Antimicrobial susceptibility testing of aquatic bacteria: quality control disk diffusion ranges for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C.
Quality control (QC) ranges for disk diffusion susceptibility testing of aquatic bacterial isolates were proposed as a result of a multilaboratory study conducted according to procedures established by the National Committee for Clinical Laboratory Standards (NCCLS). Ranges were proposed for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C for nine different antimicrobial agents (ampicillin, enrofloxacin, erythromycin, florfenicol, gentamicin, oxolinic acid, oxytetracycline, ormetoprim-sulfadimethoxine, and trimethoprim-sulfamethoxazole). All tests were conducted on standard Mueller-Hinton agar. With >/=95% of all data points fitting within the proposed QC ranges, the results from this study comply with NCCLS guidelines and have been accepted by the NCCLS Subcommittee for Veterinary Antimicrobial Susceptibility Testing. These QC guidelines will permit greater accuracy in interpreting results and, for the first time, the ability to reliably compare susceptibility test data between aquatic animal disease diagnostic laboratories.
Miller
R A
RA
Division of Animal and Food Microbiology, Center for Veterinary Medicine, Food and Drug Administration, Laurel, Maryland 20708, USA. RMiller1@cvm.fda.gov
Walker
R D
RD
Baya
A
A
Clemens
K
K
Coles
M
M
Hawke
J P
JP
Henricson
B E
BE
Hsu
H M
HM
Mathers
J J
JJ
Oaks
J L
JL
Papapetropoulou
M
M
Reimschuessel
R
R
D000333:Aeromonas / Q000187:drug effects*; D000818:Animals; D004058:Diffusion; D004926:Escherichia coli / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000592:standards*; D011786:Quality Control; D013696:Temperature; D014871:Water Microbiology