Abstract
With the β-Lacta test, production of extended-spectrum β-lactamases (ESBLs) was assayed in 200 urine samples showing Gram-negative bacilli during direct microscopic examination. While 168 samples tested negative, all samples yielding ESBL-producing Enterobacteriaceae after culture gave positive (n = 30) or uninterpretable (n = 2) results. The sensitivity and specificity of ESBL detection were 94% and 100%, respectively.