Surgical Site Infections Pathogens Research Articles

A study on clinico-demographic and microbiological profile of surgical site infection (SSI) in a tertiary care hospital, Kolkata: An alarming trend

The Centres for Disease Control and Prevention (CDC) estimates surgical site infections SSI is major contributor of healthcare associated infections (HAI). Multidrug resistant (MDR) Gram-negative bacilli are emerging pathogens. This study aimed to determine the magnitude of SSI and identify predominant pathogens with their antimicrobial susceptibility patterns. It is a hospital-based descriptive cross-sectional study including 2070 suspected SSI specimens from 25809 surgeries between 1July 2021 to 30 June 2023. Organisms’ identification and AST was done by both conventional and automated methods. Data was collected and analysed on MS-Excel sheet with various charts and tables. In our study SSI rate was 6.3%, much higher than previous study (2.83%) from this institution. SSI rate was highest in plastic surgery (8.2%). Major pathogens of SSI were Gram-negative bacilli e.g., (26.34%), (25.59%) and (74.69%) was predominant among Gram-positive cocci. Gram-negative bacilli including enterobacterales and non-fermenter and showed resistance to major classes of broad- spectrum antibiotics. Methicillin resistance (MRSA) was 43.9%, which indicates need to improve infection control practices. Our study showed significant higher proportion of SSI as compared to previous studies from the same institute with alarming number of isolated MDR Gram-negative bacilli. So, this study focusses the need of robust infection control practices and strict implementation of antimicrobial stewardship to overcome challenges of antimicrobial resistance.

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.

Spectrum of Surgical Site Infection Pathogens in Chronic Infectious Spondylitis Requiring Revision Surgery: A 5-Year Cohort Study.

Background: Spectrum monitoring of the pathogen in spondylitis patients plays a key role in preventing infectious complications of spinal reconstructions in chronic spondylitis (CS) and in the treatment of surgical site infection (SSI). The aim of this study is to characterize the spectrum of SSI pathogens in CS requiring revision surgery. Methods: The primary cohort encompassed 569 surgical patients with infectious CS. In 99 patients (61 men and 38 women) requiring revision surgical interventions due to SSI, continuous microbiological monitoring of the pathogens was conducted. The average age of the patients was 63 ± 14 years. The vast majority of the patients underwent surgery on a set of multilevel (two or more spinal-motor segments) lesions. Lesions of the lumbar spine were more often noted, and lesions of the thoracic, thoracolumbar, and cervical spine sections were less often noted. This study included all patients operated on within the scope of revision spinal reconstructions in connection with the development of infection of the surgical area over the period from January 2018 to December 2022. Inclusion criteria were etiologically verified spondylitis, age of 18 years or older, and follow-up of 6 months or more. Results: The average rate of revision surgery due to SSI was 17.4%. Germ detection from the material of vertebral localization was noted in 48.3% and pathogen strains were isolated in urine in 60.8%, in decubital ulcers in 23.9%, and in hemoculture in 15.2% of all study patients. Aseptic, deep SSI was detected in 10.1%. Gram-positive, multidrug-resistant, and Gram-negative bacteria with extreme resistance prevailed in the microbiological landscape of late SSI, early, and delayed Gram-positive strains without drug resistance. Conclusions: Infectious etiology of spondylitis is associated with a significantly higher frequency of SSI. In the absence of a positive result from bacteriological examination of the vertebral localization material, it is advisable to conduct blood, decubital ulcer discharge, and urine sampling.

Risk factors and clinical characteristics of surgical site infections in athletes undergoing Achilles tendon repair surgery.

Achilles tendon ruptures are common in athletes, requiring surgical intervention. However, the risk of surgical site infections (SSIs) post-surgery poses significant challenges. This study aims to analyse the risk factors and microbial aetiology associated with SSIs in athletes undergoing Achilles tendon repair. A comprehensive retrospective analysis was conducted from May 2021 to July 2023. The study included 25 patients with SSIs (case group) and 50 patients without SSIs (control group) post Achilles tendon repair surgery. Inclusion criteria encompassed patients with medically confirmed Achilles tendon ruptures who underwent surgical repair. Exclusion criteria included prior tendon pathologies and significant chronic illnesses. Diagnostic criteria for SSIs involved symptoms like elevated body temperature and localized tenderness, along with laboratory confirmations such as positive microbiological cultures. The study utilized VITEK® 2 for bacterial identification and involved statistical analyses like univariate and multivariate logistic regression. The study identified Staphylococcus aureus as the primary pathogen in SSIs. Significant risk factors included lack of prophylactic antibiotic use, presence of diabetes, open wounds and prolonged surgery duration. Univariate analysis revealed stark contrasts in these factors between infected and non-infected groups, while multivariate analysis underscored their importance in SSI development. S. aureus emerged as the predominant pathogen in SSIs post Achilles tendon repair. Critical risk factors such as absence of prophylactic antibiotics, diabetes, open wounds and extended surgery duration play a vital role in SSIs. Addressing these factors is essential for better postoperative outcomes in Achilles tendon repair surgeries.

Risk assessment and pathogen profile of surgical site infections in traumatic brain injury patients undergoing emergency craniotomy: A retrospective study.

Emergency craniotomy in patients with traumatic brain injury poses a significant risk for surgical site infections (SSIs). Understanding the risk factors and pathogenic characteristics of SSIs in this context is crucial for improving outcomes. This comprehensive retrospective analysis spanned from February 2020 to February 2023 at our institution. We included 25 patients with SSIs post-emergency craniotomy and a control group of 50 patients without SSIs. Data on various potential risk factors were collected, including demographic information, preoperative conditions, and intraoperative details. The BACT/ALERT3D Automated Bacterial Culture and Detection System was utilized for rapid bacterial pathogen identification. Statistical analyses included univariate and multivariate logistic regression to identify significant risk factors for SSIs. The study identified Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus as the most prevalent pathogens in SSIs. Significant risk factors for SSIs included the lack of preoperative antibiotic use, postoperative drainage tube placement, diabetes mellitus, and the incorporation of invasive procedures, all of which showed a significant association with SSIs in the univariate analysis. The multivariate analysis further highlighted the protective effect of preoperative antibiotics and the increased risks associated with anaemia, diabetes mellitus, postoperative drainage tube placement, and the incorporation of invasive procedures. Our research underscores the critical role of factors like insufficient preoperative antibiotics, postoperative drainage, invasive techniques, anaemia, and diabetes mellitus in elevating the risk of surgical site infections in traumatic brain injury patients undergoing emergency craniotomy. Enhanced focus on these areas is essential for improving surgical outcomes.

Sex differences in surgical site infections following coronary artery bypass grafting: a retrospective observational study

Surgical site infection (SSI) following cardiac surgery poses a significant challenge for healthcare providers. Despite advances in surgical techniques and infection control measures, SSI remains a leading cause of morbidity and mortality, in addition to being a significant economic burden on healthcare services. Current literature suggests there is a reproducible difference in the incidence of SSI following cardiac surgery between sexes. We aim to assess the sex-specific predictive risk factors for sternal SSI following coronary artery bypass grafting (CABG) in addition to identifying any differences in the causative organisms between groups. Adult patients undergoing isolated CABG between January 2012 and December 2022 in one UK hospital organization were included. In this 10-year, retrospective observational study, a total of 10,208 patients met the inclusion criteria. Pre-operative risk factors were identified using univariate analysis. To assess dependence between sex and organism or Gram stain, a Pearson Chi-squared test with Yates correction for continuity was performed. In total there were 8457 males of which 181 developed a sternal SSI (2.14%) and 1751 females, 128 of whom had a sternal SSI (7.31%). Male patients were found to be significantly more likely to develop an SSI secondary to a Gram-positive organism, whereas female patients were more likely to have a Gram-negative causative organism (P<0.00001). Staphylococcus was statistically more likely to be the causative organism genus in male patients. Pseudomonas aeruginosa was found to be twice as common in the female cohort compared with the male group. In our study, we found a statistically significant difference in the causative organisms and Gram stain for post-CABG sternal SSIs between males and females. Male patients predominately have Gram-positive associated SSIs, whereas female SSI pathogens are more likely to be Gram negative. The preoperative risk profiles of both cohorts are similar, including being an insulin-dependent diabetic and triple vessel coronary artery disease. Given these findings, it prompts the question, should we be tailoring our SSI treatment strategies according to sex and associated risk profiles?

Comparative genomic analyses of Cutibacterium granulosum provide insights into genomic diversity.

Cutibacterium granulosum, a commensal bacterium found on human skin, formerly known as Propionibacterium granulosum, rarely causes infections and is generally considered non-pathogenic. Recent research has revealed the transferability of the multidrug-resistant plasmid pTZC1 between C. granulosum and Cutibacterium acnes, the latter being an opportunistic pathogen in surgical site infections. However, there is a noticeable lack of research on the genome of C. granulosum, and the genetic landscape of this species remains largely uncharted. We investigated the genomic features and evolutionary structure of C. granulosum by analyzing a total of 30 Metagenome-Assembled Genomes (MAGs) and isolate genomes retrieved from public databases, as well as those generated in this study. A pan-genome of 6,077 genes was identified for C. granulosum. Remarkably, the 'cloud genes' constituted 62.38% of the pan-genome. Genes associated with mobilome: prophages, transposons [X], defense mechanisms [V] and replication, recombination and repair [L] were enriched in the cloud genome. Phylogenomic analysis revealed two distinct mono-clades, highlighting the genomic diversity of C. granulosum. The genomic diversity was further confirmed by the distribution of Average Nucleotide Identity (ANI) values. The functional profiles analysis of C. granulosum unveiled a wide range of potential Antibiotic Resistance Genes (ARGs) and virulence factors, suggesting its potential tolerance to various environmental challenges. Subtype I-E of the CRISPR-Cas system was the most abundant in these genomes, a feature also detected in C. acnes genomes. Given the widespread distribution of C. granulosum strains within skin microbiome, our findings make a substantial contribution to our broader understanding of the genetic diversity, which may open new avenues for investigating the mechanisms and treatment of conditions such as acne vulgaris.

Epidemiology of surgical site infection after abdominal surgery in Ukraine: results a multicenter study (2021-2023).

Aim: To estimate the incidence, and to describe of antimicrobial resistance in responsible pathogens, and risk factors for surgical site infection (SSI) after abdominal surgery in Ukraine. Materials and Methods: This were a multicenter, prospective cohort study performed in ten tertiary care hospitals from different regions of Ukraine. Definitions of SSIs after abdominal surgery were adapted from the European Centre for Disease Prevention and Control Surveillance of SSI. The incidence of SSI and predisposing risk factors were noted. Results: Among 6,740 patients, 1,110 (16.5%) SSIs after abdominal surgery were observed. Of these cases, 45.8% superf i cial SSIs, 37.3% deep SSIs, and 16.9% was as organ/space SSIs. Of all SSI cases, 29.9% were detected after hospital discharge. The independent predictors of SSI were open surgical approach, emergency operation, and longed operation duration. The main pathogens of SSI were Escherichia coli (52%), followed by Staphylococcus aureus (9.1%), Enterococcus spp. (7.3%), Pseudomonas aeruginosa (7.1%), Acinetobacter baumannii (6.3%), Stenotrophomonas maltophilia (5.7%), Serratia marcescens (5.3%), and Klebsiella pneumoniae (5.1%). Meticillin resistance S. aureus (MRSA) and vancomycin resistance Enterococcus spp. (VRE) was found in 21.3% and 14.8% isolates, respectively. Conclusions: This study found a high prevalence of SSI after abdominal surgery caused by multidrug-resistant organisms, varying widely depending on the bacterial species, and antimicrobial group in Ukraine. To minimise the risk of complications after abdominal surgery, it is essential to take several preventive measures before, during, and after the surgery.

Proportions of Pseudomonas aeruginosa and Antimicrobial-Resistant P aeruginosa Among Patients With Surgical Site Infections in China: A Systematic Review and Meta-analysis.

Pseudomonas aeruginosa is one of the most common pathogens in surgical site infections (SSIs). However, comprehensive epidemiological and antibiotic resistance details for P aeruginosa in Chinese SSIs are lacking. We evaluated the proportions and antimicrobial resistance of P aeruginosa among patients with SSIs in China. Relevant papers from January 2010 to August 2022 were searched in databases including PubMed, Embase, Web of Science, China Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang, and Weipu. A meta-analysis was performed to analyze the proportions and 95% confidence interval (CIs) of P aeruginosa among patients with SSIs. Meta-regression analysis was used to investigate the proportion difference among different subgroups and antimicrobial resistance. A total of 72 studies met inclusion criteria, involving 33 050 isolated strains. The overall proportion of P aeruginosa among patients with SSIs was 16.0% (95% CI, 13.9%-18.2%). Subgroup analysis showed higher proportions in orthopedic (18.3% [95% CI, 15.6%-21.0%]) and abdominal surgery (17.3% [95% CI, 9.9%-26.2%]). The proportion in the central region (18.6% [95% CI, 15.3%-22.1%]) was slightly higher than that in other regions. Antibiotic resistance rates significantly increased after 2015: cefoperazone (36.2%), ceftriaxone (38.9%), levofloxacin (20.5%), and aztreonam (24.0%). Notably, P aeruginosa resistance to ampicillin and cefazolin exceeded 90.0%. The proportion of P aeruginosa infection among patients with SSIs was higher than the data reported by the Chinese Antimicrobial Resistance Surveillance System, indicating rising antimicrobial resistance. The existing antimicrobial drug management plan should be strengthened to prevent a hospital epidemic of drug-resistant P aeruginosa strains.

Microbiological spectrum of SSI pathogens in patients with chronic infectious spondylitis requiring revision surgery: results of continuous monocentric 5-year monitoring

Objective. To analyze the results of the continuous monocentric 5-year microbiological monitoring of causative agents of surgical site infection (SSI) in patients who underwent primary surgery for chronic infectious spondylitis and required revision surgery.Material and Methods. The study included patient data from 2018 to 2022. The primary cohort included 569 consecutively operated patients with chronic infectious spondylitis of nonspecific (n1 = 214) and tuberculous (n2 = 355) etiology. The analyzed sample was formed taking into according to inclusion and exclusion criteria. Thus, in 99 patients who required revision surgical interventions due to the development of SSI, a continuous microbiological monitoring of pathogens was performed, including the assessment of drug resistance and the timing of the development of infectious complications. Periodization of the time of SSI development was performed according to the accepted classification of Prinz et al. (2020), the assessment of drug resistance spectrum was performed according to the EUCAST recommendations (2020) and taking into account the approved methodological recommendations.Results. In the general structure of surgical interventions for chronic infectious spondylitis, the share of revision interventions due to the development of SSI was 17.4 %. The highest incidence of complications was noted in the late postoperative period (χ2 = 9.237; p = 0.009). Bacterial detection from the material of vertebral localization was noted in 43 cases (48.3 %), pathogen strains were isolated in urine in 28 (60.8 %), in decubital ulcers in 11 (23.9 %) and in hemoculture in 7 (15.2 %) patients. Culture negative SSI was detected in 10 cases (10.1 %) in the late period. Infectious complications in the setting of chronic non-specific spondylitis were detected more frequently than in spondylitis of tuberculous etiology (χ2 = 21.345; p &lt; 0.001). Gram-positive multidrug-resistant and Gram-negative bacteria with extreme resistance prevailed in the microbiological landscape of late SSI, and Gram-positive strains without drug resistance in that of early and delayed SSI (χ2 = 17.516; p = 0.0032).Conclusion. Drug-resistant Gram-positive bacteria predominate in the structure of SSI with a significantly higher frequency of complication development. Nonspecific etiology of spondylitis is associated with a significantly higher incidence of SSI. In the absence of a positive result of bacteriological examination of the material of vertebral localization, it is advisable to collect blood, decubital ulcer secretion and urine sampling.

Surgical Site Infections in Elective and Emergency Abdominal Surgeries: A Prospective Observational Study About Incidence, Risk Factors, Pathogens, and Antibiotic Sensitivity at a Government Tertiary Care Teaching Hospital in India.

Background Surgical site infections (SSIs), the third most common nosocomial infection, endanger hospitals and patients. SSIs must be monitored continuously. This present study examined SSI incidence, risk factors, pathogens, and antibiotic sensitivity in emergency and elective or planned abdominal surgeries. Methods The Dr. S.N. Medical College General Surgery Department in Jodhpur, India, operated on 100 patients. The sample was divided into two 50-person groups. Group A includes emergency surgery patients, while Group B includes elective surgery patients. The samples were aseptically collected and processed according to microbiological methods. Data were processed with IBM SPSS Statistics for Windows, version 20 (released 2011; IBM Corp., Armonk, New York, United States). Results Out of a sample size of 100 patients, 17 individuals experienced SSIs. SSIincidence was 16.66% in male patients and 18.18% in female patients. In addition, the rate of SSIs was 26% in the emergency group and 8% in the planned group. The association was stronger among elderly individuals, diabetics (33.33% in Group A and 12.5% in Group B), and anemics with a history of smoking. The association was higher in those who underwent surgery for more than 60 minutes (34.37% in Group A and 18.8% in Group B). The incidence of SSIs was higher in emergency cases compared to elective surgeries, with rates of 26% and 8%, respectively, but was statistically insignificant. The infection rate in clean cases during planned surgery was 3.70%, while clean contaminated cases during planned surgery had a wound infection rate of approximately 13.04%. In emergency surgery, no clean case was operated on, but the SSI rate in the emergency group was 9.09%, 22.22%, and 47.36% in the clean-contaminated, contaminated, and dirty cases, respectively.In Group A, Escherichia coli was the predominant organism found in SSI wounds, while in Group B, Staphylococcus aureus was the predominant organism, accounting for 46.15% and 50% of infections, respectively. Amikacin and metronidazole exhibited the highest efficacy against E. coli, with amikacin demonstrating the highest sensitivity. Conclusion SSIs are more common in emergencies than planned procedures. Age, gender, diabetes, hypertension, smoking, and prolonged surgery are risk factors for SSIs. Effective antibiotic policy and infection control can greatly prevent SSIs.

Incidence and Risk Factors for Surgical Site Infection in Ankle Fractures: An Observational Study of 480 Patients in Sweden.

Surgical site infection (SSI) is a frequently reported complication after ankle fracture surgery. To our knowledge, no study has been conducted on its incidence in Sweden. The present study aimed to determine the incidence of, risk factors for, and most common causative pathogen of SSI. Patients who underwent primary surgery for an ankle fracture between 1 September 2017 and 31 August 2019 at the Sahlgrenska University Hospital were identified. Data on potential SSI risk factors and clinical outcome (infected/non-infected) were retrieved from medical records. Cox regression analysis and descriptive statistics were used. Of the 480 reviewed patients, 49 developed SSI (10.2%), of which 35 (7.3%) were superficial and 14 (2.9%) were deep. Open fractures (p < 0.001) and age (p = 0.016) were statistically significant risk factors for SSI in the univariate analysis. In the multivariable analysis, only open fracture was statistically significant (HR = 3.0; 95% C.I. = 1.3-6.9, p = 0.013). Cases of Staphylococcus aureus (S. aureus) were most common (n = 12, 24.5%). Methicillin resistance was uncommon (n = 2, 4.1%). An incidence of 10.2% was established, which is comparable to international findings. Infection monitoring is an important part of tackling the global challenge of antibiotic resistance. Future prospective studies to further establish risk factors are warranted to decrease the incidence of SSI.

Analysis of risk factors for surgical site infection after colorectal surgery: a cross-sectional study in the east of China pre-COVID-19.

The occurrence of surgical site infection (SSI) can prolong the postoperative hospital stay, increase the economic burden of patients, and even endanger their lives. The purpose of this study was to investigate the incidence, risk factors, and microbiology of SSI after colorectal surgery (CRS) and to provide a basis for the prevention and control of SSI. A single-center, prospective, cross-sectional study of adult patients undergoing CRS was conducted from 2010-2019. Univariate and multivariate logistic regression models were used to collect and analyze demographic information, hospital characteristics, and potential perioperative risk factors of SSI. A total of 3,302 eligible patients were included in this study, with 213 cases experiencing SSIs, resulting in an infection rate of 6.45%. Notably, the incidence of SSI decreased from 13.33% in 2010 to 3.56% in 2019 (Ptrend < 0.001). Escherichia coli accounted for the majority of isolated microorganisms (37.09%), with 49 strains exhibiting resistance to one or more antibiotics (35.25%). Multivariate analysis showed that diabetes, anastomosis leakage, wound classification (contaminated/dirty), operation duration, blood loss greater than 200 ml, and NNIS risk index score for 2 or 3 were independent risk factors. Conversely, laparoscopic approach, preoperative bowel preparation and preoperative albumin levels emerged as protective factors against SSI after CRS. Furthermore, compared to non-SSI patients, SSI patients had a significantly higher 30-day mortality rate following surgery (0.23% vs. 2.35%, p < 0.05). SSI after CRS was susceptible to many factors, and the pathogen of SSI was mainly Escherichia coli. In clinical practice, measures such as correcting preoperative hypoproteinemia, choosing laparoscopic surgery, preoperative bowel preparation and shortening the duration of surgery should be taken to reduce the incidence of SSI.

The main causative agents of infectious complications during reconstructive surgery using allomaterials in patients with breast cancer

Introduction: Surgical site infections (SSI) are one of the key problems in surgical practice. Despite the achievements of modern medicine, ongoing preventive measures, the incidence of wound infection remains quite high. This is especially relevant for oncoplastic surgery, since in most cases the installation of foreign materials (expanders, implants, meshes) is required to achieve a satisfactory cosmetic result.The purpose of the study: to identify the most common cause of infectious complications after reconstructive operations on the mammary gland using endoprostheses.Materials and methods: In a retrospective review of 526 consecutive implant-based breast reconstructions at a single institution from June 2020 to June 2022 was conducted. The frequency of development of infectious complications was assessed, as well as the taxonomic structure of the main pathogens that were isolated in the department of oncomammology in 2020–2022.Results: The incidence of infectious complications that led to the loss of the endoprosthesis during reconstructive surgery on the mammary gland was 6.7 %. The main causative agents of SSI leading to the loss of implants and the need for reoperations were Corynebacterium striatum (35.2 %) and Staphylococcus aureus (27.2 %). The spectrum of the most common pathogens that led to the loss of implants corresponded to the flora most often detected during bacterial culture in the department. The probability of implant loss was higher in the group of patients who underwent chemotherapy (14 of 197, 7.1 %) or chemoradiotherapy (14 of 188, 7.4 %) compared with patients who did not receive specific anticancer treatment (7 of 141, 4.9 %). However, taking patients who did not receive drug or radiation treatment as a reference group, statistical significance could not be achieved (p = 0.56 in the chemotherapy group and p = 0.49 in the chemoradiotherapy group).Conclusions: Our own experience has shown that, despite the current preventive measures, the frequency of infectious complications remains quite high. In the etiological structure of SSI pathogens, microorganisms of the genera Staphylococcus and Corynebacterium predominate. The use of broad-spectrum antibiotics in perioperative prophylaxis did not guarantee the absence of SSI in the postoperative period. An analysis of the sensitivity of isolated pathogens to antibacterial drugs, an assessment of the effectiveness of various antibiotic regimens in the future may allow us to develop an optimal antibiotic prophylaxis scheme for infectious complications during breast reconstructive surgery, therefore, further prospective studies in this direction are needed.

Risk Factors for Surgical Site Infections in Elective Orthopedic Foot and Ankle Surgery: The Role of Diabetes Mellitus

Surgical site infection (SSI) after elective orthopedic foot and ankle surgery is uncommon and may be higher in selected patient groups. Our main aim was to investigate the risk factors for SSI in elective orthopedic foot surgery and the microbiological results of SSI in diabetic and non-diabetic patients, in a tertiary foot center between 2014 and 2022. Overall, 6138 elective surgeries were performed with an SSI risk of 1.88%. The main independent associations with SSI in a multivariate logistic regression analysis were an ASA score of 3-4 points, odds ratio (OR) 1.87 (95% confidence interval (CI) 1.20-2.90), internal, OR 2.33 (95% CI 1.56-3.49), and external material, OR 3.08 (95% CI 1.56-6.07), and more than two previous surgeries, OR 2.86 (95% CI 1.93-4.22). Diabetes mellitus showed an increased risk in the univariate analysis, OR 3.94 (95% CI 2.59-5.99), and in the group comparisons (three-fold risk). In the subgroup of diabetic foot patients, a pre-existing diabetic foot ulcer increased the risk for SSI, OR 2.99 (95% CI 1.21-7.41), compared to non-ulcered diabetic patients. In general, gram-positive cocci were the predominant pathogens in SSI. In contrast, polymicrobial infections with gram-negative bacilli were more common in contaminated foot surgeries. In the latter group, the perioperative antibiotic prophylaxis by second-generation cephalosporins did not cover 31% of future SSI pathogens. Additionally, selected groups of patients revealed differences in the microbiology of the SSI. Prospective studies are required to determine the importance of these findings for optimal perioperative antibiotic prophylactic measures.

Effect of Gentamicin Collagen Sponge on Wound Healing: In Vivo Study and Assessment of Its Effectiveness against Nosocomial Bacteria

Background: Gentamicin collagen sponge (Genta-Coll) reportedly has a hemostatic effect and promotes wound healing. However, it may also interfere with wound healing by causing foreign body reactions. We planned to analyze the effect of Genta-Coll on wound healing by inducing muscle defects in the rectus abdominis muscle of rats. We also assessed the effectiveness of Genta-Coll in preventing surgical site infections (SSIs) using the zone of inhibition tests to determine the sensitivity of pathogenic bacteria.Methods: We created an 8×8-mm muscle defect in both recti abdominis of 15 white Sprague-Dawley rats and distributed them into the control group (no care) and group A (Genta-Coll). Three biopsies were performed for histologic analysis (on days 3, 7, and 27). In the second study, we placed Genta-Coll on Mueller–Hinton agar plates seeded with pathogenic microorganisms commonly responsible for SSIs. The zone of inhibition was measured after 24 and 48 hours of incubation.Results: Group A showed a slightly higher score for foreign body giant cells and inflammation, with no significant difference. Granulation and neovascularization were constantly high in group A, and muscle regeneration was also high in group A. Extracellular matrix formation advanced at a similar pace in both groups. Genta-Coll created a zone of inhibition against all microorganisms except for Candida albicans. The effect lasted without change between 24 and 48 hours.Conclusion: While foreign body reactions and inflammation increased in group A, wound healing was unaffected. Genta-Coll can promote faster wound healing with an anti-bactericidal effect against SSI pathogens.

A Novel Nonantibiotic Gut-directed Strategy to Prevent Surgical Site Infections.

To determine the efficacy of an orally delivered phosphate-rich polymer, Pi-PEG, to prevent surgical site infection (SSI) in a mouse model of spontaneous wound infection involving gut-derived pathogens. Evidence suggests that pathogens originating from the gut microbiota can cause postoperative infection via a process by which they silently travel inside an immune cell and contaminate a remote operative site (Trojan Horse Hypothesis). Here, we hypothesize that Pi-PEG can prevent SSIs in a novel model of postoperative SSIs in mice. Mice were fed either a standard chow diet (high fiber/low fat, SD) or a western-type diet (low fiber/high fat, WD), and exposed to antibiotics (oral clindamycin/intraperitoneal cefoxitin). Groups of mice had Pi-PEG added to their drinking water and SSI incidence was determined. Gross clinical infections wound cultures and amplicon sequence variant analysis of the intestinal contents and wound were assessed to determine the incidence and source of the developing SSI. In this model, consumption of a WD and exposure to antibiotics promoted the growth of SSI pathogens in the gut and their subsequent presence in the wound. Mice subjected to this model drinking water spiked with Pi-PEG were protected against SSIs via mechanisms involving modulation of the gut-wound microbiome. A nonantibiotic phosphate-rich polymer, Pi-PEG, added to the drinking water of mice prevents SSIs and may represent a more sustainable approach in lieu of the current trend of greater sterility and the use of more powerful and broader antibiotic coverage.

The utility of routine autologous bone-flap swab cultures in predicting post-cranioplasty infection.

To evaluate the utility of autologous bone-flap swab cultures performed at the time of cranioplasty in predicting postcranioplasty surgical site infection (SSI). Retrospective cohort study. Patients undergoing craniectomy (with bone-flap storage in tissue bank), followed by delayed autologous bone-flap replacement cranioplasty between January 1, 2010, and November 30, 2020. Tertiary-care academic hospital. We framed the bone-flap swab culture taken at the time of cranioplasty as a diagnostic test for predicting postcranioplasty SSI. We calculated, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Among 282 unique eligible cases, 16 (5.6%) developed SSI after cranioplasty. A high percentage of bone-flap swab cultures were positive at the time of craniectomy (66.7%) and cranioplasty (59.5%). Most organisms from bone-flap swab cultures were Cutibacterium acnes or coagulase-negative staphylococci (76%-85%), and most SSI pathogens were methicillin-susceptible Staphylococcus aureus (38%). Bone-flap swab culture had poor sensitivity (0.07; 95% CI, 0.01-0.31), specificity (0.4; 95% CI, 0.34-0.45), and positive likelihood ratio (0.12) for predicting postcranioplasty SSI. Overall, autologous bone-flap swab cultures performed at the time of cranioplasty have poor utility in predicting postcranioplasty SSI. Eliminating this low-value practice would result in significant workload reductions and associated healthcare costs.

ANTIBIOTIC RESISTANCE OF CAUSATIVE PATHOGENES OF SURGICAL SITE INFECTION

Microbiological monitoring is remaining a pressing issue in effective control of surgical diseases and prevention of complications. The aim of this study is to determine antibiotic resistance of causative pathogens of surgical site infections isolated in a tertiary medical setting in the Poltava region, Ukraine. This prospective observational study involved 121 middle-aged patients who underwent surgical operations in the surgical department of the Municipal Enterprise “M.V. Sklifosovsky Poltava Regional Clinical Hospital” (Poltava, Ukraine) for 2017-2020. Laboratory investigations of the biological material taken from the patients were conducted at the bacteriological department of the hospital. Pathogens were isolated and identified by an automatised technique, using Vitek2 (Biomérieux, France). 164 isolated and identified strains were determined to have the susceptibility to 30 antibiotics of various groups determined by the disk-diffusion method using standard disks with antibiotics placed on the surface of the Mueller-Hinton culture medium (HiMedia Laboratories Pvt Ltd. India). Statistical analysis was carried out: microorganisms’ susceptibility to antibiotics was calculated in percent. The highest level of resistance to antibacterial drugs was found in Pseudomonas aeruginosa, which, with the exception of 33.3% of strains were susceptible to levofloxacin only, showed resistance to all tested antibiotics. The maximum level of methicillin-resistant strains was found among coagulase-negative staphylococci and amounted to 91.3%. All isolated Klebsiella strains and 18.7% of E. coli strains were producers of extended spectrum beta-lactamases. A significant predominance of multiresistant strains of microorganisms, the resistance of which goes beyond the boundaries of more than two pharmacological groups of antibiotics, has been revealed.

Multidrug-resistant Cutibacterium avidum isolated from patients with acne vulgaris and other infections

Cutibacterium avidum, a human skin commensal bacterium, rarely causes infections. It has recently been shown that Cutibacterium acnes, another member of the genus, acts as an opportunistic pathogen in surgical site infections. However, the antimicrobial susceptibility and pathogenicity of C. avidum remain unknown. We investigated the epidemiological features and antimicrobial susceptibility of C. avidum isolated from patients with acne vulgaris and other infections. Cutibacterium avidum strains were isolated from patients with acne vulgaris (29 strains) and other infections (12 strains). Clarithromycin and clindamycin resistance was observed in 65.9% (27/41) of strains. In addition, ciprofloxacin resistance was observed in 34.1% (14/41) of strains, of which 13 also exhibited resistance to macrolides and clindamycin. Notably, the macrolide-clindamycin resistance gene erm(X) was found on the chromosome of 92.6% (25/27) of clindamycin-resistant strains and may be prevalent owing to transmission among C. avidum strains. Ciprofloxacin-resistant strains developed amino acid substitutions in GyrA owing to the use of antimicrobial agents. Pulsed-field gel electrophoresis (PFGE) analysis revealed that only a few strains exhibited 100% similarity. Additionally, no clustering associated with antimicrobial resistance, biofilm-forming ability or type of infection was observed. Our study revealed that erm(X) may be frequently disseminated in C. avidum, and multidrug-resistant C. avidum strains may colonise the skin of patients with acne vulgaris and other infections. Therefore, the prevalence of multidrug-resistant C. avidum and the use of antimicrobial agents for the treatment of acne vulgaris and other infections associated with C. avidum should be monitored.