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temporal bacterial community dynamics vary among ulcerative colitis patients after fecal microbiota transplantation.fecal microbiota transplantation (fmt) from healthy donors, which is an effective alternative for treatment of clostridium difficile-associated disease, is being considered for several disorders such as inflammatory bowel disease, irritable bowel syndrome, and metabolic syndrome. disease remission upon fmt is thought to be facilitated by an efficient colonization of healthy donor microbiota, but knowledge of the composition and temporal stability of patient microbiota after fmt is lacking.201324060759
evaluation of nvb302 versus vancomycin activity in an in vitro human gut model of clostridium difficile infection.first-line treatment options for clostridium difficile infection (cdi) are limited. nvb302 is a novel type b lantibiotic under evaluation for the treatment of cdi. we compared the responses to nvb302 and vancomycin when used to treat simulated cdi in an in vitro gut model.201322966180
expanded therapeutic potential in activity space of next-generation 5-nitroimidazole antimicrobials with broad structural diversity.metronidazole and other 5-nitroimidazoles (5-ni) are among the most effective antimicrobials available against many important anaerobic pathogens, but evolving resistance is threatening their long-term clinical utility. the common 5-nis were developed decades ago, yet little 5-ni drug development has since taken place, leaving the true potential of this important drug class unexplored. here we report on a unique approach to the modular synthesis of diversified 5-nis for broad exploration of thei ...201324101497
growth-inhibiting and morphostructural effects of constituents identified in asarum heterotropoides root on human intestinal bacteria.the growth-inhibiting and morphostructural effects of seven constituents identified in asarum heterotropoides root on 14 intestinal bacteria were compared with those of the fluoroquinolone antibiotic ciprofloxacin.201324083511
impact of electronic surveillance on isolation practices.to assess the impact of an electronic surveillance system on isolation practices and rates of methicillin-resistant staphylococcus aureus (mrsa).201323739073
the spore differentiation pathway in the enteric pathogen clostridium difficile.endosporulation is an ancient bacterial developmental program that culminates with the differentiation of a highly resistant endospore. in the model organism bacillus subtilis, gene expression in the forespore and in the mother cell, the two cells that participate in endospore development, is governed by cell type-specific rna polymerase sigma subunits. σ(f) in the forespore, and σ(e) in the mother cell control early stages of development and are replaced, at later stages, by σ(g) and σ(k), resp ...201324098139
genome-wide analysis of cell type-specific gene transcription during spore formation in clostridium difficile.clostridium difficile, a gram positive, anaerobic, spore-forming bacterium is an emergent pathogen and the most common cause of nosocomial diarrhea. although transmission of c. difficile is mediated by contamination of the gut by spores, the regulatory cascade controlling spore formation remains poorly characterized. during bacillus subtilis sporulation, a cascade of four sigma factors, σ(f) and σ(g) in the forespore and σ(e) and σ(k) in the mother cell governs compartment-specific gene expressi ...201324098137
global analysis of the sporulation pathway of clostridium difficile.the gram-positive, spore-forming pathogen clostridium difficile is the leading definable cause of healthcare-associated diarrhea worldwide. c. difficile infections are difficult to treat because of their frequent recurrence, which can cause life-threatening complications such as pseudomembranous colitis. the spores of c. difficile are responsible for these high rates of recurrence, since they are the major transmissive form of the organism and resistant to antibiotics and many disinfectants. des ...201323950727
expression and display of clostridium difficile protein flid on the surface of bacillus subtilis spores.the endospores of bacillus subtilis can serve as a tool for surface presentation of heterologous proteins. the unique properties of the spore protective layers make them perfect vehicles for orally administered vaccines. in this study, we successfully displayed a fragment of clostridium difficile flid protein on the surface of b. subtilis spores using the cotb, cotc, cotg and cotz spore coat proteins. the presence of the fusion proteins in the spore coat was verified by western blotting and immu ...201323475909
in vitro biological effects of two anti-diabetic medicinal plants used in benin as folk medicine.extracts from polygonum senegalensis (polygonaceae) and pseudocedrela kotschyi (meliaceae) are two important traditionally used medicinal plants in rural benin to treat many diseases and notably type 2 diabetes. the aim of the study was to investigate the α-glucosidase inhibition, antioxidant and antibacterial activities of those plants extract: polygonum senegalensis leaves, and pseudocedrela kotschyi root.201323452899
spoiva and sipl are clostridium difficile spore morphogenetic proteins.clostridium difficile is a major nosocomial pathogen whose infections are difficult to treat because of their frequent recurrence. the spores of c. difficile are responsible for these clinical features, as they resist common disinfectants and antibiotic treatment. although spores are the major transmissive form of c. difficile, little is known about their composition or morphogenesis. spore morphogenesis has been well characterized for bacillus sp., but bacillus sp. spore coat proteins are poorl ...201323292781
in pursuit of protein targets: proteomic characterization of bacterial spore outer layers.bacillus cereus, responsible for food poisoning, and clostridium difficile, the causative agent of clostridium difficile-associated diarrhea (cdad), are both spore-forming pathogens involved in food spoilage, food intoxication, and other infections in humans and animals. the proteinaceous coat and the exosporium layers from spores are important for their resistance and pathogenicity characteristics. the exosporium additionally provides an ability to adhere to surfaces eventually leading to spore ...201323998435
probiotics for the treatment of clostridium difficile associated disease.the purpose of this review paper is to update the current and potential future role of probiotics for clostridium difficile-associated disease (cdad). included in this review, is an update on the testing of newer probiotics (e.g., bacillus coagulans gbi-30, 6086) in animal models of cdad. there is a focus on the modulation of signal transduction pathways (i.e., transcription factors like camp response element-binding, activator protein 1, and nuclear factor kappa b), as well as the inhibition of ...201323946887
identification of a novel zinc metalloprotease through a global analysis of clostridium difficile extracellular proteins.clostridium difficile is a major cause of infectious diarrhea worldwide. although the cell surface proteins are recognized to be important in clostridial pathogenesis, biological functions of only a few are known. also, apart from the toxins, proteins exported by c. difficile into the extracellular milieu have been poorly studied. in order to identify novel extracellular factors of c. difficile, we analyzed bacterial culture supernatants prepared from clinical isolates, 630 and r20291, using liq ...201324303041
cyclodextrin derivatives as anti-infectives.cyclodextrin derivatives can be utilized as anti-infectives with pore-forming proteins as the targets. the highly efficient selection of potent inhibitors was achieved because per-substituted cyclodextrins have the same symmetry as the target pores. inhibitors of several bacterial toxins produced by bacillus anthracis, staphylococcus aureus, clostridium perfringens, clostridium botulinum, and clostridium difficile were identified from a library of ∼200 cd derivatives. it was demonstrated that mu ...201324011515
architecture and assembly of the gram-positive cell wall.the bacterial cell wall is a mesh polymer of peptidoglycan--linear glycan strands cross-linked by flexible peptides--that determines cell shape and provides physical protection. while the glycan strands in thin 'gram-negative' peptidoglycan are known to run circumferentially around the cell, the architecture of the thicker 'gram-positive' form remains unclear. using electron cryotomography, here we show that bacillus subtilis peptidoglycan is a uniformly dense layer with a textured surface. we f ...201323600697
identification of novel host-targeted compounds that protect from anthrax lethal toxin-induced cell death.studying how pathogens subvert the host to cause disease has contributed to the understanding of fundamental cell biology. bacillus anthracis, the causative agent of anthrax, produces the virulence factor lethal toxin to disarm host immunity and cause pathology. we conducted a phenotypic small molecule screen to identify inhibitors of lethal toxin-induced macrophage cell death and used an ordered series of secondary assays to characterize the hits and determine their effects on cellular function ...201323343607
a severe case of rat lungworm disease in hawa'i.a 23-year-old man living on the island of hawa'i developed a life threatening case of eosinophilic meningitis caused by infection with angiostrongylus cantonensis (rat lungworm disease: rlwd). he was comatose for 3 months, incurring brain and nerve damage sufficiently extensive that he was not expected to recover. the case was complicated by secondary infections of methicillin-resistant staphylococcus aureus, clostridium difficile, and pneumonia, which resulted in an empyema requiring a thoracos ...201323900708
the rise of carbapenem-resistant acinetobacter baumannii.acinetobacter spp. are gram-negative bacteria that have become one of the most difficult pathogens to treat. the species a. baumannii, largely unknown 30 years ago, has risen to prominence particularly because of its ability to cause infections in immunocompromised patients. it is now a predominant pathogen in many hospitals as it has acquired resistance genes to virtually all antibiotics capable of treating gram-negative bacteria, including the fluoroquinolones and the cephalosporins. some memb ...201322894617
microbial and metabolic interactions between the gastrointestinal tract and clostridium difficile infection.antibiotics disturb the gastrointestinal tract microbiota and in turn reduce colonization resistance against clostridium difficile. the mechanism for this loss of colonization resistance is still unknown but likely reflects structural (microbial) and functional (metabolic) changes to the gastrointestinal tract. members of the gut microbial community shape intestinal metabolism that provides nutrients and ultimately supports host immunity. this review will discuss how antibiotics alter the struct ...201324335555
equine hyperimmune serum protects mice against clostridium difficile spore challenge.clostridium (c.) difficile is a common cause of nosocomial diarrhea in horses. vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. in the current study, we prepared antiserum of equine origin against both c. difficile toxins a and b as well as whole-cell bacteria. the toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive im ...201324136208
gut microbiota patterns associated with colonization of different clostridium difficile ribotypes.c. difficile infection is associated with disturbed gut microbiota and changes in relative frequencies and abundance of individual bacterial taxons have been described. in this study we have analysed bacterial, fungal and archaeal microbiota by denaturing high pressure liquid chromatography (dhplc) and with machine learning methods in 208 faecal samples from healthy volunteers and in routine samples with requested c. difficile testing. the latter were further divided according to stool consisten ...201323469128
risk factors of mild rectal bleeding in very low birth weight infants: a case control study.mild rectal bleeding (mrb) is a particular clinical entity different from necrotizing enterocolitis, which significantly influences neonatal care in preterm infants. we aimed to determine the risk factors and to evaluate prospectively the clinical course of mrb.201324283213
bacteriotherapy for the treatment of intestinal dysbiosis caused by clostridium difficile infection.faecal microbiota transplantation (fmt) has been used for more than five decades to treat a variety of intestinal diseases associated with pathological imbalances within the resident microbiota, termed dysbiosis. fmt has been particularly effective for treating patients with recurrent clostridium difficile infection who are left with few clinical options other than continued antibiotic therapy. our increasing knowledge of the structure and function of the human intestinal microbiota and c. diffi ...201323866975
genetically diverse clostridium difficile strains harbouring abundant prophages in an estuarine environment.clostridium difficile is the leading cause of antibiotic-associated diarrhoeal disease in healthcare settings across the world. despite its pathogenic capacity, it can be carried asymptomatically and has been found in terrestrial and marine ecosystems outside hospital environments. less is known about these environmental strains and few studies have been conducted on estuarine systems. although prophage abundance and diversity is known within in clinical strains, prophage carriage within environ ...201323913427
norovirus gastroenteritis after fecal microbiota transplantation for treatment of clostridium difficile infection despite asymptomatic donors and lack of sick contacts. 201323912408
adaptive strategies and pathogenesis of clostridium difficile from in vivo transcriptomics.clostridium difficile is currently the major cause of nosocomial intestinal diseases associated with antibiotic therapy in adults. in order to improve our knowledge of c. difficile-host interactions, we analyzed the genome-wide temporal expression of c. difficile 630 genes during the first 38 h of mouse colonization to identify genes whose expression is modulated in vivo, suggesting that they may play a role in facilitating the colonization process. in the ceca of the c. difficile-monoassociated ...201323897605
active surveillance for carbapenem-resistant enterobacteriaceae using stool specimens submitted for testing for clostridium difficile.active surveillance to identify asymptomatic carriers of carbapenem-resistant enterobacteriaceae (cre) is a recommended strategy for cre control in healthcare facilities. active surveillance using stool specimens tested for clostridium difficile is a relatively low-cost strategy to detect cre carriers. further evaluation of this and other risk factor-based active surveillance strategies is warranted.201324334803
evaluation of a new automated homogeneous pcr assay, genomera c. difficile, for rapid detection of toxigenic clostridium difficile in fecal specimens.we evaluated a new automated homogeneous pcr assay to detect toxigenic clostridium difficile, the genomera c. difficile assay (abacus diagnostica, finland), with 310 diarrheal stool specimens and with a collection of 33 known clostridial and nonclostridial isolates. results were compared with toxigenic culture results, with discrepancies being resolved by the genexpert c. difficile pcr assay (cepheid). among the 80 toxigenic culture-positive or genexpert c. difficile assay-positive fecal specime ...201323804386
use of rifamycin drugs and development of infection by rifamycin-resistant strains of clostridium difficile.the relationship between rifamycin drug use and the development of resistant strains of clostridium difficile was studied at a large university hospital in houston, tx, between may 2007 and september 2011. in 49 of 283 (17.3%) patients with c. difficile infection (cdi), a rifamycin-resistant strain of c. difficile was identified that compares to a rate of 8% using the same definitions in 2006-2007 (p = 0.59). the 49 patients infected by a resistant organism were matched by date of admission to 9 ...201323545528
sequencing of bacterial genomes: principles and insights into pathogenesis and development of antibiotics.the impact of bacterial diseases on public health has become enormous, and is partly due to the increasing trend of antibiotic resistance displayed by bacterial pathogens. sequencing of bacterial genomes has significantly improved our understanding about the biology of many bacterial pathogens as well as identification of novel antibiotic targets. since the advent of genome sequencing two decades ago, about 1,800 bacterial genomes have been fully sequenced and these include important aetiologica ...201324705262
novel strategies for enhanced removal of persistent bacillus anthracis surrogates and clostridium difficile spores from skin.removing spores of clostridium difficile and bacillus anthracis from skin is challenging because they are resistant to commonly used antimicrobials and soap and water washing provides only modest efficacy. we hypothesized that hygiene interventions incorporating a sporicidal electrochemically generated hypochlorous acid solution (vashe(®)) would reduce the burden of spores on skin.201323844234
clinical approach to fever in the neurosurgical intensive care unit: focus on drug fever.as fever is one of the cardinal signs of infection, the presence of fever in a patient in the neurosurgical intensive care unit (nsicu) raises the question of whether it is infectious in etiology. infectious and noninfectious causes of fever in the nsicu may be determined based upon assessment of clinical signs and symptoms, the degree of temperature elevation, the relationship of the pulse to the fever (e.g., an infectious process resulting in hyperpyrexia and bradycardia), and when the fever o ...201323878765
development of novel sugar isomerases by optimization of active sites in phosphosugar isomerases for monosaccharides.phosphosugar isomerases can catalyze the isomerization of not only phosphosugar but also of monosaccharides, suggesting that the phosphosugar isomerases can be used as sugar isomerases that do not exist in nature. determination of active-site residues of phosphosugar isomerases, including ribose-5-phosphate isomerase from clostridium difficile (cdrpi), mannose-6-phosphate isomerase from bacillus subtilis (bsmpi), and glucose-6-phosphate isomerase from pyrococcus furiosus (pfgpi), was accomplishe ...201323204422
recent advances in antibacterial drugs.the incidence of antimicrobial resistance is on continued rise with a threat to return to the "pre-antibiotic" era. this has led to emergence of such bacterial infections which are essentially untreatable by the current armamentarium of available treatment options. various efforts have been made to develop the newer antimicrobials with novel modes of action which can act against these multi-drug resistant strains. this review aims to focus on these newly available and investigational antibacteri ...201323776832
structure of clostridium difficile pilj exhibits unprecedented divergence from known type iv pilins.type iv pili are produced by many pathogenic gram-negative bacteria and are important for processes as diverse as twitching motility, cellular adhesion, and colonization. recently, there has been an increased appreciation of the ability of gram-positive species, including clostridium difficile, to produce type iv pili. here we report the first three-dimensional structure of a gram-positive type iv pilin, pilj, demonstrate its incorporation into type iv pili, and offer insights into how the type ...201324362261
biological evaluation of benzothiazole ethyl urea inhibitors of bacterial type ii topoisomerases.the type ii topoisomerases dna gyrase (gyra/gyrb) and topoisomerase iv (parc/pare) are well-validated targets for antibacterial drug discovery. because of their structural and functional homology, these enzymes are amenable to dual targeting by a single ligand. in this study, two novel benzothiazole ethyl urea-based small molecules, designated compound a and compound b, were evaluated for their biochemical, antibacterial, and pharmacokinetic properties. the two compounds inhibited the atpase act ...201324041906
bacterial complications of respiratory tract viral illness: a comprehensive evaluation.respiratory tract infection is one of the most common reasons for hospitalization among adults, and recent evidence suggests that many of these illnesses are associated with viruses. although bacterial infection is known to complicate viral infections, the frequency and impact of mixed viral-bacterial infections has not been well studied.201323661797
discovery of a cyclic phosphodiesterase that catalyzes the sequential hydrolysis of both ester bonds to phosphorus.the bacterial c-p lyase pathway is responsible for the metabolism of unactivated organophosphonates under conditions of phosphate starvation. the cleavage of the c-p bond within ribose-1-methylphosphonate-5-phosphate to form methane and 5-phospho-ribose-1,2-cyclic phosphate (prcp) is catalyzed by the radical sam enzyme phnj. in escherichia coli the cyclic phosphate product is hydrolyzed to ribose-1,5-bisphosphate by phnp. in this study, we describe the discovery and characterization of an enzyme ...201324147537
pang, a new ketopantoate reductase involved in pantothenate synthesis.pantothenate, commonly referred to as vitamin b(5), is an essential molecule in the metabolism of living organisms and forms the core of coenzyme a. unlike humans, some bacteria and plants are capable of de novo biosynthesis of pantothenate, making this pathway a potential target for drug development. francisella tularensis subsp. tularensis schu s4 is a zoonotic bacterial pathogen that is able to synthesize pantothenate but is lacking the known ketopantoate reductase (kpr) genes, pane and ilvc, ...201323243306
the protective effect of recombinant lactococcus lactis oral vaccine on a clostridium difficile-infected animal model.oral immunization with vaccines may be an effective strategy for prevention of clostridium difficile infection (cdi). however, application of previously developed vaccines for preventing cdi has been limited due to various reasons. here, we developed a recombinant lactococcus lactis oral vaccine and evaluated its effect on a c. difficile-infected animal model established in golden hamsters in attempt to provide an alternative strategy for cdi prevention.201323865596
inhaled colistin for treatment of pneumonia due to colistin-only-susceptible acinetobacter baumannii.colistin is used for the treatment of pneumonia associated with multidrug- resistant acinetobacter baumannii and pseudomonas aeruginosa. however, the best route of administration and dosage is not known. we report our experience with aerosolized colistin in twelve patients with pneumonia caused by colistin-only-susceptible (cos) a. baumannii.201324339296
a rare case intractable diarrhea secondary to clostridium difficile and cytomegalovirus coinfection.male, 63 final diagnosis: cytomegalo virus (cmv) infection symptoms: diarrhea medication:- clinical procedure:- specialty: infectious diseases.201324298304
clostridium difficile and inflammatory bowel disease: role in pathogenesis and implications in treatment.clostridium difficile (c. difficile) is the leading cause of antibiotic associated colitis and nosocomial diarrhea. patients with inflammatory bowel disease (ibd) are at increased risk of developing c. difficile infection (cdi), have worse outcomes of cdi-including higher rates of colectomy and death, and experience higher rates of recurrence. however, it is still not clear whether c. difficile is a cause of ibd or a consequence of the inflammatory state in the intestinal environment. the burden ...201324282348
the role of the bacterial flagellum in adhesion and virulence.the bacterial flagellum is a complex apparatus assembled of more than 20 different proteins. the flagellar basal body traverses the cell wall, whereas the curved hook connects the basal body to the whip-like flagellar filament that protrudes several µm from the bacterial cell. the flagellum has traditionally been regarded only as a motility organelle, but more recently it has become evident that flagella have a number of other biological functions. the major subunit, flagellin or flic, of the fl ...201324833223
the nose knows not: poor predictive value of stool sample odor for detection of clostridium difficile. 201323166192
the intestinal microbiota dysbiosis and clostridium difficile infection: is there a relationship with inflammatory bowel disease?gut microbiota is a compilation of microorganisms dwelling in the entire mammalian gastrointestinal tract. they display a symbiotic relationship with the host contributing to its intestinal health and disease. even a slight fluctuation in this equipoise may be deleterious to the host, leading to many pathological conditions like clostridium difficile infection or inflammatory bowel disease (ibd). in this review, we focus on the role of microbial dysbiosis in initiation of c. difficile infection ...201323320050
fecal microbiota transplantation: the state of the art.clostridium difficile infection (cdi) is an emerging problem in terms of incidence, morbidity and mortality. currently available treatment options are not always effective, especially in cases of recurrent/refractory or complicated cdi. the gut microbiota transplantation is a technique that has been sporadically practiced since the '50s, but its clinical efficacy has only recently been supported by scientific evidence. in the present article, we report the pathophysiological basis and the clinic ...201324470963
treatment of clostridium difficile infection: recent trial results.clostridium difficile is a major cause of infection worldwide and is associated with increasing morbidity and mortality in vulnerable patient populations. metronidazole and oral vancomycin are the currently recommended therapies for the treatment of c. difficile infection (cdi) but are associated with unacceptably high rates of disease recurrence. novel therapies for the treatment of cdi and prevention of recurrent cdi are urgently needed. important developments in the treatment of cdi are curre ...201325525499
evaluation of luminex xtag gastrointestinal pathogen analyte-specific reagents for high-throughput, simultaneous detection of bacteria, viruses, and parasites of clinical and public health importance.acute diarrheal disease (add) can be caused by a range of pathogens, including bacteria, viruses, and parasites. conventional diagnostic methods, such as culture, microscopy, biochemical assays, and enzyme-linked immunosorbent assays (elisa), are laborious and time-consuming and lack sensitivity. combined, the array of tests performed on a single specimen can increase the turnaround time (tat) significantly. we validated a 19plex laboratory-developed gastrointestinal pathogen panel (gpp) using l ...201323850948
a laboratory-developed taqman array card for simultaneous detection of 19 enteropathogens.the taqman array card (tac) system is a 384-well singleplex real-time pcr format that has been used to detect multiple infection targets. here we developed an enteric taqman array card to detect 19 enteropathogens, including viruses (adenovirus, astrovirus, norovirus gii, rotavirus, and sapovirus), bacteria (campylobacter jejuni/c. coli, clostridium difficile, salmonella, vibrio cholerae, diarrheagenic escherichia coli strains including enteroaggregative e. coli [eaec], enterotoxigenic e. coli [ ...201323175269
comparison of maldi-tof ms, gene sequencing and the vitek 2 for identification of seventy-three clinical isolates of enteropathogens.this study was performed to evaluate the analytical and practical performance of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi-tof ms) compared to the sequencing method and the vitek 2 system for identification of enteropathogens in the clinical microbiology laboratory.201424822116
dielectrophoretic monitoring and interstrain separation of intact clostridium difficile based on their s(surface)-layers.clostridium difficile (c. difficile) infection (cdi) rates have exhibited a steady rise worldwide over the last two decades and the infection poses a global threat due to the emergence of antibiotic resistant strains. interstrain antagonistic interactions across the host microbiome form an important strategy for controlling the emergence of cdi. the current diagnosis method for cdi, based on immunoassays for toxins produced by pathogenic c. difficile strains, is limited by false negatives due to ...201425343746
detection of zoonotic pathogens and characterization of novel viruses carried by commensal rattus norvegicus in new york city.norway rats (rattus norvegicus) are globally distributed and concentrate in urban environments, where they live and feed in closer proximity to human populations than most other mammals. despite the potential role of rats as reservoirs of zoonotic diseases, the microbial diversity present in urban rat populations remains unexplored. in this study, we used targeted molecular assays to detect known bacterial, viral, and protozoan human pathogens and unbiased high-throughput sequencing to identify ...201425316698
carriage of clostridium difficile by wild urban norway rats (rattus norvegicus) and black rats (rattus rattus).clostridium difficile is an important cause of enteric infections in humans. recently, concerns have been raised regarding whether animals could be a source of c. difficile spores. although colonization has been identified in a number of domestic species, the ability of commensal pests to serve as a reservoir for c. difficile has not been well investigated. the objective of this study was to determine whether urban rats (rattus spp.) from vancouver, canada, carry c. difficile. clostridium diffic ...201424317079
fecal microbiota transplant for relapsing clostridium difficile infection using a frozen inoculum from unrelated donors: a randomized, open-label, controlled pilot study.recurrent clostridium difficile infection (cdi) with poor response to standard antimicrobial therapy is a growing medical concern. we aimed to investigate the outcomes of fecal microbiota transplant (fmt) for relapsing cdi using a frozen suspension from unrelated donors, comparing colonoscopic and nasogastric tube (ngt) administration.201424762631
diagnostic yields in solid organ transplant recipients admitted with diarrhea.although diarrhea is a frequent complaint among solid organ transplant recipients, the contribution of infectious etiologies remains incompletely defined. we sought to define the etiologies of diarrhea and the yields of testing at our institution.201425371488
intestinal microbiota pathogenesis and fecal microbiota transplantation for inflammatory bowel disease.the intestinal microbiota plays an important role in inflammatory bowel disease (ibd). the pathogenesis of ibd involves inappropriate ongoing activation of the mucosal immune system driven by abnormal intestinal microbiota in genetically predisposed individuals. however, there are still no definitive microbial pathogens linked to the onset of ibd. the composition and function of the intestinal microbiota and their metabolites are indeed disturbed in ibd patients. the special alterations of gut m ...201425356041
how well does physician selection of microbiologic tests identify clostridium difficile and other pathogens in paediatric diarrhoea? insights using multiplex pcr-based detection.the objective of this study was to compare the aetiologic yield of standard-of-care microbiologic testing ordered by physicians with that of a multiplex pcr platform. stool specimens obtained from children and young adults with gastrointestinal illness were evaluated by standard laboratory methods and a developmental version of the filmarray gastrointestinal (gi) diagnostic system (filmarray gi panel), a rapid multiplex pcr platform that detects 23 bacterial, viral and protozoal agents. results ...201425599941
comparative evaluation of two commercial multiplex panels for detection of gastrointestinal pathogens by use of clinical stool specimens.the detection of pathogens associated with gastrointestinal disease may be important in certain patient populations, such as immunocompromised hosts, the critically ill, or individuals with prolonged disease that is refractory to treatment. in this study, we evaluated two commercially available multiplex panels (the filmarray gastrointestinal [gi] panel [biofire diagnostics, salt lake city, ut] and the luminex xtag gastrointestinal pathogen panel [gpp] [luminex corporation, toronto, canada]) usi ...201425100818
the post-translational modification of the clostridium difficile flagellin affects motility, cell surface properties and virulence.clostridium difficile is a prominent nosocomial pathogen, proliferating and causing enteric disease in individuals with a compromised gut microflora. we characterized the post-translational modification of flagellin in c. difficile 630. the structure of the modification was solved by nuclear magnetic resonance and shown to contain an n-acetylglucosamine substituted with a phosphorylated n-methyl-l-threonine. a reverse genetics approach investigated the function of the putative four-gene modifica ...201425135277
preclinical studies of amixicile, a systemic therapeutic developed for treatment of clostridium difficile infections that also shows efficacy against helicobacter pylori.amixicile shows efficacy in the treatment of clostridium difficile infections (cdi) in a mouse model, with no recurrence of cdi. since amixicile selectively inhibits the action of a b vitamin (thiamine pyrophosphate) cofactor of pyruvate:ferredoxin oxidoreductase (pfor), it may both escape mutation-based drug resistance and spare beneficial probiotic gut bacteria that do not express this enzyme. amixicile is a water-soluble derivative of nitazoxanide (ntz), an antiparasitic therapeutic that also ...201424890599
the flagellin flic of clostridium difficile is responsible for pleiotropic gene regulation during in vivo infection.clostridium difficile is the main agent responsible for hospital acquired antibiotic associated diarrhoea. in recent years, epidemic strains have emerged causing more severe infections. whilst c. difficile has two major virulence factors, toxins tcda and tcdb, it is generally accepted that other virulence components of the bacterium contribute to disease. previously, it has been suggested that flagella expression from pathogenic bacteria might be implicated in virulence. in a recent study, we ob ...201424841151
clostridium difficile phages: still difficult?phages that infect clostridium difficile were first isolated for typing purposes in the 1980s, but their use was short lived. however, the rise of c. difficile epidemics over the last decade has triggered a resurgence of interest in using phages to combat this pathogen. phage therapy is an attractive treatment option for c. difficile infection, however, developing suitable phages is challenging. in this review we summarize the difficulties faced by researchers in this field, and we discuss the s ...201424808893
a low complexity rapid molecular method for detection of clostridium difficile in stool.here we describe a method for the detection of clostridium difficile from stool using a novel low-complexity and rapid extraction process called heat elution (he). the he method is two-step and takes just 10 minutes, no specialist instruments are required and there is minimal hands-on time. a test method using he was developed in conjunction with loop-mediated isothermal amplification (lamp) combined with the real-time bioluminescent reporter system known as bart targeting the toxin b gene (tcdb ...201424416173
human clostridium difficile infection: altered mucus production and composition.the majority of antibiotic-induced diarrhea is caused by clostridium difficile (c. difficile). hospitalizations for c. difficile infection (cdi) have tripled in the last decade, emphasizing the need to better understand how the organism colonizes the intestine and maintain infection. the mucus provides an interface for bacterial-host interactions and changes in intestinal mucus have been linked host health. to assess mucus production and composition in healthy and cdi patients, the main mucins m ...201425552581
human clostridium difficile infection: inhibition of nhe3 and microbiota profile.clostridium difficile infection (cdi) is principally responsible for hospital acquired, antibiotic-induced diarrhea and colitis and represents a significant financial burden on our healthcare system. little is known about c. difficile proliferation requirements, and a better understanding of these parameters is critical for development of new therapeutic targets. in cell lines, c. difficile toxin b has been shown to inhibit na(+)/h(+) exchanger 3 (nhe3) and loss of nhe3 in mice results in an alt ...201425552580
controlling hospital-acquired infection: focus on the role of the environment and new technologies for decontamination.there is increasing interest in the role of cleaning for managing hospital-acquired infections (hai). pathogens such as vancomycin-resistant enterococci (vre), methicillin-resistant staphylococcus aureus (mrsa), multiresistant gram-negative bacilli, norovirus, and clostridium difficile persist in the health care environment for days. both detergent- and disinfectant-based cleaning can help control these pathogens, although difficulties with measuring cleanliness have compromised the quality of p ...201425278571
the htra-like protease cd3284 modulates virulence of clostridium difficile.in the past decade, clostridium difficile has emerged as an important gut pathogen. symptoms of c. difficile infection range from mild diarrhea to pseudomembranous colitis. besides the two main virulence factors toxin a and toxin b, other virulence factors are likely to play a role in the pathogenesis of the disease. in other gram-positive and gram-negative pathogenic bacteria, conserved high-temperature requirement a (htra)-like proteases have been shown to have a role in protein homeostasis an ...201425047848
pleiotropic role of the rna chaperone protein hfq in the human pathogen clostridium difficile.clostridium difficile is an emergent human pathogen and the most common cause of nosocomial diarrhea. our recent data strongly suggest the importance of rna-based mechanisms for the control of gene expression in c. difficile. in an effort to understand the function of the rna chaperone protein hfq, we constructed and characterized an hfq-depleted strain in c. difficile. hfq depletion led to a growth defect, morphological changes, an increased sensitivity to stresses, and a better ability to spor ...201424982306
integration of metabolism and virulence in clostridium difficile.synthesis of the major toxin proteins of the diarrheal pathogen, clostridium difficile, is dependent on the activity of tcdr, an initiation (sigma) factor of rna polymerase. the synthesis of tcdr and the activation of toxin gene expression are responsive to multiple components in the bacterium's nutritional environment, such as the presence of certain sugars, amino acids, and fatty acids. this review summarizes current knowledge about the mechanisms responsible for repression of toxin synthesis ...201425445566
a curated c. difficile strain 630 metabolic network: prediction of essential targets and inhibitors.clostridium difficile is the leading cause of hospital-borne infections occurring when the natural intestinal flora is depleted following antibiotic treatment. current treatments for clostridium difficile infections present high relapse rates and new hyper-virulent and multi-resistant strains are emerging, making the study of this nosocomial pathogen necessary to find novel therapeutic targets.201425315994
bacteriophage behavioral ecology: how phages alter their bacterial host's habits.bacteriophages have an essential gene kit that enables their invasion, replication, and production. in addition to this "core" genome, they can carry "accessory" genes that dramatically impact bacterial biology, and presumably boost their own success. the content of phage genomes continue to surprise us by revealing new ways that viruses impact bacterial biology. the genome of a clostridium difficile myovirus, phicdhm1, contains homologs of three bacterial accessory gene regulator (agr) genes. t ...201425105060
in vitro antibacterial activity of azd0914, a new spiropyrimidinetrione dna gyrase/topoisomerase inhibitor with potent activity against gram-positive, fastidious gram-negative, and atypical bacteria.azd0914 is a new spiropyrimidinetrione bacterial dna gyrase/topoisomerase inhibitor with potent in vitro antibacterial activity against key gram-positive (staphylococcus aureus, staphylococcus epidermidis, streptococcus pneumoniae, streptococcus pyogenes, and streptococcus agalactiae), fastidious gram-negative (haemophilus influenzae and neisseria gonorrhoeae), atypical (legionella pneumophila), and anaerobic (clostridium difficile) bacterial species, including isolates with known resistance to ...201425385112
infections and chronic inflammatory bowel disease.in the more recent years since the introduction of anti-tnf therapy, the treatment strategy in chronic inflammatory bowel disease has developed more towards an early intensive, often double immunosuppression. while this leads to an improved therapeutic success, this intensified therapy also increases the risk for side effects and especially for infectious complications. the early detection of this complication in the immunocompromised patient is often more difficult due to the potential broad sp ...201426288602
the gap activity of type iii effector yope triggers killing of yersinia in macrophages.the mammalian immune system has the ability to discriminate between pathogens and innocuous microbes by detecting conserved molecular patterns. in addition to conserved microbial patterns, the mammalian immune system may recognize distinct pathogen-induced processes through a mechanism which is poorly understood. previous studies have shown that a type iii secretion system (t3ss) in yersinia pseudotuberculosis leads to decreased survival of this bacterium in primary murine macrophages by unknown ...201425165815
semiquantitative analysis of clinical heat stress in clostridium difficile strain 630 using a gelc/ms workflow with empai quantitation.clostridium difficile is considered to be the most frequent cause of infectious bacterial diarrhoea in hospitals worldwide yet its adaptive ability remains relatively uncharacterised. here, we used gelc/ms and the exponentially modified protein abundance index (empai) calculation to determine proteomic changes in response to a clinically relevant heat stress. reproducibility between both biological and technical replicates was good, and a 37°c proteome of 224 proteins was complemented by a 41°c ...201424586458
clostridium difficile glutamate dehydrogenase is a secreted enzyme that confers resistance to h2o2.clostridium difficile produces an nad-specific glutamate dehydrogenase (gdh), which converts l-glutamate into α-ketoglutarate through an irreversible reaction. the enzyme gdh is detected in the stool samples of patients with c. difficile-associated disease and serves as one of the diagnostic tools to detect c. difficile infection (cdi). we demonstrate here that supernatant fluids of c. difficile cultures contain gdh. to understand the role of gdh in the physiology of c. difficile, an isogenic in ...201424145018
identification of aminoglycoside and β-lactam resistance genes from within an infant gut functional metagenomic library.the infant gut microbiota develops rapidly during the first 2 years of life, acquiring microorganisms from diverse sources. during this time, significant opportunities exist for the infant to acquire antibiotic resistant bacteria, which can become established and constitute the infant gut resistome. with increased antibiotic resistance limiting our ability to treat bacterial infections, investigations into resistance reservoirs are highly pertinent. this study aimed to explore the nascent resist ...201425247417
a novel secreted metalloprotease (cd2830) from clostridium difficile cleaves specific proline sequences in lpxtg cell surface proteins.bacterial secreted proteins constitute a biologically important subset of proteins involved in key processes related to infection such as adhesion, colonization, and dissemination. bacterial extracellular proteases, in particular, have attracted considerable attention, as they have been shown to be indispensable for bacterial virulence. here, we analyzed the extracellular subproteome of clostridium difficile and identified a hypothetical protein, cd2830, as a novel secreted metalloprotease. foll ...201424623589
identification, immunogenicity, and cross-reactivity of type iv pilin and pilin-like proteins from clostridium difficile.the gram-positive anaerobe clostridium difficile is the major cause of nosocomial diarrhea; manifestations of infection include diarrhea, pseudomembranous colitis, and death. genes for type iv pili, a bacterial nanofiber often involved in colonization and until relatively recently described only in gram-negatives, are present in all members of the clostridiales. we hypothesized that any pilins encoded in the c. difficile genome would be immunogenic, as has been shown with pilins from gram-negati ...201424550179
importance of antimicrobial stewardship to the english national health service.antimicrobials are an extremely valuable resource across the spectrum of modern medicine. their development has been associated with dramatic reductions in communicable disease mortality and has facilitated technological advances in cancer therapy, transplantation, and surgery. however, this resource is threatened by the dwindling supply of new antimicrobials and the global increase in antimicrobial resistance. there is an urgent need for antimicrobial stewardship (ams) to protect our remaining ...201424936131
evaluation of an online program to teach microbiology to internal medicine residents.microbiology rounds are an integral part of infectious disease consultation service. during microbiology rounds, we highlight microbiology principles using vignettes. we created case-based, interactive, microbiology online modules similar to the vignettes presented during microbiology rounds. since internal medicine residents rotating on our infectious disease elective have limited time to participate in rounds and learn microbiology, our objective was to evaluate the use of the microbiology onl ...201425392364
antibiotic consumption and antibiotic stewardship in swedish hospitals.the aim of this paper was to describe and analyze the effect of antibiotic policy changes on antibiotic consumption in swedish hospitals and to review antibiotic stewardship in swedish hospitals.201424724823
interleukin-22 regulates the complement system to promote resistance against pathobionts after pathogen-induced intestinal damage.pathobionts play a critical role in disease development, but the immune mechanisms against pathobionts remain poorly understood. here, we report a critical role for interleukin-22 (il-22) in systemic protection against bacterial pathobionts that translocate into the circulation after infection with the pathogen clostridium difficile. infection with c. difficile induced il-22, and infected il22(-/-) mice harbored high numbers of pathobionts in extraintestinal organs despite comparable pathogen lo ...201425367575
severe clinical outcome is uncommon in clostridium difficile infection in children: a retrospective cohort study.clostridium difficile infection (cdi) is the most common cause of health care-associated diarrhea in children and adults. although serious complications of cdi have been reported to be increasing in adults, this trend has not yet been demonstrated in children. the purpose of this study was to examine the features of cdi in a pediatric population, with special attention to the occurrence of cdi-related severe outcomes.201424485120
fidaxomicin for clostridium difficile colitis in a peritoneal dialysis patient with underlying mitochondriopathy. 201424525607
clostridium difficile hfq can replace escherichia coli hfq for most of its function.a gene for the hfq protein is present in the majority of sequenced bacterial genomes. its characteristic hexameric ring-like core structure is formed by the highly conserved n-terminal regions. in contrast, the c-terminal forms an extension, which varies in length, lacks homology, and is predicted to be unstructured. in gram-negative bacteria, hfq facilitates the pairing of srnas with their mrna target and thus affects gene expression, either positively or negatively, and modulates srna degradat ...201425147238
multistate point-prevalence survey of health care-associated infections.currently, no single u.s. surveillance system can provide estimates of the burden of all types of health care-associated infections across acute care patient populations. we conducted a prevalence survey in 10 geographically diverse states to determine the prevalence of health care-associated infections in acute care hospitals and generate updated estimates of the national burden of such infections.201424670166
clostridium and bacillus binary enterotoxins: bad for the bowels, and eukaryotic being.some pathogenic spore-forming bacilli employ a binary protein mechanism for intoxicating the intestinal tracts of insects, animals, and humans. these gram-positive bacteria and their toxins include clostridium botulinum (c2 toxin), clostridium difficile (c. difficile toxin or cdt), clostridium perfringens (ι-toxin and binary enterotoxin, or bec), clostridium spiroforme (c. spiroforme toxin or cst), as well as bacillus cereus (vegetative insecticidal protein or vip). these gut-acting proteins for ...201425198129
cyclic di-gmp riboswitch-regulated type iv pili contribute to aggregation of clostridium difficile.clostridium difficile is an anaerobic gram-positive bacterium that causes intestinal infections with symptoms ranging from mild diarrhea to fulminant colitis. cyclic diguanosine monophosphate (c-di-gmp) is a bacterial second messenger that typically regulates the switch from motile, free-living to sessile and multicellular behaviors in gram-negative bacteria. increased intracellular c-di-gmp concentration in c. difficile was recently shown to reduce flagellar motility and to increase cell aggreg ...201425512308
clinical characteristics of clostridium difficile infection in hospitalized patients with antibiotic-associated diarrhea in a university hospital in china.the purpose of this study was to identify clinical characteristics of clostridium difficile infection (cdi) in patients with antibiotic-associated diarrhea (aad). a prospective study was conducted among patients hospitalized in fudan university hospital huashan from august 1, 2012 to july 31, 2013. toxigenic c. difficile isolates were characterized by pcr ribotyping and multilocus sequence typing. aad developed in 1.0 % (206/20437) of the antibiotic-treated hospitalized patients and toxigenic c. ...201424820293
nosocomial bacteriuria in elderly inpatients may be leading to considerable antibiotic overuse: an audit of current management practice in a secondary level care hospital in new zealand.bacteriuria in the form of symptomatic urinary tract infection (uti) and asymptomatic bacteriuria (asb) is common in the elderly. there is no clinical benefit obtained by treating elderly individuals with asb. however, its high prevalence leads to the overdiagnosis of uti and unnecessary antibiotic use, which can result in adverse events, including clostridium difficile diarrhea and reinfection with antibiotic-resistant organisms.201425419149
differential impact of infection control strategies on rates of resistant hospital-acquired pathogens in critically ill surgical patients.there were two major outbreaks of multi-drug resistant acinetobacter baumannii (mdra) in our general surgery and trauma intensive care units (icus) in 2004 and 2011. both required aggressive multi-faceted interventions to control. we hypothesized that the infection control response may have had a secondary benefit of reducing rates of methicillin-resistant staphylococcus aureus (mrsa), vancomycin-resistant enterococcus (vre), and clostridium difficile (c. diff).201425496277
biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) by recombinant escherichia coli expressing leucine metabolism-related enzymes derived from clostridium difficile.an obligate anaerobic bacterium clostridium difficile has a unique metabolic pathway to convert leucine to 4-methylvalerate, in which 4-methyl-2-pentenoyl-coa (4m2pe-coa) is an intermediate of this pathway. 4m2pe-coa is also able to be converted to 3-hydroxy-4-methylvalerate (3h4mv), a branched side chain monomer unit, for synthesis of polyhydroxyalkanoate (pha) copolymer. in this study, to synthesize 3h4mv-containing pha copolymer from leucine, the leucine metabolism-related enzymes (ldha and h ...201424484910
efficacy of sporicidal wipes for inactivation of a bacillus anthracis surrogate.to evaluate five commercially available sporicidal wipes and two disinfecting wipes for their ability to inactivate bacillus atrophaeus spores deposited onto various material surfaces.201425220421
tailored cyclodextrin pore blocker protects mammalian cells from clostridium difficile binary toxin cdt.some clostridium difficile strains produce, in addition to toxins a and b, the binary toxin clostridium difficile transferase (cdt), which adp-ribosylates actin and may contribute to the hypervirulence of these strains. the separate binding and translocation component cdtb mediates transport of the enzyme component cdta into mammalian target cells. cdtb binds to its receptor on the cell surface, cdta assembles and cdtb/cdta complexes are internalised. in acidic endosomes, cdtb mediates the deliv ...201425029374
characterization of the collagen-like exosporium protein, bcla1, of clostridium difficile spores.spores of clostridium difficile are essential for infection, persistence and transmission of c. difficile infections (cdi). proteins of the surface of c. difficile spores are thought to be essential for initiation and persistence of cdi. in this work, we demonstrate that three c. difficile collagen-like exosporium proteins (bcla) encoded in the c. difficile 630 genome are expressed during sporulation and localize to the spore via their n-terminal domains. using polyclonal antibodies against the ...201424269655
bioavailability of the anti-clostridial bacteriocin thuricin cd in gastrointestinal tract.thuricin cd is a two component narrow spectrum bacteriocin comprising two peptides with targeted activity against clostridium difficile. this study examined the bioavailability of thuricin with a view to developing it as an effective antimicrobial against intestinal infection. one of the peptides, trn-β, was found to be degraded by the gastric enzymes pepsin and α-chymotrypsin both in vitro and in vivo, whereas trn-α was resistant to digestion by these enzymes and hence was detected in the intes ...201424287693
investigation of sporulation in the desulfotomaculum genus: a genomic comparison with the genera bacillus and clostridium.the genus desulfotomaculum, belonging to the firmicutes, comprises strictly anaerobic and endospore-forming bacteria capable of dissimilatory sulfate reduction. these microorganisms are metabolically versatile and are widely distributed in the environment. spore formation allows them to survive prolonged environmental stress. information on the mechanism of sporulation in desulfotomaculum species is scarce. herein, this process was probed from a genomic standpoint, using the bacillus subtilis mo ...201425132579
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