Identification and 16s rRNA Gene Sequence Analysis of Multidrug-Resistant Pseudomonas Aeruginosa in Paper Currency Notes

Pseudomonas aeruginosa is one of the most feared opportunistic human pathogens due to its
capability to colonize a broad range of ecological sites, infect various hosts and organs and capable of
acquiring resistance to multiple antimicrobial agents.
This study aimed to investigate the likelihood of contamination of currency notes with multidrugresistant Pseudomonas aeruginosa.
One hundred and twenty used Sudanese currency notes were collected from people working in
different sites such as public transportations, shops, restaurants and hospitals, moistened using sterile
water, swabbed, inoculated in cetrimide agar plates and incubated for 24 hours. The motile gramnegative bacilli grown in cetrimide agar were subcultured in nutrient agar plates and prepared for
further identification with phenotypical, molecular and antimicrobial sensitivity tests. Bioinformatics
analyses for 16S rRNA gene sequence of the most resistant Pseudomonas aeruginosa isolate was also
performed.
Out of 120 collected samples of paper currency notes, 17.5% was found to be contaminated with
Pseudomonas aeruginosa strains. All isolates were resistant to 6 out of 13 tested antimicrobial agents
including Kanamycin, Cefuroxime and Amoxyclav. All isolates were sensitive to Ciprofloxacin,
Levofloxacin and Azithromycin, however, drugs used for treatment of Pseudomonal infections such as
ceftazidime and piperacillin showed different rates of resistance. One nucleotide substitution mutation,
T550C, was detected in the most resistant isolate’s 16S rRNA gene, however, its exact effect is unclear.
Forthcoming studies should further explore the impact of mutation detected in the 16S rDNA, the
gene that known to be stable over many generations.