Triggering Germination Represents a Novel Strategy to Enhance Killing of Clostridium difficile Spores

spores to radiation or other stressors. spores to a germination solution containing amino acids, minerals, and taurocholic acid resulted in initiation of germination in room air. Germination of spores in room air resulted in significantly enhanced killing by ultraviolet-C (UV-C) radiation and heat. On surfaces in hospital rooms, application of germination solution resulted in enhanced eradication of spores by UV-C administered by an automated room decontamination device. Initiation of germination under anaerobic, but not aerobic, conditions resulted in increased susceptibility to killing by ethanol, suggesting that exposure to oxygen might prevent spores from progressing fully to outgrowth. Stimulation of germination also resulted in reduced survival of spores on surfaces in room air, possibly due to increased susceptibility to stressors such as oxygen and desiccation.Taken together, these data demonstrate that stimulation of germination could represent a novel method to enhance killing of spores by UV-C, and suggest the possible application of this strategy as a means to enhance killing by other agents

Staphylococcus aureus intestinal colonization is associated with increased frequency of S. aureus on skin of hospitalized patients

<p>Abstract</p> <p>Background</p> <p>Intestinal colonization by <it>Staphylococcus aureus </it>among hospitalized patients has been associated with increased risk of staphylococcal infection and could potentially contribute to transmission. We hypothesized that <it>S. aureus </it>intestinal colonization is associated with increased frequency of <it>S. aureus </it>on patients' skin and nearby environmental surfaces.</p> <p>Methods</p> <p>Selected inpatients were cultured weekly for <it>S. aureus </it>from stool, nares, skin (groin and axilla), and environmental surfaces (bed rail and bedside table). Investigator's hands were cultured after contacting the patients' skin and the environmental surfaces.</p> <p>Results</p> <p>Of 71 subjects, 32 (45.1%) had negative nares and stool cultures, 23 (32.4%) had positive nares and stool cultures, 13 (18.3%) were nares carriers only, and 3 (4.2%) were stool carriers only. Of the 39 patients with <it>S. aureus </it>carriage, 30 (76.9%) had methicillin-resistant isolates. In comparison to nares colonization only, nares and intestinal colonization was associated with increased frequency of positive skin cultures (41% versus 77%; p = 0.001) and trends toward increased environmental contamination (45% versus 62%; p = 0.188) and acquisition on investigator's hands (36% versus 60%; p = 0.057). Patients with negative nares and stool cultures had low frequency of <it>S. aureus </it>on skin and the environment (4.8% and 11.3%, respectively).</p> <p>Conclusion</p> <p>We found that hospitalized patients with <it>S. aureus </it>nares and/or stool carriage frequently had <it>S. aureus </it>on their skin and on nearby environmental surfaces. <it>S. aureus </it>intestinal colonization was associated with increased frequency of positive skin cultures, which could potentially facilitate staphylococcal infections and nosocomial transmission.</p

Evaluation of an automated ultraviolet radiation device for decontamination of Clostridium difficile and other healthcare-associated pathogens in hospital rooms

<p>Abstract</p> <p>Background</p> <p>Environmental surfaces play an important role in transmission of healthcare-associated pathogens. There is a need for new disinfection methods that are effective against <it>Clostridium difficile </it>spores, but also safe, rapid, and automated.</p> <p>Methods</p> <p>The Tru-D™ Rapid Room Disinfection device is a mobile, fully-automated room decontamination technology that utilizes ultraviolet-C irradiation to kill pathogens. We examined the efficacy of environmental disinfection using the Tru-D device in the laboratory and in rooms of hospitalized patients. Cultures for <it>C. difficile</it>, methicillin-resistant <it>Staphylococcus aureus </it>(MRSA), and vancomycin-resistant <it>Enterococcus </it>(VRE) were collected from commonly touched surfaces before and after use of Tru-D.</p> <p>Results</p> <p>On inoculated surfaces, application of Tru-D at a reflected dose of 22,000 μWs/cm²for ~45 minutes consistently reduced recovery of <it>C. difficile </it>spores and MRSA by >2-3 log₁₀colony forming units (CFU)/cm²and of VRE by >3-4 log₁₀CFU/cm². Similar killing of MRSA and VRE was achieved in ~20 minutes at a reflected dose of 12,000 μWs/cm², but killing of <it>C. difficile </it>spores was reduced. Disinfection of hospital rooms with Tru-D reduced the frequency of positive MRSA and VRE cultures by 93% and of <it>C. difficile </it>cultures by 80%. After routine hospital cleaning of the rooms of MRSA carriers, 18% of sites under the edges of bedside tables (i.e., a frequently touched site not easily amenable to manual application of disinfectant) were contaminated with MRSA, versus 0% after Tru-D (<it>P </it>< 0.001). The system required <5 minutes to set up and did not require continuous monitoring.</p> <p>Conclusions</p> <p>The Tru-D Rapid Room Disinfection device is a novel, automated, and efficient environmental disinfection technology that significantly reduces <it>C. difficile</it>, VRE and MRSA contamination on commonly touched hospital surfaces.</p

A case study of a real-time evaluation of the risk of disease transmission associated with a failure to follow recommended sterilization procedures

Background Failures to follow recommendations for reprocessing of surgical instruments may place patients at risk for exposure to pathogenic microorganisms. When such failures occur, medical facilities often face considerable uncertainty and challenges in assessing the actual risks of disease transmission. Methods In 2011, staff at an Ohio hospital determined that surgical instruments inside a Steriset Container had inadvertently been autoclaved on a gravity cycle rather than on the recommended pre-vacuum cycle, potentially exposing 72 patients who underwent surgery with the instruments to risk of infection. To provide an assessment of the level of risk, we tested the effectiveness of the machine washer/disinfector step and of the sterilization process inside the Steriset Container on the gravity cycle for killing of Geobacillus stearothermophilus spores, Clostridium difficile spores, and methicillin-resistant Staphylococcus aureus (MRSA). Based on the test results, the risk of transmission of MRSA by the instruments was calculated and the risk of transmission of hepatitis B virus was estimated. Results The machine washer/disinfector consistently reduced MRSA recovery by a factor of 1:100,000. The sterilization process inside the Steriset Container consistently reduced MRSA concentrations by a factor of >1:10,000,000 and killed 105 C. difficile spores and 105 G. stearothermophilus spores. The risk of MRSA transmission due to the incident was calculated to be 1 in 100 trillion. Conclusions The risk for transmission of infection due to the failure to follow recommended sterilization processes was negligible based upon complete killing of G. stearothermophilus biological indicator spores, C. difficile spores, and MRSA under conditions that replicated the incident where proper procedures were not followed. Such real-time assessments of the risks associated with specific incidents may provide evidence-based information that can be used to inform decisions regarding disclosure of the incident to patients

Multihospital Outbreak of Clostridium difficile Infection, Cleveland, Ohio, USA

To determine whether a multihospital Clostridium difficile outbreak was associated with epidemic strains and whether use of particular fluoroquinolones was associated with increased infection rates, we cultured feces from C. difficile–infected patients. Use of fluoroquionolones with enhanced antianaerobic activity was not associated with increased infection rates

Strategies to prevent Clostridium difficile infections in acute care hospitals: 2014 update

Previously published guidelines are available that provide 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 their Clostridium difficile infection (CDI) prevention efforts. This document updates “Strategies to Prevent Clostridium difficile Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates

Probiotic Sonicates Selectively Induce Mucosal Immune Cells Apoptosis Through Ceramide Generation Via Neutral Sphingolyelinase

Background: Probiotics appear to be beneficial in inflammatory bowel disease, but their mechanism of action is incompletely understood. We investigated whether probiotic-derived sphingomyelinase mediates this beneficial effect. Methodology/Principal Findings: Neutral sphingomyelinase (NSMase) activity was measured in sonicates of the probiotic L.brevis (LB)and S. thermophilus (ST) and the non-probiotic E. coli EC) and E. faecalis (EF). Lamina propria mononuclear cells (LPMC) were obtained from patients with Crohn"s disease (CD) and Ulcerative Colitis (UC), and peripheral blood mononuclear cells (PBMC) from healthy volunteers, analysing LPMC and PBMC apoptosis susceptibility, reactive oxygen species (ROS) generation and JNK activation. In some experiments, sonicates were preincubated with GSH or GW4869, a specific NSMase inhibitor. NSMase activity of LB and ST was 10-fold that of EC and EF sonicates. LB and ST sonicates induced significantly more apoptosis of CD and UC than control LPMC, whereas EC and EF sonicates failed to induce apoptosis. Pre-stimulation with anti-CD3/CD28 induced a significant and time-dependent increase in LB-induced apoptosis of LPMC and PBMC. Exposure to LB sonicates resulted in JNK activation and ROS production by LPMC. NSMase activity of LB sonicates was completely abrogated by GW4869, causing a dose-dependent reduction of LB -induced poptosis. LB and ST selectively induced immune cell apoptosis, an effect dependent on the degree of cell activation and mediated by bacterial NSMase. Conclusions: These results suggest that induction of immune cell apoptosis is a mechanism of action of some probiotics and that NSMase-mediated ceramide generation contributes to the therapeutic effects of probiotics

Analysis of antibiotic resistance genes in multidrug-resistant acinetobacter sp. isolates from military and civilian patients treated at the Walter Reed Army Medical Center

Military medical facilities treating patients injured in Iraq and Afghanistan have identified a large number of multidrug-resistant (MDR) Acinetobacter baumannii isolates. In order to anticipate the impact of these pathogens on patient care, we analyzed the antibiotic resistance genes responsible for the MDR phenotype in Acinetobacter sp. isolates collected from patients at the Walter Reed Army Medical Center (WRAMC). Susceptibility testing, PCR amplification of the genetic determinants of resistance, and clonality were determined. Seventy-five unique patient isolates were included in this study: 53% were from bloodstream infections, 89% were resistant to at least three classes of antibiotics, and 15% were resistant to all nine antibiotics tested. Thirty-seven percent of the isolates were recovered from patients nosocomially infected or colonized at the WRAMC. Sixteen unique resistance genes or gene families and four mobile genetic elements were detected. In addition, this is the first report of blaOXA-58-like and blaPER-like genes in the U.S. MDR A. baumannii isolates with at least eight identified resistance determinants were recovered from 49 of the 75 patients. Molecular typing revealed multiple clones, with eight major clonal types being nosocomially acquired and with more than 60% of the isolates being related to three pan-European types. This report gives a “snapshot” of the complex genetic background responsible for antimicrobial resistance in Acinetobacter spp. from the WRAMC. Identifying genes associated with the MDR phenotype and defining patterns of transmission serve as a starting point for devising strategies to limit the clinical impact of these serious infections. © 2006, American Society for Microbiolog