Paper currency harbours antibiotic-resistant coliform bacteria and integron integrase

Area of Science:

• Microbiology
• Molecular Biology
• Public Health

Background:

• Antibiotic resistance is a growing global health concern.
• Coliform bacteria are common indicators of fecal contamination.
• Integrons are genetic elements that contribute to the spread of antibiotic resistance.

Purpose of the Study:

• To determine the prevalence of class 1 and class 2 integron integrase genes in antibiotic-resistant coliform bacteria found on Pakistani currency.
• To identify specific antibiotic resistance genes present in these bacteria.

Main Methods:

• Collected 500 currency notes from food vending sites in Lahore, Pakistan.
• Identified bacterial populations using biochemical and PCR techniques.
• Performed antimicrobial susceptibility testing via disc diffusion assay.
• Analyzed integron-bearing strains using PCR and sequence analysis.

Main Results:

• Highest bacterial contamination found on notes from street vendors and butcher shops.
• Escherichia coli, Klebsiella sp., and Enterobacter sp. were the most prevalent coliforms.
• Detected antibiotic resistance genes included ampC, blaTEM, blaNDM-1, qnrA, tet(A), and tet(B).
• Identified class 1 integron cassette arrays (e.g., dfrA1-aadA1) and class 2 integron cassette arrays (dfrA1-sat2-aadA1).

Conclusions:

• Circulating paper currency in Pakistan is heavily contaminated with antibiotic-resistant coliforms harboring class 1 and class 2 integron integrase genes.
• This contamination represents a potential public health threat, increasing the risk of severe bacterial infections.
• Highlights the importance of hand hygiene and community sanitation when handling currency.