Hostname: page-component-6d856f89d9-fb4gq Total loading time: 0 Render date: 2024-07-16T08:14:17.218Z Has data issue: false hasContentIssue false
  • English
  • Français

Use of a Novel Selective Medium to Detect Methicillin-Resistant Staphylococcus aureus in Colonized Patients of an Intensive Care Unit

Published online by Cambridge University Press:  02 January 2015

Cícero Gomes Dias ,
Marcos Vinícius Rosa Röpke ,
Silvana Superti ,
Laura Berquó  and
Pedro d'Azevedo
Cícero Gomes Dias*
Affiliation:
Department of Microbiology and Parasitology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, Brazil
Marcos Vinícius Rosa Röpke
Affiliation:
Department of Microbiology and Parasitology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, Brazil
Silvana Superti
Affiliation:
Laboratory, Hospital Mãe de Deus, Porto Alegre, Brazil
Laura Berquó
Affiliation:
Infection Control Service, Hospital Mãe de Deus, Porto Alegre, Brazil
Pedro d'Azevedo
Affiliation:
Department of Microbiology and Parasitology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, Brazil
*
Department of Microbiology and Parasitology, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Porto Alegre, RS, BrazilCEP: 900050-170
Get access Rights & Permissions [Opens in a new window]

Abstract

Background:

Detection of colonized patients is important for implementing control measures for methicillin-resistant Staphylococcus aureus (MRSA). Laboratory detection of MRSA carriers is increased by the use of selective screening media, helping control dissemination of such organisms.

Objective:

To evaluate three different media, including selective and nonselective media, in the detection of MRSA from clinical specimens of patients of an intensive care unit (ICU).

Patients:

Adult patients in the ICU of the Hospital Mae de Deus, Porto Alegre, Brazil.

Methods:

A total of 224 specimens were obtained from the nares of patients and plated on blood agar, mannitol sait agar containing 2 μg/mL of oxacillin (MSAO), and oxacillin resistance screening agar base (ORSAB). The presence of MRSA was investigated in typical colonies growing on the three types of media. Discrepant results were resolved by detection of the mecA gene by polymerase chain reaction and the modified penicillin binding protein known as PBP2'.

Results:

MRSA was detected in 32 (14.3%) of 224 specimens. Blood agar, MSAO, and ORSAB detected MRSA in 17, 31, and 28 specimens, respectively. After the coagulase test, no false resistance was observed.

Conclusion:

MSAO and ORSAB performed equivalently in the detection of MRSA of colonized patients and require a single supplementary test (coagulase) to confirm MRSA.

Type
Original Articles
Information
Infection Control & Hospital Epidemiology , Volume 25 , Issue 2 , February 2004 , pp. 130 - 132
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Diekema, DJ, Pfaller, MA, Turnidge, J, et al.Genetic relatedness of multidrug-resistant, methicillin (oxacillin)-resistant Staphylococcus aureus bloodstream isolates from SENTRY Antimicrobial Resistance Centers Worldwide, 1998. Microb Drug Resist 2000;6:213–221.Google Scholar
2.Sader, HS, Gales, AC, Pfaller, MA, et al.Pathogen frequency and resistance patterns in Brazilian hospitals: summary of results from three years of the SENTRY Antimicrobial Surveillance Program. Braz J Infect Dis 2001;5:200–214.CrossRefGoogle ScholarPubMed
3.Girou, E, Pujade, G, Legrand, P, Cizeau, F, Brun-Buisson, C. Selective screening of carriers for control of methicillin-resistant Staphylococcus aureus (MRSA) in high-risk hospital areas with a high level of endemie MRSA. Clin Infect Dis 1998;27:543–550.Google Scholar
4.Herwaldt, LA. Control of methicillin-resistant Staphylococcus aureus in the hospital setting. Am J Med 1999;106(suppl 5A):11–18.Google Scholar
5.Mir, N, Sánchez, M, Baquero, F, López, B, Calderón, C, Canton, R. Soft salt-mannitol agar-cloxacillin test: a highly specifie bedside screening test for detection of colonization with methicillin-resistant Staphylococcus aureus. J Clin Microbiol 1998;36:986–989.Google Scholar
6.Davies, S, Zadik, PM, Mason, CM, Whittaker, SJ. Methicillin-resistant Staphylococcus aureus: evaluation of five selective media. Br J Biomed Sci 2000;57:269–272.Google Scholar
7.Wertheim, H, Verbrugh, HA, van Pelt, C, de Man, P, van Belkum, A, Vos, MC. Improved detection of methicillin-resistant Staphylococcus aureus using phenyl mannitol broth containing aztreonam and ceftizoxime. J Clin Microbiol 2001;39:2260–2262.Google Scholar
8.Zadik, PM, Davies, S, Whittaker, S, Mason, C. Evaluation of a new selective medium for methicillin-resistant Staphylococcus aureus. J Med Microbiol 2001;50:476–479.Google Scholar
9.Gurran, C, Holliday, MG, Perry, JD, Ford, M, Morgan, S, Orr, KE. A novel selective medium for the detection of methicillin-resistant Staphylococcus aureus enabling resuit reporting in under 24 hours. J Hosp Infect 2002;52:148–151.Google Scholar
10.Simor, AE, Goodfellow, J, Louie, L, Louie, M. Evaluation of a new medium, oxacillin resistant screening agar base, for the detection of methicillin-resistant Staphylococcus aureus from clinical specimens. J Clin Microbiol 2001;39:3422.Google Scholar
11.Apfalter, P, Assadian, O, Kalczyk, A, et al.Performance of a new chromogenic oxacillin resistance screen medium (Oxoid) in the detection and presumptive identification of methicillin-resistant Staphylococcus aureus. Diagn Microbiol Infect Dis 2002;44:209–211.Google Scholar
12.National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Susceptibility Testing. Wayne, PA: National Committee for Clinical Laboratory Standards; 2002.Google Scholar
13.Kohner, P, Uhl, J, Kolbert, C, Persing, D, Cockerill, F III. Comparison of susceptibility testing methods with mecA gene analysis for determining oxacillin (methicillin) resistance in clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococcus. J Clin Microbiol 1999;37:2952–2961.Google Scholar
14.Rowe, F, Superti, SV, Scheibe, RM, Dias, CG. Agar diffusion, agar dilution, Etest, and agar screening test in the detection of methicillin resistance in staphylococci. Diagn Microbiol Infect Dis 2002;43:45–48.Google Scholar
15.Hoos, WE, Bannerman, TL. Staphylococcus and Micrococcus. In: Murray, PR, Baron, EJ, Pfaller, MA, Tenover, FC, Yolken, RH, eds. Manual of Clinical Microbiology, ed. 7. Washington, DC: ASM Press; 1999:264–282.Google Scholar
16.Vannuffel, P, Laterre, PF, Bouyer, M, et al.Rapid and specifie molecular identification of methicillin-resistant Staphylococcus aureus in endotracheal aspirates from mechanically ventilated patients. J Clin Microbiol 1998;36:2366–2368.Google Scholar
17.Aires de Souza, M, Miragaia, M, Sanches, IS, et al.Three year assessment of methicillin-resistant Staphylococcus aureus clones in Latin America from 1996 to 1998. J Clin Microbiol 2001;39:2197–2205.Google Scholar