Increase AmpC co-producer ESBL phenotypic detection by using Tazobactam with Cefepime Increase AmpC co-producer ESBL Phenotypic Detection

Introduction: Isolates that co-produce an inhibitor-resistant beta-lactamase like AmpC are unsuitable for clavulanate and third-generation cephalosporin phenotypic techniques to detect ESBL.Aim: Cefepime and tazobactam improve AmpC co-producer ESBL phenotypic identification.Materials and Methods: In total, one hundred isolates of Escherichia coli (40), Klebsiella spp. (30), Proteus spp (20), and Enterobacter spp (10) were analysed. These isolates were obtained from urine and pus samples taken from Lady Reading Hospital Peshawar, Pakistan over the course of three months, beginning in January 2022 and continuing through March 2022. Both ESBL and AmpC production in the isolated bacteria was investigated at the same time. The synthesis of AmpC was demonstrated through a modified three-dimensional test (MTDT). The findings of the classic double disc synergy test, the phenotypic disc confirmatory test (PDCT), and the modified double disc synergy test (MDDST) were compared to determine whether ESBL production was present.Results: The improved three-dimensional test verified AmpC synthesis in 38 (38.1%) of 100 positive isolates. ESBL production was verified in 100 of the 82 ESBL-positive isolates. 20 (20%) DDST identified ESBLs. MDDST ESBL-positive isolates were discovered by cefotaxime and ceftazidime + clavulanate, which detected 60 (66.6%) and 10 isolates, respectively. 20 (10.5%) MDDST-detected ESBL producers were AmpC co-producers. DDST found no ESBL in AmpC-positive isolates, however, MDDST found 15 with co-production. Cefepime detected ESBL with AmpC production best in MDDST. In 10 (10.3%) isolates with piperacillin-tazobactam, amoxicillin-clavulanate synergized. In AmpC co-producers, third-generation cephalosporins cefotaxime, ceftazidime, and cefpodoxime did not detect ESBLConclusion: ESBL detection is improved by piperacillin-tazobactum-cefepime double disc synergy testing