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

Analysis of rectal carbapenem-resistant Enterobactericeae colonization results first report in Istanbul/Turkiye: Klebsiella pneumoniae co-producing blaKPC + blaNDM + blaOXA-48 in a single strain

BACKGROUND

Carbapenemase-Producing Enterobacteriaceae (CPE) are known to be on the rise globally and are a major concern. Rapid screening of at-risk patients and implementation of infection control measures can prevent colonization from becoming a source of infection.

OBJECTIVE

We investigated the incidence of carbapenem-resistant Enterobacteriaceae (CRE) colonization, CRE-producing Enterobacteriaceae species, carbapenemase gene types and prevalence in patients subjected to CRE screening tests in rectal swab samples using the CHROMAgar culture method and real-time Polymerase Chain Reaction (PCR) method in a tertiary hospital in Istanbul, Turkiye. In addition, we investigated the effectiveness of diagnosis with PCR and CHROMAgar methods by examining whether meropenem-resistant infection foci developed in patients with CRE colonization from hospitalization to discharge.

MATERIALS AND METHODS

This study was conducted retrospectively in the Microbiology Laboratory of 3953 patients at Başakşehir Çam and Sakura City Hospital in Istanbul between January 2021 and December 2023. All data, including CRE colonization screening test results using CHROMAgar and PCR methods, age, gender, requesting clinic, and meropenem-resistant Enterobacteriaceae culture results in infection foci that developed during hospitalization, were obtained from the hospital automated system.

RESULTS

In all 3953 patients included in the study, CRE colonization was screened by CHROMAgar culture method on rectal swab samples and by real-time PCR method in 500 patients. The mean age of the patients was 42.9 ± 30.1 and 58.1% were male. There was no difference in age and gender distribution between the Upon admission to the hospital and during hospitalization groups (p > 0.05). Rectal CRE colonization was detected in 9.7% of all patients with the CROMAgar method and in 9.2% with the PCR method and in 16.2%. The most statistically significant increase was seen in intensive care units with the CHROMAgar method (p < 0.05). Among Enterobacteriaceae species, Klebsiella pneumoniae (69.6%) was most frequently grown, followed by Escherichia coli (13.7%). There was no statistically significant difference between the groups in terms of CRE growth status and microorganism distribution in rectal swab samples of patients during hospitalization and hospital admission (p > 0.05). Among the CRE genes detected by PCR, single genes were the most common. While OXA-48 positivity was detected in 113 (16.40%) of the patients, blaNDM was detected in 31 (4.50%), blaKPC was detected in 5 (0.73%) and bla VIM/IMP gene was detected in 5 (0.73%) of the others. Double gene positivity was observed in a single strain in 6 patients and blaKPC, blaNDM and blaOXA-48 genes were positive together in a single strain in 3 patients. Infection developed in one or more foci resistant to carbapenem in 159 of the patients colonized with CRE during their hospitalization. The rate of infection development was lower in patients colonized by PCR compared to chromogenic agar.

CONCLUSION

The CRE colonization rate is high and should be closely monitored with infection control precautions. Although the detection rate of CRE colonization was higher with PCR, the rate of progression to infection in any focus during hospitalization was found to be lower detected with the CHROMAgar method. This situation showed that rapid detection of CRE colonization with PCR, early diagnosis and isolation are important. Klebsiella pneumoniae colonization was the most common causative agent. Co-production of 3 CRE genes (blaKPC + blaNDM + blaOXA-48) in 3 patients in our hospital highlighted the importance of concerns about multi-resistant Enterobacteriaceae.

Management of multidrug-resistant gram-negative bacilli infections in adult solid organ transplant recipients: GESITRA-IC/SEIMC, CIBERINFEC, and SET recommendations update

Multidrug-resistant (MDR) Gram-negative bacilli (GNB) infections in solid organ transplant (SOT) recipients continue to pose a significant threat despite advances in diagnostics and treatments. The last international consensus guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) on the management of MDR GNB in adult solid organ transplant (SOT) recipients were published in 2018, underscoring the need for an update to incorporate recent advances, particularly the availability of new drugs that may improve the current standard of care. A working group consisting of members from the Study Group of Infection in Transplantation and Immunocompromised Hosts (GESITRA-IC) of SEIMC, the Center for Biomedical Research Network in Infectious Diseases (CIBERINFEC) and the Spanish Society of Transplantation (SET) developed consensus-based recommendations for managing MDR GNB infections during the transplant procedure. Recommendations were categorized based on evidence quality and strength, utilizing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The final recommendations were endorsed through a consensus meeting and approved by the expert panel.

The role of antimicrobial prophylaxis in brachytherapy for prostate, breast and gynaecological cancer: a narrative review

Proper antimicrobial prophylaxis is critical for reducing the risk of infection during interventional procedures. Brachytherapy, a highly effective radiation therapy for various malignancies, allows for precise radiation delivery; however, the use of foreign material as instrumentation for brachytherapy potentially increases the risk of infection. Understanding infectious complications and proper antimicrobial use in this case is essential for successful outcomes and patient safety. The aim of this review is to provide insights and summarize existing information on the infectious complications of brachytherapy in prostate, breast and gynaecological (cervical and endometrial) cancer, as well as on the potential benefit, if any, of administering antimicrobial prophylaxis. Infectious complication rates in prostate, breast and gynaecological cancer brachytherapy remain low with diverse prophylactic regimens, emphasizing the need to identify risk factors for tailored practices. The choice of the antimicrobial regimen, type of device and modality influences the probability of infectious complications. There is minimal overlap of existing brachytherapy guidelines with surgical prophylaxis guidelines. Infectious outcomes and antimicrobial resistance are underreported, and guidance for antimicrobial-resistant organisms is scarce. When indicated, prophylaxis for less than 24 h is efficient. More studies oriented towards antimicrobial prophylaxis on this specific population are needed.

The Challenge of Bacterial Infections During Intensive Care Unit Stay After Heart Transplantation

BACKGROUND

Infections occurring in the early post-heart transplant (HT) period heavily contribute to morbidity and mortality. Our goal is to evaluate the incidence of hospital-acquired pneumonia/ventilator-associated pneumonia (HAP/VAPs) and/or bloodstream infections (BSIs) after HT during the intensive care unit (ICU) stay and identify their associated risk factors in our tertiary hospital.

METHODS

Observational prospective study including all adult patients who consecutively underwent HT from January 1, 2015 to August 31, 2023 at Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. HAP/VAPs and BSIs diagnosed during ICU were included in the analysis.

RESULTS

A total of 106 patients were included, 38 of whom had at least one infectious episode (35.8%), for a total of 57 independent episodes and their incidence was 2.2 per 100 days (95% CI 1.7-2.8). Length of ICU stay was 8 days (IQR: 6-11) for patients without infectious events and 27 days (IQR 14-52) for those with infectious events (p < 0.001). Gram-negative bacteria were associated with 62.8% of BSIs (mainly Enterobacterales) and with 77.9% of HAP/VAP, in this setting Pseudomonas aeruginosa accounted for 17.6% of infections while Klebsiella spp. accounted for 22.1% of infections. Colonization with resistant bacteria (HR 2.21, 95% CI 1.12-4.35) was associated with increased risk of infections while perioperative antimicrobial prophylaxis (PAP) covering Gram-negative bacteria at transplant (HR 0.45, 95% CI 0.23-0.90, p = 0.023) was a protective factor.

CONCLUSION

This study shows that Gram-negative infections represent the major challenge for HT patients during ICU stay and shows some evidence in support of the PAP covering Gram-negative infections at transplant.

Perioperative Management During Liver Transplantation: A National Survey From the French Special Interest Group in "Liver Anesthesiology and Intensive Care"

BACKGROUND

Perioperative management practices in liver transplantation (LT) evolve very quickly. There are few specific recommendations, often based on a low level of evidence, resulting in wide heterogeneity of practices.

METHODS

We performed a survey in all 16 French centers in 2021 by focusing on center organization, preoperative cardiovascular assessment, antimicrobial prophylaxis, hemostasis management, intraoperative use of hemodynamic monitoring and renal replacement therapy, immunosuppression, and postoperative prevention of arterial complications and compared it with current recommendations.

RESULTS

The organization of perioperative LT care involved 1 single team throughout the perioperative LT process in 7 centers (43.7%). The coronary evaluation was systematic in one-third of the centers and guided by risk factors in the other centers. Antibiotic prophylaxis was strictly intraoperative in only 7 centers (44%). Antifungal prophylaxis targeting high-risk LT recipients was administered in 15 centers (93%). Intraoperative coagulation assessment was based on standard coagulation tests in 8 centers (50%), on viscoelastic assays in 4 centers (25%), and both methods in 4 centers (25%). Hemodynamic monitoring practices greatly varied between centers.Concerning immunosuppression, molecules and dosages were heterogeneous. Aspirin was systematically administered in one-third of cases (6 centers; 37.5%). Of the 21 recommendations tested, the concordance rate was 100% for 3 recommendations and <50% for 7 recommendations.

CONCLUSIONS

Our study precisely describes French practices regarding LT in perioperative care and highlights the paucity of data in this setting, leading to very weak recommendations that are poorly followed in LT centers.

A Self-Calibrating Chemiluminescence Sensor for Rapid and Precise Antibiotic Prescribing Guidelines on Urinary Tract Infections

Traditional antimicrobial-susceptibility testing methodologies, including the isolation and culture of bacteria from urine samples and antibiotic-susceptibility test (AST), are expensive and time-consuming. Therefore, a rapid, user-friendly phenotypic AST is urgently needed to guide treatment strategies. Several novel phenotypic AST platforms based on the physiological characteristics of bacteria obtained directly from clinical urine samples have been proposed as promising methods as rapid AST and appropriate antibiotic treatments. However, inaccurate bacterial quantification can lead to false results when high-accuracy quantitative assays are required using these procedures. Coupling the expression of catalase by pathogens with a chemiluminescence-based analytical method enables a convenient and low-cost operation. Herein, we demonstrate a rapid self-calibrating chemiluminescence sensor that can measure bacterial viability through the variation in catalase activity and its response to hydrogen peroxide after treatment with antibiotics. This rapid nanosensor platform can be utilized to determine the antibiotic susceptibility of uropathogenic Escherichia coli and Klebsiella pneumoniae, which account for 80% of all urinary tract infections, directly from clinical urine samples within 40 min without bacterial quantification. The proposed ultrafast and highly accurate AST can enable the precise guidance of antibiotic prescriptions and shorten the time required for clinical decision-making.

The Swiss Transplant Cohort Study: Implications for Transplant Infectious Diseases Research

The longitudinal, nationwide Swiss Transplant Cohort Study (STCS) follows > 92% of all transplant recipients with comprehensive data collection tailored to overall and organ-specific transplant outcomes. Transplant infectious disease events are assembled under the auspices of transplant ID specialists using common definitions. With over 6000 active patients and a median follow-up exceeding 6 years, the cohort offers a unique platform for understanding real-world epidemiology in transplanted patients. Beyond observational analysis, the STCS supports randomized controlled trials to address specific research questions. This overview highlights the achievements of the STCS and explores its future directions.

Cardoso F, P. Marques H. Carbapenem-Resistant Enterobacteriaceae Colonization or Infection Was Not Associated with Post-Liver Transplant Graft Failure: An Observational Cohort Study

Introduction

Carbapenem-resistant Enterobacteriaceae (CRE) epidemiology among liver transplant (LT) recipients is variable. We studied the impact of CRE colonization and infection on LT recipients' outcomes.

Methods

This observational cohort study included consecutive adult LT recipients between January 2019 and December 2020 at Curry Cabral Hospital, Lisbon, Portugal. Primary exposures were CRE colonization (rectal swabs under a screening program) and infection within 1 year of index LT. Primary endpoint was graft failure within 1 year of the index LT.

Results

Among 209 patients, the median (interquartile range [IQR]) age was 57 (47-64) years and 155 (74.2%) were male. CRE colonization was identified in 28 (13.4%) patients during the first year posttransplant (median [IQR] number of rectal swabs per patient of 4 [2-7]). CRE resistance genes identified were OXA48 in 8 (3.6%) patients, KPC in 19 (67.9%) patients, and VIM in 1 (3.6%) patient. Any bacterial/fungal and CRE infections were diagnosed in 88 (42.1%) and 6 (2.9%) patients, respectively, during the first year posttransplant. After adjusting for confounders, neither CRE colonization (aOR [95% CI] = 1.83 [0.71-4.70]; p = 0.21) nor infection (aOR [95% CI] = 1.35 [0.17-11.06]; p = 0.78) was associated with graft failure within 1 year of index LT.

Discussion/Conclusion

Under a screening program, CRE colonization and infection prevalence was low and neither was associated with graft failure.

Antibiotic duration for common bacterial infections-a systematic review

Background

Reducing antibiotic duration is a key stewardship intervention to mitigate antimicrobial resistance (AMR). We examined current evidence informing antibiotic duration for common bacterial infections to identify any gaps in terms of settings, patient populations and infectious conditions. Trial methodologies were assessed to identify areas for improvement.

Methods

MEDLINE and Embase were searched up to July 2024 for randomized trials comparing antibiotic durations in hospital and community settings (PROSPERO 2021, CRD42021276209). A narrative synthesis of the results was performed with a review on the major guidelines published by IDSA, NICE, WHO and other international societies to assess the impact of these trials on practice guidance.

Results

Out of 315 studies, 85% concluded equivalence or non-inferiority of shorter courses. Adult bacterial sinusitis, community-acquired pneumonia, female cystitis/pyelonephritis, uncomplicated cellulitis and intra-abdominal infection with adequate source control and perioperative prophylaxis had robust evidence supporting shorter durations. Few trials studied severe infections, such as bloodstream infections and ventilator-associated pneumonia. Twenty-three (7%) of the trials were conducted in intensive care settings and only 43 trials (14%) enrolled patients from low-to-middle- or low-income countries. Only 15% of studies were at low risk for bias.

Conclusions

Reducing antibiotic duration likely remains an important strategy for antibiotic stewardship, and an area of active research. While shorter antibiotic courses may be suitable for many bacterial infections, more evidence is needed for severe infections and in low- and middle-income settings.

[Importance of Hygiene for the Prevention of Antimicrobial Resistance]

In addition to antibiotic stewardship, infection prevention and control (IPC) measures at the hospital are crucial for containing antimicrobial resistance (AMR). Nosocomial infections can be prevented through the consistent application of recommended IPC measures. This reduces the use of antibiotics and therefore the development of AMR. In this way, antibiotic stewardship and IPC go hand in hand.

Synthesizing evidence to guide the design and implementation of effective strategies for discontinuing postoperative antibiotic prophylaxis in surgical settings: an umbrella review post-WHO 2018 recommendations

BACKGROUND

Postoperative antibiotic prophylaxis (PAP) involves using antibiotics after surgery to prevent surgical site infections (SSIs). However, studies have shown that PAP offers no additional benefits compared to discontinuation after surgical incision closure, prompting its de-implementation to prevent unnecessary antibiotic use that may contribute to antibiotic resistance. We conducted this review to synthesize evidence for guiding the design and implementation of effective strategies for discontinuing PAP practice and optimizing antibiotic use in surgical settings.

METHODS

This umbrella review searched for articles from PubMed/MEDLINE and Scopus, focusing on reviews conducted on human subjects on PAP to prevent SSIs, published in English language from 2019 to 5th July 2024. This review followed guidelines from PRISMA-P and PRIOR. The risk of bias (methodological quality) was assessed using AMSTAR-2. The pooled risk ratio (RR) was estimated using a fixed-effects model (Mantel-Haenszel method), while I2 was used to assess the heterogeneity between reviews. This review was registered with PROSPERO (CRD42024566124).

RESULTS

In our umbrella review, we screened 1156 articles, with 28 review articles found eligible for final analysis, involving over 457 primary studies. About 80,483 patients were involved in 9 meta-analysis reviews, which were used to estimate the pooled RR. We found no significant benefits to patients from continuing PAP beyond 24-h post-surgery compared to immediate discontinuation, RR: 1.07 (95% CI: 0.97-1.17, I2: 25%, p-value: 0.22). Strategies such as regularly assessing and refining guidelines to fit specific surgical settings and patients' characteristics, multidisciplinary collaboration, availability of resources needed for best practices, education and training healthcare workers on SSI prevention and antibiotic stewardship, and patient education in SSI prevention and proper antibiotic use were recommended to improve best practices in surgical settings.

CONCLUSIONS

Prolonging antibiotic prophylaxis beyond 24-h post-surgery did not show significant protective benefits against SSIs. Our findings support the 2018 WHO recommendation for the immediate discontinuation of PAP following surgical incision closure in clean and clean-contaminated procedures. Further de-implementation research studies are needed to guide the effective discontinuation of PAP practice.

Transcytosable and Ultrasound-Activated Liposome Enables Deep Penetration of Biofilm for Surgical Site Infection Management

Biofilm-associated surgical site infection (BSSI) is a common and grievous postoperative complication lacking effective remedies, mainly due to the poor drug accumulation and penetration in the biofilms featured by dense extracellular polymeric substances (EPSs). Here, it is found that the vascular cell adhesion molecule-1 (VCAM1) is highly overexpressed in the vascular cells of BSSI. It is proposed that the combination of VCAM1-mediated transcytosis and ultrasonic cavitation can consecutively overcome the biological barriers of vascular endothelial cells and EPS for biofilm eradication. To demonstrate the feasibility, a VCAM1-targeted and ultrasound (US)-activated liposome (LPCOTML) loaded with a reactive-oxygen-species (ROS)-responsive lipoid prodrug of oleoyl meropenem, sonosensitizer of lipoid Ce6, and perfluoropentane is developed. LPCOTML can recognize the receptors on vascular cells, and initiate receptor-mediated transcytosis for transendothelial transport into the BSSI periphery. LPCOTML subsequently transforms from nanoparticle into microbubble via liquid-gas phase transition under US irradiation, triggering strong ultrasonic cavitation to blow up the EPS and deeply penetrate the biofilms. The sonosensitizer Ce6 induces ROS production under US irradiation and triggers the release of meropenem to induce potent antibacterial effect in a BSSI model. This study presents an effective strategy to tackle the biological barriers in BSSI via combining receptor-mediated transcytosis and ultrasonic cavitation.

Role of Preoperative Multiple-Drug-Resistant Bacteria Intestinal Colonization in Cardiac Surgery: A Retrospective Study

Background/Objectives: Multiple-drug-resistant (MDR) bacteria are pathogens resistant to three or more antibiotic classes, and infection with these bacteria is associated with increased mortality, morbidity, and hospital management costs. Given the rise in antibiotic resistance, selecting appropriate antimicrobial drugs and avoiding the unnecessary use of new antibiotics are crucial. Due to their nosocomial nature, monitoring and preventing MDR infections are essential. Methods: This study enrolled patients who underwent cardiac surgery from January 2020 to May 2022. The patients included were those 18 years or older who tested positive for MDR intestinal colonization before surgery. Excluded were patients who tested positive after surgery, or were younger than 18, pregnant, or lactating. For each positive patient, the National Surgical Quality Improvement Program (NSQIP) score was calculated. The data collected included age, gender, body mass index (BMI), the type of surgery, the intensive care unit (ICU) length of stay, ICU readmission, mortality, and other infections (pneumonia, bacteremia, or surgical site infection) to establish a control group and postoperative outcome measures. Results: No statistically significant differences were found between the groups regarding the ICU length of stay, new ICU admissions, or mortality. Additionally, there were no differences in the infection rates, such as bacteremia, wound infections, and pneumonia. Conclusions: Preoperative rectal colonization by MDR bacteria does not appear to worsen postoperative outcomes for cardiac surgery patients. These findings suggest that patients with a preoperative MDR-positive rectal sample might undergo cardiac surgery without significantly increased risk. Besides the limitations of this study, pre-surgical antibiotic prophylaxis may not need to be adjusted for patients with preoperative MDR positivity.

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.

Infection Prevention and Control Strategies According to the Type of Multidrug-Resistant Bacteria and Candida auris in Intensive Care Units: A Pragmatic Resume including Pathogens R0 and a Cost-Effectiveness Analysis

Multidrug-resistant organism (MDRO) outbreaks have been steadily increasing in intensive care units (ICUs). Still, healthcare institutions and workers (HCWs) have not reached unanimity on how and when to implement infection prevention and control (IPC) strategies. We aimed to provide a pragmatic physician practice-oriented resume of strategies towards different MDRO outbreaks in ICUs. We performed a narrative review on IPC in ICUs, investigating patient-to-staff ratios; education, isolation, decolonization, screening, and hygiene practices; outbreak reporting; cost-effectiveness; reproduction numbers (R0); and future perspectives. The most effective IPC strategy remains unknown. Most studies focus on a specific pathogen or disease, making the clinician lose sight of the big picture. IPC strategies have proven their cost-effectiveness regardless of typology, country, and pathogen. A standardized, universal, pragmatic protocol for HCW education should be elaborated. Likewise, the elaboration of a rapid outbreak recognition tool (i.e., an easy-to-use mathematical model) would improve early diagnosis and prevent spreading. Further studies are needed to express views in favor or against MDRO decolonization. New promising strategies are emerging and need to be tested in the field. The lack of IPC strategy application has made and still makes ICUs major MDRO reservoirs in the community. In a not-too-distant future, genetic engineering and phage therapies could represent a plot twist in MDRO IPC strategies.

Efficacy and Safety of Oral Neomycin for the Decolonization of Carbapenem-Resistant Enterobacterales: An Open-Label Randomized Controlled Trial

BACKGROUND

Patients with carbapenem-resistant Enterobacterales (CRE) in the gastrointestinal (GI) tract are at risk for subsequent infections and transmission, necessitating contact precautions. Neomycin has shown in vitro activity against CRE in 66-85% of isolates. This study evaluated the efficacy and safety of neomycin for CRE decolonization.

METHODS

In this open-label randomized controlled trial, stool/rectal swab samples from high-risk patients were collected and tested for CRE colonization in the GI tract. Patients who had CRE and met eligible criteria were divided into a neomycin group (n = 26; treated with 4.2 g/day neomycin for 5 days) and a control group (n = 26). CRE detection in stool/rectal swabs was performed on days 7 ± 2 and 14 ± 2.

RESULTS

The two groups' baseline characteristics were similar. CRE presence on day 7 ± 2 was significantly lower in the neomycin group (46.2%) than in the control group (80.8%, p = 0.01). Efficacy of neomycin (4.2 g/day for 5 days) for CRE decolonization was 42.8-53.8% by day 7. By day 14 ± 2, the CRE rate in the neomycin group had risen to align with the control group's rate (73.1% vs. 61.5%, p = 0.56). The neomycin group experienced mild, temporary, gastrointestinal side-effects.

CONCLUSIONS

Neomycin effectively reduced CRE colonization on day 7 ± 2, but its impact waned by day 14 ± 2. This suggests that neomycin dosage was too low and the duration of treatment was too short for lasting CRE decolonization.

Within-host transition to GES-55 during a GES-6-producing Serratia marcescens outbreak: Emergence of ceftazidime-avibactam resistance and increased susceptibility to carbapenems

OBJECTIVES

To describe the in vivo emergence of ceftazidime-avibactam resistance in GES-type carbapenemases and to characterize an unusual outbreak of GES-6-producing Serratia marcescens during the COVID-19 pandemic in Spain.

METHODS

Retrospective study to describe a GES-CPSM outbreak based on whole genome sequencing and antimicrobial susceptibility testing (AST). Transferability of blaGES-carrying plasmid was assessed by conjugation experiments.

RESULTS

In December 2020, we identified a cluster of S. marcescens harbouring blaGES-6 involving 9 patients. Whole-genome sequence analysis revealed a clonal relationship (≤3 SNPs) between the first isolates identified in each of the evolved patients and environmental samples with GES-CPSM detection. Plasmid analysis showed that the blaGES-6 gene was located in an IncQ3-type plasmid. Triparental mating experiments using a helper plasmid demonstrated mobilization of the blaGES-6-carrying plasmid. Our results also demonstrate within-host evolution in S. marcescens isolates, leading to a transition from blaGES-6 to the new blaGES-55, caused by the P162S mutation, in a subsequent infection in one of the affected patients. In blaGES-55 we identified emergence of ceftazidime-avibactam resistance along with an increase of carbapenems susceptibility. This patient had been treated with a 14-day course of ceftazidime-avibactam. AST of the transformants bearing blaGES-6 and blaGES-55 plasmids, confirmed susceptibility variation affecting ceftazidime-avibactam and carbapenems.

CONCLUSIONS

We report an unusual outbreak of GES-6 whose incidence is becoming increasing. Transition from GES-6 to GES-55 may readily occur in vivo leading to ceftazidime-avibactam resistance, which brings to the fore the critical need for developing more accurate diagnosis tools for detection of GES β-lactamases and optimise the use of antimicrobials.

Infections in cirrhosis

Cirrhosis is an immune dysfunction state, and as such, patients with cirrhosis are susceptible to bacterial, fungal, and viral infections. Because of infection, these patients have a propensity to develop multiorgan failure, which is associated with high mortality. Bacterial infections are the most prevalent type of infection in patients with cirrhosis, with the prevalence of bacterial infections in patients admitted for an acute decompensating event ranging from 24% to 29%. Together with invasive fungal infections, bacterial infections are the most severe. Multidrug-resistant organisms have been evolving at a rapid and alarming rate around the world, which presents enormous challenges. The development of effective measures for the prevention, early detection, and treatment of infections in patients with cirrhosis is challenging, given the rising incidence of infections in this patient population.

Aerosol-Mediated Spread of Antibiotic Resistance Genes: Biomonitoring Indoor and Outdoor Environments

Antimicrobial resistance (AMR) has emerged as a conspicuous global public health threat. The World Health Organization (WHO) has launched the "One-Health" approach, which encourages the assessment of antibiotic resistance genes (ARGs) within an environment to constrain and alleviate the development of AMR. The prolonged use and overuse of antibiotics in treating human and veterinary illnesses, and the inability of wastewater treatment plants to remove them have resulted in elevated concentrations of these metabolites in the surroundings. Microbes residing within these settings acquire resistance under selective pressure and circulate between the air-land interface. Initial evidence on the indoor environments of wastewater treatment plants, hospitals, and livestock-rearing facilities as channels of AMR has been documented. Long- and short-range transport in a downwind direction disseminate aerosols within urban communities. Inhalation of such aerosols poses a considerable occupational and public health risk. The horizontal gene transfer (HGT) is another plausible route of AMR spread. The characterization of ARGs in the atmosphere therefore calls for cutting-edge research. In the present review, we provide a succinct summary of the studies that demonstrated aerosols as a media of AMR transport in the atmosphere, strengthening the need to biomonitor these pernicious pollutants. This review will be a useful resource for environmental researchers, healthcare practitioners, and policymakers to issue related health advisories.

A Digital Approach to Improve Infection Screening Among Solid Organ Transplant Candidates

BACKGROUND

Pretransplant infection screening (IS) of potential organ recipients is essential to optimal outcome of solid organ transplantation (SOT).

METHODS

A pre-post study was performed during 2020-2023 to investigate the impact of the STREAM (Solid organ TRansplant stEwArdship and Multidisciplinary approach) intervention to improve IS in SOT. The intervention, performed in 2022, included the implementation of IS through educational meetings, local guidelines, and the availability of a digital screening tool. The objective of the study was the assessment of IS completion, including a list of 17 laboratory tests and the investigation of vaccination status. The reduction of unnecessary tests was also analyzed. The test of proportions and a multilevel multivariate Poisson regression model were used to compare IS completion before and after STREAM. infectious diseases (ID) consultation and urgent evaluation were investigated as predictors of IS completion.

RESULTS

A total of 171 patients were enrolled, including liver (44%), heart (32%), and kidney (24%) transplant candidates. Mean age was 56 ± 11 years, and most patients (77%) were males. Ninety-five (56%) patients were included before the intervention and 76 (44%) after STREAM. IS completion increased after STREAM (IRR 1.41, p < 0.001) with significant improvement recorded for seven (39%) IS items. Unnecessary tests decreased by 43% after the intervention. ID consultation (IRR 1.13, p = 0.02) and urgent evaluation (p = 0.68, p < 0.001) were predictors of IS improvement.

CONCLUSIONS

STREAM was successful in improving IS completion. Further research is needed to investigate the impact of this intervention on posttransplant infections.

Burden and Management of Multi-Drug Resistant Organism Infections in Solid Organ Transplant Recipients Across the World: A Narrative Review

Solid organ transplant (SOT) recipients are particularly susceptible to infections caused by multidrug-resistant organisms (MDRO) and are often the first to be affected by an emerging resistant pathogen. Unfortunately, their prevalence and impact on morbidity and mortality according to the type of graft is not systematically reported from high-as well as from low and middle-income countries (HIC and LMIC). Thus, epidemiology on MDRO in SOT recipients could be subjected to reporting bias. In addition, screening practices and diagnostic resources may vary between countries, as well as the availability of new drugs. In this review, we aimed to depict the burden of main Gram-negative MDRO in SOT patients across HIC and LMIC and to provide an overview of current diagnostic and therapeutic resources.

Pharmacokinetics, tissue distribution, bioavailability and excretion of the anti-virulence drug Fluorothiazinon in rats and rabbits

Growing antimicrobial resistance has accelerated the development of anti-virulence drugs to suppress bacterial toxicity without affecting cell viability. Fluorothiazinon (FT), an anti-virulence, type three secretion system and flagella motility inhibitor which has shown promise to suppress drug-resistant pathogens having the potential to enhance the efficacy of commonly prescribed antibiotics when used in combination. In this study we characterized the pharmacokinetics, tissue distribution, bioavailability and excretion of FT in rats and rabbits. FT presented a dose-proportional linear increase in the blood of rats. Tissue distribution profiling confirmed that FT distributes to all organs being substantially higher than in the blood of rats. The bioavailability of FT was higher when administered with starch than with water implying FT should be ideally dosed with food. FT was primarily excreted in the feces in rats and rabbits while negligible amounts are recovered from the urine.

Risk Factors for Surgical-site Infections After Liver Transplant: Does Perioperative Antibiotic Regimen Matter?

BACKGROUND

Surgical-site infections (SSIs) are common in liver transplant recipients. The optimal SSI antimicrobial prophylaxis agent and duration are not established. We aimed to explore risk factors for SSIs after transplant, with a particular interest in the impact of perioperative antibiotic regimen on the development of SSIs.

METHODS

Retrospective study of adults undergoing liver transplant across 3 transplant programs between January 1, 2020, and June 01, 2021.

RESULTS

Of 557 patients included in the study, 32 (5.7%) were infected or colonized with a multidrug-resistant organism (MDRO) within 1 y before liver transplant. Narrow-spectrum SSI prophylaxis with ceftriaxone or cefazolin alone was administered in 488 of 577 patients (87.6%); the remaining 69 patients (12.4%) received broad-spectrum prophylaxis with vancomycin and aztreonam (n = 40), piperacillin-tazobactam (n = 11), carbapenems (n = 8), ceftriaxone and another antibiotic (n = 7), and others. Patients with pretransplant MDRO were more likely to receive broad-spectrum coverage than those without pretransplant MDROs (28.1% versus 11.4%, P  = 0.005). SSIs were identified in 40 patients (7.2%); 25 (62.5%) were organ-space infections, 3 (7.5%) were deep incisional infections, and 12 (30.0%) were superficial incisional infections. The median time from liver transplant to SSIs was 14 d (interquartile range, 10-20.2). MDROs were identified in 12 SSIs (30%). Multivariable analysis revealed no significant association between antimicrobial spectrum and risk of SSIs ( P  = 0.5), whereas surgical leak ( P <0.001) and reoperation ( P  = 0.017) were independently associated with increased risk of SSIs. SSIs were not significantly associated with composite risk of death or liver allograft failure.

CONCLUSIONS

The spectrum of antimicrobial prophylaxis did not impact the development of SSIs in liver transplant recipients.

Perioperative Antibiotic Prophylaxis—Indications and Modalities for the Prevention of Postoperative Wound Infection

BACKGROUND

Postoperative surgical site infections (SSI) account for almost 25% of all nosocomial infections in Germany and are a source of increased morbidity and mortality.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed and on national and international guidelines.

RESULTS

The individual risk factors for SSI must be assessed before any surgical procedure. A body-mass index above 30 kg/m2 is associated with an unadjusted risk ratio of 1.35 [1.28; 1.41] for SSI, which rises to 3.29 [2.99; 3.62] if the patient is also immunosuppressed. The risk of SSI is also significantly higher with certain types of procedure. Perioperative antibiotic prophylaxis (PAP) is clearly indicated for operations that carry a high risk of SSI (e.g., colorectal surgery) and for those that involve the implantation of alloplastic material (e.g., hip endoprostheses). PAP can usually be administered with basic antibiotics such as cefazoline. The basic principles of PAP are that it should be given by the anesthesia team in the interval from 60 minutes preoperatively up to shortly before the incision, and that its administration should only be for a short period of time, usually as a single shot. Continuing PAP onward into the postoperative period leads to increased toxicity, bacterial superinfections, and antibiotic resistance.

CONCLUSION

The evidence shows that perioperative antibiotic prophylaxis is a component of a bundle of measures that can help prevent SSI. Strict indications and adherence to the basic principles of PAP are essential for therapeutic success.

Antibiotic Stewardship in Surgical Departments

Antimicrobial resistance (AMR) has emerged as one of the leading public health threats of the 21st century. New evidence underscores its significance in patients' morbidity and mortality, length of stay, as well as healthcare costs. Globally, the factors that contribute to antimicrobial resistance include social and economic determinants, healthcare governance, and environmental interactions with impact on humans, plants, and animals. Antimicrobial stewardship (AS) programs have historically overlooked surgical teams as they considered them more difficult to engage. This review aims to summarize the evolution and significance of AS in surgical wards, including the surgical intensive care unit (SICU) and the role of diagnostic stewardship (DS). The contribution of AS team members is presented. The new diagnostic modalities and the new technologies including artificial intelligence (AI) are also reviewed.

Survey on the approach to antibiotic prophylaxis in liver and kidney transplant recipients colonized with "difficult to treat" Gram-negative bacteria

BACKGROUND

Performance of active screening for multidrug-resistant Gram-negative bacteria (MDR-GNB) and administration of targeted antibiotic prophylaxis (TAP) in colonized patients undergoing liver (LT) and/or kidney transplantation (KT) are controversial issues.

METHODS

Self-administered electronic cross-sectional survey disseminated from January to February 2022. Questionnaire consisted of four parts: hospital/transplant program characteristics, standard screening and antibiotic prophylaxis, clinical vignettes asking for TAP in patients undergoing LT and KT with prior infection/colonization with four different MDR-GNB (extended-spectrum cephalosporin-resistant Enterobacterales [ESCR-E], carbapenem-resistant Enterobacterales [CRE], multidrug-resistant Pseudomonas aeruginosa [MDR-Pa], and carbapenem-resistant Acinetobacter baumannii [CRAb]).

RESULTS

Fifty-five respondents participated from 14 countries, mostly infectious disease specialists (69%) with active transplant programs (>100 procedures/year for 34.5% KT and 23.6% LT), and heterogeneous local MDR-GNB prevalence from <15% (30.9%), 15%-30% (43.6%) to >30% (16.4%). The frequency of screening for ESCR-E, CRE, MDR-Pa, and CRAb was 22%, 54%, 17%, and 24% for LT, respectively, and 18%, 36%, 16%, and 11% for KT. Screening time-points were mainly at transplantation 100%, only one-third following transplantation. Screening was always based on rectal swab cultures (100%); multi-site sampling was reported in 40% of KT and 35% of LT. In LT clinical cases, 84%, 58%, 84%, and 40% of respondents reported TAP for prior infection/colonization with ESCR-E, CRE, MDR-Pa, and CRAb, respectively. In KT clinical cases, 55%, 39%, 87%, and 42% of respondents reported TAP use for prior infection/colonization with ESCR-E, CRE, MDR-Pa, and CRAb, respectively.

CONCLUSION

There is a large heterogeneity in screening and management of MDR-GNB carriage in LT and KT.

Perioperative daptomycin for prophylaxis of vancomycin-resistant Enterococcus infection in colonized liver transplant recipients

BACKGROUND

Infection with vancomycin-resistant Enterococcus (VRE) in liver transplant recipients (LTR) has been associated with extended hospital stays, increased readmission rates, graft failure, and death. A tailored perioperative surgical prophylaxis regimen targeting VRE may reduce postoperative infections in VRE-colonized patients. This study investigated the outcomes of perioperative daptomycin in this patient population.

METHODS

This retrospective, single-center cohort study included LTR ≥ 18 years old who were VRE-colonized from June 2018 to November 2022. VRE colonization was identified by a VRE rectal swab screen or a positive VRE culture prior to transplant. Two groups were analyzed: daptomycin versus no daptomycin. All LTR received perioperative piperacillin-tazobactam for 24 h. If VRE-colonized, one dose of daptomycin (6 mg/kg) was given pre- and postoperatively. Demographics, clinical characteristics, risk factors for VRE infection, and daptomycin dose were collected. The primary outcome was VRE infection at 14 days and 90 days post-transplant.

RESULTS

There were 36 VRE-colonized LTR; 19 received daptomycin and 17 did not. Baseline characteristics and risk factors for VRE infection were similar between groups. More VRE infections occurred in the no daptomycin group within 14 days post-transplant (24% vs. 0%, p = .04), but at 90 days posttransplant there was no significant difference (29% vs. 16%, p = .43). The average daptomycin dose was 7.1 mg/kg.

CONCLUSION

Perioperative daptomycin reduced the rate of VRE infections in VRE-colonized LTR within 14 days posttransplant but not at 90 days. Future studies should evaluate if higher doses and/or longer duration of perioperative daptomycin can reduce VRE infections beyond 14 days post-transplant.

Surgical Antibiotic Prophylaxis: A Proposal for a Global Evidence-Based Bundle

In the multimodal strategy context, to implement healthcare-associated infection prevention, bundles are one of the most commonly used methods to adapt guidelines in the local context and transfer best practices into routine clinical care. One of the most important measures to prevent surgical site infections is surgical antibiotic prophylaxis (SAP). This narrative review aims to present a bundle for the correct SAP administration and evaluate the evidence supporting it. Surgical site infection (SSI) prevention guidelines published by the WHO, CDC, NICE, and SHEA/IDSA/APIC/AHA, and the clinical practice guidelines for SAP by ASHP/IDSA/SIS/SHEA, were reviewed. Subsequently, comprehensive searches were also conducted using the PubMed®/MEDLINE and Google Scholar databases, in order to identify further supporting evidence-based documentation. The bundle includes five different measures that may affect proper SAP administration. The measures included may be easily implemented in all hospitals worldwide and are based on minimal drug pharmacokinetics and pharmacodynamics knowledge, which all surgeons should know. Antibiotics for SAP should be prescribed for surgical procedures at high risk for SSIs, such as clean-contaminated and contaminated surgical procedures or for clean surgical procedures where SSIs, even if unlikely, may have devastating consequences, such as in procedures with prosthetic implants. SAP should generally be administered within 60 min before the surgical incision for most antibiotics (including cefazolin). SAP redosing is indicated for surgical procedures exceeding two antibiotic half-lives or for procedures significantly associated with blood loss. In principle, SAP should be discontinued after the surgical procedure. Hospital-based antimicrobial stewardship programmes can optimise the treatment of infections and reduce adverse events associated with antibiotics. In the context of a collaborative and interdisciplinary approach, it is essential to encourage an institutional safety culture in which surgeons are persuaded, rather than compelled, to respect antibiotic prescribing practices. In that context, the proposed bundle contains a set of evidence-based interventions for SAP administration. It is easy to apply, promotes collaboration, and includes measures that can be adequately followed and evaluated in all hospitals worldwide.

Bring it on again: antimicrobial stewardship in transplant infectious diseases: updates and new challenges

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the "shorter is better" paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for "shorter is better" and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Advancements in nanosensors for detecting pathogens in healthcare environments

ESKAPEE pathogens: where we can find them in hospital environments and how to detect them through nanotechnologies devices.

Development of phage resistance in multidrug-resistant Klebsiella pneumoniae is associated with reduced virulence: a case report of a personalised phage therapy

OBJECTIVES

Phage-resistant bacteria often emerge rapidly when performing phage therapy. However, the relationship between the emergence of phage-resistant bacteria and improvements in clinical symptoms is still poorly understood.

METHODS

An inpatient developed a pulmonary infection caused by multidrug-resistant Klebsiella pneumoniae. He received a first course of treatment with a single nebulized phage (ΦKp_GWPB35) targeted at his bacterial isolate of Kp7450. After 14 days, he received a second course of treatment with a phage cocktail (ΦKp_GWPB35+ΦKp_GWPA139). Antibiotic treatment was continued throughout the course of phage therapy. Whole-genome analysis was used to identify mutations in phage-resistant strains. Mutated genes associated with resistance were further analysed by generating knockouts of Kp7450 and by measuring phage adsorption rates of bacteria treated with proteinase K and periodate. Bacterial virulence was evaluated in mouse and zebrafish infection models.

RESULTS

Phage-resistant Klebsiella pneumoniae strains emerged after the second phage treatment. Comparative genomic analyses revealed that fabF was deleted in phage-resistant strains. The fabF knockout strain (Kp7450ΔfabF) resulted in an altered structure of lipopolysaccharide (LPS), which was identified as the host receptor for the therapeutic phages. Virulence evaluations in mice and zebrafish models showed that LPS was the main determinant of virulence in Kp7450 and alteration of LPS structure in Kp7450ΔfabF, and the bacteriophage-resistant strains reduced their virulence at cost.

DISCUSSION

This study may shed light on the mechanism by which some patients experience clinical improvement in their symptoms post phage therapy, despite the incomplete elimination of pathogenic bacteria.

[Update Perioperative Antibiotic Prophylaxis in Neonatology]

This narrative review discusses basic principles of the perioperative antibiotic prophylaxis (PAP) in premature and at term newborns and refers to some particularities concerning the indication and dosing issues. Although this is a vulnerable patient population, the spectrum of activity should not be unnecessarily broad and the regular PAP must not be prolonged beyond 24 hours.

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.

Perfusion fluid-related infections in liver transplant recipients: A 5-year, single-center, retrospective study

BACKGROUND

Perfusion fluid (PRF) is employed in liver transplantation (LTx) to maintain graft viability. Still, it represents a new potential way of infection transmission in LTx recipients (LTRs). Currently, no systematic research has investigated this topic.

METHODS

Five-year single-center retrospective study conducted on LTRs from January 2017 to December 2021. We analyzed the incidence of positive PRF culture (PRF+) and perfusion fluid-related infections (PRF-RI) and their associated factors. We also assessed 1-year mortality, both overall and infection-related.

RESULTS

Overall, 234 LTx were included. PRF+ were found in 31/234 (13.2%) LTx for a total of 37 isolates, with >1 isolate identified in 5 (2.1%) cases. High-risk microorganisms (Enterobacterales 13/37, Enterococcus spp. 4/37, S. aureus 3/37, P. aeruginosa 2/37) were isolated in 25/37 (67.6%) LTRs, the remaining being coagulase-negative staphylococci (12/37, 32.4%). Antimicrobial prophylaxis was administered to all LTRs, always active against the isolate even if suboptimal in 19 cases (61.3%). PRF-RI developed in 4/234 LTx (1.7%), and prophylaxis was considered suboptimal in 2/4 of them. The isolation of >1 microorganism in PRF culture was associated with an increased risk of developing PRF-RI (OR 37.5 [95%CI 2.6-548.4], p = .01). PRF-RI were associated with longer ICU stays (p = .005) and higher 1-year mortality, both overall and related to infections (p = .001).

CONCLUSION

Despite PRF+ being infrequent, only a minority of patients develops PRF-RI. Nonetheless, once occurred, PRF-RI seems to increase morbidity and mortality rates.

Personalized infection prevention and control: a concept whose time has arrived

Personalized medicine has been progressively implemented in several diagnostic and therapeutic patients' algorithms, based on the common assumption that tailoring interventions, practices, and/or therapies to individual patients' clinical, biological, epidemiological, and genetic characteristics would optimize their effectiveness and reduce adverse effects. The potential benefit of the precision medicine approach has been recently considered for possible implementation in the field of infection prevention and control. The commentary explores available evidence and assesses possible future scenarios where, through advanced modeling approaches, we would be able to provide personalized prediction algorithms identifying at-risk patients who deserve the implementation of tailored preventive measures.

"From Nares to Wound: Exploring the mechanisms for Staphylococcal surgical site infections, implications for infection prevention"

Surgical site infections (SSIs) are important healthcare-associated infections, leading to increased morbidity and mortality, healthcare costs, and prolonged hospital stays. Staphylococcus aureus is an important and common microbial cause of SSI. Nasal carriage of S. aureus has been shown to be an important determinant for the development of SSI, and interventions aimed at eradicating preoperative nasal carriage are associated with a reduced risk of infection. Yet, it is not entirely clear how the nasally residing S. aureus causes SSI at distant body sites. In this commentary, we describe our view on how S. aureus can be transported from the nares to the incision site during surgery. In addition, we shed light on the implications of our view for infection prevention research.

High Burden of Intestinal Colonization With Antimicrobial-Resistant Bacteria in Chile: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study

BACKGROUND

Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic.

METHODS

From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive.

RESULTS

A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval [CI], 42.9-50.0), 41.2% (95% CI, 37.7-44.6), 14.5% (95% CI, 12.0-16.9), and 26.3% (95% CI, 23.2-29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4-44.6), 28.9% (95% CI, 24.2-33.6), 5.6% (95% CI, 3.2-8.0), and 4.8% (95% CI, 2.6-7.0), respectively.

CONCLUSIONS

A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

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.