Application of a fluorescent marker with quantitative bioburden methods to assess cleanliness

Evidence from an Avian Embryo Model that Zinc-Inducible MT4 Expression Protects Mitochondrial Function Against Oxidative Stress

BACKGROUND

Metallothioneins (MTs) have a strong affinity for zinc (Zn) and remain at a sufficiently high level in mitochondria. As the avian embryo is highly susceptible to oxidative damage and relatively easy to manipulate in a naturally closed chamber, it is an ideal model of the effects of oxidative stress on mitochondrial function. However, the protective roles and molecular mechanisms of Zn-inducible protein expression on mitochondrial function in response to various stressors are poorly understood.

OBJECTIVES

The study aimed to investigate the mechanisms by which Zn-induced MT4 expression protects mitochondrial function and energy metabolism subjected to oxidative stress using the avian embryo and embryonic primary hepatocyte models.

METHODS

First, we investigated whether MT4 expression alters mitochondrial function. Then, we examined the effects of Zn-induced MT4 overexpression and MT4 silencing on embryonic primary hepatocytes from breeder hens fed a normal Zn diet subjected to a tert-butyl hydroperoxide (BHP) oxidative stress challenge during incubation. In vivo, the avian embryos from hens fed the Zn-deficient and Zn-adequate diets were used to determine the protective roles of Zn-induced MT4 expression on the function of mitochondria exposed to oxidative stress induced by in ovo BHP injection.

RESULTS

An in vitro study revealed that Zn-induced MT4 expression reduced reactive oxygen species accumulation in primary hepatocytes. MT4 silencing exacerbated BHP-mediated mitochondrial dysfunction whereas Zn-inducible MT4 overexpression mitigated it. Another in vivo study disclosed that maternal Zn-induced MT4 expression protected mitochondrial function in chick embryo hepatocytes against oxidative stress by inhibiting the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)/peroxisome proliferators-activated receptor-γ (PPAR-γ) pathway.

CONCLUSION

This study underscores the potential protective roles of Zn-induced MT4 expression via the downregulation of the PGC-1α/PPAR-γ pathway on mitochondrial function stimulated by the stress challenge in the primary hepatocytes in an avian embryo model. Our findings suggested that Zn-induced MT4 expression could provide a new therapeutic target and preventive strategy for repairing mitochondrial dysfunction in disease.

Environmental cleaning and disinfection: Sustaining changed practice and improving quality in the community hospital

OBJECTIVE

Short-term improvements in hospital room cleaning can readily be achieved but are difficult to maintain. This is particularly true for high-risk, "high-touch" surfaces. Therefore, we embarked on a process to sustain improvements in surface cleaning and disinfection to reduce hospital-acquired infection (HAI) rates.

INTERVENTIONS

Our environmental services (EVS) and infection prevention departments incorporated a formal education, monitoring, and feedback process for focused cleaning and disinfection of high-touch surfaces into their routine policies and procedures in 2011. Cleaning validation was performed by infection prevention liaison nurses using a fluorescent targeting method to evaluate the thoroughness of cleaning.

RESULTS

Surface cleaning performance on medical-surgical units in 2011 was 74.7%, but this rate incrementally increased in response to the interventions and has been sustained at >90% for the past 6 years. Similar patterns of improvement were observed in the operating room, labor and delivery, endoscopy suite and cardiac catheterization laboratory. Conversely, HAI rates, particularly C. difficile rates, decreased by 75% and surgical site infection rates decreased by 55%.

CONCLUSIONS

EVS training, monitoring, and feedback interventions, instituted 10 years ago have enhanced our environmental cleaning and disinfection efforts in multiple areas of the hospital and have been sustained to the present. Although other concurrent initiatives to reduce infection rates also existed, the improvements in environmental cleaning were associated with dramatic reductions in HAI rates over the 10-year period.

A multiphase intervention of novel color additive for bleach disinfectant wipes improves thoroughness of cleaning in an academic medical center

Surface disinfection is critical for preventing health care-associated infections; however, sustaining high-quality cleaning technique is challenging without constant feedback and training of staff. A novel color additive to bleach wipes, Highlight, indicates where surfaces have been wiped and fades to colorless to provide real-time visual feedback of cleaning. In a multiphase interventional study, Highlight reduced failure rates of cleaning based on fluorescent marker removal (15.0%-4.5%) and adenosine triphosphate bioluminescence assay (3.6%-2.5%).

Comparing visual inspection and performance observation for evaluation of hospital cleanliness

BACKGROUND

Environmental cleaning is an effective measure to prevent infections. However, performance observation has been rarely delineated. This study aimed to compare correlations among visual inspection, performance observation, and effectiveness by using adenosine triphosphate bioluminescence (ATP bioluminescence) as a comparator to find out which method is better to assess hospital cleanliness.

METHODS

This prospective study was conducted at a medical center from April 2019 to October 2020. Seven high-touch surfaces were evaluated during and after terminal cleaning by performance observation, visual inspection, and ATP bioluminescence.

RESULTS

The scores by performance observation, visual inspection, and ATP were 55.4%, 87.5%, and 26.6% after cleaning. The correlations between performance observation and visual inspection and between performance observation and ATP interpretation were weak positive (φ = 0.300, 0.324, P < .001). No correlation was between the visual inspection and ATP interpretation (φ=0.137). The median of ATP readings was lower in "compliant" group by performance observation and "clean" group by visual inspection than "not compliant" group and "not clean" group (P < .001).

CONCLUSIONS

Performance observation combined with ATP would be preferred to include to audit cleanliness on high-risk surfaces. Visual inspection would be a rapid and time-saving assessment tool on low-risk surfaces.

Monitoring the effectiveness of daily cleaning practices in an intensive care unit (ICU) setting using an adenosine triphosphate (ATP) bioluminescence assay

BACKGROUND

The degree to which daily intensive care unit (ICU) cleaning practices impacts bacterial burden is controversial. The study aimed to assess the utility of using adenosine triphosphate (ATP) bioluminescence assays for monitoring effectiveness of daily cleaning in ICU environments.

METHODS

We sampled 364 total samples from 57 patient rooms and 18 common areas in 3 medical ICUs over 12 weeks, before and after routine daily cleaning. Endpoints were ATP levels (relative light units, RLU) and bacterial bioburden (colony forming units, CFU).

RESULTS

High-touch surfaces in ICU patient rooms and common areas were contaminated before and after cleaning. Routine cleaning significantly reduced bacterial burden in patient rooms (0.14 log₁₀ CFU reduction, P = .008; 0.21 log₁₀ RLU reduction, P < .001) and in ICU common areas (1.18 log₁₀ CFU reduction, P < .001; 0.72 log₁₀ RLU reduction, P < .001). Among sites with colony counts >20 CFUs, the proportion of sites with ATP readings >250 RLU was significantly higher than those with ATP readings ≤250 RLU (90.0% vs 10.0%, P < .05).

CONCLUSION

Routine cleaning significantly reduced bacterial burden on ICU environment surfaces. Although not an alternative to culture methods, ATP assays may be a useful technique to provide rapid feedback on surface cleanliness in ICU settings.

Assessment of antibiotic-resistant organism transmission among rooms of hospitalized patients, healthcare personnel, and the hospital environment utilizing surrogate markers and selective bacterial cultures

OBJECTIVE

To assess potential transmission of antibiotic-resistant organisms (AROs) using surrogate markers and bacterial cultures.

DESIGN

Pilot study.

SETTING

A 1,260-bed tertiary-care academic medical center.

PARTICIPANTS

The study included 25 patients (17 of whom were on contact precautions for AROs) and 77 healthcare personnel (HCP).

METHODS

Fluorescent powder (FP) and MS2 bacteriophage were applied in patient rooms. HCP visits to each room were observed for 2-4 hours; hand hygiene (HH) compliance was recorded. Surfaces inside and outside the room and HCP skin and clothing were assessed for fluorescence, and swabs were collected for MS2 detection by polymerase chain reaction (PCR) and selective bacterial cultures.

RESULTS

Transfer of FP was observed for 20 rooms (80%) and 26 HCP (34%). Transfer of MS2 was detected for 10 rooms (40%) and 15 HCP (19%). Bacterial cultures were positive for 1 room and 8 HCP (10%). Interactions with patients on contact precautions resulted in fewer FP detections than interactions with patients not on precautions (P < .001); MS2 detections did not differ by patient isolation status. Fluorescent powder detections did not differ by HCP type, but MS2 was recovered more frequently from physicians than from nurses (P = .03). Overall, HH compliance was better among HCP caring for patients on contact precautions than among HCP caring for patients not on precautions (P = .003), among nurses than among other nonphysician HCP at room entry (P = .002), and among nurses than among physicians at room exit (P = .03). Moreover, HCP who performed HH prior to assessment had fewer fluorescence detections (P = .008).

CONCLUSIONS

Contact precautions were associated with greater HCP HH compliance and reduced detection of FP and MS2.

Implementation of human factors engineering approach to improve environmental cleaning and disinfection in a medical center

Background

Inadequate hospital cleaning may contribute to cross-transmission of pathogens. It is important to implement effective cleaning for the safe hospital environment. We conducted a three-phase study using human factors engineering (HFE) approach to enhance environmental cleanliness.

Methods

This study was conducted using a prospective interventional trial, and 28 (33.3%) of 84 wards in a medical center were sampled. The three-phases included pre-intervention analysis (Phase 1), implementing interventions by HFE principles (Phase 2), and programmatic analysis (Phase 3). The evaluations of terminal cleaning and disinfection were performed using the fluorescent marker, the adenosine triphosphate bioluminescence assay, and the aerobic colony count method simultaneously in all phases. Effective terminal cleaning and disinfection was qualified with the aggregate outcome of the same 10 high-touch surfaces per room. A score for each high-touch surface was recorded, with 0 denoting a fail and 10 denoting a pass by the benchmark of the evaluation method, and the total terminal cleaning and disinfection score (TCD score) was a score out of 100.

Results

In each phase, 840 high-touch surfaces were collected from 84 rooms after terminal cleaning and disinfection. After the interventions, the TCD score by the three evaluation methods all showed significant improved. The carriage incidence of multidrug-resistant organism (MDRO) decreased significantly from 4.1 per 1000 patient-days to 3.6 per 1000 patient-days (P = .03).

Conclusion

The HFE approach can improve the thoroughness and the effectiveness of terminal cleaning and disinfection, and resulted in a reduction of patient carriage of MDRO at hospitals. Larger studies are necessary to establish whether such efforts of cleanliness can reduce the incidence of healthcare-associated infection.