Indwelling Medical Devices Research Articles

Antibiotic resistance and molecular characteristics of methicillin-resistant Staphylococcus epidermidis recovered from hospital personnel in China

ObjectivesStaphylococcus epidermidis is a major nosocomial pathogen predominantly associated with indwelling medical device infections. Studies reporting on S. epidermidis recovered from hospital personnel in China are scarce. The aim of this study was to evaluate the carriage and antibiotic resistance of S. epidermidis among the hospital personnel in Tianjin, China and provide insights into their genetic diversity. MethodsOne hundred and seven S. epidermidis isolates were recovered from 68 hospital personnel in two public hospitals in Tianjin between March 2018 and May 2018. Staphylococcal cassette chromosome mec (SCCmec) types were determined by the combination of mec and ccr complexes. Multi-locus sequence typing was used to determine the sequence types (ST) of S. epidermidis isolates. ResultsSixty-two (76.5%) isolates were determined to be methicillin-resistant S. epidermidis (MRSE). Thirty-five (51%) of 68 hospital personnel carried S. epidermidis, of which 32 (91%) were carriers of MRSE. All 62 MRSE isolates had high levels of resistance to penicillin (90%) and cefoxitin (100%). Thirty-seven (60%) isolates carried SCCmec type IV, followed by 15 (24%) carrying SCCmec V, and 4 (6%) SCCmec II. Novel STs were assigned to four S. epidermidis isolates (ST832, ST833, ST834 and ST835). ConclusionsIn this study, the majority of MRSE belonged to cluster II domain of CC2. The ST59-IV was a dominant clone among isolates recovered from hospital personnel. Determination of new MLST types confirmed the genetic diversity of these isolates. These observations highlight the need to review the infection control strategies to reduce the carriage of MRSE among hospital personnel.

Suppressing the phenotypic virulence factors of Uropathogenic Escherichia coli using marine polysaccharide

Uropathogenic Escherichia coli (UPEC) is one of the keystone pathogen that cause 80–90% of community acquired urinary tract infections (UTIs) and Catheter associated urinary tract infections (CAUTIs). Pathogenicity and ability of UPEC to colonize the bladder majorly relies on the expression of phenotypic virulence factors like flagella, pili, curli, and non pilus adhesion. Pathogens that colonize on the indwelling medical devices are able to communicate using quorum sensing (QS) signals. QS Plays a vital role in coordinating biofilm formation which results in the bacterial cells encased inside an extracellular polymeric substance (EPS). Chitosan is a marine polysaccharide which is known for its antibacterial activity. In the present study we investigated the ability of chitosan extracted from marine biowaste to mitigate the QS mediated biofilm formation in UPEC. Extracted chitosan (EC) and Commercial chitosan (CC) showed percentage inhibition of 80–85% and 60–75% respectively on young biofilm inhibition and preformed biofilm disruption. EC and CC were assessed for its ability to suppress QS mediated virulence in UPEC. Hemolysis assay showed a percentage inhibition of 79% against EC. Both chitosan showed profound activity to suppress the phenotypic virulence factors like swarming motility which is mediated by type I pili and colony morphology assay showed repression in cellulose production in UPEC. Furthermore, Real-Time PCR confirmed the ability of EC to down regulate the virulent genes which are responsible for invasion in UPEC. Accordingly, the current study foresees the quorum sensing inhibiting (QSI) potential of chitosan extracted from marine biowaste which offers an antibiotic free approach to combat UTI caused by UPEC.

A Feasibility Study for 3D-printed Poly(methyl methacrylate)-resin Tracheostomy Tube Using a Hamster Cheek Pouch Model.

A three-dimensional (3D) printed tracheostomy tube has potential application for patients who require a specialized tube. The aim of this study was to evaluate the characteristics of various 3D printing materials and determine their use in producing 3D-printed tracheostomy tube. Mechanical, chemical, and microbiological in vivo changes in the scaffolds were analyzed using a hamster cheek pouch (HCP) model. The poly methyl methacylate (PMMA)-resin showed superior pre- and post-insertion mechanical properties and a relatively consistent lower biofilm formation compared with other scaffolds. PMMA-resin was successfully 3D-printed with dimensional accuracy without a support system. The use of a 3D-printed PMMA tracheostomy tube in a rabbit trachea showed no definite signs of infection, allergy or foreign body reaction. PMMA-resin can be proposed as an alternative for a 3D-printed tracheostomy tube material. In addition, we suggest HCPs as an in vivo model for evaluating indwelling medical devices.

Fabricating Ultra-Smooth Diamond-Like Carbon Film and Investigating its Antifungal and Antibiofilm Activity

Diamond like carbon (DLC) a carbon-based nanomaterial has been nominated as a potential solution to prevent the biofilm formation on indwelling medical devices such as dentures and heart valves. Candida albicans is an opportunistic fungal pathogen where biofilms are a part of its pathogenicity which primarily utilized indwelling medical devices as platform to build up the biofilm. In this work, DLC deposited on silicon substrate was prepared to accomplish the optimal characteristics for bio-coating material (roughness, purity, uniformity) and then evaluated for their ability to prevent or reduce the biofilm formation of pathogenic C.albicans (SC5314) under conditions mimicking human body. Optimized DLC was synthesized via chemical vapor deposition, and then the film was characterized by Raman spectroscopy, scan electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). The potential biofilms on DLC, silicon substrate and positive control (polyvinyl chloride-PVC) were quantified via colorimetric cell viability assay (XTT); as intact and vortexed biofilms. The characteristics of formed biofilms were carried out using confocal scanning laser microscopy (CSLM) and scan electron microscope (SEM). The result showed that DLC was successfully deposited on the silicon substrate with a root mean square (RMS) roughness of 0.183± 0.09 nm. The biofilm efficaciously grown on all samples (DLC and positive control) with thickness of 46.8 ± 6.97 μm and 42.18 ± 4.65 μm, respectively. No topological and morphological changes have been observed by SEM on biofilm-DLC compared to PVC-biofilm. Moreover, all results indicated that the hydrophobicity and roughness of DLC appeared to support the attachment and the growth of C.albicans .In conclusion , there is no privilege of utilizing DLC over PVC in term of reduction or inhibition of C.albicans biofilm formation at physiological conditions. Furthermore, this study may serve as an experimental model to evaluate the potential effect of nanomaterials coating on biofilm formation at conditions mimicking human’s body.

Marine bacterial DNase curtails virulence and disrupts biofilms of Candida albicans and non-albicans Candida species

Candida is one of the most prevalent fungal pathogens in clinical settings which form antibiotic-resistant biofilms on biomedical devices. Hence, there is a need for non-antimicrobial alternatives to combat these infections. The present study investigates the anti-biofilm effect of marine bacterial DNase by targeting the eDNA present in the biofilms of Candida spp. A strain of Vibrio alginolyticus (AMSII) which showed enhanced DNase activity was isolated from marine sediment. Treatment of young and mature Candida biofilms with purified marine bacterial DNase (MBD) caused a 60-80% reduction in biofilm biomass, similar to treatment with DNase I from Bovine pancreas. Scanning electron microscopy showed that MBD significantly reduced the formation of biofilms on urinary catheters and more importantly prevented the virulent yeast to hyphae dimorphic switch in C. albicans. The present study identified a potential non-antibiotic alternative therapy to eradicate Candida biofilms and can be used to develop enzyme fabricated antifouling indwelling medical devices.

Multifunctional S-Nitroso-N-acetylpenicillamine-Incorporated Medical-Grade Polymer with Selenium Interface for Biomedical Applications.

Modern crises in implantable or indwelling blood-contacting medical devices are mainly due to the dual problems of infection and thrombogenicity. There is a paucity of biomaterials that can address both problems simultaneously through a singular platform. Taking cues from the body's own defense mechanism against infection and blood clotting (thrombosis) via the endogenous gasotransmitter nitric oxide (NO), both of these issues are addressed through the development of a layered S-nitroso-N-acetylpenicillamine (SNAP)-doped polymer with a blended selenium (Se)-polymer interface. The unique capability of the SNAP-Se-1 polymer composites to explicitly release NO from the SNAP reservoir as well as generate NO via the incorporated Se is reported for the first time. The NO release from the SNAP-doped polymer increased substantially in the presence of the Se interface. The Se interface was able to generate NO in the presence of S-nitrosoglutathione (GSNO) and glutathione (GSH), demonstrating the capability of generating NO from endogenous S-nitrosothiols (RSNO). Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) traced distribution of elemental Se nanoparticles on the interface and the surface properties were evaluated by surface wettability and roughness. The SNAP-Se-1 efficiently inhibited the growth of bacteria and reduced platelet adhesion while showing minimal cytotoxicity, thus potentially eliminating the risks of systemic antibiotic and blood coagulation therapy. The SNAP-Se-1 exhibited antibacterial activity of ∼2.39 and ∼2.25 log reductions in the growth of clinically challenging adhered Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. SNAP-Se-1 also significantly reduced platelet adhesion by 85.5% compared to corresponding controls. A WST-8-based cell viability test performed on NIH 3T3 mouse fibroblast cells provided supporting evidence for the potential biocompatibility of the material in vitro. These results highlight the prospective utility of SNAP-Se-1 as a blood-contacting infection-resistant biomaterial in vitro which can be further tuned by application specificity.

Drug Resistance and Biofilm Production among Pseudomonas aeruginosa Clinical Isolates in a Tertiary Care Hospital of Nepal

Clinical isolates of Pseudomonas aeruginosa often exhibit multidrug resistance due to their inherent ability to form biofilms. Drug resistance in Ps. aeruginosa is a major clinical problem, especially in the management of patients with nosocomial infections and those admitted to ICUs with indwelling medical devices. To evaluate the biofilm forming abilities of the clinical isolates of Ps. aeruginosa and to correlate biofilm formation with antibiotic resistance. A total of 90 consecutive isolates of Ps. aeruginosa obtained from various specimens collected from patients visiting the Manipal Teaching Hospital, Pokhara, Nepal between January 2018 - October 2018 were studied. Isolates were identified by standard microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method. All the isolates were tested for their biofilm forming abilities by employing the tissue culture plate assay. Of the 90 Ps. aeruginosa isolates, maximum i.e 42 (46.6%) were from patients in the age group of > 50 years. Majority (30; 33.3%) of the isolates were obtained from sputum samples. However, percentage isolation from other specimens like urine, endotracheal tube (ETT), pus, eye specimens and blood were 18.9%, 16.7%, 16.7%, 7.8% and 6.7% respectively. All the isolates were sensitive to polymixin B and colistin, 91.1% of the organisms were sensitive to imipenem, and more than 80% to aminoglycosides (80% to gentamicin, 83.3% to amikacin). A total of 29 (32.2%) organisms were biofilm producers. Maximum numbers of biofilm producing strains were obtained from ETT (8 of 15; 53.3%), pus (8 of 15; 53.3%) and blood (2 of 6; 33.3%) i.e from all invasive sites. None of the isolates from noninvasive specimens such as conjunctival swabs were biofilm positive. Significantly higher numbers of biofilm producers (23 of 29; 79.3%) were found to be multidrug resistant as compared to non-biofilm (6 of 61; 9.8%) producers (p=0.000). Ps. aeruginosa colonization leading to biofilm formation in deep seated tissues and on indwelling devices is a therapeutic challenge as majority of the isolates would be recalcitrant to commonly used antipseudomonal drugs. Effective monitoring of drug resistance patterns in all Pseudomonas clinical isolates should be a prerequisite for successful patient management.

Surface Proteins of Staphylococcus aureus.

The surface of Staphylococcus aureus is decorated with over 20 proteins that are covalently anchored to peptidoglycan by the action of sortase A. These cell wall-anchored (CWA) proteins can be classified into several structural and functional groups. The largest is the MSCRAMM family, which is characterized by tandemly repeated IgG-like folded domains that bind peptide ligands by the dock lock latch mechanism or the collagen triple helix by the collagen hug. Several CWA proteins comprise modules that have different functions, and some individual domains can bind different ligands, sometimes by different mechanisms. For example, the N-terminus of the fibronectin binding proteins comprises an MSCRAMM domain which binds several ligands, while the C-terminus is composed of tandem fibronectin binding repeats. Surface proteins promote adhesion to host cells and tissue, including components of the extracellular matrix, contribute to biofilm formation by stimulating attachment to the host or indwelling medical devices followed by cell-cell accumulation via homophilic interactions between proteins on neighboring cells, help bacteria evade host innate immune responses, participate in iron acquisition from host hemoglobin, and trigger invasion of bacteria into cells that are not normally phagocytic. The study of genetically manipulated strains using animal infection models has shown that many CWA proteins contribute to pathogenesis. Fragments of CWA proteins have the potential to be used in multicomponent vaccines to prevent S. aureus infections.

Role of Phenol-Soluble Modulins in Staphylococcus epidermidis Biofilm Formation and Infection of Indwelling Medical Devices

Phenol-soluble modulins (PSMs) are amphipathic, alpha-helical peptides that are secreted by staphylococci in high amounts in a quorum-sensing-controlled fashion. Studies performed predominantly in Staphylococcus aureus showed that PSMs structure biofilms, which results in reduced biofilm mass, while it has also been reported that S. aureus PSMs stabilize biofilms due to amyloid formation. We here analyzed the roles of PSMs in in vitro and in vivo biofilms of Staphylococcus epidermidis, the leading cause of indwelling device-associated biofilm infection. We produced isogenic deletion mutants for every S. epidermidis psm locus and a sequential deletion mutant in which production of all PSMs was abolished. In vitro analysis substantiated the role of all PSMs in biofilm structuring. PSM-dependent biofilm expansion was not observed, in accordance with our finding that no S. epidermidis PSM produced amyloids. In a mouse model of indwelling device-associated infection, the total psm deletion mutant had a significant defect in dissemination. Notably, the total psm mutant produced a significantly more substantial biofilm on the implanted catheter than the wild-type strain. Our study, which for the first time directly quantified the impact of PSMs on biofilm expansion on an implanted device, shows that the in vivo biofilm infection phenotype in S. epidermidis is in accordance with the PSM biofilm structuring and detachment model, which has important implications for the potential therapeutic application of quorum-sensing blockers.

RNAIII Inhibiting Peptide (RIP) and Derivatives as Potential Tools for the Treatment of S. aureus Biofilm Infections.

S. aureus under the biofilm mode of growth is often related to several nosocomial infections, more frequently associated with indwelling medical devices (catheters, prostheses, portacaths or heart valves). As a biofilm, the biopolymer matrix provides an excellent growth medium, increasing the tolerance to antibiotics and host immune system. To date, the antimicrobial therapy alone is not effective. A novel strategy to prevent biofilm formation is based on the interference with the bacterial cell-cell communication, a process known as quorum sensing (QS) and mediated by the RNA-III-activating peptide (RAP) and its target protein TRAP (Target of RAP). The RNAIII inhibiting peptide (RIP) is able to inhibit S. aureus pathogenesis by disrupting QS mechanism competing with RAP, thus inhibiting the phosphorylation of TRAP. This alteration leads to a reduced adhesion and to the inhibition of RNAIII synthesis, with the subsequent suppression of toxins synthesis. The present paper will provide an overview on the activity and potential applications of RIP as biofilm inhibiting compound, useful in the management of S. aureus biofilm infections. Moreover, medicinal chemistry strategies have been examined to better understand which modifications and/or structure alterations were able to produce new derivatives of this QS inhibitor with an improved antibiofilm activity.

A Prospective Cohort Study on the Infections Associated with Indwelling Medical Devices in a Tertiary Care Hospital in South India

A Prospective Cohort Study on the Infections Associated with Indwelling Medical Devices in a Tertiary Care Hospital in South India

Fabrication of polylysine based antibacterial coating for catheters by facile electrostatic interaction

Despite the development of advanced antibacterial biomedical materials, bacterial infection is still a serious problem for indwelling catheter because it usually induces severe complications. Hence, medical indwelling catheter with the capabilities of antibacterial activity, stability, biocompatibility is urgently needed. In this work, a water-insoluble antibacterial coating based on ε-Poly-ʟ-lysine (PL) was prepared via a facile electrostatic interaction between cation PL and anion surfactant, 1,4-bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The ease and efficacy of the PL-AOT complex preparation render it as antibacterial coating applicable to a variety of medical devices for reduction of bacterial infections. This coating was fabricated on the medical catheter with broad-spectrum antibacterial activity, long-term stability, biocompatibility. The contact-killing oriented strategy for the antibacterial action of this coating was confirmed by high-performance liquid chromatography (HPLC). Almost 100% S. aureus and E. coli as Gram-positive and Gram-negative bacteria model could be killed rapidly by this coating for thermoplastic polyurethane (TPU) film. The antibacterial properties of the coated catheters were also assessed under static and dynamic flow conditions. Regardless of the above conditions, the coated catheters displayed remarkable antibacterial activity compared to the uncoated catheters. In addition, this coating showed better antibacterial stability by mimicking the in vivo environment, that is, the antibacterial efficacy could still maintain even after 31 days immersing. Moreover, the coated catheter exhibited negligible cytotoxicity against L929 murine fibroblasts cells. For in vivo experiment, the coated catheter caused 90% less inflammation in mice and showed more remarkable antibacterial performance. Consequently, this ε-Poly-ʟ-lysine (PL) based coating have a great potential to serve as a safe and multifunctional antibacterial strategy for the medical indwelling devices.

Evaluation of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method for assessing biofilm formation in vitro by Trichosporon spp.

BACKGROUND:Invasive infections due to Trichosporon spp. have increased recently and are frequently associated with indwelling medical devices. Such infections which are associated with biofilm formation do not respond to the routinely used antifungal agents and are often persistent, associated with high mortality rate. Various methods have been described by researchers to evaluate and quantify the biofilm formation.AIM:This study was conducted to compare two methods of biofilm production by Trichosporon sp, i.e., test tube method with crystal violet (CV) staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.MATERIALS AND METHODS:Seventy-two clinical isolates of Trichosporon spp. collected from various sources were considered for the study. The identity of all the isolates was genotypically confirmed by Trichosporon-specific polymerase chain reaction (PCR). The isolates were further speciated phenotypically using biochemical profile and growth characteristics which identified the isolates as Trichosporon asahii (64/72), Trichosporon asteroides (5/72), Trichosporon cutaneum (2/72), and Trichosporon mucoides (1/72). Biofilm production was then evaluated and compared by test tube-CV method and MTT assay.RESULTS:All the Trichosporon isolates produced biofilm by MTT assay, whereas only 42 (53.6%) of the isolates were detected to be biofilm producers by CV method. Furthermore, MTT assay could differentiate better between weak and moderate biofilm producers as compared to CV method.CONCLUSION:Hence, MTT assay is a reliable method for quantification of biofilm produced by Trichosporon spp. using 96-well microtiter plate.

Phthalate and alternative plasticizers in indwelling medical devices in pediatric intensive care units.

The present study aimed to identify plasticizers present in indwelling plastic medical devices commonly used in the pediatric intensive care unit (PICU). We have analyzed a wide range of medical devices (n = 97) daily used in the PICUs of two academic hospitals in Belgium and the Netherlands. Identified compounds varied between the samples. Most of the indwelling medical devices and essential accessories were found to actively leach phthalates and alternative plasticizers. Results indicated that DEHP was predominantly present as plasticizer (60 of 97 samples), followed by bis(2-ethylhexyl) adipate (DEHA, 32 of 97), bis(2-ethylhexyl) terephthalate (DEHT, 24 of 97), tris(2-ethylhexyl) trimellitate (TOTM, 20 of 97), and tributyl-O-acetyl citrate (ATBC, 10 of 97). Other plasticizers, such as di-isononyl-cyclohexane-1,2-dicarboxylate (DINCH, 2 of 97), di-isononyl phthalate (DiNP, 4 of 97), di(2-propylheptyl) phthalate (DPHP, 4 of 97) and di-isodecyl phthalate (DiDP, 2 of 97) were detected in < 5% of the investigated samples. Several devices contained multiple plasticizers, e.g. devices containing TOTM contained also DEHP and DEHT. Our data indicate that PICU patients are exposed to a wide range of plasticizers, including the controversial DEHP. Future studies should investigate the exposure to APs in children staying in the PICU and the possible health effects thereof.

Survival of Staphylococcus epidermidis in Fibroblasts and Osteoblasts.

Staphylococcus epidermidis is a leading cause of infections associated with indwelling medical devices, including prosthetic joint infection. While biofilm formation is assumed to be the main mechanism underlying the chronic infections S. epidermidis causes, we hypothesized that S. epidermidis also evades immune killing, contributing to its pathogenesis. Here, we show that prosthetic joint-associated S. epidermidis isolates can persist intracellularly within human fibroblasts and inside human and mouse osteoblasts. We also show that the intracellularly persisting bacteria reside primarily within acidic phagolysosomes and that over the course of infection, small-colony variants are selected for. Moreover, upon eukaryotic cell death, these bacteria, which can outlive their host, can escape into the extracellular environment, providing them an opportunity to form biofilms on implant surfaces at delayed time points in implant-associated infection. In summary, the acidic phagolysosomes of fibroblasts and osteoblasts serve as reservoirs for chronic or delayed S. epidermidis infection.

Chemical composition, antimicrobial and antibiofilm efficacy of C. limon and L. angustifolia EOs and of their mixtures against Staphylococcus epidermidis clinical strains

Staphylococcus epidermidis is a Gram-positive resident of the human skin, which in certain conditions, can turn into an opportunistic pathogen, being one of the most frequent agents of nosocomial infections, particularly of those associated with indwelling medical devices. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of two essential oils (EOs) to be used alone or in combination as natural alternatives to currently available antibiotics, for treating S. epidermidis infections or preventing the contamination and further development of S. epidermidis biofilm on viable tissues or medical devices. For this purpose C. limon and L. angustifolia EOs were obtained both by hydrodistillation and microwave-assisted extraction and analyzed by GC–MS. The compositions of EOs as a function of the extraction procedure were compared and discussed. Each of the two extraction techniques was more effective in the extraction of different components of the EOs. In the case of C. limon EOs, terpinen-4-ol, α-terpineol and linalool, not found in the microwave assisted extract, are obtained by classical hydrodistillation (being compounds of high polarity) while less polar compounds (α-pinene, β-pinene, limonene, γ-terpinene) are drawn into higher percentage through the microwave-assisted procedure. In the case of L. angustifolia EOs, a higher percentage of compounds with high polarity (such as linalool) is extracted by classical hydrodistillation while the compounds with lower polarity, such as acetates (linalyl acetate and neryl acetate) are extracted in higher proportion by the microwave-assisted extraction method.The antibacterial and antibiofilm effects of the EOs and of their mixtures were tested towards five S. epidermidis clinical strains and their biological activity was correlated with the oils composition. The most active composition was represented by the binary mixture (1:1) of the EOs obtained by hydrodistillation, containing terpene alcohols (such linalool) and d-limonene, which exhibited the lowest minimum inhibitory concentration (3.9 μg/mL) and minimum biofilm eradicating concentration (0.97–7.81 μg/mL), against all tested S. epidermidis strains. Other minor constituents, such as terpinen-4-ol, α-terpineol, linalyl acetate, neryl acetate, geranyl acetate and α-pinene could be potentiated in presence of limonene and could be responsible for the high antimicrobial activity of these EOs mixture.

In vivo protective effect of geraniol on colonization of Staphylococcus epidermidis in rat jugular vein catheter model.

Staphylococcal infections associated with indwelling medical devices are difficult to eradicate owing to its recalcitrant nature of biofilms to conventional antibiotics. In our earlier study, we reported the efficacy of geraniol (GE) in inhibiting the in vitro biofilm formation of Staphylococcus epidermidis and adaptive resistant development. To examine the in vivo potential of GE in eradicating the in vivo colonization of S. epidermidis, an implanted rat jugular vein catheter model was developed. Oral supplementation of GE (GE at 200 mg/kg bw for three days) in rats infected with S. epidermidis exhibited a significant reduction of the bacterial burden in catheter, blood, heart and kidney, when compared to the untreated infection control. In addition, GE supplemented animals showed significantly reduced level of inflammatory markers such as nitric oxide and malondialdehyde in heart and kidney tissues. Furthermore, in contrast to the infection control, histopathology analysis of the heart and kidney tissues of the GE-treated group showed a normal histoarchitecture similar to animal control. Thus, the outcome of the present study exhibits the potential of GE as antibiofilm and anti-inflammatory agent against S. epidermidis infections. Furthermore, elucidating the molecular mechanism of GE is important to exploit the therapeutic efficacy of GE.

Risk factors for sepsis morbidity in a rural hospital population: A case-control study

The aim of the study was to identify risk factors for sepsis morbidity in a rural hospital population. We used a case-control study design. Patients included adult admissions to a rural health system between January 1, 2012, and December 31, 2015. Case selection was by electronic medical record search for codes of the ICD-9-CM. Cases were validated against Quick Sequential Organ Failure Assessment criteria. Multiple logistic regression modeling was performed to determine which predefined variables were significantly associated with sepsis diagnosis. A total of 220 patients were studied (110 cases and 110 controls). Cases had an in-hospital mortality of 20% compared with 0% of the controls. Indwelling medical device use during hospitalization (adjusted odds ratio [OR], 3.02; 95% confidence interval [CI], 1.44-6.30; P = .003), coronary heart disease (adjusted OR, 2.59; 95% CI, 1.13-5.97; P = .03), and type of health insurance (adjusted OR, 2.36; 95% CI, 1.13-4.93; P = .02) were independently associated with sepsis diagnosis after adjusting for potential confounders. This study underscores the need for implementation and maintenance of infection control measures during management of patients with indwelling medical devices at a rural hospital.

Prediction of Broad-Spectrum Pathogen Attachment to Coating Materials for Biomedical Devices.

Bacterial infections in healthcare settings are a frequent accompaniment to both routine procedures such as catheterization and surgical site interventions. Their impact is becoming even more marked as the numbers of medical devices that are used to manage chronic health conditions and improve quality of life increases. The resistance of pathogens to multiple antibiotics is also increasing, adding an additional layer of complexity to the problems of employing safe and effective medical procedures. One approach to reducing the rate of infections associated with implanted and indwelling medical devices is the use of polymers that resist the formation of bacterial biofilms. To significantly accelerate the discovery of such materials, we show how state of the art machine learning methods can generate quantitative predictions for the attachment of multiple pathogens to a large library of polymers in a single model for the first time. Such models facilitate design of polymers with very low pathogen attachment across different bacterial species that will be candidate materials for implantable or indwelling medical devices such as urinary catheters, cochlear implants, and pacemakers.

English

Staphylococcus epidermidis normally is a commensal inhabitant of healthy human skin and mucosa, but also a common nosocomial pathogen in immunocompromised patients, neonates, and patients with indwelling medical devices. To distinguish the pathogen and commensal strain is a big challenge when identifying this agent with its related infection. This mini-review aims to summarize recent research in this area with a special emphasis on the virulence factor of generating genotypic and phenotypic diversity in S. epidermidis . By living between a commensal and pathogen, S. epidermidis needed to establish many strategies to face different clinical environments, including the new ecological niche of biomaterials. In addition, the growing number of immunocompromised patients increased the risk for a very sensitive host. However, further exploration of the relationship between virulence factor and in vivo pathogenesis is still needed. According to the virulence factor of these bacteria, which are considered as a real pathogen, strict control measures should be taken for S. epidermidis infection.