Decolonization in Prevention of Health Care-Associated Infections

Chlorhexidine Improves Hygiene Reducing Oral Polymorphonuclear Leukocytes with Antimicrobial Effects at Distinct Microenvironments amongst Subjects Stratified by Health Status

Oral conditions such as gingivitis and oral malodor are commonly reported globally. Objective: This investigation clinically stratified subjects to healthy, malodor and gingivitis groups and enumerated oral polymorphonuclear leukocytes (PMN) as a measure of inflammation prior to and after rinsing with a chlorhexidine (CHX) mouthwash. The study also assessed clinical outcomes (dental plaque and gingival bleeding indices), malodor (halimeter scores, organoleptic and tongue coat index and microbiological parameters (anaerobic and malodor organisms of dental plaque, tongue surface and saliva) for a comprehensive assessment of the oral inflammatory burden. Methods: Consenting adults were stratified into control (n = 17), gingivitis (n = 19) and halitosis (n = 17) groups based on clinical criteria. At baseline, oral samples were examined for PMN in addition to microbiological analysis of dental plaque, saliva and tongue scrapings for anaerobic and malodor bacteria. Subjects were issued a commercially available fluoride toothpaste and a chlorhexidine mouthwash for two-week use prior to post-treatment assessments identical to baseline. Results: At baseline, PMN were lowest in the control that increased amongst the halitosis subjects, with the gingivitis group registering the highest levels (p < 0.05) with these outcomes corresponding with clinical parameters (p < 0.05). CHX use improved outcomes with a 56−61% reduction in PMN with significant differences between groups (p < 0.05). Dental plaque and bleeding indices were lower by 57−78% with oral malodor, demonstrating reductions of 33−59% (p < 0.05). Significant reductions in anaerobic and malodor organisms ranging from 78−96% and 76−94%, respectively, were noted after CHX use (p < 0.05). Conclusions: At study enrollment, PMN scores were lowest in healthy subjects, with increasing numbers amongst halitosis followed by gingivitis. Amongst all subject groups, CHX use significantly reduced oral PMN and corroborated with corresponding decreases in clinical, malodor and bacterial outcomes. Together, these results demonstrate the significant reductions in the oral inflammatory burden following CHX use.

Association between Gut Colonization of Vancomycin-resistant Enterococci and Liver Transplant Outcomes

BACKGROUND

Vancomycin-resistant enterococci (VRE) colonization is common in liver transplant recipients and has been associated with worse post-transplant outcomes.

METHODS

We conducted a retrospective cohort study at the University of Alberta Hospital including patients who underwent a liver transplant between September 2014 and December 2017.

RESULTS

Of 343 patients, 68 (19.8%) had pre-transplant VRE colonization and 27 (27/275, 9.8%) acquired VRE post-transplant, 67% were males and the median age was 56.5 years. VRE colonized patients at baseline had higher MELD scores and required longer post-transplant hospitalization. VRE colonization was associated with increased risk of early acute kidney injury (AKI) (64% vs 52%, p = 0. 044), clinically significant bacterial/fungal infection (29% vs 17%, p = 0. 012) and invasive VRE infection (5% vs 1%, p = 0. 017). Mortality at 2-years was 13% in VRE-colonized versus 7% in non-colonized (p = 0.085). On multivariate analysis, VRE colonization increased the risk of post-transplant AKI (HR 1.504, 95% CI: 1.077-2.100, p = 0.017) and clinically significant bacterial or fungal infection at 6 months (HR 2.038, 95%CI: 1.222-3.399, p = 0.006), and was associated with non-significant trend towards increased risk of mortality at 2-years post-transplant (HR 1.974 95% CI 0.890-4.378; p = 0.094).

CONCLUSIONS

VRE colonization in liver transplant patients is associated with increased risk of early AKI, clinically significant infections, and a trend towards increased mortality at 2-years. This article is protected by copyright. All rights reserved.

Preventing Infection in Implant-based Breast Reconstruction: Evaluating the Evidence for Common Practices and Standardized Protocols

Infection following implant-based breast reconstruction (IBBR) results in increased rates of hospital readmission, reoperation, patient and hospital expenses, and reconstructive failure. IBBR is a complex, multistep procedure, and there is a relative lack of high-quality plastic surgery evidence regarding "best practices" in the prevention of implant infections. In the absence of strong data, standardizing procedures based on available evidence can reduce error and improve efficacy and outcomes.

Methods

We performed a focused literature review of the available evidence supporting specific interventions for infection prevention in the preoperative, intraoperative, and postoperative phases of care that are applicable to IBBR. In addition, we examined previously published standardized perioperative protocols for implant reconstruction.

Results

Preoperative, intraoperative, and postoperative planning and organization is crucial in IBBR. Preoperative planning involves skin decolonization in advance of surgery with either chlorhexidine gluconate or mupirocin. Intraoperative methods that have shown potential benefit include double-gloving, breast pocket irrigation, separate closing instruments, and the utilization of "no-touch" techniques. In the postoperative period, the duration of drain removal and postoperative antibiotic administration play an important role in the prevention of surgical site infection.

Conclusions

There is a crucial need to establish an evidence-based set of "best practices" for IBBR, and there exists a paucity of evidence in the breast literature. These data can be utilized to develop a standardized protocol as part of a rigorous quality improvement methodology.

Reduced chlorhexidine susceptibility is associated with tetracycline resistance tet genes in clinical isolates of Escherichia coli

Chlorhexidine is a widely used antiseptic in hospital and community healthcare. Decreased susceptibility to this compound has been recently described in Klebsiella pneumoniae and Pseudomonas aeruginosa, together with cross-resistance to colistin. Surprisingly, few data are available for Escherichia coli, the main species responsible for community and healthcare-associated infections. In order to decipher chlorhexidine resistance mechanisms in E. coli, we studied both in vitro derived and clinical isolates through whole-genome sequence analysis. Comparison of strains grown in vitro under chlorhexidine pressure identified mutations in the gene mlaA coding for a phospholipid transport system. Phenotypic analyses of single-gene mutant from the Keio collection confirmed the role of this mutation in the decreased susceptibility to chlorhexidine. However, mutations in mlaA were not found in isolates from large clinical collections. In contrast, genome wide association studies (GWAS) showed that, in clinical strains, chlorhexidine reduced susceptibility was associated with the presence of tetA genes of class B coding for efflux pumps and located in a Tn10 transposon. Construction of recombinant strains in E. coli K-12 confirmed the role of tetA determinant in acquired resistance to both chlorhexidine and tetracycline. Our results reveal two different evolutionary paths leading to chlorhexidine decreased susceptibility: one restricted to in vitro evolution conditions and involving a retrograde phospholipid transport system; the other observed in clinical isolates associated with efflux pump TetA. None of these mechanisms provides cross-resistance to colistin. This work demonstrates the GWAS power to identify new resistance mechanisms in bacterial species.

Guidelines in Practice: Preoperative Patient Skin Antisepsis

Surgical site infections (SSIs) frequently involve resident bacteria (eg, Staphylococcus aureus) on the patient's skin. Strategies to help prevent SSIs include removing soil and transient microorganisms from the skin before surgery. Preoperative decolonization, preoperative bathing, and application of an effective skin antiseptic at the surgical site are components of a multimodal approach to reducing microorganisms to subpathogenic levels. As members of an interdisciplinary team, perioperative RNs are essential in the development and implementation of SSI prevention bundles to promote patient safety. This article discusses recommendations from the AORN "Guideline for preoperative patient skin antisepsis" for decolonization protocols, preoperative bathing, and selection of surgical site antiseptics. A scenario describes the process a facility team uses to determine components of an SSI prevention bundle after recognizing an increase in infections from multidrug-resistant organisms.

Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant Gram ‐negatives

Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations for Surgical Technique for Spinal Cord Stimulation

INTRODUCTION

The field of neurostimulation for the treatment of chronic pain is a rapidly developing area of medicine. Although neurostimulation therapies have advanced significantly as a result of technologic improvements, surgical planning, device placement, and postoperative care are of equal importance to optimize outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for these often-overlooked areas of neurostimulation practice.

MATERIALS AND METHODS

Authors were chosen based on their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from the last NACC publication in 2017 to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on evidence strength and consensus when evidence was scant.

RESULTS

This NACC project provides guidance on preoperative assessment, intraoperative techniques, and postoperative management in the form of consensus points with supportive evidence. These results are based on grade of evidence, strength of consensus, and expert opinion.

CONCLUSIONS

The NACC has given guidance for a surgical plan that encompasses the patient journey from the planning stage through the surgical experience and postoperative care. The overall recommendations are designed to improve efficacy and the safety of patients undergoing these neuromodulation procedures and are intended to apply throughout the international community.

Strategies for the implementation of a nasal decolonization intervention to prevent surgical site infections within the Veterans Health Administration

As part of a multicenter evidence-based intervention for surgical site infection prevention, a qualitative study was conducted with infection control teams and surgical staff members at three Department of Veterans Affairs Healthcare Systems in the USA. This study aimed to identify strategies used by nurses and other facility champions for the implementation of a nasal decolonization intervention. Site visit observations and field notes provided contextual information. Interview data were analyzed with inductive and deductive content analysis. Interview data was mapped to the Expert Recommendations for Implementing Change (ERIC) compilation of implementation strategies. These strategies were then considered in the context of power and relationships as factors that influence implementation. We found that implementation of this evidence-based surgical site infection prevention intervention was successful when nurse champions drove the day-to-day implementation. Nurse champions sustained implementation strategies through all phases of implementation. Findings also suggest that nurse champions leveraged the influence of their role as champion along with their understanding of social networks and relationships to help achieve implementation success. Nurse champions consciously used multiple overlapping and iterative implementation strategies, adapting and tailoring strategies to stakeholders and settings. Commonly used implementation categories included: "train and educate stakeholders," "use evaluative and iterative strategies," "adapt and tailor to context," and "develop stakeholder interrelationships." Future research should examine the social networks for evidence-based interventions by asking specifically about relationships and power dynamics within healthcare organizations. Implementation of evidence-based interventions should consider if the tasks expected of a nurse champion fit the level of influence or power held by the champion.

Trial registration

ClinicalTrials.gov, identifier: NCT02216227.

Nanotechnology in combating biofilm: A smart and promising therapeutic strategy

Since the birth of civilization, people have recognized that infectious microbes cause serious and often fatal diseases in humans. One of the most dangerous characteristics of microorganisms is their propensity to form biofilms. It is linked to the development of long-lasting infections and more severe illness. An obstacle to eliminating such intricate structures is their resistance to the drugs now utilized in clinical practice (biofilms). Finding new compounds with anti-biofilm effect is, thus, essential. Infections caused by bacterial biofilms are something that nanotechnology has lately shown promise in treating. More and more studies are being conducted to determine whether nanoparticles (NPs) are useful in the fight against bacterial infections. While there have been a small number of clinical trials, there have been several in vitro outcomes examining the effects of antimicrobial NPs. Nanotechnology provides secure delivery platforms for targeted treatments to combat the wide range of microbial infections caused by biofilms. The increase in pharmaceuticals' bioactive potential is one of the many ways in which nanotechnology has been applied to drug delivery. The current research details the utilization of several nanoparticles in the targeted medication delivery strategy for managing microbial biofilms, including metal and metal oxide nanoparticles, liposomes, micro-, and nanoemulsions, solid lipid nanoparticles, and polymeric nanoparticles. Our understanding of how these nanosystems aid in the fight against biofilms has been expanded through their use.

Methicillin-Resistant Staphylococcus aureus: An Update on Prevention and Control in Acute Care Settings

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of health-care-associated infections. Controversies regarding the effectiveness of various control strategies have contributed to varying approaches to MRSA control. However, new evidence from large-scale studies has emerged, particularly concerning screening and decolonization. Importantly, implementation and outcomes of control measures in practice are not only influenced by scientific evidence, but also economic, administrative, and political factors, as demonstrated by decreasing MRSA rates in a number of countries after concerted and coordinated efforts at a national level. Flexibility to adapt measures based on local epidemiology and resources is essential for successful MRSA control.

Photodynamic disinfection and its role in controlling infectious diseases

Photodynamic therapy is witnessing a revival of its origins as a response to the rise of multi-drug resistant infections and the shortage of new classes of antibiotics. Photodynamic disinfection (PDDI) of microorganisms is making progresses in preclinical models and in clinical cases, and the perception of its role in the clinical armamentarium for the management of infectious diseases is changing. We review the positioning of PDDI from the perspective of its ability to respond to clinical needs. Emphasis is placed on the pipeline of photosensitizers that proved effective to inactivate biofilms, showed efficacy in animal models of infectious diseases or reached clinical trials. Novel opportunities resulting from the COVID-19 pandemic are briefly discussed. The molecular features of promising photosensitizers are emphasized and contrasted with those of photosensitizers used in the treatment of solid tumors. The development of photosensitizers has been accompanied by the fabrication of a variety of affordable and customizable light sources. We critically discuss the combination between photosensitizer and light source properties that may leverage PDDI and expand its applications to wider markets. The success of PDDI in the management of infectious diseases will ultimately depend on the efficacy of photosensitizers, affordability of the light sources, simplicity of the procedures, and availability of fast and efficient treatments.

Efficacy comparison of chlorhexidine and iodine preparation in reduction of surgical site infection: A systemic review and meta-analysis

BACKGROUND

Chlorhexidine and povidone-iodine are the most common disinfectants used in preoperative skin preparation. However, there is no consistent conclusion regarding the prevention of surgical site infection (SSI) and bacterial culture data.

OBJECTIVE

To assess the efficacy of chlorhexidine and povidone-iodine in the prevention of postoperative SSI and relevant bacterial data.

DESIGN

Systematic Review and Meta-Analysis SETTINGS: N/A PARTICIPANTS: N/A METHOD: Literature relevant to "skin antisepsis" and "surgical site infections" was retrieved from PUBMED, Web of Science, EMBASE, CINHAL and CNKI. The incidence of SSI was the primary outcome, while the secondary outcome was bacterial data from the infected incision. All data were analyzed with Revman 5.3 and Stata Statistical Software.

RESULTS

A total of 36 studies were identified in this study, which included 16,872 participants. This study revealed that chlorhexidine is superior to povidone-iodine in the prevention of postoperative SSI (risk ratio [RR], 0.73; 95% confidence interval [CI], 0.61-0.87; p = 0.019, I² = 39%). Further meta-regression analysis revealed that the effect of chlorhexidine was directly associated with the type of incision, but failed to differentiate between the subgroups divided according to the type of incision. With respect to bacteria colonization, the most common bacteria for chlorhexidine arm were propionibacterium's, while the most common bacteria for the iodine arm were staphylococci species.

CONCLUSION

In comparison to povidone-iodine, chlorhexidine showed better results in preventing postoperative SSI.

Characteristics of infective endocarditis in a cancer population

Background

Infective endocarditis (IE) is more common in patients with cancer as compared with the general population. Due to an immunocompromised state, the need for invasive procedures, hypercoagulability and the presence of indwelling catheters, patients with cancer are particularly predisposed to the development of IE.

Objectives

Limited information exists about IE in patients with cancer. We aimed to evaluate the characteristics of patients with cancer and IE at our tertiary care centre, including a comparison of the microorganisms implicated and their association with mortality.

Methods

A retrospective chart review of patients with cancer who had echocardiography for suspicion of endocarditis was conducted. A total of 56 patients with a confirmed diagnosis of cancer and endocarditis, based on the modified Duke criteria, were included in the study. Baseline demographics, risk factors for developing IE, echocardiography findings, microbiology and mortality data were analysed.

Results

Following the findings of vegetations by echocardiography, the median survival time was 8.5 months. Staphylococcus aureus was the most common organism identified as causing endocarditis. The mitral and aortic valves were the most commonly involved sites of endocarditis. Patients with S. aureus endocarditis (SAE) had a significantly poorer survival when compared with patients without SAE (p=0.0217) over the 12-month period from diagnosis of endocarditis.

Conclusions

Overall survival of patients with cancer and endocarditis is poor, with a worse outcome in patients with SAE.

IBS Therapeutic has Broad Spectrum Antimicrobial Activity

Otilonium bromide is a poorly absorbed oral medication used to control irritable bowel syndrome. It is thought to act as a muscle relaxant in the intestine. Here we show that otilonium bromide has broad-spectrum antibacterial and antifungal activity, including against multi-drug resistant strains. Our results suggest otilonium bromide could act on enteric pathogens and may offer a new scaffold for poorly absorbed intestinal antimicrobial therapy.

Carbapenemase-producing Enterobacteriaceae in transplant patients

Carbapenemase-producing Enterobacteriaceae (CPE) are a serious public health concern and represent a major threat to immunocompromised hosts, including solid organ (SOT) and stem cell transplant (HSCT) recipients. Transplant patients are at particular risk of developing CPE colonization and/or infection due to their frequent exposure to prolonged courses of broad-spectrum antibiotics, altered immunocompetence and exposure to invasive procedures and immunosuppressive drugs. Gut colonization with CPE, in particular carbapenem-resistant Klebsiella pneumoniae, may occur before or after SOT in 2%-27% of patients and among 2%-9% of HSCT and has been associated with increased risk of developing CPE infections. In endemic areas, CPE infections occur in up to 18% of SOT, and HSCT patients can account for 5%-18% of all patients with CPE bacteraemia. Mortality rates up to 70% have been associated with CPE infections in both patient populations. The rapid initiation of an active therapy against CPE is advocated in these infections. Therapeutic options, however, are limited by the paucity of novel compounds that are currently available and by potential antibiotic-associated toxicities. Therefore, a multidisciplinary approach involving infection control and antimicrobial stewardship programmes still represents the mainstay for the management of CPE infections among transplant patients. The evidence for the use of prevention strategies such as CPE-targeted perioperative prophylaxis or gut decolonization is still scarce. Large, multicentre trials are required to better define prevention strategies and to guide the management of CPE infections in the transplant setting.

Surgical antibiotic prophylaxis in patients colonized with multidrug-resistant Gram-negative bacteria: practical and conceptual aspects

Antibiotic resistance threatens the effectiveness of surgical antibiotic prophylaxis (SAP) regimens aimed at preventing surgical site infection (SSI). With a focus on procedures in which Gram-negative bacteria (GNB) are the main pathogens causing SSI, this review summarizes the evidence and describes how SAP must evolve in response to carriage of MDR GNB among surgical patients. Randomized controlled trials of SAP for carriers of resistant GNB require prohibitively large sample sizes. No professional guidelines address the topic of adapting SAP for known carriers of resistant GNB. For patients whose carrier status is unknown, the effects of different SAP strategies have been studied for transrectal ultrasound-guided prostate biopsy and colorectal surgery. The four possible strategies for SAP in the era of antibiotic resistance are: no SAP; universal standard SAP; pre-surgical screening for carriage of antibiotic-resistant pathogens before surgery and targeted SAP (i.e. broad-spectrum antibiotics only for those who screen positive); and universal broad-spectrum SAP. The prevalence of carriage determines the efficiency of each strategy. Decolonization is a potential adjunct to SAP.

Retapamulin Activity Against Pediatric Strains of Mupirocin-resistant Methicillin-resistant Staphylococcus aureus

Retapamulin activity against 53 isolates obtained from a mupirocin-resistant community-acquired methicillin-resistant Staphylococcus aureus pediatric disease cluster was evaluated using broth microdilution. All strains were susceptible to retapamulin with minimum inhibitory concentrations ≤ 0.5 μg/mL. DNA sequence analysis of rplC and cfr identified one rplC strain variant that did not demonstrate reduced phenotypic susceptibility to retapamulin. These results demonstrate that retapamulin may be a useful alternative therapy for mupirocin-resistant community-acquired methicillin-resistant S. aureus, especially in disease clusters.

Effectiveness of a Multicomponent Intervention to Reduce Multidrug-Resistant Organisms in Nursing Homes: A Cluster Randomized Clinical Trial

IMPORTANCE

Multidrug-resistant organisms (MDROs) can cause significant morbidity and mortality. Preventing MDROs can reduce the risk of subsequent transmission and infection.

OBJECTIVE

To determine whether a multicomponent infection prevention intervention can reduce MDRO prevalence in nursing homes (NHs).

DESIGN, SETTING, AND PARTICIPANTS

This cluster randomized clinical trial of a multicomponent intervention was conducted in 6 NHs in Michigan from September 2016 to August 2018. Three NHs adopted a multicomponent intervention, while 3 control NHs continued without investigator intervention. Study visits were conducted at baseline; days 7, 14, 21, and 30; and monthly thereafter for up to 6 months or discharge. Visits included clinical data collection and MDRO surveillance culturing of multiple body sites and high-touch surfaces in patient rooms. Any patients who provided informed consent within 14 days of admission to the NH were enrolled in this study. Non-English speakers and patients receiving hospice care were ineligible. Analysis was performed from November 2018 to February 2020.

INTERVENTIONS

Intervention NHs adopted a multicomponent intervention that included enhanced barrier precautions, chlorhexidine bathing, MDRO surveillance, environmental cleaning education and feedback, hand hygiene promotion, and health care worker education and feedback. Control nursing homes continued standard care practices.

MAIN OUTCOMES AND MEASURES

The primary outcome, presence of MDROs, was measured longitudinally in the patient and room environment and was evaluated using generalized mixed effect models. The secondary outcome, time to new MDRO acquisition, was assessed using Cox proportional hazard models.

RESULTS

A total of 6 NHs were included, with 245 patients (mean [SD] age, 72.5 [13.6] years; 134 [54.7%] women) enrolled; 3 NHs with 113 patients (46.1%) were randomized to the intervention group and 3 NHs with 132 patients (53.9%) were randomized to the control group. A total of 132 patients (53.9%) were White, and 235 patients (95.9%) were receiving postacute care. Over 808 study visits, 3654 patient cultures and 5606 environmental cultures were obtained. The intervention reduced the odds of MDRO prevalence in patients' environment by 43% (aOR, 0.57; 95% CI, 0.35-0.94), but there was no statistically significant difference on the patient level before or after adjustment (aOR, 0.57; 95% CI, 0.29-1.14). There were no significant reductions in time to new acquisition for methicillin-resistant Staphylococcus aureus (hazard ratio [HR], 0.20; 95% CI, 0.04-1.09), vancomycin-resistant enterococci (HR, 0.84; 95% CI, 0.46-1.53), or resistant gram-negative bacilli (HR, 1.14; 95% CI, 0.73-1.78).

CONCLUSIONS AND RELEVANCE

This cluster randomized clinical trial found that the multicomponent intervention reduced the prevalence of MDROs in the environment of NH patients. Our findings highlight the potential for multicomponent interventions to directly and indirectly reduce MDRO prevalence in NHs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02909946.

Skin infections due to Panton-Valentine leukocidin (PVL)-producing S. aureus-Cost effectiveness of outpatient treatment

Introduction

Skin and soft tissue infections (SSTI) caused by Panton-Valentine leukocidin (PVL)-producing strains of Staphylococcus aureus (PVL-SA) are associated with recurrent skin abscesses. Secondary prevention, in conjunction with primary treatment of the infection, focuses on topical decolonization. Topical decolonization is a standard procedure in cases of recurrent PVL-SA skin infections and is recommended in international guidelines. However, this outpatient treatment is often not fully reimbursed by health insurance providers, which may interfere with successful PVL-SA decolonization.

Aim

Our goal was to estimate the cost effectiveness of outpatient decolonization of patients with recurrent PVL-SA skin infections. We calculated the average cost of treatment for PVL-SA per outpatient decolonization procedure as well as per in-hospital stay.

Methods

The study was conducted between 2014 and 2018 at a German tertiary care university hospital. The cohort analyzed was obtained from the hospital’s microbiology laboratory database. Data on medical costs, DRG-based diagnoses, and ICD-10 patient data was obtained from the hospital’s financial controlling department. We calculated the average cost of treatment for patients admitted for treatment of PVL-SA induced skin infections. The cost of outpatient treatment is based on the German regulations of drug prices for prescription drugs.

Results

We analyzed a total of n = 466 swabs from n = 411 patients with recurrent skin infections suspected of carrying PVL-SA. PVL-SA was detected in 61.3% of all patients included in the study. Of those isolates, 80.6% were methicillin-susceptible, 19.4% methicillin-resistant. 89.8% of all patients were treated as outpatients. In 73.0% of inpatients colonized with PVL-SA the main diagnosis was SSTI. The median length of stay was 5.5 days for inpatients colonized with PVL-SA whose main diagnosis SSTI; the average cost was €2,283. The estimated costs per decolonization procedure in outpatients ranged from €50-€110, depending on the products used.

Conclusion

Our data shows that outpatient decolonization offers a highly cost-effective secondary prevention strategy, which may prevent costly inpatient treatments. Therefore, health insurance companies should consider providing coverage of outpatient treatment of recurrent PVL-SA skin and soft tissue infections.

Evaluation of effectiveness and compliance with the mupirocin nasal ointment part of Staphylococcus aureus decolonization in real life using UPLC-MS/MS mupirocin quantification

BACKGROUND

Preoperative decolonization is recommended in Staphylococcus aureus nasal carriers scheduled for cardiac surgery. We aimed to evaluate the effectiveness of and compliance with mupirocin use in nasal S. aureus carriers in a real-life setting.

METHODS

Prospective study including consecutive patients scheduled for cardiac surgery screened for S. aureus nasal carriage at preoperative consultation. Carriers were prescribed mupirocin nasal ointment, chlorhexidine shower and mouthwash. Effectiveness of decolonization was evaluated with a postoperative nasal sample. Compliance was evaluated objectively by determination of nasal mupirocin concentration using UPLC-MS/MS and self-reported by questionnaire.

RESULTS

Over 10 months, 361 patients were included, 286 had preoperative screening, 75 (26.2%) were S. aureus nasal carriers and 19 of them (25.3%) failed to be effectively decolonized. No resistance to mupirocin was documented. Preoperative and postoperative strains were identical in all cases. Declared good compliance was associated with decolonization success (OR = 24; 95% CI 4-143, P < 0.0001). Mupirocin detection was significantly associated with the level of compliance. Mupirocin was detected in 52.2% (24/46) of patients effectively decolonized and in 12.5% (2/16) of patients with decolonization failure (P < 0.01). In 2/19 patients, failure of decolonization was not associated with a compliance issue. Postoperative carriage was associated with an increased risk of S. aureus infection (OR = 9.8; 95% CI 1.8-53, P < 0.01).

CONCLUSIONS

In real life, decolonization is not always effective, hence there is a persisting risk of S. aureus endogenous infection. Mupirocin concentration measurement may help to understand compliance issues and failures in decolonization.

Clinical relevance of topical antibiotic use in co-selecting for multidrug-resistant Staphylococcus aureus: Insights from in vitro and ex vivo models

Topical antibiotic preparations, such as fusidic acid (FA) or mupirocin, are used in the prevention and treatment of superficial skin infections caused by staphylococci. Previous genomic epidemiology work has suggested an association between the widespread use of topical antibiotics and the emergence of methicillin resistant Staphylococcus aureus in some settings. In this study, we provide experimental proof of co-selection for multidrug resistance in S. aureus following exposure to FA or mupirocin. Through targeted mutagenesis and phenotypic analyses, we confirmed that fusC carriage confers resistance to FA, and mupA carriage confers high-level resistance to mupirocin in multiple S. aureus genetic backgrounds. In vitro experiments demonstrated that carriage of fusC and mupA confer a competitive advantage in the presence of sub-inhibitory concentrations of FA and mupirocin, respectively. Further, we used a porcine skin colonisation model to show that clinically relevant concentrations of topical antibiotics can co-select for presence of unrelated antimicrobial resistance determinants, such as mecA, blaZ, and qacA, in fusC or mupA harbouring S. aureus These findings provide valuable insights on the role of acquired FA or mupirocin resistance in co-selecting for broader antibiotic resistance in S. aureus, prompting greater need for judicious use of topical antibiotics.

[Clustering and influencing factors of Streptococcus pneumoniae carriage among kindergarten children]

OBJECTIVE

To study the clustering and influencing factors of Streptococcus pneumoniae carriage among kindergarten children, and to provide a scientific basis for the prevention of pneumococcal diseases.

METHODS

The multi-stage stratified cluster sampling method was used to collect nasal swabs via the nasal vestibule at both sides from 1 702 kindergarten children in Liuzhou, China. A questionnaire survey was performed on their parents. The chi-square test and the random effects logistic regression analysis were used to analyze data.

RESULTS

The carriage rate of Streptococcus pneumoniae was 13.16% (224/1 702) among kindergarten children. The clustering analysis showed that the class-level random effect of Streptococcus pneumoniae carriage was statistically significant (Z=2.07, P=0.038), with an intraclass correlation coefficient of 5.9%. The random effects logistic regression analysis showed that the children aged 5-7 years had a lower risk of Streptococcus pneumoniae carriage than those aged 2-< 5 years (OR=0.55, 95%CI:0.40-0.76, P=0.001), and the children with ≥ 5 family members living together had a higher risk of Streptococcus pneumoniae carriage than those with < 5 family members (OR=1.34, 95%CI:1.01-1.79, P=0.043).

CONCLUSIONS

Streptococcus pneumoniae carriage shows a class-level clustering effect, and age and the number of cohabitants are important influencing factors for Streptococcus pneumoniae carriage in children.

Universal admission screening: a potential game-changer in hospitals with high prevalence of MRSA

INTRODUCTION

Despite the perception that meticillin-resistant Staphylococcus aureus (MRSA) is now under control in high-income countries, global prevalence remains high, even increasing in some regions. Universal admission screening and decolonization has been instituted in some hospitals to attempt control but the practice remains controversial.

METHODS

In 2014, Mater Dei Hospital in Malta introduced a universal admission screening policy, utilizing a novel, centralized and customized approach to achieve high compliance and low cost. Admissions are screened nasally by designated staff using chromogenic media, irrespective of risk factors. Carriers are decolonized without concurrent isolation or contact precautions. In this study, longitudinal, quasi-experimental evaluation was undertaken using time series analysis to analyse the impact of the intervention on the proportion of MRSA among clinical S. aureus isolates (%MRSA) and incidence per 1000 bed-days. A cost-utility analysis was also attempted to identify approximate quality-adjusted life years (QALYs) gained.

RESULTS

A transfer function model approach concluded that the intervention had a significant effect on both %MRSA and incidence. Six years following its introduction, the screening programme had led to an overall 43% long-term reduction in %MRSA from pre-screening levels [R²=0.687; Bayesian information criterion (BIC)=4.063], translating to a decrease in incidence of approximately 0.56 cases/1000 bed-days (R²=0.633, BIC=-3.063). No correlation was identified with consumption of antibiotics or alcohol hand rub. The annual cost-benefit of the programme was calculated at €1058 per QALY gain per year.

CONCLUSION

The universal admission screening and decolonization intervention was successful and cost-effective in this high-endemicity setting. It facilitated improvement in the prevalence of MRSA, achieving reduction levels rarely reported by Mediterranean hospitals.

[Clustering and influencing factors of Streptococcus pneumoniae carriage among kindergarten children]

OBJECTIVE

To study the clustering and influencing factors of Streptococcus pneumoniae carriage among kindergarten children, and to provide a scientific basis for the prevention of pneumococcal diseases.

METHODS

The multi-stage stratified cluster sampling method was used to collect nasal swabs via the nasal vestibule at both sides from 1 702 kindergarten children in Liuzhou, China. A questionnaire survey was performed on their parents. The chi-square test and the random effects logistic regression analysis were used to analyze data.

RESULTS

The carriage rate of Streptococcus pneumoniae was 13.16% (224/1 702) among kindergarten children. The clustering analysis showed that the class-level random effect of Streptococcus pneumoniae carriage was statistically significant (Z=2.07, P=0.038), with an intraclass correlation coefficient of 5.9%. The random effects logistic regression analysis showed that the children aged 5-7 years had a lower risk of Streptococcus pneumoniae carriage than those aged 2-< 5 years (OR=0.55, 95%CI:0.40-0.76, P=0.001), and the children with ≥ 5 family members living together had a higher risk of Streptococcus pneumoniae carriage than those with < 5 family members (OR=1.34, 95%CI:1.01-1.79, P=0.043).

CONCLUSIONS

Streptococcus pneumoniae carriage shows a class-level clustering effect, and age and the number of cohabitants are important influencing factors for Streptococcus pneumoniae carriage in children.

Novel Approaches to Combat Medical Device-Associated BioFilms

Biofilms are aggregates formed as a protective survival state by microorganisms to adapt to the environment and can be resistant to antimicrobial agents and host immune responses due to chemical or physical diffusion barriers, modified nutrient environments, suppression of the growth rate within biofilms, and the genetic adaptation of cells within biofilms. With the widespread use of medical devices, medical device-associated biofilms continue to pose a serious threat to human health, and these biofilms have become the most important source of nosocomial infections. However, traditional antimicrobial agents cannot completely eliminate medical device-associated biofilms. New strategies for the treatment of these biofilms and targeting biofilm infections are urgently required. Several novel approaches have been developed and identified as effective and promising treatments. In this review, we briefly summarize the challenges associated with the treatment of medical device-associated biofilm infections and highlight the latest promising approaches aimed at preventing or eradicating these biofilms.

Targeting leukocidin-mediated immune evasion protects mice from Staphylococcus aureus bacteremia

Staphylococcus aureus is responsible for various diseases in humans, and recurrent infections are commonly observed. S. aureus produces an array of bicomponent pore-forming toxins that target and kill leukocytes, known collectively as the leukocidins. The contribution of these leukocidins to impair the development of anti–S. aureus adaptive immunity and facilitate reinfection is unclear. Using a murine model of recurrent bacteremia, we demonstrate that infection with a leukocidin mutant results in increased levels of anti–S. aureus antibodies compared with mice infected with the WT parental strain, indicating that leukocidins negatively impact the generation of anti–S. aureus antibodies in vivo. We hypothesized that neutralizing leukocidin-mediated immune subversion by vaccination may shift this host-pathogen interaction in favor of the host. Leukocidin-immunized mice produce potent leukocidin-neutralizing antibodies and robust Th1 and Th17 responses, which collectively protect against bloodstream infections. Altogether, these results demonstrate that blocking leukocidin-mediated immune evasion can promote host protection against S. aureus bloodstream infection.

Assessing the Potential for Unintended Microbial Consequences of Routine Chlorhexidine Bathing for Prevention of Healthcare-associated Infections

Chlorhexidine gluconate (CHG) is an antiseptic that is widely used in healthcare due to its excellent safety profile and wide spectrum of activity. Daily bathing with CHG has proven to be effective in the prevention of healthcare-associated infections and multidrug-resistant pathogen decolonization. Despite the proven benefits of CHG use, there remain concerns and unanswered questions about the potential for unintended microbial consequences of routine CHG bathing. This review aims to explore some of these questions.

A Systematic Review of Breast Irrigation in Implant-Based Breast Surgery

BACKGROUND

Aesthetic and reconstructive implant-based breast surgeries are some of the most frequently performed procedures by plastic surgeons. As such, prevention of implant infection is of high importance. However, there remains no criterion-standard protocol for irrigation of the breast pocket. This review focuses on current irrigation practices in implant-based breast surgery.

METHODS

Four databases were used to search for all studies, including randomized controlled trials, retrospective cohort, and prospective cohort, containing original data related to the outcomes investigated in this study. Search terms included "breast," "irrigation," and "infection" in different combinations to isolate studies that focused on irrigation methods in both reconstructive and augmentation surgeries. Our selection criteria specifically concentrated on those studies that explicitly related irrigation procedures to rates of clinical infection and/or capsular contracture. Each was compiled into a table in chronological order to make comparisons between the differing irrigation methods.

RESULTS

Our search returned 239 full-text articles eligible for our review. Two independent screeners identified 9 studies that met the inclusion criteria. This included 1 prospective study and 8 retrospective studies. Two studies reported the use of chlorhexidine gluconate irrigation resulting in protection from clinical infection. Two studies investigated the role of triple antibiotic solution (TAS) either alone or combined with something else on risk of infection, and 3 reported TAS use on rates of capsular contracture. Two additional studies investigated the role of single antibiotic irrigation, concluding that some antibiotic regimen for irrigation may be sufficient in the breast pocket. Interestingly, one study noted the potential use of povidone-iodine (Betadine) as a method of irrigation.

CONCLUSIONS

These data suggest that chlorhexidine gluconate, Betadine, and TAS irrigation of the breast pocket can provide protection against infection and implant loss in both reconstruction and augmentation surgeries.

Murine model of colonization with fungal pathogen Candida auris to explore skin tropism, host risk factors and therapeutic strategies

Candida auris is an emerging multi-drug-resistant human fungal pathogen. C. auris skin colonization results in environmental shedding, which underlies hospital transmissions, and predisposes patients to subsequent infections. We developed a murine skin topical exposure model for C. auris to dissect risk factors for colonization and to test interventions that might protect patients. We demonstrate that C. auris establishes long-term residence within the skin tissue compartment, which would elude clinical surveillance. The four clades of C. auris, with geographically distinct origins, differ in their abilities to colonize murine skin, mirroring epidemiologic findings. The IL-17 receptor signaling and specific arms of immunity protect mice from long-term C. auris skin colonization. We further determine that commonly used chlorhexidine antiseptic serves as a protective and decolonizing agent against C. auris. This translational model facilitates an integrated approach to develop strategies to combat the unfolding global outbreaks of C. auris and other skin-associated microbial pathogens.

Economic Evaluations of New Antibiotics: The High Potential Value of Reducing Healthcare Transmission Through Decolonization

Background

Antibiotics designed to decolonize carriers of drug-resistant organisms could offer substantial population health benefits, particularly if they can help avert outbreaks by interrupting person-to-person transmission chains. However, cost effectiveness of an antibiotic is typically evaluated only according to its benefits to recipients, which can be difficult to demonstrate for carriers of an organism that may not pose an immediate health threat to the carrier.

Methods

We developed a mathematical transmission model to quantify the effects of 2 hypothetical antibiotics targeting carbapenem-resistant Enterobacteriaceae (CRE) among long-term acute care hospital inpatients: one assumed to decrease the death rate of patients with CRE bloodstream infections (BSIs) and the other assumed to decolonize CRE carriers after clinical detection. We quantified the effect of each antibiotic on the number of BSIs and deaths among patients receiving the drug (direct effect) and among all patients (direct and indirect effect) compared to usual care. We applied these results to a cost-effectiveness analysis with effectiveness outcome of life-years gained and assumed costs for antibiotic doses and for CRE BSI.

Results

The decolonizing antibiotic, once indirect effects were included, produced increased relative effectiveness and decreased relative costs compared to both usual care and the BSI treatment antibiotic. In fact, in most scenarios, the decolonizing drug was the dominant treatment strategy (ie, less costly and more effective).

Conclusions

Antibiotics that decolonize carriers of drug-resistant organisms can be highly cost-effective when considering indirect benefits within populations vulnerable to outbreaks. Public health could benefit from finding ways to incentivize development of decolonizing antibiotics in the US, where drugs with unclear direct benefits to recipients would pose difficulties in achieving FDA approval and financial benefit to the developer.

Access to thermally robust and abrasion resistant antimicrobial plastics: synthesis of UV-curable phosphonium small molecule coatings and extrudable additives

The threat of antibiotic-resistant, biofilm-forming bacteria necessitates a preventative approach to combat the proliferation of robust, pathogenic strains on "high touch surfaces" in the food packaging, biomedical, and healthcare industries. The development of both biocide-releasing and tethered, immobilized biocide surface coatings has risen to meet this demand. While these surface coatings have demonstrated excellent antimicrobial efficacy, there are few examples of antimicrobial surfaces with long-term durability and performance. To this end, UV-curable phosphoniums bearing benzophenone anchors with either an alkyl, aryl, or fluoroalkyl group were synthesized and their efficacy as thermally stable antimicrobial additives in extruded plastics or as surface attached coatings probed. The surface topology and characteristics of these materials were studied to gain insight into the mechanism of their antimicrobial activity. Efficacy against both Gram negative and Gram positive bacteria as either a coating or additive showed compete reductions of the initial bacterial load. Crucially, the materials maintained the ability to kill biofilm-forming bacteria even after being subject to several cycles of abrasion.

Combination of toothbrushing and chlorhexidine compared with exclusive use of chlorhexidine to reduce the risk of ventilator-associated pneumonia: A systematic review with meta-analysis

This study aimed to compare the effectiveness of 0.12% chlorhexidine alone and 0.12% chlorhexidine in combination with toothbrushing to prevent ventilator-associated pneumonia (VAP) in mechanically ventilated patients. The Embase, Latin American and Caribbean Health Science Literature, PubMed, Scientific Electronic Library Online, Scopus, LIVIVO, Web of Science, Cochrane Library, OpenThesis, and Open Access Thesis and Dissertations databases were used. Only randomized controlled trials without restrictions on the year or language of publication were included. Two reviewers assessed the risk of bias using the Joanna Briggs Institute Critical Appraisal Tool. A meta-analysis using a random-effects model estimated the combined relative risk (RR). The Grading of Recommendations, Assessment, Development and Evaluations approach was used to assess the certainty of the evidence. Initially, 2,337 studies were identified, of which 4 were considered in the systematic review and 3 in the meta-analysis (total sample: 796 patients). The studies were published between 2009 and 2017. All eligible studies had a low risk of bias. The meta-analysis revealed that the risk of VAP was 24% lower in patients receiving chlorhexidine combined with toothbrushing than in those receiving chlorhexidine alone (RR: 0.76; 95% confidence interval: 0.55-1.06), with moderate certainty of evidence and without statistical significance. In conclusion, considering the limitations of this study, a standard protocol for the prevention of VAP is not yet recommended. More studies with larger sample sizes are needed to draw strong conclusions. However, considering that toothbrushing is a simple intervention, it should be a common practice in mechanically ventilated patients, especially among patients with coronavirus disease.

Prevalence of biocide resistance genes and chlorhexidine and mupirocin non-susceptibility in Portuguese hospitals during a 31-year period (1985-2016)

OBJECTIVES

Methicillin-resistantStaphylococcus aureus (MRSA) remains a major human pathogen. MRSA decolonisation strategies frequently combine chlorhexidine baths and mupirocin nasal ointment. Although MRSA remains widespread in Portuguese hospitals, information regarding resistance to biocides and mupirocin is scarce. We evaluated the prevalence of biocide resistance genes and chlorhexidine and mupirocin non-susceptibility in a representative and well-characterised collection of MRSA isolated in Portuguese hospitals during a 31-year period (1985-2016).

METHODS

Prevalence of five biocide resistance genes (lmrS, mepA, sepA, qacAB and smr) was determined by PCR. Antibiotic susceptibility was assessed by disk diffusion and by MIC determination using broth microdilution (chlorhexidine) and Etest (mupirocin).

RESULTS

Chromosomal genessepA and mepA were detected in all isolates, while lmrS was found in 87.1%. The prevalence of plasmid-borne genes was significant for qacAB (22.4%), associated with the Iberian (ST247-I/IA) clone (P < 0.0001), and low for smr (1.0%) detected among isolates belonging to the ST239-III/IIIvariant clone. Chlorhexidine non-susceptibility (MIC ≥ 4 mg/L) was observed in two isolates belonging to the EMRSA-15 clone (ST22-IV). Non-susceptibility to mupirocin (MIC > 1 mg/L) was significant (15.4%; n = 31) and mainly found among isolates of the EMRSA-15 clone (P < 0.0001; n = 29). One isolate presented low-level mupirocin resistance (MIC = 32 mg/L), and two missense mutations N213D (A637G) and V588F (G1762T) were identified in the ileS gene.

CONCLUSION

Concerningly, we detected a high prevalence of biocide resistance genes and an association of mupirocin and chlorhexidine non-susceptibility with the dominant EMRSA-15 clone in Portuguese hospitals.

Decolonization of Staphylococcus aureus

Staphylococcus aureus infections are associated with increased morbidity, mortality, hospital stay, and health care costs. S aureus colonization has been shown to increase risk for invasive and noninvasive infections. Decolonization of S aureus has been evaluated in multiple patient settings as a possible strategy to decrease the risk of S aureus transmission and infection. In this article, we review the recent literature on S aureus decolonization in surgical patients, patients with recurrent skin and soft tissue infections, critically ill patients, hospitalized non-critically ill patients, dialysis patients, and nursing home residents to inform clinical practice.

A safer, less costly SSI prevention protocol-Universal versus targeted preoperative decolonization

Surgical site infection after total joint replacement results in significant patient suffering and health care costs. To reduce the risk of surgical site infection after total joint procedures, 1 hospital instituted preoperative universal nasal and skin decolonization, using an alcohol based nasal antiseptic and chlorhexidine bathing. This resulted in reduced infection rates, and associated patient morbidity and costs to the facility.

Efficacy of universal preoperative decolonization with Polyhexanide in primary joint arthroplasty on surgical site infections. A multicenter before-and after-study

Background

Surgical site infections (SSI) are rare but severe complications after total joint arthroplasty (TJA). Decolonization measures prior to elective orthopedic surgeries have shown to reduce the risk of SSI with Staphylococcus aureus (S. aureus).

Objective

To determine the efficacy of universal decolonization with Polyhexanide on SSI rates with a focus on Staphylococcus aureus in patients with TJA.

Methods

Patients scheduled for elective hip or knee TJA in 5 participating certified orthopedic centers were included between 2015 and 2018 into this before and after study. Data on patients, surgeries and infections were prospectively collected. CDC-criteria were used to define and categorize Infections within 90 days after surgery. From January 2017 on, patients received decolonization sets containing Polyhexanide. Patients performed a 5 day decolonization regimen starting 4 days prior to surgery which included wipes, nasal decontamination and oral solution.

Results

Thirteen thousand, three hundred fifteen patients received TJA. During intervention 4437 decolonization sets were distributed among 7175 patients.

Overall SSI rates increased from 0.68 /100 surgeries to 0.91/ 100 surgeries after implementation of the intervention (IRR 1.32; 95% CI 0.90–1.96). Time series analysis identified an increasing trend of SSI prior to the intervention. After implementation overall SSI rates plateaued. Regression analysis revealed surgery during intervention period to be an independent risk factor for developing a SSI (OR 1.34; 95%CI 1.18–1.53).

Initial SSI rates due to S. aureus were 0.24/100 surgeries and decreased to 0.14/100 surgeries (IRR 0.57; 95% CI 0.25–1.22) after introduction of decolonization. Regression analysis revealed surgery during intervention period to be an independent protective factor for developing a SSI with S. aureus (OR 0.57, 95% CI: 0.33–0.99).

Overall deep S. aureus SSI decreased significantly from 0.22/100 surgeries to 0.00/100 surgeries in patients adherent to protocol (IRR 0.00, 95% CI 0.00–.85).

Conclusion

Universal decolonization with Polyhexanide did not reduce overall surgical site infections, but was effective in reducing Staphylococcus aureus - surgical site infections following elective joint arthroplasty. Polyhexanide could extend the list of alternatives to already established decolonization strategies.

Trial registration

The trial was registered at the German Registry for clinical studies www.drks.de (DRKS00011505).

Staphylococcins: an update on antimicrobial peptides produced by staphylococci and their diverse potential applications

Staphylococcins are antimicrobial peptides or proteins produced by staphylococci. They can be separated into different classes, depending on their amino acid composition, structural complexity, and steps involved in their production. In this review, an overview of the current knowledge on staphylococcins will be presented with emphasis on the information collected in the last decade, including a brief description of new peptides. Most staphylococcins characterized to date are either lantibiotics or linear class II bacteriocins. Recently, gene clusters coding for production of circular bacteriocins, sactipeptides, and thiopeptides have been mined from the genome of staphylococcal isolates. In contrast to class II bacteriocins, lantibiotics, sactipeptides, and thiopeptides undergo post-translational modifications that can be quite extensive, depending on the peptide. Few staphylococcins inhibit only some staphylococcal species, but most of them have proven to target pathogens belonging to different genera and involved in a variety of infectious diseases of clinical or agronomic importance. Therefore, these peptides exhibit potential application as anti-infective drugs in different areas. This review will also cover this diverse and remarkable potential. To be commercialized, however, staphylococcin production should be cost-effective and result in high bacteriocin yields, which are not generally achieved from the culture supernatant of their native producers. Such low yields make their production quite costly and not suitable at large industrial scale. Efforts already made to overcome this limitation, minimizing costs and time of production of some staphylococcins and employing either chemical synthesis or in vivo biosynthesis, will be addressed in this review as well. KEY POINTS: • Staphylococci produce a variety of antimicrobial peptides known as staphylococcins. • Most staphylococcins are post-translationally modified peptides. • Staphylococcins exhibit potential biotechnological applications. Graphical abstract.

Risk of hospital readmission and associated factors after a positive sample for a multidrug-resistant microorganism

BACKGROUND

To determine the risk of hospital readmission and associated factors in patients with a positive sample for multidrug-resistant microorganisms (MRM) and to analyze whether there is a higher risk of hospital readmission with some of the more common MRM.

METHODS

Retrospective cohort study (2012-16) performed in a tertiary-care teaching hospital in Barcelona. Patients were divided into two groups, depending on the presence or absence of an MRM-positive sample during hospital admission. Logistic regression models were used to estimate the risk of hospital readmission in the first 30 and 90 days, and the first year for patients with an MRM-positive sample compared with those without. The models were stratified by the presence or absence of an MRM-positive sample and by grouped Charlson comorbidity index.

RESULTS

We included 983 patients with an MRM-positive sample and 39 323 patients without. The risk of hospital readmission in the first 30 days was 41% higher in admitted patients with an MRM-positive sample (95%CI=1.17 to 1.69) than in those without. Stratified models showed similar results to the overall results for all Charlson comorbidity index groups. When the models were stratified by the presence of an MRM-positive sample, methicillin-resistant Staphylococcus aureus showed the highest risk of readmissions within the more common MRM [103% (95%CI=1.10 to 3.75)].

CONCLUSION

MRMs seem to be an important risk factor for hospital readmissions both among patients with and without comorbidities. Specific types of MRM may represent a higher risk for hospital readmissions than other MRMs, depending on the particular environment or hospital.

Model-based Assessment of the Effect of Contact Precautions Applied to Surveillance-detected Carriers of Carbapenemase-producing Enterobacteriaceae in Long-term Acute Care Hospitals

BACKGROUND

An intervention that successfully reduced colonization and infection with carbapenemase-producing Enterobacteriaceae (CPE) in Chicago-area long-term acute-care hospitals included active surveillance and contact precautions. However, the specific effects of contact precautions applied to surveillance-detected carriers on patient-to-patient transmission are unknown, as other, concurrent intervention components or changes in facility patient dynamics also could have affected the observed outcomes.

METHODS

Using previously published data from before and after the CPE intervention, we designed a mathematical model with an explicit representation of postintervention surveillance. We estimated preintervention to postintervention changes of 3 parameters: β, the baseline transmission rate excluding contact precaution effects; δb, the rate of a CPE carrier progressing to bacteremia; and δc, the progression rate to nonbacteremia clinical detection.

RESULTS

Assuming that CPE carriers under contact precautions transmit carriage to other patients at half the rate of undetected carriers, the model produced no convincing evidence for a postintervention change in the baseline transmission rate β (+2.1% [95% confidence interval {CI}, -18% to +28%]). The model did find evidence of a postintervention decrease for δb (-41% [95% CI, -60% to -18%]), but not for δc (-7% [95% CI, -28% to +19%]).

CONCLUSIONS

Our results suggest that contact precautions for surveillance-detected CPE carriers could potentially explain the observed decrease in colonization by itself, even under conservative assumptions for the effectiveness of those precautions for reducing cross-transmission. Other intervention components such as daily chlorhexidine gluconate bathing of all patients and hand-hygiene education and adherence monitoring may have contributed primarily to reducing rates of colonized patients progressing to bacteremia.

Decreased Incidence of Methicillin-Resistant Staphylococcus aureus Bacteremia in Intensive Care Units: a 10-Year Clinical, Microbiological, and Genotypic Analysis in a Tertiary Hospital

There are limited long-term data on the trends in incidence and characteristics of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia (MRSAB) in intensive care units (ICUs) in which infection control measures have been adopted. We evaluated the trend of incidence and changes in characteristics of MRSA bacteremia in ICUs at a tertiary-care hospital over 10 years using prospective cohort data. ICU-acquired bacteremia was defined as S. aureus bacteremia (SAB) that occurred 48 h or more after ICU admission. MRSA isolates were collected and subjected to microbiological and genotypic analyses. A total of 529 SAB episodes were identified among 367,175 ICU patients. Of these episodes, 288 (54.4%) were ICU acquired, 238 (82.6%) of which were MRSAB. The incidence density of ICU-acquired MRSAB decreased from 1.32 per 1,000 patient-days to 0.19 per 1,000 patient-days (a decrease of 20% annually; P < 0.001 for trend), whereas that of non-ICU-acquired MRSAB fluctuated and did not decrease significantly. The decline in ICU-acquired MRSAB was due to lower catheter-related infection and less pneumonia. Rates of persistent bacteremia and 12-week mortality also fell significantly. A total of 183 isolates were collected from 238 ICU-acquired MRSAB cases. There were no significant changes in the geometric means of vancomycin MICs, vancomycin heteroresistance, or the sequence types of MRSA isolates over time. Chlorhexidine MICs decreased (P < 0.001 for trend) in association with a decline in frequency of the qacA or qacB gene that was related to reductions in specific spa types. The incidence of MRSAB in ICUs has decreased dramatically over time, but most of the microbiological and genotypic characteristics of MRSA isolates have not changed.

Nasal decolonization of Staphylococcus aureus in orthopedic surgeons using mupirocin and chlorhexidine

Nasal mucosa colonization by Staphylococcus aureus is a risk factor for hospital-acquired infections. This study examined the effectiveness of a decolonization strategy on orthopedic surgeons in a teaching hospital. S aureus colonization was detected in 43.2% of the surgeons, 25% of which were methicillin-resistant S aureus strains. Eradication was documented in 61.53% of the subjects who completed the decolonization strategy. Among orthopedic surgeons, mupirocin with or without chlorhexidine decolonization strategies was effective in eradicating S aureus colonization.

Povidone Iodine: Properties, Mechanisms of Action, and Role in Infection Control and Staphylococcus aureus Decolonization

Nasal decolonization is an integral part of the strategies used to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) infections. The two most commonly used agents for decolonization are intranasal mupirocin 2% ointment and chlorhexidine wash, but the increasing emergence of resistance and treatment failure has underscored the need for alternative therapies. This article discusses povidone iodine (PVP-I) as an alternative decolonization agent and is based on literature reviewed during an expert’s workshop on resistance and MRSA decolonization.

Nasal decolonization is an integral part of the strategies used to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) infections. The two most commonly used agents for decolonization are intranasal mupirocin 2% ointment and chlorhexidine wash, but the increasing emergence of resistance and treatment failure has underscored the need for alternative therapies. This article discusses povidone iodine (PVP-I) as an alternative decolonization agent and is based on literature reviewed during an expert’s workshop on resistance and MRSA decolonization. Compared to chlorhexidine and mupirocin, respectively, PVP-I 10 and 7.5% solutions demonstrated rapid and superior bactericidal activity against MRSA in in vitro and ex vivo studies. Notably, PVP-I 10 and 5% solutions were also active against both chlorhexidine-resistant and mupirocin-resistant strains, respectively. Unlike chlorhexidine and mupirocin, available reports have not observed a link between PVP-I and the induction of bacterial resistance or cross-resistance to antiseptics and antibiotics. These preclinical findings also translate into clinical decolonization, where intranasal PVP-I significantly improved the efficacy of chlorhexidine wash and was as effective as mupirocin in reducing surgical site infection in orthopedic surgery. Overall, these qualities of PVP-I make it a useful alternative decolonizing agent for the prevention of S. aureus infections, but additional experimental and clinical data are required to further evaluate the use of PVP-I in this setting.

Promising Therapeutic Strategies Against Microbial Biofilm Challenges

Biofilms are communities of microorganisms that are attached to a biological or abiotic surface and are surrounded by a self-produced extracellular matrix. Cells within a biofilm have intrinsic characteristics that are different from those of planktonic cells. Biofilm resistance to antimicrobial agents has drawn increasing attention. It is well-known that medical device- and tissue-associated biofilms may be the leading cause for the failure of antibiotic treatments and can cause many chronic infections. The eradication of biofilms is very challenging. Many researchers are working to address biofilm-related infections, and some novel strategies have been developed and identified as being effective and promising. Nevertheless, more preclinical studies and well-designed multicenter clinical trials are critically needed to evaluate the prospects of these strategies. Here, we review information about the mechanisms underlying the drug resistance of biofilms and discuss recent progress in alternative therapies and promising strategies against microbial biofilms. We also summarize the strengths and weaknesses of these strategies in detail.

Impact of formulary interventions on the minimum inhibitory concentration of methicillin-resistant Staphylococcus aureus to mupirocin, chlorhexidine, and octenidine in a Singapore tertiary institution

Methicillin-resistant Staphylococcus aureus (MRSA) decolonization is an effective measure to prevent clinical infection but resistance is a concern. We aim to evaluate the impact of mupirocin (MUP) ointment formulary removal, plateauing use of chlorhexidine gluconate (CHG), and hospital-wide introduction of octenidine (OCT)-based products on the minimum inhibitory concentration (MIC) of MRSA to MUP, CHG, and OCT in our hospital. A prevalence study was conducted at three time points (TP) on consecutive MRSA screening isolates to evaluate for their MICs to MUP, CHG, and OCT using broth microdilution sensititre plates and detection of the ileS-2 gene encoding high-level MUP resistance in 2013 (pre-intervention TP1; n = 160), 2016 (early post-intervention TP2; n = 99) and 2017 (late post-intervention TP3; n = 76). Statistical analyses were performed using Chi square test with reference from TP1. There was a significant improvement in MUP susceptibility (MIC < 4 mcg/ml) from 71.9% (TP1) to 86.9% (TP2; p = 0.006) to 88.2% (TP3; p = 0.007). The prevalence of MUP high-level resistance (MIC > 256 mcg/ml) reduced from 25.0% (TP1) to 12.1% (TP2; p = 0.014) to 5.3% (TP3; p = 0.001). Likewise, the prevalence of isolates harboring the ileS-2 gene decreased from 28.1% (TP1) to 18.2% (TP2; p = 0.072) to 9.2% (TP3; p = 0.002). OCT MIC range remains stable at 0.5 to 1 mcg/ml across all three TPs. The proportion of isolates with reduced CHG susceptibility (MIC ≥ 4 mcg/ml) increased over the three TPs from 23.1 to 27.2% (p = 0.45) to 42.1% (p = 0.003). Active formulary regulations have an impact on the resistance profile of MRSA and can be used as a strategy to preserve the MRSA decolonization armamentarium.