Contribution of the patient microbiome to surgical site infection and antibiotic prophylaxis failure in spine surgery.

Despite modern antiseptic techniques, surgical site infection (SSI) remains a leading complication of surgery. However, the origins of SSI and the high rates of antimicrobial resistance observed in these infections are poorly understood. Using instrumented spine surgery as a model of clean (class I) skin incision, we prospectively sampled preoperative microbiomes and postoperative SSI isolates in a cohort of 204 patients. Combining multiple forms of genomic analysis, we correlated the identity, anatomic distribution, and antimicrobial resistance profiles of SSI pathogens with those of preoperative strains obtained from the patient skin microbiome. We found that 86% of SSIs, comprising a broad range of bacterial species, originated endogenously from preoperative strains, with no evidence of common source infection among a superset of 1610 patients. Most SSI isolates (59%) were resistant to the prophylactic antibiotic administered during surgery, and their resistance phenotypes correlated with the patient's preoperative resistome (P = 0.0002). These findings indicate the need for SSI prevention strategies tailored to the preoperative microbiome and resistome present in individual patients.

Multifunctional Suture Coating for Combating Surgical Site Infections and Mitigating Associated Complications.

Despite advancements in preventive measures and hospital protocols, surgical site infections (SSIs) remain a significant concern following surgeries. Sutures, commonly used for wound closure, can serve as a platform for microbial adherence and contamination, leading to extensive debridement and recurrent antibiotic therapy. The emergence of drug resistance and the formation of biofilms on sutures have further complicated the management of SSIs. Drug-eluting sutures incorporating biocides like triclosan have limitations due to uncontrolled release and associated toxicity. Therefore, there is a need for alternative approaches to impart antimicrobial properties to sutures. In this study, we present a one-step covalent cross-linking method to coat surgical sutures with an antimicrobial small molecule, quaternary benzophenone-based antimicrobial (QSM). Additionally, the sutures are dip-coated with ibuprofen, a nonsteroidal anti-inflammatory drug with analgesic properties. The coated sutures maintained their morphological and tensile properties after in vivo implantation. The antimicrobial coating demonstrated efficacy against a broad-spectrum pathogens, including drug-resistant bacteria and fungi. The optimized formulation retained its biodegradability in vivo. Furthermore, the coated sutures exhibited ∼3 log reduction in methicillin-resistant Staphylococcus aureus (MRSA) burden in a subcutaneous implantation mouse model. Overall, this multifunctional coating provides antimicrobial properties to surgical sutures while preserving their mechanical integrity and biodegradability. These coated sutures have the potential to address the challenge of SSIs and contribute to improved surgical outcomes.

Prospective cohort study of surgical site infections following single dose antibiotic prophylaxis in caesarean section at a tertiary care teaching hospital in Medchal, India.

BACKGROUND: Caesarean section (CS) is considered to be a life-saving operative intervention for women and new-borns in certain antepartum and intrapartum conditions. Caesarean delivery may be accompanied by several complications including surgical site infections (SSI). However, there is a significant lack of uniformity in the administration of antibiotics for preventing surgical site infections (SSI) following caesarean deliveries. The present study was conducted to determine the incidence of post CS SSI following the adoption of single-dose antibiotic prophylaxis as recommended by WHO at a tertiary care teaching hospital in Medchal, India. Also, to identify the risk factors of SSI and reported the bacteriological profiles and the antimicrobial susceptibility pattern of the culture positive isolates. MAIN OBJECTIVES: To estimate the incidence of surgical site infections (SSI's) according to CDC criteria following WHO-recommended single-dose antibiotic prophylaxis for caesarean section at a tertiary care teaching hospital in Medchal, India. METHODS: A prospective hospital-based study was conducted between June 2017 and December 2019, in which women who underwent caesarean delivery were followed up for 30 days post-delivery. Clinical details were collected using a structured questionnaire, and participants were followed up weekly after discharge to document any signs and symptoms of SSI. Symptomatic patients were requested to come to the hospital for further investigation and treatment. Standard microbiological tests were conducted to detect microorganisms and their antibiotic sensitivity. RESULTS: The study included 2,015 participants with a mean age of 24.1 years. The majority were multigravida (n = 1,274, 63.2%) and underwent emergency caesarean delivery (n = 1,232, 61.1%). Ninety two participants (4.6%, 95% CI: 3.7% to 5.6%) developed surgical site infections, with 91 (98.9%) having superficial and 1 (1.1%) having a deep infection. Among those who developed an SSI, 84 (91.3%) did so during their hospital stay, while 8 (8.7%) developed an SSI at home. The adjusted relative risk (a RR) for developing an SSI was 2.5 (95% CI: 1.4 to 4.6; power 99.9%) among obese women and 2.3 (95% CI: 1.1 to 4.7; power 100%) among women aged 25 years or younger. Microbial growth in culture was observed from 55 (75.8%) out of total 66 samples. The most common organisms identified were Staphylococcus aureus (n = 7(12.3%)23, 46.0%), Klebsiella sp. (n = 13, 26.0%), and Escherichia coli (n = 12, 24.0%). CONCLUSION: The rate of SSI following caesarean deliveries subjected to single dose antibiotic prophylaxis was low. Young women and obese women were at high risk of developing SSI.

Differences in microorganisms causing infection after cranial and spinal surgeries.

OBJECTIVE: The primary aim of this retrospective study was to assess differences in the pathogens causing surgical site infections (SSIs) following craniectomies/craniotomies and open spinal surgery. The secondary aim was to assess differences in rates of SSI among these operative procedures. METHODS: ANOVA tests with Bonferroni correction and incidence risk ratios (RRs) were used to identify differences in pathogens by surgical site and procedure using retrospective, de-identified records of 19,993 postneurosurgical patients treated between 2007 and 2020. RESULTS: The overall infection rates for craniotomy/craniectomy, laminectomy, and fusion were 2.1%, 1.1%, and 1.5%, respectively, and overall infection rates for cervical, thoracic, and lumbar spine surgery were 0.3%, 1.6%, and 1.9%, respectively. Craniotomy/craniectomy was more likely to result in an SSI than spine surgery (RR 1.8, 95% CI 1.4-2.2, p < 0.0001). Cutibacterium acnes (RR 24.2, 95% CI 7.3-80.0, p < 0.0001); coagulase-negative staphylococci (CoNS) (methicillin-susceptible CoNS: RR 2.9, 95% CI 1.6-5.4, p = 0.0006; methicillin-resistant CoNS: RR 5.6, 95% CI 1.4-22.3, p = 0.02); Klebsiella aerogenes (RR 6.5, 95% CI 1.7-25.1, p = 0.0003); Serratia marcescens (RR 2.4, 95% CI 1.1-7.1, p = 0.01); Enterobacter cloacae (RR 3.1, 95% CI 1.2-8.1, p = 0.02); and Candida albicans (RR 3.9, 95% CI 1.2-12.3, p = 0.02) were more commonly associated with craniotomy/craniectomy cases than fusion or laminectomy SSIs. Pseudomonas aeruginosa was more commonly associated with fusion SSIs than craniotomy SSIs (RR 4.4, 95% CI 1.3-14.8, p = 0.02), whereas Escherichia coli was nonsignificantly associated with fusion SSIs compared to craniotomy SSIs (RR 4.1, 95% CI 0.9-18.1, p = 0.06). Infections with E. coli and P. aeruginosa occurred primarily in the lumbar spine (p = 0.0003 and p = 0.0001, respectively). CONCLUSIONS: SSIs due to typical gastrointestinal or genitourinary gram-negative bacteria occur most commonly following lumbar surgery, particularly fusion, and are likely to be due to contamination of the surgical bed with microbial flora in the perianal area and genitourinary tract. Cutibacterium acnes in the skin flora of the head and neck increases risk of infection due to this microbe following surgical interventions in these body sites. The types of gram-negative bacteria associated with craniotomy/craniectomy SSIs suggest potential environmental sources of these pathogens. Based on the authors' findings, neurosurgeons should consider using a two-step skin preparation with benzoyl peroxide, in addition to a standard antiseptic such as alcoholic chlorhexidine for cranial, cervical, and upper thoracic surgeries. Additionally, broader gram-negative bacterial coverage, such as use of a third-generation cephalosporin, should be considered for lumbar/lumbosacral fusion surgical antibiotic prophylaxis.

Analysis of Vacuum-Assisted Closure-Assisted Antibiotic Irrigation in Treatment of Severe Neurosurgical Central Nervous System Infections.

Objective: Severe neurosurgical central nervous system infections (sNCNSIs) are among the most serious complications of neurosurgical disease. Conventional methods have shown a poor prognosis. This study aims to analyze the clinical characteristics of vacuum-assisted closure (VAC) in sNCNSIs with the help of antibiotic irrigation treatment. Patients and Methods: A retrospective study was performed for patients diagnosed with sNCNSIs. A VAC device was placed on the incision after debridement and the surgical cavity was rinsed with antibiotic agents in the VAC group. Meanwhile the surgical cavity was drained after debridement in the control group. Medical data were reviewed and analyzed. Results: Twenty-eight patients met the inclusion criteria, including 18 cases in the VAC group and 10 cases in the control group. The basic medical data showed no differences. Bacteria was isolated from 24 (85.7%) patients. The cure rate was significantly higher in the VAC group (p < 0.05). The cure rate in patients with multi-drug-resistant (MDR) infections was significantly higher in patients treated with VAC therapy (p < 0.05). The prognosis evaluated by Glasgow Outcome Score (GOS) between the two groups showed significant difference (p < 0.05). No re-infection in the VAC group occurred in the follow-up period. Conclusions: It is suggested that VAC-assisted antibiotic irrigation is safe and effective for patients with severe NCNSIs and can improve the prognosis dramatically. The results can provide a new effective and reasonable therapeutic strategy for patients with sNCNSIs.

Comparison of bacterial colonization on absorbable non-coated suture with Triclosan- or Chlorhexidine-coated sutures: a randomized controlled study.

OBJECTIVE: The oral cavity is a colossal reservoir for the bacteria. The healing of tissues is compromised after flap surgery, particularly in the presence of sutures, as they can act as repositories for bacteria, ultimately leading to surgical site infections. Hence, antibacterial-coated sutures have been considered as an alternative to reduce the risk of these infections and further improve the wound healing of the tissues after flap surgery. Since minimal information is available on the effect of antibacterial-coated sutures on periodontal tissues, this study aims to clinically and microbiologically assess the antibacterial efficacy of Triclosan (TCS) and Chlorhexidine-coated sutures (CCS) on periodontal tissues compared to non-coated sutures (NCS). PATIENTS AND METHODS: A total of 75 subjects with moderate to severe periodontitis were included in the study and randomly allocated to one of the three groups, (TCS, CCS, and NCS groups) equally. Suture removal was performed on postoperative day 8, and parameters such as wound healing and post-operative pain were evaluated. The retrieved suture samples were subjected to microbiological analysis and the bacteria were identified quantitatively and qualitatively. RESULTS: Intragroup analysis of the wound healing index and post-operative pain for all the groups showed a significant improvement (p<0.01), from day 8 to day 30. Intergroup analysis of the wound healing index revealed significant wound healing (p<0.05) on day 15 and day 30. For post-operative pain, intergroup analyses showed significantly low pain scores (p<0.01) for the TCS group. Microbiologic analysis of aerobic colony counts in both anterior and posterior regions revealed significantly (p<0.01) least colony counts in TCS and highest colony counts in NCS groups, respectively. Although anaerobic colony counts were not statistically significant, relatively fewer colony counts were identified in the TCS group. Whereas, relatively higher anaerobic colony counts were seen in the CCS group in the anterior region and in the NCS group in the posterior region. Qualitative assessment revealed higher amounts of Streptococcus and Staphylococcus species in all the three groups (TCS, CCS, and NCS groups). CONCLUSIONS: Antibacterial-coated sutures, particularly Triclosan-coated sutures, are effective in reducing bacterial accumulation compared to non-coated sutures. Therefore, these sutures can be effectively utilized in periodontal flap surgery.

Prevention of surgical site infection and sepsis in pregnant obese women.

Obesity is a major determinant of health outcomes and is on the increase in women worldwide. It predisposes to surgical site infection (SSI). Risk factors for the SSI include extremes of age, smoking, comorbidities such as hypertension and diabetes, inappropriate vertical abdominal and or uterine wall incisions, increased operating time, subcutaneous layer of 3 cm or more, and unnecessary use of subcutaneous drain. Most bacteria that cause SSIs are human commensals. Common organisms responsible for SSI include Staphylococcus aureus and coliforms such as Proteus mirabilis, and Escherichia coli. A surgeon's gloves post caesarean section in the obese has a preponderance of Firmicutes and Bacteroidetes, which increases SSI risk. The interaction of skin commensals and vaginal microbiome at the surgical incision site increases the risk of SSI in the obese compared to non-obese. Minimizing the risk of SSI involves modification of risk factors, timely treatment of SSI to prevent sepsis and compliance with the recommended care bundles.

Bacterial reservoir in deeper skin is a potential source for surgical site and biomaterial-associated infections.

BACKGROUND: The origin of surgical site and biomaterial-associated infection is still elusive. Micro-organisms contaminating the wound may come from the air in the operating theatre, the surgical team or the skin of the patient. The skin of patients is disinfected prior to surgery, but bacteria deeper in the skin (e.g. in sweat glands or sebaceous glands) may not be reached. METHODS: A preliminary cohort study was performed to study the origin of surgical site and biomaterial-associated infection between May 2020 and February 2021. In order to investigate whether cutaneous microbiota colonize the wound when released from the skin upon cutting, aerobic and anaerobic bacteria were isolated, quantified and identified from the skin of 99 patients undergoing trauma surgery, before and after skin disinfection, from knife blades and from the wound directly after the first cut. RESULTS: Ninety-nine percent of the patients were culture-positive before disinfection with chlorhexidine. Of these, 40% were still culture-positive after disinfection. Of these, 54% had a positive culture of the wound after cutting the skin. Twenty percent of the patients with a negative culture after disinfection had a positive wound culture after cutting the skin. Staphylococcus epidermidis and Cutibacterium acnes were the most commonly cultured bacterial species. In 9% of cases, more than 100 bacterial colonies were cultured from the wound; this may cause biomaterial-associated infection. CONCLUSION: Bacteria residing in the skin and not eradicated by disinfection may enter the surgical wound upon cutting, resulting in contamination which may cause biomaterial-associated infection.

Microbiological study of sternal osteomyelitis after median thoracotomy - a retrospective cohort study.

INTRODUCTION: Deep sternal wound infection is a rare but feared complication of median thoracotomies and is usually caused by microorganisms from the patient's skin or mucous membranes, the external environment, or iatrogenic procedures. The most common involved pathogens are Staphylococcus aureus, Staphylococcus epidermidis and gram-negative bacteria. We aimed to evaluate the microbiological spectrum of deep sternal wound infections in our institution and to establish diagnostic and treatment algorithms. METHODS: We retrospectively evaluated the patients with deep sternal wound infections at our institution between March 2018 and December 2021. The inclusion criteria were the presence of deep sternal wound infection and complete sternal osteomyelitis. Eighty-seven patients could be included in the study. All patients received a radical sternectomy, with complete microbiological and histopathological analysis. RESULTS: In 20 patients (23%) the infection was caused by S. epidermidis, in 17 patients (19.54%) by S. aureus, in 3 patients (3.45%) by Enterococcus spp., in 14 patients (16.09%) by gram-negative bacteria, while in 14 patients (16.09%) no pathogen could be identified. In 19 patients (21,84%) the infection was polymicrobial. Two patients had a superimposed Candida spp. INFECTION: Methicillin-resistant S. epidermidis was found in 25 cases (28,74%), while methicillin-resistant S. aureus was isolated in only three cases (3,45%). The average hospital stay for monomicrobial infections was 29.93 ± 13.69 days and for polymicrobial infections was 37.47 ± 19.18 (p = 0.03). Wound swabs and tissue biopsies were routinely harvested for microbiological examination. The increasing number of biopsies was associated with the isolation of a pathogen (4.24 ± 2.22 vs. 2.18 ± 1.6, p < 0,001). Likewise, the increasing number of wound swabs was also associated with the isolation of a pathogen (4.22 ± 3.34 vs. 2.40 ± 1.45, p = 0.011). The median duration of antibiotic treatment was 24.62 (4-90) days intravenous and 23.54 (4-70) days orally. The length of antibiotic treatment for monomicrobial infections was 22.68 ± 14.27 days intravenous and 44.75 ± 25.87 days in total and for polymicrobial infections was 31.65 ± 22.29 days intravenous (p = 0.05) and 61.29 ± 41.45 in total (p = 0.07). The antibiotic treatment duration in patients with methicillin-resistant Staphylococci as well as in patients who developed an infection relapse was not significantly longer. CONCLUSION: S. epidermidis and S. aureus remain the main pathogen in deep sternal wound infections. The number of wound swabs and tissue biopsies correlates with accurate pathogen isolation. With radical surgical treatment, the role of prolonged antibiotic treatment remains unclear and should be evaluated in future prospective randomized studies.

Bone flap infections after craniotomy: a review of 63 cases and the implications for definitions, classification and surveillance methodologies.

BACKGROUND: Bone flap infections (BFIs) occur following neurosurgical procedures such as craniotomies. However, they are poorly defined and often not clearly differentiated from other surgical site infection in neurosurgery. AIM: To review data from a national adult neurosurgical centre to explore some clinical aspects to better inform definitions, classification and surveillance methodologies. METHODS: We retrospectively reviewed data on clinical samples sent for culture from patients with suspected BFI. We also accessed information recorded prospectively from national and local databases for evidence of BFI or related conditions based on terms used in surgical operative notes or discharge summaries and documented monomicrobial and polymicrobial infections related to craniotomy sites. FINDINGS: Between January 2016 and December 2020, we documented 63 patients with a mean age of 45 years (16-80). Craniectomy for infection of the skull was the most common terminology used to describe BFI in the coding used in a national database, 40/63 (63%), but other terms were used. A malignant neoplasm was the most common underlying condition necessitating craniectomy in 28/63 (44%) cases. Specimens submitted for microbiological investigation included 48/63 (76%) bone flaps, 38/63 (60%) fluid/pus, and 29/63 (46%) tissue. Fifty-eight (92%) patients had at least one culture-positive specimen; 32 (55%) were monomicrobial and 26 (45%) were polymicrobial. Gram-positive bacteria predominated and Staphylococcus aureus was the most common. CONCLUSION: Greater clarity on how to define BFI is required to enable better classification and the carrying out of appropriate surveillance. This will inform preventative strategies and more effective patient management.

The presence of skin bacteria in the sternal wound and contamination of implantation materials during cardiac surgery.

BACKGROUND: Sternal wound infections (SWIs) and aortic graft infections (AGIs) are serious complications after cardiac surgery. Staphylococcus aureus and coagulase-negative staphylococci are the most common causes of SWIs, whereas AGIs are less studied. AGIs may occur from contamination during surgery or postoperative haematogenous spread. Skin commensals, such as Cutibacterium acnes, are present in the surgical wound; however, their ability to cause infection is debated. AIM: To investigate the presence of skin bacteria in the sternal wound and to evaluate their potential to contaminate surgical materials. METHODS: Fifty patients undergoing coronary artery bypass graft surgery and/or valve replacement surgery at Örebro University Hospital from 2020 to 2021 were included. Cultures were collected from skin and subcutaneous tissue at two timepoints during surgery, and from pieces of vascular graft and felt that were pressed against subcutaneous tissue. The most common bacterial isolates were tested for antibiotic susceptibility with disc diffusion and gradient tests. FINDINGS: Cultures from skin had bacterial growth in 48% of patients at surgery start and in 78% after 2 h, and cultures from subcutaneous tissue were positive in 72% and 76% of patients, respectively. The most common isolates were C. acnes and S. epidermidis. Cultures from surgical materials were positive in 80-88%. No difference in susceptibility was found for S. epidermidis isolates at surgery start compared with after 2 h. CONCLUSION: The results suggest that skin bacteria are present in the wound and may contaminate surgical graft material during cardiac surgery.

Intra-wound versus systemic vancomycin for preventing surgical site infection induced by methicillin-resistant S. aureus after spinal implant surgery in a rat model.

BACKGROUND: Systemic vancomycin administration pre-operatively for the infection prophylaxis of spinal implant surgery remains unsatisfactory. This study aimed to explore the efficacy and dosage of local use of vancomycin powder (VP) in preventing surgical site infections after spinal implant surgery in a rat model. METHODS: Systemic vancomycin (SV; intraperitoneal injection, 88 mg/kg) or intraoperative intra-wound VP (VP0.5: 44 mg/kg, VP1.0: 88 mg/kg, VP2.0: 176 mg/kg) was applied after spinal implant surgery and methicillin-resistant S. aureus (MRSA; ATCC BAA-1026) inoculation in rats. General status, blood inflammatory biomarkers, microbiological and histopathological evaluation were performed during 2 weeks post-surgery. RESULTS: No post-surgical deaths, wound complications and obvious signs of vancomycin adverse effects were observed. Bacterial counts, blood and tissue inflammation were reduced in the VP groups compared with the SV group. VP2.0 group showed better outcomes in weight gain and tissue inflammation than the VP0.5 and VP1.0 group. Microbial counts indicated that no bacteria survived in the VP2.0 group, whereas MRSA was detected in VP0.5 and VP1.0 groups. CONCLUSIONS: Intra-wound VP may be more effective than systemic administration in preventing infection caused by MRSA (ATCC BAA-1026) after spinal implant surgery in a rat model.

Efficacy of skin preparation solutions in patients with total knee replacement: A randomized controlled trial.

PURPOSE: Surgical site infection following total knee replacement is considered as one of the most severe postoperative complications. The presence of bacteria at the surgical site is the most important risk factor and therefore it is essential to prevent infection through appropriate preoperative skin preparation. The purpose of this study was to examine the presence and type of native bacteria on the incision site and to assess which skin preparation is most effective to sterilize those native bacteria. METHODS: Scrub-and-paint 2 step method was used for standard preoperative skin preparation. 150 patients who underwent total knee replacement were grouped into 3 groups- Group 1 (povidone-iodine scrub-and-paint), Group 2 (chlorhexidine gluconate paint after povidone-iodine scrub), and Group 3 (povidone-iodine paint after chlorhexidine gluconate scrub). 150 specimens of post-preparation swabs were obtained and cultured. To analyze the native bacteria at the total knee replacement incision site, 88 additional swaps were performed before skin preparation and cultured. RESULTS: The positive rate of bacterial culture after skin preparation was 5.3% (8/150). Positive rates of the groups were 12% (6/50) in group 1, 2% (1/50) in group, 2 and 2% (1/50) in group 3 and positive rates of bacterial culture after skin preparation in group 2 and group 3 were lower than in group 1 (p = 0.037). Among the 55 patients who had positive bacterial culture prior to skin preparation, 26.7% (4/15) in group 1, 5.6% (1/18) in group 2, and 4.5% (1/22) in group 3 were positive. Group 1 showed 7.64 times higher positive bacterial culture rate after skin preparation than group 3 (p = 0.084). CONCLUSION: During skin preparation prior to total knee replacement surgery, chlorhexidine gluconate paint after povidone-iodine scrub or povidone-iodine paint after chlorhexidine gluconate scrub had a superior effect on sterilizing native bacteria compared to povidone-iodine scrub-and-paint method.

Use of monofilament sutures and triclosan coating to protect against surgical site infections in spinal surgery: a laboratory-based study.

PURPOSE: We investigated bacterial propagation through multifilament, monofilament sutures and whether sutures coated with triclosan would exhibit a different phenomenon. METHODS: One centimetre (cm) wide trenches were cut in the middle of Columbia blood Agar plates. We tested a 6 cm length of two Triclosan-coated (PDS plus®, Vicryl plus®) and two uncoated (PDS ®, Vicryl ®) sutures. Each suture was inoculated with a bacterial suspension containing methicillin-sensitive Staphylococcus aureus (MSSA), Escherichia coli (E. coli), Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) at one end of each suture. The plates were incubated at 36C for 48 h, followed by room temperature for a further 5 days. We established bacterial propagation by observing for any bacterial growth on the Agar on the opposite side of the trench. RESULTS: Bacterial propagation was observed on the opposite side of the trench with both suture types, monofilament PDS and multifilament Vicryl, when tested with the motile bacterium (E. coli). Propagation was not observed on the other side of the trench with the monofilament PDS suture following incubation with MSSA and S. epidermidis, and in 66% of MRSA. With multifilament suture Vicryl, propagation was observed on the other side of the trench in 90% (MSSA), 80% (S. epidermidis), and 100% (MRSA) of plates tested. No bacterial propagation was observed in any of the triclosan-coated sutures (monofilament or multifilament). CONCLUSIONS: Monofilament sutures are associated in vitro with less bacterial propagation along their course when compared to multifilament sutures. Inhibition in both sutures can be further enhanced with a triclosan coating.

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.

Development of a nomogram to predict surgical site infection after open reduction and internal fixation for closed pilon fracture: a prospective single-center study.

BACKGROUND: To explore the risk factors and develop a nomogram in order to predict surgical site infection (SSI) after open reduction and internal fixation (ORIF) for closed pilon fractures (CPF). METHODS: A prospective cohort study with one-year follow-up was carried out in a provincial trauma center. From January 2019 to January 2021, 417 adult patients with CPFs receiving ORIF were enrolled. A Whitney U test or t test, Pearson chi-square test, and multiple logistic regression analyses were gradually used for screening the adjusted factors of SSI. A nomogram model was built to predict the risk of SSI, and the concordance index (C-index), the receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) were used for evaluating the prediction performance and consistency of the nomogram model. The bootstrap method was employed to test the validity of the nomogram. RESULTS: The incidence of SSI after ORIF for CPFs was 7.2% (30/417): 4.1% (17/417) of superficial SSIs and 3.1% (13/417) of deep SSIs. The most common pathogenic bacteria were Staphylococcus aureus (36.6%, 11/30). The multivariate analysis showed tourniquet use, longer preoperative stay, lower preoperative albumin (ALB), higher preoperative body mass index (BMI) and hypersensitive C-reactive protein (Hs-CRP) were independent risk factors of SSI. Additionally, the C-index and bootstrap value of the nomogram model were 0.838 and 0.820, respectively. Finally, the calibration curve indicated that the actual diagnosed SSI had good consistency with the predicted probability, and the DCA showed that the nomogram had clinical value. CONCLUSIONS: Tourniquet use, longer preoperative stay, lower preoperative ALB, higher preoperative BMI and Hs-CRP were five independent risk factors of SSI after closed pilon fractures treated by ORIF. These five predictors are shown on the nomogram, with which we may be able to further prevent the CPS patients from SSI. Trial registration NO 2018-026-1, October /24/2018, prospectively registered. The study was registered in October 24, 2018. The study protocol was designed based on the Declaration of Helsinki and admitted by the Institutional Review Board. The ethics committee approved the study on factors related to fracture healing in orthopedic surgery. Data analyzed in the present study were acquired from the patients who underwent open reduction and internal fixation from January 2019 to January 2021.

Fracture-related infection: Prevalence and application of the new consensus definition in a cohort of 1004 surgically treated ankle fractures.

BACKGROUND: Surgical treatment of ankle fractures comes with a substantial risk of complications, including infection. An unambiguously definition of fracture-related infections (FRI) has been missing. Recently, FRI has been defined by a consensus group with a diagnostic algorithm containing suggestive and confirmatory criteria. The aim of the current study was to report the prevalence of FRI in patients operated for ankle fractures and to assess the applicability of the diagnostic algorithm from the consensus group. PATIENTS AND METHODS: Records of all patients with surgically treated ankle fractures from 2015 to 2019 were retrospectively reviewed for signs of postoperative infections. Patients with suspected infection were stratified according to confirmatory or suggestive criteria of FRI. Rate of FRI among patients with confirmatory and suggestive criteria were calculated. RESULTS: Suspected infection was found in 104 (10%) out of 1004 patients. Among those patients, confirmatory criteria were met in 76/104 (73%) patients and suggestive criteria were met in 28/104 (27%) at first evaluation. Patients with clinical confirmatory criteria (N = 76) were diagnosed with FRI. Patients with suggestive criteria were further examined with either bacterial sampling at the outpatient clinic, revision surgery including bacterial sampling, or a wait-and-see approach. Eleven (39%) of the 28 patients had positive cultures and were therefore diagnosed as having FRI at second evaluation. In total 87 (9%) patients were diagnosed with FRI according to the consensus definition. Only 73 (70%) of the 104 patients with suspected FRI had adequate bacterial sampling. CONCLUSION: The prevalence of FRI, applying the FRI-consensus criteria, for patients with surgically treated ankle fractures was 9%. Twenty-two percent of patients who met the confirmatory criteria had negative bacterial cultures. The current study shows that we did not have a systematic approach to patients with suspected FRI as recommended by the consensus group. A systematic approach to adequate bacterial sampling when FRI is suspected is paramount. The consensus definition of FRI and its diagnostic algorithm facilitates such an approach. LEVEL OF EVIDENCE: Level III - retrospective cohort study.

Incidence and predictors of sternal surgical wound infection in cardiac surgery: A prospective study.

Sternal surgical wound infection (SSWI) in cardiac surgery is associated with increased morbidity. We investigated the incidence of SSWI, the main germs implicated and predictors of SSWI. Prospective study including patients undergoing full median sternotomy between January 2017 and December 2019. Patients were followed-up for 3 months after hospital discharge. All sternal wound infections up to 90 days after discharge were considered SSWI. 1004 patients were included. During follow-up, 68 (6.8%) patients presented SSWI. Patients with SSWI had a higher incidence of postoperative renal failure (29.4% vs 17.1%, P = .007), a higher incidence of early postoperative reoperation for non-infectious causes (42.6% vs 9.1%, P < .001), longer ICU stay (3 [2-9] days vs 2 [2-4] days, P = .006), and longer hospital stay (24.5 [14.8-38.3] days vs 10 [7-18] days, P < .001). Gram-positive germs were presented in 49% of the cultures, and gram-negative bacteria in 35%. Early reoperation for non-infectious causes (OR 4.90, 95% CI 1.03-23.7), and a longer ICU stay (OR 1.37 95% CI 1.10-1.72) were independent predictors of SSWI. SSWI is rare but leads to more postoperative complications. The need for early reoperation because of non-infectious cause and a longer ICU stay were independently associated with SSWI.

Impact of large amount of intra-abdominal lavage on surveillance of surgical site infection after hepato-pancreato-biliary surgery: A prospective cohort study.

BACKGROUND/PURPOSE: In hepatobiliary and pancreatic (HBP) surgery, the role and significance of intra-abdominal lavage (IAL) for surgical site infection (SSI) is controversial. METHODS: This prospective study was performed between July 2020 and July 2022. A total of 150 patients, 10-L IAL was performed. The lavage fluid at 1-L, 5-L, and 10-L was subjected to bacterial culture examination. Risk factors for SSI were evaluated. RESULTS: Bacterial positivity rate significantly decreased as follows: 1-L, 36% (n = 54); 5-L, 27% (n = 41); 10-L, 23% (n = 35) (36% vs 23%, p = .001). Patients with positive lavage fluid culture at 10-L had significantly higher incidence of both incisional (37% vs 6%, p < .01) and organ/space (54% vs 3%, p < .01) SSI. Multivariate analysis revealed positivity for bacterial culture at 10-L as the strongest independent risk factor for incisional SSI (OR 13.0, 95% CI: 3.86-43.6, p < .01), followed by postoperative pancreatic fistula (OR 11.7, 95% CI: 3.03-45.6, p < .01). Likewise, in organ/space SSI, positivity for bacterial culture at 10-L was the strongest independent risk factor (OR 48.9, 95% CI:12.1-197.7, p < .01), followed by digestive reconstruction (OR 5.20, 95% CI: 1.45-18.6, p = .01). CONCLUSION: IAL decreased the intraperitoneal contamination rate in a volume-dependent manner and can be useful in the surveillance of SSI development in HBP surgery.