Postgraduate Program in Veterinary Medicine (PPGMV), Department of Preventive Veterinary Medicine (DMVP), Federal University of Santa Maria (UFSM). Av. Roraima, 1000, Prédio 44, Sala 5007, Bairro Camobi, Santa Maria, RS 97105-900, Brazil.
Federal University of São Francisco Valley, Rodovia BR 407 - Km 12, Lote 543, Projeto Irrigação Senador Nilo Coelho s/n°, Petrolina, CEP 56300-990, Brazil.
Med Mycol. 2020 Nov 10;58(8):1114-1119. doi: 10.1093/mmy/myaa021.
Algae of the genus Prototheca are microorganisms involved in the occurrence of diseases in humans and animals. In bovine species, Prototheca spp. cause environmental mastitis, productive losses in dairy herds, mainly leading to the discard of infected cows. Currently, there are no effective anti-Prototheca spp. drugs to combat this infection. Thus, the search for an efficacious therapy for Prototheca spp. infections have become essential. Highly soluble polypyrrole (Ppy) is a molecule with known antimicrobial activity. This study aimed to characterize Prototheca spp. isolates from bovine mastitis as well as to evaluate the susceptibility profile and to verify the morphological alterations on Prototheca spp. isolates treated with Ppy. In this research, 36 Brazilian isolates of Prototheca spp. were characterized by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) assay for the mitochondrial cytB gene. Additionally, Ppy algicidal activity against these isolates of Prototheca spp. was assessed by minimal microbicidal concentration method in microplates. Further, scanning electron microscopy (SEM) was performed in order to verify the morphological alterations on Prototheca spp. isolates in response to Ppy. The isolates were characterized as belonging to Prototheca zopfii genotype 2 (35/36) and Prototheca blaschkeae (1/36). Ppy had an algicidal effect on all isolates tested at concentrations ranging from 15.625 μg ml-1 to 62.5 μg ml-1. SEM showed changes on planktonic and sessile P. zopfii, including a decrease of the number of cells with the presence of an amorphous substance involving the cells. The algicidal activity of Ppy suggests the therapeutic potential of this molecule in the prevention and treatment of Prototheca spp. in bovine mastitis.
原核生物属藻类是参与人类和动物疾病发生的微生物。在牛种中，Prototheca spp. 引起环境性乳腺炎，导致奶牛群的生产损失，主要导致受感染奶牛的淘汰。目前，没有有效的抗 Prototheca spp. 药物来对抗这种感染。因此，寻找有效的 Prototheca spp. 感染治疗方法变得至关重要。高溶解性聚吡咯（Ppy）是一种具有已知抗菌活性的分子。本研究旨在对牛乳腺炎中的 Prototheca spp. 分离株进行特征描述，评估其药敏谱，并验证 Ppy 处理对 Prototheca spp. 分离株的形态改变。在这项研究中，通过线粒体 cytB 基因的限制性片段长度多态性聚合酶链反应（RFLP-PCR）分析，对 36 株巴西 Prototheca spp. 分离株进行了特征描述。此外，通过微孔板中的最小抑菌浓度法评估了 Ppy 对这些 Prototheca spp. 分离株的杀藻活性。进一步进行了扫描电子显微镜（SEM），以验证 Ppy 对 Prototheca spp. 分离株的形态改变。分离株被鉴定为 Prototheca zopfii 基因型 2（35/36）和 Prototheca blaschkeae（1/36）。Ppy 对所有测试的分离株在 15.625μg ml-1 至 62.5μg ml-1 的浓度范围内均具有杀藻作用。SEM 显示浮游和固着的 P. zopfii 发生了变化，包括细胞数量减少，并且存在一种涉及细胞的无定形物质。Ppy 的杀藻活性表明该分子在预防和治疗牛乳腺炎中的 Prototheca spp. 方面具有治疗潜力。
