Department of Public Health, College of Public Health and Health Informatics, Qassim University, Al-Bukairiyah, Saudi Arabia.
Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Egypt.
PLoS One. 2022 Jul 14;17(7):e0269963. doi: 10.1371/journal.pone.0269963. eCollection 2022.
Brucellosis is an endemic zoonotic disease caused by Brucella species, which are intramacrophage pathogens that make treating this disease challenging. The negative effects of the treatment regime have prompted the development of new antimicrobials against brucellosis. A new treatment modality for antibiotic-resistant microorganisms is the use of nanoparticles (NPs). In this study, we examined the antibacterial activities of silver and gold NPs (SNPs and GNPs, respectively), the resistance developed by Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) strains and the toxicity of both of these NPs in experimental rats. To test the bactericidal effects of the SNPs and GNPs, we used 22 multidrug-resistant Brucella isolates (10 B. melitensis and 12 B. abortus). The minimal inhibitory concentrations (MICs) of both types of NPs were determined utilizing the microdilution technique. To test the stability of resistance, 7 B. melitensis and 6 B. abortus isolates were passaged ten times in culture with subinhibitory concentrations of NPs and another ten times without NPs. Histopathological analysis was completed after rats were given 0.25, 0.5, 1, and 2 mg/kg NPs orally for 28 consecutive days. The MIC values (μg/ml) of the 10-nm SNPs and 20-nm GNPs against B. melitensis were 22.43 ± 2.32 and 13.56 ± 1.22, while these values were 18.77 ± 1.33 and 12.45 ± 1.59 for B. abortus, respectively. After extensive in vitro exposure, most strains showed no resistance to the 10-nm SNPs or 20-nm GNPs. The NPs and antibiotics did not cross-react in any of the evolved Brucella strains. SNPs and GNPs at doses below 2 mg/kg were not harmful to rat tissue according to organ histopathological examinations. However, a greater dose of NPs (2 mg/kg) harmed all of the tissues studied. The bactericidal properties of NPs are demonstrated in this work. Brucella strains develop similar resistance to SNPs and GNPs, and at low dosages, neither SNPs nor GNPs were hazardous to rats.
布鲁氏菌病是一种由布鲁氏菌属引起的地方性人畜共患病，属于巨噬细胞内病原体，这使得治疗这种疾病具有挑战性。治疗方案的负面影响促使人们开发针对布鲁氏菌病的新抗菌药物。一种针对抗生素耐药微生物的新治疗方式是使用纳米颗粒（NPs）。在这项研究中，我们研究了银纳米颗粒（SNPs）和金纳米颗粒（GNPs）的抗菌活性、布鲁氏菌（B. melitensis）和布鲁氏菌（B. abortus）菌株的耐药性以及这两种 NPs 在实验大鼠中的毒性。为了测试 SNPs 和 GNPs 的杀菌效果，我们使用了 22 种多药耐药布鲁氏菌分离株（10 株 B. melitensis 和 12 株 B. abortus）。利用微量稀释技术确定了两种 NPs 的最小抑菌浓度（MICs）。为了测试耐药性的稳定性，将 7 株 B. melitensis 和 6 株 B. abortus 分离株在含有亚抑菌浓度 NPs 的培养基中传代 10 次，然后在不含 NPs 的培养基中传代 10 次。连续 28 天给大鼠口服 0.25、0.5、1 和 2 mg/kg NPs 后，进行组织病理学分析。10nm SNPs 和 20nm GNPs 对 B. melitensis 的 MIC 值（μg/ml）分别为 22.43±2.32 和 13.56±1.22，而对 B. abortus 的 MIC 值分别为 18.77±1.33 和 12.45±1.59。经过体外大量暴露，大多数菌株对 10nm SNPs 或 20nm GNPs 没有耐药性。在任何进化的布鲁氏菌株中，NPs 和抗生素都没有交叉反应。根据器官组织病理学检查，低于 2mg/kg 的 NPs 和抗生素对大鼠组织没有危害。然而，更高剂量的 NPs（2mg/kg）损害了所有研究的组织。本研究证明了 NPs 的杀菌特性。布鲁氏菌菌株对 SNPs 和 GNPs 产生相似的耐药性，而且在低剂量下，NPs 和 GNPs 对大鼠都没有危害。
