DNA barcoding of Stearibia nigriceps (Meigen) and Piophila casei (Linnaeus) (Diptera: Piophilidae) from Algeria and the first African report of Stearibia nigriceps.

Stearibia (=Piophila) nigriceps (Meigen) occurs in the Palearctic Region from Europe and Far East Russia, and in the Nearctic, the Neotropical, and the Oriental regions. In this study, we report the first record of Stearibia nigriceps from Africa collected in Algeria. In addition, our results provide DNA sequences of Piophila casei (Linnaeus) and S. nigriceps that may serve as reference data for future identification. A region of the cytochrome c oxidase I (COI) gene marker of 473 bp was amplified and DNA was sequenced. Intra- and interspecific genetic distances were calculated. A phylogenetic tree was generated by the maximum likelihood (ML) method using 1000 bootstrap replicates based on the Tamura-Nei model. A total number of 9 adults of S. nigriceps were collected together with 72 adults of P. casei. The intraspecific variation of the species barcodes analysed in our study was < 3% and the interspecific nucleotide divergence of the same species was > 3%. The 473 bp COI region was sufficient to identify and distinguish unambiguously between the two species. P. casei and P. nigriceps individuals from Algeria clustered separately from each other. They were also separated from the individuals of the same species originating from other countries with a 100% high bootstrap value. There was no correlation between the clades and the geographic origins of the haplotypes. Our results contribute to update the knowledge of the distribution of Piophilidae family. They also contribute to the build-up of online DNA sequence databases.

Analgesic effect of Centaurium erythraea and molecular docking investigation of the major component swertiamarin.

Centaurium erythraea Rafn is employed in Algerian traditional medicine for treating pain. The analgesic activity of the ethanolic extract (EE) from the flowering aerial parts of this plant was examined, and molecular docking of the main bioactive compound was performed. The EE, characterised by the iridoid swertiamarin, was administered to Wistar albino rats in pain models. Peripheral analgesic activity was evaluated using the acetic acid-induced writhing test, and a hot plate test was performed for central antinociceptive activity evaluation. Treatment with EE significantly decreased rats' writhing induced by acetic acid suggesting peripheral analgesic activity. Furthermore, the elevation of mean basal reaction time in the hot plate method indicated central analgesic activity. Molecular docking studies showed good docking energy with acceptable binding interactions of swertiamarin with cyclooxygenase-2 protein. This supports the analgesic activity of C. erythraea EE, justifying the traditional use of the plant as an analgesic herbal remedy.

Impact of plastic wrapping on carcass decomposition and arthropod colonisation in northern Africa during spring.

The effect of plastic wrapping on decomposition rate and carrion fauna of rabbits (Oryctolagus cuniculus L.) was examined in spring in a semi-urban area in North Algeria. All decomposition stages were observed in all carcasses, with the same durations in the control but different durations in the wrapped carcasses. Decomposition of the carcasses in the plastic wrapping was significantly slower than that of the exposed ones. A total of 12,516 specimens, belonging to 36 families and 69 species, were morphologically identified. Thirteen species of forensic relevance were also identified at the molecular level using the cytochrome c oxidase I (COI) barcode region, and the sequences were submitted to online databases. Wrapping had a significant effect on species composition (χ2 = 569.269, df = 55, p < 0.001). Higher species richness, abundance, and diversity were found in the control group. No significant difference in species abundance was observed between the treatments. The plastic wrap did not influence the accessibility of carcasses to insects, nor did it delay the arrival of necrophagous flies. This study provides basic information on the decomposition and arthropod colonisation of wrapped remains and contributes to the literature on North African carrion fauna.

Molecular identification of the potentially forensically relevant cluster flies Pollenia rudis (Fabricius) and Pollenia vagabunda (Meigen) (Diptera: Polleniidae) - non-recorded species in Algeria.

Cluster flies are represented by the genus Pollenia Robineau-Desvoidy, 1830 of the family Polleniidae Brauer and Bergenstamm, 1889. Their larvae are known to be internal parasites or predators of earthworms. Herein, we report for the first time the occurrence of the cluster flies Pollenia rudis Fabricius, 1794 and Pollenia vagabunda (Meigen, 1826) (Diptera: Polleniidae) on carcasses in Algeria and identify them through DNA barcoding. A region of the mitochondrial cytochrome c oxidase I gene (COI) was amplified and sequenced. Genetic distances were determined. A phylogenetic tree was constructed with the maximum parsimony method using 10 000 bootstrap replicates. A total number of 157 adults of P. rudis were collected together with 325 adults of Pollenia vagabunda. The occurrence of Pollenia on animal carcasses does not seem to be correlated with a particular stage of decomposition. All the sequences were correctly identified using the BLASTn tool from the GenBank database and the BOLD identification engine. Intra- and interspecific sequence divergence values were less than 1% and greater than 3%, respectively. COI barcodes obtained from this study were robust enough to identify and distinguish unambiguously between P. rudis and P. vagabunda. In the tree-based analysis, the cluster flies were all assigned to their respective species separately from each other confirming the morphological identification. These results provide DNA barcodes that contribute to the growth of reference databases and allow fast and accurate identification.

Essential oil composition and antibacterial activity of Pteridium aquilinum (L.) Kuhn.

INTRODUCTION: The present work aims to study the chemical composition of Pteridium aquilinum (L.) Kuhn essential oil and its antibacterial activity against three important phytopathogenic Gram-negative bacteria: Erwinia amylovora, Pectobacterium carotovorum subsp. caroto-vorum, and Pseudomonas savastanoi pv. savastanoi. METHODS: The chemical composition of P. aquilinum L. essential oil produced by hydrodistillation was determined by gas chromatography-mass spectrometry. The antibacterial activity was tested using disk diffusion method and by determination of minimum inhibitory concentration values. The major components were linalool (10.29%), carvacrol (8.15%), benzaldehyde (5.95%), 2-undecanone (5.32%), and cuminaldehyde (4.57%). RESULTS: The essential oil tested revealed a powerful antibacterial effect against all tested strains, with inhibition zone diameters ranging from 32.0 ± 0.58 to 33.7 ± 0.88 mm. DISCUSSION: P. aquilinum EO contained 32.86% of oxygenated monoterpenes, which are known for their very powerful antimicrobial activities. The minimum inhibitory concentration values showed that P. aquilinum essential oil has very strong activity against E. amylovora (0.625 ul/ml), followed by P. carotovorum subsp. carotovorum (2.50 ul/ml) and P. savastanoi pv. savastanoi (5.00 ul/ml). The results obtained could contribute to the development of new potential agents for the control of bacterial diseases.