Antimicrobial Resistance of Serratia marcescens Recovered From Aquatic Environments: A Review

Serratia marcescens is a gram-negative bacillus commonly found in aquatic environments. This opportunistic human pathogen can form biofilms and acquire resistance to multiple antimicrobial classes, raising public and environmental health concerns. The occurrence of antimicrobial-resistant S. marcescens in aquatic ecosystems is alarming, yet relatively few studies have addressed this topic in depth. To compile and analyse studies on the antimicrobial susceptibility profiles and resistance mechanisms of S. marcescens isolated from aquatic environments. A systematic search was performed in PubMed, Scopus, Web of Science and the Virtual Health Library for articles published between 2019 and 2024, using descriptors related to S. marcescens from aquatic sources. Studies evaluating susceptibility profiles of isolates from water samples were included. Thirteen articles met the inclusion criteria, encompassing 90 isolates from diverse water sources. Resistance to β-lactams was most prevalent, including carbapenems, the most recent compounds in this class. Identified mechanisms included plasmid-mediated genes blaOXA-48, blaTEM-1 and aac(6')-Ic. Aquatic environments can serve as reservoirs for resistant S. marcescens, posing risks of dissemination to humans and other ecosystems. Continuous monitoring, environmental contamination control and stronger microbiological surveillance policies are crucial to mitigate this emerging public health threat.