J 2002

Comparison of MRSA-screen latex agglutination, conventional phenotypic methods and mecA gene detection for identification of oxacilin resistance in staphylococci

HÁJEK, Václav, Roman PANTŮČEK, Milan KOLÁŘ, Jiří DOŠKAŘ, Stanislav ROSYPAL et. al.

Basic information

Original name

Comparison of MRSA-screen latex agglutination, conventional phenotypic methods and mecA gene detection for identification of oxacilin resistance in staphylococci

Authors

HÁJEK, Václav (203 Czech Republic), Roman PANTŮČEK (203 Czech Republic), Milan KOLÁŘ (203 Czech Republic), Jiří DOŠKAŘ (203 Czech Republic, guarantor) and Stanislav ROSYPAL (203 Czech Republic)

Edition

Biologia, Section: Cellular and Molecular Biology, Bratislava, Slovak Academy of Sciences, 2002, 1335-6399

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

Genetics and molecular biology

Country of publisher

Slovakia

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

RIV identification code

RIV/00216224:14310/02:00007137

Organization unit

Faculty of Science

UT WoS

000180726700011

Keywords in English

Bacterial Typing Techniques; DNA; Staphylococcus aureus; Coagulase-Negative Staphylococci; Methicillin/Oxacillin Resistance; Screen Latex Agglutination

Tags

International impact, Reviewed
Změněno: 1/7/2009 18:38, prof. RNDr. Roman Pantůček, Ph.D.

Abstract

V originále

On the whole, 128 staphylococcal isolates (Staphylococcus aureus 65, Staphylococcus epidermidis 42, and Staphylococcus haemolyticus 21 strains) from patients of ten Czech hospitals were classified as susceptible or resistant to oxacillin by the standard broth dilution micro-method (using the MIC break-point of 4.0 mg/L for resistance). The MRSA-Screen test (Denka Seiken Co., Japan), a latex agglutination for the detection of penicillin binding protein PBP2a in oxacillin/methicillin-resistant staphylococci, was compared with other commonly used phenotypic susceptibility tests. The PCR detection of the mecA gene, the presence of which is equaled to oxacillin resistance, was used as a reference genotypic method. In addition, the determination of the femA gene was performed also by this procedure. All 68 isolates (S. aureus 26, S. epidermidis 21, and S. haemolyticus 21 strains), determined as oxacillin-resistant, contained the mecA gene. The femA gene was present in all these S. aureus strains. The other 60 isolates (S. aureus 39, and S. epidermidis 21 strains) were characterized as oxacillin-susceptible. All the S. aureus strains lacked the mecA gene, however, all but two were femA gene-positive. The examination of S. epidermidis strains demonstrated the mecA gene in six (29%) of them. Most of these discrepancies between the mecA PCR tests and determination of the oxacillin MICs could be avoided by decreasing of the resistance breakpoint (0.5 mg/L) according to the new recommendation of the NCCLS from 1999. In this connection, however, other phenotypic susceptibility methods (MRSA-Screen, oxacillin-agar screen, and disk difusion tests) should also be modified, as most of them give false negative results in the scope of the oxacillin MICs from 0.5 to 2.0 mg/L. When evaluating the MRSA-Screen test by 3 min, only 46 (68%) oxacillin-resistant strains agglutinated, however, other 20 (29%) strains (mostly coagulase-negative ones) were positive after prolongation of the reaction time from 3 to 9 min. The sensitivities and specificities for MRSA-Screen latex agglutination in comparison with the broth dilution micro-method, oxacillin agar screen assay, and disk difusion test were as follows: 98.5 and 100%, 98.5 and 100%, 100 and 98%, 100 and 97%, respectively. These results showed that the MRSA-Screen test has a very good sensitivity and specificity for the detection of oxacillin resistance as compared with other conventional phenotypic procedures, however, its priorities are simplicity and speed as required for routine microbiological laboratories.

Links

GA301/02/1505, research and development project
Name: Molekulární diagnostika, epidemiologie a klasifikace klinicky významných grampozitivních koků
Investor: Czech Science Foundation, Molecular diagnostic, epidemiology and classification of pathogenic Gram positive cocci
GA301/99/D075, research and development project
Name: Genotypová diagnostika a typizace klinicky významných koaguláza negativních stafylokoků
Investor: Czech Science Foundation, Genome-based diagnostics and typing of coagulase-negative staphylococci from human clinical specimens
MSM 143100008, plan (intention)
Name: Genomy a jejich funkce
Investor: Ministry of Education, Youth and Sports of the CR, Genomes and their functions