Risk of transmission of carbapenem-resistant Enterobacteriaceae and related “superbugs” during gastrointestinal endoscopy

Temporal variation of bacterial population and response to physical and chemical parameters along a petrochemical industry wastewater treatment plant

The petrochemical industry has played a considerable role in generation and release of waste in the environment. Activated sludge and facultative lagoons are commonly used for domestic and industrial wastewater treatment due to their low-cost and minimal need for operational requirements. Microorganisms present in wastewater treatment plant (WWTP) are responsible for most nutrient removal. In this study, microbiological and physicochemical parameters were used to estimate changes in bacterial community in a petrochemical industrial WWTP. The activated sludge was the place with higher heterotrophic bacterial quantification. Denitrifying bacteria was reduced at least 5.3 times throughout all collections samples. We observe a decrease in the total Kjeldahl nitrogen, oxygen demand and phosphate throughout the WWTP. In this work, we also use Matrix-Assisted Laser Desorption Ionisation-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for bacteria isolates identification comparing with 16S rDNA sequencing. The MALDI-TOF MS allowed the identification of 93% of the isolates and only 5% show different results from 16S rDNA sequencing showing that the MALDI-TOF MS can be a tool for identifying environmental bacteria. The observation of microbial community dynamics in the WWTP is important in order to understand the functioning of the ecological structure formed in a specific environment.

Predicting probability of perirectal colonization with carbapenem-resistant Enterobacteriaceae (CRE) and other carbapenem-resistant organisms (CROs) at hospital unit admission

BACKGROUND

Targeted screening for carbapenem-resistant organisms (CROs), including carbapenem-resistant Enterobacteriaceae (CRE) and carbapenemase-producing organisms (CPOs), remains limited; recent data suggest that existing policies miss many carriers.

OBJECTIVE

Our objective was to measure the prevalence of CRO and CPO perirectal colonization at hospital unit admission and to use machine learning methods to predict probability of CRO and/or CPO carriage.

METHODS

We performed an observational cohort study of all patients admitted to the medical intensive care unit (MICU) or solid organ transplant (SOT) unit at The Johns Hopkins Hospital between July 1, 2016 and July 1, 2017. Admission perirectal swabs were screened for CROs and CPOs. More than 125 variables capturing preadmission clinical and demographic characteristics were collected from the electronic medical record (EMR) system. We developed models to predict colonization probabilities using decision tree learning.

RESULTS

Evaluating 2,878 admission swabs from 2,165 patients, we found that 7.5% and 1.3% of swabs were CRO and CPO positive, respectively. Organism and carbapenemase diversity among CPO isolates was high. Despite including many characteristics commonly associated with CRO/CPO carriage or infection, overall, decision tree models poorly predicted CRO and CPO colonization (C statistics, 0.57 and 0.58, respectively). In subgroup analyses, however, models did accurately identify patients with recent CRO-positive cultures who use proton-pump inhibitors as having a high likelihood of CRO colonization.

CONCLUSIONS

In this inpatient population, CRO carriage was infrequent but was higher than previously published estimates. Despite including many variables associated with CRO/CPO carriage, models poorly predicted colonization status, likely due to significant host and organism heterogeneity.

Bioburden and transmission of pathogenic bacteria through elevator channel during endoscopic retrograde cholangiopancreatography: application of multiple-locus variable-number tandem-repeat analysis for characterization of clonal strains

OBJECTIVES

Endogenous and exogenous infection of the biliary tract could occur during endoscopic retrograde cholangiopancreatography.

METHODS

Bile samples of patients with hepatobiliary diseases, and swab samples of elevator channel samples of duodenoscope and washing instruments were prepared simultaneously and cultured aerobically and anaerobically. Antimicrobial susceptibility of the most common characterized bacterial species was tested, and their genetic relatedness was analyzed by multiple locus variable number of tandem repeats method.

RESULTS

Contamination with Pseudomonas aeruginosa was detected in 38.2% of the elevator channels' and 26.6% of the bile samples. Staphylococcus aureus, Enterococcus spp., Staphylococcus epidermidis, Escherichia coli, Enterobacter spp., and Clostridium perfringenes were among other bacterial isolates in the elevator channel swab samples. Highest antimicrobial resistance rate among P. aeruginosa isolates from the bile and swab samples were detected against gentamicin (100% and 73%, respectively), while the lowest one was measured to piperacillin-tazobactam (25% and 0%, respectively). Out of the 27 distinct MLVA profiles, relatedness of P. aeruginosa strains in the bile samples compared with those from the elevators was shown in three series of the samples.

CONCLUSION

Identity of P. aeruginosa strains among the bile and elevator channel samples showed possibility of cross-contamination among patients even at distinct time intervals. Expert opinion: Bacterial infection is considered as main complications of ERCP. Entry of bacteria into the biliary tract via contaminated device and its related instruments and their proliferation in this tissue could cause serious infections. To prevent this side effect, reprocessing of medical equipment via standard cleaning and disinfection procedures are needed. Our results showed incompliance of methods used for endoscope cleaning and disinfection procedure. Although host risk factors, such as sphincterotomy, could increase rate of infection with different types of bacteria, their ability for formation of biofilm and spore, which could help them to resist disinfectants and washing procedures seems to be main cause of persistent colonization and transmission among different patients. New standards for disinfection compared with currently used methods and use of materials to eliminate formation of bacterial microcolonies seem to be necessary to prevent cross-contamination.

Australian infection control in endoscopy consensus statements on carbapenemase-producing Enterobacteriaceae

Outbreaks of carbapenemase-producing Enterobacteriaceae clinical infections related to endoscopic transmission are well documented. The high morbidity and mortality associated with these infections emphasizes the need to reassess endoscopic reprocessing protocols. The Gastroenterological Society of Australia established a multi-society committee to formulate evidence-based consensus statements on the prevention and management of endoscopic transmission of carbapenemase-producing Enterobacteriaceae. A literature search was undertaken utilizing the MEDLINE database. Further references were sourced from published paper bibliographies. Nine statements were formulated. Using the Delphi methodology, the statements were initially reviewed electronically by the committee members and subsequently at a face-to-face meeting in Melbourne, Australia. After further discussion, four additional sub-statements were added resulting in a total of 13 statements. Each statement was assessed for level of evidence, recommendation grade and the voting on recommendation was recorded. For a statement to be accepted, five out of six committee members had to "accept completely" or "accept with some reservation." All 13 statements achieved consensus agreement. Eleven statements achieved 100% "accepted completely." Two statements were 83% "accepted completely" and 17% "accepted with some reservation." Of particular significance, automated flexible endoscope reprocessors were mandated for high-level disinfection, and the use of forced-air drying cabinets was mandated for endoscope storage. These evidence-based statements encourage preventative strategies with the aim of ensuring the highest possible standards in flexible endoscope reprocessing thereby optimizing patient safety. They must be considered in addition to the broader published guidelines on infection control in endoscopy.

Elevating the standard of endoscope processing: Terminal sterilization of duodenoscopes using a hydrogen peroxide-ozone sterilizer

BACKGROUND

The health care community is increasingly aware of the processing challenges and infection risks associated with duodenoscopes owing to published reports of outbreaks and regulatory recalls. Studies have demonstrated that the current practices are inadequate for consistently producing patient-ready endoscopes. Alternatively, terminal sterilization would offer a greater margin of safety and potentially reduce the risk of patient infection. The purpose of this study was to evaluate the efficacy of a hydrogen peroxide-ozone sterilizer with regulatory clearance for terminal sterilization of duodenoscopes.

METHODS AND RESULTS

Validation studies were performed under laboratory simulated-use and clinical in-use conditions. The overkill method study demonstrated a reduction of at least 6-log of Geobacillus stearothermophilus spores at half-cycle, providing a sterility assurance level of 10^-6. In addition, the sterilizer achieved a 6-log reduction of G stearothermophilus in the presence of inorganic and organic soils in a simulated-use study. The clinical in-use study confirmed that the sterilizer achieved sterilization of patient-soiled duodenoscopes under actual use conditions.

CONCLUSIONS

Simulated-use and clinical in-use studies demonstrated the efficacy of a hydrogen peroxide-ozone sterilizer for terminal sterilization of duodenoscopes. This offers health care facilities a viable alternative for duodenoscope processing to enhance patient safety as part of a comprehensive infection control strategy.

Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video)

BACKGROUND AND AIMS

Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing.

METHODS

We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured.

RESULTS

Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values.

CONCLUSION

The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values.

New Developments in the Prevention of Gastrointestinal Scope-Related Infections

Gastrointestinal endoscopes are used for diagnostic and therapeutic purposes and are the most common medical device implicated in health care-associated outbreaks. Infections can be divided into endogenous or exogenous. Exogenous infections were associated with lapses in reprocessing. Recent outbreaks have occurred despite compliance with reprocessing guidelines and highlight the challenges with clearance of all organisms from the duodenoscopes and the potential role of biofilms in hindering adequate reprocessing. This review provides an overview of recent developments and the current understanding of the key contributing factors related to gastrointestinal endoscope-related infections and current approaches to identify and prevent these complications.

Pediatric Endoscopic Procedure Complications

PURPOSE OF REVIEW

This review summarizes the current body of research, define high-risk patients and endoscopic processes, and outline evidence-based countermeasures aimed at minimizing the incidence of complications during endoscopy in children.

RECENT FINDINGS

Significant complications of endoscopy requiring emergency department or inpatient admission in otherwise healthy children are unusual, but more common with therapeutic procedures; risk from procedures increases incrementally with preoperative coexisting conditions. Duodenal hematoma is predominantly a pediatric endoscopic complication and is more likely in hematology-oncology patients. Air embolism is a well-defined endoscopic retrograde cholangiopancreatography (ERCP) complication in adults and is likely to increase in children with increased performance of pediatric ERCP. Increased physician expertise is the most often proposed countermeasure, especially in the context of endoscopy complications in the higher-risk patient and procedure. Endoscopy in children remains a very safe group of procedures, although a more detailed understanding of risk factors and ideal training and practice organization is lacking.

Impact of cleaning monitoring combined with channel purge storage on elimination of Escherichia coli and environmental bacteria from duodenoscopes

BACKGROUND AND AIMS

We aimed to determine whether monitoring of duodenoscope cleaning by rapid adenosine triphosphate (ATP) combined with channel-purge storage could eliminate high-concern microorganisms.

METHODS

In a simulated-use study, suction channels, as well as lever recesses, from 2 duodenoscopes models and the unsealed elevator guidewire (EGW) channel from 1 of these 2 duodenoscopes (the other model has a sealed EGW) were perfused with ATS2015 containing approximately 8 Log₁₀ colony-forming units (CFU)/mL of both Enterococcus faecalis and Escherichia coli. Pump-assisted cleaning was monitored by rapid ATP testing. Duodenoscopes exceeding 200 relative light units (RLUs) were recleaned. Clean duodenoscopes were processed through an automated endoscope reprocessor and then stored in a channel-purge storage cabinet for 1 to 3 days. Cultures of EGW channel and instrument channel combined with the lever recess (IC-LR) were taken after storage. The impacts of extended cleaning and alcohol flush were evaluated.

RESULTS

E coli was reliably eliminated in IC-LR and EGW channels of 119 duodenoscope tests (59 with sealed EGW and 60 with nonsealed EGW). However, actionable levels of E faecalis and environmental bacteria persisted. Neither alcohol flush nor extended cleaning resulted in a reduction of actionable levels for these organisms. Identification of isolates indicated that residual organisms in duodenoscope channels were hardy Gram-positive bacteria (often spore formers) that likely originated from environmental sources.

CONCLUSIONS

These data indicate that high-concern Gram-negative bacteria but not E faecalis or environmental bacteria can be reliably eliminated by use of the manufacturer's instructions for reprocessing with ATP monitoring of cleaning and channel-purge storage conditions.

Plasma-activated water: a new and effective alternative for duodenoscope reprocessing

INTRODUCTION

Duodenoscopes have been widely used for both diagnostic and therapeutic endoscopic retrograde cholangiopancreatography procedures. Numerous outbreaks of duodenoscope-associated infections involving multidrug-resistant bacteria have recently been reported. Plasma activated water (PAW) has been widely considered an effective agent for surface decontamination and is increasingly used for disinfection of medical equipment. The aim of this study was to evaluate whether the duodenoscopes currently on market are suited for the repeated use of PAW and to test the efficacy of PAW for their disinfection.

MATERIALS AND METHODS

In order to evaluate the disinfection efficacy and the required time of contact, the duodenoscope samples were contaminated by immersing them in fasted-state simulated intestinal fluid containing Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa, prior to PAW exposure. In order to test the duodenoscope polymer compatibility with PAW, a challenge test was conducted by immersing the samples in PAW for 30 minutes daily for 45 consecutive days.

RESULTS

Significant reductions in bacterial populations were achieved after 30 minutes of PAW treatment, indicating a high-level disinfection. Atomic force microscopy and scanning electron microscopy were used to demonstrate that repeated PAW treatment of duodenoscope coating polymer samples did not result in significant differences in morphological surface between the treated and untreated samples. Energy-dispersive X-ray spectroscopy analysis also showed no significant differences between the elemental composition of the duodenoscope coating polymer samples before and after repeated PAW treatment.

CONCLUSION

Considering these preliminary results, PAW could be considered as a new alternative for duodenoscope reprocessing.

Single use and disposable flexible ureteroscopes

PURPOSE OF REVIEW

Flexible ureteroscopy has been widely developed in the last decade been nowadays one of the first line treatment options for urolithiasis and conservative management for upper tract urothelial tumors. Even though some unfavorable features of the reusable flexible scopes can limit the surgical procedure such as their availability, lack of sterilization or costly repairs. Disposable scopes have been developed with the intention of improving such problems.

RECENT FINDINGS

To our knowledge, seven devices have been developed. Of the scopes features, size, deflection, image quality and ergonomic handling have to be at least as good as reusable ones as they are expected to be noninferior. Three devices match all the features of reusable scopes, although only one has been properly studied.

SUMMARY

Not all the available disposable devices have been properly studied or compared with standard scopes. Although some devices are promising more studies are needed to proof their benefits.

VIM-positive Pseudomonas aeruginosa in a large tertiary care hospital: matched case-control studies and a network analysis

Background

Emergence of multidrug-resistant Pseudomonas aeruginosa is of global concern. We aimed to identify epidemiological relationships, the most common way of transmission, and risk factors for presence of Verona Integron-encoded Metallo-β-lactamase (VIM)-positive P. aeruginosa (VIM-PA).

Methods

We conducted a network analysis and matched case-control studies (1:2:2). Controls were hospital-based and matched with cases for ward, day of admission (control group 1 and 2) and time between admission and the identification of VIM-PA (control group 1). The network was visualized using Cytoscape, and risk factors were determined using conditional logistic regression.

Results

Between August 2003 and April 2015, 144 case patients and 576 control patients were recruited. We identified 307 relationships in 114 out of these 144 patients, with most relationships (84.7%) identified at the same department < 3 months after a previous case patient was discharged. In the multivariable model, having undergone ≥1 gastroscopy (odds ratio [OR] = 4.40, 95% confidence interval [CI] = 2.00 to 9.65 and OR = 2.47; 95% CI = 1.12 to 5.49), > 10 day use of selective digestive tract decontamination (SDD) (OR = 2.97; 95% CI = 1.02 to 8.68 and OR = 4.61; 95% CI = 1.22 to 17.37), and use of quinolones (OR = 3.29; 95% CI = 1.34 to 8.10 and OR = 3.95; 95% CI = 1.13 to 13.83 and OR = 4.47; 95% CI = 1.75 to 11.43) were identified as risk factors when using both control groups.

Conclusions

The network analysis indicated that the majority of transmissions occurred on the wards, but through unidentified and presumably persistent sources, which are most likely in the innate hospital environment. Previous use of certain antibiotic regimens made patients prone to VIM-PA carriage. Additionally, gastroscopy could be considered as a high-risk procedure in patients with risk factors. Our results add to the growing body of evidence that infection control measures targeting VIM-PA should be focused on reducing antibiotics and eliminating sources in the environment.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0325-1) contains supplementary material, which is available to authorized users.

APSIC guidelines for disinfection and sterilization of instruments in health care facilities

Background

The Asia Pacific Society of Infection Control launched its revised Guidelines for Disinfection and Sterilization of Instruments in Health Care Facilities in February 2017. This document describes the guidelines and recommendations for the reprocessing of instruments in healthcare setting. It aims to highlight practical recommendations in a concise format designed to assist healthcare facilities at Asia Pacific region in achieving high standards in sterilization and disinfection.

Method

The guidelines were revised by an appointed workgroup comprising experts in the Asia Pacific region, following reviews of previously published guidelines and recommendations relevant to each section.

Results

It recommends the centralization of reprocessing, training of all staff with annual competency assessment, verification of cleaning, continual monitoring of reprocessing procedures to ensure their quality and a corporate strategy for dealing with single-use and single-patient use medical equipment/devices. Detailed recommendations are also given with respect to reprocessing of endoscopes. Close working with the Infection Prevention & Control department is also recommended where decisions related to reprocessing medical equipment/devices are to be made.

Conclusions

Sterilization facilities should aim for excellence in practices as this is part of patient safety. The guidelines that come with a checklist help service providers identify gaps for improvement to reach this goal.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0308-2) contains supplementary material, which is available to authorized users.

Analysis of OXA-204 carbapenemase-producing Enterobacteriaceae reveals possible endoscopy-associated transmission, France, 2012 to 2014

OXA-48-like beta-lactamase producing bacteria are now endemic in several European and Mediterranean countries. Among this carbapenemase family, the OXA-48 and OXA-181 variants predominate, whereas other variants such as OXA-204 are rarely reported. Here, we report the molecular epidemiology of a collection of OXA-204-positive enterobacterial isolates (n = 29) recovered in France between October 2012 and May 2014. This study describes the first outbreak of OXA-204-producing Enterobacteriaceae in Europe, involving 12 isolates of an ST90 Escherichia coli clone and nine isolates of an ST147 Klebsiella pneumoniae clone. All isolates co-produced the cephalosporinase CMY-4, and 60% of them co-produced the extended-spectrum beta-lactamase CTX-M-15. The bla_OXA-204 gene was located on a 150-kb IncA/C plasmid, isolated from various enterobacterial species in the same patient, indicating a high conjugative ability of this genetic vehicle.

Advances in Endoscope Reprocessing Technology and Its Impact on Pathogen Transmission

Pathogen transmissions via flexible endoscopes have been documented in the literature and have been historically related to human error or omission of steps in the reprocessing cycle. The 2008 Centers for Disease Control and Prevention report challenged manufacturers of automated endoscope reprocessors to improve and advance technology to automate more of the reprocessing steps. A review and synthesis of the literature following the 2008 Centers for Disease Control and Prevention report was performed to evaluate whether advances in reprocessing technology have occurred and whether these have had an impact on pathogen transmission via flexible endoscopes. The Iowa Model of Evidence-Based Practice to Promote Quality Care was used to guide the project. The literature search regarding pathogen transmission related to flexible endoscopes yielded 10 documents citing infections from 2008 to 2015. A total of 353 patients were identified as having been infected with a contaminated gastroscope, bronchoscope, or duodenoscope. An evaluation of reprocessing technology identified 3 automated endoscope reprocessors with enhanced capabilities and flushing devices intended to automate portions of the manual cleaning step.

Adenosine triphosphate bioluminescence for bacteriologic surveillance and reprocessing strategies for minimizing risk of infection transmission by duodenoscopes

BACKGROUND AND AIMS

Recent outbreaks of duodenoscope-transmitted infections underscore the importance of adequate endoscope reprocessing. Adenosine triphosphate (ATP) bioluminescence testing allows rapid evaluation of endoscopes for bacteriologic/biologic residue. In this prospective study we evaluate the utility of ATP in bacteriologic surveillance and the effects of endoscopy staff education and dual cycles of cleaning and high-level disinfection (HLD) on endoscope reprocessing.

METHODS

ATP bioluminescence was measured after precleaning, manual cleaning, and HLD on rinsates from suction-biopsy channels of all endoscopes and elevator channels of duodenoscopes/linear echoendoscopes after use. ATP bioluminescence was remeasured in duodenoscopes (1) after re-education and competency testing of endoscopy staff and subsequently (2) after 2 cycles of precleaning and manual cleaning and single cycle of HLD or (3) after 2 cycles of precleaning, manual cleaning, and HLD.

RESULTS

The ideal ATP bioluminescence benchmark of <200 relative light units (RLUs) after manual cleaning was achieved from suction-biopsy channel rinsates of all endoscopes, but 9 of 10 duodenoscope elevator channel rinsates failed to meet this benchmark. Re-education reduced RLUs in duodenoscope elevator channel rinsates after precleaning (23,218.0 vs 1340.5 RLUs, P < .01) and HLD (177.0 vs 12.0 RLUs, P < .01). After 2 cycles of manual cleaning/HLD, duodenoscope elevator channel RLUs achieved levels similar to sterile water, with corresponding negative cultures.

CONCLUSIONS

ATP testing offers a rapid, inexpensive alternative for detection of endoscope microbial residue. Re-education of endoscopy staff and 2 cycles of cleaning and HLD decreased elevator channel RLUs to levels similar to sterile water and may therefore minimize the risk of transmission of infections by duodenoscopes.

Multicenter Clinical and Molecular Epidemiological Analysis of Bacteremia Due to Carbapenem-Resistant Enterobacteriaceae (CRE) in the CRE Epicenter of the United States

Although the New York/New Jersey (NY/NJ) area is an epicenter for carbapenem-resistant Enterobacteriaceae (CRE), there are few multicenter studies of CRE from this region. We characterized patients with CRE bacteremia in 2013 at eight NY/NJ medical centers and determined the prevalence of carbapenem resistance among Enterobacteriaceae bloodstream isolates and CRE resistance mechanisms, genetic backgrounds, capsular types (cps), and antimicrobial susceptibilities. Of 121 patients with CRE bacteremia, 50% had cancer or had undergone transplantation. The prevalences of carbapenem resistance among Klebsiella pneumoniae, Enterobacter spp., and Escherichia coli bacteremias were 9.7%, 2.2%, and 0.1%, respectively. Ninety percent of CRE were K. pneumoniae and 92% produced K. pneumoniae carbapenemase (KPC-3, 48%; KPC-2, 44%). Two CRE produced NDM-1 and OXA-48 carbapenemases. Sequence type 258 (ST258) predominated among KPC-producing K. pneumoniae (KPC-Kp). The wzi154 allele, corresponding to cps-2, was present in 93% of KPC-3-Kp, whereas KPC-2-Kp had greater cps diversity. Ninety-nine percent of CRE were ceftazidime-avibactam (CAZ-AVI)-susceptible, although 42% of KPC-3-Kp had an CAZ-AVI MIC of ≥4/4 μg/ml. There was a median of 47 h from bacteremia onset until active antimicrobial therapy, 38% of patients had septic shock, and 49% died within 30 days. KPC-3-Kp bacteremia (adjusted odds ratio [aOR], 2.58; P = 0.045), cancer (aOR, 3.61, P = 0.01), and bacteremia onset in the intensive care unit (aOR, 3.79; P = 0.03) were independently associated with mortality. Active empirical therapy and combination therapy were not associated with survival. Despite a decade of experience with CRE, patients with CRE bacteremia have protracted delays in appropriate therapies and high mortality rates, highlighting the need for rapid diagnostics and evaluation of new therapeutics.

Prospective microbiologic evaluation of the forceps elevator in closed-channel duodenoscopes after reprocessing

BACKGROUND

Endoscopes are well-known sources of bacterial transmission in health care facilities offering endoscopy services. The association between multidrug-resistant bacterial infections in patients who had undergone an endoscopic retrograde cholangiopancreatography procedure with reprocessed duodenoscopes has been much discussed. Bacterial contamination of duodenoscopes has been attributed to difficulties with reprocessing these devices, specifically the distal end of the scope, which features a movable forceps elevator. In light of a recent Food and Drug Administration warning letter to Olympus regarding their closed-channel duodenoscope model TJF-Q180V, the aim of our study was to prospectively evaluate the efficacy and safety of our current reprocessing procedures with regard to the TJF-Q180V duodenoscope models used in our hospital.

METHODS

From August 2015-March 2016, we prospectively collected microbiologic surveillance samples from 6 TJF-Q180V model duodenoscopes in routine use at the Division of Gastroenterology and Hepatology using the ESwab collection system (COPAN Diagnostics Inc, Murrieta, CA).

RESULTS

A total of 237 microbiologic samples from the forceps elevator were obtained during the survey period. None of the samples yielded microorganism growth.

CONCLUSION

These findings suggest that when following a diligent and validated reprocessing standard in accordance with manufacturer's recommendations, closed-channel endoscope models can still be used. Nevertheless, validated adaptions of current closed-channel duodenoscope models are needed to allow for simple and safe reprocessing. Furthermore, comprehensive postmarket surveillance needs to be established.

Carbapenem-Resistant Pseudomonas aeruginosa Bacteremia: Risk Factors for Mortality and Microbiologic Treatment Failure

We reviewed 37 patients treated for bacteremia due to carbapenem-resistant (CR) Pseudomonas aeruginosa Although 65% of isolates were multiple-drug resistant, therapeutic options were available, as all were susceptible to ≥1 antibiotic. A total of 92% of patients received active antimicrobial therapy, but only 57% received early active therapy (within 48 h). Fourteen-day mortality was 19%. Microbiologic failure occurred in 29%. The Pitt bacteremia score (P = 0.046) and delayed active therapy (P = 0.027) were predictive of death and microbiologic failure, respectively.

Duodenoscopy related infection risk and duodenoscope cleaning and disinfection

With the development of minimally invasive techniques, duodenoscope, as an instrument for diagnosis and treatment of pancreaticobiliary diseases, has been gradually applied in clinical practice. Iatrogenic infection caused by duodenoscopy is a well-documented complication, which has gained extensive attention especially in duodenoscope cleaning and disinfecting. It has been postulated that the complexity in design of duodenoscope makes cleaning difficult and poses a risk for nosocomial infections. As such, it is of positive practical significance to analyze the factors that affect cleaning and disinfecting and to take effective measures to do them better, in order to prevent nosocomial infection. This paper briefly reviews the cleaning and sterilizing of duodenoscope and the risk of infection associated with duodenoscopy.

A novel adjunctive cleansing method to reduce colony-forming units on duodenoscopes

Background and study aims: Endoscopic retrograde cholangiopancreatography-related infections are of increasing global concern due to the emergence of multidrug-resistant bacteria such as carbapenem-resistant enterobacteriaceae (CRE), with bacterial biofilm production postulated as one cause of persistent infection from such virulent organisms. Because N-acetylcysteine (NAC) has been shown to possess antibacterial and biofilm-disruption properties, we aimed to evaluate if NAC would demonstrate clinical utility in reducing the colony forming units (CFU) at the elevator end of a duodenoscope, one of the hardest areas to clean. Patients and methods: This was a pilot study of 16 procedures involving the use of a duodenoscope. After use, the elevator tip of a duodenoscope was cultured and submerged for 30 minutes, either in 20 % NAC (200 mg/mL, intervention) or in sterile water (control). After 30 minutes, the elevator tip was re-cultured. Results: Submersion of the distal end of a duodenoscope in 20 % NAC (200 mg/mL) for 30 minutes resulted in a statistically significant reduction in bacterial colony forming units compared to control (average reduction 41.6 % vs 8.8 %, P = 0.001). There was no visible damage and no optical distortion to the duodenoscope after submersion in NAC. Conclusions: In summary, NAC may be a safe, simple, and useful adjunct to currently available methods of duodenoscope reprocessing. Further research may better define NAC's role in duodenoscope reprocessing, either broadly or specifically after procedures suspected to produce a high risk of bacterial contamination (e. g. choledocholithiasis).

Control of carbapenemase-producing Enterobacteriaceae outbreaks in acute settings: an evidence review

BACKGROUND

In recent years, infections with carbapenemase-producing Enterobacteriaceae (CPE) have been increasing globally and present a major public health challenge.

AIM

To review the international literature: (i) to describe CPE outbreaks in acute hospital settings globally; and (ii) to identify the control measures used during these outbreaks and report on their effectiveness.

METHODS

A systematic search of MEDLINE and EMBASE databases, abstract lists for key conferences and reference lists of key reviews was undertaken, and information on unpublished outbreaks was sought for 2000-2015. Where relevant, risk of bias was assessed using the Newcastle-Ottawa scale. A narrative synthesis of the evidence was conducted.

FINDINGS

Ninety-eight outbreaks were eligible. These occurred worldwide, with 53 reports from Europe. The number of cases (CPE infection or colonization) involved in outbreaks varied widely, from two to 803. In the vast majority of outbreaks, multi-component infection control measures were used, commonly including: patient screening; contact precautions (e.g. gowns, gloves); handwashing interventions; staff education or monitoring; enhanced environmental cleaning/decontamination; cohorting of patients and/or staff; and patient isolation. Seven studies were identified as providing the best-available evidence on the effectiveness of control measures. These demonstrated that CPE outbreaks can be controlled successfully using a range of appropriate, commonly used, infection control measures. However, risk of bias was considered relatively high for these studies.

CONCLUSION

The findings indicate that CPE outbreaks can be controlled using combinations of existing measures. However, the quality of the evidence base is weak and further high-quality research is needed, particularly on the effectiveness of individual infection control measures.

Disinfection and Sterilization in Health Care Facilities: An Overview and Current Issues

When properly used, disinfection and sterilization can ensure the safe use of invasive and noninvasive medical devices. The method of disinfection and sterilization depends on the intended use of the medical device: critical items (contact sterile tissue) must be sterilized before use; semicritical items (contact mucous membranes or nonintact skin) must be high-level disinfected; and noncritical items (contact intact skin) should receive low-level disinfection. Cleaning should always precede high-level disinfection and sterilization. Current disinfection and sterilization guidelines must be strictly followed.

Carbapenem-resistant Enterobacteriaceae and endoscopy: An evolving threat

BACKGROUND

Several clusters of Carbapenem-resistant Enterobacteriaceae (CRE) infections associated with contaminated endoscopes have recently been reported. Interim guidelines for mitigating endoscope-associated transmission have been proposed, but there has not been a systematic appraisal of CRE prevention practices.

METHODS

We conducted a systematic review of endoscope-associated CRE infection episodes, abstracting information on outbreak detection, mitigation, outcomes, and corrective steps taken to prevent recurrence.

RESULTS

Seven distinct outbreaks were identified in the published literature, and 5 of these were associated with duodenal endoscopy, with the remaining 2 associated with cystoscopy and ureteroscopy. Several investigators noted difficulties in cleaning protocols surrounding difficult to access components, such as the elevator on duodenoscopes. The published investigations did not report any failures of sterilization. It is unclear if routine reprocessing was ineffective, or difficult to execute properly.

CONCLUSIONS

Meticulous cleaning protocols and increased surveillance are necessary to prevent and detect future outbreaks of CRE and to determine whether more stringent measures, such as sterilization, are needed for duodenoscopes.

Reprocessing semicritical items: Current issues and new technologies

Semicritical medical devices are defined as items that come into contact with mucous membranes or nonintact skin (eg, gastrointestinal endoscopes, endocavitary probes). Such medical devices minimally require high-level disinfection. Because many of these items are temperature sensitive, low-temperature chemical methods are usually used rather than steam sterilization. Strict adherence to current guidelines is required because more outbreaks have been linked to inadequately cleaned or disinfected endoscopes and other semicritical items undergoing high-level disinfection than any other reusable medical device.

Hygiene: The Looming Achilles Heel in Endoscopy

BACKGROUND

Since the late 1970s there have been sporadic reports of nosocomial infections linked to endoscopic procedures. Infections by multidrug-resistant organisms (MDRO) have an increasing impact on healthcare systems worldwide. Since 2010 outbreaks involving MDRO have been reported as a result of endoscopic retrograde cholangiopancreatography (ERCP) from the USA, France, Germany and the Netherlands.

METHODS

This article evaluates the recent outbreaks and developments and demonstrates a structural approach to how to prevent future infections. Current national and international guidelines were used as a basis for discussions.

RESULTS

In some cases insufficient cleaning or drying supported the outbreak. In the majority of cases, outbreaks occurred despite the apparently appropriate reprocessing protocols being in use. Microlesions were identified on a number of endoscopes, which supported the growth of bacteria and represented a vehicle for the transmission of infectious material. National official bodies responded with warnings. Manufacturers informed their customers accordingly. Separate, purpose-designed reprocessing rooms and a sufficient number of competent staff provide the structural quality for a safe reprocessing. The process quality includes a thorough cleaning of all endoscope channels and crucial instrument components, followed by an automated and validated reprocessing procedure. Strict adherence to manufacturers' recommendations is essential. The outcome quality should be evaluated by regular audits, validation of reprocessing procedures and microbiological surveillance. If outbreaks occur, a close co-operation with official bodies and manufacturers is essential.

CONCLUSION

Health care professionals and manufacturers should be aware of their responsibility to ensure patient safety. A structural approach is key in prevention of endoscopy-associated infections.

Characterization of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae from a healthcare region in Hong Kong

Carbapenem-resistant Enterobacteriaceae represents a major public health issue. This study investigated the clonality and resistance mechanisms of 92 carbapenem-resistant E. coli (n = 21) and K. pneumoniae (n = 71) isolates collected consecutively from clinical specimens and patients at high risk of carriage between 2010 and 2012 in a healthcare region in Hong Kong. Combined disk tests (CDTs) and the Carba NP test were used for phenotypic detection of carbapenemases. PCR assays were used to detect carbapenemase genes. All isolates were intermediate or resistant to at least one carbapenem. Nine (9.8 %) isolates were genotypic carbapenemase producers and included six K. pneumoniae (one ST1306/bla IMP-4, one ST889/bla IMP-4, two ST11/bla KPC-2, one ST258/bla KPC-2, one ST483/bla NDM-1) and three E. coli (one ST131/bla IMP-4, two ST744/ bla NDM-1) isolates. All nine isolates carrying carbapenemase genes could be detected by the CDTs and the Carba NP test. PCR identified bla CTX-M and bla AmpC alone or in combination in 77.8 % (7/9) and 96.4 % (80/83) of the carbapenemase-producers and non-producers, respectively. Porin loss was detected in 22.2 % (2/9) and 59.0 % (49/83) of the carbapenemase-producers and non-producers, respectively. Overall, the E. coli clones were diverse (14 different STs), but 36.6 % (26/71) of the K. pneumoniae isolates belonged to ST11. In conclusion, the prevalence of carbapenemases among carbapenem-nonsusceptible E. coli and K. pneumoniae remained low in Hong Kong. Porin loss combined with AmpC and/or CTX-M type ESBL was the major mechanism of carbapenem resistance in the study population.

Atomic force microscopy-guided fractionation reveals the influence of cranberry phytochemicals on adhesion of Escherichia coli

Characterization of cranberry juice fractions for their role in anti-adhesive properties against pathogenicE. coliusing Atomic Force Microscopy (AFM).

Basis for selecting optimum antibiotic regimens for secondary peritonitis

Adequate management of severely ill patients with secondary peritonitis requires supportive therapy of organ dysfunction, source control of infection and antimicrobial therapy. Since secondary peritonitis is polymicrobial, appropriate empiric therapy requires combination therapy in order to achieve the needed coverage for both common and more unusual organisms. This article reviews etiological agents, resistance mechanisms and their prevalence, how and when to cover them and guidelines for treatment in the literature. Local surveillances are the basis for the selection of compounds in antibiotic regimens, which should be further adapted to the increasing number of patients with risk factors for resistance (clinical setting, comorbidities, previous antibiotic treatments, previous colonization, severity…). Inadequate antimicrobial regimens are strongly associated with unfavorable outcomes. Awareness of resistance epidemiology and of clinical consequences of inadequate therapy against resistant bacteria is crucial for clinicians treating secondary peritonitis, with delicate balance between optimization of empirical therapy (improving outcomes) and antimicrobial overuse (increasing resistance emergence).

Infection control implications of heterogeneous resistance mechanisms in carbapenem-resistant Enterobacteriaceae (CRE)

The Centers for Disease Control and Prevention (CDC) defines carbapenem-resistant Enterobacteriaceae (CRE) based upon a phenotypic demonstration of carbapenem resistance. However, considerable heterogeneity exists within this definitional umbrella. CRE may mechanistically differ by whether they do or do not produce carbapenemases. Moreover, patients can acquire CRE through multiple pathways: endogenously through antibiotic selective pressure on intestinal microbiota, exogenously through horizontal transmission or through a combination of these factors. Some evidence suggests that non-carbapenemase-producing CRE may be more frequently acquired by antibiotic exposure and carbapenemase-producing CRE via horizontal transmission, but definitive data are lacking. This review examines types of CRE resistance mechanisms, antibiotic exposure and horizontal transmission pathways of CRE acquisition, and the implications of these heterogeneities to the development of evidence-based CRE healthcare epidemiology policies. In our Expert Commentary & Five-Year View, we outline specific nosocomial CRE knowledge gaps and potential methodological approaches for their resolution.

Outbreak column 18: The undervalued work of outbreak: prevention, preparedness, detection and management

There are oft-quoted studies which advise that between 1% and 10% of healthcare-associated infections (HAIs) present as healthcare-associated outbreaks (HAOs). Examination of these studies showed they lacked validity due to a low sensitivity to detect HAO, and because they pre-date both advanced healthcare systems and the emergence of recent nosocomial pathogen challenges. The accepted inference: that as there are so few HAOs the focus of surveillance programmes should be on endemic and not epidemic infections (outbreaks), is therefore called into question. Current estimates of HAI burden are derived from Point Prevalence Surveys (PPS) which are neither designed to nor are capable of detecting HAOs. We considered the extensive Infection Prevention and Control Team (IPCT) work to prevent and prepare for perennial and novel HAOs and suggest that at present this endeavour is largely unseen, underestimated and undervalued. Any HAI burden estimate needs to comprise a more complete HAI summary than PPS data. This can only be done with a more inclusive surveillance system that has a wider focus than just prevalent infections. There is a real risk of redirection of the IPCT resource from outbreak prevention and preparedness work towards HAI that are counted: such a change could only further increase HAO risks.

Role of Clinical Endoscopy in Emphasizing Endoscope Disinfection

Based on the unexpected Middle East respiratory syndrome (MERS) outbreak in Korea, it was established that the virus can spread easily, MERS exposure in hospitals carries an extreme risk for infection as well as mortality, and the sharing of information was essential for infection control. Although the incidence of exogenous infections related to contaminated endoscopes is very low, the majority of published outbreaks have been caused by various shortcomings in reprocessing procedures, including insufficient training or awareness. Ever since the inauguration of "Clinical Endoscopy" as an English-language journal of the Korean Society of Gastrointestinal Endoscopy in 2011, it has published several articles on disinfection of the endoscope and its accessories. Many Science Citation Index journals have also emphasized high-level disinfection of the gastrointestinal endoscope. Many papers have been produced specifically, since the outbreak of carbapenem-resistant Enterobacteriaceae in 2013. The recent review papers concluded that quality control is the most important issue among all the aspects of procedural care, including the efficiency of the gastrointestinal endoscopy unit and reprocessing room. Thorough reprocessing of endoscopes using high-level disinfection and sterilization methods may be essential for reducing the risk of infection.

Infectious diseases linked to cross-contamination of flexible endoscopes

Flexible endoscopes are widely used to examine, diagnose, and treat medical disorders. While the risk of endoscopy-related transmission of infection is estimated to be very low, more health care-associated infections are related to contaminated endoscopes than to any other medical device. Flexible endoscopes can get highly contaminated with microorganisms, secretions and blood during use. The narrow lumens and multiple internal channels make the cleaning of flexible endoscopes a complex and difficult task. Despite the availability of international, national and local endoscope reprocessing guidelines, contamination and transmission of microorganisms continue to occur. These transmissions are mostly related to the use of defective equipment, endoscope reprocessing failures, and noncompliance with recommended guidelines. This article presents an overview of publications about case reports and outbreaks related to contamination of flexible endoscopes.

Echoendoscopes

Advances in echoendoscopes and their processors have significantly expanded the role of EUS and its clinical applications.The diagnostic and therapeutic capabilities of EUS continue to evolve and improve. EUS has made a large impact on patient care but comes with significant startup and maintenance costs. As improved technology continues to enhance image resolution while decreasing the size of EUS processors, use of endosonography will become more widespread. EUS will continue to be a vital part of patient care and complement currently available cross-sectional imaging.

Superbugs on Duodenoscopes: the Challenge of Cleaning and Disinfection of Reusable Devices

Inadequate flexible endoscope reprocessing has been associated with infection outbreaks, most recently caused by carbapenem-resistant Enterobacteriaceae. Lapses in essential device reprocessing steps such as cleaning, disinfection/sterilization, and storage have been reported, but some outbreaks have occurred despite claimed adherence to established guidelines. Recommended changes in these guidelines include the use of sterilization instead of high-level disinfection or the use of routine microbial culturing to monitor efficacy of reprocessing. This review describes the current standards for endoscope reprocessing, associated outbreaks, and the complexities associated with both microbiological culture and sterilization approaches to mitigating the risk of infection associated with endoscopy.

Profile of ceftolozane/tazobactam and its potential in the treatment of complicated intra-abdominal infections

Drug-resistant pathogens have gained a foothold especially in the most vulnerable patient populations, hospitalized and immunocompromised individuals. Furthermore, extended-spectrum β-lactamase and carbapenemase-producing organisms are finding their way even into the community, with patients presenting to the hospital with established colonization and infection with resistant Enterobacteriaceae in particular. Recently, a novel antipseudomonal cephalosporin in combination with an established Class A β-lactamase inhibitor, ceftolozane/tazobactam has been approved by the FDA for use in the treatment of complicated urinary tract infections and complicated intra-abdominal infections. Ceftolozane is a uniquely potent antipseudomonal cephalosporin because of its high affinity for the penicillin-binding proteins of Pseudomonas aeruginosa, its low affinity for the intrinsic Class C β-lactamases of P. aeruginosa, its ability to enter P. aeruginosa through the outer membrane without the utilization of OprD protein, and the fact that it is not a substrate of the often upregulated MexAB/OprM efflux system of P. aeruginosa. The biological chemistry, pharmacokinetics/pharmacodynamics, microbiologic spectrum, and clinical trials that led to the approval of ceftolozane is reviewed. A discussion regarding its potential role in the treatment of complicated intra-abdominal infections and other infectious disease syndromes associated with drug-resistant pathogens follows.

The pros, cons, and unknowns of search and destroy for carbapenem-resistant enterobacteriaceae

Antibiotic drug discovery has not kept pace with the development of microbial resistance to these agents. There are ever increasing reports where the causative agents of serious infections are multi-drug resistant and in some cases resistant to all known antibiotics. The emergence and spread of carbapenemase-producing Enterobacteriaceae has heightened awareness regarding antibiotic stewardship programs and infection prevention and control measures. There has been much controversy regarding the utility of the "search and destroy" strategy to prevent the spread of carbapenem-resistant Enterobacteriaceae. These controversies center on screening and management of carriers, including decontamination and isolation. It is however clear that a functional infection prevention and control program is fundamental to any strategy that serves to address the spread of microbes within a healthcare facility.

An outbreak of carbapenem-resistant OXA-48 - producing Klebsiella pneumonia associated to duodenoscopy

Background

Carbapenemase-producing Enterobacteriaceae (CPE) have become a major problem for healthcare systems worldwide. While the first reports from European hospitals described the introduction of CPE from endemic countries, there is now a growing number of reports describing outbreaks of CPE in European hospitals. Here we report an outbreak of Carbapenem-resistant K. pneumoniae in a German University hospital which was in part associated to duodenoscopy.

Findings

Between December 6, 2012 and January 10, 2013, carbapenem-resistant K. pneumoniae (CRKP) was cultured from 12 patients staying on 4 different wards. The amplification of carbapenemase genes by multiplex PCR showed presence of the bla_OXA-48 gene. Molecular typing confirmed the identity of all 12 isolates. Reviewing the medical records of CRKP cases revealed that there was a spatial relationship between 6 of the cases which were located on the same wards. The remaining 6 cases were all related to endoscopic retrograde cholangiopancreatography (ERCP) which was performed with the same duodenoscope. The outbreak ended after the endoscope was sent to the manufacturer for maintenance.

Conclusions

Though the outbreak strain was also disseminated to patients who did not undergo ERCP and environmental sources or medical personnel also contributed to the outbreak, the gut of colonized patients is the main source for CPE. Therefore, accurate and stringent reprocessing of endoscopic instruments is extremely important, which is especially true for more complex instruments like the duodenoscope (TJF Q180V series) involved in the outbreak described here.