Previous Article
Antimicrobial Agents and Chemotherapy, July 2000, p. 2007-2008, Vol. 44, No. 7
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
LETTERS TO THE EDITOR
Novel Fosfomycin Resistance of Pseudomonas
aeruginosa Clinical Isolates Recovered in Japan in 1996
 |
LETTER |
The antibiotic fosfomycin has been used in Japan for 21 years, and although it can be used as a single agent, it is more active when used in combination with various other antibiotics (3). Fosfomycin enters the cells of fosfomycin-susceptible bacteria by means
of two different transport uptake systems: GlpT and UhpT (10).
In our studies, we measured the MICs of fosfomycin for 412 randomly
selected Pseudomonas aeruginosa clinical isolates, collected in 1996 from across Japan, and investigated a new mechanism of resistance found among fosfomycin-resistant isolates.
Fosfomycin MICs were determined by agar dilution with an inoculum of
500 cells to the nutrient agar surface (Difco Laboratories) (4,
9). The enzymatic inactivation of fosfomycin using crude extracts
with and without cofactor (40 mM ATP) was determined by measuring
residual fosfomycin (9). The transfer frequency of
fosfomycin resistance was determined as described previously (9), using P. aeruginosa PAO2142Rp (8)
as recipient.
View larger version (18K):
[in this window]
[in a new window]
|
FIG. 1.
Inactivation of fosfomycin by crude extracts of P. aeruginosa CU252 and CU358 with and without ATP.  , heated crude
extract (CU252);  , crude extract (CU252) in the presence of ATP;
 , crude extract (CU252) without ATP;  , heated crude extract
(CU358);  , crude extract (CU358) in the presence of ATP;  , crude
extract (CU358) without ATP.
|
|
The distribution of MICs of fosfomycin for the 412 isolates of
P. aeruginosa exhibited a cluster of the majority of strains centered around an MIC value of 6.25 µg/ml and a second significant cluster centered at MICs of more than 12,800 µg/ml. Compared with the
1975 report of Goto et al. (4), our results suggested that the susceptibility of P. aeruginosa to fosfomycin has
remained almost unchanged for 21 years.
In 1977, although 65% of 60 fosfomycin-resistant
gram-negative isolates transferred some other demonstrable antibiotic
resistance to Escherichia coli K-12 in 1977 (2),
there were no occurrences of the transfer of fosfomycin resistance. Of
the 67 fosfomycin-resistant isolates in our study with MICs
greater than 800 µg/ml, none transferred this resistance to the
recipient strain PAO2142Rp. Thus, our data suggest that transferable
plasmid-encoded fosfomycin resistance has not emerged even in recent
Japanese P. aeruginosa isolates.
Crude extracts from two fosfomycin-resistant isolates,
CU252 and CU358, completely inactivated fosfomycin but only in
the presence of ATP (Fig. 1).
Fosfomycin resistance in clinical isolates is caused mainly by an
alteration of the chromosomally encoded GlpT transport system. The
plasmid-mediated fosfomycin glutathione S-transferase genes fosA and fosB, found in only a low percentage of
strains (1, 6, 7), catalyze the addition of glutathione to
fosfomycin (10).
The fosfomycin inactivation mechanism reported here appears to be new,
as it was nontransferable and ATP dependent. It will be interesting to
compare it with the mechanism in fosC and in fomA
and fomB cloned into E. coli from
fosfomycin-producing Pseudomonas syringae and
Streptomyces wedmorensis (5), respectively.
The correlation between fosfomycin resistance of P. aeruginosa and the mechanism of resistance, including enzyme
characterization, will be the subject of our future studies.
| |
ACKNOWLEDGMENTS |
This study was supported by a grant from Ministry of Health
and Welfare, Japan, 1999, for molecular characterization of antibiotic resistance and development of methods for the rapid detection of
drug-resistant bacteria.
| |
FOOTNOTES |
*
Phone: 81-43-290-2930
Fax: 81-43-290-2929
E-mail: oharak{at}p.chiba-u.ac.jp
| |
REFERENCES |
| 1.
|
Arca, P.,
G. Reguera, and C. Hardisson.
1997.
Plasmid-encoded fosfomycin resistance in bacteria isolated from the urinary tract in a multicentre survey.
J. Antimicrob. Chemother.
40:393-399[Abstract/Free Full Text].
|
| 2.
|
Baquero, F.,
M. Lopez-Brea,
A. Valls, and T. Canedo.
1977.
Fosfomycin and plasmidic resistance.
Chemotherapy
23(Suppl. 1):133-140.
|
| 3.
|
Gatermann, S.,
E. Schulz, and R. Marre.
1989.
The microbiological efficacy of combination of fosfomycin and vancomycin against clinically relevant staphylococci.
Infection
17:35-37[CrossRef][Medline].
|
| 4.
|
Goto, S.,
I. Dogasaki,
Y. Kaneko,
M. Ogawa,
T. Takita, and S. Kuwahara.
1975.
In vitro and in vivo antibacterial activity of fosfomycin.
Chemotherapy
23:1653-1661.
|
| 5.
|
Kobayashi, S.,
T. Kuzuyama, and H. Seto.
2000.
Characterization of the fomA and fomB gene products from Streptomyces wedmorensis, which confer fosfomycin resistance on Escherichia coli.
Antimicrob. Agents Chemother.
44:647-650[Abstract/Free Full Text].
|
| 6.
|
O'Hara, K.
1993.
Two different types of fosfomycin resistance in clinical isolates of Klebsiella pneumoniae.
FEMS Microbiol. Lett.
114:9-16[CrossRef][Medline].
|
| 7.
|
O'Hara, K.,
J. Kotake,
K. Omiya, and M. Kono.
1988.
Fosfomycin-inactivating enzyme from clinically isolated Pseudomonas aeruginosa.
Chemotherapy
36:905-910.
|
| 8.
|
O'Hara, K.,
T. Kawabe,
K. Taniguchi,
M. Ohnuma,
M. Nakagawa,
Y. Naitou, and T. Sawai.
1997.
A simple assay for determining aminoglycoside inactivation in intact cells of Pseudomonas aeruginosa.
Microbios
90:177-186[Medline].
|
| 9.
|
Shimizu, M.,
T. Nonomiya,
F. Shigenobu,
K. O'Hara, and T. Sawai.
1998.
Fosfomycin resistance in Escherichia coli in Japan.
J. Antibiot.
51:889-892[Medline].
|
| 10.
|
Suárez, J. E., and M. C. Mendoza.
1991.
Plasmid-encoded fosfomycin resistance.
Antimicrob. Agents Chemother.
35:791-795[Free Full Text].
|
| | | | |
Masaki Shimizu
Fritz Shigenobu
Izumi Miyakozawa
Akio Nakamura
Kyoko Nakazawa
Masato Suzuki
Satoko Mizukoshi
Koji O'Hara*
Tetsuo Sawai
Division of Microbial Chemistry
Faculty of Pharmaceutical Sciences
Chiba University
1-33, Yayoi-cho, Inage-ku
Chiba-shi, Chiba 263-8522
Japan
|
Antimicrobial Agents and Chemotherapy, July 2000, p. 2007-2008, Vol. 44, No. 7
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
MacLeod, D. L., Barker, L. M., Sutherland, J. L., Moss, S. C., Gurgel, J. L., Kenney, T. F., Burns, J. L., Baker, W. R.
(2009). Antibacterial activities of a fosfomycin/tobramycin combination: a novel inhaled antibiotic for bronchiectasis. J Antimicrob Chemother
64: 829-836
[Abstract]
[Full Text]
-
Pakhomova, S., Bartlett, S. G., Augustus, A., Kuzuyama, T., Newcomer, M. E.
(2008). Crystal Structure of Fosfomycin Resistance Kinase FomA from Streptomyces wedmorensis. J. Biol. Chem.
283: 28518-28526
[Abstract]
[Full Text]
-
Beharry, Z., Palzkill, T.
(2005). Functional Analysis of Active Site Residues of the Fosfomycin Resistance Enzyme FosA from Pseudomonas aeruginosa. J. Biol. Chem.
280: 17786-17791
[Abstract]
[Full Text]
