Antibiotic Therapy for ESBL and NDM producing Escherichia coli and Klebsiella pneumoniae isolates in a Tertiary Care Center

Objective: Antibiotic resistance is a global phenomenon wherein physicians face the most challenging decision to make for the right kind of drug, and its combinations, to tackle the ever growing ESBL and NDM on pathogens. The aim of the study is to understand outcome of hospitalized patients undergoing antibiotic therapy for bacterial infections. These patients are from Kamrup District of Assam, India. Materials and methods: A total of 185 clinical isolates of Escherichia coli and Klebsiella pneumoniae were collected from hospitalized patients of a tertiary care centre presenting symptoms of infection. Upon biochemical identification, their antibiotic susceptibility were assessed; isolates resistant to 3rd or 4th generation cephalosporins or carbapenem were phenotypically and genotypically determined for the production of extended spectrum β-lactamase (ESBL) and carbapenemase. PCR was carried out for CTX-M, TEM, SHV, OXA-48 and New Delhi Metallo-β-lactamase (NDM). Results: Bacterial infection is ubiquitous among male and female patients, with high isolation rate of Escherichia coli among female patients with urinary infection. The highest resistance against E. coli isolates was nalidixic acid (82.9%; p≤0.005) and cefixime (81.4%; p≤0.005). The highest resistance against K. pneumoniae was cefotaxime (77.7%; p≤0.005) and ceftazidime (73%; p≤0.005). Imipenem was the most effective antibiotic while ertapenem was the least. Antibiotic therapy included piperacillin (alone or in combination with tazobactam) for both E. coli and K. pneumoniae infections. Conclusions: Ceftriaxone, amikacin, cefepime, ceftriazone and imipenem were chosen as treatment options; isolates showed intermediate to negligible resistance to these drugs. Tigecycline was administered to patients infected with NDM producing pathogens. J Microbiol Infect Dis 2018; 8(4): 153-157.