The effects of a prospective sink environmental hygiene intervention on Pseudomonas aeruginosa and Stenotrophomonas maltophilia burden in hospital sinks

BACKGROUND

Opportunistic premise plumbing pathogens (OPPPs) can establish reservoirs in hospital plumbing and cause healthcare associated infections (HAIs). There is currently no widely accepted protocol for sink drain cleaning to reduce OPPP burden.

METHODS

We implemented a sink cleaning intervention in 12 intensive care unit (ICU) rooms. At low frequency (1×/week) and high frequency (5×/week) intervals, we wiped sink surfaces with 10% bleach wipes and pumped a foamed preacid disinfectant into sink drains. We also maintained untreated rooms (0×/week). We used E-swabs to sample sink drains and surrounding surfaces during one baseline, two intervention, and two post-intervention periods over 23 months. Samples were selectively cultured for bacterial growth and antimicrobial resistant organism (ARO) isolation. We conducted whole-genome sequencing (WGS) on Pseudomonas spp. and Stenotrophomonas spp. isolates to track impacts on reservoirs over time. We also collected and analysed clinical isolates from patients occupying the study rooms and information about HAIs that occurred.

FINDINGS

The intervention reduced the proportion of sink drains yielding Gram-negative bacteria by up to 85% (95% CI: 56-114%) in high frequency rooms versus the baseline period, but this was not significant in low frequency rooms. It also reduced the proportion of sink drains yielding Pseudomonas spp. and Stenotrophomonas spp. by up to 100% (95% CI: 79-121%) and 95% (95% CI: 65-125%) versus the baseline period in high frequency rooms and up to 71% (95% CI: 50-92%, p < 0.001) and 66% (95% CI: 27-105%, p < 0.05) in low frequency rooms, respectively. WGS showed strains of Pseudomonas aeruginosa and Stenotrophomonas maltophilia that colonised sink drains for over 3 years across two studies. Following the intervention periods, P. aeruginosa reservoirs were replaced with new strains, while S. maltophilia reservoirs returned with the same strains.

INTERPRETATION

This environmental hygiene intervention may be effective in reducing the burden of OPPPs in hospital sinks.

FUNDING

Agency for Healthcare Research and Quality (R01HS027621), National Institute of Allergy and Infectious Diseases (U01AI123394, 1K23AI137321), Barnes-Jewish Hospital Foundation (5102), Washington University Institute of Clinical and Translational Sciences (4462) from the National Center for Advancing Translational Sciences (UL1TR002345).

Impact of Multifaceted Interventions Including Waterless Patient Care on Endemic Occurrence of Serratia marcescens in an Intensive Care Unit

Serratia marcescens acquisition is a common problem in intensive care units (ICUs). Following an initial outbreak in 2017 with ongoing endemicity, this study aimed to analyze the impact of behavioral interventions and sink removals on S. marcescens incidence in a tertiary-care ICU. We conducted a quasi-experimental, interventional study including patients with a positive screening or clinical culture for S. marcescens, from 48 h (D2) after ICU admission to 14 days after ICU discharge. A sub-analysis considered patients positive for S. marcescens from ICU admission (D0) to 14 days after ICU discharge. Multivariate Poisson regression analyses were performed. Between January 2014 and December 2022, 167 cases of S. marcescens infection or colonization were identified (respiratory samples, 71%). Despite the presence of an aquatic reservoir, we found that neither behavioral nor architectural interventions (sink removal) reduced significantly S. marcescens incidence, yielding incidence ratios of 1.02 [95%CI 0.33-3.11] and 4.25 [95%CI 0.59-30.56], respectively. However, an association was observed with administration of selective oral decontamination (SOD) in the sub-cohort (OR 1.01; 95%CI 1.00-1.03). Behavioral change interventions and transition to a waterless ICU did not control endemic, polyclonal S. marcescens occurrence. The selective pressure exercised by SOD may have reduced the effectiveness of waterless care.

Environmental hygiene strategies to combat antimicrobial resistance in healthcare settings

In this manuscript, we highlight current literature on environmental hygiene techniques to combat reservoirs of antibiotic resistant organisms in the healthcare environment. We discuss several topics for each strategy, including mechanism of action, assessment of effectiveness based on studies, cost, and real-world translatability. The techniques and topics summarized here are not inclusive of all available environmental hygiene techniques but highlight some of the more popular and investigated strategies. We focus on the following: Ultraviolet radiation, hydrogen peroxide vapor, copper-coated surfaces, phages, interventions involving sinks, and educational initiatives.

Identifying patients at high risk for carbapenem-resistant Enterobacterales (CRE) carriage on admission to acute care hospitals: validating and expanding on a public health model

OBJECTIVE

Validate a public health model identifying patients at high risk for carbapenem-resistant Enterobacterales (CRE) on admission and evaluate performance across a healthcare network.

DESIGN

Retrospective case-control studies.

PARTICIPANTS

Adults hospitalized with a clinical CRE culture within 3 days of admission (cases) and those hospitalized without a CRE culture (controls).

METHODS

Using public health data from Atlanta, GA (1/1/2016-9/1/2019), we validated a CRE prediction model created in Chicago. We then closely replicated this model using clinical data from a healthcare network in Atlanta (1/1/2015-12/31/2021) ("Public Health Model") and optimized performance by adding variables from the healthcare system ("Healthcare System Model"). We frequency-matched cases and controls based on year and facility. We evaluated model performance in validation datasets using area under the curve (AUC).

RESULTS

Using public health data, we matched 181 cases to 764,408 controls, and the Chicago model performed well (AUC 0.85). Using clinical data, we matched 91 cases to 384,013 controls. The Public Health Model included age, prior infection diagnosis, number of and mean length of stays in acute care hospitalizations (ACH) in the prior year. The final Healthcare System Model added Elixhauser score, antibiotic days of therapy in prior year, diabetes, admission to the intensive care unit in prior year and removed prior number of ACH. The AUC increased from 0.68 to 0.73.

CONCLUSIONS

A CRE risk prediction model using prior healthcare exposures performed well in a geographically distinct area and in an academic healthcare network. Adding variables from healthcare networks improved model performance.

Identification of carbapenemase-producing Enterobacteriaceae reservoirs in wet hospital environments as a potential factor in patient acquisition: A cross-sectional study in a French university hospital in 2023

OBJECTIVES

Wet hospital environments have been documented as potential reservoirs for Carbapenemase-producing Enterobacteriaceae (CPE), possibly contributing to outbreaks among inpatients. Our objectives were to assess the prevalence of CPE reservoirs in a hospital's wet environments and to investigate the contamination of adjacent dry surfaces.

METHODS

From March to August 2023, we conducted a cross-sectional study in two hospital wards experiencing ongoing large outbreaks. Sampling of the environment was undertaken in two distinct phases. During phase 1, 38 shower drains and 38 toilet bowls, defined as the wet environment, were sampled using swabs. Phase 2 consisted in sampling adjacent dry surfaces, using wipes in rooms that had tested positive during phase 1. Samples were plated on a selective medium (chromID®CARBASMART, bioMérieux). Species were identified using the matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) technique. Carbapenemases were detected by OKNVI RESIST-5® (CORIS BioConcept).

RESULTS

From the 38 patient rooms, 76 samples were taken during phase 1. All in all, 33 (86.8%) rooms presented at least one CPE reservoir in the wet environment; there were 32 (84.2%) contaminated shower drains and six (15.8%) contaminated toilet bowls. Among 57 identified CPEs, the most frequent strain was Enterobacter cloacae VIM (13, 22.8%). During phase 2, 11 (8.3%) out of 132 samples tested positive for CPE. Enterobacter cloacae complex VIM accounted for six (54.5%) of the CPE strains.

CONCLUSION

These findings suggest that the wet hospital environments were broadly contaminated with CPE, mostly Enterobacter cloacae VIM. The spread of CPE from wet environments to dry surfaces seemed limited.

Prescribing a Green Future: A Review of Antimicrobial Waste in Pediatric Hospitals and Practices to Promote Healthcare Sustainability

Pediatric hospitals are uniquely positioned to be impacted by antimicrobial waste. To explore this issue, we reviewed the current literature to identify the reasons, costs, and potential solutions to waste. Identified reasons for waste included weight-based dosing, medication order changes due to changing patient status, loss or expiration of doses, and medication errors. The cost of waste included financial costs, promotion of antimicrobial resistance, and generation of greenhouse gases. Proposed interventions to reduce waste included an early switch from intravenous to oral administration, required stop dates, standardized dosing times, and optimization of the pharmacy batching process. However, additional studies are needed to assess the potential correlation between these proposed interventions and waste reduction. Antimicrobial stewardship programs have been identified as a group that can play a crucial role in partnering to implement these interventions to potentially reduce antimicrobial waste and promote better healthcare sustainability.

Longitudinal bacterial community dynamics and sodium hypochlorite intervention in a newly built university building

Urbanisation and building advancements have increased microbial growth in indoor environments, altering human interactions with these microorganisms. Restrooms and their sinks harbour diverse bacterial communities, that differ from those found in natural environments, that could have negative implications for human health. Over two and a half years, this study examined the diversity, temporal dynamics, and resilience of bacterial communities in restroom sink P-traps in a newly built university building. Structured into two phases, the first phase consisted of continuous monitoring of bacterial community dynamics for two years (n = 352), while the second phase involved an intervention with sodium hypochlorite (bleach) and subsequent sampling (n = 132). In the first phase, we show that sink communities converge, becoming more compositionally similar to other sinks within the building. Bacterial families such as Rhodocyclaceae and Flavobacteriaceae dominated across the sinks, and others such as Comamonadaceae, Moraxellaceae and Enterbacteriaceae were highly prevalent. When comparing bacterial structure and composition to other sinks located on the university campus, the mean bacterial dissimilarity decreased over time, indicating compositional similarity, particularly with the newer buildings on campus. The second phase demonstrated resilience by the bacterial sink communities. Following bleach treatments, a distinct increase in Acinetobacter was observed. However, by the fourth week after bleach invention, bacterial communities had re-established to levels observed prior to treatment. This study had the unique opportunity to sample a newly built building before occupancy and for the subsequent two and a half years. The findings provide crucial insights into the development and resilience of sink P-trap bacterial communities in restrooms, laying the groundwork for more targeted approaches to disinfection strategies.

Successful control of an environmental reservoir of NDM-producing Klebsiella pneumoniae associated with nosocomial transmissions in a low-incidence setting

BACKGROUND

The hospital wastewater system has been reported as a source of nosocomial acquisition of carbapenemase producing Enterobacteriaceae (CPE) in various settings. Cleaning and disinfection protocols or replacement of contaminated equipment often fail to eradicate these environmental reservoirs, which can lead to long-term transmission of CPE. We report a successful multimodal approach to control a New Delhi metallo-beta-lactamase positive Klebsiella pneumoniae (NDM-KP) nosocomial outbreak implicating contamination of sink traps in a low-incidence setting.

METHODS

Following the incidental identification of NDM-KP in a urine culture of an inpatient, we performed an epidemiological investigation, including patient and environmental CPE screening, and whole genome sequencing (WGS) of strains. We also implemented multimodal infection prevention and control (IPC) measures, namely the isolation of cases, waterless patient care, replacement of contaminated P-traps and connecting pieces, and bleach and steam disinfection of sinks for 6 months, followed by patient and environmental screenings for eradication.

RESULTS

Between February and May 2022, five NDM-KP cases were identified in an eight-bed neurosurgical intermediate care unit. Among the eight sink traps of the unit, three were positive for NDM-KP. Patient and environmental isolates belonged to multilocus sequence typing ST-268. All isolate genomes were genetically very similar suggesting cross-transmission and a potential role of the environment as the source of transmissions. Following the introduction of combined IPC measures, no new case was subsequently detected and sink traps remained negative for NDM-KP within 6 months after the intervention.

CONCLUSION

The implementation of multimodal IPC measures, including waterless patient care combined with the replacement and disinfection of P-traps and connecting pieces, was successful in the control of NDM-KP after eight months. In a low-incidence setting, this approach has made it possible to pursue the objective of zero transmission of carbapenemase-producing Enterobacteriaceae (CPE).

Towards integrated cross-sectoral surveillance of pathogens and antimicrobial resistance: Needs, approaches, and considerations for linking surveillance to action

Pathogenic and antimicrobial-resistant (AMR) microorganisms are continually transmitted between human, animal, and environmental reservoirs, contributing to the high burden of infectious disease and driving the growing global AMR crisis. The sheer diversity of pathogens, AMR mechanisms, and transmission pathways connecting these reservoirs create the need for comprehensive cross-sectoral surveillance to effectively monitor risks. Current approaches are often siloed by discipline and sector, focusing independently on parts of the whole. Here we advocate that integrated surveillance approaches, developed through transdisciplinary cross-sector collaboration, are key to addressing the dual crises of infectious diseases and AMR. We first review the areas of need, challenges, and benefits of cross-sectoral surveillance, then summarise and evaluate the major detection methods already available to achieve this (culture, quantitative PCR, and metagenomic sequencing). Finally, we outline how cross-sectoral surveillance initiatives can be fostered at multiple scales of action, and present key considerations for implementation and the development of effective systems to manage and integrate this information for the benefit of multiple sectors. While methods and technologies are increasingly available and affordable for comprehensive pathogen and AMR surveillance across different reservoirs, it is imperative that systems are strengthened to effectively manage and integrate this information.

Disinfection of sink drains to reduce a source of three opportunistic pathogens, during Serratia marcescens clusters in a neonatal intensive care unit

OBJECTIVE

Evaluate the effects of five disinfection methods on bacterial concentrations in hospital sink drains, focusing on three opportunistic pathogens (OPs): Serratia marcescens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia.

DESIGN

Over two years, three sampling campaigns were conducted in a neonatal intensive care unit (NICU). Samples from 19 sink drains were taken at three time points: before, during, and after disinfection. Bacterial concentration was measured using culture-based and flow cytometry methods. High-throughput short sequence typing was performed to identify the three OPs and assess S. marcescens persistence after disinfection at the genotypic level.

SETTING

This study was conducted in a pediatric hospitals NICU in Montréal, Canada, which is divided in an intensive and intermediate care side, with individual rooms equipped with a sink.

INTERVENTIONS

Five treatments were compared: self-disinfecting drains, chlorine disinfection, boiling water disinfection, hot tap water flushing, and steam disinfection.

RESULTS

This study highlights significant differences in the effectiveness of disinfection methods. Chlorine treatment proved ineffective in reducing bacterial concentration, including the three OPs. In contrast, all other drain interventions resulted in an immediate reduction in culturable bacteria (4-8 log) and intact cells (2-3 log). Thermal methods, particularly boiling water and steam treatments, exhibited superior effectiveness in reducing bacterial loads, including OPs. However, in drains with well-established bacterial biofilms, clonal strains of S. marcescens recolonized the drains after heat treatments.

CONCLUSIONS

Our study supports thermal disinfection (>80°C) for pathogen reduction in drains but highlights the need for additional trials and the implementation of specific measures to limit biofilm formation.

Resistome Analysis of Klebsiella pneumoniae Complex from Residential Aged Care Facilities Demonstrates Intra-facility Clonal Spread of Multidrug-Resistant Isolates

Antimicrobial-resistant Klebsiella pneumoniae is one of the predominant pathogens in healthcare settings. However, the prevalence and resistome of this organism within residential aged care facilities (RACFs), which are potential hotspots for antimicrobial resistance, remain unexplored. Here, we provide a phenotypic and molecular characterization of antimicrobial-resistant K. pneumoniae isolated from RACFs. K. pneumoniae was isolated from urine, faecal and wastewater samples and facility swabs. The antimicrobial susceptibility profiles of all the isolates were determined and the genomic basis for resistance was explored with whole-genome sequencing on a subset of isolates. A total of 147 K. pneumoniae were isolated, displaying resistance against multiple antimicrobials. Genotypic analysis revealed the presence of beta-lactamases and the ciprofloxacin-resistance determinant QnrB4 but failed to confirm the basis for the observed cephalosporin resistance. Clonal spread of the multidrug-resistant, widely disseminated sequence types 323 and 661 was observed. This study was the first to examine the resistome of K. pneumoniae isolates from RACFs and demonstrated a complexity between genotypic and phenotypic antimicrobial resistance. The intra-facility dissemination and persistence of multidrug-resistant clones is concerning, given that residents are particularly vulnerable to antimicrobial resistant infections, and it highlights the need for continued surveillance and interventions to reduce the risk of outbreaks.

Epidemiology and clinical significance of carbapenemases in Australia: a narrative review

Carbapenemase-producing gram-negative bacteria (CP-GNB) infections threaten public health with high mortality, morbidity and treatment costs. Although frequencies remain low in Australia (total number of CP-GNB infections reported was 907 in 2022), blaIMP-4 has established low levels of endemicity in many states. Imipenemase metallo-β-lactamase types alone accounted for more than half of all carbapenemases in carbapenemase-producing Enterobacterales isolates in Australia, particularly in Enterobacter cloacae complex. New Delhi metallo-β-lactamase constitutes almost 25% of all carbapenemases in Australia and was identified predominantly in Escherichia coli. The OXA-48-like carbapenemases include almost 10% of all carbapenemases and are mainly seen in Klebsiella pneumoniae and E. coli. Although K. pneumoniae carbapenemase-type carbapenemases are rare in Australia, some local outbreaks have occurred. Most carbapenem-resistant (CR) Pseudomonas aeruginosa strains in Australia do not produce carbapenemases. Finally, OXA-23-like carbapenemases are overwhelmingly positive in CR-Acinetobacter baumannii strains in Australia. Treatment of CR-GNB infections challenges physicians. Of 10 new antibiotics active against at least some CR-GNB infections that are approved by the US Food and Drug Administration, just three are approved for use in Australia. In this context, there is still an unmet need for novel antibacterials that can be used for the treatment of CR-GNB infections in Australia, as well as a pressing requirement for new mechanisms to 'de-link' antibiotic sales from their availability. In this narrative review, we aim to overview the epidemiology and clinical significance of carbapenem resistance in Australia as it pertains to Enterobacterales, P. aeruginosa and A. baumannii.

Infection prevention and control policy implementation for CPE: a cross-sectional national survey of healthcare workers reveals knowledge gaps and suboptimal practices

BACKGROUND

In 2017, Ireland pioneered a unique response to the worsening epidemiology of carbapenemase-producing Enterobacterales (CPE), declaring a national public health emergency. Subsequently, CPE mitigation guidelines and policies were implemented in acute hospitals, focused on patient screening and outbreak management, often by healthcare workers (HCWs) with limited background in infection prevention and control (IPC). CPE risks from sinks and drains remain inadequately controlled.

AIMS

To compare CPE awareness, perceptions of the role of the environment in CPE transmission, and disposal practices of liquid waste from clinical handwashing sinks between IPC HCWs and non-IPC HCWs in Ireland.

METHODS

Between December 2022 and March 2023, HCWs employed in acute hospitals in Ireland between 2017 and 2022 were invited to participate anonymously in a 30-question digital survey.

FINDINGS

Responses (N=283) were received across several clinical disciplines. In total, 21.6% of respondents were working or had previously worked in IPC roles, 84.1% of whom reported no IPC-related learning needs. In comparison with non-IPC HCWs, more IPC HCWs perceived a risk of pathogen transmission from clean water plumbing (68.9% vs 39.2%; P<0.001) and waste/drainage plumbing (81.2% vs 43.7%; P<0.001). Among nursing and medical staff, only 5.6% of IPC HCWs used clinical handwashing sinks for disposal of liquid waste, compared with 60% of non-IPC HCWs (P<0.001). In comparison with non-IPC HCWs, a greater proportion of IPC HCWs reported that they had witnessed colleagues routinely discarding liquid waste (including nutritional products, antimicrobials and patient body fluids) via clinical handwashing sinks (88.9% vs 77.9%) CONCLUSIONS: Although there is general awareness of the role of the built environment in pathogen transmission, including CPE, familiarity with sink/water-related transmission is greater among IPC HCWs. There may be opportunities to improve disposal practices for liquid waste through education targeting non-IPC HCWs.

A workflow for the detection of antibiotic residues, measurement of water chemistry and preservation of hospital sink drain samples for metagenomic sequencing

BACKGROUND

Hospital sinks are environmental reservoirs that harbour healthcare-associated (HCA) pathogens. Selective pressures in sink environments, such as antibiotic residues, nutrient waste and hardness ions, may promote antibiotic resistance gene (ARG) exchange between bacteria. However, cheap and accurate sampling methods to characterize these factors are lacking.

AIMS

To validate a workflow to detect antibiotic residues and evaluate water chemistry using dipsticks. Secondarily, to validate boric acid to preserve the taxonomic and ARG ('resistome') composition of sink trap samples for metagenomic sequencing.

METHODS

Antibiotic residue dipsticks were validated against serial dilutions of ampicillin, doxycycline, sulfamethoxazole and ciprofloxacin, and water chemistry dipsticks against serial dilutions of chemical calibration standards. Sink trap aspirates were used for a 'real-world' pilot evaluation of dipsticks. To assess boric acid as a preservative of microbial diversity, the impact of incubation with and without boric acid at ∼22 °C on metagenomic sequencing outputs was evaluated at Day 2 and Day 5 compared with baseline (Day 0).

FINDINGS

The limits of detection for each antibiotic were: 3 μg/L (ampicillin), 10 μg/L (doxycycline), 20 μg/L (sulfamethoxazole) and 8 μg/L (ciprofloxacin). The best performing water chemistry dipstick correctly characterized 34/40 (85%) standards in a concentration-dependent manner. One trap sample tested positive for the presence of tetracyclines and sulphonamides. Taxonomic and resistome composition were largely maintained after storage with boric acid at ∼22 °C for up to five days.

CONCLUSIONS

Dipsticks can be used to detect antibiotic residues and characterize water chemistry in sink trap samples. Boric acid was an effective preservative of trap sample composition, representing a low-cost alternative to cold-chain transport.

Long-term ICU outbreak of carbapenamase-producing organisms associated with contaminated sink drains

BACKGROUND

Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P. aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU). We report the investigation of this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir.

METHODS

Active case finding, environmental sampling, whole genome sequencing (WGS) analysis of patient and environmental strains and implemented control strategies were described in this study.

FINDINGS

From 2018 to 2022, 37 patients became colonised or infected with PA-VIM and/ or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strains dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pumps genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented re-colonisation of the proximal sink drain by CPO.

CONCLUSION

The persistence in the hospital environment of antibiotic-and-disinfectant resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat on ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.

Nutritional drinks and enteral feeds promote the growth of carbapenemase-producing Enterobacterales in conditions that simulate disposal in hospital sinks

BACKGROUND

Studies have shown that nutritional products are discarded via handwash sinks by healthcare workers, and this practice may promote bacterial growth, including growth of pathogens such as carbapenemase-producing Enterobacterales (CPE). Outbreaks and acquisition of CPE in nosocomial settings are associated with negative outcomes for patients and hospitals.

OBJECTIVES

To investigate the potential growth-promoting effect of nutritional support drinks (NSDs) and enteral tube-feed products (ETFPs) on CPE.

METHODS

Six different CPE strains were grown in five different diluted NSDs, five different diluted ETFPs, Mueller-Hinton broth (MHB) and M9 minimal salts media to simulate discarding a small volume of nutritional product in a u-bend, already containing liquid. CPE were enumerated at 0 h, 6 h and 24 h, and compared using two-way analysis of variance and Dunett test, with confidence levels at 95%. Spearman's r was used to measure the strength of correlation between component concentrations in nutritional products and CPE growth.

RESULTS

All NSDs and ETFPs promoted CPE growth that exceeded both M9 (negative growth control) and MHB (positive growth control). In several cases, growth in NSDs/ETFPs was significantly greater compared with growth in MHB.

CONCLUSION

Nutritional products support CPE growth under in-vitro conditions. The propensity of CPE to survive in drain pipework suggests that inappropriate product disposal may further nourish established CPE in these environmental reservoirs. The growth observed in diluted NSDs and ETFPs shows that modifiable practices should be optimized to mitigate the potential risk of CPE transmission from these reservoirs.

Sinks in patient rooms in ICUs are associated with higher rates of hospital-acquired infection: a retrospective analysis of 552 ICUs

BACKGROUND

Sinks in hospitals are a possible reservoir for healthcare-related pathogens. They have been identified as a source of nosocomial outbreaks in intensive care units (ICU); however, their role in non-outbreak settings remains unclear.

AIM

To investigate whether sinks in ICU patient rooms are associated with a higher incidence of hospital-acquired infection (HAI).

METHODS

This analysis used surveillance data from the ICU component of the German nosocomial infection surveillance system (KISS) from 2017 to 2020. Between September and October 2021, all participating ICUs were surveyed about the presence of sinks in their patient rooms. The ICUs were then divided into two groups: the no-sink group (NSG) and the sink group (SG). Primary and secondary outcomes were total HAIs and HAIs associated with Pseudomonas aeruginosa (HAI-PA).

FINDINGS

In total, 552 ICUs (NSG N=80, SG N=472) provided data about sinks, total HAIs and HAI-PA. The incidence density per 1000 patient-days of total HAIs was higher in ICUs in the SG (3.97 vs 3.2). The incidence density of HAI-PA was also higher in the SG (0.43 vs 0.34). The risk of HAIs associated with all pathogens [incidence rate ratio (IRR)=1.24, 95% confidence interval (CI) 1.03-1.50] and the risk of lower respiratory tract infections associated with P. aeruginosa (IRR=1.44, 95% CI 1.10-1.90) were higher in ICUs with sinks in patient rooms. After adjusting for confounders, sinks were found to be an independent risk factor for HAI (adjusted IRR 1.21, 95% CI 1.01-1.45).

CONCLUSIONS

Sinks in patient rooms are associated with a higher number of HAIs per patient-day in the ICU. This should be considered when planning new ICUs or renovating existing ones.

Intensive care unit sinks are persistently colonized with multidrug resistant bacteria and mobilizable, resistance-conferring plasmids

Contamination of hospital sinks with microbial pathogens presents a serious potential threat to patients, but our understanding of sink colonization dynamics is largely based on infection outbreaks. Here, we investigate the colonization patterns of multidrug-resistant organisms (MDROs) in intensive care unit sinks and water from two hospitals in the USA and Pakistan collected over 27 months of prospective sampling. Using culture-based methods, we recovered 822 bacterial isolates representing 104 unique species and genomospecies. Genomic analyses revealed long-term colonization by Pseudomonas spp. and Serratia marcescens strains across multiple rooms. Nanopore sequencing uncovered examples of long-term persistence of resistance-conferring plasmids in unrelated hosts. These data indicate that antibiotic resistance (AR) in Pseudomonas spp. is maintained both by strain colonization and horizontal gene transfer (HGT), while HGT maintains AR within Acinetobacter spp. and Enterobacterales, independent of colonization. These results emphasize the importance of proactive, genomic-focused surveillance of built environments to mitigate MDRO spread. IMPORTANCE Hospital sinks are frequently linked to outbreaks of antibiotic-resistant bacteria. Here, we used whole-genome sequencing to track the long-term colonization patterns in intensive care unit (ICU) sinks and water from two hospitals in the USA and Pakistan collected over 27 months of prospective sampling. We analyzed 822 bacterial genomes, representing over 100 different species. We identified long-term contamination by opportunistic pathogens, as well as transient appearance of other common pathogens. We found that bacteria recovered from the ICU had more antibiotic resistance genes (ARGs) in their genomes compared to matched community spaces. We also found that many of these ARGs are harbored on mobilizable plasmids, which were found shared in the genomes of unrelated bacteria. Overall, this study provides an in-depth view of contamination patterns for common nosocomial pathogens and identifies specific targets for surveillance.

Genomic dissection of endemic carbapenem resistance reveals metallo-beta-lactamase dissemination through clonal, plasmid and integron transfer

Infections caused by metallo-beta-lactamase-producing organisms (MBLs) are a global health threat. Our understanding of transmission dynamics and how MBLs establish endemicity remains limited. We analysed two decades of blaIMP-4 evolution in a hospital using sequence data from 270 clinical and environmental isolates (including 169 completed genomes) and identified the blaIMP-4 gene across 7 Gram-negative genera, 68 bacterial strains and 7 distinct plasmid types. We showed how an initial multi-species outbreak of conserved IncC plasmids (95 genomes across 37 strains) allowed endemicity to be established through the ability of blaIMP-4 to disseminate in successful strain-genetic setting pairs we termed propagators, in particular Serratia marcescens and Enterobacter hormaechei. From this reservoir, blaIMP-4 persisted through diversification of genetic settings that resulted from transfer of blaIMP-4 plasmids between bacterial hosts and of the integron carrying blaIMP-4 between plasmids. Our findings provide a framework for understanding endemicity and spread of MBLs and may have broader applicability to other carbapenemase-producing organisms.

Regional transmission patterns of carbapenemase-producing Enterobacterales: A healthcare network analysis

OBJECTIVE

Carbapenem-resistant Enterobacterales (CRE) pose a serious public health threat and spread rapidly between healthcare facilities (HCFs) during interfacility patient movement. We examined patterns of transmission of CRE associated with network clustering and positions during patient interfacility transfer.

METHODS

A retrospective cohort study was conducted in the Greater Houston region ofTexas, , and social network analysis was performed by constructing facility-to-facility patient transfer network using CRE surveillance data. The network method (community detection algorithm) was used to detect clustering patterns of CRE in the network. In addition, network measures of centrality and local connectivity (clustering coefficient) were computed for each healthcare facility. Zero-inflated negative binomial regression analysis was applied to test the association between network measures and facility-specific incidence rate of CRE.

RESULTS

A network of 268 healthcare facilities was identified, in which 10 acute-care hospitals (ACHs) alone accounted for 63% of identified CRE cases. Transmission of New Delhi metallo-β-lactamase-producing CRE occurred in 3 clusters, yet all cases were traced to patients who had had medical care abroad. The incidence rate of CRE attributed to ACHs was >4-fold (adjusted rate ratio, 4.5; 95% confidence interval [CI], 3.02-6.72) higher than that of long-term care facilities. Each additional patient shared with another HCF conferred a 3% (95% CI, 2%-4%) increase in the incidence rate of CRE at that HCF.

CONCLUSIONS

The incidence rates of CRE at a given HCF was predicted by the healthcare network metrics. Increased surveillance and selective targeting of high-risk facilities are warranted.

Methods of Cleaning Taps to Prevent Hospital-Associated Infections: An Environmental Survey-Based Study

In hospitals, outbreaks can occur due to pathogens accumulating in the areas around the wards' washbasins. Carbapenem-resistant Enterobacterales (CRE) was detected in an environmental survey in the high-care unit of a university hospital in Isehara, Japan, and effective cleaning methods were investigated. This study investigated methods of cleaning taps using commonly used detergents and disinfectants, and it assessed their effectiveness in removing hard scale and pathogens, including CRE. The taps were cleaned using various methods and cleaning agents, including environmentally neutral detergent, citric acid, baking soda, cleanser, 80% ethanol, 0.1% sodium hypochlorite, and a phosphoric acid-based environmental detergent (Space Shot). The cleaning effect was assessed based on the agent's effectiveness at removing hard scale from taps. Biofilms and scale were identified on taps, and several bacterial species were cultured. Only phosphoric acid-based detergent was effective at removing hard scale. After cleaning with the phosphoric acid-based detergent, the bacterial count decreased, and no CRE or other pathogens were detected. These results provide a reference for other facilities considering introducing this cleaning method.

Co-Occurrence of Multidrug Resistant Klebsiella pneumoniae Pathogenic Clones of Human Relevance in an Equine Pneumonia Case

The global epidemiology of multidrug resistant Klebsiella pneumoniae, a serious threat to both animal and human health, is dominated by the spread of pathogenic clones, each separately evolving via acquisition of transferable antibiotic resistance or niche-specific virulence determinants. In horses, K. pneumoniae infection can lead to severe respiratory illness. Here, we characterized multiple isolates recovered from bronchial aspirates of a mare with pneumonia refractory to antibiotics. First, we used a combination of standard microbiology, bacteriophage cross-susceptibility and antibiotic resistance testing to profile the infecting K. pneumoniae population. The genomes of isolates with distinct fingerprints (pulsed-field gel electrophoresis) and unique combined bacteriophage/antibiotic profiles were then further analyzed using whole-genome sequencing. Adhesion to human epithelial cells and biofilm production were also measured as virulence indicators. Although it is commonly expected for one clone to dominate an infection episode, we identified five coexisting multidrug resistant K. pneumoniae sharing the same niche. One was a novel sequence type (ST4656), while the other four were all members of emerging human pathogenic clonal groups (ST307, ST628, ST893 and ST392). These isolates did not display significant differences from one another in terms of virulence or resistance and differed only in plasmid content from isolates implicated in severe human infections, with equal potential to prolong duration and severity of infection when sharing the same niche. This study highlights the importance of more precise surveillance and detection measures to uncover bacterial heterogeneity, reminding us that the "single clone" concept is not an absolute in invasive bacterial infections. IMPORTANCE Multidrug resistant Klebsiella pneumoniae are agents of life-threatening infections in animals and humans, with several multidrug resistant clones causing outbreaks of disease worldwide. It is generally accepted that only one clone will be dominant in an infection episode. In this study, we investigated K. pneumoniae isolates from a horse with severe pneumonia and demonstrated co-occurrence of multiple sequence types previously identified as emerging human pathogens. The equine isolates are not significantly different from one another in terms of virulence or resistance, with equal potential to prolong duration and severity of infection, and are indistinguishable from isolates recovered from humans, except for plasmid content. Our study highlights how the "one dominant clone" concept is not an absolute in severe infection, illustrating the need for improved diagnostics to track heterogeneity of infection, and reinforces the importance of cross-monitoring of environmental and human reservoirs of multidrug resistant pathogens.

Antibiotic-resistant organisms establish reservoirs in new hospital built environments and are related to patient blood infection isolates

Background

Healthcare-associated infections due to antibiotic-resistant organisms pose an acute and rising threat to critically ill and immunocompromised patients. To evaluate reservoirs of antibiotic-resistant organisms as a source of transmission to patients, we interrogated isolates from environmental surfaces, patient feces, and patient blood infections from an established and a newly built intensive care unit.

Methods

We used selective culture to recover 829 antibiotic-resistant organisms from 1594 environmental and 72 patient fecal samples, in addition to 81 isolates from blood cultures. We conducted antibiotic susceptibility testing and short- and long-read whole genome sequencing on recovered isolates.

Results

Antibiotic-resistant organism burden is highest in sink drains compared to other surfaces. Pseudomonas aeruginosa is the most frequently cultured organism from surfaces in both intensive care units. From whole genome sequencing, different lineages of P. aeruginosa dominate in each unit; one P. aeruginosa lineage of ST1894 is found in multiple sink drains in the new intensive care unit and 3.7% of blood isolates analyzed, suggesting movement of this clone between the environment and patients.

Conclusions

These results highlight antibiotic-resistant organism reservoirs in hospital built environments as an important target for infection prevention in hospitalized patients.

Characteristics Associated With Consistent Handwashing and Satisfaction in the Workplace: A Pilot Survey of U.S. Workers

BACKGROUND

This study seeks to determine what handwashing facilities are available to workers, predominantly in the manufacturing and service industries, to find out if their workplace has the appropriate resources to conduct proper handwashing and how that affects handwashing satisfaction.

METHODS

This cross-sectional study surveyed U.S. adult workers (N = 241) on their workplace handwashing equipment and facilities. The associations between demographic characteristics, consistent handwashing, and handwashing satisfaction were evaluated using Fisher's exact test.

FINDINGS

Eighty-eight percent of respondents reported consistent handwashing. Pulling a handle to exit the restroom was negatively associated with handwashing satisfaction (p = .004) and having difficulty with an automatic faucet or dispenser was negatively marginally significant in its association with handwashing consistency (p = .10).

CONCLUSION/APPLICATIONS TO PRACTICE

Greater understanding of the available equipment in workplace restroom facilities and how to improve selection and use of that equipment may improve workers' handwashing experiences.

Carbapenem-resistant Enterobacteriaceae in sink drains of 40 healthcare facilities in Sindh, Pakistan: A cross-sectional study

In Pakistan, antimicrobial resistance (AMR) is expected to greatly increase the already high mortality and morbidity rates attributed to infections, making AMR surveillance and prevention a priority in the country. The aims of the project were to characterize the prevalence of carbapenem-resistant Enterobacteriaceae (CRE) in healthcare facility sink drains in Pakistan and to characterize how physical characteristics of sinks and healthcare facility rooms were associated with CRE in those sinks. The study took place in 40 healthcare facilities in Jamshoro Pakistan. Swabs were collected from sink drains in each facility that had a sink, and structured observations of sinks and facilities were performed at each facility. Swabs were plated on CHROMagar KPC to screen for carbapenem-resistant Enterobacteriaceae, which were then isolated on Mueller-Hinton agar plates. Antibiotic susceptibility was determined using the disk diffusion method to assess resistance to carbapenems, cephalosporins, and fluoroquinolones. Thirty-seven of the healthcare facilities had at least one sink, and thirty-nine total sinks were present and sampled from those healthcare facilities. Sinks in these facilities varied in quality; at the time of sampling 68% had water available, 51% had soap/alcohol cleanser at the sink, 28% appeared clean, and 64% drained completely. Twenty-five (64%) of the sink samples grew Enterobacteriaceae on CHROMagar KPC, sixteen (41%) of which were clinically non-susceptible to ertapenem. Seven of the 39 sampled sinks (18%) produced Enterobacteriaceae that were resistant to all three antibiotic classes tested. Several facilities and sink characteristics were associated with CRE. Sinks and drains can serve as undetected reservoirs for carbapenem-resistant Enterobacteriaceae. Control and remediation of such environments will require both systemic strategies and physical improvements to clinical environments.

Dissemination of carbapenem resistant bacteria from hospital wastewater into the environment

Infections with antibiotic resistant pathogens threaten lives and cause substantial costs. For effective interventions, knowledge of the transmission paths of resistant bacteria to humans is essential. In this study, carbapenem resistant bacteria were isolated from the wastewater of a maximum care hospital during a period of two years, starting in the patient rooms and following the sewer system to the effluent of the wastewater treatment plant (WWTP). The bacteria belonged to six different species and 44 different sequence types (STs). The most frequent STs, ST147 K. pneumoniae (bla_NDM/bla_OXA-48) and ST235 P. aeruginosa (bla_VIM) strains, were present at nearly all sampling sites from the hospital to the WWTP effluent. After core genome multi-locus sequence typing (cgMLST), all ST147 K. pneumoniae strains presented a single epidemiological cluster. In contrast, ST235 P. aeruginosa formed five cgMLST clusters and the largest cluster contained the strain from the WWTP effluent, indicating without doubt, a direct dissemination of both high-risk clones into the environment. Thus, there are - at least two - possible transmission pathways to humans, (i) within the hospital by contact with the drains of the sanitary installations and (ii) by recreational or irrigation use of surface waters that have received WWTP effluent. In conclusion, remediation measures must be installed at both ends of the wastewater system, targeting the drains of the hospital as well as at the effluent of the WWTP.

Direct-PCR from rectal swabs and environmental reservoirs: A fast and efficient alternative to detect blaOXA-48 carbapenemase genes in an Enterobacter cloacae outbreak setting

Carbapenemase-producing bacteria are a risk factor in clinical settings worldwide. The aim of the study was to accelerate the time to results during an outbreak situation with bla_OXA-48-positive Enterobacter cloacae by using a real-time multiplex quantitative PCR (qPCR) directly on rectal swab specimens and on wastewater samples to detect carbapenemase-producing bacteria. Thus, we analyzed 681 rectal swabs and 947 environmental samples during a five-month period by qPCR and compared the results to culture screening. The qPCR showed a sensitivity of 100% by testing directly from rectal swabs and was in ten cases more sensitive than the culture-based methods. Environmental screening for bla_OXA-48-carbapenemase genes by qPCR revealed reservoirs of different carbapenemase genes that are potential sources of transmission and might lead to new outbreaks. The rapid identification of patients colonized with those isolates and screening of the hospital environment is essential for earlier patient treatment and eliminating potential sources of nosocomial infections.

Preventing infections caused by carbapenemase-producing bacteria in the intensive care unit - Think about the sink

OBJECTIVE

Outbreaks caused by carbapenemase-producing bacteria (CPB) are challenging to manage in critical care settings and can be protracted due to inadvertent and ubiquitous ecological niches within the built unit environment, such as handwashing sinks. We discuss evidence from a narrative review on transmission pathways and interventions for critical care practitioners.

METHODS

A literature review was undertaken using Pubmed, CINAHL and Embase and included outbreaks of CPB, and equivalent bacteria in critical care units, between 1998 and May 2020. Intervention studies targeting elements of sinks that were employed in response to outbreaks in critical care units were included (n = 30).

FINDINGS

We found control measures included sink removal, use of physical barriers or design modification to protect patients from sinks, engineering controls to mitigate bacterial dispersal and administrative controls. A multi-disciplinary approach involving practitioners from critical care, infection prevention and control, engineering and other staff, should be involved in ongoing measures and in outbreak control activities. Ascertaining the optimal method to end CPB outbreaks in critical care is challenging due to the lack of prospective studies available. However, the literature suggests that sinks can and do serve as reservoirs of CPB near critically ill patients, and should be considered hazardous, especially when sub-optimally designed or used.

Investigation and control of an outbreak due to a contaminated hospital water system, identified following a rare case of Cupriavidus pauculus bacteraemia

BACKGROUND

Cupriavidus pauculus is rare cause of clinical infection. We describe an outbreak of C. pauculus and other Gram-negative bacteraemias in a paediatric haemato-oncology unit secondary to a contaminated water supply and drainage system.

AIM

To describe the investigation and control measures implemented for a waterborne infection outbreak in a new build hospital.

METHODS

Extensive water testing from various points within the water system was undertaken. Taps, showerheads and components including flow straighteners underwent microbiological analysis. Drains were also swabbed. Surveillance for Gram-negative infections was established on the unit.

FINDINGS

Water testing revealed widespread contamination of the water and drainage system. Outlets were also heavily contaminated, including flow straighteners. Drains were found to have underlying structural abnormalities. Water testing enabled us to detect high-risk components within the water system such as the expansion vessels and outlets and the results assisted with hypotheses generation. Review of commissioning data and risk assessments revealed extensive risks present within the water system prior to and after hospital opening.

CONCLUSION

Careful design, adequate control measures and maintenance are essential for hospital water systems in order to prevent infections due to waterborne organisms. We discuss what can be learned from this incident with a view to future prevention.

Faucet aerator design influences aerosol size distribution and microbial contamination level

Faucet aerators have been linked to multiple opportunistic pathogen outbreaks in hospital, especially Pseudomonas aeruginosa, their complex structure promoting biofilm development. The importance of bacteria aerosolization by faucet aerators and their incidence on the risk of infection remain to be established. In this study, ten different types of aerators varying in complexity, flow rates and type of flow were evaluated in a controlled experimental setup to determine the production of aerosols and the level of contamination. The aerosol particle number density and size distribution were assessed using a particle spectrometer. The bacterial load was quantified with a 14-stage cascade impactor, where aerosol particles were captured and separated by size, then analysed by culture and flow cytometry. The water was seeded with Pseudomonas fluorescens as a bacterial indicator. Aerosol particle size and mean mass distribution varied depending on the aerator model. Devices without aeration or with laminar flow produced the lowest number and mass of aerosol particles when measured with spectrometry. Models with aeration displayed wide differences in their potential production of aerosol particles. A new aerator with a low flow, no air inlet in its structure, and a spray stream produced 12 to 395 times fewer aerosol particles containing bacteria. However, the impact of low flow on biofilm development and incorporation of pathogens should be further investigated. Repeated use of aerators resulted in fouling which increased the quantity of bacteria released through aerosol particles. An in-depth mechanical cleaning including complete dismantling of the aerator was required to recover initial performances. Aerators should be selected to minimize aerosol production, considering the ease of maintenance and the main water usage at each sink. Low flow aerators produced a lower number of contaminated aerosol particles when new but may be more susceptible to fouling and quickly lose their initial advantage.

Supplemental nutrients stimulate the amplification of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a sink drain in vitro biofilm reactor model

Liquid wastes (LW) disposed in hospital handwashing sinks may affect colonization of sink P-traps by carbapenemase-producing Klebsiella pneumoniae (CPKP), causing CPKP dispersal into the patient care environment. This study aimed to determine the effect of LW on biofilm formation and CPKP colonization in a P-Trap model (PTM). PTMs containing polymicrobial biofilms grown in autoclaved municipal tap water (ATW) supplemented with 5% dextrose in water (D5W), nutritional shake (Shake), sugar-based soft drink (Soda), or ATW were inoculated with K. pneumoniae ST258 KPC+ (ST258) or K. pneumoniae CAV1016 (CAV1016) and sampled after 7, 14, and 21 d. Biofilm bio-volume, mean thickness, and heterotrophic plate counts were significantly reduced and roughness coefficient significantly increased by Soda compared with D5W, Shake, or ATW. CPKP were significantly reduced by Soda but significantly amplified by D5W (ST258; CAV1016, 7 d) and Shake (ST258) suggesting that reducing LW disposal in sinks may reduce CPKP dispersal into patient care environments.

Carbapenemase-producing Gram-negative bacteria in aquatic environments: a review

Antibiotic resistance is one of the greatest public-health challenges worldwide, especially with regard to Gram-negative bacteria (GNB). Carbapenems are the β-lactam antibiotics of choice with the broadest spectrum of activity and, in many cases, are the last-resort treatment for several bacterial infections. Carbapenemase-encoding genes, mainly carried by mobile genetic elements, are the main mechanism of resistance against carbapenems in GNB. These enzymes exhibit a versatile hydrolytic capacity and confer resistance to most β-lactam antibiotics. After being considered a clinical issue, increasing attention is being giving to the dissemination of such resistance mechanisms in the environment and especially through water. Aquatic environments are among the most significant microbial habitats on our planet, known as a favourable medium for antibiotic gene transfer, and they play a crucial role in the huge spread of drug resistance in the environment and the community. In this review, we present current knowledge regarding the spread of carbapenemase-producing isolates in different aquatic environments, which may help the implementation of control and prevention strategies against the spread of such dangerous resistant agents in the environment.

Bacterial Colonization of Intensive Care Unit Environment and Healthcare Workers in A Tertiary Care Hospital in Kolar Region, India

Direct shedding of microbes by patients and health care workers results in contamination of Intensive care unit environment. Intensive care unit acquired infections due to microbial contamination is a major concern because the patient’s immunity is already compromised. To determine the rate of bacterial contamination on environmental surfaces of Intensive care unit and health care workers and to determine the antibiogram of the isolates. Air samples and swabs from healthcare workers, their accessories, surrounding environmental surfaces were collected randomly over a period of 2 months in Adult Intensive care units. Bacterial isolates were identified by standard microbiological techniques. Antibiotic sensitivity testing was performed by Kirby Bauer disc diffusion method and data analyzed by Statistical Product and Service Solutions 22 version software. A total of 208 samples were randomly collected over 2 months, of which 56 samples yielded positive bacterial growth. Of 56 growth, 12 isolates were detected from air sampling method and 44 isolates from swabs. Among 44 isolates identified from swabs, 10 were isolated from healthcare workers, 4 from health care worker’s accessories and 30 from environmental surfaces. Six different bacterial isolates were identified, Coagulase Negative Staphylococcus (24) and Micrococcus (15) were the major isolates followed by Non fermenters (6), Staphylococcus aureus(4), Bacillus species(4) and diphtheroids (3) The antimicrobial sensitivity pattern of these bacterial isolates were sensitive to commonly used antibacterial agents. Study results showed Intensive care unit staff and environmental surfaces as probable sources of bacterial contamination. Study highlights the importance of cleaning and disinfection process and educate the health care workers about the possible sources of infections within Intensive care unit.

The nurses' role in antimicrobial stewardship: A scoping review

BACKGROUND

The role of nurses in antimicrobial stewardship is understated and not well understood. Nurses can have a significant impact on the development of antimicrobial resistant bacteria in hospitals and the wider community through their management of intravenous antibiotics.

OBJECTIVE

To investigate the nurse's role in antimicrobial stewardship and examine best practice for preparing, administering and disposing of intravenous antibiotics.

METHODS

A systematically conducted scoping review was used. Seven databases were searched for published articles. Retrieved articles were screened for eligibility against pre-set inclusion and exclusion criteria with eligible full-text articles included in the synthesis. Reference lists of eligible articles and social media were reviewed to identify further sources of literature.

RESULTS

Forty-three sources of evidence were included. The extracted data indicate that a part of the nurse's role in antimicrobial stewardship is to monitor judicious antibiotic prescribing practices. Other than literature related to medication errors, there was limited research describing best practice when preparing, administering and disposing of intravenous antibiotics. There was also little evidence of consistent policy, guidelines and education for nurses' practice related to antimicrobial stewardship.

CONCLUSIONS

The evidence for best practice when nurses prepare, administer and dispose of intravenous antibiotics in hospitals is scarce. When nurses use best practice to manage intravenous antibiotics, the risk of antimicrobial resistant bacteria developing is minimised. The role of nurses in antimicrobial stewardship needs to be supported through education and evidence-based guidelines. Tweetable abstract: Nurse work practices may prevent the development and spread of antimicrobial resistant bacteria.

Are Sink Drainage Systems a Reservoir for Hospital-Acquired Gammaproteobacteria Colonization and Infection? A Systematic Review

Increasing rates of antimicrobial-resistant organisms have focused attention on sink drainage systems as reservoirs for hospital-acquired Gammaproteobacteria colonization and infection. We aimed to assess the quality of evidence for transmission from this reservoir. We searched 8 databases and identified 52 studies implicating sink drainage systems in acute care hospitals as a reservoir for Gammaproteobacterial colonization/infection. We used a causality tool to summarize the quality of evidence. Included studies provided evidence of co-occurrence of contaminated sink drainage systems and colonization/infection, temporal sequencing compatible with sink drainage reservoirs, some steps in potential causal pathways, and relatedness between bacteria from sink drainage systems and patients. Some studies provided convincing evidence of reduced risk of organism acquisition following interventions. No single study provided convincing evidence across all causality domains, and the attributable fraction of infections related to sink drainage systems remains unknown. These results may help to guide conduct and reporting in future studies.

Bacteriophage Infections of Biofilms of Health Care-Associated Pathogens: Klebsiella pneumoniae

Members of the family Enterobacteriaceae, such as Klebsiella pneumoniae, are considered both serious and urgent public health threats. Biofilms formed by these health care-associated pathogens can lead to negative and costly health outcomes. The global spread of antibiotic resistance, coupled with increased tolerance to antimicrobial treatments in biofilm-associated bacteria, highlights the need for novel strategies to overcome treatment hurdles. Bacteriophages (phages), or viruses that infect bacteria, have reemerged as one such potential strategy. Virulent phages are capable of infecting and killing their bacterial hosts, in some cases producing depolymerases that are able to hydrolyze biofilms. Phage therapy does have its limitations, however, including potential narrow host ranges, development of bacterial resistance to infection, and the potential spread of phage-encoded virulence genes. That being said, advances in phage isolation, screening, and genome sequencing tools provide an upside in overcoming some of these limitations and open up the possibilities of using phages as effective biofilm control agents.

Carbapenemase-producing Enterobacterales in hospital drains in Southern Ontario, Canada

BACKGROUND

Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE).

AIM

To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination.

METHODS

Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling.

FINDINGS

Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related bla_KPC-containing IncN3-type plasmids (different species), related bla_KPC-3-containing IncN-type plasmids (different species), and related bla_OXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0).

CONCLUSION

Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.

Development of a tool to assess evidence for causality in studies implicating sink drains as a reservoir for hospital-acquired gammaproteobacterial infection

BACKGROUND

Decades of studies document an association between Gammaproteobacteria in sink drains and hospital-acquired infections, but the evidence for causality is unclear.

AIM

We aimed to develop a tool to assess the quality of evidence for causality in research studies that implicate sink drains as reservoirs for hospital-acquired Gammaproteobacterial infections.

METHODS

We used a modified Delphi process with recruited experts in hospital epidemiology to develop this tool from a pre-existing causal assessment application.

FINDINGS

Through four rounds of feedback and revision we developed the 'Modified CADDIS Tool for Causality Assessment of Sink Drains as a Reservoir for Hospital-Acquired Gammaproteobacterial Infection or Colonization'. In tests of tool application to published literature during development, mean percent agreement ranged from 46.7% to 87.5%, and the Gwet's AC1 statistic (adjusting for chance agreement) ranged from 0.13 to 1.0 (median 68.1). Areas of disagreement were felt to result from lack of a priori knowledge of causal pathways from sink drains to patients and uncertain influence of co-interventions to prevent organism acquisition. Modifications were made until consensus was achieved that further iterations would not improve the tool. When the tool was applied to 44 articles by two independent reviewers in an ongoing systematic review, percent agreement ranged from 93% to 98%, and the Gwet's AC1 statistic was 0.91-0.97.

CONCLUSION

The modified causality tool was useful for evaluating studies that implicate sink drains as reservoirs for hospital-acquired infections and may help guide the conduct and reporting of future research.

IncN3 and IncHI2 plasmids with an In1763 integron carrying bla IMP-1 in carbapenem-resistant Enterobacterales clinical isolates from the UK

Introduction. Imipenemase (IMP) carbapenemase genes are relatively rare among Enterobacterales in the UK. Emergence in multiple hospitals, in different strains and species, prompted an investigation into their genetic context.Aim. Our goal was to identify and describe the elements carrying bla _IMP genes in a variety of Enterobacterales from five hospitals in the UK.Methodology. Long-read nanopore sequencing was carried out on 18 IMP-positive isolates belonging to 6 species. The locations of the bla _IMP genes and other associated genetic elements were identified.Results. Ten out of 18 isolates carried bla _IMP-1 on an IncN3 plasmid (52-57 kb) in an In1763 class 1 integron. These plasmids also contained genes encoding type IV secretion and conjugal transfer proteins. Five out of 18 isolates carried bla _IMP-1 in the same In1763 integron in much larger IncHI2 plasmids. A further isolate carried the In1763 integron in a chromosomally located plasmid fragment. Two isolates carried bla _IMP-4 in IncHI2 plasmids. The isolates included three representatives of sequence type 20 of Klebsiella pneumoniae, with one carrying a distinct plasmid from the other two.Conclusion. Highly similar IncN3 plasmids were found in a range of Enterobacterales, mostly K. pneumoniae and the Enterobacter cloacae complex, from three of four London hospitals, with the same In1763 integron carrying bla _IMP-1 also being found in IncHI2 plasmids and chromosomally. These plasmids carried multiple elements facilitating self-transmission. Strain typing alone was not sufficient to investigate cross-infection among this set of isolates, many of which appeared to be unrelated until plasmid analysis was undertaken, and vice versa.

Genomic dynamics of species and mobile genetic elements in a prolonged blaIMP-4-associated carbapenemase outbreak in an Australian hospital

BACKGROUND

Hospital outbreaks of carbapenemase-producing organisms, such as blaIMP-4-containing organisms, are an increasing threat to patient safety.

OBJECTIVES

To investigate the genomic dynamics of a 10 year (2006-15) outbreak of blaIMP-4-containing organisms in a burns unit in a hospital in Sydney, Australia.

METHODS

All carbapenem-non-susceptible or MDR clinical isolates (2006-15) and a random selection of equivalent or ESBL-producing environmental isolates (2012-15) were sequenced [short-read (Illumina), long-read (Oxford Nanopore Technology)]. Sequence data were used to assess genetic relatedness of isolates (Mash; mapping and recombination-adjusted phylogenies), perform in silico typing (MLST, resistance genes and plasmid replicons) and reconstruct a subset of blaIMP plasmids for comparative plasmid genomics.

RESULTS

A total of 46/58 clinical and 67/96 environmental isolates contained blaIMP-4. All blaIMP-4-positive organisms contained five or more other resistance genes. Enterobacter cloacae was the predominant organism, with 12 other species mainly found in either the environment or patients, some persisting despite several cleaning methods. On phylogenetic analysis there were three genetic clusters of E. cloacae containing both clinical and environmental isolates, and an additional four clusters restricted to either reservoir. blaIMP-4 was mostly found as part of a cassette array (blaIMP-4-qacG2-aacA4-catB3) in a class 1 integron within a previously described IncM2 plasmid (pEl1573), with almost complete conservation of this cassette across the species over the 10 years. Several other plasmids were also implicated, including an IncF plasmid backbone not previously widely described in association with blaIMP-4.

CONCLUSIONS

Genetic backgrounds disseminating blaIMP-4 can persist, diversify and evolve amongst both human and environmental reservoirs during a prolonged outbreak despite intensive prevention efforts.

Isolation of an antimicrobial-resistant, biofilm-forming, Klebsiella grimontii isolate from a reusable water bottle

A reusable water bottle was swabbed as part of the citizen science project "Swab and Send," and a Klebsiella grimontii isolate was recovered on chromogenic agar and designated SS141. Whole-genome sequencing of SS141 showed it has the potential to be a human pathogen as it contains the biosynthetic gene cluster for the potent cytotoxin, kleboxymycin, and genes for other virulence factors. The genome also contains the antibiotic-resistant genes, bla_OXY-6-4 , and a variant of fosA, which is likely to explain the observed resistance to ampicillin, amoxicillin, and fosfomycin. We have also shown that SS141 forms biofilms on both polystyrene and polypropylene surfaces, providing a reasonable explanation for its ability to colonize a reusable water bottle. With the increasing use of reusable water bottles as an alternative to disposables and a strong forecast for growth in this industry over the next decade, this study highlights the need for cleanliness comparable to other reusable culinary items.

Bacteriophage treatment of carbapenemase-producing Klebsiella pneumoniae in a multispecies biofilm: a potential biocontrol strategy for healthcare facilities

The p-traps of hospital handwashing sinks represent a potential reservoir for antimicrobial-resistant organisms of major public health concern, such as carbapenemase-producing KPC+ Klebsiella pneumoniae (CPKP). Bacteriophages have reemerged as potential biocontrol agents, particularly against biofilm-associated, drug-resistant microorganisms. The primary objective of our study was to formulate a phage cocktail capable of targeting a CPKP strain (CAV1016) at different stages of colonization within polymicrobial drinking water biofilms using a CDC biofilm reactor (CBR) p-trap model. A cocktail of four CAV1016 phages, all exhibiting depolymerase activity, were isolated from untreated wastewater using standard methods. Biofilms containing Pseudomonas aeruginosa, Micrococcus luteus, Stenotrophomonas maltophilia, Elizabethkingia anophelis, Cupriavidus metallidurans, and Methylobacterium fujisawaense were established in the CBR p-trap model for a period of 28 d. Subsequently, CAV1016 was inoculated into the p-trap model and monitored over a period of 21 d. Biofilms were treated for 2 h at either 25 °C or 37 °C with the phage cocktail (109 PFU/ml) at 7, 14, and 21 d post-inoculation. The effect of phage treatment on the viability of biofilm-associated CAV1016 was determined by plate count on m-Endo LES agar. Biofilm heterotrophic plate counts (HPC) were determined using R2A agar. Phage titers were determined by plaque assay. Phage treatment reduced biofilm-associated CAV1016 viability by 1 log10 CFU/cm2 (p < 0.05) at 7 and 14 d (37 °C) and 1.4 log10 and 1.6 log10 CFU/cm2 (p < 0.05) at 7 and 14 d, respectively (25 °C). No significant reduction was observed at 21 d post-inoculation. Phage treatment had no significant effect on the biofilm HPCs (p > 0.05) at any time point or temperature. Supplementation with a non-ionic surfactant appears to enhance phage association within biofilms. The results of this study suggest the potential of phages to control CPKP and other carbapenemase-producing organisms associated with microbial biofilms in the healthcare environment.

Specific antibacterial activity of copper alloy touch surfaces in five long-term care facilities for older adults

BACKGROUND

Pathogens involved in healthcare-associated infections can quickly spread in the environment, particularly to frequently touched surfaces, which can be reservoirs for pathogens.

AIM

The purpose of this study was to investigate naturally occurring bacterial contamination on touch surfaces in five French long-term care facilities and to compare bacterial populations recovered from copper and control surfaces.

METHODS

More than 1300 surfaces were sampled. The collected bacteria were identified to obtain a global view of the cultivable bacterial populations colonizing touch surfaces. Haemolytic colonies and putative pathogens were also screened using specific agar plates and then identified with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. In total, more than 3400 colonies were analysed.

FINDINGS

Staphylococcus and Micrococcus were the two predominant genera present on touch surfaces, respectively occurring on 51.8% and 48.0% of control surfaces. In these facilities with relatively low bioburden, copper surfaces efficiently reduced the occurrence frequencies of three genera: Staphylococcus, Streptococcus and Roseomonas. Pathogenic species such as Staphylococcus aureus, Enterococcus faecalis and E. faecium were observed in very few samples. In addition, meticillin-resistant S. aureus was observed on five control surfaces and one copper surface.

CONCLUSION

Contamination of healthcare facilities touch surfaces can be the source for the spread of bacteria through the institution. This in situ study shows that the frequency of the contamination as well as the specific bacterial population bioburden is reduced on copper alloy surfaces.

Genomics for Molecular Epidemiology and Detecting Transmission of Carbapenemase-Producing Enterobacterales in Victoria, Australia, 2012 to 2016

Carbapenemase-producing Enterobacterales (CPE) are being increasingly reported in Australia, and integrated clinical and genomic surveillance is critical to effectively manage this threat. We sought to systematically characterize CPE in Victoria, Australia, from 2012 to 2016.

Carbapenemase-producing Enterobacterales (CPE) are being increasingly reported in Australia, and integrated clinical and genomic surveillance is critical to effectively manage this threat. We sought to systematically characterize CPE in Victoria, Australia, from 2012 to 2016. Suspected CPE were referred to the state public health laboratory in Victoria, Australia, from 2012 to 2016 and examined using phenotypic, multiplex PCR and whole-genome sequencing (WGS) methods and compared with epidemiological metadata. Carbapenemase genes were detected in 361 isolates from 291 patients (30.8% of suspected CPE isolates), mostly from urine (42.1%) or screening samples (34.8%). IMP-4 (28.0% of patients), KPC-2 (25.3%), NDM (24.1%), and OXA carbapenemases (22.0%) were most common. Klebsiella pneumoniae (48.8% of patients) and Escherichia coli (26.1%) were the dominant species. Carbapenemase-inactivation method (CIM) testing reliably detected carbapenemase-positive isolates (100% sensitivity, 96.9% specificity), identifying an additional five CPE among 159 PCR-negative isolates (IMI and SME carbapenemases). When epidemiologic investigations were performed, all pairs of patients designated “highly likely” or “possible” local transmission had ≤23 pairwise single-nucleotide polymorphisms (SNPs) by genomic transmission analysis; conversely, all patient pairs designated “highly unlikely” local transmission had ≥26 pairwise SNPs. Using this proposed threshold, possible local transmission was identified involving a further 16 patients for whom epidemiologic data were unavailable. Systematic application of genomics has uncovered the emergence of polyclonal CPE as a significant threat in Australia, providing important insights to inform local public health guidelines and interventions. Using our workflow, pairwise SNP distances between CPE isolates of ≤23 SNPs suggest local transmission.

Carbapenem sparing in the management of post-transrectal prostate biopsy bacteraemia

BACKGROUND

Sepsis following transrectal ultrasound (TRUS)-guided prostate biopsy is a major complication. With the emergence of multidrug-resistant organisms, empirical use of carbapenem antibiotics has been increasing. This study, conducted in the Illawarra Shoalhaven Local Health District (ISLHD), Australia, quantifies how much we can spare carbapenem use.

METHODS

A retrospective audit of patients who underwent TRUS prostate biopsy and were admitted post-operatively with proven bacteraemia between January 2007 and April 2016.

RESULTS

Of 2719 TRUS procedures, 50 (1.84%) cases had bacteraemia. The most common isolate was Escherichia coli in 44 of 50 (88%) of which six of 50 (12%) were extended-spectrum beta-lactamase (ESBL)-producing. Sixteen different empirical antimicrobial regimens were used, to which 42 of 50 (84%) of isolates were susceptible. Eight (16%) isolates were resistant to the chosen empiric combination, with five switched over to appropriate treatment once antimicrobial sensitivity results became available. Empirical carbapenem was utilized in 12 of 50 (24%) patients with only two of the ESBL isolates covered. A further 10 of 50 patients received carbapenems during their admission. Carbapenems could have been avoided in 18 of 22 (82%). A total of 86% of organisms (n = 43) were susceptible to the combination of amoxicillin-clavulanate and gentamicin.

CONCLUSION

Although the rates of bacteraemia with ESBL-producing organisms post-TRUS biopsy are increasing, use of carbapenem-free combination antimicrobials as empirical therapy appears to be safe and effective in our setting. Clinicians can utilize local resistance patterns to inform targeted and appropriate therapy for septic patients.

Mitigation of microbial contamination from waste water and aerosolization by sink design

BACKGROUND

Healthcare-associated infections (HAIs) are a significant cause of increased medical costs, morbidity, mortality, and have been partly associated with sinks, their waste water outlets and associated pipework.

AIM

To determine whether an engineered sink could limit microbial aerosol contaminants in the air and sink basin.

METHODS

Multiple comparisons were undertaken between an experimental sink, designed to limit aerosolization and p-trap contamination to a control hospital sink, both connected to a common drain system. The experimental sink was equipped with ultraviolet light (UV), an aerosol containment hood, ozonated water generator and a flush system to limit bacterial growth/aerosolization and limit microbial growth in the p-trap. Nutrient material was added daily to simulate typical material discarded into a hospital sink. Surface collection swabs, settle plates and p-trap contamination levels were assessed for bacteria and fungi.

FINDINGS

The experimental sink had significantly decreased levels of bacterial and fungal p-trap contamination (99.9% for Tryptic Soy (TSA) and Sabouraud agar (SAB) plates) relative to the initial levels. Aerosol-induced contaminant from the p-traps was significantly lower for the experimental vs the control sink for TSA (76%) and SAB (86%) agar settle plates.

CONCLUSIONS

Limiting microbial contamination is critical for the control of nosocomial infections of in-room sinks, which provide a major source of contamination. Our experimental sink studies document that regular ozonated water rinsing of the sink surface, decontamination of p-trap water, and UV decontamination of surfaces limits microbial aerosolization and surface contamination, with potential to decrease patient exposure and reduce hospital acquired infections.