Control of carbapenemase-producing Klebsiella pneumoniae: a region-wide intervention

Containment of carbapenem-resistant Enterobacterales colonisations and infections: Results from an integrated infection control intervention in a large hospital trust of northern Italy

PURPOSE

We describe the results of an infection control intervention, implemented in 4 tertiary hospitals in Romagna, Italy, aiming at containing the spread of carbapenem-resistant Enterobacterales (CRE).

METHODS

The intervention consisted of rectal screening in patients at risk for CRE; pre-emptive contact precaution waiting for screening results; timely notification of CRE identification and concomitant computerized alert; contact precaution for confirmed CRE-positive patients. We performed an interrupted time series analysis to compare the incidence of CRE bacteraemia, of other CRE infections, and CRE-positive rectal swabs in the pre and postintervention period (January 2015-July 2017 and August 2017-June 2020, respectively).

RESULTS

4,332 CRE isolates were collected. Klebsiella pneumoniae was the most represented pathogen (n = 3,716, 85%); KPC production was the most common resistance mechanism (n = 3,896, 90%). The incidence rate of CRE bacteraemia significantly decreased from 0.554 to 0.447 episodes per 10.000 patient days in the early postintervention period (P = .001). The incidence rate of other CRE infections significantly decreased from 2.09 to 1.49 isolations per 10.000 patient days in the early postintervention period (P = .021). The monthly number of rectal swabs doubled in the postintervention period and there was a significant reduction trend of CRE-positive swabs, sustained over time (P < .001).

CONCLUSIONS

The infection control intervention was successful in containing the spread of CRE infections and colonisations.

Effects of screening strategies to detect carbapenem-resistant gram-negative bacteria: A systematic review

OBJECTIVE

This systematic review aims to summarize the evidence on the effects of screening strategies to detect carbapenem-resistant gram-negative bacteria (Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa).

METHODS

Eligible studies were randomized trials, non-randomized controlled trials, controlled before-after studies, and interrupted time series. We conducted searches in CENTRAL, PUBMED, Embase, Epistemonikos, and in multiple databases available in the Virtual Health Library (LILACS, Scielo, WHO IBECS, and PAHO IBECS). All the searches covered the period until 4 June 2021. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned standardized form. When possible, we intended to conduct meta-analyses using a random-effect model. We assessed the certainty of the evidence (CoE) and summarized the results using the GRADE approach.

RESULTS

Our search strategy yielded 57,451 references. No randomized trials were identified. Sixteen studies (one controlled before-after study and 15 interrupted time series) met our inclusion criteria and were included in the review. Most studies were conducted in tertiary care general hospitals from the United States, Europe, and Asia. Eleven studies included adult patients hospitalized in general wards and intensive care units, one was carried out in a neonatal intensive care unit, two in hematology or oncology units, and one in a solid organ transplantation department. Eleven studies were conducted in the setting of an outbreak. Regarding the detection strategy used, all studies included screening strategies for high-risk patients at the moment of admission and 7 studies reported a contact surveillance strategy. Most studies were conducted in settings where infection prevention and control measures were concomitantly installed or reinforced. Data were not suitable for meta-analysis, so the results were presented as a narrative synthesis. Most studies showed a decline in the prevalence of both infection and colonization rates after the implementation of a policy of active surveillance, but the CoE is low. Screening strategies may result in little to no difference in the risk of all-cause mortality and the length of hospital stay.

CONCLUSIONS

Existing evidence may favor the use of surveillance culture to carbapenem-resistant gram-negative bacteria, but its quality is poor, so solid conclusions cannot be drawn. Well-conducted randomized trials or high-quality quasi-experimental studies are needed to improve the certainty of the existing evidence. These studies should assess the effect of the addition of screening strategies as a single intervention and measure clinically important outcomes such as infection, length of hospital stay, and mortality.

Clonal spread of carbapenemase-producing Enterobacteriaceae in a region, China

Background

The increasing number of carbapenemase-producing Enterobacterales (CPE) has become a serious problem globally. This study aimed to elucidate their geographically epidemiological characteristics.

Methods

Resistance genes were identified by polymerase chain reaction (PCR) and sequencing. Bacterial genotyping was studied using multilocus sequence typing (MLST) and wzi typing. The transferability of carbapenemase genes was determined by a broth mating method. The relationships between the rates of antimicrobial consumption and the prevalence of CRE were performed by Pearson's or Spearman's correlation analyses.

Results

A total of 930 phenotypically confirmed carbapenem-resistant Enterobacterales (CRE) isolates collected from 19 hospitals were genotypically characterized. K. pneumoniae (KP) and E. coli isolates were 785 (85.14%) and 96 (10.41%) among 922 CPE isolates. Two major carbapenemase genes blaKPC-2 and blaNDM in CPE isolates accounted for 84.6% (n = 780) and 13.77% (n = 127). ST11 comprised 86.83% (633/729) of KPC-2 KP isolates. Different combinations of extended spectrum-β-lactamase (ESBL) genes of blaSHV, blaCTX, and blaTEM were found in KPC-2 producing KP isolates, and blaCTM-M-14/15, blaSHV-11/12 and blaTEM-1 were common ESBL genotypes. The wzi typing method could further subdivide ST11 KP group into at least five subgroups, among which wzi209 (69.83%, 442/633) was the most frequently isolated, followed by wzi141 (25.28%, 160/633). Conjugation assays showed that high conjugation rates were observed in CPE (15.24%, 32/210) for NDM plasmids, but relatively low (8.1%, 17/210) for KPC-2 plasmids. Different STs, different wzis and temperature could influence plasmid conjugation efficiency. No associations between the rates of antibiotics consumption and CPE prevalence were observed. The number of intra-hospital and inter-hospital transfers of CPE patients increased gradually from 18 (17.82%, 101) and 12 (11.88%, 101) in 2015 to 63 (30.73%, 205) and 51 (24.88%, 205) in 2018 (p = 0.016 and p = 0.008), respectively. Evidence-based measures could effectively reduce the prevalence of ST11-wzi209 clone but failed to control the dissemination of ST11-wzi141 KP clone.

Conclusions

Clonal spread of CPE, especially KPC-2 ST11 KP was the key factor contributing to the CPE increase in the region. Continued vigilance for the importations should be maintained. Coordinated regional interventions are urgently needed to reduce CPE threat.

Reduction trend of mcr-1 circulation in Emilia-Romagna Region, Italy

This study aims to describe trends of mcr-positive Enterobacterales in humans based on laboratory surveillance with a defined catchment population. The data source is the Micro-RER surveillance system, established in Emilia-Romagna region (Italy), to monitor the trend of mcr resistance. Enterobacterales isolates from human clinical samples with minimum inhibitory concentration (MIC) ≥ 2 mg/L for colistin were sent to the study reference laboratory for the detection of mcr genes. Isolates prospectively collected in the period 2018-2020 were considered for the assessment of population rates and trends; further analyses were carried out for the evaluation of clonality and horizontal mcr gene transfer. Previous isolates from local laboratory collection were also described. In the period 2018-2020, 1164 isolates were sent to the reference laboratory, and 51 (4.4%) were confirmed as mcr-positive: 50 mcr-1 (42 Escherichia coli, 6 Klebsiella pneumoniae, 2 Salmonella enterica) and 1 mcr-4 (Enterobacter cloacae). The number of mcr-positive isolates dropped from 24 in the first half of 2018 to 3 in the whole of 2020 (trend p value < 0.001). Genomic analyses showed the predominant role of the horizontal transfer of mcr genes through plasmids or dissemination of transposable elements compared to clonal dissemination of mcr-positive microorganisms. The study results demonstrate a substantial decrease in the circulation of mcr-1 plasmid genes in Emilia-Romagna Region.

Guía de práctica clínica para la tamización de pacientes con riesgo de colonización por Enterobacterales productores de carbapenemasas y el manejo de infecciones causadas por estas bacterias

Las infecciones por Enterobacterales productores de carbapenemasas (EPC) han aumentado en los últimos años. Colombia se ha convertido en un país endémico para este grupo de microorganismos y las infecciones que causan tienen un impacto importante en términos de morbilidad y mortalidad. La identificación temprana de los portadores de EPC que ingresan como pacientes a las instituciones de salud es necesaria para implementar medidas de aislamiento y control de infecciones adecuadas que limiten la diseminación de este tipo de microorganismos en los hospitales. Además, el tratamiento de estas infecciones es difícil debido a las limitadas alternativas terapéuticas disponibles y la escasez de estudios que demuestren su efectividad en este escenario. Por lo anterior, el objetivo del presente trabajo es desarrollar una guía de práctica clínica (GPC) para la tamización de pacientes con riesgo de colonización por EPC y para el manejo de pacientes con   infecciones, ya sea sospechadas o confirmadas, causadas por este tipo de bacterias, mediante un proceso de adaptación de GPC basado en la metodología ADAPTE. Con este propósito en mente, se hacen recomendaciones informadas en evidencia para realizar la tamización y oportuna identificación de portadores de EPC admitidos en instituciones hospitalarias, así como para el adecuado manejo farmacológico de las infecciones por EPC en este escenario.

Containing Carbapenemase-producing Klebsiella pneumoniae in an endemic setting

Background

Carbapenemase-producing K. pneumoniae (CP-Kp) has been established as important nosocomial pathogen in most tertiary care hospitals in Greece. The aim of the present study was to examine the impact of an enhanced infection control program on the containment of CP-Kp in a haematology unit where the incidence of CP-Kp infections was high.

Methods

The study was conducted from June 2011 to December 2014 in a haematology unit of a tertiary-care 500-bed hospital located in Athens, Greece. A bundled intervention (active surveillance cultures, separation of carriers from non-carriers, assignment of dedicated nursing staff, contact precautions, environmental cleaning, and promotion of hand hygiene) was tested whether would reduce colonization and infection caused by CP-Kp.

Results

A total of 2507 rectal swabs were obtained; 1199 upon admission from June 2011 to June 2013 and 1307 during hospitalization from June 2011 to December 2012. During intervention the admission prevalence of CP-Kp colonization (p < 0.001 for linear trend), the hospitalization prevalence (p = 0.001 for linear trend) and the incidence rate of CP-Kp colonization (p = 0.072 for linear trend) were declining. Application of segmented linear regression revealed that both the change in the level of CP-Kp BSI incidence rates (p = 0.001) as well as the difference between pre- and post-intervention slopes were statistically significant (p < 0.001).

Conclusions

A bundled intervention including active surveillance cultures on admission can attain maximum containment of CP-Kp colonization and infection in endemic acute healthcare settings.

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.

Organ donor screening for carbapenem-resistant gram-negative bacteria in Italian intensive care units: the DRIn study

The 759 cases of brain death declaration (BDD [Italian law, 6 hours of observation time]) that occurred in 190 Italian intensive care units (ICUs) between May and September 2012 were studied to quantify carbapenem-resistant gram-negative bacteria (CR-GN) isolated in organ donors, to evaluate adherence to national screening guidelines, and to identify risk factors for CR-GN isolation. Mandatory blood, bronchoalveolar lavage, and urine cultures were performed on the BDD day in 99% of used donors. Because results were rarely made available before transplant, >20% of transplants were performed before obtaining any microbiological information, and organs from 15 of 22 CR-GN cases were used. Two (lung-liver) of the 37 recipients died, likely because of donor-derived early CR-GN sepsis. ICU stay >3 days (odds ratio [OR] = 7.49, P = .004), fever (OR = 3.11, P = .04), age <60 years (OR = 2.80, P = .06), and positive ICU epidemiology (OR = 8.77, P = .07) were associated with CR-GN isolation. An association between single ICU and risk of CR-GN was observed, as a result of differences across ICUs (ICC = 29%; 95% confidence interval [CI] 6.5%-72%) probably related to inadequate practices of infection control. Continuous education aimed at implementing priority actions, including stewardship programs for a rational use of antimicrobials, is a priority in healthcare systems and transplant networks. Improved awareness among ICU personnel regarding the importance of early CR-GN detection and timely alert systems might facilitate decisions regarding organ suitability and eventually save recipient lives.

Spread of Carbapenem-Resistant Klebsiella pneumoniae in Hub and Spoke Connected Health-Care Networks: A Case Study from Italy

The study describes the spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in a regional healthcare network in Italy. The project included several stages: (1) Establishment of a laboratory-based regional surveillance network, including all the acute care hospitals of the Marches Region (n = 20). (2) Adoption of a shared protocol for the surveillance of Multi-Drug Resistant Organisms (MDROs). Only the first CRKP isolate for each patient has been included in the surveillance in each hospital. The anonymous tracking of patients, and their subsequent microbial records within the hospital network, allowed detection of networks of inter-hospital exchange of CRKP and its comparison with transfer of patients within the hospital network. Pulsed-Field Gel Electrophoresis (PFGE) analysis has been used to study selected isolates belonging to different hospitals. 371,037 admitted patients have been included in the surveillance system. CRKP has shown an overall incidence rate of 41.0 per 100,000 days of stay (95% confidence interval, CI 38.5–43.5/100,000 DOS), a CRKP incidence rate of isolation in blood of 2.46/100,000 days of stay (95% CI 1.89–3.17/100,000 days of stay (DOS) has been registered; significant variability has been registered in facilities providing different levels of care. The network of CRKP patients’ exchange was correlated to that of the healthcare organization, with some inequalities and the identification of bridges in CRKP transfers. More than 73% of isolates were closely related. Patients’ exchange was an important route of spread of antimicrobial resistance, highlighting the pivotal role played by the hub, and selected institution to be used in prioritizing infection control efforts.

Screening for carriage of carbapenem-resistant Enterobacteriaceae in settings of high endemicity: a position paper from an Italian working group on CRE infections

Introduction

A variety of national and international guidelines exist around the management of carbapenem resistant Enterobacteriaceae (CREs), but some of these are several years old and do not reflect current epidemiology and they also do not necessarily give pragmatic advice around active surveillance of CREs in countries with a high burden of cases and limited resources. This paper aims to provide a best practice position paper to guide active surveillance in a variety of scenarios in these settings, and discusses which patients should be screened, what methods could be used for screening, and how results might influence infection prevention interventions.

Methods

This paper was developed as a result of a series of meetings of expert opinion leaders representing the major infectious disease and infection prevention societies in Italy and having the endorsement of AMCLI (Italian Association of Clinical Microbiology) and SITA (Italian Society for Anti-infective Therapy). There was no attempt to undertake a full systematic review of the evidence, as it was felt that this was inadequate to inform a pragmatic view on the best way forward based on current epidemiology and infection rates.

Key recommendations

Key recommendations focus on the urgent need to promote measures to prevent transmission and infection, focusing on high risk patients and clinical areas, as well as outbreak situations. Active surveillance leading to appropriate infection prevention precautions plays a major role in this.

Conclusions

There are limited national or international guidelines giving pragmatic advice on the most appropriate measures for active surveillance and management of colonized patients in a high-burden setting such as Italy. While individual hospitals and regions will need to formulate their own policies based on local epidemiology, this position paper attempts to highlight current best practice in this area and provide pragmatic advice for clinicians, infection prevention staff, and healthcare managers.

Carbapenem-Resistant Enterobacteriaceae in Solid Organ Transplantation: Management Principles

PURPOSE OF REVIEW

Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a worldwide problem. Given their degree of immunosuppression and the level of contact with the healthcare system, solid organ transplant (SOT) recipients are at a disproportionately higher risk of acquisition, colonization, and infection with CRE, and outcomes from infection tend to be worse compared to non-transplant patients. Therapeutic options are limited for CRE infections although several newer agents have recently been approved for use. How well these agents perform in the setting of immunosuppression and SOT is unclear. We sought to review the epidemiology of CRE in SOT and the management principles.

RECENT FINDINGS

CRE infections are becoming an increasing problem in SOT, and donor-derived infections present a challenge in the peri-transplant period. Newer treatments for CRE are emerging that are less toxic and potentially more effective than prior CRE-active agents, but supportive clinical data are limited. Newer beta-lactamase inhibitors have good activity against KPC carbapenemases, but they lack activity against metallo-beta-lactamases (e.g., NDM). Promising data is emerging with newer agents that have activity against most carbapenemases, but, again, clinical data is needed. Combination therapy in addition to optimal pharmacokinetic and pharmacodynamics may go some way to improve outcomes against these difficult-to-treat organisms. Other novel therapies that prevent the emergence of resistance (oral beta-lactamase inhibitors) and eradication of resistant Gram-negative colonization (fecal microbiota transplant) may eventually become part of a bundle approach to reduce CRE infections in the future. As in non-transplant patients, CRE infections in the transplant setting are challenging to treat and prevent. Infection prevention and control remains crucial to prevent widespread dissemination, and unique challenges exist with donor-derived CRE and how best to manage recipients in the peri-transplant period. Newer treatments are now in early-phase clinical studies, and in vitro activity data are supportive for several agents providing hope for improved outcomes with these typically difficult-to-treat and highly morbid infections in transplant recipients.

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

Carbapenem-resistant Enterobacteriaceae (CRE), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPsA) are a serious cause of healthcare-associated infections, although the evidence for their control remains uncertain. We conducted a systematic review and reanalysis to assess infection prevention and control (IPC) interventions on CRE-CRAB-CRPsA in inpatient healthcare facilities to inform World Health Organization guidelines. Six major databases and conference abstracts were searched. Before-and-after studies were reanalyzed as interrupted time series if possible. Effective practice and organization of care (EPOC) quality criteria were used. Seventy-six studies were identified, of which 17 (22%) were EPOC-compatible and interrupted time series analyses, assessing CRE (n = 11; 65%), CRAB (n = 5; 29%) and CRPsA (n = 3; 18%). IPC measures were often implemented using a multimodal approach (CRE: 10/11; CRAB: 4/5; CRPsA: 3/3). Among all CRE-CRAB-CRPsA EPOC studies, the most frequent intervention components included contact precautions (90%), active surveillance cultures (80%), monitoring, audit and feedback of measures (80%), patient isolation or cohorting (70%), hand hygiene (50%), and environmental cleaning (40%); nearly all studies with these interventions reported a significant reduction in slope and/or level. The quality of EPOC studies was very low to low.

Infection-prevention and control interventions to reduce colonisation and infection of intensive care unit-acquired carbapenem-resistant Klebsiella pneumoniae: a 4-year quasi-experimental before-and-after study

Objective

To determine whether infection-prevention and control (IPC) interventions can reduce the colonisation and infection of intensive care unit (ICU)-acquired carbapenem-resistant Klebsiella pneumoniae (CRKP) in a general ICU ward in China.

Methods

We used a quasi-experimental before-and-after study design. The study was conducted in 4 stages: baseline period, January 2013-June 2013; IPC interventions period including de-escalation and targeted bundle interventions, July 2013-June 2014; modified IPC interventions period, July 2014-June 2015; and follow-up period, July 2015-June 2016. We used modified de-escalation interventions according to patient-risk assessments to prevent the transmission of CRKP.

Results

A total of 629 patients were enrolled in study. The incidence of ICU-acquired CRKP colonisation/infection was 10.08 (4.43-16.43) per 1000 ICU patient-days during the baseline period, and significantly decreased early during the IPC interventions, but the colonisation/infections reappeared in April 2014. During the modified IPC intervention and follow-up periods, the incidence of ICU-acquired CRKP colonisations/infections reduced to 5.62 (0.69-6.34) and 2.84 (2.80-2.89), respectively, with ongoing admission of cases with previously acquired CRKP. The incidence of ICU-acquired CRKP catheter-related bloodstream infections decreased from 2.54 during the baseline period to 0.41 during the follow-up period. The incidence of ventilator-associated pneumonia and skin and soft tissue infections showed a downward trend from 2.84 to 0.41 and from 3.4 to 0.47, respectively, with slight fluctuations.

Conclusions

Comprehensive IPC interventions including de-escalation and targeted bundle interventions showed a significant reduction in ICU-acquired CRKP colonisations/infections, despite ongoing admission of patients colonised/infected with CRKP.

A Systematic Review and Meta-analyses of the Clinical Epidemiology of Carbapenem-Resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are major health care-associated pathogens and responsible for hospital outbreaks worldwide. To prevent a further increase in CRE infections and to improve infection prevention strategies, it is important to summarize the current knowledge about CRE infection prevention in hospital settings. This systematic review aimed to identify risk factors for CRE acquisition among hospitalized patients. In addition, we summarized the environmental sources/reservoirs and the most successful infection prevention strategies related to CRE. A total of 3,983 potentially relevant articles were identified and screened. Finally, we included 162 studies in the systematic review, of which 69 studies regarding risk factors for CRE acquisition were included in the random-effects meta-analysis studies. The meta-analyses regarding risk factors for CRE acquisition showed that the use of medical devices generated the highest pooled estimate (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 3.38 to 7.67), followed by carbapenem use (OR = 4.71; 95% CI = 3.54 to 6.26). To control hospital outbreaks, bundled interventions, including the use of barrier/contact precautions for patients colonized or infected with CRE, are needed. In addition, it is necessary to optimize the therapeutic approach, which is an important message to infectious disease specialists, who need to be actively involved in a timely manner in the treatment of patients with known CRE infections or suspected carriers of CRE.

Carbapenemases-producing Klebsiella pneumoniae in hospitals of two regions of Southern Italy

Carbapenem-resistant Klebsiella pneumoniae infections are reported with increasing frequency elsewhere in the world, representing a worrying phenomenon for global health. In Italy, there are hotspot data on the diffusion and type of carbapenemase-producing Enterobacteriaceae and K. pneumoniae in particular, with very few data coming from Apulia and Basilicata, two regions of Southern Italy. This study was aimed at characterizing by phenotypic and genotypic methods carbapenem-resistant K. pneumoniae isolated from several Hospitals of Apulia and Basilicata, Southern Italy. Antibiotic susceptibility was also evaluated. The relatedness of carbapenemase-producing K. pneumoniae strains was established by pulsed-field gel electrophoresis (PFGE). Among the 150 K. pneumoniae carbapenemase producers, KPC-3 genotype was the most predominant (95%), followed by VIM-1 (5%). No other genotypes were found and no co-presence of two carbapenemase genes was found. A full concordance between results obtained by both the phenotypic and the genotypic tests was observed. All strains were resistant to β-lactam antibiotics including carbapenems, and among antibiotics tested, only tetracycline and gentamycin showed low percentage of resistance (18% and 15%, respectively). Resistance to colistin was detected in 17.3% of strains studied. The analysis of PFGE profiles of the carbapenemases-positive strains shows that one group (B) of the five (A to E) main groups identified was the most prevalent and detected in almost all the hospitals considered, while the other groups were randomly distributed. Three different sequence types (ST 307, ST 258, and ST 512) were detected with the majority of isolates belonging to the ST 512. Our results demonstrated the wide diffusion of K. pneumoniae KPC-3 in the area considered, the good concordance between phenotypic and genotypic tests. Gentamicin and colistin had a good activity against these strains.

Performance of the BD MAX™ instrument with Check-Direct CPE real-time PCR for the detection of carbapenemase genes from rectal swabs, in a setting with endemic dissemination of carbapenemase-producing Enterobacteriaceae

Carbapenemase-producing Enterobacteriaceae (CPE) represent an increasing public health issue and the early detection of colonization by CPE can help the implementation of infection control measures among inpatients. In this study, BD MAX Check-Direct CPE screen, with two different Master Mixes (BDMix and CPMix), using the automatic BD MAX(™) instrument, was evaluated for the detection of blaKPC, blaOXA-48, blaVIM and blaNDM genes, in comparison to selective broth enrichment and direct culture from rectal swabs. Among a total of 557 rectal swabs samples, 29 (5.2%) tested positive for CPE (23 for blaKPC, 5 for blaVIM and one for blaOXA-48). The sensitivity, specificity, positive and negative likelihood ratios values were 93.1%, 97.3%, 34.5 and 0.07, for BMix, and 100%, 97.1 %, 34.5 and 0 for CPMix, respectively. Five samples were positive with molecular methods only. The turn-around time was reduced from 18-24 hours (direct culture), or 48 h (broth enrichment) to only 3 h.

Emergence of Carbapenemase Producing Klebsiella Pneumonia and Spread of KPC-2 and KPC-17 in Taiwan: A Nationwide Study from 2011 to 2013

The emergence of carbapenemase-producing Klebsiella pneumoniae (CPKP) has become a great concern worldwide. In this study, 994 non-duplicate, carbapenem non-susceptible Klebsiella pneumonia isolates were collected in Taiwan from 2011 to 2013 for detection of the carbapenemase genes, assessment of antimicrobial susceptibility and molecular epidemiology studies. Of these 994 isolates, 183 (18.4%) had carbapenemase genes: 157 (15.8%) KPC (145 KPC-2 and 12 KPC-17), 16 (1.6%) IMP-8, 9 (0.9%) VIM-1, and 1 (0.1%) NDM-1. KPC had the highest prevalence rate among the carbapenemases and represented a major epidemic clone circulating in Taiwan. The ST512 and ST258 KPC-2 KPs were first identified in Taiwan and were grouped into a small cluster in the PFGE profile. In addition, the genetic structure encompassing the bla_KPC gene of the ST512 and ST258 isolates showed a different pattern from that of other KPC isolates. ST11 may be a major sequence type circulating in Taiwan, although a specific minor clone has begun to be observed. This is the first report of ST258 and ST512 KPC-2 KP isolates in Taiwan, whether ST258 and ST512 will become the next endemic problems in Taiwan should be closely monitored.

Considerations About Antimicrobial Stewardship in Settings with Epidemic Extended-Spectrum β-Lactamase-Producing or Carbapenem-Resistant Enterobacteriaceae

Infections caused by gram-negative bacteria (GNB) resistant to multiple classes of antibiotics are increasing in many hospitals. Extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Enterobacteriaceae in particular are now endemic in many parts of the world and represent a serious public health threat. In this era, antimicrobial stewardship programs are essential as targeted and responsible use of antibiotics improves patient outcomes and hopefully limits the selective pressure that drives the further emergence of resistance. However, some stewardship strategies aimed at promoting carbapenem-sparing regimens remain controversial and are difficult to implement when resistance rates to non-carbapenem antibiotics are increasing. Coordinated efforts between stewardship programs and infection control are essential for reversing conditions that favor the emergence and dissemination of multidrug-resistant GNB within the hospital and identifying extra-institutional "feeder reservoirs" of resistant strains such as long-term care facilities, where colonization is common despite limited numbers of serious infections. In settings where ESBL resistance is endemic, the cost-effectiveness of expanded infection control efforts and antimicrobial stewardship is still unknown. Once a patient has been colonized, selective oral or digestive decontamination may be considered, but evidence supporting its effectiveness is limited in patients who are already colonized or in centers with high rates of resistance. Moreover, temporary success at decolonization may be associated with a higher risk of relapse with strains that are resistant to the decolonizing antibiotics.

Prevalence of Klebsiella pneumoniae strains producing carbapenemases and increase of resistance to colistin in an Italian teaching hospital from January 2012 To December 2014

Background

The aim of this study was to characterize the spread of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a tertiary level hospital using ongoing active surveillance with rectal swab cultures. Furthermore, this study analyzed the presence of CPKP in the clinical samples (CS) of a single patient as well as the evolution of Colistin-sensitive strains (CoS) to Colistin-resistant strains (CoR).

Methods

This study was performed from January 1, 2012 to December 31, 2014. In 2012, a survey was conducted in the Intensive Care Department. In autumn 2013, active monitoring was extended to the Surgery Department, and since mid-2014, the surveillance has included the Medical Department as well. Only the first isolated strain from each patient was included. Antimicrobial susceptibility testing was performed on CPKP isolates: Klebsiella pneumoniae carbapenemase, oxacillinase-48, Verona integron-encoded metallo-β-lactamase and New Delhi metallo-β-lactamase were detected using a validated in-house PCR method, and multilocus sequence typing (MLST) was used to investigate the clonal transmission of strains.

Results

A total of 15,104 patients were included in the study, and 496 consecutive non-replicated strains of CPKP were collected: 149 strains were collected in 2012 (39 [26.2 %] from surveillance rectal swabs [SRS]), 133 strains were collected in 2013 (70 [52.6 %] from SRS) and 214 strains were collected in 2014 (164 [76.6 %] from SRS). We observed a significant increase in the percentage of positive SRS cases in 2014 relative to 2013 and 2012 (p = 0.0001 and p = 0.0172, respectively) and in the proportion of CPKP first isolated by SRS relative to those identified by CS (p < 0.0001). Among all available samples, the number of CoR isolated from SRS was higher in 2013 and 2014 compared with 2012 (p = 0.0019 and p = 0.008, respectively). ST-258 and ST-512 were more prevalent in the tested specimens, and a new single locus variant (SLV) of ST-512 (ST-745) was isolated.

Conclusions

The results of this 3-year study of 15,104 patients highlight the clinical relevance of antimicrobial resistance as well as the drug-selection pressure of colistin therapy. The active surveillance in the three different departments increased the level of CPKP cases isolated by SRS.