Decoding past microbial life and antibiotic resistance in İnonü Cave's archaeological soil

Area of Science:

• Archaeology
• Microbiology
• Environmental Science

Background:

• Ancient soil microbial communities hold clues to historical human impact.
• Antibiotic resistance genes (ARGs) have a long evolutionary history.
• Understanding past microbial ecology informs present-day challenges.

Purpose of the Study:

• To investigate ancient bacterial communities and ARGs in soil from İnönü Cave, Turkiye.
• To correlate historical human activities with microbial community structure and ARG presence.
• To explore the long-term persistence of ARGs in archaeological contexts.

Main Methods:

• High-throughput sequencing of 16S rRNA genes for microbial community characterization.
• Metagenomic studies for identifying antibiotic-resistance genes.
• Analysis of soil samples from four distinct cultural levels (Chalcolithic to Early Iron Age).

Main Results:

• Diverse bacterial phyla identified, including Acidobacteriota, Actinobacteriota, and Proteobacteria.
• Detection of specific ARGs: tetA (Chalcolithic), intl1 (Early Bronze Age), and OXA58 (Late Bronze Age).
• Evidence of ARG persistence across historical periods, linked to human activities and environmental variables.

Conclusions:

• Human activities have profoundly and enduringly impacted soil microbial communities and ARG prevalence.
• Ancient ARGs demonstrate resilience and adaptability, offering insights into microbial evolution.
• An interdisciplinary approach is essential for understanding ancient microbial ecology and resistance mechanisms.