Molecular epidemiology and antibiotic resistance profiles of Mycobacterium and Nocardia species in patients with cancer: Detection of multidrug-resistant and extensively drug-resistant strains.

Molecular epidemiology and antibiotic resistance profiles of Mycobacterium and Nocardia species in patients with cancer: Detection of multidrug-resistant and extensively drug-resistant strains.

Publication date: Jul 01, 2025

Patients with cancer are vulnerable to infections caused by mycobacteria and Nocardia. Antimicrobial agents are necessary to treat these infections, but extensive antibiotic use can lead to drug-resistant strains. Due to this issue, in the present study, we aimed to isolate, molecularly identify, prevalence, and assess the resistance genes in mycobacterial and nocardial isolates from patients with cancer. 79 clinical samples were obtained from patients with cancer which were referred to Mohammad Rasolallah hospitals in Shiraz. Initial identification was conducted through phenotypic and biochemical assays, followed by molecular confirmation using PCR amplification of the 16S rRNA and hsp65 genes. Genus and species determination was achieved through direct sequencing of the 16S rRNA gene. Drug susceptibility testing was carried out using the serial dilution method, adhering to the guidelines set by the Clinical and Laboratory Standards Institute (CLSI) in 2021. Out of 79 clinical samples, 17 isolates (21. 51 %) were recovered and identified as Mycobacterium and Nocardia species through molecular and biochemical analyses. In our study, the most prevalent species were M. tuberculosis complex 6 (35. 3 %) isolates, M. avium complex 3(17. 64 %) isolates, M. terrae 2(11. 76 %)isolates, N. cyriacigeorgica 2 (11. 76 %) ‏ ‏isolates, N. nova, N. kroppenstedtii, M. arupense, and M. canariasense 1 (5/89 %) isolate each. The analysis of the resistance profile of isolates showed that the M. tuberculosis (MTB) isolates HM7 and HM9 showed multidrug-resistant (MDR), and the isolates HM11 and HM12 showed extensively drug-resistant (XDR) profile, M. avium showed MDR profile, while no resistance patterns were observed in the Nocardia isolates. Moreover, the results show that some of the MTB isolates ‏ ‏harbored katG, ermA, and rpoB resistance genes and M. avium isolates harbored katG and rpoB resistance genes. In conclusion, our results showed, that patients with cancer are vulnerable to infections caused by mycobacteria and Nocardia, moreover the emergence of antibiotic resistance further complicates the management of these infections, necessitating vigilant surveillance and the development of tailored treatment guidelines.

Concepts Keywords
Cancer Adult
Laboratory Aged
Mohammad Anti-Bacterial Agents
Mycobacteria Anti-Bacterial Agents
Vigilant Bacterial Proteins
Bacterial Proteins
DNA, Bacterial
DNA, Bacterial
Drug susceptibility test
Female
Humans
Iran
Male
Microbial Sensitivity Tests
Middle Aged
Molecular Epidemiology
Mycobacterium
Mycobacterium
Neoplasms
Nocardia
Nocardia
Nocardia Infections
Patients with cancer
Resistance genes
RNA, Ribosomal, 16S
RNA, Ribosomal, 16S

Semantics

Type Source Name
disease IDO antibiotic resistance
disease MESH cancer
disease MESH infections
disease IDO drug susceptibility
disease MESH tuberculosis
pathway KEGG Tuberculosis
disease MESH Nocardia Infections

Original Article

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