Isolation, Molecular Identification, and Antibiotic Susceptibility Patterns of Rhodococcus Species Isolated from Patients with Cancer in Shiraz, Iran

Document Type : Original Article(s)

Authors

1 PhD Candidate, Department of Microbiology, School of Basic Sciences, Islamic Azad University, Kazeroon Branch, Kazeroon, Iran.

2 Professor, Department of Microbiology, School of Basic Sciences, Islamic Azad University, Kazeroon Branch, Kazeroon, Iran.

3 Associate Professor, Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University, Shiraz Branch, Shiraz, Iran

Abstract

Background: Opportunistic infections, including those caused by Rhodococcus species, pose a substantial threat to immunocompromised individuals, particularly cancer patients. With the rising incidence of cancer and its associated complications in Iran, this study sought to isolate and molecularly characterize Rhodococcus isolates from cancer patients. Additionally, the antimicrobial susceptibility of these isolates was assessed to enhance the management of Rhodococcus-related infections and address emerging antibiotic resistance.
Methods: In 2023, 79 clinical samples were collected from cancer patients using standard methods. Initial identification was performed using phenotypic and biochemical tests, while the genus and species identification of Rhodococcus isolates was carried out through PCR and 16S rRNA sequence analysis. Drug susceptibility testing for each isolate was conducted using the serial dilution method according to CLSI 2022 guidelines.
Findings: Out of the 79 samples, 13 (16.45%) were identified as Rhodococcus species, comprising seven different species: R. erythropolis, R. atherivorans, R. ruber, R. zopfi, R. phenolicus, R. equi, and R. rhodochrous. These infections were predominantly associated with hematologic malignancies, including acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL). Rhodococcus isolates demonstrated high sensitivity to doxycycline, imipenem, and azithromycin but resisted to ciprofloxacin and cefoxitin.
Conclusion: The results indicated that Rhodococcus species are important opportunistic pathogens in cancer patients, displaying notable prevalence, diversity, and varying antibiotic susceptibility patterns. Consequently, the isolation, molecular identification, and antibiotic susceptibility testing of these bacteria are essential for effective infection management and the mitigation of antibiotic resistance in this vulnerable population.

Highlights

Majid Basri Salehi: Google Scholar

Nima Bahador: Google Scholar 

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References

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Journal of Isfahan Medical School
Volume 42, Issue 800
4th Week, March
March and April 2025
Pages 1240-1248

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History

  • Receive Date: 11 September 2024
  • Accept Date: 23 December 2024

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