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Antimicrobial Agents and Chemotherapy, February 2001, p. 641-642, Vol. 45, No. 2
0066-4804/01/$04.00+0 DOI: 10.1128/AAC.45.2.641-642.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
LETTERS TO THE EDITOR
Characterization of the mupA Gene in Strains of
Methicillin-Resistant Staphylococcus aureus with a Low
Level of Resistance to Mupirocin
 |
LETTER |
Clinical isolates of mupirocin-resistant
Staphylococcus aureus were first reported in 1987 (4), and low-level resistance was reported to be conferred
by the chromosomal location of the mupA gene
(5) in some but not all strains (6). On the
other hand, low-level resistance in S. aureus emerged as the
result of independent, spontaneous mutational events by exposure to
increasing concentrations of mupirocin. In the present study, we
examined the mupA gene for molecular heterogeneity in
S. aureus strains with low-level resistance to mupirocin
(L-Mup) which were isolated from London, United Kingdom, and different
geographic regions within the Tohoku area in Japan. A total of 25 L-Mup
strains were obtained from individual patients at King's College
Hospital, London. Three hundred methicillin-resistant
Staphylococcus aureus (MRSA) strains were collected from 14 hospitals in different geographic regions of the Tohoku area in Japan,
and two of the 300 MRSA strains (J7022 and J7023) were L-Mup. All
strains were collected from different patients and tested for low-level
resistance by the disk diffusion assay using 5- and 200-µg-mupirocin
disks (1). Genomic DNAs were extracted from all strains by
boiling as previously described (3). The mupA
gene was amplified using two oligonucleotide primer pairs. Mup1 and
Mup2 were as previously described (5). The primers used
were Mup3 (5'-TTCGGATAGTGCTCCATG-3') and Mup4 (5'-CCCCAGTTACACCGATAT-3'), which amplified a 1.1-kb product
from the mupA gene (nucleotides 2315 to 3408 [2]). PCR amplification of each fragment was performed
using the reaction mixture reported previously (5). The
amplification conditions were as follows: for fragment 1 (1.65 kb), 30 cycles of 1 min at 94°C, 2 min at 55°C, and 3 min at 72°C, with a
final extension (3 min at 72°C); for fragment 2 (1.1 kb), 30 cycles
at 92°C for 1 min, 55°C for 1 min, and 72°C for 2 min. We were
unable to detect the mupA gene in any of the 25 L-Mup
S. aureus strains from London. However, each of the 1.65- and 1.1-kb internal mupA gene fragments were amplifications
of one L-Mup MRSA strain (J7023) in Japan. To characterize potential
mutations of the mupA gene, J7023 was used. The sequence of
the 3,072-bp (a complete open reading frame A) internal mupA gene fragment was determined by dye terminator cycle sequencing using a
model 377XL sequencer (PE Applied Biosystems, Rockville, Md.) and
compared with that of the reported sequence (2). The 3,072 bp of the J7023 sequence was identical to the reported sequence. We
attempted to use in vitro inducement of high-level mupirocin resistance
to distinguish between two L-Mup strains from London, J7022 and J7023,
which include the mupA gene. These four clonally distinct
strains were incubated to transfer 10 times while being exposed to
one-half the MIC of mupirocin. For J7023, which includes the
mupA gene, the MIC was similar to those for the other three L-Mup strains (Fig. 1).
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FIG. 1.
In vitro development of mupirocin resistance. Symbols
denote two L-Mup strains (open circles and squares) isolated from
London, J7022 (filled squares), and J7023 (filled circles). These four
strains were incubated to transfer 10 times while being exposed to
one-half the MIC of mupirocin on diluted-agar plates.
|
|
In this study, we detected no evidence that the presence of the
mupA gene enhanced the ability of S. aureus
strains to become resistant to mupirocin.
| |
FOOTNOTES |
*
Phone and fax:
81-022-377-8289
E-mail: hujimura{at}mail.sp.myuac.jp
| |
REFERENCES |
| 1.
|
Cookson, B.,
H. Farrelly,
M.-F. Palepou, and R. George.
1992.
Mupirocin-resistant Staphylococcus aureus.
Lancet
339:625[Medline].
|
| 2.
|
Hodgeson, J. E.,
S. P. Curnock,
K. G. H. Dyke,
R. Morris,
D. R. Sylvester, and M. S. Gross.
1994.
Molecular characterization of the gene encoding high-level mupirocin resistance in Staphylococcus aureus J2870.
Antimicrob. Agents Chemother.
38:1205-1208[Abstract/Free Full Text].
|
| 3.
|
Nunes, E. L.,
K. R. dos Santos,
P. J. Mondino,
M. d. C. Bastos, and M. Giambiagi-deMarval.
1999.
Detection of ils-2 gene encoding mupirocin resistance in methicillin-resistant Staphylococcus aureus by multiplex PCR.
Diagn. Microbiol. Infect. Dis.
34:77-81[CrossRef][Medline].
|
| 4.
|
Rahman, M.,
W. C. Noble, and B. Cookson.
1987.
Mupirocin resistant Staphylococcus aureus.
Lancet
ii:387.
|
| 5.
|
Ramsey, M. A.,
S. F. Bradley,
C. A. Kauffman, and T. M. Morton.
1996.
Identification of chromosomal location of mupA gene, encoding low-level mupirocin resistance in staphylococcal isolates.
Antimicrob. Agents Chemother.
40:2820-2823[Abstract].
|
| 6.
|
Ramsey, M. A.,
S. F. Bradley,
C. A. Kauffman,
T. M. Morton,
J. E. Patterson, and D. R. Reagan.
1998.
Characterization of mupirocin resistant Staphylococcus aureus from different geographic areas.
Antimicrob. Agents Chemother.
42:1305[Free Full Text].
|
| | | | |
Shigeru Fujimura*
Department of Microbiology
Miyagi University
1 Gakuen, Taiwa-cho
Miyagi 981-3298, Japan
|
| | | | |
Akira Watanabe
Department of Respiratory Oncology
Institute of Development, Aging and Cancer
Tohoku University
Sendai, Japan
|
| | | | |
David Beighton
Joint Microbiology Research Unit
Guy's, King's and St. Thomas' Dental Institute
King's College School of Medicine and Dentistry
London, United Kingdom
|
Antimicrobial Agents and Chemotherapy, February 2001, p. 641-642, Vol. 45, No. 2
0066-4804/01/$04.00+0 DOI: 10.1128/AAC.45.2.641-642.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
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