Christine G Roques

Université Toulouse III - Paul Sabatier | UPS Toulouse · Faculté des sciences pharmaceutiques

The vast majority of bacteria live in sessile biofilms that colonize the channels, pores and crevices of confined structures. Flow in these structures carries the nutrients necessary for growth, but also generates stresses and detachment from surfaces. Conversely, bacteria tend to occupy a large part of the available space and, in so doing, increas...

The microbial contamination of eye drop tips and caps varies between 7.7% and 100%. In seeking patient protection and continuous improvement, the Pharmacy Department in the Sterile Ophthalmological and Oncological Preparations Unit at Cochin Hospital AP-HP, Paris, France, conducted a two-phase study to compare the antimicrobial efficiency and pract...

The interaction of foreign implants with its surrounding environment is significantly influenced by the adsorption of proteins on the biomaterial surfaces, playing role in the microbial adhesion. Therefore, understanding protein...

Pseudomonas aeruginosa, Staphylococcus aureus, and Burkholderia cepacia are notorious pathogens known for their ability to form resilient biofilms, particularly within the lung environment of cystic fibrosis (CF) patients. The heightened concentration of NaCl, prevalent in the airway liquid of CF patients' lungs, has been identified as a factor tha...

Microbial contamination of the surface of building materials and subsequent release of microbial particles into the air can significantly affect indoor air quality. Avoiding the development or, at least, reducing the quantity of microorganisms growing on building materials is a key point to reduce health risks for building occupiers. In that contex...

The antimicrobial activity of surfaces treated with zinc and/or magnesium mineral oxide microspheres is a patented technology that has been demonstrated in vitro against bacteria and viruses. This study aims to evaluate the efficiency and sustainability of the technology in vitro, under simulation-of-use conditions, and in situ. The tests were unde...

Biological pollution is one major cause of the degradation of indoor air quality. It was shown that microbial communities from outdoor might impact significantly the communities detected indoor. In addition, microbial contamination of the surfaces of building materials and their release into the indoor air also significantly affect indoor air quali...

It is now well established that biological pollution is a major cause of the degradation of indoor air quality. It has been shown that microbial communities from the outdoors may significantly impact the communities detected indoors. One can reasonably assume that the fungal contamination of the surfaces of building materials and their release into...

Dental implants provide a good solution for the replacement of tooth roots. However, the full restoration of tooth functions relies on the bone-healing period before positioning the abutment and the crown on the implant, with the associated risk of post-operative infection. This study aimed at developing a homogeneous and adherent thin calcium phos...

In this work, β-thiogalactoside mimetics bearing 1,1-diarylmethylene or benzophenone aglycons have been prepared and assayed for their affinity towards LecA, a lectin and virulence factor from Pseudomonas aeruginosa involved in bacterial adhesion and biofilm formation. The hit compound presents higher efficiency than previously described monovalent...

An electrochemical protocol was designed to enable Vero cells to transfer electrons to an electrode without any added redox mediator. The cells were cultured on the surface of electrodes polarized at the optimal potential of 400 mV/silver pseudo-reference. Gold, carbon, and CNT-coated carbon electrodes displayed similar current record patterns. Ext...

The sterility of eye drop content is a primary concern from manufacturing until opening, as well as during handling by end users, while microbial contamination of the dropper tip and cap are often disregarded. The contamination of these sites during drug administration represents a risk of microbial transmission and ocular infection. In this review...

Treatment of biofilm-associated infections has become a major challenge in biomedical and clinical fields due to the failure of conventional treatments in controlling this highly complex and tolerant structure. Therefore, the search for novel antibiofilm agents with increased efficacy as those provided by natural products, presents an urgent need....

Biofilms are sessile microbial communities whose lifestyle confers specific properties. In recent years, they have attracted great interest in many research fields. Biofilms are indeed the cause of recurrent industrial problems, while microbial contaminations can finally impact the quality of a finished product or human health. However, these same...

The limit of Mg solubility in bactericidal CuO nanorods detected by neutron powder diffraction.

In the challenging quest for a solution to reduce the risk of implant-associated infections in bone substitution surgery, the use of silver ions is promising regarding its broad spectrum on planktonic, sessile as well as multiresistant bacteria. In view of controlling its delivery in situ at the desired dose, we investigated its encapsulation in ca...

Biofilm formation is considered a major cause of therapeutic failure because bacteria in biofilms have higher protection against antimicrobials. Thus, biofilm-related infections are extremely challenging to treat and pose major concerns for public health, along with huge economic impacts. Pseudomonas aeruginosa, in particular, is a “critical priori...

The history of antimicrobial resistance (AMR) evolution and the diversity of the environmental resistome indicate that AMR is an ancient natural phenomenon. Acquired resistance is a public health concern influenced by the anthropogenic use of antibiotics, leading to the selection of resistant genes. Data show that AMR is spreading globally at diffe...

The organization of bacteria in biofilms is one of the adaptive resistance mechanisms providing increased protection against conventional treatments. Thus, the search for new antibiofilm agents for medical purposes, especially of natural origin, is currently the object of much attention. The objective of the study presented here was to explore the...

To date, there is still a lack of definite knowledge regarding the toxicity of Cu(OH)2 nanoparticles towards bacteria. This study was aimed at shedding light on the role played by released cupric ions in the toxicity of nanoparticles. To address this issue, the bactericidal activity of Cu(OH)2 was at first evaluated in sterile water, a medium in wh...

The Nernst potential of the support/cell interface is suspected to play a key role in cell adhesion and proliferation. However, the studies that have addressed this topic have generally varied the electrochemical potential of the interface by comparing different materials or by varying the chemical composition of the surface coating. It is conseque...

Objectives The rising incidence of urinary tract infections (UTIs) attributable to Escherichia coli resistant isolates is becoming a serious public health concern. Although global rates of infection vary considerably by region, the growing prevalence of this uropathogen has been associated with a high economic burden and health strain. This study a...

Animal cells from the Vero lineage and MRC5 human cells were checked for their capacity to catalyse the electrochemical oxygen reduction reaction (ORR). The Vero cells needed 72 hours’ incubation to induce ORR catalysis. The cyclic voltammetry curves were clearly modified by the presence of the cells with a shift of ORR of 50 mV towards positive po...

Objectives The rising incidence of urinary tract infections (UTIs) attributable to Escherichia coli resistant isolates is becoming a serious public health concern. Although global rates of infection vary considerably by region, the growing prevalence of this uropathogen has been associated with a high economic burden and health strain. This study a...

Abstract Background Our aim was to examine whether the length of stay, hospital charges and in-hospital mortality attributable to healthcare- and community-associated infections due to antimicrobial-resistant bacteria were higher compared with those due to susceptible bacteria in the Lebanese healthcare settings using different methodology of analy...

Data on comprehensive population-based surveillance of antimicrobial resistance is lacking. In low- and middle-income countries, the challenges are high due to weak laboratory capacity, poor health systems governance, lack of health information systems, and limited resources. Developing countries struggle with political and social dilemma, and bear...

Copper substitution together with nano-structuring are applied with the aim to increase the bactericidal performances of the rocksalt-type MgO oxide. The partial substitution of magnesium ions with Cu²⁺ has been successfully achieved in both micrometer- and nanometer-sized particles of MgO up to 20 mol% in increments of 5 mol%. Microstructural anal...

When facing an emerging virus outbreak such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a quick reaction time is key to control the spread. It takes time to develop antivirals and vaccines, and implement vaccination campaigns. Therefore, preventive measures such as rapid isolation of cases and identification and early quarantin...

Endogenous electric fields drive many essential functions relating to cell proliferation, motion, differentiation and tissue development. They are usually mimicked in vitro by using electrochemical systems to apply direct current or voltage stimuli to cell cultures. The many studies devoted to this topic have given rise to a wide variety of experim...

Background The current increase in public awareness of environmental risks is giving rise to a growth of interest in the microbiological safety of buildings. In particular, microbial proliferation on construction materials can be responsible for the degradation of indoor air quality that can increase health-risk to occupants. Raw earth materials ar...

Objectives: Currently, the global interests tend to take advantage of the plant world as a renewable source of a natural and effective molecule, to find an eco-friendly, cost-effective, and less toxic alternative to the current synthetic pesticide. In this context, the present research was carried out in an attempt to study the insecticidal activit...

Antibiotic resistance is an ecosystem problem threatening the interrelated human-animal-environment health under the "One Health" framework. Resistant bacteria arising in one geographical area can spread via cross-reservoir transmission to other areas worldwide either by direct exposure or through the food chain and the environment. Drivers of anti...

To increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds. We demonstrated 14.2% of S. capitis BSI (S.capBSI) among nosocomial BSIs. S.capBSI incidence rate was 0.59 per 1000 patient-days. A total of 55.0% of the S.capBS...

To increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds. We demonstrated 14.2% of S. capitis BSI (S.capBSI) among nosocomial BSIs. S.capBSI incidence rate was 0.59 per 1,000 patient-days. 55.0% of the S.capBSIs were la...

Antibiotics are the pillar of surgery from prophylaxis to treatment; any failure is potentially a leading cause for increased morbidity and mortality. Robust data on the burden of SSI especially those due to antimicrobial resistance (AMR) show variable rates between countries and geographical regions but accurate estimates of the incidence of surgi...

Brucite Mg(OH)2 belongs to a family of two-dimensional compounds with a CdI2-type structure built up from layers of edge-sharing octahedra delineating 2D galleries. In the current study, nanometer-sized platelets of copper substituted Mg(OH)2 were elaborated by co-precipitation at room temperature in mixed alkaline (NaOH/Na2CO3) medium. A very weak...

Background: The methicillin-resistant clone Staphylococcus capitis NRCS-A, involved in sepsis in neonatal intensive care units (NICUs) worldwide, is able to persist and spread in NICUs, suggesting the presence of reservoirs inside each setting. The purpose of the present study was to identify these reservoirs and to investigate the cycle of transm...

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the build...

Description of the relationship between protein structure and function remains a primary focus in molecular biology, biochemistry, protein engineering and bioelectronics. Moreover, the investigation of the protein conformational changes after adhesion and dehydration is of importance to tackle problems related to the interaction of proteins with so...

The production of dithiolopyrrolones by Saccharothrix algeriensis was investigated after supplementing the culture medium with ethanol and/or 1-butanol. Optimal conditions for the addition of ethanol to the culture medium provided a maximal dithiolopyrrolone titer of about 200 mg⋅L⁻¹ after 5 days of culture, roughly corresponding to a 600%-increase...

The effect of molds present in buildings on the health of the occupants is a major issue hence, when a building material is developed, its sensitivity to microbial growth should be assessed. However, few studies have investigated fungal growth on bio-based building materials with the resources available in a laboratory specializing in materials. Th...

Objective Our main objective was to compare Cutibacterium acnes (C. acnes) skin colonisation in patients with mild to moderate acne versus healthy controls and secondly, to evaluate a Myrtacine®‐based cream on C. acnes total population and antibioresistant Cutibacteria in patients with acne. Methods In 60 acne patients (Global Acne Severity Scale,...

While the commensal bacterium Propionibacterium acnes (P. acnes) is involved in the maintenance of a healthy skin, it can also act as an opportunistic pathogen in acne vulgaris. The latest findings on P. acnes shed light on the critical role of a tight equilibrium between members of its phylotypes and within the skin microbiota in the development o...

Use of photocatalytic paint-like coatings may be a way to protect building materials from microbial colonization. Numerous studies have shown the antimicrobial efficiency of TiO2 photocatalysis on various microorganisms. However, few have focused on easy-to-apply solutions and on photocatalysis under low irradiance. This paper focuses on (a) the an...

Aims: To investigate the potent control of microbial surface contamination of an innovative process which consists in incorporating metal oxide microspheres homogeneously into materials. Methods and results: Spherical microspheres containing zinc and magnesium oxides synthesized via a one-step manufacturing process (Pyrolyse Pulvérisée®) and inc...

Proteins adsorption on solid surfaces is of interest for many industrial and biomedical applications, where it represents the conditioning step for micro-organism adhesion and biofilm formation. To understand the driving forces of such interaction we focus in this paper on the investigation of the adsorption of BSA (optically non-absorbing, model p...

Le mal de gorge est un des motifs de consultation en médecine générale les plus fréquents. Pour le soulager, outre les traitements allopathiques usuels, la prise de produits de phytothérapie peut être envisagée. L’intérêt d’un produit de phytothérapie associant des extraits de sauge et de sureau, de l’huile essentielle de menthe poivrée, du miel et...

Use of bio-based products from the recycling of glycerol, a valuable by-product of agro-industry as antimicrobial coatings may be an eco-friendly alternative to the classic ways of protecting building materials against microbial proliferation such as metal-based treatments, biocides, etc. Monoglycerides (MG) can be synthetized starting from oleoche...

New agents that are effective against common pathogens are needed particularly for those resistant to conventional antimicrobial agents. Essential oils (EOs) are known for their antimicrobial activity. Using the broth microdilution method, we showed that (1) two unique blends of Cinnamomum zeylanicum, Daucus carota, Eucalyptus globulus and Rosmarin...

Living particles such as bacteria are able to transfer through membrane pores that are smaller than cell size due to the specific stiffness of this type of microorganism. This phenomenon can lead to a significant loss of selectivity in the filtration process, which is a major cause of concern in the sterilizing filtration step. This study investiga...

Aim: To determine the in vitro bactericidal activity of different chlorhexidine (CHX)-based commercial mouthwash products claiming different chlorhexidine concentrations under conditions similar to their use. Method: Bactericidal assays were performed using four major bacterial species implicated in periodontal disease: Fusobacterium nucleatum CIP1...

The interaction of proteins with silver nanoparticles (AgNPs) is of primary importance to uncover silver antimicrobial efficiency and environmental hazard. This interaction can affect silver reactivity, bioavailability and, eventually, silver toxicity towards the environmental media. Detection of the interaction of DsRed fluorescent proteins with A...

Luminescent silica nanoparticles (LSNPs) are frequently employed for biotechnology applications mainly because of easy functionalization, photo-stability and biocompatibility. Bifunctional silica nanoparticles (BSNPs) are described here as new efficient tools for the understanding of a complex biological system such as biofilms. Photoluminescence i...

The waterborne pathogen Legionella pneumophila grows as a biofilm, freely or inside amoebae. Cyclic-di-GMP (c-di-GMP), a bacterial second messenger frequently implicated in biofilm formation, is synthesized and degraded by diguanylate cyclases (DGCs) and phosphodiesterases (PDEs), respectively. To characterize the c-di-GMP-metabolizing enzymes invo...

The Discosoma recombinant red fluorescent (DsRed) protein is the latest member of the family of fluorescent proteins. It holds great promise for applications in biotechnology and cell biology. However, before being used for rational engineering, knowledge on the behavior of DsRed and the underlying mechanisms relating its structural stability and a...

The human skin microbiota is quantitatively dominated by Gram-positive bacteria, detected by both culture and metagenomics. However, metagenomics revealed a huge variety of Gram-negative taxa generally considered from environmental origin. For species affiliation of bacteria in skin microbiota, clones of 16S rRNA gene and colonies growing on divers...