Previous Article | Next Article 
Journal of Clinical Microbiology, July 1999, p. 2165-2169, Vol. 37, No. 7
Enveloppe Bactérienne, Antibiotiques et
Colonisation, CJF 96-06 INSERM, Faculté de Médecine,
Université de la Mediterranée, 13385 Marseille Cedex 05, France
Received 12 October 1998/Returned for modification 5 January
1999/Accepted 25 March 1999
The aim of this study was to determine the distribution in France
of the Enterobacter aerogenes prevalent clone isolated in the hospitals of the Marseille area (A. Davin-Regli, D. Monnet, P. Saux, C. Bosi, R. Charrel, A. Barthelemy, and C. Bollet, J. Clin.
Microbiol. 34:1474-1480, 1996). A total of 123 E. aerogenes isolates were collected from 23 hospital laboratories
and analyzed by random amplification of polymorphic DNA and
enterobacterial repetitive intergenic consensus-PCR to determine their
epidemiological relatedness. Molecular typing revealed that 21 of the
23 laboratories had isolated this prevalent clone harboring the plasmid
encoding for extended-spectrum Before 1993, Enterobacter
aerogenes was rarely encountered in French hospitals. Since 1995 there have been many reports of its presence both in France (i.e.,
Bordeaux [2], Dijon [23], Clermont-Ferrand [10, 17], Limoges
[26], St. Etienne [14], and
Strasbourg [21]) and elsewhere, including Belgium
(11, 15), Austria (1), and the United States
(13, 25). The first clinical cases described in Marseille
hospitals concerned patients in intensive care units (ICUs). In fact,
the emergence of this species is associated with medical devices, the
widespread administration of antibiotics, and immunodepression of
patients (4, 8, 9). Nosocomial infections now concern other
medical units (11, 15).
Today, E. aerogenes is the third-most-common pathogen
recovered from the respiratory tract in Marseille hospitals and is
often isolated in urine and the gastrointestinal tract, as in other countries (16, 29). The dramatic emergence of this pathogen is associated mainly with use of broad-spectrum cephalosporins and
quinolones (8, 11, 25). The first outbreaks were caused by
isolates presenting an extended-spectrum In epidemiology, it is generally agreed that strains indistinguishable
by typing scheme and sharing characteristics that can distinguish them
from epidemiologically unrelated strains constitute an epidemiological
cluster named clone, which arises from a common precursor
(27). We had demonstrated by PCR-typing methods that between
1994 and 1995 in the Marseille area hospitals 50% of the E. aerogenes infections or colonizations were due to isolates of the
same epidemiological type (8). This prevalent type, herein
called clone, was highly resistant to antibiotics except gentamicin,
imipenem, and the latest cephalosporins, such as cefepime and cefpirome.
The aim of this study was to establish the prevalence of the clone in
France. A representative selection of E. aerogenes isolates sent from 23 French hospital laboratories was analyzed by random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). The relationship between the
prevalence of this clone and multidrug resistance was illustrated by
determination of the TEM Characteristics of clinical isolates.
From August 1996 to
January 1997, 123 clinical E. aerogenes isolates were
collected from infected or colonized patients in 23 hospitals in France
(Table 1). These isolates were obtained from bronchial secretions, urine samples, closed cavity drainage fluids, catheters, blood cultures, and wound swabs. Each isolate corresponded to a single patient. All isolates were identified and
confirmed to be E. aerogenes by the API 20E identification system (bioMérieux, Marcy l'Etoile, France) according to the manufacturer's instructions. Most of them were selected by the laboratories for their marked resistance against the usual antibiotics. Susceptibility to 18 to 35 antimicrobial agents and combinations of
agents was determined by the standard disk diffusion method (22) in some laboratories or by the Walkaway 40 System
(Sanofi-Diagnostics Pasteur, Marnes-la-Coquette, France) in others.
These agents and associations were amoxicillin,
amoxicillin-clavulanate, ticarcillin, ticarcillin-clavulanate,
mezlocillin, piperacillin, cephalothin, cefamandole, cefoxitin,
cefotetan, cefotiam, cefsulodin, moxalactam, cefotaxime, ceftazidime,
ceftazidime-sulbactam, ceftriaxone, cefoperazone, cefmenoxime,
cefepime, cefpirome, imipenem, meropenem, aztreonam, gentamicin,
tobramycin, kanamycin, amikacin, chloramphenicol, trimethoprim-sulfamethoxazole, fosfomycin, colistin, pefloxacin, ofloxacin, and ciprofloxacin. The presence of ESBL activity was confirmed with the double-disk diffusion test, in which disks containing cefepime, cefotaxime, ceftazidime, or ceftriaxone were placed near a disk containing a
0095-1137/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Most Enterobacter aerogenes Strains in
France Belong to a Prevalent Clone
ABSTRACT
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
-lactamase of the TEM-24 type. Most
isolates were susceptible only to imipenem and gentamicin. Their
dissemination seems to be clonal and was probably the result of the
general use of broad-spectrum cephalosporins and quinolones. Four
isolates showed an alteration of their outer membrane proteins, causing decrease of susceptibility to third-generation cephalosporins and
imipenem and leading to the critical situation of having no alternative
therapeutic. The large dissemination of the E. aerogenes prevalent clone probably results from its good adaptation to the antibiotics administered in France and the hospital environment, particularly in intensive care units.
INTRODUCTION
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
-lactamase (ESBL) (9,
13). Today, most isolates involved in nosocomial infections are
resistant to multiple antibiotics because they have a chromosomally derepressed cephalosporinase and an ESBL (2, 8, 11, 23). In
addition, in some isolates, alteration of the membrane protein composition has led to resistance through impermeability or efflux associated with enzymatic resistance, resulting in multidrug resistance and no availability of an alternative antibiotic (5, 10, 11, 19,
24, 30).
-lactamase gene sequences and observation of envelope porin expression.
MATERIALS AND METHODS
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
-lactamase inhibitor (sodium clavulanate) under the conditions described above (9). If an ESBL was present in the organisms, the zones of inhibition around the
cephalosporin disks were enhanced between each cephalosporin disk and
the clavulanic acid disk. The clinical isolates were divided into two
antibiotic resistance phenotypes: the presence of a derepressed
cephalosporinase alone or one associated with an ESBL.
TABLE 1.
Characteristics of the 123 E. aerogenes
isolates recovered from 23 hospital centers in France
Epidemiologic typing. The isolates were investigated by using RAPD with primer AP12H (5'-CGGCCCCTGT-3') and ERIC-PCR with primer ERIC2 (5'-AAGTAAGTGACTGGGGTGAGCG-3') as described previously (8, 9, 13, 31).
(i) DNA preparation. Isolates were grown overnight at 37°C on Mueller-Hinton agar (bioMérieux). Total cellular DNA was extracted by the Chelex technique (12), and DNA concentrations were estimated on agarose gels (28).
(ii) Amplification conditions. Amplification reactions were performed in a total volume of 47 µl containing 100 µM dATP, 100 µM dCTP, 100 µM dGTP, and 100 µM dTTP, plus 0.2 µM primer, 25 ng of template DNA, and 1.25 U of Taq polymerase (Perkin-Elmer/Cetus, Norwalk, Conn.) in 1× PCR buffer (20 mM Tris-HCl, pH 8.3; 50 mM KCl; 3 mM MgCl2; 0.001% gelatin [wt/vol]). A negative control without template DNA was included in each experiment. The reaction mixtures were overlaid with mineral oil and subjected to amplification in a GenAmp PCR System 9600 (Perkin-Elmer/Cetus) programmed for 45 cycles of 1 min at 94°C, 1 min at 45°C, and 1 min at 74°C. Amplification products (10-µl samples) were electrophoresed in 1.2% agarose gels in Tris-acetate buffer (0.04 M Tris-acetate, 0.001 M EDTA; pH 8.2), stained with ethidium bromide, and photographed on a UV light transilluminator. A molecular weight standard (Marker VI; Boehringer-Mannheim, Mannheim, Germany) was included on each gel. We interpreted and compared the patterns without considering the origin of the isolates. Heterogeneity with respect to the intensity and shape of bands was not considered to be a difference. Interpretation of differences was based on guidelines proposed with fingerprints generated by pulsed-field gel electrophoresis. One band difference is likely to arise as a result of one genetic event, and such isolates can be considered very similar; two to three band differences can arise by two genetic events, and the organism is not similar but may be related, and so on. Four or more band differences are definite evidence of a completely unrelated strain. Thus, according to the total number of bands generated, isolates were considered different if their profiles differed by two or more bands (8, 27, 32).
(iii) Reproducibility. For the two PCR-based techniques, reproducibility was determined by testing independent DNA preparations extracted from single-colony cultures at different times and amplified separately.
TEM -lactamase identification. (i) PCR amplification.
PCR
amplifications were performed as described previously (18).
Amplification was achieved with an initial cycle of 5 min of
denaturation at 95°C, followed by 30 cycles of 0.5 min at 94°C, 0.5 min at 55°C, and 0.5 min at 74°C. The primers were 5'-GAC AGT TAC
CAA TGC TTA ATC A-3' and 5'-TTG GGT GCA CGA GTG GGT TA-3'.
(ii) DNA sequencing. DNA sequencing was carried out by cycle sequencing with fluorescently labeled dideoxynucleotide terminators (Applied Biosystems, Inc., Norwalk, Conn.). The sequencing reactions were analyzed with a 377 automated DNA sequencer (Applied Biosystems, Inc.).
(iii) Sequence analysis. Amino acid sequences were determined with Translate Tool on the ExPASy worldwide web molecular biology server of the Swiss Institute of Bioinfamatics (12a). Sequences were analyzed by using the table published by G. Jacoby and K. Bush on the worldwide web server of the Lahey Clinic (14a).
SDS-polyacrylamide gel electrophoresis and immunodetection of porins. Porins were immunodetected on the E. aerogenes isolates presenting a multiresistant phenotype. Exponential bacterial cells grown in Luria-Bertani broth were collected. Bacterial cell pellets were solubilized in loading buffer at 96°C, and samples were loaded onto sodium dodecyl sulfate (SDS)-polyacrylamide gels (10% polyacrylamide, 0.1% SDS) as previously described (3). Electrotransfer to nitrocellulose membranes was performed in the presence of 0.05% SDS to achieve complete transfer of the porins. An initial saturating step with Tris-buffered saline (TBS) (50 mM Tris-HCl, 150 mM NaCl; pH 8) containing 10% bovine serum was carried out overnight at 4°C. The nitrocellulose membranes were then incubated in TBS containing 10% bovine serum and 0.2% Triton X-100 for 2 h at room temperature with polyclonal antibodies directed against denatured Escherichia coli porins (OmpF and OmpC). Polyclonal antibodies directed against the E. coli porins were able to recognize the E. aerogenes porins as reported previously (20). After successive washings in the same buffer, the porins were detected with alkaline phosphatase-conjugated affinitiPure goat anti-rabit immunoglobulin G antibodies (Jackson ImmunoResearch, West Grove, Pa.). The polyclonal antibodies directed against porin monomers OmpF and OmpC have been described elsewhere (19).
| |
RESULTS |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
Antibiotic susceptibility. Among the 123 E. aerogenes isolates, 95 were susceptible only to cefepime, imipenem, or gentamicin as observed in clonal isolates (Table 1). In 11 of the 23 hospitals such a phenotype was shown by 100% of the isolates selected (Aubagne, Besançon, Toulouse, etc.). However, in eight other hospitals, 15 to 80% of the isolates were multiresistant. In four hospitals (Lyon, Metz, Narbonne, and St. Etienne), most of the isolates presented a different antibiotic resistance phenotype.
Concerning the 28 other E. aerogenes isolates, their antibiotypes had characteristics suggesting the presence of a derepressed cephalosporinase (i.e., resistance to cephamycins), but they were devoid of ESBL (i.e., they were susceptible to ceftazidime and aminosides).Epidemiologic typing. All E. aerogenes isolates were typable by RAPD and ERIC-PCR. The results obtained with the two techniques were concordant. With the RAPD methods, variations of intensity of PCR products were observed with faint bands, but they were not considered to be a difference. Figure 1 shows profiles corresponding to 40 E. aerogenes isolates from eight hospital laboratories. Among the 123 isolates, 79 presented a single type identical to the prevalent clone previously observed in the Marseille area. Figure 2 shows the distribution of the clone in each hospital. The clone was recovered in all hospitals except two (Brest and Narbonne) (Table 1). In most cases, the clone represented the majority of the isolates selected by each laboratory. Among the 79 E. aerogenes isolates belonging to the prevalent clone, 77 presented a multiresistant antibiotype and 2 (Le Mans and Nîmes) presented a phenotype corresponding to a derepressed cephalosporinase alone.
|
|
represents
porin-deficient phenotype.
-Lactamase identification.
Among the 95 E. aerogenes isolates with a phenotypic resistant profile, analysis
of the ESBL by sequencing demonstrated a TEM-24 type.
Immunodetection of outer membrane porins. Immunological probes were used to investigate the porin content in clinical isolates and to evaluate the frequency of modification of envelope protein content in a representative population of E. aerogenes isolates. Of the 95 multiresistant isolates, 4 showed a negative response with the immunological probes directed against the unspecific enterobacterial porins, reflecting a porin-deficient phenotype (Fig. 3). Two of these porin-free strains were resistant, and the two others had intermediate resistance to imipenem.
|
| |
DISCUSSION |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
An overview of most recent studies suggest that the epidemiology of E. aerogenes is characterized by the spread of a single clone through the medical units of a hospital (2, 8, 21, 23, 26); in some cases the clone has the imipenem/gentamicin-susceptible phenotype (2, 11, 21). In Belgium, E. aerogenes is responsible for 13% of the nosocomial infections, essentially in the south of the country. In 1995, two epidemiologically distinct studies using ERIC-PCR and PFGE demonstrated the existence of a multidrug resistant clone (11, 15). Isolates presented an ESBL, associated or not with a chromosomally derepressed cephalosporinase and able to resist quinolones in 80 to 100% of cases. Moreover, De Gheldre et al. observed the selection of strains resistant to imipenem and cefepime after the use of imipenem in therapy (11). The same observation was made in 1994 in a Greek hospital (30). In Austria, it has been shown by PFGE, rep-PCR, and RAPD that, during a septicemia outbreak for a 3-month period in an ICU, multidrug-resistant isolates harbored the imipenem/amikacin-sensitive phenotype (1). In the United States, Georgiou et al. studied an outbreak of E. aerogenes which occurred in 1991 in Houston, Tex., and which was due to two clusters of epidemiologically related isolates (13). Most of them (80%) presented an ESBL, and 20% were resistant to fluoroquinolones. However, in 1995 D'Agata et al. observed 11 E. aerogenes isolates in Boston, Mass., that were epidemiologically distinct as shown by PFGE but were resistant to ceftazidime, probably by expression of an ESBL (6). The epidemiology of E. aerogenes in Belgium seems similar to the situation in France. Since molecular typing of such epidemiologically related isolates was not carried out with the same molecular techniques or the same technical conditions as in the present study, the results of these other studies cannot be compared and so relationships between the different clones cannot be determined. However, some E. aerogenes isolates from previous studies may in part correspond to the prevalent clone.
It is difficult to evaluate how patients are colonized by this E. aerogenes prevalent clone. Usually, E. aerogenes is rarely found in the hospital environment. E. aerogenes could be recovered from material in direct contact with patients colonized (e.g., tubings of mechanical ventilators, and water from humidifiers) and occasionally from room surfaces and the hands of health care personnel (8, 11, 15). Also, in many cases patients have no direct contact with other infected patients. Furthermore, patients may already be colonized when they are admitted to hospitals. In France, most patients hospitalized in ICUs are discharged to a general acute care unit and then go to a rest home, a nursing home, or a retirement home. Some of them are still colonized by E. aerogenes, particularly in the urinary tract. Residence of such patients in these care centers, where the nursing personnel are not prepared to face nosocomial bacterial contaminations, favors extra hospital E. aerogenes propagation. This in part accounts for the colonization by multidrug-resistant E. aerogenes in patients coming from these care centers at the time of their first admission at hospital.
The E. aerogenes prevalent clone was multiresistant because it had a plasmid carrying ESBL of the TEM-24 type associated with a chromosomally encoded derepressed cephalosporinase. This multiresistance facilitated the spread of the species in the 21 hospitals. However, two of the prevalent clone isolates were devoid of ESBL, possibly because they had lost their plasmid. In vivo, plasmids can be lost over time, but the phenomenon minimally influence RAPD and ERIC-PCR profiles (27). The prevalent E. aerogenes clone was isolated in all but two hospitals. Selective pressure due to broad-spectrum antibiotic use in hospitals favors colonization of patients by the most resistant nosocomial bacterial species and the spread of such bacteria to all hospital units. However, it is probable that other selective factors are responsible for the exceptional adaptation of the E. aerogenes clone to the hospital environment. Effectively, some multiresistant E. aerogenes strains with different profiles as shown by PCR-typing methods that are isolated in a given hospital were not found elsewhere or showed only limited spread. These isolates apparently did not have the phenotypic or genotypic capacity or the geographic dissemination displayed by the prevalent type.
Moreover, excessive prescription in the community and in the hospital of third-generation cephalosporins or quinolones in monotherapy has made the Enterobacteriaceae strains multidrug resistant in many countries. In multidrug resistant E. aerogenes isolates, resistance to quinolones correlated with the presence of the ESBL of the TEM-24 type even in patients recently hospitalized. For 5 years now, widespread antibiotherapy misuse in France has led to the emergence of multiresistant Enterobacter isolates. This is exemplified by the appearance in 1996 of nosocomial cases of Enterobacter hormaechei infections subsequent to the emergence of a clone that was highly resistant to quinolones. The appearance of the species in patients was always correlated with the use of new quinolones (7).
It is alarming to observe that the emergence of E. aerogenes
isolates with a decreased susceptibility to imipenem is now more frequent; they represented 4 to 5% of all of the E. aerogenes studied in our laboratory (3). Arpin et
al. reported that 4.6% of their E. aerogenes isolates were
resistant to imipenem (2). We found that four E. aerogenes isolates presenting such a phenotype exhibited an
alteration of their porin content. This may be another resistance
mechanism used by the bacteria. The incidence of such mechanisms in
E. aerogenes will probably increase with the use of imipenem
in isolates presenting the imipenem/gentamicin-sensitive phenotype. It seems evident that E. aerogenes is capable to
perfectly adapt itself to antibiotic pressure. Mallea et al. have
recently described clinical E. aerogenes isolates presenting
a complex resistance strategy associating -lactamase production,
impermeability, and active efflux (19). The emergence of
imipenem resistance is a crucial problem because there are no
antibiotherapy possibilities available for such strains expressing a
multidrug-resistant phenotype. In every case the survival of patients
is seriously impaired.
In conclusion, there is currently in France a hospital pandemic due to a multidrug-resistant E. aerogenes clone particularly well adapted to the hospital environment. Modification of antibiotic use and bacterial monitoring of the hospital ecology and of the patients near the end of their hospitalization seem to be the most important means to stop this development.
| |
ACKNOWLEDGMENTS |
|---|
We thank the following for providing strains (locations in France are given parenthetically: Y. Assadourian and J. M. Schneider (Aubagne and La Ciotat); F. Barbut (Paris); C. Bebear and A. Allery (Bordeaux); B. Carbonnelle and C. Lemarie (Angers); G. Chabanon and D. Clave (Toulouse); M. Dailloux and A. Lozniewski (Nancy); J. M. Delarbre and M. F. Penner (Mulhouse); F. Denis and M. C. Ploy (Limoges); P. Y. Donnio (Rennes); F. Eb (Amiens); J. Freney, J. Etienne, and P. Girardo (Lyon); F. Geffroy (Quimper); A. Gouby (Nîmes); F. Grattard (St. Etienne); B. Joly (Clermont-Ferrand); D. Lamarca and L. Bertran (Narbonne); A. Marmonier (Le Mans); C. Perez (Montpellier); B. Picard and D. Tande (Brest); Y. Piemont (Strasbourg); C. Plesiat and Y. Michel-Briand (Besançon); P. Roos (Metz); and M. Simonet (Lille). We acknowledge A. Abeille for technical assistance.
This work was supported by Assistance Publique à Marseille (Recherche Clinique) in 1997.
| |
FOOTNOTES |
|---|
* Corresponding author. Mailing address: CJF 96-06 INSERM, Faculté de Médecine, 27 Blvd. Jean Moulin, 13385 Marseille Cedex 05, France. Phone: (33) 4-91-32-45-29. Fax: (33) 4-91-32-46-06. E-mail: cbollet{at}ap-hm.fr.
| |
REFERENCES |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
| 1. | Allerberguer, F., T. Koeuth, C. Lass-Florl, M. P. Dierich, C. Putensen, E. Scmutzhard, I. Mohsenipour, H. Grundmann, D. Hartung, A. Bauernfeind, E. Eberlein, and J. R. Lupski. 1996. Epidemiology of infections due to multiresistant Enterobacter aerogenes in a university hospital. Eur. J. Clin. Microbiol. Infect. Dis. 15:517-521[Medline]. |
| 2. | Arpin, C., C. Coze, A. M. Rogues, J. P. Gachie, C. Bebear, and C. Quentin. 1996. Epidemiological study of an outbreak due to multidrug-resistant Enterobacter aerogenes in a medical intensive care unit. J. Clin. Microbiol. 34:2163-2169[Abstract]. |
| 3. |
Charrel, R. N.,
J.-M. Pagès,
P. De Micco, and M. Mallea.
1996.
Prevalence of outer membrane porin alteration in -lactam antibiotic-resistant Enterobacter aerogenes.
Antimicrob. Agents Chemother.
40:2854-2858[Abstract].
|
| 4. | Chow, J. W., V. L. Yu, and D. M. Shlaes. 1994. Epidemiologic perspectives on Enterobacter for the infection control professional. Am. J. Infect. Control 22:195-201[Medline]. |
| 5. |
Chow, J. W., and D. M. Shlaes.
1991.
Imipenem resistance associated with the loss of a 40-kDa outer membrane protein of Enterobacter aerogenes.
J. Antimicrob. Chemother.
28:499-504 |
| 6. | D'Agata, E., L. Venkataraman, P. DeGirolami, and M. Samore. 1997. Molecular epidemiology of acquisition of ceftazidime-resistant gram-negative bacilli in a nonoutbreak setting. J. Clin. Microbiol. 35:2602-2605[Abstract]. |
| 7. | Davin-Regli, A., C. Bosi, R. N. Charrel, E. Ageron, L. Papazian, P. A. D. Grimont, A. Cremieux, and C. Bollet. 1997. A nosocomial outbreak due to Enterobacter cloacae strains with the E. hormaechei genotype in patients treated with fluoroquinolones. J. Clin. Microbiol. 35:1008-1010[Abstract]. |
| 8. | Davin-Regli, A., D. Monnet, P. Saux, C. Bosi, R. Charrel, A. Barthelemy, and C. Bollet. 1996. Molecular epidemiology of Enterobacter aerogenes acquisition: one-year prospective study in two intensive care units. J. Clin. Microbiol. 34:1474-1480[Abstract]. |
| 9. |
Davin-Regli, A.,
P. Saux,
C. Bollet,
F. Gouin, and P. de Micco.
1995.
Investigation of a series of outbreaks of Enterobacter aerogenes in an intensive care unit by random amplification polymorphic DNA.
J. Med. Microbiol.
44:89-98 |
| 10. |
De Champs, C.,
C. Henquell,
D. Guelon,
D. Sirot,
N. Gazuy, and J. Sirot.
1993.
Clinical and bacteriological study of nosocomial infections due to Enterobacter aerogenes resistant to imipenem.
J. Clin. Microbiol.
31:123-127 |
| 11. | De Gheldre, Y., N. Maes, F. Rost, R. De Ryck, P. Clevenbergh, J. L. Vincent, and M. J. Struelens. 1997. Molecular epidemiology of an outbreak of multidrug-resistant Enterobacter aerogenes infections and in vivo emergence of imipenem resistance. J. Clin. Microbiol. 35:152-160[Abstract]. |
| 12. | De Lamballerie, X., C. Zandotti, C. Vignoli, C. Bollet, and P. de Micco. 1992. A one-step microbial DNA extraction method using Chelex 100 suitable for gene amplification. Res. Microbiol. 143:785-790[Medline]. |
| 12a. | ExPASy server. 5 January 1999, revision date. Translate tool. [Online.] http://www.expasy.ch/tools/dna.html. [27 April 1999, last date accessed.] |
| 13. | Georghiou, P. R., R. J. Hamill, C. E. Wright, J. Versalovic, T. Koeuth, D. A. Watson, and J. R. Lupski. 1995. Molecular epidemiology of infections due to Enterobacter aerogenes: identification of hospital outbreak-associated strains by molecular techniques. Clin. Infect. Dis. 20:84-94[Medline]. |
| 14. | Grattard, F., B. Pozetto, L. Tabard, M. Petit, A. Ros, and O. G. Gaudin. 1995. Characterization of nosocomial strains of Enterobacter aerogenes by arbitrarily primed PCR analysis and ribotyping. Infect. Control Hosp. Epidemiol. 16:224-230[Medline]. |
| 14a. | Jacoby, G., and K. Bush. 8 March 1999, revision date. Table. [Online.] http://www.lahey.org/studies/webt.htm. [27 April 1999, last date accessed.] |
| 15. |
Jalaluddin, S.,
J.-M. Devaster,
R. Scheen,
M. Gerard, and J.-P. Butzler.
1998.
Molecular epidemiological study of nosocomial Enterobacter aerogenes isolates in a Belgian hospital.
J. Clin. Microbiol.
36:1846-1852 |
| 16. |
Jarvis, W. R., and W. J. Martone.
1992.
Predominant pathogens in hospital infections.
J. Antimicrob. Chemother.
29(Suppl. A):19-24 |
| 17. | Livrelli, V., C. De Champs, P. Di Martino, A. Darfeuille-Michaud, C. Forestier, and B. Joly. 1996. Adhesive properties and antibiotic resistance of Klebsiella, Enterobacter, and Serratia clinical isolates involved in nosocomial infections. J. Clin. Microbiol. 34:1963-1969[Abstract]. |
| 18. |
Mabilat, C., and S. Goussard.
1994.
PCR detection and identification of genes for extended-spectrum -lactamases, p. 553-559.
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.
|
| 19. |
Mallea, M.,
J. Chevalier,
C. Bornet,
A. Eyraud,
A. Davin-Regli,
C. Bollet, and J. M. Pagès.
1998.
Porin alteration and active efflux: two in vivo drug resistance strategies used by Enterobacter aerogenes.
Microbiology
144:3003-3009 |
| 20. | Mallea, M., V. Simonet, L. Eun-Hee, E. Collatz, R. Gervier, L. Gutmann, and J. M. Pagès. 1995. Biological and immunological comparisons of Enterobacter cloacae and Escherichia coli porins. FEMS Microbiol. Lett. 129:273-280[Medline]. |
| 21. | Meunier, O., P. Stoessel, P. Saint-Laurent, P. Lutun, F. Jehl, J. M. Scheftel, H. Monteil, J. D. Tempé, and M. Bientz. 1997. Rôle des laboratories d'hygiène et de bactériologie dans la prise en charge d'une épidémie à Enterobacter aerogenes multirésistant aux antibiotiques. Ann. Biol. Clin. 55:129-137. |
| 22. | National Committee for Clinical Laboratory Standards. 1997. Performance standards for antimicrobial disk susceptibility testing, 6th ed. M2A6. National Committee for Clinical Laboratory Standards, Wayne, Pa. |
| 23. |
Neuwirth, C.,
E. Siebor,
J. Lopez,
A. Pechinot, and A. Kazmierczak.
1996.
Outbreak of TEM-24-producing Enterobacter aerogenes in an intensive care unit and dissemination of the extended-spectrum -lactamase to other members of the family Enterobacteriaceae.
J. Clin. Microbiol.
34:76-79[Abstract].
|
| 24. |
Nikaido, H.
1994.
Prevention of drug access to bacterial targets: permeability barriers and active efflux.
Science
264:382-388 |
| 25. |
Pitout, J. D. D.,
K. S. Thomson,
N. D. Hanson,
A. F. Ehrhardt,
P. Coudron, and C. C. Sanders.
1998.
Plasmid-mediated resistance to expanded-spectrum cephalosporins among Enterobacter aerogenes strains.
Antimicrob. Agents Chemother.
42:596-600 |
| 26. | Ploy, M. C., C. Grelaud, C. Martin, and F. Denis. 1997. Emergence of Enterobacter aerogenes strains producing derepressed cephalosporinase at CHU in Limoges: molecular epidemiology by the RAPD technique. Pathol. Biol. (Paris) 45:404-408[Medline]. |
| 27. | Power, E. G. M. 1996. RAPD typing in microbiology. A technical review. J. Hosp. Infect. 34:247-265[Medline]. |
| 28. | Sambrook, J., E. F. Fritsch, and T. Maniatis. 1989. Quantification of DNA and RNA: appendix E.5. In Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. |
| 29. | Schaberg, D. R., D. H. Culver, and R. P. Gaynes. 1991. Major trends in the microbial etiology of nosocomial infection. Am. J. Med. 91(Suppl. 3B):72S-75S[Medline]. |
| 30. |
Tzouvelekis, L. S.,
E. Tzelepi,
M. E. Kaufmann, and A. F. Mentis.
1994.
Consecutive mutations leading to the emergence in vivo of imipenem resistance in a clinical strain of Enterobacter aerogenes.
J. Med. Microbiol.
40:403-407 |
| 31. |
Versalovic, J.,
T. Koeuth, and J. R. Lupski.
1991.
Distribution of repetitive DNA sequences in eubacteria and application to fingerprinting of bacterial genomes.
Nucleic Acids Res.
19:6823-6831 |
| 32. |
Woods, C. R., Jr.,
J. Versalovic,
T. Koeuth, and J. R. Lupski.
1992.
Analysis of relationships among isolates of Citrobacter diversus by using DNA fingerprints generated by repetitive sequence-based primers in the polymerase chain reaction.
J. Clin. Microbiol.
30:2921-2929 |
Journal of Clinical Microbiology, July 1999, p. 2165-2169, Vol. 37, No. 7
0095-1137/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Biendo, M., Canarelli, B., Thomas, D., Rousseau, F., Hamdad, F., Adjide, C., Laurans, G., Eb, F.
(2008). Successive Emergence of Extended-Spectrum {beta}-Lactamase-Producing and Carbapenemase-Producing Enterobacter aerogenes Isolates in a University Hospital. J. Clin. Microbiol.
46: 1037-1044
[Abstract] [Full Text] -
Dupont, M., James, C. E., Chevalier, J., Pages, J.-M.
(2007). An Early Response to Environmental Stress Involves Regulation of OmpX and OmpF, Two Enterobacterial Outer Membrane Pore-Forming Proteins. Antimicrob. Agents Chemother.
51: 3190-3198
[Abstract] [Full Text] -
Masi, M., Pages, J.-M., Pradel, E.
(2006). Production of the cryptic EefABC efflux pump in Enterobacter aerogenes chloramphenicol-resistant mutants. J Antimicrob Chemother
57: 1223-1226
[Abstract] [Full Text] -
Paterson, D. L., Bonomo, R. A.
(2005). Extended-Spectrum {beta}-Lactamases: a Clinical Update. Clin. Microbiol. Rev.
18: 657-686
[Abstract] [Full Text] -
Arpin, C., Dubois, V., Maugein, J., Jullin, J., Dutilh, B., Brochet, J.-P., Larribet, G., Fischer, I., Quentin, C.
(2005). Clinical and Molecular Analysis of Extended-Spectrum {beta}-Lactamase-Producing Enterobacteria in the Community Setting. J. Clin. Microbiol.
43: 5048-5054
[Abstract] [Full Text] -
Masi, M., Pages, J.-M., Villard, C., Pradel, E.
(2005). The eefABC Multidrug Efflux Pump Operon Is Repressed by H-NS in Enterobacter aerogenes. J. Bacteriol.
187: 3894-3897
[Abstract] [Full Text] -
Thiolas, A., Bollet, C., La Scola, B., Raoult, D., Pages, J.-M.
(2005). Successive Emergence of Enterobacter aerogenes Strains Resistant to Imipenem and Colistin in a Patient. Antimicrob. Agents Chemother.
49: 1354-1358
[Abstract] [Full Text] -
Poirel, L., Mammeri, H., Nordmann, P.
(2004). TEM-121, a Novel Complex Mutant of TEM-Type {beta}-Lactamase from Enterobacter aerogenes. Antimicrob. Agents Chemother.
48: 4528-4531
[Abstract] [Full Text] -
Literacka, E., Empel, J., Baraniak, A., Sadowy, E., Hryniewicz, W., Gniadkowski, M.
(2004). Four Variants of the Citrobacter freundii AmpC-Type Cephalosporinases, Including Novel Enzymes CMY-14 and CMY-15, in a Proteus mirabilis Clone Widespread in Poland. Antimicrob. Agents Chemother.
48: 4136-4143
[Abstract] [Full Text] -
Lavigne, J.-P., Bouziges, N., Chanal, C., Mahamat, A., Michaux-Charachon, S., Sotto, A.
(2004). Molecular Epidemiology of Enterobacteriaceae Isolates Producing Extended-Spectrum {beta}-Lactamases in a French Hospital. J. Clin. Microbiol.
42: 3805-3808
[Abstract] [Full Text] -
Chollet, R., Chevalier, J., Bollet, C., Pages, J.-M., Davin-Regli, A.
(2004). RamA Is an Alternate Activator of the Multidrug Resistance Cascade in Enterobacter aerogenes. Antimicrob. Agents Chemother.
48: 2518-2523
[Abstract] [Full Text] -
Bornet, C., Saint, N., Fetnaci, L., Dupont, M., Davin-Regli, A., Bollet, C., Pages, J.-M.
(2004). Omp35, a New Enterobacter aerogenes Porin Involved in Selective Susceptibility to Cephalosporins. Antimicrob. Agents Chemother.
48: 2153-2158
[Abstract] [Full Text] -
Barnaud, G., Benzerara, Y., Gravisse, J., Raskine, L., Sanson-Le Pors, M. J., Labia, R., Arlet, G.
(2004). Selection during Cefepime Treatment of a New Cephalosporinase Variant with Extended-Spectrum Resistance to Cefepime in an Enterobacter aerogenes Clinical Isolate. Antimicrob. Agents Chemother.
48: 1040-1042
[Abstract] [Full Text] -
Bell, J. M., Turnidge, J. D., Jones, R. N., the SENTRY Asia-Pacific Participants,,
(2003). Prevalence of Extended-Spectrum {beta}-Lactamase-Producing Enterobacter cloacae in the Asia-Pacific Region: Results from the SENTRY Antimicrobial Surveillance Program, 1998 to 2001. Antimicrob. Agents Chemother.
47: 3989-3993
[Abstract] [Full Text] -
Marchandin, H., Godreuil, S., Darbas, H., Jean-Pierre, H., Jumas-Bilak, E., Chanal, C., Bonnet, R.
(2003). Extended-Spectrum {beta}-Lactamase TEM-24 in an Aeromonas Clinical Strain: Acquisition from the Prevalent Enterobacter aerogenes Clone in France. Antimicrob. Agents Chemother.
47: 3994-3995
[Full Text] -
Arpin, C., Dubois, V., Coulange, L., Andre, C., Fischer, I., Noury, P., Grobost, F., Brochet, J.-P., Jullin, J., Dutilh, B., Larribet, G., Lagrange, I., Quentin, C.
(2003). Extended-Spectrum {beta}-Lactamase-Producing Enterobacteriaceae in Community and Private Health Care Centers. Antimicrob. Agents Chemother.
47: 3506-3514
[Abstract] [Full Text] -
De Gheldre, Y., Avesani, V., Berhin, C., Delmee, M., Glupczynski, Y.
(2003). Evaluation of Oxoid combination discs for detection of extended-spectrum {beta}-lactamases. J Antimicrob Chemother
52: 591-597
[Abstract] [Full Text] -
Pradel, E., Pages, J.-M.
(2002). The AcrAB-TolC Efflux Pump Contributes to Multidrug Resistance in the Nosocomial Pathogen Enterobacter aerogenes. Antimicrob. Agents Chemother.
46: 2640-2643
[Abstract] [Full Text] -
Chollet, R., Bollet, C., Chevalier, J., Mallea, M., Pages, J.-M., Davin-Regli, A.
(2002). mar Operon Involved in Multidrug Resistance of Enterobacter aerogenes. Antimicrob. Agents Chemother.
46: 1093-1097
[Abstract] [Full Text] -
Dumarche, P., De Champs, C., Sirot, D., Chanal, C., Bonnet, R., Sirot, J.
(2002). TEM Derivative-Producing Enterobacter aerogenes Strains: Dissemination of a Prevalent Clone. Antimicrob. Agents Chemother.
46: 1128-1131
[Abstract] [Full Text] -
Canton, R., Oliver, A., Coque, T. M., Varela, M. d. C., Perez-Diaz, J. C., Baquero, F.
(2002). Epidemiology of Extended-Spectrum {beta}-Lactamase-Producing Enterobacter Isolates in a Spanish Hospital during a 12-Year Period. J. Clin. Microbiol.
40: 1237-1243
[Abstract] [Full Text] -
Baraniak, A., Fiett, J., Sulikowska, A., Hryniewicz, W., Gniadkowski, M.
(2002). Countrywide Spread of CTX-M-3 Extended-Spectrum {beta}-Lactamase-Producing Microorganisms of the Family Enterobacteriaceae in Poland. Antimicrob. Agents Chemother.
46: 151-159
[Abstract] [Full Text] -
Mammeri, H., Laurans, G., Eveillard, M., Castelain, S., Eb, F.
(2001). Coexistence of SHV-4- and TEM-24-Producing Enterobacter aerogenes Strains before a Large Outbreak of TEM-24-Producing Strains in a French Hospital. J. Clin. Microbiol.
39: 2184-2190
[Abstract] [Full Text] -
Neuwirth, C., Siebor, E., Pechinot, A., Duez, J.-M., Pruneaux, M., Garel, F., Kazmierczak, A., Labia, R.
(2001). Evidence of In Vivo Transfer of a Plasmid Encoding the Extended-Spectrum {beta}-Lactamase TEM-24 and Other Resistance Factors among Different Members of the Family Enterobacteriaceae. J. Clin. Microbiol.
39: 1985-1988
[Abstract] [Full Text] -
De Gheldre, Y., Struelens, M. J., Glupczynski, Y., De Mol, P., Maes, N., Nonhoff, C., Chetoui, H., Sion, C., Ronveaux, O., Vaneechoutte, M.
(2001). National Epidemiologic Surveys of Enterobacter aerogenes in Belgian Hospitals from 1996 to 1998. J. Clin. Microbiol.
39: 889-896
[Abstract] [Full Text] -
De Champs, C., Sirot, D., Chanal, C., Bonnet, R., Sirot, J., the French Study Group,
(2000). A 1998 Survey of Extended-Spectrum beta -Lactamases in Enterobacteriaceae in France. Antimicrob. Agents Chemother.
44: 3177-3179
[Abstract] [Full Text] -
Soll, D. R.
(2000). The Ins and Outs of DNA Fingerprinting the Infectious Fungi. Clin. Microbiol. Rev.
13: 332-370
[Abstract] [Full Text] -
Bornet, C., Davin-Regli, A., Bosi, C., Pages, J.-M., Bollet, C.
(2000). Imipenem Resistance of Enterobacter aerogenes Mediated by Outer Membrane Permeability. J. Clin. Microbiol.
38: 1048-1052
[Abstract] [Full Text] -
Marchandin, H., Jean-Pierre, H., De Champs, C., Sirot, D., Darbas, H., Perigault, P. F., Carriere, C.
(2000). Production of a TEM-24 Plasmid-Mediated Extended-Spectrum beta -Lactamase by a Clinical Isolate of Pseudomonas aeruginosa. Antimicrob. Agents Chemother.
44: 213-216
[Abstract] [Full Text]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»