Antibiogram for 1999 - DOC by j5BVy999

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									                 Duke University Medical Center
                 Clinical Microbiology Laboratory
                    Durham, North Carolina 27710




                         SUMMARY OF
                 ANTIMICROBIAL SUSCEPTIBILITY
                        TEST RESULTS
                             2002

HOURS OF
OPERATION:        24 hours per day 365 days per year.

TELEPHONE:        684-2089              A certified medical technologist is
                                        on duty at all times.


CONSULTATIONS:    Page 970-8885         A physician (Medical Microbiology
                                        Fellow or Resident) is on call at all times
                                        with faculty backup.


TEACHING:         Teaching Rounds (Clinical correlations)
                  Monday-Friday 1:15-1:45 PM




                                                                                      1/2003
                                                   TABLE 1. Percent Susceptiblea, Gram-positive Cocci
                                                               (MIC breakpoint, µg per ml)

                                      Beta-lactams                                   Other Antimicrobials
                                ________________________             ___________________________________________________
Microorganism (No. tested)        AMP       NAF    CFZ                          CLI       ERY       VAN    T/S
                                  (8)       (2)     (8)                        (0.5)      (0.5)       (4) (2/38)
________________________________________________________________________________________________________________________

Enterococci b (992)                          81          NT          NT                                    NT           NT          75         NT
   E. faecalis (126)                        100          NT          NT                                    NT           NT          94         NT
   E. faecium (80)                           11          NT          NT                                    NT           NT          23         NT
   Enterococcus spp. (786)                   85          NT          NT                                    NT           NT          77         NT

Staphylococcus aureus (1938)                NT           52          52                                     40           40       100           91
   MSSA (1008)                              NT          100         100                                     68           68       100           98
   MRSA (930)                               NT            0           0                                     10           10       100           84

Staphylococcus spp., coagulase-
                                                              c
 negative (297)                             NT           24          24                                    NT           NT        100          NT

________________________________________________________________________________________________________________________
These data were obtained by broth microdilution or disk diffusion methods according to National Committee for Clinical Laboratory Standards (NCCLS)
guidelines. Data are based on microorganisms from both inpatients and outpatients. No attempt was made to differentiate nosocomial isolates.

a Susceptible implies that an infection due to the microorganism may be appropriately treated with the dosage of antimicrobial agent recommended for
  that type of infection and infecting species, unless otherwise contraindicated.
b For enterococci the designation "susceptible" implies the need for combined therapy (ampicillin or vancomycin plus an aminoglycoside) in endocarditis
  or other serious invasive infections to achieve bactericidal action and an improved therapeutic response.
c Susceptible MIC breakpoint is <0.25 µg/ml for coagulase-negative staphylococci.

MIC (minimum inhibitory concentration) is the lowest concentration of a drug which will inhibit growth of a microorganism in vitro. For the drug to be
effective in vivo, a higher concentration than the MIC of the drug (at least 2 to 4 times higher) should be achieved at the site of infection. MIC
breakpoints are based on achievable serum levels in adults with normal renal function.
________________________________________________________________________________________________________________________
NT = Not tested.      $ = Relative daily acquisition cost for recommended doses of parenteral therapy.

AMK (amikacin - $/$$)                      CIP (ciprofloxacin - $/$$$$)                   GEN (gentamicin - $)        PIP (piperacillin - $$$$$)
AMP (ampicillin - $)                       CLI (clindamycin - $)                          IMP (imipenem - $$$$$$)     TOB (tobramycin - $)
AMP/SUL (ampicillin/sulbactam - $$$$$)     CRO (ceftriaxone - $$$)                        LEV (levofloxacin - $/$$)   T/S (trimethoprim/sulfamethoxazole - $)
CAZ (ceftazidime - $$$)                    CTX (cefotaxime - $$$)                         NAF (nafcillin - $)         VAN (vancomycin - $$)
CFZ (cefazolin - $)                        ERY (erythromycin - $)                         PEN (penicillin - $)
________________________________________________________________________________________________________________________
                                                    TABLE 2. Percent Susceptible, Gram-negative Bacilli
                                                                (MIC breakpoint, µg per ml)
                                                                                                                                                    Other
                                               Beta-lactams                            Aminoglycosides                                           Antimicrobials
                               _____________________________________________        ___________________                                        ______________
                                      AMP/
Microorganism (No. tested)    AMP     SUL   CFZ      CAZ    CROb   IMP PIP          GEN     AMK      TOB      CIP   T/S
                               (8)    (8/4)  (8)      (8)    (8)    (4) (16)         (4)    (16)       (4)    (1)  (2/38)
_________________________________________________________________________________________________________________________
Alcaligenes xylosoxidans (73) NT      NT    NT         45    NT     86    82          0        0        0       8    55

Acinetobacter baumannii (58)              NT        NT        0         78        54       100       63              86         98       97       78      87

Burkholderia cepacia (71)                NT        NT       NT          61        NT         34      32               0          0        0       15      54

Citrobacter koserii (65)                   0        88       91        100        97       100       78            100        100        100     100      94

Citrobacter freundii (100)                18        50        0         54        60       100       51              85         97       82       70      74

Enterobacter aerogenes (125)               0         0        0         62        71         98      59              96         99       96       86      96

Enterobacter cloacae (199)                 0         0        0         70        71         98      66              91         97       91       88      89

Escherichia coli (2803)                   62        75       88         97        97       100       63              93         99       93       94      85

Klebsiella oxytoca (116)                   0        57       41         93        78       100       60              88         97       87       85      80

Klebsiella pneumoniae (737)                0        79       92         95        96       100       76              96         99       95       91      84

Morganella morganii (49)                   0         0        0         79        95       100       67              79       100        92       78      80

Proteus mirabilis (338)                   92        97       95        100        100      100       94              93         99       94       82      91
                                                                              a                           c
Pseudomonas aeruginosa (1288)            NT        NT       NT           79       NT         75      82              58         70       81       59      NT

Serratia marcescens (181)                  0         0        0          95       92         99      88              96         97       87       88      97

Stenotrophomonas maltophilia (165) NT NT      0      38      0      0     0           0       0     0         27     77
_______________________________________________________________________________________________________________________
Numbers in boldface indicate >10% decrease in susceptibility from 2001 to 2002.
a For P. aeruginosa, ceftazidime (CAZ) usually predicts susceptibility to aztreonam.
b For Enterobacteriaceae, ceftriaxone (CRO) usually predicts susceptibility to cefotaxime.
c For P. aeruginosa, susceptible MIC breakpoint for piperacillin (with or without tazobactam) is < 64 µg/ml which requires high doses.
                       TABLE 3. Percent Susceptible, Anaerobic Gram-negative Bacillia

             Antimicrobial                  MIC Breakpoint   B. fragilis groupb
             (cost per day)                   (µg per ml)    (No. tested = 83)
           _________________________________________________________________

             Ampicillin-sulbactam ($$$$$)                    8/4                      82
             Cefoxitin ($$$)                                  16                      61
             Clindamycin ($)                                   2                      76
             Imipenem (Meropenem) ($$$$$$)                     4                      99
             Metronidazole ($ - $$)                            8                     100
             Piperacillin-tazobactam ($$$$$)                32/4                      99
           __________________________________________________________________
           $ = Relative daily acquisition cost for recommended doses of parenteral therapy.
           a Pigmented gram-negative bacilli (Prevotella and Porphyromonas spp.), Fusobacterium spp., and gram-
             positive anaerobic cocci and bacilli are usually susceptible to -lactam antibiotics, clindamycin, and
             metronidazole.
           b Includes B. fragilis, B. thetaiotaomicron, B. ovatus, B. distasonis, B. vulgatus, B. uniformis, B. caccae,
             B. eggerthii, B. merdae, and B. stercoris.

                                      TABLE 4. Fastidious Microorganisms

1.   Haemophilus influenzae (No. tested = 115). All isolates were non-type b: 86 (75%) were ß-lactamase negative
     and predictably susceptible to ampicillin (amoxicillin); 29 (25%) were -lactamase positive and, therefore, resistant
     to ampicillin (amoxicillin). H. influenzae is predictably susceptible to cefotaxime and ceftriaxone and usually to
     cefuroxime.

2.   Streptococcus pneumoniae. Rx NOTE: Breakpoints for pneumococci are based on concentrations of
     penicillin and ceftriaxone (or cefotaxime) required to treat non-meningitis infections. Consult Infectious
     Diseases for patients with meningitis (higher doses required and susceptible breakpoints are lower). High
     doses of intravenous penicillins (e.g., at least 2 million units every 4 h in adults with normal renal function) or
     similarly ampicillin (e.g., 2 g every 6 h) are effective in treating pneumococcal pneumonia due to strains in the
     intermediate category.

               MIC Breakpoint (µg/ml) for Non-meningitis Infections with Streptococcus pneumoniae
                          (No. tested)        % Susceptible          % Intermediate             % Resistant
              Penicillin     (107)              55 (<0.06)              28 (0.1-1)                17 (>2.0)
              Ceftriaxone or
               cefotaxime    (107)               95 (<1.0)                4 (2.0)                  1 (>4.0)
              Erythromycin (107)                 65 (<0.25)               0 (0.5)                 35 (>1.0)
              Levofloxacin   (107)               99 (<2.0)                0 (4.0)                  1 (>8.0)

                                                                                            a
                                    TABLE 5. Percent Susceptible, Yeasts (1999-2002)
                                                                 (MIC breakpoint, µg per ml)
                                                             Amphotericin B                   Fluconazole
                                                   b                    c
       Microorganism (No. tested, AmphB/Flu)                       (<1)                           (<8)
                                                                                                      d
       Candida albicans               (52/110)                    100                              81
       C. tropicalis                  (24/70)                     100                              74
       C. parapsilosis                (23/51)                     100                              90
       C. krusei                      (--)                            l                             m
       C. glabrata                    (24/57)                     100                              58
       C. lusitaniae                  (--)                                                         l
       Cryptococcus neoformans (1/20)                                 l                            90
     l = usually susceptible  = often resistant m = inherently resistant
     a Percent susceptibility reflects selected patient population.
     b NCCLS M27-A (1997) Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts.
        Testing may be useful in serious or persistent infections due to organisms with unpredictable susceptibility
        profiles, especially when standard regimens fail or are contraindicated.
     c Tentative NCCLS breakpoint.
     d Most initial isolates of C. albicans are susceptible.

								
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