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Papers by ons haddad

Saudi Journal of Oral and Dental Research

Objectives: The aim of our study is to look for the different Gram + and Gram - germs present in ... more Objectives: The aim of our study is to look for the different Gram + and Gram - germs present in the biofilm of thermoplastic appliances and to note the qualitative modifications of the aligners’ bacterial flora after the use of the tea tree essential oil. Materials and Methods: Thirty-four patients were involved in the study. They were divided into two equal groups: a control group using a toothbrush and toothpaste as cleaning means and a test group using the tea tree essential oil as a supplement. Results: The results showed that the bacterial flora of the thermoplastic device is very diverse with a predominance of the genus Staphylococcus. It was isolated in more than half of the devices used by the control group. In terms of species, Enterobacter cloacae complex and Staphylococcus aureus were the most represented. In addition to the bacteria, usually found in the oral cavity, several other non-oral strains were frequently isolated, underscoring the importance of hand hygiene. Th...

South African Journal of Botany, 2019

Beet root (Beta vulgaris L.) is well known in cuisine and is also used in traditional medicine to... more Beet root (Beta vulgaris L.) is well known in cuisine and is also used in traditional medicine to prevent many diseases. We investigated the methanolic extract and juice with respect to the phenolic and flavonoid contents and evaluated their antioxidant, anticoagulant and genotoxic activities. Genotoxicity was studied with the bacterial Vitotox test and the alkaline comet assay involving human C3A liver cells. The methanolic extract had the highest phenolic and flavonoid contents with values of 39.75 mg GAE/g and 20.73 mg CE/g extract, respectively. Methanolic extract and juice showed surprising anticoagulant and antioxidant activities. They were devoid of any genotoxicity or cytotoxic effects. The results show the potential of the plant, especially the juice, as a new source of bioactive molecules for therapeutic purposes, possibly in the treatment of cardiovascular diseases.

Microbial Pathogenesis, 2018

Assessment of the antibiofilm and antiquorum sensing activities of Eucalyptus globulus essential ... more Assessment of the antibiofilm and antiquorum sensing activities of Eucalyptus globulus essential oil and its main component 1,8-cineole against methicillin-resistant Staphylococcus aureus strains

La Tunisie médicale, Oct 8, 2022

Folia Medica, 2017

Ebola virus disease (EVD) is one of the deadliest viral diseases. It is characterized by a high m... more Ebola virus disease (EVD) is one of the deadliest viral diseases. It is characterized by a high mortality rate due to the lack of effective and safe treatments or vaccines and its ability to spread at an unstoppable pace. The West Africa outbreak ended but the disease may strike again at any time. The latest epidemic was, by far, the deadliest to date. The most concern was why this outbreak was so different from the previous ones. We proposed in this review firstly to summarize the principal causes of its unprecedented spread and secondly to identify the steps for an effective management approach of a future Ebola outbreak. Attributes of the affected populations and insufficient control efforts were the main reasons of its amplification. This was complicated by a delayed international response. The health crisis was ignored for months until it got out of control. The management of Ebola presents a multitude of challenges in terms of preparedness and capacity to face an outbreak. In ...

Environmental Science and Pollution Research

The aim of this study is to evaluate the polyphenolic and flavonoid contents in the leaves extrac... more The aim of this study is to evaluate the polyphenolic and flavonoid contents in the leaves extracts of Ruscus hypophyllum. Antioxidant activity was estimated by α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays. The anticoagulant activity of Ruscus extracts was evaluated in vitro, using the prothrombin time (PT) and a PTT-activated partial thromboplastin time tests. The antibacterial activity was tested against large number of important medically and resistant bacteria by the broth dilution method. In this study, ethyl acetate and chloroform extracts displayed the highest total phenols contents (74.76 mg EAG/g and 73.89 mg EAG/g, respectively) and flavonoid content 40 and 32.43 mg EC/g, respectively. The GC-MS analysis of ethyl acetate extract confirmed the presence of oxygenated sesquiterpenes and hydrocarbon diterpenes with percentages of 16.41% and 10.72%, respectively, but chloroform extract was rich with, oxygenated monoterpenes, and oxygenated diterpenes, with percentages of 6.19 and 3.27%, respectively. Among tested extracts, ethyl acetate exhibited the best antioxidant and anticoagulant activities. Furthermore, ethyl acetate and chloroform extracts showed important antibacterial activity against resistant bacteria methicillin-resistant Staphylococcus aureus (SARM), Acinetobacter imipenem-resistant (IMP/R), P. aeruginosa imipenem-resistant (IMP/R) and extended-spectrum beta-lactamase producing E. cloacae (BLSE) with minimal inhibitory concentration (MIC) values varying between 0.125 and 0.5 mg/mL.

Molecules

The problem of antibiotic resistance among pathogens encourages searching for novel active molecu... more The problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 µg/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO...

Journal de Pédiatrie et de Puériculture, 2016

BMC Infectious Diseases, Nov 13, 2018

Background: Methicillin resistant Staphylococcus aureus (MRSA) is recognized worldwide as a leadi... more Background: Methicillin resistant Staphylococcus aureus (MRSA) is recognized worldwide as a leading cause of hospital and community infections. Biofilm formation by MRSA is an extremely important virulence factor to be understood. Our aim was to establish phenotypic and genotypic characterization of virulence factors among 43 MRSA clinical isolates in a Tunisian hospital. Methods: We investigated enzymatic profiles, biofilm production and prevalences of genes encoding intracellular adhesion molecules (icaA and icaD), Microbial Surface Components Recognizing Adhesive Matrix Molecules genes (fnbA, fnbB and cna) and exoenzymes genes (geh, sspA and sspB). Results: Our findings revealed that caseinase, gelatinase, lipase and lecithinase activities were detected in 100%, 100%, 76.6% and 93.3% of cases respectively. This study showed that 23 strains (76.7%) were slime producers on Congo red medium. Furthermore, 46.5% and 53.5% of isolates were respectively highly and moderately biofilm-forming on polystyrene. Significant association was found between both biofilm tests. PCR detection showed that 74.4%, 18.6%, 69.8%, 65.1% and 74.4% of isolates harbored fnbA, fnbB, icaA, icaD and cna genes respectively. In addition, 34.9%, 18.6% and 30.2% of MRSA strains were found positive for sspA, sspB and geh genes respectively. Further, statistical data showed that the presence of the fnbA and fnbB genes was significantly associated with a high biofilm production on polystyrene. However, no statistical association was observed for the icaA, icaD and cna genes. Conclusions: This study indicates that the detection of fnbA and fnbB contributing to the first step of biofilm formation has been predictable of high biofilm production. As studied factors contribute to MRSA virulence, this research could be of value in orienting towards the development of new preventive and therapeutic measures.

Cell phones, smartphones, and tablets are extensively used in social and professional life, so th... more Cell phones, smartphones, and tablets are extensively used in social and professional life, so they are frequently exposed to bacteria. The main goal of the present work was to isolate and characterize Staphylococci strains from students’ cell phone mobiles. Subsequently, 24 Staphylococci strains were tested against a wide range of antibiotics, for the distribution of some virulence-related genes and their ability to form biofilm. Staphylococcus spp. were cultured from all studied devices on chromogenic medium and identified using the matrix-assisted laser desorption/ionization (MALDI), time-of-flight (TOF) mass spectrometry (MS) technique (MALDI-TOF-MS). The results obtained showed that S. aureus was the dominant species (19 strains, 79.1%), followed by S. warneri (3 strains, 12.5%), and S. haemolyticus (2 strains, 8.3%). Isolated strains showed high percentages of hydrolytic enzymes production, resistance to many tested antibiotics, and 37.5% expressed the mecA gene. The tested st...

Journal de Pédiatrie et de Puériculture, 2014

souches de Staphylococcus aureus étaient résistantes à la méticilline (SARM). Elles étaient toute... more souches de Staphylococcus aureus étaient résistantes à la méticilline (SARM). Elles étaient toutes sensibles à la pristinamycine et à l'acide fusidique. Une résistance supérieure à 75 % était notée pour les aminosides. Aucune souche n'était résistante aux glycopeptides. Conclusion.-Les infections à BMR sont graves. Ainsi, la surveillance continue des résistances aux antibiotiques constitue une préoccupation majeure.