Braided silk sutures coated with photoreduced silver nanoparticles for eradicating Staphylococcus aureus and Streptococcus mutans infections.

BACKGROUND: Infections resulting from surgical procedures and wound closures continue to pose significant challenges in healthcare settings. To address this issue, the investigators have developed antibacterial non-resorbable braided silk sutures using in situ deposited silver nanoparticles (AgNPs) and investigated their efficacy in eradicating Staphylococcus aureus and Streptococcus mutans infections. METHODS: The braided silk sutures were modified through a simple and efficient in situ photoreduction method, resulting in the uniform distribution of AgNPs along the suture surface. The synthesized AgNPs were characterized using scanning electron microscopy (SEM), dynamic light scattering analysis (DLS) and Fourier Transform Infrared Spectroscopy analysis (FTIR) confirming their successful integration onto the silk sutures. The antibacterial activity of the nanoparticle coated sutures were compared and evaluated with non-coated braided silk sutures through in vitro assays against both S. aureus and S. mutans. RESULTS: The surface and cross-sectional analysis of the treated sutures revealed a uniform and homogeneous distribution of silver particles achieved through the photoreduction of silver solution. This observation confirms the successful coating of silver nanoparticles (AgNPs) on the sutures. The antimicrobial studies conducted, demonstrated significant reductions in bacterial colonies when exposed to the silver nanoparticle-coated sutures. Notably, the width of the inhibition zone surrounding the coated sutures remained consistently wide and stable for duration up to 7 days. This sustained and robust inhibitory effect against gram-positive bacteria, specifically S. aureus and S. mutans, serves as strong evidence of the antibacterial efficacy of the coated sutures. CONCLUSION: The coating of silk sutures with AgNPs provided a significant and effective antibacterial capacity to the surgical sutures, with this activity being sustained for a period of 7 days. This suggests that AgNPs-in situ photoreduction deposited sutures have the potential to effectively manage S. aureus and S. mutans infections.

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.

Effect of antimicrobial peptide conjugated surgical sutures on multiple drug-resistant microorganisms.

Surgical site infections are commonly encountered as a risk factor in clinics that increase the morbidity of a patient after a surgical operation. Surgical sutures are one of the leading factor for the formation of surgical site infections that induce bacterial colonization by their broad surface area. Current strategies to overcome with surgical site infections consist utilization of antibiotic agent coatings such as triclosan. However, the significant increase in antibiotic resistance majorly decreases their efficiency against recalcitrant pathogens such as; Pseudomonas aeruginosa and Staphylococcus aureus. Therefore, the development of a multi drug-resistant antimicrobial suture without any cytotoxic effect to combat surgical site infections is vital. Antimicrobial peptides are the first defense line which has a broad range of spectrum against Gram-positive, and Gram-negative bacteria and even viruses. In addition, antimicrobial peptides have a rapid killing mechanism which is enhanced by membrane disruption and inhibition of functional proteins in pathogens without the development of antimicrobial resistance. In the scope of the current study, the antimicrobial effect of antimicrobial peptide conjugated poly (glycolic acid-co-caprolactone) (PGCL) sutures were investigated against P. aeruginosa and methicillin-resistant S. aureus (MRSA) strains by using antimicrobial peptide sequences of KRFRIRVRV-NH2, RWRWRWRW-NH2 and their dual combination (1:1). In addition, in vitro wound scratch assays were performed to evaluate the effect of antimicrobial peptide conjugated sutures on keratinocyte cell lines. Our results indicated that antimicrobial peptide modified sutures could be a potential novel medical device to overcome surgical site infections by the superior acceleration of wound healing.

Engineering surgical stitches to prevent bacterial infection.

Surgical site infections (SSIs) account for a massive economic, physiological, and psychological burden on patients and health care providers. Sutures provide a surface to which bacteria can adhere, proliferate, and promote SSIs. Current methods for fighting SSIs involve the use of sutures coated with common antibiotics (triclosan). Unfortunately, these antibiotics have been rendered ineffective due to the increasing rate of antibiotic resistance. A promising new avenue involves the use of metallic nanoparticles (MNPs). MNPs exhibit low cytotoxicity and a strong propensity for killing bacteria while evading the typical antibiotic resistance mechanisms. In this work, we developed a novel MNPs dip-coating method for PDS-II sutures and explored the capabilities of a variety of MNPs in killing bacteria while retaining the cytocompatibility. Our findings indicated that our technique provided a homogeneous coating for PDS-II sutures, maintaining the strength, structural integrity, and degradability. The MNP coatings possess strong in vitro antibacterial properties against P aeruginosa and S. aureus-varying the %of dead bacteria from ~ 40% (for MgO NPs) to ~ 90% (for Fe2O3) compared to ~ 15% for uncoated PDS-II suture, after 7 days. All sutures demonstrated minimal cytotoxicity (cell viability > 70%) reinforcing the movement towards the use MNPs as a viable antibacterial technology.

A Novel In Vitro Method to Assess the Microbial Barrier Function of Tissue Adhesives Using Bioluminescence Imaging Technique.

Background. Tissue glues can minimize treatment invasiveness, mitigate the risk of infection, and reduce surgery time; ergo, they have been developed and used in surgical procedures as wound closure devices beside sutures, staples, and metallic grafts. Regardless of their structure or function, tissue glues should show an acceptable microbial barrier function before being used in humans. This study proposes a novel in vitro method using Escherichia coli Lux and bioluminescence imaging technique to assess the microbial barrier function of tissue glues. Different volumes and concentrations of E. coli Lux were applied to precured or cured polyurethane-based tissue glue placed on agar plates. Plates were cultured for 1 h, 24 h, 48 h, and 72 h with bioluminescence signal measurement subsequently. Herein, protocol established a volume of 5 µL of a 1 : 100 dilution of E. coli Lux containing around 2 × 107 CFU/mL as optimal for testing polyurethane-based tissue glue. Measurement of OD600nm, determination of CFU/mL, and correlation with the bioluminescence measurement in p/s unit resulted in a good correlation between CFU/mL and p/s and demonstrated good reproducibility of our method. In addition, this in vitro method could show that the tested polyurethane-based tissue glue can provide a reasonable barrier against the microbial penetration and act as a bacterial barrier for up to 48 h with no penetration and up to 72 h with a low level of penetration through the material. Overall, we have established a novel, sensitive, and reproducible in vitro method using the bioluminescence imaging technique for testing the microbial barrier function of new tissue glues.

Evaluation of Bacterial Colonization and Clinical Properties of Different Suture Materials in Dentoalveoler Surgery.

PURPOSE: This study aimed to compare the effects of 10 different suture materials commonly used in dentoalveolar surgery on wound healing, their postoperative microbial colonization, and related clinical parameters. METHODS: A total of 172 suture samples from patients who had undergone extraction of impacted third molars were included in the study. The suture materials studied were poly-glycolide-colactide, fast absorbable poly-glycolide-colactide, poly-glycolic acid-cocaprolactone, polydioxanone, silk, polypropylene, polyvinylidene difluoride, polyamide, polyester, and polytetrafluoroethylene (PTFE). The microbial colonization in all sutures and clinical parameters were evaluated after 1 week. RESULTS: Multifilament sutures had higher bacterial colonization compared with monofilament sutures (P < .001). No dental plaque accumulation was observed in any samples of polypropylene sutures. Polydioxanone, PTFE, and poly-glycolic acid-cocaprolactone sutures exhibited less postoperative slack compared with all other sutures after 1 week. Patients with silk, polyvinylidene difluoride, and PTFE sutures had less suture-related discomfort. According to the Landry index score, monofilament sutures demonstrated superior wound healing to multifilament sutures (P = .019). In addition, nonabsorbable sutures showed significantly better wound epithelization than absorbable sutures (P ˂ .001). CONCLUSIONS: Bacterial colonization and tissue reactions due to the surface properties of the suture affected the wound healing after dentoalveolar surgery. Multifilament sutures should not be applied for prolonged periods because of their tendency for microbial colonization. The tissue reaction to the absorbable suture materials may adversely affect wound healing.

INFECTIOUS ENDOPHTHALMITIS AFTER SCLERAL FIXATION OF AN INTRAOCULAR LENS.

PURPOSE: To determine the mechanism of infection, clinical features, and risk factors of endophthalmitis after scleral fixation of an intraocular lens. METHODS: We included 15 patients with infectious endophthalmitis after scleral fixation of an intraocular lens between April 2004 and December 2017, as well as four patients found through a literature search. Thus, a total of 19 patients were analyzed. RESULTS: Among 19 eyes, infectious endophthalmitis developed at a mean of 23 months (range: 1 day-10 years) after scleral fixation surgery. Nine eyes (47.4%) had early-onset endophthalmitis (≤6 weeks), and 10 eyes (52.6%) had delayed-onset endophthalmitis (>6 weeks). Eleven eyes (57.9%) had presumed microbial influx due to suture exposure. Those with delayed-onset endophthalmitis showed a higher rate of suture-related infection (80.0% vs. 33.3%) and culture of gram-negative bacteria (70.0% vs. 12.5%) than did those with early-onset endophthalmitis. CONCLUSIONS: Infectious endophthalmitis can develop late after scleral fixation of an intraocular lens, usually related to the exposed sutures, and the visual prognosis is poor. Eyes that have sutured scleral fixation should be monitored regularly, and preventive measures should be performed if an exposed suture is found.

Biomimicking Antibacterial Opto-Electro Sensing Sutures Made of Regenerated Silk Proteins.

Surgical sutures play an important role across a wide range of medical treatments and a wide variety exist, differing in strength, size, composition, and performance. Recently, increasing interest has been paid to bioactive and electronic sutures made of synthetic polymers, owing to their ability to reduce inflammation as well as medically and/or electronically facilitate wound healing. However, integrating sensing capabilities into bioactive sutures without adversely affecting their mechanical strength, biocompatibility, and/or bioactivity remains challenging. In this work, a set of biomimicking, antibacterial, and sensing sutures based on the regenerated silk fibroin is designed and fabricated. These sensing sutures, inspired by the "core-shell" multilayered structure of natural spider-silk fibers, are hierarchically structured and heterogeneously functionalized to allow for the integration of multiple, clinically favorable functions into one suture device. These functions included: reducing inflammation and bacterial infection in wound sites, measuring tension of both the tissue and suture, and aiding tissue healing via multi-modal controlled drug and growth factor release. Critically, these functions are coupled with real-time optical and electronic monitoring capabilities. This approach provides greater insight into multifunctional sutures with inherent sensing capabilities and offers enormous potential in both therapeutic and diagnostic applications.

Evaluation of Contamination of Multiuse Suture Cassettes in an HQHVSN Environment.

Historically, it has been thought that suture cassettes become contaminated by bacteria through multiuse. However, High-Quality, High-Volume Spay/Neuter (HQHVSN) veterinarians have been using them for years without issue because of their significantly lower cost. The objective of this study was to determine if absorbable suture cassettes are contaminated through multiuse in an HQHVSN environment. A total of 101 suture samples from suture cassettes were collected from 25 HQHVSN clinics or shelters. The suture samples were placed in an enrichment broth tube and aerobic and anaerobic culture with microbe ID were performed. A total of 17/101 samples were positive for microbial growth, with 11/25 clinics having at least one positive sample. Based on these results, there is a significant risk to using suture cassettes that must be balanced against cost savings. Although HQHVSN veterinarians do not report an increase in infection using suture cassettes, based on the results of this study, there is likely contaminated suture being used during sterilization surgeries at these surgery sites.

2-Methacryloyloxyethyl Phosphorylcholine Polymer Coating Inhibits Bacterial Adhesion and Biofilm Formation on a Suture: An In Vitro and In Vivo Study.

Initial bacterial adhesion to medical devices and subsequent biofilm formation are known as the leading causes of surgical site infection (SSI). Therefore, inhibition of bacterial adhesion and biofilm formation on the surface of medical devices can reduce the risk of SSIs. In this study, a highly hydrophilic, antibiofouling surface was prepared by coating the bioabsorbable suture surface with poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate) (PMB). The PMB-coated and noncoated sutures exhibited similar mechanical strength and surface morphology. The effectiveness of the PMB coating on the suture to suppress adhesion and biofilm formation of methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus was investigated both in vitro and in vivo. The bacterial adhesion test revealed that PMB coating significantly reduced the number of adherent bacteria, with no difference in the number of planktonic bacteria. Moreover, fluorescence microscopy and scanning electron microscopy observations of adherent bacteria on the suture surface after contact with bacterial suspension confirmed PMB coating-mediated inhibition of biofilm formation. Additionally, we found that the PMB-coated sutures exhibited significant antibiofouling effects in vivo. In conclusion, PMB-coated sutures demonstrated bacteriostatic effects associated with a highly hydrophilic, antibiofouling surface and inhibited bacterial adhesion and biofilm formation. Therefore, PMB-coated sutures could be a new alternative to reduce the risk of SSIs.

In vitro and in vivo study of novel antimicrobial gellan-polylysine polyion complex fibers as suture materials.

GELLAN GUM: and gellan-derived materials have never been used for suture materials due to their lack of strength and toughness. In this study, gellan and ε-polylysine formed a polyion complex in water solution, and the complex was transformed into fibers via wet-spinning. The fibers were bundled, twisted, and elongated, and the resultant twisted and elongated yarn (GPF) had a diameter of 97.53-103.76 µm and tensile strength of 4 N. The swelling ratio of GPF was 165.55%-183.23% in weight in normal saline, and the linear density was 2.84-3.31 g/km. GPF was tested using agar diffusion tests and it was found that the fibers had good antibacterial activity against Escherichia coli and Staphylococcus epidermidis. In weight loss experiments, GPF was found to be undegradable in normal saline and slightly degradable (residual weight ratio was 83.2 ± 1.2%) in simulated body fluid with trypsin within 7 days. Moreover, GPF showed no cytotoxicity toward BV-2 cells in cytotoxity tests with CCK8 and no hemolysis in hemolytic tests with fresh C57 mice blood. Finally, GPF was assessed using mouse dorsal cross-cutting model, and none of the mice that were tested with GPF showed infection or rejection reaction. Therefore, GPF is a promising suture material, and this study provides a new development direction for the application of gellan materials with improved mechanical properties.

The Role of Bacterial Colonization of the Suture Thread in Early Identification and Targeted Antibiotic Treatment of Surgical Site Infections: A Prospective Cohort Study.

Background: The aim of the present study is to investigate the role of the colonization of suture thread to identify patients at risk of developing a surgical site infection (SSI) after clean surgical procedures. Methods: Patients who underwent elective clean surgery procedures at the Surgery Unit of the AOU-University of Campania Luigi Vanvitelli in a 21-month period were prospectively enrolled. For each patient, a synthetic absorbable thread in Lactomer 9-1 was inserted into the surgical site at the end of surgery and microbiologically evaluated after 48 h. Antibiotic prophylaxis was chosen according to international guidelines. Results: A total of 238 patients were enrolled; 208 (87.4%) of them were subjected to clean procedures without the placement of prosthesis, and 30 (12.6%) with prosthesis. Of the 238 patients, 117 (49.2%) underwent an antimicrobial prophylaxis. Overall, 79 (33.2%) patients showed a bacterial colonization of the thread: among the 208 without the implantation of prosthesis, 19 (21.8%) of the 87 with antibiotic prophylaxis and in 58 (47.9%) of the 121 without it; among the 30 patients with the implantation of prosthesis, only two patients showed a colonized thread. The patients with antibiotic prophylaxis developed a colonization of the thread less frequently than those without it (17.9% vs. 47.9%, p < 0.001). SSI was observed in six (2.5%) patients, all of them showing a colonized thread (7.6% vs. 0%, p < 0.001). The bacteria identified in colonized threads were the same as those found in SSIs. Conclusions: Our study presents a new method that is able to precociously assess patients who have undergone clean procedures who may develop SSI, and identify the microorganism involved.

Effect of antiseptic gels in the microbiologic colonization of the suture threads after oral surgery.

Three different bioadhesive gels were evaluated in a double-blind randomized clinical trial in which microbial growth in the suture thread was assessed following post-surgical application of the aforementioned gels. Also assessed in this trial were, the intensity of post-surgical pain as well as the degree of healing of the patients' surgical wounds. A total of 21 patients (with 42 wisdom teeth) participated in this trial. Chlorhexidine gel, chlorhexidine-chitosan gel, and hyaluronic acid gel were evaluated, with a neutral water-based gel serving as the control agent. The aerobic and facultative anaerobic bacterial recovery on blood agar was lower in the placebo group than in the experimental groups. The most significant difference (p = 0.04) was observed in the chlorhexidine-chitosan group. in which the growth of Blood Agar and Mitis Salivarius Agar was significantly higher than in the placebo group. The intensity of post-surgical pain was very similar among all the groups. Significantly better healing rates were observed in the patients treated with chlorhexidine-chitosan gel when compared with those who used the placebo gel (p = 0.03), and in particular when compared with those patients who used hyaluronic acid gel (p = 0.01). Through our microbiological analyses, we were able to conclude that none of the bioadhesive gels tested resulted in beneficial reductions in the bacterial/fungal populations. However, the healing rates of patients who were treated with chlorhexidine-chitosan were better than those of the patients who used either the placebo gel or the hyaluronic acid gel.

Adherencia bacteriana en los materiales de sutura de uso habitual en cirugía bucal. Revision sistemática / Bacterial aggregation in the suture materials usually used in oral surgery. Systematic review

OBJETIVO: Demostrar la existencia de agregación bacteriana a los materiales de sutura que suelen emplearse en la práctica odontológica, comprobar si dicha agregación está relacionada con la inflamación que sucede al acto quirúrgico y por último dar recomendaciones sobre què tipo de sutura se adapta mejor para la prevención de la adherencia bacteriana. MATERIAL Y MÈTODO: Búsqueda bibliográfica a travès de las bases de datos PubMed, Cochrane y Scielo empleando las palabras clave: surgical sutures, bacterial adherence. Como criterios de inclusión se aceptaron los estudios publicados en los últimos 15 años, in vivo o in vitro en relación con la cirugía oral y con un nivel de evidencia científico superior a 3 según los criterios de evidencia científica. Fueron excluidas todas aquellas publicaciones que no tenían como objeto de estudio las sutura seda, Nylon™, Supramid™, Monocryl™, Vicryl™ o Vicryl Plus™. Tambièn se excluyeron todas aquellas publicaciones que no relacionaban los materiales de sutura a la agregación bacteriana. RESULTADOS: Un total de 9 publicaciones se organizaron en función del tipo de sutura empleada, si eran estudios in vivo o in vitro, el número de pacientes/muestras, tiempo transcurrido hasta la remoción de las suturas, si se realizaron controles, si existió algún tipo de reacción inflamatoria, que tipo de bacterias se agregaron y que material obtuvo mayor agregación. DISCUSIÓN: Los materiales de sutura que mayor acúmulo de placa bacteriana presentan bajo las mismas condiciones de tiempo de exposición a bacterias, son los de tipo multifilamento reabsorbible no tratados con antimicrobianos

OBJECTIVE: To demonstrate the existence of bacterial aggregation to the suture materials that are usually used in dental practice, to verify if aggregation is related to the inflammation that occurs after the surgical act and finally give recommendations on what type of suture is best suited for the prevention of bacterial adhesion. MATERIAL AND METHOD: Bibliographic search through PubMed, Cochrane and Scielo databases using the keywords: surgical sutures, bacterial adherence. Inclusion criteria were accepted studies published in the last 15 years, in vivo or in vitro in relation to oral surgery and with a level of scientific evidence of more than 3 according to the criteria of scientific evidence. All those publications that did not have the suture subject Silk, Nylon™, Supramid™, Monocryl™, Vicryl™ or Vicryl Plus™ were excluded. All publications that did not relate suture materials to bacterial aggregation were also excluded. RESULTS: A total of 9 publications were organized according to the type of suture used, whether they were in vivo or in vitro studies, the number of patients/samples, time elapsed until removal of the sutures, controls if they were performed, any type of inflammatory reaction, which type of bacteria were added and which material obtained greater aggregation. DISCUSSION: The suture materials with the greatest accumulation of bacterial plaque present under the same conditions of exposure to bacteria, are the reabsorbable multifilament type not treated with antimicrobials

Investigation of the in vitro antimicrobial activity of triclosan-coated suture material on bacteria commonly isolated from wounds in dogs.

OBJECTIVE: To investigate in vitro effects of triclosan coating of suture materials on the growth of clinically relevant bacteria isolated from wounds in dogs. SAMPLE: 6 types of suture material and 10 isolates each of methicillin-susceptible Staphylococcus pseudintermedius, methicillin-resistant S pseudintermedius, Escherichia coli, and AmpC ß-lactamase and extended-spectrum ß-lactamase-producing E coli from clinical wound infections. PROCEDURES: Isolates were cultured on Mueller-Hinton agar with 3 types of triclosan-coated suture, uncoated counterparts of the same suture types, and positive and negative controls. Zones of inhibition (ZOIs) were measured after overnight incubation. Sustained antimicrobial activity assays were performed with susceptible isolates. The ZOI measurements and durations of sustained antimicrobial activity were compared among suture types and isolates by statistical methods. Suture surface characteristics and bacterial adherence were evaluated qualitatively with scanning electron microscopy. RESULTS: ZOIs were generated only by triclosan-coated materials; triclosan-coated suture had sustained antimicrobial activity (inhibition) for 3 to 29 days against all tested pathogens. The ZOIs around triclosan-coated suture were significantly greater for S pseudintermedius isolates than for E coli isolates. Bacterial adherence to uncoated polyglactin-910 was greatest, followed by triclosan-coated polyglactin-910, and then uncoated monofilament sutures, with least adherence to coated monofilament sutures. CONCLUSIONS AND CLINICAL RELEVANCE: Surface characteristics of suture materials may be as important or more important than triclosan coating for microbial inhibition; however, triclosan coating appeared to affect bacterial adherence for multifilament sutures. Triclosan-coated, particularly monofilament, sutures inhibited pathogens commonly isolated from wounds of dogs, including multidrug-resistant bacteria. Further studies are required to assess clinical efficacy of triclosan-coated suture materials in vivo.

Forgotten pathogen: tetanus after gastrointestinal surgery.

A previously healthy 79-year-old woman underwent an urgent laparotomy and resection of a strangulated loop of small bowel. On the second postoperative day, she developed symptoms suspicious for postoperative tetanus. A transfer to the intensive care unit was necessary for aggressive supportive therapy. The patient required 5 months of intensive physiotherapy and rehabilitation and was successfully discharged home. New cases of tetanus have become rare in developed countries. This potentially lethal disease affects both non-immunised and inadequately immunised patients. The occurrence of tetanus after gastrointestinal surgery is extremely rare. Prevention is key and can be achieved with correct immunoprophylaxis. Older patients are often inadequately immunised. Should tetanus immunoprophylaxis routinely be checked for elderly patients undergoing gastrointestinal surgery? Or can we limit the immunisation to severe cases of ischaemic bowel injury with necrosis and/or soiling of the abdominal cavity?

Microbial colonization of subscapularis tagging sutures in shoulder arthroplasty: a prospective, controlled study.

BACKGROUND: Reducing intraoperative wound contamination is a critical preventive strategy for reducing the risk of prosthetic joint infection in shoulder arthroplasty. The aim of this study was to investigate the potential microbial colonization of subscapularis tagging sutures during shoulder arthroplasty. METHODS: In this prospective study, 50 consecutive patients undergoing primary shoulder arthroplasty (anatomic or reverse) were enrolled. Patients with revision shoulder arthroplasty and proximal humeral fractures were excluded. Nonabsorbable, braided tagging sutures were placed through the subscapularis tendon prior to tenotomy. A similar nonabsorbable, braided suture (control) was placed in a sterile container on the back table, open to the operating room environment. Subscapularis tagging sutures (experimental specimens) and control sutures were collected prior to subscapularis tenotomy repair and submitted for aerobic and anaerobic cultures. Cultures were held for 21 days to account for extended growth of slow-growing bacteria. RESULTS: A total of 12 of 50 experimental and 16 of 50 control sutures had positive cultures. Staphylococcus epidermidis and Cutibacterium acnes were the 2 most commonly isolated organisms. Active tobacco use (P = .038) and procedure length (P = .03) were significantly associated with positive cultures. No significant association between positive subscapularis tagging suture cultures and positive control cultures was found (P = .551). Patient age, sex, body mass index, and significant medical comorbidities were not significantly associated with positive cultures. DISCUSSION: Subscapularis tagging sutures are a potential source of microbial contaminant in shoulder arthroplasty, and we recommend exchanging the tagging suture with a suture opened immediately prior to subscapularis repair.

Does Suture Type Influence Bacterial Retention and Biofilm Formation After Irrigation in a Mouse Model?

BACKGROUND: Irrigation and débridement are frequently utilized in the management of surgical infections, but even with aggressive débridement, it is difficult to remove all the suture material from the tissues and retained suture material may harbor bacteria and/or biofilm. The degree to which barbed or braided sutures may differentially influence the risk of infection has not been defined in a well-controlled animal model. QUESTIONS/PURPOSES: We compared braided and barbed monofilament sutures after irrigation of an infected mouse air pouch model to determine whether the suture type influenced the effectiveness of the irrigation. After irrigation of infected pouches, sutures were compared for (1) bacterial adherence and bacterial retention; (2) qualitative and quantitative pouch thickness and cellular density; and (3) quantitative biofilm formation. METHODS: Soft tissue air pouches were created on the backs of 60 female, mature 10-week-old BALB/cJ mice by sequentially introducing air into the subcutaneous tissue and allowing the pouch to mature. The pouches were inoculated with Staphylococcus aureus and braided or barbed monofilament sutures were implanted. Pouch irrigation was performed Day 7 after suture implantation. Suture segments were collected before and after irrigation. After euthanasia on Day 14, pouch tissues with residual suture segments were collected for analysis: microbiologic analysis done using optical density as a measure of the concentration of bacteria in the culture (the larger concentration indicates higher number of bacteria) and histologic evaluation of the pouch tissues were semiquantitative, whereas environmental scanning electron microscopy (ESEM) and confocal analyses of the biofilm and bacteria on the sutures were qualitative. RESULTS: Histologic evaluation of pouch tissue showed all groups had inflammatory responses. Quantitatively microbiology showed no difference in bacterial number calculated from the optical density (OD) values between the two suture materials at any time point in the irrigation group. In the no-irrigation group, for the Day 7 time point, mean (± SD) OD was greater in the barbed than the OD in the braided sutures (0.52 ± 0.12 versus 0.37 ± 0.16, mean difference 0.43 [95% confidence interval, 0.08-0.13]; p = 0.007). Qualitatively, ESEM showed more bacterial retention by braided sutures before and after irrigation. Confocal imaging of the sutures demonstrated penetration of biofilm into the interstices of braided sutures and less adhesion in barbed monofilament sutures. The quantification of the biomass showed no differences between groups at all time points (before-irrigation biomass was 11.2 ± 9.3 for braided versus 5.2 ± 4.7 for barbed sutures, p = 0.196; and after-irrigation biomass was 7.2 ± 7.5 for braided versus 3.3 ± 4.3 for barbed suture, p = 0.259). CONCLUSIONS: All sutures can retain bacteria and biofilm, but it is rarely possible to remove all suture material at the time of irrigation to treat infection. After an irrigation procedure, qualitatively braided sutures appeared to harbor more bacteria and to retain more biofilm than barbed monofilaments. CLINICAL RELEVANCE: When saline irrigation was used to simulate infection treatment in an infected mouse air pouch model, bacteria/biofilm was not completely eliminated from either braided or barbed monofilament sutures. The irrigation appeared to clear more bacteria and biofilm from the monofilament despite having barbs. Unfortunately, current technologies do not allow direct quantitative comparisons of biofilm retention. Clinicians should be aware that in the face of infection, any retained sutures may harbor bacteria despite irrigation.

Comparison between antimicrobial-coated sutures and uncoated sutures for the prevention of surgical site infections in plastic surgery: a double blind control trial.

OBJECTIVE: Surgical site infection (SSI) produces considerable morbidity and increases health care costs. One of its causes is microbial adherence to the surgical sutures surface. A strategy to avoid microbial colonization is the use of antimicrobial-impregnated sutures. Recently absorbable sutures treated with chlorhexidine (CHX) have been developed. Our study purpose was to compare CHX-coated and uncoated suture in elective plastic surgery. PATIENTS AND METHODS: We conducted a randomized, double-blind, single-centre controlled trial of 18 patients undergoing elective bilateral mammary surgery and 18 patients undergoing skin lesions removals. Patients were divided into 2 groups receiving antibacterial-coated (study group) and uncoated (controlled group) sutures for wound closure. Patients were evaluated for scar results and signs of SSIs were monitored over a period of 30 days (or 1 year in case of prosthetic surgery). Statistical comparison was performed using dependent t-tests for paired samples. RESULTS: For patients undergoing mammary surgery, based on Vancouver Scale, there were no significant differences between the two groups. We noticed that in 8 patients the vertical scars belonging to the control group were larger than the contralateral 8 vertical sutures belonging to the study group. For patients undergoing skin surgery, surgical wounds treated with uncoated sutures were significantly more erythematous than the ones belonging to the study group (Media: 0,8333% vs. 1,5556%, respectively; standard deviation: 9,235 vs. 0,6157; 95%; p=0.0092). CONCLUSIONS: No wounds infection was reported between the two groups. Based on our experience, we conclude that the use of CHX-coated sutures should be considered in case of inflamed lesions removal. Further studies are needed to validate our results.