Clinical presentations of soft-tissue infections and surgical site infections

Antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at tertiary care hospital in Riyadh, Saudi Arabia

Staphylococcus aureus is an important human pathogen that has a major impact on public health. The objective of the present work was to determine the prevalence and the pattern of antibiotic susceptibility in S aureus (MRSA) isolates from the King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia. The isolates were collected from different body sites of infection and the antibiotic susceptibility was confirmed on the Vitek 2 system. A total of 371 MRSA isolates from clinical samples were received over a 12-month period from January 2021 to December 2021. The results showed that infection was predominant among males (55.8%) and most of the isolates occurred in the older age groups, with a mean age of 43.7 years and an age span from <1 to 89 years old. The majority (34.5%) recovered from wound infection followed by (14.6%) from blood. We have observed peaks of MRSA infections during the autumn, especially in September and November. All MRSA isolates were resistant to Amoxicillin + clavulanic acid, Ampicillin, Imipenem, Oxacillin, Cloxacillin, and Penicillin while all isolates were sensitive to Daptomycin and Nitrofurantoin. Furthermore, Vancomycin was resistant in (0.3%) of MRSA isolates, and (2.9%) was resistant to Linezolid. The current study concluded that MRSA strains had developed resistance toward 24 tested antibiotics, including the previous effective drugs vancomycin and linezolid. Therefore, there is an urgent need for continuous review of infection control practices to prevent any further spread of resistant strains.

Antimicrobial Management of Complicated Skin and Soft Tissue Infections in an Era of Emerging Multi-Drug Resistance: Perspectives from 5 Gulf Countries

The number of complicated skin and soft tissue infections (cSSTIs) in the Arabian Gulf region has risen in recent years, particularly those caused by multi-drug resistant (MDR) pathogens. The high prevalence of diabetes, obesity, and associated cardio-metabolic comorbidities in the region renders medical and surgical management of cSSTI patients with MDR infections challenging. An experienced panel of international and regional cSSTI experts (consensus group on cSSTIs) was convened to discuss clinical considerations for MDR infections from societal, antimicrobial stewardship, and cost perspectives, to develop best practice recommendations. This article discusses antibiotic therapies suitable for treating MDR cSSTIs in patients from the Gulf region and recommends that these should be tailored according to the local bacterial ecology by country and region. The article highlights the need for a comprehensive patient treatment pathway and defined roles of each of the multidisciplinary teams involved with managing patients with MDR cSSTIs. Aligned and inclusive definitions of cSSTIs for clinical and research purposes, thorough and updated epidemiological data on cSSTIs and methicillin-resistant <i>Staphylococcus aureus</i> in the region, clearcut indications of novel agents and comprehensive assessment of comparative data should be factored into decision-making are necessary.

Biocompatibility and Antimicrobial Activity of Nanostructured Lipid Carriers for Topical Applications Are Affected by Type of Oils Used in Their Composition

Nanostructured lipid carriers (NLCs) have gained significant attention as tools for the dermal delivery of therapeutics due to their stability, biocompatibility, and ability to improve drug bioavailability. The use of natural plant oils (NPO) in NLC formulations has numerous benefits for the skin due to their therapeutic potential. This work shows the effect of NLC composition on bioavailability in epidermal cells and antimicrobial activity against Staphylococcus aureus. Sixteen systems containing fixed (sunflower, olive, corn, peanut, coconut, castor, and sweet almond) and essential (eucalyptus) oils, with different solid lipid (SL): liquid lipid (LL) ratios, were engineered. The structural properties, bioavailability, and antimicrobial action of the particles was studied. The choice of NPO influenced the physicochemical stability by changing the diameter of NLC formulations (between 160 nm and 185 nm) and Z-potential (between −46 mV and −61 mV). All of the systems were characterized by concentration-dependent cytocompatibility with human epidermal keratinocytes (HaCaT) and human dermal fibroblasts (HDFn). The SL:LL ratio in some NLC systems impacted cell cytotoxicity differently. Antimicrobial properties were observed in all 16 systems; however, the type of oil and SL:LL ratio affected the activity of the formulations. Two NLC-NPO systems were found to be non-cytotoxic to human cells lines at concentrations that completely inhibited bacterial growth. These results present a strong argument that the use of natural oils in NLC formulations presents a promising tool for the treatment of skin infections.

Current management of necrotizing soft-tissue infections

PURPOSE OF REVIEW

The aim of the article is to present recent epidemiological, microbiological, and clinical data for the surgical, antimicrobial, and adjunctive management of necrotizing soft-tissue infections (NSTI).

RECENT FINDINGS

NSTI can be caused by a broad variety of organisms. Reports about NSTI caused by multidrug-resistant bacteria are increasing. Owing to the rareness of NSTI, general clinical awareness is low and prompt diagnosis is often delayed. New diagnostic instruments (scoring systems, MRI) have either a low accuracy or are time consuming and cannot guide clinicians reliable currently. The value of adjunctive measures (intravenous immunoglobulin, hyperbaric oxygen therapy) is uncertain as well. Morbidity and mortality in NSTI remain high, ranging from 20 up to over 30%.

SUMMARY

Early radical surgical debridement and empirical broad-spectrum antimicrobial treatment remain the cornerstones of therapy in NSTI. Further clinical research is necessary to shorten diagnostic pathways and to optimize surgical, antimicrobial, and adjunctive treatment.

Bullous Pemphigoid After Total Knee Arthroplasty

Total knee arthroplasty is one of the safest and most routinely performed orthopedic procedures. As the volume of cases is expected to rise each year, so too will the incidence of uncommon complications. We describe a rare case of bullous pemphigoid, an autoimmune skin blistering disorder, that occurred after total knee arthroplasty in an otherwise healthy patient and led to hospital readmission. Early diagnosis and treatment of this condition may limit its spread and help to avoid comorbid sequelae.

Surgical Infection Society 2020 Updated Guidelines on the Management of Complicated Skin and Soft Tissue Infections

Background: The Surgical Infection Society (SIS) Guidelines for the treatment of complicated skin and soft tissue infections (SSTIs) were published in October 2009 in Surgical Infections. The purpose of this project was to provide a succinct update on the earlier guidelines based on an additional decade of data. Methods: We reviewed the previous guidelines eliminating bite wounds and diabetic foot infections including their associated references. Relevant articles on the topic of complicated SSTIs from 2008-2020 were reviewed and graded individually. Comparisons were then made between the old and the new graded recommendations with review of the older references by two authors when there was disparity between the grades. Results: The majority of new studies addressed antimicrobial options and duration of therapy particularly in complicated abscesses. There were fewer updated studies on diagnosis and specific operative interventions. Many of the topics addressed in the original guidelines had no new literature to evaluate. Conclusions: Most recommendations remain unchanged from the original guidelines with the exception of increased support for adjuvant antimicrobial therapy after drainage of complex abscess and increased data for the use of alternative antimicrobial agents.

Baseline Characteristics and Outcomes Among Patients with Complicated Skin and Soft Tissue Infections Admitted to the Intensive Care Unit: Analysis of the Phase 3 COVERS Randomized Trial of Ceftaroline Fosamil Versus Vancomycin Plus Aztreonam

Aim

Exploratory analyses evaluated patient characteristics and outcomes among patients with complicated skin and soft tissue infection (cSSTI) in the phase 3 COVERS study who were admitted to an intensive care unit (ICU).

Methods

Adults with cSSTI (surface area ≥ 75 cm²) and evidence of systemic inflammation and/or underlying comorbidities were randomized 2:1 to intravenous ceftaroline fosamil (600 mg every 8 h [q8h]) or vancomycin (15 mg/kg every 12 h) plus aztreonam (1 g q8h) for 5–14 days. Clinical response and ICU length of stay (LOS) within first hospitalization were evaluated in the modified intent-to-treat (MITT) and clinically evaluable (CE) populations; a Cox proportional hazards model identified factors associated with increased hospital LOS.

Results

Overall, 42 of 761 randomized patients were admitted to the ICU (ceftaroline fosamil, n = 32; vancomycin plus aztreonam, n = 10) prior to, or at start of, study treatment. Baseline differences between the ICU and non-ICU populations were indicative of more severe disease in ICU patients; within this subset, there were also some notable imbalances between treatment groups. Clinical cure rates at test-of-cure (ceftaroline fosamil vs. vancomycin plus aztreonam) were generally similar in the non-ICU and ICU subsets (MITT population 79% vs. 79% and 69% vs. 90.0%, respectively; CE population 87% vs. 85% and 80% vs. 89%, respectively). Median ICU LOS was 8 vs. 13 days, respectively. ICU admission was a risk factor predicting increased hospital LOS (P < 0.001).

Conclusions

Clinical outcomes for patients admitted to the ICU were generally similar to non-ICU patients, despite more severe baseline disease, with shorter median treatment duration in the ceftaroline fosamil group. ICU admission was associated with longer hospital LOS. Given the small sample size and unbalanced patient and disease characteristics within the ICU subgroup, differences between treatment groups should be interpreted with caution.

Trial registration

ClinicalTrials.gov identifier, NCT01499277.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00297-3) contains supplementary material, which is available to authorized users.

ZnO-NPs embedded biodegradable thiolated bandage for postoperative surgical site infection: In vitro and in vivo evaluation

Post-operative surgical site infections (SSI) present a serious threat and may lead to complications. Currently available dressings for SSI lack mucoadhesion, safety, efficacy and most importantly patient compliance. We aimed to address these concerns by developing a bioactive thiolated chitosan-alginate bandage embedded with zinc oxide nanoparticles (ZnO-NPs) for localized topical treatment of SSI. The FTIR, XRD, DSC and TGA of bandage confirmed the compatibility of ingredients and modifications made. The porosity, swelling index and lysozyme degradation showed good properties for wound healing and biodegradation. Moreover, in-vitro antibacterial activity showed higher bactericidal effect as compared to ZnO-NPs free bandage. In-vivo wound healing in murine model showed significant improved tissue generation and speedy wound healing as compared to positive and negative controls. Over all, thiolated bandage showed potential as an advanced therapeutic agent for treating surgical site infections, meeting the required features of an ideal surgical dressing.

Multifunctional Zn doped hollow mesoporous silica/polycaprolactone electrospun membranes with enhanced hair follicle regeneration and antibacterial activity for wound healing

Due to the complexity of the skin tissue structure, the regeneration of the entire skin, including skin appendages such as hair follicles, is a big challenge. In addition, skin trauma is often accompanied by bacterial infections that delay the wound healing. Therefore, developing wound dressings, which promote hair follicle regeneration and inhibit bacterial infection in the wound healing process, is of great clinical significance. In this study, Zn doped hollow mesoporous silica nanospheres (HMZS) were synthesized by a sol-gel method and a novel wound healing dressing was prepared by incorporation of drug ciprofloxacin hydrochloride (CiH)-loaded Zn containing mesoporous silica nanospheres (CiH-HMZS) into polycaprolactone (PCL) electrospun fibers. The CiH-HMZS/P nano-composite electrospun fibers exhibit the ability to promote angiogenesis and skin regeneration by releasing Si ions, and the activity to enhance hair follicle regeneration and inhibit bacterial growth by releasing zinc ions and achieve the synergistic antibacterial effect with both Zn ions and CiH in low concentrations. Thus, the CiH-HMZS/P nano-composite membrane is a promising multi-functional wound healing material for inhibiting bacterial growth in infected wounds and enhancing skin wound healing including hair follicle regeneration.

Frequency of Post-operative Surgical Site Infections in a Tertiary Care Hospital in Abbottabad, Pakistan

Background

Any infection occurring in a wound after a surgical procedure is called a post-operative surgical wound infection. Surgical wound infection is a type of nosocomial infection that is acquired in hospitals when a person is admitted for reasons other than the infection. Surgical site infections (SSIs) are the second most common nosocomial (hospital-acquired) infections after urinary tract infections. SSIs contribute to a significant rate of morbidity and mortality in patients and has become a major public health problem worldwide. The increase in antibiotic resistance associated with SSIs has also become a therapeutic challenge for physicians worldwide.

Methods

This cross-sectional study was carried out among the patients admitted in various surgical wards of the Ayub Teaching Hospital. A total of 95 patients were enrolled for the study using a non-probability convenient sampling technique. Data were collected using a structured questionnaire by students carrying out the research for a time period of one month. SSIs were assessed by:

1. Pus or purulent discharge from the wound along with pain,

2. Any two cardinal signs of inflammation, and

3. Diagnosis of SSI by the surgeon.

Results

The mean age of the patients was 35.73 ± 19.73 years. SSI rate was found to be 33.68% with 32 patients developing SSIs out of 95 patients. The rate of SSIs was greater in older patients with four (44.4%) out of nine patients above 60 years developing SSIs. Patients belonging to urban areas had a higher incidence rate (52.77%) of SSIs as compared to rural areas (32.20%). The rate of SSIs in patients operated with an elective surgical plan was greater (37.93%) as compared to patients operated with an emergency surgical plan (27.77%). Patients who were obese were more prone to SSIs with seven (36.8%) patients developing SSIs out of 19. Surgeries performed by trainee medical officers had a greater rate of SSIs with 24 (35.3%) patients developing SSIs out of 68 patients. Three (66.66%) out of four patients with diabetes and 18 (40.9%) out of 44 patients with anemia developed SSIs.

Conclusion

This study concluded that the incidence rate of SSIs was high in patients admitted in Ayub Teaching Hospital. Major risk factors identified were co-morbidities, old age, obesity, duration of surgery, major surgeries, and anemia. Steps should be taken to decrease SSIs in these high-risk groups.

Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections.

Postoperative sepsis prediction in patients undergoing major cancer surgery

BACKGROUND

Cancer patients are at increased risk for postoperative sepsis. However, studies addressing the issue are lacking. We sought to identify preoperative and intraoperative predictors of 30-d sepsis after major cancer surgery (MCS) and derive a postoperative sepsis risk stratification tool.

METHODS

Patients undergoing one of nine MCSs (gastrointestinal, urological, gynecologic, or pulmonary) were identified within the American College of Surgeons National Surgical Quality Improvement Program (2005-2011, n = 69,169). Multivariable adjusted analyses (MVA) were performed to identify the predictors of postoperative sepsis. A composite sepsis risk score (CSRS) was constructed using the regression coefficients of predictors significant on MVA. The score was stratified into low, intermediate, and high risk, and its predictive accuracy for sepsis, septic shock, and mortality was assessed using the area under the curve analysis.

RESULTS

Overall, 4.3% (n = 2954) of patients developed postoperative sepsis. In MVA, Black race (odds ratio [OR] = 1.30, P = 0.002), preoperative hematocrit <30 (OR = 1.40, P = 0.022), cardiopulmonary and cerebrovascular comorbidities (P < 0.010), American Society of Anesthesiologists score >3 (P < 0.05), operative time (OR = 1.002, P < 0.001), surgical approach (OR = 1.81, P < 0.001), and procedure type (P < 0.001) were significant predictors of postoperative sepsis. CSRS demonstrated favorable accuracy in predicting postoperative sepsis, septic shock, and mortality (area under the curve 0.72, 0.75, and 0.74, respectively). Furthermore, CSRS risk stratification demonstrated high concordance with sepsis rates, 1.3% in low-risk patients versus 9.7% in high-risk patients. Similarly, 30-d mortality rate varied from 0.5% to 5.5% (10-fold difference) in low-risk patients versus high-risk patients.

CONCLUSIONS

Our study identifies the major risk factors for 30-d sepsis after MCS. These risk factors have been converted into a simple, accurate bedside sepsis risk score. This tool might facilitate improved patient-physician interaction regarding the risk of postoperative sepsis and septic shock.

Insight into membrane selectivity of linear and branched polyethylenimines and their potential as biocides for advanced wound dressings

We report here structure-property relationship between linear and branched polyethylene imines by examining their antimicrobial activities against wide range of pathogens. Both the polymers target the cytoplasmic membrane of bacteria and yeasts, eliciting rapid microbicidal properties. Using multiscale molecular dynamic simulations, we showed that, in both fully or partially protonated forms LPEI discriminates between mammalian and bacterial model membranes whereas BPEI lacks selectivity for both the model membranes. Simulation results suggest that LPEI forms weak complex with the zwitterionic lipids whereas the side chain amino groups of BPEI sequester the zwitterionic lipids by forming tight complex. Consistent with these observations, label-free cell impedance measurements, cell viability assays and high content analysis indicate that BPEI is cytotoxic to human epithelial and fibroblasts cells. Crosslinking of BPEI onto electrospun gelatin mats attenuate the cytotoxicity for fibroblasts while retaining the antimicrobial activity against Gram-positive and yeasts strains. PEI crosslinked gelatin mats elicit bactericidal activity by contact-mediated killing and durable to leaching for 7days. The potent antimicrobial activity combined with enhanced selectivity of the crosslinked ES gelatin mats would expand the arsenel of biocides in the management of superficial skin infections. The contact-mediated microbicidal properties may avert antimicrobial resistance and expand the diversity of applications to prevent microbial contamination.

STATEMENT OF SIGNIFICANCE

Current commercially available advanced wound dressings are either impregnated with metallic silver or silver salts which have side effects or may not avert antimicrobial resistance. In this article, we have used multidisciplinary approach comprising of computational, chemical and biological methods to understand the antimicrobial properties and biocompatibility of linear (LPEI) and branched (BPEI) polyethylenimines. We then applied this knowledge to develop dual purpose wound dressings containing these polymers, which encourages healing while maintain antimicrobial activity. In addition, the approach can be expanded to rationalize the antimicrobial vs. cytotoxicity of other cationic polymers and the method of crosslinking would enhance their potentials as biocides for advanced materials.

Staphylococcus aureus-Associated Skin and Soft Tissue Infections: Anatomical Localization, Epidemiology, Therapy and Potential Prophylaxis

Skin and soft tissue infections (SSTIs) are among the most common infections worldwide. They range in severity from minor, self-limiting, superficial infections to life-threatening diseases requiring all the resources of modern medicine. Community (CA) and healthcare (HA) acquired SSTIs are most commonly caused by Staphylococcus aureus . They have variable presentations ranging from impetigo and folliculitis to surgical site infections (SSIs). Superficial SSTIs may lead to even more invasive infections such as bacteraemia and osteomyelitis. Here we describe the anatomical localization of the different SSTI associated with S. aureus, the virulence factors known to play a role in these infections, and their current epidemiology. Current prevention and treatment strategies are also discussed. Global epidemiological data show increasing incidence and severity of SSTIs in association with methicillin-resistant S. aureus strains (MRSA). CA-SSTIs are usually less morbid compared to other invasive infections caused by S. aureus, but they have become the most prevalent, requiring a great number of medical interventions, extensive antibiotic use, and therefore a high cost burden. Recurrence of SSTIs is common after initial successful treatment, and decolonization strategies have not been effective in reducing recurrence. Furthermore, decolonization approaches may be contributing to the selection and maintenance of multi-drug resistant strains. Clinical studies from the early 1900s and novel autovaccination approaches suggest an alternative strategy with potential effectiveness: using vaccines to control S. aureus cutaneous infections.

Tigecycline in the Treatment of Patients with Necrotizing Skin and Soft Tissue Infections Due to Multiresistant Bacteria

BACKGROUND

Necrotizing skin and soft tissue infections (NSTI) form a group of aggressive diseases that require radical debridement for infection control. Simultaneously, a high-dose broad spectrum antibiotic regimen needs to be initiated with control of septic complications in the intensive care setting. The aim of this work is to analyze the efficacy and safety of tigecycline in a subpopulation of hospitalized, severely ill surgical NSTI patients who were documented in a large multicenter non-interventional study on tigecycline use in routine clinical practice.

METHODS

A total of 1,025 patients with severe infections including complicated skin and soft-tissue infections (cSSTI, n=163; 15,9%) were enrolled in a prospective multi-center non-interventional study. Patients were to receive an initial intravenous dose of 100 mg tigecycline, followed by 50 mg twice daily. Prospectively documented parameters included clinical findings, APACHE II score, microbiological and standard laboratory assessments, surgical measures, and clinical outcomes including adverse events.

RESULTS

Of 163 patients were treated for cSSTI, with the largest subgroup being NSTI patients (n=50, 30.7% of all cSSTI, mean age 61 y, median APACHE II score 20). Forty-eight NSTI patients (96%) had at least one comorbidity. In 80% of patients, the treatment was started after previous antibiotic treatment had failed and in 34% resistant pathogens were isolated (28% methicillin resistant Staphyloccocus aureus [MRSA], 4% extended-spectrum-beta-lactamase (ESBL)-producing bacteria, and 2% vancomycin-resistant Enterococci (VRE). Tigecycline was administered as a single agent in 32 patients; 17 received combination regimens. Data from one patient were not reported. Rates of clinical cure or improvement with tigecycline treatment were 90.2%. Two patients (4%) had drug related adverse events (one thrombocytopenia and one fever/chills); 10 patients (20%) died.

CONCLUSIONS

Tigecycline alone or in combination therapy was an effective and safe antibiotic treatment in critically ill and antimicrobially pre-treated patients with NSTI frequently caused by resistant pathogens.

In vitro and clinical experience of Cutimed Sorbact: the evidence base

In the previous chapter, Keith Cutting and James McGuire explored the link between infection and wound chronicity and explained how Cutimed Sorbact can be used to promote healing in chronic wounds. The following sections summarise the existing evidence for the Cutimed Sorbact range of dressings.

Bullous pemphigoid after bilateral forefoot surgery

The case of a 76-year-old woman who developed blisters on both forefeet within 2 weeks of bilateral forefoot surgery is reported; the diagnosis of bullous pemphigoid was made by histological and immunofluorescence studies. The pathogenesis and management of this autoimmune condition, which occurs mainly in patients older than 70 years and may occasionally be associated with surgical wounds, are reviewed. It is important for foot and ankle specialists to be aware of and consider the diagnosis when a bullous contact dermatitis-like eruption persists at a surgical site.

LEVEL OF EVIDENCE

Therapeutic Level IV: Case report.

Clinical and Economic Consequences of Failure of Initial Antibiotic Therapy for Hospitalized Patients With Complicated Skin and Skin-Structure Infections

Objective.

To estimate the consequences of failure of initial antibiotic therapy for patients with complicated skin and skin-structure infections.

Design.

Retrospective cohort study.

Setting.

Large US multihospital database.

Patients.

We identified a total of 47,219 patients (age 18 years or older) who were admitted to the hospital for complicated skin and skin-structure infections from April 1, 2003, through March 31, 2004, and who received intravenous antibiotics during the first 2 hospital-days (ie, initial antibiotic therapy). Failure of therapy was defined as drainage, debridement, or receipt of other intravenous antibiotics at any subsequent time (except for changes to narrower-spectrum agents or any therapy change immediately before discharge). Predictors of failure of antibiotic therapy and mortality were examined using multivariate logistic regression. Analysis of covariance was used to estimate the impact of treatment failure on duration of intravenous antibiotic therapy, length of stay, and total inpatient charges.

Results.

For 10,782 admitted patients (22.8%), there was evidence of failure of initial antibiotic therapy. In multivariate analyses, treatment failure was associated with receipt of vasoactive medications during the first 2 hospital-days (odds ratio [OR], 1.66 [95% confidence interval {CI}, 1.19-2.31]), initiation of antibiotic therapy in the intensive care unit (OR, 1.53 [95% CI, 1.28-1.84]), and the patient's Charlson comorbidity index (OR per 1-point increase, 1.06 [95% CI, 1.04-1.08]); treatment failure was also was associated with a 3-fold increase in mortality (OR, 2.91 [95% CI, 2.34-3.62]). Compared with patients for whom initial treatment was successful, patients who experienced treatment failure received intravenous antibiotic therapy for a mean of 5.7 additional days, were hospitalized for a mean of 5.4 additional days, and incurred a mean of $5,285 (in 2003 dollars) in additional inpatient charges (all P <.01).

Conclusion.

Failure of initial antibiotic therapy in the treatment of complicated skin and skin-structure infections is associated with significantly worse clinical and economic outcomes.

Effects of cyclotides against cutaneous infections caused by Staphylococcus aureus

The main bacterium associated with skin infection is Staphylococcus aureus, occurring especially in infections acquired via surgical wounds, commonly leading to lethal hospital-acquired infections, emphasizing the importance of identifying new antimicrobial compounds. Among them, cyclotides have gained interest due to their high stability and multifunctional properties. Here, cycloviolacin 2 (CyO2) and kalata B2 (KB2) were evaluated to determinate their anti-staphylococcal activities using a subcutaneous infection model. Anti-staphylococcal activities of 50mM for KB2 and 25mM for CyO2 were detected with no cytotoxic activities against RAW 264.7 monocytes. In the in vivo assays, both cyclotides reduced bacterial load and CyO2 demonstrated an increase in the phagocytosis index, suggesting that the CyO2 in vivo anti-staphylococcal activity may be associated with phagocytic activity, additionally to direct anti-pathogenic activity.

Surgical site infections

Surgical site infections are a major contributor to morbidity and mortality in postsurgical care. Risk for surgical site infection is multifactorial and includes a host of microbial, patient-related, and procedure-related factors. Prevention of surgical infection relies on optimization of patient factors and use of a variety of evidence-based pharmacologic and nonpharmacologic measures. At the forefront of these measures is antimicrobial prophylaxis, which has been shown to be effective at reducing risk of surgical site infection. As guidelines for prevention of surgical site infection become increasingly complex and nuanced, surgical infection outcomes are increasing tied to quality outcome and performances measures.

An evaluation of differences in risk factors for individual types of surgical site infections after colon surgery

BACKGROUND

Most studies and national programs aggregate the different types of surgical site infections (SSIs) potentially masking and misattributing risk. Determining that risk factors for superficial, deep, and organ space SSIs are unique is essential to improve SSI rates.

METHODS

This cohort study utilized data of 59,365 patients who underwent colon resection at hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program from 2007 to 2009. Four independent, multivariable, predictive models were developed to assess the unique associations between risk factors and each SSI group: Superficial, deep, organ space, and an aggregate of all 3 types of SSIs.

RESULTS

Overall, 13% of colon cases developed SSIs: Superficial (8%), deep (1.4%), and organ space (3.8%). Each model was different. Morbidly obese patients were more likely to develop SSIs than normal weight patients across all models; however, risk factors common to all models (eg, body mass index [BMI], duration of operation, wound class, laparoscopic approach) had very different levels of risk. Unique risks for superficial SSIs include diabetes, chronic obstructive pulmonary disease, and dyspnea. Deep SSIs had the greatest magnitude of association with BMI and the greatest incidence of wound disruption (19.8%). Organ space SSIs were often owing to anastomotic leaks and were uniquely associated with disseminated cancer, preoperative dialysis, preoperative radiation treatment, and a bleeding disorder, suggesting a physically frail or compromised patient may put the anastomosis at risk.

CONCLUSION

Risk factors for superficial, deep, and organ space SSI differ. More effective prevention strategies may be developed by reporting and examining each type of SSI separately.

Chinese herbal medicines for treating skin and soft-tissue infections

BACKGROUND

Skin and soft-tissue infections (SSTIs) are common infections of the epidermis, dermis or subcutaneous tissue. SSTIs range in severity from minor, self-limiting, superficial infections to deep, aggressive, gangrenous, life-threatening infections. Some classifications divide SSTIs into 'complicated' and 'uncomplicated' infections based on clinical severity. Treatments of SSTIs involves antibiotic therapy, surgical debridement or drainage, and resuscitation if required. Sometimes these treatments are limited by high treatment costs, bacterial resistance to antibiotics and side effects, therefore, many people with SSTIs are turning to Chinese herbal medicines to treat this problem.Chinese herbal medicines are natural substances that have been used for centuries in China where they are generally considered to be effective for SSTIs. Some Chinese herbal medicines have been shown to have antibacterial and anti-inflammatory properties, although a few herbal medicines have been reported to have side effects. Therefore there is a need to review the current clinical evidence systematically to inform current practice and guide future studies on Chinese herbal medicines for SSTIs.

OBJECTIVES

To evaluate the benefits and harms of Chinese herbal medicines for treating skin and soft-tissue infections (SSTIs).

SEARCH METHODS

Searches were not restricted by date, language or publication status. In July 2014 we searched the following electronic databases: the Cochrane Wounds Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; Ovid AMED (Allied and Complementary Medicine); and EBSCO CINAHL.

SELECTION CRITERIA

All randomised controlled trials (RCTs) in people with SSTIs that compared Chinese herbal medicines with another intervention or control.

DATA COLLECTION AND ANALYSIS

Two review authors screened the literature search results independently; there were no disagreements.

MAIN RESULTS

We identified no RCTs that met the inclusion criteria.

AUTHORS' CONCLUSIONS

There is currently no information available from RCTs to support or refute the use of Chinese herbal medicines in treating people with SSTIs.

Clostridium perfringens surgical site infection after osteotomy for knee deformity correction in a non-immunocompromised child

BACKGROUND

Clostridium perfringens myonecrosis following an elective surgical procedure in a previously healthy child is a rare incident.

METHODS

Case report and literature review.

RESULTS

A two-year old boy admitted for elective bilateral osteotomies of tibiae was detected to be febrile at day one post-operatively with crepitus felt at his left ankle. An emergency wound debridement was performed followed by a course of antibiotics. Clostridium perfringens was isolated from tissue culture. His wound was later covered with a split-thickness skin graft.

CONCLUSION

Clostridium perfringens infection following a surgical procedure in a healthy child is rare. A high index of suspicion is important to recognize this debilitating infection.

Initial treatment failure in patients with complicated skin and skin structure infections

BACKGROUND

Consequences of initial antibiotic failure in patients hospitalized for complicated skin and skin-structure infections (cSSSI) are not well understood.

METHODS

Using data from >100 hospitals in the United States, we identified all adults hospitalized for cSSSI between January 1, 2000 and June 30, 2009. We defined "initial therapy" as all parenteral antibiotics administered <24 h of admission, and such therapy was assumed to have failed if the patient (1) received new antibiotic(s) subsequently (excluding similar/narrower spectrum antibiotics or those begun at discharge), or (2) underwent drainage/debridement/amputation>72 h after admission. We limited attention to the 40 most commonly used antibiotic regimens in 2009. We compared clinical and economic outcomes of patients who experienced initial treatment failure and those who did not.

RESULTS

The rate of initial treatment failure was 16.6% in acute infections (n=13,498), 34.1% in chronic/ulcerative infections (n=1,116), and 26.7% in surgical site infections (SSIs) (n=2,929). Treatment failure was associated with 4.1-7.3 additional days in the hospital and $11,995-$23,655 in additional inpatient charges; the case fatality rate was from 4- to 12-fold higher in patients who experienced treatment failure than in those who did not (all comparisons, p<0.01).

CONCLUSION

Initial treatment failure in patients hospitalized for cSSSI is associated with significantly worse clinical outcomes, longer hospital stays, and higher hospital charges than with successful initial treatment.

The efficacy and safety of arbekacin and vancomycin for the treatment in skin and soft tissue MRSA infection: preliminary study

Background

Methicillin-resistant Staphylococcus aureus (MRSA) has become a one of the most important causes of nosocomial infections, and use of vancomycin for the treatment of MRSA infection has increased. Unfortunately, vancomycin-resistant enterococcus have been reported, as well as vancomycin-resistant S. aureus. Arbekacin is an antibacterial agent and belongs to the aminoglycoside family of antibiotics. It was introduced to treat MRSA infection. We studied the clinical and bacteriological efficacy and safety of arbekacin compared to vancomycin in the treatment of infections caused by MRSA.

Materials and Methods

This was a retrospective case-control study of patients who were admitted to tertiary Hospital from January 1st, 2009 to December 31st, 2010, and received the antibiotics arbekacin or vancomycin. All the skin and soft tissue MRSA infected patients who received arbekacin or vancomycin were enrolled during the study period. The bacteriological efficacy response (BER) was classified with improved and failure. The improved BER was defined as no growth of MRSA, where failure was defined as growth of MRSA, culture at the end of therapy or during treatment. Clinical efficacy response (CER) was classified as improved and failure. Improved CER was defined as resolution or reduction of the majority of signs and symptoms related to the original infection. Failure was defined as no resolution and no reduction of majority of the signs and symptoms, or worsening of one or more signs and symptoms, or new symptoms or signs associated with the original infection or a new infection.

Results

Totally, 122 patients (63/99 in arbekacin, 59/168 in vancomycin group) with skin and soft tissue infection who recieved arbekacin or vancomcyin at least 4 days were enrolled and analysed. The bacteriological efficacy response [improved, arbekacin vs vancomycin; 73.0% (46/63), 95% confidence interval (CI) 60.3 to 83.4% vs 83.1% (49/59), 95% CI 71.0 to 91.6%] and clinical efficacy response [improved, arbekacin vs vancomycin; 67.2% (41/61), 95% CI 52.0 to 76.7% vs 78.0% (46/59), 95% CI 65.3 to 87.7%] were similar between the two groups (P=0.264, 0.265). The complication rate was significantly higher in the vancomycin group [29/59(49.2%), 95% CI 35.9 to 62.5%] than arbekacin [10/63(15.9%), 95% CI 8.4 to 29.0%] (P<0.001).

Conclusions

Arbekacin could be considered as an alternative antibiotics for vancomycin in skin and soft tissue infection with MRSA. However, further prospective randomized trials are needed to confirm this finding.

Necrotizing soft-tissue infections

NSTI is a life-threatening, surgical, and medical emergency. Clinical presentation, at least in the initial phase, can be misleading. Various studies have shown that delay in surgical debridement is associated with increased mortality. A high index of suspicion is important in early recognition and in instituting prompt therapy without delay. Early diagnosis, aggressive surgical debridement, aggressive supportive care, and optimal presumptive antibiotic therapy significantly improve morbidity and mortality associated with NSTIs.

CANVAS 1 and 2: analysis of clinical response at day 3 in two phase 3 trials of ceftaroline fosamil versus vancomycin plus aztreonam in treatment of acute bacterial skin and skin structure infections

Scientific and regulatory interest in assessing clinical endpoints after 48 to 72 h of treatment for acute bacterial skin and skin structure infections (ABSSSI) has increased. Historical, pre-antibiotic-era data suggest that a treatment effect relative to untreated controls can be discerned in this time interval. Ceftaroline fosamil, a broad-spectrum bactericidal cephalosporin with activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative organisms was efficacious in two phase 3 trials of complicated skin infections (CANVAS 1 and 2) using clinical cure rates at the test-of-cure visit. To assess an early clinical response in the CANVAS trials, a retrospective analysis using a day 3 clinical endpoint was conducted. Adults with ABSSSI received intravenous ceftaroline fosamil at 600 mg every 12 h (q12h) or vancomycin at 1 g plus aztreonam at 1 g (V/A) q12h for 5 to 14 days. Clinical response at day 3, defined as cessation of infection spread and absence of fever, was analyzed in patients with a lesion size of ≥ 75 cm(2) and either deep and/or extensive cellulitis, major abscess, or an infected wound. Day 3 integrated CANVAS clinical response rates were 74.0% (296/400) for ceftaroline and 66.2% (263/397) for V/A (difference, 7.8%; 95% confidence interval [CI], 1.3% to 14.0%). In the individual studies, absolute treatment differences of 9.4% (CANVAS 1) and 5.9% (CANVAS 2) favoring ceftaroline were observed. For ABSSSI due to MRSA, response rates were 81.7% and 77.4% in the ceftaroline and V/A groups, respectively. In this retrospective analysis, ceftaroline fosamil monotherapy had a numerically higher clinical response than V/A at day 3 in the treatment of ABSSSI.

Empirical antibiotics use in soft tissue infections

PURPOSE

Various antibiotics are available to treat soft-tissue infections. However, it is unclear if the empirical antibiotic is always appropriate or the most economical.

OBJECTIVE

To determine the percentage of empirically treated wounds susceptible to the antibiotic therapy prescribed, and to determine the percentage of wounds treated with the most economical antibiotic therapy.

METHODS

A retrospective chart review was performed on all charts with a diagnosis of 'soft-tissue infection' between January 1, 2005, and June 30, 2005, at St Joseph's Hospital, Hamilton, Ontario. Eligible charts were identified using the medical diagnosis coding system. The following diagnoses (including subheadings) were included: cellulitis, lymphangitis, abscess, carbuncle or furuncle. The following was extracted: patient demographics; soft-tissue diagnosis; name, dose and duration of antibiotics used; culture results; and Gram-stain results. A comparison between the empirical antibiotic prescribed and the microbiology result was made. An assessment was performed on the cost of the initial empirical antibiotic treatment compared with less-expensive effective alternatives.

RESULTS

For soft-tissue infections with positive culture growth, empirical antibiotic treatment was appropriate in all abscess cases, 50% of ulcer cases and 83% of cellulitis cases. For cellulitis patients receiving a single empirical antibiotic, it was appropriate in 89% of cases. Only 42% of culture-positive patients were treated with the most economical regimen, multiple antibiotics being the most common fault.

CONCLUSIONS

To be most economical, a single empirical antibiotic should be used to treat cellulitis. Culture results should be used to guide any antibiotic changes.

Treatment of complicated skin and soft-tissue infections caused by resistant bacteria: value of linezolid, tigecycline, daptomycin and vancomycin

Antibiotic-resistant organisms causing both hospital- and community-acquired complicated skin and soft-tissue infections (cSSTI) are increasingly reported. A substantial medical and economical burden associated with MRSA colonisation or infection has been documented. The number of currently available appropriate antimicrobial agents is limited. Good quality randomised, controlled clinical trial data on antibiotic efficacy and safety is available for cSSTI caused by MRSA. Linezolid, tigecycline, daptomycin and vancomycin showed efficacy and safety in MRSA-caused cSSTI. None of these drugs showed significant superiority in terms of clinical cure and eradication rates.To date, linezolid offers by far the greatest number of patients included in controlled trials with a strong tendency of superiority over vancomycin in terms of eradication and clinical success.. - Tigecycline is an alternative in polymicrobial infections except by diabetic foot infections. Daptomycin might be a treatment option for cases of cSSTI with MRSA bacteremia. cSSTI caused by resistant Gram-negative bacteria are a matter of great concern. The development of new antibiotics in this area is an urgent priority to avoid the risk of a postantibiotic era with no antimicrobial treatment options. An individual approach for every single patient is mandatory to evaluate the optimal antimicrobial treatment regimen.

Severe skin and soft tissue infections and associated critical illness

Skin and soft tissue infections (SSTIs) span a broad spectrum of clinical entities from limited cellulitis to rapidly progressive necrotizing fasciitis, which may be associated with septic shock or a toxic shock-like syndrome. These infections may be the primary instigators of critical illness requiring hospitalization and management in the intensive care unit. Alternatively, these infections may arise from metastatic spread of microorganisms from a distant focus. Regardless of the source, SSTIs may lead to critical illness. The complex interplay of environment, host, and pathogen are important to consider when evaluating SSTIs and planning therapy. This second of a two-part review focuses on severe SSTIs due to Clostridium spp, microorganisms associated with water sources, and polymicrobial/mixed infections. The key to a successful outcome is early identification of risk factors for specific pathogens and early initiation of empiric antimicrobial therapy. For some SSTIs, surgical intervention for diagnosis and/or therapy is also required.

Efficacy and safety of linezolid in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infection (cSSTI): a meta-analysis

OBJECTIVE

To evaluate the clinical and microbiological outcomes of linezolid versus vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft-tissue infection (cSSTI) using a meta-analysis.

RESEARCH DESIGN AND METHODS

Clinical trials were identified using PubMed, the Cochrane Central Register of Controlled Trials, and the International Pharmaceutical Abstracts from inception to March 2009. Primary outcomes evaluated resolution of signs and symptoms of infection in clinically evaluable (CE) patients, and microbiological eradication in both the modified intent-to-treat (MITT) and MRSA evaluable (MRSA ME) patients. MITT patients had a culture-confirmed Gram-positive pathogen (S. aureus) at baseline. Secondary outcomes included mortality, adverse drug reactions (ADR), and discontinuation due to ADRs. The Mantel-Haenszel odds ratios (OR) with 95% confidence intervals (CI) were calculated using the fixed effects model based on the assumption that there was little to no heterogeneity between the studies in the primary analysis. Sensitivity analyses were performed for each outcome by removing the most weighted study.

RESULTS

Five studies with a total of 2652 patients (1361/linezolid; 1291/vancomycin) were identified. Resolution of infection in CE patients (OR = 1.41; 95% CI: 1.03, 1.95) and MITT patients (OR = 1.91; 95% CI: 1.33, 2.76) favored the use of linezolid over vancomycin, but did not remain significant after sensitivity analyses (CE: OR = 1.29; 95% CI: 0.81, 2.05; MITT: OR = 1.73; 95% CI: 0.87, 3.41). Microbiological eradication in MRSA ME patients consistently favored the use of linezolid over vancomycin (OR = 2.90; 95% CI: 1.90, 4.41). No difference in mortality was observed between the two groups (OR = 1.17; 95% CI: 0.85, 1.62). Higher proportions of linezolid patients were found to have diarrhea (119/1361 vs. 52/1291), nausea (102/1361 vs. 46/1291) and thrombocytopenia (54/1121 vs. 8/1071), whereas a higher proportion of vancomycin patients were found to have renal insufficiency compared to linezolid (16/634 vs. 4/703). Inconsistent results were seen with the incidence of anemia and rash between the base-case (anemia: OR = 1.36; 95% CI: 0.90, 2.08; rash: OR = 0.26; 95% CI: 0.10, 0.68) and sensitivity analyses (anemia: OR = 2.33; 95% CI: 1.24, 4.37; rash: OR = 0.57; 95% CI: 0.12, 2.71). Discontinuation due to ADRs was not statistically different between linezolid and vancomycin (OR = 1.06; 95% CI: 0.75, 1.51).

CONCLUSION

Resolution of infection in CE and MITT patients were inconsistent; however, a sub-analysis revealed that linezolid was more likely to consistently achieve microbiologic eradication in MRSA ME patients. Apparent risks of thrombocytopenia, nausea, diarrhea, and possibly anemia may limit linezolid use in treating MRSA cSSTI. This study was limited due to an inability to assess for the effects of hetero-resistance and appropriate vancomycin dosing on outcomes. Moreover, the small number of studies made controlling for heterogeneity challenging.

Skin and soft tissue infections

Skin and soft tissue infections are a common cause of hospitalization and use of antibiotic therapy, and may result in significant disability. Infections managed by surgeons may vary from simple, noncomplicated cellulitis to severe necrotizing soft tissue infections. The differentiation of necrotizing infections from nonnecrotizing infections is critical to achieving adequate surgical therapy. An understanding of the changing epidemiology of all complicated skin and soft tissue infections is required for selection of appropriate empiric antibiotic therapy.