Risk Factors for Recurrence of Carbapenem-Resistant Enterobacteriaceae Carriage: Case-Control Study

Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality.

AIM

To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion.

METHODS

A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN).

FINDINGS

Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae.

CONCLUSION

CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Prevalence of carbapenemase producing Enterobacterales colonization and risk factor of clinical infection

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are global concerns in infection control, and the number of CPE outbreaks in hospitals is increasing despite the strengthening of contact precautions. This study aimed to confirm the prevalence and transition rate of CPE infection from stool surveillance culture and to identify the acquisition pathway of CPE.

METHODS

This is a longitudinal review of patients with stool surveillance cultures at a tertiary center in Seoul, South Korea, from July 2018 to June 2020. Pulsed-field gel electrophoresis, multi-locus sequence typing, and whole genome sequencing were performed for carbapenemase-producing Klebsiella pneumoniae and Escherichia coli strains.

RESULTS

Among 1620 patients who had undergone stool CPE surveillance cultures, only 7.1% of active surveillance at the Emergency Room (ER) and 4.4% of universal surveillance in the Intensive Care Unit (ICU) were stool CPE positive. The transition rates from stool carriers to clinical CPE infections were 29.4% in the ER and 31.3% in the ICU. However, it was significantly high (55.0%) in the initial stool CPE-negative ICU patients. Among the initial stool CPE-positive patients, hypertension (61% vs. 92.3%, P = 0.004), malignancy (28.8% vs. 53.8%, P = 0.027), and mechanical ventilation (25.4% vs. 53.8%, P = 0.011) were significant risk factors for clinical CPE infection. Molecular typing revealed that sequence type (ST) 307 and ST 395 were dominant in K. pneumoniae, and ST 410 was dominant in E. coli isolates.

CONCLUSIONS

Active surveillance showed a higher detection rate than universal stool CPE screening, and one-third of positive stool CPE specimens ultimately developed subsquent clinical CPE infection. According to the molecular typing of the identified CPE strains, in-hospital spread prevailed over external inflow, and the transition rate to clinical CPE was particularly high in the ICU. Therefore, in order to control CPE propagation, not only active surveillance to block inflow from outside, but also continuous ICU monitoring within the hospital is necessary.

Intestinal colonization with multidrug-resistant Enterobacterales: screening, epidemiology, clinical impact, and strategies to decolonize carriers

The clinical impact of infections due to extended-spectrum β-lactamase (ESBL)- and/or carbapenemase-producing Enterobacterales (Ent) has reached dramatic levels worldwide. Infections due to these multidrug-resistant (MDR) pathogens-especially Escherichia coli and Klebsiella pneumoniae-may originate from a prior asymptomatic intestinal colonization that could also favor transmission to other subjects. It is therefore desirable that gut carriers are rapidly identified to try preventing both the occurrence of serious endogenous infections and potential transmission. Together with the infection prevention and control countermeasures, any strategy capable of effectively eradicating the MDR-Ent from the intestinal tract would be desirable. In this narrative review, we present a summary of the different aspects linked to the intestinal colonization due to MDR-Ent. In particular, culture- and molecular-based screening techniques to identify carriers, data on prevalence and risk factors in different populations, clinical impact, length of colonization, and contribution to transmission in various settings will be overviewed. We will also discuss the standard strategies (selective digestive decontamination, fecal microbiota transplant) and those still in development (bacteriophages, probiotics, microcins, and CRISPR-Cas-based) that might be used to decolonize MDR-Ent carriers.

Oral Capsulized Fecal Microbiota Transplantation for Eradication of Carbapenemase-producing Enterobacteriaceae Colonization With a Metagenomic Perspective

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) infections lead to considerable morbidity and mortality. We assessed the potential of fecal microbiota transplantation (FMT) to eradicate CPE carriage and aimed to explain failure or success through microbiome analyses.

METHODS

In this prospective cohort study, all consenting eligible CPE carriers received oral capsulized FMT for 2 days. Primary outcome was CPE eradication at 1 month, defined by 3 consecutive negative rectal swabs, the last also negative for carbapenemase gene by polymerase chain reaction. Comprehensive metagenomics analysis of the intestinal microbiome of donors and recipients before and after FMT was performed.

RESULTS

Fifteen CPE carriers received FMT, 13 of whom completed 2 days of treatment. CPE eradication at 1 month was successful in 9/15 and 9/13, respectively. Bacterial communities showed significant changes in both beta and alpha diversity metrics among participants who achieved CPE eradication that were not observed among failures. Post-FMT samples' beta-diversity clustered according to the treatment outcome, both in taxonomy and in function. We observed a significant decrease in beta diversity in participants who received post-FMT antibiotics. Enterobacteriaceae abundance decreased in post-FMT samples of the responders but increased among failures. Functionally, a clear demarcation between responders (who were similar to the donors) and failures was shown, driven by antimicrobial resistance genes.

CONCLUSIONS

Our study provides the biological explanation for the effect of FMT against CPE carriage. Decolonization of CPE by FMT is likely mediated by compositional and functional shifts in the microbiome. Thus, FMT might be an efficient strategy for sustained CPE eradication.

CLINICAL TRIALS REGISTRATION

NCT03167398.

The Israeli national policy for discontinuation of isolation of carbapenem-resistant Enterobacterales carriers by carbapenemase type: a retrospective cohort study

OBJECTIVES

The Israeli national policy for containing carbapenemase-producing Enterobacterales (CPE) includes a protocol allowing for discontinuation of carrier status following spontaneous decolonization. We examined the strategy's effectiveness based on carbapenemase type.

METHODS

We performed a retrospective cohort study comparing individuals colonized with KPC- or NDM-producing Enterobacterales who underwent the process of isolation discontinuation. The primary outcome was reversion of carrier status, i.e. re-identification of the same CPE species following isolation discontinuation. We used survival analysis to estimate overall hazard ratio and performed competing-risks analysis using a Fine-Gray subdistribution hazard model and cause-specific hazard ratios.

RESULTS

Between 1 January 2006 and 1 January 2019 we identified 1694 individuals who met inclusion criteria, including 1337 (78.9%) carriers of KPC-producing Enterobacterales, 305 (18.0%) carriers of NDM-producing Enterobacterales and 52 (3.1%) carriers of dual KPC-/NDM-producing Enterobacterales. A total of 134 individuals (7.9%) had reversion of carrier status: 9.1% (121/1337) and 4.3% (13/305) of individuals with KPC- and NDM-producing Enterobacterales, respectively. The subdistribution hazard ratio of status reversion was not increased among carriers of NDM producers compared with KPC producers (0.567, 95% CI 0.320-1.000], p 0.052). Cause-specific hazard ratios yielded similar results (0.522, 95% CI 0.291-0.937, p 0.029.

CONCLUSIONS

Carriage of NDM-producing Enterobacterales was not associated with higher rates of reversion to carrier status following spontaneous decolonization than was carriage of KPC-producing Enterobacterales.

National Policy for Carbapenem-Resistant Enterobacteriaceae (CRE) Clearance and Discontinuation of Contact Precautions for CRE Carriers in Post-Acute Care Hospitals in Israel: Impact on Isolation-Days and New Acquisitions

BACKGROUND

In 2009, the Israeli Ministry of Health implemented in post-acute care hospitals (PACHs) a process of discontinuing carbapenem-resistant Enterobacteriaceae (CRE) carrier status. We evaluated the policy's impact on isolation-days, CRE prevalence among known carriers who had completed clearance testing, and CRE acquisition among noncarriers.

METHODS

This retrospective study summarized findings from all 15 PACHs in 2009-2017. CRE carriers were considered cleared and removed from contact isolation after 2 rectal cultures negative for CRE and polymerase chain reaction negative for carbapenemases. Data sources included routine surveillance and 4 point prevalence surveys conducted from 2011 to 2017.

RESULTS

During the study period, 887 of 6101 CRE carriers (14.5%) completed clearance testing. From 2013 to 2016, the percentage of patient-days in CRE isolation decreased from 9.4% to 3.9% (P = .008). In all surveys combined, there were 819 known CRE carriers; 411 (50%) had completed clearance testing. Of these, 11.4% (47/411) were CRE positive in the survey. At the ward level, the median percentage of patients with no CRE history who were positive on survey decreased from 11.3% in 2011 to 0% in 2017 (P < .001). We found no ward-level correlation between the proportion of carriers who completed clearance and new acquisitions (ρ = 0.02, P = .86).

CONCLUSIONS

A process for discontinuing CRE carrier status in PACHs led to a significant reduction in the percentage of patient-days in contact isolation without increasing CRE acquisitions among noncarriers.

A survey of infection control strategies for carbapenem-resistant Enterobacteriaceae in Department of Veterans' Affairs facilities

A survey of Veterans' Affairs Medical Centers on control of carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-producing CRE (CP-CRE) demonstrated that most facilities use VA guidelines but few screen for CRE/CP-CRE colonization regularly or regularly communicate CRE/CP-CRE status at patient transfer. Most respondents were knowledgeable about CRE guidelines but cited lack of adequate resources.

Clinical characteristics, risk factors, and outcomes of patients hospitalized in the US military health system with carbapenem-resistant Enterobacteriaceae infection

BACKGROUND

We aimed to characterize the epidemiology, identify risk factors, and measure outcomes of carbapenem-resistant Enterobacteriaceae (CRE) infections among hospitalized patients.

METHODS

We performed a retrospective study of hospitalized patients with CRE infection using records from the US military health system database. Cases included patients admitted for ≥2 days from 2008-2015, with a clinical culture growing any Enterobacteriaceae reported as resistant to a carbapenem. Multivariable logistic regression was used to identify comorbid conditions and procedures associated with CRE infection, and a high-dimensional propensity score was used for a case-mix adjusted evaluation of CRE-associated in-hospital mortality, length of stay, and hospitalization costs.

RESULTS

From 1,162,686 hospitalized patients, we identified 143 with CRE infection over the 7-year study period. Conditions associated with CRE infection included manipulation of the gastrointestinal tract, musculoskeletal trauma, orthopedic procedures, septicemia, and both recent and remote exposure to broad-spectrum β-lactam antibiotics. Patients hospitalized with CRE infection had significantly higher hospitalization costs (attributable difference, $206,664; P < .001), longer hospital stays (attributable difference, 28.8 days; P < .001), and increased odds of in-hospital mortality (adjusted odds ratio, 3.34; 95% confidence interval, 1.82-6.12).

CONCLUSIONS

CRE are a significant threat to hospitalized patients. Our study quantifies the health care burden associated with CRE infection in the inpatient setting and highlights the importance of initiatives aimed at curbing the spread of these costly infections.

Knowing More of the Iceberg: How Detecting a Greater Proportion of Carbapenem-Resistant Enterobacteriaceae Carriers Influences Transmission

BACKGROUND

Clinical testing detects a fraction of carbapenem-resistant Enterobacteriaceae (CRE) carriers. Detecting a greater proportion could lead to increased use of infection prevention and control measures but requires resources. Therefore, it is important to understand the impact of detecting increasing proportions of CRE carriers.

METHODS

We used our Regional Healthcare Ecosystem Analyst-generated agent-based model of adult inpatient healthcare facilities in Orange County, California, to explore the impact that detecting greater proportions of carriers has on the spread of CRE.

RESULTS

Detecting and placing 1 in 9 carriers on contact precautions increased the prevalence of CRE from 0% to 8.0% countywide over 10 years. Increasing the proportion of detected carriers from 1 in 9 up to 1 in 5 yielded linear reductions in transmission; at proportions >1 in 5, reductions were greater than linear. Transmission reductions did not occur for 1, 4, or 5 years, varying by facility type. With a contact precautions effectiveness of ≤70%, the detection level yielding nonlinear reductions remained unchanged; with an effectiveness of >80%, detecting only 1 in 5 carriers garnered large reductions in the number of new CRE carriers. Trends held when CRE was already present in the region.

CONCLUSION

Although detection of all carriers provided the most benefits for preventing new CRE carriers, if this is not feasible, it may be worthwhile to aim for detecting >1 in 5 carriers.

Carbapenemase-producing Enterobacteriaceae - once positive always positive?

PURPOSE OF REVIEW

This review provides an overview of gastrointestinal tract colonization with carbapenemase-producing Enterobacteriaceae (CPE), including risk factors for colonization, determinants for duration of colonization, and whether patients can decolonize, either spontaneously or via targeted interventions.

RECENT FINDINGS

CPE colonization is disseminating globally with increasing numbers of carbapenemases being identified in increasing patient cohorts. Numerous risk factors including repeated healthcare contact, patient co-morbidities and international travel have all been linked to increased rates of colonization. Duration of colonization has been investigated in various healthcare settings and ranges many months or even years. Although new methods for expediting decolonization are being investigated, including faecal microbiota transplantation, high quality evidence of impact is lacking.

SUMMARY

Current evidence indicates that CPE colonization usually persists throughout the duration of most hospital admissions, although the majority of patients will subsequently spontaneously decolonize. Difficulties remain in determining the point at which patients can be considered decolonized because of the lack acceptable criteria for defining eradication. This has significance implications for infection prevention and control measures during the initial and subsequent hospital admissions. Strategies to reduce the healthcare burden of CPE colonization continue to rely predominantly on preventing acquisition, whereas decolonization efforts remain a focus of research.

VIM-carbapenemase-producing Escherichia coli in a residential care home in The Netherlands

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are an important and increasing threat to public health. In hospitals and long-term care facilities, carriers should be identified to prevent transmission; however, guidelines for infection control are not applicable to all types of care homes.

AIM

To report the outbreak investigation of a VIM-metallo-β-lactamase-producing Escherichia coli in a Dutch residential care home, where residents lived in private apartments but also used shared facilities.

METHODS

Contact and environmental screening rounds were performed to assess carriage and colonization rates. Due to the domestic characteristics of the home, customized infection control measures were needed. A bundle of interventions was implemented, including contact precautions, improved hygiene and education.

FINDINGS

In total, eight CPE carriers, including the index case, were identified among 110 residents. VIM-CPE spread was associated with the use of shared toilets in communal areas. Seven months after the first finding, all carriers were found to be VIM-negative, and after 1 year, VIM CPE was no longer detectable in the environment.

CONCLUSION

A customized bundled approach was needed to control the outbreak successfully. Current guidelines should be adapted to be suitable for all types of residential care homes in order to combat the spread of multi-resistant pathogens effectively.

ESCMID-EUCIC clinical guidelines on decolonization of multidrug-resistant Gram-negative bacteria carriers

SCOPE

The aim of these guidelines is to provide recommendations for decolonizing regimens targeting multidrug-resistant Gram-negative bacteria (MDR-GNB) carriers in all settings.

METHODS

These evidence-based guidelines were produced after a systematic review of published studies on decolonization interventions targeting the following MDR-GNB: third-generation cephalosporin-resistant Enterobacteriaceae (3GCephRE), carbapenem-resistant Enterobacteriaceae (CRE), aminoglycoside-resistant Enterobacteriaceae (AGRE), fluoroquinolone-resistant Enterobacteriaceae (FQRE), extremely drug-resistant Pseudomonas aeruginosa (XDRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), cotrimoxazole-resistant Stenotrophomonas maltophilia (CRSM), colistin-resistant Gram-negative organisms (CoRGNB), and pan-drug-resistant Gram-negative organisms (PDRGNB). The recommendations are grouped by MDR-GNB species. Faecal microbiota transplantation has been discussed separately. Four types of outcomes were evaluated for each target MDR-GNB:(a) microbiological outcomes (carriage and eradication rates) at treatment end and at specific post-treatment time-points; (b) clinical outcomes (attributable and all-cause mortality and infection incidence) at the same time-points and length of hospital stay; (c) epidemiological outcomes (acquisition incidence, transmission and outbreaks); and (d) adverse events of decolonization (including resistance development). The level of evidence for and strength of each recommendation were defined according to the GRADE approach. Consensus of a multidisciplinary expert panel was reached through a nominal-group technique for the final list of recommendations.

RECOMMENDATIONS

The panel does not recommend routine decolonization of 3GCephRE and CRE carriers. Evidence is currently insufficient to provide recommendations for or against any intervention in patients colonized with AGRE, CoRGNB, CRAB, CRSM, FQRE, PDRGNB and XDRPA. On the basis of the limited evidence of increased risk of CRE infections in immunocompromised carriers, the panel suggests designing high-quality prospective clinical studies to assess the risk of CRE infections in immunocompromised patients. These trials should include monitoring of development of resistance to decolonizing agents during treatment using stool cultures and antimicrobial susceptibility results according to the EUCAST clinical breakpoints.

Successful control of the first OXA-48 and/or NDM carbapenemase-producing Klebsiella pneumoniae outbreak in Slovenia 2014-2016

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) occur only sporadically in Slovenia.

AIM

To describe the first Slovenian carbapenemase-producing (CP) Klebsiella pneumoniae and Escherichia coli outbreak which occurred at the tertiary teaching hospital University Medical Centre Ljubljana from October 2014 to April 2015.

METHODS

A CPE-positive case was defined as any patient infected or colonized with CPE. A strict definition of a contact patient was adopted. Measures to prevent cross-transmission included cohorting of all CPE carriers with strict contact precautions and assignment of dedicated healthcare workers, cohorting of all contact patients until obtaining the result of screening cultures, systematic rectal screening of contact patients, and tagging of all CPE-positive cases and their contacts. Educational campaigns on CPEs were implemented. Clinical specimens were processed using standard procedures. Pulsed-field gel electrophoresis (PFGE) was used to determine relatedness. Multi-locus sequence typing was performed on CP K. pneumoniae isolates that belonged to different pulsotypes.

FINDINGS

Before the outbreak was brought under control, 40 patients were colonized or infected with OXA-48 and/or New Delhi metallo-β-lactamase (NDM)-producing CPE; in 38 patients OXA-48 and/or NDM-producing K. pneumoniae was detected, in seven OXA-48 and/or NDM-producing E. coli was found together with K. pneumoniae, and in two patients only CP E. coli was isolated. The outbreak was oligoclonal with two major CP K. pneumoniae clusters belonging to ST437 and ST147 in epidemiologically linked patients.

CONCLUSION

Initial standard control measures failed to prevent the outbreak. Once the problem had been recognized, strict infection control measures and the education of healthcare workers contributed to the successful control of the outbreak.

The Infinity War: How to Cope with Carbapenem-resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are now spread worldwide. In Korea, the number of CRE isolation is rapidly increasing, and impending endemicity is a concern. To cope well with CRE, thorough infection control, such as active surveillance, early detection, strict contact precaution, cleaning the environment, and antibiotic stewardship is very important. Therapeutic options include polymyxin, tigecycline, fosfomycin or the combination of them with carbapenem, which is currently the mainstay of treatment. In addition, various combination regimens with new carbapenemase inhibitors such as avibactam, vaborbactam, or relebactam, and other classes of antimicrobials such as plazomicin and siderophore cephalosporin are in the process of evaluation.

Epidemiology of and risk factors for infection with extended-spectrum β-lactamase-producing carbapenem-resistant Enterobacteriaceae: results of a double case-control study

Purpose

Carbapenem-resistant Enterobacteriaceae (CRE) have been increasingly reported worldwide and pose a serious public threat, but the clinical significance of extended-spectrum β-lactamase (ESBL) production in CRE is not well established.

Patients and methods

A retrospective case–case–control study was conducted to identify the clinical characteristics of patients with ESBL-CRE. The susceptibility of isolates obtained from these patients was assessed. The detection of ESBL and carbapenemase-related genes was performed by PCR methods. Predictors of 30-day mortality in patients with ESBL-CRE infection were also identified in our study.

Results

A total of 149 patients with CRE infection caused by Enterobacter cloacae (n=74), Escherichia coli (n=38), and Klebsiella pneumoniae (n=37) were identified in Chongqing, Southwestern China, between January 2011 and December 2014. Of the 35 isolates detected with carbapenemase-related genes, 16 isolates had New Delhi metallo-β-lactamase (NDM), nine isolates had K. pneumoniae carbapenemase (KPC), seven isolates had imipenemase (IMP), and four isolates had oxacillinase (OXA)-1. One strain of enterobacter cloacae carried both NDM-1 and IMP-8 genes. ESBL isolates included the genes CTX-M (72/149), SHV (64/149), and TEM (54/149). All ESBL-CRE isolates exhibited ertapenem resistance, and the rate of cephalosporin resistance was relatively high in general. Independent risk factors for infection with ESBL-CRE included previous exposure to β-lactam antibiotics, transfer from another hospital, and some underlying diseases. In addition, solid tumors, hypoalbuminemia, and central venous catheters were independent predictors of mortality in patients with ESBL-CRE infection.

Conclusion

Physicians should understand the peculiar predictors for the identification of these organisms among high-risk patients.

Course of colonization by multidrug-resistant organisms after allogeneic hematopoietic cell transplantation

Multidrug-resistant organisms (MDRO) have been developing as an emerging problem in allogeneic hematopoietic cell transplantation (HCT). Since no data are available on the course of MDRO colonization after HCT, we investigated in this retrospective, single-center study, persistence and clearance of MDRO after HCT. From June 2010 to December 2015, 121 consecutive HCT patients were included. Patients received a MDRO screening before conditioning as well as surveillance cultures after HCT. In MDRO-colonized patients, surveillance specimens were taken until MDRO were no longer detectable. Thirty-three patients (27%) were found to be colonized by at least one MDRO at any time point until day 100 post HCT. Day 100 (2-year) non-relapse mortality (NRM) and overall survival (OS) of MDRO-colonized (MDRO⁺) versus non-colonized (MDRO^-) patients were essentially the same. NRM is 15% (21%) versus 15% (24%). Two-year OS is 60 versus 55% for MDRO⁺ versus MDRO^- patients. Out of the 33 MDRO⁺ patients, 21 cleared the MDRO. Median time to non-detectability of MDRO was 6 months. In 12 patients, the MDRO persisted. There was a significant (p < 0.0001) survival difference between patients who cleared the MDRO versus those with MDRO persistence (2-year OS 80 vs 40%). Except for the length of antibiotic therapy as a potential risk factor for MDRO persistence after HCT, no other conventional factors could be identified. (a) colonization by MDRO per se had no negative impact on the outcome, (b) MDRO can be cleared by the majority of patients after allogeneic HCT, and (c) to increase the probability to clear MDRO, the use of antibiotics in MDRO⁺ patients should be reviewed critically.

Risk factors for fecal carriage of IMP-6-producing Enterobacteriaceae at a long-term care hospital in Japan: A follow-up report from the northern Osaka multicentre study group

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing at medical institutions in Japan without even noticing. Recently, we performed a point prevalence survey for CRE carriage at a medical facility in northern Osaka that demonstrated an unexpectedly high prevalence of bla_IMP-6-positive CRE, particularly at long-term care hospitals (LTCH). To identify the risk factors for CRE carriage, we collected clinical data of patients at a representative LTCH. Of 140 patients who were included in this study, 27 (19.3%) were colonized with metallo-beta-lactamase (IMP-6) producers. Pulsed-field gel electrophoresis of the IMP-6 producing Enterobacteriaceae suggested a non-clonal transmission of Escherichia coli, while a clonal spread was shown for Klebsiella pneumoniae. Risk factors for CRE colonization were a longer stay at the hospital stay and a lower independence state, as measured by Norton scales. We propose that a paradigm shift in infection control, inciting a coordinated regional effort to involve LTCHs, should be discussed in the aging society of Japan.

Reducing the impact of carbapenem-resistant Enterobacteriaceae on vulnerable patient groups: what can be done?

PURPOSE OF REVIEW

Carbapenem-resistant Enterobacteriaceae (CRE) is a worldwide challenge and associated with a high mortality rate in critically ill patients. This review focused on rapid diagnosis, optimization of antimicrobial therapy, and implication of effective infection control precautions to reduce impact of CRE on vulnerable patients.

RECENT FINDINGS

Several new diagnostic assays have recently been described for the early diagnosis of CRE. Retrospective studies are supportive for colistin plus meropenem combination for the treatment of CRE infections; however, solid evidence is still lacking. Ceftazidime-avibactam may be an effective therapeutic agent for infections caused by carbapenem-hydrolyzing oxacillinase-48 and Klebsiella pneumoniae carbapenamase-producing Enterobacteriaceae, but not for New Delhi metallo-β-lactamase producers. Gastrointestinal screening may permit early identification of patients with CRE infections. There is not enough evidence to recommend selective digestive decontamination for CRE carriers.

SUMMARY

The information for rapid diagnosis of CRE is accumulating. There are new agents with high in-vitro activity against CRE, but clinical experience is limited to case reports. Active surveillance with a high rate of compliance to basic infection control precautions seems to be the best approach to reduce the impact of CRE on vulnerable patients.

Israeli National Policy for Carbapenem-Resistant Enterobacteriaceae Screening, Carrier Isolation and Discontinuation of Isolation

Since 2006, Israel has been confronting an outbreak of carbapenem-resistant Enterobacteriaceae (CRE), and in 2007 Israel implemented a national strategy to contain spread. The intervention was initially directed toward acute-care hospitals and later expanded to include an established reservoir of carriage in long-term-care hospitals. It included regular reporting of CRE cases to a central registry and daily oversight of management of the outbreak at the institutional level. Microbiological methodologies were standardized in clinical laboratories nationwide. Uniform requirements for carrier screening and isolation were established, and a protocol for discontinuation of carrier status was formulated. In response to the evolving epidemiology of CRE in Israel and the continued need for uniform guidelines for carrier detection and isolation, the Ministry of Health in 2016 issued a regulatory circular updating the requirements for CRE screening, laboratory diagnosis, molecular characterization, and carrier isolation, as well as reporting and discontinuation of isolation in healthcare institutions nationwide. The principal elements of the circular are contained herein. Infect Control Hosp Epidemiol 2018;39:85-89.

Infection prevention and control measures and tools for the prevention of entry of carbapenem-resistant Enterobacteriaceae into healthcare settings: guidance from the European Centre for Disease Prevention and Control

Background

Infections with carbapenem-resistant Enterobacteriaceae (CRE) are increasingly being reported from patients in healthcare settings. They are associated with high patient morbidity, attributable mortality and hospital costs. Patients who are “at-risk” may be carriers of these multidrug-resistant Enterobacteriaceae (MDR-E).

The purpose of this guidance is to raise awareness and identify the “at-risk” patient when admitted to a healthcare setting and to outline effective infection prevention and control measures to halt the entry and spread of CRE.

Methods

The guidance was created by a group of experts who were functioning independently of their organisations, during two meetings hosted by the European Centre for Disease Prevention and Control. A list of epidemiological risk factors placing patients “at-risk” for carriage with CRE was created by the experts. The conclusions of a systematic review on the prevention of spread of CRE, with the addition of expert opinion, were used to construct lists of core and supplemental infection prevention and control measures to be implemented for “at-risk” patients upon admission to healthcare settings.

Results

Individuals with the following profile are “at-risk” for carriage of CRE: a) a history of an overnight stay in a healthcare setting in the last 12 months, b) dialysis-dependent or cancer chemotherapy in the last 12 months, c) known previous carriage of CRE in the last 12 months and d) epidemiological linkage to a known carrier of a CRE.

Core infection prevention and control measures that should be considered for all patients in healthcare settings were compiled. Preliminary supplemental measures to be implemented for “at-risk” patients on admission are: pre-emptive isolation, active screening for CRE, and contact precautions. Patients who are confirmed positive for CRE will need additional supplemental measures.

Conclusions

Strengthening the microbiological capacity, surveillance and reporting of new cases of CRE in healthcare settings and countries is necessary to monitor the epidemiological situation so that, if necessary, the implemented CRE prevention strategies can be refined in a timely manner. Creating a large communication network to exchange this information would be helpful to understand the extent of the CRE reservoir and to prevent infections in healthcare settings, by applying the principles outlined here.

This guidance document offers suggestions for best practices, but is in no way prescriptive for all healthcare settings and all countries. Successful implementation will result if there is local commitment and accountability. The options for intervention can be adopted or adapted to local needs, depending on the availability of financial and structural resources.

Electronic supplementary material

The online version of this article (10.1186/s13756-017-0259-z) contains supplementary material, which is available to authorized users.

Antibiotic resistance: What is so special about multidrug-resistant Gram-negative bacteria?

In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.

Rate of colonization of health care workers by carbapenem-resistant Enterobacteriaceae in an endemic hospital: A prospective study

The role of health care workers in transmission of carbapenem-resistant Enterobacteriaceae (CRE) has not been evaluated thoroughly. We sought to determine the rate of fecal carriage of CRE among health care workers in our hospital, which is endemic for CRE (prevalence of 19 out of 800 beds and incidence of 128 out of 49,325 hospital admissions). We found no carriers among the 177 health care workers that participated in the study, suggesting that transmission does not occur through personnel gastrointestinal carriage of the bacteria.

Duration of Colonization With Klebsiella pneumoniae Carbapenemase-Producing Bacteria at Long-Term Acute Care Hospitals in Chicago, Illinois

Knowledge of the duration of colonization with KPC is essential for infection control measures. We found that only 17% of LTACH patients lost colonization within four weeks. Half of the KPC-positive patients were still carriers when readmitted after nine months.

Background. High prevalence of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae has been reported in long-term acute care hospitals (LTACHs), in part because of frequent readmissions of colonized patients. Knowledge of the duration of colonization with KPC is essential to identify patients at risk of KPC colonization upon readmission and to make predictions on the effects of transmission control measures.

Methods. We analyzed data on surveillance isolates that were collected at 4 LTACHs in the Chicago region during a period of bundled interventions, to simultaneously estimate the duration of colonization during an LTACH admission and between LTACH (re)admissions. A maximum-likelihood method was used, taking interval-censoring into account.

Results. Eighty-three percent of patients remained colonized for at least 4 weeks, which was the median duration of LTACH stay. Between LTACH admissions, the median duration of colonization was 270 days (95% confidence interval, 91–∞).

Conclusions. Only 17% of LTACH patients lost colonization with KPC within 4 weeks. Approximately half of the KPC-positive patients were still carriers when readmitted after 9 months. Infection control practices should take prolonged carriage into account to limit transmission of KPCs in LTACHs.

The global epidemiology of carbapenemase-producing Enterobacteriaceae

Carbapenemase-producing Enterobacteriaceae (CPE) are an important and increasing threat to global health. Both clonal spread and plasmid-mediated transmission contribute to the ongoing rise in incidence of these bacteria. Among the 4 classes of β-lactamases defined by the Ambler classification system, the carbapenemases that confer carbapenem resistance in Enterobacteriaceae belong to 3 of them: Class A (K. pneumoniae carbapenemases, KPC), Class B (metallo-β-lactamases, MBL including New Delhi metallo-β-lactamases, NDM) and Class D (OXA-48-like carbapenemases). KPC-producing CPE are the most commonly occurring CPE in the United States. MBL-producing CPE have been most commonly associated with the Indian Subcontinent as well as with specific countries in Europe, including Romania, Denmark, Spain, and Hungary. The epicenter of OXA-48-like-producing is in Turkey and surrounding countries. Detailed knowledge of the epidemiology and molecular characteristics of CPE is essential to stem the spread of these pathogens.

KlebSeq, a Diagnostic Tool for Surveillance, Detection, and Monitoring of Klebsiella pneumoniae

Health care-acquired infections (HAIs) kill tens of thousands of people each year and add significantly to health care costs. Multidrug-resistant and epidemic strains are a large proportion of HAI agents, and multidrug-resistant strains of Klebsiella pneumoniae, a leading HAI agent, have caused an urgent public health crisis. In the health care environment, patient colonization by K. pneumoniae precedes infection, and transmission via colonization leads to outbreaks. Periodic patient screening for K. pneumoniae colonization has the potential to curb the number of HAIs. In this report, we describe the design and validation of KlebSeq, a highly informative screening tool that detects Klebsiella species and identifies clinically important strains and characteristics by using highly multiplexed amplicon sequencing without a live-culturing step. We demonstrate the utility of this tool on several complex specimen types, including urine, wound swabs and tissue, and several types of respiratory and fecal specimens, showing K. pneumoniae species and clonal group identification and antimicrobial resistance and virulence profiling, including capsule typing. Use of this amplicon sequencing tool to screen patients for Klebsiella carriage could inform health care staff of the risk of infection and outbreak potential. KlebSeq also serves as a model for next-generation molecular tools for public health and health care, as expansion of this tool can be used for several other HAI agents or applications.

Predicting Antibiotic Resistance in Urinary Tract Infection Patients with Prior Urine Cultures

To improve antibiotic prescribing, we sought to establish the probability of a resistant organism in urine culture given a previous resistant culture in a setting endemic for multidrug-resistant (MDR) organisms. We performed a retrospective analysis of inpatients with paired positive urine cultures. We focused on ciprofloxacin-resistant (cipro(r)) Gram-negative bacteria, extended-spectrum-beta-lactamase (ESBL)-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae (CRE), and carbapenem-resistant nonfermenters (CRNF). Comparisons were made between the frequency of each resistance phenotype following a previous culture with the same phenotype and the overall frequency of that phenotype, and odds ratios (ORs) were calculated. We performed a regression to assess the effects of other variables on the likelihood of a repeat resistant culture. A total of 4,409 patients (52.5% women; median age, 70 years) with 19,546 paired positive urine cultures were analyzed. The frequencies of cipro(r) bacteria, ESBL-producing Enterobacteriaceae, CRE, and CRNF among all cultures were 47.7%, 30.6%, 1.7%, and 2.6%, respectively. ORs for repeated resistance phenotypes were 1.87, 3.19, 48.25, and 19.02 for cipro(r) bacteria, ESBL-producing Enterobacteriaceae, CRE, and CRNF, respectively (P < 0.001 for all). At 1 month, the frequencies of repeated resistance phenotypes were 77.4%, 66.4%, 57.1%, and 33.3% for cipro(r) bacteria, ESBL-producing Enterobacteriaceae, CRE, and CRNF, respectively. Increasing time between cultures and the presence of an intervening nonresistant culture significantly reduced the chances of a repeat resistant culture. Associations were statistically significant over the duration of follow-up (60 months) for CRE and for up to 6 months for all other pathogens. Knowledge of microbiology results in the six preceding months may assist with antibiotic stewardship and improve the appropriateness of empirical treatment for urinary tract infections (UTIs).

Natural history and decolonization strategies for ESBL/carbapenem-resistant Enterobacteriaceae carriage: systematic review and meta-analysis

BACKGROUND

ESBL-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae (CRE) are rapidly spreading worldwide. Their natural reservoir is intestinal.

METHODS

We carried out a systematic review and meta-analysis to estimate CRE and ESBL carriage duration and to evaluate the effect of decolonization therapy. We included cohort and comparative studies examining the natural history of CRE/ESBL colonization, examining rates of carriage following decolonization or comparing decolonization and no decolonization conducted in the healthcare setting or in the community. A comprehensive search was conducted until November 2015. We compiled carriage rates at 1, 3, 6 and 12 months with and without decolonization therapy and assessed the effect of decolonization.

RESULTS

Thirty-seven studies fulfilled inclusion criteria. In healthcare settings, pooled ESBL/CRE colonization rates decreased without intervention from 76.7% (95% CI = 69.3%-82.8%) at 1 month to 35.2% (95% CI = 28.2%-42.9%) at 12 months of follow-up. Following decolonization, the rate was 37.1% (95% CI = 27.5%-47.7%) at end of therapy and 57.9% (95% CI = 43.1%-71.4%) at 1 month. In two randomized trials, carriage was significantly reduced at end of therapy (risk ratio = 0.42, 95% CI = 0.25-0.65), but the effect was not significant after 1 month (risk ratio = 0.72, 95% CI = 0.48-1.05), with no longer follow-up. Heterogeneity was explained by surveillance methodology, with no differences observed between ESBLs and CREs. Among community dwellers, ESBL colonization decreased from 52.3% (95% CI = 29.5%-74.2%) at 1 month to 19.2% (95% CI = 9.7%-34.4%) at 6 months.

CONCLUSIONS

A significant proportion of ESBL and CRE carriers remain colonized up to 1 year in the healthcare setting. While short-term decolonization therapy reduces carriage during therapy, its longer-term effects are unclear.

Hospital Readmissions in Patients With Carbapenem-Resistant Klebsiella pneumoniae

BACKGROUND

Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated ("CRKP readmission") potentially contribute to transmission of CRKP.

OBJECTIVE

To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe).

DESIGN

Cohort study from December 24, 2011, through July 1, 2013.

SETTING

Multicenter consortium of acute care hospitals in the Great Lakes region.

PATIENTS

All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture.

METHODS

All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models.

RESULTS

Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32-6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72-17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission.

CONCLUSION

Hospitalized patients with CRKP-specifically those with a history of malignancy-are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.