Antimicrobial categories in describing multidrug resistance, extensive drug resistance and pan-drug resistance in Pseudomonas aeruginosa and Acinetobacter baumannii: a systematic review

Introduction and objectives: Employment of different terms in expressing resistance in Pseudomonas aeruginosa and Acinetobacter baumannii is a controversial issue. The aim of this systematic review is to assess antimicrobial categories for the terms multidrug resistance (MDR), extensive-drug resistance (XDR) and pan-drug resistance (PDR) for P. aeruginosa and A. baumannii. Materials and methods: We searched the database in the medical literature for relevant studies from 2006 up to 2016. Out of the 164 studies analyzed, 106 articles focused on definitions of MDR, XDR and PDR in A. baumannii, 53 articles focused on P. aeruginosa while five articles discussed both bacteria. Results: The most prevalent MDR, XDR and PDR A. baumannii was defined as acquired resistance to amikacin (42; 64.6%), ceftazidime (42; 64.6%) and imipenem (40; 61.5%) in MDR definition and (11; 34.4%) in XDR definition. The term MDR P. aeruginosa more often refers to resistance state to the drugs such as imipenem, ciprofloxacin (26; 76.5%) and amikacin (22; 64.7%). The most common antibiotic resistance in XDR P. aeruginosa was related to ceftazidime, piperacillin-tazobactam, ciprofloxasin (11; 73.3%) and meropenem (10; 66.7%). The term PDR P. aeruginosa was used in two studies for antibiotics such as amikacin, gentamicin and tobramycin, ceftazidime, cefepime, imipenem, meropenem and ciprofloxacin (100%). Conclusion: The current study lists the antibiotics which may be useful in clearly describing the extent of antibiotic resistance of P. aeruginosaand A. baumannii for each term.