Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes

Terrestrial actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents

Effect of sorafenib and olmesartan on the serum level of VEGF in EAC- bearing mice.

<p><b>A</b>) Effect of sorafenib (30 mg/kg), olmesartan (3, 10 or 30 mg/kg) and their combination on the serum level of VEGF in EAC-bearing mice. <b>B</b>) Effect of concurrent administration of angiotensin (1–7) agonist (30 µg/kg/day, i.p.) or angiotensin (1–7) antagonist (3.3 mg/kg/trice/week, i.p.) and olmesartan on the serum level of VEGF in EAC-bearing mice. EAC: Ehrlich's ascites carcinoma. VEGF: vascular endothelial growth factor. Values are expressed as the mean ± S.E.M. and analyzed using one-way ANOVA followed by Bonferroni's <i>post-hoc</i> test at <i>P</i><0.05. ^oSignificantly different from the normal group. *Significantly different from EAC-control. ^ΔSignificantly different from sorafenib monotherapy. •Significantly different from olmesartan (3 mg/kg) group.^€Significantly different from olmesartan (10 mg/kg) group.^$Significantly different from olmesartan (30 mg/kg) group.^◊Significantly different from the combination of olmesartan and angiotensin (1–7) agonist.</p

Immunostaining and optical density of IGF receptor type -I.

<p><b>A</b>) Immunostaining for IGF receptor type-I in the experimental groups. <b>B</b>) Effect of sorafenib (30 mg/kg), olmesartan (3, 10 or 30 mg/kg) and their combination on the optical density of IGF receptor type-I immunostaining. <b>C</b>) Effect of concurrent administration of angiotensin (1–7) agonist (30 µg/kg/day, i.p.) or angiotensin (1–7) antagonist (3.3 mg/kg/trice a week, i.p.) and olmesartan on the intratumoral level of IGF receptors type-I. Photomicrographs are captured at 200× magnification. EAC: Ehrlich's ascites carcinoma. Values are expressed as the mean ± S.E.M. and analyzed using one-way ANOVA followed by Bonferroni's <i>post-hoc</i> test at <i>P</i><0.05. * Significantly different from EAC-control. ^ΔSignificantly different from sorafenib monotherapy.•Significantly different from olmesartan (3 mg/kg) group. ^€Significantly different from olmesartan (10 mg/kg) group.^$Significantly different from the olmesartan (30 mg/kg) group.^◊Significantly different from the combination of olmesartan and angiotensin (1–7) agonist.</p

Effect of sorafenib and olmesartan on the serum level of IGF-I in EAC- bearing mice.

<p><b>A</b>) Effect of sorafenib (30 mg/kg), olmesartan (3, 10 or 30 mg/kg) and their combination on the serum level of IGF-I in EAC-bearing mice. <b>B</b>) Effect of concurrent administration of an angiotensin (1–7) agonist (30 µg/kg/day, i.p.) or an angiotensin (1–7) antagonist (3.3 mg/kg/trice/week, i.p.) and olmesartan on serum level of IGF-I in EAC-bearing mice. EAC: Ehrlich's ascites carcinoma. IGF-1: insulin growth factor-1. Values are expressed as the mean ± S.E.M. and data were analyzed using one-way ANOVA followed by Bonferroni's <i>post-hoc</i> test at P<0.05. ^oSignificantly different from the normal group. *Significantly different from EAC-control. ^ΔSignificantly different from sorafenib monotherapy. •Significantly different from olmesartan (3 mg/kg) group. ^€Significantly different from olmesartan (10 mg/kg) group.^$Significantly different from olmesartan (30 mg/kg) group.^◊Significantly different from the combination of olmesartan and angiotensin (1–7) agonist.</p

Immunostaining and optical density of CD₃₁ expression.

<p><b>A</b>) Immunostaining for CD₃₁ in the experimental groups. <b>B</b>) Effect of sorafenib (30 mg/kg), olmesartan (3, 10 or 30 mg/kg) and their combination on the optical density of CD₃₁ immunostaining. <b>C</b>) Effect of concurrent administration of angiotensin (1–7) agonist (30 µg/kg/day, i.p.) or angiotensin (1–7) antagonist (3.3 mg/kg/trice/week, i.p.) and olmesartan on CD₃₁ expression. Photomicrographs are captured at 200× magnification. EAC: Ehrlich's ascites carcinoma. Values are expressed as the mean ± S.E.M. and were analyzed using one-way ANOVA followed by Bonferroni's <i>post-hoc</i> test at <i>P</i><0.05. *Significantly different from EAC-control. ^ΔSignificantly different from sorafenib monotherapy. •Significantly different from olmesartan (3 mg/kg) group. ^€Significantly different from olmesartan (10 mg/kg) group.^$Significantly different from olmesartan (30 mg/kg) group.^◊Significantly different from the combination of olmesartan and angiotensin (1–7) agonist.</p

Effect of sorafenib and olmesartan on tumor weight in EAC- bearing mice.

<p><b>A</b>) Effect of sorafenib (30 mg/kg), olmesartan (3, 10 or 30 mg/kg) and their combination on tumor weight in EAC-bearing mice. <b>B</b>) Effect of concurrent administration of an angiotensin (1–7) agonist (30 µg/kg/day, i.p.) or an angiotensin (1–7) antagonist (3.3 mg/kg/trice/week, i.p.) and olmesartan on the tumor weight of EAC-bearing mice. EAC: Ehrlich's ascites carcinoma. Values are expressed as the mean ± S.E.M. anddata were analyzed using one-way ANOVA followed by Bonferroni's <i>post-hoc</i> test at<i>P</i><0.05. *Significantly different from the EAC-control. ^ΔSignificantly different from sorafenib monotherapy. •Significantly different from olmesartan (3 mg/kg) group. ^€Significantly different from olmesartan (10 mg/kg) group.^$Significantly different from olmesartan (30 mg/kg) group.^◊Significantly different from the combination of olmesartan and angiotensin (1–7) agonist.</p