Clostridioides
(klos-trid'ē-oyd'ēz 
)
[L. Clostridium, a genus name, fr. Gr. klōstēr, spindle]
A genus of gram-positive, anaerobic, spore-forming bacilli in the family Bacillaceae. The genus comprises more than 250 species inhabit soil, water, and the intestinal tracts of humans and animals. Many species are pathogenic in humans, including those that colonize dead tissue, secrete numerous proteolytic enzymes, and cause gas gangrene.
SEE: gas gangrene.
ABBR: C. diff.
A species that causes watery diarrhea, fever, anorexia, and abdominal pain, sometimes accompanied by pseudomembranous colitis, esp. in patients previously treated with antibiotics or confined in health care settings. Most antibiotics (except aminoglycosides) have been associated with the development of C. diff.-associated disease, which varies in clinical significance from a relatively mild diarrheal illness, to one complicated by dehydration, electrolyte disturbances, toxic megacolon, and death. The disease is caused by two exotoxins released by the bacterium into the colon: TcdA and TcdB.Infections with C. diff. may be detected with cytotoxin neutralization assays, enzyme immunoassays, polymerase chain reaction (PCR) assays, or loop-mediated isothermal amplification.
Most patients should be treated with fidaxomicin. Individuals with a recurrence of C. diff. within 6 months of a prior infection should be given antibiotic therapy plus a monoclonal antibody that neutralizes C. difficile toxin B. Patients who have had a recurrence should also receive a fecal microbiota transplant or a suppressive dose of oral vancomycin. Patients with toxic megacolon may need surgery to remove damaged bowel. Fluid support intravenously and other elements of general supportive care also apply.
SEE: pseudomembranous colitis.