Search results for: Abdelmoumen Guedri

Authors: Samira Tlili, Amina Grairia, Sihem Benayache, Saida Bouyegh, Sabrina Ladjama, Abdelmoumen Guedri

Abstract:

Phosphorites from Djebel Onk Tebessa/Algeria deposit contain a CaO of 50-52 wt. % and P₂O₅ level of ≥ 30.20 wt. %. The microstructure revealed using a spectroscopy electronic microscope (SEM) consists of phosphate granules with an ovular form. In this investigation, we have identified phosphate with varying particle sizes using mineralogical methods. The phosphogypsum formed by the mineralization of natural phosphate has also been discovered. This co-product was formed during the attack on natural phosphates by sulfuric acid. This study demonstrated the effectiveness of the thermoanalytical technique of differential scanning calorimetry (DSC), X-ray diffraction, and EDS/MEB analysis. FTIR analyses also validated the identification of mineral phases with the observation of bands from structural phosphate groups.

Keywords: phosphate, Djebel Onk deposit, mineralogy, valorization, phosphogypsum

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Authors: Nadine khadraoui, Rym Essid, Olfa Tabbene, Imen Chniba, Safa Boujemaa, Selim Jallouli, Nadia Fares, Behija Mlik, Boutheina Ben Abdelmoumen Mardassi

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Background and aim: Mycoplasma hominis is an opportunistic pathogen that can cause various gynecological infections such cervicitis, infertility, and, less frequently, extra-genital infections. Previous studies on the antimicrobial susceptibility of Mycoplasma hominis Tunisian strains have highlighted a significant resistance, even multi-resistance, to the most used antibiotic in the therapy of consequential infections. To address this concern, the present study aimed for the alternative of phytotherapy. Peganum harmala seed extract was tested as an antibacterial agent against multidrug-resistant M.hominis clinical strains. Material and Methods: Peganum harmala plant was collected from Ain Sebaa, Tabarka, North West region of Tunisia in April 2018, air-dried, grounded and extracted by different solvents.The crude methanolic extract was further partitioned with n-HEX, DCM, EtOAC and n-BuOl. Antibacterial activity was evaluated against M. hominis ATCC 23114 and 20 M. hominis clinical strains.The antimycoplasmal activity was tested by the microdilution method, and MIC values were determined. Phytochemical analysis and hemolytic activity on human erythrocytes were also performed. The active fraction was then subjected to purification, and the chemical identification of the active compound was investigated. Results: Among the tested fractions, the n-BuOH extract was the most active fraction since it exhibited an inhibitory effect against M. hominis ATCC 23114 and 80% of the tested clinical strains with MIC between 125 and 1000 µg/ml. The phytochemical analysis of the n-BuOH revealed its metabolic abundance in polyphenols, flavonoids and condensed tannin with levels of 257.37 mg AGE/g, 172.27 mg EC/g and 58.27 mg EC/g, respectively. In addition, P. harmala n-BuOH extract exhibited potent bactericidal activity against all M. hominis isolates with CMB values ranging between 125 and 4000 µg/ml. Further, the active fraction exhibited weak cytotoxicity effect at active concentrations when tested on human erythrocytes. The active compound was identified by gas chromatography–mass spectrometry as an indole alkaloid harmaline. Conclusion: In summary, Peganum harmala extract demonstrated an interesting anti-mycoplasmal activity against M. hominis Tunisian strains. Therefore, it could be considered as a potential candidate for the treatment of consequential infections. However, further studies are necessary to evaluate its mechanism of action in mycoplasmas.

Keywords: mycoplasma hominis, peganum harmala, antibioresistance, phytotherapy, phytochemical analysis

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Authors: Boutheina Ben Abdelmoumen Mardassi, Salim Chibani, Safa Boujemaa, Amaury Vaysse, Julien Guglielmini, Elhem Yacoub

Abstract:

Background and aim: Mycoplasma hominis (MH) is a pathogenic bacterium belonging to the Mollicutes class. It causes a wide range of gynecological infections and infertility among adults. Recently, we have explored for the first time the phylodistribution of Tunisian M. hominis clinical strains using an expanded MLST. We have demonstrated their distinction into two pure lineages, which each corresponding to a specific pathotype: genital infections and infertility. The aim of this project is to gain further insight into the evolutionary dynamics and the specific genetic factors that distinguish MH pathotypes Methods: Whole genome sequencing of Mycoplasma hominis clinical strains was performed using illumina Miseq. Denovo assembly was performed using a publicly available in-house pipeline. We used prokka to annotate the genomes, panaroo to generate the gene presence matrix and Jolytree to establish the phylogenetic tree. We used treeWAS to identify genetic loci associated with the pathothype of interest from the presence matrix and phylogenetic tree. Results: Our results revealed a clear categorization of the 62 MH clinical strains into two distinct genetic lineages, with each corresponding to a specific pathotype.; gynecological infections and infertility[AV1] . Genome annotation showed that GC content is ranging between 26 and 27%, which is a known characteristic of Mycoplasma genome. Housekeeping genes belonging to the core genome are highly conserved among our strains. TreeWas identified 4 virulence genes associated with the pathotype gynecological infection. encoding for asparagine--tRNA ligase, restriction endonuclease subunit S, Eco47II restriction endonuclease, and transcription regulator XRE (involved in tolerance to oxidative stress). Five genes have been identified that have a statistical association with infertility, tow lipoprotein, one hypothetical protein, a glycosyl transferase involved in capsule synthesis, and pyruvate kinase involved in biofilm formation. All strains harbored an efflux pomp that belongs to the family of multidrug resistance ABC transporter, which confers resistance to a wide range of antibiotics. Indeed many adhesion factors and lipoproteins (p120, p120', p60, p80, Vaa) have been checked and confirmed in our strains with a relatively 99 % to 96 % conserved domain and hypervariable domain that represent 1 to 4 % of the reference sequence extracted from gene bank. Conclusion: In summary, this study led to the identification of specific genetic loci associated with distinct pathotypes in M hominis.

Keywords: mycoplasma hominis, infertility, gynecological infections, virulence genes, antibiotic resistance

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