Control of an outbreak of Acinetobacter baumannii infections using vaporized hydrogen peroxide

Hygiene requirements for cleaning and disinfection of surfaces: recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

This recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) addresses not only hospitals, but also outpatient health care facilities and compiles current evidence. The following criteria are the basis for the indications for cleaning and disinfection: Infectious bioburden and tenacity of potential pathogens on surfaces and their transmission routes, influence of disinfecting surface cleaning on the rate of nosocomial infections, interruption of cross infections due to multidrug-resistant organisms, and outbreak control by disinfecting cleaning within bundles. The criteria for the selection of disinfectants are determined by the requirements for effectiveness, the efficacy spectrum, the compatibility for humans and the environment, as well as the risk potential for the development of tolerance and resistance. Detailed instructions on the organization and implementation of cleaning and disinfection measures, including structural and equipment requirements, serve as the basis for their implementation. Since the agents for surface disinfection and disinfecting surface cleaning have been classified as biocides in Europe since 2013, the regulatory consequences are explained. As possible addition to surface disinfection, probiotic cleaning, is pointed out. In an informative appendix (only in German), the pathogen characteristics for their acquisition of surfaces, such as tenacity, infectious dose and biofilm formation, and the toxicological and ecotoxicological characteristics of microbicidal agents as the basis for their selection are explained, and methods for the evaluation of the resulting quality of cleaning or disinfecting surface cleaning are presented.

Inactivation of human coronaviruses using an automated room disinfection device

The emergence of more virulent and epidemic strains of viruses, especially in the context of COVID-19, makes it more important than ever to improve methods of decontamination. The objective of this study was to evaluate the potential of on-demand production of chlorine species to inactivate human coronaviruses. The commercial prototype disinfection unit was provided by Unipolar Water Technologies. The Unipolar device generates active chlorine species using an electrochemical reaction and dispenses the disinfectant vapour onto surfaces with an aspirator. The minimum effective concentration and exposure time of disinfectant were evaluated on human hepatoma (Huh7) cells using 50% tissue culture infectious dose (TCID50) assay and human coronavirus 229E (HCoV-229E), a surrogate for pathogenic human coronaviruses. We showed that chlorine species generated in the Unipolar device inactivate HCoV-229E on glass surfaces at ≥ 400 parts per million active chlorine concentration with a 5 min exposure time. Here, inactivation refers to the inability of the virus to infect the Huh7 cells. Importantly, no toxic effect was observed on Huh7 cells for any of the active chlorine concentrations and contact times tested.

Human serum albumin (HSA) regulates the expression of histone-like nucleoid structure protein (H-NS) in Acinetobacter baumannii

According to the Centers for Disease Control and Prevention, Acinetobacter baumannii is listed among the most threatening pathogens. A. baumannii is mainly a nosocomial pathogen with a distinctive ability to survive in multiple environments. These characteristics together with this bacterium's ability to acquire antibiotic resistance determinants make it a notorious pathogen. The presence of human serum albumin (HSA) is associated with modification of expression levels in numerous genes. The presence of HSA in the culture medium is also correlated with a reduction in levels of the global suppressor histone-like nucleoid structure protein, H-NS. Comparative transcriptome analysis of the wild type and isogenic Δhns strains cultured in lysogeny broth (LB) in the presence or absence of HSA revealed that the expression of a subset of eleven genes are modified in the Δhns cultured in LB and the wild-type strain in the presence of HSA, pointing out these genes as candidates to be regulated by the presence of HSA through H-NS. Six and five of these genes were up- or down-regulated, respectively. Three of these genes have functions in quorum sensing (acdA, kar and fadD), one in quorum quenching (aidA), two in stress response (katE, ywrO), three in metabolism (phaC, yedL1, and yedL2), one in biofilm formation (csuAB), and one in β-oxidation of fatty acids (fadA). The regulation of these genes was assessed by: (i) transcriptional analysis and qPCR at the transcriptional level; and (ii) by determining the phenotypic characteristics of each function. The results of these studies support the hypothesis that HSA-mediated reduction of H-NS levels may be one very important regulatory circuit utilized by A. baumannii to adapt to selected environments, such as those where HSA-containing human fluids are abundant.

Biocide resistance in Acinetobacter baumannii: appraising the mechanisms

A global upsurge in antibiotic-resistant Acinetobacter baumannii requires supervised selection of biocides and disinfectants to avert nosocomial infections by reducing its spread. Moreover, inadequate and improper biocides have been reported as a contributing factor in antimicrobial resistance. Regardless of the manner of administration, a biocidal concentration that does not kill the target bacteria creates a stress response, propagating the resistance mechanisms. This is an essential aspect of the disinfection programme and the overall bio-contamination management plan. Knowing the mechanisms of action of biocides and resistance modalities may open new avenues to discover novel agents. This review describes the mechanisms of action of some biocides, resistance mechanisms, and approaches to study susceptibility/resistance to these agents.

Biocide-tolerance and antibiotic-resistance in community environments and risk of direct transfers to humans: Unintended consequences of community-wide surface disinfecting during COVID-19?

During the current pandemic, chemical disinfectants are ubiquitously and routinely used in community environments, especially on common touch surfaces in public settings, as a means of controlling the virus spread. An underappreciated risk in current regulatory guidelines and scholarly discussions, however, is that the persisting input of chemical disinfectants can exacerbate the growth of biocide-tolerant and antibiotic-resistant bacteria on those surfaces and allow their direct transfers to humans. For COVID-19, the most commonly used disinfecting agents are quaternary ammonium compounds, hydrogen peroxide, sodium hypochlorite, and ethanol, which account for two-thirds of the active ingredients in current EPA-approved disinfectant products for the novel coronavirus. Tolerance to each of these compounds, which can be either intrinsic or acquired, has been observed on various bacterial pathogens. Of those, mutations and horizontal gene transfer, upregulation of efflux pumps, membrane alteration, and biofilm formation are the common mechanisms conferring biocide tolerance in bacteria. Further, the linkage between disinfectant use and antibiotic resistance was suggested in laboratory and real-life settings. Evidence showed that substantial bacterial transfers to hands could effectuate from short contacts with surrounding surfaces and further from fingers to lips. While current literature on disinfectant-induced antimicrobial resistance predominantly focuses on municipal wastes and the natural environments, in reality the community and public settings are most severely impacted by intensive and regular chemical disinfecting during COVID-19 and, due to their proximity to humans, biocide-tolerant and antibiotic-resistant bacteria emerged in these environments may pose risks of direct transfers to humans, particularly in densely populated urban communities. Here we highlight these risk factors by reviewing the most pertinent and up-to-date evidence, and provide several feasible strategies to mitigate these risks in the scenario of a prolonging pandemic.

Systematic review on use, cost and clinical efficacy of automated decontamination devices

BACKGROUND

More evidence is emerging on the role of surface decontamination for reducing hospital-acquired infection (HAI). Timely and adequate removal of environmental pathogens leads to measurable clinical benefit in both routine and outbreak situations.

OBJECTIVES

This systematic review aimed to evaluate published studies describing the effect of automated technologies delivering hydrogen peroxide (H202) or ultra-violet (UV) light on HAI rates.

METHODS

A systematic review was performed using relevant search terms. Databases were scanned from January 2005 to March 2020 for studies reporting clinical outcome after use of automated devices on healthcare surfaces. Information collected included device type, overall findings; hospital and ward data; study location, length and size; antimicrobial consumption; domestic monitoring; and infection control interventions. Study sponsorship and duplicate publications were also noted.

RESULTS

While there are clear benefits from non-touch devices in vitro, we found insufficient objective assessment of patient outcome due to the before-and-after nature of 36 of 43 (84%) studies. Of 43 studies, 20 (47%) used hydrogen peroxide (14 for outbreaks) and 23 (53%) used UV technology (none for outbreaks). The most popular pathogen targeted, either alone or in combination with others, was Clostridium difficile (27 of 43 studies: 63%), followed by methicillin-resistant Staphylococcus aureus (MRSA) (16 of 43: 37%). Many owed funding and/or personnel to industry sponsorship (28 of 43: 65%) and most were confounded by concurrent infection control, antimicrobial stewardship and/or cleaning audit initiatives. Few contained data on device costs and rarely on comparable costs (1 of 43: 2%). There were expected relationships between the country hosting the study and location of device companies. None mentioned the potential for environmental damage, including effects on microbial survivors.

CONCLUSION

There were mixed results for patient benefit from this review of automated devices using H202 or UV for surface decontamination. Most non-outbreak studies lacked an appropriate control group and were potentially compromised by industry sponsorship. Concern over HAI encourages delivery of powerful disinfectants for eliminating pathogens without appreciating toxicity or cost benefit. Routine use of these devices requires justification from standardized and controlled studies to understand how best to manage contaminated healthcare environments.

Investigation of Acinetobacter baumannii Activity in Vascular Surgery Units through Epidemiological Management Based on the Analysis of Antimicrobial Resistance, Biofilm Formation and Genotyping

Background/Objectives: The genus Acinetobacter demonstrates resistance to antibiotics and has been shown to spread in the hospital environment causing epidemic outbreaks among hospitalized patients. The objectives of the present study was to investigate the antibiotic resistance, biofilm formation, and clonality among Acinetobacter baumannii strains. Materials and Methods: The study involved 6 (I Outbreak) and 3 (II Outbreak) A. baumannii strains isolated from patients hospitalized in vascular surgery unit. Results: All tested A. baumannii strains were extensively drug resistant (XDR) and all the isolates were carbapenem-resistant and among them, all carried the bla_OXA-51 gene, the bla_OXA-24 gene, as well as the bla_OXA-23 gene. All of the investigated strains had the ability to form a biofilm, but all of them produced less biofilm than the reference strain. Multi-locus sequence typing (MLST) showed that all strains belonged to the ST2 clone. Pulsed-field gel electrophoresis (PFGE) divided the tested outbreak strains into two clones (A and B). Conclusion: This study shows a nosocomial spread of XDR A. baumannii ST2 having the bla_OXA-51 gene, the bla_OXA-24 gene, as well as the bla_OXA-23 gene, low biofilm formers, that was prevalent in the vascular surgery unit. To identify the current situation of vascular surgery departments targeted epidemiological investigation was needed. Effective implementation of infection control prevented the spread of the epidemic outbreaks.

Decontamination of microbiologically contaminated abiotic porous surfaces in an oral surgery clinic using vaporised hydrogen peroxide (VHP)

PURPOSE

The aims of the study were to identify microorganisms, including those in the VBNC state, inhabiting porous surfaces in oral surgery offices and to assess the biocidal effectiveness and impact of 300 ppm vaporised hydrogen peroxide (VHP) for 20 min on decontaminated materials.

METHODS

From the surfaces of textured armrests of dental chairs, pinewood doors and window frames and cotton medical aprons, 30 swabs were taken with moistened sponges. The identification of isolated microorganisms was performed using molecular methods with MALDI-TOF MS, DNA Sanger sequencer and Illumina MiSeq. To evaluate the impact of VHP decontamination (independent variable) on the number of microorganisms (response variable) ANOVA and LSD tests were used. After application of 10 processes of VHP decontamination, changes in the properties of the materials were assessed using FTIR spectroscopy, SEM microscopy and XPS spectrometry.

RESULTS

The concentration of microorganisms was 10¹-10⁴ CFU/100 cm² on the tested surfaces and 10² CFU/m³ in the air. Twenty species of bacteria, one yeast and 16 filamentous fungi were identified, with the predominance of Bacillus, Staphylococcus, Alternaria, Aspergillus and Penicillium. Moreover, Janthinobacterium, Acremonium, Aureobasidium, Coprinellus and Cosmospora in the VBNC state were metagenomically detected. VHP decontamination resulted in a reduction in the majority of tested microbial strains by a minimum of 3 log, and all tested mixed cultures inhabiting porous surfaces were above 98% and in the air, 100%. VHP decontamination did not affect the structural and morphological properties of cotton fibres, wood or stainless steel.

CONCLUSIONS

VHP decontamination at a concentration of 300 ppm for 20 min can be used for the holistic disinfection of air, surfaces and equipment in oral surgery offices.

Examination of Material Compatibilities with Ionized and Vaporized Hydrogen Peroxide Decontamination

Hydrogen peroxide (HP) decontamination is effective for a wide spectrum of pathogenic microorganisms. However, exposure to HP causes deleterious effects on some materials. The purpose of this study was to examine material compatibilities with ionized and vaporized hydrogen peroxide (iHP and VHP). With regard to iHP, 24 kinds of materials were exposed up to 100 cycles to iHP. The tested materials included plastics, metals, woods and plated or coated goods. The procedure of iHP decontamination was as following: gas time (11 min), dwell time (15 min) and aeration time (120 min). iHP decontamination caused some damage to copper, brass, chromium plate and galvanized iron immediately after exposure. Repeated iHP decontamination caused marked damage in stainless steel and urethane-, silicone- or epoxy-coating materials. Condensation of iHP decontamination posed severe damage for the material surfaces. With regard to VHP, 36 kinds of materials were exposed for up to 200 cycles to VHP decontamination. Under dry (dehumidified) conditions, VHP decontamination caused few changes on the surfaces of resin materials in dry conditions, although some resins began to develop hardening or softening. Discoloration was found in the stainless steel and changes in its coating materials. Bleaching was also observed in wooden materials. Under condensation conditions of VHP, nylon softened and butyl rubber hardened. Condensation of VHP caused material damage such as discoloration in the stainless steel, corrosion of zinc-plated steel, and air-bubbling under the color-steel sheet. The high concentrations of HP with condensation caused severe changes in metals and resins after repeated exposure. The VHP decontamination tests provided evidence that the material damage was more severe under condensation conditions than under dry conditions. Our results demonstrate the importance of condensation of HP when using it to decontaminate equipment.

Trends and Development in the Antibiotic-Resistance of Acinetobacter baumannii: A Scientometric Research Study (1991-2019)

Objective

Data visualization software were used to display and analyze the research status, hotspot and development trend of the antibiotic-resistance of Acinetobacter baumannii objectively and comprehensively, so as to provide guidance and reference for the research of the antibiotic-resistant Acinetobacter baumannii.

Materials and Methods

The data of relevant publications on antibiotic-resistant Acinetobacter baumanii from 1991 to 2019 were retrieved from Web of Science (WOS) Core database. VOSviewer and CiteSpace software were used to conduct co-citation visualization network rendering and cluster analysis on the publications’ years, authors, countries, institutions, keywords and citations.

Results

A total of 3915 valid records on the study of antibiotic-resistant Acinetobacter baumanii were retrieved. The number of relevant publications was increasing year after year. The United States is the most influential country in the field, which works closely with other countries and publishes most of the papers. University of Sydney is the leading institution in this area. Bonomo Robert A publishes most of the papers. There are the highest number of publications in the research areas of antimicrobial agents and chemotherapy. “Nucleotide sequence” and “outbreak” were once the hotspots in this field, but recently “bacteriophage”, “biofilm” and “colistin resistance” have become the research hotspots.

Conclusion

Since 1991, the number of publications on antibiotic-resistant Acinetobacter baumannii has grown rapidly, and various countries and institutions have paid close attention to the problem of antibiotic resistance. Countries, institutions and researchers, which have strong influential power, collaborate with each other closely. The future research direction of antibiotic-resistant Acinetobacter baumannii should lie in the further breakthrough of antibacterial peptides, bacteriophage therapy, CRISPR system and various combined therapies.

Role of Hydrogen Peroxide Vapor (HPV) for the Disinfection of Hospital Surfaces Contaminated by Multiresistant Bacteria

The emergence of multiresistant bacterial strains as agents of healthcare-related infection in hospitals has prompted a review of the control techniques, with an added emphasis on preventive measures, namely good clinical practices, antimicrobial stewardship, and appropriate environmental cleaning. The latter item is about the choice of an appropriate disinfectant as a critical role due to the difficulties often encountered in obtaining a complete eradication of environmental contaminations and reservoirs of pathogens. The present review is focused on the effectiveness of hydrogen peroxide vapor, among the new environmental disinfectants that have been adopted. The method is based on a critical review of the available literature on this topic.

Sustained fall in inpatient MRSA prevalence after a video-reflexive ethnography project; an observational study

BACKGROUND

Maintaining optimal infection prevention and control (IPC) in a busy, clinical environment is challenging. Video-reflexive ethnography (VRE) is a collaborative, interventionist approach to practice improvement. We hypothesised that giving clinicians opportunities to view and reflect on video footage of everyday ward activities would raise awareness of, and suggest strategies to reduce, pathogen transmission risks. We undertook a VRE project, between March and September 2013, in two tertiary hospital surgical wards, with persistently high methicillin resistant Staphylococcus aureus (MRSA) endemicity, despite previous IPC interventions.

METHODS

This study was a retrospective/prospective observational study, using interrupted time-series analyses, to assess the effects of the VRE project on hand hygiene compliance, inpatient MRSA infections (newly infected patients, per 1000 occupied bed days) and inpatient MRSA colonisation prevalence, measured by serial point prevalence surveys. Follow-up continued until June 2016.

RESULTS

The VRE project was associated with changes in IPC behaviour and outcomes. Hand hygiene compliance increased (from 62% to 75%; p < 0.0001) and MRSA colonisation prevalence decreased significantly, in both wards (baseline 42%; average post-VRE 12%; p=<0.0001), MRSA infection rate decreased in one ward. Interpretation of results was complicated by a potential confounding effect of unplanned environmental hydrogen peroxide decontamination (HPD). Improved hand hygiene compliance was a predicted outcome of VRE, but also a potential contributor to reduced MRSA transmission.

CONCLUSION

Separate contributions of VRE (the intervention), HPD and hand hygiene compliance were uncertain, but their combined effect was significantly reduced MRSA endemicity, which previously had been resistant to attempted IPC interventions.

An overview of automated room disinfection systems: When to use them and how to choose them

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution, and contact time of the agent. Automated room disinfection (ARD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapor (H₂O₂ vapor), aerosolized hydrogen peroxide (aHP), and ultraviolet (UV) light. These systems have important differences in their active agent, delivery mechanism, efficacy, process time, and ease of use. The choice of ARD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation, and cost considerations.

Assessment of surface cleaning and disinfection in neonatal intensive care unit

Background

Surveillance for healthcare-associated infections (HAI) is a priority in the neonatal intensive care unit (NICU), given the critical immune status of patients. The aim of this study was to assess surface bacterial contamination before and after improving cleaning and disinfection practices.

Materials and methods

This was a cross-sectional study conducted in March 2018. Surface samples were taken from the same areas in three steps: after cleaning, after "improved" cleaning, and after terminal disinfection using hydrogen peroxide vapor (VHP). Sampling and culture was carried out according to standard ISO14698-1: 2004. Results interpretation was based on the thresholds defined by good hospital pharmacy practice. Statistical analysis was performed by SPSS 21.0 and a P-value < 0.05 was considered to be significant.

Results

In total, 290 samples were taken from different zones: fixed equipment (69%), aseptic washbasins (12%), pneumatic system (9%), computer equipment (6%) and mobile equipment (4%). Prevalence of non-compliances after cleaning and disinfection was 75%, 10% after “improved” cleaning, and 0% after automated VHP (P < 0.0001). Median of CFU was 24[EI (0–625)] after standard cleaning, 2[EI (0–35)] after “improved” cleaning and 0 [EI (0–3)] after VHP (P < 0.0001). Isolated germs werecoagulase-negative Staphylococcus (31.2%), Acinetobacter baumannii (26%), Staphylococcus aureus (19.5%), Pseudomonas aeruginosa (9%), Klebsiella pneumoniae (9%), E. coli (4%) and Enterobacter sp (1.3%).

Conclusion

Improved cleaning and disinfection practices associated to VHP give microbiological satisfactory results. It is important to educate cleaning staff for effective surface cleaning and disinfection operations to control HAI.

Fighting AMR in the Healthcare Environment: Microbiome-Based Sanitation Approaches and Monitoring Tools

Healthcare-associated infections (HAIs) affect up to 15% of all hospitalized patients, representing a global concern. Major causes include the persistent microbial contamination of hospital environment, and the growing antimicrobial-resistance (AMR) of HAI-associated microbes. The hospital environment represents in fact a reservoir of potential pathogens, continuously spread by healthcare personnel, visiting persons and hospitalized patients. The control of contamination has been so far addressed by the use of chemical-based sanitation procedures, which however have limitations, as testified by the persistence of contamination itself and by the growing AMR of hospital microbes. Here we review the results collected by a microbial-based sanitation system, inspired by the microbiome balance principles, in obtaining more effective control of microbial contamination and AMR. Whatever the sanitation system used, an important aspect of controlling AMR and HAIs relates to the ability to check any variation of a microbial population rapidly and effectively, thus effective monitoring procedures are also described.

Antimicrobial effect of copper alloys on Acinetobacter species isolated from infections and hospital environment

Background

An increased proportion of Gram-negative bacteria have recently been reported among etiologic agents of infection. In Poland, Acinetobacter baumannii is a big problem for hospitals, especially intensive care units. Touch surfaces made from materials with antimicrobial properties, especially copper alloys, are recommended as a supplementary method of increasing biological safety in the hospital environment.

Aim of the study

The objective of this study is to determine the susceptibility to selected copper alloys of three clinical Acinetobacter baumannii strains, one Acinetobacter lwoffi and an A. pittii strain isolated from the hospital environment.

Material and method

The modification of the Japanese Standard, which the ISO 22196:2011 norm was used for testing antimicrobial properties of CuZn37, CuSn6 and CuNi18Zn20 and Cu-ETP and stainless steel as positive and negative control, respectively.

Results

The highest cidal efficiency, expressed as both time and the degree of reduction of the initial suspension density, against all of the tested Acinetobacter strains was found for ETP copper. But, the results of our study also confirmed effective activity (bacteriocidal or bacteriostatic) of copper alloys selected for the study, contrary to the stainless steel. The reduction in bacterial suspension density is significantly different depending on the strain and copper alloy composition.

Conslusions

The results of our study confirmed the effective antibacterial activity of copper and its selected alloys against clinical Acinetobacter baumannii and Acinetobacter lwoffii strains, and Acinetobacter pittii strain isolated from the hospital environment.

Acinetobacter baumannii isolated from hospital-acquired infection: biofilm production and drug susceptibility

Acinetobacter baumannii cause opportunistic nosocomial infections and is often multidrug resistant. It has ability to form biofilm. The possession of drug resistance mechanism and ability of biofilm formation seems to be the different way to enhancement of viability in stressful environment. In this study, we evaluate relation between these two factors. The biofilm formation was investigated in M63 medium with casein in microtiter plates, and the drug susceptibility was performed by disk diffusion methods. We found that 80-98% strains formed a biofilm. Strains showing sensitivity to amikacin and tobramycin from ICU produced more biofilm than strains showing resistance to these antibiotics. Ceftazidime-sensitive strains formed a smaller biofilm than resistant. The logistic regression shows association between drug resistance and strains originating from ICU. In case of ceftazidime, strong biofilm formation and descending from ICU reduced the likelihood of drug sensitivity. For other drugs such as aminoglycosides, fluoroquinolones, trimethoprim/sulfamethoxazole, and tetracycline, we found opposite relation (but it was not statistically significance). However, generally it seems that strong biofilm producers from ICUs are often more susceptible to antibiotics. This situation can be explained by the fact that bacteria protected in biofilm do not need mechanisms responsible for resistance of planktonic cells.

High-touch surfaces: microbial neighbours at hand

Despite considerable efforts, healthcare-associated infections (HAIs) continue to be globally responsible for serious morbidity, increased costs and prolonged length of stay. Among potentially preventable sources of microbial pathogens causing HAIs, patient care items and environmental surfaces frequently touched play an important role in the chain of transmission. Microorganisms contaminating such high-touch surfaces include Gram-positive and Gram-negative bacteria, viruses, yeasts and parasites, with improved cleaning and disinfection effectively decreasing the rate of HAIs. Manual and automated surface cleaning strategies used in the control of infectious outbreaks are discussed and current trends concerning the prevention of contamination by the use of antimicrobial surfaces are taken into consideration in this manuscript.

Emergence of carbapenem-resistant Acinetobacter baumannii ST787 in clinical isolates from blood in a tertiary teaching hospital in Northern Taiwan

BACKGROUND/PURPOSE

The purpose of this study is to investigate the predominant clones of carbapenem-resistant Acinetobacter baumannii (CRAB) in our hospital in Taiwan by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) technique.

METHODS

We collected 108 non-duplicate A. baumannii clinical blood isolates from January 2012 to December 2013 in MacKay Memorial Hospital. PFGE and MLST were used for typing the A. baumannii isolates and for investigation of the predominant clones. Bacteria isolates were screened by polymerase chain reaction for the presence of the carbapenemase-encoding genes.

RESULTS

All 108 isolates were classified as 33 pulsotypes by PFGE. The predominant clones were pulsotype 10 (12.04%) in 2012 and pulsotype 8 (16.67%) in 2013, respectively. The 31 predominant pulsotype isolates were typed by MLST, and ST787 (54.84%) and ST455 (45.16%) were identified. All isolates carried bla_OXA-51-like genes, and bla_OXA-23-like genes was founded in 101 isolates (93.52%). Other identified resistance genes included bla_OXA-24-like and bla_OXA-IMP.

CONCLUSION

To the best of our knowledge, this study is the first to describe the microbiological characteristics of CRAB ST787, which carried high genetic resistance to carbapenem, but remained susceptible to colistin. CRAB ST787 was the predominant clone in our hospital in the study period.

Development and evaluation of a core genome multilocus typing scheme for whole-genome sequence-based typing of Acinetobacter baumannii

We have employed whole genome sequencing to define and evaluate a core genome multilocus sequence typing (cgMLST) scheme for Acinetobacter baumannii. To define a core genome we downloaded a total of 1,573 putative A. baumannii genomes from NCBI as well as representative isolates belonging to the eight previously described international A. baumannii clonal lineages. The core genome was then employed against a total of fifty-three carbapenem-resistant A. baumannii isolates that were previously typed by PFGE and linked to hospital outbreaks in eight German cities. We defined a core genome of 2,390 genes of which an average 98.4% were called successfully from 1,339 A. baumannii genomes, while Acinetobacter nosocomialis, Acinetobacter pittii, and Acinetobacter calcoaceticus resulted in 71.2%, 33.3%, and 23.2% good targets, respectively. When tested against the previously identified outbreak strains, we found good correlation between PFGE and cgMLST clustering, with 0–8 allelic differences within a pulsotype, and 40–2,166 differences between pulsotypes. The highest number of allelic differences was between the isolates representing the international clones. This typing scheme was highly discriminatory and identified separate A. baumannii outbreaks. Moreover, because a standardised cgMLST nomenclature is used, the system will allow inter-laboratory exchange of data.

Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals

Experts agree that careful cleaning and disinfection of environmental surfaces are essential elements of effective infection prevention programs. However, traditional manual cleaning and disinfection practices in hospitals are often suboptimal. This is often due in part to a variety of personnel issues that many Environmental Services departments encounter. Failure to follow manufacturer’s recommendations for disinfectant use and lack of antimicrobial activity of some disinfectants against healthcare-associated pathogens may also affect the efficacy of disinfection practices.

Improved hydrogen peroxide-based liquid surface disinfectants and a combination product containing peracetic acid and hydrogen peroxide are effective alternatives to disinfectants currently in widespread use, and electrolyzed water (hypochlorous acid) and cold atmospheric pressure plasma show potential for use in hospitals. Creating “self-disinfecting” surfaces by coating medical equipment with metals such as copper or silver, or applying liquid compounds that have persistent antimicrobial activity surfaces are additional strategies that require further investigation.

Newer “no-touch” (automated) decontamination technologies include aerosol and vaporized hydrogen peroxide, mobile devices that emit continuous ultraviolet (UV-C) light, a pulsed-xenon UV light system, and use of high-intensity narrow-spectrum (405 nm) light. These “no-touch” technologies have been shown to reduce bacterial contamination of surfaces. A micro-condensation hydrogen peroxide system has been associated in multiple studies with reductions in healthcare-associated colonization or infection, while there is more limited evidence of infection reduction by the pulsed-xenon system. A recently completed prospective, randomized controlled trial of continuous UV-C light should help determine the extent to which this technology can reduce healthcare-associated colonization and infections.

In conclusion, continued efforts to improve traditional manual disinfection of surfaces are needed. In addition, Environmental Services departments should consider the use of newer disinfectants and no-touch decontamination technologies to improve disinfection of surfaces in healthcare.

KatG and KatE confer Acinetobacter resistance to hydrogen peroxide but sensitize bacteria to killing by phagocytic respiratory burst

AIMS

Catalase catalyzes the degradation of H2O2. Acinetobacter species have four predicted catalase genes, katA, katE, katG, and katX. The aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to H2O2, and to assess the role of catalase in Acinetobacter virulence.

MAIN METHODS

Mutants of Acinetobacter baumannii and Acinetobacter nosocomialis with deficiencies in katA, katE, katG, and katX were tested for sensitivity to H2O2, either by halo assays or by liquid culture assays. Respiratory burst of neutrophils, in response to A. nosocomialis, was assessed by chemiluminescence to examine the effects of catalase on the production of reactive oxygen species (ROS) in neutrophils. Bacterial virulence was assessed using a Galleria mellonella larva infection model.

KEY FINDINGS

The capacities of A. baumannii and A. nosocomialis to degrade H2O2 are largely dependent on katE. The resistance of both A. baumannii and A. nosocomialis to H2O2 is primarily determined by the katG gene, although katE also plays a minor role in H2O2 resistance. Bacteria lacking both the katG and katE genes exhibit the highest sensitivity to H2O2. While A. nosocomialis bacteria with katE and/or katG were able to decrease ROS production by neutrophils, these cells also induced a more robust respiratory burst in neutrophils than did cells deficient in both katE and katG. We also found that A. nosocomialis deficient in both katE and katG was more virulent than the wildtype A. nosocomialis strain.

SIGNIFICANCE

Our findings suggest that inhibition of Acinetobacter catalase may help to overcome the resistance of Acinetobacter species to microbicidal H2O2 and facilitate bacterial disinfection.

Molecular Epidemiology and Drug Resistance of Acinetobacter baumannii Isolated from Hospitals in Southern Poland: ICU as a Risk Factor for XDR Strains

The objectives of the present study were to investigate the carbapenemase and metallo-beta-lactamase genes of Acinetobacter baumannii clinical isolates by polymerase chain reaction (PCR) and real time PCR and to determine the molecular epidemiology of the strains using the DiversiLab tool. From these data, correlations between drug resistance, resistance genes, and epidemiological clones may be revealed. The study was conducted on 125 A. baumannii collected over the 2013 year. The majority of the isolates from both intensive care unit (ICU) and non-ICU cases originated from pneumonia infections (79.2%), isolates from blood infections accounted for 17.6% and 3.2% were from meningitis infections. In the ICU cases compared with the non-ICU cases, bloodstream infections were more frequently diagnosed (19.2% vs. 11.5%). Sixty percent of A. baumannii strains were resistant to all the antimicrobials tested with the exception of colistin. All strains were susceptible to colistin and polymyxin B. Extensively drug-resistant (XDR) strains accounted for 80.8% of the isolates tested and these XDR strains were more frequently isolated from ICU cases than from non-ICU cases (93.9% vs. 30.8%). Among the 101 isolates of A. baumannii exhibiting the XDR pattern of resistance, 80 possessed the blaOXA-24 gene and 29 had the blaOXA-23 gene. Only two isolates possessed the blaVIM gene. The presence of the ISAba1element was confirmed among 10 strains from patients hospitalized in the ICU. Using repetitive extragenic palindromic sequence PCR (DiversiLab typing), six clones and 12 unique strains were identified, of which two clones dominated. Most isolates belonging to clone 1 (66.7%) and clone 2 (85.5%) were susceptible only to colistin. In summary, it is clear from our findings and those of other studies that carbapenem resistance among A. baumannii strains presents a serious clinical problem worldwide. Furthermore, the presence of XDR international clone II in ICUs poses a potential risk for future outbreaks of A. baumannii infection and controlling A. baumannii infections in hospitals presents a serious challenge.

Outbreak of carbapenem-resistant Acinetobacter baumannii in the intensive care unit: a multi-level strategic management approach

An outbreak of carbapenem-resistant Acinetobacter baumannii (CRAb) occurred in an interdisciplinary intensive care unit, affecting 10 patients. Within hours of recognition of the spread of CRAb an intervention team was instituted for collection of available data, decision-making, communication and monitoring of all interventions performed, including cohorting, temporary stop of admissions, staff education, and enforcement of infection control measures. An area was defined for cohortation of patients colonized with CRAb, with a separate nursing team and a second set of mobile equipment. New transmissions were no longer observed after only four days into the institution of enhanced infection control measures.

Antimicrobial resistance: one world, one fight!

The lack of new antibiotic classes calls for a cautious use of existing agents. Yet, every 10 min, almost two tons of antibiotics are used around the world, all too often without any prescription or control. The use, overuse and misuse of antibiotics select for resistance in numerous species of bacteria which then renders antimicrobial treatment ineffective. Almost all countries face increased antimicrobial resistance (AMR), not only in humans but also in livestock and along the food chain. The spread of AMR is fueled by growing human and animal populations, uncontrolled contamination of fresh water supplies, and increases in international travel, migration and trade. In this context of global concern, 68 international experts attending the fifth edition of the World HAI Resistance Forum in June 2015 shared their successes and failures in the global fight against AMR. They underlined the need for a “One Health” approach requiring research, surveillance, and interventions across human, veterinary, agricultural and environmental sectors. This strategy involves concerted actions on several fronts. Improved education and increased public awareness are a well-understood priority. Surveillance systems monitoring infections need to be expanded to include antimicrobial use, as well as the emergence and spread of AMR within clinical and environmental samples. Adherence to practices to prevent and control the spread of infections is mandatory to reduce the requirement of antimicrobials in general care and agriculture. Antibiotics need to be banned as growth promoters for farm animals in countries where it has not yet been done. Antimicrobial stewardship programmes in animal husbandry have proved to be efficient for minimising AMR, without compromising productivity. Regarding the use of antibiotics in humans, new tools to provide highly specific diagnoses of pathogens can decrease diagnostic uncertainty and improve clinical management. Finally, infection prevention and control measures – some of them as simple as hand hygiene – are essential and should be extended beyond healthcare settings. Aside from regulatory actions, all people can assist in AMR reduction by limiting antibiotic use for minor illnesses. Together, we can all work to reduce the burden of AMR.

A gloves-associated outbreak of imipenem-resistant Acinetobacter baumannii in an intensive care unit in Guangdong, China

Background

Imipenem-resistant Acinetobacter baumannii (IRAB) is an important cause of hospital-acquired infection. We aimed to describe an outbreak of IRAB infection and to investigate its possible source in an intensive care unit.

Methods

An environmental investigation was undertaken. Antimicrobial susceptibility testing was performed by microdilution. These isolates were genotyped by use of repetitive extragenic palindromic polymerase chain reaction (rep-PCR; DiversiLab). The study included 11 patients infected with IRAB and 14 control patients free of IRAB. Case and control patients were compared for possible predisposing factors. A multifaceted intervention was implemented to control the outbreak.

Results

Thirty-nine IRABs were isolated from patients and the environmental surveillance culture in August, November, and December 2011. All isolates were resistant to imipenem. The IRAB strains belonged to seven clones (A–G) by the use of rep-PCR. There were four epidemic clones (D–G) in the outbreak, and Clone D was predominant. For the case–control study, patients with chronic obstructive pulmonary disease were susceptible to infection with IRAB. The hospital mortality of the case group was significantly higher than that of the control group.

Conclusions

The outbreak strains were transmitted among infected patients and equipment by inappropriate use of gloves. A combination of aggressive infection control measures is essential for preventing recurrent nosocomial outbreaks of IRAB.

Efficiency of hydrogen peroxide in improving disinfection of ICU rooms

INTRODUCTION

The primary objective of this study was to determine the efficiency of hydrogen peroxide (H₂O₂) techniques in disinfection of ICU rooms contaminated with multidrug-resistant organisms (MDRO) after patient discharge. Secondary objectives included comparison of the efficiency of a vaporizator (HPV, Bioquell) and an aerosolizer using H₂O₂, and peracetic acid (aHPP, Anios) in MDRO environmental disinfection, and assessment of toxicity of these techniques.

METHODS

This prospective cross-over study was conducted in five medical and surgical ICUs located in one University hospital, during a 12-week period. Routine terminal cleaning was followed by H₂O₂ disinfection. A total of 24 environmental bacteriological samplings were collected per room, from eight frequently touched surfaces, at three time-points: after patient discharge (T0), after terminal cleaning (T1) and after H₂O₂ disinfection (T2).

RESULTS

In total 182 rooms were studied, including 89 (49%) disinfected with aHPP and 93 (51%) with HPV. At T0, 15/182 (8%) rooms were contaminated with at least 1 MDRO (extended spectrum β-lactamase-producing Gram-negative bacilli 50%, imipenem resistant Acinetobacter baumannii 29%, methicillin-resistant Staphylococcus aureus 17%, and Pseudomonas aeruginosa resistant to ceftazidime or imipenem 4%). Routine terminal cleaning reduced environmental bacterial load (P <0.001) without efficiency on MDRO (15/182 (8%) rooms at T0 versus 11/182 (6%) at T1; P = 0.371). H₂O₂ technologies were efficient for environmental MDRO decontamination (6% of rooms contaminated with MDRO at T1 versus 0.5% at T2, P = 0.004). Patient characteristics were similar in aHPP and HPV groups. No significant difference was found between aHPP and HPV regarding the rate of rooms contaminated with MDRO at T2 (P = 0.313). 42% of room occupants were MDRO carriers. The highest rate of rooms contaminated with MDRO was found in rooms where patients stayed for a longer period of time, and where a patient with MDRO was hospitalized. The residual concentration of H₂O₂ appears to be higher using aHPP, compared with HPV.

CONCLUSIONS

H₂O₂ treatment is efficient in reducing MDRO contaminated rooms in the ICU. No significant difference was found between aHPP and HPV regarding their disinfection efficiency.

Controlling hospital-acquired infection: focus on the role of the environment and new technologies for decontamination

There is increasing interest in the role of cleaning for managing hospital-acquired infections (HAI). Pathogens such as vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), multiresistant Gram-negative bacilli, norovirus, and Clostridium difficile persist in the health care environment for days. Both detergent- and disinfectant-based cleaning can help control these pathogens, although difficulties with measuring cleanliness have compromised the quality of published evidence. Traditional cleaning methods are notoriously inefficient for decontamination, and new approaches have been proposed, including disinfectants, steam, automated dispersal systems, and antimicrobial surfaces. These methods are difficult to evaluate for cost-effectiveness because environmental data are not usually modeled against patient outcome. Recent studies have reported the value of physically removing soil using detergent, compared with more expensive (and toxic) disinfectants. Simple cleaning methods should be evaluated against nonmanual disinfection using standardized sampling and surveillance. Given worldwide concern over escalating antimicrobial resistance, it is clear that more studies on health care decontamination are required. Cleaning schedules should be adapted to reflect clinical risk, location, type of site, and hand touch frequency and should be evaluated for cost versus benefit for both routine and outbreak situations. Forthcoming evidence on the role of antimicrobial surfaces could supplement infection prevention strategies for health care environments, including those targeting multidrug-resistant pathogens.

Best practice in healthcare environment decontamination

There is now strong evidence that surface contamination is linked to healthcare-associated infections (HCAIs). Cleaning and disinfection should be sufficient to decrease the microbial bioburden from surfaces in healthcare settings, and, overall, help in decreasing infections. It is, however, not necessarily the case. Evidence suggests that there is a link between educational interventions and a reduction in infections. To improve the overall efficacy and appropriate usage of disinfectants, manufacturers need to engage with the end users in providing clear claim information and product usage instructions. This review provides a clear analysis of the scientific evidence supporting the role of surfaces in HCAIs and the role of education in decreasing such infections. It also examines the debate opposing the use of cleaning versus disinfection in healthcare settings.

Control of a two-decade endemic situation with carbapenem-resistant Acinetobacter baumannii: electronic dissemination of a bundle of interventions

BACKGROUND

Our institution continued to experience a hyperendemic situation with carbapenem-resistant Acinetobacter baumannii despite a bundle of interventions. We aim to describe the effect of the subsequent implementation of electronic dissemination of the weekly findings of a bundle of interventions.

METHODS

This was a quasiexperimental study performed at a 1,500-bed, public, teaching hospital. From January 2011 to March 2012, weekly electronic communications were sent to the hospital leadership and intensive care units (ICUs). These communications aimed to describe, interpret, and package the findings of the previous week's active surveillance cultures, environmental cultures, environmental disinfection, and hand cultures. Additionally, action plans based on these findings were shared with recipients.

RESULTS

During 42 months and 1,103,900 patient-days, we detected 438 new acquisitions of carbapenem-resistant A baumannii. Hospital wide, the rate of acquisition decreased from 5.13 ± 0.39 to 1.93 ± 0.23 per 10,000 patient-days, during the baseline and postintervention periods, respectively (P < .0001). This effect was also observed in the medical and trauma ICUs, with decreased rates from 67.15 ± 10.56 to 17.4 ± 4.6 (P < .0001) and from 55.9 ± 8.95 to 14.71 ± 4.45 (P = .0004), respectively.

CONCLUSION

Weekly and systematic dissemination of the findings of a bundle of interventions was successful in decreasing the rates of carbapenem-resistant A baumannii across a large public hospital.

Cold air plasma to decontaminate inanimate surfaces of the hospital environment

The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.

A guide to no-touch automated room disinfection (NTD) systems

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. ‘No-touch’ automated room disinfection (NTD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapour (H₂O₂ vapour), aerosolised hydrogen peroxide (aHP) and ultraviolet (UV) radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

Cleaning and decontamination of the healthcare environment

Evidence is accumulating for the role of cleaning in controlling hospital infections. Hospital pathogens such as meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), norovirus, multi-resistant Gram-negative bacilli and Clostridium difficile persist in the healthcare environment for considerable lengths of time. Cleaning with both detergent and disinfectant-based regimens help control these pathogens in both routine and outbreak situations. The most important transmission risk comes from organisms on frequently handled items because hand contact with a contaminated site could deliver a pathogen to a patient. Cleaning practices should be tailored to clinical risk, near-patient areas and hand-touch-sites and scientifically evaluated for all surfaces and equipment in today’s hospitals.

The Role of the Hospital Environment in the Prevention of Healthcare-Associated Infections by Contact Transmission

OBJECTIVE:

This article describes the role of the hospital environment in the spread of pathogens by direct and indirect contact. In addition, the prevention of transmission through interventions involving the built environment is discussed.

BACKGROUND:

The hospital environment can become contaminated with pathogenic microorganisms, some of which can persist for long periods of time. Although contamination is common, the contribution of the hospital environment to the development of healthcare-associated infections remains unclear. In part spurred by the development of newer technologies to enhance environmental cleaning or to prevent contamination, research into the role of the environment in causing healthcare-associated infections has accelerated.

TOPICAL HEADINGS:

A review of the recent literature finds an increasing body of evidence implicating contaminated surfaces in patient care areas in the transmission of pathogens and the development of infections. Single-patient rooms and optimally placed alcohol hand rub dispensers and other design features can mitigate infection risk. Enhanced environmental cleaning including touchless technologies and self-cleaning surfaces can reduce environmental contamination and may prevent infections.

CONCLUSIONS:

The hospital environment contributes to transmission of pathogens in hospitals and to the development of healthcare-associated infections. Newer technologies to prevent environmental contamination or to enhance cleaning are promising although additional studies with the endpoints of reduction of infections are needed before the role of these technologies is known.

Outbreak of extensively drug-resistant Acinetobacter baumannii indigo-pigmented strains

Acinetobacter baumannii pigmented strains are not common in clinical settings. Here, we report an outbreak caused by indigo-pigmented A. baumannii strains isolated in an acute care hospital in Argentina from March to September 2012. Pan-PCR assays exposed a unique pattern belonging to the recently described regional CC113(B)/CC79(P) clonal complex that confirms the relevant relationships among the indigo-pigmented A. baumannii strains. All of them were extensively drug resistant and harbored different genetic elements associated with horizontal genetic transfer, such as the transposon Tn2006, class 2 integrons, AbaR-type islands, IS125, IS26, strA, strB, florR, and the small recombinase ISCR2 associated with the sul2 gene preceded by ISAba1.

The role of 'no-touch' automated room disinfection systems in infection prevention and control

BACKGROUND

Surface contamination in hospitals is involved in the transmission of pathogens in a proportion of healthcare-associated infections. Admission to a room previously occupied by a patient colonized or infected with certain nosocomial pathogens increases the risk of acquisition by subsequent occupants; thus, there is a need to improve terminal disinfection of these patient rooms. Conventional disinfection methods may be limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. These problems can be reduced by the use of 'no-touch' automated room disinfection (NTD) systems.

AIM

To summarize published data related to NTD systems.

METHODS

Pubmed searches for relevant articles.

FINDINGS

A number of NTD systems have emerged, which remove or reduce reliance on the operator to ensure distribution, contact time and process repeatability, and aim to improve the level of disinfection and thus mitigate the increased risk from the prior room occupant. Available NTD systems include hydrogen peroxide (H(2)O(2)) vapour systems, aerosolized hydrogen peroxide (aHP) and ultraviolet radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. Typically, there is a trade-off between time and effectiveness among NTD systems. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

CONCLUSION

NTD systems are gaining acceptance as a useful tool for infection prevention and control.