Clostridioides Difficile Spores Research Articles

Robust and Transparent Silver Oxide Coating Fabricated at Room Temperature Kills Clostridioides difficile Spores, MRSA, and Pseudomonas aeruginosa.

Antimicrobial coatings can inhibit the transmission of infectious diseases when they provide a quick kill that is achieved long after the coating application. Here, we describe the fabrication and testing of a glass coating containing Ag2O microparticles that was prepared from sodium silicate at room temperature. The half-lives of both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa on this coating are only 2-4 min. The half-life of Clostridioides difficile spores is about 9-12 min, which is extremely short for a spore. Additional tests on MRSA demonstrate that the coating retains its antimicrobial activity after abrasion and that an increased loading of Ag2O leads to a shorter half-life. This coating combines the properties of optical transparency, robustness, fast kill, and room temperature preparation that are highly desirable for an antimicrobial coating.

The design, synthesis, and inhibition of Clostridioides difficile spore germination by acyclic and bicyclic tertiary amide analogs of cholate

Clostridioides difficile infection (CDI) is a major identifiable cause of antibiotic-associated diarrhea. In our previous study (J. Med. Chem., 2018, 61, 6759–6778), we have identified N-phenyl-cholan-24-amide as a potent inhibitor of spore germination. The most potent compounds in our previous work are N-arylamides. We were interested in the role that the conformation of the amide plays in activity. Previous research has shown that secondary N-arylamides exist exclusively in the coplanar trans conformation while tertiary N-methyl-N-arylamides exist in a non-planar, cis conformation. The N-methyl-N-phenyl-cholan-24-amide was 17-fold less active compared to the parent compounds suggesting the importance of the orientation of the phenyl ring. To lock the phenyl ring into a trans conformation, cyclic tertiary amides were prepared. Indoline and quinoline cholan-24-amides were both inhibitors of spore germination; however, the indoline analogs were most potent. Isoindoline and isoquinoline amides were inactive. We found that the simple indoline derivative gave an IC50 value of 1 μM, while the 5′-fluoro-substituted compound (5d) possessed an IC50 of 400 nM. To our knowledge, 5d is the most potent known spore germination inhibitor described to date. Taken together, our results indicate that the trans, coplanar conformation of the phenyl ring is required for potent inhibition.

Efficacy of a far-ultraviolet-C light technology for continuous decontamination of air and surfaces.

A wall-mounted, far-ultraviolet-C light technology reduced aerosolized bacteriophage MS2 by >3 log10 plaque-forming units within 30 minutes. Vegetative bacterial pathogens on steel disk carriers in the center of the room were reduced by >3 log10 after 45 minutes of exposure, but Candida auris and Clostridioides difficile spores were not.

Single-spore germination analyses reveal that calcium released during Clostridioides difficile germination functions in a feedforward loop.

Clostridioides difficile infections begin when its metabolically dormant spores germinate in response to sensing bile acid germinants alongside amino acid and divalent cation co-germinants in the small intestine. While bile acid germinants are essential for C. difficile spore germination, it is currently unclear whether both co-germinant signals are required. One model proposes that divalent cations, particularly Ca2+, are essential for inducing germination, while another proposes that either co-germinant class can induce germination. The former model is based on the finding that spores defective in releasing large stores of internal Ca2+ in the form of calcium dipicolinic acid (CaDPA) cannot germinate when germination is induced with bile acid germinant and amino acid co-germinant alone. However, since the reduced optical density of CaDPA-less spores makes it difficult to accurately measure their germination, we developed a novel automated, time-lapse microscopy-based germination assay to analyze CaDPA mutant germination at the single-spore level. Using this assay, we found that CaDPA mutant spores germinate in the presence of amino acid co-germinant and bile acid germinant. Higher levels of amino acid co-germinants are nevertheless required to induce CaDPA mutant spores to germinate relative to WT spores because CaDPA released by WT spores during germination can function in a feedforward loop to potentiate the germination of other spores within the population. Collectively, these data indicate that Ca2+ is not essential for inducing C. difficile spore germination because amino acid and Ca2+ co-germinant signals are sensed by parallel signaling pathways. IMPORTANCE Clostridioides difficile spore germination is essential for this major nosocomial pathogen to initiate infection. C. difficile spores germinate in response to sensing bile acid germinant signals alongside co-germinant signals. There are two classes of co-germinant signals: Ca2+ and amino acids. Prior work suggested that Ca2+ is essential for C. difficile spore germination based on bulk population analyses of germinating CaDPA mutant spores. Since these assays rely on optical density to measure spore germination and the optical density of CaDPA mutant spores is reduced relative to WT spores, this bulk assay is limited in its capacity to analyze germination. To overcome this limitation, we developed an automated image analysis pipeline to monitor C. difficile spore germination using time-lapse microscopy. With this analysis pipeline, we demonstrate that, although Ca2+ is dispensable for inducing C. difficile spore germination, CaDPA can function in a feedforward loop to potentiate the germination of neighboring spores.

The effect of cold storage and cooking on the viability of Clostridioides difficile spores in consumer foods.

The increased detection of clinical cases of Clostridioides difficile coupled with the persistence of clostridial spores at various stages along the food chain suggest that this pathogen may be foodborne. This study examined C. difficile (ribotypes 078 and 126) spore viability in chicken breast, beef steak, spinach leaves and cottage cheese during refrigerated (4°C) and frozen (-20°C) storage with and without a subsequent sous vide mild cooking (60°C, 1h). Spore inactivation at 80°C in phosphate buffer solution, beef and chicken were also investigated to provide D80°C values and determine if PBS was a suitable model system for real food matrices. There was no decrease in spore concentration after chilled or frozen storage and/or sous vide cooking at 60°C. Non-log-linear thermal inactivation was observed for both C. difficile ribotypes at 80°C in phosphate buffer solution (PBS), beef and chicken. The predicted PBS D80°C values of 5.72±[2.90, 8.55] min and 7.50±[6.61, 8.39] min for RT078 and RT126, respectively, were in agreement with the food matrices D80°C values of 5.65min (95% CI range from 4.29 to 8.89min) for RT078 and 7.35min (95% CI range from 6.81 to 7.01min) for RT126. It was concluded that C. difficile spores survive chilled and frozen storage and mild cooking at 60°C but may be inactivated at 80°C. Moreover thermal inactivation in PBS was representative of that observed in real food matrices (beef and chicken).

Mechanism of germination inhibition of Clostridioides difficile spores by an aniline substituted cholate derivative (CaPA).

Clostridioides difficile infection (CDI) is the major identifiable cause of antibiotic-associated diarrhea and has been declared an urgent threat by the CDC. C. difficile forms dormant and resistant spores that serve as infectious vehicles for CDI. To cause disease, C. difficile spores recognize taurocholate and glycine to trigger the germination process. In contrast to other sporulating bacteria, C. difficile spores are postulated to use a protease complex, CspABC, to recognize its germinants. Since spore germination is required for infection, we have developed anti-germination approaches for CDI prophylaxis. Previously, the bile salt analog CaPA (an aniline-substituted cholic acid) was shown to block spore germination and protect rodents from CDI caused by multiple C. difficile strains and isolates. In this study, we found that CaPA is an alternative substrate inhibitor of C. difficile spore germination. By competing with taurocholate for binding, CaPA delays C. difficile spore germination and reduces spore viability, thus diminishing the number of outgrowing vegetative bacteria. We hypothesize that the reduction of toxin-producing bacterial burden explains CaPA's protective activity against murine CDI. Previous data combined with our results suggests that CaPA binds tightly to C. difficile spores in a CspC-dependent manner and irreversibly traps spores in an alternative, time-delayed, and low yield germination pathway. Our results are also consistent with kinetic data suggesting the existence of at least two distinct bile salt binding sites in C. difficile spores.

Survival of Clostridioides difficile spores in thermal and chemo-thermal laundering processes and influence of the exosporium on their adherence to cotton bed sheets.

Clostridioides difficile spores were previously demonstrated to survive industrial laundering. Understanding interactions between heat, disinfectants and soiling (e.g. bodily fluids) affecting C. difficile spore survival could inform the optimization of healthcare laundry processes. Reducing spore attachment to linen could also enhance laundering efficacy. This study aimed to compare the sensitivity of C. difficile spores to heat and detergent, with and without soiling and to investigate adherence to cotton. Survival of C. difficile spores exposed to industrial laundering temperatures (71-90°C), reference detergent and industrial detergent was quantified with and without soiling. The adherence to cotton after 0 and 24 h air drying was determined with the exosporium of C. difficile spores partially or fully removed. Clostridioides difficile spores were stable at 71°C for 20 min (≤0·37 log10 reduction) while 90°C was sporicidal (3 log10 reduction); soiling exerted a protective effect. Industrial detergent was more effective at 71°C compared to 25°C (2·81 vs 0·84 log10 reductions), however, specifications for sporicidal activity (>3 log10 reduction) were not met. Clostridioides difficile spores increasingly adhered to cotton over time, with 49% adherence after 24 h. Removal of the exosporium increased adherence by 19-23% compared to untreated spores. Further understanding of the role of the exosporium in attachment to cotton could enhance spore removal and aid decontamination of linen.

Airborne spores’ dissemination of a swine associated Clostridioides difficile clone

This study supports the airborne dissemination of Clostridioides difficile spores. Of the sieve impaction samples collected at a swine production unit, 66.7% were positive and all belonged to the predominantly established clone. Spores’ density varied according to the characteristics of the animal population, suggesting the possibility of airborne transmission.

Implementation of Antibacterial Nanoparticles in Additive Manufacturing to Increase Part Strength and Stiffness

The introduction of novel composites suited for additive manufacturing machines offers a solution for the current slow adoption of the technology. Many composites offer secondary functions and mechanical improvements to suit unique applications better. This article presents the creation of a set of novel nanocomposites consisting of zinc oxide (ZnO) and a photocurable resin using a masked stereolithography additive machine. These nanocomposites are produced in 1%, 2.5%, 5%, and 7.5% concentrations and are characterized based on their mechanical and surface properties. Using ZnO allows for the creation of mechanically stronger parts with reduced wettability while offering antibacterial properties throughout the entire part. Best results were observed at a 5% concentration of ZnO with a nearly 25% strength increase and 45% decrease in wettability. Additionally, SEM analysis demonstrated proper dispersion with minimal agglomerations present. In the sporicidal effect analysis, the ZnO (with 7.5% concentration) reduced 31.5% of Clostridioides difficile spores. These results demonstrate the capability of producing antibacterial nanocomposites using low-cost additive manufacturing to enhance public health options.

Efficacy of Dry Heat Treatment against Clostridioides difficile Spores and Mycobacterium tuberculosis on Filtering Facepiece Respirators.

The COVID-19 pandemic has required novel solutions, including heat disinfection of personal protective equipment (PPE) for potential reuse to ensure availability for healthcare and other frontline workers. Understanding the efficacy of such methods on pathogens other than SARS-CoV-2 that may be present on PPE in healthcare settings is key to worker safety, as some pathogenic bacteria are more heat resistant than SARS-CoV-2. We assessed the efficacy of dry heat treatment against Clostridioides difficile spores and Mycobacterium tuberculosis (M. tb) on filtering facepiece respirator (FFR) coupons in two inoculums. Soil load (mimicking respiratory secretions) and deionized water was used for C. difficile, whereas, soil load and PBS and Tween mixture was used for M. tb. Dry heat treatment at 85 °C for 240 min resulted in a reduction equivalent to 6.0-log10 CFU and 7.3-log10 CFU in C. difficile spores inoculated in soil load and deionized water, respectively. Conversely, treatment at 75 °C for 240 min led to 4.6-log10 CFU reductions in both soil load and deionized water. C. difficile inactivation was higher by >1.5-log10 CFU in deionized water as compared to soil load (p < 0.0001), indicating the latter has a protective effect on bacterial spore inactivation at 85 °C. For M. tb, heat treatment at 75 °C for 90 min and 85 °C for 30 min led to 8-log10 reduction with or without soil load. Heat treatment near the estimated maximal operating temperatures of FFR materials (which would readily eliminate SARS-CoV-2) did not achieve complete inactivation of C. difficile spores but was successful against M. tb. The clinical relevance of surviving C. difficile spores when subjected to heat treatment remains unclear. Given this, any disinfection method of PPE for potential reuse must ensure the discarding of any PPE, potentially contaminated with C. difficile spores, to ensure the safety of healthcare workers.

Efficacy of five ‘sporicidal’ surface disinfectants against Clostridioides difficile spores in suspension tests and 4-field tests

A sporicidal surface disinfection is recommended both for the outbreak and the endemic setting but a comparative evaluation on the efficacy of 'sporicidal' surface disinfectants using suspension tests and 4-field tests has not been performed. To determine the efficacy of five 'sporicidal' surface disinfectants (three ready-to-use wipes (A, B, E), two concentrates (C, D) based on peroxides or aldehydes against C.difficile spores. The efficacy was determined under clean conditions using a suspension test and the 4-field test. Each test was performed in duplicate in two separate laboratories. Wipes were wrung to collect the solution for the suspension tests. Product A (peracetic acid; 5min), product C (peracetic acid; 2% solution in 15min or 1% solution in 30min) and product D (peracetic acid; only 2% solution in 15min) were effective with at least a 4 log10-reduction of C.difficile spores in suspension and on surfaces. Product B (hydrogen peroxide) was not effective in suspension (0.9 log10 after 15min; 3.2 log10 after 1h) and on surfaces (2.8 log10 after 15 and 60min). Product E based on glutaraldehyde, (ethylendioxy)dimethanol and DDAC demonstrated 0.9 log10 after 4h in suspension and 4.5 log10 after 4h on surfaces. Not all surface disinfectants with a sporicidal claim were effective against C.difficile spores in standardized suspension tests and in the 4-field test. In clinical practice preference should be given to products that reliably pass the efficacy criteria of both types of tests.

Survivability of Clostridioides difficile spores in fermented pork summer sausage during refrigerated storage.

Background and Aim:Clostridioides difficile is a spore-forming pathogen that causes serious enteric disease in humans. Strains have been isolated from food animals and meat, including pork, which suggest a potential for foodborne transmission. Pork summer sausage is a popular fermented meat product, which is consumed cooked or cooked to a lower internal temperature due to acidification of the product. The effect of acidity and cooking on the viability of C. difficile spores in a fermented meat product has not been determined. Therefore, the aim was to study the survivability of C. difficile spores in fermented pork summer sausage.Materials and Methods:Fermented pork sausages were prepared according to a commercial recipe with or without starter culture and C. difficile spores followed by fermentation at 37°C for ~12 h under 85% relative humidity until pH 5.0 was reached and further processed as cooked (>57°C) or uncooked (≤57°C) and stored at 4°C. C. difficile spores in sausages were enumerated at 1 h following inoculation and on days 0, 1, 7, 14, 21, 30, 60, and 90 of storage.Results:It was observed that C. difficile spore viability in control unfermented treatment was significantly different on day 0 from the fermented, fermented cooked, and control unfermented cooked treatments (p<0.05); however, there was no significant difference among the latter three treatment groups throughout 90 days of storage (p>0.05). On day 90 of storage, the unfermented control sausages yielded ~4.0 log colony-forming unit (CFU)/g of C. difficile spores compared to ~3.5 log CFU/g recovered from fermented samples and the unfermented cooked control samples identifying spore viability in all treatment groups.Conclusion:C. difficile spores were found to survive the acidity and cooking of fermented pork summer sausage and storage at 4°C for 3 months, thereby highlighting the need for effective intervention strategies to reduce the risk of C. difficile contamination in pork products.

Using a ligate intestinal loop mouse model to investigate Clostridioides difficile adherence to the intestinal mucosa in aged mice.

Interaction of Clostridioides difficile spores with the intestinal mucosa contributes to the persistence and recurrence of the infection. Advanced age is one of the main risk factors for C. difficile infection and recurrence of the disease. However, interaction of C. difficile spores with the intestinal mucosa during aging has not been evaluated. In the present work, using intestinal ligated loop technique in a mouse model, we analyzed C. difficile spore adherence and internalization to the ileum and colonic mucosa during aging. Additionally, we provide visual documentation of the critical steps of the procedure. Consequently, our data suggest that spore internalization in the ileum and colonic mucosa is higher in elderly mice rather than adults or young mice. Also, our data suggest that spore adherence to the ileum and colonic mucosa decreases with aging.

A lipoprotein allosterically activates the CwlD amidase during Clostridioides difficile spore formation.

Spore-forming pathogens like Clostridioides difficile depend on germination to initiate infection. During gemination, spores must degrade their cortex layer, which is a thick, protective layer of modified peptidoglycan. Cortex degradation depends on the presence of the spore-specific peptidoglycan modification, muramic-∂-lactam (MAL), which is specifically recognized by cortex lytic enzymes. In C. difficile, MAL production depends on the CwlD amidase and its binding partner, the GerS lipoprotein. To gain insight into how GerS regulates CwlD activity, we solved the crystal structure of the CwlD:GerS complex. In this structure, a GerS homodimer is bound to two CwlD monomers such that the CwlD active sites are exposed. Although CwlD structurally resembles amidase_3 family members, we found that CwlD does not bind Zn2+ stably on its own, unlike previously characterized amidase_3 enzymes. Instead, GerS binding to CwlD promotes CwlD binding to Zn2+, which is required for its catalytic mechanism. Thus, in determining the first structure of an amidase bound to its regulator, we reveal stabilization of Zn2+ co-factor binding as a novel mechanism for regulating bacterial amidase activity. Our results further suggest that allosteric regulation by binding partners may be a more widespread mode for regulating bacterial amidase activity than previously thought.

Impact of Oral Metronidazole, Vancomycin, and Fidaxomicin on Host Shedding and Environmental Contamination With Clostridioides difficile.

Shedding of Clostridioides difficile spores from infected individuals contaminates the hospital environment and contributes to infection transmission. We assessed whether antibiotic selection affects C. difficile shedding and contamination of the hospital environment. In this prospective, unblinded, randomized controlled trial of hospitalized adults with C. difficile infection, patients were randomized 1:1:1 to receive fidaxomicin, oral vancomycin, or metronidazole. The primary outcome was change in environmental contamination rate during treatment. Secondary outcomes included stool shedding, total burden of contamination, and molecular relatedness of stool versus environmental C. difficile isolates. Of 33 patients enrolled, 31 (94%) completed the study. Fidaxomicin (-0.36 log10 colony-forming units [CFUs]/d [95% confidence interval (CI), -.52 to -.19]; P < .01) and vancomycin (-0.17 log10 CFUs/d [-.34 to -.01]; P = .05) were associated with more rapid decline in C. difficile shedding than metronidazole (-0.01 log10 CFUs/d [95% CI, -.10 to .08). Both vancomycin (6.3% [95% CI, 4.7-8.3) and fidaxomicin (13.1% [10.7-15.9]) were associated with lower rates of environmental contamination than metronidazole (21.4% [18.0-25.2]). With specific modeling of within-subject change over time, fidaxomicin (adjusted odds ratio, 0.83 [95% CI, .70-.99]; P = .04) was associated with more rapid decline in environmental contamination than vancomycin or metronidazole. Overall, 207 of 233 environmental C. difficile isolates (88.8%) matched patient stool isolates by ribotyping, without significant difference by treatment. Fidaxomicin, and to a lesser extent vancomycin, reduces C. difficile shedding and contamination of the hospital environment relative to metronidazole. Treatment choice may play a role in reducing healthcare-associated C. difficile transmission. NCT02057198.

A cortex-specific penicillin-binding protein contributes to heat resistance in Clostridioides difficile spores

BackgroundSporulation is a complex cell differentiation programme shared by many members of the Firmicutes, the end result of which is a highly resistant, metabolically inert spore that can survive harsh environmental insults. Clostridioides difficile spores are essential for transmission of disease and are also required for recurrent infection. However, the molecular basis of sporulation is poorly understood, despite parallels with the well-studied Bacillus subtilis system. The spore envelope consists of multiple protective layers, one of which is a specialised layer of peptidoglycan, called the cortex, that is essential for the resistant properties of the spore. We set out to identify the enzymes required for synthesis of cortex peptidoglycan in C. difficile. MethodsBioinformatic analysis of the C. difficile genome to identify putative homologues of Bacillus subtilis spoVD was combined with directed mutagenesis and microscopy to identify and characterise cortex-specific PBP activity. ResultsDeletion of CDR20291_2544 (SpoVDCd) abrogated spore formation and this phenotype was completely restored by complementation in cis. Analysis of SpoVDCd revealed a three domain structure, consisting of dimerization, transpeptidase and PASTA domains, very similar to B. subtilis SpoVD. Complementation with SpoVDCd domain mutants demonstrated that the PASTA domain was dispensable for formation of morphologically normal spores. SpoVDCd was also seen to localise to the developing spore by super-resolution confocal microscopy. ConclusionsWe have identified and characterised a cortex specific PBP in C. difficile. This is the first characterisation of a cortex-specific PBP in C. difficile and begins the process of unravelling cortex biogenesis in this important pathogen.

Inactivation of Clostridioides Difficile Spores in Carpeting and Upholstery to Reduce Disease Recurrence in Households and Nursing Care Facilities

Objective: Clostridioides difficile (formerly Clostridium difficile) is among the most reported hospital and community-acquired gastrointestinal infections. Spores produced by this bacterium cause the initial disease and recurrent C. difficile infections (rCDI) and survive for long periods in the environment. Killing of C. difficile spores in carpeting and upholstery is very challenging without destruction or alteration of the fiber matrix material. In this study, we evaluated a fiber-safe standardized method for inhibiting germination of C. difficile spores recovered from in carpeting and upholstery material and thereby reduce the risk of disease incidence in households and nursing care facilities. Methods and Results : In this study, we found that the most effective procedure for the recovery of C. difficile spores from short-fiber textile surfaces used an ammonium phosphate-gelatin buffer, stainless steel beads to extract the spores from the carpet samples, and the addition of a heat activation step prior to plating. Virasept®, a known sporicide containing hydrogen peroxide and peroxyacetic acid, was evaluated for marked reduction of viable C. difficile spore number in carpet and fabric models. After a 30 min contact time, application of the sporicide at ~ 75 ml m2 of carpet (or 51.2 ml m2 upholstery fabric) resulted in a 3-log reduction in germination of five different C. difficile spore types (a ~99.9% decrease), representing five different Nap biotypes. Despite effective inhibition of C. difficile spore germination, Virasept treatment did not visibly damage or discolor carpet or fabric fibers. Conclusions: Results of this study show the potential effectiveness of a robust regimen for the practical treatment of carpeting and upholstery fabric in nursing care facilities, and residential homes to prevent community- and environmentally-acquired reinfection and recurrence of CDI in susceptible individuals.

Use of simulations to evaluate the effectiveness of barrier precautions to prevent patient-to-patient transfer of healthcare-associated pathogens.

There is controversy regarding whether the addition of cover gowns offers a substantial benefit over gloves alone in reducing personnel contamination and preventing pathogen transmission. Simulated patient care interactions. To evaluate the efficacy of different types of barrier precautions and to identify routes of transmission. In randomly ordered sequence, 30 personnel each performed 3 standardized examinations of mannequins contaminated with pathogen surrogate markers (cauliflower mosaic virus DNA, bacteriophage MS2, nontoxigenic Clostridioides difficile spores, and fluorescent tracer) while wearing no barriers, gloves, or gloves plus gowns followed by examination of a noncontaminated mannequin. We compared the frequency and routes of transfer of the surrogate markers to the second mannequin or the environment. For a composite of all surrogate markers, transfer by hands occurred at significantly lower rates in the gloves-alone group (OR, 0.02; P < .001) and the gloves-plus-gown group (OR, 0.06; P = .002). Transfer by stethoscope diaphragms was common in all groups and was reduced by wiping the stethoscope between simulations (OR, 0.06; P < .001). Compared to the no-barriers group, wearing a cover gown and gloves resulted in reduced contamination of clothing (OR, 0.15; P < .001), but wearing gloves alone did not. Wearing gloves alone or gloves plus gowns reduces hand transfer of pathogens but may not address transfer by devices such as stethoscopes. Cover gowns reduce the risk of contaminating the clothing of personnel.

Room Contamination by Patients Colonized with Clostridiodes Difficile

<h3>Background</h3> Clostridioides difficile (CD) infection is a major cause of infectious diarrhea among Bone Marrow Transplant (BMT) patients. Previous research showed asymptomatic colonized patients with CD may confer a risk for nosocomial transmission. We found that 14% of patients admitted to our BMT unit were colonized with toxigenic CD. The objective of this study is to determine patient room contamination by asymptomatic patients colonized with CD. <h3>Methods</h3> The BMT unit implemented CD colonization screening upon admission using polymerase chain reaction (PCR) CD testing on formed stools. Screening was performed on patients undergoing BMT, experiencing complications, or patients with a hematology diagnosis. PCR CD testing was performed on the first formed stool. Three surfaces: toilet, bathroom sink, and in-room computer keyboard were sampled by swabbing the surface with a sponge moistened with buffer. The sponge was mechanically stomached to release recovered microorganisms. Samples were dilution plated onto agar plates and incubated anaerobically at 37°C for two days. Sample cutoffs are reported as < 10 colony forming units (CFUs) as the lower limit of detection. Samples with < 10 CFUs are considered negative. <h3>Results</h3> Six hundred ninety eight patients had specimens submitted for screening. One hundred one (14%) patients screened positive for CD toxin. Of the 101 patients who screened positive, thirty eight rooms were cultured. Seventeen of the rooms were negative at all sites for CD spores, while 6 rooms were positive at all sites. The remaining fifteen rooms had a least one site positive. Seventeen toilet seats were positive for CD spores, followed by 14 keyboards and 8 bathroom sinks. <h3>Conclusions</h3> Room contamination from asymptomatic BMT patients colonized with CD does occur. Further analysis of the data may delineate the environmental risk from asymptomatic colonized patients. These findings may have implications for infection control measures needed to mitigate the risk of healthcare-associated CD infection.

The effect of pulsed xenon ultraviolet light disinfection on healthcare-associated Clostridioides difficile rates in a tertiary care hospital

Ultraviolet (UV) light has destructive activity against pathogenic bacteria including Clostridioides difficile spores. Portable pulsed-xenon UV disinfecting devices were implemented for terminal room cleaning in 6 units of our academic hospital with high C. difficile infection (CDI) rates. CDI rates were measured in a 9-month period before and a 9-month period after device implementation. Despite documented administration of UV disinfection for 87% of terminal room cleaning, no impact on CDI rates was detected.