RESUMO
There are several well-studied examples of protective symbiosis between insect host and symbiotic actinobacteria, producing antimicrobial metabolites to inhibit host pathogens. These mutualistic relationships are best described for some wasps and leaf-cutting ants, while a huge variety of insect species still remain poorly explored. For the first time, we isolated actinobacteria from the harvester ant Messor structor and evaluated the isolates' potential as antimicrobial producers. All isolates could be divided into two morphotypes of single and mycelial cells. We found that the most common mycelial morphotype was observed among soldiers and least common among larvae in the studied laboratory colony. The representative of this morphotype was identified as Streptomyces globisporus subsp. globisporus 4-3 by a polyphasic approach. It was established using a E. coli JW5503 pDualRep2 system that crude broths of mycelial isolates inhibited protein synthesis in reporter strains, but it did not disrupt the in vitro synthesis of proteins in cell-free extracts. An active compound was extracted, purified and identified as albomycin δ2. The pronounced ability of albomycin to inhibit the growth of entomopathogens suggests that Streptomyces globisporus subsp. globisporus may be involved in defensive symbiosis with the Messor structor ant against infections.
RESUMO
INTRODUCTION: The objective of this study was to assess the impact of a single-pill combination (SPC) of perindopril/indapamide (PER/IND) at full doses (10/2.5 mg) on endothelial and cognitive function as a clinical intermediate marker of vascular improvement. METHODS: This open-label, uncontrolled, observational study enrolled 30 patients (20 females and 10 males) with grade II-III uncontrolled arterial hypertension (SBP/DBP ≥ 160/100 mmHg) and no evidence of cerebrovascular disease. All patients underwent assessment of macro- and microvascular endothelial function parameters at baseline and after 12 months of treatment with SPC PER/IND using photoplethysmography and video capillaroscopy. Cognitive function was assessed using the Montreal Cognitive Assessment scale (MoCA). RESULTS: All patients (mean age 60.06 ± 10.19 years) were at high risk for cardiovascular events: mean body mass index (BMI) 31.2 ± 3.9 kg/m2, 33% diagnosed with coronary artery disease angina class I, 30% with impaired glucose tolerance, and 7% with type 2 diabetes. Impaired endothelial function was observed at the both micro- and macrovascular levels. Endothelial function parameters improved after 12-month treatment with SPC PER/IND with an increase in occlusion index from 1.4 to 1.8 (P < 0.00005) and phase shift from 5.0 to 10.8 (P < 0.00001); all values achieved levels in the normal range. Resting capillary network density (CND) increased from 44.8 to 52 cap/mm2 (P < 0.00007), and CND after a venous occlusion test increased from 55 to 61 cap/mm2 (P < 0.006). Signs of cognitive impairment were present at baseline with a mean MoCA score of 23 (normal cognitive function score ≥ 26), but improved after 12-month treatment with a mean MoCA score of 27 (P< 0.0001). Treatment was well tolerated. CONCLUSION: SPC PER/IND at full doses for 12 months improves endothelial function, structural and functional parameters of the microcirculation, as well as cognitive function in patients with arterial hypertension at high cardiovascular risk. FUNDING: Les Laboratoires Servier.
