The significance of nasal carriage of Staphylococcus aureus and the incidence of postoperative wound infection

Application of Octenidine into Nasal Vestibules Does Not Influence SARS-CoV-2 Detection via PCR or Antigen Test Methods

The targeted or universal decolonization of patients through octenidine for nasal treatment and antiseptic body wash for 3 to 5 days prior elective surgery has been implemented in several surgical disciplines in order to significantly reduce surgical site infections (SSIs) caused by Staphylococcus aureus carriage. However, as most healthcare facilities also screen patients on admission for pilot infection, it is imperative that a prophylactic nasal decolonization procedure not yield a false negative SARS-CoV-2 status in otherwise positive patients. We assessed the effect of a commercially available octenidine-containing nasal gel on two different screening methods-antigen (Ag) detection based on colloidal gold immunochromatography and RT-PCR-in a prospective-type accuracy pilot study in asymptomatic SARS-CoV-2-positive inpatients. All patients still showed a positive test result after using the octenidine-containing nasal gel for about 3 days; therefore, its application did not influence SARS-CoV-2 screening, which is of high clinical relevance. Of note is that Ag detection was less sensitive, regardless of the presence of octenidine. From an infection prevention perspective, these results favor octenidine-based decolonization strategies, even during seasonal SARS-CoV-2 periods. As only asymptomatic patients are considered for elective interventions, screening programs based on RT-PCR technology should be preferred.

Nasal decolonization: What antimicrobials and antiseptics are most effective before surgery and in the ICU

BACKGROUND

Staphylococcus aureus colonization is a key risk factor for S. aureus infections in surgical patients and in hospitalized patients. Many studies have assessed various decolonization agents, protocols, and settings. This review summarizes key findings about nasal decolonization for 2 different patient populations: patients undergoing surgery and patients hospitalized in intensive care units.

METHODS

We reviewed major studies related to decolonization of patients colonized with S. aureus and who were either undergoing surgical procedures or were hospitalized in intensive care units. We focused on recent studies, particularly randomized controlled trials and robust quasi-experimental trials. We also reviewed select non-randomized trials when more rigorous trials were limited.

DISCUSSION/CONCLUSIONS

Mupirocin is the best-studied agent for decolonization. Its use reduces the risk of surgical site infection following orthopedic surgery (strongest data) and cardiac surgery. Mupirocin decolonization also reduces the incidence of S. aureus clinical cultures in the intensive care unit. Povidone-iodine is less well-studied. Current data suggest that it decreases the risk of surgical site infections after orthopedic surgical procedures. In contrast, povidone-iodine is less effective than mupirocin for reducing the incidence of S aureus clinical cultures in the intensive care unit. Both mupirocin and povidone-iodine have important limitations, highlighting the need for future decolonization research.

A Novel Protocol for Nasal Decolonization Using Prolonged Application of an Alcohol-Based Nasal Antiseptic Reduces Surgical Site Infections in Total Joint Arthroplasty Patients: A Retrospective Cohort Study

Background: Current nasal decolonization strategies utilize pre-operative agents without consideration for short-term re-colonization or de novo colonization. Many strategies utilize an antibiotic-based agent, raising concerns of limited gram-negative antimicrobial coverage and the emergence of resistant bacterial strains. This study evaluated the clinical utility of a non-antibiotic, alcohol-based nasal decolonization agent in decreasing surgical site infection (SSI) rates after total joint arthroplasty. Patients and Methods: We retrospectively compared an 18-month cohort of elective primary total joint arthroplasty patients treated peri-operatively with an alcohol-based sanitizer to historical controls. The alcohol-based agent was administered pre-operatively the day of surgery and for two weeks after surgery. Patients were followed for 90 days and assessed for signs or symptoms of SSI. Patient and caregiver compliance was recorded. There were 779 patients included in the experimental group and 647 included in the historical control group. Results: Patients receiving alcohol-based nasal decolonization had a lower rate of SSI compared with controls not receiving nasal decolonization (0.64% [5/779] vs. 1.55% [10/647]; p = 0.048; odds ratio, 2.43). Utilization of an alcohol-based nasal sanitizer in the pre-operative and prolonged post-operative setting decreased infection rates by 41.3% in our elective total joint arthroplasty setting. Conclusions: When used pre- and post-operatively, alcohol-based nasal decolonization of bacteria in patients undergoing total joint arthroplasty led to a substantial decrease in SSIs.

Isolation and functional analysis of phage-displayed antibody fragments targeting the staphylococcal superantigen-like proteins

Staphylococcus aureus produces numerous virulence factors that manipulate the immune system, helping the bacteria avoid phagocytosis. In this study, we are investigating three immune evasion molecules called the staphylococcal superantigen-like proteins 1, 5, and 10 (SSL1, SSL5, and SSL10). All three SSLs inhibit vital host immune processes and contribute to S. aureus immune evasion. This study aimed to identify single-chain variable fragment (scFvs) antibodies from synthetic antibody phage libraries, which can recognize either of the three SSLs and could block the interaction between the SSLs and their respective human targets. The antibodies were isolated after three rounds of panning against SSL1, SSL5, and SSL10, and their ability to bind to the SSLs was studied using a time-resolved fluorescence-based immunoassay. We successfully obtained altogether 44 unique clones displaying binding activity to either SSL1, SSL5, or SSL10. The capability of the SSL-recognizing scFvs to inhibit the SSLs' function was tested in an MMP9 enzymatic activity assay, a P-selectin glycoprotein ligand 1 competitive binding assay, and an IgG1-mediated phagocytosis assay. We could show that one scFv was able to inhibit SSL1 and maintain MMP9 activity in a concentration-dependent manner. Finally, the structure of this inhibiting scFv was modeled and used to create putative scFv-SSL1-complex models by protein-protein docking. The complex models were subjected to a 100-ns molecular dynamics simulation to assess the possible binding mode of the antibody.

Amikacin-Loaded Chitosan Hydrogel Film Cross-Linked with Folic Acid for Wound Healing Application

PURPOSE

Numerous carbohydrate polymers are frequently used in wound-dressing films because they are highly effective materials for promoting successful wound healing. In this study, we prepared amikacin (AM)-containing hydrogel films through the cross-linking of chitosan (CS) with folic acid along with methacrylic acid (MA), ammonium peroxodisulfate (APS), and methylenebisacrylamide (MBA). In the current studies, an effort has been made to look at the possibilities of these materials in developing new hydrogel film wound dressings meant for a slow release of the antibiotic AM and to enhance the potential for wound healing.

METHODS

Free-radical polymerization was used to generate the hydrogel film, and different concentrations of the CS polymer were used. Measurements were taken of the film thickness, weight fluctuation, folding resistance, moisture content, and moisture uptake. HPLC, FTIR, SEM, DSC, and AFM analyses were some of the different techniques used to confirm that the films were successfully developed.

RESULTS

The AM release profile demonstrated regulated release over a period of 24 h in simulated wound media at pH 5.5 and 7.4, with a low initial burst release. The antibacterial activity against gram-negative bacterial strains exhibited substantial effectiveness, with inhibitory zones measuring approximately 20.5 ± 0.1 mm. Additionally, in vitro cytocompatibility assessments demonstrated remarkable cell viability, surpassing 80%, specifically when evaluated against human skin fibroblast (HFF-1) cells.

CONCLUSIONS

The exciting findings of this study indicate the promising potential for further development and testing of these hydrogel films, offering effective and controlled antibiotic release to enhance the process of wound healing.

Implementation of a Prevention Bundle to Decrease Rates of Staphylococcus aureus Surgical Site Infection at 11 Veterans Affairs Hospitals

Importance

While current evidence has demonstrated a surgical site infection (SSI) prevention bundle consisting of preoperative Staphylococcus aureus screening, nasal and skin decolonization, and use of appropriate perioperative antibiotic based on screening results can decrease rates of SSI caused by S aureus, it is well known that interventions may need to be modified to address facility-level factors.

Objective

To assess the association between implementation of an SSI prevention bundle allowing for facility discretion regarding specific component interventions and S aureus deep incisional or organ space SSI rates.

Design, Setting, and Participants

This quality improvement study was conducted among all patients who underwent coronary artery bypass grafting, cardiac valve replacement, or total joint arthroplasty (TJA) at 11 Veterans Administration hospitals. Implementation of the bundle was on a rolling basis with the earliest implementation occurring in April 2012 and the latest implementation occurring in July 2017. Data were collected from January 2007 to March 2018 and analyzed from October 2020 to June 2023.

Interventions

Nasal screening for S aureus; nasal decolonization of S aureus carriers; chlorhexidine bathing; and appropriate perioperative antibiotic prophylaxis according to S aureus carrier status. Facility discretion regarding how to implement the bundle components was allowed.

Main Outcomes and Measures

The primary outcome was deep incisional or organ space SSI caused by S aureus. Multivariable logistic regression with generalized estimating equation (GEE) and interrupted time-series (ITS) models were used to compare SSI rates between preintervention and postintervention periods.

Results

Among 6696 cardiac surgical procedures and 16 309 TJAs, 95 S aureus deep incisional or organ space SSIs were detected (25 after cardiac operations and 70 after TJAs). While the GEE model suggested a significant association between the intervention and decreased SSI rates after TJAs (adjusted odds ratio, 0.55; 95% CI, 0.31-0.98), there was not a significant association when an ITS model was used (adjusted incidence rate ratio, 0.88; 95% CI, 0.32-2.39). No significant associations after cardiac operations were found.

Conclusions and Relevance

Although this quality improvement study suggests an association between implementation of an SSI prevention bundle and decreased S aureus deep incisional or organ space SSI rates after TJAs, it was underpowered to see a significant difference when accounting for changes over time.

Is nanomaterial- and vancomycin-loaded polymer coating effective at preventing methicillin-resistant Staphylococcus aureus growth on titanium disks? An in vitro study

PURPOSE

Periprosthetic joint infections induced by methicillin-resistant Staphylococcus aureus (MRSA) pose a major socioeconomic burden. Given the fact that MRSA carriers are at high risk for developing periprosthetic infections regardless of the administration of eradication treatment pre-operatively, the need for developing new prevention modalities is high.

METHODS

The antibacterial and antibiofilm properties of vancomycin, Al₂O₃ nanowires, and TiO₂ nanoparticles were evaluated in vitro using MIC and MBIC assays. MRSA biofilms were grown on titanium disks simulating orthopedic implants, and the infection prevention potential of vancomycin-, Al₂O₃ nanowire-, and TiO₂ nanoparticle-supplemented Resomer® coating was evaluated against biofilm controls using the XTT reduction proliferation assay.

RESULTS

Among the tested modalities, high- and low-dose vancomycin-loaded Resomer® coating yielded the most satisfactory metalwork protection against MRSA (median absorbance was 0.1705; [IQR = 0.1745] vs control absorbance 0.42 [IQR = 0.07]; p = 0.016; biofilm reduction was 100%; and 0.209 [IQR = 0.1295] vs control 0.42 [IQR = 0.07]; p < 0.001; biofilm reduction was 84%, respectively). On the other hand, polymer coating alone did not provide clinically meaningful biofilm growth prevention (median absorbance was 0.2585 [IQR = 0.1235] vs control 0.395 [IQR = 0.218]; p < 0.001; biofilm reduction was 62%).

CONCLUSIONS

We advocate that apart from the well-established preventative measures for MRSA carriers, loading implants with bioresorbable Resomer® vancomycin-supplemented coating may decrease the incidence of early post-op surgical site infections with titanium implants. Of note, the payoff between localized toxicity and antibiofilm efficacy should be considered when loading polymers with highly concentrated antimicrobial agents.

Gentamicin-loaded chitosan/folic acid-based carbon quantum dots nanocomposite hydrogel films as potential antimicrobial wound dressing

BACKGROUND

To provide effective healing in the wound, various carbohydrate polymers are commonly utilized that are highly potent platforms as wound dressing films. In this work, novel antibacterial flexible polymeric hydrogel films were designed via crosslinking polymeric chitosan (CS) with folic acid-based carbon quantum dots (CQDs). To end this, folic acid as a bio-precursor is used to synthesize CQDs through the hydrothermal technique. The synthesized CQDs as a crosslinking agent was performed at different concentrations to construct nanocomposite hydrogel films via the casting technique. Also, gentamicin (GM), L-Arginine and glycerol were supplemented in the formulation of nanocomposite since their antibiotic, bioactivity and plasticizing ability, respectively.

RESULTS

The successful construction of films were verified with different methods (FT-IR, UV-Vis, PL, SEM, and AFM analyses). The GM release profile displayed a controlled release manner over 48 h with a low initial burst release in the simulated wound media (PBS, pH 7.4). Antibacterial and in vitro cytotoxicity results showed a significant activity toward different gram-positive and negative bacterial strains (about 2.5 ± 0.1 cm inhibition zones) and a desired cytocompatibility against Human skin fibroblast (HFF-1) cells (over 80% cell viability), respectively.

CONCLUSION

The obtained results recommend CQDs-crosslinked CS (CS/CQD) nanocomposite as a potent antimicrobial wound dressing.

Eleven-Year surveillance of methicillin-resistant Staphylococcus aureus infections at an Academic Health Centre

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen associated with nosocomial and community infections. There is a continual focus on the epidemiology of this public health threat owing to the increase in its spread and rapid development of resistance.

AIM

We aimed to demonstrate the time trend of antibiotic resistance by describing the epidemiology of MRSA infections at an academic health centre.

METHODOLOGY

We retrospectively reviewed cases during an 11-year period (from January 2009 to December 2019) with positive cultures for MRSA from various clinical sites in King Fahad Hospital of the University, to understand their clinical and microbiological profiles. Screening and colonisation samples were excluded.

RESULTS

A total of 1338 MRSA isolates were identified, with an increasing trend from 5.2% to 14.5% during 2009-2019. Skin and soft tissue samples were the most common source (52.4%) of MRSA infections. Vancomycin activity remained stable against MRSA, and only one isolate showed resistance to linezolid (< 1%). A significant reduction in susceptibility to clindamycin (p = 0.003), trimethoprim-sulfamethoxazole (p = 0.001), and rifampin (p < 0.0001) was detected over the study period.

CONCLUSIONS

MRSA infections still represent a significant burden on healthcare systems. Our data support the need for constant local and regional surveillance to devise relevant protocols to manage MRSA infections. Empirical therapy needs to consider the changing antimicrobial susceptibility trends among MRSA isolates.

Topical antibiotic prophylaxis for surgical wound infections in clean and clean-contaminated surgery: a systematic review and meta-analysis

Background

Topical antibiotics are widely prescribed as prophylaxis for surgical site infection (SSI). Despite giving high drug concentrations at local wound sites, their efficacy remains controversial. This study is a systematic review and meta-analysis designed to compare the efficacy and safety of topical antibiotics with non-antibiotic agents in preventing SSI.

Methods

Randomized controlled trials (RCTs) comparing topical antibiotics in patients with clean and clean-contaminated postsurgical wounds were included. Relevant trials published before 30 September 2020, were searched in the PubMed, Embase, and Cochrane databases, without language restrictions. The primary outcome was the incidence of SSIs, presented as the event rate. The secondary outcome was the incidence of contact dermatitis (safety outcome). Data were synthesized using the random-effects model, with the results expressed as risk ratio (RR) with 95 per cent confidence intervals (c.i.).

Results

Thirteen RCTs were included. The incidence of SSIs and contact dermatitis showed no significant difference between topical antibiotics and non-antibiotic agents (RR 0.89, 95 per cent c.i. 0.59 to 1.32 (P = 0.56, I² = 48 per cent); and RR 2.79, 95 per cent c.i. 0.51 to 15.19 (P = 0.24, I² = 0 per cent), respectively). In the subgroup analyses, a reduction in SSIs was also not observed in dermatological (RR 0.77, 95 per cent c.i. 0.39 to 1.55; P = 0.46, I² = 65 per cent), ocular (RR 0.08, 95 per cent c.i. 0.00 to 1.52; P = 0.09), spinal (RR 1.34, 95 per cent c.i. 0.65 to 2.77; P = 0.43, I² = 0 per cent), orthopaedic (RR 0.69, 95 per cent c.i. 0.37 to 1.29; P = 0.25, I² = 0 per cent), or cardiothoracic surgeries (RR 1.60, 95 per cent c.i. 0.79 to 3.25; P = 0.19).

Conclusion

Given the current evidence, the routine application of topical antibiotics to surgical wounds did not reduce the incidence of SSI. Further trials are needed to assess their effectiveness in high-risk surgeries or in selected patient groups.

An evaluation of risk factors for Staphylococcus aureus colonization in a pre-surgical population

Staphylococcus aureus (SA) colonization has significant implications in healthcare-associated infections. Here we describe a prospective study conducted in pre-surgical outpatients, done with the aim of identifying demographic and clinical risk factors for SA colonization. We found younger age to be a potential predictor of SA colonization.

Interactions of two enantiomers of a designer antimicrobial peptide with structural components of the bacterial cell envelope

Antimicrobial peptides (AMPs) have great potential in treating multi-drug resistant bacterial infections. The antimicrobial activity of d-enantiomers is significantly higher than l-enantiomers and sometimes selectively enhanced against Gram-positive bacteria. Unlike phospholipids in the bacterial plasma membrane, the role of other bacterial cell envelop components is often overlooked in the mode of action of AMPs. In this work, we explored the structural interactions between the main different structural components in Gram-negative/Gram-positive bacteria and the two enantiomers of a designer AMP, GL13K. We observed that both l-GL13K and d-GL13K formed self-assembled amyloid-like nanofibrils when the peptides interacted with lipopolysaccharide and lipoteichoic acid, components of the outer membrane of Gram-negative bacteria and cell wall of Gram-positive bacteria, respectively. Another cell wall component, peptidoglycan, showed strong interactions exclusively with d-GL13K and formed distinct laminar structures. This specific interaction between peptidoglycans and d-GL13K might contribute to the enhanced activity of d-GL13K against Gram-positive bacteria as they have a much thicker peptidoglycan layer than Gram-negative bacteria. A better understanding of the specific role of bacterial cell envelop components in the AMPs mechanism of action can guide the design of more effective Gram-selective AMPs.

Risk of methicillin-resistant staphylococcus aureus prosthetic joint infection in elective total hip and knee arthroplasty following eradication therapy

BACKGROUND

Prosthetic joint infection (PJI) is a devastating complication requiring prolonged treatment and multiple operations, leading to significant morbidity for the patient. Patients are routinely tested for methicillin-resistant staphylococcus aureus (MRSA) colonisation. MRSA positive patients are given eradication therapy. We hypothesise that patients who are MRSA positive pre-operatively, have increased risk of developing PJI.

AIM

To identify deep wound infection (PJI) rates in patients who are colonised MRSA positive compared with those who are not colonised; and long term clinical and radiological outcomes.

METHODS

All patients who underwent total hip and knee replacements (THR/TKR) between December 2009 and December 2019 were identified. Patients who were also identified as being MRSA positive at pre-operative assessment were then selected. Confirmation of prescribing eradication treatment was recorded. Patient records, including consultation letters, operation notes and microbiology results were reviewed retrospectively. Comparison of outcomes for each MRSA positive patient was made with 2 MRSA negative patients undergoing the same operation of a similar age by the same consultant.

RESULTS

Screening identified 42 knee and 32 hip arthroplasty patients as MRSA positive, 84 MRSA negative knee and 64 hip patients were reviewed. Patients were matched with medical co-morbidities in each group. Mean follow up was 5 years. PJI was identified in 4/32 (12.5%) of THR MRSA positive and 3/42 (7%) of TKR patients. All patients had PJI within one year of surgery.

CONCLUSION

MRSA positive patients are given eradication therapy routinely. However, no confirmation of eradication is sought. Patients who have MRSA colonisation pre-operatively, in our study had a significantly increased risk of PJI, when compared to negative patients. We would recommend establishing true eradication after treatment prior to arthroplasty.

Antibiotics for Spinal Cord Stimulation Trials and Implants: A Survey Analysis of Practice Patterns

Background

Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. Published guidelines exist to aid physicians in proper antibiotic use during and after spinal cord stimulation trials and implants. In this brief review, we present and analyze the current antibiotic practice patterns of clinicians.

Methods

The study protocol was reviewed and granted an exemption by an Institutional Review Board. The survey queried practice parameters in regards to spinal cord stimulation therapy. The American Society of Regional Anesthesia and Pain Medicine (ASRA) and Society of Interventional Spine (SIS) distributed the survey to their active members by emails with a web link to the survey.

Results

Our results indicate that 82% and 69% of physicians do not utilize nasal swabs for methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA), respectively, prior to SCS trial and implantation. During trials, 47% providers administer a single dose of antibiotics, 35% administer antibiotics for the duration of the trial, and 17% do not administer antibiotics. During implantation, 44% of physicians administer a single dose during the procedure, 11% administer antibiotics up to 24 hours, 24% administer antibiotics between 3-5 days, 14% administer antibiotics for more than 5 days, and 4% do not administer antibiotics.

Conclusions

Our study suggests a portion of pain physicians do not adhere to the Neuromodulation Appropriateness Consensus Committee (NACC) guidelines in regards to antibiotic administration for SCS trial and implantation. Further analysis and surveys would allow insight into common practices. More information and education would be beneficial to optimize peri-procedure antibiotic use to reduce infection risk and decrease antimicrobial resistance.

Complicated Carriage with Methicillin-Resistant Staphylococcus aureus: Evaluation of the Effectiveness of Decolonization Regimens Advised in the Dutch National Guideline

Methicillin-resistant Staphylococcus aureus (MRSA) colonization leads to increased infection rates and mortality. Decolonization treatment has been proven to prevent infection and reduce transmission. As the optimal antimicrobial strategy is yet to be established, different regimens are currently prescribed to patients. This study aimed to evaluate the efficacy of the decolonization treatments recommended by the Dutch guideline. A retrospective multicenter cohort study was conducted in five Dutch hospitals. All patients who visited the outpatient clinic because of complicated MRSA carriage between 2014 and 2018 were included. We obtained data on patient characteristics, clinical and microbiological variables relevant for MRSA decolonization, environmental factors, decolonization regimen, and treatment outcome. The primary outcome was defined as three negative MRSA cultures after treatment completion. Outcomes were stratified for the first-line treatment strategies. A total of 131/224 patients were treated with systemic antibiotic agents. Treatment was successful in 111/131 (85%) patients. The success rate was highest in patients treated with doxycycline-rifampin (32/37; 86%), but the difference from any of the other regimens did not reach statistical significance. There was no difference in the success rate of a 7-day treatment compared to that with 10 to 14 days of treatment (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.39 to 2.53; P = 1.00). Side effects were reported in 27/131 (21%) patients and consisted mainly of mild gastrointestinal complaints. In a multivariable analysis, an immunocompromised status was an independent risk factor for failure at the first treatment attempt (OR, 4.65; 95% CI, 1.25 to 17.25; P = 0.02). The antimicrobial combinations recommended to treat complicated MRSA carriage yielded high success rates. Prolonged treatment did not affect treatment outcome. A randomized trial is needed to resolve whether the most successful regimen in this study (doxycycline plus rifampin) is superior to other combinations.

Carboxymethyl cellulose/tetracycline@UiO-66 nanocomposite hydrogel films as a potential antibacterial wound dressing

Designing an antibacterial agent with a suitable water vapor permeability, good mechanical properties, and controlled antibiotic release is a promising method for stopping bacterial infection in wound tissue. In this respect, this work aims to prepare novel flexible polymeric hydrogel films via integrating UiO-66 into the polymeric carboxymethyl cellulose (CMC) hydrogel for improving the mechanical and antibiotic release performances. First, we performed a green hydrothermal synthetic method to synthesis UiO-66 and followed by encapsulating Tetracycline (TC) through immersion in its aqueous solution. Also, the casting technique was utilized to integrate different concentrations of the TC-encapsulated UiO-66 (TC@UiO-66, 5% to 15%) in the polymeric CMC matrix (CMC/TC@UiO-66) cross-linked by citric acid and plasticized by glycerol. The release performance showed a low initial burst release with a controlled release over 72 h in the artificial sweat and simulated wound exudate (PBS, pH 7.4) media. The in vitro cytotoxicity and antibacterial activity results revealed a good cytocompatibility toward Human skin fibroblast (HFF-1) cells and a significant activity against both E. coli and S. aureus with 1.3 and 1.7 cm inhibition zone, respectively. The obtained results recommend CMC/TC@UiO-66 films as a potential antibacterial wound dressing.

Determination of nasal carriage and skin colonization, antimicrobial susceptibility and genetic relatedness of Staphylococcus aureus isolated from patients with atopic dermatitis in Szczecin, Poland

BACKGROUND

Atopic dermatitis (AD) is one of the most frequent chronic and inflammatory skin condition. AD is characterized by damaged epidermal barrier, xerosis and pruritus of eczematous skin lesions which tend to flare. The duration and frequency of exacerbation of AD symptoms markedly affects the quality of patient life. AD results from the interplay between host genetics, immunity, and environmental factors, however the detailed pathogenesis of this disease is still not entirely cleared. Furthermore, disturbances of the skin microbiota and skin functional impairment predispose to secondary skin infections. Staphylococcus aureus colonizes skin and mucous membranes of 20 to 80% of healthy individuals and of 90% of patients with AD in whom this bacterium is accounted as an important AD exacerbating factor. It is also proven, that S. aureus nasal carriage significantly increases the risk for self-transmission and endogenous infection. In the current study the presence of S. aureus either in nasal vestibule and on lesioned skin of 64 patients with AD enrolled in 10-year autovaccination program was determined. The genetic relatedness of 86 S. aureus isolated from patients nose and skin using Pulsed Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility of all strains to methicillin, erythromycin, clindamycin, mupirocin, gentamicin, amikacin, tetracycline, chloramphenicol and cotrimoxazole was also evaluated.

RESULTS

In total 23 PFGE genotypes and 24 unique patterns were distinguished. 34 patients were S. aureus nasal carriers. Simultaneous presence of S. aureus in nose and on affected skin was found in 16 carriers colonized by indistinguishable or potentially related S. aureus vs 2 carriers colonized with non-related S. aureus in nasal vestibule and on skin. 4 isolates were methicillin resistant (MRSA) among which 3 showed constitutive MLSB resistance phenotype and remaining one was resistant to tetracycline and chloramphenicol. In 4 isolates inducible MLSB resistance phenotype was found, one of them was additionally resistant to tetracycline. 7 S. aureus were mupirocin resistant among them 3 - isolated from one patient, were resistant simultaneously to tetracyclines and chloramphenicol. 7 strains demonstrated resistance to chloramphenicol and susceptibility to all tested antimicrobial agents. The susceptibility to gentamicin, amikacin and cotrimoxazole among all examined S. aureus was confirmed.

CONCLUSION

The obtained results indicated non-clonal structure of S. aureus circulating in AD patients. PFGE results showed the clonal-structure of vast majority of S. aureus isolated from nose and skin from nasal carriers what may prove the autoinfection in these patients. All examined patients the moderate or strong severity of AD was reported. Susceptibility to most antibiotics among isolated strains was also observed.

Potential antimicrobial properties of the Ulva lactuca extract against methicillin-resistant Staphylococcus aureus-infected wounds: A review

Methicillin-resistant Staphylococcus aureus (MRSA), currently a major problem in hospitals worldwide, is one of the most common causes of nosocomial disease through surgical wound infection. MRSA-infected wounds have very low recovery rates and have become more problematic as some antibiotics are not effective against MRSA. Several antimicrobial and anti-inflammatory agents of green algae (Ulva lactuca) in the form of alkaloids, triterpenoids, steroids, saponins, and flavonoids have the potential to accelerate the wound healing process following MRSA wound infection. Various active compounds contained in the U. lactuca extract are thought to have multiple antibacterial and anti-inflammatory properties that can overcome the MRSA antimicrobial resistance and accelerate tissue growth in the wound healing process. This review aims to describe the potential of Ulva lactuca extract against MRSA-infected wound healing.

Nasal Microbiota and Infectious Complications After Elective Surgical Procedures

IMPORTANCE

The association of the nasal microbiome with outcomes in surgical patients is poorly understood.

OBJECTIVE

To characterize the composition of nasal microbiota in patients undergoing clean elective surgical procedures and to examine the association between characteristics of preoperative nasal microbiota and occurrence of postoperative infection.

DESIGN, SETTING, AND PARTICIPANTS

Using a nested matched case-control design, 53 individuals who developed postoperative infection were matched (approximately 3:1 by age, sex, and surgical procedure) with 144 individuals who were not infected (ie, the control group). The 2 groups were selected from a prospective cohort of patients undergoing surgical procedures at 2 tertiary care university hospitals in Baltimore, Maryland, who were at high risk for postoperative infectious complications. Included individuals were aged 40 years or older; had no history of autoimmune disease, immunocompromised state, immune-modulating medication, or active infection; and were scheduled to undergo elective cardiac, vascular, spinal, or intracranial surgical procedure. Data were analyzed from October 2015 through September 2020.

EXPOSURES

Nasal microbiome cluster class served as the main exposure. An unsupervised clustering method (ie, grades of membership modeling) was used to classify nasal microbial samples into 2 groups based on features derived from 16S ribosomal RNA gene sequencing. The microbiome cluster groups were derived independently and agnostic of baseline clinical characteristics and infection status.

MAIN OUTCOMES AND MEASURES

Composite of surgical site infection, bacteremia, and pneumonia occurring within 6 months after surgical procedure.

RESULTS

Among 197 participants (mean [SD] age, 64.1 [10.6] years; 63 [37.7%] women), 553 bacterial taxa were identified from preoperative nasal swab samples. A 2-cluster model (with 167 patients in cluster 1 and 30 patients in cluster 2) accounted for the largest proportion of variance in microbial profiles using grades of membership modeling and was most parsimonious. After adjusting for potential confounders, the probability of assignment to cluster 2 was associated with 6-fold higher odds of infection after surgical procedure (odds ratio [OR], 6.18; 95% CI, 3.33-11.7; P < .001) independent of baseline clinical characteristics, including nasal carriage of Staphylococcus aureus. Intrasample (ie, α) diversity was inversely associated with infectious outcome in both clusters (OR, 0.57; 95% CI, 0.42-0.75; P < .001); however, probability of assignment to cluster 2 was associated with higher odds of infection independent of α diversity (OR, 4.61; 95% CI, 2.78-7.86; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that the nasal microbiome was an independent risk factor associated with infectious outcomes among individuals who underwent elective surgical procedures and may serve as a biomarker associated with infection susceptibility in this population.

Pharyngeal Detection of Staphylococcus aureus as a Possible Factor Related to Disgust Sensitivity in Humans

Disgust triggers behavioral avoidance of pathogen-carrying and fitness-reducing agents. However, because of the cost involved, disgust sensitivity should be flexible, varying as a function of an individual’s immunity. Asymptomatic colonization with Staphylococcus aureus often results from weakened immunity and is a potential source of subsequent infections. In this study, we tested if pharyngeal colonization with S. aureus, evaluated based on a single swab collection, is related to an individual’s disgust sensitivity, measured with the Three Domain Disgust Scale. Levels of immunomodulating hormones (cortisol and testosterone), general health, and body adiposity were controlled. Women (N = 95), compared to men (N = 137), displayed higher sexual disgust sensitivity, but the difference between individuals with S. aureus and without S. aureus was significant only in men, providing support for prophylactic hypothesis, explaining inter-individual differences in disgust sensitivity. Men (but not women) burdened with asymptomatic S. aureus presence in pharynx exhibit higher pathogen disgust (p = 0.04) compared to individuals in which S. aureus was not detected. The positive relationship between the presence of the pathogen and sexual disgust was close to the statistical significance level (p = 0.06), and S. aureus colonization was not related with moral disgust domain.

Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans

Introduction

Surgical site infection is one of the most severe complications of surgical treatments. However, the optimal procedure to prevent such infections remains uninvestigated. Ultraviolet radiation C (UVC) with a short wavelength has a high bactericidal effect; however, it is cytotoxic. Nonetheless, given that UVC with a wavelength of 222 nm reaches only the stratum corneum, it does not affect the skin cells. This study aimed to investigate the safety of 222-nm UVC irradiation and to examine its skin sterilization effect in healthy volunteers.

Methods

This trial was conducted on 20 healthy volunteers. The back of the subject was irradiated with 222-nm UVC at 50–500 mJ/cm², and the induced erythema (redness of skin) was evaluated. Subsequently, the back was irradiated with a maximum amount of UVC not causing erythema, and the skin swabs before and after the irradiation were cultured. The number of colonies formed after 24 hours was measured. In addition, cyclobutene pyrimidine dimer (CPD) as an indicator of DNA damage was measured using skin tissues of the nonirradiated and irradiated regions.

Results

All subjects experienced no erythema at all doses. The back of the subject was irradiated at 500 mJ/cm², and the number of bacterial colonies in the skin swab culture was significantly decreased by 222-nm UVC irradiation. The CPD amount produced in the irradiated region was slightly but significantly higher than that of the non-irradiated region.

Conclusion

A 222-nm UVC at 500 mJ/cm² was a safe irradiation dose and possessed bactericidal effects. In the future, 222-nm UVC irradiation is expected to contribute to the prevention of perioperative infection.

The extreme drug resistance (XDR) Staphylococcus aureus strains among patients: A retrospective study

The objective of the present work was to observe and profile various antibiotic resistant strains of Staphylococcus aureus and highlight the need for continuous surveillance. Data regarding antibiotic-resistant S. aureus strains isolated and identified at the Medical Microbiology Department, King Khalid Hospital, Riyadh was obtained. Bacterial isolates were collected from several sites of infections in patients and an evaluation of susceptibility were carried out using a fully automated Vitek2 system. Relative frequency (%), odds ratios and Ward's minimum variance were calculated. The results showed that wounds were a source of more than 40% of the S. aureus (MRSA) strains that have ability to resist methicillin, and more than 45% of the methicillin-susceptible S. aureus (non-MRSA) strains. 40% of the isolates were MRSA (N = 251), and all MRSA strains were sensitive to vancomycin, daptomycin, teicoplanin, tigecycline, nitrofurantoin, and itraconazole while all non-MRSA (N = 338) strains were sensitive to vancomycin, cefoxitin, daptomycin, gentamicin, oxacillin, teicoplanin, tigecycline, and mupirocin. Strength of association between antibiotic-resistant S. aureus strains and source of samples (site of infection) was established. The study concluded that S. aureus strains had developed resistance towards 20 (for non-MRSA) and 22 (for MRSA) of the antibiotics tested. All MRSA strains were non-sensitive to amoxicillin/clavulanate, ampicillin cefoxitin, cefazolin, imipenem, oxacillin, and penicillin.

Biophysical differentiation of susceptibility and chemical differences in Staphylococcus aureus

Differentiating bacteria strains using biophysical forces has been the focus of recent studies using dielectrophoresis (DEP). The refinement of these studies has created high-resolution separations such that very subtle properties of the cells are enough to induce significant differences in measurable biophysical properties. These high-resolution capabilities build upon the advantages of DEP which include small sample sizes and fast analysis times. Studies focusing on differentiating antimicrobial resistant and susceptible bacteria potentially have significant impact on human health and medical care. A prime example is Staphylococcus aureus, which commonly colonizes adults without ill effects. However, the pathogen is an important cause of infections, including surgical site infections. Treatment of S. aureus infections is generally possible with antimicrobials, but antimicrobial resistance has emerged. Of special importance is resistance to methicillin, an antimicrobial created in response to resistance to penicillin. Here, dielectrophoresis is used to study methicillin-resistant (MRSA) and -susceptible S. aureus (MSSA) strains, both with and without the addition of a fluorescent label. The capture onset potential of fluorescently-labeled MRSA (865 ± 71 V) and thus the ratio of electrokinetic to dielectrophoretic mobility, was found to be higher than that of fluorescently-labeled MSSA (685 ± 61 V). This may be attributable to the PBP2a enzyme present in the MRSA strain and not in the MSSA bacteria. Further, unlabeled MRSA was found to have a capture onset potential of 732 ± 44 V, while unlabeled MSSA was found to have a capture onset potential of 562 ± 59 V. This shows that the fluorescently-labeled bacteria require a higher applied potential, and thus ratio of mobilities, to capture than the unlabeled bacteria.

Identifying gram-positive cocci in dermatoscopes and smartphone adapters using MALDI-TOF MS: a cross-sectional study

Background

The increasingly frequent use of dermoscopy makes us think about the possibility of transfer of microorganisms, through the dermatoscope, between doctor and patients.

Objectives

To identify the most frequent gram-positive cocci in dermatoscopes and smartphone adapters, as well as the resistance profile, and to evaluate the factors associated with a higher risk of bacterial contamination of the dermatoscopes.

Methods

A cross-sectional study was carried out with 118 dermatologists from Porto Alegre/Brazil between September 2017 and July 2018. Gram-positive cocci were identified by MALDI-TOF MS and habits of use of the dermatoscope were evaluated through an anonymous questionnaire.

Results

Of the dermatoscopes analysed, 46.6% had growth of gram-positive cocci on the lens and 37.3% on the on/off button. The microorganisms most frequently found were S. epidermidis, S. hominis and S. warneri. Attending a hospital, using the dermatoscope at the hospital, with inpatients and in the intensive care unit were significantly associated with colonisation by gram-positive cocci. The highest resistance rates were observed for penicillin, erythromycin and sulfamethoxazole-trimethoprim.

Study limitations

The non-search of gram-negative bacilli, fungi and viruses. Moreover, the small number of adapters did not make it possible to better define if the frequency differences were statistically significant.

Conclusion

Coagulase-negative staphylococci were frequently identified. S. aureus was detected only on the lens.

S. aureus colonization in healthy Australian adults receiving an investigational S. aureus 3-antigen vaccine

OBJECTIVES

Assess Staphylococcus aureus (S. aureus) colonization in healthy Australian adults receiving an investigational S. aureus 3-antigen vaccine (SA3Ag).

METHODS

In this phase 1, double-blind, sponsor-unblinded study, participants were randomized to receive a single dose (1 of 3 dose levels) of SA3Ag or placebo and a booster dose or placebo at 6 months. S. aureus isolates from nasal, perineal, and oropharyngeal swabs before and through 12 months post-vaccination were identified.

RESULTS

Baseline S. aureus colonization prevalence was 30.6% (any site), with nasal carriage (27.0%) more common than oropharyngeal/perineal (3.2% each). Following initial vaccination (low-dose: 102; mid-dose: 101; high-dose: 101; placebo: 102) and booster (low-dose: 45; mid-dose: 44; high-dose: 27; placebo: 181), placebo and SA3Ag groups showed similar S. aureus carriage through 12 months. Most colonized participants (74.0%) were colonized by single spa types. Placebo and SA3Ag groups had similar persistence of colonization, with 19.6-30.7% due to single spa types. Acquisition was observed in mid- and high-dose recipients (∼20%) and low-dose and placebo recipients (∼12%). Vaccination resulted in substantial increases in antibodies to all 3 antigens, irrespective of carriage status.

CONCLUSIONS

Based on descriptive analyses of this small study, SA3Ag vaccination did not impact S. aureus acquisition or carriage. Carriage status did not impact antibody responses to SA3Ag.

Risk factors for Staphylococcus aureus colonization in a presurgical orthopedic population

BACKGROUND

Preoperative colonization with Staphylococcus aureus (SA) increases risk of surgical site infection. Screening for SA followed by skin and nasal decolonization can help to reduce the risk of postoperative infections. Risk factors for colonization are, however, not completely understood.

METHODS

A case-control study using questionnaires and patient demographics specifically designed to observe SA colonization risk factors in a presurgical orthopedic population. A total of 115 subjects with a positive preoperative screen for SA nasal colonization prior to orthopedic surgery completed a questionnaire to assess for SA risk factors: these subjects served as our cases. An additional 476 controls completed similar questionnaires. Data collected included demographic, health, and lifestyle information. Multivariable logistic regression was used to generate odds ratios (OR) for risk of SA colonization.

RESULTS

Several risk factors were identified. Male sex (OR 2.3; 95% confidence interval [CI], [1.4-3.8]) and diabetes (OR 3.8 [1.8-7.8]) significantly increased the risk of SA colonization. Older age, visiting public places (OR 0.2 [0.1-0.3]), recent antibiotic use (OR 0.2 [0.1-0.6]), and the presence of facial hair (OR 0.3 [0.1-0.6]) significantly lowered the risk of SA colonization.

CONCLUSIONS

By identifying patients who may be at greater risk of SA colonization, we can better streamline our presurgical techniques to help reduce risk of surgical site infections and improve patient outcomes.

Hydrogen-Peroxide-Generating Electrochemical Scaffold Eradicates Methicillin-Resistant Staphylococcus aureus Biofilms

Increasing rates of chronic wound infections caused by antibiotic-resistant bacteria are a crisis in healthcare settings. Biofilms formed by bacterial communities in these wounds create a complex environment, enabling bacteria to persist, even with antibiotic treatment. Wound infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are major causes of morbidity in clinical practice. There is a need for new therapeutic interventions not based on antibiotics. Hydrogen peroxide (H2O2) is a known antibacterial/antibiofilm agent, continuous delivery of which has been challenging. A conductive electrochemical scaffold (e-scaffold) is developed, which is composed of carbon fabric that electrochemically reduces dissolved oxygen into H2O2 when polarized at -0.6 VAg/AgCl, as a novel antibiofilm wound dressing material. In this study, the in vitro antibiofilm activity of the e-scaffold against MRSA is investigated. The developed e-scaffold efficiently eradicates MRSA biofilms, based on bacterial quantitation and ATP measurements. Moreover, imaging hinted at the possibility of cell-membrane damage as a mechanism of action. These results suggest that an H2O2-generating e-scaffold may be a novel platform for eliminating MRSA biofilms without using antibiotics and may be useful to treat chronic MRSA wound infections.

Nasal decolonization: What antimicrobials are most effective prior to surgery?

BACKGROUND

Surgical site infection (SSI) is one of the most common health care-associated infections. Staphylococcus aureus remains the most common etiologic agent causing SSIs. Studies confirm S aureus carriage increases the risk of S aureus SSIs. The purpose of this article is to review the strategies to reduce SSIs due to S aureus focusing on nasal decolonization.

RESULTS

Published studies indicate screening patients for S aureus nasal carriage and decolonizing carriers during the preoperative period decreases the risk of S aureus SSIs in cardiac and orthopedic surgery. Mupirocin remains the best topical agent at eradicating nasal S aureus however, concerns over resistance have led to development of alternative agents. Nasal povidone-iodine, alcohol-based nasal antiseptic, and photodynamic therapy are promising new interventions, but more studies are needed.

CONCLUSIONS

Short term nasal mupirocin is still the most studied and effective topical agent in eradicating S aureus nasal colonization. However, increasing mupirocin resistance remains an ongoing concern and newer agents are needed. Currently, preoperative S aureus decolonization often uses combination chlorhexidine gluconate bathing and nasal mupirocin considering that colonization of multiple body sites is commonly seen.

An update on the best approaches to prevent complications in penile prosthesis recipients

Placement of inflatable penile prosthesis is a procedure frequently performed for medication-refractory erectile dysfunction. Device implantation is not without risks, and as the frequency of device implantation increases, so do associated complications. The aim of this work is to review the most frequent operative complications associated with implantation of inflatable penile prostheses, and to review the best approaches to prevent these most common complications. Complications can broadly be categorized as infectious, noninfectious tissue-related, device-related, or related to patient and partner satisfaction. With understanding of these complications and ways to avoid them, as well as with appropriate patient selection and counseling, the inflatable penile prosthesis is an excellent option for the treatment of erectile dysfunction.

Mussel-inspired in situ forming adhesive hydrogels with anti-microbial and hemostatic capacities for wound healing

All kinds of commercially available wound dressings are clinically used as fleshly obstacles and therapeutic materials in opposition to microbial incursion. Few researches focused on effective-bleeding and anti-bacteria at the same time. In order to better solve this problem, two hydrogels were synthetized in this study. One is phosphate buffer solution-activated dopamine-modified-γ-poly glutamic acid (PBS-PD) hydrogel, the other one is cirsium setosum extracts-activated dopamine-modified-γ-poly glutamic acid (CSE-PD) hydrogel. The two hydrogels are prepared by applying an enzyme-catalyzed crosslinking means in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The chemical structures were characterized through 1H-NMR and FT-IR. In conclusion, both PBS-PD and CSE-PD hydrogels exhibit superior tissue adhesion properties, and remarkable anti-infection quality. In addition, these two hydrogels manifest prominent hemostatic efficiency. The bio adhesion performance can achieve 30 kPa, meanwhile the CSE-PD hydrogels show good germicidal properties, and the antibacterial rate can reach 98%. The hydrogels could reduce blood loss without any obvious side effect, and present a new prospect in the field of hemostasis rapidly.

Cost-effectiveness of pre-operative Staphylococcus aureus screening and decolonization

OBJECTIVE

We developed a decision analytic model to evaluate the impact of a preoperative Staphylococcus aureus decolonization bundle on surgical site infections (SSIs), health-care-associated costs (HCACs), and deaths due to SSI.

METHODS

Our model population comprised US adults undergoing elective surgery. We evaluated 3 self-administered preoperative strategies: (1) the standard of care (SOC) consisting of 2 disinfectant soap showers; (2) the "test-and-treat" strategy consisting of the decolonization bundle including chlorhexidine gluconate (CHG) soap, CHG mouth rinse, and mupirocin nasal ointment for 5 days) if S. aureus was found at any of 4 screened sites (nasal, throat, axillary, perianal area), otherwise the SOC; and (3) the "treat-all" strategy consisting of the decolonization bundle for all patients, without S. aureus screening. Model parameters were derived primarily from a randomized controlled trial that measured the efficacy of the decolonization bundle for eradicating S. aureus.

RESULTS

Under base-case assumptions, the treat-all strategy yielded the fewest SSIs and the lowest HCACs, followed by the test-and-treat strategy. In contrast, the SOC yielded the most SSIs and the highest HCACs. Consequently, relative to the SOC, the average savings per operation was $217 for the treat-all strategy and $123 for the test-and-treat strategy, and the average savings per per SSI prevented was $21,929 for the treat-all strategy and $15,166 for the test-and-treat strategy. All strategies were sensitive to the probability of acquiring an SSI and the increased risk if SSI if the patient was colonized with SA.

CONCLUSION

We predict that the treat-all strategy would be the most effective and cost-saving strategy for preventing SSIs. However, because this strategy might select more extensively for mupirocin-resistant S. aureus and cause more medication adverse effects than the test-and-treat approach or the SOC, additional studies are needed to define its comparative benefits and harms.

Previous antibiotic exposure and antibiotic resistance of commensal Staphylococcus aureus in Spanish primary care

INTRODUCTION

Commensal flora of healthy people is becoming an important reservoir of resistant bacteria.

OBJECTIVES

To evaluate the relationship of previous antibiotic-dispensed and resistance pattern of strains of Staphylococcus aureus in primary care patients.

METHODS

A cross-sectional study was carried out in seven primary care centres in Catalonia, Spain, from October 2010 to May 2011, as part of the APRES (The appropriateness of prescribing antibiotics in primary care in Europe concerning antibiotic resistance) study. Outpatients aged 4 or more who did not present an infectious disease and had not taken antibiotic or had not been hospitalised in the previous 3 months were invited to participate. Nasal swabs were collected for S. aureus culture, and antimicrobial susceptibility testing was carried out. Antibiotics dispensed boxes in the previous 4 years were extracted from Information System for Research in Primary Care.

RESULTS

A total of 4,001 nasal swabs were collected, and 3,969 were tested for identification, 765 S. aureus were tested for resistance. Resistance rates to penicillin, azithromycin and methicillin were 87.1%, 11.6% and 1.3%, respectively, and a total of 10 MRSA strains were isolated (1.3%). Penicillin-resistant staphylococci were statistically significantly associated with the previous number of packages of penicillin dispensed (OR, 1.18; 95% CI, 1.04-1.35).

CONCLUSION

Although no causal inference is possible, an association was observed between previous antibiotic dispensation and isolation of resistant organisms in community-dwelling individuals, mainly between packages of penicillin and penicillin-resistant staphylococci.

Randomized controlled trial of a self-administered five-day antiseptic bundle versus usual disinfectant soap showers for preoperative eradication of Staphylococcus aureus colonization

OBJECTIVE

To determine the efficacy in eradicating Staphylococcus aureus (SA) carriage of a 5-day preoperative decolonization bundle compared to 2 disinfectant soap showers, with both regimens self-administered at home.

DESIGN

Open label, single-center, randomized clinical trial.

SETTING

Ambulatory orthopedic, urologic, neurologic, colorectal, cardiovascular, and general surgery clinics at a tertiary-care referral center in the United States.ParticipantsPatients at the University of Minnesota Medical Center planning to have elective surgery and not on antibiotics.

METHODS

Consenting participants were screened for SA colonization using nasal, throat, axillary, and perianal swab cultures. Carriers of SA were randomized, stratified by methicillin resistance status, to a decolonization bundle group (5 days of nasal mupirocin, chlorhexidine gluconate [CHG] bathing, and CHG mouthwash) or control group (2 preoperative showers with antiseptic soap). Colonization status was reassessed preoperatively. The primary endpoint was absence of SA at all 4 screened body sites.

RESULTS

Of 427 participants screened between August 31, 2011, and August 9, 2016, 127 participants (29.7%) were SA carriers. Of these, 121 were randomized and 110 were eligible for efficacy analysis (57 decolonization bundle group, 53 control group). Overall, 90% of evaluable participants had methicillin-susceptible SA strains. Eradication of SA at all body sites was achieved for 41 of 57 participants (71.9%) in the decolonization bundle group and for 13 of 53 participants (24.5%) in the control group, a difference of 47.4% (95% confidence interval [CI], 29.1%-65.7%; P<.0001).

CONCLUSION

An outpatient preoperative antiseptic decolonization bundle aimed at 4 body sites was significantly more effective in eradicating SA than the usual disinfectant showers (ie, the control).Trial RegistrationClinicalTrials.gov identifier: NCT02182115.

Relationship Between Staphylococcus aureus Carriage and Surgical Site Infections Following Total Hip and Knee Arthroplasty in the South Asian Population: Protocol for a Prospective Cohort Study

Background

Surgical site infections following total hip or knee arthroplasties have a reported rate of 0.49%-2.5% and can cause significant morbidity as well as tripling the cost of health care expenses. Both methicillin sensitive and methicillin resistant strains of Staphylococcus aureus surgical site infections have been established as a major risk factor for postoperative surgical site infections. S. aureus colonizes the nose, axillae, and perineal region in up to 20%-30% of individuals. Although the literature has reported a higher prevalence of methicillin resistant S. aureus in the South Asian population, routine preoperative screening and prophylaxis have not yet been implemented.

Objective

The primary objective of our study is to identify the relationship between preoperative colonization status of S. aureus and incidence of postoperative surgical site infections in patients undergoing following total hip and knee arthroplasties. As part of the secondary objectives of this study, we will also investigate patient characteristics acting as risk factors for S. aureus colonization as well as the outcomes of total hip and knee arthroplasty patients which are affected by surgical site infections.

Methods

This prospective cohort study will comprise of screening all patients older than 18 years of age admitted to the Aga Khan University Hospital for a primary total hip or knee arthroplasty for preoperative colonization with S. aureus. The patients will be followed postoperatively for up to one year following the surgery to assess the incidence of surgical site infections. The study duration will be 2 years (March 2018 to March 2020). For the purpose of screening, pooled swabs will be taken from the nose, axillae, and groin of each patient and inoculated in a brain heart infusion, followed by subculture onto mannitol salt agar and sheep blood agar. For methicillin resistant S. aureus identification, a cefoxitin disk screen will be done. Data will be analyzed using SPSS v23 and both univariate and multivariate regression analysis will be conducted.

Results

Data collection for this study will commence at the Aga Khan University Hospital, Pakistan during March 2018.

Conclusions

This study will not only estimate the true burden caused by S. aureus in the population under study but will also help identify the patients at a high risk of surgical site infections so that appropriate interventions, including prophylaxis with antibiotics such as muciprocin ointment or linezolid, can be made. Given the differences in lifestyle, quality, and affordability of health care and the geographical variation in patterns of antibiotic resistance, this study will contribute significantly to providing incentive for routine screening and prophylaxis for S. aureus including methicillin resistant S. aureus colonization in the South Asian population.

Registered Report Identifier

RR1-10.2196/10219

Peri-Operative Nasal Eradication Therapy Prevents Staphylococcus aureus Surgical Site Infections in Aortoiliac Surgery

BACKGROUND

Surgical site infections (SSIs) cause considerable morbidity and deaths among patients undergoing vascular surgery. Pre-operative screening and subsequent treatment of nasal Staphylococcus aureus carriers with mupirocin and chlorhexidine reduces the risk of SSIs in cardiothoracic and orthopedic surgery. The aim of this study was to investigate the effect of this screen-and-treat strategy on the development of SSI in patients undergoing aortoiliac surgery.

METHODS

A prospective study was performed that enrolled an intervention cohort comprising all patients undergoing aortoiliac surgery from February 2013 to December 2016. Before surgery, patients were screened for S. aureus nasal carriage and, if positive, were treated with mupirocin nasal ointment and chlorhexidine body washes. The presence of SSI was recorded on the basis of the criteria of the U.S. Centers for Disease Control and Prevention. A historic control group was used, consisting of aortoiliac surgery patients in 2010 who tested positive for S. aureus but received no treatment.

RESULTS

A total of 374 patients in the study cohort were screened of whom 75 (20.1%) tested positive for S. aureus. Of these patients, 68 were given eradication therapy. In the 2010 cohort, 22 patients (15.7%) were positive. The incidence of S. aureus infection was 0 of 75 in the treatment group versus 3 of 22 (13.6%) in the control group (p = 0.021). Both the 30-day mortality rate (1.3% vs. 13.6%; p = 0.035) and the rate of re-interventions (12.0% vs. 31.8%) were significantly lower in the treated group.

CONCLUSION

We conclude that S. aureus nasal screening and eradication with mupirocin and chlorhexidine reduces S. aureus SSI and its complications after aortoiliac surgery.

Metastatic MSSA infection of the spine and extremities

Here, we present a rare case of metastatic methicillin sensitive Staphylococcus aureus (MSSA) infection arising from an unknown focus and spreading throughout the lumbar spine with associated pyomyositis of the paraspinal musculature, and septic arthritis of the knee, ankle and sternoclavicular joint. This case highlights the potential for missed aspects and delay in diagnosis in the care of metastatic S. aureus and the need for multispecialty intervention. Treatment of S. aureus infections requires a high index of suspicion and careful examination of multiple organ systems to identify the full extent of the disease. A discussion on metastatic S. aureus infection follows the report.

Plant phenolics and terpenoids as adjuvants of antibacterial and antifungal drugs

BACKGROUND

The intensive use of antibacterial and antifungal drugs has dramatically increased the microbial resistance and has led to a higher number of difficult-to-eradicate infections. Combination therapy with two or more antimicrobial drugs has emerged some years ago to overcome the issue, but it has proven to be not completely effective. Natural secondary metabolites of MW ≤ 500 represent promising adjuvants for antimicrobials and have been the object of several researches that have increased in the last two decades.

PURPOSE

The purpose of this Review is to do a literature search of the natural compounds that showed high enhancing capacity of antibacterials' and antifungals' effects against planktonic bacteria and fungi and to analyze which are the natural products most used in combination with a focus on polyphenols and terpenoids.

RESULTS

One hundred of papers were collected for reviewing. Fifty six (56) of them deal with combinations of low MW natural products with antibacterial drugs against planktonic bacteria and forty four (44) on natural products with antifungal drugs against planktonic fungi. Of the antibacterial adjuvants, 41 (73%) were either polyphenols (27; 48%) or terpenes (14; 25%). The remaining 15 papers (27%), deal with different class of natural products. Since most natural potentiators belong to the terpene or phenolic structural types, a more detailed description of the works dealing with these type of compounds is provided here. Bacterial and fungal resistance mechanisms, the modes of action of the main classes of antibacterial and antifungal drugs and the methodologies most used to assess the type of interactions in the combinations were included in the Review too.

CONCLUSIONS AND PERSPECTIVES

Several promising results on the potentiation effects of antifungals' and antibacterials' activities by low MW natural products mainly on polyphenols and terpenes were reported in the literature and, in spite of that most works included only in vitro assays, this knowledge opens a wide range of possibilities for the combination antimicrobial therapy. Further research including in vivo assays and clinical trials are required to determine the relevance of these antimicrobial enhancers in the clinical area and should be the focus of future studies in order to develop new antimicrobial combination agents that overpass the drawbacks of the existing antibiotics and antifungals in clinical use.

Risk of Surgical Site Infection in Elective Hip and Knee Replacements After Confirmed Eradication of MRSA in Chronic Carriers

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is globally endemic and is a leading cause of surgical site infection (SSI). The purpose of this study was to evaluate the incidence of SSI in MRSA carriers undergoing elective hip or knee arthroplasty, who had confirmed eradication and to compare it with incidence of SSI in non-MRSA carriers.

METHODS

This is a retrospective analysis of 6613 patients who underwent elective total hip arthroplasty (THA; n = 3347) and total knee arthroplasty (TKA; n = 3266) at our institution. A cohort of patients who were preoperatively colonized with MRSA was identified. We compared the infection rates with non-MRSA carriers.

RESULTS

We had a colonization rate of 1.3% (83 patients). A total of 79 patients had confirmed eradication of carrier status before surgical intervention. Of these, 38 were THAs and 41 were TKAs. Five of 79 patients (6.32%; 95% confidence interval [CI]: 2.35%-14.79%) had "deep SSI" within 1 year of surgery. There were 2 MRSA infections in THAs (relative risk 4.46; 95% CI: 1.12-17.82). There were 2 MRSA and 1 methicillin-sensitive Staphylococcus aureus infections in TKAs (relative risk 5.61; 95% CI: 1.81-17.38). A significant statistical difference in infection rates from MRSA negative control group was noted, which had a deep sepsis rate of 1.17% in THAs and 1.3% in TKAs over the same period.

CONCLUSION

In spite of a selective treatment program for carriers and confirmed eradication, there is still a significantly increased risk of SSI in MRSA-colonized patients undergoing hip or knee arthroplasties.

Nasal colonization and bacterial contamination of mobile phones carried by medical staff in the operating room

Background

Mobile phones (MPs) have been an essential part of the lives of healthcare professionals and have improved communication, collaboration, and sharing of information. Nonetheless, the widespread use of MPs in hospitals has raised concerns of nosocomial infections, especially in areas requiring the highest hygienic standards such as operating rooms (ORs). This study evaluated the incidence of bacterial contamination of the MPs carried by medical staff working in the OR and determined its association with bacterial colonization of this personnel.

Methods

This is an observational cohort study. Medical staffs working in the OR were asked to take bacterial cultures from their MPs, anterior nares, and dominant hands. To identify the relation between MP contamination and bacterial colonization of the medical staff, genotyping of Staphylococcus aureus (SA) was done via Staphylococcus protein A gene (spa) typing and pulsed-field gel electrophoresis (PFGE).

Results

A total of 216 swab samples taken from 72 medical-staff members were analyzed. The culture-positive rate was 98.1% (212/216). In 59 (27.3%) samples, the bacteria were possible clinical pathogens. The anterior nares were the most common site of colonization by clinical pathogens (58.3%, 42/72), followed by MPs (13.9%, 10/72) and the dominant hand (9.7%, 7/72). SA was the most commonly isolated clinical pathogen and was found in 43 (19.9%) samples. In 66 (94.3%) of the 70 staff members for whom bacteria were detected on their MPs, the same bacteria were detected in nares or hand. Among 31 medical staff who were carriers of SA in the anterior nares or dominant hand, 8 (25.8%) were found to have SA on their MPs, and genotyping confirmed the same SA strain in 7 (87.5%) of them.

Conclusion

A high rate of bacterial nasal colonization and MPs contamination were found among the OR medical staff. An MP may be a reservoir for pathogen contamination in the OR.

Vaccine development to prevent Staphylococcus aureus surgical-site infections

BACKGROUND

Staphylococcus aureus surgical-site infections (SSIs) are a major cause of poor health outcomes, including mortality, across surgical specialties. Despite current advances as a result of preventive interventions, the disease burden of S. aureus SSI remains high, and increasing antibiotic resistance continues to be a concern. Prophylactic S. aureus vaccines may represent an opportunity to prevent SSI.

METHODS

A review of SSI pathophysiology was undertaken in the context of evaluating new approaches to developing a prophylactic vaccine to prevent S. aureus SSI.

RESULTS

A prophylactic vaccine ideally would provide protective immunity at the time of the surgical incision to prevent initiation and progression of infection. Although the pathogenicity of S. aureus is attributed to many virulence factors, previous attempts to develop S. aureus vaccines targeted only a single virulence mechanism. The field has now moved towards multiple-antigen vaccine strategies, and promising results have been observed in early-phase clinical studies that supported the recent initiation of an efficacy trial to prevent SSI.

CONCLUSION

There is an unmet medical need for novel S. aureus SSI prevention measures. Advances in understanding of S. aureus SSI pathophysiology could lead to the development of effective and safe prophylactic multiple-antigen vaccines to prevent S. aureus SSI.

The Neurostimulation Appropriateness Consensus Committee (NACC) Recommendations for Infection Prevention and Management

INTRODUCTION

The use of neurostimulation for pain has been an established therapy for many decades and is a major tool in the arsenal to treat neuropathic pain syndromes. Level I evidence has recently been presented to substantiate the therapy, but this is balanced against the risk of complications of an interventional technique.

METHODS

The Neurostimulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society convened an international panel of well published and diverse physicians to examine the best practices for infection mitigation and management in patients undergoing neurostimulation. The NACC recommendations are based on evidence scoring and peer-reviewed literature. Where evidence is lacking the panel added expert opinion to establish recommendations.

RESULTS

The NACC has made recommendations to improve care by reducing infection and managing this complication when it occurs. These evidence-based recommendations should be considered best practices in the clinical implantation of neurostimulation devices.

CONCLUSION

Adhering to established standards can improve patient care and reduce the morbidity and mortality of infectious complications in patients receiving neurostimulation.

Impact of Probiotics for Reducing Infections in Veterans (IMPROVE): Study protocol for a double-blind, randomized controlled trial to reduce carriage of Staphylococcus aureus

BACKGROUND

Staphylococcus aureus (S. aureus) is an organism of great public health importance, causing 20,000 deaths annually. Decolonization of patients with S. aureus may prevent infections, yet current options are limited to antimicrobials that promote antibiotic resistance and can cause adverse side effects. Probiotics have potential to reduce colonization of pathogenic bacteria, representing a promising alternative for S. aureus decolonization, but thus far lack rigorous evaluation.

METHODS

Potential subjects were recruited from inpatient and outpatient settings within a VA medical center and screened for S. aureus gastrointestinal (GI) or extra-GI colonization using swabs at multiple body sites. Positive, eligible, consenting participants were stratified by colonization site and randomized in a 1:1 ratio to 4-weeks of daily placebo or Lactobacillus rhamnosus (L. rhamnosus) HN001 probiotic treatment. Blood and stool samples, and treatment adherence reports were collected from each subject throughout the study, along with a final set of swabs at study completion to detect S. aureus carriage. The outcomes of this study are GI or extra-GI carriage by S. aureus at the end of 4weeks of therapy, change in phagocytic activity of polymorphonuclear cells from pre-intervention to post-intervention, and symptomatic S. aureus infection at any site during the study period.

CONCLUSION

114 participants have been recruited for this study. Analysis of outcomes is underway. This is the first clinical trial to examine the efficacy of L. rhamnosus HN001 for decolonization of S. aureus, and investigates the mechanism by which L. rhamnosus HN001 mediates its effect on S. aureus colonization. ClinicalTrials.govIdentifier NCT01321606.

Evaluation of Staphylococcus aureus Eradication Therapy in Vascular Surgery

INTRODUCTION

Surgical site infections (SSI) are a serious complication in vascular surgery which may lead to severe morbidity and mortality. Staphylococcus aureus nasal carriage is associated with increased risk for development of SSIs in central vascular surgery. The risk for SSI can be reduced by perioperative eradication of S. aureus carriage in cardiothoracic and orthopedic surgery. This study analyzes the relation between S. aureus eradication therapy and SSI in a vascular surgery population.

METHODS

A prospective cohort study was performed, including all patients undergoing vascular surgery between February 2013 and April 2015. Patients were screened for S. aureus nasal carriage and, when tested positive, were subsequently treated with eradication therapy. The presence of SSI was recorded based on criteria of the CDC. The control group consisted of a cohort of vascular surgery patients in 2010, who were screened, but received no treatment.

RESULTS

A total of 444 patients were screened. 104 nasal swabs were positive for S. aureus, these patients were included in the intervention group. 204 patients were screened in the 2010 cohort. 51 tested positive and were included in the control group. The incidence of S. aureus infection was 5 out of 51 (9.8%) in the control group versus 3 out of 104 in the eradication group (2.2%; 95% confidence interval 0.02-1.39; P = 0.13). A subgroup analysis showed that the incidence of S. aureus infection was 3 out of 23 (13.0%) in the control group in central reconstructive surgery versus 0 out of 44 in the intervention group (P = 0.074). The reduction of infection pressure by S. aureus was stronger than the reduction of infection pressure by other pathogens (exact maximum likelihood estimation; OR = 0.0724; 95% CI: 0.001-0.98; p = 0.0475).

CONCLUSION

S. aureus eradication therapy reduces the infection pressure of S. aureus, resulting in a reduction of SSIs caused by S. aureus.

Phytochemical, Antimicrobial, and Toxicological Evaluation of Traditional Herbs Used to Treat Sore Throat

The in vitro antibacterial activities of 29 traditional medicinal plants used in respiratory ailments were assessed on multidrug resistant Gram-positive and Gram-negative bacteria isolated from the sore throat patients and two reference strains. The methanolic, n-hexane, and aqueous extracts were screened by the agar well diffusion assay. Bioactive fractions of effective extracts were identified on TLC coupled with bioautography, while their toxicity was determined using haemolytic assay against human erythrocytes. Qualitative and quantitative phytochemical analysis of effective extracts was also performed. Methanolic extract of 18 plants showed antimicrobial activity against test strains. Adhatoda vasica (ZI = 17–21 mm, MIC: 7.12–62.5 μg/mL), Althaea officinalis (ZI = 16–20 mm, MIC: 15.62–31.25 μg/mL), Cordia latifolia (ZI = 16–20 mm, MIC: 12.62–62.5 μg/mL), Origanum vulgare (ZI = 20–22 mm, MIC: 3–15.62 μg/mL), Thymus vulgaris (ZI = 21–25 mm, MIC: 7.81–31.25 μg/mL), and Ziziphus jujuba (ZI = 14–20 mm, MIC: 7.81–31.25 μg/mL) showed significant antibacterial activity. Alkaloid fractions of Adhatoda vasica, Cordia latifolia, and Origanum vulgare and flavonoid fraction of the Althaea officinalis, Origanum vulgare, Thymus Vulgaris, and Ziziphus jujuba exhibited antimicrobial activity. Effective plant extracts show 0.93–0.7% erythrocyte haemolysis. The results obtained from this study provide a scientific rationale for the traditional use of these herbs and laid the basis for future studies to explore novel antimicrobial compounds.

Efficacy of a hospital-wide environmental cleaning protocol on hospital-acquired methicillin-resistant Staphylococcus aureus rates

BACKGROUND

Environmental contamination has been associated with over half of methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in hospitals. We explored if a hospital-wide environmental and patient cleaning protocol would lower hospital acquired MRSA rates and associated costs.

OBJECTIVE

This study evaluates the impact of implementing a hospital-wide environmental and patient cleaning protocol on the rate of MRSA infection and the potential cost benefit of the intervention.

METHODS

A retrospective, pre-post interventional study design was used. The intervention comprised a combination of enhanced environmental cleaning of high touch surfaces, daily washing of patients with benzalkonium chloride, and targeted isolation of patients with active infection. The rate of MRSA infection per 1000 patient days (PD) was compared with the rate after the intervention (Steiros Algorithm^®) was implemented. A cost-benefit analysis based on the number of MRSA infections avoided was conducted.

RESULTS

The MRSA rates decreased by 96% from 3.04 per 1000 PD to 0.11 per 1000 PD (P <0.0001). This reduction in MRSA infections, avoided an estimated $1,655,143 in healthcare costs.

DISCUSSION

Implementation of this hospital-wide protocol appears to be associated with a reduction in the rate of MRSA infection and therefore a reduction in associated healthcare costs.