Study of the formation of a biofilm by clinical strains of Staphylococcus aureus.

A study on biofilm formation was carried out using five methicillin-sensitive [MSSA] and five methicillin-resistant [MRSA] strains of S. aureus. In each group, there were four strains isolated from patients from Kinshasa (Democratic Republic of Congo, DRC) and one reference strain.

Interaction between tobramycin and CSA-13 on clinical isolates of Pseudomonas aeruginosa in a model of young and mature biofilms.

The bactericidal activity of a cholic acid antimicrobial derivative, CSA-13, was tested against eight strains of Pseudomonas aeruginosa (both reference and clinical strains) and compared with the response to tobramycin. In planktonic cultures, the minimal inhibitory and minimal bactericidal concentrations of CSA-13 and tobramycin were in the 1-25 mg/L range except for one mucoid clinical strain which was much less sensitive to tobramycin (minimal bactericidal concentration, 65-125 mg/L). In young (24 h) biofilms, the sensitivity to CSA-13 was reduced (half-maximal concentration CSA-13 averaged 88 mg/L) and varied among the eight strains.

Erythrocyte indices in the assessment of iron status in dialysis-dependent patients with end-stage renal disease on continuous erythropoietin receptor activator versus epoetin beta therapy.

Background: European guidelines stress that iron status should be regularly assessed for the optimal management of renal anemia. These guidelines include the hemoglobin content of reticulocytes and the percentage of hypochromic RBC as markers for functional iron deficiency. Recently, equivalents of these indices have become available on the automated hematology analyzer Sysmex XE-2100, these being reticulocyte hemoglobin equivalent (Ret-He) and DF-HYPO XE, respectively.

Study of the initial phase of biofilm formation using a biofomic approach.

Aims: The purpose of this work was to study the initial steps of formation of a biofilm using the BioFilm Ring Test and the Crystal violet staining technique.

Methods And Results: Eight strains of Pseudomonas aeruginosa were studied. The two methods revealed that four strains formed a rapid biofilm.

Evaluation of long-term co-administration of tobramycin and clarithromycin in a mature biofilm model of cystic fibrosis clinical isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa colonisation and chronic lung infection associated with biofilm formation is a major cause of morbidity and mortality in cystic fibrosis (CF) patients. There is thus an urgent need to develop alternative ways to treat biofilm-associated clinical infections. A kinetic study of twice-daily co-administration of the antibiotics tobramycin and clarithromycin was performed over 28 days on 12-day-old mature P.

Effect of antibiotic co-administration on young and mature biofilms of cystic fibrosis clinical isolates: the importance of the biofilm model.

The prognosis of patients with cystic fibrosis (CF) has improved dramatically over the last three decades although the majority of patients still die in early adulthood. Infection with Pseudomonas aeruginosa has generally been associated with declining lung function and increased mortality in patients. This study aimed to investigate the in vitro activity of tobramycin/clarithromycin combination on biofilms of clinical isolates of P.

In vitro activity of antibiotic combinations against Pseudomonas aeruginosa biofilm and planktonic cultures.

In order to investigate the hypothesis that the combination of clarithromycin with other antibacterial agents offers a successful treatment in the eradication of Pseudomonas aeruginosa biofilm, we first determined the activity of eight antimicrobial agents against planktonic cultures of P. aeruginosa isolates by the microdilution technique. Second, we determined the in vitro effects of these antimicrobial agents individually and in combination against planktonic cultures and pre-formed biofilms of P.

Direct and indirect antimicrobial effects and antioxidant activity of Cordia gilletii De Wild (Boraginaceae).

Cordia gilletii De Wild (Boraginaceae) root bark is traditionally used in Democratic Republic of Congo (DRC) for the treatment of various disorders, including malaria, diarrhea, wounds and skin diseases; part of these activities may rely on antimicrobial and antioxidant properties. Successive extracts of root barks powder with n-hexane, dichloromethane, ethyl acetate, methanol and water were tested for antimicrobial activity, both direct and indirect (antibiotic resistance reversal), against 10 strains of bacteria and 1 strain of fungi by broth microdilution and agar diffusion methods. The eventual synergy between plant extracts and antibiotics was investigated by the determination of the fractional inhibitory concentration index (FIC index).

Characteristics of the home bacterial contamination and endotoxin related release.

In several occupational settings, endotoxin, a characteristic external fraction from the outer membrane of Gram negative bacteria (GNB), is an important component of the environmental endotoxin exposure may have a dual influence on atopy and asthma. The aim of this study was to characterise the bacterial and endotoxin composition of settled and airborne dusts from domestic environments. In the nine studied homes, 52 species of GNB were identified on settled dusts and only 13 in the airborne dust.

Modulation by LL-37 of the responses of salivary glands to purinergic agonists.

The interaction of mice submandibular gland cells with LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES), a cationic peptide with immunomodulatory properties, was investigated. LL-37 at a concentration that did not affect the integrity of the cells increased the uptake of calcium and activated a calcium-insensitive phospholipase A(2) (PLA(2)). The small release of ATP induced by LL-37 could not account for this stimulation because apyrase did not significantly block the response to LL-37.

Bacterial contamination of indoor air, surfaces, and settled dust, and related dust endotoxin concentrations in healthy office buildings.

Endotoxin, a characteristic external fraction of the outer membrane from Gram-negative bacteria, continuously shed into the environment, is considered as an important risk factor for human health. Our purpose was to study the bacterial species contaminating healthy working environments. Airborne, working surfaces and carpet dust samples were collected from 25 offices.

Synthesis and enzymatic degradation of epichlorohydrin cross-linked pectins.

The water solubility of pectin was successfully decreased by cross-linking with increasing amounts of epichlorohydrin in the reaction media. The initial molar ratios of epichlorohydrin/ galacturonic acid monomer in the reaction mixtures were 0, 0.37, 0.

Immunologic and virologic response after tetanus toxoid booster among HIV-1- and HIV-2-infected Senegalese individuals.

Twelve HIV-1-infected, nine HIV-2-infected patients and eight HIV-negative subjects were given a 40IU booster dose of tetanus toxoid (TT). Blood was collected on days 0, 7 and 30 after immunization. Changes in HIV-1 or HIV-2 RNA load were evaluated by nested PCR.

Detection of rifampicin resistance in Mycobacterium tuberculosis isolates from diverse countries by a commercial line probe assay as an initial indicator of multidrug resistance.

The line probe assay (LiPA), a rapid molecular method for detecting rifampicin resistance (RMPr) in Mycobacterium tuberculosis, correctly identified all 145 rifampicin-sensitive (RMPs) and 262 (98.5%) of 266 RMPr strains among 411 isolates collected from diverse countries. If used as a marker of multidrug-resistant tuberculosis (MDR-TB), detection of RMPr by LiPA would have detected 236 of the 240 MDR strains in this study but would have wrongly suggested the presence of MDR in 26 RMP-monoresistant isolates (sensitivity 98.

Spontaneous apoptosis and highly active antiretroviral therapy (HAART).

Increased programmed cell death (PCD) or apoptosis has been detected in the T cells of HIV-infected subjects; it is held partially responsible for the continuous loss of CD4+ T cells during the natural course of HIV infection. Highly active antiretroviral therapy (HAART) decreases the viral load and leads to an increase of CD4+ count in vivo. In this study we evaluated PCD in total peripheral blood mononuclear cells, CD8+ and CD4+ lymphocytes before and four weeks after initiation of HAART.

Studies of pectin HM/Eudragit RL/Eudragit NE film-coating formulations intended for colonic drug delivery.

Theophylline pellets were coated with Eudragit NE30D aqueous dispersions, containing various pectin HM/Eudragit RL30D ionic complexes, using an Uni-Glatt fluidized-bed apparatus. Dissolution studies were then carried out on the coated pellets at pH 6.0, in absence and in presence of commercial pectinolytic enzymes.

Effect of pectinolytic enzymes on the theophylline release from pellets coated with water insoluble polymers containing pectin HM or calcium pectinate.

Theophylline pellets were coated with cellulosic (Aquacoat ECD 30, Surelease clear) or acrylic (Eudragit NE30D, RS30D) polymer aqueous dispersions, containing 10% (related to the insoluble polymer content) of pectin HM or calcium pectinate, using a Uni-Glatt fluidized-bed coating apparatus. When commercial pectinolytic enzymes were added to the dissolution media (0.05 M acetate - phosphate buffer, pH 6.

Study on the activation of phospholipases A2 by purinergic agonists in rat submandibular ductal cells.

Extracellular ATP and benzoyl-ATP (Bz-ATP) increased the release of [3H]arachidonic acid ([3H]AA) from prelabeled rat submandibular gland (RSMG) ductal cells respectively two- and threefold. Both agonists also increased the release of [3H]AA from acini but at a lower level (+50% and +100% respectively). Carbachol had no significant effect on either cellular population.

Evaluation of the preservative properties of Thymus vulgaris essential oil in topically applied formulations under a challenge test.

The preservative properties of thyme essential oil (3%) with a known composition were evaluated in two types of final formulations, suitable for use as pharmaceutical or cosmetic vehicles, by means of a standard challenge test proposed by the latest European Pharmacopoeia. The required preservation efficacy criteria were satisfied against the bacterial strains, against the yeast in one of the formulations, but not against the mould strain involved in this study. Interactions between the essential oil compounds and other factors present in the final formulation might have influenced the activity of this essential oil, leading to an incomplete satisfaction of the criteria.

Pseudomonas aeruginosa serotype O12 outbreak studied by arbitrary primer PCR.

A total of 16 colonizing and infecting ofloxacin-resistant Pseudomonas aeruginosa strains and two strains isolated from ventilation equipment fluids, all with similar colonial morphologies and with minor but distinct susceptibility differences, were suspected of belonging to a single outbreak and were studied by arbitrary primer (AP) PCR. Thirteen nonrelated strains were included to evaluate the discriminatory capacity of the technique. AP PCR fingerprinting was compared with serotyping, phage typing, and antibiotic susceptibility testing.

Influence of protamine on the in vitro sensitivity of Pseudomonas aeruginosa to antibiotics.

We have studied the influence of protamine on the sensitivity of three strains of Pseudomonas aeruginosa to various antibiotics: streptomycin, gentamicin, polymyxin B, and beta-lactams. While protamine enhanced the antibacterial action of beta-lactams towards P. aeruginosa, it did not alter the effect of aminoglycosides.

Relationship between slime production, antibiotic sensitivity and the phagetype of coagulase-negative staphylococci.

Three hundred and three strains of coagulase-negative staphylococci (CNS) were collected from the fingers of healthy donors (289) and from blood cultures (14). Twelve different species were identified (5 S. auricularis, 45 S.

Bactericidal activity of disinfectants on Listeria.

The bactericidal activity on Listeria spp. of nine disinfectants used in the food industry was studied by previously published methods. The disinfectants were diluted to the test concentration in sterile standard hard water.

Phage typing of coagulase-negative staphylococci.

Seventy-nine staphylococcal strains isolated from blood cultures (57 coagulase-negative staphylococci (CNS) and 22 S. aureus) and 308 CNS isolated from the skin of healthy donors were phage typed. S.