Impact of evolving epidemiology on treatments for complicated skin and skin structure infections: the surgical perspective

Antibiotic resistance of bacteria responsible for postoperative wound infections seen in the laboratory of the University Hospital of Befelatanana

The management of postoperative wound infections is a major problem in hospitals due to the frequent ineffectiveness of antibiotic treatment. The objectives of this study are to identify the bacteria responsible for postoperative wound infections and to describe these antibiotic resistances in order to improve the management of these infections. It is a prospective study of 52 bacteriological results of postoperative wounds for a period of six months from January 2021 to June 2021 in the laboratory of the University Hospital of Befelatanana. This study showed 26 (50%) isolates of staphylococci, 17 (32.7%) isolates of enterobacteria, 6 (11.5%) isolates of streptococci and 3 (5.8%) isolates of nonfermenting gram-negatif bacilli. Antibiotic resistance, varies from 0% (vancomycin) to 92.3% (penicillin G) for staphylococci isolates, 0% (imipenem, amikacin) to 94.1% (amoxicillin) for enterobacteria isolates, 0% (vancomycin) to 50% (penicillin G) for streptococci isolates and 33% (imipenem, amikacin) to 100% (cotrimoxazole) for the isolates of nonfermenting gram-negatif bacilli. The knowledge of antibiotic resistance of bacteria responsible for postoperative wound infections allows better patient management.

Duration of Antibiotic Therapy in Necrotizing Soft Tissue Infections: Shorter is Safe

Background: Early debridement improves outcome in necrotizing soft tissue infection (NSTI), but there is no consensus on duration of antimicrobial therapy. We recently changed practice to discontinue antibiotic agents early with a goal of 48 hours after adequate source control. We hypothesized that discontinuing antibiotic agents after a short course is safe in the treatment of NSTI. Patients and Methods: This was a prospective study of patients with NSTI comparing short duration of antibiotic agents to a control population after a change in practice. In 2018 we began discontinuing antibiotic agents within 48 hours of source control (absence of cellulitis and no evidence of active infection). Previously, antibiotic duration was at the discretion of the attending surgeon (generally 7-10 days). Patients were excluded from analysis if they were initially debrided at a referring facility, immune compromised, or died prior to source control. Patient characteristics and outcomes were evaluated. The primary outcome was treatment failure requiring antibiotic agents to be restarted with or without further debridement of infected tissue. Secondary outcomes included the duration of antibiotic therapy after source control. Results: We evaluated 151 patients; 119 admitted between January 1, 2011 and January 31, 2018 (PRE) and 32 admitted after January 31, 2018 (POST). Patients were not statistically different regarding characteristics, admission physiologic variables, and comorbidities. The median duration of antibiotic agents after source control in the PRE group was 180.3 hours (interquartile range [IQR], 100.7-318.8) versus 48 hours (IQR, 32.3-100.8) in the POST group (p < 0.01). Patients in each group were treated as described above, and treatment failure occurred in seven (5.9%) PRE patients and two (6.3%) POST (99.3% post hoc power at non-inferiority limit 20%, significance p < 0.05). Thirty-day all-cause mortality was not different between groups (6.7% vs. 6.3%; p = 0.94). Conclusions: Short-duration (48 hours) antibiotic agents after NSTI source control is as safe and effective as a longer course.

Antibiotic Profile of Pathogenic Bacteria Isolated from Postsurgical Site Infections in Public Hospitals in Northern Jordan

Background

Surgical site infections are hospital-acquired, vary from one hospital to another, and can cause significant postoperative morbidity, mortality, and prolonged hospital stay.

Objective

The main aim of the study was to identify the bacterial pathogens associated with surgical site infections and their antibiotic susceptibility in a public hospital in northern Jordan.

Methods

Postsurgical wound samples were collected and processed in a microbiology laboratory using standard microbiological techniques. Antibiotic susceptibility tests were performed using 13 antibiotics covering the gram-positive and gram-negative bacteria using the disc diffusion test.

Results

The bacterial species that were identified in this study include Escherichia coli 8 (29%), Pseudomonas aeruginosa 3 (11%), Proteus mirabilis 1 (3.5%), Klebsiella pneumoniae 4 (14%), Salmonella enterica 2 (7%), Staphylococcus aureus 8 (29%), Staphylococcus epidermidis 1 (3.5%), and Streptococcus pyogenes 1 (4%). The antibiotic profiles of these bacteria showed high resistance. The MAR indices showed that 17 of 28 bacteria isolated were above 0.2 indicating high resistance.

Conclusion

Resistant bacteria are becoming more dominant in wound infections with a high prevalence of multidrug resistant isolates. Hospital disinfection and treatment protocols regarding the use of antibiotics should be practiced vigorously and monitored regularly to combat resistance.

OUP accepted manuscript

Background

Surgical site infection (SSI) is a common complication after abdominal surgery. The effectiveness of wound edge protectors in reducing infection of the surgical sites is still unclear. The purpose of this study was to determine the clinical effectiveness of a wound edge protector (WEP) in reducing SSI rates after abdominal surgery.

Methods

PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched to obtain relevant articles published up to September 2021. Publications were retrieved if they contain primary data on the use of WEPs in reducing SSI compared with standard care in patients undergoing abdominal surgery. Subgroup analyses were performed for different WEP types, surgical sites, and levels of contamination. The outcome of interest was a clinically defined SSI. Qualitative variables were pooled using risk ratios (RRs).

Results

Twenty-two eligible randomized clinical trials involving 4492 patients were included in this meta-analysis. WEP was associated with the reduced incidence of overall SSI (RR = 0.66; 95 per cent c.i. 0.53 to 0.83; P = 0.0003), and superficial SSI (RR = 0.59; 95 per cent c.i. 0.38 to 0.91; P = 0.02). In addition, WEP also successfully reduced the risk of SSI in clean-contaminated wounds (RR = 0.61; 95 per cent c.i. 0.40 to 0.93; P = 0.02) as well as in contaminated wounds (RR = 0.47; 95 per cent c.i. 0.33 to 0.67; P < 0.0001); however, WEP did not reduce SSI incidence in colorectal surgery (RR = 0.68; 95 per cent c.i. 0.46 to 1.01; P = 0.05).

Conclusion

This study suggests that WEP was efficient in reducing superficial SSI. Both double-ringed and single-ringed devices were efficient in reducing SSI. WEP was effective in reducing SSI incidence in clean-contaminated and contaminated surgery; however, its use does not reduce the SSI rate in colorectal surgery.

Analysis of Pooled Phase III Efficacy Data for Delafloxacin in Acute Bacterial Skin and Skin Structure Infections

Background

Delafloxacin is an oral or intravenous (IV) antibiotic indicated for the treatment of acute bacterial skin and skin structure infections (ABSSSI), including both gram-positive (including methicillin-resistant Staphylococcus aureus [MRSA]) and gram-negative organisms. Chemically distinct from other quinolones, delafloxacin exhibits enhanced potency, particularly against gram-positive pathogens. The integration of efficacy data across the Phase III ABSSSI studies is presented here and allows for additional examination of results across subgroups.

Methods

Results of 2 multicenter, randomized, double-blind trials of 1510 adults with ABSSSI were pooled for this analysis. Subjects in the vancomycin arm received 15 mg/kg, plus 1–2 g of aztreonam every 12 hours. Delafloxacin was dosed at 300 mg IV every 12 hours in Study 302; dosing in Study 303 was 300 mg IV every 12 hours for 3 days, with a mandatory, blinded switch to delafloxacin at 450 mg orally every 12 hours. The primary endpoint was objective response (OR), defined as a ≥20% reduction of lesion spread of erythema area at the primary infection site at 48 to 72 hours (±2 hours), in the absence of clinical failure. Investigator-assessed response, based on the resolution of signs and symptoms at follow-up (FU; Day 14 ± 1) and late follow-up (LFU; Day 21– 28), were secondary endpoints.

Results

In the intent-to-treat analysis set, the OR was 81.3% in the delafloxacin arm and 80.7% in the comparator arm (mean treatment difference 0.8%, 95% confidence interval -3.2% to 4.7). Results for OR in the defined subgroups showed delafloxacin to be comparable to vancomycin/aztreonam. Investigator-assessed success was similar at FU (84.7% versus 84.1%) and LFU (82.0% versus 81.7%). Delafloxacin was comparable to vancomycin/aztreonam in the eradication of MRSA, at 98.1% versus 98.0%, respectively, at FU. The frequencies of treatment-emergent adverse events between the groups were similar.

Conclusions

Overall, IV/oral delafloxacin fixed-dose monotherapy was non-inferior to IV vancomycin/aztreonam combination therapy and was well tolerated in each Phase III study, as well as in the pooled analysis, regardless of endpoint or analysis population.

N-alkylimidazolium Salts Functionalized with p-Coumaric and Cinnamic Acid: A Study of Their Antimicrobial and Antibiofilm Effects

The bacterial resistance to antibiotics has compromised the therapies used for bacterial infections. Nowadays, many strategies are being carried out to address this problem. Among them, the use of natural compounds like cinnamic and p-coumaric acids stands out. Nevertheless, their utilization is limited because of their unfavorable physicochemical properties. Due to the lack of new therapeutic alternatives for bacterial infections, novel strategies have emerged, such as the use of ionic liquids; given that they can show a broad spectrum of antibacterial activity, this is why we herein report the antibacterial and antibiofilm activity of a series of N-alkylimidazolium salts functionalized with p-coumaric and cinnamic acids. The results from this study showed better antibacterial activity against Gram-positive bacteria, with a predominance of the salts derived from coumaric acid and a correlation with the chain length. Additionally, a lower efficacy was observed in the inhibition of biofilm formation, highlighting the antibiofilm activity against Staphylococcus aureus, which decreased the production of the biofilm by 52% over the control. In conclusion, we suggest that the salts derived from p-coumaric acid are good alternatives as antibacterial compounds. Meanwhile, the salt derived from cinnamic acid could be a good alternative as an antibiofilm compound.

Meta-analysis Comparing Outcomes of Two Different Negative Pressure Therapy Systems in Closed Incision Management

BACKGROUND

Closed incision negative pressure therapy (ciNPT) is an emerging approach to managing closed incisions of patients at risk of postoperative complications. There are primarily 2 different commercially available ciNPT systems. Both systems consist of a single-use, battery-powered device and foam- or gauze-based peel-and-place dressing designed for closed incisions. These systems vary in design, and there are no data comparing outcomes between the 2 systems.

METHODS

We performed 2 separate meta-analyses to compare surgical site infection (SSI) rates postuse of (1) ciNPT with foam dressing (FOAM) versus conventional dressings and (2) ciNPT with multilayer absorbent dressing (MLA) versus conventional dressings.

RESULTS

Seven articles and 2 abstracts met inclusion criteria in the FOAM group (n = 489) versus the control group (n = 489) in meta-analysis 1; 7 articles and 1 abstract met inclusion criteria in the MLA group (n = 532) versus the control group (n = 540) in meta-analysis 2. Meta-analysis 1 showed that patients in the control group were 3.17 times more likely to develop an SSI compared with patients in the FOAM group [weighted mean odds ratios of FOAM group versus control group was 3.17 (P < 0.0001) with the 95% confidence intervals of 2.17-4.65]. Meta-analysis 2 showed no significant difference in SSI rates between patients in the MLA group and patients in the control group [weighted mean odds ratios of MLA group versus control group was 1.70 (P = 0.08) with the 95% confidence intervals of 0.94-3.08].

CONCLUSIONS

Comparing outcomes of two different ciNPT systems with a common comparator (conventional dressings) may provide an interim basis for comparing ciNPT systems until further comparative evidence is available. More comparative research is required to determine outcomes in clinical practice.

Efficacy and safety of delafloxacin compared with vancomycin plus aztreonam for acute bacterial skin and skin structure infections: a Phase 3, double-blind, randomized study

Background

Delafloxacin is an investigational anionic fluoroquinolone in development for oral or intravenous administration for the treatment of infections caused by Gram-positive (including MRSA), Gram-negative, atypical and anaerobic organisms.

Objectives

To establish the non-inferiority of delafloxacin compared with vancomycin plus aztreonam for the treatment of acute bacterial skin and skin structure infections and to compare the safety of the two antimicrobials.

Patients and methods

A Phase 3, multicentre, randomized, double-blind, active-controlled study with 660 patients compared delafloxacin 300 mg or vancomycin 15 mg/kg plus aztreonam 2 g each administered twice daily intravenously for 5–14 days. Non-inferiority was evaluated by objective response (≥20% erythema reduction) at 48–72 h after initiation of study drug, investigator subjective assessment of outcome and microbiological responses. Clinical Trials Registration: NCT01811732. EudraCT number: 2012-001767-71.

Results

In the ITT analysis set, the objective response was 78.2% in the delafloxacin arm and 80.9% in the vancomycin/aztreonam arm (mean treatment difference, −2.6%; 95% CI, −8.78% to 3.57%). Investigator-assessed cure was similar between the two groups at follow-up (52.0% versus 50.5%) and late follow-up (70.4% versus 66.6%). Bacterial eradication of MRSA was 100% and 98.5% in the delafloxacin group and the vancomycin/aztreonam group, respectively. Frequency of treatment-emergent adverse events in the delafloxacin and vancomycin/aztreonam groups was similar. Treatment-emergent adverse events leading to study drug discontinuation were higher in the vancomycin/aztreonam group compared with the delafloxacin group (4.3% versus 0.9%).

Conclusions

Delafloxacin, an anionic fluoroquinolone, was statistically non-inferior to vancomycin/aztreonam at 48–72 h following the start of therapy and was well tolerated as monotherapy in the treatment of acute bacterial skin and skin structure infections.

Experiences with skin and soft tissue infections among people who inject drugs in Philadelphia: A qualitative study

OBJECTIVES

To understand how people who inject drugs (PWID) experience skin and soft tissue infections (SSTI) and make decisions to seek or delay medical treatment.

METHODS

We conducted semi-structured, in-depth interviews in 2015 with 19 PWID at a syringe exchange program in Philadelphia. We analyzed the data using standard qualitative techniques.

RESULTS

PWID described adequate knowledge about SSTI, although they could not always implement knowledge about SSTI prevention due to environmental constraints. Participants reported different experiences with incident SSTI. Some sought immediate medical care at initial presentation. Most, however, waited to seek care. Previous positive and negative healthcare experiences, both in general -including stigma and withdrawal- and specific to SSTI, influenced this decision. Among those who delayed medical care, some reported self-treatment, including increased drug use for pain control, and lancing and draining their own wounds.

CONCLUSION

Reducing the incidence of SSTI and promoting earlier treatment are important public health priorities. Both require ongoing attention and improvements to the environments in which PWID inject and receive care.

Decreasing Incidence of Skin and Soft Tissue Infections With a Seasonal Pattern at an Academic Medical Center, 2006-2014

The incidence of SSTIs at University of Chicago Medicine decreased significantly in children and adults with seasonal variation, peaking during the summer months. This suggests a reversal of the massive increase in SSTI incidence after 2000 in the U.S.

Background. The incidence of skin and soft tissue infections (SSTIs) in the United States increased sharply after 2000 with the emergence of USA300 methicillin-resistant Staphylococcus aureus. We examined trends in SSTI incidence in 2006–2014 at the University of Chicago Medicine (UCM).

Methods. Data were obtained for patient encounters at UCM with an International Classification of Diseases, Ninth Revision-coded SSTI diagnosis between January 1, 2006 and March 31, 2014. Incidence density was calculated per 1000 encounters by quarter and year. Encounters were stratified by inpatient, outpatient clinic and emergency department (ED) encounters and by age group, gender, and race. Poisson regression was used to assess change over time.

Results. In 2006–2014, data were collected for 38 201 SSTI-associated encounters among 31 869 subjects. Among all patients treated at UCM, there was a decrease of 1% per year in the incidence of SSTIs during 2006–2013, with an overall decrease of 16%. There was a significant decrease in SSTI-related encounters among inpatients (rate ratio [RR] = 0.97; 95% confidence interval [CI], .96–.98), ED patients (RR = 0.98; 95% CI, .97–.98), adults (RR = 0.98; 95% CI, .97–.98), children (RR = 0.96; 95% CI, .95–.97), and African Americans (RR = 0.99; 95% CI, .98–.99). There was an annual seasonal trend, with the peak incidence occurring during the late summer.

Conclusions. The incidence of SSTIs at UCM decreased in children and adults with seasonal variation, peaking during the summer months. This suggests a reversal of the massive increase in SSTI incidence in the United States after 2000.

Skin and soft-tissue infections: a critical review and the role of telavancin in their treatment

Skin and soft-tissue infections (SSTIs) are an important cause of morbidity and mortality among hospitalized patients and a major therapeutic challenge for clinicians. Although uncomplicated SSTIs are managed successfully on an outpatient basis, more serious infections extending to the subcutaneous tissue, fascia, or muscle require complex management. Early diagnosis, selection of appropriate antimicrobials, and timely surgical intervention are key to successful treatment. Surgical-site infections, an important category of SSTI, occur in approximately half a million patients in North America annually. SSTIs are also a potential source for life-threatening bacteremia and metastatic abscesses. Gram-positive organisms, such as Staphylococcus aureus and Streptococcus pyogenes, are the dominant organisms isolated early in the infectious process, whereas gram-negative organisms are found in chronic wounds. Methicillin-resistant S. aureus (MRSA) is a potential bloodstream invader that requires aggressive antimicrobial treatment and surgery. Recent concerns regarding vancomycin activity include heteroresistance in MRSA and increase in the minimum inhibitory concentrations (>1 or 2 µg/mL); however, alternative agents, such as telavancin, daptomycin, linezolid, ceftaroline, dalbavancin, oritavancin, and tedizolid, are now available for the treatment of severe MRSA infections. Here, we present a review of the epidemiology, etiology, and available treatment options for the management of SSTIs.