Preliminary insights into the potential role of Acanthamoeba-Pseudomonas interactions in the development of antibiotic resistance

Full text loading... Abstract Bacteria are known to develop resistance to Acanthamoeba digestion and use them to exercise virulence factors. We hypothesise that Acanthamoeba species may also play a role in promoting antimicrobial resistance (AMR) in amoeba-resistant bacteria. This study investigated whether Acanthamoeba castellanii enhanced AMR development in Pseudomonas putida under lethal ciprofloxacin concentrations. P. putida KT2440 was co-incubated with A. castellanii at ciprofloxacin concentrations starting at four times the minimum inhibitory concentration (MIC). The survival of the co-incubated Pseudomonas and the development of resistance were monitored, and antimicrobial susceptibility tests were conducted using multiple antibiotics. P. putida co-incubated with A. castellanii exhibited tolerance to ciprofloxacin, with MIC increasing from 0.5 µg/ml to 20 µg/ml after 17 days. In contrast, the naïve strain did not survive at a 2 µg/ml concentration. The co-incubated bacteria developed resistance to ciprofloxacin, chloramphenicol, azithromycin, and enrofloxacin while retaining susceptibility to streptomycin and tetracycline. Acanthamoeba significantly accelerated AMR development in P. putida exposed to ciprofloxacin. This finding highlights the need for further research on the molecular mechanisms involved to better identify strategies for combatting the emergence of antibiotic resistance in clinical and environmental settings. - Received: - Version Posted: