Lotfy Momen M, Hassan Hossam M, Mohammed Rabab, Hetta Mona, El-Gendy Ahmed O, Rateb Mostafa E, Zaki Mohamed A, Gamaleldin Noha M
Department of Pharmacognosy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt.
Department of Pharmacognosy, Faculty of Pharmacy, Nahda University, Beni-Suef, Egypt.
Front Microbiol. 2019 Apr 12;10:787. doi: 10.3389/fmicb.2019.00787. eCollection 2019.
Chemical and biological studies of the River Nile derived-microorganisms are limited. Hence, this work was carried out to screen the River Nile habitat. Identification of the isolated organisms, chemical profiling of their ethyl acetate extracts as well as screening of their antimicrobial, antileishmanial, antitrypanosomal, and antimalarial activities were investigated.
Identification of the microbial isolates were carried out using bacterial 16S rRNA and fungal 18S rRNA gene sequencing. Chemical profiling of the EtOAc extracts using LC-HRESIMS spectroscopy was carried out. The antimicrobial screening using the modified version of the CLSI method, antileishmanial and antitrypanosomal activities were screened using promastigote assay, axenic amastigote assay, trypamastigotes assay and THP1 toxicity assay. The antimalarial activities against D6 (chloroquine sensitive) and W2 (chloroquine-resistant) strains of were evaluated.
Seven isolated microorganisms were identified as sp., and . Chemical investigation of different extracts showed several bioactive compounds, identified as; nigragillin, 5-caboxybenzofuran and dyramide B from and actinopolysporin B from . On the other hand many nitrogenous compounds with high molecular weights showed no hits that may correspond to new long chain and/or cyclic peptides. The EtOAc extract of fermentation broth showed the highest activity against D6 and W2 (IC = 25.94 and 27.28 μg/mL, respectively), while two isolates and sp. RN-011 extracts showed the highest antitrypanosomal activity (IC = 0.8 and 0.96 μg/mL).
The River Nile could be a new source for production of promising bioactive leading compound where antimicrobial and antiparasitic activities may be correlated.
对尼罗河衍生微生物的化学和生物学研究有限。因此，开展本研究以筛选尼罗河流域的栖息地。对分离出的微生物进行鉴定，对其乙酸乙酯提取物进行化学分析，并对其抗菌、抗利什曼原虫、抗锥虫和抗疟活性进行筛选。
使用细菌16S rRNA和真菌18S rRNA基因测序对微生物分离株进行鉴定。采用LC-HRESIMS光谱法对乙酸乙酯提取物进行化学分析。使用改良的CLSI方法进行抗菌筛选，使用前鞭毛体试验、无菌无鞭毛体试验、锥鞭毛体试验和THP1毒性试验筛选抗利什曼原虫和抗锥虫活性。评估对D6（氯喹敏感）和W2（氯喹耐药）菌株的抗疟活性。
七种分离出的微生物被鉴定为 属、 属和 属。对不同提取物的化学研究显示了几种生物活性化合物，分别鉴定为：来自 的黑曲霉毒素、5-羧基苯并呋喃和二酰胺B，以及来自 的放线多孢菌素B。另一方面，许多高分子量的含氮化合物未显示出可能对应于新的长链和/或环肽的匹配结果。 发酵液的乙酸乙酯提取物对D6和W2显示出最高活性（IC50分别为25.94和27.28μg/mL），而两种分离株 和 属RN-011的提取物显示出最高的抗锥虫活性（IC50分别为0.8和0.96μg/mL）。
尼罗河可能是生产有前景的生物活性先导化合物的新来源，其抗菌和抗寄生虫活性可能相关。
