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Ten monoclonal microalgal cultures were obtained from several Tunisian inland water bodies, and their dichloromethane and methanolic extracts were screened for antibacterial, antileishmanial, and antioxidant properties, as well as phycobiliprotein production capacity. Cylindrospermopsis raciborskii has been shown to synthesize high levels of phycocyanin and may be an effective alternative source to other sources used for commercial production of phycocyanin. Chroococcus sp. and Leptolyngbya sp1. exhibited the strongest radical scavenging activity against DPPH (IC50 = 212.15 and 263.91 μg ml−1, respectively), indicating their promising potential for use as new effective and non-toxic antioxidants. Furthermore, Dunaliella sp. showed an interesting antileishmanial activity against the pathogens Leishmania infantum and Leishmania major (IC50 = 151 and 284 μg ml−1, respectively), thus representing a good candidate for use against cutaneous and visceral leishmaniasis in Tunisia, a country endemic to these diseases where thousands of new cases are registered every year. These results suggest that the strains of microalgae featured in this work have the potential to serve as natural alternative, safe and sustainable sources of high value-added products that could be used to improve the final biomass value.

AimsThis study aimed to determine the antibacterial and antileishmanial potential of Micromeria nervosa extracts. The identification of the antileishmanial compound and the study of its molecular mechanism of action have also been undertaken.Methods and resultsEthanol extract showed high polyphenol content and diethyl ether extract exhibited high DPPH scavenging and low beta-carotene bleaching activity (IC50 = 13.04 ± 0.99 and 200.18 ± 3.32 μg mL−1, respectively). However, diethyl ether extract displayed high antibacterial activity against Gram-positive strains including methicillin-resistant Staphylococcus aureus (MIC = 31.25 μg mL−1), Staph. aureus ATCC6538 (MIC = 62.5 μg mL−1), and Listeria monocytogenes ATCC 19115 (MIC = 125 μg mL−1), as well as high antileishmanial activity against the promastigote forms of L. infantum and L. major (IC50 = 11.45 and 14.53 μg mL−1, respectively). The active compound was purified using bioassay-guided fractionation and thin layer chromatography, and identified as ursolic acid using high-performance liquid chromatography coupled with a photodiode array and mass spectrometry. The purified compound was strongly inhibitory against the promastigote and amastigote forms of L. infantum and L. major (IC50 = 5.87 and 6.95 μg mL−1 versus 9.56 and 10. 68 μg mL−1, respectively) without overt cytotoxicity against Raw 264.7 macrophage cells (SI = 13.53 and 11.43, respectively). The commercial compound (ursolic acid) showed similar activity against amastigotes and promastigotes forms of L. infantum and L. major. Moreover, its molecular mode of action against leishmaniasis seems to involve the expression of the ODC and SPS genes involved in thiol pathway.ConclusionExtracts of M. nervosa can be considered as a potential alternative to antimicrobial and antileishmanial drugs.

Cyclic lipopeptides produced by Bacillus species exhibit interesting therapeutic potential. However, their clinical use remains limited due to their low stability, undesirable interactions with host macromolecules, and their potential toxicity to mammalian cells. The present work aims to develop suitable lipopeptide-loaded chitosan nanoparticles with improved biological properties and reduced toxicity. Surfactin and bacillomycin D lipopeptides produced by Bacillus amyloliquefaciens B84 strain were loaded onto chitosan nanoparticles by ionotropic gelation process. Nanoformulated lipopeptides exhibit an average size of 569 nm, a zeta potential range of 38.8 mV, and encapsulation efficiency (EE) of 85.58%. Treatment of Candida (C.) albicans cells with encapsulated lipopeptides induced anti-adhesive activity of 81.17% and decreased cell surface hydrophobicity (CSH) by 25.53% at 2000 µg/mL. Nanoformulated lipopeptides also induced antileishmanial activity against Leishmania (L.) major promastigote and amastigote forms at respective IC50 values of 14.37 µg/mL and 22.45 µg/mL. Nanoencapsulated lipopeptides exerted low cytotoxicity towards human erythrocytes and Raw 264.7 macrophage cell line with respective HC50 and LC50 values of 770 µg/mL and 234.56 µg/mL. Nanoencapsulated lipopeptides could be used as a potential delivery system of lipopeptides to improve their anti-adhesive effect against C. albicans cells colonizing medical devices and their anti-infectious activity against leishmania.

Leishmaniasis is a parasitic disease affecting millions of people in Africa, Asia, and South America. It is considered as a major public health problem causing morbidity and mortality worldwide. Actually, the luck of vaccines and effective and less expensive antileishmanial therapy, have oriented pharmacological researches on natural antileishmanial drugs from medicinal plants. Hence, the purpose of this work is to optimize extraction parameters such as the percentage of aqueous ethanol mixture, the temperature and the time through the ultrasound bath equipment using a Box–Behnken Design (BBD) for maximal antileishmanial activity extraction from Moringa oleifera leaves. The cytotoxicity of the optimum extract was evaluated on RAW 264.7 macrophage cell line. The synergism between M. oleifera optimal extract and amphotericin B was also investigated using checkboard method. The optimum extract exhibiting the highest percent inhibition of Leishmania major promastigotes (99.15 ± 0.34%) was obtained using 16%v/v ethanol, at 60 °C for 20 min. Interestingly, this extract showed the best IC50 value of 6.87 ± 0.32 and 9.31 ± 0.72 μg/mL against promastigote and amastigote forms, respectively with no cytotoxicity on macrophage cells Raw 264.7 (SI = 17.53). Moreover, this extract showed a synergistic effect with amphotericin B (FIC = 0.375). HPLC analysis showed that at least six phenolic compounds were identified. Resorcinol, luteolin7-O-glucoside and syringic acid were the most active ones against L. major with IC50 values 3.788 ± 0.48, 10.70 ± 0.59 and 13.41 ± 0.59 μg/mL, respectively. Rutin and ferulic acid were further identified and showed moderate antileishmanial activity with IC50 values 78.51 ± 1.09 and 89.34 ± 1.22 μg/mL, respectively. Kaempferol 3-O-rutinoside was less active with IC50 value 204.4 ± 1.63 μg/mL.

The inhibitory effects of essential oil (EO) on bacteria development give them an important role in the fields of the food industry as an additive in food packaging. This study was aimed to identify the effect of Lavandula stoechas EO at different concentrations on chicken fillets quality during refrigerated storage. Antimicrobial and antioxidant activities showed that EO extracted has an important antibacterial activity and antiradical potential. In chicken fillets, the lavender EO (100 and 200 ppm) reduced their oxidation and microbial proliferation during refrigerated storage and with no cytotoxicity effect towards murine macrophage cells. During the storage period, the values of pH, dry matter, acidity and cooking loss of treated fillets were lower than that of the control. The statistical analyses proved greatly significant variations of color between the control and the treated by LEO, during storage. The sensory analysis selected an improvement effect in the organoleptic quality of the chicken meat when it was supplemented by 100 ppm of LEO. The statistical analysis of the microbiological characteristics clearly discriminated the control and those treated with LEO (p

Biofilm formation of the opportunistic pathogen Pseudomonas (P). aeruginosa is one of the major global challenges to control nosocomial infections due to their high resistance to antimicrobials and host defense mechanisms. The present study aimed to assess the antibacterial and the antibiofilm activities of Peganum (P). harmala seed extract against multidrug-resistant P. aeruginosa isolates. Chemical identification of the active compound and determination of its molecular mechanism of action were also investigated. Results showed that P. harmala n-butanol "n-BuOH" extract exhibited antibacterial activity against multidrug-resistant P. aeruginosa isolates. This extract was even more active than conventional antibiotics cefazolin and vaamox when tested against three P. aeruginosa multidrug-resistant isolates. In addition, P. harmala n-BuOH extract exhibited potent bactericidal activity against PAO1 strain at MIC value corresponding to 500 µg/mL and attained 100% killing effect at 24 h of incubation. Furthermore, P. harmala n-BuOH extract showed an antibiofilm activity against P. aeruginosa PAO1 and exhibited 80.43% inhibition at sub-inhibitory concentration. The extract also eradicated 83.99% of the biofilm-forming bacteria. The active compound was identified by gas chromatography-mass spectrometry as an indole alkaloid harmaline. Transcriptomic analysis showed complete inhibition of the biofilm-related gene pilA when PAO1 cells were treated with harmaline. Our results revealed that P. harmala seed extract and its active compound harmaline could be considered as a candidate for a new treatment of multidrug-resistant P. aeruginosa pathogens-associated biofilm infections.

The aim of this study was to elaborate a suitable hydrogel to be used as drug carrier for antileishmanial treatment. Therefore, a PVP hydrogel was synthesized using gamma radiation technique. In the first step, PVP, agar and PEG concentrations were modified as a function of dose rate. Then, established polymers were characterized using FTIR, solid-state 13C NMR and TGA analyses. After that, rheological measurements followed to determine elastic and viscous modulus. Based on these techniques, it was found that synthesized PVP–hydrogels have the structure of a semi-interpenetrated network (SIPN). The sample containing 3% of PEG was selected to test its potential as antileishmanial drug carrier because it had the elastic modulus that fits more the application as wound dressing. As antileishmanial drug carrier, it has been shown that in the presence of hydrogel, the activity of conventional drug (Amphotericin B) on Leishmania promastigotes was markedly improved with an increase in selectivity index from 10.54 to 56.8.

Cupressus sempervirens L. is largely used in traditional medicine as an antimicrobial agent. The present study investigated the antioxidant, antibacterial and antileishmanial activities of C. sempervirens organic extracts at different phenological stages. Antioxidant activity was determined by DPPH (2,2-diphenyl-1-picrylhydrazylradical) scavenging assay, ferric reducing power and total antioxidant capacity. The antibacterial activity was evaluated against five clinical strains by disk diffusion method and minimum inhibitory concentration (MIC). The antileishmanial activity was determined against promastigote and amastigote forms of Leishmania (L.) infantum and L. major. Results of antioxidant activity showed that methanolic extract from vegetative stage had the most important activity. The ethyl acetate extract of C. sempervirens from flowering stage was the most active against Bacillus cereus (ATCC 14579) and Staphylococcus aureus (ATCC 25923) with MIC of 100 μg/mL and 50 μg/mL, respectively. Interestingly, this extract exhibited high antileishmanial activity against promastigote form of L. infantum and L. major (IC50 = 1.47 and 2.8 μg/mL, respectively) and amastigote form (IC50 = 3.61 and 5.42 μg/mL, respectively). Furthermore, ethyl acetate extract showed low cytotoxicity on macrophage cells Raw264.7 with selectivity index of 34.15 and 17.93 for L. infantum and L. major, respectively. The identification by HPLC and HPLC-MSn of active extracts of C. sempervirens revealed that major compounds of methanolic extract from vegetative stage and ethyl acetate extract from flowering stage were cupressuflavone and amentoflavone. Based on these results, C. sempervirens extracts could be used as an alternative to chemical drugs for the treatment of oxidative stress and infectious diseases.

A new heterogeneous acid catalyst based on a natural resource, Tunisian clay (Clay-H0.5), has been prepared and characterized by FT-IR, FE-SEM, and powder X-ray diffraction (XRD), as well as chemical composition, cation exchange capacity, specific surface area, and pore volume. Acid treatment for 0.5 h enlarged the surface area from 78.24 to 186.10 m$^{2}$/g and pore volume (PV) from 0.186 to 0.281 cm$^{3}$/g. The catalytic activity of this material was investigated in ketalization reaction under mild solvent-free conditions. This achieved up to 92% isolated yield for only 10 wt.% of the catalyst. This environmentally friendly method has advantages such as simple work-up procedure, avoidance of organic solvents, and good performance in ketalization reactions. Importantly, the Clay-H0.5 catalyst showed good recyclability where insignificant activity loss was exhibited even after six runs. Synthesized cyclic ketals were tested for their possible antileishmanial and antibacterial activities as well as antifungal activity. Biological screening showed that compound 11 had important antileishmanial activity against both L. major and L. infantum, while compound 14 also had significant antibacterial activity against four gram-positive and two gram-negative bacteria, and antifungal activity against Candida albicans, with minimal inhibitory concentration values ranging from 15.62 μg/mL to 125 μg/mL.

The aim of this study was to investigate antimicrobial and antioxidant activities of different fractions obtained from edible Tunisian Ziziphus Lotus leaves of Tozeur region. Different organic extracts were tested: cyclohexane, dichloromethane, ethyl acetate, n-butanol and water. Bio-guided fractionation revealed that dichloromethane fraction is the most active against S. aureus and Methicillin-resistant S. aureus strains. Moreover, this fraction showed the highest antileishmanial activity with IC

A strain B84 producing surfactin and bacillomycin D lipopeptides was identified as Bacillus amyloliquefaciens. B84 lipopeptides were extracted by acid precipitation, identified by mass spectrometry and loaded onto chitosan nanoparticles by ionotropic gelation process. The lipopeptide / chitosan nanoparticles have an average size of 569 nm, a zeta potential range of 38.8 mV and encapsulation efficiency (EE) of 85.58 %. The treatment of C. albicans cells with encapsulated lipopeptides showed an anti-adhesive activity of 81.17 % and a decreased effect of cell surface hydrophobicity « CSH » by 25.53%. An anti-leishmanial activity was also recorded with IC50 of 14.37 µg ml-1 and 22.45 µg mL-1 against L. major promastigote and amastigote forms, respectively. Cytotoxicity studies on human cells showed low cytotoxicity effect with HC50 value of 770 µg mL-1 towards human red blood cells and LC50 value of 234.56 µg mL-1 towards macrophage Raw 264.7 cell line. These lipopeptide / chitosan nanoparticles could be used as a potential delivery system of lipopeptides to improve both their anti-adhesive effect against C. albicans cells colonizing medical devices and their anti-infectious activity against leishmania.

Cryptosporidium is an enteric parasite infecting a wide range of hosts. It has emerged as an important cause of chronic life-threatening diarrhea in humans worldwide. Several subtypes of Cryptosporidium sp. have been described to be responsible for several large outbreaks related to water contamination in developed countries. However, there is a lack of information in the genetic diversity of Cryptosporidium among human population especially in developing countries. The present study aimed to update and report the genetic diversity of human Cryptosporidium spp. at the subtype level in an urban area of Tunisia using the 18S rRNA and gp60 gene. Genotyping of 42 Cryptosporidium positive isolates from different human populations at the 18S rRNA locus has identified three Cryptosporidium species: C. hominis (n = 20), C. parvum (n = 19), C. meleagridis (n = 2) and a co-infection C. hominis/C. meleagridis (n = 1). The sub-genotyping of these isolates at the 60-kda glycoprotein (gp60) locus was possible in 40 cases. It showed the presence of three subtype families (IIa, IIb and IIc) within C. parvum, a single subtype family within C. hominis and C. meleagridis isolates (Ia and IIIb respectively). Several subtypes were implicated in different human populations with the dominance of IaA26G1R1, IIaA15G2R1, IIdA16G1R1, IIdA22G2R1 and IIIbA26G1R1 variant respectively for C. hominis, C. parvum and C. meleagridis. The distribution of Cryptosporidium isolates in urban area of Northern Tunisia was dominated by the anthroponotic transmission via C. hominis species and the IIc subtype of C. parvum. However, zoonotic transmission is still possible in this region via zoonotic subtypes of C. parvum (IIa and IId) and C. meleagridis (IIIb). Subtype diversity was higher in this area.

Background Cryptosporidiosis represents a major public health problem. This infection, caused by a protozoan parasite of the genus Cryptosporidium, has been reported worldwide as a frequent cause of diarrhoea. In the immunocompetent host, the typical watery diarrhea can be self-limiting. However, it is severe and chronic, in the immunocompromised host and may cause death. Cryptosporidium spp. are coccidians, which complete their life cycle in both humans and animals. The two species C. hominis and C. parvum are the major cause of human infection. Compared to studies on C. hominis and C. parvum, only a few studies have developed methods to identify C. meleagridis. Aim To develop a new real time PCR-coupled High resolution melting assay allowing the detection for C. meleagridis, in addition of the other dominant species (C. hominis and C. parvum). Methods The polymorphic sequence on the dihydrofolate reductase gene (DHFR) of three species was sequenced to design primers pair and establish a sensitive real-time PCR coupled to a high-resolution melting-curve (HRM) analysis method, allowing the detection of Cryptosporidium sp. and discrimination between three prevalent species in Tunisia. We analyzed a collection of 42 archived human isolates of the three studied species. Results Real-time PCR coupled to HRM assay allowed detection of Cryptosporidium, using the new designed primers, and basing on melting profile, we can distinguish C. meleagridis species in addition to C. parvum and C. hominis. Conclusion We developed a qPCR-HRM assay that allows Cryptosporidium genotyping. This method is sensitive and able to distinguish three Cryptosporidium species.

International audience; Cryptosporidium spp. are a major cause of gastrointestinal diseases in humans worldwide. While a single subtype of Cryptosporidium hominis has been shown to be responsible for several large outbreaks related to water contamination in developed countries, little is known about the epidemiology of C. hominis in developing countries. This study reports the first genetic characterization of C. hominis at the subtype level in several human populations in Tunisia using the gp60 gene. Eighteen isolates were identified as C. hominis by a restriction fragment length polymorphism (RFLP) analysis. The prevalence of this species in different human populations ranges from 1.53% to 13.04% with a high prevalence being reported in immunocompromised children (13.04%) followed by patients with malignent myeloma (5.5%) and HIV-infected patients (4.59%). The gp60 analysis on C. hominis isolates, performed in 14 cases, showed the presence of a single subtype family: "Ia". Different subtypes were identified within this family (A11G1R1, A12R3, A23G1R1, A26G1R1, A27G1R1, A28G1R1). The IaA26G1R1 subtype was the most dominant subtype described in this area (50%). Despite the high genetic diversity of Cryptosporidium spp, a low heterogeneity at the subtype level was observed within C. hominis circulating in Tunisia. This distribution is an indicator for intensive and stable anthroponotic cryptosporidiosis in this region. Besides, the presence of a unique genotype in 5 HIV-infected patients attending the same hospital ward suggests the possible occurrence of hospital-acquired infection and underlines the need to implement preventive measures to avoid nosocomial transmission.

Objective To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents. Methods Phytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin–Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests. Results Preliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxidant, antimicrobial and had a moderate antileishmanial activity. Conclusions These observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

In the present study the phytochemical composition and biological activities of the aerial part extracts of Asteriscus graveolens against pathogenic bacteria and leishmania parasite were evaluated. Phytochemical analysis revealed the presence of polyphenols, flavonoids and tannins. The ethyl acetate fraction exhibited high antioxidant potential of 359.72 ± 32.03 μg and 326.76 ± 15.86 μg of ascorbic acid equivalents and 13.32 ± 0.19 μg/mL by PM, FRAP and DPPH assays respectively. This fraction also displayed a moderate antibacterial activity against Listeria monocytogenes ATCC 19115 (MIC = 0.312 mg/mL) and strong antileishmanial activity against both promastigote and amastigote forms with IC50 ranging from 22.93 ± 0.39 μg/mL to 35.23 ± 0.62 μg/mL. Furthermore the ethyl acetate fraction exhibited low cytotoxicity and good selectivity index towards the macrophage cell line Raw 264.7. HPLC analysis of the active fraction revealed the presence of hydroxycinnamic acid as major compound (30.56%). Asteriscus graveolens is a promising source of bioactive compounds that could be potentially used in cosmetic and pharmaceutical industry.

International audience; An endophytic Bacillus amyloliquefaciens strain called C5, able to produce biosurfactant lipopeptides with a broad antibacterial activity spectrum, has been isolated from the roots of olive tree. Optimization of antibacterial activity was undertaken using grape seed flour (GSF) substrate at 0.02, 0.2, and 2% (w/v) in M9 medium. Strain C5 exhibited optimal growth and antimicrobial activity (MIC value of 60 μg/ml) when incubated in the presence of 0.2% GSF while lipopeptide production culminated at 2% GSF. Thin layer chromatography analysis of lipopeptide extract revealed the presence of at least three active spots at Rf 0.35, 0.59, and 0.72 at 0.2% GSF. Data were similar to those obtained in LB-rich medium. MALDI-TOF/MS analysis of lipopeptide extract obtained from 0.2% GSF substrate revealed the presence of surfactin and bacillomycin D. These results show that GSF could be used as a low-cost culture medium supplement for optimizing the production of biosurfactants by strain C5.

Introduction Despite the significant developments occurring in the treatment of cancer, multiple myeloma remains the second haematological deadly disease. The aim of this study was to investigate the antiproliferative and apoptotic activities of Olea europaea L. cv Chetoui leaf and stem extracts (OLE and OSE) on human myeloma cells, given that plant compounds provide antitumor drugs. Methods Anti-cancer activity was tested on U266 human multiple myeloma cell line using MTT and trypan blue assays. Cell cycle analysis, cell death mechanism, mitochondrial membrane potential levels and caspases activities were assessed in U266 cells using flow cytometry. The nuclear morphology of U266 cells was observed using Hoechst 33342 using fluorescent microscopy. Results Our data revealed that treatment with OLE and OSE induced anti-proliferative effects on U266 myeloma cells in dose and time dependent manner. The IC50 of OLE and OSE were 55 and 35 μg/mL, respectively after 48 h of exposure. Interestingly, cell cycle analysis showed significant decrease of U266 cells in G1 phase related to significant increase in sub-G1 population after 24 h of extract treatment. Moreover, OLE and OSE significantly induced apoptosis in U266 cell line after 24 h of treatment by inducing mitochondria dysfunctions and caspase 3/7 expression. Conclusion To our knowledge this is the first paper to be conducted on olive stem extract. Our study showed that OLE and OSE had potent anti-multiple myeloma properties. This work may form the basis for further investigation on olive extracts as potential therapeutic agent on multiple myeloma.

Four hundred and fifty bacteria were evaluated for antagonistic activity against bacterial soft rot of potato caused by Pectobacterium carotovorum sp strain II16. A strain Ar10 exhibiting potent antagonist activity has been identified as Bacillus amyloliquefaciens on the basis of biochemical and molecular characterization. Cell free supernatant showed a broad spectrum of antibacterial activity against human and phytopathogenic bacteria in the range of 10-60 AU/mL. Incubation of P. carotovorum cells with increasing concentrations of the antibacterial compound showed a killing rate of 94.8 and 96% at MIC and 2xMIC respectively. In addition, the antibacterial agent did not exert haemolytic activity at the active concentration and has been preliminary characterized by TLC and GC–MS as a glycolipid compound. Treatment of potato tubers with strain Ar10 for 72 h significantly reduced the severity of disease symptoms (100 and 85.05% reduction of necrosis deep / area and weight loss respectively). The same levels in disease symptoms severity was also recorded following treatment of potato tubers with cell free supernatant for 1 h. Data suggest that protection against potato soft rot disease may be related to glycolipid production by strain Ar10. The present study affords new alternatives for anti-Pectobacterium carotovorum bioactive compounds against the soft rot disease of potato.

The use of synthetic food additive and the appearance of antibiotic resistance are at the basis of important human health problems. The substitution of synthetic compounds with new natural substances extracted from plants or microorganisms is therefore the ideal solution to this scourge. The objective of this work was to evaluate the phyto-constituents (polyphenols, flavonoids and condensed tannins), and to test the biological activities (antioxidant, antibacterial and antiviral) of the Ajuga iva (L) aerial part extracts. The antioxidant activity assayed by DPPH method showed an IC50 of 0.43 ± 0.03 mg/mL. Antibacterial activity of aqueous and hydro methalonic extracts was tested against seven pathogenic bacteria (Staphylococcus aureus, Methicillin Resistant Staphylococcus aureus (MRS), Listeria monocytogenes, Pseudomonas aeruginosa, Bacillus cereus, Escherichia coli and Salmonella enteritidis) using the diffusion method. A Thin Layer Chromatography-bioautotography-guided was performed, and the isolated antibacterial fraction was identified by CG-MS analysis. Antiviral effect of methanolic extract performed on 4 viruses: Coxsackie Virus type B-3 (CVB-3), Adenovirus type 5 (ADV-5), Respiratory Syncytial Virus type B (RSV-B) and Herpes Simplex Virus type 2 (HSV-2) showed an activity against Coxsackie Virus. As a result of this study, the aerial parts of Ajuga iva (L) extract could be used in the food, cosmetic, medical and health sectors.

International audience; The current study investigated the putative antileishmanial and cytotoxic activity of twelve essential oils (EOs) and their major components on Leishmania (L.) major and Leishmania infantum promastigotes. Data showed that three EOs isolated from Ferula communis, Teucrium polium and Pelargonium graveolens displayed potent leishmaniacidal activity against L. major and L. infantum promastigotes (IC50 < 1 mu g/mL) with low toxicity against Raw 264.7 macrophage cell line used as control. The best selectivity index was obtained for F. communis EO. Three major compounds namely beta-caryophyllene, geraniol and carvacrol exhibited high leishmaniacidal activity with no evident cytotoxicity. Our study suggests that antileishmanial activity was not solely due to the major compounds from EOs but also to other components of the EOs. These findings could be a starting point for the development of new antileishmanial drugs from natural sources that combine various EOs containing bioactive compounds. (C) 2015 Elsevier B.V. All rights reserved.

The present study aimed to investigate the anti-Candida activity of ten essential oils (EOs) and to evaluate their potential synergism with conventional drugs. The effect on secreted aspartic protease (SAP) activity and the mechanism of action were also explored. The antifungal properties of essential oils were investigated using standard micro-broth dilution assay. Only Cinnamomum verum, Thymus capitatus, Syzygium aromaticum, and Pelargonium graveolens exhibited a broad spectrum of activity against a variety of pathogenic Candida strains. Chemical composition of active essential oils was performed by gas chromatography-mass spectrometry (GC-MS). Synergistic effect was observed with the combinations C. verum/fluconazole and P. graveolens/fluconazole, with FIC value 0.37. Investigation of the mechanism of action revealed that C. verum EO reduced the quantity of ergosterol to 83%. A total inhibition was observed for the combination C. verum/fluconazole. However, P. graveolens EO may disturb the permeability barrier of the fungal cell wall. An increase of MIC values of P. graveolens EO and the combination with fluconazole was observed with osmoprotectants (sorbitol and PEG6000). Furthermore, the combination with fluconazole may affect ergosterol biosynthesis and disturb fatty acid homeostasis in C. albicans cells as the quantity of ergosterol and oleic acid was reduced to 52.33 and 72%, respectively. The combination of P. graveolens and C. verum EOs with fluconazole inhibited 78.31 and 64.72% SAP activity, respectively. To our knowledge, this is the first report underlying the mechanism of action and the inhibitory effect of SAP activity of essential oils in synergy with fluconazole. Naturally occurring phytochemicals C. verum and P. graveolens could be effective candidate to enhance the efficacy of fluconazole-based therapy of C. albicans infections.

Biofilm formation by the pathogenic strain Candida albicans (C. albicans) is a crucial virulence factor on biotic and abiotic surfaces especially in medical devices. The present study investigated the effects of Cinnamomum verum and Thymus capitatus essential oils (EOs) and their combination with antifungal drugs on the development of biofilm and mature biofilm. The molecular mechanism of action was also investigated. Results showed that C. verum and T. capitatus EOs were broadly effective against C. albicans biofilm formation exhibiting 85.57% and 80.6% inhibition at half MIC values, respectively. Furthermore, they showed 92.79 and 94.46% eradication of C. albicans mature biofilm at 2xMIC values. Moreover, these EOs were able to reduce the production of secreted aspartic proteases by >90% at 0.75xMIC. The antibiofilm potency was improved when EOs were combined with AMB, effectively eradicating C. albicans mature biofilm on central venous catheter (CVC). Transcriptomic analyses indicated that EOs, especially when combined with AMB, down-regulate Ras-cAMP-Efg and MAPK signaling genes. In addition, EOs and their combination with AMB significantly inhibited the expression of adhesion and secreted aspartyl proteinase virulence factor genes. Our results demonstrated that C. verum and T. capitatus EOs and their combination with AMB could provide an effective treatment against C. albicans biofilm on medical devices.

In Tunisia, detection of Plasmodium in asymptomatic individuals from endemic countries is a critical measure in national program of malaria eradication. The screening is based on microscopic examination of thick and thin blood smears. However, the performance of this diagnosis is closely related to the experience of biologist and the parasitaemia.The objective of this study was to evaluate the contribution of the PCR in the screening of malaria.This prospective study involved 260 students from malaria endemic areas who were screened for malaria between september 2011 and june 2013. Each subject had a blood sample which was examined for malaria by microscopy and nested multiplex PCR.PCR detected the presence of Plasmodium in 13 blood samples (5%). While microscopy was positive only in nine cases (3.5%). The discordances involved five negative samples at microscopy and which were positive in PCR and a negative sample in PCR which was positive at microscopy. A mixed infection with Plasmodium falciparum and Plasmodium malariae was identified by PCR. For this case, microscopy diagnosed only Plasmodium falciparum specie.PCR is more efficient than microscopy in detecting low parasitaemia ; particularly observed in asymptomatic subjects. This technique allows to reduce asymptomatic carriage of Plasmodium and reduce the risk of a resumption of transmission of malaria in our country.

Resume Introduction En Tunisie, les cryptosporidies sont frequemment identifiees dans les selles diarrheiques d’enfants et de sujets immunodeprimes. L’infection est generalement benigne chez les sujets immunocompetents, mais elle peut etre severe en cas d’immunodepression congenitale ou acquise. Si l’infection chez les sujets infectes par le virus de deficience humaine (VIH) a bien ete etudiee, on dispose de peu de donnees concernant la cryptosporidiose chez les enfants atteints de deficits immunitaires primitifs (DIP). Patients et methodes Nous avons collige retrospectivement 5 cas de cryptosporidioses diagnostiquees chez 11 enfants suivis pour DIP et adresses pour une recherche de cryptosporidies dans le cadre du bilan etiologique d’une diarrhee chronique evoluant par poussee. La preuve parasitologique a repose sur la mise en evidence des oocystes sur des frottis de selles colores avec la technique de Ziehl-Neelsen modifiee (ZNM) et de l’acide desoxyribonucleique (ADN) parasitaire par une reaction de polymerisation en chaine (PCR) nichee. L’analyse des profils de restriction a permis l’identification des especes de Cryptosporidium sp. Les donnees epidemiologiques et clinicobiologiques au moment du diagnostic de l’infection sont presentees. Resultats Les 5 enfants avaient un deficit immunitaire combine par defaut d’expression de proteines du complexe majeur d’histocompatibilite (CMH) de classe II. Un retard staturoponderal avait ete note dans tous les cas. La PCR etait positive dans tous les echantillons de selles alors que la coloration au ZNM ne l’etait que dans 3 cas. L’identification de l’espece avait revele la presence de Cryptosporidium hominis dans 2 cas, Cryptosporidium meleagridis dans un cas et Cryptosporidium parvum dans un autre cas. Une co-infection C. hominis/C. meleagridis avait ete observee dans le dernier cas. L’espece C. hominis etait presente chez des enfants d’origine rurale, ce qui suggere que l’infection avait pu etre contractee a l’hopital et donc etre de nature nosocomiale. L’un des enfants porteurs de C. hominis qui avait la charge parasitaire la plus importante avait developpe une cholangite sclerosante. Conclusion L’infection a Cryptosporidium sp. peut etre grave chez les enfants presentant un DIP, particulierement en cas de deficit immunitaire combine par defaut d’expression des proteines du CMH de classe II. Un depistage precoce et regulier du parasite, ameliore par la PCR, est preconise chez cette population a risque. La predominance de C. hominis, l’espece anthropophile, chez des patients d’origine rurale, incite a accentuer les mesures d’hygiene dans les institutions ou les DIP sont suivis.

We report the first case of an imported Plasmodium ovale relapse in a Tunisian man who developed malaria three years after leaving sub- Saharan Africa. A 29-year-old Tunisian man consulted in September 2011 because of a fever, myalgia, and headache that had begun eight days earlier and persisted despite treatment with oral antibiotics. On questioning, the patient stated that he had resided three years ago for six months in Ivory Coast, where he acquired malaria. He was treated with artemether-lumefantrine. The patient said he had no recent travel to any other malaria-endemic area and had not received a blood transfusion. A first microscopy of peripheral blood smears was negative for malaria parasites. The diagnosis was established 17 days after onset of symptoms. A repeat microscopic examination of blood smears confirmed the presence of Plasmodium ovale with a parasitemia lower than 0.1%. The patient was treated with artemether lumefantrine, followed by primaquine. This case emphasizes the possibility of relapse of some plasmodial species. It highlights the importance of repeating microscopic examination of blood when the diagnosis of malaria is suspected.

Microsporidiosis and cryptosporidiosis are emerging opportunistic infections responsible for intestinal manifestations that are often severe in immunocompromised patients. A case of microsporidiosis-cryptosporidiosis coinfection is reported in an HIV-infected newborn. The patient was a 17-day-old female, exclusively breastfed and with no contact with animals. Microsporidiosis and cryptosporidiosis were diagnosed after systematic screening in stool samples using both specific staining and PCR. Two species of microsporidia, Encephalitozoon intestinalis and Enterocytozoon bieneusi, and Cryptosporidium hominis were identified. The contamination of the newborn probably resulted from direct human-to-human transmission during close contact with the mother (who had diarrhea and refused stool sampling). This report highlights the usefulness of the screening of intestinal microsporidiosis and cryptosporidiosis in HIV-infected subjects for better management.

Several volatile organic compounds (VOCs) producing endophyte bacteria were isolated from the leaves of olive trees and tested for their antifungal activity against several pathogenic fungi. An antagonistic strain called P2 showed 97 % of homology with Pseudomonas sp. strains on the basis of its 16S rDNA sequence and biochemical properties. P2 strain drastically inhibited the growth of Rhizoctonia solani mycelia (86 %) at 5 day-post-confrontation (dpc) and strongly reduced fungi infection on potato slices at 10(7) bacteria ml(-1) for 3 and 7 dpc. P2 strain was also positive for protease activity as well as siderophore production. Light microscopy analysis showed that treatment of R. solani mycelia with P2 strain induced thickening of the cell-wall, vesiculation of protoplasm and blockage of fungal hyphae branching. VOCs analysis using GC-MS allowed the detection of two major products with m/z of 93.9910 and 125.9630 corresponding to dimethyl disulfide and dimethyl trisulfide respectively. VOCs-producing P2 strain could be a promising agent in the protection of tuber crops against fungal diseases.

International audience; Prevalence and species distribution of Cryptosporidium spp. were determined among 633 immunocompetent children less than five years of age and 75 patients hospitalized for immunodeficiency who lived in northern Tunisia. Microscopy was used for initial screening to detect positive samples and a nested polymerase chain reaction and restriction fragment length polymorphism analysis was used to determine the species. Cryptosporidium spp. was identified in 2.7% of cases (19 stool samples), and there was a significant difference between samples collected from immunocompromised patients and those collected from healthy children (10.7% versus 1.7%). Prevalence was also significantly higher in diarrheal specimens than in formed specimens (6.3% versus 1.6%). Cyptosporidium hominis and C. parvum were responsible for most Cryptosporidium spp. infections (78.9%). Cryptosporidium hominis was more prevalent in children from urban areas than in those from rural areas, and C parvum was found with similar prevalence rates in the two populations. Cryptosporidium meleagridis was identified in four children on farms.

Introduction et objectifs La cryptosporidiose constitue un probleme majeur au cours de l’infection par le VIH, en raison d’une morbi-mortalite elevee. L’objectif de ce travail est de determiner la prevalence du portage des cryptosporidies intestinales chez les patients infectes par le VIH et d’identifier les especes de cryptosporidies en cause. Materiels et methodes Il s’agit d’une etude prospective menee de 2005 a 2008 sur un echantillon de 110 patients infectes par le VIH, 55 femmes et 55 hommes, suivis au service des Maladies Infectieuses de l’hopital La Rabta. La recherche des cryptosporidies a ete effectuee par la coloration de Ziehl-Neelsen modifiee et par PCR. L’identification des especes a ete determinee par le profil de restriction (RFLP). Resultats L’âge moyen des patients etait de 37 ans. Le chiffre moyen des lymphocytes T4 etait de 314/mm 3 . Des cryptosporidies ont ete isolees chez 18 patients (16,4 %) âges en moyenne de 36 ans. Six d’entre eux etaient homosexuels. Le taux moyen des lymphocytes T4 etait de 167 cellule/mm 3 . La consommation de lait cru et la presence d’animaux dans l’entourage ont ete rapportees par plus des deux tiers des patients. Treize des sujets parasites etaient diarrheiques dont 9 presentaient des douleurs abdominales febriles. Cryptosporidium parvum a ete l’espece la plus frequemment isolee (9 cas) suivie par Cryptospordium hominis (6 cas) et Cryptosporidium meleagridis (2 cas). L’evolution a ete fatale chez 5 patients. Conclusion La prevalence de la cryptosporidiose est elevee chez les patient infectes par le VIH en Tunisie. Le renforcement des mesures preventives individuelles chez ces sujets fragilises est necessaire surtout que certaines des especes identifiees presentent un risque de contamination interhumaine en milieu hospitalier. Le pronostic de la maladie reste, en l’absence de therapeutique efficace, sombre dans les cas refractaires au traitement symptomatique et a la tritherapie.