Antimicrobial resistance and antibiotic consumption in intensive care units, Switzerland, 2009 to 2018

Clinical and Molecular Characteristics of Patients with Bloodstream Infections Caused by KPC and NDM Co-Producing Carbapenem-Resistant Klebsiella pneumoniae

Purpose

Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-β-lactamase (NDM) co-producing carbapenem-resistant Klebsiella pneumoniae (KPC-NDM-CRKP) isolates have been increasingly reported worldwide but have not yet been systematically studied. Thus, we have conducted a study to compare the risk factors, molecular characteristics, and mortality involved in clinical bloodstream infections (BSIs) caused by KPC-NDM-CRKP and KPC-CRKP strains.

Methods

A retrospective study was conducted on 231 patients with BSIs caused by CRKP at Jinling Hospital in China from January 2020 to December 2022. Antimicrobial susceptibility testing, carbapenemase genes detection and whole-genome sequencing were performed subsequently.

Results

Overall, 231 patients were included in this study: 25 patients with KPC-NDM-CRKP BSIs and 206 patients with KPC-CRKP BSIs. Multivariate analysis implicated ICU-acquired BSI, surgery within 30 days, and longer stay of hospitalization prior to CRKP isolation as independent risk factors for KPC-NDM-CRKP BSIs. The 30-day mortality rate of the KPC-NDM-CRKP BSIs group was 56% (14/25) compared with 32.5% (67/206) in the KPC-CRKP BSIs control group (P = 0.02). The ICU-acquired BSIs, APACHE II score at BSI onset, and BSIs caused by KPC-NDM-CRKP were independent predictors for 30-day mortality in patients with CRKP bacteremia. The most prevalent ST in KPC-NDM-CRKP isolates was ST11 (23/25, 92%), followed by ST15 (2/25, 8%).

Conclusion

In patients with CRKP BSIs, KPC-NDM-CRKP was associated with an excess of mortality. The likelihood that KPC-NDM-CRKP will become the next "superbug" highlights the significance of epidemiologic surveillance and clinical awareness of this pathogen.

A quasi-experimental study of a bundled diagnostic stewardship intervention for ventilator-associated pneumonia

OBJECTIVES

Diagnostic error in the use of respiratory cultures for ventilator-associated pneumonia (VAP) fuels misdiagnosis and antibiotic overuse within intensive care units. In this prospective quasi-experimental study (NCT05176353), we aimed to evaluate the safety, feasibility, and efficacy of a novel VAP-specific bundled diagnostic stewardship intervention (VAP-DSI) to mitigate VAP over-diagnosis/overtreatment.

METHODS

We developed and implemented a VAP-DSI using an interruptive clinical decision support tool and modifications to clinical laboratory workflows. Interventions included gatekeeping access to respiratory culture ordering, preferential use of non-bronchoscopic bronchoalveolar lavage for culture collection, and suppression of culture results for samples with minimal alveolar neutrophilia. Rates of adverse safety outcomes, positive respiratory cultures, and antimicrobial utilization were compared between mechanically ventilated patients (MVPs) in the 1-year post-intervention study cohort (2022-2023) and 5-year pre-intervention MVP controls (2017-2022).

RESULTS

VAP-DSI implementation did not associate with increases in adverse safety outcomes but did associate with a 20% rate reduction in positive respiratory cultures per 1000 MVP days (pre-intervention rate 127 [95% CI: 122-131], post-intervention rate 102 [95% CI: 92-112], p < 0.01). Significant reductions in broad-spectrum antibiotic days of therapy per 1000 MVP days were noted after VAP-DSI implementation (pre-intervention rate 1199 [95% CI: 1177-1205], post-intervention rate 1149 [95% CI: 1116-1184], p 0.03).

DISCUSSION

Implementation of a VAP-DSI was safe and associated with significant reductions in rates of positive respiratory cultures and broad-spectrum antimicrobial use. This innovative trial of a VAP-DSI represents a novel avenue for intensive care unit antimicrobial stewardship. Multicentre trials of VAP-DSIs are warranted.

Relationship between Antibiotic Consumption and Resistance: A Systematic Review

Background

Unreserved use of antibiotics exerted selective pressure on susceptible bacteria, resulting in the survival of resistant strains. Despite this, the relationship between antibiotic resistance (ABR) and antibiotic consumption (ABC) is rarely studied. This systematic review aims to review the relationship between ABC and ABR from 2016 to 2022.

Methods

Articles published over 7 years (2016-2022) were searched from December 23 to 31, 2022. The search strategy was developed by using keywords for ABC and ABR. From 3367 articles, 58 eligible articles were included in the final review.

Results

The pooled ABC was 948017.9 DPDs and 4108.6 DIDs where over 70% of antibiotics were from the Watch and Reserve category based on the WHO AWaRe classification. The average pooled prevalence of ABR was 38.4%. Enterococcus faecium (59.4%), A. baumannii (52.6%), and P. aeruginosa (48.6%) were the most common antibiotic-resistant bacteria. Cephalosporins (76.8%), penicillin (58.3%), and aminoglycosides (52%) were commonly involved antibiotics in ABR. The positive correlation between ABR and consumption accounted for 311 (81%). The correlation between ABR P. aeruginosa and ABC accounted for 87 (22.7%), followed by 78 (20.3%) and 77 (20.1%) for ABR E. coli and K. pneumoniae with ABCs, respectively. Consumption of carbapenems and fluoroquinolones was most commonly correlated with resistance rates of P. aeruginosa, K. pneumoniae, E. coli, and A. baumannii.

Conclusion

There is a positive correlation between ABC and the rate of ABR. The review also revealed a cross-resistance between the consumption of different antibiotics and ABR. Optimizing antibiotic therapy and reducing unnecessary ABC will prevent the emergence and spread of ABR. Thus, advocating the implementation of stewardship programs plays a pivotal role in containing ABR.

Bacteremia During the First Year After Solid Organ Transplantation: An Epidemiological Update

Background

There are limited contemporary data on the epidemiology and outcomes of bacteremia in solid organ transplant recipients (SOTr).

Methods

Using the Swiss Transplant Cohort Study registry from 2008 to 2019, we performed a retrospective nested multicenter cohort study to describe the epidemiology of bacteremia in SOTr during the first year post-transplant.

Results

Of 4383 patients, 415 (9.5%) with 557 cases of bacteremia due to 627 pathogens were identified. One-year incidence was 9.5%, 12.8%, 11.4%, 9.8%, 8.3%, and 5.9% for all, heart, liver, lung, kidney, and kidney-pancreas SOTr, respectively (P = .003). Incidence decreased during the study period (hazard ratio, 0.66; P < .001). One-year incidence due to gram-negative bacilli (GNB), gram-positive cocci (GPC), and gram-positive bacilli (GPB) was 5.62%, 2.81%, and 0.23%, respectively. Seven (of 28, 25%) Staphylococcus aureus isolates were methicillin-resistant, 2/67 (3%) enterococci were vancomycin-resistant, and 32/250 (12.8%) GNB produced extended-spectrum beta-lactamases. Risk factors for bacteremia within 1 year post-transplant included age, diabetes, cardiopulmonary diseases, surgical/medical post-transplant complications, rejection, and fungal infections. Predictors for bacteremia during the first 30 days post-transplant included surgical post-transplant complications, rejection, deceased donor, and liver and lung transplantation. Transplantation in 2014-2019, CMV donor-negative/recipient-negative serology, and cotrimoxazole Pneumocystis prophylaxis were protective against bacteremia. Thirty-day mortality in SOTr with bacteremia was 3% and did not differ by SOT type.

Conclusions

Almost 1/10 SOTr may develop bacteremia during the first year post-transplant associated with low mortality. Lower bacteremia rates have been observed since 2014 and in patients receiving cotrimoxazole prophylaxis. Variabilities in incidence, timing, and pathogen of bacteremia across different SOT types may be used to tailor prophylactic and clinical approaches.

Burden of severe infections due to carbapenem-resistant pathogens in intensive care unit

Intensive care units (ICU) for various reasons, including the increasing age of admitted patients, comorbidities, and increasingly complex surgical procedures (e.g., transplants), have become "the epicenter" of nosocomial infections, these are characterized by the presence of multidrug-resistant organisms (MDROs) as the cause of infection. Therefore, the perfect match of fragile patients and MDROs, as the cause of infection, makes ICU mortality very high. Furthermore, carbapenems were considered for years as last-resort antibiotics for the treatment of infections caused by MDROs; unfortunately, nowadays carbapenem resistance, mainly among Gram-negative pathogens, is a matter of the highest concern for worldwide public health. This comprehensive review aims to outline the problem from the intensivist's perspective, focusing on the new definition and epidemiology of the most common carbapenem-resistant MDROs (Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacterales) to emphasize the importance of the problem that must be permeating clinicians dealing with these diseases.

Hospital antibiotic consumption-an interrupted time series analysis of the early and late phases of the COVID-19 pandemic in Poland, a retrospective study

BACKGROUND

COVID-19 has been challenging for the entire healthcare system, due to the lack of sufficient treatment protocols, especially during initial phases and as regards antibiotic use. The aim of this study was to identify the trends of antimicrobial consumption in one of the largest tertiary hospitals in Poland during COVID-19.

METHODS

This is a retrospective study conducted at the University Hospital in Krakow, Poland, between Feb/Mar 2020 and Feb 2021. It included 250 patients. All included patients were hospitalized due to COVID-19 with confirmed SARS-CoV-2 infection without bacterial co-infections during the first phase of COVID-19 in Europe and following 3-month intervals: five equal groups of patients in each. COVID severity and antibiotic consumption were assessed according to WHO recommendations.

RESULTS

In total 178 (71.2%) patients received antibiotics with a incidence rate of laboratory-confirmed healthcare-associated infection (LC-HAI) was 20%. The severity of COVID-19 was mild in 40.8%, moderate in 36.8%, and severe in 22.4% cases. The ABX administration was significantly higher for intensive care unit (ICU) patients (97.7% vs. 65.7%). Length of hospital stay was extended for patients with ABX (22.3 vs. 14.4 days). In total, 3 946.87 DDDs of ABXs were used, including 1512.63 DDDs in ICU, accounting for 780.94 and 2522.73 per 1000 hospital days, respectively. The median values of antibiotic DDD were greater among patients with severe COVID-19 than others (20.92). Patients admitted at the beginning of the pandemic (Feb/Mar, May 2020) had significantly greater values of median DDDs, respectively, 25.3 and 16.0 compared to those admitted in later (Aug, Nov 2020; Feb 2021), respectively, 11.0, 11.0 and 11.2, but the proportion of patients receiving ABX therapy was lower in Feb/Mar and May 2020 (62.0 and 48.0%), whereas the highest during the late period of the pandemic, i.e., in Aug, Nov. 2020 and Feb. 2021 (78% and both 84.0%).

CONCLUSIONS

Data suggest great misuse of antibiotics without relevant data about HAIs. Almost all ICU patients received some antibiotics, which was correlated with prolonged hospitalization.

Antibiotic treatment durations for common infectious diseases in Switzerland: comparison between real-life and local and international guideline recommendations

OBJECTIVES

Shortening the duration of antibiotic therapy (DAT) for common infectious diseases may be an effective strategy to tackle antimicrobial resistance. Shorter DAT has been proven safe and effective for community-acquired pneumonia (CAP), cellulitis, and cholangitis.

METHODS

In a retrospective multicentre quality-control study, medical records of 770 patients hospitalized with CAP, cellulitis, and cholangitis at three tertiary care hospitals in Switzerland during 2017-2018 were randomly selected. Appropriateness of antibiotic treatment duration was assessed according to international and local guidelines.

RESULTS

Records of 271, 260, and 239 patients with CAP, cellulitis, and cholangitis were included, respectively. Median DAT was seven days (interquartile range [IQR] 6-9), ten days (IQR 8-13), and nine days (IQR 6-13) in CAP, cellulitis, and cholangitis, respectively. DAT longer than recommended by local and international guidelines was observed in 32% and 37% of CAP patients, 23% and 70% of cellulitis patients, and 33% and 37% of cholangitis patients, respectively. Positive blood cultures (odds ratio [OR] = 2.42 (95% confidence interval [CI] 1.33-4.34]), infectious diseases consultation (OR = 1.79 [95% CI 1.05-2.78]), impaired renal function (OR = 0.99 [95% CI 0.98-1.00] per 1 ml/min / 1.73 m² increase in estimated glomerular filtration rate) and a higher degree of inflammation on admission (OR = 1.0 [95% CI 1.001-1.005] per 10 mg/L increase in C-reactive protein) were independently associated with a DAT longer than recommended in international guidelines.

CONCLUSIONS

DAT exceeded recommendations in a significant proportion of patients with mostly community-acquired infections.

Epidemiological Characteristics and Antimicrobial Resistance Changes of Carbapenem-Resistant Klebsiella pneumoniae and Acinetobacter baumannii under the COVID-19 Outbreak: An Interrupted Time Series Analysis in a Large Teaching Hospital

Background: To investigate the epidemiological characteristics and resistance changes of carbapenem-resistant organisms (CROs) under the COVID-19 outbreak to provide evidence for precise prevention and control measures against hospital-acquired infections during the pandemic. Methods: The distribution characteristics of CROs (i.e., carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii) were analyzed by collecting the results of the antibiotic susceptibility tests of diagnostic isolates from all patients. Using interrupted time series analysis, we applied Poisson and linear segmented regression models to evaluate the effects of COVID-19 on the numbers and drug resistance of CROs. We also conducted a stratified analysis using the Cochran–Mantel–Haenszel test. Results: The resistance rate of carbapenem-resistant Acinetobacter baumannii (CRAB) was 38.73% higher after the COVID-19 outbreak compared with before (p < 0.05). In addition, the long-term effect indicated that the prevalence of CRAB had a decreasing trend (p < 0.05). However, the overall resistance rate of Klebsiella pneumoniae did not significantly change after the COVID-19 outbreak. Stratified analysis revealed that the carbapenem-resistant Klebsiella pneumoniae (CRKP) rate increased in females (OR = 1.98, p < 0.05), those over 65 years old (OR = 1.49, p < 0.05), those with sputum samples (OR = 1.40, p < 0.05), and those in the neurology group (OR = 2.14, p < 0.05). Conclusion: The COVID-19 pandemic has affected the change in nosocomial infections and resistance rates in CROs, highlighting the need for hospitals to closely monitor CROs, especially in high-risk populations and clinical departments. It is possible that lower adherence to infection control in crowded wards and staffing shortages may have contributed to this trend during the COVID-19 pandemic, which warrants further research.

The Effect of Decreased Antipseudomonal Drug Consumption on Pseudomonas aeruginosa Incidence and Antimicrobial Susceptibility Profiles over 9 Years in a Lebanese Tertiary Care Center

Pseudomonas aeruginosa (PAE) is intrinsically resistant to numerous classes of antimicrobials such as tetracycline and β-lactam antibiotics. More epidemiological surveillance studies on the antimicrobial susceptibility profiles of PAE are needed to generate clinically significant data and better guided therapeutic options. We describe and analyze in a retrospective study the epidemiologic trends of 1827 Pseudomonas spp. isolates (83.5% PAE, 16.4% Pseudomonas sp., and 0.2% Pseudomonas putida) from various clinical specimens with their resistance patterns to antimicrobial consumption at a tertiary medical center in Lebanon between January 2010 and December 2018. We report a significant drop in the incidence of PAE from sputum (p-value = 0.05), whereas bloodstream infection isolation density showed no trend over the study period. We also registered a minimal but statistically significant drop in resistance of Pseudomonas to certain antibiotics and a decrease in the consumption of antipseudomonal antibiotics (p-value < 0.001). Only 61 PAE isolates from a total of 1827 Pseudomonas cultures (3.33%) were difficult to treat, of which only one was a bacteremia. Interestingly, we found that the carbapenem susceptibility of Pseudomonas was unaffected by the decrease in their consumption. These results augur that antimicrobial pressure may not be the sole contributor to resistance emergence. Finally, antimicrobial stewardship seems to have a positive impact on nosocomial epidemiology.

Stimuli-Activable Metal-Bearing Nanomaterials and Precise On-Demand Antibacterial Strategies

Bacterial infections remain the leading cause of death worldwide today. The emergence of antibiotic resistance has urged the development of alternative antibacterial technologies to complement or replace traditional antibiotic treatments. In this regard, metal nanomaterials have attracted great attention for their controllable antibacterial functions that are less prone to resistance. This review discusses a particular family of stimuli-activable metal-bearing nanomaterials (denoted as SAMNs) and the associated on-demand antibacterial strategies. The various SAMN-enabled antibacterial strategies stem from basic light and magnet activation, with the addition of bacterial microenvironment responsiveness and/or bacteria-targeting selectivity and therefore offer higher spatiotemporal controllability. The discussion focuses on nanomaterial design principles, antibacterial mechanisms, and antibacterial performance, as well as emerging applications that desire on-demand and selective activation (i.e., medical antibacterial treatments, surface anti-biofilm, water disinfection, and wearable antibacterial materials). The review concludes with the authors' perspectives on the challenges and future directions for developing industrial translatable next-generation antibacterial strategies.

Antibiotic resistance surveillance of Klebsiella pneumoniae complex is affected by refined MALDI-TOF identification, Swiss data, 2017 to 2022

Background

Modern laboratory methods such as next generation sequencing and MALDI-TOF allow identification of novel bacterial species. This can affect surveillance of infections and antimicrobial resistance. From 2017, increasing numbers of medical microbiology laboratories in Switzerland differentiated Klebsiella variicola from Klebsiella pneumoniae complex using updated MALDI-TOF databases, whereas many laboratories still report them as K. pneumoniae or K. pneumoniae complex.

Aim

Our study explored whether separate reporting of K. variicola and the Klebsiella pneumoniae complex affected the ANRESIS surveillance database.

Methods

We analysed antibiotic susceptibility rates and specimen types of K. variicola and non-K. variicola-K. pneumoniae complex isolates reported by Swiss medical laboratories to the ANRESIS database (Swiss Centre for Antibiotic Resistance) from January 2017 to June 2022.

Results

Analysis of Swiss antimicrobial resistance data revealed increased susceptibility rates of K. variicola compared with species of the K. pneumoniae complex other than K. variicola in all six antibiotic classes tested. This can lead to underestimated resistance rates of K. pneumoniae complex in laboratories that do not specifically identify K. variicola. Furthermore, K. variicola strains were significantly more often reported from blood and primarily sterile specimens than isolates of the K. pneumoniae complex other than K. variicola, indicating increased invasiveness of K. variicola.

Conclusion

Our data suggest that refined differentiation of the K. pneumoniae complex can improve our understanding of its taxonomy, susceptibility, epidemiology and clinical significance, thus providing more precise information to clinicians and epidemiologists.

Correlation Between Individual Child-Level Antibiotic Consumption and Antibiotic-Resistant Among Commensal Escherichia coli: Results from a Cohort of Children Aged 1-3 Years in Rural Ujjain India

Background

The global expansion of antibiotic-resistant bacteria is a serious concern and is increasing worldwide in both pathogenic and commensal bacteria. The study determined the correlation between individual child-level antibiotic consumption and antibiotic resistance among the commensal Escherichia coli (E.coli) in a cohort of 125 children in rural Ujjain, India.

Methods

During a two-year period between August 2014 and September 2016, stool samples were collected at seven-time points from a cohort of 125 children; aged 1–3. A total of six colonies of E.coli per stool sample were collected for antibiotic susceptibility testing. Antibiotic consumption data was collected during the healthcare-seeking follow–up done during the same period. At each of the seven-time points correlation between antibiotic consumption (Defined Daily Dose-DDD/100 patient-days) and antibiotic resistance (number of resistant isolates) was analyzed independently using the Spearman correlation coefficient. Further, mixed-effects logistic regression models were built to study correlation between child-level consumption of penicillin with the number of E.coli isolates resistant to ampicillin, consumption of cephalosporin with resistance to cefotaxime and ceftazidime, consumption of fluoroquinolones with resistance to nalidixic acid and consumption of cotrimoxazole with resistance to cotrimoxazole.

Results

Out of 756 illness episodes reported in 125 children 42% were with antibiotic prescriptions and reported a total antibiotic consumption of 55DDD/100 patient-days. The most common antibiotics used were cefixime (J01DD08;72 DDD/100patient/days) followed by ofloxacin (J01MA01;51DDD/100patient-days), cefpodoxime (J01DD13;38DDD/100patient-days) and amoxicillin (J01CA04;28DDD/100patient-days). The highest percentage of resistance was found to the ampicillin (67%) followed by nalidixic acid (52%) and cefotaxime (44%) and when summarized, more than 90% were resistant to cefotaxime, ceftazidime, and co-trimoxazole in commensal E.coli isolates. The consumption of cephalosporins showed weak positive correlation with the resistance to cefotaxime (Coefficient±SE=0.13 ± 0.09,p<0.001).

Conclusion

Our findings showed no correlation between individual-level antibiotic consumption and resistance development in commensal E.coli in a rural community environment.

Clinical prediction models for multidrug-resistant organism colonisation or infection in critically ill patients: a systematic review protocol

INTRODUCTION

Multidrug-resistant organisms (MDROs) are pathogenic bacteria that are the leading cause of hospital-acquired infection which is associated with high morbidity and mortality rates in intensive care units, increasing hospitalisation duration and cost. Predicting the risk of MDRO colonisation or infection for critically ill patients supports clinical decision-making. Several models predicting MDRO colonisation or infection have been developed; however, owing to different disease scenarios, bacterial species and few externally validated cohorts in different prediction models; the stability and applicability of these models for MDRO colonisation or infection in critically ill patients are controversial. In addition, there are currently no standardised risk scoring systems to predict MDRO colonisation or infection in critically ill patients. The aim of this systematic review is to summarise and assess models predicting MDRO colonisation or infection in critically ill patients and to compare their predictive performance.

METHODS AND ANALYSIS

We will perform a systematic search of PubMed, Cochrane Library, CINAHL, Embase, Web of science, China National Knowledge Infrastructure and Wanfang databases to identify all studies describing the development and/or external validation of models predicting MDRO colonisation or infection in critically ill patients. Two reviewers will independently extract and review the data using the Data Extraction for Systematic Reviews of Prediction Modelling Studies checklist; they will also assess the risk of bias using the Prediction Model Risk of Bias Assessment Tool. Quantitative data on model predictive performance will be synthesised in meta-analyses, as applicable.

ETHICS AND DISSEMINATION

Ethical permissions will not be required because all data will be extracted from published studies. We intend to publish our results in peer-reviewed scientific journals and to present them at international conferences on critical care.

PROSPERO REGISTRATION NUMBER

CRD42022274175.

A Point Prevalence Survey of Healthcare-Associated Infections and Antimicrobial Use in Public Acute Care Hospitals in Crete, Greece

Background: Both healthcare-associated infections (HAIs) and antimicrobial resistance are associated with an increased length of stay and hospital costs, while they have also been linked to high morbidity and mortality rates. In 2016 and 2017, the latest point prevalence survey (PPS) of HAIs and antimicrobial use in European acute care hospitals highlighted an HAI prevalence of 6.5%, while Greece had a higher HAI prevalence of 10%. The aim of this PPS was to record the prevalence of HAIs and antimicrobial use in all eight public acute care hospitals in Crete, Greece during the COVID-19 pandemic in order to highlight the types of infections and antimicrobial practices that need to be prioritized for infection control initiatives. Methods: The PPS was conducted between 30 March and 15 April 2022, according to the ECDC standardized relevant protocol (version 5.3). Statistics were extracted using the ECDC Helics.Win.Net application (software version 4.1.0). Results: A total of 1188 patients were included. The overall point prevalence of patients with at least one HAI was 10.6%. The most frequent types of infections were pneumonia (34.3%), bloodstream infections (10.5%), systemic infections and urinary tract infections (10.5% and 9.1%, respectively). In 14 (12.4%) cases, the pathogen responsible for HAI was SARS-CoV-2 following onsite spread, accounting for almost 10% of all HAIs. Microorganisms were identified in 60.1% of HAIs. Antimicrobials were administered in 711 (59.8%) patients, with 1.59 antimicrobials used per patient. Conclusion: The prevalence of HAI and antimicrobial use among hospitalized patients in Crete, Greece was similar to the national HAI prevalence in 2016 despite the enormous pressure on public hospitals due to the COVID-19 pandemic. Nevertheless, both HAI prevalence and antimicrobial use remain high, underlining the need to implement adequate infection control and antimicrobial stewardship interventions.