Optimizing Contact Precautions to Curb the Spread of Antibiotic-resistant Bacteria in Hospitals: A Multicenter Cohort Study to Identify Patient Characteristics and Healthcare Personnel Interactions Associated With Transmission of Methicillin-resistant Staphylococcus aureus

A survey of healthcare workers on the acceptance and value of personal protective equipment for patient care

OBJECTIVE

Assess healthcare workers' (HCW) attitudes toward universal masking, and gowns and gloves used as part of transmission-based precautions.

DESIGN

Cross-sectional survey.

SETTING

Academic, tertiary care medical center in Baltimore, Maryland.

PARTICIPANTS

HCW who work in patient care areas and have contact with patients.

METHODS

In May 2023, a 15-question web-based survey was distributed by the hospital's communications team via email. The survey contained questions to assess HCW perceptions of universal masking policies prior to the availability of COVID-19 vaccines and at the time of the survey, and the use of gowns and gloves for transmission-based precautions. Descriptive statistics were used to summarize data. Differences in agreement with universal masking over time, level of agreement with gown and glove policies, and with all PPE types across respondent characteristics were assessed.

RESULTS

257 eligible respondents completed the survey. Nurses and patient care technicians (43%) and providers (17%) were the most commonly reported roles. Agreement with universal mask use decreased from 84% early in the pandemic to 55% at the time of the survey. 70% and 72% of HCW agreed masks protect themselves and others, respectively. 63% expressed any level of annoyance with mask wearing, the most often due to communication challenges or physical discomfort. 75% agreed with gown use for antibiotic-resistant bacteria compared with 90% for glove use.

CONCLUSIONS

The majority of HCW agree with the use of PPE to prevent pathogen transmission in the healthcare setting. Agreement with universal mask use for patient care shifted during the COVID-19 pandemic.

Healthcare as a driver, reservoir and amplifier of antimicrobial resistance: opportunities for interventions

Antimicrobial resistance (AMR) is a global health challenge that threatens humans, animals and the environment. Evidence is emerging for a role of healthcare infrastructure, environments and patient pathways in promoting and maintaining AMR via direct and indirect mechanisms. Advances in vaccination and monoclonal antibody therapies together with integrated surveillance, rapid diagnostics, targeted antimicrobial therapy and infection control measures offer opportunities to address healthcare-associated AMR risks more effectively. Additionally, innovations in artificial intelligence, data linkage and intelligent systems can be used to better predict and reduce AMR and improve healthcare resilience. In this Review, we examine the mechanisms by which healthcare functions as a driver, reservoir and amplifier of AMR, contextualized within a One Health framework. We also explore the opportunities and innovative solutions that can be used to combat AMR throughout the patient journey. We provide a perspective on the current evidence for the effectiveness of interventions designed to mitigate healthcare-associated AMR and promote healthcare resilience within high-income and resource-limited settings, as well as the challenges associated with their implementation.

Evaluation of the Xpert Carba-R assay for quantifying carbapenemase-producing bacterial load in stool samples

BACKGROUND

The spread of Carbapenemase-producing Organisms (CPO) remains a major threat globally. Within clinical settings, the existing method of determining gene load involves traditional culture to determine bacterial load and polymerase-chain-reaction-based Xpert Carba-R Assay to determine carbapenemase gene type. However, there is a need for a fast and accurate method of quantifying CPO colonisation to study the risk of persistent CPO carriage.

OBJECTIVE

This study evaluated the accuracy of Xpert Carba-R Ct value in estimating carbapenamase producing bacterial loads in stool samples.

METHODS

Stool samples were obtained from an ongoing study investigating the household transmission of CPO in Singapore. Stool samples lacking carbapenemase producing organisms were spiked with organism carrying a single carbapenemase gene (blaKPC, blaNDM, blaVIM, blaOXA-48(-like) or blaIMP-1) and serially diluted before being subjected to Xpert Carba-R assay and traditional culture. Standard curves with regression lines showing correlation between Ct values and plate counts were generated. The standard curves were validated with stool samples collected from patients.

RESULTS

The limit of detection of blaNDM, blaKPC, and blaOXA-48 was approximately 103 cfu/mL, while that of blaIMP-1 and blaVIM was approximately 104 cfu/mL. Validation of the blaNDM and blaOXA-48 curves revealed average delta values of 0.56 log(cfu/mL) (95% CI 0.24-0.88) and 0.80 log(cfu/mL) (95% CI 0.53-1.07), respectively.

CONCLUSIONS

Our validation data for stool positive for blaNDM and blaOXA-48-type suggests that bacterial loads can be estimated within a reasonable range of error.

Healthcare personnel opinions regarding the feasibility of a risk-tailored approach to contact precautions for methicillin-resistant Staphylococcus aureus in the acute care setting

"All or none" approaches to the use of contact precautions for methicillin-resistant Staphylococcus aureus (MRSA) both fail to recognize that transmission risk varies. This qualitative study assessed healthcare personnel perspectives regarding the feasibility of a risk-tailored approach to use contact precautions for MRSA more strategically in the acute care setting.

Impact of discontinuation of contact precautions on surveillance- and whole genome sequencing-defined methicillin-resistant Staphylococcus aureus healthcare-associated infections

Objective

Prior studies evaluating the impact of discontinuation of contact precautions (DcCP) on methicillin-resistant Staphylococcus aureus (MRSA) outcomes have characterized all healthcare-associated infections (HAIs) rather than those likely preventable by contact precautions. We aimed to analyze the impact of DcCP on the rate of MRSA HAI including transmission events identified through whole genome sequencing (WGS) surveillance.

Design

Quasi experimental interrupted time series.

Setting

Acute care medical center.

Participants

Inpatients.

Methods

The effect of DcCP (use of gowns and gloves) for encounters among patients with MRSA carriage was evaluated using time series analysis of MRSA HAI rates from January 2019 through December 2022, compared to WGS-defined attributable transmission events before and after DcCP in December 2020.

Results

The MRSA HAI rate was 4.22/10,000 patient days before and 2.98/10,000 patient days after DcCP (incidence rate ratio [IRR] 0.71 [95% confidence interval 0.56-0.89]) with a significant immediate decrease (P = .001). There were 7 WGS-defined attributable transmission events before and 11 events after DcCP (incident rate ratio 0.90 [95% confidence interval 0.30-2.55]).

Conclusions

DcCP did not result in an increase in MRSA HAI or, in WGS-defined attributable transmission events. Comprehensive analyses of the effect of transmission prevention measures should include outcomes specifically measuring transmission-associated HAI.

Factors associated with patient-to-healthcare personnel (HCP) and HCP-to-subsequent patient transmission of methicillin-resistant Staphylococcus aureus

BACKGROUND

Transient acquisition of methicillin-resistant Staphylococcus aureus (MRSA) on healthcare personnel (HCP) gloves and gowns following patient care has been examined. However, the potential for transmission to the subsequent patient has not been studied. We explored the frequency of MRSA transmission from patient to HCP, and then in separate encounters from contaminated HCP gloves and gowns to a subsequent simulated patient as well as the factors associated with these 2 transmission pathways.

METHODS

We conducted a prospective cohort study with 2 parts. In objective 1, we studied MRSA transmission from random MRSA-positive patients to HCP gloves and gowns after specific routine patient care activities. In objective 2, we simulated subsequent transmission from random HCP gloves and gowns without hand hygiene to the next patient using a manikin proxy.

RESULTS

For the first objective, among 98 MRSA-positive patients with 333 randomly selected individual patient-HCP interactions, HCP gloves or gowns were contaminated in 54 interactions (16.2%). In a multivariable analysis, performing endotracheal tube care had the greatest odds of glove or gown contamination (OR, 4.06; 95% CI, 1.3-12.6 relative to physical examination). For the second objective, after 147 simulated HCP-patient interactions, the subsequent transmission of MRSA to the manikin proxy occurred 15 times (10.2%).

CONCLUSION

After caring for a patient with MRSA, contamination of HCP gloves and gown and transmission to subsequent patients following HCP-patient interactions occurs frequently if contact precautions are not used. Proper infection control practices, including the use of gloves and gown, can prevent this potential subsequent transmission.

Methicillin Resistant Staphylococcus aureus: Molecular Mechanisms Underlying Drug Resistance Development and Novel Strategies to Combat

Antimicrobial resistance (AMR) represents a major threat to global health. Infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) is one of the well-recognized global public health problem globally. In some regions, as many as 90% of S. aureus infections are reported to be MRSA, which cannot be treated with standard antibiotics. WHO reports indicated that MRSA is circulating in every province worldwide, significantly increasing the risk of death by 64% compared to drug-sensitive forms of the infection which is attributed to its antibiotic resistance. The emergence and spread of antibiotic-resistant MRSA strains have contributed to its increased prevalence in both healthcare and community settings. The resistance of S. aureus to methicillin is due to expression of penicillin-binding protein 2a (PBP2a), which renders it impervious to the action of β-lactam antibiotics including methicillin. The other is through the production of beta-lactamases. Although the treatment options for MRSA are limited, there are promising alternatives to antibiotics to combat the infections. Innovative therapeutic strategies with wide range of activity and modes of action are yet to be explored. The review highlights the global challenges posed by MRSA, elucidates the mechanisms underlying its resistance development, and explores mitigation strategies. Furthermore, it focuses on alternative therapies such as bacteriophages, immunotherapy, nanobiotics, and antimicrobial peptides, emphasizing their synergistic effects and efficacy against MRSA. By examining these alternative approaches, this review provides insights into the potential strategies for tackling MRSA infections and combatting the escalating threat of AMR. Ultimately, a multifaceted approach encompassing both conventional and novel interventions is imperative to mitigate the impact of MRSA and ensure a sustainable future for global healthcare.

Efficacy of a continuously active disinfectant wipe on the environmental bioburden in the intensive care unit: A randomized controlled study

OBJECTIVE

To evaluate the efficacy of a new continuously active disinfectant (CAD) to decrease bioburden on high-touch environmental surfaces compared to a standard disinfectant in the intensive care unit.

DESIGN

A single-blind randomized controlled trial with 1:1 allocation.

SETTING

Medical intensive care unit (MICU) at an urban tertiary-care hospital.

PARTICIPANTS

Adult patients admitted to the MICU and on contact precautions.

INTERVENTION

A new CAD wipe used for daily cleaning.

METHODS

Samples were collected from 5 high-touch environmental surfaces before cleaning and at 1, 4, and 24 hours after cleaning. The primary outcome was the mean bioburden 24 hours after cleaning. The secondary outcome was the detection of any epidemiologically important pathogen (EIP) 24 hours after cleaning.

RESULTS

In total, 843 environmental samples were collected from 43 unique patient rooms. At 24 hours, the mean bioburden recovered from the patient rooms cleaned with the new CAD wipe (intervention) was 52 CFU/mL, and the mean bioburden was 92 CFU/mL in the rooms cleaned the standard disinfectant (control). After log transformation for multivariable analysis, the mean difference in bioburden between the intervention and control arm was -0.59 (95% CI, -1.45 to 0.27). The odds of EIP detection were 14% lower in the rooms cleaned with the CAD wipe (OR, 0.86; 95% CI, 0.31-2.32).

CONCLUSIONS

The bacterial bioburden and odds of detection of EIPs were not statistically different in rooms cleaned with the CAD compared to the standard disinfectant after 24 hours. Although CAD technology appears promising in vitro, larger studies may be warranted to evaluate efficacy in clinical settings.

Active Surveillance and Contact Precautions for Preventing Methicillin-Resistant Staphylococcus aureus Healthcare-Associated Infections During the COVID-19 Pandemic

BACKGROUND

Statistically significant decreases in methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated infections (HAIs) occurred in Veterans Affairs (VA) hospitals from 2007 to 2019 using a national policy of active surveillance (AS) for facility admissions and contact precautions for MRSA colonized (CPC) or infected (CPI) patients, but the impact of suspending these measures to free up laboratory resources for testing and conserve personal protective equipment for coronavirus disease 2019 (COVID-19) on MRSA HAI rates is not known.

METHODS

From July 2020 to June 2022 all 123 acute care VA hospitals nationwide were given the rolling option to suspend (or re-initiate) any combination of AS, CPC, or CPI each month, and MRSA HAIs in intensive care units (ICUs) and non-ICUs were tracked.

RESULTS

There were 917 591 admissions, 5 225 174 patient-days, and 568 MRSA HAIs. The MRSA HAI rate/1000 patient-days in ICUs was 0.20 (95% confidence interval [CI], .15-.26) for facilities practicing "AS + CPC + CPI" compared to 0.65 (95% CI, .41-.98; P < .001) for those not practicing any of these strategies, and in non-ICUs was 0.07 (95% CI, .05-.08) and 0.12 (95% CI, .08-.19; P = .01) for the respective policies. Accounting for monthly COVID-19 facility admissions using a negative binomial regression model did not change the relationships between facility policy and MRSA HAI rates. There was no significant difference in monthly facility urinary catheter-associated infection rates, a non-equivalent dependent variable, in the policy categories in either ICUs or non-ICUs.

CONCLUSIONS

Facility removal of MRSA prevention practices was associated with higher rates of MRSA HAIs in ICUs and non-ICUs.

Comparison of two swab types for recovery of Staphylococcus aureus and Candida auris from gloves and gowns

Known concentrations of Staphylococcus aureus and Candida auris were applied on gloves and gowns then sampled with E-swabs and BBL liquid Amies swabs. The mean numbers of colony-forming units per milliliter (CFU/mL) obtained from culture of the 2 swab types were not different, suggesting that either can be used for recovery of these two pathogens from personal protective equipment.

Clinical and Bacterial Characteristics Associated with Glove and Gown Contamination by Carbapenem-Resistant Klebsiella pneumoniae in the Health Care Setting

Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a pathogen of significant concern to public health, as it has become increasingly associated with difficult-to-treat community-acquired and hospital-associated infections. Transmission of K. pneumoniae between patients through interactions with shared health care personnel (HCP) has been described as a source of infection in health care settings. However, it is not known whether specific lineages or isolates of K. pneumoniae are associated with increased transmission. Thus, we used whole-genome sequencing to analyze the genetic diversity of 166 carbapenem-resistant K. pneumoniae isolates from five U.S. hospitals in four states as part of a multicenter study examining risk factors for glove and gown contamination by carbapenem-resistant Enterobacterales (CRE). The CRKp isolates exhibited considerable genomic diversity with 58 multilocus sequence types (STs), including four newly designated STs. ST258 was the most prevalent ST, representing 31% (52/166) of the CRKp isolates, but was similarly prevalent among patients who had high, intermediate, and low CRKp transmission. Increased transmission was associated with clinical characteristics including a nasogastric (NG) tube or an endotracheal tube or tracheostomy (ETT/Trach). Overall, our findings provide important insight into the diversity of CRKp associated with transmission from patients to the gloves and gowns of HCP. These findings suggest that certain clinical characteristics and the presence of CRKp in the respiratory tract, rather than specific lineages or genetic content, are more often associated with increased transmission of CRKp from patients to HCP. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a significant public health concern that has contributed to the spread of carbapenem resistance and has been linked to high morbidity and mortality. Transmission of K. pneumoniae among patients through interactions with shared health care personnel (HCP) has been described as a source of infection in health care settings; however, it remains unknown whether particular bacterial characteristics are associated with increased CRKp transmission. Using comparative genomics, we demonstrate that CRKp isolates associated with high or intermediate transmission exhibit considerable genomic diversity, and there were no K. pneumoniae lineages or genes that were universally predictive of increased transmission. Our findings suggest that certain clinical characteristics and the presence of CRKp, rather than specific lineages or genetic content of CRKp, are more often associated with increased transmission of CRKp from patients to HCP.

SHEA/IDSA/APIC Practice Recommendation: Strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in acute-care hospitals: 2022 Update

Previously published guidelines have provided comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing efforts to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and infection. This document updates the "Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Transmission and Infection in Acute Care Hospitals" published in 2014.1 This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

Molecular concordance of methicillin-resistant Staphylococcus aureus isolates from healthcare workers and patients

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant nosocomial pathogen in the ICU. MRSA contamination of healthcare personnel (HCP) gloves and gowns after providing care to patients with MRSA occurs at a rate of 14%-16% in the ICU setting. Little is known about whether the MRSA isolates identified on HCP gown and gloves following patient care activities are the same as MRSA isolates identified as colonizing or infecting the patient.

METHODS

From a multisite cohort of 388 independent patient MRSA isolates and their corresponding HCP gown and glove isolates, we selected 91 isolates pairs using a probability to proportion size (PPS) sampling method. To determine whether the patient and HCP gown or gloves isolates were genetically similar, we used 5 comparative genomic typing methods: phylogenetic analysis, spa typing, multilocus sequence typing (MLST), large-scale BLAST score ratio (LSBSR), and single-nucleotide variant (SNV) analysis.

RESULTS

We identified that 56 (61.5%) of isolate pairs were genetically similar at least by 4 of the methods. Comparably, the spa typing and the LSBSR analyses revealed that >75% of the examined isolate pairs were concordant, with the thresholds established for each analysis.

CONCLUSIONS

Many of the patient MRSA isolates were genetically similar to those on the HCP gown or gloves following a patient care activity. This finding indicates that the patient is often the primary source of the MRSA isolates transmitted to the HCP, which can potentially be spread to other patients or hospital settings through HCP vectors. These results have important implications because they provide additional evidence for hospitals considering ending the use of contact precautions (gloves and gowns) for MRSA patients.

Inanimate Surfaces as a Source of Hospital Infections Caused by Fungi, Bacteria and Viruses with Particular Emphasis on SARS-CoV-2

The carriers of nosocomial infections are the hands of medical personnel and inanimate surfaces. Both hands and surfaces may be contaminated as a result of contact with the patient, their body fluids, and touching contaminated surfaces in the patient's surroundings. Visually clean inanimate surfaces are an important source of pathogens. Microorganisms have properties thanks to which they can survive in unfavorable conditions, from a few days to several months. Bacteria, viruses and fungi are able to transmit from inanimate surfaces to the skin of the patient and the medical staff. These pathogens include SARS-CoV-2, which can survive on various types of inanimate surfaces, being a potential source of infection. By following the recommendations related to washing and disinfecting hands and surfaces, and using appropriate washing and disinfecting agents with a broad biocidal spectrum, high material compatibility and the shortest duration of action, we contribute to breaking the chain of nosocomial infections.

Comparative Genomics Identifies Features Associated with Methicillin-Resistant Staphylococcus aureus (MRSA) Transmission in Hospital Settings

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious public health concern in the United States. Patients colonized and/or infected can transmit MRSA to healthcare workers and subsequent patients However, the components of this transmission chain are just becoming evident, including certain patient factors, specific patient-healthcare worker interactions, and microbial factors. We conducted a comparative genomic analysis of 388 isolates from four hospitals in three states: Maryland, California, and New York. Isolates from nasal surveillance or clinical cultures were categorized as high, moderate, or low transmission surrogate outcomes based on the number of times the species was identified on the gloves or gowns of healthcare providers. The comparative analyses included a single gene, multigene, and core genome phylogenetic analysis, as well as a genome-wide association analysis to identify molecular signatures associated with the observed transmission surrogate outcomes, geographic origin, or sample source of isolation. Based on the phylogenetic analysis, 95% (n = 372) of the MRSA isolates were from four well-described genomic clades, with most of the isolates being part of the USA300 containing clade (n = 187; 48%). Genome-wide association studies also identified genes that were exclusive or prevalent among specific geographic locations. The identified genes provide insights into the transmission dynamics of MRSA isolates providing additional insights into the basis of the geographical differences of MRSA for molecular diagnostics. IMPORTANCE Methicillin-resistant Staphylococcus aureus (MRSA) is considered a serious threat to public health and contributes to the dissemination of S. aureus in both the healthcare and community setting. Transmission of MRSA between patients via healthcare worker (HCW) has been described. However, what is not understood are the genetic determinants that contribute to the transmission of MRSA from patients to HCWs. In this study, we demonstrated that certain genes may be associated with transmission in the hospital setting.

Methicillin-Resistant Staphylococcus aureus: An Update on Prevention and Control in Acute Care Settings

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of health-care-associated infections. Controversies regarding the effectiveness of various control strategies have contributed to varying approaches to MRSA control. However, new evidence from large-scale studies has emerged, particularly concerning screening and decolonization. Importantly, implementation and outcomes of control measures in practice are not only influenced by scientific evidence, but also economic, administrative, and political factors, as demonstrated by decreasing MRSA rates in a number of countries after concerted and coordinated efforts at a national level. Flexibility to adapt measures based on local epidemiology and resources is essential for successful MRSA control.

Comparative Genomic Analysis Provides Insights into the Evolution and Genetic Diversity of Community-Genotype Sequence Type 72 Staphylococcus aureus Isolates

Staphylococcus aureus sequence type (ST) 72, the predominant community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) lineage in South Korea, has emerged as a major cause of bloodstream infection in hospital settings. However, relatively little information is available regarding the genomic characteristics and dissemination of ST72. Here, we characterized the whole-genome sequence of 24 ST72 isolates from China, along with 83 ST72 genomes from global sources. Of these 107 ST72 isolates, 63 were MRSA and 44 were methicillin-susceptible S. aureus (MSSA). Phylogenetic analysis revealed four distinct clades (A, B, C, and D), of which clade D contained only MSSA isolates. By characterizing the evolutionary dynamics of the ST72 lineage, we found that the MRSA from China might not have developed from the MSSA in China. Furthermore, we observed both international transmission of ST72 isolates and interregional transmission within China. The distributions of the SCCmec and spa types of isolates differed among clades. Additionally, in silico analyses revealed that the distributions of resistance genes, virulence genes, and mobile genetic elements (MGEs) also differed among isolates of the four clades. This was especially true for clade D isolates, which had the lowest level of antimicrobial resistance and had obtained specific virulence genes such as tsst-1 by acquisition of specific MGEs. Notably, ST72 MRSA isolates were more antibiotic resistant than ST72 MSSA isolates, but comparably virulent. Our findings provide insight into the potential transmission and genotypic features of ST72 clones across the globe.

IMPORTANCE Understanding the evolution and dissemination of community-genotype ST72 Staphylococcus aureus isolates is important, as isolates of this lineage have rapidly spread into hospital settings and caused serious health issues. In this study, we first carried out genome-wide analysis of 107 global ST72 isolates to characterize the evolution and genetic diversity of the ST72 lineage. We found that the MSSA lineage in China might have evolved independently from the MRSA isolates from China, and that ST72 isolates have the potential to undergo both international transmission and interregional transmission within China. The diversity of isolates correlated with distinct acquisitions of SCCmec elements, antibiotic resistance genes, virulence genes, and mobile genetic elements. The comprehensive information on the ST72 lineage emerging from this study will enable improved therapeutic approaches and rapid molecular diagnosis.

A 'time bomb' in the human intestine-the multiple emergence and spread of antibiotic-resistant bacteria

Antibiotics have a strong killing effect on bacteria and are the first choice for the prevention and treatment of bacterial infectious diseases. Therefore, they have been widely used in the medical field, animal husbandry and planting industry. However, with the massive use of antibiotics, more and more antibiotic-resistant bacteria (ARB) have emerged. Because human intestines are rich in nutrients, have suitable temperature, and are high in bacterial abundance, they can easily become a hotbed for the spread of ARB and antibiotic-resistant genes (ARGs). When opportunistic pathogenic bacteria in the intestine acquire ARGs, the infectious diseases caused by such opportunistic pathogens will become more difficult to treat, or even impossible to cure. Therefore, ARB in the human intestine are like a 'time bomb'. In this review, we discuss the sources of intestinal ARB and the transmission routes of ARGs in the human intestine from the perspective of One Health. Further, we describe various methods to prevent the emergence of ARB and inhibit the spread of ARGs in the human intestine. Finally, we may be able to overcome ARB in the human intestine using an interdisciplinary 'One Health' approach.

Isolation gowns as a potential work hazard

OBJECTIVES

Isolation gowns are used as a barrier to bacterial transmission from patient to provider and vice versa. If an isolation gown is ineffective, the patient and provider have a potential breach of safety and increased infection risk. This study compared the bacterial permeability of differently rated, commonly uses isolation gowns to assess their effectiveness in preventing simulated bacterial transmittance, and thus contamination, from patient to provider.

METHODS

Serial dilutions of Staphylococcus epidermidis in sterile saline were applied to a simulated skin surface. Unrated and Levels 1 through 4 non-sterile isolation gowns contacted the solution, simulating patient contact. Both sides of the contaminated gowns were then cultured on blood agar by rolling a sterile swab across the gown and evenly inoculating the culture plate. Colony counts from inside and outside of the gowns were compared. Separately, S. epidermidis was placed on a sample of each gown and scanning electron microscopy was used to visualize the contaminated gowns' physical structure.

RESULTS

Mean bacterial transmittance from outside of the gown (i.e. patient contact side) to inside of the gowns (i.e. provider clothing or skin side) based on gown rating was as follows: unrated: 50.4% (SD 9.0%); Level 1: 39.7% (SD 11.2%); Level 2: 16.3% (SD 10.3%); Level 3: 0.3% (SD 0.8%); Level 4: 0.0% (SD 0.0%). Scanning electron microscope imaging of unrated, Level 1, and Level 2 gowns revealed gown pore sizes much larger than the bacteria. The Welch one-way analysis of variance statistic showed significant difference dependent on gown-level rating.

CONCLUSIONS

Unrated, Level 1, and Level 2 isolation gowns do not provide effective bacterial isolation barriers when bacteria like S. epidermidis make contact with one side of the gown material. Not studied, but implied, is that unrated and lower rated isolation gowns would be as or even more physically permeable to virus particles, which are much smaller than bacteria.

Risk factors for transmission of carbapenem-resistant Enterobacterales to healthcare personnel gloves and gowns in the USA

BACKGROUND

Hospitals are sources for acquisition of carbapenem-resistant Entero-bacterales (CRE), and it is believed that the contamination of healthcare personnel (HCP) hands and clothing play a major role in patient-to-patient transmission of antibiotic-resistant bacteria.

AIM

The aim of this study was to determine which HCP types, HCP-patient interactions, and patient characteristics are associated with greater transmission of CRE to HCP gloves and gowns in the hospital.

METHODS

This was a prospective observational cohort study that enrolled patients with recent surveillance or clinical cultures positive for CRE at five hospitals in four states in the USA. HCP gloves and gown were cultured after patient care. Samples were also obtained from patients' stool, perianal area, and skin of the chest and arm to assess bacterial burden.

FINDINGS

Among 313 CRE-colonized patients and 3070 glove and gown cultures obtained after patient care, HCP gloves and gowns were found to be contaminated with CRE 7.9% and 4.3% of the time, respectively. Contamination of either gloves or gowns occurred in 10.0% of interactions. Contamination was highest (15.3%) among respiratory therapists (odds ratio: 3.79; 95% confidence interval: 1.61-8.94) and when any HCP touched the patient (1.52; 1.10-2.12). Associations were also found between CRE transmission to HCP gloves or gown and: being in the intensive care unit, having a positive clinical culture, and increasing bacterial burden on the patient.

CONCLUSION

CRE transmission to HCP gloves and gown occurred frequently. These findings may inform evidence-based policies about what situations and for which patients contact precautions are most important.

Effectiveness of barrier precautions for prevention of patient-to-patient transfer of a viral DNA surrogate marker

BACKGROUND

Gloves and gowns are used during patient care to reduce contamination of personnel and prevent pathogen transmission.

OBJECTIVE

To determine whether the use of gowns adds a substantial benefit over gloves alone in preventing patient-to-patient transfer of a viral DNA surrogate marker.

METHODS

In total, 30 source patients had 1 cauliflower mosaic virus surrogate marker applied to their skin and clothing and a second to their bed rail and bedside table. Personnel caring for the source patients were randomized to wear gloves, gloves plus cover gowns, or no barrier. Interactions with up to 7 subsequent patients were observed, and the percentages of transfer of the DNA markers were compared among the 3 groups.

RESULTS

In comparison to the no-barrier group (57.8% transfer of 1 or both markers), there were significant reductions in transfer of the DNA markers in the gloves group (31.1% transfer; odds ratio [OR], 0.16; 95% confidence interval [CI], 0.02-0.73) and the gloves-plus-gown group (25.9% transfer; OR, 0.11; 95% CI, 0.01-0.51). The addition of a cover gown to gloves during the interaction with the source patient did not significantly reduce the transfer of the DNA marker (P = .53). During subsequent patient interactions, transfer of the DNA markers was significantly reduced if gloves plus gowns were worn and if hand hygiene was performed (P < .05).

CONCLUSIONS

Wearing gloves or gloves plus gowns reduced the frequency of patient-to-patient transfer of a viral DNA surrogate marker. The use of gloves plus gowns during interactions with the source patient did not reduce transfer in comparison to gloves alone.

Draft Genome Sequences of Five Diverse Klebsiella Species Isolates from Intensive Care Unit Patients

We have examined the draft genomes of five isolates from two different Klebsiella species obtained from intensive care unit patients at two geographically distributed hospitals to examine the genomic diversity of hospital-acquired organisms in this understudied population.

Shedding of multidrug-resistant gram-negative bacilli by colonized patients during procedures and patient care activities

BACKGROUND

Medical procedures and patient care activities may facilitate environmental shedding of health care-associated pathogens.

METHODS

We conducted a cohort study of hospitalized patients in contact precautions for carriage of extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacilli (N = 38) or carbapenem-resistant gram-negative bacilli (CR-GNB) (N = 22) to determine the frequency of environmental shedding during procedures and care activities. Perirectal, wound, and skin were cultured for ESBL-producing and CR-GNB. High-touch surfaces and portable equipment were disinfected before and cultured after procedures; control cultures were collected in the absence of procedures.

RESULTS

Of 60 patients enrolled, 34 (57%) had positive perirectal and/or skin or wound cultures. For these 34 patients, 15 (44%) shed their colonizing organism to surfaces during 1 or more procedures. Patients with shedding had significantly higher concentrations of the pathogens recovered from perirectal swabs than those with no shedding (mean, 3.5 vs 2.2 log₁₀ colony-forming units per swab; P < .01). Environmental shedding occurred more frequently during procedures and care activities than in the absence of a procedure (21 of 117, 18% vs 1 of 61, 2%; P < .01), and 6 of 56 (10%) portable devices used for procedures became contaminated.

CONCLUSIONS

Environmental shedding of antibiotic-resistant gram-negative bacilli occurs frequently during medical procedures and patient care activities. Decontamination of surfaces and equipment and approaches that reduce the burden of carriage could reduce the risk for dissemination.

Epidemiologic and Microbiologic Characteristics of Hospitalized Patients Co-colonized With Multiple Species of Carbapenem-Resistant Enterobacteriaceae in the United States

We describe the epidemiologic and microbiologic characteristics of patients co-colonized with different species of carbapenem-resistant Enterobacteriaceae (CRE) from 5 hospitals in 4 states. Twenty-eight of 313 patients (8.9%) were co-colonized with at least 2 different CRE species. Different species within the same patient showed identical mechanism resistance in 18/28 (64%) cases.

Examination of Staphylococcus aureus Isolates from the Gloves and Gowns of Intensive Care Unit Health Care Workers

Interactions with health care workers are often thought to be associated with the spread of microbes in the hospital setting. We have examined the genomic diversity of methicillin-resistant Staphylococcus aureus isolates from the gloves and gowns of health care workers from four hospitals in three states.

Interactions with health care workers are often thought to be associated with the spread of microbes in the hospital setting. We have examined the genomic diversity of methicillin-resistant Staphylococcus aureus isolates from the gloves and gowns of health care workers from four hospitals in three states.

Patient to healthcare personnel transmission of MRSA in the non-intensive care unit setting

The transmission rate of methicillin-resistant Staphylococcus aureus (MRSA) to gloves or gowns of healthcare personnel (HCP) caring for MRSA patients in a non-intensive care unit setting was 5.4%. Contamination rates were higher among HCP performing direct patient care and when patients had detectable MRSA on their body. These findings may inform risk-based contact precautions.

Examination of 388 Staphylococcus aureus Isolates from Intensive Care Unit Patients

We have examined the draft genomes of 388 methicillin-resistant Staphylococcus aureus isolates obtained from intensive care unit patients at three geographically distributed hospitals to determine genomic diversity associated with potential health care worker-associated transmission.

Improving the Use of Personal Protective Equipment: Applying Lessons Learned

Unrecognized transmission of pathogens in healthcare settings can lead to colonization and infection of both patients and healthcare personnel. The use of personal protective equipment (PPE) is an important strategy to protect healthcare personnel from contamination and to prevent the spread of pathogens to subsequent patients. However, optimal PPE use is difficult, and healthcare personnel may alter delivery of care because of the PPE. Here, we summarize recent research from the Prevention Epicenters Program on healthcare personnel contamination and improvement of the routine use of PPE as well as Ebola-specific PPE. Future efforts to optimize the use of PPE should include increasing adherence to protocols for PPE use, improving PPE design, and further research into the risks, benefits, and best practices of PPE use.