Aerococcus Infections and Associated Clinical Implications

Aerococcus species are gram-positive cocci traditionally regarded as commensal constituents of the human urogenital microbiota. Over the past decade, improved identification techniques have revealed A. urinae and A. sanguinicola as significant uropathogens, particularly among elderly patients and those with genitourinary abnormalities. Beyond uncomplicated urinary tract infections, these organisms can invade the bloodstream, leading to bacteraemia and, less commonly, infective endocarditis. Risk factors include advanced age, male gender, catheterisation and structural urinary tract disorders. Clinical presentation spans asymptomatic bacteriuria to acute cystitis, pyelonephritis and systemic sepsis, often with nonspecific symptoms that obscure prompt diagnosis. Conventional culture methods may underestimate Aerococcus due to slow growth and misidentification as streptococci. Modern approaches such as matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and molecular assays have enhanced detection fidelity. Antibiotic susceptibility profiles are generally favourable, with most isolates susceptible to β-lactams and vancomycin, though resistance to macrolides and fluoroquinolones is emerging. The ability of certain strains to form biofilms underpins persistent infection and complicates treatment of endocardial and musculoskeletal involvement. Experimental models have begun to unravel host–pathogen interactions, demonstrating organ tropism and the influence of host genetics on infection outcomes. Collectively, these insights inform clinical management, emphasise the need for robust surveillance of antimicrobial resistance and highlight potential avenues for therapeutic innovation.

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Aerococcus Infections and Associated Clinical Implications publication trend

The graph below shows the total number of articles in aerococcus infections and associated clinical implications across all publications each year (not limited to Nature Index journals).

Technical terms

Minimal inhibitory concentration (MIC): The lowest concentration of an antimicrobial that prevents visible growth of a microorganism in vitro.

Integrative and conjugative element (ICE): A mobile genetic element capable of excising from and integrating into bacterial chromosomes, often carrying antibiotic resistance genes.

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS): A technique for rapid and accurate microbial identification based on protein mass patterns.

Biofilm: A structured community of bacterial cells enclosed in a self-produced polymeric matrix adherent to a surface, conferring resistance to antibiotics and host defences.

Urosepsis: A systemic inflammatory response syndrome resulting from a primary urinary tract infection.

References

1. Macrolide Resistance in the Aerococcus urinae Complex: Implications for Integrative and Conjugative Elements. Antibiotics (2024).
2. Susceptibility of Aerococcus urinae and Aerococcus sanguinicola to Standard Antibiotics and to Nitroxoline. Microbiology Spectrum (2023).
3. Aerococcus urinae and Aerococcus sanguinicola: Susceptibility Testing of 120 Isolates to Six Antimicrobial Agents Using Disk Diffusion (EUCAST), Etest, and Broth Microdilution Techniques. The Open Microbiology Journal (2017).
4. Aerococcus urinae – A potent biofilm builder in endocarditis. PLOS ONE (2020).
5. Clinical Characteristics and Laboratory Identification of Aerococcus Infections: An Australian Tertiary Centre Perspective. International Journal of Microbiology (2017).
6. A mouse model displays host and bacterial strain differences in Aerococcus urinae urinary tract infection. Biology Open (2021).
7. Clinical and microbiological characterization of Aerococcus urinae bacteraemias at Helsinki metropolitan area, Finland. European Journal of Clinical Microbiology & Infectious Diseases (2022).