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Antimicrobial Agents and Chemotherapy, May 2001, p. 1343-1348, Vol. 45, No. 5
Department of Microbiology, School of
Medicine and Environmental Infectious Disease, Graduate School of
Medical Sciences, Kitasato University, Sagamihara, Kanagawa
228-8555,1 and Department of
Otolaryngology, Nagasaki University School of Medicine, Nagasaki
852-8501,2 Japan
Received 3 July 2000/Returned for modification 20 August
2000/Accepted 30 January 2001
In 1996, Serratia marcescens KU3838 was isolated from
the urine of a patient with a urinary tract infection at a hospital in
northern Japan and was found to contain the plasmid pKU501. Previously,
we determined that pKU501 carries blaIMP and
the genes for TEM-1-type Carbapenems such as imipenem,
panipenem, and meropenem are the most potent agents for treatment of
gram-negative infections due to the stability of these agents against
the majority of However, some clinical isolates have been reported to be resistant to
carbapenems due to production of metallo- Previously, we described pKU501 as a novel plasmid carrying not only
blaIMP but also the genes for TEM-1-type
Bacterial strains and plasmids.
The bacterial strains and
plasmids used in this study are listed in Table
1. In 1996, Serratia
marcescens KU3838 was isolated from the urine of a patient with a
urinary tract infection at a hospital in northern Japan
(41) and was found to contain plasmid pKU501.
Escherichia coli K12 ML4901 (18) was used as
the recipient for plasmids. E. coli KU3999 is a
transconjugant that contains the conjugative plasmid pKU501 from
S. marcescens KU3838 to E. coli K12 ML4901.
Plasmids pHSG398 (37) and pBluescript (36) are vector plasmids that confer resistance to chloramphenicol and
tetracycline-ampicillin, respectively. E. coli KU1917 is a transformant that contains pMS361 (16), which carries the
4.1-kb fragment encoding IMP-1 on the multicloning region of pHSG398.
0066-4804/01/$04.00+0 DOI: 10.1128/AAC.45.5.1343-1348.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Plasmid-Encoded Metallo-
-Lactamase (IMP-6)
Conferring Resistance to Carbapenems, Especially Meropenem
ABSTRACT
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
-lactamases as well as producing both types
of -lactamases (H. Yano, A. Kuga, K. Irinoda, R. Okamoto, T. Kobayashi, and M. Inoue, J. Antibiot. 52:1135-1139, 1999). pKU502 is a
recombinant plasmid that contains a 1.5-kb DNA fragment, including the
metallo--lactamase gene, and is obtained by PCR amplification of
pKU501. The sequence of the metallo--lactamase gene in pKU502 was
determined and revealed that this metallo--lactamase gene differed
from the gene encoding IMP-1 by one point mutation, leading to one
amino acid substitution: 640-A in the base sequence of the IMP-1 gene
was replaced by G, and Ser-196 was replaced by Gly in the mature
enzyme. This enzyme was designated IMP-6. The strains that produced
IMP-6 were resistant to carbapenems. The MICs of panipenem and
especially meropenem were higher than the MIC of imipenem for these
strains. The kcat/Km value of IMP-6 was about sevenfold higher against meropenem than against imipenem, although the MIC of meropenem for KU1917, which produced IMP-1, was lower than that of imipenem, and the MIC of panipenem was equal to that of imipenem. These results support the
hypothesis that IMP-6 has extended substrate profiles against carbapenems. However, the activity of IMP-6 was very low against penicillin G and piperacillin. These results suggest that IMP-6 acquired high activity against carbapenems, especially meropenem, via
the point mutation but in the process lost activity against penicillins. Although IMP-6 has reduced activity against penicillins due to this point mutation, pKU501 confers resistance to a variety of
antimicrobial agents because it also produces TEM-1-type enzyme.
INTRODUCTION
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
-lactamases and their high rate of permeation
through bacterial outer membranes. In addition, imipenem, panipenem,
and meropenem have a high affinity for penicillin-binding protein (PBP)
2 of gram-negative bacteria except for Pseudomonas
aeruginosa. In P. aeruginosa, imipenem and panipenem
have a high affinity for PBP 2 and meropenem has an affinity for PBP 3 (6, 19, 40).
-lactamases. There have
been increasing reports, especially from Japan (7, 14, 21, 27,
35), of gram-negative bacteria that carry the transferable
carbapenem resistance gene blaIMP, including isolates of P. aeruginosa and Serratia
marcescens. The metallo--lactamases are class B enzymes in
Ambler's molecular classification (1) and belong to Bush
group 3 (3, 31). Most of these metallo--lactamases confer resistance not only to carbapenems but also to other -lactams and are poorly inhibited by the presence of -lactamase inhibitors such as clavulanic acid, sulbactam, and tazobactam (31).
Therefore, there is a possibility that therapeutic failures occur in
patients infected with the strains that produce metallo--lactamase,
and the spread of these strains has resulted in serious medical
problems in hospitals.
-lactamases as well as producing both types of -lactamases
(41). A strain carrying pKU501 was more resistant to
meropenem and panipenem, especially meropenem, than to imipenem. In
this report, we describe the metallo--lactamase encoded by pKU501
that hydrolyzes carbapenems, especially meropenem.
MATERIALS AND METHODS
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
TABLE 1.
Bacterial strains and plasmids used in this study
Antibacterial agents.
The antibacterial agents listed below
were used in this study. Reference powders of known potency for the
drugs were provided by the respective manufacturers. Penicillin G
(Meiji Seika Kaisha., Ltd., Tokyo, Japan) and piperacillin (Toyama
Chemical Co., Ltd., Toyama, Japan) were used as representative
penicillins, while cephalothin (Shionogi and Co., Ltd., Osaka, Japan),
cefotiam (Takeda Chemical Industries, Ltd., Osaka, Japan), cefmetazole
(Sankyo Co., Ltd., Tokyo, Japan), cefotaxime (Nippon Hoechst Marion
Roussel, Tokyo, Japan), and cefepime (Bristol-Myers Squibb K. K.,
Tokyo, Japan) were used as representative cephems. Other -lactams,
including imipenem (Banyu Pharmaceutical Co., Ltd., Tokyo, Japan),
panipenem (Sankyo Co.), meropenem (Sumitomo Pharmaceutical Ltd., Osaka, Japan), and aztreonam (Eizai Co., Ltd., Tokyo, Japan), as well as
chloramphenicol (Sankyo Co.), tetracycline (Lederle Japan, Tokyo,
Japan), streptomycin (Meiji Seika Kaisha), and nalidixic acid (Daiichi
Pharmaceutical Co., Ltd., Tokyo, Japan) were also used. Clavulanic acid
(SmithKline Beecham Pharmaceuticals, Tokyo, Japan) was used as a
representative -lactamase inhibitor.
Transconjugation. Conjugation was done by broth method, as previously described (10). Exponential-phase L-broth (24) cultures of donor strain ML4901 and recipient strain KU3838 were mixed at a volume ratio of 1:10. This mating mixture was incubated for 2 h at 35°C. The transconjugants were selected on sensitivity disk agar (Nissui Pharmaceutical Co., Tokyo, Japan) containing 32 µg of nalidixic acid and cefotaxime per ml.
PCR amplification, cloning, and sequencing of the
metallo--lactamase gene.
Isolation of plasmid DNA using the
small-scale alkaline method (33) and gene amplification by
PCR (29, 41) were performed as previously described.
Primer pairs P1 (5'-CGG ATG AAG GCA CGA ACC CA-3') and P2
(5'-AAG CAG ACT TGA CCT GAT AGT-3') (TaKaRa Shuzo Co., Ltd.
Kyoto, Japan), which were chosen on the basis of the published pMS350
integron and 3'-conserved region sequence (17), were used
in the PCR experiments. pKU501 was used as a template DNA. The PCR
experiments involved using a commercially available PCR kit (Gene Amp
PCR reaction kit with Ampli Taq DNA polymerase; TaKaRa Shuzo
Co.) and a DNA thermal cycler PH2000 (Perkin-Elmer Cetus Instruments,
Emeryville, Calif.) and involved 25 cycles of denaturation at 94°C
for 1 min, annealing at 55°C for 1 min, and elongation at 72°C for
1 min, followed by heating at 72°C for 30 min. The 1.5-kb DNA
fragment obtained by PCR amplification of pKU501 was purified and
cloned into the EcoRV site of pBluescript using the
TA-cloning technique (9) with T4 DNA ligase (Nippon Gene,
Tokyo, Japan). The recombinant DNAs were introduced into E. coli K12 ML4901 by electroporation with a Bio-Rad gene pulser and
a pulse controller unit (Bio-Rad Laboratories, Hercules, Calif.).
Drug susceptibility assay. MICs were determined by the agar dilution method with sensitivity disk agar (Nissui Pharmaceutical Co.) in accordance with the specified drug sensitivity assay methods of the Japan Society of Chemotherapy, except for the antibiotic concentrations used (12).
-Lactamase preparation and purification.
Purification of
the metallo--lactamase was performed according to a previously
reported method (26). E. coli KU4867 harboring plasmid pKU503 was cultured in Mueller-Hinton broth (Nissui
Pharmaceutical Co.), diluted 100-fold into 5 liters of the same broth,
and incubated overnight with shaking at 35°C. The cells were
harvested by centrifugation at 6,000 × g for 10 min
and suspended in 50 mM phosphate buffer (pH 7.0) with 10 µM
ZnCl2. The cells were disrupted by sonication (model
UD-201; Tomy Seiko, Tokyo, Japan), and the cellular debris was removed
by centrifugation at 18,000 × g for 30 min at 4°C. Streptomycin (2% [wt/vol]) was added to the supernatant, and the mixture was agitated for 2 h at 4°C. After centrifugation at
18,000 × g for 30 min at 4°C, the supernatant was
dialyzed against 5 mM phosphate buffer (pH 7.0) with 10 µM
ZnCl2. The dialysate was centrifuged at 18,000 × g for 30 min at 4°C, and the supernatant then obtained was
applied to a carboxymethyl cellulose CM52 column (Whatman Ltd., Kent,
United Kingdom). The metalloenzyme was eluted in 50 mM phosphate buffer
(pH 7.0) with 10 µM ZnCl2, and the active enzyme
fractions were pooled and concentrated. The concentrated enzyme was
applied to a Sephadex G-75 column (Amersham Pharmacia Biotech) and
eluted with 5 mM phosphate buffer (pH 7.0)-10 µM ZnCl2.
The active enzyme fractions were pooled and concentrated. The
concentrated enzyme was applied to a Mono S column equipped with
fast-protein-liquid-chromatography equipment (Amersham Pharmacia Biotech). The enzyme was eluted with a 0 to 0.5 M linear gradient of
sodium chloride and detected by absorbance at 280 nm and by enzyme
activity. The purity of the preparation was checked by sodium dodecyl
sulfate-polyacrylamide gel electrophoresis (39), and final
preparation showed a single band with more than 95% purity.
Assay of -lactamase.
Enzyme activity was determined by
spectrophotometry (UV2000; Shimazu Corp., Tokyo, Japan) at 30°C in 50 mM phosphate buffer (pH 7.0) with 10 µM ZnCl2
(41). One unit of enzyme activity was defined as the
amount of enzyme hydrolyzing 1 µmol of substrate in 1 min at 30°C.
Protein concentrations were determined by using the Bio-Rad protein
assay (Bio-Rad Laboratories) as the standard.
-lactamase inhibitor at concentrations
from 50 to 100 µM for 5 min, and data were analyzed using a Dixon
plot (13).
Nucleotide sequence accession number. The nucleotide sequence data reported in this paper will appear in the DDBJ, EMBL, and GenBank nucleotide sequence databases with the accession number AB040994.
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RESULTS |
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Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
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Sequence of the metallo--lactamase gene.
A schematic
representation of the structure of the metallo--lactamase gene and
its flanking regions in pKU502 is shown in Fig.
1. The putative integrase gene and a gene
of unknown function were identified in the upstream and downstream
regions of the metallo--lactamase gene, respectively.
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, position of the sequences
similar to the GTTRRRY sequence; 
, position of the
inverted repeat.
-lactamase gene and its
flanking regions in pKU502 is shown in Fig.
2. Sequence analysis revealed that this
metallo--lactamase gene differed from that carried by pMS350 (IMP-1)
by one point mutation, leading to one amino acid substitution: 640-A in
the base sequence of IMP-1 was converted to G, and Ser-196 was replaced
by Gly in the mature enzyme (Fig. 2). Since this one amino acid
substitution has not been previously described in IMP-type enzymes
produced by clinical strains, the enzyme in the current study was
designated IMP-6.
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Susceptibility to antibiotics.
The MICs of -lactams for
S. marcescens KU3838 and the transconjugant strain of
E. coli KU3999, which acquired pKU501 by conjugation at a
frequency of 10
5, as well as those of the transformant
strains of E. coli KU4866, KU4867, and KU1917 are shown in
Table 2.
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-lactam antibiotics, including piperacillin, piperacillin/clavulanic acid, aztreonam, and carbapenems. The MICs of all selected carbapenems were 0.5 µg/ml or less for the parent E. coli K12
ML4901 strain and increased for both the transconjugant (KU3999)
and the transformants (KU4866 and KU4867) all of which bear carbapenem
resistance genes. The MICs of cephalosporins were increased
significantly compared with those for the parent E. coli K12
ML4901 strain.
Moreover, KU4866, the transformant that contained pKU502, was resistant
to piperacillin, cephalosporins, and carbapenems. In the presence of
clavulanic acid (5 µg/ml), the MIC of piperacillin was decreased.
KU4867, the transformant that contained pKU503, was resistant to
cephalosporins and carbapenems but susceptible to piperacillin. As with
KU3999, the MICs of meropenem and panipenem, especially of meropenem,
for both KU4866 and KU4867 were also higher than that of imipenem, and
both strains were sensitive to aztreonam. The MIC of meropenem for
KU1917, the transformant carrying an IMP-1 type -lactamase gene, was
lower than that of imipenem, and the MIC of panipenem was equal to that
of imipenem.
Assay of -lactamase.
IMP-6 was purified from the culture
supernatant of KU4867 as described in Materials and Methods. IMP-6 was
completely purified by a carboxymethyl cellulose CM52, a Sephadex G-75,
and Mono S column chromatography, and the specific activity of purified
enzyme (38.6 U/mg of protein) was 701-fold higher than that of the
crude extract (0.055 U/mg of protein), using 100 µM of imipenem as
the substrate. The values of kcat,
Km, and
kcat/Km for eight
antibiotics are shown in Table 3. As for
carbapenems, the kcat/Km
value of the IMP-1 for meropenem was almost equal than that for
imipenem (22). However, the
kcat/Km value of the
IMP-6 for meropenem was about sevenfold higher than that for imipenem.
In addition, the values of
kcat/Km of the IMP-6 for
cephalothin and cefotaxime were higher than that of IMP-1. On the other
hand, the values of
kcat/Km of the IMP-6 for
penicillins were low compared with those of the IMP-1. No hydrolysis of
aztreonam was detected.
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DISCUSSION |
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Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
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Antibiotic resistance has evolved over the past 50 years from the
rapid microbiological development of resistant strains to a serious
medical problem in hospitals all over the world (11). The
use of broad-spectrum antimicrobial agents has had a profound effect on
the emergence of antibiotic resistance (28). Resistance to
various classes of antibiotics, including recently developed ones, has
been reported in almost all species, for example, gram-negative bacteria possessing carbapenem-hydrolyzing metallo--lactamases (2).
The majority of the carbapenem-hydrolyzing metallo--lactamase genes
are chromosomally encoded (31). After a plasmid-mediated metallo--lactamase carried by P. aeruginosa was reported
by Watanabe et al. (39) in 1991, the
metallo--lactamases have been found frequently among gram-negative
isolates, such as members of the family Enterobacteriaceae
and P. aeruginosa (7, 14, 21, 27, 35). The
majority of isolates of IMP-1 type metallo--lactamase-producing gram-negative bacteria have been reported from Japan. In addition, variants of blaIMP, such as IMP-2 and IMP-3,
have been reported recently by Cornaglia et al. (5),
Riccio et al. (32), and Iyobe et al. (15).
The transfer of a plasmid carrying a metallo--lactamase gene
suggests the possibility of clinical spread of plasmid-encoded metallo--lactamases by cell-to-cell contact. Since
metallo--lactamases confer resistance not only to carbapenems but
also to other -lactams except for monobactams, antibiotics are
frequently ineffective against gram-negative rods carrying this enzyme.
Therefore, the appearance of metallo--lactamase-producing bacterial
pathogens is a matter of major concern for antimicrobial chemotherapy.
In this study, we characterized a new carbapenem-hydrolyzing
metallo--lactamase, IMP-6.
KU3999, KU4866, and KU4867, which produce IMP-6, were resistant to carbapenems. The MICs especially of meropenem but also of panipenem were higher than the MIC of imipenem for these strains. However, the MIC of meropenem for KU1917, which produced IMP-1, was lower than that of imipenem, and the MIC of panipenem was equal to that of imipenem. The kcat/Km values of the IMP-6 against meropenem and panipenem, especially against meropenem, were higher than that against imipenem. In previous studies on IMP-1 (22, 26), the kcat/Km values against panipenem and meropenem were almost equal to or less than the kcat/Km against imipenem. These results support the hypothesis that IMP-6 is extended substrate profiles against carbapenems. The DNA sequence of the IMP-6 gene shows that its high activity against carbapenems is due to a point mutation that changes Ser-196 of IMP-1 to Gly. This suggests that the hydroxyl group of Ser-196 plays an important role in meropenem hydrolysis.
Metallo--lactamases confer resistance not only to carbapenems
but also to penicillins and cephems (31). However, the
kcat/Km values of KU4867,
carrying a plasmid pKU503 with deletion of the ampicillin resistance
gene in pBluescript, were very low against penicillin G and
piperacillin. The MICs of piperacillin and piperacillin/clavulanic acid
for this strain were 1 and 0.5 µg/ml, respectively, as with the
recipient E. coli strain ML4901. These results showed that IMP-6 hydrolyzes penicillins very poorly and also suggest that IMP-6
acquired high activity against carbapenems, especially meropenem, via
the point mutation but lost activity against penicillins. pKU501
carries blaIMP and the genes for TEM-1-type
-lactamases and produces both enzymes, as we have reported
previously (41). Therefore, although IMP-6 is inactive
against penicillins due to this point mutation, pKU501 confers
resistance to a variety of antimicrobial agents because it also
produces TEM-1 type enzyme.
Iyobe et al. (15) have reported an IMP-3
metallo--lactamase in which the gene differed from IMP-1 by a
seven-point mutation, leading to two amino acid substitutions: both
314- and 640-A in the base sequence of IMP-1 were converted to G, and
both Glu-87 and Ser-196 were replaced by Gly in the mature enzyme.
Iyobe et al. obtained pMS402, which has a hybrid bla gene
from blaIMP-1 and
blaIMP-3, by DNA recombination techniques and
found that pMS402 has identical amino acid sequences to IMP-6, in which
Ser-196 was replaced by Gly. They showed that the kinetic parameters
between the hybrid and IMP-3 had similar patterns against various
-lactams and that the values of
kcat/Km of both the
hybrid and IMP-3 for penicillins were much lower than those of IMP-1.
Iyobe et al. mentioned that replacement of Ser-196 by Gly is important
to hydrolyze -lactams (15). However, they did not
evaluate the kinetic parameters for hydrolysis of carbapenems such as
panipenem and meropenem. This study is a first report of IMP-6 in a
clinical sample and shows that IMP-6 acquired high activity against
carbapenems, especially meropenem.
Recently, clinical isolates producing class A extended-spectrum
-lactamases (ESBLs) that differ by a few point mutations have been
described (13, 20, 25, 38). These enzymes hydrolyze cephalosporins and monobactams, in addition to ampicillin and piperacillin. However, ESBLs do not hydrolyze cefoxitin and
cefmetazole, which belong to the cephamycin group, or carbapenems. The
IMP-6 gene differed from IMP-1 by a one-point mutation, like ESBLs. More rational and appropriate use of antibiotics may reduce the selective pressure for resistance mutations such as IMP-6.
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ACKNOWLEDGMENTS |
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We thank Shizuko Iyobe, Laboratory of Drug Resistance in Bacteria, Gunma University School of Medicine, for kindly providing the PCR primers. We also thank Takeshi Nakamura, Department of Parasitology, Kitasato University School of Medicine, for technical assistance.
This work was supported in part by grant-in-aid 12670264 from the Ministry of Science, Education and Culture of Japan.
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FOOTNOTES |
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* Corresponding author. Mailing address: Department of Otolaryngology, Nagasaki University School of Medicine, Nagasaki 852-8501, Japan. Phone: 81-95-849-7350. Fax: 81-95-849-7352. E-mail: d300042c{at}stcc.nagasaki-u.ac.jp.
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REFERENCES |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
| 1. |
Ambler, R. P.
1980.
The structure of -lactamases.
Philos. Trans. R. Soc. London Biol.
289:321-331 |
| 2. |
Bush, K.
1998.
Metallo--lactamases: a class apart.
Clin. Infect. Dis.
27(Suppl. 1):S48-S53.
|
| 3. |
Bush, K.,
G. A. Jacoby, and A. A. Medeiros.
1995.
A functional classification scheme for -lactamases and its correlation with molecular structure.
Antimicrob. Agents Chemother.
39:1211-1233[Medline].
|
| 4. |
Bush, K., and R. B. Sykes.
1986.
Methodology for the study of -lactamases.
Antimicrob. Agents Chemother.
30:6-10 |
| 5. |
Cornaglia, G.,
M. L. Riccio,
A. Mazzariol,
L. Lauretti,
R. Fontana, and G. M. Rossolini.
1999.
Appearance of IMP-1 metallo--lactamase in Europe.
Lancet
353:899-900[CrossRef][Medline].
|
| 6. |
Cornaglia, G.,
K. Russell,
G. Satta, and R. Fontana.
1995.
Relative importances of outer membrane permeability and group 1 -lactamase as determinants of meropenem and imipenem activities against Enterobacter cloacae.
Antimicrob. Agents Chemother.
39:350-355 |
| 7. |
Hirakata, Y.,
K. Izumikawa,
T. Yamaguchi,
H. Takemura,
H. Tanaka,
R. Yoshida,
J. Matsuda,
M. Nakano,
K. Tomono,
S. Maesaki,
M. Kaku,
Y. Yamada,
S. Kamihira, and S. Kohno.
1998.
Rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo--lactamase gene blaIMP.
Antimicrob. Agents Chemother.
42:2006-2011 |
| 8. | Hiraoka, M., S. Masuyoshi, S. Mitsuhashi, K. Tomatsu, and M. Inoue. 1988. Cephalosporinase interactions and antimicrobial activity of BMY-28142, ceftazidime and cefotaxime. J. Antibiot. 41:86-93[Medline]. |
| 9. |
Holton, T. A., and M. W. Graham.
1991.
A simple and efficient method for direct cloning of PCR products using ddT-tailed vectors.
Nucleic Acids Res.
19:1156 |
| 10. | Inoue, M., J. Itoh, and S. Mitsuhashi. 1983. pMS76, a plasmid capable of amplification by treatment with chloramphenicol. Plasmid 9:86-97[CrossRef][Medline]. |
| 11. | Inoue, M., A. Kuga, C. Shimauchi, H. Yano, and R. Okamoto. 1998. Why do antimicrobial agents become ineffectual? Yonsei Med. J. 39:502-513[Medline]. |
| 12. | Inoue, M., R. Okamoto, T. Okubo, K. Inoue, and S. Mitsuhashi. 1992. Comparative in vitro activity of RP59500 against clinical bacterial isolates. J. Antimicrob. Chemother. 30(Suppl. A):45-51. |
| 13. |
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].
|
| 14. |
Ito, H.,
Y. Arakawa,
S. Ohsuka,
R. Wacharotayankun,
N. Kato, and M. Ohta.
1995.
Plasmid-mediated dissemination of the metallo--lactamase gene blaIMP among clinically isolated strains of Serratia marcescens.
Antimicrob. Agents Chemother.
39:824-829[Abstract].
|
| 15. |
Iyobe, S.,
H. Kusadokoro,
J. Ozaki,
N. Matsumura,
S. Minami,
S. Haruta,
T. Sawai, and K. O'Hara.
2000.
Amino acid substitutions in a variant of IMP-1 metallo--lactamase.
Antimicrob. Agents Chemother.
44:2023-2027 |
| 16. |
Iyobe, S.,
M. Tsunoda, and S. Mitsuhashi.
1994.
Cloning and expression in Enterobacteriaceae of the extended-spectrum -lactamase gene from a Pseudomonas aeruginosa plasmid.
FEMS Microbiol. Lett.
121:175-180[Medline].
|
| 17. |
Iyobe, S.,
H. Yamada, and S. Minami.
1996.
Insertion of a carbapenemase gene cassette into an integron of a Pseudomonas aeruginosa plasmid.
J. Antimicrob. Chemother.
38:1114-1115 |
| 18. |
Katsu, K.,
M. Inoue, and S. Mitsuhashi.
1982.
Transposition of the carbenicillin-hydrolyzing -lactamase gene.
J. Bacteriol.
150:483-489 |
| 19. | Kitzis, M. D., J. F. Acar, and L. Gutmann. 1989. Antibacterial activity of meropenem against gram-negative bacteria with a permeability defect and against staphylococci. J. Antimicrob. Chemother. 24:125-132. |
| 20. |
Kunugita, C.,
F. Higashitani,
A. Hyodo,
N. Unemi, and M Inoue.
1995.
Characterization of a new plasmid-mediated extended-spectrum -lactamase from Serratia marcescens.
J. Antibiot.
48:1453-1459[Medline].
|
| 21. | Kurokawa, H., T. Yagi, N. Shibata, K. Shibayama, and Y. Arakawa. 1999. Worldwide proliferation of carbapenem-resistant gram-negative bacteria. Lancet 354:955[Medline]. |
| 22. |
Laraki, N.,
N. Franceschini,
G. M. Rossolini,
P. Santucci,
C. Meunier,
E. de Pauw,
G. Amicosante,
J. M. Frere, and M. Galleni.
1999.
Biochemical characterization of the Pseudomonas aeruginosa 101/1477 metallo--lactamase IMP-1 produced by Escherichia coli.
Antimicrob. Agents Chemother.
43:902-906 |
| 23. |
Laraki, N.,
M. Galleni,
I. Thamm,
M. L. Riccio,
G. Amicosante,
J.-M. Frere, and G. M. Rossolini.
1999.
Structure of In31, a blaIMP-containing Pseudomonas aeruginosa integron phyletically related to In5, which carries an unusual array of gene cassettes.
Antimicrob. Agents Chemother.
43:890-901 |
| 24. | Lennox, E. S. 1995. Transduction of linked genetic characters of the host by bacteriophage P1. Virology 1:190-206. |
| 25. |
Livermore, D. M., and M. Yuan.
1996.
Antibiotic resistance and production of extended-spectrum -lactamases amongst Klebsiella spp. from intensive care units in Europe.
J. Antimicrob. Chemother.
38:409-424 |
| 26. |
Marumo, K.,
A. Takeda,
Y. Nakamura, and K. Nakaya.
1995.
Purification and characterization of metallo--lactamase from Serratia marcescens.
Microbiol. Immunol.
39:27-33[Medline].
|
| 27. |
Minami, S.,
M. Akama,
H. Araki,
Y. Watanabe,
H. Narita,
S. Iyobe, and S. Mitsuhashi.
1996.
Imipenem and cephem resistant Pseudomonas aeruginosa carrying plasmids coding for class B -lactamase.
J. Antimicrob. Chemother.
37:433-444 |
| 28. | Neu, H. C. 1992. The crisis in antibiotic resistance. Science 257:1064-1073. |
| 29. |
Okamoto, R.,
T. Okubo, and M. Inoue.
1996.
Detection of genes regulating -lactamase production in Enterococcus faecalis and Staphylococcus aureus.
Antimicrob. Agents Chemother.
40:2550-2554[Abstract].
|
| 30. |
Osano, E.,
Y. Arakawa,
R. Wacharotayankun,
M. Ohta,
T. Horii,
H. Ito,
F. Yoshimura, and N. Kato.
1994.
Molecular characterization of an enterobacterial metallo -lactamase found in a clinical isolate of Serratia marcescens that shows imipenem resistance.
Antimicrob. Agents Chemother.
38:71-78 |
| 31. |
Rasmussen, B. A., and K. Bush.
1997.
Carbapenem-hydrolyzing -lactamases.
Antimicrob. Agents Chemother.
41:223-232[Medline].
|
| 32. |
Riccio, M. L.,
N. Franceschini,
L. Boschi,
B. Caravelli,
G. Cornaglia,
R. Fontana,
G. Amicosante, and G. M. Rossolini.
2000.
Characterization of the metallo--lactamase determinant of Acinetobacter baumannii AC-54/97 reveals the existence of blaIMP allelic variants carried by gene cassettes of different phylogeny.
Antimicrob. Agents Chemother.
44:1229-1235 |
| 33. | Sambrook, J., E. F. Fritsch, and T. Maniatis. 1989. Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. |
| 34. |
Sanger, F.,
S. Nicklen, and A. R. Coulson.
1977.
DNA sequencing with chain-terminating inhibitors.
Proc. Natl. Acad. Sci. USA
74:5463-5467 |
| 35. |
Senda, K.,
Y. Arakawa,
K. Nakashima,
H. Ito,
S. Ichiyama,
K. Shimokata,
N. Kato, and M. Ohta.
1996.
Multifocal outbreaks of metallo--lactamase-producing Pseudomonas aeruginosa resistant to broad-spectrum -lactams, including carbapenems.
Antimicrob. Agents Chemother.
40:349-353[Abstract].
|
| 36. |
Short, J. M.,
J. M. Fernandez,
J. A. Sorge, and W. D. Huse.
1988.
Lambda ZAP: a bacteriophage lambda expression vector with in vivo excision properties.
Nucleic Acids Res.
16:7583-7600 |
| 37. |
Takeshita, S.,
M. Sato,
M. Toba,
W. Masahashi, and T. Hashimoto-Gotoh.
1987.
High-copy-number and low-copy-number plasmid vectors for lacZ -complementation and chloramphenicol- or kanamycin-resistance selection.
Gene
61:63-74[CrossRef][Medline].
|
| 38. |
Tenover, F. C.,
M. J. Mohammed,
T. S. Gorton, and Z. F. Dembek.
1999.
Detection and reporting of organisms producing extended-spectrum -lactamases: survey of laboratories in Connecticut.
J. Clin. Microbiol.
37:4065-4070 |
| 39. |
Watanabe, M.,
S. Iyobe,
M. Inoue, and S. Mitsuhashi.
1991.
Transferable imipenem resistance in Pseudomonas aeruginosa.
Antimicrob. Agents Chemother.
35:147-151 |
| 40. | Yamagata, T., M. Y. Momoi, K. Murai, K. Ikematsu, K. Suwa, K. Sakamoto, and A. Fujimura. 1998. Panipenem-betamipron and decreases in serum valproic acid concentration. Ther. Drug Monit. 20:396-400[CrossRef][Medline]. |
| 41. |
Yano, H.,
A. Kuga,
K. Irinoda,
R. Okamoto,
T. Kobayashi, and M. Inoue.
1999.
Presence of genes for -lactamases of two different classes on a single plasmid from a clinical isolate of Serratia marcescens.
J. Antibiot.
52:1135-1139[Medline].
|
Antimicrobial Agents and Chemotherapy, May 2001, p. 1343-1348, Vol. 45, No. 5
0066-4804/01/$04.00+0 DOI: 10.1128/AAC.45.5.1343-1348.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
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