the Package Insert
Contents
1. Positive Percent Agreement 95 1 564 593 95 Cl 93 1 96 6 Negative Percent Agreement 90 9 1636 1800 95 Cl 89 5 92 1 Table 8 Site by Site Performance Obtained for SA with the BD MAX StaphSR Assay in Comparison to Direct Culture Clinical Sites Positive Percent Negative Percent Agreement with 95 Cla Agreement with 95 Cla 93 0 213 229 93 4 682 730 89 0 95 7 91 4 95 0 Site 2 94 9 149 157 88 6 419 473 90 3 97 4 85 4 91 1 97 6 202 207 89 6 535 597 94 5 99 0 86 9 91 8 95 1 564 593 90 9 1636 1800 93 1 96 6 89 5 92 1 a Confidence interval Out of 2399 nasal swab specimens tested with the BD MAX StaphSR assay that were compliant at the specimen and PCR level 15 0 6 were reported as Unresolved after initial testing The Unresolved Rate after repeat testing was 0 04 1 2399 Table 9 Table 9 Unresolved Rates Initial Unresolved Rates Unresolved Rates After Repeat 0 6 15 2399 95 Cl 0 4 1 0 0 04 1 2399 95 Cl 0 0 2 Total number based on compliant specimens and BD MAX StaphSR assay results Out of the same 2399 nasal swab specimens tested with the BD MAX StaphSR assay 14 0 6 were initially reported as Indeterminate No result remained Indeterminate upon repeat two specimens were not retested Eight 8 0 3 were initially reported as Incomplete No result remained Incomplete upon repeat one spe2. A total of 2451 specimens were enrolled in the study Of those 94 specimens were regarded as noncompliant per protocol criteria and three 3 fully compliant specimens gave final non reportable PCR results A total of 2354 specimen results were used to determine the clinical performance of the BD MAX StaphSR assay in comparison to the Reference Method Tables 1 to 4 Compared to the Reference Method Direct Enriched Culture the BD MAX StaphSR assay identified 93 1 of the MRSA positive specimens and 97 5 of the MRSA negative specimens Tables 1 and 2 For the population tested this resulted in a Negative Predictive Value NPV of 99 5 and a Positive Predictive Value PPV of 73 2 11 Table 1 Results Obtained for MRSA with the BD MAX StaphSR Assay in Comparison to the Reference Method All Sites Reference Method Positive Positive io w am BD MAX StaphSR Assay Negative 111 2140 2151 Toal 160 2194 2354 Sensitivity 93 1 149 160 95 CI 88 1 96 1 Specificity 97 5 2140 2194 95 Cl 96 8 98 1 PPV 73 2 95 Cl 67 8 78 3 NPV 99 5 95 Cl 99 1 99 7 Further investigation was performed on specimens with discordant results between the Reference Method and the BD MAX StaphSR assay e 12 of 54 MRSA False Positive BD MAX StaphSR specimens were also found to be positive after repeat of Reference Method e 5of 11 MRSA False Negative BD MAX StaphSR specimens were also f
3. Refer to the latest edition Clinical and Laboratory Standards Institute User Protocol for Evaluation of Qualitative Test Performance Approved Guideline Document EP12 Refer to the latest edition BD MAX System User s Manual refer to the latest version BD Diagnostics Sparks MD USA Pasanen T et al A selective broth enrichment combined with real time nuc mecA PCR in the exclusion of MRSA APMIS 2010 118 74 80 doi 10 1111 j 1600 0463 2009 02562 x Temperature limitation Authorized Representative in the European Community Manufacturer Perforation Catalog number Batch Code Lot In Vitro Diagnostic Medical Device Use by YYYY MM DD YYYY MM MM end of month CE marked Medical Device Contains sufficient for lt en gt tests Keep away trom light Consult Instructions for Use H lt q wo f mer GF Keep Dry Rx Only USA only Caution Federal law restricts this device to sale by or on the order of a licensed practitioner This product is sold under license and purchase of this product does not include rights to use for certain blood and tissue screening applications nor for certain industrial applications The purchase of this product allows the purchaser to use it for amplification and detection of nucleic acid sequences for providing human in vitro diagnostics No general patent or other license of any kind other than this specific right of use from purchase is granted hereby BD BD Diagnos
4. Reproducibility The reproducibility study was performed using the same sample categories as defined above for the Precision Study samples in each category were tested in triplicate on 5 distinct days wherein each day 2 panels were tested by 2 different technologists at 3 clinical sites using 1 lot of reagents Site to Site One 1 of these clinical sites participated in an extended study where 2 additional lots of reagents were tested Lot to Lot Results are shown for each sample category with the data from both MRSA strains pooled and MSSA Strains For Site to Site Reproducibility the overall percent agreement was 100 for MRSA MP and TN categories 96 7 and 97 8 for MRSA LP and MSSA LP respectively and 36 7 and 30 0 for MRSA HN and MSSA HN respectively Table 13 17 Table 13 Site To Site Reproducibility Study Results Using One Lot of the BD MAX StaphSR Assay SITE Overall Percent Site 1 Site 2 Site 3 Agreement Category T SS Percent Count Percent Count Percent Count Agreement Agreement Agreement HNIMSSA 16 7 5 30 23 3 7 30 50 0 15 30 30 0 21 5 40 1 HNMRSA 40 0 12 30 26 7 8 30 43 3 13 30 36 7 27 4 47 0 LP MSSA 96 7 29 30 100 0 30 30 96 7 29 30 97 8 92 3 99 4 LP MRSA 95 0 57 60 98 3 59 60 96 7 58 60 96 7 92 9 98 5 MPMRSA 100 0 30 30 100 0 30 30 100 0 30 30 100 0 95 9 100 0 m tone enon tenon ooo sone 100 0 30 30 100 0 30 30 100 0 30 30 100 0 9
5. 1 of Rack A either by scanning the 1D barcode with the scanner or by manual entry Click on the lt Lot Number gt field and using the pull down menu select the appropriate kit lot number on the outer box This will automatically populate the remaining lot number fields for Rack A with the same lot number Enter the information for the next position in the Rack and continue for all remaining Sample Buffer Tubes in the rack NOTE Steps 12 and 13 must be repeated for each new kit lot number Repeat steps 10 to 13 for Rack B Place the BD MAX StaphSR Sample Buffer Tube s in the BD MAX Rack s following the same order as entered in the worklist Do not skip or leave empty positions between tubes NOTE Place the tubes into the sample rack with 1D barcode labels facing outward this makes scanning tubes easier during sample login Place the required number of BD MAX PCR Cartridge s into the BD MAX System see Figure 2 e Each cartridge accommodates 2 runs of up to 12 samples for a total of 24 specimens e The BD MAX System will automatically select the position and row on the PCR cartridge for each run e Cartridges are used on a per run AND rack basis 2 runs per cartridge and 1 cartridge per rack 2 Eo ee o gt i Se 2a d te Figure 2 Load PCR Cartridges 17 Load rack s into the BD MAX System Figure 3 Ensure that the placement of rack s left to right corresponds to the worklist
6. BD MAX StaphsR 442999 P0153 01 2013 12 For n Vitro Diagnostic Use For use with the BD MAX System 25 C A C Rx Only USA INTENDED USE The BD MAX StaphSR assay performed on the BD MAX System is an automated qualitative in vitro diagnostic test for the direct detection and differentiation of Staphylococcus aureus SA and methicillin resistant Staphylococcus aureus MRSA DNA from nasal swabs in patients at risk for nasal colonization The test utilizes real time polymerase chain reaction PCR for the amplification of MRSA SA DNA and fluorogenic target specific hybridization probes for the detection of the amplified DNA The BD MAX staphSR assay is intended to aid in the prevention and control of MRSA and SA infections in healthcare settings It is not intended to diagnose MRSA or SA infections nor guide or monitor treatment for MRSA SA infections A negative result does not preclude nasal colonization Concomitant cultures are necessary to recover organisms for epidemiological typing or for further susceptibility testing SUMMARY AND EXPLANATION OF THE PROCEDURE S aureus is a major cause of nosocomial infections such as bloodstream infections and surgical site infections with clinical manifestations ranging from pustules to sepsis and death It is commonly found in the nose or on the skin of healthy individuals asymptomatic carriers Treatment of S aureus infections has become a real challenge with the emergence of
7. and can be found in other bacterial genera e g S epidermidis SA UNR MRSA UNR Unresolved result e Fluorescence signal not detected for nuc gene mecA mecC or MREJ targets and e Fluorescence signal not detected for the SPC Inhibitory specimen or reagent failure IND Indeterminate result e BD MAX System failure with Warning or Error Codes Refer to the Troubleshooting section of the BD MAX System User s Manual for interpretation of warning and error codes INC Incomplete run e BD MAX System failure with Warning or Error Codes Refer to the Troubleshooting section of the BD MAX System User s Manual for interpretation of warning and error codes REPEAT TEST PROCEDURE NOTE 1 Sufficient volume is available for only one repeat test from the Sample Buffer Tube on the BD MAX System For Sample Buffer Tubes stored at 25 2 C retesting must be performed within 36 hours of the steps covered in the Specimen Preparation section above Alternatively for Sample Buffer Tubes stored at 2 8 C retesting may be performed within 120 hours 5 days of the steps covered in the Specimen Preparation section above NOTE 2 New samples may be tested in the same run with repeat samples Unresolved Result Unresolved results may be obtained in the event that an inhibitory substance or a reagent failure prevents proper target or SPC amplification Sample s can be repeated from their corresponding Sample Buf
8. and reagent strip are loaded into the BD MAX System The BD MAX System automates sample lysis DNA extraction and concentration reagent rehydration nucleic acid amplification and detection of the target nucleic acid sequence using real time polymerase chain reaction PCR Amplified targets are detected with hydrolysis probes labeled with quenched fluorophores The amplification detection and interpretation of the signals are done automatically by the BD MAX System PRINCIPLES OF THE PROCEDURE The BD MAX System uses a combination of lytic and extraction reagents to perform cell lysis and DNA extraction Following enzymatic cell lysis at elevated temperature the released nucleic acids are captured by magnetic affinity beads The beads with the bound nucleic acids are washed and the nucleic acids are eluted by heat in Elution Buffer Eluted DNA is neutralized with Neutralization Buffer and transferred to the Master Mix Tube to rehydrate the PCR reagents The reconstituted amplification reagent is dispensed into the BD MAX PCR Cartridge Microvalves in the BD MAX PCR Cartridge are sealed by the system prior to initiating PCR to prevent evaporation and amplicon contamination The amplified DNA targets are detected using hydrolysis TaqMan probes labeled at one end with a fluorescent reporter dye fluorophore and at the other end with a quencher moiety Probes labeled with different fluorophores are used to detect a specific ampli
9. are not provided by BD Various types of External Controls are recommended to allow the user to select the most appropriate control for their laboratory quality control program e Commercially available control materials e g a reference MRSA strain ATCC 43300 and methicillin susceptible Staphylococcus aureus strain e g ATCC 29213 can be used as positive controls Staphylococcus epidermidis strain e g ATCC 12228 can be used as negative control e Previously characterized specimens known to be positive or negative for S aureus or MRSA NOTE It is recommended that bacterial strains be freshly prepared in saline to a turbidity of 0 5 McFarland 1 0 x 108 CFU mL from isolated colonies and subsequently diluted with saline to obtain a final concentration of 1 0 x 104 CFU mL Dip a swab into the diluted bacterial suspension express the excess liquid place the swab in a corresponding Sample Buffer Tube and follow instructions described in step 5 of the Specimen Preparation section One 1 External Positive Control and one 1 External Negative Control should be run daily until adequate process validation is achieved on the BD MAX System The MRSA and the MSSA control strains should be tested alternately each of them being tested every other day Reduced frequency of control testing should be based on a protocol and data as determined by the individual laboratory An External Negative Control that yields a positive test
10. corresponding to 5 SCCmec types 14 I Il Ill IV and XI as well as 2 MSSA strains The swabs were then eluted in simulated nasal matrix Each MRSA and MSSA strain was tested in replicates of 24 per concentration by 2 different operators using 3 different production lots of the BD MAX StaphSR assay Analytical sensitivity LoD defined as the lowest concentration at which at least 95 of all replicates tested positive ranged from 64 to 343 CFU swab Table 10 for the detection of MRSA strains and from 174 to 211 CFU swab Table 11 for the detection of MSSA strains Table 10 Limit of Detection of MRSA Genotypes by the BD MAX StaphSR Assay MRSA Strain MREJ Genotype SCCmec type LoD Concentration CFU swab Cl2 pType 84 49 142 2 yei o S 64 167 _ Type iii II 160 93 278 Type iv II 68 7 109 pe v8 228 o 6 Type N84 186 632 ip i 058 pType ix N _ 144 82255 po Type with D 64 56 i 0 Tew ND 78 _ 48 127 Tyext X 12 4 197 1SCCmec type does not correlate to the MREJ type as these are two different typing methods 2Cl Confidence Intervals 3ND not determined 4mecC containing MRSA strains Also known as mecALcazs strain Table 11 Limit of Detection of MSSA by the BD MAX StaphSR Assay NSS ES teri LoD Concentration CFU swab 95 Cl 1 174 89 341 211 105 428 1Cl Confidence Intervals Analytical Inclusivity An analytical inclusivity
11. may occur due to loss of nucleic acid from inadequate collection transport or storage of specimens or due to inadequate bacterial cell lysis The Sample Processing Control has been added to the test to aid in the identification of specimens that contain inhibitors to PCR amplification and as a control for reagent integrity and of the assay system as a whole The Sample Processing Control does not indicate if nucleic acid has been lost due to inadequate collection transport or storage of specimens or if bacterial cells have been adequately lysed In a mixed culture the detection of MRSA or SA is variable when high concentrations of MRSE are present Competition from MRSE was observed at an MRSA MRSE ratio of 1 2 1x103 and at an SA MRSE ratio of 1 2 1x105 In a mixed culture the detection of MRSA is variable when high concentrations of MSSA are present Competition from MSSA was observed at an MRSA MSSA ratio of 1 2 1x104 BD MAX StaphSR assay results may sometimes be Unresolved due to an invalid Sample Processing Control or be Indeterminate or Incomplete due to instrument failure and require retesting that can lead to a delay obtaining final results Mutations or polymorphisms in primer or probe binding regions may affect detection of new or unknown MRSA or SA variants resulting in a false negative result with the BD MAX StaphSR assay As with all in vitro diagnostic tests positive and negative predictive values are highly dependent on
12. to meet the acceptance criteria for a negative specimen the result will be reported as Unresolved An Unresolved result is indicative of specimen associated inhibition or processing or reagent failure Repeat any specimen reported as Unresolved according to the Repeat Test Procedure section below RESULTS INTERPRETATION Results are available on the Results tab in the Results window on the BD MAX System monitor The BD MAX System software automatically interprets test results A test result may be called as SA NEG MRSA NEG negative SA POS MRSA POS MRSA positive SA POS MRSA NEG SA positive or SA UNR MRSA UNR Unresolved based on the amplification status of the target and of the Sample Processing Control IND Indeterminate or INC Incomplete results are due to BD MAX System failure Results are based on the following decision algorithm ASSAY RESULT REPORTED INTERPRETATION OF RESULT SA POS MRSA POS MRSA DNA detected SA POS SA DNA detected MRSA NEG No MRSA DNA detected SA UNR Unresolved result No target MRSA UNR amplification no SPC amplification Indeterminate result due to BD MAX System failure with Warning or Error Codes Incomplete Run with Warning or Error Codes Refer to the Troubleshooting section of the BD MAX System User s Manual for oo of warning and error codes SA POS MRSA POS MRSA DNA detected e Fluorescence signal is detected for both MREJ S au
13. 15 TT HN MSSA LP MSSA LNA HN MSSA LP MSSA HN MREJ Type ii Type ii 24 63 88 19 50 87 52 P JE 320 eile Te m 078 E 2A HN MSSA TN a duin HN MSSA HNMREJ Type ii Type ii N o a Near SPC4 Cy5 5 Channel 5D RCV 1Values shown are those obtained for the MREJ target in the samples that gave a SA POS MRSA POS result 2Values shown are those obtained for the mecA or mecC target in the samples that gave a SA POS MRSA POS result Values shown are those obtained for the nuc target in the samples that gave a SA POS MRSA NEG result Calculated for the Specimen Processing Control of the samples that gave a SA NEG MRSA NEG result Carry Over Cross Contamination A study was conducted to investigate the potential for carry over cross contamination between high MRSA 2107 CFU swab specimens and negative specimens throughout the BD MAX StaphSR workflow Twelve 12 replicates of the high positive sample and 12 replicates of the negative sample were tested in each run by alternating negative and positive replicates Four 4 operators performed a total of 18 runs of 24 samples Overall from 203 reportable results out of 216 expected negative samples 3 false positive results were obtained 3 203 1 5 due to carry over contamination 19 RE 1 11 12 a E oO 2 FERENCES Centers for Disease Control and Prevention Methicillin resistant S
14. 5 9 100 0 Percent Agreement correlates to the percent of negative results 2Confidence Interval For Lot to Lot Reproducibility the overall percent agreement was 100 for MRSA MP and TN 96 7 for MRSA LP and MSSA LP 40 0 and 44 4 for MRSA HN and MSSA EN respectively Table 14 Table 14 Lot To Lot Reproducibility Study Results using Three Lots of the BD MAX StaphSR Assay LOT Overall Percent Lot 1 Lot 2 Lot 3 Agreement Percent Percent Percent Agreement gouni Agreement goun Agreement puni Category Hissa 50 0 15 30 36 7 11 30 46 7 14 30 44 4 34 6 54 7 HNMRSA 43 3 13 30 43 3 13 30 33 3 10 30 40 0 30 5 50 3 wm or wm ws mm ws an rs arr Percent Agreement correlates to the percent of negative results 2Confidence Interval second Derivative Peak Abscissa SDPA an underlying numerical value used to determine a final assay result was selected as an additional means of assessing assay reproducibility Overall mean SDPA values with variance components SD and CV are shown in Table 15 18 Table 15 Site to Site and Lot to Lot Reproducibility Study Underlying Numerical SDPA Overall Results Site to Site Lot to Lot HNMRSA LPMRSA MPMRSA HNMRSA LPMRSA MPMRSA 33 NRE MREJ ypes Mean J JE pooled FAM Channel 0 106 03 CV 2 2 3 4 2 3 2 2 3 0 1 2 N m w s im v moea or meee ROX Mean JE JE ME SD T42 D54 TCV
15. Good laboratory technique is essential for the proper performance of this assay Due to the high analytical sensitivity of this test extreme care should be taken to preserve the purity of all materials and reagents screening determines the colonization status at a given time Colonization may vary depending upon patient treatment e g decolonization regime patient status e g transient SA or MRSA colonization or exposure to high risk environments e g contact with SA or MRSA carrier and or prolonged hospitalization Colonization status should be monitored according to institutional policies A BD MAX StaphSR positive result does not necessarily indicate eradication treatment failure since DNA presence may persist A negative result following a previously positive test result may indicate eradication treatment success or may occur due to intermittent colonization A positive test result does not necessarily indicate the presence of viable organisms A positive result is indicative of the presence of SA or MRSA DNA The BD MAX StaphSR assay simultaneously detects the mecA or mecC gene carried within the SCCmec cassette and a S aureus specific sequence located within the junction of the SCCmec cassette and the orfX gene MREJ The BD MAX StaphSR assay also detects S aureus specific nuc gene The BD MAX StaphSR assay is designed to detect MREJ genotypes ii iii iv v vi Vil IX xiii Xiv and xxi which represents most of mecA
16. Reagent Strip Unitized Reagent strip containing all liquid reagents and disposable pipette tips 24 tests 442999 necessary for specimen processing and DNA extraction BD MAX StaphSR Extraction Tube B8 Dried extraction reagent containing DNA magnetic affinity beads 24 tests Achromopeptidase and Sample Processing Control BD MAX StaphSR Sample Buffer Tube 94 tests with 25 septum caps EQUIPMENT AND MATERIALS REQUIRED BUT NOT PROVIDED BBL CultureSwab Liquid Stuart single or double swab BD catalog no 220099 or 220109 Copan Venturi Transystem Liquid Stuart single or double swab Copan catalog no 141C or 139C VWR Multi Tube Vortexer VWR catalog no 58816 115 NALGENE Cryogenic Vial Holder VWR catalog no 66008 783 Disposable gloves powderless Sterile scissors optional sterile Gauze Stopwatch or timer BD MAX PCR Cartridges BD catalog no 437519 WARNINGS AND PRECAUTIONS For in vitro diagnostic use Do not use the kit if the label that seals the outer box is broken Do not use reagents if the protective pouches are open or torn upon arrival Close reagent protective pouches promptly with the zip seal after each use Remove any excess air in the pouches prior to sealing Do not remove desiccant from reagent pouches Check reagent strips for proper liquid fills ensure that the liquids are at the bottom of the tubes see Figure 1 Check reagent strips to ensure that all pipette tips are p
17. Reference Method and the BD MAX StaphSR assay e 28 of 118 SA False Positive BD MAX StaphSR specimens were also found to be positive after repeat of Reference Method e 23 of 52 SA False Negative BD MAX StaphSR specimens were also found to be negative after repeat of Reference Method 12 Table 4 Site by Site Performance Obtained for SA with the BD MAX StaphSR Assay in Comparison to the Reference Method Clinical Sites Prevalence 4 27 2 261 960 Sensitivity with 95 CI 90 0 235 261 85 8 93 1 91 5 162 177 86 5 94 8 94 8 202 213 91 0 97 1 92 0 599 651 89 7 93 9 Specificity with 95 Cl 96 3 672 698 94 6 97 4 90 9 412 453 88 0 93 3 90 8 501 552 88 1 92 9 93 1 1585 1703 91 8 94 2 27 8 213 765 Overall 27 5 653 2375 a Prevalence based on reference method only b Confidence interval c 2375 specimens were reference method compliant Results Obtained with the BD MAX StaphSR Assay in Comparison to Direct Culture A total of 2451 specimens were enrolled in the study Of those 54 specimens were regarded as noncompliant per protocol criteria and four 4 fully compliant specimens gave final non reportable PCR results A total of 2393 specimen results were used to determine the positive and negative percent agreement of the BD MAX StaphSR assay in comparison to Direct Culture Tables 5 to 8 Compared to Direct Culture the BD MAX StaphSR assay
18. V IBERIAN and mecC variant mecA containing S aureus strain LGA251 tested at a concentration of 2 3 x LoD exhibited SA POS MRSA POS results e Four 4 out of 4 BORSA strains Borderline oxacillin resistant S aureus tested at 210 CFU swab exhibited SA POS MRSA NEG results 15 e Five 5 out of 5 MSSA strains tested at 210 CFU swab exhibited SA POS MRSA NEG results e One 1 out of 1 methicillin resistant Staphylococcus epidermidis MRSE strains tested at 2108 CFU swab exhibited a negative result SA NEG MRSA NEG Analytical Specificity The BD MAX StaphSR assay was performed on samples containing high levels of non target organisms and MSSA strains using the BD MAX System to demonstrate the specificity of the assay for detection of MRSA and SA e Fifteen 15 out of 15 empty cassette variant MSSA strains tested at 210 CFU swab produced SA POS MRSA NEG results e Fifty seven 57 out of 57 strains of various non staphylococcal species tested at a concentration of 210 CFU mL except for Cryptococcus neoformans which was tested at 3x10 CFU swab produced negative results SA NEG MRSA NEG e Forty five 45 Coagulase Negative staphylococcal strains CoNS and Coagulase Positive staphylococcal strains CoPS representing 28 species were tested at a concentration of 0 5 McFarland with the BD MAX StaphSR assay Forty five 45 of the 45 strains tested exhibited negative results SA NEG MRSA NEG e Fifty 50 o
19. and mecC harboring MRSA strains belonging to different SCCmec MREJ types accounting for more than 98 of worldwide strains tested by BD to date The ability of the BD MAX StaphSR assay to detect other MREJ genotypes is unknown The BD MAX StaphSR assay does not report Borderline Oxacillin Resistant S aureus BORSA as MRSA it will report as SA only The mechanism of oxacillin resistance in BORSA strains is due to an increased production of B lactamases not the mecA or mecC gene BORSA strains are rare The BD MAX StaphSR assay performance in detecting modified S aureus MOD SA is not known as those strains have not been evaluated The mechanism of oxacillin resistance in MOD SA strains is due to changes in affinity of penicillin binding proteins for oxacillin MOD SA strains are rare The BD MAX StaphSR assay will generate a false positive MRSA result when testing a co colonized nasal specimen containing both a methicillin resistant coagulase negative Staphylococcus MRCoNS and an empty cassette methicillin susceptible SA variant Co colonization with MRCoNS and an empty cassette methicillin susceptible SA is rare As with all PCR based in vitro diagnostic tests extremely low levels of target below the LoD of the assay may be detected but results may not be reproducible Tobramycin may cause inhibition in the BD MAX StaphSR assay refer to Interfering Substances section for further details False negative results
20. cimen was not retested Empty Cassette Variants For a specimen to be identified as MRSA positive with the BD MAX StaphSR assay a positive result must be obtained for both MREJ and mecA or mecC nuc gene is not mandatory A specimen that carries MREJ but neither mecA nor mecC gene is MRSA negative as it is methicillin sensitive This situation occurs when the mecA or mecC gene is excised from the SCCmec cassette but the right extremity fragment MREJ remains yielding a positive MREJ result This specimen type is sometimes referred to as empty cassette variant The ability to detect the mecA and mecC genes allows the BD MAX StaphSR assay to correctly discriminate and identify this variant as SA POS MRSA NEG Among the 2354 eligible specimens included in the clinical performance determination Table 1 a total of 10 specimens fit the empty cassette profile resulting in detection of MREJ without mecA or mecC gene detection All of the 10 specimens were verified true negative MRSA and true positive SA relative to the Reference Method Analytical Sensitivity The analytical sensitivity Limit of Detection or LoD for the BD MAX StaphSR assay was determined as follows positive specimens were prepared by soaking swabs in a wide range of MRSA or MSSA bacterial suspensions prepared and quantified from cultures The tested strains included 11 MRSA strains representing 11 MREJ genotypes i ii ili iv v vi Vil IX xiii xiv and xxi
21. con in the SCCmec right extremity junction MREJ the genes for methicillin resistance mecA and mecC the nuc gene encoding a thermostable nuclease of S aureus and SPC amplicons in four different optical channels of the BD MAX System MREJ amplicons are detected in the FAM channel mecA and mecC amplicons are detected in the ROX channel nuc amplicons are detected in the VIC channel and SPC amplicons are detected in the Cy5 5 channel When the probes are in their native state the fluorescence of the fluorophore is quenched due to its proximity to the quencher However in the presence of target DNA the probes hybridize to their complementary sequences and are hydrolyzed by the 5 3 exonuclease activity of the DNA polymerase as it synthesizes the nascent strand along the DNA template As a result the fluorophores are separated from the quencher molecules and fluorescence is emitted The amount of fluorescence detected in the four optical channels used for the BD MAX StaphSR assay is directly proportional to the quantity of the corresponding probe that is hydrolyzed The BD MAX System measures these signals at the end of each amplification cycle and interprets the data to provide a result REAGENTS Contents Quantity BD MAX StaphSR Master Mix B7 Dried PCR Master Mix containing polymerase nucleotides and specific molecular 24 tests probes and primers along with Sample Processing Control specific molecular probe BD MAX StaphSR
22. created top to bottom Side A Side B Figure 3 Load Rack s into the BD MAX System 18 Close the BD MAX System lid and click the lt Start Run gt button to begin processing 19 At the end of the run check results immediately or store Sample Buffer Tubes at 2 8 C until the results are checked NOTE If a septum was damaged during the run replace it with a new one before storing the specimen NOTE Sample Buffer Tubes can be stored at 25 2 C for a maximum of 36 hours or at 2 8 C for a maximum of 120 hours 5 days after the run has been started When an Indeterminate IND Unresolved UNR or Incomplete INC result is obtained or when an External Control failure occurs a repeat test from the Sample Buffer Tube must be performed within this timeframe see Repeat Test Procedure section QUALITY CONTROL Quality control procedures monitor the performance of the assay Laboratories must establish the number type and frequency of testing control materials according to guidelines or requirements of local provincial state and country regulations or accreditation organizations For general QC guidance the user may wish to refer to CLS MM3 and EP1210 l An External Positive Control is intended to monitor for substantial reagent failure while an External Negative Control is used to detect reagent or environmental contamination or carry over from other specimens or SA or MRSA amplicons External Control materials
23. ens as if they are infectious and in accordance with safe laboratory procedures such as those described in CLS Document M29 and in Biosafety in Microbiological and Biomedical Laboratories Wear protective clothing and disposable gloves while handling kit reagents Wash hands thoroughly after performing the test Do not pipette by mouth Do not smoke drink or eat in areas where specimens or kit reagents are being handled Dispose of unused reagents and waste in accordance with country federal provincial state and local regulations STORAGE AND STABILITY Collected specimens should be kept between 2 C and 25 C during transport Protect against freezing or exposure to excessive heat Specimens can be stored at 25 2 C for a maximum of 48 hours or at 2 8 C for a maximum of 120 hours 5 days before testing BD MAX StaphSR assay reagents and components are stable at 2 25 C through the stated expiration date Do not use expired components BD MAX StaphSR Master Mix and Extraction Tubes are provided in sealed pouches To protect product from humidity immediately re seal after opening e Reagent tubes are stable for up to 7 days at 2 25 C after initial opening and re sealing of the pouch e Unreconstituted Extraction and Master Mix reagent tubes are stable for up to 5 hours at 2 25 C after being removed from their protective pouch INSTRUCTIONS FOR USE Specimen Collection Transport Using a recommended swab tran
24. es Remove the cap from the Sample Buffer Tube 4 Remove the swab from the sample transport tube and place the swab in the corresponding Sample Buffer Tube 5 Hold the swab by the stem near the rim of the tube use sterile gauze to minimize risk of contamination Lift the swab approximately one 1 cm from the bottom of the Sample Buffer Tube and bend the stem against the edge of the tube to break it Alternative method use sterile scissors to cut the stem 6 Close the Sample Buffer Tube with a septum cap 7 Place Sample Buffer Tube in a NALGENE Cryogenic Vial Holder and vortex at maximum speed for one 1 minute with the Multi Tube Vortexer Up to 24 samples can be processed simultaneously with the Multi Tube Vortexer BD MAX System Operation NOTE Refer to the BD MAX System User s Manual for detailed instructions Operation section NOTE The BD MAX StaphSR assay must be performed immediately after the vortexing step above Specimen Preparation Step 7 If retesting is necessary re vortex sample s Te 3 10 11 12 cy 14 19 16 Turn on the BD MAX System and log in by entering lt user name gt and lt password gt Gloves must be changed before manipulating reagents and cartridges Remove the required number of BD MAX StaphSR Reagent Strips from the BD MAX StaphSR Kit Gently tap each strip onto a hard surface to ensure that all the liquids are at the bottom of the tub
25. es Remove the required number of StaphSR Extraction Tube s and StaphSR Master Mix tube s from their protective pouches Remove excess air and close pouches with the zip seal For each specimen and external control to be tested place one 1 BD MAX StaphSR Reagent Strip on the BD MAX System Rack starting with Position 1 of Rack A and continuing sequentially Do not skip Spaces Snap one 1 BD MAX StaphSR Extraction Tube white foil into Position 1 of each BD MAX staphSR Reagent Strip see Figure 1 snap one 1 BD MAX StaphSR Master Mix tube green foil into Position 2 of each BD MAX staphSR Reagent Strip see Figure 1 Waste Pipette Tips E 2 2 t r E a Extraction Tube Master Mix tube Figure 1 Snap BD MAX StaphSR Extraction tubes and Master Mix tubes into reagent strip On the BD MAX software select the lt Consumable info gt tab under the Run screen Enter the kit lot number for the BD MAX StaphSR assay for lot traceability by either scanning the barcode with the scanner or by manual entry NOTE Repeat steps 8 and 9 for each new kit lot number select the lt Work List gt tab click on the lt Assay gt field and using the pull down menu select lt BD MAX StaphSR gt This will automatically populate the remaining assay fields for Rack A with BD MAX StaphSR Enter the BD MAX StaphSR Sample Buffer Tube ID Patient ID and Accession Number if applicable for Position
26. fer Tube s within the timeframes defined above Vortex the sample s for one 1 minute and restart following the BD MAX System Operation section Indeterminate Result Indeterminate results may be obtained in the event that a System failure occurs Sample s can be repeated from their corresponding Sample Buffer Tube s within the timeframes defined above Vortex the sample s for one 1 minute and restart following the BD MAX System Operation section For the interpretation of warning or error code messages refer to the BD MAX System User s Manuali Troubleshooting section Incomplete Result Incomplete results may be obtained in the event that a terminating warning or error code occurs or in the event that the Sample Preparation or the PCR did not reach its expected time points The Incomplete results may apply to a run or a lane Sample s can be repeated from their corresponding Sample Buffer Tube s within the timeframes defined above Vortex the sample s for one 1 minute and restart following BD MAX System Operation section For the interpretation of warning or error code messages refer to the BD MAX System User s Manual Troubleshooting section External Control Failure External Controls should yield expected results when tested If specimens have to be repeated due to an incorrect External Control result they should be repeated from their Sample Buffer Tubes along with freshly prepared E
27. identified 96 5 of the MRSA positive specimens and 96 9 of the MRSA negative specimens Tables 5 and 6 Table 5 Results Obtained for MRSA with the BD MAX StaphSR Assay in Comparison to Direct Culture All Sites Direct Culture Positive Total Positive 137 69 206 BD MAX StaphSR Assay Negative 5 2182 2187 Total 142 2251 2393 Positive Percent Agreement 96 5 137 142 95 Cl 92 0 98 5 Negative Percent Agreement 96 9 2182 2251 95 Cl 96 1 97 6 Table 6 Site by Site Performance Obtained for MRSA with the BD MAX StaphSR Assay in Comparison to Direct Culture Clinical Sites Positive Percent Agreement with 95 Cla Negative Percent Agreement with 95 Cla site 1 a Confidence interval Compared to Direct Culture the BD MAX StaphSR assay identified 95 1 of the SA positive specimens 100 35 35 90 1 100 Site 2 93 5 29 31 79 3 98 2 96 1 73 76 89 0 98 6 96 5 137 142 92 0 98 5 Site 3 Overall and 90 9 of the SA negative specimens Tables 7 and 8 13 98 6 911 924 97 6 99 2 97 8 586 599 96 3 98 7 94 1 685 728 92 1 95 6 96 9 2182 2251 96 1 97 6 Table 7 Results Obtained for SA with the BD MAX StaphSR Assay in Comparison to Direct Culture Direct Culture AISI Positive Negative Total Positive 564 164 728 BD MAX StaphSR Assay Negative 29 1636 1665 Total 2393
28. ound to be negative after repeat of Reference Method Table 2 Site by Site Performance Obtained for MRSA with the BD MAX StaphSR Assay in Comparison to the Reference Method Clinical Sites Prevalence Sensitivity 95 CI Specificity 95 CI Site 1 92 7 38 41 98 9 908 918 80 6 97 5 98 0 99 4 Site 2 5 8 38 650 86 8 33 38 98 5 583 592 72 7 94 2 97 1 99 2 Site 3 10 6 81 765 96 3 78 81 94 9 649 684 89 7 98 7 93 0 96 3 6 7 160 2375 T 149 160 97 5 2140 2194 88 1 96 1 96 8 98 1 a Prevalence based on reference method only b Confidence interval c 2375 specimens were reference method compliant Compared to the Reference Method Direct Enriched Culture the BD MAX StaphSR assay identified 92 0 of the SA positive specimens and 93 1 of the SA negative specimens Tables 3 and 4 For the population tested this resulted in a NPV of 96 8 and a PPV of 83 4 Table 3 Results Obtained for SA with the BD MAX StaphSR Assay in Comparison to the Reference Method All Sites Reference Method Positive 599 1181 717 BD MAX StaphSR Assay Negative 52 1585 1637 Total 651 1703 2354 Sensitivity 92 0 599 651 95 Cl 89 7 93 9 Specificity 93 1 1585 1703 95 Cl 91 8 94 2 PPV 83 4 95 Cl 80 9 85 8 NPV 96 8 95 Cl 96 0 97 6 Further investigation was performed on specimens with discordant results between the
29. prevalence BD MAX StaphSR assay performance may vary depending on the prevalence and population tested The BD MAX StaphSR assay requires use of four 4 optical channels from the BD MAX System FAM channel 475 520nm ROX channel 585 630nm VIC channel 530 565 nm and Cy5 5 channel 680 715 nm Performance of the remaining optical channel has not been established with this assay 10 EXPECTED VALUES In the BD MAX StaphSR assay clinical study a total of 2395 reportable results from specimens compliant at the specimen and PCR levels were obtained from 3 geographically diverse sites and compared with Direct and Enriched culture The study population was grouped into in patient out patient categories The number and percentage of positive cases as determined by the BD MAX StaphSR assay are presented in the table below BD MAX StaphSR Assay Positive Total Number Number of Number of MRSA Positive SA of Specimens MRSA SA Percentage Percentage p Positive Positive g 10 6 32 5 In patient 1685 178 548 i 178 1685 548 1685 3 9 25 6 Out patient 710 28 182 Spa 28 710 182 710 8 6 30 5 Total 2395 206 730 206 2395 730 2395 1Total specimens based on compliant PCR results PERFORMANCE CHARACTERISTICS Clinical Performance Clinical performance characteristics of the BD MAX StaphSR assay were determined in a multi site prospective investigational study Three 3 inve
30. resent see Figure 1 Do not use reagents if desiccant is not present or broken inside reagent pouches Do not use reagents if the foil has been opened or damaged Do not mix reagents from different pouches and or kits and or lots Do not use expired reagents and or materials Do not mix caps between tubes or re use caps as contamination may occur and compromise test results Proceed with caution when using chemical solutions as Master Mix and Extraction tube barcode readability may be altered To avoid contamination of the environment with SA or MRSA amplicons do not break apart the BD MAX PCR Cartridge after use The seals in the BD MAX PCR Cartridges prevent contamination The laboratory should routinely perform environmental monitoring to minimize the risk of cross contamination Performing the assay outside of the recommended time ranges may produce invalid results Assays not performed within specified time ranges should be repeated Additional controls may be tested according to guidelines or requirements of local state provincial and or federal regulations or accrediting organizations In cases where culture or other PCR tests are conducted in the same general area of the laboratory care must be taken to ensure that the BD MAX StaphSR assay any additional reagents required for testing and the BD MAX System are not contaminated Gloves must be changed before manipulating reagents and cartridges Always handle specim
31. result is indicative of a specimen handling and or contamination problem Review the specimen handling technique to avoid mix up and or contamination An External Positive Control that yields a negative result is indicative of a specimen handling preparation problem Review the specimen handling preparation technique An External Control that yields an Unresolved Indeterminate or Incomplete test result is indicative of a reagent or a BD MAX System failure Check the BD MAX System monitor for any error messages Refer to the System Error Summary section of the BD MAX System Users Manual for interpretation of warning and error codes If the problem persists use reagents from an unopened pouch or use a new BD MAX StaphSR assay kit NOTE External Positive and Negative Controls are not used by the BD MAX System software for the purpose of sample test result interpretation External Controls are treated as if they were patient samples Each BD MAX StaphSR assay Extraction Tube contains a Sample Processing Control SPC which is a plasmid containing a synthetic target DNA sequence The SPC will be extracted eluted and amplified along with any DNA present in the processed specimen ensuring the predictivity of the assay The SPC monitors the efficiency of DNA capture washing and elution during the sample processing steps as well as the efficiency of DNA amplification and detection during PCR analysis If the SPC result fails
32. reus specific and mecA or mecC targets and e The nuc gene target may or may not be detected since it has been shown that in rare instances the nuc gene may be absent for MRSA and e The SPC is ignored since MRSA target amplification overrides this control SA POS MRSA NEG SA DNA detected No MRSA DNA detected e Fluorescence signal is detected for the nuc gene target only indicative of an SA strain or e Fluorescence signal is detected for the nuc gene and mecA or mecC target in the absence of MREJ sequences indicative of an SA strain present with co colonization of a non SA methicillin resistant bacterial strain or e Fluorescence signal is detected for the nuc gene and MREJ target indicative of an empty cassette variant or e Fluorescence signal is detected for the MREJ target only indicative of a S aureus empty cassette variant MREJ is specific to S aureus species and thus is indicative of an SA strain The detection of nuc gene is not necessary to obtain an SA POS MRSA NEG result for an empty cassette variant e SPC is ignored since SA target amplification overrides this control SA NEG MRSA NEG No SA no MRSA DNA detected e Fluorescence signal is not detected by the BD MAX StaphSR assay for any target nuc mecA mecC and MREJ targets and fluorescence signal is detected for the SPC or e Fluorescence signal is detected for the mecA or mecC gene only the mecA and mecC genes are not unique to S aureus species
33. sport device refer to Equipment and Materials Required But Not Provided section nasal specimens should be collected according to institutional and laboratory standard operating procedures and or the following 1 Moisten the swab s with two drops approximately 50 uL of sterile physiological saline or use dry 2 Carefully insert the swab s into the patient s nostril a swab tip should be inserted up to 2 5 cm 1 inch from the edge of the nares Roll the swab s along the mucosa inside the nostril 5 times Insert the same swab s into the second nostril and repeat steps 2 and 3 Place the swab s in its transport tube Label the transport tube Transport the swab s to the laboratory according to institutional and laboratory standard operating procedures Refer to Storage and Stability section ee St a a Specimen Preparation NOTE One 1 Sample Buffer Tube one 1 Septum Cap one 1 Master Mix B7 one 1 Extraction Tube B8 and one 1 Reagent Strip are required for each specimen and each External Control to be tested NOTE For culturing clinical specimens prior to performing the BD MAX StaphSR assay refer to Culturing of Clinical Specimens section 1 Obtain the number of Sample Buffer Tubes corresponding to the number of specimens and external controls to be run 2 Label each Sample Buffer Tube with the appropriate patient identification making sure not to obscure write or label over the barcod
34. stigational centers participated in the study To be enrolled in the study patients had to be eligible for MRSA or SA testing according to institutional policies Eligibility requirements for targeted screening as per clinical site policies included but were not limited to patients admitted into the particular healthcare system patients admitted to the Intensive Care Unit patients transferred to the Intensive Care Unit pre elective surgery patients and patients being admitted from long term care facilities Specimens from patients previously enrolled in the study were excluded The Comparative Reference Method consisted of direct culture complemented by enriched culture Enriched culture analysis was completed for all specimens that were negative for MRSA or SA by direct culture Presumptive S aureus colonies observed on selective S aureus chromogenic medium were subcultured onto Blood Agar BA Identification was confirmed with an agglutination test while methicillin resistance was confirmed by Cefoxitin disk 30 ug diffusion susceptibility testing Enrichment in Trypticase Soy Broth with 6 5 NaCl TSB 6 5 NaCl was completed in the event that MRSA or SA was not confirmed by the initial direct culture method Turbid TSB 6 5 NaCl broth was used to inoculate additional chromogenic medium and BA plates MRSA confirmation was performed as described above Results Obtained with the BD MAX StaphSR Assay in Comparison to the Reference Method
35. strains resistant to previously effective antimicrobial agents Methicillin resistant strains of S aureus are frequently encountered in health care settings and represent nearly 60 of isolates from hospital acquired S aureus in some North American and European healthcare facilities In hospital settings MRSA may be transmitted from patient to patient through the contaminated hands of healthcare workers Risk factors for colonization with MRSA in healthcare settings include prolonged hospital stay proximity to patients infected with MRSA exposure to multiple and prolonged broad spectrum antibiotic treatments and MRSA carriage MRSA infection is increased in patients colonized with MRSA S aureus is one of the leading causes of surgical site infections SSI 24 It is responsible for 20 to 56 of SSI among which MRSA represents up to 57 of isolates The mortality rate associated with both pathogens varies from 5 to 22 In most patients with SSI the S aureus infection is from an endogenous source Traditional techniques used for the detection of S aureus and MRSA require culture steps and isolation of pure colonies followed by agglutination testing to identify S aureus and either oxacillin susceptibility testing detection of the mecA gene for methicillin resistance or detection of the penicillin binding protein PBP 2a to identify MRSA A minimum of 24 hours are required to resolve the S aureus and MRSA status with a median
36. study was performed using a variety of MRSA and MSSA strains taking into account geographic origin MREJ genotype wild type and mutant SCCmec type Pulsed Field Gel Electrophoresis PFGE type temporal diversity and susceptibility pattern Seventy seven 77 MRSA strains from 27 countries and 51 MSSA strains from 16 countries were tested in this study including strains from public collections and from well characterized clinical isolates including vancomycin resistant Staphylococcus aureus VRSA and vancomycin intermediate Staphylococcus aureus VISA strains The BD MAX StaphSR assay detected MREJ types i ii iii iv v vi vii ix xiii xiv and xxi when tested at low bacterial load 2 3 x LoD The BD MAX StaphSR assay detected MRSA SCCmec types Il Ill IV V VI VII VIII and XI as well as MRSA PFGE types USA 100 to 800 1000 and 1100 at 2 3 x LoD All MRSA strains displaying additional resistance to vancomycin VRSA and VISA were also detected The BD MAX StaphSR assay detected all 51 MSSA strains tested including mecA empty cassette variants Evaluation of a Well Characterized Challenge Strain Panel An additional analytical study was carried out to evaluate the analytical performance of the BD MAX staphSR assay using a well characterized challenge strain panel e Seventeen 17 out of 17 MRSA strains with high and low oxacillin minimum inhibitory concentrations MICs including PFGE types USA 100 to 800 1000 PFGE type I
37. taphylococcus aureus skin or soft tissue infection in a state prison Mississippi 2000 MMWR 2001 50 919 922 National Nosocomial Infections Surveillance NNIS System Report data summary from January 1992 to June 2004 issued October 2004 Am J Infect Control 2004 32 470 485 Dulon M et al MRSA prevalence in European healthcare settings a review BMC Infectious Diseases 2011 11 138 doi 10 1186 1471 2334 11 138 Jernigan J Is the burden of Staphylococcus aureus among patients with surgical site infections growing Infect Control Hosp Epidemiol 2004 25 6 457 460 Mc Garry S et al Surgical site infection due to Staphylococcus aureus among elderly patients mortality duration of hospitalization and cost Infect Control Hosp Epidemiol 2004 25 6 461 467 Kluytmans J and Wertheilm H Nasal carriage of Staphylococcus aureus and prevention of nosocomial infections Infection 2005 33 1 93 99 Clinical and Laboratory Standards Institute Protection of laboratory workers from occupationally acquired infections Approved Guideline Document M29 Refer to the latest edition Centers for Disease Control and Prevention and National Institutes of Health Biosafety in microbiological and biomedical laboratories Chosewood L C and Wislon D E eds 2009 HHS Publication No CDC 21 1112 Clinical and Laboratory Standards Institute Molecular Diagnostic Methods for Infectious Diseases Approved Guideline Document MM3
38. tics Technical Service 1 800 638 8663 GeneOhm Sciences Canada Inc Benex Limited 2500 Boul du Parc Technologique Pottery Road Dun Laoghaire Qu bec QC G1P 4S5 Canada Co Dublin Ireland Made in Canada Brands are trademarks of their respective owners BD BD Logo and all other trademarks are property of Becton Dickinson and Company 2013 BD 20
39. time of more than 48 hours when using these conventional methods With the increased morbidity and mortality associated with S aureus infections the emergence of mecA drop out strains and the spreading of a new methicillin resistance gene i e mecC gene the ability to detect and differentiate S aureus and MRSA within hours instead of day s represents a definite advantage over current practices and allows for more effective patient treatment and management P0153 01 A nasal specimen is collected and transported to the laboratory using the recommended swab refer to Equipment and Materials Required But Not Provided section The swab is placed in a BD MAX StaphSR Sample Buffer Tube The Sample Buffer Tube is vortexed to release cells from the swab into the buffer The Sample Buffer Tube is placed into the BD MAX System and the following automated procedures occur the bacterial cells are lysed DNA is extracted on magnetic beads and concentrated and then an aliquot of the eluted DNA is added to PCR reagents which contain the SA and MRSA specific primers used to amplify the genetic targets if present The assay also includes a Sample Processing Control SPC The SPC is present in the Extraction Tube and undergoes the extraction concentration and amplification steps to monitor for inhibitory substances as well as process inefficiency due to instrument or reagent failure No operator intervention is necessary once the clinical sample
40. ut of 50 MSSA strains tested at high concentrations 210 CFU swab produced SA POS MRSA NEG results e Seventeen 17 viruses representing 12 different viral species were tested at 2 10 PFU mL All 17 viruses produced negative results SA NEG MRSA NEG Interfering Substances Twenty nine 29 microorganisms and chemical substances which might be used in the nares or found in nasal swab specimens were evaluated for potential interference with the BD MAX StaphSR assay Table 12 MRSA negative samples and MRSA positive samples at 2 3 x LoD were tested with the highest amount of each compound or microorganism likely to be found at the sampling site or on the nasal swab sample Results demonstrated no reportable interference with any microorganisms or chemical substance except for Tobramycin which showed inhibition in the BD MAX StaphSR assay when tested at a concentration of 4 5 x 10 3 g swab Table 12 Endogenous and Exogenous Substances Tested with the BD MAX StaphSR Assa Substance Result Substance Result Mucin from bovine submaxillary glands Rhinocort aqua Zicam No Drip Liquid Nasal Dexamethasone Sodium Phosphate Ophtalmic Solution TM i USP 0 1 Dexamethasone Phosphate Equivalent Sor PIENE Congestion 7 Relief j Staphylococcus hominis subsp E Haemophilus influenzae Streptococcus pneumoniae 1NI No reportable interference with the BD MAX StaphSR assay I Reportable interference
41. with the BD MAX StaphSR assay 16 Microbial Competitive Inhibitory Effect Potential microbial inhibitory effect was evaluated with e an increasing concentration of MRSE when co spiked with a low concentration 1 2 x LoD of MRSA or MSSA and e an increasing concentration of MSSA when co spiked with a low concentration 1 2 x LoD of MRSA Results demonstrated competition from e MRSE at an MRSA MRSE ratio of 1 2 1x10 e MRSE at an MSSA MRSE ratio of 1 2 1x105 e MSSA at an MRSA MSSA ratio of 1 2 1x104 Precision Within laboratory precision was evaluated for the BD MAX StaphSR assay at one 1 site The Precision panel consisted of 4 sample categories near the LoD Each specimen contained simulated nasal matrix MRSA and MSSA strains were tested as follows e Moderate Positive MP MRSA MREJ ii 2 2 and lt 5 x LoD Low Positive LP MRSA MREJ ii 2 1 and lt 2 x LoD Low Positive LP MRSA MREJ vii 2 1 and lt 2 x LoD Low Positive LP MSSA 2 1 and lt 2 x LoD High Negative HN MRSA MREJ ii lt 1 x LoD High Negative HN MSSA lt 1 x LoD True negative TN Negative specimens no target Testing was performed in duplicate over 12 days with 2 runs per day by 2 different technologists Precision study results for TN MP LP and HN MRSA samples demonstrated 100 100 97 9 and 27 1 agreement respectively Precision study results for LP and HN MSSA samples demonstrated 100 and 56 2 agreement respectively
42. xternal Controls within the timeframes defined above Vortex the samples for one 1 minute and restart following the BD MAX System Operation section CULTURING OF CLINICAL SPECIMENS In order to perform antimicrobial susceptibility testing or epidemiological typing clinical specimens may be cultured from the collection device swab prior to performing the Specimen Preparation Procedure using a Streak Plate method or after the Specimen Preparation Procedure using an Enrichment Broth method Immediately after the end of the initial PCR run swabs may be stored at 2 8 C for up to 36 hours in sample Buffer Tubes before culturing following hospital procedures LIMITATIONS OF THE PROCEDURE e This product is intended for use with nasal swab specimens collected using specimen collection and transport devices listed in the Equipment and Materials Required But Not Provided section Performance of the BD MAX StaphSR assay using Liquid Amies single or double swab transport device has not been established e This product should only be used with the BD MAX System e Incorrect test results may occur from improper specimen collection handling or storage technical error Sample mix up or because the number of organisms in the specimen is below the analytical sensitivity of the test Careful compliance with the package insert instructions and the BD MAX System User s Manual are necessary to avoid erroneous results e
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