Antibiotics Amoxicillin, Ampicillin and Their Mixture-Impact on Bacteria, Fungi, Ostracods and Plants

Area of Science:

• Environmental microbiology
• Soil science
• Ecotoxicology

Background:

• Ampicillin (AMP) and amoxicillin (AMX) are widely used penicillin-derived antibiotics in human and veterinary medicine.
• Antibiotic residues in soil can potentially impact microbial communities and plant growth.

Purpose of the Study:

• To investigate the effects of AMP, AMX, and their mixtures on soil microbial counts (bacteria and fungi).
• To assess the impact of these antibiotics on the growth and development of wheat seedlings (Triticum aestivum).
• To evaluate the effects on the mortality and growth of the fungus *Harpellales incongruens*.

Main Methods:

• Soil samples were treated with AMP, AMX, and their mixtures.
• Bacterial and fungal populations were quantified using colony-forming units (CFU) per gram of soil dry weight.
• Wheat seedlings were exposed to antibiotics to measure fresh weight, shoot length, dry weight, and root length.

Main Results:

• AMP, AMX, and their mixtures did not significantly alter total bacterial counts, with minimal amounts potentially increasing them.
• Fungal abundance showed an increase in response to the tested antibiotics.
• Wheat seedlings treated with AMX and the AMP + AMX mixture showed no significant changes in yield parameters, while AMP increased fresh weight and shoot length.
• Both AMP and AMX exhibited inhibitory effects on wheat seedling root length at the highest concentrations.

Conclusions:

• Ampicillin and amoxicillin have a limited impact on overall soil bacterial populations but can stimulate fungal growth.
• While generally safe for wheat, ampicillin demonstrates growth-promoting effects, whereas both antibiotics can inhibit root development at elevated levels.
• The findings suggest differential effects of these common antibiotics on soil ecosystems and plant physiology.