Update on the CLSI Standards for Antimicrobial Susceptibility Testing: What s New with the Gram Positive Organisms?

2 0 1 3 CASES (with answers!) Update on the CLSI Standards for Antimicrobial Susceptibility Testing: What s New with the Gram Positive Organisms? Susan E. Sharp, Ph.D., DABMM, FAAM Director - Regional and Sunnyside Medical Center Laboratories Director - Regional Clinical Microbiology Kaiser Permanente Associate Professor - Department of Pathology Oregon Health & Sciences University Portland, OR

Case 1 32 year old pregnant woman had a vaginal-rectal specimen sent for GBS culture. The culture was positive and results were sent to the doctor. Two days later the doctor s office calls and requests suceptibility testing because the patient is very allergic to penicillin and the doctor needs the results for a non - lactam antibiotic for this patient. You subculture the isolate for susceptibility testing. 2

Case 1 When testing GBS from a prenatal screen culture, the most important drugs to test and report are? Drugs to Test (and why): Drugs to Report (and why): 3

Case 1 CDC Guidelines ** If an isolate is resistant to erythromycin, it might have inducible resistance to clindamycin, even if it appears susceptible to clindamycin. If a GBS isolate is susceptible to clindamycin, resistant to erythromycin, and testing for inducible clindamycin resistance is negative, then clindamycin can be used for GBS intrapartum prophylaxis instead of vancomycin. 7

Case 1: Group B Streptococcus Intrapartum prophylaxis CLSI M100-S23. Table 1B. Rx: Recommendations for intrapartum prophylaxis for Group B streptococci are penicillin or ampicillin. Although cefazolin is recommended for penicillin-allergic women at low risk for anaphylaxis, those at high risk for anaphylaxis may receive clindamycin. Group B streptococci are susceptible to ampicillin, penicillin, and cefazolin, but may be resistant to erythromycin and clindamycin. When a Group B Streptococcus is isolated from a pregnant woman with severe penicillin allergy (high risk for anaphylaxis), erythromycin and clindamycin (including inducible clindamycin resistance) should be tested, and only clindamycin should be reported. (see Table 2H-1 Supplemental Table 1.) 8

Case 2: Specimen: Wound drainage Diagnosis: Trauma - Staphylococcus aureus MIC ( g/ml) clindamycin erythromycin oxacillin penicillin vancomycin 0.5 - S 0.5 - S 0.5 - S R 0.5 - S Patient is receiving piperacillin-tazobactam for nosocomial pneumonia. The physician asks that piperacillin-tazobactam be tested on this S. aureus? What do you tell them and why? 9

Case 2: Staphylococcus spp. M100-S22. Table 2C. 2013 - Eliminated breakpoints fo Penicillins BL/BL inhibitor combos Cephalosporins Carbapenems

Case 2: Staphylococcus spp. β-lactam Breakpoints Remaining Penicillin Represents penicillinase-labile penicillins Oxacillin Represents penicillinase-stable penicillins Cefoxitin Surrogate for oxacillin Ceftaroline (added 2013) Cephalosporin with anti-mrsa activity

Case 2: Staphylococcus spp. Penicillins and Penicillinases Penicillinase-labile Penicillins Amoxicillin Ampicillin Carbenicillin Mezlocillin Penicillin Piperacillin Ticarcillin Penicillinase-stable Penicillins Cloxacillin Dicloxacillin Flucloxacillin Methicillin Nafcillin Oxacillin 12

Case 2: Staphylococcus spp. - β-lactams Use Pen and Ox results to predict results for other ß-lactams Test Results Oxacillin Penicillin (cefoxitin) S R R S S R Predicts Susceptible to: All penicillins ß-lac / ß-lactamase inhibitor combos Cephems Carbapenems Resistant to: Penicillinase-labile penicillins Susceptible to: Penicillinase-stable penicillins ß-lac / ß-lactamase inhibitor combos Cephems Carbapenems Resistant to: All ß-lactams (except cephems with anti- MRSA activity, e.g., ceftaroline)

Case 2: Specimen: Wound drainage Diagnosis: Trauma - Staphylococcus aureus MIC ( g/ml) clindamycin 0.5 - S erythromycin 0.5 - S oxacillin 0.5 - S* penicillin R vancomycin 0.5 - S *Oxacillin-S staphylococci are susceptible to pip/tazobactam. 14

Case 2a: Specimen: Wound drainage Diagnosis: Trauma - Staphylococcus aureus clindamycin erythromycin oxacillin penicillin vancomycin MIC ( g/ml) >8.0 - R >8.0 - R >16 - R R 0.5 - S Clinician calls; serious infection, can t use vanco in this patient, needs other drug choices. What do you tell them, what do you do, and why? 15

16 Case 2a: Specimen: Wound drainage Diagnosis: Trauma - Staphylococcus aureus MIC ( g/ml) ceftaroline 0.5 S clindamycin >4 R daptomycin 0.5 S doxycycline* 1 S erythromycin >4 R linezolid 1 S oxacillin >8 R penicillin R rifampin* 0.5 S SXT* 0.5/9.5 S vancomycin 2 S Possible Chart comment: MRSA are resistant to all β-lactam agents except ceftaroline. *Doxycycline, rifampin or SXT should not be used alone for serious MRSA infections.

Case 2a: Ceftaroline Broad-spectrum cephalosporin (with anti-mrsa activity) IV only FDA clinical indications Acute bacterial skin and skin structure infections, communityacquired bacterial pneumonia Activity spectrum: GPC (staphylococci including MRSA; β-hemolytic streptococci; S.pneumoniae) Enterobacteriaceae Not - ESBL, ampc, or carbapenemase producers H.influenzae Not - Pseudomonas aeruginosa 17

Case 3 You want to change from your current staphylococci disk diffusion susceptibility panel to a new panel on your automated AST system. What is your current process? What will be your process in 2014? 18

Case 3 Prior to adding a new AST panel Must perform verification according to CLIA 493.1253 Testing ATCC QC strains alone is insufficient for verification testing (per CLSI and CLIA) Ref: Cumitech 31A: Verification/Validation of Procedures in the Clinical Microbiology Laboratory. (ASM Press) 19

Case 3 Verification & Validation 20

22 Verification The documentation of either commercial or laboratory-developed test performance. For FDA cleared or approved tests, it is the process of examination or evaluation of a test system to determine whether the claims stipulated by the manufacturer in the package insert as they relate to the product, the process, the results, or the interpretation can be achieved. Verification requires determination or confirmation of the test performance characteristics, including sensitivity, specificity, and, where appropriate, the predictive values, precision, and accuracy of the test. Verification is a onetime process, completed before the test or system is used for patient testing. See Appendix A. Method selection and verification example. Validation The documentation that a test which has already been verified is repeatedly giving the expected results as the test is performed over a period of time. Validation confirms that the test continues to perform satisfactorily according to the laboratory s requirements or the manufacturer s claims or, for laboratorydeveloped tests, according to its intended use. The requirements for test validation may include personnel competency assessment, quality control, internal and external proficiency testing, and correlation with clinical findings. Validation thus becomes an integral part of the laboratory s quality assurance program.

Verification Testing CAP Phase II COM.10600 Manufacturer Instructions For FDA approved/cleared tests, the laboratory follows manufacturer instructions or provides documentation of validation study(ies) if the test has been modified. NOTE: For example, the laboratory must verify established performance specifications of FDA approved assays (accuracy, precision, analytic sensitivity, interferences, reference range and reportable range, as applicable). If the laboratory modifies manufacturer instructions, the test is categorized as a non-fda approved/cleared test, and the modification mush be validated by the laboratory. A change in the specimen type of collection device is considered a modification. 23

Case 3 Perform appropriate QC strain(s) for either: 20-30 day QC plan 3x5 (15 replicate) QC plan Test a min. of 30 representative isolates from your institution on the new automated AST panel Test these 30 isolates also by a reference method (disk diffusion, frozen MIC panel), send to a reference lab, or use organisms with known results. 24

Case 3 - NEW AST QC: 3x5 (15) Plan - 2013 An alternate QC plan using a two-phase, 15 replicate (3 X 5 day) plan is described in Table 3C as follows: 15 replicate (3 X 5 day) plan Test three replicates using individual inocula preparations of the appropriate QC strains for 5 consecutive test days to perform the 15 replicate (3 x 5 day) plan. Each QC strain tested is evaluated separately according to the acceptance criteria and recommended action described below (e.g., pass, test another 3 replicates for 5 days, fail). Upon successful completion of the QC plan, the laboratory can convert from daily to weekly QC testing. If unsuccessful investigate, take corrective action as appropriate and continue daily QC testing. 25

Case 3 - NEW AST QC 3x5 (15) - 2013 Table 3C* Number out of range with initial testing (based on 15 replicates) Conclusion from initial testing Number out of range after repeat testing (based on all 30 replicates) Conclusion after repeat testing 0-1 QC plan successful. Convert to weekly QC testing. NA NA 2-3 Test another 3 replicates for 5 days. 2-3 QC plan successful. Can convert to weekly testing. 4 or greater QC plan fails. Investigate and take corrective action as appropriate. Continue QC each test day. 4 or greater QC plan fails. Investigate and take corrective action as appropriate. Continue QC each test day. 26 *Assess each QC strain individually

Case 3 - NEW AST QC 3x5 (15) - 2013 Test 3 replicated of each QC strain for 5 days using individually prepared inoculum 0-1 of 15 out of range? Pass. Convert to weekly QC. 2-3 of 15 out of range? Test another 3 replicates for 5 days > 4 of 15 out of range? Fail. Continue to include QC each test day. Take corrective action. 2-3 of 30 out of range? > 4 of 30 out of range? 27 Pass. Convert to weekly QC.

Case 3 Rest of verification testing Acceptance rate per CUMITECH < 10% combination of major errors (S/R) and minor errors (S/I; I/R) With no more than 5% major errors Overall EA & CA of > 90% Essential Agreement: Agreement within +1 twofold dilution of the drug as compared to the reference method Categorical Agreement: Both are S, or I, or R 28

Case 3: EXAMPLE - 1 NEW panel results Biapenem: 20 isolates (<1; 2; >4) MSSA (20) 0.12 9 0.12 0.25 0.5 1.0 2.0 4.0 8.0 0.25 8 0.5 1 a Reference method results S I R 1.0 1 2.0 1 a,b 4.0 8.0 29 Major errors: 0% EA: 90% (a,b - 2/20) Minor errors: 5% (b) CA: 95% (b - 1/20)

Case 3: EXAMPLE - 1 1) < 10% combination of major & minor errors (With no more than 5% major errors) 2) Overall EA & CA of > 90% Our example: Major errors: 0% (0) EA: 90% (2) Minor errors: 5% (1) CA: 95% (1) 30

Case 3: EXAMPLE - 2 NEW panel results Biapenem: 20 isolates (<1; 2; >4) MSSA (20) 0.12 11 0.12 0.25 0.5 1.0 2.0 4.0 8.0 0.25 2 Reference method results 0.5 1 1 S I R 1.0 1 1 1 2.0 1 4.0 1 8.0 Major errors:? % EA:? % Minor errors:? % CA:? % 32

Case 3: EXAMPLE - 2 NEW panel results Biapenem: 20 isolates (<1; 2; >4) MSSA (20) 0.12 11 Reference method results 0.12 0.25 0.5 1.0 2.0 4.0 8.0 0.25 2 0.5 1 a 1 S I R 1.0 1 b 1 1 2.0 1 c 4.0 1 d 8.0 33 Major errors: 5% (d) EA: 80% (4/20 a,b,c,d ) Minor errors: 5% (c) CA: 90% (2/20) c,d

Case 3: EXAMPLE - 2 1) < 10% combination of major & minor errors (With no more than 5% major errors) 2) Overall EA & CA of > 90% Our example: Major errors: 5% (1) EA: 80% (4) Minor errors: 5% (1) CA: 90% (2) 34

Case 3: EXAMPLE - 2 Accuracy of the new or revised test does not satisfy the verification requirements Withdraw the test for consideration, or Corrective action must be taken by the user &/or the manufacturer After corrective action, verification must again take place 36

Case 4 SPECIMEN: Blood culture DIAGNOSIS: Endocarditis ORGANISM: Staphylococcus aureus MIC ( g/ml) clindamycin 8 R erythromycin 16 R oxacillin < 0.5 S vancomycin < 0.5 S 37

Case 4 SPECIMEN: Blood culture DIAGNOSIS: Endocarditis ORGANISM: Staphylococcus aureus MIC ( g/ml) clindamycin 8 R erythromycin 16 R oxacillin < 0.5 S vancomycin < 0.5 S Physician calls with an additional request 38

Case 4 The physician would like to treat this patient with penicillin as it will be a long and protracted course of therapy for this patient. They notice that penicillin was not resulted on the patient s report. What do you tell the physician about the penicillin result on this patient s isolate? What further steps do you take regarding this request? 39

Case 4: Staphylococcus aureus Penicillin (MIC 0.12 µg/ml) Reporting Nitrocefin β-lactamase positive Penicillin MIC 0.12 µg/ml A B A Nitrocefin β- lactamase negative Note: If doing disk diffusion routinely, just examine zone edge for those with zone sizes of > 29mm. Report penicillin R Perform penicillin disk zone-edge test 29 mm fuzzy Report penicillin S 29 mm sharp Report penicillin R 40 M100-S22. Table 2C Supplemental Table 1. Page 80

Case 4: Staphylococcus aureus Disk Zone Edge Test (10 U penicillin disk and standard DD method) Fuzzy / beach = β-lactamase negative, Penicillin - S S. aureus supplemental QC: Neg - ATCC 25923 Sharp / cliff = β-lactamase positive, Penicillin - R Pos - ATCC 29213 41 Reference: M100-S22. Table 2C Supplemental Table 1. Page 83

Case 4 This is an appropriate request for endocarditis. Test penicillin by an MIC or DD method to penicillin. If pen = R (>0.25 g/ml / <28mm); done = Report R If pen = S (<0.25 g/ml / > 28mm) Perform -lactamase test: If +; done = Report R If -; DD for beach/cliff Beach; Report penicillin S (- -lactamase production) Cliff; Report penicillin R (+ -lactamase production) 42

Case 5 25 y/o woman with acute cystitis. UR culture grows >100,000 Staphylococcus species The physician wants additional identification and AST done. What is the most likely species of this organism? Do you perform any additional laboratory tests? What do you tell the physician? 43

Case 5 25 y/o woman with acute cystitis. UR culture grows >100,000 cfu/ml Staphylococcus species S.saprophyticus most likely agent in young sexually active women 44

Case 5 Organism / Drug Novobiocin Fosfomycin Fusidic Acid S.aureus/S.lugdunensis S.epidermidis S.haemolyticus There is no intrinsic resistance in these species. There is no intrinsic resistance in this species. There is no intrinsic resistance in this species. S.saprophyticus R R R S.capitis R S.cohnii S.xylosus R R 45 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 5 25 y/o woman with acute cystitis. UR culture grows >100,000 cfu/ml Staphylococcus saprophyticus The physician wants additional identification and AST done. CLSI 2012; Table 2C, General comment #6 Routine testing of urine isolates of S.saprophyticus is not advised, because infections respond to concentrations achieved in urine of antibimcrobial agents commonly used to treat acute, uncomplicated urinary tract infections (eg., nitrofurantoin, trimethoprim +/- sulfamethoxazole, or a fluoroquinolone). 46

Case 6 Young boy 3 y/o presents with pneumonia. The suctioned sputum grows out the pathogen: Streptococcus pneumoniae. You do AST and get the following results : Erythromycin-R, Penicillin-R, Ceftriaxone-S, SXT-R, Levofloxacin-S Doc wants to use clindamycin for this patient. What and how do you test, and how do you report the susceptibility results? 47

Case 6 S.pneumoniae & inducible CLI-R: The clinical significance of this mechanism of clindamycin resistance is not known for S.pneumoniae, but inducible clindamycin resistance can be detected using D-zone testing and is now included in the 2013 CLSI documents. If testing S.pneumoniae to clindamycin and the isolate is clindamycin-s, a test for inducible clindamycin resistance should be performed. 12mm for spacing of disks for disk diffusion testing 1 g/ml Ery + 0.5 g/ml Clinda for broth microdilution testing 48

Case 7 Patient develops pain and swelling in the abdomen. Ascetic fluid is collected and sent for culture. The specimen Gram stain Many PMNs Moderate GPC in chains resembling streptococci The culture grows a pure culture of many Streptococcus anginosus group. 49

Case 7 You report out your normal AST of the following for this organism: pencillin (R), ceftriaxone (S), vancomycin (S), clindamycin (S), erythromycin (S) The physician calls and asks for azithromycin to be tested. You do have azithromycin disks. What do you do? The physician calls and asks for doripenem to be tested. You do have doripenem disks and it is also in your streptococci broth microtiter panels. What do you do? 50

Case 7 The physician calls and asks for azithromycin to be tested. You do have azithromycin disks. What do you do? Table 1B: (page 39 M100-S23) Footnote a Susceptibility and resistance to azithromycin, clarithromycin, and dirithomycin can be predicted by testing erythromycin. Tell the doctor that based on the erythromycin susceptible result azithromycin will be S and testing is not necessary. 51 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 7 Doripenem The physician calls and asks for doripenem to be tested. What do you do? Complicated Intra-Abdominal Infections Indicated as a single agent for the treatment of complicated intra-abdominal infections caused by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacteroides caccae, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus, Streptococcus intermedius, Streptococcus constellatus and Peptostreptococcus micros. Complicated Urinary Tract Infections, Including Pyelonephritis Indicated as a single agent for the treatment of complicated urinary tract infections, including pyelonephritis caused by Escherichia coli including cases with concurrent bacteremia, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Acinetobacter baumannii. 52

Case 7 Doripenem No CLSI disk diffusion breakpoints; only MIC breakpoints You test by appropriate MIC method Result is 2 g/ml What do you do? 53

Case 7 Doripenem (Gram positive s) (No disk diffusion criteria) S ( g/ml) I ( g/ml) R ( g/ml) Streptococcus Viridans group (O) < 1.0 - - -Streptococcus (O) < 0.12 - - S.pneumoniae (O) < 1.0 - - S.aureus* - - - For some organism/antimicrobial agent combinations, the absence or rare occurrence of resistant strains precluded designing any result categories other than susceptible. For strains yielding results suggestive of a nonsusceptible category, organism identification and antimicrobial susceptibility test results should be confirmed. *Remember: 54 Only penicillin, oxacillin [cefoxitin], ceftaroline for staph with the -lactams in 2013.

Case 7 Doripenem No CLSI disk diffusion breakpoints; only MIC breakpoints You test by appropriate MIC method Result is 2 g/ml What do you do? Repeat ID and AST, if all ok Report as Non-susceptible 55

Case 8 An E.coli is isolated from a osteomyelitis (bone) specimen and has the following AST: MIC g/ml Ampicillin 64 R Cefazolin 16 R Ceftriaxone 8 R Ceftazidime 8 I Cefepime 8? Gentamicin 1 S SXT 1/19 S Ciprofloxacin 0.5 S 56 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 8 Cefepime MIC = 8 g/ml How would you report the interpretive criteria today? How will you report the interpretive criteria in January, 2014? 57 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 8 S-DD Enterobacteriaceae and cefepime ISSUE: When the cephalosporin breakpoints to the Enterobacteriaceae were change (lowered) in 2010, cefepime was also reviewed but the committee at that time left the breakpoint unchanged at < 8 / 16 / > 32 ug/ml. RESULT: The committee voted to change cefepime breakpoints for the Enterobacteriaceae from current to the below: S < 2 ug/ml SDD 4-8 ug/ml (SDD = susceptible, dose-dependent) R > 16 ug/ml 58 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 8 S-DD In January, your physician calls and wants to know what the heck SDD is?? 59 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 8 S-DD Enterobacteriaceae and cefepime SDD indicates that approved, higher therapeutic levels of this drug can be used to treat serious infections with organisms having an MIC in this range. SDD indicates that this drug may be used in high doses to achieve the maximum achievable drug doses. Rx Comment The SDD breakpoint was derived based on a dosage regimens of 1 g Q 8 hr or 2 g Q 12 hr for organisms with a MIC of 4 ug/ml, and 2 g Q 8 hr for those with a MIC of 8 ug/ml. 60 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

Case 8 E.coli from Osteomyelitis (bone) specimen has the following AST: MIC g/ml Ampicillin 64 R Cefazolin 16 R Ceftriaxone 8 R Ceftazidime 8 I Cefepime 8 SDD* Gentamicin 1 S SXT 1/19 S Ciprofloxacin 0.5 S *Possible Chart Comment: SDD = susceptible dose dependent; dosage regimens of 1g Q 8 hr or 2g Q 12 hr for organisms with MICs of 4 ug/ml, and 2g Q 8 hr for those with MICs of 8 ug/ml. 61 January 8, 2014 2011 Kaiser Foundation Health Plan, Inc. For internal use only.

QC #1 Previously, Antibiotic A was not on our routine test panel. When we were asked to test Antibiotic A on a patient s isolate, we tested the patient s isolate and performed QC testing for Antibiotic A on the same day. Now we want to begin testing Antibiotic A routinely. Can we use the last 20 consecutive QC results to justify conversion from daily to weekly QC testing of Antibiotic A? Only one QC result for antibiotic A was out of control during the past 20 days on which we tested Antibiotic A and this corrected upon repeat testing. What is your current process? What will be your process in 2014? 62

QC #1: Implementing Weekly QC OLD: Test 20-30 consecutive day QC: < 1/20 or < 3/30 acceptable. NEW: 3x15 QC plan Number out of range with initial testing (based on 15 replicates) Conclusion from initial testing Number out of range after repeat testing (based on all 30 replicates) Conclusion after repeat testing 0-1 QC plan successful. Convert to weekly QC testing. NA NA 2-3 Test another 3 replicates for 5 days. 2-3 QC plan successful. Can convert to weekly testing. 63 4 or greater QC plan fails. Investigate and take corrective action as appropriate. Continue QC each test day. 4 or greater QC plan fails. Investigate and take corrective action as appropriate. Continue QC each test day.

QC #1: Implementing Weekly QC New for 2014 (we hope!) Review old records: Acceptable if you have been performing QC testing of a drug each time you test a patient s organism, you will be able to use that contemporary (within the last year) retrospective data in order to collect data that can be used for going to weekly QC testing. For example, if you have QC tested a drug approximately 2x/month for the last year, you can use the most recent 20 QC tests to document your ability to go to weekly QC testing for the drug. 64

QC #2 I am seeking assistance regarding the following; our laboratory was recently cited during a CAP inspection for not following the CLSI guidelines regarding an unacceptable MIC value for one drug per one QC organism per one instance with weekly QC done for the month of March. Repeat testing on said organism was okay the following day. (Please keep in mind, although we could not define an obvious error, this was only one instance for one drug on one QC organism; aside from this exception, our weekly controls are typically within expected ranges). What is your current process? What will be your process in 2014? 65

QC #2 OLD = If no clear reason can be found for the error, then repeat testing for 5 days; if all in-range, acceptable to return to weekly testing; if > 1 result(s) are out of range, return to 20-30 day testing scheme. NEW = If the 4 previous QC results were acceptable (same lot #s of materials) and you obtain an out-of-range result, repeat the QC as soon as possible; if this repeat is within range, the corrective action is successful and you can resume weekly testing. If the repeat is out-of-range you must take additional corrective action, and daily QC tests must be continued until final resolution of the problem is achieved. If 4 previous QC results were not acceptable or not available or were not tested with the same lot #s of materials test sufficient QC replicates to satisfy the requirement for a total of 5 acceptable results (up to 3 QC replicates can be tested in a single day if individual inoculum preparations are used). 66

QC #3 Here is your current QC sheet for weekly QC of the disk diffusion you use for testing isolates of P.aeruginosa PSA QC E.coli (ATCC 25922) PSA (ATCC 27853) E.Coli (ATCC 35218) Test date Tester initials QC OK? y/n Pip/Tazo 25 30 28 1/13/13 SS Y Ceftazidime 30 25 1/13/13 SS Y Gentamicin 22 20 1/13/13 SS Y Ciprofloxacin 37 27 1/13/13 SS Y Meropenem 31 31 1/13/13 SS Y Cefepime 32 27 1/13/13 SS Y Tobramycin 21 22 1/13/13 SS Y 67

QC #3 Here is your EDITED QC sheet for weekly QC of the disk diffusion you use for testing isolates of P.aeruginosa PSA QC E.coli (ATCC 25922) PSA (ATCC 27853) E.Coli (ATCC 35218) Test date Tester initials QC OK? Y/N Pip/Tazo 25 30 28 1/13/13 SS Y Ceftazidime 30 25 1/13/13 SS Y Gentamicin 22 20 1/13/13 SS Y Ciprofloxacin 37 27 1/13/13 SS Y Meropenem 31 31 1/13/13 SS Y Cefepime 32 27 1/13/13 SS Y Tobramycin 21 22 1/13/13 SS Y 69

QC #3 Here is your NEW QC sheet for weekly QC of the disk diffusion you use for testing isolates of P.aeruginosa PSA QC PSA (ATCC 27853) E.Coli (ATCC 35218) Test date Tester initials QC OK? y/n Pip/Tazo 30 28 1/13/13 SS Y Ceftazidime 25 1/13/13 SS Y Gentamicin 20 1/13/13 SS Y Ciprofloxacin 27 1/13/13 SS Y Meropenem 31 1/13/13 SS Y Cefepime 27 1/13/13 SS Y Tobramycin 22 1/13/13 SS Y 70