Otago Diagnostic Laboratories' (ODL) Method for the detection of beta-lactamases in Enterobacteriaceae.
OBJECTIVE
The rapid evolvement of beta-lactamases in Enterobacteriaceae is an important concern and the clinical microbiology laboratory is required to detect them, where possible, using a rapid, reliable, simple and low cost methodology.


METHODS
A disc diffusion method using NCCLS breakpoints, Jarlier's principle and cefoxitin test for AmpC was carried out. It incorporated seven antimicrobial discs in one agar plate: cefotaxime, aztreonam, amoxicillin-clavulanate, ceftazidime, cefpodoxime, cefepime and cefoxitin. NCCLS disc confirmation test for extended-spectrum beta-lactamase (ESBL) was carried out simultaneously.


RESULTS
AmpC, ESBL, CTX-M, and K1 were detected using these tests. The prevalence of ESBL was <1% in the hospital.


CONCLUSIONS
The method is recommended for the phenotypic detection of beta-lactamases in Enterobacteriaceae or for confirmation after the results are obtained by conventional automated systems.
Han
C T W
CT
Otago Diagnostic Laboratories, Dunedin Hospital, Otago District Health Board, New Zealand.
Parnell
K D
KD
Chiew
Y F
YF
Lin
J Y H
JY
Turner
P
P
Wilson
A S
AS
Davies
J D
JD
Robinson
J A
JA
de Ruyter
A M
AM
Thompson
K M
KM
Moodie
J A
JA
Johnstone
M C
MC
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects / Q000201:enzymology*; D004756:Enterobacteriaceae Infections; D006801:Humans; D007755:Laboratories, Hospital; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009520:New Zealand; D010641:Phenotype; D001618:beta-Lactamases / Q000032:analysis / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases