Beta-lactam antibiotics - ISA-medium        2009-01-28

MIC-breakpoints for antibiotics marked with a "+" were harmonised through the European process.
Yellow markings denote changes in zone diameter breakpoints  (replacing previous breakpoints).

Previously used breakpoints can be accessed here!

Pre-view of ongoing development!

Antibiotic

Disk
µg

Enterobact-
eriaceae

Pseudo-
monas

Acineto-
bacter

Staphylo-
coccus

Entero-
coccus

Streptococcus
A,B,C,G

S.pneu-
moniae

Other
streptococci

Haemo-
philus

M.ca-
tarrhal

P.mul-
tocida

Bacter-
oides

C.per-
fring

Method*

 

A

A

A

A

B

B

B

B

B

B

B

B

B

Penicillin G+ 10 U -- -- -- Note Note Note Note Note IE

--

IE

-- 22/18
Penicillin V+

10 U

-- -- -- -- -- Note Note Note -- -- 25/24 -- --

Oxacillin+

1

--

--

--

Note

--

Screen:
18/17

Screen:
18/17

--

--

--

--

--

--

Cefoxitin+

10

--

--

--

Screen:
S.aureus_22/21
CNS_27/21

--

--

--

--

--

--

--

--

--

Ampicillin+ 10 30/11 -- --

Note
(S.sapro: 26/25  )

20/16 Note Note Note Note

Note

23/22

Note Note
Pivmecillinam (U) 10 14/13

--

--

Note

-- -- -- -- -- -- -- -- --
Pip/tazobactam+

30/6

21/17

18/17

IE

Note

Note

Note Note  

IE

IE

IE

21/17

21/17

Imipenem+

10

25/20a

21/17

25/20

Note

E.faecalis 19/16
E.faecium --

Note Note   23/22 23/22 --

25/21

25/21

Meropenem+

10

27/19 27/21 27/19

Note

-- Note pneum
Meningit - MIC
  23/22
Meningit - MIC
23/22 IE 30/26 30/26
Ertapenem+ 10 30/29 -- --

Note

--

mic pneum   mic mic IE mic --
Aztreonam+

30

28/22 50/22

--

--

--

--

--

-- IE IE IE -- --
Antibiotic

Disk
µg

Enterobact-
eriaceae

Pseudo-
monas

Acineto-
bacter

Staphylo-
coccus

Entero-
coccus

Streptococcus
A,B,C,G

S.pneu-
moniae

Other
streptococci

Haemo-
philus

M.ca-
tarrhal

P.mul-
tocida

Bacter-
oides

C.per-
fring

Cefadroxilb

30

30/13
see footnote

--

--

22/18

--

22/18

Note --

--

--

--

--

--

Lorakarbef

30

23/19

--

--

Note

--

25/21

Note --

23/19

23/19

IE

--

--
Cefpodoximeb

10

note -- --

Note

-- -- -- -- -- -- -- -- --

Ceftibuten

30

27/23

--

--

Note

--

IE

Note --

Note

IE

IE

--

--

Cefixim

5

--

--

--

Note

--

21/17

Note --

30/26

IE

IE

--

--

Cefuroxim-axetil

30

--

--

--

Note

--

29/25

Note --

--

--

IE

-- --
Cefuroxim+

30

19/18c -- --

Note

--

(29/25)

Note   (27/23) (27/23) IE -- --
Cefotaxim+ 5

24/20

-- --

Note

-- 22/21 Note   28/27 (28/27) 28/27 -- --
Ceftriaxon+ 30 d -- --

Note

-- d Note   d d IE -- --
Ceftazidim+ 10 24/17 18/17 --

Note

-- -- Note   -- -- -- -- --
Cefepim+ 30

mic

mic

--

Note

-- mic Note -- mic mic IE -- --

aProteus and Morganella species are considered poor targets for imipenem and testing should be avoided.
bCefadroxil 30 µg or cefpodoxime 10 µg can be used for screening for enzymatic cephalosporine resistance (ESBL). 
cCefuroxime Enterobacteriaceae breakpoints are valid for Escherichia coli, Klebsiella spp and Proteus mirabilis in infections originating in the urinary tract and for a dosage of 1.5 g x 3 or more.
dUse cefotaxime for susceptibility categorisation of cefotaxime and ceftriaxone.
 

Note anger en länk till en fotnot. För den som skriver ut tabellen på papper är det viktigt att även alla fotnoter skrivs ut och följer med tabellen.
Text = a link to a footnote. If you print the table on paper, remember to print the footnotes - they contain important information on methodology.
17/13 - zon brytpunkter:  S>17 mm and  R<13 mm
17/13 - zon brytpunkter som ändrats jämfört med den tidigare utgåvan av tabellen.
(17/13) - RAF avråder från rutinmässig resistensbestämning med det aktuella medlet. I vissa falla rekommenderas alternativ test.
mic - utför resistensbestämning med MIC-bestämning (se MIC-tabell)
IE - Klinisk effekt utesluts ej men in vitro och/eller in vivo dokumentation saknas.


--  RAF avråder från resistensbestämning. Ej relevant behandlingsalternativ: 

  • godkänd indikation saknas
  • otillräcklig aktivitet även mot bakterier som ej utvecklat resistens
  • resistens så vanlig (>50%) att medlet får anses oanvändbart

(U) = Brytpunkterna gäller endast vid nedre okomplicerad urinvägsinfektion.

17/13 - zone breakpoints: interpretate S>17 mm and  R<13 mm.
17/13 - zone breakpoints altered since the previous version of the table.
(17/13) - SRGA does not recommend testing against this disk in routine susceptibility testing. Sometimes an alternative disk is recommended.
mic - perform MIC-determination.
IE - clinical effect is not ruled out but the SRGA has not been able to find enough evidence to make a reasonable breakpoint decision.


--  SRGA advices against susceptibility testing. Not a relevant alternative:

  • no approved indication
  • insufficient activity
  • extensive resistance development - the drug may be considered obsolete.

(U) = Breakpoints valid for lower urinary tract infections only.

Metod:
A
= grundmedium utan tillsatser. Inkubation 35o C i luft.
B = grundmedium + 5% skakhästblod + NAD. Inkubation 35o C i 5 % CO2 (och för anaerober i anaerob atmosfär). 
Method:
A
= medium without additives. Incubation in air, 35o C.
B = medium + 5% defibrinated horse blood + NAD. Incubation at 35o C in 5 % CO2 (and for anaerobes in anaerobic atmosphere).
För resistensbestämning av Stenotrophomonas maltophilia hänvisas till fotnoten för Pseudomonas. For susceptibility testing of Stenotrophomonas maltophilia, see the Pseudomonas footnote.

RAF och RAF-M. 1996
Uppdaterat 2009-03-01, G Kahlmeter