Surgical site infections caused by multi-drug resistant organisms: a case-control study in general surgery

The Promising Effect of Ascorbic Acid and Paracetamol as Anti-Biofilm and Anti-Virulence Agents against Resistant Escherichia coli

Escherichia coli is a major cause of serious infections, with antibiotic resistance rendering many treatments ineffective. Hence, novel strategies to combat this pathogen are needed. Anti-virulence therapy is a promising new approach for the subsequent era. Recent research has examined the impact of sub-inhibitory doses of ascorbic acid and paracetamol on Escherichia coli virulence factors. This study evaluated biofilm formation, protease production, motility behavior, serum resistance, expression of virulence-regulating genes (using RT-PCR), and survival rates in a mouse model. Ascorbic acid significantly reduced biofilm formation, protease production, motility, and serum resistance from 100% in untreated isolates to 22-89%, 10-89%, 2-57%, and 31-35% in treated isolates, respectively. Paracetamol also reduced these factors from 100% in untreated isolates to 16-76%, 1-43%, 16-38%, and 31-35%, respectively. Both drugs significantly down-regulated virulence-regulating genes papC, fimH, ompT_m, stcE, fliC, and kpsMTII. Mice treated with these drugs had a 100% survival rate compared with 60% in the positive control group control inoculated with untreated bacteria. This study highlights the potential of ascorbic acid and paracetamol as anti-virulence agents, suggesting their use as adjunct therapies alongside conventional antimicrobials or as alternative treatments for resistant Escherichia coli infections.

Comparison of the Efficacy of Cephalosporins and Non-cephalosporins in Preventing Surgical Site Infections in Colorectal Surgery Patients: An Updated Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to compare the efficacy of cephalosporin and non-cephalosporin antibiotics in preventing surgical site infections (SSIs) in patients undergoing colorectal surgery, providing a scientific basis for the selection of perioperative antibiotics through systematic review and meta-analysis.

METHODS

Adhering to the PRISMA guidelines, this research employed an extensive literature search strategy across multiple databases to identify relevant studies, including randomized controlled trials (RCTs) and observational studies. Inclusion criteria were studies on adults undergoing colorectal surgery who received preoperative prophylaxis with either cephalosporin or non-cephalosporin antibiotics. Exclusion criteria included preoperative diagnosis of infectious diseases and preoperative use of antimicrobial agents. Meta-analysis was conducted using RevMan 5.3 software to assess the effectiveness of both antibiotic classes in preventing SSIs, including subgroup analyses.

RESULTS

Eight studies met the inclusion criteria, comprising 872 patients. Meta-analysis revealed that the incidence of SSI in the cephalosporin group was lower than in the non-cephalosporin group (14.8% vs 25.1%), with statistical significance (OR = 1.94, 95% CI: 1.38-2.74, PP = =0.0001). However, no significant difference in SSI risk was observed between the groups within 30 days (OR = =1.92, 95% CI: 1.08-3.42). Subgroup analysis indicated that higher-quality studies were associated with larger effect sizes.

CONCLUSION

This study suggests that cephalosporin antibiotics may be superior to non-cephalosporins in preventing SSIs following colorectal surgery, especially in the short term. However, their long-term efficacy in SSI prevention may be similar. The selection of perioperative antibiotics should consider factors such as the antimicrobial spectrum, pharmacokinetic properties, and bacterial resistance.

Phage therapy as a glimmer of hope in the fight against the recurrence or emergence of surgical site bacterial infections

PURPOSE

Over the last decade, surgery rates have risen alarmingly, and surgical-site infections are expanding these concerns. In spite of advances in infection control practices, surgical infections continue to be a significant cause of death, prolonged hospitalization, and morbidity. As well as the presence of bacterial infections and their antibiotic resistance, biofilm formation is one of the challenges in the treatment of surgical wounds.

METHODS

This review article was based on published studies on inpatients and laboratory animals receiving phage therapy for surgical wounds, phage therapy for tissue and bone infections treated with surgery to prevent recurrence, antibiotic-resistant wound infections treated with phage therapy, and biofilm-involved surgical wounds treated with phage therapy which were searched without date restrictions.

RESULTS

It has been shown in this review article that phage therapy can be used to treat surgical-site infections in patients and animals, eliminate biofilms at the surgical site, prevent infection recurrence in wounds that have been operated on, and eradicate antibiotic-resistant infections in surgical wounds, including multi-drug resistance (MDR), extensively drug resistance (XDR), and pan-drug resistance (PDR). A cocktail of phages and antibiotics can also reduce surgical-site infections more effectively than phages alone.

CONCLUSION

In light of these encouraging results, clinical trials and research with phages will continue in the near future to treat surgical-site infections, biofilm removal, and antibiotic-resistant wounds, all of which could be used to prescribe phages as an alternative to antibiotics.

Tailored Pre-Operative Antibiotic Prophylaxis to Prevent Post-Operative Surgical Site Infections in General Surgery

The average American today undergoes three inpatient and two outpatient surgical procedures during one's life, each of which carries with it a risk of post-operative infection. It has long been known that post-operative infections cause significant morbidity in the immediate peri-operative period, but recent evidence suggests that they can have long-term consequences as well, increasing a patient's risk of infectious complications in unrelated surgeries performed months or even years later. While there are several theories on the origin of this association, including bacterial colonization of a post-operative infectious wound site, antimicrobial resistance from curative courses of antibiotics, subclinical immunosuppression, or the creation of an inflammatory "pathobiome" following an infectious insult, it is ultimately still unclear why patients who experience a single post-operative infection seem to be at a significantly higher risk of experiencing subsequent ones. Regardless, this association has significant implications for the routine use of pre-operative antibiotic prophylaxis. Indeed, while the prescription of antibiotics pre-operatively has dramatically reduced the rate of post-operative infections, the chosen prophylaxis regimens are typically standardized according to national guidelines, are facing increasing antimicrobial resistance patterns, and have been unable to reduce the risk of post-operative infection to acceptably low levels for certain surgeries. As a result, some clinicians have speculated that tailoring pre-operative antibiotic prophylaxis according to a patient's prior infectious and operative history could improve efficacy and further reduce the rate of post-operative infections. The purpose of this review is to describe the evidence for the link between multiple post-operative infections and explore the efficacy of individualized pre-operative prophylaxis.

Postoperative infectious complications are associated with diminished overall survival of patients undergoing resection for colorectal liver metastases

INTRODUCTION

Postoperative infectious complications (PIC) remain one of the most common complications after surgery. The influence of PIC on long-term survival for patients after liver surgery for colorectal liver metastases (CRLM) needs further investigation.

METHODS

Data of patients who underwent liver resection for CRLM between 2012 and 2017 at the Department of Surgery, Campus Charité Mitte and Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin were evaluated. Overall survival (OS) was stratified according to the development of PIC. Independent predictors of PIC and diminished survival were identified using regression models.

RESULTS

Of 270 patients, eighty-four (31%) patients developed PIC including intraabdominal infections (n = 51, 61%), cholangitis (n = 5, 6%), pneumonia (n = 12, 14%), wound infections (n = 28, 33%), urinary tract infections (n = 5, 6%), or central line-associated bloodstream infections (n = 4, 5%). PIC were associated with a significantly diminished five-year OS (30% vs. 43%, p = 0.008). Age >65 years (p = 0.016, hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.2-4.0), comorbidity (p = 0.019, HR [95% CI] = 2.4 [1.2-4.9]), simultaneous resection of primary tumor (p = 0.005, HR [95% CI] = 4.3 [1.6-11.9]), biliary drainage (p < 0.001, HR [95% CI] = 4.1 [2.0-8.5]), and length of procedure ≥272 min (p = 0.012, HR [95% CI] = 2.2 [1.2-4.1]) were independent predictors for the development of PIC. Body-mass index (BMI) > 30 kg/m2 (p = 0.002, HR [95% CI] = 2.4 [1.4-4.0]), postoperative major complications (p = 0.003, HR [95% CI] = 2.2 [1.3-3.8]), and 3- or 4-MRGN bacteria (p = 0.001, HR [95% CI] = 7.7 [2.2-27.3]) were independently associated with diminished OS.

CONCLUSIONS

PIC are associated with diminished OS after resection for CRLM. Age >65 years, comorbidities, simultaneous resection of the primary tumor, and biliary drainages were identified as independent risk factors for the development of PIC. High BMI, postoperative major morbidity and 3-/4-MRGN bacteria were independently predictive of worse OS. These factors need to be considered in perioperative management for patients with CRLM.

Severe and complicated soft tissue infections: a single-centre case series

OBJECTIVE

To assess the demographic and clinical characteristics, laboratory findings, and economic burden of patients with a diagnosis of complicated skin and soft tissue infection (cSSTI).

METHOD

The demographic and clinical characteristics, laboratory findings, surgical interventions, cost of treatment, and outcome of patients diagnosed with cSSTIs between January 2017 and December 2019 were retrospectively analysed.

RESULTS

A total of 24 patients with cSSTIs were included in the study. The median age was 53 (22-85) years, and 14 (58%) were female. The most common comorbidity was diabetes (54%). On admission, 75% of patients presented with sepsis, and 70% had a high-grade Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score. The causative microorganism was isolated from 21 (87%) patients, and the multidrug resistance rate of Gram-negative bacteria was 50%. The median number of debridements was 3 (1-12). In all, 11 patients were followed up in the intensive care unit, and the mortality rate was 29%. The presence of confusion (p=0.025), causative Gram-negative microorganisms (p=0.009), hyponatraemia (p=0.034), the need for intensive care (p=0.001), anti-meticillin-resistant Staphylococcus aureus antibiotics (p=0.023) and the rate of antibiotic changes during treatment (p=0.019) were significantly higher in the non-survival patient group. Hyponatraemia was a significant independent risk factor for mortality (p=0.048). The median cost of per-patient treatment was $9453 USD in the non-surviving and $1536 in the surviving group.

CONCLUSION

It is important to know possible factors and local resistance rates at the beginning of empirical antibacterial and surgical treatment. The presence of hyponatraemia, sepsis and a high LRINEC score can be considered to be the mortality predictors.

Transmission of Staphylococcus aureus in the anaesthesia work area has greater risk of association with development of surgical site infection when resistant to the prophylactic antibiotic administered for surgery

BACKGROUND

The extent to which the transmission of prophylactic-antibiotic-resistant bacteria from the anaesthesia work area increases the risk of surgical site infection (SSI) is unknown. It was hypothesized that the risk of SSI would increase progressively from no transmission to transmission of prophylactic-antibiotic-resistant isolates.

METHODS

This was a retrospective analysis of archival samples collected in two previously published studies with similar inclusion criteria and sample collection methodology (observational study 2009-2010 and randomized trial 2018-2019). Archival isolates were linked by barcode to all patient demographic and procedural information, including the prophylactic antibiotic administered, transmission and development of SSI. For this study, all archival isolates underwent prophylactic antibiotic susceptibility testing, and the ordered association of transmission of Staphylococcus aureus (no transmission, transmission of prophylactic-antibiotic-susceptible isolates and transmission of prophylactic-antibiotic-resistant isolates) with SSI was assessed.

RESULTS

The risk of development of SSI was 2% (8/406) without S. aureus transmission, 11% (9/84) with transmission of S. aureus isolates that were susceptible to the prophylactic antibiotic used, and 18% (4/22) with transmission of prophylactic-antibiotic-resistant S. aureus isolates. The Cochrane-Armitage two-sided test for ordered association was P<0.0001. Treating these three groups as 0, 1 and 2, by exact logistic regression, the odds of SSI increased by 3.59 with each unit increase (95% confidence interval 1.92-6.64; P<0.0001).

CONCLUSIONS

Transmission of S. aureus in the anaesthesia work area reliably increases the risk of SSI, especially when the isolates are resistant to the prophylactic antibiotic administered.

A Six-Year Retrospective Study of Microbiological Characteristics and Antimicrobial Resistance in Specimens from a Tertiary Hospital’s Surgical Ward

Surgery has revolutionized the practice of medicine by allowing the treatment of conditions amenable to conservative medical management with some of them pathophysiologically involving the prevalence of pathogenic microorganisms. On the other hand, infections such as surgical site infections or urinary tract infections may complicate patients hospitalized in surgical wards leading to considerable morbidity, mortality, and increased healthcare-associated costs. The aim of this study was to present the microbiological characteristics and antimicrobial resistance of all isolates identified in microbiological specimens from a surgical ward of a tertiary hospital in Greece during a six-year period. Only specimens that yielded at least one microorganism were included in the analysis. In total, 1459 strains in 789 positive cultures were isolated. The most common sample sent to the microbiology department was pus from surgical wounds. The most common pathogens among all 1459 strains isolated were Enterobacterales at 33% (n = 482), however, the most common genus was Enterococcus at 22.3% (n = 326). Antimicrobial resistance against third-generation cephalosporins was 23% (n = 111/482) among Enterobacterales, while, the rate of vancomycin-resistant enterococci (VRE) was 18.5% (n = 60/324) among Enterococcus species and was increasing in the last years of the study. Antimicrobial resistance of Acinetobacter baumannii to carbapenems was 68.8% (n = 11/16), which was lower than the corresponding rate in other wards in Greece. The antimicrobial resistance rates noted herein raise questions regarding the appropriateness of currently suggested antimicrobials in guidelines and imply that a revision could be required. Practicing clinicians should always be aware of local microbiological data that allow the selection of appropriate antimicrobials for the management of infections. Finally, the increasing rates of VRE noted herein mandate further actions from the point of infection control and antimicrobial stewardship.

Sustaining Improvements of Surgical Site Infections by Six Sigma DMAIC Approach

SSIs (surgical site infections) are associated with increased rates of morbidity and mortality. The traditional quality improvement strategies focusing on individual performance did not achieve sustainable improvement. This study aimed to implement the Six Sigma DMAIC method to reduce SSIs and to sustain improvements in surgical quality. The surgical procedures, clinical data, and surgical site infections were collected among 42,233 hospitalized surgical patients from 1 January 2019 to 31 December 2020. Following strengthening leadership and empowering a multidisciplinary SSI prevention team, DMAIC (Define, Measure, Analyze, Improve, and Control) was used as the performance improvement model. An evidence-based prevention bundle for reduction of SSI was adopted as performance measures. Environmental monitoring and antimicrobial stewardship programs were strengthened to prevent the transmission of multi-drug resistant microorganisms. Process change was integrated into a clinical pathway information system. Improvement cycles by corrective actions for the risk events of SSIs were implemented to ensure sustaining improvements. We have reached the targets of the prevention bundle elements in the post-intervention period in 2020. The carbapenem resistance rates of Enterobacteriaceae and P. aeruginosa were lower than 10%. A significant 22.2% decline in SSI rates has been achieved, from 0.9% for the pre-intervention period in 2019 to 0.7% for the post-intervention period in 2020 (p = 0.004). Application of the Six Sigma DMAIC approach could significantly reduce the SSI rates. It also could help hospital administrators and quality management personnel to create a culture of patient safety.