Device-associated Infections Research Articles

Evaluation of Biofilm Forming Potential and Antimicrobial Resistance Profile of S. aureus and P. aeruginosa Isolated from Peripheral Venous Catheters and Urinary Catheters In Algeria, in vitro Study

Abstract Pseudomonas aeruginosa and Staphylococcus aureus are prominent pathogens responsible for device-associated infections that pose a significant challenge in clinical management. The biofilm-forming ability of these bacteria is a major factor contributing to treatment failures and the recurrence of infections. This study was conducted to evaluate the biofilm production potential of these bacteria isolated from urinary and peripheral venous catheters. Additionally, the study aimed to determine the antibiotic resistance pattern of biofilm producers and non-biofilm producers strains. The identification of bacteria followed conventional microbiological procedures, while the detection of biofilm production involved both qualitative and quantitative methods using Congo red agar (CRA) and Tissue Culture Plate (TCP) techniques, respectively. Antibiotic susceptibility was determined through the Kirby-Bauer disc diffusion method. Of the 22 strains of P. aeruginosa and 29 strains of S. aureus isolated from 116 Peripheral venous catheters and 20 urinary catheters, the CRA method identified 27.27% of P. aeruginosa and 24.14% of S. aureus strains as strong biofilm producers. Meanwhile, 9.09% of P. aeruginosa and 51.72% of S. aureus strains were moderate biofilm producers. The TCP method detected 9.09% of P. aeruginosa and 37.93% of S.aureus strains as strong biofilm producers, while 54.55% of P. aeruginosa and 48.28% of S. aureus strains were moderate biofilm producers. The antibiotic susceptibility test revealed that biofilm-producing bacteria were mostly more resistant to antibiotics than nonbiofilm producers. All S. aureus strains, were resistant to Penicillin (100%), but susceptible to Vancomycin (100%) and Teicoplanin (100%). All P. aeruginosa strains were susceptible to almost all groups of antibiotics, except for Ticarcillin (18.18%), Piperacillin (27.27%), Imipenem (100%), and Rifampicin (100%). Our findings showed that biofilm-producer strains exhibited high resistance rates to only some antibiotics, and emphasized the importance of seeking new strategies to prevent biofim formation and combat the emergence of antibiotic resistance.

Control of Candida auris Septicemia in Patients of Trauma Intensive Care Unit in a Tertiary Care Hospital

Introduction: Candida auris is associated with nosocomial outbreaks in intensive care settings, and transmission despite the implementation of enhanced infection prevention and control (IPC) measures is a particular concern. Objective: Isolation and identification of C. auris from suspected cases of fungal septicemia and its surveillance. Materials and Methods: Blood culture samples of all suspected cases of fungal septicemia were taken from the trauma intensive care unit (TICU) of a tertiary care hospital in New Delhi between September 2019 and November 2019 as part of surveillance of device-associated infections. All the samples were obtained by central venous catheter line. Samples were processed in BacT/Alert automated blood culture system. Positive flagged bottles were further subcultured unto blood agar, MacConkey agar, and Sabouraud Dextrose Agar with and without cycloheximide and incubated at 37°C. All suspected Candida isolates were identified by conventional methods and the suspected C. auris isolates were further confirmed by matrix-assisted laser desorption time of flight. Results: Out of 24 suspected fungal septicemia cases from TICU, three patients had C. auris septicemia and all three isolates were resistant to fluconazole and voriconazole. Action Taken: IPC practices were reinforced as per the Centers for Disease Control and Prevention guidelines by the infection control team. Conclusion: This article depicts the emergence of multidrug-resistant C. auris and controlling its spread by appropriate infection control measures.

Effectiveness Of Multifaceted Care Bundle Approach To Reduce Device Associated Infection (Dai) In Critical Care Unit (Ccu) In A Multi Specialty Hospital, Mangaluru

Device-associated infections (DAI) can cause major medical and economic sequelae. Multifaceted care bundle is considered as an important part of routine nursing activity, not only as a measures DAI prevention, but as a crucial treatment with a profound effect on the patients general health.
 Objectives
 
 To measure the Device associated infection status of CLABSI, CAUTI, and VAP in pre implementation phase according to HAI surveillance guidelines.
 To determine the compliance status of health care workers of care bundles on prevention and care of device associated infections in CCU in Phase III.
 To evaluate the effectiveness of multifaceted care bundle approach on device associated infections status of CLABSI, CAUTI, & VAP in CCU
 To find the risk of DAI in patients in the Post implementation phase (Phase III)
 
 Methods: An experimental approach was adopted to study the effectiveness of multifaceted care bundle approach to reduce device associated infection (DAI) in critical care unit (CCU) in a multispecialty hospital, Mangaluru. Universal sampling technique was adopted to select the 472 sample retrospectively (MRD and HIC records of DAI patients of critically care units) and 409 samples as prospectively (current critically ill patients) then implementation of bundle was done and post implementation evaluation done.
 Results: While comparing pre and post implementation phases, it is found that there was reduction in CAUTI rate /1000 catheter days and CLASBI rate/1000 central line days from Phase I to phase III and increase in VAP rate /1000 ventilator days from Phase I to phase III. Increase in device utilization ratio of CAUTI and CLASBI from Phase I to III and reduction in VAP device utilization ratio from Phase I to III, also observed that during pre-implementation phase, the VAP rate, CLABSI rate and CAUTI rate for all the ICU’s taken together were 134.37/1000 ventilator days, 412/1000 central line days, and 332.92/1000 urinary catheter days, respectively. However, during the post implementation the rates reduced into 133.92, 287.98, and 242 per 1000 device days respectively. There was a month wise decreasing trend of VAP rate, CLABSI rate, and CAUTI rate during the study period.
 In males CAUTI, CLABSI AND VAP rates were reported highest in the both Phases (I and III) and CAUTI, CLABSI and VAP difference in both Phases was not statistically significant according to age and gender (p=0.500) .Highest number of CAUTI was reported in Phase I compared to Phase III .Total number of device days were more (352) for CAUTI whereas 340 ventilator days for VAP, 292 central line days in the Phase I. While comparing both Phases significant difference was found in CAUTI (0.0017) CLASBI (0.002) and VAP (0.0016 ).
 Conclusion: From the findings of the study it can concluded that multifaceted care bundle significantly reduced DAIs in critically ill patients

Assessment of nurses’ knowledge and compliance to evidence based guidelines regarding bundle of ventilator associated pneumonia in a military hospital

Ventilator-associated pneumonia is the most common hospital-acquired infection among patients receiving mechanical ventilation in an intensive care unit. Different evidence based guidelines for the prevention of ventilator-associated pneumonia have been developed and recommended. Intensive Care Units’ nurses have been found to be in the best position to put knowledge into practice as they are at the patient’s bedside 24 hours daily providing nursing care and therefore play an important role in the prevention of VAP. This study focuses on enhancing nurses’ knowledge and compliance regarding ventilator-associated pneumonia (VAP) bundle for prevention of ventilator-associated pneumonia (VAP) in intensive care units in a Military Hospital. Objectives: To assess the critical care nurses' knowledge of and compliance with the preventive care bundle of ventilator associated pneumonia. All head and staff nurses (N=80) working in different intensive care units (N=9) in a Military Hospital were included. The study tools included a self-administered questionnaire designed to test nurse's knowledge and an observational checklist to test nurses’ compliance with ventilator associated pneumonia bundle. Results: The total mean score of nurses’ compliance (70.6%) was more than the total mean score of nurses’ knowledge (52.4 %) of evidence based guidelines regarding ventilator associated pneumonia bundle. Nurses’ knowledge levels were excellent in 16% of the studied nurses, very good in 7.2%, good in 17.6%, fair in 14.9% & poor in 44.3% of the studied nurses. Nurses’ compliance levels were excellent in 56.4%, very good in 3.5%, good in 2%, fair in 24.5% & Poor in 13.43% of the studied nurses. In conclusion: The knowledge of VAP bundle components in the study group was considerably lower than the compliance levels, which indicates that training educational programs directed towards infection prevention and control of device-associated infections should stress on explaining the principle behind the procedure, and manuals, information booklets and self-instruction modules should be implemented to guide healthcare personnel in areas of prevention of VAP.

Inclusion Complexation of S-Nitrosoglutathione for Sustained Nitric Oxide Release from Catheter Surfaces: A Strategy to Prevent and Treat Device-Associated Infections.

S-Nitrosoglutathione (GSNO) is a nontoxic nitric oxide (NO)-donating compound that occurs naturally in the human body. The use of GSNO to deliver exogenous NO for therapeutic and protective applications is limited by the high lability of dissolved GSNO in aqueous formulations. In this paper, we report a host-guest chemistry-based strategy to modulate the GSNO reactivity and NO release kinetics for the design of anti-infective catheters and hydrogels. Cyclodextrins (CDs) are host molecules that are typically used to encapsulate hydrophobic guest molecules into their hydrophobic cavities. However, we found that CDs form inclusion complexes with GSNO, an extremely hydrophilic molecule with a solubility of over 1 M at physiological pH. More interestingly, the host-guest complexation reduces the decomposition reactivity of GSNO in the order of αCD > γCD > hydroxypropyl βCD. The lifetime of 0.1 M GSNO is increased to up to 15 days in the presence of CDs at 37 °C, which is more than twice the lifetime of free GSNO. Quantum chemistry calculations indicate that GSNO in αCD undergoes a conformational change that significantly reduces the S-NO bond distance and increases its stability. The calculated S-NO bond dissociation enthalpies of free and complexed GSNO well agree with the experimentally observed GSNO decomposition kinetics. The NO release from GSNO-CD solutions, compared to GSNO solutions, has suppressed initial bursts and extended durations, enhancing the safety and efficacy of NO-based therapies and device protections. In an example application as an anti-infective lock solution for intravascular catheters, the GSNO-αCD solution exhibits potent antibacterial activities for both planktonic and biofilm bacteria, both intraluminal and extraluminal environments, both prevention and treatment of infections, and against multiple bacterial strains, including a multidrug-resistant strain. In addition to solutions, the inclusion complexation also enables the preparation of GSNO hydrogels with enhanced stability and improved antibacterial efficacy. Since methods to suppress and control the GSNO decomposition rate are rare, this supramolecular strategy provides new opportunities for the formulation and application of this natural NO donor.

2148. No Device, But Still a Problem: A Five Year Review of Healthcare Associated Bloodstream and Urinary Tract Infections in a Children’s Hospital

Abstract Background Central line-associated bloodstream infection (CLABSI) and catheter-associated urinary tract infection (CAUTI) continue to be the focus of external reporting of healthcare associated infections based on CDC-NHSN criteria. As facilities decrease CLABSI and CAUTI, we sought to understand our non-central line bloodstream infections (NCLABSI) and non-catheter urinary tract infections (NCAUTI). Methods We retrospectively reviewed total healthcare associated bloodstream infections (HABSI) (NCLABSI + CLABSI) and healthcare associated urinary tract infections (HAUTI) (NCAUTI + CAUTI) from July 1, 2016 to June 30, 2021 at our 334-bed quaternary care Children’s Hospital. CLABSI and CAUTI were both defined using CDC-NHSN criteria. Epidemiologic and microbiologic data, total antibiotic days related to infection, and mortality were analyzed for each subgroup. Results In a 5-year period, 255 patients were identified with HABSI and HAUTI; 164 were HABSI (26% NCLABSI, 74% CLABSI) and 91 were HAUTI (79% NCAUTI, 21% CAUTI). While our NCLABSI, CLABSI, and CAUTI infections per fiscal year (FY) have remained relatively stable, our NCAUTIs have increased since FY17 (Figure 1). Total antibiotic days for NCLABSI versus CLABSI and for NCAUTI versus CAUTI were similar (Figure 2). Staphylococcus aureus was the predominant pathogen in all HABSIs (16% CLABSI, 31% NCLABSI). Pseudomonas aeruginosa was seen in 15% of CLABSIs but in no NCLABSIs. P. aeruginosa was seen in both CAUTI (32%) and NCAUTI (11%). Escherichia coli was the predominant pathogen in NCAUTI (39%) (Figure 3). There were 2 NCLABSI (5%), 16 CLABSI (13%), 2 NCAUTI (3%) and 2 CAUTI (11%) patient deaths during hospitalization. Conclusion Our data shows that non-device related healthcare associated infections are a significant proportion of our total healthcare associated infections, comprising one quarter of HABSIs and three quarters of HAUTIs. In addition, P. aeruginosa, typically an important pathogen in device-associated infections, also contributes to non-device associated infections. We feel that total HABSI and HAUTI may provide more objective measures to report. Infection prevention measures to decrease NCLABSI and NCAUTI also need attention. Disclosures All Authors: No reported disclosures.

Strategies to Mitigate and Treat Orthopaedic Device-Associated Infections.

Orthopaedic device implants play a crucial role in restoring functionality to patients suffering from debilitating musculoskeletal diseases or to those who have experienced traumatic injury. However, the surgical implantation of these devices carries a risk of infection, which represents a significant burden for patients and healthcare providers. This review delineates the pathogenesis of orthopaedic implant infections and the challenges that arise due to biofilm formation and the implications for treatment. It focuses on research advancements in the development of next-generation orthopaedic medical devices to mitigate against implant-related infections. Key considerations impacting the development of devices, which must often perform multiple biological and mechanical roles, are delineated. We review technologies designed to exert spatial and temporal control over antimicrobial presentation and the use of antimicrobial surfaces with intrinsic antibacterial activity. A range of measures to control bio-interfacial interactions including approaches that modify implant surface chemistry or topography to reduce the capacity of bacteria to colonise the surface, form biofilms and cause infections at the device interface and surrounding tissues are also reviewed.

2144. Duration of perioperative antibiotic prophylaxis in ventriculoperitoneal shunt surgery in children

Abstract Background Placement of ventriculoperitoneal (VP) shunt is an important treatment for pediatric hydrocephalus. Although prolonged perioperative antibiotic prophylaxis has theoretically no benefit in reducing device-associated infections, duration of antibiotic prophylaxis for VP shunt placement in pediatrics is not well established. As a part of antimicrobial stewardship program (ASP), our ASP team recommended to stop perioperative antibiotic prophylaxis for sterile medical placement within 48 hours following surgery in April 2017. Our aim of this study was to evaluate rate of VP shunt-associated infections following shunt placement between children received < 48 hours and ≧ 48 hours of perioperative antibiotic prophylaxis. Methods Children aged 15 years old or younger who underwent VP shunt insertion between April 2014 and November 2021 were enrolled at Tokyo Metropolitan Children's Medical Center. Children with co-existing infection at time of surgery were excluded. Rates of VP shunt-associated infections following 1 month and 6 months of post-surgical periods were compared between children who received < 48 hours and ≧ 48 hours of perioperative antibiotic prophylaxis. Results A total of 110 children were identified. Among them, 11 cases with VP shunt-associated meningitis and 15 cases with other infections were excluded. Girl ratio was 44%. Median age was 4.5 months old (IQR 8-40). Numbers of children with cefazolin and vancomycin-contained regimen were 83 (98.8%) and 1 (1.2%), respectively. Numbers of children who received perioperative antibiotic prophylaxis for < 48 hours and ≧ 48 hours were 43 (51.2%) and 41 (48.8%), respectively. Incidence of VP shunt-associated infections for 1 month of post-surgical period in < 48 hours and ≧ 48 hours antibiotic prophylaxis groups were 4.65% (2/43) and 12.2% (5/41), respectively. (P=0.211) Incidence of VP shunt-associated infections for 6 months of post-surgical period in < 48 hours and ≧ 48 hours antibiotic prophylaxis groups were 11.6% (5/43) and 12.2% (5/41), respectively. (P=0.936). Conclusion Shorter duration of < 48 hours of perioperative antibiotic prophylaxis did not increase rates of VP shunt-associated infections among children in short and long terms. Disclosures All Authors: No reported disclosures.

Triple combination of SPR741, clarithromycin, and erythromycin against Acinetobacter baumannii and its tolerant phenotype.

Extensively drug-resistant (XDR) Acinetobacter baumannii poses a severe threat to public health due to its ability to form biofilms and persister cells, which contributes to critical drug resistance and refractory device-associated infections. A novel strategy to alleviate such an emergency is to identify promising compounds that restore the antimicrobial susceptibility of existing antibiotics against refractory infections. Here, we found a significant synergy among three combinations of SPR741, clarithromycin and erythromycin with a potent antimicrobial activity against XDR A. baumannii (SPR741/CLA/E at 8/10/10 μg ml-1 for XDR AB1069 and at 10/16/10 μg ml-1 for XDR AB1208, respectively). Moreover, the triple combination therapy exhibits a significant antipersister and antibiofilm effect against XDR strains. Mechanistic studies demonstrate that SPR741 may promote intracellular accumulation of macrolides by permeabilizing the outer membrane as well as disrupting membrane potential and further enhance the quorum sensing inhibition activity of the macrolides against XDR A. baumannii and its biofilms. In addition, the triple combination of SPR741 with clarithromycin and erythromycin was not easy to induce resistance in A. baumannii and had effective antimicrobial activity with low toxicity in vivo. Collectively, these results reveal the potential of SPR741 in combination with clarithromycin and erythromycin as a clinical therapy for refractory infections caused by XDR A. baumannii.

Meram Devlet Hastanesi genel yoğun bakım ünitesinde gelişen sağlık hizmeti ilişkili enfeksiyonlarının değerlendirilmesi

Aim: Healthcare-associated infections are a major source of concern in all areas of hospitals, particularly in intensive care units. The goal of our study was to look at the current situation and evaluate the measures that can be taken based on the data obtained by examining the rates and factors of healthcare-associated infections in the general intensive care units of our hospital over a one-year period. Materials and Methods: Between January 2020 and December 2020, 665 patients who were followed up and treated in the general intensive care unit of Meram State Hospital were followed up in terms of healthcare-associated infections, and their outcomes were evaluated. Results: 5354 hospitalization days of 665 patients who were followed up in the general intensive care units for a year were evaluated, and it was determined that 53 of the patients developed healthcare-associated infections. Twenty-two (41.5%) of patients with healthcare-associated infections were female, while 31 (58.5%) were male. It was discovered that the patients' mean age was 71,7±14 (19-94). The infection rate was calculated to be 5.86 and the density to be 7.28. Furthermore, the rates of invasive device-associated nosocomial infection are as follows: 1.02 for central line-associated bloodstream infections, 0.56 for catheter-associated urinary tract infections, and 0 for ventilator-associated pneumonia. Conclusion: Healthcare-associated infections are a significant cause of mortality and morbidity in intensive care units. Due to the improvement in medical care and the increase in life expectancy in parallel with this, effective surveillance practices are of critical importance.

Catheter-associated urinary tract infection by Pseudomonas aeruginosa progresses through acute and chronic phases of infection

Healthcare-associated infections are major causes of complications that lead to extended hospital stays and significant medical costs. The use of medical devices, including catheters, increases the risk of bacterial colonization and infection through the presence of a foreign surface. Two outcomes are observed for catheterized patients: catheter-associated asymptomatic bacteriuria and catheter-associated urinary tract infection (CAUTI). However, the relationship between these two events remains unclear. To understand this relationship, we studied a murine model of Pseudomonas aeruginosa CAUTI. In this model, we also observe two outcomes in infected animals: acute symptoms that is associated with CAUTI and chronic colonization that is associated with asymptomatic bacteriuria. The timing of the acute outcome takes place in the first week of infection, whereas chronic colonization occurs in the second week of infection. We further showed that mutants lacking genes encoding type III secretion system (T3SS), T3SS effector proteins, T3SS injection pore, or T3SS transcriptional activation all fail to cause acute symptoms of CAUTI. Nonetheless, all mutants defective for T3SS colonized the catheter and bladders at levels similar to the parental strain. In contrast, through induction of the T3SS master regulator ExsA, all infected animals showed acute phenotypes with bacteremia. Our results demonstrated that the acute symptoms, which are analogous to CAUTI, and chronic colonization, which is analogous to asymptomatic bacteriuria, are independent events that require distinct bacterial virulence factors. Experimental delineation of asymptomatic bacteriuria and CAUTI informs different strategies for the treatment and intervention of device-associated infections.

An effective laser surface treatment method to reduce biofilm coverage of multiple bacterial species associated with medical device infection

Device associated infection (DAI) is recognized as a worldwide health challenge in total joint replacement (TJR). Bacteria exhibit very strong antibiotic tolerance when they attach to a device and form a biofilm and thus DAI is difficult to treat. In this study, a one-step, clean (no chemicals or additional materials involved) and effective surface engineering approach via laser surface treatment (LST) to tackle the DAI challenge is reported. Commercially pure (CP) Ti were laser-treated in open air using continuous wave (CW) fibre laser. The laser-treated CP Ti was tested against five bacterial species including Gram positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram negative (Pseudomonas aeruginosa, Escherichia coli and Proteus mirabilis). Live/Dead staining and image analysis results indicated that LST can significantly reduce biofilm coverage of the five tested bacterial species on the CP Ti surfaces. Overall biofilm coverage as a percentage of the surface reduced after laser treatment averaging from 4.24 % to 17.4 %. This meant that relative to the untreated surface, biofilm coverage was reduced after laser treatment, ranging from 84.9 % to 95.6 % across the five species. Furthermore, cytotoxicity results (using MTT assay) showed that the laser-treated CP Ti is non-toxic across both L929 fibroblast and RAW macrophage cell lines. Surface properties after LST were investigated using WLI and AFM (measuring micro-/nano-surface roughness and topography) as well as ToF-SIMS (measuring surface chemistry and oxide thickness), respectively. The cross-sectional microstructure at the surface was imaged using SEM and analysed by XRD, whilst the surface wettability was measured using sessile drop method. To summarise, the reduction of biofilm coverage can be attributed to the favourable changes in surface roughness and topography together with the increased concentration of oxides at the topmost surface after LST.

Systematic review of efficacy, safety and pharmacokinetics of intravenous and intraventricular vancomycin for central nervous system infections.

Objective: The decision of vancomycin dosage for central nervous system (CNS) infections is still a challenge because its bactericidal nature in cerebrospinal fluid (CSF) has not been confirmed by human studies. This study systematically reviewed the literatures on vancomycin in patients with meningitis, ventriculitis, and CNS device-associated infections, to assess efficacy, safety, and pharmacokinetics to better serve as a practical reference. Methods: Medline, Embase, and Cochrane Library were searched using terms vancomycin, Glycopeptides, meningitis, and central nervous system infections. Data were extracted including characteristics of participants, causative organism(s), administration, dosage, etc., The clinical response, microbiological response, adverse events and pharmacokinetic parameters were analyzed. Results: Nineteen articles were included. Indications for vancomycin included meningitis, ventriculitis, and intracranial device infections. No serious adverse effects of intravenous (IV) and intraventricular (IVT) vancomycin have been reported. Dosages of IV and IVT vancomycin ranged from 1000-3000mg/day and 2-20mg/day. Duration of IV and IVT vancomycin therapy most commonly ranged from 3-27days and 2-21days. Therapeutic drug monitoring was conducted in 14 studies. Vancomycin levels in CSF in patients using IV and IVT vancomycin were varied widely from 0.06 to 22.3mg/L and 2.5-292.9mg/L. No clear relationships were found between vancomycin CSF levels and efficacy or toxicity. Conclusion: Using vancomycin to treat CNS infections appears effective and safe based on current evidence. However, the optimal regimens are still unclear. Higher quality clinical trials are required to explore the vancomycin disposition within CNS.

Antibacterial brush polypeptide coatings with anionic backbones

Preventing initial colonization of bacteria on biomaterial surfaces is crucial to address the medical device-associated infection issues. Antimicrobial peptide (AMP) or cationic polymer modified surfaces have shown promising potentials to inhibit the initial colonization of bacteria by contact killing. However, their development has been impeded because of bacterial adhesion and high cytotoxicity. Herein, we report a series of brush polypeptide coatings with anionic backbones and cationic AMP mimetic side-chains that displayed superior bactericidal activity, antibacterial adhesion property, and biocompatibility. The cationic side-chain density played an important role in the bioactivities of the brush polypeptide modified surfaces. Brush polypeptide coating with low side-chain density exhibited improved bactericidal activity and antibacterial adhesion property, ascribing to the cooperative effects of adjacent side-chains and backbones/side-chains, respectively. It also showed negligible hemolysis/cytotoxicity in vitro and potent anti-infection property (≥99.9% bactericidal efficacy) in vivo. Brush polymers with anionic backbones and cationic side-chains can be used as a promising design motif to potentiate both antibacterial property and biocompatibility of coatings for combating device-associated infections. Statement of significanceDevice-associated infections (DAIs) have led to increased medical cost, pain, and even mortality of patients. Antimicrobial peptide and cationic polymer coatings provide an important strategy to combat DAIs by preventing initial colonization of bacteria on biomaterial surfaces. Nevertheless, they have suffered bacterial adhesion and cytotoxicity issues. Herein, we developed a brush polypeptide coating with anionic backbones and cationic side-chains. The brush polypeptide coating showed superior bactericidal and antibacterial adhesion properties outperforming conventional antibacterial coatings based on antimicrobial peptide (i.e., melittin), lysozyme (i.e., lysostaphin), cationic polymer, anionic polymer, and the blends of cationic/anionic polymers. It also showed good biocompatibility and potent anti-infection property, making it a promising candidate to combat the DAIs.

Prediction of Catheter-Associated Urinary Tract Infections Among Neurosurgical Intensive Care Patients: A Decision Tree Analysis

Catheter-associated urinary tract infections (CAUTIs) are the most common device-associated infections in hospitals and can be prevented. To identify the risk factors and develop a risk prediction model for CAUTIs among neurosurgical intensive care unit (NICU) patients. All patients admitted to the NICU of a tertiary hospital between January 2019 and January 2020 were enrolled. Two decision tree models were applied to analyze the risk factors associated with CAUTIs in NICU patients. The performance of the decision tree model was evaluated. A total of 537 patients admitted to the NICU with indwelling catheters were recruited for this study. The rate of CAUTIs was 4.44 per 1000 catheter days, and Escherichia coli was the predominant pathogen causing CAUTIs among indwelling catheter patients. The classification and regression tree model displayed good power of prediction (area under the curve : 0.920). Nine CAUTI risk factors (age ≥60years (P=0.004), Glasgow Coma Scale score ≤8 (P=0.009), epilepsy at admission (P=0.007), admission to the hospital during the summer (P<0.001), ventilators use (P=0.007), receiving less than 2 types of antibiotics (P<0.001), albumin level <35g/L (P=0.002), female gender (P=0.002), and having an indwelling catheter for 7-14days (P=0.001) were also identified. We developed a novel scoring model for predicting the risk of CAUTIs in patients with neuro-critical illness in daily clinical practice. This model identified several risk factors for CAUTI among NICU patients, novel factors including epilepsy and admission during the summer, can be used to help providers prevent and reduce the risk of CAUTI among vulnerable groups.

The issue beyond resistance: Methicillin-resistant Staphylococcus epidermidis biofilm formation is induced by subinhibitory concentrations of cloxacillin, cefazolin, and clindamycin.

Staphylococcus epidermis is one of the most frequent causes of device-associated infections due to biofilm formation. Current reports noted that subinhibitory concentrations of antibiotics induce biofilm production in some bacteria. Accordingly, we evaluated the effect of exposure of different subinhibitory concentrations of cloxacillin, cefazolin, clindamycin, and vancomycin on the biofilm formation of methicillin-resistant S. epidermidis (MRSE). Antimicrobial susceptibility testing and minimum inhibitory/bactericidal concentration of antimicrobial agents were determined. MRSE isolates were selected, and their biofilm formation ability was evaluated. The effect of subinhibitory concentrations of cloxacillin, cefazolin, clindamycin, and vancomycin, antibiotics selected among common choices in the clinic, on MRSE biofilm formation was determined by the microtitre method. Besides, the effect of subinhibitory concentrations of cloxacillin, cefazolin, clindamycin, and vancomycin on the expression of the biofilm-associated genes icaA and atlE was evaluated by Reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR). Antimicrobial susceptibility patterns of MRSE strains showed a high level of resistance as follows: 80%, 53.3%, 33.3%, 33.3%, and 26.6%, for erythromycin, trimethoprim-sulfamethoxazole, tetracycline, clindamycin, and gentamicin, respectively. Besides, 73.3% of S. epidermidis strains were Multidrug-resistant (MDR). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were in the range of 0.5 to512 μg/mL and 1 to1024 μg/mL for cloxacillin, 0.125 to256 μg/mL and 1 to512 μg/mL for cefazolin, 0.125 to64 μg/mL and 4 to&gt;1024 μg/mL for clindamycin, and 2 to32 μg/mL and 4 to32 μg/mL for vancomycin, respectively. The findings showed that subinhibitory concentrations of cloxacillin, cefazolin, and clindamycin induce biofilm production in MRSE strains. In particular, the OD values of strains were in the range of 0.09-0.95, 0.05-0.86, and 0.06-1 toward cloxacillin, cefazolin, and clindamycin, respectively. On the other hand, exposure to subinhibitory vancomycin concentrations did not increase the biofilm formation in MRSE strains. The findings also demonstrated that sub-MIC of antibiotics up-regulated biofilm-associated genes. In particular, atlE and icaA were up-regulated 0.062 to 1.16 and 0.078 to 1.48 folds, respectively, for cloxacillin, 0.11 to 0.8, and 0.1 to 1.3 folds for cefazolin, 0.18 to 0.98, and 0.19 to 1.4 folds, respectively, for clindamycin. In contrast, the results showed that sub-MIC of vancomycin did not increase the biofilm-associated genes. These findings overall show that exposure to sub-MIC of traditional antibiotics can cause biofilm induction in MRSE, thereby increasing the survival and persistence on various surfaces that worsen the condition of comorbid infections.

Antimicrobial cationic surfactant-loaded hydrogel coatings in preventing medical device-associated infections

Hydrogels described herein were developed as anti-microbial coating materials. Three different hydrogels, p(HEMA), p(85%HEMA-co-15% MMA), and p(85% HEMA-co-15% MAA) were loaded with two cationic surfactants, BAK, and DDAB, respectively. DDAB owned better effectivity than BAK in killing S. aureus and E. coli. Compared to unmodified(HEMA), all drug-loaded samples exhibited significant anti-adherence ability against&amp;nbsp;E. coli, but on surfaces of all DDAB-loaded hydrogels, bacteria were below the limit of detection, so DDAB was more effective than BAK in conferring anti-adherent properties.

Recent Advance in Polymer Coatings Combating Bacterial Adhesion and Biofilm Formation†

Comprehensive SummaryImplantable medical device‐associated infections (DAIs) originating from bacterial adhesion and biofilm formation have threatened to the health and life of patients. Antibacterial polymer coatings with antifouling and/or bactericidal properties have showed great potentials to combat DAI issues. In this review, we report recent advances in antibacterial polymer coatings fighting bacterial adhesion and biofilm formation on implantable biomaterial surfaces. We summarize the mechanisms of bacterial adhesion and biofilm formation, which provides guidance for the design of antibacterial coatings. We describe the polymer and coating preparation methods and discuss the structure‐property relationships of antibacterial polymer coatings. Applications of these polymer coatings in medical catheters, orthopaedic implants, and other applications are elaborated. Future challenges and prospects associated with antibacterial polymer coatings for implantable medical devices are discussed.

Multifunctional Surface Modification of PDMS for Antibacterial Contact Killing and Drug-Delivery of Polar, Nonpolar, and Amphiphilic Drugs.

Medical device-associated infections pose major clinical challenges that emphasize the need for improved anti-infective biomaterials. Polydimethylsiloxane (PDMS), a frequently used elastomeric biomaterial in medical devices, is inherently prone to bacterial attachment and associated infection formation. Here, PDMS surface modification strategy is presented consisting of a cross-linked lyotropic liquid crystal hydrogel microparticle coating with antibacterial functionality. The microparticle coating composed of cross-linked triblock copolymers (diacrylated Pluronic F127) was deposited on PDMS by physical immobilization via interpenetrating polymer network formation. The formed coating served as a substrate for covalent immobilization of a potent antimicrobial peptide (AMP), RRPRPRPRPWWWW-NH2, yielding high contact-killing antibacterial effect against Staphylococcus epidermidis and Staphylococcus aureus. Additionally, the coating was assessed for its ability to selectively host polar, amphiphilic, and nonpolar drugs, resulting in sustained release profiles. The results of this study put forward a versatile PDMS modification strategy for both contact-killing antibacterial surface properties and drug-delivery capabilities, offering a solution for medical device-associated infection prevention.

Blood Stream Infection Caused by Carbapenem-resistant Chryseobacterium indologenes Harboring blaNDM-1 Gene Isolated from a Tertiary Care Hospital in Tripura: An Emerging Threat.

Chryseobacterium indologenes has recently been identified as an inherently drug-resistant organism, responsible for a wide spectrum of infections, mainly device-associated infections in hospital settings. The presence of carbapenem resistance due to blaNDM-1 metallo-β-lactamase (MBL) gene further complicates the matter, leading to widespread dissemination of carbapenem resistance. This study aims to find out the presence of blaNDM-1 gene among C. indologenes strains causing bloodstream infections in a tertiary care hospital. During 1 year of the study period, blood culture samples were collected from patients with features of bacteremia, and C. indologenes strains were isolated and identified as per protocol. Antibiotic sensitivity test was performed by using VITEK 2 Compact Automated AST machine (Biomerieux, France). Carbapenem-resistant strains were subjected to a combined disk diffusion test for detecting the presence of MBL enzyme. Strains positive for MBL production were subjected to a polymerase chain reaction (PCR) for detection of blaNDM-1 gene. Out of 21 strains isolated during the study period, 12 strains (57.1%) were carbapenem-resistant. Among them, seven strains (58.3%) were MBL producers. After PCR, 3 strains (42.9%) were found to be harboring blaNDM-1 gene Discussion: As per our knowledge, this is the first report of blaNDM-1 gene harboring C. indologenes strain from Northeast India. This shows the emerging therapeutic dilemma due to the narrowing of treatment options against bloodstream infections due to C. indologenes strains. Strict antimicrobial stewardship has to be implemented to prevent the further compounding of the problem.