The association between colonization with carbapenemase-producing enterobacteriaceae and overall ICU mortality: an observational cohort study

A comprehensive evaluation of risk factors for mortality, infection and colonization associated with CRGNB in adult solid organ transplant recipients: a systematic review and meta-analysis

BACKGROUND

The burden of carbapenem-resistant gram-negative bacteria (CRGNB) among solid organ transplant (SOT) recipients has not been systematically explored. Here, we discern the risk factors associated with CRGNB infection and colonization in SOT recipients.

METHODS

This study included observational studies conducted among CRGNB-infected SOT patients, which reported risk factors associated with mortality, infection or colonization. Relevant records will be searched in PubMed, Embase and Web of Science for the period from the time of database construction to 1 March 2023.

RESULTS

A total of 23 studies with 13,511 participants were included, enabling the assessment of 27 potential risk factors. The pooled prevalence of 1-year mortality among SOT recipients with CRGNB was 44.5%. Prolonged mechanical ventilation, combined transplantation, reoperation and pre-transplantation CRGNB colonization are salient contributors to the occurrence of CRGNB infections in SOT recipients. Renal replacement therapy, post-LT CRGNB colonization, pre-LT liver disease and model for end-stage liver disease score increased the risk of infection. Re-transplantation, carbapenem use before transplantation and ureteral stent utilization increaesd risk of CRGNB colonization.

CONCLUSION

Our study demonstrated that SOT recipients with CRGNB infections had a higher mortality risk. Invasive procedure may be the main factor contribute to CRGNB infection.

Carbapenem- and colistin-resistant Enterobacterales in intensive care unit patients in Mediterranean countries, 2019

Introduction

The colonization of patients by carbapenemase-producing Enterobacterales (CPE) has been associated with heightened mortality, especially in vulnerable individuals within intensive care units (ICUs). Our study aimed to comprehensively assess CPE prevalence among ICU patients across the Mediterranean region pre-COVID-19, conducting a multicenter prevalence study in the first quarter of 2019.

Methods

We collected clinical data and rectal or fecal samples from 256 ICU patients for CPE testing. Additionally, we performed whole-genome sequencing on 40 representative CPE strains to document their molecular characteristics.

Results

Among the 256 patients, CPE was detected in 73 samples (28.5%), with prevalence varying from 3.3 to 69.0% across participating centers. We observed 13 colistin-resistant CPE strains, affecting three ICUs. Genetic analysis revealed highly diverse E. coli and K. pneumoniae strains, predominantly from international high-risk clones. Notably, blaOXA-48 and blaNDM-1 were the most prevalent carbapenemase genes. Molecular typing uncovered potential patient clusters in six centers. Significantly, longer hospital stays were associated with increased CPE carriage (p < 0.001). Nine centers across Morocco, Tunisia, Egypt, and Lebanon voluntarily participated.

Discussion

Our study provides CPE prevalence in Mediterranean ICUs and reaffirms established CPE presence in this setting but also provides updates on the molecular diversity of CPE strains. These findings highlight the imperative of reinforcing infection control measures in the participating ICUs to curtail escalated mortality rates, and of strictly applying isolation measures around patients originating from the Mediterranean region when transferred to other healthcare institutions.

Carbapenem-producing Enterobacteriaceae in mothers and newborns in southeast Gabon, 2022

Introduction

Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) pose a significant threat, leading to severe morbidity and mortality among newborns.

Methods

This study, conducted at Franceville hospital's maternity and neonatology wards from February 22nd to June 20th, 2022, investigated the prevalence of CPE in 197 parturients and 203 newborns. Rectal swabs were taken from parturients before delivery and from newborns 30 minutes after birth. Blood culture samples were collected if signs of infection were observed in newborns during a 28-day follow-up. A total of 152 environmental samples were obtained, comprising 18 from sinks, 14 from incubators, 27 from cradles, 39 from maternal beds, 14 from tables and desks, four from the two baby scales and 36 from bedside furniture.

Results

None of the 203 newborns were found to be CPE carriers 30 minutes after delivery. CPE carriage was found in 4.6% of mothers. When comparing colonized and uncolonized parturients, well-established risk factors for CPE carriage, such as recent hospitalization and antibiotic therapy, were more frequently observed among CPE carriers (33.3 vs 10.6% for hospitalization in the past 15 days; 55.5 vs 30.3% for hospitalization during pregnancy, and 55.5 vs 35.1% for antibiotic therapy during pregnancy). Notably, the prevalence of treatment with amoxicillin and clavulanic acid was 44.4% in CPE carriers compared to 17.0% in non-carriers. The incidence density of CPE-associated bloodstream infection was 0.49 per 100 newborns, accounting for a fatal case of CPE-associated bacteremia identified in one of the 203 newborns. Seven environmental samples returned positive for CPE (5 sinks and two pieces of furniture). Whole genome sequencing, performed on the 25 CPE isolates, revealed isolates carrying blaNDM-7 (n=10), blaNDM-5 (n=3), blaOXA181 (n=10), blaOXA48 (n=2) or blaOXA244 (n=1), along with genetic traits associated with the ability to cause severe and difficult-to-treat infections in newborns. Core genome comparison revealed nine CPE belonging to three international high-risk clones: E. coli ST410 (four mothers and a sink), two E. coli ST167 (a mother and a piece of furniture), and K. pneumoniae ST307 (a sink and a piece of furniture), with highly similar genetic backgrounds shared by maternal and environmental isolates, suggesting maternal contamination originating from the environment.

Discussion

Our study reveals key findings may guide the implementation of infection control measures to prevent nosocomial infections in newborns: the prevalence of CPE carriage in one out of 20 parturients, an infection occurring in one out of 400 newborns, substantial contamination of the care environment, clinical and environmental CPE isolates possessing genetic traits associated with the ability to cause severe and challenging infections, and clonal relationships between clinical and environmental isolates suggesting CPE spread within the wards, likely contributing to the acquisition and colonization of CPE by parturients during pregnancy.

Pathogenesis and therapeutic opportunities of gut microbiome dysbiosis in critical illness

For many years, it has been hypothesized that pathological changes to the gut microbiome in critical illness is a driver of infections, organ dysfunction, and other adverse outcomes in the intensive care unit (ICU). The advent of contemporary microbiome methodologies and multi-omics tools have allowed researchers to test this hypothesis by dissecting host-microbe interactions in the gut to better define its contribution to critical illness pathogenesis. Observational studies of patients in ICUs have revealed that gut microbial communities are profoundly altered in critical illness, characterized by markedly reduced alpha diversity, loss of commensal taxa, and expansion of potential pathogens. These key features of ICU gut dysbiosis have been associated with adverse outcomes including life-threatening hospital-acquired (nosocomial) infections. Current research strives to define cellular and molecular mechanisms connecting gut dysbiosis with infections and other outcomes, and to identify opportunities for therapeutic modulation of host-microbe interactions. This review synthesizes evidence from studies of critically ill patients that have informed our understanding of intestinal dysbiosis in the ICU, mechanisms linking dysbiosis to infections and other adverse outcomes, as well as clinical trials of microbiota-modifying therapies. Additionally, we discuss novel avenues for precision microbial therapeutics to combat nosocomial infections and other life-threatening complications of critical illness.

Antimicrobial Multidrug Resistance: Clinical Implications for Infection Management in Critically Ill Patients

The increasing incidence of antimicrobial resistance (AMR) worldwide represents a serious threat in the management of sepsis. Due to resistance to the most common antimicrobials prescribed, multidrug-resistant (MDR) pathogens have been associated with delays in adequate antimicrobial therapy leading to significant increases in mortality, along with prolonged hospital length of stay (LOS) and increases in healthcare costs. In response to MDR infections and the delay of microbiological results, broad-spectrum antibiotics are frequently used in empirical antimicrobial therapy. This can contribute to the overuse and misuse of antibiotics, further promoting the development of resistance. Multiple measures have been suggested to combat AMR. This review will focus on describing the epidemiology and trends concerning MDR pathogens. Additionally, it will explore the crucial aspects of identifying patients susceptible to MDR infections and optimizing antimicrobial drug dosing, which are both pivotal considerations in the fight against AMR. Expert commentary: The increasing AMR in ICUs worldwide makes the empirical antibiotic therapy challenging in septic patients. An AMR surveillance program together with improvements in MDR identification based on patient risk stratification and molecular rapid diagnostic tools may further help tailoring antimicrobial therapies and avoid unnecessary broad-spectrum antibiotics. Continuous infusions of antibiotics, therapeutic drug monitoring (TDM)-based dosing regimens and combination therapy may contribute to optimizing antimicrobial therapy and limiting the emergence of resistance.

Predictors of bacteremia and death, including immune status, in a large single-center cohort of unvaccinated ICU patients with COVID-19 pneumonia

BACKGROUND

We investigated the possible role of the immune profile at ICU admission, among other well characterized clinical and laboratory predictors of unfavorable outcome in COVID-19 patients assisted in ICU.

METHODS

Retrospective analysis of clinical and laboratory data collected for all consecutive patients admitted to the ICUs of the General Hospital of Pescara (Abruzzo, Italy), between 1^st March 2020 and 30^th April 2021, with a confirmed diagnosis of COVID-19 respiratory failure. Logistic regressions were used to identify independent predictors of bacteremia and mortality.

RESULTS

Out of 431 patients included in the study, bacteremia was present in N = 191 (44.3%) and death occurred in N = 210 (48.7%). After multivariate analysis, increased risk of bacteremia was found for viral reactivation (OR = 3.28; 95% CI:1.83-6.08), pronation (3.36; 2.12-5.37) and orotracheal intubation (2.51; 1.58-4.02). Increased mortality was found for bacteremia (2.05; 1.31-3.22), viral reactivation (2.29; 1.29-4.19) and lymphocytes < 0.6 × 10³c/µL (2.32; 1.49-3.64).

CONCLUSIONS

We found that viral reactivation, mostly due to Herpesviridae, was associated with increased risk of both bacteremia and mortality. In addition, pronation and intubation are strong predictors of bacteremia, which in turn together with severe lymphocytopenia due to SARS-CoV2 was associated with increased mortality. Most episodes of bacteremia, even due to Acinetobacter spp, were not predicted by microbiological evidence of colonization.

Associated factors for bacterial colonization in patients admitted to the intensive care unit of the Clinical Hospital of Infectious Diseases

Introduction

This study aimed to identify isolates from colonization and assess the risk factors for bacterial colonization and the risk of death in patients admitted to the intensive care unit (ICU) of the Constanţa County Infectious Diseases Hospital between September 2017 and September 2019.

Methods

This was a retrospective case-control study in a single center that included all patients admitted to the ICU in Constanţa, Romania, who underwent bacteriological screening upon admission and 7 days after admission, between September 2017 and September 2019. In total, 253 patients were included in this study. The nasal exudate, pharyngeal exudate, and rectal swab samples were screened.

Results

In this study, 253 patients were screened bacteriologically, of which 53 had bacterial colonization and 200 did not. Among the bacterial strains, Klebsiella spp. (43.39%) was the most frequently isolated. The predominant resistance mechanism detected in the bacterial isolates was extended-spectrum β-lactamase (ESBL). Multivariate analysis identified a Carmeli score of 3 as an independent risk factor for acquiring bacterial colonization in the ICU. The mortality rate of patients with bacterial colonization was 11.32% and 6% for the patients without colonization (p>0.05).

Conclusions

Our study revealed an increased prevalence of Enterobacterales colonization in the ICU. Risk factors for acquiring bacterial colonization differed depending on the type of bacterial colonization, such as ESBL, carbapenemases, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). An independent risk factor for acquiring bacterial colonization was the Carmeli score of 3.

In-hospital mortality and one-year survival of critically ill patients with cancer colonized or not with carbapenem-resistant gram-negative bacteria or vancomycin-resistant enterococci: an observational study

BACKGROUND

Patients with cancer are at risk of multidrug-resistant bacteria colonization, but association of colonization with in-hospital mortality and one-year survival has not been established in critically ill patients with cancer.

METHODS

Using logistic and Cox-regression analyses adjusted for confounders, in adult patients admitted at intensive care unit (ICU) with active cancer, we evaluate the association of colonization by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci with in-hospital mortality and one-year survival.

RESULTS

We included 714 patients and among them 140 were colonized (19.6%). Colonized patients more frequently came from ward, had longer hospital length of stay before ICU admission, had unplanned ICU admission, had worse performance status, higher predicted mortality upon ICU admission, and more hematological malignancies than patients without colonization. None of the patients presented conversion of colonization to infection by the same bacteria during hospital stay, but 20.7% presented conversion to infection after hospital discharge. Colonized patients had a higher in-hospital mortality compared to patients without colonization (44.3 vs. 33.4%; p < 0.01), but adjusting for confounders, colonization was not associated with in-hospital mortality [Odds ratio = 1.03 (0.77-1.99)]. Additionally, adjusting for confounders, colonization was not associated with one-year survival [Hazard ratio = 1.10 (0.87-1.40)].

CONCLUSIONS

Adult critically ill patients with active cancer and colonized by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci active cancer have a worse health status compared to patients without colonization. However, adjusting for confounders, colonization by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci are not associated with in-hospital mortality and one-year survival.

Epidemiology and Mortality Analysis Related to Carbapenem-Resistant Enterobacterales in Patients After Admission to Intensive Care Units: An Observational Study

Purpose

The prevalence of carbapenem-resistant Enterobacterales (CRE) is rapidly increasing worldwide. Patients in the intensive care unit (ICU) are susceptible to CRE infections, and the related mortality rate is increased. It is necessary to understand CRE strains and risk factors for CRE infection in the ICU, to facilitate development of effective prophylactic strategies and treatments for ICU patients.

Patients and Methods

This observational study was conducted in a tertiary hospital between 2016 and 2021. The subjects were patients with CRE cultured from specimens obtained after ICU admission. Genotypes of strains of CRE and carbapenemase-producing Enterobacterales (CPE) were identified, CRE infection was distinguished from mere colonization, and the clinical course of these patients was investigated.

Results

Among 327 CRE cases, 84 (25.7%) showed infection and 243 (74.3%) showed colonization. Of these patients, 138 (42.2%) died. The CRE strains were Klebsiella pneumoniae (253 cases, 77.4%), Enterobacter cloacae (44 cases, 13.5%), and Escherichia coli (15 cases, 4.6%). Among CRE cases, CPE was found in 249 (76.1%), including Klebsiella pneumoniae carbapenemase (KPC) in 164 (65.9%), and Guiana extended-spectrum (GES) in 64 (25.7%). A bedridden state, longer ICU stay, chronic kidney disease, malignancy, connective tissue disease, ICU admission for cardiac arrest, and CRE infection were associated with higher mortality, but cerebrovascular disease and ICU admission for trauma were associated with lower mortality. GES outbreak was caused by person-to-person transmission and was controlled through active surveillance.

Conclusion

The frequency of K. pneumoniae and KPC was the highest, but E. cloacae and GES was characteristically high in this study. Active CRE surveillance can be helpful for controlling outbreak.

Gut colonisation with multidrug-resistant Klebsiella pneumoniae worsens Pseudomonas aeruginosa lung infection

Carbapenemase-producing Enterobacterales (CPE) are spreading rapidly in hospital settings. Asymptomatic CPE gut colonisation may be associated with dysbiosis and gut-lung axis alterations, which could impact lung infection outcomes. In this study, in male C57BL/6JRj mice colonised by CPE, we characterise the resulting gut dysbiosis, and analyse the lung immune responses and outcomes of subsequent Pseudomonas aeruginosa lung infection. Asymptomatic gut colonisation by CPE leads to a specific gut dysbiosis and increases the severity of P. aeruginosa lung infection through lower numbers of alveolar macrophages and conventional dendritic cells. CPE-associated dysbiosis is characterised by a near disappearance of the Muribaculaceae family and lower levels of short-chain fatty acids. Faecal microbiota transplantation restores immune responses and outcomes of lung infection outcomes, demonstrating the involvement of CPE colonisation-induced gut dysbiosis in altering the immune gut-lung axis, possibly mediated by microbial metabolites such as short-chain fatty acids.

Ceftazidime/Avibactam, Polymyxin or Tigecycline as a Rescue Strategy for the Treatment of Carbapenem-Resistant Klebsiella pneumoniae in Bloodstream Infection: A Retrospective Cohort Study

Objective

To analyze the clinical characteristics, outcomes, and risk factors of patients treated with ceftazidime/avibactam, polymyxin, or tigecycline (CPT) compared with those receiving a conventional therapy (CT) (ie, imipenem, levofloxacin, or gentamicin).

Methods

A single-center retrospective cohort study included patients with carbapenem-resistant Klebsiella pneumoniae bloodstream infection (CRKP-BSI) treated at one Chinese tertiary hospital between March 2012 and November 2022 was performed. Clinical characteristics, outcomes, and risk factors of patients treated with CPT or CT were compared. Predictors of 30-day mortality of patients with CRKP-BSI were also analysed in our study.

Results

Among 184 recruited patients with CRKP-BSI, 39.7% (73/184) were treated with CPT, while 60.3% (111/184) were treated with CT. Compared to patients treated with CT, patients treated with CPT had worse conditions, as evidenced by a higher rate of underlying diseases and invasive procedures; however, they also had a better prognosis and lower rates of 14-day treatment failure (p = 0.024). In addition, univariate analysis and multivariate analysis showed that SOFA score [odds ratio (OR) = 1.310, 95% confidence interval (CI) 1.157-1.483; p < 0.001] and cold weather (OR = 3.658, 95% CI 1.474-9.081; p = 0.005) were independent risk factors for 30-day mortality.

Conclusion

Compared to CRKP-BSI patients treated with CT, patients treated with CPT had worse conditions but better prognoses. CRKP-BSI occurred more frequently in hot weather; however, higher 30-day mortality was associated with cold weather. A randomized trial is needed to confirm these observational results.

Predictors of carbapenem-resistant Enterobacteriaceae (CRE) strains in patients with COVID-19 in the ICU ward: a retrospective case-control study

Objective

To identify carbapenem-resistant Enterobacteriaceae (CRE) in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; COVID-19) and to determine whether they had different risk factors for the acquisition of CRE than patients without COVID-19.

Methods

This retrospective single-centre, case–control study enrolled patients with and without COVID-19. The demographic, clinical, infection, colonization and mortality data were compared between the two groups.

Results

A total of 38 patients with COVID-19 and 26 patients without COVID-19 were enrolled. The majority of isolates detected in COVID-19 patients were Klebsiella spp. Leukopenia at admission (odds ratio [OR] 4.70; 95% confidence interval [CI] 1.37, 16.10), invasive mechanical ventilation (OR 5.74; 95% CI 1.07, 30.63), carbapenem treatment (OR 5.09; 95% CI 1.21, 21.27) and corticosteroid treatment (OR 7.06; 95% CI 1.53, 32.39) were independent risk factors for CRE acquisition in COVID-19 patients. Intensive care unit (ICU) mortality was significantly higher in COVID-19 patients compared with patients without COVID-19 (OR 20.62; 95% CI 5.50, 77.23). Length of ICU stay increased the risk of death in patients with COVID-19 (subdistribution hazard ratio 3.81; 95% CI 1.33, 10.92).

Conclusion

CRE strains were more common in patients with COVID-19 and they had different risks for CRE compared with patients without COVID-19.

ANTIMICROBIAL RESISTANCE AND MORTALITY

Background

Antibiotic resistance has been a long-debated topic since decades ago. The development of stronger, newer antibiotics, implementation of antibiotic stewardship and revised guidelines remain the main focus of our society to prevent resistancy. But is it really resistancy that cause higher mortality to patients with multidrug resistance (MDR) infections?

Methods

We conducted a cohort retrospective study from 2016 to 2019 in our Intensive care unit (ICU). Antimicrobial susceptibility test (AST) results were analyzed for their association with patient mortality outcomes.

Results

Over the four-year period, 381 positive bacterial cultures were analyzed and 51% of them grew MDR pathogens upon their first culture. The overall mortality rate was 19% (38/195), and there was no significant association between MDR and mortality; p 0.387. A strong association was however found between patients with medical cases with an OR 1.76; CI 1.76-2.55; p 0.003 and those with APACHE scores ≥20 upon admittance to the ICU, OR 1.32; CI 1.68-8.29; p 0.001.

Conclusion

Resistancy is not the true cause of mortality. Infection by resistant microbes does not necessarily mean the worst outcome since virulency is the actual cause of pathogenicity, and thus mortality.

Association between Timing of Colonization and Risk of Developing Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Infection in Hospitalized Patients

Colonization by KPC-producing Klebsiella pneumoniae (KPC-Kp) is associated with the risk of developing KPC-Kp infection. The impact of the time elapsed since a patient becomes colonized on this risk is not well known. An observational, prospective, longitudinal cohort study of colonized patients undergoing active rectal culture screening to rule out KPC-Kp colonization (July 2012 to November 2017). Patients with a positive culture at inclusion (colonized at start of follow-up) and those with a negative culture at inclusion who became colonized within 90 days (colonized during follow-up) were included in the analysis. CART analysis was used to dichotomize variables according to their association with infection. Kaplan–Meier infection-free survival curves and the log-rank test were used for group comparisons. Logistic regression was used to identify variables associated with KPC-Kp infection. Among 1310 patients included, 166 were colonized at the end of follow-up. Forty-seven out of 118 patients colonized at start of follow-up developed infection (39.8%) versus 31 out of 48 patients colonized during follow-up (64.6%; P = 0.006). Variables associated with KPC-Kp infection in the logistic regression analysis were: colonization detection during follow-up (OR, 2.74; 95% CI, 1.07 to 7.04; P = 0.03), Giannella risk score (OR, 1.51; 95% CI, 1.32 to 1.73; P < 0.001), high-risk ward (OR, 4.77; 95% CI, 1.61 to 14.10; P = 0.005) and urological manipulation after admission (OR, 3.69; 95% CI, 1.08 to 12.60; P = 0.04). In 25 out of 31 patients (80.6%) colonized during follow-up who developed KPC-Kp infection, infection appeared within 15 days after colonization. The risk of KPC-Kp infection was higher when colonization is recently acquired during hospitalization. In this prospective study, we concluded that the timing of colonization was a factor to assess when considering empirical treatment for suspected KPC-Kp infection and prophylaxis or infection control.

IMPORTANCE In this study, it was confirmed that patients who became colonized during hospitalization had a higher risk of developing KPC-Kp infection than hospitalized patients who were already colonized at the start of follow-up. Besides, the risk of infection in the group of patients who became colonized during follow-up was greater in the first weeks immediately after colonization was confirmed. Our findings support the need for designing preventive strategies for patients at the highest risk of infection development, including those admitted in high-risk hospital wards and those undergoing urological procedures.

A Computational Model of Bacterial Population Dynamics in Gastrointestinal Yersinia enterocolitica Infections in Mice

Simple Summary

Computational modeling of bacterial infection is an attractive way to simulate infection scenarios. In the long-term, such models could be used to identify factors that make individuals more susceptible to infection, or how interference with bacterial growth influences the course of bacterial infection. This study used different mouse infection models (immunocompetent, lacking a microbiota, and immunodeficient models) to develop a basic mathematical model of a Yersinia enterocolitica gastrointestinal infection. We showed that our model can reflect our findings derived from mouse infections, and we demonstrated how crucial the exact knowledge about parameters influencing the population dynamics is. Still, we think that computational models will be of great value in the future; however, to foster the development of more complex models, we propose the broad implementation of the interdisciplinary training of mathematicians and biologists.

Abstract

The complex interplay of a pathogen with its virulence and fitness factors, the host’s immune response, and the endogenous microbiome determine the course and outcome of gastrointestinal infection. The expansion of a pathogen within the gastrointestinal tract implies an increased risk of developing severe systemic infections, especially in dysbiotic or immunocompromised individuals. We developed a mechanistic computational model that calculates and simulates such scenarios, based on an ordinary differential equation system, to explain the bacterial population dynamics during gastrointestinal infection. For implementing the model and estimating its parameters, oral mouse infection experiments with the enteropathogen, Yersinia enterocolitica (Ye), were carried out. Our model accounts for specific pathogen characteristics and is intended to reflect scenarios where colonization resistance, mediated by the endogenous microbiome, is lacking, or where the immune response is partially impaired. Fitting our data from experimental mouse infections, we can justify our model setup and deduce cues for further model improvement. The model is freely available, in SBML format, from the BioModels Database under the accession number MODEL2002070001.

Isolation of extensively drug resistant Acinetobacter baumannii from environmental surfaces inside intensive care units

BACKGROUND

Acinetobacter baumannii is a nosocomial pathogen that has emerged as a major threat in the health-care settings, particularly intensive care units (ICUs). The aim of this study was to investigate the prevalence of A. baumannii in the environment of intensive care and emergency units in 4 hospitals in Jordan.

METHODS

A total of 311 surface and 26 air samples were collected from 6 different ICUs and 2 emergency units. Examined high-touch surfaces included bed rails, sinks, food tables, trolley handles, ventilator inlets, blankets, sheets, door handles, light switches, bedside tables and drawers, curtains, normal saline stands and neonatal incubators. A. baumannii isolates were identified by CHROMagar and confirmed using 2 different PCR assays. All obtained isolates were characterized for their antibiotic resistance phenotypes, biofilm formation capacities and were typed by multi-locus sequence typing.

RESULTS

Of the 337 samples, 24 A. baumannii isolates were recovered, mostly from surfaces in the internal medicine ICUs. Among the 24 isolates, 10 isolates were classified as extensively-resistant (XDR), harbored the bla_OXA-23 like gene and able to form biofilms with varying capacities. ST2 was the most frequent sequence type, with all ST2 isolates classified as XDRs.

CONCLUSIONS

Our results showed that high-touch surfaces of adult and pediatric ICUs were contaminated with XDR A. baumannii isolates. Therefore, the cleaning practices of the surfaces and equipment surrounding ICU patients should be optimized, and health-care workers should continuously wash their hands and change their gloves constantly to control the spread of this pathogen.

The Monte Carlo Simulation of Three Antimicrobials for Empiric Treatment of Adult Bloodstream Infections With Carbapenem-Resistant Enterobacterales in China

Introduction: The aim of this study was to predict and evaluate three antimicrobials for treatment of adult bloodstream infections (BSI) with carbapenem-resistant Enterobacterales (CRE) in China, so as to optimize the clinical dosing regimen further.

Methods: Antimicrobial susceptibility data of blood isolates were obtained from the Blood Bacterial Resistance Investigation Collaborative Systems in China. Monte Carlo simulation was conducted to estimate the probability target attainment (PTA) and cumulative fraction of response (CFR) of tigecycline, polymyxin B, and ceftazidime/avibactam against CRE.

Results: For the results of PTAs, tigecycline following administration of 50 mg every 12 h, 75 mg every 12 h, and 100 mg every 12 h achieved > 90% PTAs when minimum inhibitory concentration (MIC) was 0.25, 0.5, and 0.5 μg/mL, respectively; polymyxin B following administration of all tested regimens achieved > 90% PTAs when MIC was 1 μg/mL with CRE; ceftazidime/avibactam following administration of 1.25 g every 8 h, 2.5 g every 8 h achieved > 90% PTAs when MIC was 4 μg/mL, 8 μg/mL with CRE, respectively. As for CFR values of three antimicrobials, ceftazidime/avibactam achieved the lowest CFR values. The highest CFR value of ceftazidime/avibactam was 77.42%. For tigecycline and ceftazidime/avibactam, with simulated regimens daily dosing increase, the CFR values were both increased; the highest CFR of tigecycline values was 91.88%. For polymyxin B, the most aggressive dosage of 1.5 mg/kg every 12 h could provide the highest CFR values (82.69%) against CRE.

Conclusion: This study suggested that measurement of MICs and individualized therapy should be considered together to achieve the optimal drug exposure. In particular, pharmacokinetic and pharmacodynamic modeling based on local antimicrobial resistance data can provide valuable guidance for clinicians for the administration of empirical antibiotic treatments for BSIs.

Carbapenemase-producing Enterobacteriaceae in an inpatient post-acute care facility: impact on time to functional recovery

BACKGROUND

The carriage of carbapenemase-producing Enterobacteriaceae (CPE) might lengthen the time to functional recovery (TTFR) for inpatients in post-acute care (PAC) units.

OBJECTIVE

We aimed to assess the impact of CPE carriage on TTFR in a PAC facility.

METHODS

This 2-year retrospective cohort study included 20 CPE-positive patients and 54 CPE-negative patients admitted to 3 PAC units (general, orthopaedic and neurologic rehabilitation units) in a teaching hospital from January 2017 to December 2019. Potential risk factors and demographic data were collected from patients' medical records, the French national hospital discharge database, and the hospital's CPE surveillance database. Functional recovery was defined as the median difference in functional independence measure (FIM) between admission and discharge from each unit. Survival analysis and multiple Cox regression models were used to predict the TTFR and identify factors associated with functional recovery.

RESULTS

The overall median [interquartile range] TTFR was 50 days [36-66]. Longer median TTFR was associated with CPE carriage (63 vs 47 days in the CPE-negative group; adjusted hazard ratio (aHR) 0.35, 95% CI 0.13-0.97) and presence of a peripheral venous catheter (aHR 3.51, 1.45-8.46); shorter TTFR was associated with admission to an orthopaedic versus general rehabilitation unit (aHR 3.11, 1.24-7.82).

CONCLUSIONS

CPE carriage in inpatient PAC facilities was associated with long TTFR. Further studies are needed to explore the mechanisms involved in these adverse events and to identify possible preventive measures.

Screening for Antimicrobial-Resistant Gram-negative bacteria in hospitalised patients, and risk of progression from colonisation to infection: Systematic review

BACKGROUND

Transmission of antimicrobial-resistant Gram-negative bacteria (AMR-GNB) among hospitalised patients can lead to new cases of carriage, infection and outbreaks, hence the need for early carrier identification. We aim to explore two key elements that may guide control policies for colonisation/infection in hospital settings: screening practices on admission to hospital wards and risk of developing infection from colonisation.

METHODS

We searched on PubMed, Scopus and Cochrane databases for studies published from 2010 up to 2021 reporting on adult patients hospitalised in high-income countries.

RESULTS

The search retrieved 11853 articles. After screening, 100 studies were included. Combining target patient groups and setting type, we identified six screening approaches. The most reported approach was all admitted patients to high-risk (HR) wards (49.4%). The overall prevalence of AMR-GNB was 13.8% (95%CI 9.3-19.0) with significant differences across regions and time. Risk of progression to infection among colonised patients was 11.0% (95%CI 8.0-14.3) and varied according to setting and pathogens' group (p value<0.0001), with higher values reported for Klebsiella species (18.1%; 95%CI 8.9-29.3).

CONCLUSIONS

While providing a comprehensive overview of the screening approaches, our study underlines the considerable burden of AMR-GNB colonisation and risk of progression to infection in hospitals by pathogen, setting and time.

Association between rectal colonization by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae and mortality: a prospective, observational study

BACKGROUND

We evaluated the association of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) rectal colonization with crude mortality and whether this association is independent of the risk of KPC-Kp infection..

METHODS

Prospective cohort study of patients followed up 90 days after a study of rectal colonization. Cox-regression was used to study the variables associated with crude mortality. Sensitivity analyses for crude 90-day mortality in different subcohorts were performed.

RESULTS

A total of 1244 patients (1078 non-colonized and 166 colonized) were included. None of the non-colonized patients and 78 (47.0%) of the colonized patients developed KPC-Kp infection. Crude 90-day mortality was 18% (194/1078) in non-colonized patients and 41.6% (69/166) in colonized patients. Rectal colonization was not associated with crude mortality (Hazard Ratio [HR] 1.03; 95% CI 0.69-1.54; p = 0.85) when the model was adjusted for severe KPC-Kp infection (INCREMENT-CPE score [ICS] > 7). KPC-Kp infection with ICS > 7 was associated with an increased risk of all-cause mortality (HR 2.21; 95% CI 1.35-3.63; p = 0.002). In the sensitivity analyses, KPC-Kp colonization was not associated with mortality in any of the analyzed subcohorts, including patients who did not develop KPC-Kp infection (HR 0.93; 95%CI: 0.60-1.43; p=0.74).

CONCLUSIONS

KPC-Kp rectal colonization was not associated with crude mortality. Mortality increased when colonized patients developed severe KPC-Kp infection (ICS > 7). Rectal colonization was a necessary although insufficient condition to die from a KPC-Kp infection.

A Novel Switching State-Space Model for Post-ICU Mortality Prediction and Survival Analysis

Predicting mortality risk in patients accurately during and after intensive care unit (ICU) stay is an essential component for supporting critical care decision-making. To date, various scoring systems have been designed for survival analysis and mortality prediction by providing risk scores based on patient's vital signs and lab results. However, it is challenging using these universal scores to represent the overall severity level of illness and to look into patient's deterioration leading to high mortality risk during ICU stay. Thus, a close monitoring of the severity level over time during ICU stay is more preferable. In this study, we design a new switching state-space model by correlating patient's condition dynamics in last hours of ICU stay to the risk probabilities in a short time period (1-6 days) after ICU discharge. More specifically, we propose to integrate a cumulative hazard function estimating survival probability into the autoregressive hidden Markov model using time-interval sequential SAPS II scores as features. We demonstrate the significant improvement of mortality prediction comparing to SAPS I, SAPS II, and SOFA scoring systems for the PhysioNet MIMIC II Challenge data.

Accuracy of Xpert Carba-R Assay for the Diagnosis of Carbapenemase-Producing Organisms from Rectal Swabs and Clinical Isolates: A Meta-Analysis of Diagnostic Studies

The Cepheid Xpert Carba-R assay has demonstrated a promising value for the detection of carbapenemase-producing organisms, but its diagnostic performance remains unclear. Studies were retrieved from Cochrane Library, EMBASE, and PubMed databases according to predetermined selection criteria. The specificity, sensitivity, negative likelihood ratio, positive likelihood ratio, and area under the summary receiver operating characteristic curves of Xpert Carba-R were analyzed by STATA version 13.0. The quality of each study was examined by Quality Assessment of Diagnostic Accuracy Studies using RevMan version 5.2. In total, 17 unique studies involving 15,972 samples met the inclusion criteria. Nine studies performed Xpert Carba-R on rectal swabs. The pooled sensitivity, specificity, and area under the curve were as follows: 0.95 (95% CI, 0.91-0.97; I² = 90.80%), 0.99 (95% CI, 0.97-0.99; I² = 97.17%), and 0.99 (95% CI, 0.98-1.00), respectively. The sensitivity and specificity of Xpert Carba-R in high-risk populations were 0.99 (95% CI, 0.76-1.00; I² = 78.51%) and 0.98 (95% CI, 0.97-0.99; I² = 84.95%), respectively. The sensitivity and specificity in low-prevalence regions were 0.96 (95% CI, 0.88-0.99; I² = 74.58%) and 0.99 (95% CI, 0.98-0.99; I² = 77.66%), respectively. Eight studies performed Xpert Carba-R on clinical isolates. The pooled sensitivity and specificity were 1.00 (95% CI, 0.97-1.00; I² = 97.43%) and 0.98 (95% CI, 0.97-0.99; I² = 55.27%), respectively. This meta-analysis indicates that Xpert Carba-R assay has excellent diagnostic accuracy for diagnosing carbapenemase-producing organisms on rectal swabs and clinical isolates, especially for high-risk populations and low-prevalence regions.

Performance of a loop-mediated isothermal amplification assay (Isoplex CRE-ART) to detect common carbapenemase-encoding genes in Gram-negative bacteria

Carbapenem-resistant Gram-negative bacteria (CR-GNB) are a major source of nosocomial infections worldwide. In this study, the ability of a loop-mediated isothermal amplification (LAMP)-based method (Isoplex CRE-ART) to rapidly detect carbapenemase-encoding genes bla _OXA-48-like, bla _OXA-23-like, bla _OXA-24-like, bla _KPC, bla _VIM, bla _NDM and bla _IMP in 231 carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii isolates was investigated. The accuracy of the LAMP test was compared to results of molecular isolate characterization using a Laboratory Developed Test multiplex carbapenemase PCR assay. The LAMP test correctly identified the presence of on-panel carbapenemases with a sensitivity of 99.16 % [95 % confidence interval (CI): 95.39-99.96 %] and a specificity of 98.21 % (95 % CI: 93.72-99.68 %) in 60 min. Our findings suggest that the Isoplex CRE-ART assay is able to rapidly identify carbapenemase genes in CR-GNB and improves options for pathogen characterization in the context of clinical microbiological and infection control diagnostics.

Taxonomic signatures of cause-specific mortality risk in human gut microbiome

The collection of fecal material and developments in sequencing technologies have enabled standardised and non-invasive gut microbiome profiling. Microbiome composition from several large cohorts have been cross-sectionally linked to various lifestyle factors and diseases. In spite of these advances, prospective associations between microbiome composition and health have remained uncharacterised due to the lack of sufficiently large and representative population cohorts with comprehensive follow-up data. Here, we analyse the long-term association between gut microbiome variation and mortality in a well-phenotyped and representative population cohort from Finland (n = 7211). We report robust taxonomic and functional microbiome signatures related to the Enterobacteriaceae family that are associated with mortality risk during a 15-year follow-up. Our results extend previous cross-sectional studies, and help to establish the basis for examining long-term associations between human gut microbiome composition, incident outcomes, and general health status.

Colonization With Extensively Drug-Resistant Acinetobacter baumannii and Prognosis in Critically Ill Patients: An Observational Cohort Study

Background: Acinetobacter baumannii is one of the most frequently isolated opportunistic pathogens in intensive care units (ICUs). Extensively drug-resistant A. baumannii (XDR-AB) strains lack susceptibility to almost all antibiotics and pose a heavy burden on healthcare institutions. In this study, we evaluated the impact of XDR-AB colonization on both the short-term and long-term survival of critically ill patients. Methods: We prospectively enrolled patients from two adult ICUs in Qilu Hospital of Shandong University from March 2018 through December 2018. Using nasopharyngeal and perirectal swabs, we evaluated the presence of XDR-AB colonization. Participants were followed up for 6 months. The primary endpoints were 28-day and 6-month mortality after ICU admission. The overall survival rate was estimated by the Kaplan-Meier method. We identified risk factors associated with 28-day and 6-month mortality using the logistic regression model and a time-dependent Cox regression model, respectively. Results: Out of 431 patients, 77 were colonized with XDR-AB. Based on the Kaplan-Meier curve results, the overall survival before 28 days did not differ by colonization status; however, a significantly lower overall survival rate was obtained at 6 months in colonized patients. Univariate and multivariate analysis results confirmed that XDR-AB colonization was not associated with 28-day mortality, but was an independent risk factor of lower overall survival at 6 months (HR = 1.749, 95% CI = 1.174-2.608). Conclusions: XDR-AB colonization has no effect on short-term overall survival, but is associated with lower long-term overall survival in critically ill patients.

Assessment of Piperacillin-Tazobactam-Meropenem Synergy against Serine Carbapenemase-Producing Enterobacterales Using Time-Kill Assays

Synergy between piperacillin-tazobactam and meropenem against KPC-producing Klebsiella pneumoniae was recently demonstrated. We sought to test the combination against a broader range of serine carbapenemase producers. We tested the combination against 10 KPC-producing Escherichia coli and 10 OXA-48 family-producing K. pneumoniae isolates. Antibiotic concentrations used are achievable in critically ill patients. The combination was synergistic against 7 of 10 KPC producers and 9 of 10 OXA-48 producers. There was no synergy detected in control isolates producing NDM-1.

The role of antimicrobial resistance on long-term mortality and quality of life in critically ill patients: a prospective longitudinal 2-year study

Background

In the recent era, antimicrobial resistance has been identified as one of the most important threats to human health worldwide. The rapid emergence of antibiotic-resistant pathogens (ABRP) in the modern intensive care unit (ICU) also represents a “nightmare scenario” with unknown clinical consequences. In the Greek ICU, in particular, gram negative ABRPs are now considered endemic. However, the possible longitudinal impact of ABRPs on long-term outcomes of ICU patients has not yet been determined.

Methods

In this two-year (January 2014-December 2015) single-centre observational longitudinal study, 351 non-neurocritical ICU patients ≥ 18 year-old were enrolled. Patients’ demographic, clinical and outcome data were prospectively collected. Quality-adjusted life years (QALY) were calculated at 6, 12, 18 and 24 months after ICU admission.

Results

Fifty-eight patients developed infections due to ABRP (ABRP group), 57 due to non-ABRP (non-ABRP group), and 236 demonstrated no infection (no-infection group) while in ICU. Multiple regression analysis revealed that multiple organ dysfunction syndrome score (OR: 0.676, 95%CI 0.584–0.782; P < 0.001) and continuous renal replacement therapy (OR: 4.453, 95%CI 1.805–10.982; P = 0.001) were the only independent determinants for ABRP infections in ICU. Intra-ICU, 90-day and 2-year mortality was 27.9%, 52.4% and 61.5%, respectively. Compared to the non-ABRP and no-infection group, the ABRP group demonstrated increased intra-ICU, 90-day and 2-year mortality (P ≤ 0.022), worse 2-year survival rates in ICU patients overall and ICU survivor subset (Log-rank test, P ≤ 0.046), and poorer progress over time in 2-year QALY kinetics in ICU population overall, ICU survivor and 2-year survivor subgroups (P ≤ 0.013). ABRP group was further divided into multi-drug and extensively-drug resistant subgroups [MDR (n = 34) / XDR (n = 24), respectively]. Compared to MDR subgroup, the XDR subgroup demonstrated increased ICU, 90-day and 2-year mortality (P ≤ 0.031), but similar 90-day and 2-year QALYs (P ≥ 0.549). ABRP infections overall (HR = 1.778, 95% CI 1.166–2.711; P = 0.008), as well as XDR [HR = 1.889, 95% CI 1.075–3.320; P = 0.027) but not MDR pathogens, were independently associated with 2-year mortality, after adjusting for several covariates of critical illness.

Conclusions

The present study may suggest a significant association between ABRP (especially XDR) infections in ICU and increased mortality and inability rates for a prolonged period post-discharge that requires further attention in larger-scale studies.

Development of a Risk Prediction Model for Carbapenem-Resistant Enterobacteriaceae Infection after Liver Transplantation: A Multinational Cohort Study

BACKGROUND

Patients colonized with carbapenem resistant Enterobacteriaceae (CRE) are at higher risk of developing CRE infection after liver transplantation (LT) with associated high morbidity and mortality. Prediction model for CRE infection after LT among carriers could be useful to target preventive strategies.

METHODS

Multinational multicenter cohort study of consecutive adult patients underwent LT and colonized with CRE before or after LT, from January 2010 to December 2017. Risk factors for CRE infection were analyzed by univariate analysis and by Fine-Gray sub-distribution hazard model, with death as competing event. A nomogram to predict 30- and 60-day CRE infection risk was created.

RESULTS

840 LT recipients found to be colonized with CRE before (n=203) or after (n=637) LT were enrolled. CRE infection was diagnosed in 250 (29.7%) patients within 19 (IQR 9-42) days after LT. Pre-and post-LT colonization, multisite post-LT colonization, prolonged mechanical ventilation, acute renal injury, and surgical re-intervention were retained in the prediction model. Median 30 and 60-day predicted risk was 15% (IQR 11-24%) and 21% (IQR 15-33%), respectively. Discrimination and prediction accuracy for CRE infection was acceptable on derivation (AUC 74.6, Brier index 16.3) and bootstrapped validation dataset (AUC 73.9, Brier index 16.6). Decision-curve analysis suggested net benefit of model-directed intervention over default strategies (treat all, treat none) when CRE infection probability exceeded 10%. The risk prediction model is freely available as mobile application at https://idbologna.shinyapps.io/CREPostOLTPredictionModel/.

CONCLUSIONS

Our clinical prediction tool could enable better targeting interventions for CRE infection after transplant.

Bacterial but no SARS-CoV-2 contamination after terminal disinfection of tertiary care intensive care units treating COVID-19 patients

Background

In intensive care units (ICUs) treating patients with Coronavirus disease 2019 (COVID-19) invasive ventilation poses a high risk for aerosol and droplet formation. Surface contamination of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) or bacteria can result in nosocomial transmission.

Methods

Two tertiary care COVID-19 intensive care units treating 53 patients for 870 patient days were sampled after terminal cleaning and preparation for regular use to treat non-COVID-19 patients.

Results

A total of 176 swabs were sampled of defined locations covering both ICUs. No SARS-CoV-2 ribonucleic acid (RNA) was detected. Gram-negative bacterial contamination was mainly linked to sinks and siphons. Skin flora was isolated from most swabbed areas and Enterococcus faecium was detected on two keyboards.

Conclusions

After basic cleaning with standard disinfection measures no remaining SARS-CoV-2 RNA was detected. Bacterial contamination was low and mainly localised in sinks and siphons.

Multicenter Evaluation of Xpert Carba-R Assay for Detection and Identification of the Carbapenemase Genes in Rectal Swabs and Clinical Isolates

Rapid detection of carbapenemase-producing organisms is clinically desirable for hospital infection control and antibiotic stewardship. In this multicenter study, the Xpert Carba-R assay was evaluated for detection of the five carbapenemase genes (bla_KPC, bla_NDM, bla_IMP, bla_OXA-48, and bla_VIM) in 2404 nonduplicate rectal swabs of admitted inpatients and 521 Gram-negative isolates from four tertiary hospitals in China, compared with the reference growth-based method with DNA sequence analysis of colonies. All suspected false-positive results in rectal swabs were resolved by supplementary sequencing from broth cultures. A total of 197 bla_KPC, 171 bla_NDM, 142 bla_IMP, 6 bla_VIM, and 5 bla_OXA-48 genes were detected by Xpert Carba-R in 417 rectal swabs, with overall positive and negative percentage agreements ranging from 94.5% to 100% and from 94.8% to 99.9%, respectively. Notably, 17.5% (263/1500) of inpatients had rectal colonization with carbapenem-nonsusceptible organisms detected in intensive care units, and 63.1% (166/263) were Xpert Carba-R positive. Among the 469 carbapenem-nonsusceptible and 52 carbapenem-susceptible isolates examined, 373 were Enterobacteriaceae, 55 were Pseudomonas aeruginosa, and 93 were Acinetobacter baumannii. Compared with the reference isolate sequencing, overall positive and negative percentage agreements were 99.7% and 98.0%, respectively. The intra-assay and interassay coefficient of variability values were both <2%. Thus, we show that Xpert Carba-R assay provides good reproducibility and reliable results for detection and differentiation of five carbapenemase genes in both rectal swabs and clinical isolates.

Mortalidad y desenlaces clínicos en pacientes críticamente enfermos con infecciones por bacterias productoras de carbapenemasas en un hospital de alta complejidad en Bogotá, Colombia

Introducción: Los microorganismos capaces de producir carbapenemasas vienen incrementándose a nivel mundial y se han convertido en un problema de salud pública global. En Colombia actualmente la resistencia a carbapenémicos en las unidades de cuidado intensivo está aumentando y se desconoce su impacto en desenlaces clínicos. Objetivos: Determinar las características demográficas, clínicas, y los desenlaces de los pacientes adultos en estado crítico con infección por microorganismos productores de carbapenemasas en una unidad de cuidado intensivo polivalente de una institución de alta complejidad. Métodos: Estudio observacional, descriptivo y retrospectivo, incluyendo pacientes con infección por bacterias resistentes a carbapenémicos, ingresados a la unidad de cuidado intensivo entre el 1 de Enero de 2014 y el 1 de Enero de 2018. Se excluyeron los pacientes colonizados. Se evaluaron complicaciones clínicas, estancia en UCI y hospitalaria, así como la mortalidad en UCI y hospitalaria. Resultados: Se incluyó 58 pacientes. La mortalidad global fue de 67,2%, de los cuales 55,17% murió durante su estancia en la unidad de cuidado intensivo y 12.06% en hospitalización. La mediana de estancia en la unidad de cuidado intensivo fue de 18 días (RIQ 4-28). La causa más frecuente de mortalidad fue choque séptico en 51% y las complicaciones más comunes fueron lesión renal aguda y delirium en un 55,2% y 43,1%, respectivamente. La mediana de estancia en la UCI fue de 18 días (RIQ 4-28). Conclusiones: Las infecciones por bacterias resistentes a carbapenémicos en pacientes críticamente enfermos se relacionan con altas tasas de mortalidad, complicaciones y estancia prolongada en UCI

Risk stratification for multidrug-resistant Gram-negative infections in ICU patients

PURPOSE OF REVIEW

Antimicrobial resistance among Gram-negative microorganisms has alarmingly increased in the past 10 years worldwide. Infections caused by these microorganisms are difficult to treat, especially in critically ill patients.The present review examines how to accurately predict which patients carry a greater risk of colonization or infection on which to base the timely choice of an effective empirical antibiotic treatment regimen and avoid antibiotic overuse.

RECENT FINDINGS

There are many risk factors for acquiring one of many multidrug-resistant Gram-negative microorganisms (MDR-GN); however, scores anticipating colonization, infection among those colonized, or mortality among those infected have a variable accuracy. Accuracy of scores anticipating colonization is low. Scores predicting infections among colonized patients are, in general, better, and ICU patients infected with MDR-GN have a worse prognosis than those infected by non-resistant microorganisms. Scores are, in general, better at excluding patients.

SUMMARY

Despite these limitations, scores continue to gain popularity including those by Giannella, Tumbarello, Johnson, or the scores INCREMENT carbapenem-producing Enterobacteriaceae score, Cano, Tartof, or CarbaSCORE.

Risk factors and outcomes of patients colonized with carbapenemase-producing and non–carbapenemase-producing carbapenem-resistant Enterobacteriaceae

Objective:

To compare risk factors and outcome of patients colonized with carbapenemase-producing (CP) carbapenem-resistant Enterobactereaceae (CRE) and non–CP-CRE.

Design:

A comparative historical study.

Setting:

A 1,000-bed tertiary-care university hospital.

Patients:

Adults with CP-CRE positive rectal swab cultures, non–CP-CRE positive rectal swab cultures, and negative rectal swab cultures (non-CRE).

Methods:

CP-CRE and non–CP-CRE colonized adult patients versus patients not colonized with CRE hospitalized during 24 months were included. We identified patients retrospectively through the microbiology laboratory, and we reviewed their files for demographics, underlying diseases, Charlson Index, treatment, and outcome.

Results:

This study included 447 patients for whom a rectal swab for CRE was obtained: 147 positive for CP-CRE, 147 positive for non–CP-CRE, and 147 negative for both. Patients with CP-CRE and non–CP-CRE versus no CRE more frequently resided in nursing homes (P<0.001), received antibiotics 3 months prior to admission (P < .001), and received glucocorticosteroids 3 months prior to admission (P = .047 and P < .001, respectively). Risk factors unique for non–CP-CRE versus CP-CRE colonization included mechanical ventilation and patient movement between hospital departments. Non–CP-CRE was a predictor for mechanical ventilation 2.5 that of CP-CRE colonization. In-hospital mortality was highest among non–CP-CRE–colonized patients. On COX multivariate regression for mortality prediction age, Charlson index and steroid treatment 3 months before admission influenced mortality (P = .027, P = .023, and P = .013, respectively).

Conclusions:

Overlapping and unique risk factors are associated with CP-CRE and non–CP-CRE colonization. Non–CP-CRE colonized patients had a higher in-hospital mortality rate.

Impact of KPC Production and High-Level Meropenem Resistance on All-Cause Mortality of Ventilator-Associated Pneumonia in Association with Klebsiella pneumoniae

Carbapenemase-producing Enterobacterales and specifically Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) are rapidly spreading worldwide. The prognosis of ventilator-associated pneumonia (VAP) caused by KPC-Kp is not well known. Our study tries to assess whether ventilator-associated pneumonia caused by a KPC-Kp strain is associated with higher all-cause mortality than that caused by carbapenem-susceptible isolates. This is a retrospective cohort study of patients with VAP due to K. pneumoniae from a 35-bed polyvalent intensive care unit in a university hospital (>40,000 annual admissions) between January 2012 and December 2016. Adjusted multivariate analysis was used to study the association of KPC-Kp with 30-day all-cause mortality (Cox regression). We analyze 69 cases of K. pneumoniae VAP, of which 39 were produced by a KPC-Kp strain with high-level resistance to meropenem (MIC > 16 mg/ml). All-cause mortality at 30 days was 41% in the KPC-Kp group (16/39) and 33.3% in the carbapenem-susceptible cases (10/30). KPC-Kp etiology was not associated with higher mortality when controlled for confounders (adjusted hazard ratio [HR], 1.25; 95% confidence interval [CI], 0.46 to 3.41). Adequate targeted therapy (HR, 0.03; 95% CI, <0.01 to 0.23) was associated with all-cause mortality. Assuming the limitations due to the available sample size, the prognosis of VAP caused by KPC-Kp is similar to VAPs caused by carbapenem-susceptible K. pneumoniae when appropriate treatment is used.

Clinical impact of endemic NDM-producing Klebsiella pneumoniae in intensive care units of the national referral hospital in Jakarta, Indonesia

OBJECTIVE

A prospective observational study was performed to assess the epidemiology and clinical impact of carbapenem-non-susceptible Klebsiella pneumoniae (CNKP) in intensive care units (ICUs) of the national referral hospital in Jakarta, Indonesia.

MATERIALS/METHODS

Adult patients consecutively hospitalized for > 48 h in two ICUs of the national referral hospital were included from April until October 2013 and from April until August 2014. K. pneumoniae from clinical cultures and standardized screening of rectum and throat on admission, discharge and weekly if hospitalized > 7 days were collected. Environmental niches and healthcare workers (HCWs) were also screened. Susceptibility was determined phenotypically and the presence of carbapenemase genes by PCR. Raman spectroscopy as well as multiple-locus variable number tandem repeat analysis (MLVA) were used for typing.

RESULTS

Twenty-two out of 412 (5.3%) patients carried CNKP on admission and 37/390 (9.5%) acquired CNKP during ICU stay. The acquisition rate was 24.7/1000 patient-days at risk. One out of 31 (3.2%) environmental isolates was a CNKP. None of the HCWs carried CNKP. Acquisition of CNKP was associated with longer ICU stay (adjusted Hazard Ratio: 2.32 [CI₉₉: 1.35-3.68]). ICU survival was lower among patients with CNKP compared to patients with carbapenem-susceptible K. pneumoniae (aHR 2.57, p = 0.005). Ninety-six of the 100 (96%) CNKP isolates carried a carbapenemase gene, predominantly bla_NDM. Raman typing revealed three major clusters among 48 Raman types identified, whereas MLVA distinguished six major clusters among a total of 30 different genotypes.

CONCLUSIONS

NDM-producing CNKP are introduced into these ICUs and some strains expand clonally among patients and the environment, resulting in endemic CNKP. CNKP acquisition was associated with prolonged ICU stay and may affect ICU survival.

TRIAL REGISTRATION

The study was registered at Netherlands Trial Register http://www.trialregister.nl. Candidate number: 23527, NTR number: NTR5541, NL number: NL5425 (https://www.trialregister.nl/trial/5424), Retrospectively registered: NTR: 22 December 2015.

Evaluation of Phenotypic and Genotypic Characteristics of Carbapnemases-producing Enterobacteriaceae and Its Prevalence in a Referral Hospital in Tehran City

Background & Objective

Carbapenem-resistant Enterobacteriaceae is a growing concern worldwide including Iran. The emergence of this pathogen is worrying as carbapenem is one of the 'last-line' antibiotics for treatment of infections caused by multi drug resistant gram- negative bacteria. The main objective of this study was to determine the prevalence of carbapenem-resistant Enterobacteriaceae in a referral hospital in Tehran, Iran.

Methods

In this study, all positive isolates of Enterobacteriaceae recorded in blood, urine, and other body fluids were studied during April 2017 to April 2018 in a referral hospital in Tehran. All cases of resistance to carbapenems were first tested by modified Hodge test. All cases with positive or negative test, after gene extraction, were examined genotypically based on the primers designed for the three Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), and OXA-48 genes by conventional PCR method.

Results

108 isolates (13.6%) were resistant to all cephalosporins as well as to imipenem and meropenem. In a genotypic study, including 45 isolates, 13 isolates were positive for OXA-48 gene, 11 isolates for OXA-48 and NDM genes, 11 isolates for OXA-48, NDM and KPC genes, 4 isolates for OXA-48 genes and KPC, 3 isolates for NDM, one isolate for KPC. On the other hand, two isolates were negative for all three genes examined.

Conclusion

OXA-48 gene was one of the most common genes resistant to carbapenems in Iran. According to studies, the prevalence of antibiotic resistance in Iran is rising dramatically, which reduces the choice of antibiotics to treat severe infections in the future.

Infections due to carbapenemase-producing bacteria, clinical burden, and impact of screening strategies on outcome

OBJECTIVES

To characterize the risk factors, impact of screening, and clinical burden of colonization and/or infection by carbapenemase-producing bacteria (CPB) in hospitalized patients.

METHOD

Retrospective study in a tertiary care hospital between 2008 and 2016.

RESULTS

Among 88 included patients, 41% were colonized, 59% developed an infection, and 69% of all cases were hospital-acquired. Risk factors for CPB contamination included recent invasive medical device (94% of patients), antibiotic therapy (82%), travel abroad (17%), and hospitalization (>50%) with 80% of all patients with underlying chronic condition. Intestinal carriage represented 89% of all colonization cases and 50% of infections were located in the urinary tract. The recent use of mechanical ventilation devices was significantly more observed in infected patients than colonized patients. The most frequent CPB was Klebsiella pneumoniae and the most frequent carbapenemase was OXA-48. Overall mortality rate was 19%. Prevalence of CPB detection in intensive care units (ICU) based on systematical rectal screen swab upon admission remained <0.5%. The infected/colonized ratio (CPB colonization cases evolving into an infection) was 23%. The time between CPB infection diagnosis and start of appropriate antimicrobial therapy increased from 1 day in previously screened patients with positive CPB to 4 days in patients with previous negative or absent screening.

CONCLUSION

Our results emphasize the importance of CPB screening in all ICU patients and in at-risk patients hospitalized in other units, to allow earlier adequate antibiotic therapy in case of infection which occurred in 23% of the colonized patients.

Gastrointestinal colonization with multidrug-resistant Gram-negative bacteria during extracorporeal membrane oxygenation: effect on the risk of subsequent infections and impact on patient outcome

Background

In ICU patients, digestive tract colonization by multidrug-resistant (MDR) Gram-negative (G−) bacteria is a significant risk factor for the development of infections. In patients undergoing extracorporeal membrane oxygenation (ECMO), colonization by MDR bacteria and risk of subsequent nosocomial infections (NIs) have not been studied yet. The aim of this study is to evaluate the incidence, etiology, risk factors, impact on outcome of gastrointestinal colonization by MDR G− bacteria, and risk of subsequent infections in patients undergoing ECMO.

Methods

This is a retrospective analysis of prospectively collected data: 105 consecutive patients, treated with ECMO, were admitted to the ICU of an Italian tertiary referral center (San Gerardo Hospital, Monza, Italy) from January 2010 to November 2015. Rectal swabs for MDR G− bacteria were cultured at admission and twice a week. Only colonization and NIs by MDR G− bacteria were analyzed.

Results

Ninety-one included patients [48.5 (37–56) years old, 63% male, simplified acute physiology score II 37 (32–47)] underwent peripheral ECMO (87% veno-venous) for medical indications (79% ARDS). Nineteen (21%) patients were colonized by MDR G− bacteria. Male gender (OR 4.03, p = 0.029) and duration of mechanical ventilation (MV) before ECMO > 3 days (OR 3.57, p = 0.014) were associated with increased risk of colonization. Colonized patients had increased odds of infections by the colonizing germs (84% vs. 29%, p < 0.001, OR 12.9), longer ICU length of stay (LOS) (43 vs. 24 days, p = 0.002), MV (50 vs. 22 days, p < 0.001) and ECMO (28 vs. 12 days, p < 0.001), but did not have higher risk of death (survival rate 58% vs. 67%, p = 0.480, OR 0.68). Infected patients had almost halved ICU survival (46% vs. 78%, p < 0.001, OR 4.11).

Conclusions

In patients undergoing ECMO for respiratory and/or circulatory failure, colonization by MDR G− bacteria is frequent and associated with more the tenfold odds for subsequent infection. Those infections are associated with an increased risk of death.

A review of the use of time-varying covariates in the Fine-Gray subdistribution hazard competing risk regression model

In survival analysis, time‐varying covariates are covariates whose value can change during follow‐up. Outcomes in medical research are frequently subject to competing risks (events precluding the occurrence of the primary outcome). We review the types of time‐varying covariates and highlight the effect of their inclusion in the subdistribution hazard model. External time‐dependent covariates are external to the subject, can effect the failure process, but are not otherwise involved in the failure mechanism. Internal time‐varying covariates are measured on the subject, can effect the failure process directly, and may also be impacted by the failure mechanism. In the absence of competing risks, a consequence of including internal time‐dependent covariates in the Cox model is that one cannot estimate the survival function or the effect of covariates on the survival function. In the presence of competing risks, the inclusion of internal time‐varying covariates in a subdistribution hazard model results in the loss of the ability to estimate the cumulative incidence function (CIF) or the effect of covariates on the CIF. Furthermore, the definition of the risk set for the subdistribution hazard function can make defining internal time‐varying covariates difficult or impossible. We conducted a review of the use of time‐varying covariates in subdistribution hazard models in articles published in the medical literature in 2015 and in the first 5 months of 2019. Seven percent of articles published included a time‐varying covariate. Several inappropriately described a time‐varying covariate as having an association with the risk of the outcome.

Pharmacokinetic and pharmacodynamic profiling of four antimicrobials against Acinetobacter baumannii infection

BACKGROUND

The aim of this study was to evaluate common antimicrobial regimens used in eradicating Acinetobacter baumannii in Shenyang, China.

METHODS

Monte Carlo simulation was conducted to estimate the probability target attainment (PTA) and cumulative fraction of response (CFR) for imipenem, cefoperazone/sulbactam (2:1), tigecycline and colistin methanesulfonate.

RESULTS

For the results of PTAs, imipenem following administration of 0.5 g q6 h, 1 g q8 h, and 1 g q6 h for both 0.5 h and 2 h infusion achieved＞90% PTAs when MIC was 8 μg/ml; cefoperazone/ sulbactam (2:1) following administration of 4.5 g q6 h and 6 g q6 h achieved＞90% PTAs when MIC was 64μg/ml; tigecycline following administration of 50 mg q12 h and 100 mg q12 h achieved＞90% PTAs when MIC was 1 μg/ml; colistin methanesulfonate with high dosages (3MU q8 h) could provide high PTA (95.13%) in patients with CL_Cr＜60 ml/min when MIC was 2 μg/ml. As for CFR values of four antibiotics, imipenem achieved the lowest CFR values. For cefoperazone/sulbactam (2:1) and tigecycline, with simulated regimens improvement, the CFR values were both increased, and there were obviously increasing CFR values against Acinetobacter baumannii. For colistin methanesulfonate, the most aggressive dosage of 3MU q8 h could provide satisfactory CFR values (≥86.94%) against Acinetobacter baumannii in patients at various CL_Cr.

CONCLUSION

This study suggested that measurement of MICs, individualized therapy and therapeutic drug-level monitoring should be considered together to achieve the optimal drug exposure. That will provide the best chance of achieving the highest probability of a successful clinical or microbiological response, and avoiding the induced resistance.

Antibiotic Resistance and the Risk of Recurrent Bacteremia

Background

Direct health effects of antibiotic resistance are difficult to assess. We quantified the risk of recurrent bacteremia associated with resistance.

Methods

We extracted antimicrobial susceptibility testing data on blood isolates from the Dutch surveillance system for antimicrobial resistance between 2008 and 2017. First and first recurrent (4–30 days) bacteremia episodes were categorized as susceptible, single nonsusceptible, or co-nonsusceptible to third-generation cephalosporins without or with carbapenems (Enterobacteriaceae), ceftazidime without or with carbapenems (Pseudomonas species), aminopenicillins without or with vancomycin (Enterococcus species), or as methicillin-sensitive/-resistant S. aureus (MSSA/MRSA). We calculated risks of recurrent bacteremia after nonsusceptible vs susceptible first bacteremia, estimated the crude population attributable effect of resistance for the Netherlands, and calculated risks of nonsusceptible recurrent bacteremia after a susceptible first episode.

Results

Risk ratios for recurrent bacteremia after a single- and co-nonsusceptible first episode, respectively, vs susceptible first episode, were 1.7 (95% confidence interval [CI], 1.5–2.0) and 5.2 (95% CI, 2.1–12.4) for Enterobacteriaceae, 1.3 (95% CI, 0.5–3.1) and 5.0 (95% CI, 2.9–8.5) for Pseudomonas species, 1.4 (95% CI, 1.2–1.7) and 1.6 (95% CI, 0.6–4.2) for Enterococcus species, and 1.6 (95% CI, 1.1–2.4) for MRSA vs MSSA. The estimated population annual number of recurrent bacteremias associated with nonsusceptibility was 40. The risk of nonsusceptible recurrent bacteremia after a susceptible first episode was at most 0.4% (Pseudomonas species).

Conclusions

Although antibiotic nonsusceptibility was consistently associated with higher risks of recurrent bacteremia, the estimated annual number of additional recurrent episodes in the Netherlands (40) was rather limited.

Association between carbapenem-resistant Enterobacteriaceae and death: A systematic review and meta-analysis

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) has emerged in health care facilities around the world. Several studies demonstrated data regarding clinical outcomes for CRE infections including death. This systematic review and meta-analysis summarized literature discussing association between CRE and mortality.

METHODS

A systematic literature review was performed by searching EMBASE, International Pharmaceutical Abstract databases, PubMed, and Scopus and to identify studies that assessed the association between CRE and death published from April 2012 to October 2017. A meta-analysis was performed using a random effect model. Heterogeneity was assessed using the I²-statistic.

RESULTS

Twenty-one studies were included in this meta-analysis. The underlying populations were moderately heterogeneous (I² = 60%; P = .01). Pooled risk estimates from 9 studies revealed a significant association between CRE and death (pooled-adjusted odds ratio: 2.85; 95% confidence interval: 1.88, 4.30). The unadjusted variable pooled from 18 studies demonstrated a significant association between CRE and death (pooled-unadjusted odds ratio: 3.73; 95% confidence interval: 2.02, 6.88).

DISCUSSION

The finding that CRE infection was positively associated with death agreed with the previous meta-analysis of studies published before April 2012.

CONCLUSIONS

This meta-analysis found that CRE was associated with increased risk of death. Our analysis implies a need for strict infection control measures.

Antibiotic-resistant pathogens in different patient settings and identification of surveillance gaps in Switzerland - a systematic review

The prevalence of antimicrobial resistance (AMR) varies significantly among different patient populations. We aimed to summarise AMR prevalence data from screening studies in different patient settings in Switzerland and to identify surveillance gaps. We performed a systematic review, searching Pubmed, MEDLINE, Embase (01/2000–05/2017) and conference proceedings for Swiss studies reporting on carbapenemase-producing Enterobacteriaceae (CPE), extended-spectrum beta-lactamases (ESBL), mobilised colistin-resistance, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) within different patient settings. We identified 2345 references and included 46 studies. For acute care patients, most screening data come from admission screenings, whereas AMR prevalence among hospitalised patients is largely unknown. Universal admission screenings showed ESBL-prevalences of 5–8% and MRSA-prevalences of 2–5%. For targeted screening, ESBL-prevalence ranged from 14–21%; MRSA-prevalence from 1–4%. For refugees, high ESBL (9–24%) and MRSA (16–24%) carriage rates were reported; returning travellers were frequently (68–80%) colonised with ESBL. Screening data for other pathogens, long-term care facility (LTCF) residents and pediatric populations were scarce. This review confirms high ESBL- and MRSA-carriage rates for risk populations in Switzerland. Emerging pathogens (CPE and VRE) and certain populations (inpatients, LTCF residents and children) are understudied. We encourage epidemiologists and public health authorities to consider these findings in the planning of future surveillance studies.

Carbapenemase producing Enterobacteriaceae in intensive care units in Ecuador: Results from a multicenter study

INTRODUCTION

Carbapenemase-producing Enterobacteriaceae (CPE) are of global concern due to the growing number of patients who acquire them and their association with high mortality rates. Although there are some reports of endemicity in developing countries, little is known about this microorganism, and Ecuador is not an exception. Subsequently, our objective was to clinically and molecularly characterize carbapenemase producing-Enterobacteriaceae in intensive care units (ICUs) in Guayaquil, Ecuador.

METHODS

To determine CPE colonization, we obtained perineal and inguinal swabs from patients admitted to seven intensive-care adult units in Guayaquil-Ecuador between February and April 2016. The Centers for Disease Control and Prevention (CDC) laboratory protocol and chromogenic agar were used to process the cultures. Polymerase chain reaction was used to confirm carbapenemase production. Genotypic analysis was performed by Multilocus Sequence Typing (MLST) and pulsed-field electrophoresis (PFEG). Demographic and clinical data were obtained from the electronic charts and patient's relatives.

RESULTS

Six hundred seventy-seven patients were included in the study, of whom 255 were colonized/infected by CPE. The CPE prevalence was 37.67%. Previous use of antimicrobials, use of invasive procedures and being burned at admission were associated with CPE. The most frequent infection was found after a surgical procedure. Klebsiella pneumoniae (n=249) was the predominant microorganism harbouring bla_KPC, followed by Enterobactercloacae (n=8), Klebsiella aerogenes (n=4), Escherichia coli (n=4) and Klebsiella oxytoca (n=1). NDM was present in Proteus mirabilis. The strains were distributed in 19 sequence types (ST), and 10 were not reported previously in Ecuador. ST 258 was the sequence type isolated most frequently.

CONCLUSION

This study shows a high prevalence of CPE in ICUs, particularly K. pneumoniae bla_KPC ST 258. The identification of KPC alleles may help to understand the routes of dissemination and control spread within ICUs in Guayaquil, Ecuador.

Bacteriological Profile and Antibiogram of Cultures Isolated from Tracheal Secretions

Background Respiratory infections are associated with high morbidity and mortality, especially in critically ill patients. The excessive use of broad-spectrum antibiotics has led to the development of drug resistance, thus resulting in the emergence of pathogens which are difficult to treat. The aim of this study was to identify common pathogens in tracheal secretions and to study the patterns of their sensitivity and resistance to various antibiotics. Materials and methods This descriptive cross-sectional study was conducted in the Department of Pathology and Microbiology, Holy Family Hospital, Rawalpindi, Pakistan, from August 2017 to December 2017, using the convenient sampling technique. Tracheal secretions from patients in the intensive care unit (ICU), tested in the Pathology and Microbiology Department of Holy Family Hospital, were included in the study. The culture was done on blood and MacConkey agar and the sensitivity pattern was performed on Muller Hinton agar. Data were analyzed using SPSS v.23.0. Results Out of the bacteria isolated from positive growth cultures, Acinetobacter (45; 53.6%) was the most common isolate followed by Klebsiella (11; 13.1%). Acinetobacter was most sensitive to tigecycline (94.7%), and gram-negative bacteria such as Acinetobacter, Klebsiella, and Pseudomonas showed resistance to higher generation cephalosporins. Conclusion Acinetobacter was the most common gram-negative bacilli isolated. Tigecycline was found to be effective against Acinetobacter.

Evaluation of the rapid carbapenem inactivation method (rCIM): a phenotypic screening test for carbapenemase-producing Enterobacteriaceae

Objectives

Fast and accurate diagnostic tests to identify carbapenemase-producing Enterobacteriaceae (CPE) are mandatory for proper antimicrobial therapy and implementing infection control measures. Here, we have developed a rapid Carbapenem Inactivation Method (rCIM) for CPE detection.

Methods

The rCIM consists of the incubation of a potential carbapenemase producer with meropenem discs and use of the resulting supernatant to challenge a susceptible indicator strain. Growth of the indicator strain is monitored using a nephelometer. The performances of the rCIM were compared with the CIM and Carba NP tests using a collection of 113 well-characterized carbapenem-resistant enterobacterial isolates, including 85 carbapenemase producers and 28 non-carbapenemase producers. In addition, rCIM was compared with the Carba NP test and PCR sequencing in a prospective analysis of 101 carbapenem-resistant enterobacterial isolates addressed to the French National Reference Center for Antimicrobial Resistance in July 2017.

Results and discussion

The rCIM correctly identified 84/85 carbapenemase producers and 28/28 non-carbapenemase producers, yielding a sensitivity of 99% and a specificity of 100%, slightly higher than the CIM and Carba NP test. In the prospective validation study, the rCIM showed a sensitivity and specificity of 97% and 95%, respectively. Two cephalosporinase-hyperproducing Enterobacter cloacae gave false-positive results, whereas an IMI-17-producing Enterobacter asburiae gave a false-negative result. The result was, however, positive when the isolate was grown on selective antibiotic-containing media.

Conclusions

The rCIM is a rapid (less than 3 h), cheap and accurate test for the detection of CPEs, which can be implemented in low-resource settings, making it a useful tool for microbiology laboratories.

Clinical prediction models for ESBL-Enterobacteriaceae colonization or infection: a systematic review

BACKGROUND

β-Lactamase resistance among certain Gram-negative bacteria has been associated with increased mortality, length of hospitalization, and hospital costs.

AIM

To identify and critically appraise existing clinical prediction models of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-EKP) infection or colonization.

METHODS

Electronic databases, reference lists, and citations were searched from inception to April 2018. Papers were included in any language describing the development or validation, or both, of models and scores to predict the risk of ESBL-EKP infection or colonization.

FINDINGS

In all, 1795 references were screened, of which four articles were included in the review. The included studies were carried out in different geographical locations with differing study designs, and inclusion and exclusion criteria. Most if not all studies lacked external validation and blinding of reviewers during the evaluation of the predictor variables and outcome. All studies excluded missing data and most studies did not report the number of patients excluded due to missing data. Fifteen predictors of infection or colonization with ESBL-EKP were identified. Commonly included predictors were previous antibiotic use, previous hospitalization, transfer from another healthcare facility, and previous procedures (urinary catheterization and invasive procedures).

CONCLUSION

Due to limitations and variations in the study design, clinicians would have to take these differences into consideration when deciding on how to use these models in clinical practice. Due to lack of external validation, the generalizability of these models remains a question. Therefore, further external validation in local settings is needed to confirm the usefulness of these models in supporting decision-making.

Drug-resistant Enterobacteriaceae colonization is associated with healthcare utilization and antimicrobial use among inpatients in Pune, India

Background

Healthcare exposure may increase drug-resistant Enterobacteriaceae colonization risk. Nascent antimicrobial stewardship efforts in low- and middle-income countries require setting-specific data. We aimed to evaluate risk factors for inpatient drug resistant Enterobacteriaceae colonization in a resource-limited setting in India.

Methods

Patients age ≥ 6 months admitted with ≥24 h of fever to a tertiary hospital in Pune, India were enrolled in a prospective cohort. Perirectal swabs, collected on admission and hospitalization day 3 or 4, were cultured in vancomycin- and ceftriaxone-impregnated media to assess for ceftriaxone-resistant Enterobacteriaceae (CTRE) and carbapenem-resistant Enterobacteriaceae (CPRE). Multivariable analyses assessed risk factors for drug-resistant Enterobacteriaceae colonization among participants without admission colonization.

Results

Admission perirectal swabs were collected on 897 participants; 87 (10%) had CTRE and 14 (1.6%) had CPRE colonization. Admission CTRE colonization was associated with recent healthcare contact (p < 0.01). Follow-up samples were collected from 620 participants, 67 (11%) had CTRE and 21 (3.4%) had CPRE colonization. Among 561 participants without enrollment CTRE colonization, 49 (9%) participants were colonized with CTRE at follow-up. Detection of CTRE colonization among participants not colonized with CTRE at admission was independently associated with empiric third generation cephalosporin treatment (adjusted odds ratio [OR] 2.9, 95% CI 1.5–5.8). Follow-up transition to CPRE colonization detection was associated with ICU admission (OR 3.0, 95% CI 1.0–8.5).

Conclusions

Patients who receive empiric third generation cephalosporins and are admitted to the ICU rapidly develop detectable CTRE and CPRE colonization. Improved antimicrobial stewardship and infection control measures are urgently needed upon hospital admission.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3390-4) contains supplementary material, which is available to authorized users.