Antibiotic resistance in common pathogens reinforces the need to minimise surgical site infections

The role of antimicrobial prophylaxis in laparoscopic nephrectomy for renal cell carcinoma

BACKGROUND

To investigate the role of antimicrobial prophylaxis in laparoscopic nephrectomy for renal cell carcinoma.

METHODS

We retrospectively enrolled 1000 patients who underwent laparoscopic nephrectomy from August 2019 to November 2021 in the Peking Union Medical College Hospital. Patients were divided into group without antimicrobial prophylaxis (n = 444) and group with antimicrobial prophylaxis (n = 556). Outcomes including 30-day postoperative infection rate, the increase rate of pre- and post-operative white blood cell counts and hospital stay were analyzed.

RESULTS

The overall infection rate was 5.0% (28/556) in the group with antimicrobial prophylaxis, which was similar to 4.1% (18/444) in the group without antimicrobial prophylaxis (P = 0.461). The increase rate of pre- and post-operative white blood cell counts was significantly lower (85.5% versus 97.0%) in the group with antimicrobial prophylaxis (P = 0.004). The postoperative hospital stay was 5 (4, 6) days in both groups (P = 0.483). Logistic regression analyses identified the use of antimicrobial prophylaxis had no influence on the occurrence of infection events (odds ratio = 0.797; 95% confidence interval, 0.435-1.460; P = 0.462). Hemoglobin (odds ratio = 0.430; 95% confidence interval, 0.257-0.719; P = 0.001) and partial nephrectomy (odds ratio = 2.292; 95% confidence interval, 1.724-3.046; P < 0.001) influenced the use of antimicrobial prophylaxis independently.

CONCLUSIONS

The use of antimicrobial prophylaxis had no impact on postoperative infection in patients receiving laparoscopic nephrectomy for renal cell carcinoma.

An Antibiotic-Loaded Silicone-Hydrogel Interpenetrating Polymer Network for the Prevention of Surgical Site Infections

Surgical site infections (SSIs) are among the most frequent healthcare-associated infections, resulting in high morbidity, mortality, and cost. While correct hygiene measures and prophylactic antibiotics are effective in preventing SSIs, even in modern healthcare settings where recommended guidelines are strictly followed, SSIs persist as a considerable problem that has proven hard to solve. Surgical procedures involving the implantation of foreign bodies are particularly problematic due to the ability of microorganisms to adhere to and colonize the implanted material and form resilient biofilms. In these cases, SSIs may develop even months after implantation and can be difficult to treat once established. Locally applied antibiotics or specifically engineered implant materials with built-in antibiotic-release properties may prevent these complications and, ultimately, require fewer antibiotics compared to those that are systemically administered. In this study, we demonstrated an antimicrobial material concept with intended use in artificial vascular grafts. The material is a silicone-hydrogel interpenetrating polymer network developed earlier for drug-release catheters. In this study, we designed the material for permanent implantation and tested the drug-loading and drug-release properties of the material to prevent the growth of a typical causative pathogen of SSIs, Staphylococcus aureus. The novelty of this study is demonstrated through the antimicrobial properties of the material in vitro after loading it with an advantageous combination, minocycline and rifampicin, which subsequently showed superiority over the state-of-the-art (Propaten) artificial graft material in a large-animal study, using a novel porcine tissue-implantation model.

Antibiotic Prophylaxis in Surgery: Current Insights and Future Directions for Surgical Site Infection Prevention

Surgical site infections (SSIs) remain a significant concern in the field of surgery, contributing to patient morbidity, prolonged hospital stays, and increased healthcare costs. Antibiotic prophylaxis, the administration of antibiotics before surgery, has been a cornerstone in preventing SSIs for decades. This review explores the current state of antibiotic prophylaxis in surgery, offering insights into its effectiveness, challenges, and emerging trends. In this comprehensive analysis, we delve into the historical development of antibiotic prophylaxis, examining its evolution from early practices to modern guidelines. We explore the various classes of antibiotics commonly used, their dosing regimens, and the importance of timing in optimizing prophylactic interventions. Additionally, we investigate the role of patient-specific factors, such as comorbidities and allergies, in tailoring antibiotic prophylaxis to individual needs. While antibiotic prophylaxis has undeniably reduced the incidence of SSIs, concerns about antimicrobial resistance and adverse effects necessitate a reevaluation of current practices. This review presents a critical assessment of the challenges posed by the overuse and misuse of antibiotics in surgery and highlights the urgent need for judicious antibiotic stewardship. Moreover, the future of antibiotic prophylaxis holds promise with the emergence of innovative strategies such as antimicrobial coatings, probiotics, and immunomodulatory agents. We discuss these novel approaches and their potential to enhance SSI prevention while minimizing antibiotic-related risks. In conclusion, antibiotic prophylaxis in surgery has been instrumental in reducing SSIs, but its continued effectiveness requires a multifaceted approach. By addressing current challenges, promoting antibiotic stewardship, and embracing innovative strategies, we can advance the field of SSI prevention and improve patient outcomes in the years to come. This review provides valuable insights and direction for clinicians, researchers, and policymakers as they navigate the evolving landscape of surgical prophylaxis.

Recent developments in membrane targeting antifungal agents to mitigate antifungal resistance

Fungal infections cause severe and life-threatening complications especially in immunocompromised individuals. Antifungals targeting cellular machinery and cell membranes including azoles are used in clinical practice to manage topical to systemic fungal infections. However, continuous exposure to clinically used antifungal agents in managing the fungal infections results in the development of multi-drug resistance via adapting different kinds of intrinsic and extrinsic mechanisms. The unique chemical composition of fungal membranes presents attractive targets for antifungal drug discovery as it is difficult for fungal cells to modify the membrane targets for emergence of drug resistance. Here, we discussed available antifungal drugs with their detailed mechanism of action and described different antifungal resistance mechanisms. We further emphasized structure-activity relationship studies of membrane-targeting antifungal agents, and classified membrane-targeting antifungal agents on the basis of their core scaffold with detailed pharmacological properties. This review aims to pique the interest of potential researchers who could explore this interesting and intricate fungal realm.

Severe wound infection by MRCNS following bilateral inguinal herniorrhaphy

BACKGROUND

Wound infection after inguinal hernia surgery is not uncommon in the clinical setting. The common microbial aetiology of postoperative inguinal hernia wound infection is Gram-positive bacteria. Staphylococcus aureus is a common pathogen causing wound infection while Staphylococcus epidermidis and Pseudomonas are rare. Staphylococcus epidermidis as a cause of severe wound infection is rarely described in literature. We herein present a case of a 79-year-old man with a rare wound infection after bilateral inguinal herniorrhaphy caused by MRCNS (Methicillin Resistant Coagulase Negative Staphylococcus).

CASE PRESENTATION

We present a case of wound infection accompanied by fever with a temperature of 38.8 °C after bilateral inguinal herniorrhaphy in a 79-year-old man. Bilateral inguinal wounds were marked by redness and swelling, with skin necrosis. In addition, an abscess of approximately 1.5 cm × 1.5 cm was seen on the left wrist. A small amount of gas under the skin in the wound area was observed after pelvic computed tomography (CT) scans. No bacteria were cultured from the inguinal wound discharge, while blood culture detected MRCNS, and Acinetobacter lwoffi was cultured from the pus in the left wrist. We chose appropriate antibiotics based on the results of the bacterial culture and the drug susceptibility results. Vacuum assisted closure (VAC) therapy was used after debridement. The patient was discharged after the wounds improved. He was followed up for ten months and showed no signs of complications. We are sharing our experience along with literature review.

CONCLUSIONS

We are presenting a rare case of MRCNS wound infection following open inguinal hernia surgery. Although a rarity, clinicians performing inguinal hernia surgery must consider this entity in an infected wound and follow up the patient for complications of MRCNS.

Do antibiotics prevent infection after third molar surgery? A network meta-analysis

The aim of this systematic review was to determine whether antibiotics, compared to placebo, can prevent infection or dry socket after third molar surgery. A systematic review and network meta-analysis (NMA) was performed following registration of the protocol (CRD42021276266). Four databases and the grey literature were searched, and papers were selected based on the PICOS question. RoB 2 and GRADE were used to evaluate the risk of bias and certainty of the evidence, respectively. The NMA was performed using Stata. Of 58 randomized clinical trials identified, 34 were included in the NMA. Patients treated with amoxicillin (relative risk (RR) 0.56, 95% confidence interval (CI) 0.38-0.84; low quality of evidence) and those treated with metronidazole (RR 0.51, 95% CI 0.31-0.84; low quality of evidence) showed a lower risk of infection and dry socket when compared to patients given a placebo. Postoperative amoxicillin (750 mg) and amoxicillin plus clavulanate (500 mg + 125 mg, or 2000 mg + 125 mg), and preoperative metronidazole (800 mg) are useful to prevent infection or dry socket when compared to placebo. The low rate of infection after third molar surgery, the correct concept of antibiotic prophylaxis, and antibiotic resistance must be taken into account when choosing to treat healthy patients undergoing third molar surgery with antibiotics.

Sonication improves microbiologic diagnosis of periprosthetic elbow infection

BACKGROUND

Periprosthetic joint infection (PJI) is a relatively frequent and oftentimes devastating complication after total elbow arthroplasty (TEA). Its microbiologic diagnosis is usually based on periprosthetic tissue culture (hereafter referred to as tissue culture), but the sensitivity of tissue culture is variable. Although implant sonication culture has been shown to be superior to tissue culture for the diagnosis of hip and knee PJI, only a single small study (of fewer than 10 infected implants) has assessed sonication for PJI diagnosis after elbow arthroplasty.

METHODS

We retrospectively analyzed 112 sonicate fluid cultures from patients who underwent revision of a TEA at a single institution between 2007 and 2019, comparing results to those of tissue cultures. We excluded patients who had fewer than 2 tissues submitted for culture. Using the Infectious Diseases Society of America guidelines to define PJI, there were 49 infected and 63 non-infected cases. Median ages in the PJI and non-infected groups were 66 and 61 years, respectively. In the non-infected group, 65% were female vs. 63% in the PJI group. We reviewed clinical characteristics and calculated the sensitivity and specificity of tissue compared with sonicate fluid culture. In addition, we compared the sensitivity of tissue culture to the combination of tissue and sonicate fluid culture.

RESULTS

The most common pathogens were coagulase-negative Staphylococcus sp (49%), followed by Staphylococcus aureus (12%). Sensitivity of tissue culture was 63%, and sensitivity of sonicate fluid culture was 76% (P = .109). Specificity of tissue culture was 94% and specificity of sonicate fluid culture was 100%. Sensitivity of sonicate fluid culture in combination with tissue culture was 84% (P = .002 compared to tissue culture alone).

CONCLUSION

In this study, we found that the combination of sonicate fluid and tissue culture had a greater sensitivity than tissue culture alone for microbiologic diagnosis of PJI after TEA.

In Vitro Studies of Jatropha curcas L. Latex Spray Formulation for Wound Healing Applications

Objectives

There is an increasing demand for wound healing products of natural origin. Our objective was to develop a spray formulation from Jatropha curcas (J. curcas) L. latex extracts for wound healing applications.

Materials and Methods

J. curcas L. latex was subjected to solvent extraction. The phytochemical structure was elucidated by ¹H-NMR and confirmed by liquid chromatography-mass spectrometer spectrometry. A topical spray formulation prepared from J. curcas latex extracts was evaluated in terms of its antimicrobial activity and radical scavenging activity. The toxicity of the formulation on fibroblast cell lines, collagen production, and wound healing activities were tested.

Results

The ¹H-NMR and mass spectrometric analyses revealed the pure compound as curcacycline A. The J. curcas latex extract formulation had radical scavenging and antibacterial activities. Moreover, the formulation was not toxic to the human fibroblast cells and it stimulated collagen production and healed cell injury in 24 h.

Conclusion

The J. curcas latex extract promoted wound healing after cell injury. Our findings indicate the possibility of utilizing the J. curcas latex extract spray formulation as a potential antibacterial, antioxidant, and wound healing product from nature.

Basic study on improvement of plastic drape adhesion for surgery: effect of adhesive layer thickness on drape detachment from wound edge

BACKGROUND

Plastic drapes are used in surgery for a wide range of purposes, but currently marketed drapes often become detached from the wound edge during surgery. The purpose of this study was to determine the appropriate adhesive layer thickness for optimal peel and shear strength and the smallest peeled area to improve surgical drape wound adhesion.

METHODS

Thirty-two rats were randomly assigned to four groups of different adhesive layer thickness (50, 100, 300 and 800-1000 μm). The rats were anaesthetized, and drapes were applied to the dorsal chest. After incision, the peeled area was visualized by dropping ink in the wound site to measure the peeled area over time.

RESULTS

All drapes peeled off from the wound edge, and the peeled area increased over time. The peeled area decreased in the order of 50 μm > 100 μm > 800-1000 μm > 300 μm.

CONCLUSIONS

It is possible to control the peeling of plastic drapes during surgery by limiting the peeled area at the time of cutting. Three-hundred micrometres is the suitable adhesive layer thickness to minimize the peeled area at cutting.

Review of Clinically and Epidemiologically Relevant Coagulase-Negative Staphylococci in Africa

Coagulase-negative staphylococci (CoNS) have engendered substantial interest in recent years as pathogenic causes of infections in both human and veterinary medicine, especially in the immunocompromised, critically ill, long-term hospitalized and in those harboring invasive medical devices such as catheters. They have been implicated in infections such as urinary tract infections, bloodstream infections, and invasive device-related infections, and are responsible for substantial economic losses in livestock production. The advancement of diagnostic techniques has increased our understanding of their molecular mechanisms of pathogenicity, even though distinguishing between innocuousness and pathogenicity is still challenging. The incidence of CoNS varied across the continent in humans and animals (mainly cattle), ranging from 6% to 68% in suspected human infections and from 3% to 61.7% in suspected animal infections, distributed across different geographic locations. Furthermore, there were varying antibiotic resistance patterns observed in CoNS isolates, with high methicillin resistance in some cases, leading to crossresistance against many antibiotics. Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus xylosus were most commonly reported in studies herein reviewed, while the enterotoxin C gene, atl E gene, ica gene, and hemolysin virulence factors were linked with enhanced pathogenicity. Advancement in identification and typing methods, including whole genome sequencing, virulence screening, and the assessment of the immune status of subjects in studies will help to thoroughly assess the true pathogenic potential of isolated CoNS species in developing countries. Careful antibiotic stewardship guidelines should be followed due to the ability of CoNS to develop multidrug resistance.

Seasonal, monthly, and yearly variability of surgical site infections at a single institution-A report of more than 95,000 procedures

To determine whether deep surgical site infection (dSSI) rate exhibits temporal variability, dSSI rates following 98,068 cases were analyzed. The overall dSSI rate decreased significantly between 2009 and 2018. Summer had a significantly greater rate of dSSI than winter. There was no difference in dSSI rate in July versus other months.

Multicentre randomised double-blind placebo controlled trial of combination vancomycin and cefazolin surgical antibiotic prophylaxis: the Australian surgical antibiotic prophylaxis (ASAP) trial

INTRODUCTION

Resistant Gram-positive organisms, such as methicillin-resistant staphylococci, account for a significant proportion of infections following joint replacement surgery. Current surgical antimicrobial prophylaxis guidelines recommend the use of first-generation or second-generation cephalosporin antibiotics, such as cefazolin. Cefazolin, however, does not prevent infections due to these resistant organisms; therefore, new prevention strategies need to be examined. One proposed strategy is to combine a glycopeptide antibiotic with cefazolin for prophylaxis. The clinical benefit and cost-effectiveness of this combination therapy compared with usual therapy, however, have not been established.

METHODS AND ANALYSIS

This randomised, double-blind, parallel, superiority, placebo-controlled, phase 4 trial will compare the incidence of all surgical site infections (SSIs) including superficial, deep and organ/space (prosthetic joint) infections, safety and cost-effectiveness of surgical prophylaxis with cefazolin plus vancomycin to that with cefazolin plus placebo. The study will be performed in patients undergoing joint replacement surgery. In the microbiological sub-studies, we will examine the incidence of SSIs in participants with preoperative staphylococci colonisation (Sub-Study 1) and incidence of VRE acquisition (Sub-Study 2). The trial will recruit 4450 participants over a 4-year period across 13 orthopaedic centres in Australia. The primary outcome is the incidence of SSI at 90 days post index surgery. Secondary outcomes include the incidence of SSI according to joint and microorganism and other healthcare associated infections. Safety endpoints include the incidence of acute kidney injury, hypersensitivity reactions and all-cause mortality. The primary and secondary analysis will be a modified intention-to-treat analysis consisting of all randomised participants who undergo eligible surgery. We will also perform a per-protocol analysis.

ETHICS AND DISSEMINATION

The study protocol was reviewed and approved by The Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/102) on 9 July 2018. Study findings will be disseminated in the printed media, and learnt forums.

TRIAL REGISTRATION NUMBER

ACTRN12618000642280.

Prevention of Postoperative Wound Infections

Surgery creates most hospital infections, injuries, accidents, invalidity and death in the global healthcare system. The number of surgically treated patients per year is high and increasing.

Surgical site infection (SSI) is dependent on type of operation and may occur in 5–20% after surgery, triggers 7–11 extra postoperative days in hospitals and results in 2–11 times higher risk of death than comparable, noninfected patients. Up to 60% of SSI can be prevented. Prevention of postoperative wound infection is done by good general hygiene, operative sterility and effective barriers against transmission of infections, before, during and after surgery. A basic support by hospital leaders, knowledge and skill of the surgical teams, enough resources, excellent treatment of the complete patient admission and monitoring patients after discharge may lead to significant reduction of SSIs, lower death rates and a less expensive health system.

Antimicrobial Activity of Nitric Oxide-Releasing Ti-6Al-4V Metal Oxide

Titanium and titanium alloy materials are commonly used in joint replacements, due to the high strength of the materials. Pathogenic microorganisms can easily adhere to the surface of the metal implant, leading to an increased potential for implant failure. The surface of a titanium-aluminum-vanadium (Ti-6Al-4V) metal oxide implant material was functionalized to deliver an small antibacterial molecule, nitric oxide. S-nitroso-penicillamine, a S-nitrosothiol nitric oxide donor, was covalently immobilized on the metal oxide surface using self-assembled monolayers. Infrared spectroscopy was used to confirm the attachment of the S-nitrosothiol donor to the Ti-Al-4V surface. Attachment of S-nitroso-penicillamine resulted in a nitric oxide (NO) release of 89.6 ± 4.8 nmol/cm² under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli and Staphylococcus epidermidis growth by 41.5 ± 1.2% and 25.3 ± 0.6%, respectively. Combining the S-nitrosothiol releasing Ti-6Al-4V with tetracycline, a commonly-prescribed antibiotic, increased the effectiveness of the antibiotic by 35.4 ± 1.3%, which allows for lower doses of antibiotics to be used. A synergistic effect of ampicillin with S-nitroso-penicillamine-modified Ti-6Al-4V against S. epidermidis was not observed. The functionalized Ti-6Al-4V surface was not cytotoxic to mouse fibroblasts.

The Seasonal Variability in Surgical Site Infections and the Association With Warmer Weather: A Population-Based Investigation

OBJECTIVE To determine whether the seasonality of surgical site infections (SSIs) can be explained by changes in temperature. DESIGN Retrospective cohort analysis. SETTING The National Inpatient Sample database. PATIENTS All hospital discharges with a primary diagnosis of SSI from 1998 to 2011 were considered cases. Discharges with a primary or secondary diagnoses of specific surgeries commonly associated with SSIs from the previous and current month served as our "at risk" cohort. METHODS We modeled the national monthly count of SSI cases both nationally and stratified by region, sex, age, and type of institution. We used data from the National Climatic Data Center to estimate the monthly average temperatures for all hospital locations. We modeled the odds of having a primary diagnosis of SSI as a function of demographics, payer, location, patient severity, admission month, year, and the average temperature in the month of admission. RESULTS SSI incidence is highly seasonal, with the highest SSI incidence in August and the lowest in January. During the study period, there were 26.5% more cases in August than in January (95% CI, 23.3-29.7). Controlling for demographic and hospital-level characteristics, the odds of a primary SSI admission increased by roughly 2.1% per 2.8°C (5°F) increase in the average monthly temperature. Specifically, the highest temperature group, >32.2°C (>90°F), was associated with an increase in the odds of an SSI admission of 28.9% (95% CI, 20.2-38.3) compared to temperatures <4.4°C (<40°F). CONCLUSIONS At population level, SSI risk is highly seasonal and is associated with warmer weather. Infect Control Hosp Epidemiol 2017;38:809-816.

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.

Cyanoacrylate microbial sealants for skin preparation prior to surgery

BACKGROUND

Surgical site infections (i.e. incisions that become infected) are a continuing concern in health care. Microbial sealant is a liquid that can be applied to the skin immediately before surgery and is thought to help reduce the incidence of surgical site infections (SSIs) by sealing in the skin flora, thus preventing contamination and infection of the surgical site.

OBJECTIVES

To assess the effects of the preoperative application of microbial sealants (compared with no microbial sealant) on rates of SSI in people undergoing clean surgery.

SEARCH METHODS

For this second update we searched the following electronic databases in May 2015: the Cochrane Wounds 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 and EBSCO CINAHL. There were no restrictions based on language or date of publication or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were eligible for inclusion if they involved people undergoing clean surgery (i.e. surgery that does not involve the breathing system, gut, genital or urinary tract, or any part of the body with an existing infection) in an operating theatre and compared the use of preoperative microbial sealants with no microbial sealant.

DATA COLLECTION AND ANALYSIS

All review authors independently extracted data on the characteristics, risk of bias and outcomes of the eligible trials.

MAIN RESULTS

Seven trials (859 participants undergoing clean surgery) met the inclusion criteria. The trials all compared cyanoacrylate microbial sealant with no sealant. We found there were fewer SSIs with the use of microbial sealant (23/443 participants) than with the control comparison (46/416 participants). There was no evidence of a difference between the two groups in surgical site infection rates following the use of microbial sealants when the results were pooled (risk ratio (RR) 0.53, 95% CI 0.24 to 1.18). There were adverse events in three studies, but these were not judged to be a result of the use of microbial sealant.

AUTHORS' CONCLUSIONS

In this second update there is still insufficient evidence available to determine whether the use of microbial sealants reduces the risk of surgical site infection or not. Further rigorous, adequately-powered RCTs are required to investigate this properly.

Improved Diagnosis of Prosthetic Joint Infection by Culturing Periprosthetic Tissue Specimens in Blood Culture Bottles

Despite known low sensitivity, culture of periprosthetic tissue specimens on agars and in broths is routine. Culture of periprosthetic tissue samples in blood culture bottles (BCBs) is potentially more convenient, but it has been evaluated in a limited way and has not been widely adopted. The aim of this study was to compare the sensitivity and specificity of inoculation of periprosthetic tissue specimens into blood culture bottles with standard agar and thioglycolate broth culture, applying Bayesian latent class modeling (LCM) in addition to applying the Infectious Diseases Society of America (IDSA) criteria for prosthetic joint infection. This prospective cohort study was conducted over a 9-month period (August 2013 to April 2014) at the Mayo Clinic, Rochester, MN, and included all consecutive patients undergoing revision arthroplasty. Overall, 369 subjects were studied; 117 (32%) met IDSA criteria for prosthetic joint infection, and 82% had late chronic infection. Applying LCM, inoculation of tissues into BCBs was associated with a 47% improvement in sensitivity compared to the sensitivity of conventional agar and broth cultures (92.1 versus 62.6%, respectively); this magnitude of change was similar when IDSA criteria were applied (60.7 versus 44.4%, respectively; P = 0.003). The time to microorganism detection was shorter with BCBs than with standard media (P < 0.0001), with aerobic and anaerobic BCBs yielding positive results within a median of 21 and 23 h, respectively. Results of our study demonstrate that the semiautomated method of periprosthetic tissue culture in blood culture bottles is more sensitive than and as specific as agar and thioglycolate broth cultures and yields results faster.

Prosthetic joint infections are a devastating complication of arthroplasty surgery. Despite this, current microbiological techniques to detect and diagnose infections are imperfect. This study examined a new approach to diagnosing infections, through the inoculation of tissue samples from around the prosthetic joint into blood culture bottles. This study demonstrated that, compared to current laboratory practices, this new technique increased the detection of infection. These findings are important for patient care to allow timely and accurate diagnosis of infection.

Microbiology of surgical site infections after gastrointestinal surgery in the south region of The Netherlands

AIM

To give an overview of the microbiology of blood and wound samples from surgical site infections (SSIs) after gastrointestinal surgery, as well as the antimicrobial susceptibility of the microorganisms involved, and to discuss the appropriateness of the prophylactic antibiotics administered.

MATERIALS & METHODS

During a 3.5-year study period, wound swabs and blood samples of patients with an SSI were taken in the first 48 h after surgery until 30 days thereafter.

RESULTS

Most pathogens were isolated from wound swabs. Escherichia coli (25%) and Pseudomonas aeruginosa (10%) were the most frequently found microorganisms. Both microorganisms showed a slight tendency towards a decrease in susceptibility for the tested antibiotics, although after correction, this was not significant.

CONCLUSION

The comparison between wound swabs taken in the first 48 h after a surgical procedure and swabs in the 30 days thereafter provides important information concerning the microbiology of SSIs and the development of antibiotic resistance of the causative agents over time.

Use of incisional negative pressure wound therapy on closed median sternal incisions after cardiothoracic surgery: clinical evidence and consensus recommendations

Negative pressure wound therapy is a concept introduced initially to assist in the treatment of chronic open wounds. Recently, there has been growing interest in using the technique on closed incisions after surgery to prevent potentially severe surgical site infections and other wound complications in high-risk patients. Negative pressure wound therapy uses a negative pressure unit and specific dressings that help to hold the incision edges together, redistribute lateral tension, reduce edema, stimulate perfusion, and protect the surgical site from external infectious sources. Randomized, controlled studies of negative pressure wound therapy for closed incisions in orthopedic settings (which also is a clean surgical procedure in absence of an open fracture) have shown the technology can reduce the risk of wound infection, wound dehiscence, and seroma, and there is accumulating evidence that it also improves wound outcomes after cardiothoracic surgery. Identifying at-risk individuals for whom prophylactic use of negative pressure wound therapy would be most cost-effective remains a challenge; however, several risk-stratification systems have been proposed and should be evaluated more fully. The recent availability of a single-use, closed incision management system offers surgeons a convenient and practical means of delivering negative pressure wound therapy to their high-risk patients, with excellent wound outcomes reported to date. Although larger, randomized, controlled studies will help to clarify the precise role and benefits of such a system in cardiothoracic surgery, limited initial evidence from clinical studies and from the authors' own experiences appears promising. In light of the growing interest in this technology among cardiothoracic surgeons, a consensus meeting, which was attended by a group of international experts, was held to review existing evidence for negative pressure wound therapy in the prevention of wound complications after surgery and to provide recommendations on the optimal use of negative pressure wound therapy on closed median sternal incisions after cardiothoracic surgery.

High prevalence of methicillin resistant staphylococci strains isolated from surgical site infections in Kinshasa

INTRODUCTION

Surgical site infections (SSIs) after surgery are usually caused by Staphylococcus aureus and coagulase-negative staphylococci (CNS). In low income countries, methicillin resistant Staphylococcus aureus (MRSA) and methicillin resistant coagulase-negative staphylococci (MR-CNS) surgical site infections are particularly associated with high treatment cost and remain a source of mortality and morbidity. This study aimed to determine the prevalence and the sensitivity to antibiotics of MRSA and MR-CNS isolated from SSIs.

METHODS

Wound swabs were collected from 130 hospitalized surgical patients in two major hospitals of Kinshasa. S. aureus and CNS strains were identified by standard microbiological methods and latex agglutination test (Pastorex Staph-Plus). The antibiotic susceptibility of all staphylococcal strains was carried out using disk-diffusion method.

RESULTS

Eighty nine staphylococcal strains were isolated. Out of 74 S. aureus and 15 CNS isolated, 47 (63.5%) and 9 (60%) were identified as MRSA and MR-CNS respectively. Among the MRSA strains, 47 strains (100%) were sensitive to imipenem, 39 strains (89%) to amoxycillin-clavulanic acid and 38 strains (81%) to vancomycin. All MR-CNS were sensitive to imipenem, amoxycillin-clavulanic acid and vancomycin. The isolated MRSA and MR-CNS strains showed multidrug resistance. They were both resistant to ampicillin, cotrimoxazole, erythromycin, clindamycin, ciprofloxacin, cefotaxime and ceftazidime.

CONCLUSION

The results of the present study showed a high prevalence of MRSA and MR-CNS. Imipenem, amoxycillin-clavulanic acid and vancomycin were the most active antibiotics. This study suggests that antibiotic surveillance policy should become national priority as MRSA and MR-CNS were found to be multidrug resistant.

Alcoholic Chlorhexidine or Alcoholic Iodine Skin Antisepsis (ACAISA): protocol for cluster randomised controlled trial of surgical skin preparation for the prevention of superficial wound complications in prosthetic hip and knee replacement surgery

INTRODUCTION

Wound complications following arthroplasty are associated with significant impact on the patient and healthcare system. Skin cleansing prior to surgical incision is a simple and effective method to prevent wound complications however, the question of which agent is superior for surgical skin antisepsis is unresolved.

METHODS AND ANALYSIS

This cluster randomised controlled trial aims to compare the incidence of superficial wound complications in patients undergoing elective prosthetic hip or knee replacement surgery receiving surgical skin antisepsis with either: 0.5% chlorhexidine gluconate (CHG) in 70% alcohol or 10% povidone in 70% alcohol. The trial will be conducted at an Australian tertiary, university affiliated hospital over a 3-year period involving 750 participants. Participants will be drawn from the surgical waiting list. Consent for this study will be 'opt-out' consent. On a given day, all eligible participants will have skin preparation either with 0.5% chlorhexidine in 70% alcohol or 10% povidone iodine in 70% alcohol. The primary outcome is superficial wound complications (comprised of superficial incisional surgical site infections (SSI) and/or prolonged wound ooze) in the first 30 days following prosthetic joint replacement surgery. Secondary outcomes will include the incidence of wound complications according to the joint replaced, assessment of the causative agents of SSI and cost-effectiveness analysis. The primary analysis is an intention-to-treat analysis including all participants who undergo randomisation and will be performed at the individual level taking into account the clustering effect.

ETHICS AND DISSEMINATION

The study design and protocol was reviewed and approved by the St Vincent's Hospital Human Research Ethics Committee (HREC-A 016/14 10/3/2014). Study findings will be disseminated in the printed media, and learned forums. A written lay summary will be available to study participants on request.

TRIAL REGISTRATION NUMBER

The trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000177651.

Effectiveness of N-butyl cyanoacrylate-based microbial skin sealant on the prevention of surgical site infections

BACKGROUND

Surgical site infections (SSIs) are a serious concern in health care, and wound contamination by endogenous skin flora is a major factor in the development of SSIs. Despite preventive tactics in pre-operative skin care, antibiotic prophylaxis, surgical technique, and post-operative incision care, complete sterilization of the skin is not possible. Recently developed microbial skin sealant forms a continuous but breathable barrier that prevents migration of endogenous skin flora into the incision. The skin sealant closes dermal microabrasions, preventing re-colonization of potential pathogens at the incision. The purpose of this study was to determine the effect of an N-butyl cyanoacrylate-based microbial skin sealant in reducing the occurrence of SSIs in an experimental rodent model.

METHODS

This was a randomized, controlled animal trial. Forty-eight Wistar albino rats were divided into six groups of eight rats each. Three groups received application of sealant against specific bacteria, and three matched control groups received only the bacteria without the sealant. Group one underwent pre-operative hair removal, followed by application of skin sealant, then abdominal incision and closure. Group two (control) simply underwent hair removal, followed by incision and closure, with no skin sealant applied. Group three received an application of cage swabs (containing a mixture of urine, stool and sawdust from the animals' cages) before application of skin sealant, and group four (control) received cage swabs without subsequent skin sealant. Group five received methicillin-resistant Staphylococcus aureus (MRSA) followed by skin sealant, and group six (control) received MRSA without skin sealant. Seven days after surgery, the animals were sacrificed. Samples were taken from the abdomen of each rat and placed in culture medium. Proliferation of the following bacteria were observed: Coagulase-negative staphylococci (CoNS), gram-positive bacilli (GPB), Pseudomonas aeruginosa, and MRSA.

RESULTS

There was a statistically significant difference between the median number of GPB in the group that received cage swabs+sealant and the group that received cage swabs without sealant (median, GPB count 29,430 colony-forming units [CFU]/g vs 359,100  colony-forming units [CFU]/g; p<0.05). The study results showed that microbial skin sealant was not as effective in preventing CoNS or MRSA contamination as it was in preventing GPB contamination.

CONCLUSIONS

Use of a microbial skin sealant before surgery can lower the rate of SSIs by reducing the migration of some specific bacterial agents. Additional data are needed to validate its use in clinical practice.

Cyanoacrylate microbial sealants for skin preparation prior to surgery

BACKGROUND

Surgical site infections (i.e. incisions that become infected) are a continuing concern in health care. Microbial sealant is a liquid that can be applied to the skin immediately before surgery and is thought to help reduce the incidence of surgical site infections (SSIs) by sealing in the skin flora, thus preventing contamination and infection of the surgical site.

OBJECTIVES

To assess the effects of the preoperative application of microbial sealants (compared with no microbial sealant) on rates of SSI in people undergoing clean surgery.

SEARCH METHODS

For this first update we searched the following electronic databases in July 2013: the Cochrane Wounds Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid MEDLINE - In-Process & Other Non-Indexed Citations, Ovid EMBASE and EBSCO CINAHL.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were eligible for inclusion if they involved people undergoing clean surgery (i.e. surgery that does not involve the breathing system, gut, genital or urinary tract or any part of the body with an existing infection) in an operating theatre and compared the use of preoperative microbial sealants with no microbial sealant.

DATA COLLECTION AND ANALYSIS

All review authors independently extracted data on the characteristics, risk of bias and outcomes of the eligible trials.

MAIN RESULTS

Three trials (524 participants undergoing clean surgery) met the inclusion criteria. The trials all compared cyanoacrylate microbial sealant with no sealant, and, when pooled, we found there were fewer SSIs with the use of microbial sealant (10/261 participants) than with the control comparison (29/274 participants). The difference between the two groups was statistically significant (risk ratio (RR) 0.36, 95% CI 0.18 to 0.72) but given the number of participants and quality of the studies, they should be treated with caution. There were some adverse events in one study, but these were not judged to be a result of the use of microbial sealant.

AUTHORS' CONCLUSIONS

In this first update there is still insufficient evidence available to determine whether the use of microbial sealants reduces the risk of surgical site infection or not. Further rigorous, adequately-powered RCTs are required to investigate this properly.

Implementation of an antibiotic prophylaxis protocol in an intensive care unit

BACKGROUND

When properly employed, the prophylactic use of antimicrobials is associated with a reduction in surgical site infections (SSIs). We found that the appropriate use of antimicrobial prophylaxis was only 50.5% (53/105) among patients undergoing surgery in the adult intensive care unit of our hospital. In 2001, a protocol was designed to improve compliance with recommended practice.

METHODS

We used a prospective interventional study and a case control study carried out between 2001 and 2007, including follow-up and daily intervention to improve compliance with antimicrobial prophylaxis guidelines and to monitor antimicrobial consumption and SSI rates. Cases of noncompliance to the prophylaxis protocol (group I) were matched to controls (group II) with appropriate prophylaxis and compared with regards to type of surgery, operative duration, intraoperative antimicrobial use, type of antimicrobial used, length of hospital stay, severity of illness, comorbidities, invasive devices, possible adverse reactions, and death.

RESULTS

Compliance with antimicrobial prophylaxis metrics reached 85%; however, we were unable to detect a change in SSI rate or consumption and cost of antimicrobials. Inappropriate use was not associated with higher likelihood of death. There were no other significant differences between the 2 groups.

CONCLUSION

Our intervention increased compliance with appropriate antimicrobial surgical prophylaxis with no negative impact on patient safety.

Antimicrobial prophylaxis is not necessary in clean category minimally invasive surgery for renal and adrenal tumors: a prospective study of 373 consecutive patients

OBJECTIVE

To assess the feasibility of the nonuse of antimicrobial prophylaxis (AMP) on the incidence of infectious complications after clean category minimally invasive surgery for renal and adrenal tumors.

METHODS

We evaluated 415 consecutive patients who underwent gasless laparoendoscopic single-port surgery (GasLESS) for renal or adrenal tumors between 2006 and 2010. Forty-two patients with poorly controlled diabetes mellitus, coexisting infection, or opening of the urinary tract during partial nephrectomy were excluded from this study. The remaining 373 patients underwent radical nephrectomy (n = 187), partial nephrectomy (n = 103), or adrenalectomy (n = 83) without AMP. Perioperative infections were categorized into superficial surgical site infection (SSI), deep SSI, and remote infection (RI) and graded using an established 5-grade modification of the original Clavien-Dindo classification system. We investigated the association between the incidence of infectious complications and clinical or perioperative factors.

RESULTS

Infectious complications occurred in 16 cases (4.3%), including 4 superficial SSIs (1.1%), 2 deep SSIs (0.5%), and 10 RIs (2.7%). Neither superficial SSI nor deep SSI was significantly associated with any clinical or perioperative factors. The incidence of RI, however, was associated with longer operative time and higher National Nosocomial Infection Surveillance (NNIS) risk index. All perioperative infections were successfully treated with antibiotics without surgical interventions. No infectious complications equal to or greater than grade IIIa occurred.

CONCLUSION

The nonuse of AMP and the on-demand use of antibiotics seem to be sufficient for perioperative infectious management in clean category minimally invasive surgery for renal and adrenal tumors.

Clinical outcomes of open heart surgery in patients with atopic dermatitis

Atopic dermatitis is a skin condition often complicated by colonization with Staphylococcus aureus, which increases the risk of infective endocarditis, skin cellulitis and osteomyelitis. Positive cultures for Staphylococcus aureus are obtained from 70% to 80% of wounds in patients with mediastinitis. Thus sternotomy carries increased risk of mediastinitis in patients with atopic dermatitis. We retrospectively reviewed 25 patients with atopic dermatitis who underwent cardiac surgery via a median sternotomy or thoracotomy from January 1997 to September 2010 at our institution. Postoperative mediastinitis due to methicillin-resistant Staphylococcus aureus was found in 3 patients who had a median sternotomy. They were ultimately discharged in good condition. No mediastinitis occurred in patients undergoing thoracotomy. Mediastinitis may occur due to direct exposure of the bone marrow to methicillin-resistant Staphylococcus aureus in patients with atopic dermatitis whose skin is colonized with such bacteria. Thoracotomy may be a better surgical approach in patients with atopic dermatitis who require thoracic surgery.

First experience with a new negative pressure incision management system on surgical incisions after cardiac surgery in high risk patients

BACKGROUND

Sternal wound infection remains a serious potential complication after cardiac surgery. A recent development for preventing wound complications after surgery is the adjunctive treatment of closed incisions with negative pressure wound therapy. Suggested mechanisms of preventive action are improving the local blood flow, removing fluids and components in these fluids, helping keep the incision edges together, protecting the wound from external contamination and promoting incision healing. This work reports on our initial evaluation and clinical experience with the Prevena™Incision Management System, a recently introduced new negative pressure wound therapy system specifically developed for treating closed surgical incisions and helping prevent potential complications. We evaluated the new treatment on sternal surgical incisions in patients with multiple co-morbidities and consequently a high risk for wound complications.

METHODS

The Prevena™incision management system was used in 10 patients with a mean Fowler risk score of 15.1 [Range 8-30]. The negative pressure dressing was applied immediately after surgery and left in place for 5 days with a continuous application of -125 mmHg negative pressure. Wounds and surrounding skin were inspected immediately after removal of the Prevena™ incision management system and at day 30 after surgery.

RESULTS

Wounds and surrounding skin showed complete wound healing with the absence of skin lesions due to the negative pressure after removal of the Prevena™ dressing. No device-related complications were observed. No wound complications occurred in this high risk group of patients until at least 30 days after surgery.

CONCLUSIONS

The Prevena™system appears to be safe, easy to use and may help achieve uncomplicated wound healing in patients at risk of developing wound complications after cardiothoracic surgery.

Infections in vascular surgery

Infections in vascular surgery are usually of multifactorial nature resulting from a complex interplay of patient, surgical and environmental factors. Preventative measures initiated from the stage of pre-operative screening, maintenance of patient homeostasis and the use of organism-directed antibiotics can contribute to reduce infection rates. Graft preservation techniques are becoming increasingly popular as a method to treat established graft infections. In this article we report on the current trends and techniques on the management of infections in vascular surgery. Ongoing studies are required to continue to accumulate data on the effectiveness of these techniques.

Cyanoacrylate as a microbial sealant: examining the evidence

This article examines the evidence base for the use of microbial sealant as a skin preparation prior to surgery. Firstly, using the steps of evidence-based practice the use of cyanoacrylate as a microbial sealant was explored. Next the evidence regarding the use of cyanoacrylate based microbial sealant was sought and then critically appraised. Having found evidence to support its use to be lacking in rigour and quality, an argument is made for the omission of cyanoacrylate-based microbial sealants as part of current preoperative preparation.

Silver nanoparticles-modified films versus biomedical device-associated infections

A serious issue related to biomedical devices (BDs) is that of bacterial infections. BDs colonized by bacteria may cause infection or mortality. To prevent such infections, an effective strategy is to develop novel BDs with antibacterial abilities via various surface modification processes. Thus, plenty of silver nanoparticles (Ag NPs)-modified films were brought forward to because of their potential applications in improving the antibacterial properties of BDs. This article reviews the difficulties in diagnosing and treating biomedical device-associated infections as well as the state of arts in fabricating the Ag NPs-modified films for antibacterial applications. In addition, the nanoeffect of silver particles and the cytotoxicity of Ag NPs are also discussed. It is clear that safe and durable Ag NPs-modified films are more desirable for the BDs prone to bacteria. To further extend the investigations on controlling the toxicity path of Ag NPs to both bacteria and mammalian cells, developing novel green fabrication processes with more 'cleaner' (without accompaniment of ligands or reduction agents) Ag NPs should be the first mission for the material scientists to complete.

Cyanoacrylate microbial sealants for skin preparation prior to surgery

BACKGROUND

Surgical site infections are a continuing concern in health care. Microbial sealant is a liquid applied to the skin immediately before surgery. It is thought to contribute to reducing surgical site infections by sealing in the skin flora to prevent contamination and infection of the surgical site.

OBJECTIVES

To assess the effects of the preoperative application of microbial sealants (compared with no microbial sealant) on the rates of surgical site infection in people undergoing clean surgery.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (searched 10 May 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), Ovid MEDLINE (1950 to April Week 3 2010), Ovid MEDLINE - In-Process & Other Non-Indexed Citations (searched 10 May 2010), Ovid EMBASE (1980 to 2010 Week 18) and EBSCO CINAHL (1982 to 10 May 2010). We searched bibliographies and contacted manufacturers of microbial sealants for unpublished studies. There were no restrictions based on language, date or publication status.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were eligible for inclusion if they involved people undergoing clean surgery in an operating theatre and compared the use of preoperative microbial sealants with no microbial sealant.

DATA COLLECTION AND ANALYSIS

All review authors independently extracted data on the characteristics, risk of bias and outcomes of the eligible trial.

MAIN RESULTS

One small trial (177 participants undergoing hernia repair) met the inclusion criteria. There was no statistically significant difference in the rates of surgical site infection (three patients in the control group developed a surgical site infection compared with none in the intervention group; risk ratio (RR) 0.17, 95% CI 0.01 to 3.19, P = 0.23).

AUTHORS' CONCLUSIONS

There is currently insufficient evidence as to whether the use of microbial sealants reduces the risk of surgical site infection in people undergoing clean surgery and further rigorous RCTs are required.

[Etiology of surgical site infections at the orthopaedic trauma units]

OBJECTIVES

The aim of the study was to analyze the epidemiological and microbiological analysis of surgical site infections in the orthopedic wards.

MATERIALS AND METHODS

A 6-month prospective cohort study was conducted at the major teaching hospital in Belgrade. Patient's basic demographic data and data about surgical site infections were collected. Bacteria cultured from the surgical site were also analyzed.

RESULTS

A total of 277 patients operated in the Institute of Orthopedics and trauma surgery, Clinical Center of Serbia. Sixty-three cases of SSI were detected, and the overall incidence rate was 22.7% (95% IP = 17.8-27.6). Fifty-three (84.1%) SSIs had microbiological confirmation and overall 82 bacterial strains were isolated. The most frequent isolated bacteria were Staphylococcus aureus, Acinetobacter sp, Klebsiella pp, Pseudomonas sp and Enterococcus sp. Nineteen (79.2%) strains of Staphylococcus aureus isolated from infected surgical sites were meticillin- resistant.

CONCLUSION

This study suggests that it is necessary to maintain continuous surveillance of surgical site infections. It is important to emphasize the need for implementation the measures of contact isolation in order to prevent the nosocomial transmission of resistant bacteria.