Emerging Issues on Antibiotic-Resistant Bacteria Colonizing Plastic Waste in Aquatic Ecosystems

Area of Science:

• Environmental microbiology
• Public health
• Antimicrobial resistance

Background:

• Plastic substrates in aquatic environments can harbor pathogenic bacteria.
• Antibiotic-resistant bacteria (ARB) pose significant threats to environmental and human health.
• Understanding the prevalence of ARB and their antibiotic-resistant genes (ARGs) on plastics is crucial.

Purpose of the Study:

• To investigate the presence of Staphylococcus spp. and Klebsiella spp. on plastic substrates in an inland water body.
• To identify antibiotic resistance profiles and ARGs in these bacterial isolates.
• To assess the potential health risks associated with plastic-associated ARB.

Main Methods:

• Microbiological analysis using selective and chromogenic media.
• Biochemical and molecular identification (16S rDNA sequencing, BLAST analysis).
• Antibiotic susceptibility testing (Kirby-Bauer disc diffusion) and genotypic ARG profiling.

Main Results:

• Klebsiella spp. were confirmed. Staphylococcus spp. were identified as Lysinibacillus spp. (63.6%) and Exiguobacterium acetylicum (36.3%).
• All isolated bacteria showed high resistance to nine tested antibiotics.
• Class 1 integron genes and eighteen ARGs were detected, indicating a significant resistance burden.

Conclusions:

• Plastic debris acts as a reservoir for opportunistic human pathogens with extensive antibiotic resistance.
• Aquatic plastic pollution contributes to the spread of ARB and ARGs.
• This highlights emerging risks to environmental and human health from plastic waste.