Pseudomonas Species and Acinetobacter baumannii Associated Urinary Tract Infection: Antimicrobial Resistance Patterns and Therapeutic Alternatives

Abstract

Background: Pseudomonas species and Acinetobacter baumannii are uncommon opportunistic pathogens in our environment, they recently emerged as significant aetiological agents in healthcare associated infections particularly in immunocompromised individuals and have become increasingly resistant to antibiotics on a global scale, this is largely due to the widespread use of broad-spectrum antibiotics, such as carbapenems and fifth generation cephalosporins. This study's goal was to examine changes in antibiotic susceptibility profiles of A. baumannii and Pseudomonas spp isolates over the course of the one-year study period in our facility. Methods: This was a retrospective study that involved a review of the medical microbiology laboratory records for the antimicrobial susceptibility patterns of Pseudomonas spp and Acinetobacter baumannii isolated from the urinary samples of patients who were been assessed for Urinary tract infection between April 2020 to March 2021. The bacteria were isolated and identified from routine urine samples using standard bacteria identification methods, including Analytical Profile Index (API). In vitro antibiotic susceptibility test (AST) to Aztreonam, Piperacillin-tazobactam, Cefoperazone, Levofloxacin, Amikacin, Ceftazidime, Imipenem and Meropenem was routinely performed by the modified Kirby-Bauer disk diffusion test and susceptibility break points determined using the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Acinetobacter baumannii isolates showed the more resistance rate to Ceftazidime (46.2%), Piperacillin-tazobactam (46.1%) and Levofloxacin (53.9%) but had least resistance to Aztreonam (0%), and Amikacin (15.4%). Similarly, Pseudomonas aeruginosa isolates were most resistant to Piperacillin-tazobactam (53.3%), followed by Ceftazidime and Cefoperazone (40%) respectively, however 60% of all Pseudomonas aeruginosa isolates were susceptible to Ceftazidime and Meropenem, while 46.7% were sensitive to Amikacin. Conclusion: In our setting, the empirical treatment of urinary tract infections (UTI) due to A. baumannii are effectively treated by Aztreonam, Amikacin and Meropenem. While for Pseudomonas aeruginosa associated UTIs, Meropenem and Ceftazidime can be used for empirical treatment. Finally, with the greater than 20% resistance rates to Carbapenems noticed in A. baumannii and some Pseudomonas species especially Pseudomonas aeruginosa, this emphasizes the need for antibiotic stewardship programme within our facility.