Poloxamer 338 affects cell adhesion and biofilm formation in escherichia coli: Potential applications in the management of catheter-associated urinary tract infections

Poloxamers are nontoxic, amphiphilic copolymers used in different formulations. Due to its surfactant properties, Poloxamer 338 (P388) is herein proposed as a strategy to avoid biofilm formation often causing recalcitrant catheter-associated urinary tract infections (CAUTI). The aim is to evaluate the ability of P388 coatings to affect the adhesion of Ec5FSL and Ec9FSL Escherichia coli strains on silicone urinary catheters. Attenuated total reflection infrared spectroscopy, atomic force microscopy, and static water contact angle measurement were employed to characterize the P388-coated silicone catheter in terms of amount of P388 layered, coating thickness, homogeneity, and hydrophilicity. In static conditions, the antifouling power of P388 was defined by comparing the E. coli cells adherent on a hydrophilic P388-adsorbed catheter segment with those on an uncoated one. A P388-coated catheter, having a homogeneous coverage of 35 nm in thickness, reduced of 0.83 log10 and 0.51 log10 the biofilm of Ec5FSL and Ec9FSL, respectively. In dynamic conditions, the percentage of cell adhesion on P388-adsorbed silicone channels was investigated by a microfluidic system, simulating the in vivo conditions of catheterized patients. As a result, both E. coli isolates were undetected. The strong and stable antifouling property against E. coli biofilm lead us to consider P388 as a promising anti-biofilm agent for CAUTIs control

SV-IV Peptide1–16 reduces coagulant power in normal Factor V and Factor V Leiden

Native Factor V is an anticoagulant, but when activated by thrombin, Factor X or platelet proteases, it becomes a procoagulant. Due to these double properties, Factor V plays a crucial role in the regulation of coagulation/anticoagulation balance

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

Modeling pathways to health behaviors of young-adult survivors of childhood cancer

Currently there are over 300,000 childhood cancer survivors living in the United States, many of whom face serious or life-threatening late effects as a result of their cancer treatment. The current study sought to examine the pathways that lead to various health behaviors related to tobacco and alcohol use, diet, exercise, sunscreen use, medication compliance and follow-up screening practices in young-adult survivors of childhood cancer. Data was collected from a sample of 18 to 30 year old cancer survivors (N=125) who completed an online questionnaire and was used to test a causal model examining the main and mediating roles of interpersonal support and nonsupport, personal agency, avoidance, depressive symptoms and self-efficacy as they related to and were predictive of health behaviors. A preliminary factor analysis indicated a three-factor solution for all reported health behaviors, with the three factors being tobacco use, unhealthy lifestyle behaviors, and risk/neglectful behaviors. Path analyses were utilized to test three separate models predictive of each health behavior factor. Findings indicated direct causal effect between avoidance and tobacco use, avoidance and unhealthy lifestyle behaviors, and depressive symptoms and unhealthy lifestyle behaviors. Smaller, indirect effects from variables support, nonsupport, and personal agency were observed for tobacco use and unhealthy lifestyle behaviors. No support for the model including risk/neglectful behaviors was found. Tests of mediation indicated that depressive symptoms mediated the relationships between support and unhealthy lifestyle behaviors and personal agency and unhealthy lifestyle behaviors, and also indicated that self-efficacy mediated the relationships between support and unhealthy lifestyle behaviors, depression and unhealthy lifestyle behaviors, and personal agency and unhealthy lifestyle behaviors. Findings form this study may be used to guide health promotion program development in survivorship provider agencies and long-term follow-up clinics. Results indicate a number of recommendations for health behavior promotion intervention

Anti- staphylococcal biofilm efficacy of Daptomycin and Tigecycline: an in vitro evaluation

Given the potential for antibiotic resistance featuring biofilm–based infections, one on the most fascinating challenge is currently to develop new treatment strategies specifically designed for sessile growing bacteria. In fact, a highly competitive race is under way from a decade among drug companies to develop terapeutic strategies based on new antimicrobials able to counteract biofilm–based infections, especially those caused by the most insidious bugs . The aim of our study was to evaluate the in vitro anti-biofilm activity of Daptomycin and Tigecycline since these two antibiotics claim a strong efficacy against biofilm-based staphylococcal infections. In all the experiments the strong biofilm-producer Staphylococcus epidermidis ATCC 35984 strain was used. Antibiotic susceptibility of planktonic bacteria was determined by the disk diffusion test and the Minimum Biofilm Eradication Concentration (MBEC) was assessed by the 96-wells microplate assay. On the basis of the MBEC results, biofilm eradication assays were prepared on 96-well plates and evaluated by crystal violet staining and colony forming units assay. Untreated and antibiotic-treated biofilms were examined by a Field Emission Scanning Electron Microscope (Zeiss Sigma) to analize their surface features , while a Live/Dead Baclight bacterial viability kit was adopted for confocal laser scanning microscopy (CLSM) observations. In our experiments a significant ability in reducing a mature biofilm of S. epidermidis was exhibited at similar levels by Daptomycin and Tigecycline . However, both these drugs failed to show the complete biofilm disruption and a full bactericidal effect despite the antibiotic concentrations used would be 100 times higher than MIC

Understanding the Health Behaviors of Survivors of Childhood and Young-Adult Cancer: Preliminary Analysis and Model Development

The current study presents preliminary correlational data used to develop a model depicting the psychosocial pathways that lead to the health behaviors of survivors of childhood and young-adult cancer. Data collected from a sample of 18- to 30-year-old cancer survivors (n = 125) was used to examine the relations among interpersonal support and nonsupport, personal agency, avoidance, depressive symptoms and self-efficacy as they related to health behaviors. The outcome measures examined included tobacco and alcohol use, diet, exercise, sunscreen use, medication compliance and follow-up/screening practices. Correlational analyses revealed a number of significant associations among variables. Results are used to inform the development of a health behavior model. Implications for health promotion and survivorship programming are discussed, as well as directions for future research

Subinhibitory concentrations of metronidazole increase biofilm formation in Clostridium difficile strains

Resistance mechanism to metronidazole is still poorly understood, even if the number of reports on Clostridium difficile strains with reduced susceptibility to this antibiotic is increasing. In this study, we investigated the ability of the C. difficile strains 7032994, 7032985 and 7032989, showing different susceptibility profiles to metronidazole but all belonging to the PCR ribotype 010, to form biofilm in vitro in presence and absence of subinhibitory concentrations of metronidazole. The quantitative biofilm production assay performed in presence of metronidazole revealed a significant increase in biofilm formation in both the susceptible strain 7032994 and the strain 7032985 exhibiting a reduced susceptibility to this antibiotic, while antibiotic pressure did not affect the biofilm-forming ability of the stable-resistant strain 7032989. Moreover, confocal microscopy analysis showed an abundant biofilm matrix production by the strains 7032994 and 7032885, when grown in presence of metronidazole, but not in the stable-resistant one. These results seem to demonstrate that subinhibitory concentrations of metronidazole are able to enhance the in vitro biofilm production of the above-mentioned PCR ribotype 010 C. difficile strains, susceptible or with reduced susceptibility to this antibiotic, suggesting a possible role of biofilm formation in the multifactorial mechanism of metronidazole resistance developed by C. difficile

Antibiotic pressure can induce the viable but nonculturable state in Staphylococcus aureus growing in biofilms

Objectives: Staphylococcal biofilms are among the main causes of chronic implant-associated infections. We have recently suggested that their transformation into viable but non-culturable (VBNC) forms (i.e. forms capable of resuscitation) could be responsible for the recurrent symptoms. This work aims to establish whether Staphylococcus aureus biofilms can give rise to VBNC forms capable of being resuscitated in suitable environmental conditions, the role of different stressors in inducing the VBNC state and the conditions favouring resuscitation. Methods: S. aureus 10850 biofilms were exposed to different concentrations of antibiotic (vancomycin or quinupristin/ dalfopristin) and/or to nutrient depletion until loss of culturability. The presence of viable cells and their number were examined by epifluorescence microscopy and flow cytometry. Gene expression was measured by real-time PCR. Resuscitation ability was tested by growth in rich medium containing antioxidant factors. Results: Viable subpopulations were detected in all non-culturable biofilms. However, viable cell numbers and gene expression remained constant for 150 days from loss of culturability in cells from antibiotic-exposed biofilms, but not in those that had only been starved. Resuscitation was obtained in rich medium supplemented with 0.3% sodium pyruvate or with 50% filtrate of a late-log culture. Conclusions: Our findings demonstrate that S. aureus can enter the VBNC state in infectious biofilms. The presence of vancomycin or quinupristin/dalfopristin can inadvertently induce a true VBNC state or its persistence in S. aureus cells embedded in biofilms, supporting previous findings on the role of staphylococcal biofilms in recurrent infection