Pargali Razieh Helali, Salehi Majid Baseri, Bahador Nima
Department of Microbiology, Kazeroun Branch, Islamic Azad University, Kazeroun, Iran.
Department of Microbiology, Kazeroun Branch, Islamic Azad University, Kazeroun, Iran.
Microb Pathog. 2025 Jul;204:107514. doi: 10.1016/j.micpath.2025.107514. Epub 2025 Mar 26.
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.
癌症患者易受分枝杆菌和诺卡氏菌引起的感染。抗菌药物对于治疗这些感染是必要的，但广泛使用抗生素会导致耐药菌株的出现。由于这个问题，在本研究中，我们旨在从癌症患者中分离、分子鉴定分枝杆菌和诺卡氏菌分离株，评估其流行情况，并检测耐药基因。从转诊至设拉子的穆罕默德·拉索尔阿拉医院的癌症患者中获取了79份临床样本。首先通过表型和生化检测进行初步鉴定，随后使用16S rRNA和hsp65基因的PCR扩增进行分子确认。通过16S rRNA基因的直接测序确定属和种。按照临床和实验室标准协会（CLSI）2021年制定的指南，采用系列稀释法进行药敏试验。在79份临床样本中，通过分子和生化分析回收并鉴定出17株分离株（21.51%）为分枝杆菌和诺卡氏菌属。在我们的研究中，最常见的菌种是结核分枝杆菌复合群6株（35.3%）、鸟分枝杆菌复合群3株（17.64%）、地分枝杆菌2株（11.76%）、乔治亚州诺卡氏菌2株（11.76%），新星诺卡氏菌、克氏诺卡氏菌、阿鲁彭斯分枝杆菌和加那利分枝杆菌各1株（5/89%）。分离株耐药谱分析表明，结核分枝杆菌（MTB）分离株HM7和HM9显示多重耐药（MDR），分离株HM11和HM12显示广泛耐药（XDR）谱，鸟分枝杆菌显示MDR谱，而诺卡氏菌分离株未观察到耐药模式。此外，结果表明，一些MTB分离株携带katG、ermA和rpoB耐药基因，鸟分枝杆菌分离株携带katG和rpoB耐药基因。总之，我们的结果表明，癌症患者易受分枝杆菌和诺卡氏菌引起的感染，而且抗生素耐药性的出现使这些感染的管理更加复杂，需要进行警惕的监测并制定针对性的治疗指南。
