Plant-derived bioactive compounds for the inhibition of biofilm formation: a comprehensive review.

Biofilm formation is a widespread phenomenon that impacts different fields, including the food industry, agriculture, health care and the environment. Accordingly, there is a serious need for new methods of managing the problem of biofilm formation. Natural products have historically been a rich source of varied compounds with a wide variety of biological functions, including antibiofilm agents. In this review, we critically highlight and discuss the recent progress in understanding the antibiofilm effects of several bioactive compounds isolated from different plants, and in elucidating the underlying mechanisms of action and the factors influencing their adhesion. The literature shows that bioactive compounds have promising antibiofilm potential against both Gram-negative and Gram-positive bacterial and fungal strains, via several mechanisms of action, such as suppressing the formation of the polymer matrix, limiting O2 consumption, inhibiting microbial DNA replication, decreasing hydrophobicity of cell surfaces and blocking the quorum sensing network. This antibiofilm activity is influenced by several environmental factors, such as nutritional cues, pH values, O2 availability and temperature. This review demonstrates that several bioactive compounds could mitigate the problem of biofilm production. However, toxicological assessment and pharmacokinetic investigations of these molecules are strongly required to validate their safety.

Chemical extraction, characterization, and inspection of the antimicrobial and antibiofilm activities of shrimp chitosan against foodborne fungi and bacteria.

Nowadays, the exploitation of biopolymers in the industrial sector has become a trend. Chitosan is considered one of the most investigated biopolymers due to its abundance and antibacterial, antifungal, and antibiofilm activities. In this work, chitosan was chemically extracted from shrimp shells. Solutions of HCl 1 M, NaOH 4 M, and NaOH 15 M were used for the demineralization, deproteinization, and deacetylation process, respectively. The utilized methods of characterization (FTIR, 1 H NMR, 13 C NMR, and SEC-MALS) revealed that the obtained chitosan has a moderate degree of deacetylation and low molecular weight (DDA = 74% and Mw = 72.14 kDa). The microdilution method and inoculation of solid medium were carried out to assess the antibiofilm action of chitosan against Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus hirae, Escherichia coli, Rhizopus sp., and Aspergillus sp. which are known as foodborne microorganisms. Results showed that the produced chitosan at 1 g/L inhibits between 63.44 and 99.75% of the microbial biofilm depending on the tested strains. These promising results confirm the potential deployment of the obtained chitosan in the food industry as a replacement for synthetic antimicrobial agents.

Anti-adhesive activity of some secondary metabolites against Staphylococcus aureus on 3D printing medical materials.

Recent improvements in 3D printing technology have increased the usage of 3D printed materials in several areas. An exciting and emerging area of applying these next-generation manufacturing strategies is the development of devices for biomedical applications. The main aim of this work was to investigate the effect of tannic acid, gallic acid, and epicatechin gallate on the physicochemical characteristics of acrylonitrile butadiene-styrene (ABS) and Nylon 3D printing materials using the contact angle method. The adhesion of Staphylococcus aureus on untreated and treated materials was evaluated by scanning electron microscopy (SEM) analysis and the images were treated by MATLAB software. The results of the contact angle measurements showed a significant change in the physicochemical properties of both surfaces, indicated an increase in the electron donor character of 3D printing materials following treatment. Thus, the ABS surfaces treated with tannic acid, gallic acid, and epicatechin gallate have become more electron donating. Furthermore, our results proved the ability of S. aureus to adhere on all materials with a percentage of 77.86% for ABS and 91.62% for nylon. The SEM has shown that all actives molecules were sufficient to obtain better inhibition of bacterial adhesion, which tannic acid has shown a total inhibition of S. aureus on ABS. From these results, our treatment presents a high potential for utilization as an active coating to prevent bacterial attachment and the eventual biofilm development in medical field.

Salvia officinalis extract mitigates the microbiologically influenced corrosion of 304L stainless steel by Pseudomonas aeruginosa biofilm.

The mitigation of microbiologically influenced corrosion (MIC) of 304L stainless steel (SS) against Pseudomonas aeruginosa by a Salvia officinalis extract was investigated using electrochemical and surface analysis techniques. The extract was characterized by HPLC-Q-TOF-MS and its antibiofilm property was evaluated. The data revealed the presence of well-known antimicrobial and anticorrosion compounds in the extract. The S. officinalis extract was found effective in preventing biofilm formation and inhibiting mature biofilm. Electrochemical results indicated that P. aeruginosa accelerated the MIC of 304L SS, while the extract was found to prevent the MIC with an inhibition efficiency of 97.5 ±â€¯1.5%. This was attributed to the formation of a protective film by the adsorption of some compounds from the extract on the 304L SS surface.

[Imported malaria in northern central Morocco, 1997-2007]. / Le paludisme importé dans le Centre Nord du Maroc entre 1997 à 2007.

After the elimination of autochthonous malaria in Morocco in 2004, control of imported malaria, based on epidemiological monitoring of the parasite and vector control, has become a priority. This retrospective study concerns imported malaria cases identified by optical microscopy at the regional epidemiological diagnostic laboratory of the Regional Health Department of Fes from 1997 through 2007. The results obtained showed that 56 of 68 (82%) samples examined were positive. Women accounted for 21% of cases, and all patients were older than 15 years. The positive cases were imported from 13 African countries, in particular, Côte d'Ivoire (14%) and Congo and Burkina Faso (11%). Incidence was highest in 2002 with 11 cases, 1998 with 9 cases, and 2004 and 2005, with 8 each year. Only one death was recorded, in 2002. The species found were Plasmodium falciparum, in 50 cases (89%), Plasmodium vivax in 4 (7%) and Plasmodium ovale in 2 (4%). The city of Fes, capital of the Fes-Boulemane region in northern central Morocco, as a capital, university town, and important spiritual centre, attracts many visitors from countries of sub-Saharan Africa where malaria is endemic. It is thus essential to maintain a high level of malaria monitoring and control in this area. The results of this study will undoubtedly help to guide the programme for imported malaria control and monitoring in our area, as well as the national programme against this disease.