597. In Vitro Activity of ACHN-490 Tested Against Gram-Negative and Gram-Positive Pathogens Isolated from Patients in Canadian Hospitals in 2011: CANWARD Surveillance Study
Session: Poster Abstract Session: Novel Antimicrobial Agents
Friday, October 21, 2011
Room: Poster Hall B1
Background: ACHN-490, a broad-spectrum aminoglycoside with differentiated activity against multi-drug resistant Enterobacteriaceae, including those with Klebsiella pneumoniae carbapenemases (KPC), is being developed as a first-line treatment for resistant bacterial pathogens. We determined the in vitro activity of ACHN-490 along with aminoglycoside and non-aminoglycoside comparators versus Gram-negative and Gram-positive pathogens isolated from January 2011 to present from patients in medical and surgical wards, intensive care units, clinics, and emergency rooms at 15 Canadian hospitals.

Methods: Antimicrobial susceptibility testing was performed using in-house broth microdilution panels following the method recommended by CLSI. 

Results: The activity of ACHN-490 and comparators is summarized below.

Organism (n)

MIC50/MIC90 (mg/mL)

ACHN-490

GENT

TOBRA

AMIK

CIP

CAZ

E. coli (233)

0.5/1

≤0.5/2

1/2

≤2/4

≤0.06/>16

≤0.5/1

K. pneumoniae (41)

0.25/0.25

≤0.5/≤0.5

≤0.5/1

≤2/≤2

≤0.06/0.5

≤0.5/1

E. cloacae (32)

0.5/1

≤0.5/≤0.5

≤0.5/1

≤2/2

≤0.06/0.12

0.5/>32

S. marcescens (25)

0.25/0.5

≤0.5/1

1/2

≤2/4

≤0.06/1

0.5/1

P. mirabilis (27)

0.25/0.5

1/2

1/2

≤2/4

≤0.06/2

≤0.5/≤0.5

K. oxytoca (28)

0.25/0.5

≤0.5/≤0.5

1/1

≤2/2

≤0.06/0.12

≤0.5/0.5

E. aerogenes (20)

0.5/0.5

≤0.5/≤0.5

≤0.5/1

≤2/2

≤0.06/0.5

0.5/>32

P. aeruginosa (102)

2/8

4/16

2/8

8/32

0.5/8

4/32

S. maltophilia (22)

64/>64

32/>32

>32/>32

>64/>64

4/>16

>32/>32

A. baumannii (11)

0.5/1

1/2

1/2

≤2/4

0.25/1

8/32

S. aureus (144)

1/2

≤0.5/1

2/8

4/8

0.5/8

16/32

MRSA (82)

0.5/1

≤0.5/2

2/>16

16/64

>16/>16

>32/>32

S. epidermidis (33)

0.25/8

1/>32

4/>32

≤2/16

4/>16

32/>32

E. faecalis (17)

16/>32

16/>32

32/>32

>64/>64

1/>16

>32/>32

GENT, gentamicin; TOBRA, tobramycin; AMIK, amikacin; CIP, ciprofloxacin; CAZ, ceftazidime.

Conclusion: ACHN-490 demonstrated potent in vitro activity against recent clinical isolates of Enterobacteriaceae, P. aeruginosa, A. baumannii and S. aureus including MRSA.  ACHN-490 demonstrates promise for the treatment of infections caused by these organisms.


Subject Category: A. Antimicrobial agents and Resistance

George G. Zhanel, PhD1, James Karlowsky, PhD2, Heather J. Adam, PhD2, Melanie Baxter, MSc1, Andrew Walkty, MD1, Philippe LagacÚ-Wiens3, Frank Schweizer, PhD1 and Daryl J. Hoban, PhD2, (1)University of Manitoba, Winnipeg, MB, Canada, (2)Health Sciences Centre, Winnipeg, MB, Canada, (3)Microbiology, St. Boniface Hospital, Winnipeg, MB, Canada

Disclosures:

G. G. Zhanel, Pfizer Inc: Research Contractor, Research support

J. Karlowsky, None

H. J. Adam, None

M. Baxter, None

A. Walkty, None

P. LagacÚ-Wiens, None

F. Schweizer, None

D. J. Hoban, None

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