Detection of AmpC Enzyme in Gram Negative Bacteria by Phenotypic and Molecular Methods

In this study, the ability of some gram-negative bacteria isolated from different clinical samples to produce AmpC enzymes by phenotypic and molecular methods was investigated. The percentage of its occurrence was (40.6 %) by the use of cefoxitin disk as this antibiotic is used to screen for isolates that can produce this enzymes, the highest rate was for bacteria Pseudomonas aeruginosa (15.5 %) followed by Klebsiella pneumoniae (12.5 %), as for the three dimensional extraction method, the percentage of this enzyme reached (13.2 %), which depend on the use of crude enzymatic extracts instead of live microbial cells, the highest rate was for Pseudomonas aeruginosa (12.5 %) followed by Klebsiella pneumoniae (9.3 %), (37.5 %) by using disk antagonism test method which is one of the best methods for investigating these enzymes. As for molecular methods PCR assay was used to detect the blaAmpC gene encoding for this enzyme, the highest percentage was for Klebceiala pneumoniae, Pseudomonas aeruginosa reached(13.3 %).