2011 CLSI guideline update 관동의대 명지병원 이혁민

Basic rationale for selection of antibiotics 국가, 지역, 병원의 특성 및 항균제 내성 역학 분석 – 주요 내성균 치료에 적합한 항균제 지역 및 기관에서 사용되는 항균제 감수성 검사 방법에 적절한 항균제 – 검사실별 감수성 시험 방법 디스크 확산법 자동화 장비 – Polymyxin B (disk diffusion 부적합 )

Classification of antimicrobial agents I Class: 동일 계열의 항균제 – 특정 균종 : spectrum 과 항균력이 거의 동일 – 동일 class 내의 다른 항균제에 적용 가능 (Extrapolation)

Test DrugsOrganismsDrugs for which result can be extrapolated Penicillin G Staphylococcus spp. Neisseria gonorrhoeae Ampicillin, amoxicillin, carbenicillin, mezlocillin, ticarcillin, piperacillin, etc AmpicillinAllAmoxicillin, bacampicillin, etc AmpicillinEnterococcus spp.Penicillin OxacillinStaphylococcus spp.All β-lactam antibiotics CephalothinEnterobacteriaceae Cephapirin, cephradine, cephalexin, cefaclor, and cefadroxil but not other cephalosporins ErythromycinGram-positive cocci Azithromycin, clarithromycin, dirithromycin, roxithromycin ClindamycinAllLincomycin Tetracycline All (Except Staphylococcus, ENT, and Acc spp. Doxycycline, minocycline, chlortetracycline, demeclocycline, oxytetracycline, methacycline SulfisoxazoleAllAll sulfonamide Cephalothin or cefazolin EnterobacteriaceaeSusceptibility to broad-spectrum cephalosporins Table 1. Antibacterial susceptibility results that may be extrapolated From Manual of Clinical Microbiology 9 th. Ed.

Classification of antimicrobial agents II Cluster: 시험관 내 감수성 또는 임상 효과 유사 – 동일 박스 내에 위치한 항균제 (CLSI) – 해당 의료기관에서 사용 중인 항균제 시험 Related group: 동일 cluster 중 ‘or’ 로 표시된 항균제 – 한 항균제에 대한 검사 결과를 다른 항균제에 적용 Major error 및 very major error < 3% Minor error < 10%

ClassAntibioticsS. aureusEnterobacteriaceae 3 rd -generation cephalosporin, Monobactam CRO, CTX, CAZ, AZT(OXA) CRO or CTX CAZ, AZT AminoglycosideAMK, GM, TOBGM AMK GM, TOB MLS B EM, AZTH, CLTH, TEL, CLN EM or AZTH or CLTH NT TEL CLN QuinoloneCIP, LEVO. OFL, MOX CIP or LEVO or OFL MOX CIP, LEVO OFL Table 2. Clusters and related groups in CLSI CLSI guideline, 2009 Related groupsCluster

Groups A, B, C and U A group: 1 차 시험 약제균 (primary testing group) – 항상 감수성을 시험 보고 B group: 1 차 시험 약제균 (primary testing group) – A 군과 동일하게 1 차로 감수성 시험  선택 보고 A 군에서 시험한 동일 class 의 항균제가 내성인 경우 일부 특정 부위의 감염, Polymicrobial 또는 multiorgan infection A 군 항균제에 대한 allergy 또는 intolerance A 군 항균제에 의한 치료 실패 감염 관리를 위한 치료 C group – A 군 및 B 군 항균제에 내성 세균이 많은 병원 – 추가 시험 및 선택 보고 U group: Urine isolate only

Group A Group BGroup CGroup U AZTH, CRTH, EMDAPCHLLOME, NOR CLNLINECIP or LEVO or OFLNT OX(FOX)TELQDA PENDOXY, TETGM SXTVAN RIF Table 3. Antibiotics recommended for AST in S. aureus in CLSI 2009

Enterobacteriaceae Antibiotics classABCU β PenicillinAMPPIP β-lactam-InhibitorAMC, AMS, PTZ, TCC CephalosporinCPZ CFX CAZCEP CTX or CRO FEP FOX, CTT CarbapenemDOR, ETP, IPM, MEM MonobactamAZT AminoglycosideGM, TOBAMK FluoroquinoloneCIP, LEVLOM or OFL, NOR OthersSXT TET NIT SUL CHL TMP

General Comments Salmonella and Shigella spp. – Fecal isolates: AMP, FQ and SXT routinely – Extraintestinal Salmonella spp.: 3 rd generation cephalosporin, chloramphenicol if requested – 1 st /2 nd generation ceph. and cephamycin may appear active in vitro Not effective clinically and should not be reported as susceptible Cefazolin (A) – CSF isolates: CTX or CRO in place of Cefazolin 2010 revised interpretive criteria for cephalosporins – Routine ESBL testing is no longer necessary – ESBL testing Old criteria used Epidemiological and infection control purpose

Cephalothin – Only to predict result the oral agent (No recent data) – Cefadroxil, cefpodoxime, cephalexin and loracarbef Dosage regimen – Plasma drug level on which breakpoints were based – Adults with normal renal and hepatic functions – Cefazolin: 2 g every 8 h – Cefepime: 1 g every 8 h or 2 g every 12 h – CTX or CRO: 1 g every 8 h for CTX, 1 g every 24 h for CRO – Imipenem: 500 mg every 6 hr or 1 g every 8 h – Meropenem: 1 g every 8 h Cefazolin breakpoint changed YearDisc content Disc diffusion (mm)MIC (μg/mL) SIRSIR μg---≤12≥ μg≥ ≤19≤24≥8

Carbapenemase-producing K. pneumonaie Klebsiella pneumoniae carbapenemase (KPC) Serine β-lactamase with carbapenem-hydrolizing activity Difficult to detect because MIC ranges form 1 to 8 μg/mL Anderson KF, et al. J Clin Microbiol 2007

Carbapenem breakpoint changed – Recently described carbapenemase producing strains – Limited treatment options in the intermediate range Change of maximum dose and time of infusion – Modified hodge test (Routine MHT is no longer necessary) Old criteria used Epidemiological and infection control purpose AgentYear Disc diffusion (mm)MIC (μg/mL) SIRSIR Doripenem ≥ ≤19≤12≥4≥4 Ertapenem 2010≥ ≤15≤24≥8≥8 2011≥ ≤19≤ ≥1≥1 Imipenem 2010≥ ≤13≤48≥ ≥ ≤19≤12≥4≥4 Meropenem 2010≥ ≤13≤48≥ ≥ ≤19≤12≥4≥4 New Interpretive Criteria for Carbapenems and Enterobacteriaceae ( update)

Endimiani A, et al. J Clin Microbiol 2010

Pasteran F, et al. J Clin Microbiol 2011

CriteriaNew criteriaOld criteria TestConfirmatoryInitial screenPhenotypic confirmatory MethodMHTDisk diffusionBroth microdilutionMHT MediumMHA CAMHBMHA Antimicrobial conc. Ertapenem 10 μg or Meropenem 10 μg Ertapenem 1 μg/mL or Imipenem 1 μg/mL or Meropenem 1 μg/mL Ertapenem 10 μg or Meropenem 10 μg Inoculum0.5 McF E. coli ATCC  1:10 dilution  Routine disk diffusion inoculation procedure  Dry for 3 to 10 min  Pick 3 to 5 colonies of test organisms with 10 μL loop or swab  Streak at least 20 to 25 mm in length Standard 0.5 McF E. coli ATCC  1:10 dilution  Routine disk diffusion inoculation procedure  Dry for 3 to 10 min  Pick 3 to 5 colonies of test organisms with 10 μL loop or swab  Streak at least 20 to 25 mm in length Temp35 ± 2°C Time16-20 hours16-18 hours16-20 hours ResultsEnhanced growth around test organism streak  Positive carbapenemase Ertapenem disk mm Meropenem disk mm  MHT confirmatory test Ertapenem 2-4 μg/mL Imipenem 2-8 μg/mL Meropenem 2-8 μg/mL  MHT confirmatory test Enhanced growth around test organism streak  Positive carbapenemase ReportingNo change in the carbapenem AST result for MHT-positive isolates MHT positive and Ertapenem MIC of 2-4 μg/mL, Imipenem MIC of 2-8 μg/mL, or Meropenem MIC of 2-8 μg/mL  All carbapenem as R

Pseudomonas aeruginosa Antibiotics classABCU β PenicillinPIP β-lactam+InhibitorPTZ, TCC CephalosporinCAZFEP CarbapenemIPM, MEM MonobactamAZT AminoglycosideGM, TOBAMK FluoroquinoloneCIP, LEVLOM or OFL, NOR Cystic fibrosis – extended incubation for up to 24 hours before reporting as susceptible Resistance in P. aeruginosa may develop during prolonged therapy – All antimicrobial agents within 3 to 4 days Dosage regimen – Ceftazidime: 1 g every 6 h or 2 g every 8 h – Cefepime: 1 g every 8 h or 2 g every 12 h – Aztreonam: 1 g every 6 h or 2 g every 8 h Deleted – Ceftizoxime, cefoperazone, moxalactam, ceftriaxone and cefotaxime – No longer available or limited indication for P. aeruginosa

Acinetobacter species Antibiotics classABCU β PenicillinPIP (80) β-lactam+InhibitorAMS (70)PTZ (78), TCC (77) CephalosporinCAZ (78) CTX (80), CRO FEP (76) CarbapenemIPM (72), MEM AminoglycosideGM (77), TOB (64)AMK (53) FluoroquinoloneCIP (78), LEV (73) Others DOXI, MIN (6), TET SXT (78)

Stenotrophomonas maltophilia Antibiotics classABCU β β-lactam+Inhibitor TCC* Cephalosporin CAZ* FluoroquinoloneLEV OthersSXT CHL* MIN * MIC testing only: disk diffusion test unreliable Burkholderia cepacia Antibiotics classABCU β β-lactam+Inhibitor TCC* CephalosporinCAZ CarbapenemMEM Fluoroquinolone LEV* OthersSXT CHL* MIN

Other Non-Enterobacteriacease Antibiotics classABCU β PenicillinPIP β-lactam+InhibitorPZT, TCC CephalosporinCAZFEPCTX, CRO CarbapenemIPM, MEM MonobactamAZT AminoglycosideGM, TOBAMK FluoroquinoloneCIP, LEVLOM or OFL, NOR OthersSXTCHL SUL TET Exclusion of Burkholderia mallei and B. pseudomallei – CLSI document M45, Methods for antimicrobial dilution and disk susceptibility testing of infrequently isolated or fastidious bacteria – Campylobacter spp., H. pylori, L. monocytogenes, – Potential agent of bioterrorism

Staphylococcus species Antibiotics classABCU β-lactam PEN OXA (FOX) MLS B AZT or CLA or EM TELQDA CLN AminoglycosideGM Fluoroquinolone CIP or LEV or OFL, MOX LOM, NOR GlycopeptideVAN OxazolidinoneLIN LipopeptideDAP OthersSXT DOX, MIN, TET CHL NIT SUL RFP TMP

General comment Susceptibility to β-lactam – Testing only penicillin and either cefoxitin or oxacillin – Routine testing for other β-lactam in not advised Oxacillin-resistance SAU and CNS – Other β-lactam except anti-MRSA ceph. are not effective clinically – Clarified “relevant cephems” in comment Detection of oxacillin resistance – Tests for mecA or PBP2a: most accurate, MRSA – Discrepancy between oxacillin and cefoxitin Oxacillin MIC ≥ 4 μg/mL and mecA negative or PBP2a negative Oxacillin resistant and cefoxitin susceptible in disk diffusion Rare oxacillin-resistance by mutation or hyperproduction: Report as oxacillin resistant

Oxacillin resistance in CNS – Some non-S. epidermidis: Oxacillin MIC μg/mL (R ≥ 0.5 μg/mL) without mecA – For serious CNS infection other than S. epidermidis MIC range μg/mL mecA or PBP 2a test or cefoxitin disk diffusion test Clarified performance of induced β-lactamase testing on S. aureus isolates – All isolates with penicillin MIC ≤ 0.12 μg/mL or zone diameter ≥ 29mm – Rare isolates that have blz show negative in induction test In serious infection requiring penicillin therapy Penicillin MIC and induction test should be tested, and PCR may be considered

Routine testing of S. saprophyticus in urine is not advised – Generally respond to concentrations achieved in urine Vancomycin – MIC test should be performed – Disk diffusion: Not detect VISA and S, I, R in CNS, Only VRSA can detect Minocycline – Added in Group B – Indication for skin and soft tissue infection of CA-MRSA Added information on not reporting daptomycin for isolates from the lower respiratory tract – Not indicated for lower respiratory infection and printed in product label – Inferior to vancomycin in phase 3 trials (inactivated by pulmonary surfactant)

Silverman JA, et al. J Infect Dis 2005

Table 1. CLSI screening guidelines for S. aureus ResistanceScreening tests Confirmative test β-lactamase Chromogenic cephalosporin or Other method If negative, Yes Oxacillin resistance Agar dilution; MHA with 4% NaCl and 6 μg/mL oxacillin No mecA-mediated oxacillin resistance Broth microdilution and disk diffusion with cefoxitin No Vancomycin ≥ 8μg/mL Agar dilution; MHA with 6 μg/mL vancomycin If positive, Yes Inducible clindamycin resistance Broth microdilution and disk diffusion with clindamycin and erythromycin No High-level mupirocin resistance Broth microdilution and disk diffusion with mupirocin No

β-lactamase in S. aureus A specific type of β-lactamase in Class A – Penicillinase Hydrolysing the β-lactam ring Widely spread in S. aureus – 97-99% of S. aureus Test – Disk diffusion (10 unit): S ≥ 29mm – MIC: S ≤ 0.12 μg/mL

A total of 197 non-duplicate isolates of S. aureus (Penicillin MIC ≤ 0.12 μg/mL by Vitek 2) Test with disk diffusion (BP 28 and 29 mm) and PCR for blaZ 14.2% (28/197) of penicillin-susceptible S. aureus (Vitek 2)  PCR positive Sensitivity of disk diffusion: 57.1% Kaase M, et al. Clin Microbiol Infect 2008

Mupirocin resistance Pseudomonic acid A – Strong inhibition of protein and RNA synthesis by inhibit isoleucine t-RNA synthetase (IleRS) – Topical agent for gram-positive bacteria such as MRSA Nasal formulation for eradicating MRSA colonization

High-level mupirocin resistance Organism groupsS. aureus Test methodDisk diffusionBroth microdilution MediumMHACAMHB Antimicrobial concentration 200 μg MUP diskSingle 256 μg/mL well InoculumStandard method Incubation conditions35 ± 2 °C; ambient air Incubation length24 hours; Read with transmitted light Results Examine carefully for light growth within zone of inhibition No zone = High-level MUP R Growth = High-level MUP R Further testing and reporting Report isolates with no zone as high-level MUP R Report growth in the 256 μg/mL well as high-level MUP R

Enterococcus species Antibiotics classABCU PenicillinAMP, PEN MLS B QDA AminoglycosideHLGM, HLSM FluoroquinoloneCIP, LEV, NOR GlycopeptideVAN OxazolidinoneLIN Lipopeptide DAP* Others NIT TET Enterococcus spp. Added information on not reporting daptomycin for isolates from the lower respiratory tract

General comment Ceph., aminoglycoside (except high-level synergy), clindamycin, SXT – Not effective clinically, and should not be reported as susceptible Synergy between AMP, PNE, VAN with aminogylocoside – In serious infection such as endocarditis: Synergistic killing – High-level aminoglycoside screening test – GM and SM: Other aminoglycoside are not superior to GM and SM Ampicillin – Class representative for ampicillin and amoxicillin – AMC, AMS, PIP, PTZ in non-β-lactamase producing enterococci – In EFA, can predeict imipenem susceptibility Pencillin – AMP, AMX, AMS, AMC, PIP, PTZ non-β-lactamase producing enterococci – Ampicillin susceptibility cannot be assumed to be susceptible to penicillin

β-lactamase produciton – Rare mechanism for AMP and PEN resistance (Not routinely tested) – Nitrocefin test: not detected by routine diffusion or dilution test – If positive: resistant to penicillin, aminopenicillin and ureidopenicillin Vancomycin – Full 24 hr incubation and haze or any growth in zone of inhibition was vancomycin resistance – Isolates with MIC of 8 to 16 μg/mL Biochemical test for motility and pigment production Rule out intrinsic and intermediate vancomycin resistance Daptomycin – Disk testing is not reliable for testing daptomycin – Added information on not reporting daptomycin for isolates from the lower respiratory tract

Hemophilus influenzae and H. parainfluenzae Antibiotics classABC PenicillinAMP β-lactam+InhibitorAMSAMC Cephalosporin CFX (PN) CFX (Oral) CCL, CPZ CTX or CAZ or CRO CDR or FIX or CPD CarbapenemMEMERT or IPM MonobactamAZT Fluoroquinolone CIP or LEV or MOX or OFL, GEM MLS B AZT, CLA TEL OthersSXTCHL RFP TET

General comment Other Hemophilus spp.: CLSI document M45 H. influenzae in CSF – AMP, one of the 3 rd -generation ceph., CHL, MEM should be reported AST of oral agent for surveillance or epidemiological study Ampicillin – Predict the activity of amoxicillin – Majority of ampicillin resistance due to TEM-type β-lactamase – Direct β-lactamase test can provide rapid detection of resistance β-lactamase negative ampicillin-resistance (BLNAR) – Mutation in target site – Resistant to AMC, AMS, PTZ, cefaclor, etc despite in vitro susceptibility

Streptococcus pneumoniae Antibiotics classABC PenicillinPEN (OXA) AMX*, AMC* β-lactam+Inhibitor CephalosporinFEP*, CTX*, CRO*CFX Carbapenem MEM*ERT, IPM FluoroquinoloneGEM, LEV, MOX, OFL MLS B EM CLN TEL GlycopeptideVAN OxazolidinoneLIN OthersSXTTET CHL RFP

General comment AMX, AMP, FEP, CTX, CRO, IPM, MEM, ERT – AST should be tested by MIC method – Not reliable disk diffusion test In CSF isolates – PEN, CTX, CRO or MEM should be tested by reliable MIC method and reported routinely – VAN should be tested using MIC or disk method Oxacillin disk diffusion – Only susceptible strains – Non-susceptible strains PEN, CTX, CRO or MEM MICs should be determined Pencillin breakpoint – Parenteral penicillin: meningitis, non-meningitis (Dose diff. for S and I) – Oral penicillin CTX, CRO and FEP breakpoint: meningitis vs non-meningitis

β-hemolytic Streptococcus species Antibiotics classABC PenicillinAMP*, PEN* CephalosporinFEP, CTX, CRO MLS B EM CLN GlycopeptideVAN OxazolidinoneLIN OthersCHL Incorporated recommendations for nonsusceptible penicillin and ampicillin isolates being sent to a public health laboratory Added information on not reporting daptomycin for isolates from the lower respiratory tract Inducible clindamycin resistance – All isolates from invasive infections – Disk diffusion or broth microdilution

Viridans group Streptococcus species Antibiotics classABC PenicillinPEN or AMP CephalosporinFEP or CTX or CRO FluoroquinoloneLEV, OFL MLS B EM QDA CLN GlycopeptideVAN OxazolidinoneLIN LipopeptideDAP OthersCHL Added information on not reporting daptomycin for isolates from the lower respiratory tract

Bacteroides fragilis group and Other Gram-negative anaerobes Antibiotics classAB Penicillin PEN, AMP PIP β-lactam+InhibitorAMC, AMS, PTZ, TCC Cephalosporin CRO, CTZ CTT, FOX CarbapenemERT, IPM, MEM Monobactam FluoroquinoloneMOX MLS B CLN OthersMETCHL Members of B. fragilis group are presumed to resistant to ampicillin Other GN anaerboes may be screened for β-lactamase with chromogenic ceph. If positive, report as resistant to PEN, AMP, AMX

Gram-positive anaerobes Antibiotics classAB PenicillinAMP, PENPIP, TIC β-lactam+InhibitorAMC, AMS, PTZ, TCC CephalosporinCFZ, CRO, CTT, FOX CarbapenemERT, IPM, MEM Monobactam FluoroquinoloneMOX MLS B CLN OthersMETTET

Conclusion Breakpoint change of carbapenem in Enterobacteriaceae Dose regimen for cephalosporin and carbapenem Deletion of fastidious and bio-terrorism isolate and transfer to CLSI-M45 Inducible clindamycin resistance in β-hemolytic streptococci Adding of antimicrobial susceptibility test for anaerbe