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TAXONOMY: Terrabacteria group -> Firmicutes -> Clostridia -> Clostridiales -> Peptostreptococcaceae -> Peptoclostridium -> Peptoclostridium difficile
'C. difficile'. Peptoclostridium difficile is a major nosocomial pathogen world-wide causing disease ranging from antibiotic-associated diarrhoea to life-threatening pseudomembranous colitis.Pathogenic C. difficile strains produce multiple toxins. The most well-characterized are enterotoxin (Clostridium difficile toxin A) and cytotoxin (Clostridium difficile toxin B), both of which may produce diarrhea and inflammation in infected patients (Clostridium difficile colitis), although their relative contributions have been debated. Toxins A and B are glucosyltransferases that target and inactivate the Rho family of GTPases. Toxin B (cytotoxin) induces actin depolymerization by a mechanism correlated with a decrease in the ADP-ribosylation of the low molecular mass GTP-binding Rho proteins. Another toxin, binary toxin, also has been described, but its role in disease is not fully understood. Antibiotic treatment of C. diff infections may be difficult, due both to antibiotic resistance and physiological factors of the bacteria (spore formation, protective effects of the pseudomembrane). The emergence of a new, highly toxic strain of C. difficile, resistant to fluoroquinolone antibiotics, such as ciprofloxacin and levofloxacin, said to be causing geographically dispersed outbreaks in North America, was reported in 2005. The U.S. Centers for Disease Control (CDC) in Atlanta warned of the emergence of an epidemic strain with increased virulence, antibiotic resistance, or both. C. difficile is transmitted from person to person by the fecal-oral route. However, the organism forms heat-resistant spores that are not killed by alcohol-based hand cleansers or routine surface cleaning. Thus, these spores survive in clinical environments for long periods. Because of this, the bacteria may be cultured from almost any surface. Once spores are ingested, their acid-resistance allows them to pass through the stomach unscathed. They germinate and multiply into vegetative cells in the colon upon exposure to bile acids. A 2015 CDC study estimated that C. diff afflicted almost half a million Americans and caused 29,000 deaths in 2011. The study estimated that 40 percent of cases began in nursing homes or community health care settings, while 24 percent occurred in hospitals.
Consumption of microbiota-accessible carbohydrates (MACs) found in dietary plant polysaccharides may have a significant effect on C. difficile infection. C. difficile burdens are suppressed through the addition of either a diet containing a complex mixture of MACs or a simplified diet containing inulin as the sole MAC source. Switches between these dietary conditions are coincident with changes to microbiota membership, its metabolic output and C. difficile-mediated inflammation. The outgrowth of MAC-utilizing taxa and the associated end products of MAC metabolism, namely, the short-chain fatty acids acetate, propionate and butyrate, are associated with decreased C. difficile fitness despite increased C. difficile toxin expression in the gut. [PMID: 29686297]
Synonyms : Clostridium difficile, NCTC 11209, NCIMB 10666, LMG 15861, JCM 1296, DSM 1296, CIP 104282, CCUG 4938, CCRC 10642, Bacillus difficilis, BCRC 10642, ATCC 9689.