Epidemiology and prevention of carbapenem-resistant Enterobacteriaceae in the United States

Healthcare-associated carbapenem-resistant Klebsiella pneumoniae infections are associated with higher mortality compared to carbapenem-susceptible K. pneumoniae infections in the intensive care unit: a retrospective cohort study

BACKGROUND

Klebsiella pneumoniae (KP) is an opportunistic pathogen causing severe pneumonia and sepsis. Carbapenem-resistant KP (CRKP) has become a major pathogen in many centres.

AIM

To investigate the association between carbapenem resistance and the mortality rate, length of stay, and hospital cost in patients with Klebsiella pneumoniae infection.

METHODS

The retrospective cohort study was conducted in the intensive care units of a large teaching tertiary hospital in southwest China between January 1st, 2020 and December 31st, 2022. To examine the impact of carbapenem resistance on mortality rates and economic burden, multivariate Cox regression and generalized linear models were constructed.

FINDINGS

The study included 282 adult patients with KP infection (135 CSKP; 147 CRKP). CRKP-infected patients demonstrated higher mortality risk (unadjusted hazard ratio (aHR): 1.980; 95% confidence interval (CI): 1.206-3.248; P = 0.007; aHR: 1.767; 95% CI: 1.038-3.005; P = 0.036) compared to CSKP-infected patients. Stratified analysis, according to type of KP infection, revealed that patients with healthcare-associated CRKP infection had a significantly higher mortality risk compared to those with CSKP infection (log-rank P = 0.015). Patients with CRKP infection had longer hospital stays than those infected with CSKP (adjusted mean: 38.74 vs 29.71 days; P = 0.003), and hospital-related expenses were notably higher among CRKP patients than CSKP patients (adjusted cost: £40,126.73 vs 25,713.74; P < 0.001).

CONCLUSION

CRKP infections increase mortality rates, prolong hospital stays, and raise healthcare costs. Healthcare facilities should adopt targeted strategies, including curtailing pre-infection hospitalization periods and managing medications more judiciously.

Epidemiology of carbapenem-resistant organisms in Alameda County, California, 2019-2021

Objective

Carbapenem-resistant organisms (CROs) are an urgent health threat. Since 2017, Alameda County Health Public Health Department (ACPHD) mandates reporting of carbapenem-resistant Enterobacterales (CRE) and encourages voluntary reporting of non-CRE CROs including carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Surveillance data from ACPHD were analyzed to describe the epidemiology of CROs and target public health interventions.

Methods

Healthcare facilities in Alameda County reported CRO cases and submitted isolates to ACPHD to characterize carbapenemase genes; deaths were identified via the California Electronic Death Registration System. CRO cases with isolates resistant to one or more carbapenems were analyzed from surveillance data from July 2019 to June 2021.

Results

Four hundred and forty-two cases of CROs were reported to Alameda County from 408 patients. The county case rate for CROs was 29 cases per 100,000 population, and cases significantly increased over the 2-year period. CRPA was most commonly reported (157 cases, 36%), and cases of CRAB increased 1.83-fold. One-hundred eighty-six (42%) cases were identified among residents of long-term care facilities; 152 (37%) patients had died by January 2022. One hundred and seven (24%) cases produced carbapenemases.

Conclusions

The high burden of CROs in Alameda County highlights the need for continued partnership on reporting, testing, and infection prevention to limit the spread of resistant organisms. A large proportion of cases were identified in vulnerable long-term care residents, and CRAB was an emerging CRO among this population. Screening for CROs and surveillance at the local level are important to understand epidemiology and implement public health interventions.

Genomic insights and antimicrobial resistance profiles of CRKP and non-CRKP isolates in a Beijing geriatric medical center: emphasizing the blaKPC-2 carrying high-risk clones and their spread

Background

The escalating resistance of Klebsiella pneumoniae, a prevalent pathogen in healthcare settings, especially its carbapenem-resistant K. pneumoniae (CRKP), to a wide array of antibiotics, notably β-lactams, constitutes a formidable challenge for healthcare and global public health management.

Methods

This research compared the resistance phenotypes and genomic profiles of CRKP and Non-CRKP isolates in a Beijing hospital, focusing on high-risk blaKPC-2 gene-bearing CRKP clones and the structure of mobile genetic elements facilitating their spread across hospital departments. Forty K. pneumoniae isolates were collected from various departments of the hospital and subjected to antimicrobial susceptibility testing and whole-genome sequencing to analyze their resistance phenotypes and genomic features.

Results

The study revealed that among the 31 CRKP isolates, ST11 is the most common sequence type, with K47 and OL101 being the dominant capsule types, primarily observed in the respiratory department. In terms of antimicrobial susceptibility: 87.5% of the isolates exhibited multidrug resistance (MDR), with a high resistance rate of 30% against tigecycline. All CRKP isolates demonstrated resistance to multiple drug classes (≥5 CLSI classes). Non-CRKP isolates also showed high resistance rates to minocycline and doxycycline (77.8%). the ST11-KL47-OL101 type emerged as the predominant clone among the CRKP isolates carrying the blaKPC-2 gene. This dominance appears to be mediated by the pKpnR03_2 plasmid, which harbors not only blaKPC-2 and rmtb but also gene clusters pertinent to iron transport and arsenic resistance. These isolates, clustering in the C3 clade of the phylogenetic tree, exhibited minor genetic variations and close evolutionary relationships, suggesting a plasmid-driven spread across various hospital departments.

Conclusion

In summary, our study highlights the extensive spread of antibiotic-resistant K. pneumoniae across various departments in our hospital, with a particular emphasis on the dominant clonal proliferation of the ST11-KL47-OL101 CRKP strain. This finding underscores the significant role of plasmid-mediated gene transfer in the evolution and dissemination of resistant strains within hospital environments. The study emphasizes the necessity for ongoing surveillance of antibiotic resistance and genomic analysis in hospital settings to effectively monitor and manage these challenges.

Clonal Lineages and Virulence Factors of Carbapenem Resistant E. coli in Alameda County, California, 2017-2019

The prevalence of carbapenem-resistant Enterobacterales (CRE) has been increasing since the year 2000 and is considered a serious public health threat according to the Centers for Disease Control and Prevention. Limited studies have genotyped Carbapenem-resistant Escherichia coli using whole genome sequencing to characterize the most common lineages and resistance and virulence genes. The aim of this study was to characterize sequence data from carbapenem-resistant E. coli isolates (n = 82) collected longitudinally by the Alameda County Public Health Laboratory (ACPHL) between 2017 and 2019. E. coli genomes were screened for antibiotic resistance genes (ARGs) and extraintestinal pathogenic E. coli virulence factor genes (VFGs). The carbapenem-resistant E. coli lineages were diverse, with 24 distinct sequence types (STs) represented, including clinically important STs: ST131, ST69, ST95, and ST73. All Ambler classes of Carbapenemases were present, with NDM-5 being most the frequently detected. Nearly all isolates (90%) contained genes encoding resistance to third-generation cephalosporins; bla_CTX-M genes were most common. The number of virulence genes present within pandemic STs was significantly higher than the number in non-pandemic lineages (p = 0.035). Virulence genes fimA (92%), trat (71%), kpsM (54%), and iutA (46%) were the most prevalent within the isolates. Considering the public health risk associated with CRE, these data enhance our understanding of the diversity of clinically important E. coli that are circulating in Alameda County, California.

Major infections following pediatric cardiac surgery pre- and post-CLABSI bundle implementation

Background

Postoperative infection contributes to the worsening of congenital cardiac surgery (CCS) outcomes. Surgical site infection (SSI), bloodstream infection (BSI) and ventilator associated pneumonia (VAP) are common. An additional bundle of preventive measures against central-line associated bloodstream infection (CLABSI) bundle was implemented in April 2019.

Objectives

To compare the incidence of major infections after pediatric CCS before and after the implementation of the CLABSI bundle and to identify risk factors for major infections.

Methods

We conducted a single-center, retrospective study to assess the incidence of major infections including bloodstream infection (BSI), surgical site infection (SSI), and ventilator-associated pneumonia (VAP) after pediatric CCS one year before and after implementation of the CLABSI bundle during April 2018-March 2020. The demographics and outcomes of the patients were explored, and risk factors for major infections were identified using multivariate analysis.

Results

A total of 548 children (53% male) underwent CCS with a median age of 1.9 years (range 0.01-17.5 years). The median Aristotle Basic Complexity score was 7.1 (range 3-14.5). The CLABSI bundle was applied in 262 patients. Overall mortality was 5.5%. 126 patients (23%) experienced major postoperative infections. During the year after the implementation of the CLABSI bundle, BSI was reduced from 8.4% to 3.1% (p = 0.01), with a smaller reduction in VAP (21% to 17.6%; p = 0.33). The incidence of SSI was unchanged (1.7% to 1.9%; p = 0.77). The independent risk factors for major infections were age at surgery <6 months (p = 0.04), postoperative ventilator usage >2 days (p < 0.01), central line usage >4 days (p = 0.04), and surgery during the pre-CLABSI bundle period (p = 0.01).

Conclusion

Following the implementation of the CLABSI prevention package in our pediatric CCS unit, the incidence of BSI was significantly reduced. The incidence of VAP tended to decrease, while the SSI was unchanged. Sustainability of the prevention package through nurse empowerment and compliance audits is an ongoing challenge.

Epidemiology and Early Bacteriology of Extremely Severe Burns from an LPG Tanker Explosion in Eastern China

The incidence of liquefied petroleum gas (LPG)-related accidents in China has increased over the recent years. In addition, infection remains a big challenge in cases of severe burns. Therefore, the present study aimed to provide valuable information for a better control of infections in the event of such disasters. In this study, a total of 16 patients who suffered extremely severe burns after an LPG tanker explosion were included. Thereafter, bacteriological culture results were collected within a week. Of 16 patients, 13 (81.25%) were male and the average age of all patients was 60.63 years. In addition, the mean burned area was 83.03% TBSA. Additionally, a total of 553 organism cultures were conducted out of which 287 isolates (51.90%) showed positive results. Notably, 38.52% were Gram-negative bacteria, 7.59% were Gram-positive bacteria and 5.79% were fungi. Moreover, the most prevalent Gram-negative bacteria were Stenotrophomonas maltophilia (28.97%) followed by Acinetobacter baumannii (28.53%), and Klebsiella pneumoniae (14.02%). On the other hand, the three most predominant Gram-positive bacteria were Enterococcus faecalis (33.33%), Staphylococcus aureus (28.89%) and Staphylococcus sciuri (17.78%). Furthermore, the most common fungi included Candida (38.24%), Fusarium (20.59%) and Aspergillus fumigatus (14.71%). With regard to the bacterial resistance patterns, carbapenem-resistant organisms included Acinetobacter baumannii (97.80%), Pseudomonas aeruginosa (67.57%), and Klebsiella pneumoniae (75.56%). In addition, Staphylococcus sciuri, Staphylococcus epidermidis, and Staphylococcus haemolyticus were identified to be methicillin-resistant. This study revealed that there was a high incidence of infection in victims of severe burns as a result of mass burn accidents, accompanied by early fungal infection.

Accessory Genomes Drive Independent Spread of Carbapenem-Resistant Klebsiella pneumoniae Clonal Groups 258 and 307 in Houston, TX

Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent public health threat. Worldwide dissemination of CRKp has been largely attributed to clonal group (CG) 258. However, recent evidence indicates the global emergence of a CRKp CG307 lineage. Houston, TX, is the first large city in the United States with detected cocirculation of both CRKp CG307 and CG258. We sought to characterize the genomic and clinical factors contributing to the parallel endemic spread of CG258 and CG307. CRKp isolates were collected as part of the prospective, Consortium on Resistance against Carbapenems in Klebsiella and other Enterobacterales 2 (CRACKLE-2) study. Hybrid short-read and long-read genome assemblies were generated from 119 CRKp isolates (95 originated from Houston hospitals). A comprehensive characterization of phylogenies, gene transfer, and plasmid content with pan-genome analysis was performed on all CRKp isolates. Plasmid mating experiments were performed with CG307 and CG258 isolates of interest. Dissection of the accessory genomes suggested independent evolution and limited horizontal gene transfer between CG307 and CG258 lineages. CG307 contained a diverse repertoire of mobile genetic elements, which were shared with other non-CG258 K. pneumoniae isolates. Three unique clades of Houston CG307 isolates clustered distinctly from other global CG307 isolates, indicating potential selective adaptation of particular CG307 lineages to their respective geographical niches. CG307 strains were often isolated from the urine of hospitalized patients, likely serving as important reservoirs for genes encoding carbapenemases and extended-spectrum β-lactamases. Our findings suggest parallel cocirculation of high-risk lineages with potentially divergent evolution. IMPORTANCE The prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKp) infections in nosocomial settings remains a public health challenge. High-risk clones such as clonal group 258 (CG258) are particularly concerning due to their association with blaKPC carriage, which can severely complicate antimicrobial treatments. There is a recent emergence of clonal group 307 (CG307) worldwide with little understanding of how this successful clone has been able to adapt while cocirculating with CG258. We provide the first evidence of potentially divergent evolution between CG258 and CG307 with limited sharing of adaptive genes. Houston, TX, is home to the largest medical center in the world, with a large influx of domestic and international patients. Thus, our unique geographical setting, where two pandemic strains of CRKp are circulating, provides an indication of how differential accessory genome content can drive stable, endemic populations of CRKp. Pan-genomic analyses such as these can reveal unique signatures of successful CRKp dissemination, such as the CG307-associated plasmid (pCG307_HTX), and provide invaluable insights into the surveillance of local carbapenem-resistant Enterobacterales (CRE) epidemiology.

A Nomogram With Six Variables Is Useful to Predict the Risk of Acquiring Carbapenem-Resistant Microorganism Infection in ICU Patients

Background

Carbapenem-resistant microorganism (CRO) transmission in the medical setting confers a global threat to public health. However, there is no established risk prediction model for infection due to CRO in ICU patients. This study aimed to develop a nomogram to predict the risk of acquiring CRO infection in patients with the first ICU admission and to determine the length of ICU stay (ICU-LOS) and 28-day survival.

Methods

Patient data were retrieved from the Medical Information Mart for Intensive Care (MIMIC-IV) database based on predetermined inclusion and exclusion criteria. A CRO was defined as a bacterium isolated from any humoral microbial culture that showed insensitivity or resistance to carbapenems. The characteristics of CRO and non-CRO patients in the first ICU admission were compared. Propensity score matching was applied to balance the differences between the CRO and non-CRO cohorts. Kaplan–Meier curves were constructed to determine the 28-day survival rate and ICU-LOS. Furthermore, after randomization of the CRO cohort into the training and validation sets, a predictive nomogram was constructed based on LASSO regression and Logistic regression analysis, and its performance was verified by internal validation.

Results

Overall, 4531 patients who had first ICU admission as recorded in MIMIC-IV were enrolled, 183 (4.04%) of whom were diagnosed with CRO infection. Moreover, CRO infection was independently associated with 28-day survival and ICU-LOS in ICU patients. Parameters eligible for inclusion in this nomogram were male sex, hemoglobin-min, temperature-max, use of a peripherally inserted central catheter line, dialysis treatment, and use of carbapenems. This nomogram showed a better performance as indicated by the area under the receiver operating characteristic curve values of 0.776 (95% confidence interval [CI] 0.667-0.750) and 0.723 (95% CI 0.556-0.855) in the training and validation sets, respectively, in terms of predicting the risk of acquiring CRO infection.

Conclusions

CRO infection was independently associated with ICU-LOS and 28-day survival in patients with first ICU admission. The nomogram showed the best prediction of the risk of acquiring CRO infection in ICU patients. Based on the nomogram-based scoring, we can management the risk factors and guide individualized prevention and control of CRO.

Risk Factors for a Hospital-Acquired Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infection: A Five-Year Retrospective Study

Purpose

This study aimed to describe trends in Klebsiella pneumoniae (KP) resistance in bloodstream infections (BSI) and to identify risk factors for a hospital-acquired carbapenem-resistant Klebsiella pneumoniae (CRKP) BSI and 28-day mortality from a hospital-acquired KP BSI.

Patients and Methods

We recorded the results of antimicrobial susceptibility testing of 396 KP-positive blood cultures from January 2016 to December 2020. A total of 277 patients with a KP BSI were included in this study, of which 171 had a hospital-acquired infection and 84 had a hospital-acquired CRKP BSI. Multivariate logistic regression analysis was used to identify risk factors for a hospital-acquired CRKP BSI and 28-day mortality from a hospital-acquired KP BSI.

Results

The proportion of hospital-acquired infections among KP BSI patients increased from 53.1% in 2016 to 72.8% in 2020. The detection rate of CRKP among KP BSI patients increased from 18.8% in 2016 to 37.7% in 2020. Multivariate logistic regression showed that β-lactam/β-lactamase inhibitor combinations (BLBLIs) exposure (P  = 0.022, OR 2.863), carbapenems exposure (P  = 0.007, OR 3.831) and solid organ transplantation (P   <0.001, OR 19.454) were independent risk factors for a hospital-acquired CRKP BSI. Risk factors for a 28-day mortality from hospital-acquired KP BSI were CRKP BSI (P  =0.009, OR 5.562), septic shock (P  =0.002, OR 4.862), mechanical ventilation>96 hours (P =0.020, OR 8.765), and platelet counts <100×10⁹/L (P  =0.003, OR 4.464).

Conclusion

The incidence of hospital-acquired KP BSI continues to rise and the proportion of CRKP BSI is also increasing. We believe that the use of the BLBLIs needs to be carefully evaluated in hospital-acquired infection. Hospital-acquired KP BSI Patients with CRKP BSI, septic shock, mechanical ventilation and deficiency of platelets are more likely to have a poor prognosis.

Carbapenem Resistance among Marine Bacteria-An Emerging Threat to the Global Health Sector

The emergence of antibiotic resistance among pathogenic microorganisms is a major issue for global public health, as it results in acute or chronic infections, debilitating diseases, and mortality. Of particular concern is the rapid and common spread of carbapenem resistance in healthcare settings. Carbapenems are a class of critical antibiotics reserved for treatment against multidrug-resistant microorganisms, and resistance to this antibiotic may result in limited treatment against infections. In addition to in clinical facilities, carbapenem resistance has also been identified in aquatic niches, including marine environments. Various carbapenem-resistant genes (CRGs) have been detected in different marine settings, with the majority of the genes incorporated in mobile genetic elements, i.e., transposons or plasmids, which may contribute to efficient genetic transfer. This review highlights the potential of the marine environment as a reservoir for carbapenem resistance and provides a general overview of CRG transmission among marine microbes.

Rapid identification from rectal swabs of the clinically most relevant carbapenemase genes from gram-negative bacteria using the BD MAX Check-Points CPO Assay

We conducted an international multicentre evaluation to assess the clinical performance characteristics of the new multiplex PCR-based BD MAX Check-Points CPO assay to detect the 5 major carbapenemase families: KPC, VIM/IMP (tested simultaneously), NDM and OXA-48 compared to a reference method consisting of 2 culture methods (to improve recovery of CPO isolates from the rectal swabs), followed by carbapenem susceptibility testing and sequencing of target carbapenemase genes. Tests were performed from rectal swab specimens in ESwab collection and transport devices. Positive percent agreement (PPA) for BD MAX Check-Points CPO for KPC and OXA-48 were 88.2% (95% CI:72.6-96.7) and 96.2% (95% CI:80.4-99.9), respectively. Negative percent agreement was ≥99% for each gene. Insufficient samples (≤10) were positive for VIM/IMP or NDM tests to calculate meaningful PPA values. The BD MAX Check-Points CPO assay represents an accurate tool for rapid recognition of patients with rectal colonization by the most commonly encountered CPOs.

Changes in prevalence of nosocomial infection pre- and post-COVID-19 pandemic from a tertiary Hospital in China

BACKGROUND

Nosocomial infections (NIs) are an important cause of mortality, and increasing evidence reveals that the prevalence of NIs can be reduced through effective prevention and control measures. The aim of this study was to investigate the impact of the prevention and control measures for the COVID-19 pandemic on NIs.

METHODS

A retrospective study was conducted to analyze the prevalence of NIs before and after COVID-19 pandemic for 6 months in the Children's Hospital of Soochow University.

RESULTS

A total of 39,914 patients in 2019 and 34,645 patients in 2020 were admitted to the hospital during the study. There were 1.39% (481/34645) of patients with NIs in 2020, which was significantly lower than the 2.56% (1021/39914) of patients in 2019. The rate of critical and fatal cases was also decreased. In addition, the rate of appropriate handwashing, the number of protective gloves and aprons used per person and the number of healthcare staff per patients were significantly increased. Except for the ICU, the prevalence of nosocomial infection in most departments decreased from 2019 to 2020. Regarding the source of infections, a significant reduction was mainly observed in respiratory (0.99% vs 0.42%, p = 0.000) and digestive tract (0.63% vs 0.14%, p = 0.000). The microorganism analysis of respiratory infections indicated an obvious decline in acinetobacters and fungi. The most significant decline of pathogens in gastrointestinal infections was observed for rotavirus. The comparison of catheter-related nosocomial infections between 2019 and 2020 did not show significant differences.

CONCLUSIONS

The prevention and control measures for the COVID-19 pandemic have reduced the nosocomial infection in almost all departments, except the ICU, mainly regarding respiratory, gastrointestinal, and oral infections, while catheter-related infections did not show any differences.

Modified CIM test as a useful tool to detect carbapenemase activity among extensively drug-resistant Klebsiella pneumoniae, Escherichia coli and Acinetobacter baumannii

Purpose

Timely detection of carbapenemases is essential for developing strategies to control the spread of infections by carbapenem-resistant isolates. The purpose of this study was to determine the epidemiology of carbapenemase genes among carbapenem-resistant isolates of Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli. In addition, the efficacy of the modified Hodge test (MHT), Carba NP test, and modified carbapenem inactivation method (mCIM) were compared.

Methods

A total of 122 carbapenem-resistant clinical isolates including 77 K. pneumoniae, 39 A. baumannii, and six E. coli were collected from hospitalized patients. Three phenotypic methods, including the MHT, Carba NP test, and mCIM were used for investigation of carbapenemase production. In addition, polymerase chain reaction (PCR) was performed to detect carbapenemase-encoding genes.

Result

The sensitivity and specificity of the MHT were 75.0% and 100%, respectively. In addition, Carba NP displayed 80.8% sensitivity and 100% specificity, whereas the sensitivity and specificity were 90.4% and 100% for the mCIM test, respectively. Among carbapenem-resistant isolates, 70, 84, and 87 isolates exhibited positive results according to the MHT, Carba NP test, and mCIM, respectively. PCR indicated the presence of one or more carbapenemase genes in 119 of carbapenem-resistant isolates, with blaKPC and blaVIM being the most commonly encountered. Co-production of ‘KPC and OXA-48’, ‘KPC and VIM’, and ‘KPC and IMP’ was detected in three, nine, and seven isolates, respectively.

Conclusion

Our results confirm that the mCIM test is a useful tool for the reliable detection of carbapenemase activity in enterobacterial isolates, especially in clinical microbiological laboratories with limited resources.

[Impact of an active surveillance program and infection control measures on the incidence of carbapenem-resistant Gram-negative bacilli in an intensive care unit]

Hospital-acquired infections caused by carbapenem-resistant Gram-negative bacteria (CRGNB) have been increasingly reported worldwide and are associated with high rates of mortality especially in intensive care units(ICUs). Early identification through rectal surveillance cultures and implementation of infection control measures(ICM) including contact precautions, staff education on cleaning and hand hygiene may reduce the spread of these microorganisms. The aim of this work was to assess the impact of enhanced ICM on CRGNB colonization and to describe the molecular epidemiology of these bacteria in a polyvalent ICU in a tertiary level hospital. A prospective study including audits and active surveillance culture program, with molecular characterization, was conducted before and after the implementation of prevention programs and infection control measures. Microbiological screening was performed in chromogenic media; PCR targeting β-lactamases genes (bla_KPC, bla_NDM, bla_VIM and bla_OXA-48, bla_SHV and bla_CTX-M), molecular typing by PFGE; and MLST in K. pneumoniae were performed. CRGNB colonization was reduced from 16.92% to 9.67% upon implementing the infection control measures. In K. pneumoniae the most frequent carbapenemase type was KPC-2 associated with SHV-2 and CTX-M-15, and was disseminated in various STs (ST17, ST13, ST2256, ST353); there was no persistence of particular clones and virulence factors showed no association with hypervirulence. IMP-1 carbapenemase predominated in A. baumannii and the PFGE analysis individualized 3 clusters, assuming that the dissemination in the ICU was clonal. The early detection of patients colonized with CRBGN by using epidemiological surveillance cultures and the implementation of prophylactic measures are key to reducing the incidence of these microorganisms.

Characterization of Carbapenem-Resistant Klebsiella pneumoniae ST15 Clone Coproducing KPC-2, CTX-M-15 and SHV-28 Spread in an Intensive Care Unit of a Tertiary Hospital

Objective

Nosocomial infection caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is a great threat to severely ill patients. Here we report an outbreak of K. pneumoniae ST15 isolates co-producing KPC-2, CTX-M-15, and SHV-28 in the cardiac surgery intensive care unit (CSICU) of a tertiary hospital.

Materials and Methods

From November 2019 to August 2020, all non-duplicated CRKP isolates were collected from the CSICU. The VITEK-2 compact system was used for bacterial identification and antimicrobial susceptibility testing. Clinical data were retrieved from electronic case records. All strains were also subjected to antibiotic resistance genes detection. Clonal relationships were analyzed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE).

Results

A total of 28 non-duplicated CRKP isolates were collected, including 23 strains belonging to ST15 and 5 strains belonging to ST11. All ST15 isolates were susceptible to amikacin, tigecycline, polymyxin B and ceftazidime/avibactam, but resistant to carbapenems, cephalosporins, quinolones, tobramycin and gentamicin. The detection of resistant determinants showed that 21 strains of ST15 CRKP co-harboured bla_KPC-2, bla_CTX-M-15, bla_SHV-28, bla_TEM-1, bla_OXA-1 and aac(6')-Ib-cr. All the 28 CRKP isolates were classified into five PFGE patterns (A, B, C, D and E), of which type A and B belonged to ST15 and type C, D and E belonged to ST11. PFGE type A was the predominant clonotype of this nosocomial infection and belonged to ST15.

Conclusion

K. pneumoniae ST15 co-producing KPC-2, CTX-M-15, SHV-28, TEM-1, OXA-1 and aac(6')-Ib-cr is the predominant clone spread in the CSICU. Surveillance and comprehensive infection control measures should be strengthened in clinical practice.

Resistance Trends of Klebsiella pneumoniae Causing Urinary Tract Infections in Chongqing, 2011-2019

Purpose

To analyze the characteristics and trends of drug resistance for Klebsiella pneumoniae (K. pneumoniae), isolated from urinary tract infections (UTIs), to common antibiotics used in clinics.

Methods

This retrospective study was conducted in a teaching hospital in Chongqing from 2011 to 2019. Laboratory data of isolated bacteria were collected and analyzed.

Results

Among the 17,966 non-repetitive strains isolated from the urine sample, a total of 1543 K. pneumoniae isolates were identified, with an isolation frequency secondary only to Escherichia coli (E. coli) and there was a peak in the K. pneumoniae isolates in the year 2013. During the period, the rate of extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae fell from 48.4% in 2011 to 32.9% in 2019, and a marked jump of resistance was seen in carbapenems from 2.2% to 18.0%. The peak of carbapenem resistance rate (22.6%) to K. pneumoniae was observed in 2017 along with a low ESBL-producing rate (30.9%). Piperacillin/tazobactam and cefepime resistance levels went up from 4.4% to 25.7% and from 18.2% to 30.5%, respectively. Moreover, the K. pneumoniae isolates resistance rate to carbapenems and amikacin gradually grew up, showing their peaks in 2017, and then dropped year by year. However, ceftazidime and aztreonam resistance levels were relatively stable, fluctuating between 21.8% and 35.6%, 32.2% and 39.4%, respectively.

Conclusion

There is a significant upward tendency in carbapenem resistance rate and a downward tendency in ESBL-production rate in K. pneumoniae isolates from UTIs, and continuous surveillance is necessary in the future.

Modeling Regional Transmission and Containment of a Healthcare-associated Multidrug-resistant Organism

BACKGROUND

The Centers for Disease Control and Prevention (CDC) recently published interim guidance for a public health response to contain novel or targeted multidrug-resistant organisms (MDROs). We assessed the impact of implementing the strategy in a US state using a mathematical model.

METHODS

We used a deterministic compartmental model, parametrized via a novel analysis of carbapenem-resistant Enterobacteriaceae data reported to the National Healthcare Safety Network and patient transfer data from the Centers for Medicare and Medicaid Services. The simulations assumed that after the importation of the MDRO and its initial detection by clinical culture at an index hospital, fortnightly prevalence surveys for colonization and additional infection control interventions were implemented at the index facility; similar surveys were then also implemented at those facilities known to be connected most strongly to it as measured by patient transfer data; and prevalence surveys were discontinued after 2 consecutive negative surveys.

RESULTS

If additional infection-control interventions are assumed to lead to a 20% reduction in transmissibility in intervention facilities, prevalent case count in the state 3 years after importation would be reduced by 76% (interquartile range: 73-77%). During the third year, these additional infection-control measures would be applied in facilities accounting for 42% (37-46%) of inpatient days.

CONCLUSIONS

CDC guidance for containing MDROs, when used in combination with information on transfer of patients among hospitals, is predicted to be effective, enabling targeted and efficient use of prevention resources during an outbreak response. Even modestly effective infection-control measures may lead to a substantial reduction in transmission events.

Intravenous Compatibility of Ceftazidime-Avibactam and Aztreonam Using Simulated and Actual Y-site Administration

PURPOSE

The objective of this communication was to determine the intravenous compatibility of ceftazidime/avibactam and aztreonam using simulated and actual Y-site administration.

METHODS

Ceftazidime-avibactam was reconstituted and diluted to concentrations of 8, 25, and 50 mg/mL in 0.9% sodium chloride. Aztreonam was reconstituted and diluted to concentrations of 10 and 20 mg/mL. Each combination of concentrations was tested for compatibility using visual, Tyndall beam, microscopy, turbidity, and pH assessments. Microscopy results were compared to those from sodium chloride 0.9% in water, pH was compared to that at time 0, and turbidity of combinations was compared to that of individual agents. Actual Y-site mixing was conducted over 2-h infusions with samples collected at 0, 1, and 2 h. Test results were evaluated at 0, 1, 2, 4, 8, and 12 h after mixing. All experiments were completed in triplicate.

FINDINGS

Across simulated and actual Y-site experiments, no evidence of incompatibility between combinations of ceftazidime-avibactam + aztreonam was observed. Visual and microscopic tests revealed no particulate matter, color changes, or turbidity. Tyndall beam tests were negative with all combinations. No evidence of incompatibility was observed in turbidity testing. The pH values were consistent across each of the 6 combinations, from immediately after mixing until 12 h after mixing. When the addition of agents was reversed in simulated Y-site experiments, no differences in compatibility were observed. No differences in compatibility between actual and simulated Y-site administration were observed, and there was minimal variability across all replicate experiments.

IMPLICATIONS

Ceftazidime-avibactam, at concentrations of 8, 25, and 50 mg/mL, appeared compatible with aztreonam at concentrations of 10 and 20 mg/mL.

Evaluation of NG-Test Carba 5 for Rapid Phenotypic Detection and Differentiation of Five Common Carbapenemase Families: Results of a Multicenter Clinical Evaluation

NG-Test Carba 5 is a rapid in vitro multiplex immunoassay for the phenotypic detection and differentiation of five common carbapenemase families (KPC, OXA-48-like, VIM, IMP, and NDM) directly from bacterial colonies. The assay is simple to perform and has recently received U.S. Food and Drug Administration clearance. A method comparison study was performed at geographically diverse medical centers (n = 3) in the United States, where 309 Enterobacterales and Pseudomonas aeruginosa isolates were evaluated by NG-Test Carba 5 (NG Biotech, Guipry, France), the Xpert Carba-R assay (Cepheid, Inc., Sunnyvale, CA), the modified carbapenem inactivation method (mCIM), the EDTA-modified carbapenem inactivation method, and disk diffusion with carbapenems. Colonies from tryptic soy agar with 5% sheep blood (blood agar) and MacConkey agar were tested, and the results were compared to those obtained by a composite reference method. Additionally, a fourth medical center performed a medium comparison study by evaluating the performance characteristics of NG-Test Carba 5 from blood, MacConkey, and Mueller-Hinton agars with 110 isolates of Enterobacterales and P. aeruginosa These results were compared to the expected genotypic and mCIM results. For the multicenter method comparison study, the overall positive percent agreement (PPA) and the overall negative percent agreement (NPA) of NG-Test Carba 5 with the composite reference method were 100% for both blood and MacConkey agars. The medium comparison study at the fourth site showed that the PPA ranged from 98.9% to 100% and that the NPA ranged from 95.2% to 100% for blood, MacConkey, and Mueller-Hinton agars. NG-Test Carba 5 accurately detected and differentiated five common carbapenemase families from Enterobacterales and P. aeruginosa colonies on commonly used agar media. The results of this test will support a streamlined laboratory work flow and will expedite therapeutic and infection control decisions.

Evaluation of Resistance Mechanisms in Carbapenem-Resistant Enterobacteriaceae

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) is a major concern leading to morbidity and mortality in the world. CRE often is becoming a cause of therapeutic failure in both hospital and community-acquired infections.

AIM

This study aimed to investigate the resistance mechanisms of CRE by phenotypic and molecular methods.

MATERIALS AND METHODS

Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Antimicrobial susceptibility testing was carried out using phenotypic methods. The carbapenem resistance mechanisms including efflux pump hyperexpression, AmpC overproduction, carbapenemase genes, and deficiency in OmpK35 and OmpK36 were determined by phenotypic and molecular methods, respectively.

RESULTS

Sixty CRE (50 Klebsiella pneumoniae, 6 Escherichia coli, and 4 Enterobacter spp.) were isolated from October 2018 to June 2019. Amikacin was found to be the most effective drug against CRE isolates. All isolates were resistant to imipenem and meropenem by the micro-broth dilution. AmpC overproduction was observed in all Enterobacter spp. and three K. pneumoniae isolates. No efflux pump activity was found. Carba NP test and Modified Hodge Test could find carbapenemase in 59 (98%) isolates and 57 (95%) isolates, respectively. The most common carbapenemase gene was bla OXA-48-like (72.8%) followed by bla NDM (50.8%), bla IMP (18.6%), bla VIM (11.8%), and bla KPC (6.7%). The ompK35 and ompK36 genes were not detected in 10 and 7 K. pneumoniae isolates, respectively.

CONCLUSION

The amikacin is considered as a very efficient antibiotic for the treatment of CRE isolates in our region. Carbapenemase production and overproduction of AmpC are the main carbapenem resistance mechanisms in CRE isolates. Finally, Carba NP test is a rapid and reliable test for early detection of carbapenemase-producing isolates.

Identifying Oxacillinase-48 Carbapenemase Inhibitors Using DNA-Encoded Chemical Libraries

Bacterial resistance to β-lactam antibiotics is largely mediated by β-lactamases, which catalyze the hydrolysis of these drugs and continue to emerge in response to antibiotic use. β-Lactamases that hydrolyze the last resort carbapenem class of β-lactam antibiotics (carbapenemases) are a growing global health threat. Inhibitors have been developed to prevent β-lactamase-mediated hydrolysis and restore the efficacy of these antibiotics. However, there are few inhibitors available for problematic carbapenemases such as oxacillinase-48 (OXA-48). A DNA-encoded chemical library approach was used to rapidly screen for compounds that bind and potentially inhibit OXA-48. Using this approach, a hit compound, CDD-97, was identified with submicromolar potency (Ki = 0.53 ± 0.08 μM) against OXA-48. X-ray crystallography showed that CDD-97 binds noncovalently in the active site of OXA-48. Synthesis and testing of derivatives of CDD-97 revealed structure-activity relationships and informed the design of a compound with a 2-fold increase in potency. CDD-97, however, synergizes poorly with β-lactam antibiotics to inhibit the growth of bacteria expressing OXA-48 due to poor accumulation into E. coli. Despite the low in vivo activity, CDD-97 provides new insights into OXA-48 inhibition and demonstrates the potential of using DNA-encoded chemistry technology to rapidly identify β-lactamase binders and to study β-lactamase inhibition, leading to clinically useful inhibitors.

Statewide surveillance of carbapenemase-producing carbapenem-resistant Escherichia coli and Klebsiella species in Washington state, October 2012–December 2017

Background:

Carbapenem-resistant Enterobacterales (CRE) are common causes of healthcare-associated infections and are often multidrug resistant with limited therapeutic options. Additionally, CRE can spread within and between healthcare facilities, amplifying potential harms.

Objective:

To better understand the burden, risk factors, and source of acquisition of carbapenemase genes in clinical Escherichia coli and Klebsiella spp isolates from patients in Washington to guide prevention efforts.

Design:

Multicenter prospective surveillance study.

Methods:

Escherichia coli and Klebsiella spp isolates meeting the Washington state CRE surveillance case definition were solicited from clinical laboratories and tested at Washington Public Health Laboratories using polymerase chain reaction (PCR) for the 5 most common carbapenemase genes: blaKPC, blaNDM, blaIMP, blaVIM, and blaOXA-48. Case patients positive by PCR were investigated by the public health department.

Results:

From October 2012 through December 2017, 363 carbapenem-resistant E. coli and Klebsiella spp isolates were tested. Overall, 45 of 115 carbapenem-resistant K. pneumoniae (39%), 1 of 8 K. oxytoca (12.5%), and 28 of 239 carbapenem-resistant E. coli (11.7%) were carbapenemase positive. Of 74 carbapenemase-positive isolates, blaKPC was most common (47%), followed by blaNDM (30%), blaOXA-48 (22%), and blaIMP (1%). Although all cases had healthcare exposure, blaKPC acquisition was associated with US health care, whereas non-blaKPC acquisition was associated with international health care or travel.

Conclusions:

We report that blaKPC, the most prevalent carbapenemase in the United States, accounts for nearly half of carbapenemase cases in Washington state and that most KPC-cases are likely acquired through in-state health care.

Clonal dissemination of KPC-2-producing Klebsiella pneumoniae ST11 and ST48 clone among multiple departments in a tertiary teaching hospital in Jiangsu Province, China

Background

The world-wide prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a threat to the public health. The objective of this study was to determine the epidemiological and molecular patterns of KPC-producing Klebsiella pneumoniae (K. pneumoniae) clinical isolates.

Methods

In this study, a total of 82 non-duplicated CRKP isolates were analyzed for the prevalence of resistant determinants including carbapenemase, extended spectrum β-lactamase (ESBLs), and AmpC as well as integrons and cassette regions by polymerase chain reaction (PCR) and DNA sequencing. The genetic relatedness was investigated by pulsed field gel electrophoresis (PFGE) and multi-locus sequencing typing (MLST).

Results

Overall, bla _KPC-2 (n=75) was the predominant carbapenemase gene, followed by high prevalence of bla _SHV (92.7%) and bla _CTX-M (90.2%). PFGE and MLST analysis revealed that 65 out of 68 KPC-2-producing CRKP belonged to the ST11 clone and were distributed mainly in the department of neurology ICU. Moreover, first report on clonal dissemination of KPC-2-producing CRKP ST48 clone and NDM-5-producing CRKP ST337 clone was also identified. Class I integron were detected in 17 (20.7%) of 82 isolates with aadA2 being the most common cassette. And a novel cassette array of integron, aac(6')-II-bla _CARB/PSE-1 was identified.

Conclusions

All in all, KPC-2-producing CRKP ST11 and ST48 clone were widely disseminated in multiple departments of our hospital, which triggers the need for active surveillance and implementation of infection control measures.

Antimicrobial susceptibility testing of Enterobacteriaceae: determination of disk content and Kirby-Bauer breakpoint for ceftazidime/avibactam

BACKGROUND

Detection of ceftazidime/avibactam (CAZ/AVI) antibacterial activity is absolutely vital with the rapid growth of carbapenem resistant Enterobacteriaceae (CRE). But now, there is no available automated antimicrobial susceptibility testing card for CAZ/AVI, so Kirby-Bauer has become an economical and practical method for detecting CAZ/AVI antibacterial activity against Enterobacteriaceae.

RESULT

In this study, antimicrobial susceptibility testing of CAZ/AVI against 386 Enterobacteriaceae (188 Klebsiella pneumoniae, 122 Escherichia coli, 76 Enterobacter cloacae) isolated from clinical patients was performed by broth microdilution. Of the 386 strains, 54 extended spectrum β lactamases negative (ESBL(-)), 104 extended spectrum β lactamases positive (ESBL(+)), 228 CRE. 287 isolates were susceptible to CAZ/AVI and 99 isolates were resistant to CAZ/AVI. At the same time, to obtain optimal content avibactam (AVI) disk containing ceftazidime (30 μg), inhibition zone diameter of four kinds of ceftazidime (30 μg) disk containing different AVI content (0 μg, 10 μg, 25 μg, 50 μg) were tested by Kirby-Bauer method. The microdilution broth method interpretation was used as the standard to estimate susceptible or resistance and then coherence analysis was carried out between Kirby-Bauer and broth microdilution. The result shows the inhibition zone diameter of 30 μg/50 μg disk, susceptible isolates: 20.5 mm-31.5 mm, resistance isolates: 8.25 mm-21.5 mm. The inhibition zone diameter of 30 μg/25 μg disk, susceptible isolates: 19.7 mm-31.3 mm, resistance isolates: 6.5 mm-19.2 mm. The inhibition zone diameter of 30 μg/10 μg disk, susceptible isolates: 19.5 mm-31 mm, resistance isolates: 6.5 mm-11 mm. The inhibition zone diameter of ceftazidime (30 μg), susceptible isolates: 6.5 mm-27.5 mm, resistance isolates 6.5 mm.

CONCLUSION

Our results show that 30 μg/50 μg, 30 μg/25 μg, 30 μg/10 μg CAZ/AVI disk have significant statistical differences to determinate CAZ/AVI antibacterial activity, but for 30 μg/50 μg disk, there has a cross section between susceptible isolates (minimum 20.5 mm) and resistance isolates (maximum 21.5 mm). For 30 μg/25 μg disk, it is hard to distinguish the difference between susceptible isolates (minimum 19.7 mm) and resistance isolates (maximum 19.2 mm), so 30 μg/10 μg CAZ/AVI disk is more conducive to determinate antibacterial activity.

Health outcomes attributable to carbapenemase-producing Enterobacteriaceae infections: A systematic review and meta-analysis

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) pose a significant global health threat.

OBJECTIVE

To conduct a systematic review of health outcomes and long-term sequelae attributable to CPE infection.

METHODS

We followed PRISMA reporting guidelines and published our review protocol on PROSPERO (CRD42018097357). We searched Medline, Embase, CINAHL and the Cochrane Library. We included primary studies with a carbapenem-susceptible control group in high-income countries, published in English. Quality appraisal was completed using Joanna Briggs Institute checklists. We qualitatively summarized frequently reported outcomes and conducted a meta-analysis.

RESULTS

Our systematic review identified 8,671 studies; 17 met the eligibility criteria for inclusion. All studies reported health outcomes; none reported health-related quality-of-life. Most studies were from Europe (65%), were conducted in teaching or university-affiliated hospitals (76%), and used case-control designs (53%). Mortality was the most commonly reported consequence of CPE-infections; in-hospital mortality was most often reported (62%). Our meta-analysis (n = 5 studies) estimated an absolute risk difference (ARD) for in-hospital bloodstream infection mortality of 0.25 (95% confidence interval [CI], 0.17-0.32). Duration of antibiotic therapy (range, 4-29.7 vs 1-23.6 days) and length of hospital stay (range, 21-87 vs 15-43 days) were relatively higher for CPE-infected patients than for patients infected with carbapenem-susceptible pathogens. Most studies (82%) met >80% of their respective quality appraisal criteria.

CONCLUSIONS

The risk of in-hospital mortality due to CPE bloodstream infection is considerably greater than carbapenem-susceptible bloodstream infection (ARD, 0.25; 95% CI, 0.17-0.32). Health outcome studies associated with CPE infection are focused on short-term (eg, in-hospital) outcomes; long-term sequelae and quality-of-life are not well studied.

TRIAL REGISTRATION

PROSPERO (CRD42018097357).

Molecular and phenotypic characterization of clinical isolates belonging to a KPC-2-producing strain of ST15 Klebsiella pneumoniae from a Vietnamese pediatric hospital

Background

Carbapenem-resistant Klebsiella pneumoniae are becoming increasingly common in hospital settings worldwide and are a source of increased morbidity, mortality and health care costs. The global epidemiology of carbapenem-resistant K. pneumoniae is characterized by different strains distributed geographically, with the strain ST258 being predominant in Europe and USA, and ST11 being most common in East Asia. ST15 is a less frequently occurring strain but has nevertheless been reported worldwide as a source of hospital outbreaks of carbapenem-resistant K. pneumoniae.

Methods

In this study, whole-genome sequencing and antimicrobial susceptibility testing was used to characterize 57 clinical isolates of carbapenem-resistant K. pneumoniae belonging to a strain of ST15, which were collected at a Vietnamese pediatric hospital from February throughout September 2015.

Results

Aside from the carbapenem resistance gene bla_KPC-2, which was carried by all isolates, prevalence of resistance genes to other antibiotics including aminoglycosides, macrolides, quinolones, fosfomycin and trimethoprim, was also high. All isolates were multidrug-resistant. Susceptibility was highest to ceftazidime/avibactam (96%), gentamicin (91%) and tigecycline (82%). Notably, the colistin resistance rate was very high (42%). Single-nucleotide polymorphism analysis indicated that most isolates belonged to a single clone.

Conclusions

The diverse variety of antibiotic resistance genes and the high antibiotic resistance rates to last-resort antibiotics such as carbapenems and colistin, is indicative of a highly adaptable strain. This emphasizes the importance of implementation of infection controls measures, continued monitoring of antibiotic resistance and prudent use of antibiotics to prevent further selection of resistant strains and the emergence of pan-resistant clones.

Epigenetic Regulation of IL-17-Induced Chemokines in Lung Epithelial Cells

Epithelial cells are known to have barrier functions in multiple organs and regulate innate immune responses. Airway epithelial cells respond to IL-17 by altering their transcriptional profiles and producing antimicrobial proteins and neutrophil chemoattractants. Although IL-17 has been shown to promote inflammation through stabilizing mRNA of CXCR2 ligands, how IL-17 exerts its downstream effects on its target cells through epigenetic mechanisms is largely unknown. Using primary human bronchial epithelial cells and immortalized epithelial cell line from both human and mouse, we demonstrated that IL-17-induced CXCR2 ligand production is dependent on histone acetylation specifically through repressing HDAC5. Furthermore, the chemokine production induced by IL-17 is strictly dependent on the bromodomain and extraterminal domain (BET) family as BET inhibition abolished the IL-17A-induced proinflammatory chemokine production, indicating a pivotal role of the recognition of acetylated histones. In combination with single-cell RNA-seq analysis, we revealed that the cell lines we employed represent specific lineages and their IL-17 responses were regulated differently by the DNA methylation mechanisms. Taken together, our data strongly support that IL-17 sustains epithelial CXCR2 ligand production through epigenetic regulation and the therapeutic potential of interrupting histone modification as well as the recognition of modified histones could be evaluated in neutrophilic lung diseases.

Relation between flomoxef minimum inhibitory concentrations and clinical outcomes of patients treated with flomoxef for Enterobacteriaceae bacteremia

Background

Flomoxef is potentially effective against β-lactamase-producing Enterobacteriaceae because limited clinical data demonstrate its effectiveness against Enterobacteriaceae bloodstream infections (BSIs) based on its minimum inhibitory concentrations (MICs). This study was conducted to determine the optimal breakpoints based on the survival of patients with Enterobacteriaceae BSIs treated with flomoxef.

Methods

The 30-day crude mortality rate was analyzed among 224 adults who initiated flomoxef monotherapy for Enterobacteriaceae BSIs at a medical center over a 3-year period, according to the flomoxef MICs of the initial isolates. The outcome was evaluated by classification and regression tree modeling and by logistic regression analysis.

Results

The 30-day crude mortality was approximately two fold greater in patients whose isolates had flomoxef MICs of ≥2 mg/L (54.9% [62/113]) than in those with isolates with MICs of ≤1 mg/L (26.1% [29/111]); the differences were significant in bivariate analysis (P<0.01) and in survival analysis (log-rank test; P<0.001). The classification and regression tree analysis revealed a split between MICs of 1 and 2 mg/L and predicted the same difference in mortality, with a P-value of <0.001. Flomoxef for Enterobacteriaceae BSIs caused by isolates with flomoxef MICs of ≥2 mg/L was an independent predictor of 30-day crude mortality (adjusted OR 3.76, 95% CI 1.94–7.29).

Conclusion

Patients with Enterobacteriaceae bacteremia who received flomoxef had a lower 30-day crude mortality when the flomoxef MICs of the isolates were ≤1 mg/L than those with MICs ≥2 mg/L.

Diversity of resistance mechanisms in carbapenem-resistant Enterobacteriaceae at a health care system in Northern California, from 2013 to 2016

The mechanism of resistance in carbapenem-resistant Enterobacteriaceae (CRE) has therapeutic implications. We comprehensively characterized emerging mechanisms of resistance in CRE between 2013 and 2016 at a health system in Northern California. A total of 38.7% (24/62) of CRE isolates were carbapenemase gene-positive, comprising 25.0% (6/24) bla_{OXA-48 like}, 20.8% (5/24) bla_KPC, 20.8% (5/24) bla_NDM, 20.8% (5/24) bla_SME, 8.3% (2/24) bla_IMP, and 4.2% (1/24) bla_VIM. Between carbapenemases and porin loss, the resistance mechanism was identified in 95.2% (59/62) of CRE isolates. Isolates expressing bla_KPC were 100% susceptible to ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam; bla_{OXA-48 like}-positive isolates were 100% susceptible to ceftazidime-avibactam; and metallo β-lactamase-positive isolates were nearly all nonsusceptible to above antibiotics. Carbapenemase gene-negative CRE were 100% (38/38), 92.1% (35/38), 89.5% (34/38), and 31.6% (12/38) susceptible to ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, and ceftolozane-tazobactam, respectively. None of the CRE strains were identical by whole genome sequencing. At this health system, CRE were mediated by diverse mechanisms with predictable susceptibility to newer β-lactamase inhibitors.

Carbapenem resistance among clinical and environmental Gram-negative isolates recovered from hospitals in Gaza strip, Palestine

Background

The world is threatened by the ongoing emergence of carbapenem resistant organisms, which are contributing to increasing morbidity and mortality rates. The main objective of this study was to highlight carbapenem resistance among clinical and environmental Gram-negative bacteria (GNB) isolates.

Methods

A cross-sectional study wherein 210 clinical isolates, 150 environmental swabs, and 110 air samples were collected from three major hospitals in Gaza strip: Al-Shifa, AlNaser and the European Gaza hospitals. The study lasted for seven months (September 2016 to March 2017). All isolates/samples were cultured and identified using conventional bacteriological methods. All GNB isolates were tested for their antimicrobial susceptibility using the disk diffusion method. Modified Hodge Test (MHT) was performed to investigate carbapenemases production.

Results

The overall percentage of carbapenem resistance among GNB was (30/247) 12.1%. Resistance to imipenem was (20/247) 8.1% while resistance to ertapenem and meropenem was (8/226) 3.5% and (2/247) 0.8%, respectively. The intensive care units exhibited the highest resistance rate 9/17 (52.9%). Carbapenem resistance among Enterobacteriaceae was (30/226) 13.2% while in Pseudomonas it was (0/21) 0%. Klebsiella spp. was the most resistant to carbapenems 13/90 (14.4%), followed by E. coli (9/91) 9.8%. Seven isolates out of 30 (23.3%) were positive for MHT. All Enterobacteriaceae isolates had a multiple antibiotic resistance (MAR) index higher than 0.2, while those of Pseudomonas had an average of 0.2. GNB were isolated from 19/110 (17.2%) and 21/150 (14%) of air and environmental samples, respectively.

Conclusion

The resistance found, after a recent introduction of carbapenem use in Gaza, shows the need for policies to prevent misuse and overuse of carbapenems, the need for infection control procedures and screening policies for carbapenem resistance on a routine basis.

Can octapeptin antibiotics combat extensively drug-resistant (XDR) bacteria?

INTRODUCTION

The octapeptins are a family of cyclic lipopeptides first reported in the 1970s then largely ignored. At the time, their reported antibiotic activity against polymyxin-resistant bacteria was a curiosity. Today, the advent of widespread drug resistance in Gram-negative bacteria has prompted their 'rediscovery.' The paucity of new antibiotics in the clinical pipeline is coupled with a global spread of increasing antibiotic resistance, particularly to meropenem and polymyxins B and E (colistin). Areas covered: We review the original discovery of octapeptins, their recent first chemical syntheses, and their mode of action, then discuss their potential as a new class of antibiotics to treat extensively drug-resistant (XDR) Gram-negative infections, with direct comparisons to the closely related polymyxins. Expert commentary: Cyclic lipopeptides in clinical use (polymyxin antibiotics) have significant dose-limiting nephrotoxicity inherent to their chemotype. This toxicity has prevented improved polymyxin analogs from progressing to the clinic, and tainted the perception of lipopeptide antibiotics in general. We argue that the octapeptins are fundamentally different from the polymyxins, with a disparate mode of action, spectra of action against MDR and XDR bacteria and a superior preclinical safety profile. They represent early-stage candidates that can help prime the antibiotic discovery pipeline.

Impact of active surveillance and infection control measures on carbapenem-resistant Gram-negative bacterial colonization and infections in intensive care

BACKGROUND

Carbapenem-resistant Gram-negative bacteria (CRGNB) infections constitute a global threat for critically ill patients and the outcome of their hospitalization. Early identification of CRGNB through rectal surveillance cultures and routine infection control measures including contact precautions, use of appropriate disinfectants, staff education on cleaning, and hand hygiene may reduce the dissemination of CRGNB.

AIM

To assess the impact of enhanced infection control measures on CRGNB infections in a nine-bed polyvalent intensive care unit in a tertiary level hospital in an endemic area.

METHODS

A quasi-experimental study, which included patients with CRGNB infection retrospectively for six months and those participating in an active surveillance programme prospectively for the subsequent 22 months. Active surveillance programme (weekly rectal swabs) was implemented including two sub-periods with infection control measures and enhanced infection control measures. CRGNB incidence, prevalence, colonization pressure, infections and compliance with infection control measures and enhanced infection control measures were recorded. Analysis was performed through time-series and interrupted time-series.

FINDINGS

During the active surveillance programme, enhanced infection control measures led to a steeper downwards trend in incidence, prevalence, and colonization pressure for CRGNB compared to the infection control measures sub-period. The linear trend was for carbapenem-resistant Klebsiella pneumoniae (CRKP) and Pseudomonas aeruginosa (CRPA) infections to decrease from 19.6 to 8.1 infections per 1000 bed-days (IBD) (P = 0.001) and from 5.1 to 1.79 IBD (P = 0.043), respectively. By contrast, carbapenem-resistant Acinetobacter baumannii infections increased from 5.2 to 15.3 IBD (P = 0.001).

CONCLUSION

Enhanced infection control measures including enhanced hand hygiene, active surveillance combined with contact precautions, education, audits and feedback policies and interventions could reduce CRKP and CRPA in endemic areas.

The Economic Value of the Centers for Disease Control and Prevention Carbapenem-Resistant Enterobacteriaceae Toolkit

OBJECTIVEWhile previous work showed that the Centers for Disease Control and Prevention toolkit for carbapenem-resistant Enterobacteriaceae (CRE) can reduce spread regionally, these interventions are costly, and decisions makers want to know whether and when economic benefits occur.DESIGNEconomic analysisSETTINGOrange County, CaliforniaMETHODSUsing our Regional Healthcare Ecosystem Analyst (RHEA)-generated agent-based model of all inpatient healthcare facilities, we simulated the implementation of the CRE toolkit (active screening of interfacility transfers) in different ways and estimated their economic impacts under various circumstances.RESULTSCompared to routine control measures, screening generated cost savings by year 1 when hospitals implemented screening after identifying ≤20 CRE cases (saving $2,000-$9,000) and by year 7 if all hospitals implemented in a regional coordinated manner after 1 hospital identified a CRE case (hospital perspective). Cost savings was achieved only if hospitals independently screened after identifying 10 cases (year 1, third-party payer perspective). Cost savings was achieved by year 1 if hospitals independently screened after identifying 1 CRE case and by year 3 if all hospitals coordinated and screened after 1 hospital identified 1 case (societal perspective). After a few years, all strategies cost less and have positive health effects compared to routine control measures; most strategies generate a positive cost-benefit each year.CONCLUSIONSActive screening of interfacility transfers garnered cost savings in year 1 of implementation when hospitals acted independently and by year 3 if all hospitals collectively implemented the toolkit in a coordinated manner. Despite taking longer to manifest, coordinated regional control resulted in greater savings over time.Infect Control Hosp Epidemiol 2018;39:516-524.

Clinical benefit of ertapenem compared to flomoxef for the treatment of cefotaxime-resistant Enterobacteriaceae bacteremia

Objectives

Cefotaxime-resistant Enterobacteriaceae (CE) infections are intractable, with limited treatment options. Though carbapenems are frequently prescribed for CE infections, the emergence of carbapenem-resistant Enterobacteriaceae is of huge concern. Flomoxef is effective against CE in vitro, and some clinical data on its demonstrated effectiveness against CE bloodstream infections (BSIs) exists.

Patients and methods

We conducted a retrospective study on adults with BSI caused by flomoxef-susceptible CE to investigate the efficacy of flomoxef compared with that of ertapenem. The outcome was evaluated with propensity score-based matching and logistic regression analysis.

Results

Demographic and clinical characteristics of patients treated with flomoxef (n = 58) or ertapenem (n = 188) were compared. In the multivariate analysis, severe sepsis (adjusted odds ratio [AOR] = 3.84; 95% confidence interval [CI], 1.16–12.78; p = 0.03), high BSI mortality score (AOR = 5.59; 95% CI, 2.37–13.21; p < 0.01), ultimately or rapidly fatal comorbidity (AOR = 10.60; 95% CI, 3.43–32.75; p < 0.01), and pneumonia (AOR = 10.11; 95% CI, 3.43–29.81; p < 0.01) were independently associated with 28-day mortality. Using propensity scores, 58 flomoxef-treated patients were matched to 116 ertapenem-treated patients. There were no intergroup differences in BSI severity, comorbidity, or BSI sources. The 28-day mortality rates (20.7% vs 13.8%, p = 0.28) did not differ significantly. However, hospitalization length was shorter in the ertapenem group (10.2 ± 8.5 vs. 14.6 ± 9.4 days, p < 0.01).

Conclusion

Although similar outcomes were observed between the groups, ertapenem therapy was associated with a shorter hospitalization time in adults after CE BSI.

PIOMETRAS EM CADELAS: RELAÇÃO ENTRE O PROGNÓSTICO CLÍNICO E O DIAGNÓSTICO LABORATORIAL

Resumo Piometra é uma afecção resultante da interação bacteriana com a hiperplasia cística do endométrio. O objetivo deste estudo foi identificar bactérias em condições de aerobiose e anaerobiose da secreção intrauterina de cadelas com piometra, presença da síndrome da resposta inflamatória sistêmica, status da cérvix, peritonite, dosagens bioquímicas séricas e comparar com o prognóstico de cadelas tratadas cirurgicamente. Utilizaram-se 15 cadelas com piometra, submetidas à ovariohisterectomia. Hemogramas e dosagens séricas de ureia, creatinina, FA e ALT foram realizados no pré-operatório imediato. Coletou-se urina por cistocentese. Após a remoção do útero e ovários, a secreção intrauterina foi aspirada; as amostras foram então cultivadas em aerobiose e anaerobiose, as amostras de urina em aerobiose. Os animais foram divididos em dois grupos, G1 (alta hospitalar em até 48 horas) e G2 (alta hospitalar após 48 horas ou óbito). Onze amostras de conteúdo intrauterino (73,3%) apresentaram crescimento bacteriano em aerobiose e anaerobiose e em uma amostra isolou-se Arizona hinshawii. Quatro amostras de urina (26,6%) tiveram crescimento bacteriano. Houve diferença significativa das variáveis status da cérvix, ureia, creatinina e fosfatase alcalina entre G1 e G2. Embora a diversidade etiológica encontrada nas culturas de conteúdo intrauterino tenha sido alta, a avaliação da azotemia, status da cérvix e dosagem de FA sérica mostraram-se bons marcadores prognósticos em cadelas com piometra.

Geographical variation in therapy for bloodstream infections due to multidrug-resistant Enterobacteriaceae: a post-hoc analysis of the INCREMENT study

We describe regional differences in therapy for bloodstream infection (BSI) caused by extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) or carbapenemase-producing Enterobacteriaceae (CPE). Patients (n = 1482) in 12 countries from an observational study of BSI caused by ESBL-E or CPE were included. Multivariate logistic regression was used to calculate adjusted odds ratios (aORs) for the influence of country of recruitment on empirical use of β-lactam/β-lactamase inhibitors (BLBLIs) or carbapenems, targeted use of BLBLIs for ESBL-E and use of targeted combination therapy for CPE. Compared with Spain, BLBLI use for empirical therapy was least likely in sites from Israel (aOR 0.34, 95% CI 0.14-0.81), Greece (aOR 0.49, 95% CI 0.26-0.94) and Canada (aOR 0.31, 95% CI 0.11-0.88) but more likely in Italy (aOR 1.58, 95% CI 1.11-2.25) and Turkey (aOR 2.09, 95% CI 1.14-3.81). Empirical carbapenem use was more likely in sites from Taiwan (aOR 1.73, 95% CI 1.03-2.92) and USA (aOR 1.89, 95% CI 1.05-3.39) and less likely in Italy (aOR 0.44, 95% CI 0.28-0.69) and Canada (aOR 0.10, 95% CI 0.01-0.74). Targeted BLBLIs for ESBL-E was more likely in Italian sites. Treatment at sites within Israel, Taiwan, Turkey and Brazil was associated with less combination therapy for CPE. Although this study does not provide precise data on the relative prevalence of ESBL-E or CPE, significant variation in therapy exists across countries even after adjustment for patient factors. Better understanding of what influences therapeutic choices for these infections will aid antimicrobial stewardship efforts.

Randomized controlled trial of piperacillin-tazobactam, cefepime and ertapenem for the treatment of urinary tract infection caused by extended-spectrum beta-lactamase-producing Escherichia coli

BACKGROUND

Due to limited therapeutic options, the spread of extended-spectrum beta-lactamases (ESBLs) have become a major public health concern. We conducted a prospective, randomized, open-label comparison of the therapeutic efficacy of piperacillin-tazobactam (PTZ), cefepime, and ertapenem in febrile nosocomial urinary tract infection with ESBL-producing Escherichia coli (ESBL-EC).

METHODS

This study was conducted at three university hospitals between January 2013 and August 2015. Hospitalized adult patients presenting with fever were screened for healthcare-associated urinary tract infection (HA-UTI). When ESBL-EC was solely detected and susceptible to a randomized antibiotic in vitro, the case was included in the final analysis. Participants were treated for 10-14 days with PTZ, cefepime, or ertapenem.

RESULTS

A total of 66 participants were evenly assigned to the PTZ and ertapenem treatment groups. After the recruitment of six participants, assignment to the cefepime treatment group was stopped because of an unexpectedly high treatment failure rate. The baseline characteristics of these participants did not differ from participants in other treatment groups. The clinical and microbiological response to PTZ treatment was estimated to be 94% and was similar to the response to ertapenem treatment. The efficacy of cefepime was 33.3%. In the cefepime group, age, Charlson comorbidity index, genotype, and minimal inhibitory concentration (MIC) did not significantly affect the success of treatment. Similarly, genotype seemed to be irrelevant with respect to clinical outcome in the PTZ group. Expired cases tended to involve septic shock with a high Charlson comorbidity index and high MIC.

CONCLUSION

Results from this study suggest that PTZ is effective in the treatment of urinary tract infection caused by ESBL-EC when the in vitro test indicates susceptibility. In addition, cefepime should not be used as an alternative treatment for urinary tract infection caused by ESBL-EC.

TRIAL REGISTRATION

The trial was registered with the Clinical Research Information Service of Korea Centers for Disease Control and Prevention. (KCT0001895).

Carbapenem-Resistant Enterobacteriaceae: A Strategic Roadmap for Infection Control

The incidence of carbapenem-resistant Enterobacteriaceae (CRE) has increased worldwide with great regional variability. Infections caused by these organisms are associated with crude mortality rates of up to 70%. The spread of CRE in healthcare settings is both an important medical problem and a major global public health threat. All countries are at risk of falling victim to the emergence of CRE; therefore, a preparedness plan is required to avoid the catastrophic natural course of this epidemic. Proactive and adequate preventive measures locally, regionally, and nationally are required to contain the spread of these bacteria. The keys to success in preventing the establishment of CRE endemicity in a region are early detection through targeted laboratory protocols and containment of spread through comprehensive infection control measures. This guideline provides a strategic roadmap for infection control measures based on the best available evidence and expert opinion, to enable preparation of a multifaceted preparedness plan to abort epidemics of CRE. Infect Control Hosp Epidemiol 2017;38:580-594.

A Prolonged Outbreak of KPC-3-Producing Enterobacter cloacae and Klebsiella pneumoniae Driven by Multiple Mechanisms of Resistance Transmission at a Large Academic Burn Center

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae has been recently recognized in the United States. Whole-genome sequencing (WGS) has become a useful tool for analysis of outbreaks and for determining transmission networks of multidrug-resistant organisms in health care settings, including carbapenem-resistant Enterobacteriaceae (CRE). We experienced a prolonged outbreak of CRE E. cloacae and K. pneumoniae over a 3-year period at a large academic burn center despite rigorous infection control measures. To understand the molecular mechanisms that sustained this outbreak, we investigated the CRE outbreak isolates by using WGS. Twenty-two clinical isolates of CRE, including E. cloacae (n = 15) and K. pneumoniae (n = 7), were sequenced and analyzed genetically. WGS revealed that this outbreak, which seemed epidemiologically unlinked, was in fact genetically linked over a prolonged period. Multiple mechanisms were found to account for the ongoing outbreak of KPC-3-producing E. cloacae and K. pneumoniae This outbreak was primarily maintained by a clonal expansion of E. cloacae sequence type 114 (ST114) with distribution of multiple resistance determinants. Plasmid and transposon analyses suggested that the majority of bla_KPC-3 was transmitted via an identical Tn4401b element on part of a common plasmid. WGS analysis demonstrated complex transmission dynamics within the burn center at levels of the strain and/or plasmid in association with a transposon, highlighting the versatility of KPC-producing Enterobacteriaceae in their ability to utilize multiple modes to resistance gene propagation.

Rapid detection of blaNDM-1 in multidrug-resistant organisms using a novel electrochemical biosensor

The traditional detection methods of multidrug-resistant organisms (MDROs) are costly and comprise multiple steps. In this study, we successfully established a fast electrochemical method for blaNDM-1 in MDROs based on the LNA probes.

Potential economic burden of carbapenem-resistant Enterobacteriaceae (CRE) in the United States

OBJECTIVES

The Centers for Disease Control and Prevention considers carbapenem-resistant Enterobacteriaceae (CRE) an urgent public health threat; however, its economic burden is unknown.

METHODS

We developed a CRE clinical and economics outcomes model to determine the cost of CRE infection from the hospital, third-party payer, and societal, perspectives and to evaluate the health and economic burden of CRE to the USA.

RESULTS

Depending on the infection type, the median cost of a single CRE infection can range from $22 484 to $66 031 for hospitals, $10 440 to $31 621 for third-party payers, and $37 778 to $83 512 for society. An infection incidence of 2.93 per 100 000 population in the USA (9418 infections) would cost hospitals $275 million (95% CR $217-334 million), third-party payers $147 million (95% CR $129-172 million), and society $553 million (95% CR $303-1593 million) with a 25% attributable mortality, and would result in the loss of 8841 (95% CR 5805-12 420) quality-adjusted life years. An incidence of 15 per 100 000 (48 213 infections) would cost hospitals $1.4 billion (95% CR $1.1-1.7 billion), third-party payers $0.8 billion (95% CR $0.6-0.8 billion), and society $2.8 billion (95% CR $1.6-8.2 billion), and result in the loss of 45 261 quality-adjusted life years.

CONCLUSIONS

The cost of CRE is higher than the annual cost of many chronic diseases and of many acute diseases. Costs rise proportionally with the incidence of CRE, increasing by 2.0 times, 3.4 times, and 5.1 times for incidence rates of 6, 10, and 15 per 100 000 persons.

A Rapid Spin Column-Based Method to Enrich Pathogen Transcripts from Eukaryotic Host Cells Prior to Sequencing

When analyzing pathogen transcriptomes during the infection of host cells, the signal-to-background (pathogen-to-host) ratio of nucleic acids (NA) in infected samples is very small. Despite the advancements in next-generation sequencing, the minute amount of pathogen NA makes standard RNA-seq library preps inadequate for effective gene-level analysis of the pathogen in cases with low bacterial loads. In order to provide a more complete picture of the pathogen transcriptome during an infection, we developed a novel pathogen enrichment technique, which can enrich for transcripts from any cultivable bacteria or virus, using common, readily available laboratory equipment and reagents. To evenly enrich for pathogen transcripts, we generate biotinylated pathogen-targeted capture probes in an enzymatic process using the entire genome of the pathogen as a template. The capture probes are hybridized to a strand-specific cDNA library generated from an RNA sample. The biotinylated probes are captured on a monomeric avidin resin in a miniature spin column, and enriched pathogen-specific cDNA is eluted following a series of washes. To test this method, we performed an in vitro time-course infection using Klebsiella pneumoniae to infect murine macrophage cells. K. pneumoniae transcript enrichment efficiency was evaluated using RNA-seq. Bacterial transcripts were enriched up to ~400-fold, and allowed the recovery of transcripts from ~2000–3600 genes not observed in untreated control samples. These additional transcripts revealed interesting aspects of K. pneumoniae biology including the expression of putative virulence factors and the expression of several genes responsible for antibiotic resistance even in the absence of drugs.

Carbapenem-Resistant Klebsiella pneumoniae Infection in Three New York City Hospitals Trended Downwards From 2006 to 2014

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is a rising public health threat since its first outbreaks in New York City (NYC) in the early 2000s. We investigated annual trends of CRKP infection in hospital-acquired infections (HAIs) and community-onset infections (COIs) treated in 3 NYC hospitals from 2006 to 2014.

METHODS

We extracted K pneumoniae infection data including carbapenem susceptibility and anatomical sites, compared clinical characteristics between CRKP and carbapenem-susceptible K pneumoniae infections, and determined CRKP infection proportions in total K pneumoniae infections in HAI and COI to identify statistically significant trends from 2006 to 2014 using the Cochran-Armitage trend test.

RESULTS

Carbapenem-resistant K pneumoniae contributed 17.3% (601 of 3477) of hospital-acquired K pneumoniae infection compared with 7.7% (149 of 1926) in COI from 2006 to 2014. Carbapenem-resistant K pneumoniae proportions in HAI and COI were positively correlated over time (r = 0.83, P < .01), and there were downward annual trends of CRKP proportions from 2006 to 2014 in both HAI and COI (25.8% to 10.5% in HAI, P < .001; 13.6% to 3.1% in COI, P < .001). By anatomical site, significant downward annual trends were present only in urinary tract infection (P < .001 for both HAI and COI) from 2006 to 2014.

CONCLUSIONS

Annual trends of CRKP proportions from 2006 to 2014 were downward in both HAI and COI, and HAI and COI were positively correlated. Efforts to reduce and prevent CRKP infections in both hospital and community settings were successful and warrant continuation.

Spread of Carbapenem-Resistant Enterobacteriaceae Among Illinois Healthcare Facilities: The Role of Patient Sharing

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) spread regionally throughout healthcare facilities through patient transfer and cause difficult-to-treat infections. We developed a state-wide patient-sharing matrix and applied social network analyses to determine whether greater connectedness (centrality) to other healthcare facilities and greater patient sharing with long-term acute care hospitals (LTACHs) predicted higher facility CRE rates.

METHODS

We combined CRE case information from the Illinois extensively drug-resistant organism registry with measures of centrality calculated from a state-wide hospital discharge dataset to predict facility-level CRE rates, adjusting for hospital size and geographic characteristics.

RESULTS

Higher CRE rates were observed among facilities with greater patient sharing, as measured by degree centrality. Each additional hospital connection (unit of degree) conferred a 6% increase in CRE rate in rural facilities (relative risk [RR] = 1.056; 95% confidence interval [CI], 1.030-1.082) and a 3% increase among Chicagoland and non-Chicago urban facilities (RR = 1.027; 95% CI, 1.002-1.052 and RR = 1.025; 95% CI, 1.002-1.048, respectively). Sharing 4 or more patients with LTACHs was associated with higher CRE rates, but this association may have been due to chance (RR = 2.08; 95% CI, .85-5.08; P = .11).

CONCLUSIONS

Hospitals with greater connectedness to other hospitals in a statewide patient-sharing network had higher CRE burden. Centrality had a greater effect on CRE rates in rural counties, which do not have LTACHs. Social network analysis likely identifies hospitals at higher risk of CRE exposure, enabling focused clinical and public health interventions.