Aeromonas Infections in Humans-Antibiotic Resistance and Treatment Options

Area of Science:

• Microbiology
• Environmental Health
• Infectious Diseases

Background:

• The genus *Aeromonas* is ubiquitous in aquatic environments and a significant fish pathogen.
• It is also a cause of human infections, with *A. dhakensis* emerging as a notable pathogen.
• Transmission routes include ingestion of contaminated food or water and direct contact with aquatic sources.

Purpose of the Study:

• To review the current understanding of *Aeromonas* as a human pathogen.
• To highlight the growing antibiotic resistance within *Aeromonas* species.
• To assess the implications of this resistance for public health.

Main Methods:

• Literature review of studies on *Aeromonas* epidemiology and antibiotic resistance.
• Analysis of reported cases of human infections caused by *Aeromonas*.
• Examination of resistance patterns to various antibiotic classes, including beta-lactams and colistin.

Main Results:

• *Aeromonas* species, particularly *A. dhakensis*, are increasingly implicated in human infections.
• Significant resistance to penicillins, cephalosporins, and carbapenems is reported.
• Colistin resistance, potentially linked to aquaculture, is also rising, with rates exceeding 30% in some cases.
• Co-occurrence of resistance genes for third-generation cephalosporins and carbapenems is increasing.

Conclusions:

• *Aeromonas* poses a growing threat as a human pathogen due to increasing antibiotic resistance.
• The emergence of colistin resistance, coupled with beta-lactam resistance, positions *Aeromonas* as a potential reservoir for transferable resistance genes.
• This poses a significant public health risk, with potential for transfer to other clinically relevant bacteria like *Enterobacterales*.