Prevalence of Multidrug-Resistant Organisms and Risk Factors for Carriage among Patients Transferred from Long-Term Care Facilities

Development and validation of a novel prediction model for Carbapenem-resistant organism infection in a large-scale hospitalized patients

Carbapenem-resistant organism (CRO) are defined as gram-negative bacteria. The lack of safe and effective antibiotics has led to an increase in incidence rate. The purpose of this study is to establish and determine a risk nomogram to predict CRO infection in hospitalized patients. Hospitalized patients' information were collected from the electronic medical record system of hospital between January 2019 and December 2022. Based on the inclusion and exclusion criteria, we identified 131390 inpatients who met the criteria for this study. For the training cohort, the area under the curves (AUC) for predicting the CRO infection was 0.935. For the validation cohort, the AUC for predicting the CRO infection was 0.937. We have developed the first novel nomogram to predict CRO infection in hospitalized patients, which is reliable and high-performance. The nomogram performs well among hospitalized patients and has good predictive ability.

Trends of antimicrobial susceptibilities and multidrug-resistant colonization rate in patients transferred from long-term care facilities during 2017-2022: a cross-sectional study

BACKGROUND

With the global increase in the older population, the proportion of those receiving care in long-term care facilities (LTCFs) has also been increasing. We assessed the epidemiology, antibiotic susceptibility, and colonization status of drug-resistant organisms in patients transferred from LTCFs.

METHODS

We retrospectively reviewed the medical records of patients transferred from LTCFs between 2017 and 2022. The reasons for admission, antimicrobial susceptibility, and colonization rates of carbapenem-resistant Enterobacterales (CRE), methicillin-resistant Staphylococcus aureus (MRSA), and carbapenem-resistant Acinetobacter baumannii (CRAB) were recorded. We analyzed the susceptibility and colonization rates by year to identify trends.

RESULTS

Of the 936 patients transferred from LTCFs, 54.3% were admitted to the intensive care unit and 12.5% died. The most common reason for admission was infection (n = 573, 61.2%), followed by gastrointestinal bleeding (n = 67, 7.2%) and cerebrovascular disorder (n = 65, 6.9%). A total of 452 Enterobacterales strains were isolated, and their susceptibility rates to ciprofloxacin and cefotaxime were 33.3% and 35.6%, respectively. A total of 54.9% were extended-spectrum beta-lactamase-producing strains, and 4.9% of them were carbapenem-resistant, both of which showed an increasing trend (P = 0.024 and P < 0.001, respectively). The prevalence rates of CRE, CRAB, and MRSA colonization were 9.2%, 7.1%, and 23.1%, respectively. CRE colonization showed a significant increase (P < 0.001), with carbapenemase-producing Enterobacterales accounting for 75.9% of cases.

CONCLUSIONS

Patients transferred from LTCFs are primarily affected by infections and exhibit high resistance rates. The increasing trend in CRE colonization rates each year highlights the need for the implementation of rigorous infection control measures for effective management.

Antibiogram of Multidrug-Resistant Bacteria Based on Sepsis Onset Location in Korea: A Multicenter Cohort Study

BACKGROUND

Administration of adequate antibiotics is crucial for better outcomes in sepsis. Because no uniform tool can accurately assess the risk of multidrug-resistant (MDR) pathogens, a local antibiogram is necessary. We aimed to describe the antibiogram of MDR bacteria based on locations of sepsis onset in South Korea.

METHODS

We performed a prospective observational study of adult patients diagnosed with sepsis according to Sepsis-3 from 19 institutions (13 tertiary referral and 6 university-affiliated general hospitals) in South Korea. Patients were divided into four groups based on the respective location of sepsis onset: community, nursing home, long-term-care hospital, and hospital. Along with the antibiogram, risk factors of MDR bacteria and drug-bug match of empirical antibiotics were analyzed.

RESULTS

MDR bacteria were detected in 1,596 (22.7%) of 7,024 patients with gram-negative predominance. MDR gram-negative bacteria were more commonly detected in long-term-care hospital- (30.4%) and nursing home-acquired (26.3%) sepsis, whereas MDR gram-positive bacteria were more prevalent in hospital-acquired (10.9%) sepsis. Such findings were consistent regardless of the location and tier of hospitals throughout South Korea. Patients with long-term-care hospital-acquired sepsis had the highest risk of MDR pathogen, which was even higher than those with hospital-acquired sepsis (adjusted odds ratio, 1.42; 95% confidence interval, 1.15-1.75) after adjustment of risk factors. The drug-bug match was lowest in patients with long-term-care hospital-acquired sepsis (66.8%).

CONCLUSION

Gram-negative MDR bacteria were more common in nursing home- and long-term-care hospital-acquired sepsis, whereas gram-positive MDR bacteria were more common in hospital-acquired settings in South Korea. Patients with long-term-care hospital-acquired sepsis had the highest the risk of MDR bacteria but lowest drug-bug match of initial antibiotics. We suggest that initial antibiotics be carefully selected according to the onset location in each patient.

Clinical Risk Factors and Microbiological and Intestinal Characteristics of Carbapenemase-Producing Enterobacteriaceae Colonization and Subsequent Infection

Gastrointestinal colonization with carbapenem-resistant Enterobacteriaceae (CRE) is always a prerequisite for the development of translocated infections. Here, we sought to screen for fecal carriage of CRE and identify the risk factors for CRE colonization as well as subsequent translocated pneumonia in critically ill patients admitted to the intensive care unit (ICU) of a university hospital in China. We further focused on the intestinal flora composition and fecal metabolic profiles in CRE rectal colonization and translocated infection patients. Animal models of gastrointestinal colonization with a carbapenemase-producing Klebsiella pneumoniae (carbapenem-resistant K. pneumoniae [CRKP]) clinical isolate expressing green fluorescent protein (GFP) were established, and systemic infection was subsequently traced using an in vivo imaging system (IVIS). The intestinal barrier, inflammatory factors, and infiltrating immune cells were further investigated. In this study, we screened 54 patients hospitalized in the ICU with CRE rectal colonization, and 50% of the colonized patients developed CRE-associated pneumonia, in line with the significantly high mortality rate. Upon multivariate analysis, risk factors associated with subsequent pneumonia caused by CRE in patients with fecal colonization included enteral feeding and carbapenem exposure. Furthermore, CRKP colonization and translocated infection influenced the diversity and community composition of the intestinal microbiome. Downregulated propionate and butyrate probably play important and multiangle roles in regulating immune cell infiltration, inflammatory factor expression, and mucus and intestinal epithelial barrier integrity. Although the risk factors and intestinal biomarkers for subsequent infections among CRE-colonized patients were explored, further work is needed to elucidate the complicated mechanisms. IMPORTANCE Carbapenem-resistant Enterobacteriaceae have emerged as a major threat to modern medicine, and the spread of carbapenem-resistant Enterobacteriaceae is a clinical and public health problem. Gastrointestinal colonization by potential pathogens is always a prerequisite for the development of translocated infections, and there is a growing need to assess clinical risk factors and microbiological and intestinal characteristics to prevent the development of clinical infection by carbapenem-resistant Enterobacteriaceae.

Risk factors for colonization by carbapenemase-producing bacteria in Spanish long-term care facilities: a multicentre point-prevalence study

BACKGROUND

The emergence of carbapenemase-producing bacteria (CPB) has become a major public health concern. Long-term care facilities (LTCF) are potential reservoirs for multidrug-resistant micro-organisms (MDRO). However, data on CPB is limited. The study aims to determine the prevalence of MDRO and risk factors for CPB colonization among residents of LTCFs.

METHODS

A point-prevalence study was conducted at 14 LTCFs in Tenerife (Spain) between October 2020 and May 2021. Nasal and rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenemase-producing Enterobacterales, MDR Acinetobacter baumannii (MDR-Ab) and MDR Pseudomonas aeruginosa. Antimicrobial susceptibility testing and molecular detection of resistance genes were performed. Risk factors for colonization by carbapenemase-producing bacteria (CPB) were determined by univariate and multivariate analysis.

RESULTS

A total of 760 LTCF residents were recruited. The prevalence of colonization by CPB was 9.3% (n = 71) with the following distribution: 35 (49.3%) K. pneumoniae, 26 (36.6%) MDR-Ab, 17 (23.9%) E. coli, and 1 (1.4%) C. koseri. In addition, the prevalence of colonization by MRSA was 28.1% (n = 215) and only one case of VRE was isolated. Multivariate analysis identified male sex (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.86-3.11; P = 0.01), having a high health requirement (OR, 6.32; 95% CI, 1.91-20.92; P = 0.003) and previous hospitalization (OR, 3.60; 95% CI, 1.59-8.15 P = 0.002) as independent risk factors for CPB rectal carriage.

CONCLUSIONS

LTCFs are an important reservoir for MDRO, including CPB. We have identified some predictors of colonization by CPB, which enable a more targeted management of high-risk residents. Antimicrobial stewardship programmes and infection control preventive measures are needed to stop acquisition and transmission of MDRO.

Current Status and Prospect of Qualitative Assessment of Antibiotics Prescriptions

Identifying inappropriately prescribed antibiotics for infectious diseases by monitoring the quality of antibiotics use is essential for effective implementation of antibiotic stewardship. Qualitative assessment of the use of antibiotics has been conducted in some countries, including Korea, since the 2000s. The qualitative assessment generally involves an assessment of each component of the antibiotics prescription process, based on specific criteria. However, there is no standardized assessment method or cycle, and infectious diseases or antibiotics included in the assessments vary from country-to-country. According to the results reported in the United States, Europe, Australia, and Korea so far, approximately 20 - 55% of all antibiotics prescriptions are inappropriate. In this review, we describe the current progress in the quality assessment of the use of antibiotics on a global scale. Further, we highlight the future directions to improve antibiotic stewardship activities and the quality assessment of the use of antibiotics in Korea.

Current Status of Antibiotic Stewardship and the Role of Biomarkers in Antibiotic Stewardship Programs

The importance of antibiotic stewardship is increasingly emphasized in accordance with the increasing incidences of multidrug-resistant organisms and accompanying increases in disease burden. This review describes the obstacles in operating an antibiotic stewardship program (ASP), and whether the use of biomarkers within currently available resources can help. Surveys conducted around the world have shown that major obstacles to ASPs are shortages of time and personnel, lack of appropriate compensation for ASP operation, and lack of guidelines or appropriate manuals. Sufficient investment, such as the provision of full-time equivalent ASP practitioners, and adoption of computerized clinical decision systems are useful measures to improve ASP within an institution. However, these methods are not easy in terms of both time commitments and cost. Some biomarkers, such as C-reactive protein, procalcitonin, and presepsin are promising tools in ASP due to their utility in diagnosis and forecasting the prognosis of sepsis. Recent studies have demonstrated the usefulness of algorithmic approaches based on procalcitonin level to determine the initiation or discontinuation of antibiotics, which would be helpful in decreasing antibiotics use, resulting in more appropriate antibiotics use.

Multidrug-resistant bacteria: a national challenge requiring urgent addressal

Background: Multidrug-resistant bacterial infections are a worldwide threat owing to their increased prevalence, and poor prognosis due to inadequate antibacterial drugs.Current Concepts: Until 2019, several new antibacterial agents, targeting gram-positive bacteria—including telavancin, oritavancin, dalbavancin, ceftaroline, lefamulin, and delafloxacin—had been approved for use in the United States and Europe. Newer antibiotics targeting gram-negative bacteria include ceftazidime-avibactam, imipenem-cilastatin-relebactam, meropenem-vaborbactam, cefiderocol, eravacycline, and plazomicin. The guidance on the treatment of multidrug-resistant bacteria by the Infectious Diseases Society of America, published in February 2022, recommend the use of new antibacterial agents recently approved. However these drugs have not yet been introduced in Korea, thus impeding their prescription by physicians. Multidrug-resistant bacterial infections demonstrably contribute to a high mortality rate and socioeconomic burden.Discussion and Conclusion: Considering the societal impact of antibiotic resistance, the government should monitor and encourage antimicrobial stewardship to reduce the prevalence of multidrug-resistant bacteria, and hasten the introduction of new antibacterial agents for treating multidrug-resistant bacterial infections in Korea.

Impact of the Antimicrobial Stewardship Mandate on Multidrug-Resistant Organisms and Clostridioides difficile Infection Among Long-term Care Facility Residents

Objective To determine whether the long-term care facility (LTCF) Centers for Medicare & Medicaid Services (CMS) Antimicrobial Stewardship (AMS) mandate was associated with a change in the combined rate of LTCF-acquired multidrug-resistant organism infection or colonization (MDRO-I/C) and Clostridioides difficile infection (CDI). Design Retrospective quasi-experimental study. Setting A 233-bed community hospital. Participants LTCF residents 75 years of age and older with MDRO-I/C or CDI admitted to the hospital before the AMS mandate in 2015 through 2016 or after the mandate in 2018 through 2019. Intervention LTCF CMS AMS mandate. Main Outcomes Measures Rates of LTCF-acquired MDRO-I/C and CDI. MDRO-I/C were defined by a culture positive for methicillin-resistant Staphylococcus aureus or extended-spectrum beta-lactamase-producing Enterobacterales. CDI was defined by a positive test for C. difficile using a multistep algorithm of toxin, glutamate dehydrogenase, and nucleic acid amplification tests. These specimens must have been collected within 48 hours of hospital admission. Results There were 33 residents with either LTCF-acquired MDRO-I/C or CDI out of a total of 205 hospitalized residents with MDRO-I/C or CDI in 2015 and 2016, resulting in a rate of 16.10%. In comparison, there were 38 residents with either LTCF-acquired MDRO-I/C or CDI out of a total of 253 hospitalized residents with MDRO-I/C or CDI in 2018 and 2019 resulting in a rate of 15.02%. The difference in the combined rate of LTCF-acquired MDRO-I/C and CDI was -1.08% (P = 0.75). Conclusion The AMS mandate was not associated with a significant change in the combined rate of LTCF-acquired MDRO-I/C and CDI, suggesting a need for more robust AMS programs in LTCFs.

Epidemiological Characteristics of Carbapenemase Producing Carbapenem-Resistant Enterobacteriaceae Colonization

PURPOSE

This study identified the epidemiological characteristics, including the size and major strains, of carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) and CP-CRE-related factors by comparing the characteristics of patients in the CP-CRE and non-CP-CRE groups and the CP-CRE and non-CRE groups.

METHODS

This secondary data analysis study included 24 patients in the CP-CRE group, 113 patients in the non-CP-CRE group, and 113 in the non-CRE group. The size and type of CP-CRE were analyzed in terms of frequency and percentage, and CP-CRE risk factors were identified using multiple logistic regression analysis.

RESULTS

The rate of CP-CRE positivity among patients with CRE was 17.5%, and the most common causative organism in the CP-CRE group was Klebsiella pneumoniae (81.8%). There were no significant differences between patients in the CP-CRE and non-CP-CRE groups. When compared with the non-CRE group, the isolation of multidrug-resistant organisms except for CRE, particularly vancomycin resistant Enterococcus, was confirmed as a major risk factor.

CONCLUSION

To prevent CP-CRE acquisition, patients with multidrug-resistant organisms require treatment with more thorough adherence to CRE prevention and management guidelines.

Approaches to multidrug-resistant organism prevention and control in long-term care facilities for older people: a systematic review and meta-analysis

BACKGROUND

Despite clear evidence of benefits in acute-care hospitals, controversy over the effectiveness of IPC measures for MDROs is perceptible and evidence-based practice has not been established.

OBJECTIVE

To investigate the effects of IPC interventions on MDRO colonization and infections in LTCFs.

DATA SOURCES

Ovid MEDLINE, EMBASE, and CINAHL from inception to September 2020.

ELIGIBILITY CRITERIA

Original and peer-reviewed articles examining the post-intervention effects on MDRO colonization and infections in LTCFs.

INTERVENTIONS

(i) Horizontal interventions: administrative engagement, barrier precautions, education, environmental cleaning, hand hygiene, performance improvement, and source control; and (ii) vertical intervention: active surveillance plus decolonization.

STUDY APPRAISAL AND SYNTHESIS

We employed a random-effects meta-analysis to estimate the pooled risk ratios (pRRs) for methicillin-resistant Staphylococcus aureus (MRSA) colonization by intervention duration; and conducted subgroup analyses on different intervention components. Study quality was assessed using Cochrane risk of bias tools.

RESULTS

Of 3877 studies identified, 19 were eligible for inclusion (eight randomized controlled trials (RCTs)). Studies reported outcomes associated with MRSA (15 studies), vancomycin-resistant Enterococci (VRE) (four studies), Clostridium difficile (two studies), and Gram-negative bacteria (GNB) (two studies). Eleven studies were included in the meta-analysis. The pRRs were close to unity regardless of intervention duration (long: RR 0.81 [95% CI 0.60-1.10]; medium: RR 0.81 [95% CI 0.25-2.68]; short: RR 0.95 [95% CI 0.53-1.69]). Vertical interventions in studies with a small sample size showed significant reductions in MRSA colonization while horizontal interventions did not. All studies involving active administrative engagement reported reductions. The risk of bias was high in all but two studies.

CONCLUSIONS

Our meta-analysis did not show any beneficial effects from IPC interventions on MRSA reductions in LTCFs. Our findings highlight that the effectiveness of interventions in these facilities is likely conditional on resource availability-particularly decolonization and barrier precautions, due to their potential adverse events and uncertain effectiveness. Hence, administrative engagement is crucial for all effective IPC programmes. LTCFs should consider a pragmatic approach to reinforce standard precautions as routine practice and implement barrier precautions and decolonization to outbreak responses only.

Proteomic profiling of the endogenous peptides of MRSA and MSSA

Staphylococcus aureus is a Gram-positive bacterium that can cause diverse skin and soft tissue infections. Methicillin-resistant Staphylococcus aureus (MRSA) can cause more severe infections than methicillin-susceptible Staphylococcus aureus (MSSA). Nevertheless, the physiological and metabolic regulation of MSSA and MRSA has not been well studied. In light of the increased interest in endogenous peptides and recognition of the important roles that they play, we studied the endogenous peptidome of MSSA and MRSA. We identified 1,065 endogenous peptides, among which 435 were differentially expressed (DE), with 292 MSSA-abundant endogenous peptides and 35 MRSA-abundant endogenous peptides. MSSA-abundant endogenous peptides have significantly enriched “VXXXK” motif of at the C-terminus. MSSA-abundant endogenous peptides are involved in penicillin-binding and immune responses, whereas MRSA-abundant endogenous peptides are associated with antibiotic resistance and increased toxicity. Our characterization of the peptidome of MSSA and MRSA provides a rich resource for future studies to explore the functional regulation of drug resistance in S. aureus and may also help elucidate the mechanisms of its pathogenicity and the development of treatments.