Increasing microplastics pollution: An emerging vector for potentially pathogenic bacteria in the environment.

Area of Science:

• Environmental Science
• Microbiology
• Public Health

Background:

• Microplastics (MPs) are ubiquitous environmental contaminants with potential health risks.
• MPs can serve as substrates for bacterial colonization, forming biofilms.
• Understanding MP-associated bacteria is crucial for assessing environmental and public health impacts.

Purpose of the Study:

• To investigate the role of microplastics as vectors for bacterial biofilms in the Susurluk basin, Türkiye.
• To evaluate the influence of seasonal variations, water quality, and polymer type on bacterial colonization of MPs.
• To identify potentially pathogenic bacteria associated with MPs.

Main Methods:

• Collection of microplastics from various aquatic environments (lentic and lotic systems) in the Susurluk basin during wet and dry seasons.
• Identification and quantification of bacterial biofilms on different microplastic types (polyethylene, polypropylene, polystyrene).
• Analysis of water quality parameters and their correlation with bacterial abundance and diversity on microplastics.

Main Results:

• Bacterial biofilms were predominantly found on polyethylene (PE), polypropylene (PP), and polystyrene (PS) microplastics.
• Potentially pathogenic bacteria, including Pseudomonas, Comamonas, Salmonella, and Shigella, were prevalent on MPs.
• PE and PP harboured human/animal-associated bacteria like Staphylococcus, Proteus, Escherichia, Enterococcus, and Enterobacter.
• Water quality significantly influenced bacterial abundance; higher salinity reduced it, while polluted freshwater increased it.
• Seasonal variations and anthropogenic impacts affected bacterial communities on MPs.

Conclusions:

• Microplastics serve as significant vectors for potentially pathogenic bacteria in aquatic ecosystems.
• Environmental factors like water quality and season, alongside polymer type, critically modulate bacterial colonization on microplastics.
• This study highlights the complex interactions between microplastics, bacteria, and environmental conditions, with implications for public health and environmental management.