scholarly journals Biocide Resistance and Transmission of Clostridium difficile Spores Spiked onto Clinical Surfaces from an American Health Care Facility

2019 ◽  
Vol 85 (17) ◽  
Author(s):  
Calie Dyer ◽  
Lee P. Hutt ◽  
Robert Burky ◽  
Lovleen Tina Joshi
Keyword(s):  
Health Care ◽  
Clostridium Difficile ◽  
High Strength ◽  
Control Measures ◽  
Content Type ◽  
Infection Control Measures ◽  
Biocide Resistance ◽  
Antibiotic Associated Diarrhea ◽  
Sodium Dichloroisocyanurate ◽  
Spore Transmission

ABSTRACT Clostridium difficile is the primary cause of antibiotic-associated diarrhea globally. In unfavorable environments, the organism produces highly resistant spores which can survive microbicidal insult. Our previous research determined the ability of C. difficile spores to adhere to clinical surfaces, finding that spores had markedly different hydrophobic properties and adherence abilities. Investigation into the effect of the microbicide sodium dichloroisocyanurate on C. difficile spore transmission revealed that sublethal concentrations increased spore adherence without reducing viability. The present study examined the ability of spores to transmit across clinical surfaces and their response to an in-use disinfection concentration of 1,000 ppm of chlorine-releasing agent sodium dichloroisocyanurate. In an effort to understand if these surfaces contribute to nosocomial spore transmission, surgical isolation gowns, hospital-grade stainless steel, and floor vinyl were spiked with 1 × 106 spores/ml of two types of C. difficile spore preparations: crude spores and purified spores. The hydrophobicity of each spore type versus clinical surface was examined via plate transfer assay and scanning electron microscopy. The experiment was repeated, and spiked clinical surfaces were exposed to 1,000 ppm sodium dichloroisocyanurate at the recommended 10-min contact time. Results revealed that the hydrophobicity and structure of clinical surfaces can influence spore transmission and that outer spore surface structures may play a part in spore adhesion. Spores remained viable on clinical surfaces after microbicide exposure at the recommended disinfection concentration, demonstrating ineffectual sporicidal action. This study showed that C. difficile spores can transmit and survive between various clinical surfaces despite appropriate use of microbicides. IMPORTANCE Clostridium difficile is a health care-acquired organism and the causative agent of antibiotic-associated diarrhea. Its spores are implicated in fecal to oral transmission from contaminated surfaces in the health care environment due to their adherent nature. Contaminated surfaces are cleaned using high-strength chemicals to remove and kill the spores; however, despite appropriate infection control measures, there is still high incidence of C. difficile infection in patients in the United States. Our research examined the effect of a high-strength biocide on spores of C. difficile which had been spiked onto a range of clinically relevant surfaces, including isolation gowns, stainless steel, and floor vinyl. This study found that C. difficile spores were able to survive exposure to appropriate concentrations of biocide, highlighting the need to examine the effectiveness of infection control measures to prevent spore transmission and to consider the prevalence of biocide resistance when decontaminating health care surfaces.

scholarly journals TheClostridium difficile spo0AGene Is a Persistence and Transmission Factor

2012 ◽  
Vol 80 (8) ◽  
pp. 2704-2711 ◽  
Author(s):  
Laura J. Deakin ◽  
Simon Clare ◽  
Robert P. Fagan ◽  
Lisa F. Dawson ◽  
Derek J. Pickard ◽  
...  
Keyword(s):  
Health Care ◽  
Clostridium Difficile ◽  
Murine Model ◽  
Persistent Infection ◽  
Transcriptional Regulator ◽  
Transmission Factor ◽  
Content Type ◽  
Antibiotic Associated Diarrhea ◽  
Significant Health

ABSTRACTClostridium difficileis a major cause of chronic antibiotic-associated diarrhea and a significant health care-associated pathogen that forms highly resistant and infectious spores. Spo0A is a highly conserved transcriptional regulator that plays a key role in initiating sporulation inBacillusandClostridiumspecies. Here, we use a murine model to study the role of theC. difficile spo0Agene during infection and transmission. We demonstrate thatC. difficile spo0Amutant derivatives can cause intestinal disease but are unable to persist within and effectively transmit between mice. Thus, theC. difficileSpo0A protein plays a key role in persistent infection, including recurrence and host-to-host transmission in mice.

scholarly journals Seroprevalence of SARS-CoV-2 Antibodies Among Health Care Personnel at a Health Care System in Pakistan

2021 ◽  
pp. 101053952110110
Author(s):  
Salma Abbas ◽  
Aun Raza ◽  
Ayesha Iftikhar ◽  
Aamir Khan ◽  
Shahzaib Khan ◽  
...  
Keyword(s):  
Health Care ◽  
Control Measures ◽  
Health Care Personnel ◽  
Test Results ◽  
Antibody Testing ◽  
Chain Reaction ◽  
Past Infection ◽  
Infection Control Measures ◽  
History Of ◽  
Polymerase Chain

Health care personnel (HCP) are at high risk for coronavirus disease-2019 acquisition. Serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) indicate past infection. Our institution offered SARS-CoV-2 antibody testing to HCP. We surveyed HCP with positive test results to explore past exposure to SARS-CoV-2, details of symptoms during the preceding 6 months, and a history of SARS-CoV-2 polymerase chain reaction testing. A total of 2162 HCP underwent antibody testing. Eight hundred fifty-seven (39.6%) employees tested positive and, of these, 820 (95.7%) participated in the survey. When adjusted for age, males had higher odds of testing positive for SARS-CoV-2 antibodies compared with females (OR = 1.68; 95% CI = 1.37-2.05; P = .00) and clinical staff had higher odds of SARS-CoV-2 seropositivity compared with nonclinical staff (OR = 1.273; 95% CI = 1.06-1.53; P = .01). Implementation of effective infection control measures is essential to protect HCP from coronavirus disease-2019.

scholarly journals Molecular and Epidemiological Characterization of IMP-Type Metallo-β-Lactamase-Producing Enterobacter cloacae in a Large Tertiary Care Hospital in Japan

2014 ◽  
Vol 58 (6) ◽  
pp. 3441-3450 ◽  
Author(s):  
Kayoko Hayakawa ◽  
Tohru Miyoshi-Akiyama ◽  
Teruo Kirikae ◽  
Maki Nagamatsu ◽  
Kayo Shimada ◽  
...  
Keyword(s):  
Hospital Mortality ◽  
Tertiary Care ◽  
Enterobacter Cloacae ◽  
Control Measures ◽  
Care Hospital ◽  
Invasive Procedures ◽  
Content Type ◽  
Infection Control Measures ◽  
Large Tertiary Care ◽  
Close Relationship

ABSTRACTIMP-type metallo-β-lactamase enzymes have been reported in different geographical areas and in various Gram-negative bacteria. However, the risk factors and epidemiology pertaining to IMP-type metallo-β-lactamase-producingEnterobacter cloacae(IMP-producingE. cloacae) have not been systematically evaluated. We conducted a retrospective, matched case-control study of patients from whom IMP-producingE. cloacaeisolates were obtained, in addition to performing thorough molecular analyses of the clinically obtained IMP-producingE. cloacaeisolates. Unique cases with IMP-producingE. cloacaeisolation were included. Patients with IMP-producingE. cloacaewere matched to uninfected controls at a ratio of 1 to 3. Fifteen IMP-producingE. cloacaecases were identified, with five of the isolates being obtained from blood, and they were matched to 45 uninfected controls. All (100%) patients from whom IMP-producingE. cloacaeisolates were obtained had indwelling devices at the time of isolation, compared with one (2.2%) uninfected control. Independent predictors for isolation of IMP-producingE. cloacaewere identified as cephalosporin exposure and invasive procedures within 3 months. Although in-hospital mortality rates were similar between cases and controls (14.3% versus 13.3%), the in-hospital mortality of patients with IMP-producingE. cloacae-caused bacteremia was significantly higher (40%) than the rate in controls. IMP-producingE. cloacaeisolates were frequently positive for other resistance determinants. The MICs of meropenem and imipenem were not elevated; 10 (67%) and 12 (80%) of the 15 IMP-producingE. cloacaeisolates had a MIC of ≤1 μg/ml. A phylogenetic tree showed a close relationship among the IMP-producingE. cloacaesamples. Indwelling devices, exposure to cephalosporin, and a history of invasive procedures were associated with isolation of IMP-producingE. cloacae. Screening for carbapenemase production is important in order to apply appropriate clinical management and infection control measures.

scholarly journals Cwp19 Is a Novel Lytic Transglycosylase Involved in Stationary-Phase Autolysis Resulting in Toxin Release inClostridium difficile

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Sandra Wydau-Dematteis ◽  
Imane El Meouche ◽  
Pascal Courtin ◽  
Audrey Hamiot ◽  
René Lai-Kuen ◽  
...  
Keyword(s):  
Health Care ◽  
Clostridium Difficile ◽  
Stationary Phase ◽  
Catalytic Domain ◽  
Brain Heart Infusion ◽  
Surface Protein ◽  
Wild Type ◽  
Content Type ◽  
Lytic Transglycosylase ◽  
Cell Autolysis

ABSTRACTClostridium difficileis the major etiologic agent of antibiotic-associated intestinal disease. Pathogenesis ofC. difficileis mainly attributed to the production and secretion of toxins A and B. Unlike most clostridial toxins, toxins A and B have no signal peptide, and they are therefore secreted by unusual mechanisms involving the holin-like TcdE protein and/or autolysis. In this study, we characterized the cell surface protein Cwp19, a newly identified peptidoglycan-degrading enzyme containing a novel catalytic domain. We purified a recombinant His6-tagged Cwp19 protein and showed that it has lytic transglycosylase activity. Moreover, we observed that Cwp19 is involved in cell autolysis and that aC. difficilecwp19mutant exhibited delayed autolysis in stationary phase compared to the wild type when bacteria were grown in brain heart infusion (BHI) medium. Wild-type cell autolysis is correlated to strong alterations of cell wall thickness and integrity and to release of cytoplasmic material. Furthermore, we demonstrated that toxins were released into the extracellular medium as a result of Cwp19-induced autolysis when cells were grown in BHI medium. In contrast, Cwp19 did not induce autolysis or toxin release when cells were grown in tryptone-yeast extract (TY) medium. These data provide evidence for the first time that TcdE and bacteriolysis are coexisting mechanisms for toxin release, with their relative contributionsin vitrodepending on growth conditions. Thus, Cwp19 is an important surface protein involved in autolysis of vegetative cells ofC. difficilethat mediates the release of the toxins from the cell cytosol in response to specific environment conditions.IMPORTANCEClostridium difficile-associated disease is mainly known as a health care-associated infection. It represents the most problematic hospital-acquired infection in North America and Europe and exerts significant economic pressure on health care systems. Virulent strains ofC. difficilegenerally produce two toxins that have been identified as the major virulence factors. The mechanism for release of these toxins from bacterial cells is not yet fully understood but is thought to be partly mediated by bacteriolysis. Here we identify a novel peptidoglycan hydrolase inC. difficile, Cwp19, exhibiting lytic transglycosylase activity. We show that Cwp19 contributes toC. difficilecell autolysis in the stationary phase and, consequently, to toxin release, most probably as a response to environmental conditions such as nutritional signals. These data highlight that Cwp19 constitutes a promising target for the development of new preventive and curative strategies.

scholarly journals Clostridium difficileLipoprotein GerS Is Required for Cortex Modification and Thus Spore Germination

mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Oscar R. Diaz ◽  
Cameron V. Sayer ◽  
David L. Popham ◽  
Aimee Shen
Keyword(s):  
Clostridium Difficile ◽  
Spore Germination ◽  
Protective Layer ◽  
Thick Layer ◽  
Lytic Enzyme ◽  
Gram Positive ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Antibiotic Associated Diarrhea ◽  
Biochemical Analyses

ABSTRACTClostridium difficile, also known asClostridioides difficile, is a Gram-positive, spore-forming bacterium that is a leading cause of antibiotic-associated diarrhea.C. difficileinfections begin when its metabolically dormant spores germinate to form toxin-producing vegetative cells. Successful spore germination depends on the degradation of the cortex, a thick layer of modified peptidoglycan that maintains dormancy. Cortex degradation is mediated by the SleC cortex lytic enzyme, which is thought to recognize the cortex-specific modification muramic-δ-lactam.C. difficilecortex degradation also depends on thePeptostreptococcaceae-specific lipoprotein GerS for unknown reasons. In this study, we tested whether GerS regulates production of muramic-δ-lactam and thus controls the ability of SleC to recognize its cortex substrate. By comparing the muropeptide profiles of ΔgerSspores to those of spores lacking either CwlD or PdaA, both of which mediate cortex modification inBacillus subtilis, we determined thatC. difficileGerS, CwlD, and PdaA are all required to generate muramic-δ-lactam. Both GerS and CwlD were needed to cleave the peptide side chains from N-acetylmuramic acid, suggesting that these two factors act in concert. Consistent with this hypothesis, biochemical analyses revealed that GerS and CwlD directly interact and that CwlD modulates GerS incorporation into mature spores. Since ΔgerS, ΔcwlD, and ΔpdaAspores exhibited equivalent germination defects, our results indicate thatC. difficilespore germination depends on cortex-specific modifications, reveal GerS as a novel regulator of these processes, and highlight additional differences in the regulation of spore germination inC. difficilerelative toB. subtilisand other spore-forming organisms.IMPORTANCEThe Gram-positive, spore-forming bacteriumClostridium difficileis a leading cause of antibiotic-associated diarrhea. BecauseC. difficileis an obligate anaerobe, its aerotolerant spores are essential for transmitting disease, and their germination into toxin-producing cells is necessary for causing disease. Spore germination requires the removal of the cortex, a thick layer of modified peptidoglycan that maintains spore dormancy. Cortex degradation is mediated by the SleC hydrolase, which is thought to recognize cortex-specific modifications. Cortex degradation also requires the GerS lipoprotein for unknown reasons. In our study, we tested whether GerS is required to generate cortex-specific modifications by comparing the cortex composition of ΔgerSspores to the cortex composition of spores lacking two putative cortex-modifying enzymes, CwlD and PdaA. These analyses revealed that GerS, CwlD, and PdaA are all required to generate cortex-specific modifications. Since loss of these modifications in ΔgerS, ΔcwlD, and ΔpdaAmutants resulted in spore germination and heat resistance defects, the SleC cortex lytic enzyme depends on cortex-specific modifications to efficiently degrade this protective layer. Our results further indicate that GerS and CwlD are mutually required for removing peptide chains from spore peptidoglycan and revealed a novel interaction between these proteins. Thus, our findings provide new mechanistic insight intoC. difficilespore germination.

scholarly journals Clostridium difficile Toxins TcdA and TcdB Cause Colonic Tissue Damage by Distinct Mechanisms

2016 ◽  
Vol 84 (10) ◽  
pp. 2871-2877 ◽  
Author(s):  
Nicole M. Chumbler ◽  
Melissa A. Farrow ◽  
Lynne A. Lapierre ◽  
Jeffrey L. Franklin ◽  
D. Borden Lacy
Keyword(s):  
Clostridium Difficile ◽  
Apoptotic Cell ◽  
Large Body ◽  
Health Care Facilities ◽  
Dependent Manner ◽  
Content Type ◽  
Culture Model ◽  
Care Facilities ◽  
Antibiotic Associated Diarrhea ◽  
A Cell

As the major cause of antibiotic-associated diarrhea,Clostridium difficileis a serious problem in health care facilities worldwide.C. difficileproduces two large toxins, TcdA and TcdB, which are the primary virulence factors in disease. The respective functions of these toxins have been difficult to discern, in part because the cytotoxicity profiles for these toxins differ with concentration and cell type. The goal of this study was to develop a cell culture model that would allow a side-by-side mechanistic comparison of the toxins. Conditionally immortalized, young adult mouse colonic (YAMC) epithelial cells demonstrate an exquisite sensitivity to both toxins with phenotypes that agree with observations in tissue explants. TcdA intoxication results in an apoptotic cell death that is dependent on the glucosyltransferase activity of the toxin. In contrast, TcdB has a bimodal mechanism; it induces apoptosis in a glucosyltransferase-dependent manner at lower concentrations and glucosyltransferase-independent necrotic death at higher concentrations. The direct comparison of the responses to TcdA and TcdB in cells and colonic explants provides the opportunity to unify a large body of observations made by many independent investigators.

scholarly journals Observations on the Role of TcdE Isoforms in Clostridium difficile Toxin Secretion

2015 ◽  
Vol 197 (15) ◽  
pp. 2600-2609 ◽  
Author(s):  
Revathi Govind ◽  
Leah Fitzwater ◽  
Rebekah Nichols
Keyword(s):  
Amino Acids ◽  
Clostridium Difficile ◽  
Cell Viability ◽  
Virulence Factors ◽  
Start Codon ◽  
Nosocomial Pathogen ◽  
Content Type ◽  
Antibiotic Associated Diarrhea ◽  
Toxin Secretion

ABSTRACTClostridium difficileis a major nosocomial pathogen and the principal causative agent of antibiotic-associated diarrhea. The toxigenicC. difficilestrains that cause disease secrete virulence factors, toxin A and toxin B, that cause colonic injury and inflammation.C. difficiletoxins have no export signature and are secreted by an unusual mechanism that involves TcdE, a holin-like protein. We isolated a TcdE mutant of the epidemic R20291 strain with impaired toxin secretion, which was restored by complementation with functional TcdE. In the TcdE open reading frame (ORF), we identified three possible translation start sites; each translated isoform may play a specific role in TcdE-controlled toxin release. We created plasmid constructs that express only one of the three TcdE isoforms and complemented the TcdE mutant with these isoforms. Western blot analysis of the complemented strains demonstrated that TcdE is translated efficiently from the start codon at the 25th and 27th positions in the predicted ORF, producing proteins with 142 amino acids (TcdE142) and 140 amino acids (TcdE140), respectively. TcdE166was not detected when expressed from its own ribosomal binding site (RBS). The effects of all three TcdE isoforms onC. difficilecell viability and toxin release were determined. Among the three isoforms, overexpression of TcdE166and TcdE142had a profound effect on cell viability compared to the TcdE140isoform. Similarly, TcdE166and TcdE142facilitated toxin release more efficiently than did TcdE140. The importance of these variations among TcdE isoforms and their role in toxin release are discussed.IMPORTANCEC. difficileis a nosocomial pathogen that has become the most prevalent cause of antibiotic-associated diarrhea in North America and in several countries in Europe. Most strains ofC. difficileproduce two high-molecular-weight toxins that are regarded as the primary virulence factors. The mechanism by which these large toxins are secreted from bacterial cells is not yet clear but involves TcdE, a holin-like protein. In this work, we show that TcdE could be translated from three different start codons, resulting in the production of three TcdE isoforms. Furthermore, we investigated the role of these isoforms in toxin release and cell lysis inC. difficile. An understanding of TcdE-dependent toxin secretion may be helpful for the development of strategies for preventing and treatingC. difficileinfections.

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