We examined a partial SSU-rDNA sequence from 20 Acanthamoeba isolates associated with keratitis infections. The phylogenetic tree inferred from this partial sequence allowed to assign isolates to genotypes. Among the 20 isolates examined, 16 were found to be of the T4 genotype, 2 were T3, 1 was a T5, and 1 was a T2, confirming the predominance of T4 in infections. However, the study highlighted other genotypes more rarely associated with infections, particularly the T2 genotype. Our study is the second one to detect that this genotype is associated with keratitis. Additionally, the phylogenetic analyses showed five main emerging clusters, T4/T3/T11, T2/T6, T10/T12/T14, T13/T16, and T7/T8/T9/T17, regularly obtained whichever method was used. A similar branching pattern was found when the full rDNA sequence was investigated.

1) Background: Viral respiratory infections cause life-threatening diseases in millions of people worldwide every year. Human coronavirus and several picornaviruses are responsible for worldwide epidemic outbreaks, thus representing a heavy burden to their hosts. In the absence of specific treatments for human viral infections, natural products offer an alternative in terms of innovative drug therapies. (2) Methods: We analyzed the antiviral properties of the leaves and stem bark of the mulberry tree (Morus spp.). We compared the antiviral activity of Morus spp. on enveloped and nonenveloped viral pathogens, such as human coronavirus (HCoV 229E) and different members of the Picornaviridae family-human poliovirus 1, human parechovirus 1 and 3, and human echovirus 11. The antiviral activity of 12 water and water-alcohol plant extracts of the leaves and stem bark of three different species of mulberry-Morus alba var. alba, Morus alba var. rosa, and Morus rubra-were evaluated. We also evaluated the antiviral activities of kuwanon G against HCoV-229E. (3) Results: Our results showed that several extracts reduced the viral titer and cytopathogenic effects (CPE). Leaves' water-alcohol extracts exhibited maximum antiviral activity on human coronavirus, while stem bark and leaves' water and water-alcohol extracts were the most effective on picornaviruses. (4) Conclusions: The analysis of the antiviral activities of Morus spp. offer promising applications in antiviral strategies.

Water extract of Acacia seyal bark is used traditionally by the population in Djibouti for its anti-infectious activity. The evaluation of in vitro antibacterial, antioxidant activities and cytotoxicity as well as chemical characterization of Acacia seyal bark water and methanolic extracts were presented. The water extract has a toxicity against the MRC-5 cells at 256 μg/mL while the methanolic extract has a weak toxicity at the same concentration. The methanolic extract has a strong antioxidant activity with half maximal inhibitory concentration (IC50) of 150 ± 2.2 μg/mL using 1-diphenyl-2-picrylhydrazyl (DPPH) and IC50 of 27 ± 1.3 μg/mL using 2,2′-azino-bis 3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical methods. For ferric reducing/antioxidant power (FRAP) assay, the result is 45.74 ± 5.96 μg Vitamin C Equivalent (VCE)/g of dry weight (DW). The precipitation of tannins from methanol crude extract decreases the MIC from 64 µg/mL to 32 µg/mL against Staphylococcus aureus and Corynebacterium urealyticum. However, the antioxidant activity is higher before tannins precipitation than after (IC50 = 150 µg/mL for methanolic crude extract and 250 µg/mL after tannins precipitation determined by DPPH method). By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, the results showed that the condensed tannins consist of two types of catechin and gallocatechin-based oligomers. The fractionation led to the identification of three pure compounds: two flavanols catechin and epicatechin; one triterpene as lupeol; and a mixture of three steroids and one fatty acid: campesterol, stigmasterol, clionasterol, and oleamide.