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Antimicrobial Agents and Chemotherapy, April 1998, p. 827-832, Vol. 42, No. 4
0066-4804/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Cefotaxime-Resistant Enterobacteriaceae
Isolates from a Hospital in Warsaw, Poland: Identification of a New
CTX-M-3 Cefotaxime-Hydrolyzing
-Lactamase That Is Closely Related to
the CTX-M-1/MEN-1 Enzyme
Marek
Gniadkowski,1,*
Ines
Schneider,2
Andrzej
Pa
ucha,1
Renate
Jungwirth,2
Barbara
Mikiewicz,3 and
Adolf
Bauernfeind2
Sera and Vaccines Central Research
Laboratory, 00-725 Warsaw,1 and
Health
Care Center Praga-Pó
noc, 03-719 Warsaw,3 Poland, and
Max von
Pettenkofer-Institut, 80336 Munich, Germany2
Received 14 July 1997/Returned for modification 12 November
1997/Accepted 2 February 1998
 |
ABSTRACT |
A group of cefotaxime-resistant Citrobacter freundii
and Escherichia coli isolates were collected by a clinical
laboratory in a hospital in Warsaw, Poland, in July 1996. Detailed
analysis has shown that all of these produced a
-lactamase (pI, 8.4)
belonging to the CTX-M family, one of the minor extended-spectrum
-lactamase families with a strong cefotaxime-hydrolyzing activity.
Sequencing has revealed that C. freundii isolates produced
a new CTX-M-3 enzyme which is very closely related to the CTX-M-1/MEN-1
-lactamase, sporadically identified in Europe over a period of 6 years. Amino acid sequences of these two
-lactamases differ at four
positions: Val77Ala, Asp114Asn, Ser140Ala, and Asn288Asp (the first
amino acid of each pair refers to CTX-M-1/MEN-1 and second refers to CTX-M-3). The partial sequence of the E. coli CTX-M gene
was identical to the corresponding region of
blaCTX-M-3, but a transconjugant of the
E. coli isolate expressed higher levels of resistance to
-lactams than did C. freundii transconjugants. These
resistance differences correlated with differences in plasmid DNA
restriction patterns. Our results suggest that CTX-M genes have been
spread among different species of the family
Enterobacteriaceae in the hospital and that the
CTX-M-3-expressing C. freundii strain causing routine
urinary tract infections has been maintained for a relatively long time
in the hospital environment.
 |
INTRODUCTION |
Class A plasmidic CTX-M
-lactamases constitute one of the minor families of
extended-spectrum
-lactamases (ESBLs) which are much more
active against cefotaxime than ceftazidime (5). Three
members of this group have been reported to date: CTX-M-1/MEN-1 (3, 5), CTX-M-2 (4), and Toho-1 (10).
CTX-M-producing strains of the family Enterobacteriaceae
were isolated sporadically between 1989 and 1994 but over an extremely
wide geographic area including Europe, South America, and the Middle
and Far East (6, 7, 10).
Very little is known about the possible origins, evolution, or
structural determinants of the CTX-M enzyme activity. Comparative analysis of protein sequences has revealed the similarity of these enzymes to the
-lactamases of Klebsiella oxytoca and
Citrobacter diversus (>70% homology), which, to date, are
known to be exclusively chromosomally encoded enzymes (2, 3, 7,
15, 16). The K. oxytoca
-lactamase was reported to
possess a weak activity against oxyimino-
-lactams (2,
16). The amino acid residue(s) and the position(s) critical for
the high cefotaxime-hydrolyzing activity of the CTX-M enzymes are not
known; however, the Ser-237 residue, common to members of the family
and not to the K. oxytoca and C. diversus
enzymes, has been proposed to play this role (3).
At the beginning of July 1996, a clinical microbiology laboratory in
the Praski Hospital in Warsaw, Poland, started to routinely test for
ESBL activity in isolates of Enterobacteriaceae by the double-disc method (11). During this month, three
Citrobacter freundii isolates and one Escherichia
coli isolate, collected from urine samples from different
patients, were identified as ESBL producers expressing high resistance
to cefotaxime and susceptibility to ceftazidime in in vitro
susceptibility tests. In this paper, we present results of the detailed
analysis of these strains which led to the identification of the next
CTX-M variant and the first description for Europe of the persistence
of CTX-M-producing microorganisms in the microflora of a given hospital
environment.
 |
MATERIALS AND METHODS |
Bacterial strains.
Three C. freundii clinical
isolates (2524/96, 2525/96, and 2526/96) and one E. coli
clinical isolate (2527/96) resistant to cefotaxime and identified as
ESBL producers were collected in July 1996 at the Praski Hospital from
different patients with urinary tract infections: two from the internal
medicine ward, one from the urological ward, and one from the surgical
ward of the hospital. All the patients suffered from urological
complications and/or were subjected to invasive procedures
(catheterization, cystoscopy, and nephrostomy). Two patients were
diabetic, and one had cancer. Species identification, routine
susceptibility tests, and double-disc tests for ESBL activity
(11) were performed by the hospital microbiology laboratory.
Species identification was confirmed by the ID32E ATB test
(bioMerieux).
Ribotyping and randomly amplified polymorphic DNA (RAPD).
Genomic DNA was extracted from 200 µl of the overnight cultures grown
in tryptic soy broth (Oxoid) at 37°C with the Genomic DNA Prep Plus
kit (A & A Biotechnology, Gda
sk, Poland). For ribotyping, a
mixture of two DNA probes corresponding to the 23S ribosomal DNA (rDNA)
and 16S rDNA sequences of E. coli (9) was used.
The probes were obtained in PCRs with genomic DNA of E. coli
ATCC 25922 as a template and the following primers:
5'-GGTTAAGCGACTAAGCGTAC-3' and
5'-CAGCTTCGGCGTTGTAAGG-3' for 23S rDNA amplification and
5'-GGGGGACCTTCGGGC-3' and 5'-GGTGTGACGGGCGGTGTG-3'
for 16S rDNA amplification. The PCR products were gel purified
and labelled with the DIG DNA labelling kit (Boehringer Mannheim)
according to the manufacturer's recommended procedure. Total DNA
preparations of analyzed isolates were digested with EcoRI
and HindIII restriction enzymes (MBI Fermentas),
electrophoresed in a 1% agarose gel (FMC Bioproducts), and blotted
onto a positively charged nylon membrane (Boehringer Mannheim).
Chemiluminescent detection of the hybridization signal was performed
with a DIG luminescent detection kit (Boehringer Mannheim) according to
the manufacturer's instructions.
The RAPD analysis was performed with the RAPD-7 (18) primer.
About 10 ng of total DNA, 50 pmol of the primer, 100 µM
deoxynucleoside triphosphates, 2.5 mM MgCl2, 10 µg of
bovine serum albumin, 2 U of Taq polymerase (MBI Fermentas),
and buffer supplied by the manufacturer of the enzyme were used for
each single reaction mixture. Reactions were run under the following
conditions: 5 min at 94°C; five cycles of 15 s at 94°C,
30 s at 35°C, and 1.5 min at 72°C; and 30 cycles of 15 s
at 94°C, 15 s at 55°C, 30 s at 72°C, and finally 7 min
at 72°C in a GeneAmp PCR System 2400 (Perkin-Elmer). PCR products
were electrophoresed in 2% agarose gels (FMC Bioproducts). C. freundii L-601, belonging to the culture collection of the Sera
and Vaccines Central Research Laboratory, Warsaw, Poland, was used as
an epidemiologically nonrelated control in both typing analyses. (The
L-601 strain was isolated in January 1995 at the University Hospital in
Szczecin, Poland).
Susceptibility testing.
MICs of various antibiotics were
determined by the agar dilution method according to National Committee
for Clinical Laboratory Standards guidelines (14). The
following antibiotics were used: ampicillin, cefotaxime, and gentamicin
(Polfa, Tarchomin, Poland); aztreonam (Bristol-Myers Squibb, New
Brunswick, N.J.); cefoxitin (Sigma Chemical Co., St. Louis, Mo.);
ceftazidime (Glaxo Wellcome, Stevenage, United Kingdom); lithium
clavulanate (SmithKline Beecham Pharmaceuticals, Betchworth, United
Kingdom); imipenem (Merck, Sharp & Dohme Research, Rahway, N.J.);
piperacillin (Lederle Piperacillin Inc., Carolina, Puerto Rico);
tazobactam (Lederle Laboratories, Pearl River, N.Y.); and tobramycin
(Eli Lilly, Indianapolis, Ind.). In all
-lactam-inhibitor
combinations, the constant concentrations of clavulanate and tazobactam
were 2 and 4 µg/ml, respectively. C. freundii 870/97,
isolated at the Praski Hospital in May 1997, was used as a wild-type
control strain for antimicrobial susceptibility testing of
ESBL-producing C. freundii isolates. E. coli ATCC
25922 was used as the reference strain.
Resistance transfer.
One-milliliter volumes of cultures of
the donor and recipient strains (109 CFU of each strain per
ml) grown in tryptic soy broth (Oxoid) were mixed and incubated for
18 h at 35°C. E. coli A15 R
resistant
to rifampin was used as the recipient strain. Transconjugants were
selected on MacConkey agar (Oxoid) supplemented with cefotaxime (2 mg/liter) and rifampin (128 mg/liter).
Isoelectric focusing (IEF) of
-lactamases and detection of
cefotaxime-hydrolyzing activity within the IEF gel lane.
Sonicates
of clinical isolates and transconjugants were subjected to analytical
IEF over the pH range of 3 to 10. IEF was performed according to the
method of Matthew et al. (13) with modifications described
previously (5), with a Multiphor apparatus (Pharmacia LKB).
Following electrophoresis, gels were stained with nitrocefin (Oxoid).
After IEF of transconjugant extracts, cefotaxime-hydrolyzing activity
was assigned to specific
-lactamase bands by the bioassay approach
as previously described (5).
Plasmid DNA preparation and plasmid fingerprinting.
Plasmid
DNA was purified from transconjugant cells with the Qiagen Plasmid Midi
kit (Qiagen, Hilden, Germany), according to the manufacturer's
recommended procedure, as described previously (8). For the
fingerprinting analysis, about 5 µg of plasmid DNA was digested with
10 U of PstI restriction enzyme (Boehringer Mannheim) for
2 h at 37°C. DNA was electrophoresed in a 1% agarose gel (FMC
Bioproducts).
PCR amplification of the blaCTX-M-3
gene.
For partial gene PCR amplification, primers P1
(5'-GCGATGTGCAGCACCAGTAA-3') and P2
(5'-GGTTGAGGCTGGGTGAAGTA-3'), specific for the
blaCTX-M-1 gene (7), were used in
reactions with plasmid DNA preparations as templates. The entire coding
sequence was amplified in a PCR with the P1C
(5'-TCGTCTCTTCCAGA-3') and P2D (5'-CAGCGCTTTTGCCGTCTAAG-3') oligonucleotides as primers. A
single reaction mixture contained about 1 µg of plasmid DNA, 50 pmol of each primer, 100 µM deoxynucleoside triphosphates, 1 U of
Taq polymerase (Boehringer Mannheim), and buffer with 2.5 mM
MgCl2 supplied by the manufacturer of the enzyme. A
Perkin-Elmer 9600 apparatus was used, and reactions were run under the
following conditions: 3 min at 95°C; 30 cycles of 30 s at
95°C, 30 s at 55°C, and 30 s at 72°C; and finally 3 min
at 72°C. The resulting products were run in a 1% agarose gel (FMC
Bioproducts) and purified for direct sequencing reactions with a
QIAquick PCR purification kit (Qiagen).
DNA sequencing.
Sequencing reactions were performed with
consecutive primers specific for the blaCTX-M-1
gene (7) according to the dideoxy chain termination method
of Sanger et al. (17). An automatic sequencer (373A; Applied
Biosystems, Weiterstadt, Germany) was used.
Nucleotide sequence accession number.
The
blaCTX-M-3 gene nucleotide sequence data will
appear in the EMBL database under accession no. Y10278.
 |
RESULTS |
Typing.
The three C. freundii isolates were typed
by ribotyping and RAPD approaches. All the isolates were found to
produce identical ribotyping patterns which were different from that of
the epidemiologically nonrelated control strain (Fig.
1). These results were confirmed by the
RAPD analysis (data not shown).

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FIG. 1.
Ribotyping of C. freundii isolates. The three
C. freundii isolates belonged to the same ribotype, which
was different from that of the epidemiologically nonrelated control
L-601 strain. Lanes: 1, 1-kb DNA ladder (Gibco BRL); 2, C. freundii 2524/96; 3, C. freundii 2525/96; 4, C. freundii 2526/96; 5, C. freundii L-601.
|
|
Antimicrobial susceptibilities of clinical isolates.
Results
of the analysis are shown in Table 1. Of
the
-lactams tested, all the ESBL-producing isolates were resistant
to ampicillin (MICs, >512 µg/ml), piperacillin (MICs, >512
µg/ml), cefotaxime (MICs,
512 µg/ml), and aztreonam (MICs, 32 or
128 µg/ml) but remained susceptible or intermediate to ceftazidime (MICs, 4 or 16 µg/ml) and susceptible to imipenem (MICs, 0.125 µg/ml).
-Lactamase inhibitors restored activities of piperacillin, cefotaxime, and aztreonam. C. freundii isolates were
resistant to cefoxitin (MICs, 128 µg/ml) whereas E. coli
2527/96 was intermediate to this antibiotic (MIC, 16 µg/ml). MICs of
-lactam antibiotics tested for the wild-type C. freundii
strain (C. freundii 870/97) were substantially lower than
those for the three ESBL-producing isolates, except for cefoxitin (MIC,
128 µg/ml) and imipenem (MIC, 0.25 µg/ml). All the ESBL-expressing
isolates were found to be resistant to both aminoglycosides tested,
gentamicin and tobramycin (MICs, 256 µg/ml). MICs obtained for the
three C. freundii isolates were identical; E. coli 2527/96 was usually characterized by higher MICs.
Resistance transfer and susceptibility testing of transconjugant
strains.
Transconjugants were obtained for all the analyzed
isolates. A very high frequency of conjugation (10
2 per
donor cell) was observed with the C. freundii isolates. (For E. coli 2527/96, the frequency was 10
6 per
donor cell.) Susceptibility testing (Table 1) has revealed that the
transconjugant of E. coli 2527/96 was characterized by substantially higher MICs of piperacillin, cefotaxime, ceftazidime, and
aztreonam than those for transconjugants of C. freundii
isolates. The MICs of cefotaxime were higher than those of ceftazidime
by 64 and 128 times for C. freundii and E. coli
transconjugants, respectively. The cefoxitin resistance of C. freundii isolates was not transferred to recombinant strains. In
all cases, resistance to gentamicin and tobramycin was cotransferred
with the ESBL activity to the transconjugants.
IEF of
-lactamases and cefotaxime-hydrolyzing activity
detection.
Two major nitrocefin-hydrolyzing bands were visualized
in extracts of all clinical isolates and transconjugants (results not shown). One band with a pI of 8.4 comigrated with the CTX-M-1 enzyme
produced by the original E. coli GRI CTX-M-1 strain
(5); the second one was characterized by a pI value of 5.4. The subsequent bioassay experiment revealed that only the
-lactamase
with a pI of 8.4 possessed the cefotaxime-hydrolyzing activity (results not shown).
Plasmid fingerprinting.
Plasmids isolated from transconjugants
of all three C. freundii isolates revealed identical
PstI restriction patterns which were different from that of
the plasmid isolated from the E. coli 2527/96 transconjugant
cells (Fig. 2).

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FIG. 2.
Plasmid fingerprinting analysis. Plasmids isolated from
transconjugants of C. freundii 2524/96, C. freundii 2525/96, and C. freundii 2526/96 were found to
have identical PstI restriction patterns, and these were
different from that of the R+ [E. coli
2527/96] strain. Lanes: 1, DNA molecular weight marker set VI
(Boehringer Mannheim); 2, DNA molecular weight marker set I (Boehringer
Mannheim); 3, R+ [C. freundii 2524/96]; 4, R+ [C. freundii 2525/96]; 5, R+
[C. freundii 2526/96]; 6, R+ [E.
coli 2527/96].
|
|
PCR amplification and sequencing of the
blaCTX-M-3 gene.
Partial gene
amplification products of the expected size of ca. 600 bp were obtained
in all cases (results not shown). Sequencing the PCR products has
revealed that within the region of about 450 to 500 bp all four
nucleotide sequences were identical except for six positions (two amino
acid differences in deduced protein sequences: Asp114Asn and Ser140Ala)
compared with the homologous part of the
blaCTX-M-1 gene.
The entire

-lactamase coding sequence was amplified in the PCR with
the plasmid preparation from the
C. freundii 2526/96
transconjugant. The PCR product of the expected size of about
1 kb was
obtained (result not shown) and sequenced. Comparative
analysis has
revealed that the CTX-M coding sequence differs from
that of the
blaCTX-M-1 gene at 10 nucleotide positions (Fig.
3).
Four of the observed differences
determine amino acid differences
in deduced protein sequences. The
analyzed enzyme was designated
CTX-M-3, and its amino acid differences
from the CTX-M-1

-lactamase
are as follows: Val77Ala, Asp114Asn,
Ser140Ala, and Asn288Asp
(the first amino acid in each pair refers to
CTX-M-1, and the
second refers to CTX-M-3).

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FIG. 3.
Nucleotide sequence of the
blaCTX-M-3 coding region. The deduced amino acid
sequence of CTX-M-3 is presented below. Nucleotide residues different
from those in the blaCTX-M-1 gene are shown in
boldface; residues characteristic of the
blaCTX-M-1 gene are presented above these. The
CTX-M-1 amino acid residues different from those of CTX-M-3 are
presented in parentheses next to the
blaCTX-M-1-specific nucleotides. Amino acid
numbering is according to the work of Ambler (1).
|
|
 |
DISCUSSION |
In this study, we report the identification of CTX-M-3, an enzyme
which expands one of the minor families of ESBLs. The CTX-M family
includes class A cefotaxime-hydrolyzing enzymes and to date consists of
three members: the CTX-M-1/MEN-1 (3, 5), the CTX-M-2
(4), and the Toho-1 (10)
-lactamases. DNA
regions coding for CTX-M-2 (7) and Toho-1 (10)
differ by only one nucleotide, which determines a single amino acid
difference in their deduced protein sequences. The CTX-M-1/MEN-1 enzyme
is less similar to the others, with an amino acid sequence homology
with CTX-M-2 of about 84% (7). CTX-M-3 differs from
CTX-M-1/MEN-1 by four amino acid residues (10 nucleotide differences in
protein coding regions) and is therefore closely related to this
enzyme.
The pattern of antimicrobial susceptibility caused by the production of
the CTX-M-3
-lactamase (Table 1) corresponds very well to those
observed for the CTX-M-1/MEN-1 (4, 5), CTX-M-2 (4), and Toho-1 (10) enzymes. Its activity for
cefotaxime is approximately 2 orders of magnitude higher than that for
ceftazidime as evaluated with MICs for transconjugant strains.
Recombinant strains expressing CTX-M-1/MEN-1, CTX-M-2, and Toho-1
-lactamases were characterized by MICs of cefotaxime 8, 32, and more
than 128 times higher than that of ceftazidime, respectively (4, 5, 10). The Toho-1 enzyme hydrolyzes cefotaxime with a relative maximum rate about 100 times higher than that for ceftazidime (10). Comparison of antimicrobial susceptibilities (Table 1) demonstrates that CTX-M-3-expressing C. freundii isolates
are clearly distinguishable from wild-type strains present in the same
hospital by much higher MICs of
-lactam antibiotics tested, except
for cefoxitin and imipenem. The observed cefoxitin resistance of
C. freundii isolates was most probably due to induction of the chromosomal AmpC cephalosporinase (12) and certainly not to activity of CTX-M-3.
CTX-M ESBL-producing strains have been incidentally identified for 7 years as single clinical isolates in very distant geographic regions.
CTX-M-2 was found in isolates from Argentina and Israel in 1992 and
from Paraguay and again in two isolates from Argentina in 1994 (7). The almost identical Toho-1 enzyme was identified in
1993 in Japan (10). Isolation of CTX-M-1/MEN-1-producing strains has been restricted to Europe to date; the first isolates were
found in 1989 in Germany (5) and in France (from a patient originating from Italy) (3), and the next two strains were collected in 1994 in two different cities in Germany (6). No outbreak caused by CTX-M-1/MEN-1-producing strains has ever been reported. The isolation of CTX-M-3-producing strains in Poland in 1996 suggests a wider distribution of CTX-M-1/MEN-1-related cefotaxime-hydrolyzing enzymes in Europe.
Isolates expressing the CTX-M-3
-lactamase, collected in July 1996 in a single Warsaw hospital, may represent the first reported nosocomial epidemic caused by organisms producing a
CTX-M-1/MEN-1-related enzyme in Europe. Ribotyping and RAPD approaches
have suggested that the C. freundii isolates may be
identical; moreover, this hypothesis is also supported by the same
plasmid fingerprints,
-lactamase IEF patterns, and susceptibility
data. These isolates were the only C. freundii isolates
resistant to cefotaxime identified in the hospital in July 1996. Two
were collected from patients hospitalized in the internal medicine
ward, and one was from a patient in the urological ward. All patients
were severely debilitated and predisposed to infections; the C. freundii isolates were identified as the etiological agents of
urinary tract infections. It is impossible to say whether the
CTX-M-3-producing C. freundii strain first appeared in the
hospital in July 1996 or whether it was present prior to this time.
Incidental isolations of cefotaxime-resistant C. freundii
were reported by the hospital microbiological laboratory in the first
half of 1996, but the isolates were neither collected nor typed at the
time. The routine testing of Enterobacteriaceae isolates for
the detection of ESBL activity was started in the laboratory at the
beginning of July 1996. Over the next few months (August 1996 to
January 1997), 19 new ESBL-producing, cefotaxime-resistant C. freundii isolates were identified in urine samples by the
laboratory. Seven of them (November 1996 to January 1997) were
collected and found to represent the same ribotypes and RAPD types as
isolates 2524/96, 2525/96, and 2526/96 (data not shown). Most probably, the CTX-M-3-producing C. freundii strain has been persisting
in the hospital environment for at least a year and regularly causing urinary tract infections in susceptible patients.
The second aspect of the CTX-M presence in the analyzed hospital is
E. coli 2527/96. This strain is characterized by the same pattern of plasmid-mediated
-lactamases as those of the C. freundii isolates (enzymes with pIs of 8.4 and 5.4), and the
partial (ca. 450 bp) nucleotide sequence of its CTX-M gene was
identical to the corresponding region of the
blaCTX-M-3 gene. However, MICs of piperacillin,
cefotaxime, ceftazidime, and aztreonam characterizing the
transconjugant R+ [E. coli 2527/96] were
substantially higher than those for C. freundii
transconjugants. This effect could be due to eventual differences in
coding sequences apart from the sequenced region of the E. coli
blaCTX-M gene or differences in levels of CTX-M-3 production. Plasmid DNA purified from R+ [E.
coli 2527/96] was actually found to have a different
PstI restriction map than that of plasmids extracted from
C. freundii transconjugants, and so, the different sequence
context of the
-lactamase gene might be responsible for quantitative
differences in the phenotypes of the strains. It is noteworthy that at
least two different plasmids carrying CTX-M genes have been spread
among strains of different Enterobacteriaceae species
present in the hospital and that these plasmids also contain a gene
encoding another
-lactamase (with a pI of 5.4; probably the TEM-1
enzyme) and determine resistance to aminoglycosides.
 |
ACKNOWLEDGMENTS |
M.G. was partially supported by the FEMS fellowship.
We thank Ewa Wasi
ska for her contribution in susceptibility
testing and Waleria Hryniewicz and Stephen Murchan for critical reading
of the manuscript.
 |
FOOTNOTES |
*
Corresponding author. Mailing address: Sera and
Vaccines Central Research Laboratory, ul. Chelmska 30/34, 00-725 Warsaw, Poland. Phone: (48) 22 651 4670. Fax: (48) 22-41 29 49. E-mail: marekg{at}ibbrain.ibb.waw.pl.
 |
REFERENCES |
| 1.
|
Ambler, R. P.
1980.
The structure of -lactamases.
Philos. Trans. R. Soc. Lond. B
289:321-331[Abstract/Free Full Text].
|
| 2.
|
Arakawa, Y.,
M. Ohta,
N. Kido,
M. Mori,
H. Ito,
T. Komatsu,
Y. Fujii, and N. Kato.
1989.
Chromosomal -lactamase of Klebsiella oxytoca, a new class A enzyme that hydrolyzes broad-spectrum -lactam antibiotics.
Antimicrob. Agents Chemother.
33:63-70[Abstract/Free Full Text].
|
| 3.
|
Barthélémy, M.,
J. Peduzzi,
H. Bernard,
C. Tancrède, and R. Labia.
1992.
Close amino acid sequence relationship between the new plasmid-mediated extended-spectrum -lactamase MEN-1 and chromosomally encoded enzymes of Klebsiella oxytoca.
Biochim. Biophys. Acta
1122:15-22[Medline].
|
| 4.
|
Bauernfeind, A.,
J. M. Casellas,
M. Goldberg,
M. Holley,
R. Jungwirth,
P. Mangold,
T. Röhnisch,
S. Schweighart, and R. Wilhelm.
1992.
A new plasmidic cefotaximase from patients infected with Salmonella typhimurium.
Infection
20:158-163[Medline].
|
| 5.
|
Bauernfeind, A.,
H. Grimm, and S. Schweighart.
1990.
A new plasmidic cefotaximase in a clinical isolate of Escherichia coli.
Infection
18:294-298[Medline].
|
| 6.
| Bauernfeind, A., H. Grimm, I. Stemplinger, S. Ernst,
and R. Jungwirth. 1995. Repeated incidence of CTX-M-1 (MEN)
extended spectrum -lactamase in Europe, abstr. 4210. Can. J. Infect. Dis. 6(Suppl. C):470C.
|
| 7.
|
Bauernfeind, A.,
I. Stemplinger,
R. Jungwirth,
S. Ernst, and J. M. Casellas.
1996.
Sequences of -lactamase genes encoding CTX-M-1 (MEN-1) and CTX-M-2 and relationship of their amino acid sequences with those of other -lactamases.
Antimicrob. Agents Chemother.
40:509-513[Abstract].
|
| 8.
|
Bauernfeind, A.,
I. Stemplinger,
R. Jungwirth,
P. Mangold,
S. Amann,
E. Akalin,
Ö. Ang,
C. Bal, and J. M. Casellas.
1996.
Characterization of -lactamase gene blaPER-2, which encodes an extended-spectrum class A -lactamase.
Antimicrob. Agents Chemother.
40:616-620[Abstract].
|
| 9.
|
Brosius, J.,
T. J. Dull,
D. D. Sleeter, and H. F. Noller.
1981.
Gene organization and primary structure of a ribosomal RNA operon from Escherichia coli.
J. Mol. Biol.
148:107-127[Medline].
|
| 10.
|
Ishii, Y.,
A. Ohno,
H. Taguchi,
S. Imajo,
M. Ishiguro, and H. Matsuzawa.
1995.
Cloning and sequence of the gene encoding a cefotaxime-hydrolyzing class A -lactamase isolated from Escherichia coli.
Antimicrob. Agents Chemother.
39:2269-2275[Abstract].
|
| 11.
|
Jarlier, V.,
M. Nicolas,
G. Fournier, and A. Philippon.
1988.
Extended broad-spectrum -lactamases conferring transferable resistance to newer -lactam agents in Enterobacteriaceae: hospital prevalence and susceptibility patterns.
Rev. Infect. Dis.
10:867-878[Medline].
|
| 12.
|
Livermore, D. M.
1995.
-Lactamases in laboratory and clinical resistance.
Clin. Microbiol. Rev.
8:557-584[Abstract].
|
| 13.
|
Matthew, M.,
A. M. Harris,
M. J. Marshall, and G. W. Ross.
1975.
The use of analytical isoelectric focussing for detection and identification of -lactamases.
J. Gen. Microbiol.
88:169-178[Medline].
|
| 14.
|
National Committee for Clinical Laboratory Standards.
1997.
Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. Approved standard M7-A4.
National Committee for Clinical Laboratory Standards, Wayne, Pa.
|
| 15.
|
Perilli, M.,
N. Franceschini,
B. Segatore,
G. Amicosante,
A. Oratore,
C. Duez,
B. Joris, and J. M. Frère.
1991.
Cloning and sequencing of the gene encoding the -lactamase from Citrobacter diversus.
FEMS Microbiol. Lett.
83:79-84.
|
| 16.
|
Reynaud, A.,
J. Peduzzi,
M. Barthélémy, and R. Labia.
1991.
Cefotaxime-hydrolysing activity of the -lactamase of Klebsiella oxytoca D488 could be related to a threonine residue at position 140.
FEMS Microbiol. Lett.
81:185-192.
|
| 17.
|
Sanger, F.,
S. Nicklen, and A. R. Coulson.
1977.
DNA sequencing with chain-terminating inhibitors.
Proc. Natl. Acad. Sci. USA
74:5463-5467[Abstract/Free Full Text].
|
| 18.
|
van Belkum, A.,
J. Kluytmans,
W. van Leeuwen,
R. Bax,
W. Quint,
E. Peters,
A. Fluit,
C. Vandenbroucke-Grauls,
A. van den Brule,
H. Koeleman,
W. Melchers,
J. Meis,
A. Elaichouni,
M. Vaneechoutte,
F. Moonens,
N. Maes,
M. Struelens,
F. Tenover, and H. Verbrugh.
1995.
Multicenter evaluation of arbitrary primed PCR for typing of Staphylococcus aureus strains.
J. Clin. Microbiol.
33:1537-1547[Abstract].
|
Antimicrobial Agents and Chemotherapy, April 1998, p. 827-832, Vol. 42, No. 4
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Copyright © 1998, American Society for Microbiology. All rights reserved.
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-
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-
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-
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-
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[Full Text]
-
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[Abstract]
[Full Text]
-
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[Abstract]
[Full Text]
-
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-
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[Full Text]
-
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[Full Text]
-
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-
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[Full Text]
-
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[Abstract]
[Full Text]
-
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[Abstract]
[Full Text]
-
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[Abstract]
[Full Text]
-
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[Abstract]
[Full Text]
-
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39: 175-182
[Abstract]
[Full Text]
-
Yan, J.-J., Ko, W.-C., Tsai, S.-H., Wu, H.-M., Jin, Y.-T., Wu, J.-J.
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38: 4320-4325
[Abstract]
[Full Text]
-
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[Abstract]
[Full Text]
-
Galán, J. C., Reig, M., Navas, A., Baquero, F., Blázquez, J.
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[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]
-
Doucet-Populaire, F., Ghnassia, J. C., Bonnet, R., Sirot, J.
(2000). First Isolation of a CTX-M-3-Producing Enterobacter cloacae in France. Antimicrob. Agents Chemother.
44: 3239-3240
[Full Text]
-
Bonnet, R., Sampaio, J. L. M., Labia, R., De Champs, C., Sirot, D., Chanal, C., Sirot, J.
(2000). A Novel CTX-M beta -Lactamase (CTX-M-8) in Cefotaxime-Resistant Enterobacteriaceae Isolated in Brazil. Antimicrob. Agents Chemother.
44: 1936-1942
[Abstract]
[Full Text]
-
Sabaté, M., Tarragó, R., Navarro, F., Miró, E., Vergés, C., Barbé, J., Prats, G.
(2000). Cloning and Sequence of the Gene Encoding a Novel Cefotaxime-Hydrolyzing beta -Lactamase (CTX-M-9) from Escherichia coli in Spain. Antimicrob. Agents Chemother.
44: 1970-1973
[Abstract]
[Full Text]
-
Silva, J., Aguilar, C., Ayala, G., Estrada, M. A., Garza-Ramos, U., Lara-Lemus, R., Ledezma, L.
(2000). TLA-1: a New Plasmid-Mediated Extended-Spectrum beta -Lactamase from Escherichia coli. Antimicrob. Agents Chemother.
44: 997-1003
[Abstract]
[Full Text]
-
Palucha, A., Mikiewicz, B., Hryniewicz, W., Gniadkowski, M.
(1999). Concurrent outbreaks of extended-spectrum {beta}-lactamase-producing organisms of the family Enterobacteriaceae in a Warsaw hospital. J Antimicrob Chemother
44: 489-499
[Abstract]
[Full Text]
-
Palucha, A., Mikiewicz, B., Gniadkowski, M.
(1999). Diversification of Escherichia coli Expressing an SHV-Type Extended-Spectrum beta -Lactamase (ESBL) during a Hospital Outbreak: Emergence of an ESBL-Hyperproducing Strain Resistant to Expanded-Spectrum Cephalosporins. Antimicrob. Agents Chemother.
43: 393-396
[Abstract]
[Full Text]
-
Bradford, P. A., Yang, Y., Sahm, D., Grope, I., Gardovska, D., Storch, G.
(1998). CTX-M-5, a Novel Cefotaxime-Hydrolyzing beta -Lactamase from an Outbreak of Salmonella typhimurium in Latvia. Antimicrob. Agents Chemother.
42: 1980-1984
[Abstract]
[Full Text]