Antimicrobial Resistance Dynamics in Proteus Species

Proteus species, notably Proteus mirabilis, are ubiquitous opportunistic pathogens implicated in urinary tract infections, wound infections and foodborne disease. These bacteria possess intrinsic resistance to certain antimicrobials and readily acquire additional resistance determinants through horizontal gene transfer. The growing prevalence of extended-spectrum β-lactamases, carbapenemases and mobile genetic elements such as plasmids, transposons and integrative conjugative elements has transformed Proteus into a reservoir of multidrug resistance. Swarming motility, biofilm formation and urease production further enhance colonisation and persistence in clinical and environmental settings. The interplay between genomic plasticity, selective antibiotic pressure and inter-species gene exchange underpins the global dissemination of resistance in Proteus. Surveillance studies reveal a shift from single-agent resistance to extensively drug-resistant and even pan-resistant phenotypes, posing urgent challenges for diagnostics, infection control and therapeutic management. One Health investigations highlight the role of animals, food and environmental niches in perpetuating a hidden cycle of resistance gene movement between Proteus and other Enterobacterales.

Research from Nature Portfolio

AtpD gene sequencing of Proteus mirabilis isolates from ducks has provided a phylogenetic framework linking virulence traits, biofilm formation and resistance profiles. A substantial proportion of isolates were found to be extensively drug-resistant, harbouring multiple β-lactamase genes including blaTEM, blaOXA-1 and blaCTX-M and, alarmingly, carbapenemases such as NDM-1 and KPC. Biofilm proficiency and urease activity were almost universal, underscoring the combined threat of persistence and resistance in livestock reservoirs. This work emphasises the zoonotic potential of XDR and PDR Proteus strains and the need for integrated surveillance across human and animal health sectors.

Longitudinal genomic analysis of OXA-23 and OXA-58-producing Proteus mirabilis has identified a single clonal lineage circulating in human and veterinary contexts since the late 1990s. Carbapenemase genes are chromosomally embedded within composite transposons, demonstrating stable inheritance and broad host range. The study revealed that class D carbapenemases, traditionally associated with non-Proteus species, have become entrenched in Proteus, driving an expanded reservoir of hard-to-detect carbapenem resistance that evades routine laboratory screening.

Antimicrobial Resistance Dynamics in Proteus Species publication trend

The graph below shows the total number of articles in antimicrobial resistance dynamics in proteus species across all publications each year (not limited to Nature Index journals).

Technical terms

Extended-spectrum β-lactamases (ESBLs): Enzymes that hydrolyse penicillins, cephalosporins and monobactams, conferring broad β-lactam resistance.

Carbapenemases: β-lactamases of Ambler classes A, B or D that degrade carbapenem antibiotics, often found on mobile elements.

Integrative and Conjugative Elements (ICEs): Chromosomally integrated mobile genetic elements capable of excision and transfer to new bacterial hosts.

ISCR1 element: A mobile insertion sequence commonly associated with class 1 integrons that captures and mobilises resistance genes.

IncX3 plasmid: A conjugative plasmid family frequently implicated in the dissemination of blaNDM carbapenemase genes across Enterobacterales.

References

1. atpD gene sequencing, multidrug resistance traits, virulence-determinants, and antimicrobial resistance genes of emerging XDR and MDR-Proteus mirabilis. Scientific Reports (2021).
2. A single Proteus mirabilis lineage from human and animal sources: a hidden reservoir of OXA-23 or OXA-58 carbapenemases in Enterobacterales. Scientific Reports (2020).
3. OXA-48-like carbapenemases in Proteus mirabilis – novel genetic environments and a challenge for detection. Emerging Microbes & Infections (2024).
4. Whole-Genome Analysis of blaNDM-Bearing Proteus mirabilis Isolates and mcr-1-Positive Escherichia coli Isolates Carrying blaNDM from the Same Fresh Vegetables in China. Foods (2023).
5. Genetic analysis of resistance and virulence characteristics of clinical multidrug-resistant Proteus mirabilis isolates. Frontiers in Cellular and Infection Microbiology (2023).