Control of Carbapenem-resistant Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa in Healthcare Facilities: A Systematic Review and Reanalysis of Quasi-experimental Studies

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

BACKGROUND

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

OBJECTIVE

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

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

INTERVENTIONS

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

STUDY APPRAISAL AND SYNTHESIS

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

RESULTS

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

CONCLUSIONS

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

Molecular Surveillance of Carbapenem-Resistant Gram-Negative Bacteria in Liver Transplant Candidates

Background: Carbapenem-resistant Gram-negative bacteria (CRGN) cause life-threatening infections due to limited antimicrobial treatment options. The occurrence of CRGN is often linked to hospitalization and antimicrobial treatment but remains incompletely understood. CRGN are common in patients with severe illness (e.g., liver transplantation patients). Using whole-genome sequencing (WGS), we aimed to elucidate the evolution of CRGN in this vulnerable cohort and to reconstruct potential transmission routes.

Methods: From 351 patients evaluated for liver transplantation, 18 CRGN isolates (from 17 patients) were analyzed. Using WGS and bioinformatic analysis, genotypes and phylogenetic relationships were explored. Potential epidemiological links were assessed by analysis of patient charts.

Results: Carbapenem-resistant (CR) Klebsiella pneumoniae (n=9) and CR Pseudomonas aeruginosa (n=7) were the predominating pathogens. In silico analysis revealed that 14/18 CRGN did not harbor carbapenemase-coding genes, whereas in 4/18 CRGN, carbapenemases (VIM-1, VIM-2, OXA-232, and OXA-72) were detected. Among all isolates, there was no evidence of plasmid transfer-mediated carbapenem resistance. A close phylogenetic relatedness was found for three K. pneumoniae isolates. Although no epidemiological context was comprehensible for the CRGN isolates, evidence was found that the isolates resulted of a transmission of a carbapenem-susceptible ancestor before individual radiation into CRGN.

Conclusion: The integrative epidemiological study reveals a high diversity of CRGN in liver cirrhosis patients. Mutation of carbapenem-susceptible ancestors appears to be the dominant way of CR acquisition rather than in-hospital transmission of CRGN or carbapenemase-encoding genetic elements. This study underlines the need to avoid transmission of carbapenem-susceptible ancestors in vulnerable patient cohorts.

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.

Cost-effectiveness of carbapenem-resistant Enterobacteriaceae (CRE) surveillance in Maryland

Objective:

We analyzed the efficacy, cost, and cost-effectiveness of predictive decision-support systems based on surveillance interventions to reduce the spread of carbapenem-resistant Enterobacteriaceae (CRE).

Design:

We developed a computational model that included patient movement between acute-care hospitals (ACHs), long-term care facilities (LTCFs), and communities to simulate the transmission and epidemiology of CRE. A comparative cost-effectiveness analysis was conducted on several surveillance strategies to detect asymptomatic CRE colonization, which included screening in ICUs at select or all hospitals, a statewide registry, or a combination of hospital screening and a statewide registry.

Setting:

We investigated 51 ACHs, 222 LTCFs, and skilled nursing facilities, and 464 ZIP codes in the state of Maryland.

Patients or participants:

The model was informed using 2013–2016 patient-mix data from the Maryland Health Services Cost Review Commission. This model included all patients that were admitted to an ACH.

Results:

On average, the implementation of a statewide CRE registry reduced annual CRE infections by 6.3% (18.8 cases). Policies of screening in select or all ICUs without a statewide registry had no significant impact on the incidence of CRE infections. Predictive algorithms, which identified any high-risk patient, reduced colonization incidence by an average of 1.2% (3.7 cases) without a registry and 7.0% (20.9 cases) with a registry. Implementation of the registry was estimated to save $572,000 statewide in averted infections per year.

Conclusions:

Although hospital-level surveillance provided minimal reductions in CRE infections, regional coordination with a statewide registry of CRE patients reduced infections and was cost-effective.

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.

A comprehensive approach to ending an outbreak of rare blaOXA-72 gene-positive carbapenem-resistant Acinetobacter baumannii at a Community Hospital, Kansas City, MO, 2018

We identified a cluster of extensively drug-resistant, carbapenemase gene-positive, carbapenem-resistant Acinetobacter baumannii (CP-CRAB) at a teaching hospital in Kansas City. Extensively drug-resistant CRAB was identified from eight patients and 3% of environmental cultures. We used patient cohorting and targeted environmental disinfection to stop transmission. After implementation of these measures, no additional cases were identified.

Admission screening and cohort care decrease carbapenem resistant enterobacteriaceae in Vietnamese pediatric ICU's

Objectives

To assess if admission screening for Carbapenem Resistant Enterobacteriaceae (CRE) and cohort care can reduce CRE acquisition (CRE colonization during hospital stay), Hospital Acquired Infections (HAI), hospital-stay, mortality, and costs in three Intensive Care Units (ICU’s) at the Vietnamese National Children’s Hospital.

Method

CRE screening using rectal swabs and ChromIDCarbas elective culture at admission and if CRE negative, once weekly. Patients were treated in cohorts based on CRE colonization status.

Results

CRE colonization at baseline point-prevalence screening was 76.9% (103/134). Of 941 CRE screened at admission, 337 (35.8%) were CREpos. 694 patients met inclusion criteria. The 244 patients CRE negative at admission and screened > 2 times were stratified in 8 similar size groups (periods), based on time of admission. CRE acquisition decreased significant (OR − 3.2, p < 0.005) from 90% in period 2 (highest) to 48% in period 8 (last period). Patients with CRE acquisition compared to no CRE acquisition had a significantly higher rate of culture confirmed HAI, n = 20 (14%) vs. n = 2 (2%), longer hospital stays, 3.26 vs. 2.37 weeks, and higher total treatment costs, 2852 vs. 2295 USD.

Conclusion

Admission CRE screening and cohort care in pediatric ICU’s significantly decreased CRE acquisition, cases of HAI and duration of hospital-stay.

Outbreak of Pseudomonas aeruginosa producing VIM carbapenemase in an intensive care unit and its termination by implementation of waterless patient care

BACKGROUND

Long-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa.

METHODS

We report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir.

RESULTS

Between April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 8 months after the intervention.

DISCUSSION

Implementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks.

A five-component infection control bundle to permanently eliminate a carbapenem-resistant Acinetobacter baumannii spreading in an intensive care unit

Background

Carbapenem-resistant Acinetobacter baumannii (CRAB) infection outbreaks are difficult to control and sometimes require cohorting of CRAB-positive patients or temporary ward closure for environmental cleaning. We aimed at controlling the deadly 2018 CRAB outbreak in a 12 bed- intensive care unit (ICU) including 9 beds in a 220 m² open space. We implemented a new multimodal approach without ward closure, cohorting or temporarily limiting admissions.

Methods

A five-component bundle was introduced in 2018 including reinforcement of hand hygiene and sample extension of screening, application of contact precautions to all patients, enhanced environmental sampling and the one-time application of a cycling radical environmental cleaning and disinfection procedure of the entire ICU.

The ICU-CRAB incidence density (ID), ICU alcohol-based hand rub consumption and antibiotic use were calculated over a period of 6 years and intervention time series analysis was performed. Whole genome sequencing analysis (WGS) was done on clinical and environmental isolates in the study period.

Results

From January 2013, nosocomial ICU-CRAB ID decreased from 30.4 CRAB cases per 1000 patients-days to zero cases per 1000 patients-days. Our intervention showed a significant impact (-2.9 nosocomial ICU-CRAB cases per 1000 bed-days), while no influence was observed for antibiotic and alcohol-based hand rub (AHR) consumption.

WGS demonstrated that CRAB strains were clonally related to an environmental reservoir which confirms the primary role of the environment in CRAB ICU spreading.

Conclusion

A five-component bundle of continuous hand hygiene improvement, extended sampling at screening including the environment, universal contact precautions and a novel cycling radical environmental cleaning and disinfection procedure proved to be effective for permanently eliminating CRAB spreading within the ICU. Cohorting, admission restriction or ICU closure were avoided.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00990-z.

[Clinical characteristics and prognostic risk factors analysis of carbapenem-resistant organism in the department of hematology]

Objective: To study the distribution and drug resistance of Carbapenem-Resistant Organism (CRO) and to analysis the risk factors of CRO 30-day mortality. Methods: A total of 181 patients with CRO infection diagnosed in Department of Hematology, Fujian Medical University Union Hospital from January 2018 to June 2020 were retrospectively investigated. The clinical and laboratory data of the patients were collected, the prognosis of patients diagnosed with CRO infection in day 30 was followed up, and the risk factors of prognosis were analyzed. The clinical significance of Carbapenem-Resistant Enterobacteriaceae (CRE) active screening was further evaluated in the CRE subgroup. Results: Among the total of 181 CRO isolates, 47.2% were CRE, 37.0% were Pseudomonas aeruginosa, and 32.6% were Klebsiella pneumoniae, which were highly resistant to carbapenem and had high MIC value, 76.8% (139/181) of CRO were MIC of imipenem resistance≥16 μg/ml. The main sources of isolates were blood and sputum. The 30-day all-cause mortality rates of patients with CRO or CRE infection were (41.4±3.7) % and (44.7±5.4) %, respectively. The COX multivariate regression analysis showed that the level of procalcitonin >0.2 ng/ml and the MIC value of imipenem resistance ≥ 16 μg/ml were independent risk factors for 30-day mortality of CRO infected patients. The CRE subgroup analysis showed that MIC value of imipenem resistance ≥16 μg/ml were independent risk factors for 30-day mortality of CRE infected patients. The 30-day cumulative survival rate of patients with CRE active screening was higher than the patients without CRE active screening [ (68.0±9.3) % vs (50.0±6.5) %, P=0.21]. Conclusion: The high MIC value of imipenem resistance isolates seriously affects the prognosis of patients with CRO infection in the hematology department, and the mortality rate was high. CRE active screening is expected for early prevention, early diagnosis, and early treatment for high-risk patients.

Does enhanced environmental cleaning reduce carbapenem-resistant Acinetobacter baumannii colonization in the intensive care unit?

OBJECTIVE

To evaluate the impact of enhanced environmental cleaning (two times per day) compared with conventional cleaning on the acquisition of carbapenem-resistant Acinetobacter baumannii (CRAB) in a highly endemic intensive care unit (ICU).

METHODS

The intervention consisted of alternating environmental cleaning and conventional cleaning every 3 months during the study period from July 2018 to June 2019. CRAB acquisition was assessed using incidence and prevalence rates, and colonization pressure.

RESULTS

The incidence rates of CRAB with and without enhanced cleaning were 16.3 and 13.9 cases per 1000 population, respectively; and the prevalence rates were 66.9 and 61.7 cases per 1000 population, respectively. Colonization pressure was 53.3% with enhanced cleaning and 51.3% without enhanced cleaning. No association was found between enhanced environmental cleaning and the incidence (P=0.156), prevalence (P=0.888) and colonization pressure (P=0.825) of CRAB acquisition. The ventilator utilization ratio increased the colonization pressure of CRAB acquisition (P=0.010, β coefficient=0.37). The proportion of new nurses with <3 years of clinical practice experience was positively correlated with the incidence and prevalence of CRAB acquisition.

CONCLUSION

Enhanced environmental cleaning alone failed to reduce CRAB acquisition in a highly endemic ICU. The ventilator utilization ratio may be of more importance than environmental cleaning. Inexperienced nurses may need to be monitored regarding infection control activities in addition to hand hygiene adherence.

Outbreak of OXA-48-producing Enterobacterales in a haematological ward associated with an uncommon environmental reservoir, France, 2016 to 2019

The hospital water environment, including the wastewater drainage system, is increasingly reported as a potential reservoir for carbapenemase-producing Enterobacterales (CPE). We investigated a persistent outbreak of OXA-48 CPE (primarily Citrobacter freundii) in a haematological ward of a French teaching hospital by epidemiological, microbiological and environmental methods. Between January 2016 and June 2019, we detected 37 new OXA-48 CPE-colonised and/or ‑infected patients in the haematological ward. In October 2017, a unit dedicated to CPE-colonised and/or ‑infected patients was created. Eleven additional sporadic acquisitions were identified after this date without any obvious epidemiological link between patients, except in one case. Environmental investigations of the haematological ward (June–August 2018) identified seven of 74 toilets and one of 39 drains positive for OXA-48 CPE (seven C. freundii, one Enterobacter sakazakii, one Escherichia coli). Whole genome comparisons identified a clonal dissemination of OXA-48-producing C. freundii from the hospital environment to patients. In addition to strict routine infection control measures, an intensive cleaning programme was performed (descaling and bleaching) and all toilet bowls and tanks were changed. These additional measures helped to contain the outbreak. This study highlights that toilets can be a possible source of transmission of OXA-48 CPE.

In vitro activity of the novel β-lactamase inhibitor taniborbactam (VNRX-5133), in combination with cefepime or meropenem, against MDR Gram-negative bacterial isolates from China

OBJECTIVES

To evaluate in vitro activity of the novel β-lactamase boronate inhibitor taniborbactam (VNRX-5133) combined with cefepime or meropenem against 500 urinary Gram-negative bacilli.

METHODS

Cefepime/taniborbactam and 14 comparators were tested by broth microdilution or agar dilution methods. A total of 450 Enterobacteriaceae and 50 Pseudomonas aeruginosa were selected from 2017 to 2019 based on different β-lactamase-producing or resistance phenotypes. For carbapenem-non-susceptible isolates, the modified carbapenem inactivation method (mCIM), EDTA-CIM (eCIM) and amplification of carbapenemase genes were performed. For NDM-producing isolates and those with cefepime/taniborbactam MICs >8 mg/L, the MICs of meropenem/taniborbactam and/or mutations in PBP3 were investigated.

RESULTS

Taniborbactam improved cefepime activity with the same efficiency as avibactam improved ceftazidime activity against 66 KPC-2 producers, 30 non-carbapenemase-producing carbapenem-non-susceptible Enterobacteriaceae and 28 meropenem-susceptible P. aeruginosa. However, cefepime/taniborbactam exhibited more potent activity than ceftazidime/avibactam against 56 ESBL-producing, 61 AmpC-producing, 32 ESBL and AmpC co-producing, 87 NDM-producing and 21 MBL-producing Enterobacteriaceae predicted by phenotypic mCIM and eCIM, 82 Enterobacteriaceae that were susceptible to all tested β-lactams and 22 carbapenem-non-susceptible P. aeruginosa. A four-amino acid 'INYR' or 'YRIN' insertion, with or without a one/two-amino acid mutation in PBP3, may have caused cefepime/taniborbactam MICs >8 mg/L among 96.6% (28/29) of the NDM-5-producing Escherichia coli, which accounted for the majority of isolates with cefepime/taniborbactam MICs >8 mg/L (76.1%, 35/46).

CONCLUSIONS

Taniborbactam's superior breadth of activity, when paired with cefepime or meropenem, suggests these β-lactam/β-lactamase inhibitor combinations could be promising candidates for treating urinary tract infections caused by ESBL and/or AmpC, KPC or NDM-producing Enterobacteriaceae or P. aeruginosa.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Infection control response to an outbreak of OXA-23 carbapenemase-producing carbapenem-resistant Acinetobacter baumannii in a skilled nursing facility in Utah

BACKGROUND

Antibiotic-resistant Acinetobacter species are a growing public health threat, yet are not nationally notifiable, and most states do not mandate reporting. Additionally, there are no standardized methods to detect Acinetobacter species colonization.

METHODS

An outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) was identified at a Utah ventilator unit in a skilled nursing facility. An investigation was conducted to identify transmission modes in order to control spread of CRAB. Culture-based methods were used to identify patient colonization and environmental contamination in the facility.

RESULTS

Of the 47 patients screened, OXA-23-producing CRAB were detected in 10 patients (21%), with 7 patients (15%) having been transferred from out-of-state facilities. Of patients who screened positive, 60% did not exhibit any signs or symptoms of active infection by chart review. A total of 38 environmental samples were collected and CRAB was recovered from 37% of those samples. Whole genome sequencing analyses of patient and environmental isolates suggested repeated CRAB introduction into the facility and highlighted the role of shared equipment in transmission.

CONCLUSIONS

The investigation demonstrated this ventilated skilled nursing facility was an important reservoir for CRAB in the community and highlights the need for improved surveillance, strengthened infection control and inter-facility communication within and across states.

Trends and correlation between antibacterial consumption and carbapenem resistance in gram-negative bacteria in a tertiary hospital in China from 2012 to 2019

Background

To investigate the trends and correlation between antibacterial consumption and carbapenem resistance in Gram-negative bacteria from 2012 to 2019 in a tertiary-care teaching hospital in southern China.

Methods

This retrospective study included data from hospital-wide inpatients collected between January 2012 and December 2019. Data on antibacterial consumption were expressed as defined daily doses (DDDs)/1000 patient-days. Antibacterials were classified according to the Anatomical Therapeutic Chemical (ATC) classification system. The trends in antimicrobial usage and resistance were analyzed by linear regression, while Pearson correlation analysis was used for assessing correlations.

Results

An increasing trend in the annual consumption of tetracyclines, β-lactam/β-lactamase inhibitor (BL/BLI) combinations, and carbapenems was observed (P < 0.05). Carbapenem resistance in Acinetobacter baumannii (A. baumannii) significantly increased (P < 0.05) from 18% in 2012 to 60% in 2019. Moreover, significant positive correlations were found between resistance to carbapenems in A. baumannii (P < 0.05) and Escherichia coli (E. coli; P < 0.05) and consumption of carbapenems, while the resistance rate of A. baumannii to carbapenems was positively correlated with cephalosporin/β-lactamase inhibitor (C/BLI) combinations (P < 0.01) and tetracyclines usage (P < 0.05). We also found that use of quinolones was positively correlated with the resistance rate of Burkholderia cepacia (B. cepacia) to carbapenems (P < 0.05), and increasing uses of carbapenems (P < 0.01) and penicillin/β-Lactamase inhibitor (P/BLI) combinations (P < 0.01) were significantly correlated with reduced resistance of Enterobacter cloacae (E. cloacae) to carbapenems.

Conclusion

These results revealed significant correlations between consumption of antibiotics and carbapenem resistance rates in Gram-negative bacteria. Implementing proper management strategies and reducing the unreasonable use of antibacterial drugs may be an effective measure to reduce the spread of carbapenem-resistant Gram-negative bacteria (CRGN), which should be confirmed by further studies.

Interventions to reduce infections caused by multidrug resistant Enterobacteriaceae (MDR-E): A systematic review and meta-analysis

OBJECTIVES

We aimed to evaluate different interventions to reduce multidrug-resistant Enterobacteriaceae (MDR-E) infection/colonization.

METHODS

A systematic review and meta-analysis evaluating interventions for prevention of MDR-E infection/colonization among hospitalized adult patients. The co-primary outcomes were mortality and MDR-E infections. PubMed, Cochrane library, and LILACS databases were searched up till December 2019, as well as grey literature sources. We included randomized controlled trials and observational studies. Infection/colonization/acquisition outcomes were reported per patient-days as pooled incidence ratios (IRs) with 95% confidence intervals (CIs). Interrupted time series (ITS) analysis studies were reported separately.

RESULTS

Sixty-three studies were included, 16 RCTs, 33 observational studies, and 14 ITS. For the intervention of antimicrobial stewardship program (ASP), 23 studies were included. No differences in mortality or MDR-E infections were observed with ASP, however, MDR-E colonization was significantly reduced (IR 0.69, 95% CI 0.57-0.82). Seventeen studies examined decolonization without significant difference in outcomes. Other interventions were scarcely represented. Among 14 ITS publications, most evaluating ASP, 11 showed benefit of the intervention.

CONCLUSIONS

ASP is an effective measure in preventing MDR-E colonization. Decolonization did not show significant benefit in reducing infection or colonization. Studies are needed to evaluate the cost effectiveness of ASP and assess bundles of interventions.

Multimodal intervention to reduce acquisition of carbapenem-non-susceptible Gram-negative bacteria in intensive care units in the National Referral Hospital of Indonesia: An interrupted time series study

PURPOSE

To evaluate a low-cost multimodal intervention on the acquisition of carbapenem-non-susceptible Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa by patients in low-resource intensive care units.

MATERIALS AND METHODS

We performed a quasi-experimental study in a referral hospital in Jakarta, Indonesia: pre-intervention phase 1 (2013-2014), intervention phase 2 (2014-2015) and post-intervention phase 3 (2015-2016). The intervention was hand hygiene promotion and environmental cleaning and disinfection combined with patient disinfection and cohorting. The primary outcome was acquisition of resistant bacteria per 100 patient-days at risk, which was assessed by active microbiological surveillance and analysed with a multilevel Poisson segmented regression model.

RESULTS

In phase 1 (387 patients), the acquisition rate was 4.3/100 days for carbapenem-non-susceptible A. baumannii versus 1.1/100 days for both K. pneumoniae and P. aeruginosa. There was a significant step change from phase 1 to phase 3 (361 patients) in the acquisition of carbapenem-non-susceptible strains, the incidence rate ratio (IRR) was 0.343 (99%CI: 0.164-0.717). This significant change was mainly due to reduced acquisitions of resistant A. baumannii (IRR 0.4, 99%CI: 0.181-1.061). Negative confounding was observed.

CONCLUSION

A multimodal intervention to prevent acquisition of resistant pathogens is feasible and may be effective in ICUs in lower-middle income countries.

Molecular detection of carbapenem resistance genes in rectal swabs from patients in Gulf Cooperation Council hospitals

BACKGROUND

Gram-negative organisms harbouring carbapenem resistance genes (CRGs) are spreading globally, including in Gulf Cooperation Council (GCC) countries. However, relatively few data are available about carriage of CRGs in hospitalized patients in this region.

AIM

To determine prevalence of CRG carriage and risk factors for colonization among patients in GCC hospitals.

METHODS

Rectal swabs were obtained from ∼50 intensive care unit (ICU) patients from each of 11 hospitals in five GCC countries between March and November 2019. The swabs were tested for the presence of bla_KPC, bla_NDM, bla_VIM, bla_IMP, and bla_OXA-48 CRG using a commercial polymerase chain reaction test. Data on risk factors for colonization were collected and analysed.

FINDINGS

Of 529 specimens screened, 138 (26.1%) were positive for one or more CRGs. The positivity rates among the hospitals ranged from 8.0% to 67.3%; ∼20% of the positive specimens harboured ≥2 CRGs. The most common CRG detected was bla_OXA-48, which was present in 82 specimens (15.5%). Additional CRGs included bla_NDM, bla_VIM, bla_KPC, and bla_IMP either alone or in combination. Overall, 31.1% of patients on antibiotics on admission to the ICU were positive for CRGs compared to 16.5% not on antibiotic therapy (P < 0.001). CRG detection was also more common among patients aged >65 years (P = 0.027) and increased with hospital length of stay (P = 0.025).

CONCLUSION

The rate of CRGs detected in hospitalized patients in GCC countries varied considerably. Prior antibiotic exposure, increasing age, and prolonged length of stay were associated with CRG detection.

Identification of novel tetracycline resistance gene tet(X14) and its co-occurrence with tet(X2) in a tigecycline-resistant and colistin-resistant Empedobacter stercoris

Tigecycline is one of the last-resort antibiotics to treat severe infections. Recently, tigecycline resistance has sporadically emerged with an increasing trend, and Tet(X) family represents a new resistance mechanism of tigecycline. In this study, a novel chromosome-encoded tigecycline resistance gene, tet(X14), was identified in a tigecycline-resistant and colistin-resistant Empedobacter stercoris strain ES183 recovered from a pig fecal sample in China. Tet(X14) shows 67.14-96.39% sequence identity to the other variants [Tet(X) to Tet(X13)]. Overexpression of Tet(X14) in Escherichia coli confers 16-fold increase in tigecycline MIC (from 0.125 to 2 mg/L), which is lower than that of Tet(X3), Tet(X4) and Tet(X6). Structural modelling predicted that Tet(X14) shared a high homology with the other 12 variants with RMSD value from 0.003 to 0.055, and Tet(X14) can interact with tetracyclines by a similar pattern as the other Tet(X)s. tet(X14) and two copies of tet(X2) were identified on a genome island with abnormal GC content carried by the chromosome of ES183, and no mobile genetic elements were found surrounding, suggesting that tet(X14) might be heterologously obtained by ES183 via recombination. Blasting in Genbank revealed that Tet(X14) was exclusively detected on the chromosome of Riemerella anatipestifer, mainly encoded on antimicrobial resistance islands. E. stercoris and R. anatipestifer belong to the family Flavobacteriaceae, suggesting that the members of Flavobacteriaceae maybe the major reservoir of tet(X14). Our study reports a novel chromosome-encoded tigecycline resistance gene tet(X14). The expanded members of Tet(X) family warrants the potential large-scale dissemination and the necessity of continuous surveillance for tet(X)-mediated tigecycline resistance.

Risk factors for nosocomial rectal colonization with carbapenem-resistant Acinetobacter baumannii in hospital: a matched case-control study

BACKGROUND

During the last decade carbapenem-resistant Acinetobacter baumannii (CRAB) became hyper-endemic in hospitals due to difficult to control spreading. Our aim is to identify risk factors for nosocomial rectal CRAB colonization in an endemic hospital.

METHODS

A retrospective matched case-control study (ratio 1:2) with a prospective inclusion of cases and concurrent selection of controls was conducted from January 2017 to December 2018 in a tertiary-care hospital. Universal active surveillance for CRAB was implemented. Univariate and multivariate logistic regression was carried out using a stepwise selection method to compare prognostic factors between cases and controls. A sub-analysis was carried out according to the type of department.

RESULTS

Forty-five cases with nosocomial rectal CRAB colonization and 90 controls were included. One hundred and two (75%) patients were hospitalized in medical departments. At multivariable analysis significant risk factors associated with CRAB colonization were: use of permanent devices (OR 10.15, 95% CI 2.27-45.39; P = 0.002), mechanical ventilation (OR 40.01, 95% CI 4.05-395.1; P = 0.002), urinary catheters (OR 4.9, 95% CI 1.52-16.19; P = 0.008), McCabe score (OR 5.45, 95% CI 1.87-15.89; P = 0.002), length of stay (OR 1.03, 95% CI 1.01-1.05; P = 0.002), carbapenem use (OR 5.39, 95% CI 1.14-25.44; P = 0.033). The sub-analysis showed that patients admitted to different departments had different risk factors. In geriatric department a fatal disease and a longer hospital stay represented significant risk factors both in univariate and multivariate analysis, while in internal medicine department the use of permanent devices, current antibiotic therapy and antibiotic polytherapy represented significant risk factors for CRAB at the univariate analysis, also confirmed in multivariate analysis.

CONCLUSIONS

Our data suggest that active surveillance for rectal CRAB colonization should be addressed to patients with an unfavourable prognosis, longer hospitalizations and carriers of multiple devices. To counter CRAB spreading in endemic settings, clinicians must limit the use of carbapenems, and reinforce interventions aimed at proper use of devices.

Bacterial Contamination in Health Care Centers: Differences between Urban and Rural Settings

This study aims to assess the airborne bioburden of rural and urban Portuguese Primary Health Care Centers (PHCC) using active and passive sampling methods and identify the potential differences in airborne microbiota between both environments. The highest total aerobic mesophilic bacterial load in indoor air were found in the Vaccination Room (448 CFU.m−3) in the Rural PHCC and in the Waiting Room (420 CFU.m−3) for Urban PHCC. The total coliforms contamination level in indoor air was detected only in the Cleaning Supplies Room (4 CFU.m−3) in the Urban PHCC. The most frequent bacteria genera identified was Micrococcus (21% Rural PHCC; 31% Urban PHCC). The surface samples showed a highest total aerobic mesophilic bacterial contamination in the Treatment Room (86 × 103 CFU.m−2) from the Rural PHCC and in the Front Office (200 × 103 CFU.m−2) from the Urban PHCC. The electrostatic dust cloth (EDC) samples showed a highest bacterial load in the Urban PHCC. Total aerobic mesophilic bacterial load in settled dust and in the Heating, Ventilating and Air Conditioning (HVAC) filter samples in the Urban PHCC (8 CFU.g−1 and 6 × 103 CFU.m−2) presented higher values compared with the Rural PHCC (1 CFU.g−1 and 2.5 × 103 CFU.m−2). Urban PHCC presented higher bacterial airborne contamination compared with the Rural PHCC for the majority of sampling sites, and when compared with the indoor air quality (IAQ) Portuguese legislation it was the Rural PHCC in two sampling places who did not comply with the established criteria.

Antipseudomonal β-Lactams Resistance in Iran

Over the last years, the mortality rate of Pseudomonas aeruginosa, which is one of the major reasons for severe infections, has been significantly increasing. This bacterium is highly resistant to many antibiotics, especially carbapenems, thanks to its complicated mechanism by which it can acquire exogenous genes. The purpose of this research is to have a review of empirical studies surveying the P. aeruginosa resistance to beta-lactams in Iran in order to investigate the most reliable methods by which the incidence of P. aeruginosa infections can be decreased and controlled. We performed a systematic review of all articles published from 2008 until 2018. Studies which did not address P. aeruginosa resistance to beta-lactams were excluded from the analysis. Studies with less than 10 cases were also excluded. Studies with more than ten cases, which did not have repetitive information, were taken into account for the final selection; 133 out of 893 articles were chosen. The resistance rate of P. aeruginosa among the articles was as follows: more than 72% of studies revealed >50% level of resistance to cefepime, followed by aztreonam (53.2%), ceftazidime (61%), piperacillin/tazobactam (54.5%), meropenem (48.3%), and imipenem (42.4%). The selection of empiric antipseudomonal antibiotics is absolutely uncertain and hazardous, and the risk of clinical failure may be more among cephalosporins and piperacillin-tazobactam as well as aztreonam. The results of this study illustrate that the methods enabling clinics to identify the bacterium resistance pattern and its genetic basis and to have the opportunity of empiric therapies through access to updated local data of antimicrobial susceptibility pattern are the most effective methods. However, the widespread usage of these approaches undoubtedly needs reliable molecular and nucleic acid-based devices, which are both affordable and available.

Do contact precautions reduce the incidence of ICU-acquired Pseudomonas aeruginosa infections? The DPCPYO cluster-randomized crossover trial

BACKGROUND

Issue of contact precautions as contributory factors for reducing P. aeruginosa (Pa) infections in intensive care units (ICUs) remains questioned. We evaluated the impact of the addition of contact precautions to standard precautions for Pa-positive patients on the incidence of ICU-acquired Pa infections.

METHODS

In this multicenter cluster-randomized crossover trial, 10 French ICUs were randomly assigned (1:1) to sequence 0-1 (6-month control period [CP]/3-month washout period/6-month intervention period [IP]) or sequence 1-0 (6-month IP/3-month washout period/6-month CP). A surveillance screening program for Pa was implemented. Competing-risks regression models were built with death and discharge without the occurrence of ICU-acquired Pa infection (the primary outcome), as competing events. Models were adjusted for within-ICU correlation, patient- and ICU-level covariates. The Simpson diversity index (SDI) and the transmission index (TI) of Pa isolates were derived from pulsed-field gel electrophoresis typing.

RESULTS

Within recruited ICUs, the cumulative incidence and the incidence rate of ICU-acquired Pa infections were 3.38% (55/1625) vs 3.44% (57/1658) and 3.31 vs 3.52 per 1 000 patient-days at risk during CP and IP, respectively. Multivariable models indicated that the intervention did not significantly change the cumulative incidence (subdistribution hazard ratio 0.91, 95% confidence interval [CI] 0.49-1.67, p=0.76) and the rate (cause-specific hazard ratio 1.36, 95%CI 0.71-2.63, p=0.36) of the primary outcome. SDI and TI did not significantly differ between CP and IP.

CONCLUSIONS

The addition of contact precautions to standard precautions for Pa-positive patients with a surveillance screening program does not significantly reduce ICU-acquired Pa infections in non-outbreak situations.

The Effect of Host Immunity on Predicting the Mortality of Carbapenem-Resistant Organism Infection

Carbapenem-resistant organisms (CROs) are associated with considerable mortality clinically. There is a lack of effective tool to predict individual prognosis. We aim to determine if host immunity can be utilized to predict the prognosis of patients infected with CRO. From December 2018 to August 2019, we recruited CRO-infected patients to evaluate risk factors for 30-day mortality. Clinical, routine laboratory, immune and microbiological features were investigated and subjected to univariate and multivariate analyses. The final predictive models were established based on the regression coefficients of multivariate logistic regression. A total of 127 CRO-infected patients were enrolled in our study, including 85 survivors and 42 non-survivors. The number and IFN-γ producing ability of lymphocytes were remarkably decreased in non-survivors. The number of IFN-γ⁺CD4⁺ T cells could effectively predict 30-day mortality of CRO infection. Its area under the receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy, were 0.889 (95% confidence interval [CI], 0.834-0.945), 81.0, 80.0, and 80.3%, respectively. In multivariate analysis of laboratory parameters, IFN-γ⁺CD4⁺ T cell number and creatinine concentration were selected for the 2-marker model to predict prognosis fleetly. Its area under the ROC curve, sensitivity, specificity and accuracy were 0.894 (95% CI, 0.841-0.947), 83.3, 82.4, and 82.7%, respectively. Impaired lymphocyte function was an important factor to affect the outcome of CRO-infected patients. A 2-marker model based on the combination of IFN-γ⁺CD4⁺ T cell number and creatinine showed good performance in predicting the prognosis of CRO infection.

Identification of a Novel Acinetobacter baumannii Phage-Derived Depolymerase and Its Therapeutic Application in Mice

The rapid expansion of Acinetobacter baumannii clinical isolates exhibiting resistance to most or all available antibiotics is a global concern. Current treatments for infections caused by this bacterium have become less effective, and the need to explore new alternative therapies is urgent. Depolymerases derived from phages are emerging as attractive anti-virulence agents. In this study, a previously isolated A. baumannii phage (designated as vB_AbaM_IME285) was characterized, and genomic study was carried out using various bioinformatics tools. A gene predicted as encoding for the depolymerase was cloned and expressed, and the depolymerase activity of the recombinant enzyme (Dp49) was identified both in vitro and in experimental mice. The results showed that phage IME285 formed translucent halos around the plaques when inoculated onto a lawn of the host bacteria, exibiting depolymerase activity against this strain. On the basis of complete genome sequencing and bioinformatics analysis, ORF49 was speculated to be a gene encoding for the putative capsule depolymerase. The expressed recombinant Dp49 displayed an effective depolymerase activity and had a spectrum of activity similar to its parental phage IME285, which was active against 25 out of 49 A. baumannii strains. It was found that Dp49 greatly improved the inhibitory effect of serum on bacterial growth in vitro, and the administration of this enzyme significantly increased the survival rates of A. baumannii-infected mice in the animal experiment. In conclusion, the phage-encoded depolymerase Dp49 might be a promising alternative means of controlling infections mediated by multidrug-resistant A. baumannii.

Barrier Precautions in the Era of Multidrug Pathogens

Purpose of review

There is a continuing debate regarding contact precaution (CP) usage for endemic multidrug-resistant organisms (MDROs). In this review, we examine current recommendations for CP and highlight differences in CP use between endemic and non-endemic MDROs.

Recent findings

The discontinuation of CP had no effect on the incidence of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci. The evidence regarding CP for extended-spectrum beta-lactamase producing Enterobacteriaceae is inconclusive, highlighting the need for more research to determine best infection control strategies. Carbapenem-resistant Enterobacteriaceae maintains a sporadic pattern in the USA, supporting current recommendations to use CP for colonized and infected patients. MDR Acinetobacter baumannii (MDR-AB) is extremely virulent and responsible for outbreaks in healthcare settings, emphasizing the need for CP use with MDR-AB infected patients. Candida auris (C. auris) is often misdiagnosed; it is resistant to UV light and quaternary ammonium low-level disinfection. Because little is known about the transmission of C. auris, significant caution and CP use are necessitated. There is little research on vancomycin-resistant S. aureus (VRSA) control strategies due to its rarity; thus, CP is strongly recommended.

Summary

Contact precautions are frequently part of a bundled infection control approach that involves meticulous hand hygiene, patient decolonization, chlorhexidine gluconate bathing, and reducing the use of invasive devices. Healthcare facilities should continue to utilize CP for non-endemic MDROs and the presence of endemic MDROs; however, CP may not add benefit to the current infection prevention bundle approach.

Perceptions of patients' and healthcare workers' experiences in cohort isolation units: a qualitative study

BACKGROUND

Given the scarce therapeutic options for carbapenemase-producing Enterobacterales (CPE), aggressive interventions are implemented to limit its spread among hospitalized patients. One such option is contact isolation by cohorting patients in designated units.

AIM

To describe the experiences in a cohort isolation unit (CIU) due to CPE from the perspectives of patients admitted to this unit and their families, and those of healthcare workers (HCWs) who served in the same unit.

METHODS

Qualitative study. Face-to-face, semi-structured interviews were conducted in a large tertiary hospital. Twenty-four participants were interviewed, including 15 HCWs, three patients and six family members. Data were coded using thematic analysis.

FINDINGS

The CIU provoked negative feelings such as fear, risk, loneliness, distrust and unfairness. They also created a sense of conflict with the curative assumptions of hospital care. The poor CIU infrastructure was echoed in perceptions of crowdedness in the site. Moreover, family members described HCWs' inconsistent protective behaviours that led them to a state of vigilance. The hospital infection control unit imparted and refreshed HCWs' knowledge and expected behaviours regarding the CIU. However, patients and families expressed dissatisfaction with the information, guidance and education regarding the 'why and how' of the CIU. They were not guided consistently about recommended behaviours after discharge. In retrospect, HCWs found that the CIU took a psychological, physical and professional toll.

CONCLUSION

The CIU was planned as a temporary containment mechanism. It needs to develop into a permanent system, capable of addressing the various needs of all involved.

Development and Evaluation of a Loop-Mediated Isothermal Amplification Assay for Rapid and Specific Identification of Carbapenem-Resistant Acinetobacter baumannii Strains Harboring blaOXA-23, and the Epidemiological Survey of Clinical Isolates

Acinetobacter baumannii is an important nosocomial pathogen in hospital-acquired infections, and carbapenem resistance has been increasingly observed worldwide. Oxacillinase production by bla_OXA-23 is a predominant and prevalent carbapenem resistance mechanism of A. baumannii, especially in China. Rapid and specific detection of bla_OXA-23 may offer valuable insight for administration of directed antimicrobial therapy. In this study, we aimed to develop a loop-mediated isothermal amplification (LAMP)-based method for identifying carbapenem-resistant A. baumannii (CRAB) harboring the bla_OXA-23 gene. High-specificity primers for screening bla_OXA-23 were designed and synthesized, and the LAMP reactions were performed. Clinical A. baumannii strains isolated from the Former 307th Hospital of People's Liberation Army were used to determine the sensitivity and specificity of this method compared with those of phenotypic antimicrobial susceptibility testing and the traditional PCR method. Multilocus sequence typing (MLST) was performed to investigate the epidemiology of the A. baumannii bacterial population. Compared with antimicrobial susceptibility testing, the sensitivity and specificity of LAMP in detecting bla_OXA-23 were 88.4% and 97.7%, respectively. However, the LAMP method is much simpler and less time-consuming (within 60 minutes) than conventional PCR and phenotypic susceptibility testing. The 113 isolates could be clustered into 30 sequence types, and most strains (83/113) belonged to clonal complex (CC) 92, which is also the dominant CC in China. The LAMP-based method detected bla_OXA-23 in a simpler manner and could provide rapid results for identifying CRAB. Consequently, bla_OXA-23 may serve as a surrogate marker for the presence of CRAB in patients with serious infections in clinical practice.

Cohorting for preventing the nosocomial spread of Carbapenemase-Producing Enterobacterales, in non-epidemic settings: is it mandatory?

BACKGROUND

Worldwide dissemination of Carbapenemase-Producing Enterobacterales (CPE) has led to national and international guidance recommending the implementation of cohorting in healthcare settings (HS). However, in view of recent data regarding the spread of Extended-spectrum Beta-lactamase-producing Enterobacterales, we may wonder about the usefulness of this measure in a non-outbreak settings; here, individual contact isolation may be sufficient to control the risk of dissemination.

AIM/METHODS

We conducted a narrative review of the literature and discussed the role of cohorting.

FINDINGS

CPE are responsible for outbreaks in HS, which are considered the epicentre of spread of resistance strains. CPE are responsible for adverse effects such as increases in hospital stay and costs, less therapeutic options and thus higher risk of clinical failures and mortality. Environment and materials have also been described contaminated with CPE and can be the source of outbreak. Even if guidelines and publications have supported implementation of cohorting, there are no randomized studies demonstrating the mandatory nature of this measure. Most studies are descriptive and cohorting is usually one of several other measures to control outbreaks. Cohorting is not adapted to all HS, which requires human and material resources. Other measures must be strengthened such as compliance of hand hygiene, antibiotic stewardship and surveillance of contact patients. Individual risk factors of acquisition should also be evaluated.

CONCLUSION

Local epidemiology and resources must be assessed before implementing cohorting.

Microbiology and Risk Factors for Hospital-Associated Bloodstream Infections Among Pediatric Hematopoietic Stem Cell Transplant Recipients

Background

Children undergoing hematopoietic stem cell transplantation (HSCT) are at high risk for hospital-associated bloodstream infections (HA-BSIs). This study aimed to describe the incidence, microbiology, and risk factors for HA-BSI in pediatric HSCT recipients.

Methods

We performed a single-center retrospective cohort study of children and adolescents (<18 years of age) who underwent HSCT over a 20-year period (1997–2016). We determined the incidence and case fatality rate of HA-BSI by causative organism. We used multivariable Poisson regression to identify risk factors for HA-BSI.

Results

Of 1294 patients, the majority (86%) received an allogeneic HSCT, most commonly with umbilical cord blood (63%). During the initial HSCT hospitalization, 334 HA-BSIs occurred among 261 (20%) patients. These were classified as gram-positive bacterial (46%), gram-negative bacterial (24%), fungal (12%), mycobacterial (<1%), or polymicrobial (19%). During the study period, there was a decline in the cumulative incidence of HA-BSI (P = .021) and, specifically, fungal HA-BSIs (P = .002). In multivariable analyses, older age (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], 1.01–1.06), umbilical cord blood donor source (vs bone marrow; IRR, 1.69; 95% CI, 1.19–2.40), and nonmyeloablative conditioning (vs myeloablative; IRR, 1.85; 95% CI, 1.21–2.82) were associated with a higher risk of HA-BSIs. The case fatality rate was higher for fungal HA-BSI than other HA-BSI categories (21% vs 6%; P = .002).

Conclusions

Over the past 2 decades, the incidence of HA-BSIs has declined among pediatric HSCT recipients at our institution. Older age, umbilical cord blood donor source, and nonmyeloablative conditioning regimens are independent risk factors for HA-BSI among children undergoing HSCT.

A proposal for a comprehensive approach to infections across the surgical pathway

Despite evidence supporting the effectiveness of best practices in infection prevention and management, many healthcare workers fail to implement them and evidence-based practices tend to be underused in routine practice. Prevention and management of infections across the surgical pathway should always focus on collaboration among all healthcare workers sharing knowledge of best practices. To clarify key issues in the prevention and management of infections across the surgical pathway, a multidisciplinary task force of experts convened in Ancona, Italy, on May 31, 2019, for a national meeting. This document represents the executive summary of the final statements approved by the expert panel.

Simultaneous Infection with Enterobacteriaceae and Pseudomonas aeruginosa Harboring Multiple Carbapenemases in a Returning Traveler Colonized with Candida auris

We report our clinical experience treating a critically ill patient with polymicrobial infections due to multidrug-resistant Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa in a 56-year-old woman who received health care in India and was also colonized by Candida auris A precision medicine approach using whole-genome sequencing revealed a multiplicity of mobile elements associated with NDM-1, NDM-5, and OXA-181 and, supplemented with susceptibility testing, guided the selection of rational antimicrobial therapy.

The antimicrobial peptide ZY4 combats multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii infection

The emergence of carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa raises fears of untreatable infections and poses the greatest health threats. Antimicrobial peptides (AMPs) are regarded as the most ideal solution to this menace. In this study, a set of peptides was designed based on our previously reported peptide cathelicidin-BF-15, and the lead peptide ZY4, a cyclic peptide stabilized by a disulfide bridge with high stability in vivo (the half-life is 1.8 h), showed excellent activity against P. aeruginosa and A. baumannii, including standard and clinical multidrug-resistant (MDR) strains. ZY4 killed bacteria by permeabilizing the bacterial membrane and showed low propensity to induce resistance, exhibited biofilm inhibition and eradication activities, and also killed persister cells. Notably, administration of ZY4 decreased susceptibility to lung infection by P. aeruginosa and suppressed dissemination of P. aeruginosa and A. baumannii to target organs in a mouse septicemia infection model. These findings identify ZY4 as an ideal candidate against MDR bacterial infections.

Antecedent Carbapenem Exposure as a Risk Factor for Non-Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae and Carbapenemase-Producing Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) can be mechanistically classified into carbapenemase-producing Enterobacteriaceae (CPE) and non-carbapenemase-producing carbapenem nonsusceptible Enterobacteriaceae (NCPCRE). We sought to investigate the effect of antecedent carbapenem exposure as a risk factor for NCPCRE versus CPE. Among all patients with CRE colonization and infection, we conducted a case-control study comparing patients with NCPCRE (cases) and patients with CPE (controls). The presence of carbapenemases was investigated with phenotypic tests followed by PCR for predominant carbapenemase genes. We included 843 unique patients with first-episode CRE, including 387 (45.9%) NCPCRE and 456 (54.1%) CPE. The resistance genes detected in CPEs were bla _NDM (42.8%), bla _KPC (38.4%), and bla _OXA-48-like (12.1%). After adjusting for confounders and clustering at the institutional level, the odds of prior 30-day carbapenem exposure was three times higher among NCPCRE than CPE patients (adjusted odds ratio [aOR], 3.48; 95% confidence interval [CI], 2.39 to 5.09; P < 0.001). The odds of prior carbapenem exposure and NCPCRE detection persisted in stratified analyses by Enterobacteriaceae species (Klebsiella pneumoniae and Escherichia coli) and carbapenemase gene (bla _NDM and bla _KPC). CPE was associated with male gender (aOR, 1.45; 95% CI, 1.07 to 1.97; P = 0.02), intensive care unit stay (aOR, 1.84; 95% CI, 1.24 to 2.74; P = 0.003), and hospitalization in the preceding 1 year (aOR, 1.42; 95% CI, 1.01 to 2.02; P = 0.05). In a large nationwide study, antecedent carbapenem exposure was a significant risk factor for NCPCRE versus CPE, suggesting a differential effect of antibiotic selection pressure.

Active surveillance culture program in asymptomatic patients as a strategy to control multidrug-resistant gram-negative organisms: What should be considered?

The increasing burden of multidrug-resistant gram-negative bacilli (MDR-GNB) infection has highlighted the urgent requirement for efficient prevention and control strategies. A routine active surveillance culture (ASC) program of asymptomatic carriers as part of an infection prevention strategy for MDR-GNB still has some controversy. An ASC program for colonized patients may be beneficial depending on the targeted population, level of endemicity, the species of pathogen, and the combination of multifaceted strategies. Multimodal infection control and prevention strategies are crucial for implementation in resources-limited settings. After discovering the culprit, it is a challenge to control MDR-GNB by containment or eradication and prevent cross-transmission. An ASC program should consider both the local epidemiology and cost-effectiveness based on the available resources in endemic MDR-GNB areas in the Asia-Pacific region.

Likelihood of persistent carriage of carbapenem-resistant Acinetobacter baumannii on readmission in previously identified carriers

Patients with carbapenem-resistant Acinetobacter baumannii-positive clinical cultures during a prior hospitalization were screened using high sensitivity methods upon first readmission. Of 38 patients, 31.6% screened positive; 42% screened positive within 2 months from discharge, and 14% screened positive more than 5 months from discharge. Carriage was persistent up to 285 days.

Ts2631 Endolysin from the Extremophilic Thermus scotoductus Bacteriophage vB_Tsc2631 as an Antimicrobial Agent against Gram-Negative Multidrug-Resistant Bacteria

Bacteria that thrive in extreme conditions and the bacteriophages that infect them are sources of valuable enzymes resistant to denaturation at high temperatures. Many of these heat-stable proteins are useful for biotechnological applications; nevertheless, none have been utilized as antibacterial agents. Here, we demonstrate the bactericidal potential of Ts2631 endolysin from the extremophilic bacteriophage vB_Tsc2631, which infects Thermus scotoductus, against the alarming multidrug-resistant clinical strains of Acinetobacter baumannii, Pseudomonas aeruginosa and pathogens from the Enterobacteriaceae family. A 2–3.7 log reduction in the bacterial load was observed in antibacterial tests against A. baumannii and P. aeruginosa after 1.5 h. The Ts2631 activity was further enhanced by ethylenediaminetetraacetic acid (EDTA), a metal ion chelator (4.2 log reduction in carbapenem-resistant A. baumannii) and, to a lesser extent, by malic acid and citric acid (2.9 and 3.3 log reductions, respectively). The EDTA/Ts2631 combination reduced all pathogens of the Enterobacteriaceae family, particularly multidrug-resistant Citrobacter braakii, to levels below the detection limit (>6 log); these results indicate that Ts2631 endolysin could be useful to combat Gram-negative pathogens. The investigation of A. baumannii cells treated with Ts2631 endolysin variants under transmission electron and fluorescence microscopy demonstrates that the intrinsic antibacterial activity of Ts2631 endolysin is dependent on the presence of its N-terminal tail.

Messages from the third International Conference on Clinical Metagenomics (ICCMg3)

Clinical metagenomics (CMg), referring to as the application of metagenomic sequencing of clinical samples in order to recover clinically-relevant information, has been rapidly evolving these last years. Following this trend, we held the third International Conference on Clinical Metagenomics (ICCMg3) in Geneva in October 2018. During the two days of the conference, several aspects of CMg were addressed, which we propose to summarize in the present manuscript. During this ICCMg3, we kept on following the progresses achieved worldwide on clinical metagenomics, but also this year in clinical genomics. Besides, the use of metagenomics in cancer diagnostic and management was addressed. Some new challenges have also been raised such as the way to report clinical (meta)genomics output to clinicians and the pivotal place of ethics in this expanding field.

Epidemiologic analysis and control strategy of Klebsiella pneumoniae infection in intensive care units in a teaching hospital of People's Republic of China

BACKGROUND

Klebsiella pneumoniae (KP) is the most common pathogen isolated in intensive care units (ICUs) and the most frequently encountered carbapenemase-producing Enterobacteriaceae. Increasing antimicrobial drug resistance, especially in carbapenem-resistant KP (CRKP), can limit the choice of antibiotics used for the treatment of infectious diseases and further poses a negative impact on patient outcome. However, the reason behind this increasing resistance is not well known.

PATIENTS AND METHODS

A retrospective analysis of laboratory records and clinical cases of KP infection in the ICUs of a hospital from January 2013 to December 2017 was conducted. The disk diffusion method and double-paper synergy test were used to test drug sensitivity for extended-spectrum β-lactamase (ESBL) detection. WHONET5.6 and SPSS 21.0 software were used for statistical analysis.

RESULTS

A total of 64.8% (570/847) of patients with KP infection were older than 60 years. The lower respiratory tract was the main infection site, accounting for 70.84% (600/847); the highest rate of ICU admission was for neurosurgery, accounting for 28.69% (243/847). Some 444 multidrug-resistant KP strains were detected, including 69 CRKP and 299 ESBL-producing strains. In the past 5 years, the resistance rate of detected strains to common antibiotics increased to various degrees, particularly carbapenem-resistant strains which increased from 4.76% (9/189) in 2013 to 16.00% (28/175) in 2017. All carbapenem-resistant isolates were resistant to β-lactam antibiotics, and no isolates were resistant to tigecycline.

CONCLUSION

CRKP and ESBLKP prevalence and resistance rates gradually increased in our ICUs in the past 5 years. The reasons for this are manifold. Regular surveillance of resistance, rational use of antibiotics, and other effective infection control measures need to be strengthened to slow down the production of multidrug-resistant bacteria and prevent their spread in ICU settings.