Previous Article | Next Article 
Journal of Clinical Microbiology, January 2001, p. 53-56, Vol. 39, No. 1
Medical Microbiology Division, Department of
Pathology, University of Iowa College of Medicine, Iowa City, Iowa
52242
Received 21 August 2000/Returned for modification 10 October
2000/Accepted 18 October 2000
The Vitek automated susceptibility testing system with a modified
Gram-Positive Susceptibility (GPS) 106 Card (bioMerieux Vitek, Inc.,
Hazelwood, Mo.) and a rapid slide latex agglutination test
(MRSA-Screen; Denka Seiken Co., Ltd., Tokyo, Japan) were evaluated for
their ability to detect oxacillin resistance in Staphylococcus
aureus. The oxacillin-salt agar screen (OS) test, the reference
broth microdilution method, and the detection of the mecA
gene by PCR were compared with the commercial products. A total of 200 contemporary (1999) bloodstream infection isolates were collected from
the SENTRY Antimicrobial Surveillance Program, representing diverse
geographic areas throughout the world. Among the 99 mecA-positive isolates, 3 isolates were found negative by
the MRSA-Screen. Another two isolates did not grow on OS plates and had
MICs of 0.5 and 2 µg/ml with the Vitek GPS card. All 101 mecA-negative isolates were also found negative by the
MRSA-Screen and were categorized as susceptible by the GPS card.
Overall, the MRSA-Screen, GPS card, and OS test had sensitivities of
96.9, 98.0, and 98.0% and specificities of 100.0, 100.0, and 98.0%, respectively. MRSA-Screen was a rapid ( Methicillin-resistant
Staphylococcus aureus (MRSA) is a significant pathogen that
has steadily emerged over the last four decades to now cause both
nosocomial and community-acquired infections (2). The
optimal phenotypic method for detecting (methicillin) oxacillin
resistance in S. aureus remains controversial. Moreover, errors in the detection of oxacillin resistance can lead to important adverse clinical consequences. False-susceptible results may contribute to treatment failure as well as to the unchecked spread of MRSA due to
a failure to apply appropriate infection control measures. False-resistant results contribute to increased health care costs related to unnecessary isolation precautions, in addition to the consequences of overuse of glycopeptide antimicrobials agents, with
associated resistance risk (8). The definitive genotypic test for oxacillin resistance in S. aureus (mecA
gene detection by PCR) is not practical for routine performance in
clinical laboratories. Therefore, there is an urgent need for a rapid,
sensitive, and specific test for MRSA that can be easily performed in
clinical microbiology laboratories.
This study was performed to compare two newly available tests: (i) the
Vitek automated susceptibility testing system with the recently
modified Gram-Positive Susceptibility (GPS) 106 Card (bioMerieux Vitek,
Inc., Hazelwood, Mo.) and (ii) a rapid slide latex agglutination test
(16) for the detection of oxacillin resistance in recent
(1999) blood culture isolates of S. aureus obtained from
patients worldwide.
Bacterial isolates.
A total of 200 bloodstream infection
isolates were obtained from the SENTRY Antimicrobial Surveillance
Program (19), representing diverse geographic areas (81 isolates from North America, 33 isolates from Latin America, 48 isolates from the Western Pacific, and 38 isolates from Europe). These
isolates were selected on the basis of oxacillin MIC distribution using
SENTRY-based results from reference broth microdilution testing as
recommended by the National Committee for Clinical Laboratory Standards
(NCCLS). The isolates used in this study had the following oxacillin
MICs (number of isolates): Susceptibility testing methods.
The MRSA-Screen test was
performed according to the manufacturer's instructions. Briefly, a
1-µl loop of bacterial cells was taken from a fresh subculture,
suspended in 4 drops of extraction reagent 1, and boiled for 3 min.
After the suspension was allowed to cool to room temperature, 1 drop of
extraction reagent 2 was added and vortexed thoroughly. The suspension
was centrifuged at 1,500 × g for 5 min. A 50-µl
aliquot of the supernatant was mixed with 1 drop of anti-PBP 2a
monoclonal antibody-sensitized latex beads. A negative control
consisted of 50 µl of supernatant mixed with 1 drop of negative
control latex. The samples were placed on a shaker for 3 min prior to
visual assessment of agglutination.
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.1.53-56.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Comparison of the Vitek Gram-Positive
Susceptibility 106 Card and the MRSA-Screen Latex Agglutination Test
for Determining Oxacillin Resistance in Clinical Bloodstream Isolates
of Staphylococcus aureus
ABSTRACT
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
15 min) and simple test to
perform, and the GPS card provided results in <8 h. Both methods were
sensitive and specific for detecting staphylococcal oxacillin resistance in the clinical microbiology laboratory.
INTRODUCTION
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
MATERIALS AND METHODS
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
0.06 µg/ml (1), 0.12 µg/ml (13), 0.25 µg/ml (31), 0.5 µg/ml (19), 1 µg/ml (23), 2 µg/ml (14), 4 µg/ml (4), 8 µg/ml (2), and >8 µg/ml (93). All of the isolates
had species level identification confirmed by conventional tests
(9), specifically, slide and tube coagulase tests
and an automated procedure (bioMerieux Vitek). All isolates
were frozen at 
70°C until processed. Prior to being tested, each
isolate was subcultured at least twice on blood agar plates (Remel,
Lenexa, Kans.) to ensure purity and optimal growth characteristics. All
isolates were subjected to blind testing with the MRSA-Screen (Denka
Seiken Co., Ltd., Tokyo, Japan) test, oxacillin-salt agar screen (OS)
test, and determination of oxacillin MICs by use of the Vitek GPS 106 Card and the reference NCCLS broth microdilution test (17,
18). Control strains used for all assays included MRSA ATCC
43300 and a well-characterized MRSA clinical strain as well as the
quality control strain S. aureus ATCC 29213 (oxacillin susceptible).
2 µg/ml; MIC for resistant, 
4 µg/ml [17, 18].
Antimicrobial susceptibility testing of isolates using OS plates
(Mueller-Hinton agar plates supplemented with 4% NaCl and 6 µg of
oxacillin per ml [Remel]) and broth microdilution trays was performed
in accordance with NCCLS guidelines (17, 18).
PCR was performed for the detection of mecA as previously
described (3, 5). When S. aureus isolates
yielded discrepant results among the tests used, the tests were
repeated in triplicate with specimens from the same organism source.
| |
RESULTS |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
Table 1 summarizes the results
obtained with the MRSA-Screen test, the Vitek GPS 106 Card, the OS
test, and the reference broth microdilution method. Of the 200 isolates
tested, 99 isolates were found positive by mecA PCR and 101 were found negative. The MRSA-Screen test was able to accurately detect
oxacillin resistance in almost all isolates (sensitivity, 96.9%).
There were no false-positive results (specificity, 100.0%). However,
oxacillin resistance was not detected in three isolates (Tables 1 and
2). Upon retesting of these isolates, two
isolates produced visible agglutination with anti-PBP 2a-sensitized
latex within the 3 min recommended by the manufacturer (sensitivity,
99.0%). The other isolate was found positive when the slide latex
agglutination reaction was extended to 10 min.
|
|
The Vitek GPS 106 Card also had high sensitivity (98.0%) and specificity (100.0%). However, the GPS card falsely categorized two isolates as oxacillin susceptible, with MICs of 0.5 and 2 µg/ml (Table 2). One of these isolates also was categorized as oxacillin susceptible by the broth microdilution method (MIC, 2 µg/ml), and the other isolate was borderline oxacillin resistant (MIC, 4 µg/ml). Both isolates were found negative (susceptible) by the OS test. The OS test was also reliable for the detection of MRSA, with a sensitivity and a specificity of 98.0%. Two false-positive (susceptible) tests resolved when the test was repeated in triplicate (specificity, 100.0%).
Upon replicate testing of a panel of isolates, the MRSA-Screen was found to be 100% reproducible (data not shown).
| |
DISCUSSION |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
This investigation showed that the detection of PBP 2a by the MRSA-Screen test and the Vitek automated susceptibility testing system with the modified GPS 106 Card were sensitive and specific for detecting staphylococcal oxacillin resistance in clinical bloodstream infection isolates. Since the isolates used in this study were selected from diverse geographic areas (epidemiologically unique) and their oxacillin MIC distribution approximated that of all S. aureus isolates in the SENTRY Program, this collection can be regarded as a reflection of S. aureus strains seen in clinical laboratories throughout the world. This study validated each rapid method tested (15 min to 8 h), as well as the NCCLS methods, in this high-priority clinical setting.
The MRSA-Screen test was very rapid and easy to perform, providing
results within 15 min. This test has been evaluated by several
investigators, and our results were similar (1, 14, 15, 21,
22). Previous studies were done with locally endemic clinical
strains from western Europe, Canada, and Australia. When false-negative
results were observed (three mecA-positive isolates), most
(two) were positive when repeated. We assume that the false-negative results occurred secondary to a low inoculation volume. The recent study by Louie et al. (14) indicated that the use of a
larger inoculum, of approximately 50 colonies, resulted in improved
sensitivity without a loss of specificity. The remaining single
discordant isolate showed no agglutination after 3 min of rotation
(recommended by the manufacturer), but when the reaction time was
extended to 10 min, visible agglutination occurred, confirming the
observations of others (21). von Griethuysen et al.
(21) reported five mecA-positive isolates that
demonstrated only weak positive results after 3 min of rotation, but
agglutination became stronger when rotation was extended to 6 min. The
manufacturer has recently modified the package insert recommendations,
indicating the need for extended time (10 min) for agglutination. On
the other hand, some oxacillin-susceptible isolates may show
false-positive reactions due to the prolonged reaction time. In fact,
we found weak positive reactions for oxacillin-susceptible isolates,
including the ATCC 25923 control strain, when incubation was prolonged
for 15 min. Therefore, it is suggested that any strain showing
agglutination after 10 min should undergo a mecA PCR as the
final and conclusive confirmatory assay.
The Vitek system with the GPS 106 Card was easy to use and could provide results within 8 h. The GPS card was revised to a total of three oxacillin-containing wells, and new software (R07.01) was developed to analyze this pattern of concentrations. Although the GPS card was also modified to meet the new NCCLS oxacillin breakpoint for coagulase-negative staphylococci (17, 18), an assessment of the ability of the GPS card to detect methicillin-resistant coagulase-negative staphylococci is pending.
Prior studies using earlier versions of Vitek system cards have raised persisting concerns over their accuracy for detecting oxacillin resistance (6, 7, 12, 20), but interim modifications of the system have led to improved detection of this resistance (4, 10, 11). As an example of earlier problems, Skulnick et al. (20) compared results obtained by reference methods, including broth microdilution and mecA gene probe, with those obtained by the Vitek GPS-SA Card. These investigations in 1992 reported 14.2% very major (false-susceptible) errors (20). In contrast, Knapp et al. (10) examined 67 oxacillin-resistant isolates of S. aureus with the Vitek GPS-SA Card and found nearly complete agreement with the mecA results. More recently, Frebourg et al. (4) evaluated the ability of three automated systems to detect oxacillin resistance. In that study, the Vitek system with the GPS 503 Card was judged acceptable, but it failed to detect 3 of 64 mecA-positive S. aureus isolates (4.7% false-susceptible results) (4). Only 2% of mecA-positive isolates were misclassified as oxacillin susceptible in our evaluation, and we confirmed the Vitek system accuracy using the latest GPS card and associated software.
Nevertheless, there remain several concerns regarding the accuracy of detection of oxacillin resistance in heterogeneously resistant populations of clinical S. aureus isolates using phenotypic methods. Difficulties in the differentiation of MRSA from borderline oxacillin-resistant isolates may still occur (2, 13). Although we did not evaluate the accuracy of the Vitek system and the MRSA-Screen with such rare but challenging isolates, previous studies indicated that both tests are able to accurately detect heteroresistant isolates (1, 4). MRSA-Screen has also been found to be able to differentiate borderline oxacillin-resistant S. aureus from true MRSA (14). However, one study of mecA-negative S. aureus strains with borderline susceptibility to oxacillin revealed that 10% of such strains were classified as MRSA by earlier Vitek cards (11), and the Vitek GPS 106 Card (tested here) must be assessed in this area. Thus, the MRSA-Screen could emerge as a useful and technically simple test for the direct assessment of mecA in clinical laboratories where PCR for this gene or the Vitek system is not readily available.
In conclusion, we found the MRSA-Screen and the Vitek system with the modified GPS 106 Card to be reliable for the detection of oxacillin resistance in S. aureus. Both tests were rapid and easy to perform, and each has the potential for wider use in clinical microbiology laboratories.
| |
ACKNOWLEDGMENTS |
|---|
Toshiaki Yamazumi was partly supported by a grant from the Japan Clinical Pathology Foundation for International Exchanges. This study was supported in part by a grant from bioMerieux Vitek, Inc., and funds from the Department of Pathology, University of Iowa College of Medicine.
MRSA-Screen tests used in this study were kindly provided by Denka Seiken Co.
| |
FOOTNOTES |
|---|
* Corresponding author. Present address: 345 Beaver Kreek Centre, Suite A, North Liberty, IA 52317. Phone: (319) 665-3370. Fax: (319) 665-3371.
Present address: Department of Clinical Pathology, Kinki University
School of Medicine, Ohnohigashi, Osakasayama, Osaka, Japan 589-8511.
| |
REFERENCES |
|---|
|
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
|
|---|
| 1. |
Cavassini, M.,
A. Wenger,
K. Jaton,
D. S. Blanc, and J. Bille.
1999.
Evaluation of MRSA-Screen, a simple anti-PBP 2a slide latex agglutination kit, for rapid detection of methicillin resistance in Staphylococcus aureus.
J. Clin. Microbiol.
37:1591-1594 |
| 2. | Chambers, H. F. 1997. Methicillin resistance in staphylococci: molecular and biochemical basis and clinical implications. Clin. Microbiol. Rev. 10:781-791[Abstract]. |
| 3. | Cormican, M. G., W. W. Wilke, M. S. Barrett, M. A. Pfaller, and R. N. Jones. 1996. Phenotypic detection of mecA-positive staphylococcal blood stream isolates: high accuracy of simple disk diffusion tests. Diagn. Microbiol. Infect. Dis. 25:107-112[CrossRef][Medline]. |
| 4. |
Frebourg, N. B.,
D. Nouet,
L. Lemee,
E. Martin, and J. F. Lemeland.
1998.
Comparison of ATB staph, rapid ATB staph, Vitek, and E-test methods for detection of oxacillin heteroresistance in staphylococci possessing mecA.
J. Clin. Microbiol.
36:52-57 |
| 5. |
Geha, D. J.,
J. R. Uhl,
C. A. Gustaferro, and D. H. Persing.
1994.
Multiplex PCR for identification of methicillin-resistant staphylococci in the clinical laboratory.
J. Clin. Microbiol.
32:1768-1772 |
| 6. |
Hansen, S. L., and T. J. Walsh.
1987.
Detection of intrinsically resistant (heteroresistant) Staphylococcus aureus with the Sceptor and AutoMicrobic systems.
J. Clin. Microbiol.
25:412-415 |
| 7. |
Henry, D.,
L. Kunzer,
J. Ngui-Yen, and J. Smith.
1986.
Comparative evaluation of four systems for determining susceptibility of gram-positive organisms.
J. Clin. Microbiol.
23:718-724 |
| 8. | Hiramatsu, K. 1998. The emergence of Staphylococcus aureus with reduced susceptibility to vancomycin in Japan. Am. J. Med. 29:7S-10S. |
| 9. | Kloos, W. K., and T. L. Bannerman. 1999. Staphylococcus and Micrococcus, p. 264-282. In P. R. Murray, E. J. Baron, M. A. Pfaller, F. C. Tenover, and R. H. Yolken (ed.), Manual of clinical microbiology, 7th ed. ASM Press, Washington, D.C. |
| 10. |
Knapp, C. C.,
M. D. Ludwig, and J. A. Washington.
1994.
Evaluation of differential inoculum disk diffusion method and Vitek GPS-SA card for detection of oxacillin-resistant staphylococci.
J. Clin. Microbiol.
32:433-436 |
| 11. | Knapp, C. C., M. D. Ludwig, J. A. Washington, and H. F. Chambers. 1996. Evaluation of Vitek GPS-SA card for testing of oxacillin against borderline-susceptible staphylococci that lack mec. J. Clin. Microbiol. 34:1603-1605[Abstract]. |
| 12. |
Lally, R. T.,
M. N. Ederer, and B. F. Woolfrey.
1986.
Evaluation of the newly modified AutoMicrobic system gram-positive susceptibility-MIC card for detection of methicillin-resistant Staphylococcus aureus.
J. Clin. Microbiol.
23:387 |
| 13. | Liu, H., G. Buescher, N. Lewis, S. Snyder, and D. Jungkind. 1990. Detection of borderline oxacillin-resistant Staphylococcus aureus and differentiation from methicillin-resistant strains. Eur. J. Clin. Microbiol. Infect. Dis. 9:717-724[CrossRef][Medline]. |
| 14. |
Louie, L.,
S. O. Matsumura,
E. Choi,
M. Louie, and A. E. Simor.
2000.
Evaluation of three rapid methods for detection of methicillin resistance in Staphylococcus aureus.
J. Clin. Microbiol.
38:2170-2173 |
| 15. |
Marriott, D. J.,
T. Karagiannis,
J. L. Harkness, and P. Kearney.
1999.
Further evaluation of the MRSA-Screen kit for rapid detection of methicillin resistance.
J. Clin. Microbiol.
37:3783-3784 |
| 16. | Nakatomi, Y., and J. Sugiyama. 1998. A rapid latex agglutination assay for the detection of penicillin-binding protein 2'. Microbiol. Immunol. 42:739-743[Medline]. |
| 17. | National Committee for Clinical Laboratory Standards. 2000. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. Approved standard M7-A5. National Committee for Clinical Laboratory Standards, Wayne, Pa. |
| 18. | National Committee for Clinical Laboratory Standards. 2000. Performance standards for antimicrobial susceptibility testing. Tenth informational supplement. M100-S10. National Committee for Clinical Laboratory Standards, Wayne, Pa. |
| 19. |
Pfaller, M. A.,
R. N. Jones,
G. V. Doern,
K. Kugler, and the SENTRY Participants Group.
1998.
Bacterial pathogens isolated from patients with bloodstream infection: frequencies of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (United States and Canada, 1997).
Antimicrob. Agents Chemother.
42:1762-1770 |
| 20. |
Skulnick, M.,
A. E. Simor,
D. Gregson,
M. Patel,
G. W. Small,
B. Kreiswirth,
D. Hathoway, and D. E. Low.
1992.
Evaluation of commercial and standard methodology for determination of oxacillin susceptibility in Staphylococcus aureus.
J. Clin. Microbiol.
30:1985-1988 |
| 21. |
van Griethuysen, A.,
M. Pouw,
N. van Leeuwen,
M. Heck,
P. Willemse,
A. Buiting, and J. Kluytmans.
1999.
Rapid slide latex agglutination test for detection of methicillin resistance in Staphylococcus aureus.
J. Clin. Microbiol.
37:2789-2792 |
| 22. |
van Leeuwen, W. B.,
C. van Pelt,
A. Luijendijk,
H. A. Verbrugh, and W. H. Goessens.
1999.
Rapid detection of methicillin resistance in Staphylococcus aureus isolates by the MRSA-Screen latex agglutination test.
J. Clin. Microbiol.
37:3029-3030 |
Journal of Clinical Microbiology, January 2001, p. 53-56, Vol. 39, No. 1
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.1.53-56.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Nadarajah, J., Lee, M. J. S., Louie, L., Jacob, L., Simor, A. E., Louie, M., McGavin, M. J.
(2006). Identification of different clonal complexes and diverse amino acid substitutions in penicillin-binding protein 2 (PBP2) associated with borderline oxacillin resistance in Canadian Staphylococcus aureus isolates.. J Med Microbiol
55: 1675-1683
[Abstract] [Full Text] -
Bressler, A. M., Williams, T., Culler, E. E., Zhu, W., Lonsway, D., Patel, J. B., Nolte, F. S.
(2005). Correlation of Penicillin Binding Protein 2a Detection with Oxacillin Resistance in Staphylococcus aureus and Discovery of a Novel Penicillin Binding Protein 2a Mutation. J. Clin. Microbiol.
43: 4541-4544
[Abstract] [Full Text] -
Kaplan, S., Marlowe, E. M., Hogan, J. J., Doymaz, M., Bruckner, D. A., Simor, A. E.
(2005). Sensitivity and Specificity of a Rapid rRNA Gene Probe Assay for Simultaneous Identification of Staphylococcus aureus and Detection of mecA. J. Clin. Microbiol.
43: 3438-3442
[Abstract] [Full Text] -
Miller, M. B., Meyer, H., Rogers, E., Gilligan, P. H.
(2005). Comparison of Conventional Susceptibility Testing, Penicillin-Binding Protein 2a Latex Agglutination Testing, and mecA Real-Time PCR for Detection of Oxacillin Resistance in Staphylococcus aureus and Coagulase-Negative Staphylococcus. J. Clin. Microbiol.
43: 3450-3452
[Abstract] [Full Text] -
Pottumarthy, S., Schapiro, J. M., Prentice, J. L., Houze, Y. B., Swanzy, S. R., Fang, F. C., Cookson, B. T.
(2004). Clinical Isolates of Staphylococcus intermedius Masquerading as Methicillin-Resistant Staphylococcus aureus. J. Clin. Microbiol.
42: 5881-5884
[Abstract] [Full Text] -
Diekema, D. J., Dodgson, K. J., Sigurdardottir, B., Pfaller, M. A.
(2004). Rapid Detection of Antimicrobial-Resistant Organism Carriage: an Unmet Clinical Need. J. Clin. Microbiol.
42: 2879-2883
[Full Text] -
Donay, J.-L., Mathieu, D., Fernandes, P., Pregermain, C., Bruel, P., Wargnier, A., Casin, I., Weill, F. X., Lagrange, P. H., Herrmann, J. L.
(2004). Evaluation of the Automated Phoenix System for Potential Routine Use in the Clinical Microbiology Laboratory. J. Clin. Microbiol.
42: 1542-1546
[Abstract] [Full Text] -
Bauer, T. T.
(2003). Nosocomial Pneumonia: Therapy Is Just Not Good Enough. Chest
124: 1632-1634
[Full Text] -
Felten, A., Grandry, B., Lagrange, P. H., Casin, I.
(2002). Evaluation of Three Techniques for Detection of Low-Level Methicillin-Resistant Staphylococcus aureus (MRSA): a Disk Diffusion Method with Cefoxitin and Moxalactam, the Vitek 2 System, and the MRSA-Screen Latex Agglutination Test. J. Clin. Microbiol.
40: 2766-2771
[Abstract] [Full Text] -
Merlino, J., Watson, J., Rose, B., Beard-Pegler, M., Gottlieb, T., Bradbury, R., Harbour, C.
(2002). Detection and expression of methicillin/oxacillin resistance in multidrug-resistant and non-multidrug-resistant Staphylococcus aureus in Central Sydney, Australia. J Antimicrob Chemother
49: 793-801
[Abstract] [Full Text] -
Sakoulas, G., Gold, H. S., Venkataraman, L., DeGirolami, P. C., Eliopoulos, G. M., Qian, Q.
(2001). Methicillin-Resistant Staphylococcus aureus: Comparison of Susceptibility Testing Methods and Analysis of mecA-Positive Susceptible Strains. J. Clin. Microbiol.
39: 3946-3951
[Abstract] [Full Text] -
Yamazumi, T., Furuta, I., Diekema, D. J., Pfaller, M. A., Jones, R. N.
(2001). Comparison of the Vitek Gram-Positive Susceptibility 106 Card, the MRSA-Screen Latex Agglutination Test, and mecA Analysis for Detecting Oxacillin Resistance in a Geographically Diverse Collection of Clinical Isolates of Coagulase-Negative Staphylococci. J. Clin. Microbiol.
39: 3633-3636
[Abstract] [Full Text] -
Swenson, J. M., Williams, P. P., Killgore, G., O'Hara, C. M., Tenover, F. C.
(2001). Performance of Eight Methods, Including Two New Rapid Methods, for Detection of Oxacillin Resistance in a Challenge Set of Staphylococcus aureus Organisms. J. Clin. Microbiol.
39: 3785-3788
[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»