Antibiotic Profile and czcA Heavy Metal Resistance Gene of Pseudomonas aeruginosa Isolated from the Tanjaro River, a Heavy Metal-Contaminated Water Source in Sulaimaniyah City, Kurdistan Region, Iraq.

October 2025 , Pages 689-704

Authors

Aras R. Mohammed Mohammed 1 ; Bahast N. Edan Edan 2 ; Shanga T. Ahmed Ahmed 2 ; Bakhcha S. Abdulrahman Abdulrahman 2

1 - Assistant lecturer, college of Science, University of Sulaimani, KRG.Iraq

2 - B.Sc. Biology, College of Science, University of Sulaimani, KRG.Iraq

DOI logo 10.17656/11771

Keywords

Abstract

Freshwater ecosystems are being increasingly threatened by human activities, particularly by the disposal of industrial waste and heavy metals. The Tanjaro River in Sulaymaniyah , Kurdistan Region, Iraq, serve as a prime case study and has been severely affected by rampant pollution due to uncontrolled urbanization and industrial activities. Water samples were collected from the Tanjaro River and sampling was conducted on October 1, 2024, from eight distinct locations. At each sampling point sterile 100 mL plastic container were used to collect water. Water samples were transported to the laboratory in cool box to maintain microbial viability. Directly inoculated to the Tryptic Soy Broth (TSB) and incubated at 37°C for 24 hours under aerobic conditions to enhance bacterial growth.  In this research, Pseudomonas aeruginosa , a well studied multidrug resistant and metal-tolerant bacterium, was isolated and identified from this polluted water source. Sampling was conducted from eight distinct locations. Twenty P. aeruginosa  strains were identified using cultural characteristics, microscopic features, and biochemical tests, and were further confirmed using the VITEK® 2 COMPACT system. Antibiotic susceptibility testing revealed that all isolates were  susceptible to ciprofloxacin, levofloxacin, gentamicin, and meropenem, while showing lower sensitivity to aztreonam. Genomic DNA was extracted and specific primers were designed to target the czcA gene. PCR amplification showed the existence of the czcA gene that codes for the key component of the CzcCBA efflux pump system, able to release cobalt, zinc, and cadmium from bacterial cells. In addition to heavy metal contamination, there was no multidrug resistance, showing that the isolates remain treatable using regular antibiotics. This shows that P. aeruginosa  of Tanjaro River is not only a bioindicator of environmental pollution but also as one candidate for bioremediation of heavy metal-contaminated sites. The findings underscore the necessity for immediate, increased environmental surveillance, controlled dumping, and synchronized public health responses to reduce the risks emanating from such contamination.

Statistics
  • Article view295
  • Downloads8
  • First online20 October 2025
  • Published at20 October 2025

  • RIS
  • BibTeX
  • EndNote
  • Mendeley
  • APA (7th edition)
  • MLA (9th edition)
  • Chicago
  • Harvard
  • IEEE
  • Vancouver