EVALUATION OF MULTIPLEX PCR TECHNIQUES FOR KLEBSIELLA PRODUCING AMPC-Β LACTAMASES IN CLINICALLY SIGNIFICANT KLEBSILLA ISOLATES

Multiplex PCR for the detection of AmpC genes has proved useful as a rapid screening tool to distinguish cefoxitin resistant non-AmpC producers from cefoxitin resistant AmpC producers. In addition to AmpC gene detection, the data generated from the multiplex PCR method can distinguish which family of AmpC gene is present in the resistant organism there by distinguishing possible inducible AmpC producers from non-inducible producers of AmpC. The present study was designed to evaluate these issues among cephalosporin-resistant isolates of Klebsiella spp. and to assess the performance characteristics of phenotypic tests, using different inhibitors, compared to the PCR, for their rapid and accurate detection. Fifty eight out of 100 isolates were AmpC producers by PCR. Fifty six out of 58 isolates that were positive by PCR test were resistant to FOX. Thirty out of 58 AmpC producers were ESBL positive by E- test and MDDST in detection of ESBL in the presence of AmpC. While 23 /58 were positive by DDST for detection of ESBL in presence of Amp. This study reveals high prevalence of pAmpC and ESBL enzymes among bacterial isolates from our hospital. ESBL production may mask the phenotypic detection of pAmpC enzymes. Modified 3 dimensional (M3D) is a simple and reliable method for detection of pAmpCs. MDDST serve as reliable confirmatory tests for detection of ESBLs in AmpC-positive isolates.