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At least 289 records · Page 16Linked to original sources
PubMed2003

Rapid MRSA detection by a latex kit.

Methicillin resistant strains of Staphylococcus aureus (MRSA) are implicated in serious infections and nosocomial outbreaks, and show resistance to a wide range of antibiotics, thus limiting the treatment options. Therefore, rapid detection is clinically crucial for both treatment and infection control measures. This study assessed the performance of a rapid latex agglutination kit marketed to detect MRSA clinical isolates (MRSA-Screen test Denka Seiken Co Ltd, Tokyo, Japan) based on detecting a specific penicillin binding protein 2a (PBP2a) in comparison to the NCCLS oxacillin salt agar screen plate, the 1 microg oxacillin disk diffusion test, and the oxacillin MIC by E-test. Testing was carried out on 133 isolates consisting of 99 MRSA and 34 methicillin sensitive strains of S. aureus (MSSA). Concordant results were observed between the latex kit and all the other tests for the 99 MRSA isolates. Only 1 of the 34 MSSA isolates gave a positive agglutination reaction in the latex kit. The kit sensitivity and specificity were determined to be 100% and 97%, respectively. This reliable performance indicates that the MRSA-Screen latex test is very useful test for the rapid detection of MRSA isolates in the clinical microbiology laboratory.

Agglutination↗
PubMed2001

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.

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 test; Denka Seiken Co., Ltd., Tokyo, Japan) were evaluated for their abilities to detect oxacillin resistance in coagulase-negative staphylococci (CoNS). The reference broth microdilution method and the detection of the mecA gene by PCR ("gold standard" reference result) were used to compare the results obtained with the commercial products. A total of 123 clinical isolates consisting of eight species were selected from U.S. surveillance collections. Among the mecA-positive isolates (95 strains), 30 isolates were initially negative on the MRSA-Screen test read at 3 min. When the agglutination reaction was extended for 10 min, 26 of the 30 isolates became positive. For a different four isolates, the oxacillin MIC was < or =0.25 microg/ml on the Vitek GPS 106 card. Among the mecA-negative isolates (28 strains), for two Staphylococcus warneri, two S. lugdunensis, and two S. saprophyticus strains MICs were > or =0.5 microg/ml by the reference broth microdilution method. Four of these isolates were also categorized as resistant with the Vitek GPS 106 card and two isolates were positive by the MRSA-Screen test. Overall, the MRSA-Screen test, GPS 106 card, and reference broth microdilution method had sensitivities of 95.7 (result at 10 min), 95.7, and 100%, respectively, and specificities of 92.8, 85.7, and 78.5%, respectively. Although the MRSA-Screen test required a slight procedural modification, both commercial methods achieved a sensitivity and specificity at detecting oxacillin resistance in CoNS at a level that was acceptable for clinical laboratory use.

Bacterial Proteins↗
PubMed2005

Rapid detection of methicillin resistance in teicoplanin-resistant coagulase-negative staphylococci by a penicillin-binding protein 2' latex agglutination method.

Thirty-five clinical isolates of coagulase-negative staphylococci with decreased glycopeptide sensitivity were examined by a penicillin-binding protein (PBP2') latex agglutination (LA) test and were compared to the detection of the mecA gene by PCR, and oxacillin susceptibility determined minimum inhibitory concentrations. The latex test demonstrated high sensitivity and specificity for detecting methicillin resistance in coagulase-negative staphylococci after PBP2' induction with oxacillin.

Anti-Infective Agents↗
PubMedDate not supplied

[Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

Bacterial Proteins↗
PubMed1975

Relationship of early readings of minimal inhibitory concentrations to the results of overnight tests.

Broth dilution minimal inhibitory concentration (MIC) readings were compared after different incubation periods and with different inoculum concentrations. The purpose was to determine the best conditions for obtaining early results as close as possible to overnight readings. Initially, 76 antibiotic-organism combinations were tested using the International Collaborative Study technique and inoculum and were read after 3, 8, and 18 h of incubation. Approximately 28% of tests showed fourfold or greater increases in MICs after 18 h of incubation compared with the 3-h readings. No overnight MICs were lower than early readings. MICs of single antibiotics against seven organisms were also read with an automatic particle counter to confirm the validity of the visual readings. Experiments were made to determine whether inoculum manipulation could reconcile the differences between 3- and 18-h MIC results. One hundred and eight organism-antibiotic combinations were tested comparing 3-h MIC readings using an inoculum of 10(7) organisms per ml with overnight readings using 10(5) per ml. In 71 cases, readings with both inocula were within the range tested and 57 (86%) were within +/-1 log(2) of each other and followed an approximately normal distribution. Improved comparability between early read and overnight MICs thus may be achieved by inoculum manipulation, and this may be a suitable approach in the future development of automated procedures.

Anti-Bacterial Agents↗
PubMed2001

Evaluation of the MRSA-Screen Test in detecting oxacillin resistance in community and hospital isolates of Staphylococcus aureus.

The MRSA-Screen Test (Denka Seiken Co., Japan), a latex agglutination test to detect penicillin-binding protein 2a, was compared with PCR for the detection of oxacillin resistance in Staphylococcus aureus. A total of 77 oxacillin-sensitive and 269 oxacillin-resistant (ORSA) isolates were evaluated. Of the ORSA isolates, 186 were non-multiresistant (NORSA), defined as being resistant to two or fewer antibiotics other than beta-lactams. Eighty-three were multiresistant ORSA (MORSA) strains. If PCR is considered the gold standard test, then the sensitivity, specificity, positive and negative predictive values of the MRSA-Screen Test were 100, 99, 99 and 100%, respectively. The endpoint was hard to read with NORSA strains that took longer than 60 s to react. MORSA strains took a median 12 s (range 5-60 s) to give a positive reaction with the MRSA-Screen Test, whereas NORSA strains took a median 30 s (range 5-180 s), a difference which was significantly different (P < 0.0001, two-tailed Mann-Whitney unpaired two sample test). NORSA strains had an MIC50 of 128 mg/l and MIC90 of 256mg/l, whereas MORSA strains had an MIC50 and MIC90 of >256mg/l. The time that the MRSA-Screen Test took to agglutinate with ORSA strains correlated weakly with the MIC (r2 = 0.26). Detection of methicillin resistance cost AUD$9 per isolate with the MRSA-Screen Test, compared with AUD$13 per isolate with mecA PCR. The MRSA-Screen Test gave excellent sensitivity and specificity, and was quicker and cheaper than PCR. The full 3 min should be allowed to elapse before calling a test negative. Organisms giving indeterminate reactions should be tested for the mecA gene by PCR.

Antibodies, Monoclonal↗
PubMed2004

Evaluation of the methicillin-resistant Staphylococcus aureus (MRSA)-Screen latex agglutination test for detection of MRSA of animal origin.

Methicillin (oxacillin)-resistant staphylococci (MRS) have emerged as major clinical and epidemiological pathogens, and there have been frequent reports of MRS infections in the veterinary field. The MRSA-Screen latex agglutination test (Denka Seiken Co., Ltd., Tokyo, Japan) was compared with an oxacillin agar screen test, MIC determination, and mecA PCR assay, the "gold standard." In an analysis of 15 mecA-positive and 48 mecA-negative S. aureus animal isolates, as well as 9 mecA-positive and 147 mecA-negative, coagulase-negative staphylococcal animal isolates, the latex agglutination test surpassed the widely used oxacillin agar screen method and MIC determination, with a sensitivity and a specificity of 100%. The MRSA-Screen test is a reliable and rapid method of detecting MRS in the veterinary field.

Animals↗
PubMed2001

Rapid detection of methicillin resistance in coagulase-negative staphylococci by a penicillin-binding protein 2a-specific latex agglutination test.

The detection of PBP 2a by the MRSA-Screen latex agglutination test with 201 clinical coagulase-negative staphylococci had an initial sensitivity of 98% and a high degree of specificity for Staphylococcus epidermidis strains compared to PCR for mecA. Determination of oxacillin MICs evaluated according to the new breakpoint (0.5 microg/ml) of the National Committee for Clinical Laboratory Standards exhibited an extremely low specificity for this population.

Bacterial Proteins↗