TABLE 1.

Results of the phenotypic method in the detection of MBL-producing gram-negative bacilli

OrganismNo. of isolatesNo. (%) of isolates positive on phenotypic plateMBL gene type
MBL-positive isolates84
    Serratia marcescens3737 (100)IMP-4
    P. aeruginosa1919 (100)IMP-4
    P. aeruginosa11 (100)VIM-4
    Pseudomonas stutzeri11 (100)VIM-2
    Klebsiella pneumoniae1010 (100)IMP-4
    Klebsiella oxytoca11 (100)IMP-4
    Escherichia coli66 (100)IMP-4
    Enterobacter cloacae66 (100)IMP-4
    Citrobacter koseri11 (100)IMP-4
    Acinetobacter junii11 (100)IMP-4
    Acinetobacter baumannii11 (100)IMP-1
MBL-negative isolates52
    P. aeruginosa151 (7)NDa
    Pseudomonas mendocina10 (0)ND
    A. baumannii100 (0)ND
    E. cloacae50 (0)ND
    S. marcescens40 (0)ND
    E. coli40 (0)ND
    K. pneumoniae30 (0)ND
    K. oxytoca30 (0)ND
    Citrobacter braakii10 (0)ND
    Achromobacter xylosoxidans30 (0)ND
    Burkholderia cepacia20 (0)ND
    Ralstonia pickettii10 (0)ND
  • a ND, not detected.