Abstract
An automated system, MicroScan WalkAway-96, in conjugation with Combo Pos® 28 panels, was validated for the identification and methicillin susceptibility of coagulase-negative staphylococci (CNS). The performance of this system was evaluated on 428 CNS. Identification results were compared using a validated in-house method. Methicillin susceptibility was compared with oxacillin MIC testing and the presence of the mecA gene by PCR (in-house real-time method). The MicroScan system correctly identified 94.6% of the staphylococci (405 out of 428). 3.5% of the strains (15 out of 428) were not correctly identified. 1.9% of the isolates (8 out of 428) were correctly identified with a low probability. Identification of Staphylococcus warneri and Staphylococcus lugdunensis was determined with the least accuracy. Microscan combines both oxacillin and cefoxitin for determination of the methicillin susceptibility result. Correlation between this result and the mecA method was 97.6%. Correlation with the oxacillin MIC method was also 97.6%. Fourteen isolates showed a discrepant result, 8 were reported to be resistant in mecA-negative strains, 2 were reported false-susceptible in mecA positive strains and 4 strains showed a discrepant result with oxacillin MIC, but not with mecA determination. The automated system can be considered a simple and reliable method for identification and methicillin susceptibility of CNS.
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References
Chambers H (1997) Methicillin resistance in staphylococci: molecular and biochemical basis and implications. Clin Microbiol Rev 10:781–791
Diekema DJ, Pfaller MA, Schmitz FJ, Smayevsky J, Bell J, Jones RN, Beach M, The Sentry Participants Group (2001) Survey of infections due to Staphylococcus species: frequency of occurrence and antimicrobial susceptibility of isolates collected in the United States, Canada, Latin America, Europe, and the Western Pacific region for the SENTRY antimicrobial surveillance program. Clin Infect Dis 32:S114–S132
Ferreira R, Iorio N, Malvar K, Nunes A, Fonseca L, Bastos C, Santos K (2003) Coagulase-Negative Staphylococci: comparison of phenotypic and genotypic oxacillin susceptibility tests and evaluation of the agar screening test by using different concentrations of oxacillin. J Clin Microbiol 41:3609–3614
Gradelski E, Valera L, Aleksunes L, Bonner D, Fung-tomc T (2001) Correlation between genotype and phenotypic categorization of staphylococci based on methicillin susceptibility and resistance. J Clin Microbiol 39:2961–2963
John JF, Harvin AM (2007) History and evolution of antibiotic resistance in CNS: susceptibility profiles of new anti-staphylococcal agents. Ther Clin Risk Manag 3:1143–1152
Ieven M, Verhoeven J, Pattyn SR, Goossens H (1995) Rapid and economical method for species identification of clinically significant coagulase-negative staphylococci. J Clin Microbiol 33:1060–1063
Caierão J, Musskopf M, Superti S, Roesch E, Dias CG, d’Azevedo PA (2004) Evaluation of phenotypic methods for methicillin resistance characterization in CNS. J Med Microbiol 53:1195–1199
Caiero J, Superti S, Dias C, d’Azevedo PA (2006) Automated systems in the identification and determination of methicillin resistance among CNS. Mem Inst Oswaldo Cruz 101:277–279
Hussain Z, Stoakes L, Stevens DL, Schieven BC, Lannigan R, Jones C (1986) Comparison of the MicroScan system with the API Staphy-Ident system for species identification of CNS. J Clin Microbiol 23:126–128
Miyoung K, Ran HS, Soon CH, Hyelin K, Jeong SP, Moon-Woo S, Do-Hoon L, Kyoung PU, Junghan S, Eui-Chong K (2008) Comparison of the MicroScan Vitek 2 and Crystal GP with 16S rRNA sequencing and MicroSeq 500 v2.0 analysis for CNS. BMC Microbiol 8:233–239
Sáa AI, Vivas J, Tinajas A, Barbeyto L, Rodriguez LA (1999) Evaluation of the MicroScan system for identification of Staphylococci. J Basic Microbiol 39:373–376
Stoakes L, Schieven BC, Ofori E, Ewan P, Lannigan R, Hussain Z (1992) Evaluation of MicroScan Pos Combo panels for identification of staphylococci. J Clin Microbiol 30:93–95
Bannerman TL (2007) Staphylococcus, Micrococcus, and other catalase-positive cocci that grow aerobically. In: Murray PR (ed) Manual of clinical microbiology, 9th edn. ASM Press, Washington, DC, pp 384–397
Weinstein MP, Mirrett S, Van Pelt L, McKinnon M, Zimmer BL, Kloos W, Reller LB (1998) Clinical importance of identifying CNS isolated from blood cultures: evaluation of MicroScan Rapid and Dried Overnight Gram-Positive Panels versus a conventional reference method. J Clin Microbiol 36:2089–2092
Grant CE, Sewell DL, Pfaller M, Bumgardner RV, Williams JA (1994) Evaluation of two commercial systems for identification of CNS to species level. Diagn Microbiol Infect Dis 18:1–5
Hussain Z, Stoakes L, Massey V, Diagre D, Fitzgerald V, El Sayed S, Lannigan R (2000) Correlation of Oxacillin MIC with mecA gene carriage in CNS. J Clin Microbiol 38:752–754
Acknowledgements
We thank Siemens Healthcare Diagnostics NV, Anderlecht, Belgium for providing instrumentation, reagents, and panels during the study period, Lindsey Peeters and Carlo Emeleer for their practical input, and finally Inge Neels and Olivier Bossu for their technical support.
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Patteet, L., Goossens, H. & Ieven, M. Validation of the MicroScan-96 for the species identification and methicillin susceptibility testing of clinical significant coagulase-negative staphylococci. Eur J Clin Microbiol Infect Dis 31, 747–751 (2012). https://doi.org/10.1007/s10096-011-1368-x
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DOI: https://doi.org/10.1007/s10096-011-1368-x