Myreen E. Tomas

Contamination of Health Care Personnel During Removal of Personal Protective Equipment

IMPORTANCE Contamination of the skin and clothing of health care personnel during removal of personal protective equipment (PPE) contributes to dissemination of pathogens and places personnel at risk for infection. OBJECTIVES To determine the frequency and sites of contamination on the skin and clothing of personnel during PPE removal and to evaluate the effect of an intervention on the frequency of contamination. DESIGN, SETTING, AND PARTICIPANTS We conducted a point-prevalence study and quasi-experimental intervention from October 28, 2014, through March 31, 2015. Data analysis began November 17, 2014, and ended April 21, 2015. Participants included a convenience sample of health care personnel from 4 Northeast Ohio hospitals who conducted simulations of contaminated PPE removal using fluorescent lotion and a cohort of health care personnel from 7 study units in 1 medical center that participated in a quasi-experimental intervention that included education and practice in removal of contaminated PPE with immediate visual feedback based on fluorescent lotion contamination of skin and clothing. MAIN OUTCOMES AND MEASURES The primary outcomes were the frequency and sites of contamination on skin and clothing of personnel after removal of contaminated gloves or gowns at baseline vs after the intervention. A secondary end point focused on the correlation between contamination of skin with fluorescent lotion and bacteriophage MS2, a nonpathogenic, nonenveloped virus. RESULTS Of 435 glove and gown removal simulations, contamination of skin or clothing with fluorescent lotion occurred in 200 (46.0%), with a similar frequency of contamination among the 4 hospitals (range, 42.5%-50.3%). Contamination occurred more frequently during removal of contaminated gloves than gowns (52.9% vs 37.8%, P = .002) and when lapses in technique were observed vs not observed (70.3% vs 30.0%, P < .001). The intervention resulted in a reduction in skin and clothing contamination during glove and gown removal (60.0% before the intervention vs 18.9% after, P < .001) that was sustained after 1 and 3 months (12.0% at both time points, P < .001 compared with before the intervention). During simulations of contaminated glove removal, the frequency of skin contamination was similar with fluorescent lotion and bacteriophage MS2 (58.0% vs 52.0%, P = .45). CONCLUSIONS AND RELEVANCE Contamination of the skin and clothing of health care personnel occurs frequently during removal of contaminated gloves or gowns. Educational interventions that include practice with immediate visual feedback on skin and clothing contamination can significantly reduce the risk of contamination during removal of PPE.

A Modified R-Type Bacteriocin Specifically Targeting Clostridium difficile Prevents Colonization of Mice without Affecting Gut Microbiota Diversity

ABSTRACT Clostridium difficile is a leading cause of nosocomial infections worldwide and has become an urgent public health threat requiring immediate attention. Epidemic lineages of the BI/NAP1/027 strain type have emerged and spread through health care systems across the globe over the past decade. Limiting person-to-person transmission and eradicating C. difficile, especially the BI/NAP1/027 strain type, from health care facilities are difficult due to the abundant shedding of spores that are impervious to most interventions. Effective prophylaxis for C. difficile infection (CDI) is lacking. We have genetically modified a contractile R-type bacteriocin (“diffocin”) from C. difficile strain CD4 to kill BI/NAP1/027-type strains for this purpose. The natural receptor binding protein (RBP) responsible for diffocin targeting was replaced with a newly discovered RBP identified within a prophage of a BI/NAP1/027-type target strain by genome mining. The resulting modified diffocins (a.k.a. Avidocin-CDs), Av-CD291.1 and Av-CD291.2, were stable and killed all 16 tested BI/NAP1/027-type strains. Av-CD291.2 administered in drinking water survived passage through the mouse gastrointestinal (GI) tract, did not detectably alter the mouse gut microbiota or disrupt natural colonization resistance to C. difficile or the vancomycin-resistant Enterococcus faecium (VREF), and prevented antibiotic-induced colonization of mice inoculated with BI/NAP1/027-type spores. Given the high incidence and virulence of the pathogen, preventing colonization by BI/NAP1/027-type strains and limiting their transmission could significantly reduce the occurrence of the most severe CDIs. This modified diffocin represents a prototype of an Avidocin-CD platform capable of producing targetable, precision anti-C. difficile agents that can prevent and potentially treat CDIs without disrupting protective indigenous microbiota. IMPORTANCE Treatment and prevention strategies for bacterial diseases rely heavily on traditional antibiotics, which impose strong selection for resistance and disrupt protective microbiota. One consequence has been an upsurge of opportunistic pathogens, such as Clostridium difficile, that exploit antibiotic-induced disruptions in gut microbiota to proliferate and cause life-threatening diseases. We have developed alternative agents that utilize contractile bactericidal protein complexes (R-type bacteriocins) to kill specific C. difficile pathogens. Efficacy in a preclinical animal study indicates these molecules warrant further development as potential prophylactic agents to prevent C. difficile infections in humans. Since these agents do not detectably alter the indigenous gut microbiota or colonization resistance in mice, we believe they will be safe to administer as a prophylactic to block transmission in high-risk environments without rendering patients susceptible to enteric infection after cessation of treatment. Treatment and prevention strategies for bacterial diseases rely heavily on traditional antibiotics, which impose strong selection for resistance and disrupt protective microbiota. One consequence has been an upsurge of opportunistic pathogens, such as Clostridium difficile, that exploit antibiotic-induced disruptions in gut microbiota to proliferate and cause life-threatening diseases. We have developed alternative agents that utilize contractile bactericidal protein complexes (R-type bacteriocins) to kill specific C. difficile pathogens. Efficacy in a preclinical animal study indicates these molecules warrant further development as potential prophylactic agents to prevent C. difficile infections in humans. Since these agents do not detectably alter the indigenous gut microbiota or colonization resistance in mice, we believe they will be safe to administer as a prophylactic to block transmission in high-risk environments without rendering patients susceptible to enteric infection after cessation of treatment.

Metabolomics analysis identifies intestinal microbiota-derived biomarkers of colonization resistance in clindamycin-treated mice.

Background The intestinal microbiota protect the host against enteric pathogens through a defense mechanism termed colonization resistance. Antibiotics excreted into the intestinal tract may disrupt colonization resistance and alter normal metabolic functions of the microbiota. We used a mouse model to test the hypothesis that alterations in levels of bacterial metabolites in fecal specimens could provide useful biomarkers indicating disrupted or intact colonization resistance after antibiotic treatment. Methods To assess in vivo colonization resistance, mice were challenged with oral vancomycin-resistant Enterococcus or Clostridium difficile spores at varying time points after treatment with the lincosamide antibiotic clindamycin. For concurrent groups of antibiotic-treated mice, stool samples were analyzed using quantitative real-time polymerase chain reaction to assess changes in the microbiota and using non-targeted metabolic profiling. To assess whether the findings were applicable to another antibiotic class that suppresses intestinal anaerobes, similar experiments were conducted with piperacillin/tazobactam. Results Colonization resistance began to recover within 5 days and was intact by 12 days after clindamycin treatment, coinciding with the recovery bacteria from the families Lachnospiraceae and Ruminococcaceae, both part of the phylum Firmicutes. Clindamycin treatment caused marked changes in metabolites present in fecal specimens. Of 484 compounds analyzed, 146 (30%) exhibited a significant increase or decrease in concentration during clindamycin treatment followed by recovery to baseline that coincided with restoration of in vivo colonization resistance. Identified as potential biomarkers of colonization resistance, these compounds included intermediates in carbohydrate or protein metabolism that increased (pentitols, gamma-glutamyl amino acids and inositol metabolites) or decreased (pentoses, dipeptides) with clindamycin treatment. Piperacillin/tazobactam treatment caused similar alterations in the intestinal microbiota and fecal metabolites. Conclusions Recovery of colonization resistance after antibiotic treatment coincided with restoration of several fecal bacterial metabolites. These metabolites could provide useful biomarkers indicating intact or disrupted colonization resistance during and after antibiotic treatment.

Overdiagnosis of Urinary Tract Infection and Underdiagnosis of Sexually Transmitted Infection in Adult Women Presenting to an Emergency Department

ABSTRACT Urinary tract infections (UTIs) and sexually transmitted infections (STIs) are commonly diagnosed in emergency departments (EDs). Distinguishing between these syndromes can be challenging because of overlapping symptomatology and because both are associated with abnormalities on urinalysis (UA). We conducted a 2-month observational cohort study to determine the accuracy of clinical diagnoses of UTI and STI in adult women presenting with genitourinary (GU) symptoms or diagnosed with GU infections at an urban academic ED. For all urine specimens, UA, culture, and nucleic acid amplification testing for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis were performed. Of 264 women studied, providers diagnosed 175 (66%) with UTIs, 100 (57%) of whom were treated without performing a urine culture during routine care. Combining routine care and study-performed urine cultures, only 84 (48%) of these women had a positive urine culture. Sixty (23%) of the 264 women studied had one or more positive STI tests, 22 (37%) of whom did not receive treatment for an STI within 7 days of the ED visit. Fourteen (64%) of these 22 women were diagnosed with a UTI instead of an STI. Ninety-two percent of the women studied had an abnormal UA finding (greater-than-trace leukocyte esterase level, positive nitrite test result, or pyuria). The positive and negative predictive values of an abnormal UA finding were 41 and 76%, respectively. In this population, empirical therapy for UTI without urine culture testing and overdiagnosis of UTI were common and associated with unnecessary antibiotic exposure and missed STI diagnoses. Abnormal UA findings were common and not predictive of positive urine cultures.

Chlorhexidine Only Works If Applied Correctly: Use of a Simple Colorimetric Assay to Provide Monitoring and Feedback on Effectiveness of Chlorhexidine Application

We used a colorimetric assay to determine the presence of chlorhexidine on skin, and we identified deficiencies in preoperative bathing and daily bathing in the intensive care unit. Both types of bathing improved with an intervention that included feedback to nursing staff. The assay provides a simple and rapid method of monitoring the performance of chlorhexidine bathing.

A Clostridium difficile infection (CDI) stewardship initiative improves adherence to practice guidelines for management of CDI.

A Clostridium difficile infection (CDI) stewardship initiative reduced inappropriate prescription of empirical CDI therapy and improved timeliness of treatment and adherence to clinical practice guidelines for management of CDI. The initiative required minimal resources and could easily be incorporated into traditional antimicrobial stewardship programs.

Effect of Variation in Test Methods on Performance of Ultraviolet-C Radiation Room Decontamination

OBJECTIVE To determine the effect of variation in test methods on performance of an ultraviolet-C (UV-C) room decontamination device. DESIGN Laboratory evaluation. METHODS We compared the efficacy of 2 UV-C room decontamination devices with low pressure mercury gas bulbs. For 1 of the devices, we evaluated the effect of variation in spreading of the inoculum, carrier orientation relative to the device, type of organic load, type of carrier, height of carrier, and uninterrupted versus interrupted exposures on measured UV-C killing of methicillin-resistant Staphylococcus aureus and Clostridium difficile spores. RESULTS The 2 UV-C room decontamination devices achieved similar log10 colony-forming unit reductions in the pathogens with exposure times ranging from 5 to 40 minutes. On steel carriers, spreading of the inoculum over a larger surface area significantly enhanced killing of both pathogens, such that a 10-minute exposure on a 22-mm2 disk resulted in greater than 2 log reduction in C. difficile spores. Orientation of carriers in parallel rather than perpendicular with the UV-C lamps significantly enhanced killing of both pathogens. Different types of organic load also significantly affected measured organism reductions, whereas type of carrier, variation in carrier height, and interrupted exposure cycles did not. CONCLUSIONS Variation in test methods can significantly impact measured reductions in pathogens by UV-C devices during experimental testing. Our findings highlight the need for standardized laboratory methods for testing the efficacy of UV-C devices and for evaluations of the efficacy of short UV-C exposure times in real-world settings.

Acquisition of Clostridium difficile on Hands of Healthcare Personnel Caring for Patients with Resolved C. difficile Infection

In an observational study, we found that healthcare personnel frequently acquired Clostridium difficile on their hands when caring for patients with recently resolved C. difficile infection (CDI) (<6 weeks after treatment) who were no longer under contact precautions. Continuing contact precautions after diarrhea resolves may be useful to reduce transmission.

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.

Tigecycline exhibits inhibitory activity against Clostridium difficile in the intestinal tract of hospitalised patients

No new acquisition of Clostridium difficile occurred among 12 hospitalised patients receiving tigecycline, and pre-existing colonisation was reduced to undetectable levels in 2 patients. Moreover, 91% of stool suspensions obtained during tigecycline therapy exhibited inhibitory activity against C. difficile. These results suggest that tigecycline achieves sufficient concentrations to inhibit intestinal colonisation by C. difficile.