents Chemother. 45: 1730-1736 [Abstract] [Full Text]  
  • Poirel, L., Girlich, D., Naas, T., Nordmann, P. (2001). OXA-28, an Extended-Spectrum Variant of OXA-10 {beta}-Lactamase from Pseudomonas aeruginosa and Its Plasmid- and Integron-Located Gene. Antimicrob. Agents Chemother. 45: 447-453 [Abstract] [Full Text]  
  • Naas, T., Mikami, Y., Imai, T., Poirel, L., Nordmann, P. (2001). Characterization of In53, a Class 1 Plasmid- and Composite Transposon-Located Integron of Escherichia coli Which Carries an Unusual Array of Gene Cassettes. J. Bacteriol. 183: 235-249 [Abstract] [Full Text]  
  • Girlich, D., Naas, T., Bellais, S., Poirel, L., Karim, A., Nordmann, P. (2000). Biochemical-Genetic Characterization and Regulation of Expression of an ACC-1-Like Chromosome-Borne Cephalosporinase from Hafnia alvei. Antimicrob. Agents Chemother. 44: 1470-1478 [Abstract] [Full Text]  
  • Tzelepi, E., Giakkoupi, P., Sofianou, D., Loukova, V., Kemeroglou, A., Tsakris, A. (2000). Detection of Extended-Spectrum beta -Lactamases in Clinical Isolates of Enterobacter cloacae and Enterobacter aerogenes. J. Clin. Microbiol. 38: 542-546 [Abstract] [Full Text]  
  • Mimoz, O., Elhelali, N., Leotard, S., Jacolot, A., Laurent, F., Samii, K., Petitjean, O., Nordmann, P. (1999). Treatment of experimental pneumonia in rats caused by a PER-1 extended-spectrum {beta}-lactamase-producing strain of Pseudomonas aeruginosa. J Antimicrob Chemother 44: 91-97 [Abstract] [Full Text]  

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
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 Naas, T.
Right arrow Articles by Nordmann, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Naas, T.
Right arrow Articles by Nordmann, P.

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