Technical Note: Simple, scalable, and sensitive protocol for retrieving Bacillus anthracis (and other live bacteria)...

Area of Science:

• Microbiology
• Forensic Science
• Public Health

Background:

• Injectional anthrax, caused by Bacillus anthracis, has led to significant deaths among heroin users in Europe.
• Previous forensic investigations have failed to isolate live Bacillus anthracis from heroin samples.
• Low concentrations of bacterial endospores in heroin pose challenges for molecular detection methods.

Purpose of the Study:

• To develop and validate a culture-based method for isolating live bacteria, including Bacillus anthracis, from heroin.
• To address the bioforensic need for retrieving microbial evidence from drug samples linked to anthrax cases.
• To establish a protocol for analyzing the original microbiota of uncut heroin.

Main Methods:

• A culture-based protocol was designed for direct bacterial isolation from heroin.
• Artificially spiked heroin samples with attenuated Bacillus anthracis endospores were used for method validation.
• A wash solution of 0.5% Tween 20 in water was employed for bacterial retrieval.
• Eighty-two uncut heroin samples from a German Federal Criminal Police Office program were analyzed.

Main Results:

• The culture method achieved 84-98% recovery rates for artificially introduced Bacillus anthracis endospores.
• While Bacillus anthracis was not isolated from the tested heroin batches, other bacteria were successfully cultured.
• The analysis of 82 heroin samples revealed a surprisingly low number of culturable bacteria.

Conclusions:

• The developed culture-based method is effective for isolating live bacteria from heroin.
• The protocol can aid in the bioforensic investigation of injectional anthrax cases linked to heroin use.
• The method allows for the analysis of original heroin microbiota, distinguishing it from contamination introduced during cutting.