Bochra Kouidhi

University of Monastir | UTM · Department of Biology

In this study, Box-Behnken design combining seven factors with three levels were used to optimize the elimination of CI Reactive Red 66 in artificial seawater, by the combination of eco-friendly bio-sorbents and acclimated halotolerant microbial strain. Results showed that macro-algae and cuttlebone (2 %) were the best natural bio-sorbent. Addition...

Quorum sensing (QS) is a bacterial communication strategy controlling cells density, biofilm formation, virulence, sporulation, and survival. Since QS is considered a virulence factor in drug-resistant pathogenic bacteria, inhibition of QS can contribute to control the spread of these bacteria. We propose in this study to test in silico, 19 natural...

In the current study, a simple method for the synthesis of 3-methyl-2-propyl-2H-[1,2,4]triazolo[4,3b][1,2,4,6]thiatriazine-1,1-dioxide (2) was carried out. In the presence of pyridine, a reaction between amidine (1) and sulfuryl chloride occurs. FTIR spectroscopy, 1 H and 13 C NMR, mass spectra, and elemental analysis were utilized in order to veri...

Dyes are chemicals found in industrial water discharge, which may harm aquatic life and humans. In this study, halophilic bacteria was isolated from sea water in Jeddah, KSA, and then identified using 16SrDNA sequencing technique. Mathematical modeling has been achieved to predict the number of runs needed to reach the maximum of dye removal. Then...

Aflatoxin B1 (AFB1) is the most harmful mycotoxin. Aflatoxin occurrence in tea makes this beverage unsuitable for consumption and presented risks to human health. Therefore, researches in aflatoxin microbial degradation are necessary to overcome this problem. Kombucha beverage is associated with health promoting effects. Thus, novel strains (Lactic...

Commiphora gileadensis, locally known as becham, is a plant used in traditional Arabian medicine for treating headache, constipation, stomach, joint pain, and inflammatory disorders. Several studies have reported its antibacterial properties; however, no study has demonstrated its antiviral activity. This study aimed to evaluate the antiviral activ...

The persistence of pathogenic bacteria in the marine environment has been thoroughly investigated. The potential threat that these microorganisms pose to public health in recreational waters has always been a concern. In this study, the persistence and the response of Pseudomonas aeruginosa ATCC27853 to starvation and osmotic stress were studied af...

Almonds and peanuts are a rich source of proteins, vitamins and unsaturated fatty acids. However, they can be also contaminated by mycotoxigenic fungi; a reason that has enhanced to investigate efficient strategies of management of these fungal contaminations. Some Lactic acid bacteria have been proven capable of inhibiting growth and mycotoxin pro...

Mycotoxins are secondary metabolites produced by various toxigenic fungi belonging to the genera Aspergillus, Fusarium and Penicillium. They have mutagenic, teratogenic, carcinogenic, immunosuppressive and endocrine disrupting effects on both humans and animals. The ubiquitous occurrence and heat stability of these mycotoxins during food and feed p...

Synthesized Pyridin-2-yl hexanoate was screened for its antibacterial and antibiofilm activities using the broth microdilution method and XTT assay respectively. The obtained results revealed that synthesized molecule inhibited the growth of pathogenic bacteria (MICs value ranged from 80 to 640 μg ml-1). Moreover, it induced a strong antibiofilm ef...

Domoic acid (DA) is a neurotoxin that causes amnesic shellfish poisoning. It is produced by algae and accumulates in shellfish. Consumption of these contaminated shellfishes is suspected to produce exceptional health hazards for humans. Effect of DA on cancer cell lines remained unclear. Human endothelial cells EA.hy 927, Human leukaemia K562 cells...

Dental caries remains the most prevalent oral infectious disease worldwide. In this study the antibacterial and antibiofilm activities of five essential oils (EO's): eugenol (EUG), carvacrol (CAR), thymol (TYH), p-cymene (CYM) and γ-terpinene were tested (alone or in combinaison with tetracycline) against oral bacteria. In addition, their potential...

A strategy to reduce the deleterious effects of mycotoxins is to use dietary supplements that contain microorganisms that bind mycotoxins and decrease their gastrointestinal absorption. Novel strains were isolated from a Kefir culture and assessed for their mycotoxin adsorption and biotransformation ability. The most active strains were identified...

The Aims of the study was to evaluate the antibacterial susceptibility and the biofilm eradication of three natural compounds carvacrol (CAR), thymol (TH) and eugenol (EUG), alone or in combination with nalidixic acid (NA) against twelve Salmonella Typhimurium strains. The minimum inhibitory concentration (MIC) and the minimum biofilm eradication c...

Objectives: This study aims to investigate the antimicrobial and the anti-biofilm activities of Lactobacillus plantarum extract (LPE) against a panel of oral Staphylococcus aureus (n=9) and S. aureus ATCC 25923. The in vitro ability of LPE to modulate bacterial resistance to tetracycline, benzalchonium chloride (BC), and chlorhexidine (CHX) were t...

In this study the minimal inhibitory concentration)MICs(of tetracycline (Tet), erythromycin (Ery) and benzalkonium chloride (BC) in absence and in presence of a sub-MIC of juglone (Jug) were determined. In addition, the Ethidium bromide (EtBr) efflux assay was performed to assess the effect of Jug on EtBr cells accumulation. Our results showed a se...

In this study, three lactic acid bacteria (LAB), isolated from barley, traditional dried meat and fermented olive were characterized and tested for their anti-bacterial and anti-biofilm activities against oral bacteria. Our results revealed that the tested LAB were γ-hemolytic and were susceptible to four antibiotics. All the strains were resistant...

Three bacterial strains (TE1, TD3 and FB2) were isolated from date palm (degla), pistachio and barley. The presence of nitrate reductase (narG) and nitrite reductase (nirS and nirK) genes in the selected strains was detected by PCR technique. Molecular identification based on 16S rDNA sequencing method was applied to identify positive strains. In a...

The occurrence of several microbial species in the oral cavity of 4–12-year-old Tunisian children was investigated. Samples were taken from 158 children (81 caries actives and 77 caries free). Genomic DNA was extracted and analyzed for the presence of 17 microbial species using a polymerase chain reaction assay. All samples were positive for at lea...

Tunisian Juglans regia bark ethanol extract (JREE) was examined for antibacterial, antibiofilm, and antioxidant activity. Its anti-proliferative effect was evaluated on normal (MRC-5) and cancer (HT29 and HEp-2) cell lines. The data revealed that JREE inhibited the growth of pathogenic bacteria (MICs value ranged from 32 to 128 μg.mL-1) and induced...

Three Lactobacilli were isolated from traditional Tunisian fermented food and then characterized for its ability to inhibit Listeria monocytogenes growth. Antagonistic effect of Lactobacillus plantarum on four L. monocytogenes strains was tested in soft artisanal cheese. Anti-biofilm activity of Lactobacillus extracts was also tested. Our results d...

Staphylococcus aureus is an important pathogen associated to dental infection. Many antiseptic agents are used in hygienic handwash to prevent nosocomial infections by methicillin-resistant staphylococci. In this study, 22 Staphylococcus aureus strains isolated from the oral cavity of Tunisian children were investigated for their susceptibility to...

We investigate in this work the chemical composition by GC–EIMS, the antibacterial and the cytotoxic activities of Tunisian Nigella sativa essential oil and its bioactive compound, thymoquinone, were tested against various clinical cariogenic bacteria (n=30). Eighty-four compounds were identified in the essential oil. The major one was p-cymene (49...

ABSTRACT: Staphylococcus aureus and Coagulase-negative staphylococci (CoNS) are a major source of infections associated with indwelling medical devices. Many antiseptic agents are used in hygienic handwash to prevent nosocomial infections by Staphylococci. Our aim was to determine the antibiotic susceptibility and resistance to quaternary ammonium...

Candida is a major Human pathogen causing a variety of infections and can survive for extended period of time in aquatic environment including marine and fresh water. In this study we compared a colorimetric XTT assay to colony forming units (CFU) count to evaluate the survival potential of Candida albicans incubated in water microcosms. Our result...

Enterococci are increasingly associated with opportunistic infections in Humans but the role of the oral cavity as a reservoir for this species is unclear. This study aimed to explore the carriage rate of Enterococci in the oral cavity of Tunisian children and their antimicrobial susceptibility to a broad range of antibiotics together with their ad...

The presence of resistant bacteria in the oral cavity can be the major cause of dental antibiotic prophylaxis failure. Multidrug efflux has been described for many organisms, including bacteria and fungi as part of their drugs resistance strategy. The discovery of a new efflux pump inhibitor could extend the useful lifetime of some antibiotics. In...

Thymoquinone is an active principle of Nigella sativa seed known as "Habbah Al-Sauda" in Arabic countries and "Sinouj" in Tunisia. Bacterial biofilms tend to exhibit significant tolerance to antimicrobials drugs during infections. The antibacterial activity of Thymoquinone (TQ) and its biofilm inhibition potencies were investigated on 11 human path...

The occurrence of dental caries is mainly associated with oral pathogens, especially cariogenic bacteria. Numerous studies have validated the traditional use of medicinal plants by investigating the biological activity of essential oils. The Eugenia caryophyllata (clove) essential oil was tested in vitro against a large number of oral pathogens (11...

The emergence of resistance makes therapy in infectious diseases more difficult. The origin of the mounted resistance is probably multifactorial. The genetic and biochemical mechanisms responsible for yeast resistance to antifungal drugs used to better understand the epidemiology of the spread and selection of resistance strains. The accumulation o...

Propolis is a multifunctional substance used by bees to maintain the safety of their hives. It is worldwide used for its potential therapeutic effects. In this study, Tunisian propolis ethanol extract (EEP) was tested for their anti-cariogenic, anti-biofilms and antiproliferative effects of many cell lines. The Tunisian EEP was evaluated in vitro a...

This study aims to investigate the antibiotic susceptibility of strains isolated from the oral cavity of Tunisian children. Strains were isolated from the oral cavity of Tunisian children (60 caries-actives and 30 caries-free). Molecular characterization was assessed by PCR assay to detect erythromycin methylase gene (ermB), macrolide efflux (mefI)...

Biofilm formation is the leading cause of the pathogenesis of S. aureus associated with biomaterial infections. In S. aureus polysaccharide intercellular adhesin (PIA) was encoded by icaA and icaD genes. Production of PIA is currently responsible for staphylococcal biofilm development. In this study, S. aureus strains isolated from auricular infect...

Staphylococcus aureus is an important pathogen that forms biofilm. In this study, 22 S. aureus have been isolated from the oral cavity of Tunisian children and investigated for slime production using Congo red agar method (CRA) and semi quantitative adherence assay. The hydrophobicity of strains was evaluated by the microbial adhesion to solvent (M...

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are important food-borne mycotoxins that have been implicated in human health. In this study, independent and combinative toxicities of AFB1 and OTA were tested in cultured monkey kidney Vero cells. The experiments reported here were conducted to evaluate the effect of these toxins on cell viability follow...

Polyarylsulfone group is one of the most important polymeric materials used in the biomedical field, due to its excellent properties, such as good thermal, chemical, and mechanical stability. There are three important polyarylsulfone polymers, all of which have excellent electrical properties: polysulfone (PSu), polyarylsulfone (PAS) and polyarylet...