Carriage of Extended-spectrum Beta-lactamase-producing Enterobacteriaceae and the Risk of Surgical Site Infection After Colorectal Surgery: A Prospective Cohort Study

Antimicrobial Resistance Trends and Epidemiological Characteristics of Isolates from Intra-Abdominal Infections in China: A 6-Year Retrospective Study (2017-2022)

Background: Antimicrobial resistance represents a continuing threat to the health of patients with intra-abdominal infections (IAIs). This study aimed to provide clinicians with guidance to optimize antibiotic therapy. Methods: The clinical data and antibiotic susceptibility results of pathogens from patients with IAIs from 2017 to 2022 were retrospectively collected. The 6-year period was segmented into two stages, namely, the early (2017-2020) and recent stages (2021-2022). The distribution and antibiotic resistance of pathogens were compared between the stages. Results: In total, 5,795 pathogens were isolated from 2,283 patients diagnosed with IAIs. Gram-negative bacteria, Gram-positive bacteria, and fungi accounted for 71.0%, 21.4%, and 7.5% of the isolates, respectively. Klebsiella pneumoniae (1,037, 17.9%) was the primary isolate. The proportion of extended-spectrum β-lactamase-producing Enterobacteriaceae was 89.8% (2,028/2,259), with extended-spectrum β-lactamase-producing Escherichia coli and K. pneumoniae accounting for 27.4% and 43.2%, respectively, of all such isolates. The carbapenem resistance rates of E. coli and K. pneumoniae were 17.1% and 75.9%, respectively. Compared with that in the early stage, the imipenem resistance rate of E. coli was significantly higher in the recent stage (13.8% vs. 25.1%, p < 0.001). Among Gram-positive bacteria, 88 strains of vancomycin-resistant Enterococcus were detected, giving a resistance rate of 10.3%, and the detection rate of methicillin-resistant Staphylococcus aureus was 65.7%. Conclusions: Enterobacteriales and non-fermentative bacteria from IAIs remain highly resistant to carbapenems. The epidemiological characteristics and antibiotic resistance profiles of pathogens in various regions should be closely monitored to mitigate the appearance of drug-resistant bacteria in clinical settings.

Mechanically powered negative pressure dressing reduces surgical site infection after stoma reversal

Background

The use of closed-incision negative pressure wound therapy (ci-NPWT) has been shown to reduce postoperative wound complications and surgical site infections (SSI) after stoma closures. However, use of this approach has not been widely adopted due to high cost of the devices. We present a novel approach to stoma closure in which a self-contained mechanically powered negative pressure dressing (MP-NPD) is applied to primarily closed stoma reversal wounds. We hypothesized that SSI and wound complication rates would be improved compared to traditional stoma closure methods.

Methods

This was a prospective investigator-initiated study, in which consecutive patients that underwent stoma reversal with primary stoma wound closure dressed with MP-NPD from May 2021-March 2022. 30-day outcomes from the study group, including surgical site infection, other wound complications, hospital length of stay (LOS), and readmission rates, were then reported.

Results

Forty-six patients undergoing local ileostomy or colostomy closure were identified for the study group. Patient demographics and surgical variables were reported. One (2.2 %) patient in the study cohort developed superficial SSI within 30 days of their surgery. Post-op LOS in the study group versus was 4.1 days.

Conclusion

Intestinal stoma reversal wounds closed primarily and dressed with the MP-NPD dressings had very low stoma site SSI rates. These results are promising as they pertain to the use of MP-NPD in stoma reversal procedures, however further large prospective RCTs with a matched control group could help better corroborate these findings.

Role of rectal colonization by third-generation cephalosporin-resistant Enterobacterales on the risk of surgical site infection after hepato-pancreato-biliary surgery

The impact of third-generation cephalosporin-resistant Enterobacterales (3GCR-E) rectal colonization in the development of subsequent infection after surgery is controversial. In particular, there is a lack of data in the context of hepato-pancreato-biliary (HPB) surgery. The objective of this study was to assess the prevalence of 3GCR-E intestinal carriage among patients undergoing elective HPB resection surgery and its impact on the incidence and etiology of surgical site infections (SSIs). This retrospective cohort study (January 2016-December 2022) was performed at Valme University Hospital (Seville, Spain). The inclusion criteria included (i) 18 years of age or older, (ii) undergoing elective HPB resection surgery, and (iii) availability of a periprocedural surveillance rectal swab culture to detect 3GCR-E. The prevalence of 3GCR-E intestinal carriage at elective HPB resection surgery was assessed, as well as SSI incidence at 30 days and possible associated factors. Two hundred nine patients were included. Eleven (5.3%) patients were colonized by 3GCR-E at baseline. According to 3GCR-E carriage status, 6 (55%) of the carriers developed SSI, whereas this occurred in 50 (25%) of non-carriers (P = 0.033). Likewise, the rates of SSI caused specifically by 3GCR-E were 83% (5 of 6) in 3GCR-E carriers and 6% (3 of 50) in non-carriers (P < 0.001). After multivariate analyses, 3GCR-E colonization at the time of surgery was identified as an independent predictor for developing SSI (adjusted odds ratio 4.63, 95% confidence interval: 1.177-18.232, P = 0.028). Despite a low prevalence of 3GCR-E intestinal carriage at surgery, 3GCR-E rectal colonization is associated with a higher risk of SSI among patients undergoing elective HPB resection surgery, with most SSIs being caused by the colonizing bacteria.

IMPORTANCE

In this Spanish retrospective cohort study, previous 3GCR-E rectal colonization was associated with a higher risk of SSI after hepato-pancreato-biliary resection surgeries. Most of SSIs were caused by the colonizing bacteria, suggesting a rationale for adapted perioperative antibiotic prophylaxis in known 3GCR-E colonized patients.

Carriage and antimicrobial susceptibility patterns of rectal ESBL E. coli in surgical patients at the University Teaching Hospitals in Lusaka, Zambia

Background

Surgical site infections (SSIs) are on the rise and are a global concern as they complicate the recovery of patients postoperatively. Bacterial colonization of the patient's skin and alimentary tract are known to be major contributing sources to SSIs. However, Zambia lacks data relating to carriage rates of antibiotic-resistant rectal Escherichia coli among surgical patients.

Methods

This was a cross-sectional study aimed at determining the preoperative (preop) and postoperative (postop) carriage and antimicrobial susceptibility patterns of rectal ESBL-producing E. coli (ESBL-Ec) in elective surgery patients at the highest tertiary hospital in Lusaka, Zambia. Phenotypic methods were used in the identification of E. coli. Antibiotic susceptibility patterns and identification of ESBL-Ec was determined by Kirby-Bauer disc diffusion.

Results

A total of 120 study participants were recruited, of which 75 were followed up at least 72 h after surgery. From 195 rectal swabs cultured, 177 (90.8%) were positive for E. coli, of which 53 (29.9%) were ESBL-Ec, with a significantly (P < 0.0001) higher proportion in postop (47.9%) than preop (17.3%) participants. Overall, ESBL-Ec isolates showed higher resistance in postop than preop to cefotaxime (100% versus 88.9%, respectively), ampicillin (100% versus 94.4%), ciprofloxacin (88.3% versus 83.3%), amoxicillin/clavulanic acid (80% versus 66.7%) and cefepime (80% versus 77.8%). MDR ESBL-Ec strains were more frequent in postop than in preop participants (91.4% versus 88.9%).

Conclusions

The study showed a significantly higher rate of antimicrobial-resistant rectal E. coli in postop than preop participants. There is a need to ascertain the source of the resistance and to institute robust infection control measures, preop screening of surgical patients for ESBL-Ec, and to raise awareness on prudent use of antibiotics.

Public health case for microbiome-sparing antibiotics and new opportunities for drug development

Although antibiotics remain a cornerstone of modern medicine, the issues of widespread antibiotic resistance and collateral damage to the microbiome from antibiotic use are driving a need for drug developers to consider more tailored, patient-directed products to avoid antibiotic-induced perturbations of the structure and function of the indigenous microbiota. This perspective summarizes a cascade of microbiome health effects that is initiated by antibiotic-mediated microbiome disruption at an individual level and ultimately leads to infection and transmission of multidrug-resistant pathogens across patient populations. The scientific evidence behind each of the key steps of this cascade is presented. The interruption of this cascade through the use of highly targeted, microbiome-sparing antibiotics aiming to improve health outcomes is discussed. Further, this perspective reflects on some key clinical trial design and reimbursement considerations to be addressed as part of the drug development path.

Preventing Surgical Site Infections in the Era of Escalating Antibiotic Resistance and Antibiotic Stewardship

Importance

According to the Centers for Disease Control and Prevention and governing bodies within the American College of Surgeons, the administration of antibiotics as prophylaxis against infection prior to a planned elective procedure is, with rare exception, routinely recommended. The goal of "getting to zero" infections remains a high priority for policymakers, practitioners, and certainly for patients.

Observations

Despite the many advances in surgical technique, skin decontamination, sterile procedure, and enhanced recovery programs, surgical site infections continue to adversely affect procedures as diverse as dental implant surgery, joint arthroplasty, and major abdominal surgery. Although surgical site infection rates are at historically low levels, progress has stalled in recent reporting periods and such infections remain disabling, costly, and occasionally lethal. Stakeholders in the field, including surgeons, infectious diseases specialists, and industry, advocate for strategies emphasizing greater levels of intraoperative sterility or broader-spectrum antibiotic coverage as the most appropriate path forward.

Conclusions and Relevance

The current emphasis on ever-increasing levels of intraoperative sterility and extended-spectrum antibiotic use are not sustainable long-term solutions. Continuing to escalate these approaches may contribute to unintended consequences including antimicrobial resistance. Principles of antimicrobial stewardship and microbiome sciences can be applied to inform a more effective and sustainable approach to infection prevention in the field of surgery.

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.

Current practice of screening and antimicrobial prophylaxis to prevent Gram-negative bacterial infection in high-risk haematology patients: results from a pan-European survey

Background

Bacterial infections frequently occur in haematological patients, especially during prolonged neutropenia after intensive chemotherapy, often leading to bloodstream infections and pneumonia.

Objective

Routine antimicrobial prophylaxis (AMP) for high-risk haematology patients is still debated while prevalence of multi-drug resistant (MDR) Gram-negative bacteria (GNB) is rising globally. We aimed to assess the current practice of AMP in this population.

Design

Cross-sectional observational survey study.

Methods

Haematologists and infectious diseases physicians Europewide were invited to an online survey including questions on routine screening for GNB, incidence of MDR-GNB colonization, antimicrobial prophylaxis practices, rates of bloodstream infections (BSI), ICU admission and mortality differentiated by infections due to GNB versus MDR-GNB.

Results

120 haematology centres from 28 countries participated. Screening for MDR-GNB is performed in 86.7% of centres, mostly via rectal swabs (58.3%). In 39.2% of routine AMP is used, mostly with fluoroquinolones. Estimates of GNB-BSI yielded higher rates in patients not receiving anti-GNB prophylaxis than in those who do for E. coli (10% vs 7%) Klebsiella spp. (10% vs 5%), and Pseudomonas spp. (5% vs 4%). Rates for MDR-GNB infection were estimated lower in centres that administer AMP for MDR E. coli (5% vs 3%) Klebsiella spp. (5% vs 3%), and Pseudomonas spp. (2% vs 1%). In an exploratory analysis, Southern and Eastern European countries expected higher rates of MDR-GNB infections with lower ICU admission and mortality rates which may be subject to estimation bias.

Conclusion

Screening for MDR-GNB is frequently performed. AMP against GNB infections is still often implemented. Estimated BSI rates are rather low, while the rate of MDR-GNB infections rises. Tailored prophylaxis including antimicrobial stewardship becomes more important.

Antimicrobial Stewardship in the Hospital Setting: A Narrative Review

The increasing global threat of antibiotic resistance, which has resulted in countless fatalities due to untreatable infections, underscores the urgent need for a strategic action plan. The acknowledgment that humanity is perilously approaching the "End of the Miracle Drugs" due to the unjustifiable overuse and misuse of antibiotics has prompted a critical reassessment of their usage. In response, numerous relevant medical societies have initiated a concerted effort to combat resistance by implementing antibiotic stewardship programs within healthcare institutions, grounded in evidence-based guidelines and designed to guide antibiotic utilization. Crucial to this initiative is the establishment of multidisciplinary teams within each hospital, led by a dedicated Infectious Diseases physician. This team includes clinical pharmacists, clinical microbiologists, hospital epidemiologists, infection control experts, and specialized nurses who receive intensive training in the field. These teams have evidence-supported strategies aiming to mitigate resistance, such as conducting prospective audits and providing feedback, including the innovative 'Handshake Stewardship' approach, implementing formulary restrictions and preauthorization protocols, disseminating educational materials, promoting antibiotic de-escalation practices, employing rapid diagnostic techniques, and enhancing infection prevention and control measures. While initial outcomes have demonstrated success in reducing resistance rates, ongoing research is imperative to explore novel stewardship interventions.

Colonization of multidrug-resistant Gram-negative bacteria increases risk of surgical site infection after hemorrhoidectomy: a cross-sectional study of two centers in southern China

PURPOSE

The present study aims to determine the rectoanal colonization rate and risk factors for the colonization of present multidrug-resistant bacteria (MDRBs). In addition, the relationship between MDRB colonization and surgical site infection (SSI) following hemorrhoidectomy was explored.

METHODS

A cross-sectional study was conducted in the Department of Colorectal Surgery of two hospitals. Patients with hemorrhoid disease, who underwent hemorrhoidectomy, were included. The pre-surgical screening of multidrug-resistant Gram-negative bacteria (MDR-GNB) colonization was performed using rectal swabs on the day of admission. Then, the MDRB colonization rate was determined through the rectal swab. Logistic regression models were established to determine the risk factors for MDRB colonization and SSI after hemorrhoidectomy. A p-value of < 0.05 was considered statistically significant.

RESULTS

A total of 432 patients met the inclusion criteria, and the MDRB colonization prevalence was 21.06% (91/432). The independent risk factors for MDRB colonization were as follows: patients who received ≥ 2 categories of antibiotic treatment within 3 months (odds ratio (OR): 3.714, 95% confidence interval (CI): 1.436-9.605, p = 0.007), patients with inflammatory bowel disease (IBD; OR: 6.746, 95% CI: 2.361-19.608, p < 0.001), and patients with high serum uric acid (OR: 1.006, 95% CI: 1.001-1.010, p = 0.017). Furthermore, 41.57% (37/89) of MDRB carriers and 1.81% (6/332) of non-carriers developed SSIs, with a total incidence of 10.21% (43/421). Based on the multivariable model, the rectoanal colonization of MDRBs (OR: 32.087, 95% CI: 12.052-85.424, p < 0.001) and hemoglobin < 100 g/L (OR: 4.130, 95% CI: 1.556-10.960, p = 0.004) were independently associated with SSI after hemorrhoidectomy.

CONCLUSION

The rectoanal colonization rate of MDRBs in hemorrhoid patients is high, and this was identified as an independent risk factor for SSI after hemorrhoidectomy.

Antimicrobial Resistance in Organ Transplant Recipients

The overall burden of the main clinically relevant bacterial multidrug-resistant organisms (MDROs) (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase producing or extended-spectrum cephalosporin-resistant Enterobacterales, carbapenem-resistant or carbapenemase-producing Enterobacterales, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii) in solid organ transplant (SOT) populations is summarized showing prevalence/incidence, risk factors, and impact on graft/patient outcome according to the type of SOT. The role of such bacteria in donor-derived infections is also reviewed. As for the management, the main prevention strategies and treatment options are discussed. Finally, nonantibiotic-based strategies are considered as future directions for the management of MDRO in SOT setting.

Implications of reducing antibiotic treatment duration for antimicrobial resistance in hospital settings: A modelling study and meta-analysis

BACKGROUND

Reducing antibiotic treatment duration is a key component of hospital antibiotic stewardship interventions. However, its effectiveness in reducing antimicrobial resistance is uncertain and a clear theoretical rationale for the approach is lacking. In this study, we sought to gain a mechanistic understanding of the relation between antibiotic treatment duration and the prevalence of colonisation with antibiotic-resistant bacteria in hospitalised patients.

METHODS AND FINDINGS

We constructed 3 stochastic mechanistic models that considered both between- and within-host dynamics of susceptible and resistant gram-negative bacteria, to identify circumstances under which shortening antibiotic duration would lead to reduced resistance carriage. In addition, we performed a meta-analysis of antibiotic treatment duration trials, which monitored resistant gram-negative bacteria carriage as an outcome. We searched MEDLINE and EMBASE for randomised controlled trials published from 1 January 2000 to 4 October 2022, which allocated participants to varying durations of systemic antibiotic treatments. Quality assessment was performed using the Cochrane risk-of-bias tool for randomised trials. The meta-analysis was performed using logistic regression. Duration of antibiotic treatment and time from administration of antibiotics to surveillance culture were included as independent variables. Both the mathematical modelling and meta-analysis suggested modest reductions in resistance carriage could be achieved by reducing antibiotic treatment duration. The models showed that shortening duration is most effective at reducing resistance carriage in high compared to low transmission settings. For treated individuals, shortening duration is most effective when resistant bacteria grow rapidly under antibiotic selection pressure and decline rapidly when stopping treatment. Importantly, under circumstances whereby administered antibiotics can suppress colonising bacteria, shortening antibiotic treatment may increase the carriage of a particular resistance phenotype. We identified 206 randomised trials, which investigated antibiotic duration. Of these, 5 reported resistant gram-negative bacteria carriage as an outcome and were included in the meta-analysis. The meta-analysis determined that a single additional antibiotic treatment day is associated with a 7% absolute increase in risk of resistance carriage (80% credible interval 3% to 11%). Interpretation of these estimates is limited by the low number of antibiotic duration trials that monitored carriage of resistant gram-negative bacteria, as an outcome, contributing to a large credible interval.

CONCLUSIONS

In this study, we found both theoretical and empirical evidence that reducing antibiotic treatment duration can reduce resistance carriage, though the mechanistic models also highlighted circumstances under which reducing treatment duration can, perversely, increase resistance. Future antibiotic duration trials should monitor antibiotic-resistant bacteria colonisation as an outcome to better inform antibiotic stewardship policies.

Surgical outcomes and factors associated with postoperative complications of colorectal cancer in a Colombian Caribbean population: Results from a regional referral hospital

INTRODUCTION

Colorectal cancer is the most common malignant neoplasm of the gastrointestinal tract. Its incidence and mortality vary markedly at a global level. Assessing the epidemiological behavior of this condition allows reevaluating diagnostic, therapeutic and prognostic options, based on new findings. In Colombia, few studies have correlated variables associated with surgical and oncological outcomes in this type of cancer. Then, the aim of this study was to evaluate the surgical outcomes and factors associated with postoperative complications of colorectal cancer in a Colombian Caribbean Population.

METHODS

Retrospective cross-sectional study, including patients with a histopathological diagnosis of colorectal cancer who underwent open or laparoscopic surgery, during a period of two years (2018-2020), from a regional referral hospital. Clinical history variables were collected. Frequencies and prevalence ratios were calculated.

RESULTS

A total of 84 patients were finally included. Adenocarcinoma of non-special type with advanced clinical stages was the most prevalent (72.6%). Rectal neoplasia (45.2%) was the most frequent anatomical subsite, followed by proximal colon (p = 0.026). The anatomical subsite of the neoplasm, intraoperative complication (PR 1.38; 95% CI, 1.21-1.59, p = 0.001) and intensive care stay (PR 1.062; 95% CI, 1.01-1.12, p = 0.048) were associated with postoperative outcome.

CONCLUSIONS

The anatomical subsite of the neoplasm location, the presence of intraoperative complications and the stay in intensive care may be associated with the surgical and oncological outcome of individuals with colon cancer from the Colombian Caribbean region.

ESCMID/EUCIC clinical practice guidelines on perioperative antibiotic prophylaxis in patients colonized by multidrug-resistant Gram-negative bacteria before surgery

SCOPE

The aim of the guidelines is to provide recommendations on perioperative antibiotic prophylaxis (PAP) in adult inpatients who are carriers of multidrug-resistant Gram-negative bacteria (MDR-GNB) before surgery.

METHODS

These evidence-based guidelines were developed after a systematic review of published studies on PAP targeting the following MDR-GNB: extended-spectrum cephalosporin-resistant Enterobacterales, carbapenem-resistant Enterobacterales (CRE), aminoglycoside-resistant Enterobacterales, fluoroquinolone-resistant Enterobacterales, cotrimoxazole-resistant Stenotrophomonas maltophilia, carbapenem-resistant Acinetobacter baumannii (CRAB), extremely drug-resistant Pseudomonas aeruginosa, colistin-resistant Gram-negative bacteria, and pan-drug-resistant Gram-negative bacteria. The critical outcomes were the occurrence of surgical site infections (SSIs) caused by any bacteria and/or by the colonizing MDR-GNB, and SSI-attributable mortality. Important outcomes included the occurrence of any type of postsurgical infectious complication, all-cause mortality, and adverse events of PAP, including development of resistance to targeted (culture-based) PAP after surgery and incidence of Clostridioides difficile infections. The last search of all databases was performed until April 30, 2022. The level of evidence and strength of each recommendation were defined according to the Grading of Recommendations Assessment, Development and Evaluation approach. Consensus of a multidisciplinary expert panel was reached for the final list of recommendations. Antimicrobial stewardship considerations were included in the recommendation development.

RECOMMENDATIONS

The guideline panel reviewed the evidence, per bacteria, of the risk of SSIs in patients colonized with MDR-GNB before surgery and critically appraised the existing studies. Significant knowledge gaps were identified, and most questions were addressed by observational studies. Moderate to high risk of bias was identified in the retrieved studies, and the majority of the recommendations were supported by low level of evidence. The panel conditionally recommends rectal screening and targeted PAP for fluoroquinolone-resistant Enterobacterales before transrectal ultrasound-guided prostate biopsy and for extended-spectrum cephalosporin-resistant Enterobacterales in patients undergoing colorectal surgery and solid organ transplantation. Screening for CRE and CRAB is suggested before transplant surgery after assessment of the local epidemiology. Careful consideration of the laboratory workload and involvement of antimicrobial stewardship teams before implementing the screening procedures or performing changes in PAP are warranted. High-quality prospective studies to assess the impact of PAP among CRE and CRAB carriers performing high-risk surgeries are advocated. Future well-designed clinical trials should assess the effectiveness of targeted PAP, including the monitoring of MDR-GNB colonization through postoperative cultures using European Committee on Antimicrobial Susceptibility Testing clinical breakpoints.

Pharmacokinetics of cefmetazole in plasma, peritoneal fluid, peritoneum, and subcutaneous adipose tissue of patients scheduled for lower gastrointestinal surgery: Dosing considerations based on site-specific pharmacodynamic target attainment

INTRODUCTION

Cefmetazole (CMZ) has gained interest as a carbapenem-sparing alternative to the epidemic of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E). In this study, we investigated the pharmacokinetics (PK) of CMZ in plasma, peritoneal fluid, peritoneum, and subcutaneous adipose tissue to assess the dosing regimen needed to achieve pharmacodynamic (PD) goals at the target site.

METHODS

Patients scheduled for elective lower gastrointestinal surgery were intravenously administered CMZ. Plasma, peritoneal fluid, peritoneum, and subcutaneous adipose tissue samples were collected after CMZ infusion and during the surgery, and CMZ concentrations were measured. The non-compartmental and compartmental PK parameters were estimated and used to evaluate site-specific PD target attainment.

RESULTS

A total of 38 plasma, 27 peritoneal fluid, 36 peritoneum, and 38 subcutaneous adipose tissue samples were collected from 10 patients. The non-compartmental PK analysis revealed the ratios of the mean area under the drug concentration-time curve (AUC_0-3.5 h) of peritoneal fluid-to-plasma, peritoneum-to-plasma, and subcutaneous adipose tissue-to-plasma were 0.60, 0.36, and 0.11, respectively. The site-specific PD target attainment analyses based on the breakpoints for ESBL-E per the Japanese surgical site infection (SSI) surveillance (MIC₉₀ = 8 mg/L) revealed that 2 g CMZ every 3.5 h achieved desired bactericidal effect at all sites and 2 g CMZ every 6 h achieved PD goals at peritoneum and peritoneal fluid.

CONCLUSION

These findings clarify the PK of CMZ in abdominal tissues and could help decide optimal dosing regimens to treat intra-abdominal infection and prophylaxis of SSI.

Colonisation with Extended-Spectrum Cephalosporin-Resistant Enterobacterales and Infection Risk in Surgical Patients: A Systematic Review and Meta-analysis

INTRODUCTION

Limited evidence has been reported for surgical site infections (SSIs) in patients undergoing surgery who are carriers of extended-spectrum cephalosporin-resistant Enterobacterales (ESCR-E). A systematic review and meta-analysis were conducted to evaluate the risk of postoperative infections in adult inpatients colonised with ESCR-E before surgery.

METHODS

The Medline, Embase and Cochrane databases were searched between January 2011 and April 2022, following PRISMA indications. Random effects meta-analysis was used to quantify the association between ESCR-E colonisation and infection.

RESULTS

Among the 467 articles reviewed, 9 observational studies encompassing 7219 adult patients undergoing surgery were included. The ESCR-E colonisation rate was 13.7% (95% CI 7.7-19.7). The most commonly reported surgeries included abdominal surgery (44%) and liver transplantation (LT; 33%). The SSI rate was 23.2% (95% CI 13.2-33.1). Pooled incidence risk was 0.36 (95% CI 0.22-0.50) vs 0.13 (95% CI 0.02-0.24) for any postoperative infection and 0.28 (95% CI 0.18-0.38) vs 0.17 (95% CI 0.07-0.26) for SSIs in ESCR-E carriers vs noncarriers, respectively. In ESCR-E carriers, the ESCR-E infection ratio was 7 times higher than noncarriers. Postoperative infection risk was higher in carriers versus noncarriers following LT. Sources of detected heterogeneity between studies included ESCR-E colonisation and the geographic region of origin.

CONCLUSIONS

Patients colonised with ESCR-E before surgery had increased incidence rates of post-surgical infections and SSIs compared to noncarriers. Our results suggest considering the implementation of pre-surgical screening for detecting ESCR-E colonisation status according to the type of surgery and the local epidemiology.

Pharmacokinetics of flomoxef in plasma, peritoneal fluid, peritoneum, and subcutaneous adipose tissue of patients undergoing lower gastrointestinal surgery: Dosing considerations based on site-specific pharmacodynamic target attainment

INTRODUCTION

Flomoxef is generally used to treat abdominal infections and as antibiotic prophylaxis during lower gastrointestinal surgery. It is reportedly effective against extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and an increasingly valuable alternative to carbapenems. However, its abdominal pharmacokinetics remain unclear. Herein, pharmacokinetic analysis of flomoxef in the abdominal tissue was conducted to simulate dosing regimens for pharmacodynamic target attainment in abdominal sites.

METHODS

Flomoxef (1 g) was administered intravenously to a patient 30 min before commencing elective lower gastrointestinal surgery. Samples of plasma, peritoneal fluid, peritoneum, and subcutaneous adipose tissue were collected during surgery. The flomoxef tissue concentrations were measured. Accordingly, non-compartmental and compartmental pharmacokinetic parameters were calculated, and simulations were conducted to evaluate site-specific pharmacodynamic target values.

RESULTS

Overall, 41 plasma samples, 34 peritoneal fluid samples, 38 peritoneum samples, and 41 subcutaneous adipose samples from 10 patients were collected. The mean peritoneal fluid-to-plasma ratio in the areas under the drug concentration-time curve was 0.68, the mean peritoneum-to-plasma ratio was 0.40, and the mean subcutaneous adipose tissue-to-plasma was 0.16. The simulation based on these results showed the dosing regimens (q8h [3 g/day] and q6h [4 g/day]) achieved the bactericidal effect (% T > minimum inhibitory concentration [MIC] = 40%) in all tissues at an MIC of 1 mg/L.

CONCLUSIONS

We elucidated the pharmacokinetics of flomoxef and simulated pharmacodynamics target attainment in the abdominal tissue. This study provides evidence concerning the use of optimal dosing regimens for treating abdominal infection caused by strains like ESBL-producing bacteria.

Individualized surgical antibiotic prophylaxis – why, when, and how?

"Surgical site infections (SSI) greatly concern clinicians, as they are associated with significant morbidity and mortality, prolonged hospitalization, and costs. Antibiotic prophylaxis plays a pivotal role among the procedures that are usually employed for the prevention of surgical-related infections. This narrative review aims to cover some of the particular situations when the clinician might consider individualizing antibiotic prophylaxis for a patient. With the rising incidence of multi-drug resistant bacteria carriage among not only hospitalized or institutionalized patients but also patients from the community, there might be a tendency to use extended-spectrum antibiotics for longer periods for surgical infection prevention. However, the inappropriate use of antibiotics increases the selection pressure, thus favoring the spreading of resistant bacteria. Moreover, specific patient characteristics or pathologies might need to be considered to customize the type, dose, or length of administration of an antibiotic as surgical prophylaxis. Using prosthetic material or prolonged surgeries with large fluid shifts are other situations when individualized antibiotic prophylaxis might be thought of. Keeping in mind that it is of utmost importance that everyone adheres to the current guidelines for surgical antibiotic prophylaxis, customization of local protocols according to well-thought-out strategies might prove beneficial in SSI prevention."

Systematic review on efficacy of preventive measures for surgical site infection by multiple-drug resistant gram-negative bacilli

BACKGROUND

There are no specific recommendations for prevention of surgical site infection (SSI) caused by multidrug resistant Gram-negative bacilli (MDR-GNB). Our objective was to systematically review the literature evaluating the efficacy and safety of measures specifically designed to prevent MDR-GNB SSI.

METHODS

We searched MEDLINE, EMBASE, CINAHL and LILACS databases up to February 18, 2020. Randomized trials and observational cohort studies evaluating the efficacy of preventive measures against MDR-GNB SSI in adult surgical patients were eligible. We evaluated methodological quality of studies and general quality of evidence using Newcastle-Ottawa scale, Cochrane ROBINS-I and GRADE method. Random-effects meta-analyses were performed using Review Manager V.5.3 software.

RESULTS

A total of 10,663 titles by searching databases were identified. Two retrospective observational studies, comparing surgical antibiotic prophylaxis (SAP) with or without aminoglycoside in renal transplantation recipients, and one non-randomized prospective study, evaluating ertapenem vs. cephalosporin plus metronidazole for SAP in extended spectrum beta-lactamase producing Enterobacteriales carriers undergoing colon surgery, were included. Risk of bias was high in all studies. Meta-analysis was performed for the renal transplantation studies, with 854 patients included. Combined relative risk (RR) for MDR GNB SSI was 0.57 (95%CI: 0.25-1.34), favoring SAP with aminoglycoside (GRADE: moderate).

CONCLUSIONS

There are no sufficient data supporting specific measures against MDR-GNB SSI. Prospective, randomized studies are necessary to assess the efficacy and safety of SAP with aminoglycoside for MDR-GNB SSI prevention among renal transplantation recipients and other populations. PROSPERO 2018 CRD42018100845.

The Microbiota and the Relationship with Colorectal Cancer: Surgical Complications—A Review

Colorectal cancer (CRC) is one of the most common cancers and represents a major global health burden. While genetics are implicated in a portion of CRC patients, most cases are sporadic. A new possibility of tumor initiation and promotion might be microbiome composition. It was recently shown that bacteria from the gut microbiome might be used as biomarkers for CRC detection, especially Fusobacterium nucleatum, Peptostreoptococcus stomatis, Parvimonas mica, Solobacterium moorei, and Peptostreptococcus anaerobius. Conversely, the healthy gut microbiome is mostly colonized by Bacterioides (Bacterioides fragilis, vulgatus, uniformis), Firmicutes (Clostridium spp., Ruminococcus faecis, Enterococcus faecium), and Actinobacteria (Bifidobacterium bifidum). Some strains of gut bacteria favor tumor promotion through DNA and RNA damage (directly or through interaction with other known food carcinogens) and through local immune inhibition. It is possible that bacteria (e.g., Bacillus polyfermenticus, Alistipes shahii, Lactobacillus casei) exist with protective functions against tumor promotion. Despite current advances in colorectal cancer treatment, especially in the medical oncology and radiotherapy domains, surgery remains the mainstay of curative treatment for colorectal cancer patients, even in the oligometastatic setting. Surgical complications like anastomotic leakage, excessive blood loss, abscess, and abdominal sepsis can reduce 1-year and 5-year overall survival and increase the recurrence rates for these patients; therefore, we reviewed currently published data focusing on the relationship between gut microbiota and postoperative complications for colorectal cancer patients.

Empiric Treatment in HAP/VAP: “Don’t You Want to Take a Leap of Faith?”

Ventilator-associated pneumonia is a frequent cause of ICU-acquired infections. These infections are associated with high morbidity and mortality. The increase in antibiotic resistance, particularly among Gram-negative bacilli, makes the choice of empiric antibiotic therapy complex for physicians. Multidrug-resistant organisms (MDROs) related infections are associated with a high risk of initial therapeutic inadequacy. It is, therefore, necessary to quickly identify the bacterial species involved and their susceptibility to antibiotics. New diagnostic tools have recently been commercialized to assist in the management of these infections. Moreover, the recent enrichment of the therapeutic arsenal effective on Gram-negative bacilli raises the question of their place in the therapeutic management of these infections. Most national and international guidelines recommend limiting their use to microbiologically documented infections. However, many clinical situations and, in particular, the knowledge of digestive or respiratory carriage by MDROs should lead to the discussion of the use of these new molecules, especially the new combinations with beta-lactamase inhibitors in empirical therapy. In this review, we present the current epidemiological data, particularly in terms of MDRO, as well as the clinical and microbiological elements that may be taken into account in the discussion of empirical antibiotic therapy for patients managed for ventilator-associated pneumonia.

Changes in the gut bacterial communities in colon cancer surgery patients: an observational study

BACKGROUND

Colon surgery has been shown to modulate the intestinal microbiota. Our objective was to characterize these changes using state-of-the-art next generation sequencing techniques.

METHODS

We performed a single-centre prospective observational cohort study to evaluate the changes in the gut microbiota, i.e., taxon distribution, before and after elective oncologic colon surgery in adult patients with different antimicrobial prophylaxis regimens (standard prophylaxis with cefuroxime/metronidazole versus carbapenems for extended-spectrum beta-lactamase-producing Enterobacterales [ESBL-E] carriers). We obtained rectal samples on the day of surgery, intraoperative luminal samples, and rectal or stoma samples 3 days after surgery. We performed metataxonomic analysis based on sequencing of the bacterial 16S rRNA gene marker. Similarities and differences between bacterial communities were assessed using Bray-Curtis similarity, visualised using principal coordinates analysis and statistically tested by PERMANOVA. Comparison of taxa relative abundance was performed using ANCOM.

RESULTS

We included 27 patients between March 27, 2019 and September 17, 2019. The median age was 63.6 years (IQR 56.4-76.3) and 44% were females. Most (81%) patients received standard perioperative prophylaxis as they were not ESBL carriers. There was no significant association between ESBL carriage and differences in gut microbiome. We observed large and significant increases in the genus Enterococcus between the preoperative/intraoperative samples and the postoperative sample, mainly driven by Enterococcus faecalis. There were significant differences in the postoperative microbiome between patients who received standard prophylaxis and carbapenems, specifically in the family Erysipelotrichaceae.

CONCLUSION

This hypothesis-generating study showed rapid changes in the rectal microbiota following colon cancer surgery.

Surgical Antibiotic Prophylaxis in an Era of Antibiotic Resistance: Common Resistant Bacteria and Wider Considerations for Practice

The increasing incidence of antimicrobial resistance (AMR) presents a global crisis to healthcare, with longstanding antimicrobial agents becoming less effective at treating and preventing infection. In the surgical setting, antibiotic prophylaxis has long been established as routine standard of care to prevent surgical site infection (SSI), which remains one of the most common hospital-acquired infections. The growing incidence of AMR increases the risk of SSI complicated with resistant bacteria, resulting in poorer surgical outcomes (prolonged hospitalisation, extended durations of antibiotic therapy, higher rates of surgical revision and mortality). Despite these increasing challenges, more data are required on approaches at the institutional and patient level to optimise surgical antibiotic prophylaxis in the era of antibiotic resistance (AR). This review provides an overview of the common resistant bacteria encountered in the surgical setting and covers wider considerations for practice to optimise surgical antibiotic prophylaxis in the perioperative setting.

Hypericin and Pheophorbide a Mediated Photodynamic Therapy Fighting MRSA Wound Infections: A Translational Study from In Vitro to In Vivo

High prevalence rates of methicillin-resistant Staphylococcus aureus (MRSA) and lack of effective antibacterial treatments urge discovery of alternative therapeutic modalities. The advent of antibacterial photodynamic therapy (aPDT) is a promising alternative, composing rapid, nonselective cell destruction without generating resistance. We used a panel of clinically relevant MRSA to evaluate hypericin (Hy) and pheophobide a (Pa)-mediated PDT with clinically approved methylene blue (MB). We translated the promising in vitro anti-MRSA activity of selected compounds to a full-thick MRSA wound infection model in mice (in vivo) and the interaction of aPDT innate immune system (cytotoxicity towards neutrophils). Hy-PDT consistently displayed lower minimum bactericidal concentration (MBC) values (0.625-10 µM) against ATCC RN4220/pUL5054 and a whole panel of community-associated (CA)-MRSA compared to Pa or MB. Interestingly, Pa-PDT and Hy-PDT topical application demonstrated encouraging in vivo anti-MRSA activity (>1 log₁₀ CFU reduction). Furthermore, histological analysis showed wound healing via re-epithelization was best in the Hy-PDT group. Importantly, the dark toxicity of Hy was significantly lower (p < 0.05) on neutrophils compared to Pa or MB. Overall, Hy-mediated PDT is a promising alternative to treat MRSA wound infections, and further rigorous mechanistic studies are warranted.

Surgical antibiotic prophylaxis in patients colonized with multidrug-resistant Gram-negative bacteria: practical and conceptual aspects

Antibiotic resistance threatens the effectiveness of surgical antibiotic prophylaxis (SAP) regimens aimed at preventing surgical site infection (SSI). With a focus on procedures in which Gram-negative bacteria (GNB) are the main pathogens causing SSI, this review summarizes the evidence and describes how SAP must evolve in response to carriage of MDR GNB among surgical patients. Randomized controlled trials of SAP for carriers of resistant GNB require prohibitively large sample sizes. No professional guidelines address the topic of adapting SAP for known carriers of resistant GNB. For patients whose carrier status is unknown, the effects of different SAP strategies have been studied for transrectal ultrasound-guided prostate biopsy and colorectal surgery. The four possible strategies for SAP in the era of antibiotic resistance are: no SAP; universal standard SAP; pre-surgical screening for carriage of antibiotic-resistant pathogens before surgery and targeted SAP (i.e. broad-spectrum antibiotics only for those who screen positive); and universal broad-spectrum SAP. The prevalence of carriage determines the efficiency of each strategy. Decolonization is a potential adjunct to SAP.

Antimicrobial Lessons From a Large Observational Cohort on Intra-abdominal Infections in Intensive Care Units

Severe intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by disease-specific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed.

Priorities in peritonitis

PURPOSE OF REVIEW

Timely and adequate management are the key priorities in the care of peritonitis. This review focuses on the cornerstones of the medical support: source control and antiinfective therapies.

RECENT FINDINGS

Peritonitis from community-acquired or healthcare-associated origins remains a frequent cause of admission to the ICU. Each minute counts for initiating the proper management. Late diagnosis and delayed medical care are associated to dramatically increased mortality rates. The diagnosis of peritonitis can be difficult in these ICU cases. The signs of organ failures are more relevant than biological surrogates. A delayed source control and a late anti-infective therapy are of critical importance. The quality of source control and medical management are other key elements of the prognosis. The conventional rules applied for sepsis are applicable for peritonitis, including hemodynamic support and anti-infective therapy. Growing proportions of multidrug resistant pathogens are reported from surgical samples, mainly related to Gram-negative bacteria. The increasing complexity in the care of these critically ill patients is a strong incentive for a multidisciplinary approach.

SUMMARY

Early clinical diagnosis, timely and adequate source control and antiinfective therapy are the essential pillars of the management of peritonitis in ICU patients.

Cost-Effectiveness Analysis of the Prophylactic Use of Ertapenem for the Prevention of Surgical Site Infections after Elective Colorectal Surgery

Standard surgical antimicrobial prophylaxis (SAP) regimens are less effective in preventing surgical site infections (SSIs) due to rising antimicrobial resistance (AMR) rates, particularly for patients undergoing colorectal surgery. This study aimed to evaluate whether ertapenem should be a preferred strategy for the prevention of SSIs following elective colorectal surgery compared to three standard SAP regimens: amoxicillin-clavulanate, cefoxitin, and cefazolin plus metronidazole. A cost-effectiveness analysis was conducted using decision tree models. Probabilities of SSIs and AMR-SSIs, costs, and effects (in terms of quality-adjusted life-years) were considered in the assessment of the alternative strategies. Input parameters integrated real data from the Italian surveillance system for SSIs with data from the published literature. A sensitivity analysis was conducted to assess the potential impact of the decreasing efficacy of standard SAP regimens in preventing SSIs. According to our models, ertapenem was the most cost-effective strategy only when compared to amoxicillin-clavulanate, but it did not prove to be superior to cefoxitin and cefazolin plus metronidazole. The sensitivity analysis found ertapenem would be the most cost-effective strategy compared to these agents if their failure rate was more than doubled. The findings of this study suggest ertapenem should not be a preferred strategy for SAP in elective colorectal surgery.

The effect of prophylaxis with ertapenem versus cefuroxime/metronidazole on intestinal carriage of carbapenem-resistant or third-generation-cephalosporin-resistant Enterobacterales after colorectal surgery

OBJECTIVES

Compared to cephalosporin-based prophylaxis, ertapenem prophylaxis lowers the risk of surgical site infection among carriers of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PEs) undergoing colorectal surgery. We aimed to determine whether ertapenem prophylaxis leads to increased postoperative colonization with carbapenem-resistant Enterobacterales (CREs) and third-generation-cephalosporin-resistant Enterobacterales (3GCR-Es).

METHODS

This study was nested within a quality improvement study of prophylaxis for ESBL-PE carriers undergoing colorectal surgery. Patients were screened 4-6 days after surgery for carriage of ESBL-PEs or other 3GCR-Es and CREs. When CREs were detected, pre- and postsurgical clones were compared using Fourier-transform infrared (FT-IR) spectroscopy.

RESULTS

The sample consisted of 56 patients who carried ESBL-PEs before surgery and received cefuroxime/metronidazole prophylaxis (Group 1), 66 who carried ESBL-PEs before surgery and received ertapenem (Group 2), and 103 ESBL-PE non-carriers who received cefuroxime/metronidazole prophylaxis (Group 3). CRE carriage was detected postoperatively in one patient (1.5%) in Group 2 versus eight patients (14.3%) in Group 1 (RD -12.8%; 95%CI -22.4% to -3.1%). For seven out of nine patients, preoperative ESBL-PE and postoperative CRE isolates were compared; in five of them, the pre- and postoperative clones were identical. Postoperative 3GCR-E carriage was detected in 37 patients (56.1%) in Group 2 versus 46 patients in Group 1 (82.1%) (aRD -20.7%, 95%CI -37.3% to -4.1%).

CONCLUSIONS

Among ESBL-PE carriers undergoing colorectal surgery, detection of short-term postsurgical colonization by CREs and 3GCR-Es was significantly lower among patients who received ertapenem prophylaxis than those who received cephalosporin-metronidazole prophylaxis. Resistance development in a colonizing bacterial clone, rather than carbapenemase acquisition, was the major mechanism of carbapenem resistance.

Linking antimicrobial resistance surveillance to antibiotic policy in healthcare settings: the COMBACTE-Magnet EPI-Net COACH project

OBJECTIVES

To systematically summarize the evidence on how to collect, analyse and report antimicrobial resistance (AMR) surveillance data to inform antimicrobial stewardship (AMS) teams providing guidance on empirical antibiotic treatment in healthcare settings.

METHODS

The research group identified 10 key questions about the link between AMR surveillance and AMS using a checklist of 9 elements for good practice in health research priority settings and a modified 3D combined approach matrix, and conducted a systematic review of published original studies and guidelines on the link between AMR surveillance and AMS.

RESULTS

The questions identified focused on AMS team composition; minimum infrastructure requirements for AMR surveillance; organisms, samples and susceptibility patterns to report; data stratification strategies; reporting frequency; resistance thresholds to drive empirical therapy; surveillance in high-risk hospital units, long-term care, outpatient and veterinary settings; and surveillance data from other countries. Twenty guidelines and seven original studies on the implementation of AMR surveillance as part of an AMS programme were included in the literature review.

CONCLUSIONS

The evidence summarized in this review provides a useful basis for a more integrated process of developing procedures to report AMR surveillance data to drive AMS interventions. These procedures should be extended to settings outside the acute-care institutions, such as long-term care, outpatient and veterinary. Without proper AMR surveillance, implementation of AMS policies cannot contribute effectively to the fight against MDR pathogens and may even worsen the burden of adverse events from such interventions.

Surgical site infection after liver transplantation in the era of multidrug-resistant bacteria: what new risks should be considered?

Surgical site infection (SSI) is a frequent infection site after liver transplantation (LT), and multidrug-resistant bacteria are common agents of those infections. This study aimed to analyze risk factors for SSI, including SSI caused by a multidrug-resistant microorganism (MDRO) after LT. We performed a cohort study of patients who underwent an LT from 2010 to 2018. The outcomes were SSI and SSI caused by MDRO. We analyzed features related to surgical procedure, patients' characteristics, and post-LT intercurrence. Surveillance for carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant Enterococcus (VRE), and carbapenem-resistant Acinetobacter baumannii (CRAB) was performed through rectal swab at the LT admission and weekly until hospital discharge during all study periods. SSI was identified in 30.1% (229/762) of LTs. We observed a decline in the SSI rate from 37.5% in 2014 to 16.7% in 2018 (P 0.02). SSI caused by MDRO occurred in 109 (14.3%) patients. Klebsiella pneumoniae was the most common agent of both SSI and SSI caused by MDRO. The pre-LT colonization was 98 (12.9%) by CRE, 73 (9.6%) by VRE, and 28 (3.7%) by CRAB. Risk factors for SSI caused by MDRO identified were dialysis after LT (P 0.01), CRAB acquisition before LT (0.03), and CRE acquisition before LT (P 0.004); use of adjusted prophylaxis by MDRO risk was the only protective factor identified (P 0.01). MDROs were frequent agents of SSI after LT, and the carbapenem-resistant Gram-negative colonization before LT increased the risk of SSI by these agents.

Prevalence and associated factors for carriage of Enterobacteriaceae producing ESBLs or carbapenemase and methicillin-resistant Staphylococcus aureus in Hong Kong community

OBJECTIVES

We conducted a cross-sectional study in Hong Kong community to estimate the carriage prevalence, associated factors and genotypes of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E), methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase-producing Enterobacteriaceae (CPE).

METHODS

Seemingly healthy subjects were asked to provide nasal, handprint and stool samples from March to April 2017. Isolates were characterized by molecular methods. We used multivariable logistic regression models within a generalized estimating equation framework to identify risk factors for ESBL-E carriage. Characteristics of MRSA/CPE carriage were summarized.

RESULTS

The prevalence of ESBL-E, MRSA and CPE were 52.8% (104/197), 2.5% (5/197) and 0.5% (1/197) respectively. Most ESBL-E isolates were E. coli (85.6%; 113/132). Most ESBL genes belonged to bla_CTX-M-G9 (68.9%) and bla_TEM (53.0%) types. Self-reported antibiotic consumption (≥2 courses) in the past six months was associated with ESBL-E carriage (adjusted odds ratio: 4.71-5.47).

CONCLUSIONS

Abundance of ESBL-E in the community are causes of concern, and antibiotic use is associated with its carriage. Presence of MRSA and CPE in community members without clear healthcare exposure hints on a change in their epidemiology. This study establishes a baseline to formulate infection control policies and future studies in combating antimicrobial resistance.

Quantifying antibiotic impact on within-patient dynamics of extended-spectrum beta-lactamase resistance

Antibiotic-induced perturbation of the human gut flora is expected to play an important role in mediating the relationship between antibiotic use and the population prevalence of antibiotic resistance in bacteria, but little is known about how antibiotics affect within-host resistance dynamics. Here we develop a data-driven model of the within-host dynamics of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae. We use blaCTX-M (the most widespread ESBL gene family) and 16S rRNA (a proxy for bacterial load) abundance data from 833 rectal swabs from 133 ESBL-positive patients followed up in a prospective cohort study in three European hospitals. We find that cefuroxime and ceftriaxone are associated with increased blaCTX-M abundance during treatment (21% and 10% daily increase, respectively), while treatment with meropenem, piperacillin-tazobactam, and oral ciprofloxacin is associated with decreased blaCTX-M (8% daily decrease for all). The model predicts that typical antibiotic exposures can have substantial long-term effects on blaCTX-M carriage duration.

Eravacycline: a new treatment option for complicated intra-abdominal infections in the age of multidrug resistance

Aim: Recently approved for use in complicated intra-abdominal infection, eravacycline is a novel fluorocycline with broad spectrum of activity against resistant Gram-negative pathogens. This manuscript is a pooled analysis of two Phase III trials. Clinical efficacy: Clinical cure rates were 86.8% for eravacycline versus 87.6% for ertapenem, and 90.8% for eravacycline versus 91.2% for meropenem in the Intent to Treat (micro-ITT) populations, and 87.0% for eravacycline versus 88.8% ertapenem, and 92.4 versus 91.6% for meropenem in the Modified Intent to Treat (MITT) populations. Safety: Eravacycline is well tolerated, with lower rates of nausea, vomiting and diarrhea than other tetracyclines. Conclusion: Eravacycline is an effective new option for use in complicated intra-abdominal infections, and in particular, for the treatment of extended-spectrum β-lactamase- and carbapenem-resistant Enterobacteriaceae-expressing organisms.

Reducing anastomotic leak in colorectal surgery: The old dogmas and the new challenges

Anastomotic leak (AL) constitutes a significant issue in colorectal surgery, and its incidence has remained stable over the last years. The use of intra-abdominal drain or the use of mechanical bowel preparation alone have been proven to be useless in preventing AL and should be abandoned. The role or oral antibiotics preparation regimens should be clarified and compared to other routes of administration, such as the intravenous route or enema. In parallel, preoperative antibiotherapy should aim at targeting collagenase-inducing pathogens, as identified by the microbiome analysis. AL can be further reduced by fluorescence angiography, which leads to significant intraoperative changes in surgical strategies. Implementation of fluorescence angiography should be encouraged. Progress made in AL comprehension and prevention might probably allow reducing the rate of diverting stoma and conduct to a revision of its indications.

Outcomes of extended-spectrum beta-lactamases producing Enterobacteriaceae colonization among patients abdominal surgery patients

Preoperative enteric screening for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae was conducted in 360 patients prospectively observed for surgical site infection (SSI). ESBL colonization (adjusted odds ratio [aOR], 2.4) and dirty wound classification (aOR, 3.6) were associated with SSI; no association between carbapenem prophylaxis and reduction in SSI was detected.

Active surveillance culture program in asymptomatic patients as a strategy to control multidrug-resistant gram-negative organisms: What should be considered?

The increasing burden of multidrug-resistant gram-negative bacilli (MDR-GNB) infection has highlighted the urgent requirement for efficient prevention and control strategies. A routine active surveillance culture (ASC) program of asymptomatic carriers as part of an infection prevention strategy for MDR-GNB still has some controversy. An ASC program for colonized patients may be beneficial depending on the targeted population, level of endemicity, the species of pathogen, and the combination of multifaceted strategies. Multimodal infection control and prevention strategies are crucial for implementation in resources-limited settings. After discovering the culprit, it is a challenge to control MDR-GNB by containment or eradication and prevent cross-transmission. An ASC program should consider both the local epidemiology and cost-effectiveness based on the available resources in endemic MDR-GNB areas in the Asia-Pacific region.

Strategies for the eradication of extended-spectrum beta-lactamase or carbapenemase-producing Enterobacteriaceae intestinal carriage

Introduction: Among the multidrug resistant pathogens, extended-spectrum beta-lactamase (ESBL-E) or carbapenemase-producing Enterobacteriaceae (CPE) are currently considered the main threat due to the scarcity of therapeutic options and their rapid spread around the globe. In addition to developing new antibiotics and stopping transmission, recent research has focused on 'decolonization' strategies to eradicate the carriage of ESBL-E/CPE before infection occurs. Areas covered: In this narrative review, we aim to describe the current evidence of decolonization strategies for ESBL-E or CPE intestinal carriage. We first define decolonization and highlight the issues related to the lack of standardized definitions, then we summarize the available data on the natural history of colonization. Finally, we review the strategies assessed over the past 10 years for ESBL and CPE decolonization: oral antibiotics, probiotics and more recently fecal microbiota transplantation. We conclude by presenting the risks and uncertainties associated with these strategies. Expert opinion: The evidence available today is too low to recommend decolonization strategies for ESBL-E or CPE in routine clinical practice. The potential increase of resistance and the impact of microbiome manipulation should not be underestimated. Some of these decolonization strategies may nevertheless be effective, at least in temporarily suppressing colonization, which could be useful for specific populations such as high-risk patients. Effectiveness and long-term effects must be properly assessed through well-designed randomized controlled trials.

Carrier prevalence and risk factors for colonisation of multiresistant bacteria in Danish emergency departments: a cross-sectional survey

OBJECTIVES

The aim of this study was to describe the carrier prevalence and demographic variation of four different multiresistant bacteria (MRB) among acute patients in Danish emergency departments (EDs): methicillin-resistant Staphylococcus aureus (MRSA), carbapenemase-producing enterobacteria (CPE), extended-spectrum beta-lactamase-producing enterobacteria (ESBL) and vancomycin-resistant enterococci (VRE), and to analyse the association of MRB carriage to a range of potential risk factors.

DESIGN

Multicentre descriptive and analytic cross-sectional survey.

SETTING

Eight EDs and four clinical microbiology departments in Denmark.

PARTICIPANTS

Adults visiting the ED.

MAIN OUTCOME MEASURES

Swabs from nose, throat and rectum were collected and analysed for MRSA, ESBL, VRE and CPE. The primary outcome was the prevalence of MRB carriage, and secondary outcomes relation to risk factors among ED patients.

RESULTS

We included 5117 patients in the study. Median age was 68 years (54-77) and gender was equally distributed. In total, 266 (5.2%, 95% CI 4.6 to 5.8) were colonised with at least one MRB. No significant difference was observed between male and female patients, between age groups and between university and regional hospitals. Only 5 of the 266 patients with MRB were colonised with two of the included bacteria and none with more than two. CPE prevalence was 0.1% (95% CI 0.0 to 0.2), MRSA prevalence was 0.3% (95% CI 0.2 to 0.5), VRE prevalence was 0.4% (95% CI 0.3 to 0.6) and ESBL prevalence was 4.5% (95% CI 3.9 to 5.1). Risk factors for MRB carriage were previous antibiotic treatment, previous hospital stay, having chronic respiratory infections, use of urinary catheter and travel to Asia, Oceania or Africa.

CONCLUSION

Every 20th patient arriving to a Danish ED brings MRB to the hospital. ESBL is the most common MRB in the ED. The main risk factors for MRB carriage are recent antibiotic use and travel abroad.

TRIAL REGISTRATION NUMBER

NCT03352167;Post-results.

Performance of surgical site infection risk prediction models in colorectal surgery: external validity assessment from three European national surveillance networks

OBJECTIVE

To assess the validity of multivariable models for predicting risk of surgical site infection (SSI) after colorectal surgery based on routinely collected data in national surveillance networks.

DESIGN

Retrospective analysis performed on 3 validation cohorts.

PATIENTS

Colorectal surgery patients in Switzerland, France, and England, 2007-2017.

METHODS

We determined calibration and discrimination (ie, area under the curve, AUC) of the COLA (contamination class, obesity, laparoscopy, American Society of Anesthesiologists [ASA]) multivariable risk model and the National Healthcare Safety Network (NHSN) multivariable risk model in each cohort. A new score was constructed based on multivariable analysis of the Swiss cohort following colorectal surgery, then based on colon and rectal surgery separately.

RESULTS

We included 40,813 patients who had undergone elective or emergency colorectal surgery to validate the COLA score, 45,216 patients to validate the NHSN colon and rectal surgery risk models, and 46,320 patients in the construction of a new predictive model. The COLA score's predictive ability was poor, with AUC values of 0.64 (95% confidence interval [CI], 0.63-0.65), 0.62 (95% CI, 0.58-0.67), 0.60 (95% CI, 0.58-0.61) in the Swiss, French, and English cohorts, respectively. The NHSN colon-specific model (AUC, 0.61; 95% CI, 0.61-0.62) and the rectal surgery-specific model (AUC, 0.57; 95% CI, 0.53-0.61) showed limited predictive ability. The new predictive score showed poor predictive accuracy for colorectal surgery overall (AUC, 0.65; 95% CI, 0.64-0.66), for colon surgery (AUC, 0.65; 95% CI, 0.65-0.66), and for rectal surgery (AUC, 0.63; 95% CI, 0.60-0.66).

CONCLUSION

Models based on routinely collected data in SSI surveillance networks poorly predict individual risk of SSI following colorectal surgery. Further models that include other more predictive variables could be developed and validated.

Personalized Ertapenem Prophylaxis for Carriers of Extended-spectrum β-Lactamase–producing Enterobacteriaceae Undergoing Colorectal Surgery

Background

Carriers of extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-PE) who receive cephalosporin-based prophylaxis have twice the risk of surgical site infection (SSI) following colorectal surgery as noncarriers. We tested whether ESBL-PE screening and personalized prophylaxis with ertapenem reduces SSI risk among carriers.

Methods

We conducted a prospective nonrandomized, nonblinded, interventional study in 3 hospitals in Israel, Switzerland, and Serbia. Patients were screened for ESBL-PE carriage before elective colorectal surgery. During the baseline phase, departmental guidelines advised prophylaxis with a cephalosporin plus metronidazole. In the intervention phase, guidelines were changed for ESBL-PE carriers to receive ertapenem. The primary outcome was any type of SSI within 30 days. We calculated adjusted risk differences (ARDs) following logistic regression.

Results

The intention-to-treat analysis compared 209 ESBL-PE carriers in the baseline phase to 269 in the intervention phase. SSI rates were 21.5% and 17.5%, respectively (ARD, –4.7% [95% confidence interval {CI}, –11.8% to 2.4%]). Unplanned crossover was high (15%), so to assess efficacy we performed an as-treated analysis comparing 247 patients who received cephalosporin-based prophylaxis with 221 who received ertapenem. SSI rates were 22.7% and 15.8%, respectively (ARD, –7.7% [95% CI, –14.6% to –.8%]), and rates of SSI caused by ESBL-PE were 6.5% and 0.9%, respectively (ARD, –5.6% [95% CI, –8.9% to –2.3%]). There was no significant difference in the rate of deep SSI. The number needed to treat to prevent 1 SSI in ESBL-PE carriers was 13.

Conclusions

Screening for ESBL-PE carriage before colorectal surgery and personalizing prophylaxis for carriers is efficacious in reducing SSI.