FIG. 5.

ELISA validation. (a) Eleven clinical isolates (set 1) were blindly screened with the AmpC ELISA. Shown are AmpC ELISA results and results for two positive controls (P99 β-lactamase and cefepime-resistant E. aerogenes [EA]). All unknown samples were diluted 1:5 with 0.1% BSA in PBS. (b) PCR analysis of 11 clinical isolates (set 1) with SHV primers and AmpC primers. PCR amplicons were run on a 1% ethidium bromide-stained agarose gel. Lanes: M, DNA sizing standard (φX174 replicative-form DNA HaeIII fragments); A, K. pneumoniae containing ACT-1 β-lactamase amplicons; P, P99 β-lactamase amplicons; C, 194-61 CMY-2 β-lactamase amplicons; B, blank; S, SHV β-lactamase amplicons.