Page Banner

United States Department of Agriculture

Agricultural Research Service

Related Topics

2007 Veterinary Isolates Final Report- Accessible Version
headline bar
1 - Introduction, Materials and Methods and Data Analysis
2 - Antimicrobials and breakpoints
3 - Isolates tested- all organisms
4 - Salmonella (Tables 1 and 2)
5 - Salmonella (Tables 3 and 4)
6 - Salmonella (Table 5)
7 - Salmonella (Table 6)
8 - Salmonella (Table 7)
9 - Salmonella (Table 8)
10 - Salmonella (Tables 9-12)
11 - Salmonella (Tables 13-16)
12 - Campylobacter (All tables)
13 - E. coli (All tables)
Antimicrobials and breakpoints

 

 

Table 1. Breakpoints (µg/ml) Used for Susceptibility Testing of Salmonella and E.coli
CLSI Subclass Antimicrobial Susceptible breakpoint Intermediate breakpoint Resistant breakpoint
Aminoglycosides Amikacin

<=16

32

>=64

Gentamicin

<=4

8

>=16

Kanamycin

<=16

32

>=64

Streptomycin

<=32

N/A

>=64

Aminopenicillins Ampicillin

<=8

16

>=32

Beta-Lactam/Beta-Lactamase Inhibitor Combinations Amoxicillin/Clavulanic Acid

<=8/4

16/8

>=32/16

Cephalosporins I Cephalothin

<=8

16

>=32

Cephalosporins III Ceftiofur

<=2

4

>=8

Ceftriaxone

<=8

16 and 32

>=64

Cephamycins Cefoxitin

<=8

16

>=32

Folate Pathway Inhibitors Sulfanomides

<=256

N/A

>=512

Trimethoprim/Sulfamethoxazole

<=2/38

N/A

>=4/76

Phenicols Chloramphenicol

<=8

16

>=32

Fluoroquinolones Ciprofloxacin

<=1

2

>=4

Quinolones Nalidixic Acid

<=16

N/A

>=32

Tetracyclines Tetracycline

<=4

8

>=16

Table 1 notes:

Breakpoints established by CLSI (Clinical and Laboratory Standards Institute) were used when available

CLSI subclasses are in accordance with CLSI M100 document.

No CLSI breakpoints are available for streptomycin

N/A - Not applicable

 

Table 2. Breakpoints (µg/ml) Used for Susceptibility Testing of Campylobacter
CLSI Subclass Antimicrobial Broth Microdilution Breakpoints (2005-2007) Etest Breakpoints (1998-2004)
Susceptible Intermediate Resistant Susceptible Intermediate Resistant
Aminoglycosides Gentamicin

<=2

4

>=8

<=4

8

>=16

Lincosamides Clindamycin

<=2

4

>=8

<=0.5

1 and 2

>=4

Macrolides Azithromycin

<=2

4

>=8

<=0.25

0.5 and 1

>=2

Erythromycin

<=8

16

>=32

<=0.5

1 and 4

>=8

Ketolides Telithromycin

<=4

8

>=16

NT

NT

NT

Phenicols Florfenicol

<=4

N/A

N/A

NT

NT

NT

Chloramphenicol

NT

NT

NT

><=8

16

>=32

Fluoroquinolones Ciprofloxacin

<=1

2

>=4

<=1

2

>=4

Quinolones Nalidixic acid

<=16

32

>=64

<=16

N/A

>=32

Tetracyclines Tetracycline

<=4

8

>=16

<=4

8

>=16

 

Table 2 notes:

Breakpoints established by CLSI (Clinical and Laboratory Standards Institute) were used when available. CLSI breakpoints are available only for erythromycin, ciprofloxacin, and tetracycline

CLSI subclasses are in accordance with CLSI M100 document.

N/A - Not applicable

NT - Not tested

 

 

 

 

<< Previous    1     [2]     3     4     5     6     7     8     9     10     11     12     13     Next >>

Last Modified: 11/21/2008
Footer Content Back to Top of Page