Departamento de Bioquímica, Centro de Biociências, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
Centro de Tecnologias Estratégicas do Nordeste, Recife, Brazil.
Microb Pathog. 2018 Nov;124:152-162. doi: 10.1016/j.micpath.2018.08.027. Epub 2018 Aug 22.
The Alpinia purpurata inflorescence contains a lectin (ApuL), which has immunomodulatory activities on human cells. In the present work, it was evaluated the antibacterial and antifungal effects of ApuL against human pathogens. ApuL showed bacteriostatic activity against non-resistant (UFPEDA-02) and an oxacillin-resistant isolate (UFPEDA-672) of Staphylococcus aureus with minimal inhibitory concentrations (MIC) of 50 and 400 μg/mL, respectively. In addition, it showed bactericidal effect on the non-resistant isolate (minimal bactericidal concentration: 200 μg/mL). For Candida albicans and Candida parapsilosis, ApuL showed fungistatic effect (MIC: 200 and 400 μg/mL, respectively). The lectin was able to impair the viability of the microorganism cells, as indicated by propidium iodide (PI) staining. Analysis of growth curves, protein leakage, and ultrastructural changes supported that ApuL acts through distinct mechanisms on S. aureus isolates. Ultrastructural analysis of ApuL-treated Candida cells revealed malformations with elongations and bulges. ApuL-oxacillin combination showed synergistic effect on the oxacillin-resistant isolates UFPEDA-670 and 671, which were not sensitive to lectin alone. Synergism was also detected for ApuL-ceftazidime against a multidrug-resistant isolate of Pseudomonas aeruginosa. Synergistic action of ApuL-fluconazole was detected for C. parapsilosis, which was insensitive to the drug alone. Biofilm formation by S. aureus non-resistant isolate and C. albicans was remarkably inhibited by ApuL at sub-inhibitory concentrations. In conclusion, ApuL showed differential effects on non-resistant and resistant bacterial isolates, was active against Candida species, and showed synergistic action in combination with antibiotics.
高良姜花序含有一种凝集素（ApuL），它对人类细胞具有免疫调节活性。在本工作中，评估了 ApuL 对人类病原体的抗菌和抗真菌作用。ApuL 对非耐药（UFPEDA-02）和耐甲氧西林（oxacillin-resistant）金黄色葡萄球菌分离株（UFPEDA-672）具有抑菌活性，最小抑菌浓度（MIC）分别为 50 和 400μg/mL。此外，它对非耐药分离株（最低杀菌浓度：200μg/mL）表现出杀菌作用。对于白色念珠菌和近平滑念珠菌，ApuL 表现出抑菌作用（MIC：分别为 200 和 400μg/mL）。碘化丙啶（PI）染色表明，凝集素能够损害微生物细胞的活力。生长曲线分析、蛋白质渗漏和超微结构变化表明，ApuL 对金黄色葡萄球菌分离株的作用机制不同。超微结构分析表明，用 ApuL 处理的念珠菌细胞发生畸形，出现伸长和膨胀。ApuL-oxacillin 组合对耐 oxacillin 的 UFPEDA-670 和 671 分离株具有协同作用，这些分离株单独使用凝集素不敏感。ApuL-ceftazidime 对多药耐药铜绿假单胞菌分离株也显示出协同作用。ApuL-fluconazole 对单独用药不敏感的近平滑念珠菌也表现出协同作用。ApuL 在亚抑菌浓度下显著抑制非耐药金黄色葡萄球菌分离株和白色念珠菌的生物膜形成。综上所述，ApuL 对非耐药和耐药细菌分离株表现出不同的作用，对念珠菌属具有活性，并与抗生素联合表现出协同作用。
