Escherichia coli Resistance to Nonbiocidal Antibiofilm Polysaccharides Is Rare and Mediated by Multiple Mutations Leading to Surface Physicochemical Modifications

Antivirulence strategies targeting bacterial behavior, such as adhesion and biofilm formation, are expected to exert low selective pressure and have been proposed as alternatives to biocidal antibiotic treatments to avoid the rapid occurrence of bacterial resistance. Here, we tested this hypothesis using group 2 capsule polysaccharide (G2cps), a polysaccharidic molecule previously shown to impair bacterium-surface interactions, and we investigated the nature of bacterial resistance to a nonbiocidal antibiofilm strategy. We screened an Escherichia coli mutant library for an increased ability to form biofilm in the presence of G2cps, and we identified several mutants displaying partial but not total resistance to this antibiofilm polysaccharide. Our genetic analysis showed that partial resistance to G2cps results from multiple unrelated mutations leading to modifications in surface physicochemical properties that counteract the changes in ionic charge and Lewis base properties induced by G2cps. Moreover, some of the identified mutants harboring improved biofilm formation in the presence of G2cps were also partially resistant to other antibiofilm molecules. This study therefore shows that alterations of bacterial surface properties mediate only partial resistance to G2cps. It also experimentally validates the potential value of nonbiocidal antibiofilm strategies, since full resistance to antibiofilm compounds is rare and potentially unlikely to arise in clinical settings.     

Rehabilitation of muscle after injury – the role of anti‐inflammatory drugs

Non‐steroidal anti‐inflammatory drugs (NSAIDs) are widely consumed among athletes worldwide in relation to muscle injury and soreness. This review aims to provide an overview of studies investigating their effects on skeletal muscle, in particular the repair processes in injured muscle. Muscle injury occurs in diverse situations and the nature of muscle injuries varies significantly, complicating extrapolations between experimental models and “real life.” Classical muscle strain injuries occur at the interphase between the muscle fibers and connective tissue, most often in the myotendinuous junction, whereas contusion or overload injury can damage both myofibers and intramuscular connective tissue. The role of NSAIDs in muscle repair is complicated by differences in injury models used, variables evaluated, and time point(s) selected for evaluations. While the temporal pattern of the influence of NSAIDs on muscle repair is difficult to settle on, it appears that a potential beneficial effect of NSAIDs in the early phase after injury is not maintained in the long term, or is even negated by a long‐term repair deficit. At the cellular level, evidence exists for a negative influence of NSAIDs on the muscle stem cell population (satellite cells). At a structural level, it is known that muscle connective tissue undergoes significant remodeling during muscle regeneration, but the potential of NSAID exposure to alter this response in humans needs investigation.     

Hypnose et bloc paravertébral échoguidé dans la chirurgie du cancer du sein

The combination of hypnosis and paravertebral block (PVB) was studied in three patients scheduled for breast cancer surgery. The three procedures were realized under hypnosis. Median postoperative pain was rated at zero and comfort felt at 8 on a 10 points scale. Hypnosis could be an alternative to conventional anesthesia in combination with a PVB for breast cancer surgery.     

Growth Delay in Inflammatory Bowel Diseases: The Importance of Surgery

Digestive Diseases and Sciences -     

Increased HLA-G Expression in Tissue-Infiltrating Cells in Inflammatory Bowel Diseases

Background

Since HLA-G is an immune checkpoint molecule and since Crohn’s disease (CD) and ulcerative colitis (UC) exhibit deregulated immune-mediated mechanisms, we aimed to evaluate intestinal HLA-G expression and soluble HLA-G (sHLA-G) levels in CD/UC patients stratified according to the CD phenotype/localization and UC extension.

Methods

HLA-G tissue expression was assessed by immunohistochemistry in biopsies collected from 151 patients (90 CD, 61 UC) and in surgical resection specimens (28 CD, 12 UC). Surgical material from 24 healthy controls was also assessed. Plasma sHLA-G levels (97 CD, 81 UC, and 120 controls) were evaluated using ELISA.

Results

HLA-G expression was similarly observed in the intestinal epithelial cells of control and CD/UC specimens. However, in biopsies, the plasma cells/lymphocytes infiltrating the lamina propria in CD/UC presented (1) increased HLA-G expression compared to controls (P?<?0.0001), (2) greater cell staining in UC cells than in CD cells irrespective of disease extent (P?=?0.0011), and (3) an increased number of infiltrating cells in the inflammatory CD phenotype compared to that in the stenosing and fistulizing phenotypes (P?=?0.0407). In surgical specimens, CD/UC patients exhibited higher infiltrating cell HLA-G expression in lesion areas than in margins. sHLA-G levels were higher in UC/CD patients (P?<?0.0001) than in controls, but no difference was observed between diseases.

Conclusions

Increased infiltrating cell HLA-G expression associated with increased sHLA-G levels in CD/UC patients may reflect ongoing host strategies to suppress chronic inflammation.