First isolation of metallo-beta-lactamase-producing multiresistant Klebsiella pneumoniae from a patient in Brazil

Abstract

A multiresistant Klebsiella pneumoniae isolate was taken from the blood of a 75-year-old patient with nosocomial pneumonia who developed septic shock and failed therapy with imipenem. The isolate presented an MIC of imipenem of 128 microg/ml, and the production of a metallo-beta-lactamase was confirmed by phenotypic and genotypic techniques. We here report, for the first time, the detection of a metalloenzyme (IMP-1)-producing K. pneumoniae clinical strain in Latin America. The gene responsible for this phenotype was found to be bla(IMP-1), carried in a class 1 integron.

FIG. 1.

Appearance of a zone of growth inhibition in CTX-M- and IMP-producing K. pneumoniae strain KpBr-1. An assay using AZT (ATM), amoxicillin-clavulanic acid (AMC), and ceftazidime (CAZ) (top left panel) and an assay using AZT (ATM) and ticarcillin-clavulanic acid (TIM) for ESBL screening (bottom left panel) for ESBL screening are shown. (Right panel) Results of an assay for MBL screening using CAZ, 2-mercaptoacetic acid (2-MAA), 2-mercaptopropionic acid (2-MPA), EDTA, and IMP. Marked growth inhibition of KpBr-1 was observed for both β-lactamases.