Cytotoxicity and antimicrobial susceptibility of Clostridium difficile isolated from hospitalized children with acute diarrhea

Ferreira, Claudia Elisa Alves; Nakano, Viviane; Avila-Campos, Mario Júlio

doi:10.1016/j.anaerobe.2004.02.003

Cited by 12 publications

(9 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bouza and colleagues have reported that a 15% increase in sensitivity can be achieved by culture combined with cytotoxin testing of isolates (8). However, the data are hard to interpret, since actual and described culture techniques (such as the use of enrichment procedures, heat or alcohol shock, and the composition of CCFA) vary (14), as do the tests against which they are compared, the number of tests performed, and the populations tested. Comparative North American and European studies have demonstrated that prereduced CCFA with a high cycloserine concentration, as proposed by George et al (15), may be optimal (26,30).…”

Section: Discussionmentioning

confidence: 99%

Yield of Stool Culture with Isolate Toxin Testing versus a Two-Step Algorithm Including Stool Toxin Testing for Detection of Toxigenic Clostridium difficile

Reller¹,

Lema²,

et al. 2007

View full text Add to dashboard Cite

We examined the incremental yield of stool culture (with toxin testing on isolates) versus our two-step algorithm for optimal detection of toxigenic Clostridium difficile. Per the two-step algorithm, stools were screened for C. difficile-associated glutamate dehydrogenase (GDH) antigen and, if positive, tested for toxin by a direct (stool) cell culture cytotoxicity neutralization assay (CCNA). In parallel, stools were cultured for C. difficile and tested for toxin by both indirect (isolate) CCNA and conventional PCR if the direct CCNA was negative. The "gold standard" for toxigenic C. difficile was detection of C. difficile by the GDH screen or by culture and toxin production by direct or indirect CCNA. We tested 439 specimens from 439 patients. GDH screening detected all culture-positive specimens. The sensitivity of the two-step algorithm was 77% (95% confidence interval [CI], 70 to 84%), and that of culture was 87% (95% CI, 80 to 92%). PCR results correlated completely with those of CCNA testing on isolates (29/29 positive and 32/32 negative, respectively). We conclude that GDH is an excellent screening test and that culture with isolate CCNA testing detects an additional 23% of toxigenic C. difficile missed by direct CCNA. Since culture is tedious and also detects nontoxigenic C. difficile, we conclude that culture is most useful (i) when the direct CCNA is negative but a high clinical suspicion of toxigenic C. difficile remains, (ii) in the evaluation of new diagnostic tests for toxigenic C. difficile (where the best reference standard is essential), and (iii) in epidemiologic studies (where the availability of an isolate allows for strain typing and antimicrobial susceptibility testing).Since its identification in 1978, Clostridium difficile has emerged as the predominant cause of antibiotic-associated colitis and the leading cause of diarrhea in hospitalized patients (4). Strains of C. difficile can be toxigenic or nontoxigenic; however, only toxigenic strains produce disease. The two main virulence factors are toxin A, a 308-kDa enterotoxin with some cytopathic effects (TcdA), and Toxin B (TcdB), a potent 270-kDa cytotoxin that affects various tissue cell lines in vitro and inhibits bowel motility in vivo (3, 12). The genes encoding both toxins, tcdA and tcdB, have been sequenced, and both are known to disrupt the actin cytoskeleton of intestinal epithelial cells by modifying Rho family proteins. Toxin A has long been considered more important (19,20), but an increasing number of reports of colitis due to TcdA-negative but TcdB-positive strains have now been made (5, 35). Furthermore, other virulence factors have now been identified. Recently, an increase in the frequency and severity of C. difficile-associated colitis, which is associated with a new strain that produces binary toxin (actin-specific ADP-ribosyltransferase) and is resistant to fluoroquinolones in vitro, has refocused attention on early, accurate diagnosis (2,9,23,29,36).Cell culture cytotoxicity neutralization assays (CCNA), which detect ...

show abstract

Section: Discussionmentioning

confidence: 99%

Yield of Stool Culture with Isolate Toxin Testing versus a Two-Step Algorithm Including Stool Toxin Testing for Detection of Toxigenic Clostridium difficile

Reller¹,

Lema²,

et al. 2007

View full text Add to dashboard Cite

show abstract

“…It has been reported in a few cases of severe infections in both animals and man. In most cases, C. limosum was isolated as a part of a mixed infection [2–6]. …”

Section: Resultsmentioning

confidence: 99%

Isolation of Clostridium limosum from an outbreak of metritis in farmed mink

et al. 2015

View full text Add to dashboard Cite

BackgroundAn outbreak of sudden death of pregnant farmed mink in Finland occurred during the busiest whelping period in the spring of 2013. The affected farms were all located in western Finland in a rather narrow geographic area, Ostrobothnia. Dead mink from 22 farms were submitted for laboratory diagnostics to the Finnish Food Safety Authority (Evira). The carcasses were necropsied and tissue specimens were prepared for histology. Samples of internal organs and peritoneal fluid were cultured bacteriologically.ResultsMajor pathological findings included hemorrhagic vaginal discharge, severely inflamed uteri with luminal hemorrhagic exudate and dead fetuses. Dead fetuses were present in the peritoneal cavity and associated severe peritonitis occurring as sequela of uterine rupture were found in most minks. Histological findings included hemorrhages, neutrophil infiltrations, degenerative inflammatory cells, edema, fibrin and rod-shaped bacteria on all layers of the uterine wall. In most samples abundant and pure anaerobic bacterial growth of Clostridium limosum was found.ConclusionsThis is the first report of C. limosum associated metritis in farmed mink. Disease was only observed in pregnant females and the uterus was the primary site of infection. The source of infection and the route of transmission remained unclear, but feed borne transmission was suspected.

show abstract

“…Pathogens such as C. perfringens and C. difficile are known to have cytotoxic activity [24,25]. To investigate whether Clostridium sp.…”

Section: Methodsmentioning

confidence: 99%

Genome sequencing of multidrug resistant novel Clostridium sp. BL8 reveals its potential for pathogenicity

et al. 2014

View full text Add to dashboard Cite

BackgroundThe human gut microbiome is important for maintaining the health status of the host. Clostridia are key members of the human gut microbiome, carrying out several important functions in the gut environment. Hence understanding the role of different Clostridium species isolated from human gut is essential. The present study was aimed at investigating the role of novel Clostridium sp. isolate BL8 in human gut using genome sequencing as a tool.FindingsThe genome analysis of Clostridium sp. BL8 showed the presence of several adaptive features like bile resistance, presence of sensory and regulatory systems, presence of oxidative stress managing systems and presence of membrane transport systems. The genome of Clostridium sp. BL8 consists of a wide variety of virulence factors like phospholipase C (alpha toxin), hemolysin, aureolysin and exfoliative toxin A, as well as adhesion factors, proteases, Type IV secretion system and antibiotic resistance genes. In vitro antibiotic sensitivity testing showed that Clostridium sp. BL8 was resistant to 11 different tested antibiotics belonging to 6 different classes. The cell cytotoxicity assay confirmed the cytotoxic effect of Clostridium sp. BL8 cells, which killed 40% of the Vero cells after 4 hrs of incubation.ConclusionsClostridium sp. BL8 has adapted for survival in human gut environment, with presence of different adaptive features. The presence of several virulence factors and cell cytotoxic activity indicate that Clostridium sp. BL8 has a potential to cause infections in humans, however further in vivo studies are necessary to ascertain this fact.

show abstract

Cytotoxicity and antimicrobial susceptibility of Clostridium difficile isolated from hospitalized children with acute diarrhea

Cited by 12 publications

References 22 publications

Yield of Stool Culture with Isolate Toxin Testing versus a Two-Step Algorithm Including Stool Toxin Testing for Detection of Toxigenic Clostridium difficile

Yield of Stool Culture with Isolate Toxin Testing versus a Two-Step Algorithm Including Stool Toxin Testing for Detection of Toxigenic Clostridium difficile

Isolation of Clostridium limosum from an outbreak of metritis in farmed mink

Genome sequencing of multidrug resistant novel Clostridium sp. BL8 reveals its potential for pathogenicity

Contact Info

Product

Resources

About