Toxin production by and adhesive properties of Clostridium difficile isolated from humans and horses with antibiotic-associated diarrhea

2007 ◽  
Vol 30 (3) ◽  
pp. 163-174 ◽  
Author(s):  
Sawsan Taha ◽  
Orjan Johansson ◽  
Stephan Rivera Jonsson ◽  
Daniel Heimer ◽  
Karel Krovacek
Keyword(s):  
Clostridium Difficile ◽  
Toxin Production ◽  
Adhesive Properties ◽  
Antibiotic Associated Diarrhea

scholarly journals Human Hypervirulent Clostridium difficile Strains Exhibit Increased Sporulation as Well as Robust Toxin Production

2010 ◽  
Vol 192 (19) ◽  
pp. 4904-4911 ◽  
Author(s):  
Michelle Merrigan ◽  
Anilrudh Venugopal ◽  
Michael Mallozzi ◽  
Bryan Roxas ◽  
V. K. Viswanathan ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Stationary Phase ◽  
Severe Disease ◽  
Toxin Production ◽  
Negative Regulator ◽  
Comparative Genomic ◽  
Toxin Gene ◽  
Antibiotic Associated Diarrhea ◽  
Quantitative Examination ◽  
Mechanistic Basis

ABSTRACT Toxigenic Clostridium difficile strains produce two toxins (TcdA and TcdB) during the stationary phase of growth and are the leading cause of antibiotic-associated diarrhea. C. difficile isolates of the molecular type NAP1/027/BI have been associated with severe disease and hospital outbreaks worldwide. It has been suggested that these “hypervirulent” strains produce larger amounts of toxin and that a mutation in a putative negative regulator (TcdC) allows toxin production at all growth phases. To rigorously explore this possibility, we conducted a quantitative examination of the toxin production of multiple hypervirulent and nonhypervirulent C. difficile strains. Toxin gene (tcdA and tcdB) and toxin gene regulator (tcdR and tcdC) expression was also monitored. To obtain additional correlates for the hypervirulence phenotype, sporulation kinetics and efficiency were measured. In the exponential phase, low basal levels of tcdA, tcdB, and tcdR expression were evident in both hypervirulent and nonhypervirulent strains, but contrary to previous assumptions, toxin levels were below the detectable thresholds. While hypervirulent strains displayed robust toxin production during the stationary phase of growth, the amounts were not significantly different from those of the nonhypervirulent strains tested; further, total toxin amounts were directly proportional to tcdA, tcdB, and tcdR gene expression. Interestingly, tcdC expression did not diminish in stationary phase, suggesting that TcdC may have a modulatory rather than a strictly repressive role. Comparative genomic analyses of the closely related nonhypervirulent strains VPI 10463 (the highest toxin producer) and 630 (the lowest toxin producer) revealed polymorphisms in the tcdR ribosome binding site and the tcdR-tcdB intergenic region, suggesting that a mechanistic basis for increased toxin production in VPI 10463 could be increased TcdR translation and read-through transcription of the tcdA and tcdB genes. Hypervirulent isolates produced significantly more spores, and did so earlier, than all other isolates. Increased sporulation, potentially in synergy with robust toxin production, may therefore contribute to the widespread disease now associated with hypervirulent C. difficile strains.

Toxin A and B genes expression of Clostridium difficile in the sub-minimum inhibitory concentration of clindamycin, vancomycin and in combination with ceftazidime

2020 ◽  
Author(s):  
Mohammad Moradi ◽  
Shahla Mansouri ◽  
Nouzar Nakhaee ◽  
Farhad Sarafzadeh ◽  
Ebrahim Rezazadeh Zarandi
Keyword(s):  
Gene Expression ◽  
Clostridium Difficile ◽  
Inhibitory Concentration ◽  
Toxin Production ◽  
Toxin Gene ◽  
Transcription Level ◽  
The Third ◽  
Genes Expression ◽  
Antibiotic Associated Diarrhea ◽  
Toxin Gene Expression

Background and Objectives: Antibiotics prescribed for infections have diverse effects on microbiota and the pathogen Clostridium difficile (C. difficile) as the most important antibiotic-associated diarrhea. This study aims to determine the gene expression of toxins A and B at the transcription level in the sub-MIC of vancomycin (VAN), clindamycin (CLI), and cef- tazidime (CAZ) alone and in combination. Materials and Methods: The MIC and fractional inhibitory concentration (FIC) of two C. difficile samples (a clinical isolate and ATCC 9689) were determined by microdilution and checkerboard microdilution methods, respectively. The total RNA was extracted from the medium inoculated with ~106  CFU/mL of fresh bacteria in the pre-reduced medium containing  ½ MIC of antibiotics alone and ½ FIC of antibiotics in combination. Real-time PCR was performed by sybrGreen methods in triplicate, and the data were analyzed by the comparative ∆∆CT  method. Results: All antibiotics except CAZ (alone and in combination) decreased the gene expression of toxins A and B within 24 hours. VAN and CLI reduced toxin gene expression within 24 and 48 hours. However, CAZ alone and in combination with VAN as well as CLI increased the gene expression of toxins A and B. Conclusion: The results confirmed toxin gene transcription and toxin production are associated with the type of isolates and antibiotics, as well as the combined form of antibiotics. This could be the reason which can explain the occurrence of C. difficile infection among patients who were treated with the third generation of cephalosporins alone and in combination with another antibiotic in the form of combinational therapy.

scholarly journals Cyclic Diguanylate Regulates Virulence Factor Genes via Multiple Riboswitches inClostridium difficile

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Robert W. McKee ◽  
Carissa K. Harvest ◽  
Rita Tamayo
Keyword(s):  
Gene Expression ◽  
Clostridium Difficile ◽  
Biofilm Formation ◽  
Toxin Production ◽  
Intestinal Colonization ◽  
Cyclic Diguanylate ◽  
Signaling Molecule ◽  
Content Type ◽  
Surface Motility

ABSTRACTThe intracellular signaling molecule cyclic diguanylate (c-di-GMP) regulates many processes in bacteria, with a central role in controlling the switch between motile and nonmotile lifestyles. Recent work has shown that inClostridium difficile(also calledClostridioides difficile), c-di-GMP regulates swimming and surface motility, biofilm formation, toxin production, and intestinal colonization. In this study, we determined the transcriptional regulon of c-di-GMP inC. difficile,employing overexpression of a diguanylate cyclase gene to artificially manipulate intracellular c-di-GMP. Consistent with prior work, c-di-GMP regulated the expression of genes involved in swimming and surface motility. c-di-GMP also affected the expression of multiple genes encoding cell envelope proteins, several of which affected biofilm formationin vitro. A substantial proportion of the c-di-GMP regulon appears to be controlled either directly or indirectly via riboswitches. We confirmed the functionality of 11 c-di-GMP riboswitches, demonstrating their effects on downstream gene expression independent of the upstream promoters. The class I riboswitches uniformly functioned as “off” switches in response to c-di-GMP, while class II riboswitches acted as “on” switches. Transcriptional analyses of genes 3′ of c-di-GMP riboswitches over a broad range of c-di-GMP levels showed that relatively modest changes in c-di-GMP levels are capable of altering gene transcription, with concomitant effects on microbial behavior. This work expands the known c-di-GMP signaling network inC. difficileand emphasizes the role of the riboswitches in controlling known and putative virulence factors inC. difficile.IMPORTANCEInClostridium difficile, the signaling molecule c-di-GMP regulates multiple processes affecting its ability to cause disease, including swimming and surface motility, biofilm formation, toxin production, and intestinal colonization. In this study, we used RNA-seq to define the transcriptional regulon of c-di-GMP inC. difficile. Many new targets of c-di-GMP regulation were identified, including multiple putative colonization factors. Transcriptional analyses revealed a prominent role for riboswitches in c-di-GMP signaling. Only a subset of the 16 previously predicted c-di-GMP riboswitches were functionalin vivoand displayed potential variability in their response kinetics to c-di-GMP. This work underscores the importance of studying c-di-GMP riboswitches in a relevant biological context and highlights the role of the riboswitches in controlling gene expression inC. difficile.

scholarly journals Proteins released during high toxin production in Clostridium difficile

Microbiology ◽  
2002 ◽  
Vol 148 (7) ◽  
pp. 2245-2253 ◽  
Author(s):  
Kakoli Mukherjee ◽  
Sture Karlsson ◽  
Lars G. Burman ◽  
Thomas Åkerlund
Keyword(s):  
Clostridium Difficile ◽  
Toxin Production

scholarly journals Clinical and microbial characterization of toxigenic Clostridium difficile isolated from antibiotic associated diarrhea in Egypt

2020 ◽  
Author(s):  
Sherein G. Elgendy ◽  
Sherine A. Aly ◽  
Rawhia Fathy ◽  
Enas A.E. Deaf ◽  
Naglaa H. Abu Faddan ◽  
...  
Keyword(s):  
Risk Factors ◽  
Clostridium Difficile ◽  
Pediatric Patients ◽  
Direct Detection ◽  
Diagnostic Methods ◽  
Adult Patients ◽  
Specific Method ◽  
Healthcare Associated Infection ◽  
Direct Pcr ◽  
Antibiotic Associated Diarrhea

Background and Objectives: Clostridium difficile infection (CDI) has become a significant healthcare-associated infection throughout the world and is particularly important in developing countries. This study aimed to investigate clinical characterization and risk factors related to toxigenic C. difficile infection in adult and pediatric patients, antimicrobial susceptibility pattern. Also, to evaluate different diagnostic methods for rapid detection of C. difficile associated diarrhea (CDAD) in Egypt. Materials and Methods: Stool samples were collected from 95 pediatric patients and 37 adult patients suffering from antibiotic associated diarrhea and were subjected to direct toxin immunoassay and culture on cycloserine/cefoxitin/fructose agar. The presence of tcdA and tcdB genes was tested by PCR. Results: Toxigenic C. difficile was isolated from pediatric and adult patients at a rate of 17.89% (17/95) and 27% (10/37) respectively. The sensitivity and specificity of direct PCR from stool are (100%, 100% and 82.4%, 100%) in adult and pediatric samples respectively. The susceptibility of C. difficile to vancomycin and metronidazole were found to be 66.7% and 48.2% respectively. Conclusion: Diabetes mellitus, prior antibiotic treatment, hematological malignancy on chemotherapy, malnutrition, neutropenia and Ryle feeding are risk factors for development of CDAD. Tight restriction of unnecessary antibiotic uses is necessary in our locality. Direct detection of toxin genes in stool by PCR is sensitive and specific method for early detection of C. difficile.

Clinical epidemiology of Clostridium difficile infection among hospitalized patients with antibiotic-associated diarrhea in a university hospital of Brazil

Anaerobe ◽  
2018 ◽  
Vol 54 ◽  
pp. 65-71 ◽  
Author(s):  
Guilherme Grossi Lopes Cançado ◽  
Rodrigo Otávio Silveira Silva ◽  
Maja Rupnik ◽  
Amanda Pontes Nader ◽  
Joana Starling de Carvalho ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Clostridium Difficile Infection ◽  
Clinical Epidemiology ◽  
Hospitalized Patients ◽  
University Hospital ◽  
Antibiotic Associated Diarrhea

scholarly journals 2422. Effectiveness of a Probiotic for Primary Prevention of Clostridium difficile Infection and Antibiotic-Associated Diarrhea among Hospitalized Patients Receiving Broad-Spectrum Antibiotics

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S836-S837
Author(s):  
Khanh-Linh Le ◽  
Heather Young ◽  
Timothy C Jenkins ◽  
Robert Tapia ◽  
Katherine C Shihadeh
Keyword(s):  
Primary Prevention ◽  
Clostridium Difficile ◽  
Clostridium Difficile Infection ◽  
Broad Spectrum ◽  
Hospitalized Patients ◽  
Broad Spectrum Antibiotic ◽  
Probiotic Group ◽  
Broad Spectrum Antibiotics ◽  
Days Of Therapy ◽  
Antibiotic Associated Diarrhea

Abstract Background Prior to 2016, Denver Health Medical Center had a higher-than-expected rate of hospital onset Clostridium difficile infection (HO-CDI). A multifaceted CDI prevention plan was implemented, including the use of a probiotic as primary prevention for HO-CDI and antibiotic-associated diarrhea (AAD) in inpatients receiving broad-spectrum antibiotics. We aimed to study the effectiveness of probiotic use in this clinical context. Methods During the intervention, inpatient orders for a broad-spectrum antibiotic triggered a best practice advisory recommending once daily co-administration of 100 billion units of a probiotic containing Lactobacillus casei, L. rhamnosus, and L. acidophilus (BioK+ ®). To evaluate effectiveness and safety of this intervention, we performed a retrospective cohort study including adult inpatients who received > 24 hours of a broad-spectrum antibiotic between April 2016 and March 2018. The primary endpoint was the incidence of HO-CDI (> 3 days after admission) compared between patients who received antibiotics alone vs. antibiotics plus the probiotic. Secondary endpoints were the incidence of AAD, defined as a negative CDI test after antibiotic initiation, and the incidence of Lactobacillus species identified in clinical cultures. Results 3,291 patients were included; 1,835 received antibiotics alone and 1,456 received antibiotics plus the probiotic. Baseline characteristics between groups were similar, except patients in the antibiotic alone group had a greater incidence of cirrhosis and proton-pump inhibitor use (16.1% vs 10.1%, P < 0.001; 39.1% vs 31.5%, P < 0.001). Length of stay and antibiotic days of therapy were longer in the antibiotic plus probiotic group [6 days (IQR, 3–11) vs 6 days (IQR, 4–12), P = 0.014; 4 days (IQR, 3–7) vs 5 days (IQR, 3–7), P < 0.001]. The incidence of HO-CDI (37, 2% vs 35, 2.4%; P = 0.450) and AAD (231, 12.6% vs 199, 13.7%; P = 0.362) were similar between groups. Lactobacillus was identified in at least one clinical culture from 0.2% (3/1835) and 0.3% (4/1456) of patients in the antibiotic alone group and antibiotic plus probiotic group, respectively (P = 0.497). Conclusion In hospitalized patients receiving broad-spectrum antibiotics, co-administration of a probiotic did not appear to reduce the incidence of HO-CDI or AAD. Disclosures All authors: No reported disclosures.

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