Why Does Doxycycline Pose a Relatively Low Risk for Promotion of Clostridioides difficile Infection?

Background: Clinical studies suggest that doxycycline poses a low risk for promotion of Clostridioides difficile infection, but the microbiologic explanation for this finding is unclear. Methods: Mice treated with oral doxycycline, oral azithromycin, subcutaneous ceftriaxone, doxycycline plus ceftriaxone, or azithromycin plus ceftriaxone were challenged with 104 colony-forming units of 2 different C. difficile strains on day 2 of 5 of treatment. The concentration of C. difficile was measured in stool 2 and 5 days after challenge. The impact of the treatments on the microbiota was assessed by sequencing. Results: Doxycycline and azithromycin treatment did not promote colonization by either C. difficile strain in comparison to saline controls. Doxycycline treatment significantly reduced ceftriaxone-induced overgrowth of a C. difficile strain with doxycycline minimum-inhibitory concentration (MIC) of 0.06 µg/mL (P<0.01) but not a strain with doxycycline MIC of 48 µg/mL (P>0.05); azithromycin treatment did not reduce ceftriaxone-induced overgrowth of either strain. 16S rRNA amplicon sequencing revealed significantly lower bacterial diversity in the stool of ceftriaxone-treated mice, in comparison to doxycycline-treated and azithromycin-treated mice. Conclusions: These findings suggest that doxycycline may have a low propensity to promote C. difficile colonization because it causes relatively limited alteration of the indigenous microbiota that provide colonization resistance and because it provides inhibitory activity against some C. difficile strains.

What are the sources of exposure in healthcare personnel with coronavirus disease 2019 infection?

In our facility, 25% of personnel with coronavirus disease 2019 (COVID-19) had a higher-risk exposure to an infected patient or co-worker and 14% reported a higher-risk exposure in the community. All higher-risk exposures to infected patients occurred on non-COVID-19 units, often when there was a delay in diagnosis because COVID-19 was not initially suspected. Higher-risk exposures to co-workers with COVID-19 often involved lapses in compliance with masking in nonpatient care areas such as nursing stations and staff work or break rooms.

Efficacy of a novel ultraviolet light-emitting diode device for decontamination of shared pens in a health care setting.

Shared pens and styluses are a potential source for transmission of health care-associated pathogens and respiratory viruses in health care facilities. A novel ultraviolet light-emitting diode device was effective in reducing bacteria and viruses inoculated on pens and in reducing methicillin-resistant Staphylococcus aureus transferred to pens by colonized patients. The device could be useful in reducing the risk of transmission of pathogens by shared writing utensils.

Effectiveness of foam disinfectants in reducing sink-drain gram-negative bacterial colonization.

BACKGROUND: Sink drainage systems are not amenable to standard methods of cleaning and disinfection. Disinfectants applied as a foam might enhance efficacy of drain decontamination due to greater persistence and increased penetration into sites harboring microorganisms. OBJECTIVE: To examine the efficacy and persistence of foam-based products in reducing sink drain colonization with gram-negative bacilli. METHODS: During a 5-month period, different methods for sink drain disinfection in patient rooms were evaluated in a hospital and its affiliated long-term care facility. We compared the efficacy of a single treatment with 4 different foam products in reducing the burden of gram-negative bacilli in the sink drain to a depth of 2.4 cm (1 inch) below the strainer. For the most effective product, the effectiveness of foam versus liquid-pouring applications, and the effectiveness of repeated foam treatments were evaluated. RESULTS: A foam product containing 3.13% hydrogen peroxide and 0.05% peracetic acid was significantly more effective than the other 3 foam products. In comparison to pouring the hydrogen peroxide and peracetic acid disinfectant, the foam application resulted in significantly reduced recovery of gram-negative bacilli on days 1, 2, and 3 after treatment with a return to baseline by day 7. With repeated treatments every 3 days, a progressive decrease in the bacterial load recovered from sink drains was achieved. CONCLUSIONS: An easy-to-use foaming application of a hydrogen peroxide- and peracetic acid-based disinfectant suppressed sink-drain colonization for at least 3 days. Intermittent application of the foaming disinfectant could potentially reduce the risk for dissemination of pathogens from sink drains.

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.

A crossover trial comparing contamination of healthcare personnel during removal of a standard gown versus a modified gown with increased skin coverage at the hands and wrists.

In a crossover trial, a gown designed to increase skin coverage at the hands and wrists significantly reduced contamination of personnel during personal protective equipment (PPE) removal, and education on donning and doffing technique further reduced contamination. Simple modifications of PPE and education can reduce contamination during PPE removal.

Impact of routine use of a spray formulation of bleach on Clostridium difficile spore contamination in non-C difficile infection rooms.

The frequency of recovery of Clostridium difficile spores from surfaces after postdischarge cleaning of non-C difficile infection rooms was significantly reduced from 24%-5% after a commercial spray formulation of bleach was substituted for a quaternary ammonium disinfectant. These results suggest that routine use of a sporicidal disinfectant in all postdischarge rooms could potentially be beneficial in reducing the risk for C difficile transmission from contaminated surfaces.

Contamination of health care personnel during removal of contaminated gloves.

In simulations of contaminated glove removal, 37% of health care personnel using their typical doffing technique contaminated their skin with a fluorescent solution. The frequency of contamination was significantly lower when the technique recommended by the Centers for Disease Control and Prevention was used versus not used (8 of 34, 24% vs 29 of 66, 44%). In simulations in which only the palm of the glove was contaminated, a modified doffing technique, to minimize the risk for contact with contaminated surfaces, reduced contamination of personnel.

Tapering Courses of Oral Vancomycin Induce Persistent Disruption of the Microbiota That Provide Colonization Resistance to Clostridium difficile and Vancomycin-Resistant Enterococci in Mice.

Vancomycin taper regimens are commonly used for the treatment of recurrent Clostridium difficile infections. One rationale for tapering and pulsing of the dose at the end of therapy is to reduce the selective pressure of vancomycin on the indigenous intestinal microbiota. Here, we used a mouse model to test the hypothesis that the indigenous microbiota that provide colonization resistance against C. difficile and vancomycin-resistant enterococci (VRE) is repopulated during tapering courses of vancomycin. Mice were treated orally with vancomycin daily for 10 days, vancomycin in a tapering dose for 42 days, fidaxomicin for 10 days, or saline. To assess colonization resistance, subsets of mice were challenged with 104 CFU of C. difficile or VRE at multiple time points during and after completion of treatment. The impact of the treatments on the microbiome was measured by cultures, real-time PCR for selected anaerobic bacteria, and deep sequencing. Vancomycin taper-treated mice developed alterations of the microbiota and disruption of colonization resistance that was persistent 18 days after treatment. In contrast, mice treated with a 10-day course of vancomycin exhibited recovery of the microbiota and of colonization resistance by 15 days after treatment, and fidaxomicin-treated mice maintained intact colonization resistance. These findings demonstrate that alteration of the indigenous microbiota responsible for colonization resistance to C. difficile and VRE persist during and after completion of tapering courses of vancomycin.

A Randomized Trial of Two Cover Gowns Comparing Contamination of Healthcare Personnel During Removal of Personal Protective Equipment.

In a randomized trial, a gown designed to allow easy removal at the neck and with increased skin coverage and snugness of fit at the wrist significantly reduced contamination of personnel during personal protective equipment (PPE) removal. Our results suggest that simple modifications of PPE can reduce contamination of personnel. Infect Control Hosp Epidemiol 2018;39:97-100.

How well does transfer of bacterial pathogens by culture swabs correlate with transfer by hands?

In laboratory testing and in isolation rooms, pickup and transfer of health care-associated pathogens by premoistened rayon swabs correlated well with pickup and transfer by bare hands or moistened gloves. These results suggest that swab cultures provide a useful surrogate indicator of the risk for pathogen pickup and transfer by hands.

Evaluation of an automated room decontamination device using aerosolized peracetic acid.

Because manual cleaning is often suboptimal, there is increasing interest in use of automated devices for room decontamination. We demonstrated that an ultrasonic room fogging system that generates submicron droplets of peracetic acid and hydrogen peroxide eliminated Clostridium difficile spores and vegetative pathogens from exposed carriers in hospital rooms and adjacent bathrooms.

Are health care personnel trained in correct use of personal protective equipment?

Effective use of personal protective equipment (PPE) is essential to protect personnel and patients in health care settings. However, in a survey of 222 health care personnel, PPE training was often suboptimal with no requirement for demonstration of proficiency. Fourteen percent of physicians reported no previous training in use of PPE.

Utility of a Novel Reflective Marker Visualized by Flash Photography for Assessment of Personnel Contamination During Removal of Personal Protective Equipment.

In an experimental study, the frequency of contamination of healthcare personnel during removal of contaminated personal protective equipment (PPE) was similar for bacteriophage MS2 and a novel reflective marker visualized using flash photography. The reflective marker could be a useful tool to visualize and document personnel contamination during PPE removal. Infect Control Hosp Epidemiol 2016;37:711-713.

A Novel, Sporicidal Formulation of Ethanol for Glove Decontamination to Prevent Clostridium difficile Hand Contamination During Glove Removal.

Decontamination of gloves before removal could reduce the risk for contamination of hands of personnel caring for patients with Clostridium difficile infection. We demonstrated that a novel sporicidal formulation of ethanol rapidly reduced C. difficile spores on gloved hands without adverse odor, respiratory irritation, or staining of clothing.