Survey of incidence of Clostridium difficile infection in Canadian hospitals and diagnostic approaches

A questionnaire relating to Clostridium difficile disease incidence and diagnostic practices was sent to 380 Canadian hospitals (all with > 50 beds). The national questionnaire response rate was 63%. In-house testing was performed in 17.6, 61.5, and 74.2% of the hospitals with < 300, 300 to 500, and > 500 beds, respectively. The average test positivity rates were 17.2, 15.3, and 13.2% for hospitals with < 300, 300 to 500, and > 500 beds, respectively. The average disease incidences were 23.5, 30.8, and 40.3 cases per 100,000 patient days in the hospitals with < 300, 300 to 500, and > 500 beds, respectively. In the 81 hospitals where in-house testing was performed, cytotoxin testing utilizing tissue culture was most common (44.4%), followed by enzyme-linked immunosorbent assay (38.3%), culture for toxigenic C. difficile (32.1%), and latex agglutination (13.6%). The clinical criteria for C. difficile testing were variable, with 85% of hospitals indicating that a test was done automatically if ordered by a doctor. Our results show that C. difficile-associated diarrhea is a major problem in hospitals with > or = 200 beds. Despite a lower disease incidence in smaller hospitals, there was a higher diagnostic test positivity rate. This may reflect the preference of smaller hospitals for culture and latex agglutination tests.     

Some aspects of the Clostridium difficile infection

Clostridium difficile is now regarded as the most common nosocomial enteric pathogen. C. difficile infection has a wide spectrum of a clinical presentation ranging from asymptomatic carriage to the fulminant colitis. Antibiotic therapy is the most important risk factor in pathogen contagion, however other factors are also involved. Typical pathophysiology: 1. alteration of the indigenous colonic flora by antibodies, 2. ingestion of spores, 3. colonization by Clostridium difficile, 4. production of its toxins. Both entherotoxin A and cytotoxin B are active in human colon. The mode of action of these toxins is already quite well known. The main treatment includes withdrawal of the inducing agents, supported occasionally by oral Vancomycin and Metronidazole. Relapse is a major complication.     

Review article: antibiotic-induced Clostridium difficile infection

The great majority of cases of Clostridium difficile infection are hospital-acquired, and the reported incidence in England and Wales has increased sixfold between 1990 and 1993, with at least 17 patients dying in a recent large nosocomial outbreak. C. difficile infection accounts for an average 3-week increased length of stay in hospital. Acquisition of a toxigenic strain of Clostridium difficile may be followed by asymptomatic carriage, diarrhoea, colitis or pseudomembranous colitis. Antibiotic treatment and older age are major risk factors for the development of symptomatic disease, but less well-defined differences in strain virulence and host susceptibility are also probably important. Accurate data on the relative risks of different antibiotics to induce symptomatic C. difficile infection are scarce, but third-generation cephalosporins are frequently implicated. New kits are becoming available for the laboratory diagnosis of C. difficile infection but many of these lack sensitivity. Oral metronidazole or vancomycin are the main treatment options but avoidance of further antibiotics should also be encouraged where possible. The role of environmental C. difficile spores, which are highly resistant to conventional disinfectants, needs to be defined. Proven strategies for the prevention of C. difficile infection are required, in particular protocols to ensure that cross-infection does not occur.     

Review article: treatment of Clostridium difficile infection

AIM: A systematic review of controlled trials of therapy of Clostridium difficile intestinal infection using methodology described by the Cochrane Collaboration. METHODS: Trials were identified by searching computer databases over the years 1978-1996. Trials were included if they were (a) prospective randomized, controlled trials and (b) included patients with symptomatic disease. The primary end-point was clinical resolution of diarrhoea. Secondary end-points were clinical relapse and stool clearance of C. difficile and C. difficile toxin. RESULTS: Nine trials (469 patients) satisfying the inclusion criteria were identified. Two trials were placebo controlled. Six trials compared vancomycin to other antibiotics (fusidic acid, bacitracin, teicoplanin and metronidazole). For clinical resolution response rates ranged from 21 (placebo) to 100% (vancomycin). On pooling the trials, no antibiotic showed clear therapeutic superiority. Rates of clinical relapse ranged from 5 to 42%. Only one trial showed significant advantage of one antibiotic over another for prevention of relapse (teicoplanin vs. fusidic acid). CONCLUSION: The published data are limited, and further studies are required.     

Clostridium difficile infection in patients with reactive arthritis of undetermined etiology

BACKGROUND: Multiple sensory neuropeptides are present in human airways and may contribute to diseases such as asthma. This study quantified and characterised substance P (SP), neurokinin A (NKA), and calcitonin gene related peptide (CGRP) immunoreactivity in bronchoalveolar lavage fluid in asthmatic and normal subjects. METHODS: Using specific radioimmunoassay (RIA), SP, NKA and CGRP were measured in bronchoalveolar lavage fluid from asthmatic subjects (n = 5), normal subjects (n = 5), atopic non-asthmatic subjects (n = 6), and asthmatic subjects four hours after allergen challenge (n = 12). Peptide immunoreactivity was characterised using high performance liquid chromatography (HPLC) and RIA. RESULTS: No SP or CGRP immunoreactivity was detected in any of the fractions from samples after extraction, HPLC, and RIA. Non-specific binding resulted in spurious SP immunoreactivity being detected in bronchoalveolar lavage fluid when no extraction process was employed. NKA was detected in significant amounts in asthmatic (median 550, range 425-625 pg/ml) and normal subjects (median 725, range 350-1425 pg/ml). The level of NKA was significantly higher in the asthmatic subjects after allergen challenge (median 750, range 350-1250 pg/ml) than in unchallenged asthmatic subjects (median 600, range 425-600 pg/ml, p < 0.01). CONCLUSIONS: Extraction and characterisation of peptides from bronchoalveolar lavage fluid must be performed to ensure that the measured immunoreactivity represents target peptide. NKA is present in bronchoalveolar lavage fluid in high concentrations and is the predominant tachykinin. The concentrations of NKA are similar in normal subjects and subjects with mild asthma.     

Clostridium difficile colitis associated with treatment of Helicobacter pylori infection

Helicobacter pylori infection of the stomach is being detected and treated more often now than ever before. This is likely to result in an increase in complications such as antibiotic-associated diarrhea. However, there is no literature on the incidence of such diarrhea, particularly Clostridium difficile colitis, in patients treated for Helicobacter pylori infection. We report the case of a patient who developed Clostridium difficile colitis after treatment for Helicobacter pylori infection with metronidazole, amoxicillin, H2 blockers, and bismuth subsalicylate. This patient presented with severe diarrhea that responded to a course of metronidazole with rapid disappearance of symptoms. The incidence of Clostridium difficile colitis in patients treated for Helicobacter pylori infection has not been studied. This unique association, although not unexpected, has not yet been reported in the literature. The increasing number of patients being diagnosed and treated for this infection requires a heightened awareness on the part of physicians, to assure early diagnosis and treatment of this treatable, yet potentially dangerous, complication.     

A prospective study of Clostridium difficile infection and colonization in pediatric oncology patients

BACKGROUND: Tumescent liposuction has proven to be an extremely safe and effective method of liposuction. However, the infusion of tumescent anesthesia can take 1 hour or more to complete. OBJECTIVE: To document the types, dosages, and routes of administration of premedication utilized by four experienced tumescent liposuction surgeons. To determine if infusion rates for tumescent anesthesia are affected by types of premedication. METHODS: Four experienced liposuction surgeons were asked to review their most recent 100 tumescent liposuction patients with respect to types and dosages of premedication and routes of administration. Data were also provided on corresponding infusion pump settings and infusion rates. Volumes of tumescent anesthesia and corresponding volumes of fat aspirated were also collected on the same 400 patients. RESULTS: Infusion of tumescent anesthesia could be performed more rapidly in patients who were given greater amounts of premedication. Volumes of tumescent anesthesia infused were generally two or more times the volume of fat aspirated. Patients could be infused with less premedication if slow infiltration was employed. CONCLUSION: Infusion rates for tumescent anesthesia can be increased of greater amounts of premedication are given. However, this must be balanced against the safety of the premedication.     

Antibacterial activity of teicoplanin against Clostridium difficile

The in vitro inhibitory action of teicoplanin, vancomycin, metronidazole and clindamycin against clinical isolates of Clostridium difficile was investigated. Minimum inhibitory concentrations (MICs) were determined using E test. Teicoplanin (MIC range 0.023-0.75 microgram/ml), vancomycin (MIC range 0.5-3 micrograms/ml) and metronidazole (MIC range 0.19-1 microgram/ml) were all very active against the isolates examined. No resistant strains of C. difficile to those three antimicrobial agents were observed, whereas resistance to clindamycin was found in 39.5% of the tested strains. Teicoplanin was about 4-times more potent than vancomycin. It appears to be a more promising antimicrobial for treatment of C. difficile enteric disease.     

Physical map of the Clostridium difficile chromosome

The present study was designed to investigate the effect of mercuric chloride administration on copper, zinc, and iron concentrations in the liver, kidney, lung, heart, spleen, and muscle of rats. The results showed that after dose and time exposure to mercuric chloride, the concentration of mercury in the six tissues was significantly elevated. Data showed that there were no interaction between mercury and tissue iron. There was a considerable elevation of the content of copper in the kidney and liver. The most significant changes in the copper concentration took place in the kidneys. About a twofold increase in the copper content of the kidney was noted after exposure to mercuric chloride (3 mg and 5 mg/kg). Only slight elevations in the copper content occurred in the liver especially in high dose and longer exposure time. In the remaining organs, the copper content was not changed significantly (p > 0.05). The most significant changes in the zinc concentration took place in liver, kidney, lung and heart (5 mg/kg). Marked changes in kidney zinc concentrations were observed at any of the specified doses. Zinc concentrations were significantly increased in kidney of rats sacrificed 9-48 h after s.c. injection of HgCl2 (5 mg/kg); in liver obtained from rats at 18, 24 or 48 h after injection; and in lung after 24 or 48 h of treatment. The heart and spleen zinc concentrations were elevated at 24 and 48 h after injection of HgCl2 (5 mg/kg), respectively. The results of this study implicate that effects on copper and zinc concentrations of the target tissues of mercury may play an important role in the pathogenesis of acute mercuric chloride intoxication.     

Study of the thermoresistance of Clostridium difficile spores

Thermoresistance of C. difficile spores was investigated. C. difficile strains were isolated from different sources. As control, toxigenic VPI 10463 and nontoxigenic NIH BRIGGS 8050 C. difficile strains were used. The inhibition of growth majority of C. difficile after heating at 85 degrees C was shown. No correlation between thermoresistance of C. difficile spores, toxigenicity and source of the strains was observed.     

Evaluation of a new enzyme immunoassay for Clostridium difficile toxin A

AIM: To evaluate a new enzyme immunoassay (EIA) method for detection of Clostridium difficile toxin by comparing it to cytotoxicity assay. To investigate the nature of false negative and false positive EIA results by evaluating clinical and therapeutic parameters. METHODS: 737 consecutive diarrhoeal specimens collected from patients clinically suspected of having C difficile colitis were tested for the presence of C difficile toxin by EIA for toxin A and by cytotoxicity assay. Clinical data were evaluated in all cases positive by either method. RESULTS: With the cytotoxicity assay as a gold standard, the specificity of EIA for toxin detection was 99.3% and the sensitivity was 62.2%. No false negative EIA specimens were obtained from patients already being treated for C difficile colitis. Among patients with cytotoxicity positive specimens, those with EIA positive samples had no clinical features distinguishing them from patients with EIA negative samples. CONCLUSIONS: Although specific, the new EIA method directed against toxin A lacks sensitivity compared to cytotoxicity. False negative EIA tests are not associated with concurrent treatment for C difficile colitis nor with any specific clinical features examined in our study.     

Purification and characterization of Clostridium difficile glutamate dehydrogenase

Recombinant Clostridium difficile glutamate dehydrogenase (L-glutamate:NAD oxidoreductase, EC 1.4.1.2) was purified 177-fold to electrophoretic homogeneity with a 62% recovery through a four-step procedure involving gel filtration and ion-exchange and dye affinity chromatography. The approximate molecular weights of the native enzyme by gel filtration and subunits by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were consistent with a hexameric structure for the purified enzyme. The enzyme-catalyzed glutamate oxidation was an NAD-dependent sequential process in which NADP could not be substituted as coenzyme. Several dinucleotide analogs of NAD structurally altered in either the pyridine or the purine moiety were observed to function as coenzymes when substituted for NAD. Nicotinamide mononucleotide did not serve as a coenzyme for glutamate oxidation. Product inhibition by NADH was competitive with respect to NAD. In deadend inhibition studies, adenosine diphosphoribose was shown to be an effective coenzyme-competitive inhibitor.     

Clostridium difficile toxin B induces apoptosis in intestinal cultured cells

Toxigenic strains of the anaerobic bacterium Clostridium difficile produce at least two large, single-chain protein exotoxins involved in the pathogenesis of antibiotic-associated diarrhea and colitis. Toxin A (CdA) is a cytotoxic enterotoxin, while toxin B (CdB) is a more potent cytotoxin lacking enterotoxic activity. This study dealt with CdB, providing the first evidence that intestinal cells exposed to this toxin exhibit typical features of apoptosis in that a significant proportion of the treated cells displayed nuclear fragmentation and chromatin condensation. In keeping with ultrastructural data, CdB-treated cells showed the typical flow cytometric hallmark of apoptosis consisting of a distinct sub-G1 peak. The CdB-induced apoptotic response was dose and time dependent and not simply due to the actin-disrupting effect of the toxin or to the subsequent impairment of cell anchorage. Rather, the inhibition of proteins belonging to the Rho family due to CdB seems to play a role in the induction of apoptosis in intestinal cells. The origin of cells and the growth rate may also be cofactors relevant to such a response.     

Atypical presentation of Clostridium difficile colitis in patients with cystic fibrosis

OBJECTIVE: This report describes the unusual presentation of Clostridium difficile colitis in five patients with cystic fibrosis and the role of CT in first suggesting the correct diagnosis in this group of patients. Because of the absence of watery diarrhea and the presence of abdominal bloating and decreased stooling, cystic fibrosis patients with C. difficile colitis will be treated for stool impaction, meconium ileus equivalent, or distal intestinal obstruction syndrome. CT of the abdomen, performed in these five patients because of their lack of improvement after standard therapy for stool impaction, showed an extensive pancolitis later confirmed to be caused by C. difficile infection. CONCLUSION: In patients with cystic fibrosis, imaging findings of a pancolitis should raise the possibility of C. difficile colitis despite the lack of watery diarrhea. Anticlostridial treatment can be initiated before bacteriologic confirmation is obtained.     

Evaluation of an enzyme immunoassay kit for the detection of Clostridium difficile enterotoxin

The Premier Clostridium difficile toxin A enzyme immunoassay (EIA) kit was evaluated for the detection of C. difficile enterotoxin in fecal samples. A total of 314 samples was tested by culture, cytotoxin detection and EIA kit. Compared to a combined culture/cytotoxin result the Premier EIA kit had a sensitivity of 88.3%, a specificity of 100%, a predictive value positive of 100% and a predictive value negative of 87.4%. Test results were available within 3 hrs providing a rapid and reliable means of detecting C. difficile enterotoxin.     

Clostridium difficile infection is a risk factor for bacteremia due to vancomycin-resistant enterococci (VRE) in VRE-colonized patients with acute leukemia

A cohort study was conducted in a cancer center to identify risk factors for bacteremia with vancomycin-resistant enterococci (VRE) in neutropenic cancer patients colonized with VRE. There were 10 patients with VRE bacteremia among 56 colonized with VRE, of whose charts 51 were available for review. One hundred percent of patients with VRE bacteremia (10 of 10) vs. 56% of patients without VRE bacteremia (23 of 41) had acute leukemia (P = .01, Fisher's exact test). Four of the 10 patients with VRE bacteremia had a positive Clostridium difficile toxin assay within 6 days of their first positive VRE blood culture. Both C. difficile infection and antimicrobial (vancomycin and ciprofloxacin) use during VRE colonization were significant risk factors for VRE bacteremia in univariate analysis. When a Cox proportional hazards model was used to account for differences in follow-up time, C. difficile infection was the only statistically significant risk factor (risk ratio, 8.2; P = .007) for VRE bacteremia in VRE-colonized patients with acute leukemia.