Antibiotic-associated colitis--a review of 66 cases

Connecting Gut Microbial Diversity with Plasma Metabolome and Fecal Bile Acid Changes Induced by the Antibiotics Tobramycin and Colistin Sulfate

The diversity of microbial species in the gut has a strong influence on health and development of the host. Further, there are indications that the variation in expression of gut bacterial metabolic enzymes is less diverse than the taxonomic profile, underlying the importance of microbiome functionality, particularly from a toxicological perspective. To address these relationships, the gut bacterial composition of Wistar rats was altered by a 28 day oral treatment with the antibiotics tobramycin or colistin sulfate. On the basis of 16S marker gene sequencing data, tobramycin was found to cause a strong reduction in the diversity and relative abundance of the microbiome, whereas colistin sulfate had only a marginal impact. Associated plasma and fecal metabolomes were characterized by targeted mass spectrometry-based profiling. The fecal metabolome of tobramycin-treated animals had a high number of significant alterations in metabolite levels compared to controls, particularly in amino acids, lipids, bile acids (BAs), carbohydrates, and energy metabolites. The accumulation of primary BAs and significant reduction of secondary BAs in the feces indicated that the microbial alterations induced by tobramycin inhibit bacterial deconjugation reactions. The plasma metabolome showed less, but still many alterations in the same metabolite groups, including reductions in indole derivatives and hippuric acid, and furthermore, despite marginal effects of colistin sulfate treatment, there were nonetheless systemic alterations also in BAs. Aside from these treatment-based differences, we also uncovered interindividual differences particularly centering on the loss of Verrucomicrobiaceae in the microbiome, but with no apparent associated metabolite alterations. Finally, by comparing the data set from this study with metabolome alterations in the MetaMapTox database, key metabolite alterations were identified as plasma biomarkers indicative of altered gut microbiomes resulting from a wide activity spectrum of antibiotics.

Meta-analysis of Postoperative Mortality and Morbidity After Total Abdominal Colectomy Versus Loop Ileostomy With Colonic Lavage for Fulminant Clostridium Difficile Colitis

BACKGROUND

Emergency surgery is often required for fulminant Clostridium difficile colitis. Total abdominal colectomy has been the treatment of choice despite high morbidity and mortality.

OBJECTIVE

The aim of this meta-analysis was to evaluate postoperative mortality and morbidity after total abdominal colectomy and loop ileostomy with colonic lavage in patients with fulminant C difficile colitis.

DATA SOURCES

Studies comparing total abdominal colectomy to loop ileostomy for fulminant C difficile colitis were identified by a systematic search of PubMed, Cochrane Library, MEDLINE, and CINAHL.

STUDY SELECTION

Relevant records were detected and screened using a cascade system (title, abstract, and/or full text article).

INTERVENTION(S)

Total abdominal colectomy (rectal-sparing resection of the entire colon with end ileostomy) was compared to loop ileostomy (exteriorization of an ileal loop not far from the ileocecal junction for colonic lavage).

MAIN OUTCOMES MEASURES

This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines. Primary outcome was postoperative mortality, defined as death occurring within 30 days after the intervention. Secondary end points were the rates of ostomy reversal, deep venous thrombosis/embolism, surgical site infection, urinary tract infection, respiratory complications, reoperations, and adverse events. Mantel-Haenszel method with random-effects model was used for meta-analysis.

RESULTS

Five observational studies (3 cohort and 2 database analysis studies) totaling 3683 patients were included. Postoperative mortality rate was 31.3% after total abdominal colectomy and 26.2% after loop ileostomy (OR = 1.36 (95% CI, 0.83-2.24); p = 0.22; number needed to treat/harm = 20; I = 55%). Ostomy reversal rate was both statistically and clinically significantly higher after loop ileostomy as compared with total abdominal colectomy (80% vs 25%; OR = 0.08 (95% CI, 0.02-0.30); p = 0.002; number needed to treat/harm = 2) with low heterogeneity (I = 0%).

LIMITATIONS

A limitation is the observational nature of the included studies introducing an overall high risk of selection bias.

CONCLUSIONS

This meta-analysis suggests that loop ileostomy with colonic lavage for fulminant C difficile colitis may be associated with similar survival and decreased surgical site infection rates as compared with total abdominal colectomy. Although loop ileostomy with colonic lavage was associated with higher ostomy reversal rates, this finding was based on the data from only 2 studies.

Impact of Microbes on the Pathogenesis of Primary Biliary Cirrhosis (PBC) and Primary Sclerosing Cholangitis (PSC)

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) represent the major clinical entities of chronic cholestatic liver diseases. Both disorders are characterized by portal inflammation and slowly progress to obliterative fibrosis and eventually liver cirrhosis. Although immune-pathogenic mechanisms have been implicated in the pathogenesis of PBC and PSC, neither disorder is considered to be a classical autoimmune disease, as PSC and PBC patients do not respond to immune-suppressants. Furthermore, the decreased bile flow resulting from the immune-mediated tissue assault and the subsequent accumulation of toxic bile products in PBC and PSC not only perpetuates biliary epithelial damage, but also alters the composition of the intestinal and biliary microbiota and its mutual interactions with the host. Consistent with the close association of PSC and inflammatory bowel disease (IBD), the polyclonal hyper IgM response in PBC and (auto-)antibodies which cross-react to microbial antigens in both diseases, an expansion of individual microbes leads to shifts in the composition of the intestinal or biliary microbiota and a subsequent altered integrity of epithelial layers, promoting microbial translocation. These changes have been implicated in the pathogenesis of both devastating disorders. Thus, we will discuss here these recent findings in the context of novel and alternative therapeutic options.

Systematic review of loperamide: No proof of antibiotics being superior to loperamide in treatment of mild/moderate travellers' diarrhoea

Looking at the worldwide emergency of antimicrobial resistance, international travellers appear to have a central role in spreading the bacteria across the globe. Travellers' diarrhoea (TD) is the most common disease encountered by visitors to the (sub)tropics. Both TD and its treatment with antibiotics have proved significant independent risk factors of colonization by resistant intestinal bacteria while travelling. Travellers should therefore be given preventive advice regarding TD and cautioned about taking antibiotics: mild or moderate TD does not require antibiotics. Logical alternatives are medications with effects on gastrointestinal function, such as loperamide. The present review explores literature on loperamide in treating TD. Adhering to manufacturer's dosage recommendations, loperamide offers a safe and effective alternative for relieving mild and moderate symptoms. Moreover, loperamide taken singly does no predispose to contracting MDR bacteria. Most importantly, we found no proof that would show antibiotics to be significantly more effective than loperamide in treating mild/moderate TD.

Uncovering effects of antibiotics on the host and microbiota using transkingdom gene networks

OBJECTIVE

Despite widespread use of antibiotics for the treatment of life-threatening infections and for research on the role of commensal microbiota, our understanding of their effects on the host is still very limited.

DESIGN

Using a popular mouse model of microbiota depletion by a cocktail of antibiotics, we analysed the effects of antibiotics by combining intestinal transcriptome together with metagenomic analysis of the gut microbiota. In order to identify specific microbes and microbial genes that influence the host phenotype in antibiotic-treated mice, we developed and applied analysis of the transkingdom network.

RESULTS

We found that most antibiotic-induced alterations in the gut can be explained by three factors: depletion of the microbiota; direct effects of antibiotics on host tissues and the effects of remaining antibiotic-resistant microbes. Normal microbiota depletion mostly led to downregulation of different aspects of immunity. The two other factors (antibiotic direct effects on host tissues and antibiotic-resistant microbes) primarily inhibited mitochondrial gene expression and amounts of active mitochondria, increasing epithelial cell death. By reconstructing and analysing the transkingdom network, we discovered that these toxic effects were mediated by virulence/quorum sensing in antibiotic-resistant bacteria, a finding further validated using in vitro experiments.

CONCLUSIONS

In addition to revealing mechanisms of antibiotic-induced alterations, this study also describes a new bioinformatics approach that predicts microbial components that regulate host functions and establishes a comprehensive resource on what, why and how antibiotics affect the gut in a widely used mouse model of microbiota depletion by antibiotics.

Overview of severe Clostridium difficile infection

Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus that can produce severe colitis resulting in death. There has been an overall increase in the incidence of Clostridium difficile-associated disease and, particularly, an increase in the more virulent forms of the disease. Treatment of severe C difficile infection includes management of severe sepsis and shock, pathogen-directed antibiotic therapy, and, in selected cases, surgical intervention. Ultimately, prevention is the key to limiting the devastating effects of this microorganism.

Case-control analysis of clostridium difficile-associated diarrhea on a gynecologic oncology service

Objective: The incidence, morbidity, and risk factors associated with Clostridium difficile-associated diarrhea (CDAD) were studied in a group of gynecologic oncology patients.

Methods: A case-control analysis of gynecologic oncology patients with CDAD was carried out from August 1986 through January 1989 in a university medical center.

Results: One hundred twenty-three stool samples were tested for C. difficile using the CDT latex agglutination test (Marion Diagnostics, Kansas City, MO). Thirty episodes of CDAD developed in 23 patients. From August 1986 through July 1988, the incidence was stable at 1.5 episodes/100 admissions. From August 1988 through January 1989, the incidence increased to 9.9 episodes/100 admissions (P = 0.005). Compared with patients with nonspecific antibiotic-associated diarrhea, the study patients were hospitalized longer prior to the development of symptoms (mean 15.2 vs. 9.2 days, P = 0.006) and were admitted more frequently with diarrhea (37% vs. 11%, P = 0.015). The rates of surgery, chemotherapy, and radiation therapy were similar. Fever (57% vs. 14%, P < 0.001), abdominal pain (40% vs. 6%, P < 0.001), bloody stools (27% vs. 3%, P = 0.006), and leukocytosis (64% vs. 26%, P = 0.011) were more common among the study cases. The duration, indication, and number of antibiotics administered were similar, though once started, the mean time to symptoms was longer in the study cases (13.7 vs. 6.1 days, P = 0.004). Seven relapses, 1 death, and 1 unplanned colostomy occurred among women with CDAD.

Conclusions: C. difficile is a serious cause of nosocomial morbidity in gynecologic oncology patients. Diarrhea developing after antibiotic exposure is more likely to be associated with C. difficile in patients whose symptoms develop several days after completing antibiotics and in patients with a history of CDAD.

Clostridium difficile colitis

Clostridium difficile is the most common cause of infectious diarrhea in hospitalized patients. Its effects are mediated by C difficile toxins A and B. Recent outbreaks of severe colitis have been associated with a new strain of the bacterium that produces large amounts of the toxins. Although oral metronidazole and oral vancomycin can be used to treat C difficile-associated disease, intraluminal vancomycin is preferable for more severe C difficile colitis. Early surgical intervention can improve outcomes with fulminant colitis, although overall mortality remains high.

Absence of pseudomembranes in Clostridium difficile-associated diarrhea in patients using immunosuppression agents

OBJECTIVE

Clostridium difficile is a major cause of diarrhea in hospitalized patients. Although pseudomembranes are crucial evidence for diagnosis of C. difficile-associated diarrhea (CDAD), some cases do not show any pseudomembranes. The aim of this study was to verify the hypothesis that pseudomembranes are not generated in immunosuppressed patients because of the absence of immunoreactions.

MATERIAL AND METHODS

We investigated the endoscopic findings of patients with ulcerative colitis (UC) or who had received hematopoietic stem cell transplantation, and who presented with C. difficile toxin A and had undergone colonoscopy between April 2002 and July 2007 at our institutes. Results. In 4 patients the diagnosis was UC and C. difficile infection, and in another 4 patients the diagnosis was CDAD after hematopoietic stem cell transplantation. None of these cases showed pseudomembranes. Shallow ulcers were found in all four cases with UC. Only non-specific findings were obtained for the CDAD patients after hematopoietic stem cell transplantation.

CONCLUSIONS

Pseudomembranes, the typical evidence for CDAD, were not detected in any patients using immunosuppressive agents. Additional bacterial examination is therefore essential when UC becomes exacerbated and when patients present with diarrhea after hematopoietic stem cell transplantation, even in the absence of pseudomembranes.

Clinical recognition and diagnosis of Clostridium difficile infection

Prompt and precise diagnosis is an important aspect of effective management of Clostridium difficile infection (CDI). CDI causes 15%-25% of all cases of antibiotic-associated diarrhea, the severity of which ranges from mild diarrhea to fulminant pseudomembranous colitis. Several factors, especially advanced age and hospitalization, should be considered in the diagnosis of CDI. In particular, nosocomial diarrhea arising >72 hours after admission among patients receiving antibiotics is highly likely to have resulted from CDI. Testing of stool for the presence of C. difficile toxin confirms the diagnosis of CDI. However, performance of an enzyme immunoassay is the usual method by which CDI is confirmed, but this test appears to be relatively insensitive, compared with the cell cytotoxicity assay and stool culture for toxigenic C. difficile on selective medium. Endoscopy and computed tomography are less sensitive than stool toxin assays but may be useful when immediate results are important or other confounding conditions rank high in the differential diagnosis. Often overlooked aspects of this diagnosis are high white blood cell counts (which are sometimes in the leukemoid range) and hypoalbuminemia.

Historical perspectives on studies of Clostridium difficile and C. difficile infection

The initial period of studies on Clostridium difficile (published during 1978-1980) appeared to provide a nearly complete portfolio of criteria for diagnosing and treating C. difficile infection (CDI). The putative pathogenic role of C. difficile was established using Koch's postulates, risk factors were well-defined, use of a cell cytotoxicity assay as the diagnostic test provided accurate results, and treatment with oral vancomycin was highly effective and rapidly incorporated into practice. During the next 10 years, enzyme immunoassays (EIAs) were introduced as diagnostic tests and became the standard for most laboratories. This was not because EIAs were as good as the cell cytotoxicity assay; rather, EIAs were inexpensive and yielded results quickly. Similarly, metronidazole became the favored treatment because it was less expensive and quelled fears of colonization with vancomycin-resistant organisms, not because it was better than vancomycin therapy. Cephalosporins replaced clindamycin as the major inducers of CDI because they were so extensively used, rather than because they incurred the same risk. Some serious issues remained unresolved during this period: the major challenges were to determine ways to treat seriously ill patients for whom it was not possible to get vancomycin into the colon and to find methods that stop persistent relapses. These concerns persist today.

Limitations of presently available glycopeptides in the treatment of Gram-positive infection

The glycopeptide antibacterial drugs vancomycin and teicoplanin are widely used in hospitals for therapy of severe or multiresistant Gram-positive infections, notably staphylococcal, enterococcal and rarely pneumococcal. Vancomycin has also been used in the management of Clostridium difficile enteropathy. The incidence and potential for resistance differ between agents. The in vitro activity, pharmacokinetics and clinical use of glycopeptide, as well as epidemiology of glycopeptide resistance are discussed. There are limited comparative studies indicating the need for further investigation. Therapeutic drug monitoring has been widely used for vancomycin and less commonly for teicoplanin, but remains controversial. Advances in our understanding of their pharmacodynamics and clinical studies are helping clarify the situation. This paper reviews the current literature and highlights limitations of glycopeptides in treating Gram-positive infection.

Clostridium difficile colitis after kidney and kidney-pancreas transplantation

OBJECTIVE

To determine the timing and risk factors involved in the development of Clostridium difficile (CD) colitis in kidney and kidney-pancreas transplant recipients.

BACKGROUND DATA

The incidence of CD colitis after kidney and kidney-pancreas transplantation has not been studied in detail. The question of whether the immunosuppressed transplant recipient is more prone to CD colitis and its complications (i.e., megacolon, perforations) and the risk factors involved have not been determined.

METHODS

We retrospectively reviewed our experience in kidney and kidney-pancreas recipients who received transplants between January 1, 1985 and December 31, 1994. We divided these recipients into three groups: pediatric kidney recipients, adult kidney recipients, and kidney-pancreas recipients. For each group, we assessed the timing of infection, primary disease, colitis treatment, and any concurrent complications or risk factors.

RESULTS

Of 1932 transplants, 159 recipients developed post-transplant CD colitis. 132 charts were available for review. Forty-three pediatric kidney recipients developed CD colitis. Their mean age was 3.2 yr; 74% (n = 37) of them developed their colitis during their initial hospital stay, with the mean timing of infection being 33 d. Forty-one (95%) had undergone intra-abdominal placement of the graft, with renal artery anastomoses to the aorta. Fifty adult kidney recipients developed CD colitis. Thirteen (26%) developed colitis during their initial hospital stay, with the mean timing of infection (for all adult kidney recipients) being 15 months. Thirty-nine kidney-pancreas recipients developed CD colitis. Mean timing of infection was 6 months. The overall incidence of CD colitis was 8%, with 16% in the pediatric kidney group, 15.5% in the kidney-pancreas group, and 3.5% in the adult kidney group. The difference in mean timing of infection was significant between the three groups (p < 0.001 for pediatric versus adult kidney recipients, p = 0.002 for pediatric kidney versus kidney-pancreas recipients, and p = 0.2846 for adult kidney versus kidney-pancreas recipients).

CONCLUSION

The incidence of CD colitis is increased in pediatric kidney and kidney-pancreas recipients. Young recipient age ( < 5 yr), female gender, treatment of rejection with monoclonal antibodies, antibiotic use, and intra-abdominal graft placement have been shown to increase the incidence of this disease. Further studies concerning prevention in the high-risk groups are needed.

Clostridium difficile infection as a cause of severe sepsis

Although colitis is often seen in critically all patients who have received multiple broad-spectrum antibiotics, there are no reports describing severe sepsis as a result of Clostridium difficile infection. We describe three cases of severe sepsis with local intestinal Clostridium difficile infection as the only identifiable etiology. The mechanism of severe sepsis may be a derangement of the gastrointestinal barrier function. This could result in absorption of microbes or endotoxin or activation of inflammatory cascades in the submucosa of the intestine or liver.

Pseudomembranous panenteritis and septicaemia in a patient with ulcerative colitis

Pseudomembranous colitis may occur in the immunocompromised chronic colitic patient without a prior history of antibiotic use. The entire gastrointestinal tract can be involved and the presentation can be that of a severe systemic infection that warrants prompt recognition and aggressive management.

Effects of antibiotics on epithelial ion transport in the rabbit distal colon in-vitro

One side-effect of the therapeutic use of antimicrobial agents is respiratory paralysis as a result of inhibition of skeletal neuromuscular transmission; cholinergic neuro-effector motor transmission in the gastrointestinal tract is inhibited by the same classes of antimicrobial agent. Study of the effects of several classes of antibiotic compound on intestinal motility has suggested that antibiotic-induced alterations of intestinal motility may be related to the onset of diarrhoea or the development of antibiotic-associated colitis. These compounds may, however, also initiate or exacerbate diarrhoea by altering control of epithelial function, a possibility that has not previously been rigorously investigated. This series of experiments investigated the effect of six antibiotics on rabbit distal colonic epithelial ion transport. Of all the antibiotics studied, only ampicillin was without effect. Clindamycin, erythromycin, gentamicin and lincomycin, each reduced the response of the epithelium to electrical field stimulation. In addition, the lincosamides clindamycin and lincomycin reduced basal short circuit current and the epithelial response to acetylcholine. Vancomycin had no effect on the response to electrical field stimulation or acetylcholine but enhanced the secretory action of prostaglandin E2. These data suggest that, in addition to their ability to alter intestinal motility, a number of potential antibiotic interactions with the epithelium and its innervation may contribute to the pathogenesis of antibiotic-associated diarrhoea and colitis.

Clostridium difficile-associated diarrhea and colitis

OBJECTIVES

To review and summarize the status of diagnosis, epidemiology, infection control, and treatment of Clostridium difficile-associated disease (CDAD).

DIAGNOSIS

A case definition of CDAD should include the presence of symptoms (usually diarrhea) and at least one of the following positive tests: endoscopy revealing pseudomembranes, stool cytotoxicity test for toxin B, stool enzyme immunoassay for toxin A or B, or stool culture for C difficile (preferably with confirmation of organism toxicity if a direct stool toxin test is negative or not done). Testing of asymptomatic patients, including those who are asymptomatic after treatment, is not recommended other than for epidemiologic purposes. Lower gastrointestinal endoscopy is the only diagnostic test for pseudomembranous colitis, but it is expensive, invasive, and insensitive (51% to 55%) for the diagnosis of CDAD. Stool culture is the most sensitive laboratory test currently in clinical use, but it is not as specific as the cell cytotoxicity assay.

EPIDEMIOLOGY

C difficile is the most frequently identified cause of nosocomial diarrhea. The majority of C difficile infections are acquired nosocomially, and most patients remain asymptomatic following acquisition. Antimicrobial exposure is the greatest risk factor for patients, especially clindamycin, cephalosporins, and penicillins, although virtually every antimicrobial has been implicated. Cases of CDAD unassociated with prior antimicrobial or antineoplastic use are very rare. Hands of personnel, as well as a variety of environmental sites within institutions, have been found to be contaminated with C difficile, which can persist as spores for many months. Contaminated commodes, bathing tubs, and electronic thermometers have been implicated as sources of C difficile. Symptomatic and asymptomatic infected patients are the major reservoirs and sources for environmental contamination. Both genotypic and phenotypic typing systems for C difficile are available and have enhanced epidemiologic investigation greatly.

INFECTION CONTROL

Successful infection control measures designed to prevent horizontal transmission include the use of gloves in handling body substances and replacement of electronic thermometers with disposable devices. Isolation, cohorting, handwashing, environmental disinfection, and treatment of asymptomatic carriers are recommended practices for which convincing data of efficacy are not available. The most successful control measure directed at reduction in symptomatic disease has been antimicrobial restriction.

TREATMENT

Treatment of symptomatic (but not asymptomatic) patients with metronidazole or vancomycin for 10 days is effective; metronidazole may be preferred to reduce risk of vancomycin resistance among other organisms in hospitals. Recurrence of symptoms occurs in 7% to 20% of patients and is due to both relapse and reinfection. Over 90% of first recurrences can be treated successfully in the same manner as initial cases. Combination treatment with vancomycin plus rifampin or the addition orally of the yeast Saccharomyces boulardii to vancomycin or metronidazole treatment has been shown to prevent subsequent diarrhea in patients with recurrent disease.

Toxic megacolon complicating pseudomembranous enterocolitis

PURPOSE

Toxic megacolon is a rare complication of pseudomembranous enterocolitis. We reviewed our recent experience with this complication.

METHODS

The first five patients of the series were studied retrospectively, and six others were followed prospectively.

RESULTS

Between June 1992 and May 1994, 11 patients (8 male, 3 female) developed toxic megacolon secondary to pseudomembranous enterocolitis. Mean age was 60.7 +/- 11.8 (range, 40-79) years. Presenting symptoms and signs included diarrhea, 100 percent; malaise, 91 percent; abdominal pain, 82 percent; abdominal distention, 82 percent; abdominal tenderness, 72 percent; anemia less than 12 gm, 72 percent; albumin less than 3 gm, 64 percent; tachycardia greater than 100, 55 percent; fever greater than 38.5 degrees celsius, 45 percent; shock or hypotension, 45 percent. Predisposing factors included antibiotics, 64 percent; immunosuppressants or chemotherapy, 36 percent; antidiarrheals, 27 percent; and barium enema in one patient. Five patients (45 percent) had more than one predisposing factor. X-rays showed transverse colon dilation and loss of haustrations in eight patients (72 percent), with a mean diameter of 9.9 +/- 3.4 cm. Flexible proctosigmoidoscopy showed pseudomembranes in all scoped patients, and toxin assay for Clostridium difficile was positive in all patients. One patient had emergency surgery. Ten patients were initially treated medically with nasogastric suction and intravenous resuscitation (90 percent) and antibiotics (100 percent), usually in the intensive care unit (80 percent). Four patients did not respond and underwent surgery; two others improved, then deteriorated, and also underwent surgery. Altogether, 7 of 11 patients (64 percent) underwent surgery. Three patients (27 percent) responded well to medical treatment. One patient was deemed too ill to undergo surgery and died. Mean delay to surgery was 3.0 +/- 1.3 days. No sealed or overt perforation was found at laparotomy. All patients who underwent surgery had a subtotal colectomy, with either a Hartmann's stump (71 percent) or a mucous fistula (29 percent). Eventually, five of seven patients who were operated on and two of four medically treated patients died (overall mortality, 64 percent). Only one patient underwent closure of ileostomy and anastomosis.

CONCLUSION

Toxic megacolon complicating pseudomembranous enterocolitis is a serious problem that carries a high morbidity and mortality rate, regardless of treatment.

Patterns and prognosis of Clostridium difficile colitis

The incidence of Clostridium difficile colitis has increased during recent years, presumably because of liberal use of broad-spectrum antibiotic regimens.

METHODS

A retrospective review to determine patterns of C. difficile colitis development, morbidity, and treatment results was undertaken. During an 18-month period, 90 patients were diagnosed with C. difficile colitis by fecal toxin assays. Patient demographics, symptoms, previously administered antibiotic regimens, diagnostic evaluations, treatment modalities, morbidity, and mortality were identified, entered into a computer data base, and analyzed.

RESULTS

The mean age was 58 years; males outnumbered females 1.2:1. Among 90 patients, 41 (46 percent) developed C. difficile colitis after surgical procedures. Eighty (89 percent) patients received antibiotic therapy before developing C. difficile colitis: 35 (44 percent) for documented infections and 45 (56 percent) as empiric or prophylactic therapy. Cephalosporins, penicillins, quinolones, vancomycin, and aminoglycosides were the most frequently administered antibiotic classes prior to C. difficile colitis diagnosis. Ten (11 percent) patients developed C. difficile colitis without previous antibiotic therapy. Eighty-two (91 percent) patients presented with diarrhea, while eight (9 percent) had fever only. Primary C. difficile colitis treatment for both groups included vancomycin (66 percent), metronidazole (24 percent), or both drugs (10 percent). Ten (11 percent) patients received no treatment. No patient developed toxic colitis or megacolon. Colonoscopy was performed in four (4 percent) patients; pseudomembranes were identified in one (25 percent) patient. There was one C. difficile colitis recurrence after treatment, but no C. difficile colitis-associated morbidity. Mortality (14 patients, 16 percent) was not related to C. difficile colitis, but to underlying illness. No difference in patient age, sex, previous antibiotic administration, serum albumin, total days hospitalized, duration of C. difficile colitis antibiotic therapy, C. difficile colitis treatment regimens, or mortality was identified between nonsurgical and surgical patients. The white blood cell count was significantly lower in the nonsurgical group however. Clostridium difficile colitis developed most commonly after antibiotic administration with symptoms of diarrhea, but did occur without previous antibiotic administration or diarrhea.

CONCLUSION

Despite the clinical setting, C. difficile colitis had no associated morbidity and treatment was highly effective. Mortality was related to underlying medical illness, not C. difficile colitis.

Management and control of a large outbreak of diarrhoea due to Clostridium difficile

In the six-month period 1 November 1991 to 1 May 1992 175 patients developed diarrhoea due to Clostridium difficile in three hospitals in Manchester, UK. Most patients (90%) were over 60 years old and had been admitted to acute geriatric or medical wards with other illnesses. Infection is thought to have contributed to 17 deaths. Twenty-two patients relapsed clinically after antibiotic treatment. The outbreak began in one ward and affected 15 patients and two nurses. During the following months cases occurred on 34 wards. The pattern of spread suggested that a ward index case was followed by several secondary cases. Pyrolysis mass spectrometry showed that 79% of isolates of C. difficile belong to a single cluster and this putative outbreak strain also extensively colonizes the hospital environment. It was also responsible for a smaller outbreak in 1991 and many 'sporadic' cases in our hospitals before then. An outbreak control team was convened at an early stage and expert opinion co-opted. Infection control measures included: intensive education of staff; increased vigilance; strict enteric precautions; cohort nursing in a designated ward; rigorous cleaning procedures including emptying and 'deep' cleaning of wards where several cases had occurred; restriction of staff and patient movement; and restriction of antibiotic use. Subsequent to these measures there has been a substantial and sustained decrease in the number of new cases.

Toxins A and B of Clostridium difficile

The toxins produced by Clostridium difficile share several functional properties with other bacterial toxins, like the heat-labile enterotoxin of Escherichia coli and cholera toxin. However, functional and structural differences also exist. Like cholera toxin, their main target is the disruption of the microfilaments in the cell. However, since these effects are not reversible, as found with cholera toxin, additional mechanisms add to the cytotoxic potential of these toxins. Unlike most bacterial toxins, which are built from two structurally and functionally different small polypeptide chains, the functional and binding properties of the toxins of C. difficile are confined within one large polypeptide chain, making them the largest bacterial toxins known so far.

Clostridium difficile: clinical disease and diagnosis

Clostridium difficile is an opportunistic pathogen that causes a spectrum of disease ranging from antibiotic-associated diarrhea to pseudomembranous colitis. Although the disease was first described in 1893, the etiologic agent was not isolated and identified until 1978. Since clinical and pathological features of C. difficile-associated disease are not easily distinguished from those of other gastrointestinal diseases, including ulcerative colitis, chronic inflammatory bowel disease, and Crohn's disease, diagnostic methods have relied on either isolation and identification of the microorganism or direct detection of bacterial antigens or toxins in stool specimens. The current review focuses on the sensitivity, specificity, and practical use of several diagnostic tests, including methods for culture of the etiologic agent, cellular cytotoxicity assays, latex agglutination tests, enzyme immunoassay systems, counterimmunoelectrophoresis, fluorescent-antibody assays, and polymerase chain reactions.

Epidemiological aspects of infections caused by Bacteroides fragilis and Clostridium difficile

Bacteroides fragilis and Clostridium difficile are two of the most common anaerobes associated with human disease. Studies on the epidemiology of Bacteroides fragilis are limited and are based predominantly on serogrouping, which suggests intraspecies differences. Further studies using newer techniques for typing are required to elucidate the epidemiological characteristics of this important pathogen. By contrast, numerous phenotypic, immunological and molecular methods have been developed for typing and fingerprinting of Clostridium difficile and applied in epidemiological studies to show conclusively that Clostridium difficile is nosocomially acquired and that there is transmission and cross-infection between hospital patients.

Low levels of coagulation inhibitors in patients with Clostridium difficile infection

To investigate levels of coagulation inhibitors in sera from patients with Clostridium difficile-associated diarrhoea and colitis, commercially available antigen assays were used for immunochemical determination of antithrombin III, protein C and free protein S. Sera from patients with Clostridium difficile-associated diarrhoea and colitis showed significantly lowered levels of all measured inhibitors as compared to controls (Student's t test). Protein C (mean +/- SD): 0.70 +/- 0.30 vs. 1.28 +/- 0.23, t = 6.61, p less than 0.001; antithrombin: 0.70 +/- 0.21 vs. 0.90 +/- 0.17, t = 3.12, p less than 0.01; free protein S: 0.27 +/- 0.06 vs. 0.37 +/- 0.08, t = 3.7, p less than 0.001. Infection with C. difficile may lead to loss of coagulation inhibitors and constitutes a risk for thromboembolic complications.

Acute abdomen as the first presentation of pseudomembranous colitis

Acute abdomen was the presenting manifestation of pseudomembranous colitis in six men who had previously been treated with antibiotics and presented with abdominal distention, pain, fever, and leukocytosis with absent or mild diarrhea. Plain abdominal radiographs revealed megacolon in two, combined small and large bowel dilation in three, with one of them showing volvuluslike pattern, and isolated small bowel ileus in one. Emergency colonoscopy was performed successfully in all patients and revealed pseudomembranes in five and nonspecific colitis in one. All patients had positive latex test results for Clostridium difficile, and two tested positive for cytotoxicity. All patients were treated with IV metronidazole, resulting in resolution of symptoms and abdominal findings. In addition, two patients underwent colonoscopic decompression with improvement. Endoscopically, complete resolution of the pseudomembranes occurred at 4 weeks in all cases. No patient had a recurrence. It is concluded that (a) pseudomembranous colitis may present as abdominal distention mimicking small bowel ileus. Ogilvie's syndrome, volvulus, or ischemia; (b) in such cases, emergency colonoscopy is safe and useful for diagnosis and therapeutic decompression and may obviate the need for surgery; and (c) treatment with IV metronidazole is effective. Colitis due to C. difficile should be considered in the differential diagnosis of acute abdomen in patients previously treated with antibiotics.

Prospective, controlled study of vinyl glove use to interrupt Clostridium difficile nosocomial transmission

PURPOSE

Despite recognition that Clostridium difficile diarrhea/colitis is a nosocomial infection, the manner in which this organism is transmitted is still not clear. Hands of health care workers have been shown to be contaminated with C. difficile and suggested as a vehicle of transmission. Therefore, we conducted a controlled trial of the use of disposable vinyl gloves by hospital personnel for all body substance contact (prior to the institution of universal body substance precautions) to study its effect on the incidence of C. difficile disease.

PATIENTS AND METHODS

The incidence of nosocomial C. difficile diarrhea was monitored by active surveillance for six months before and after an intensive education program regarding glove use on two hospital wards. The interventions included initial and periodic in-services, posters, and placement of boxes of gloves at every patient's bedside. Two comparable wards where no special intervention was instituted served as controls.

RESULTS

A decrease in the incidence of C. difficile diarrhea from 7.7 cases/1,000 patient discharges during the six months before intervention to 1.5/1,000 during the six months of intervention on the glove wards was observed (p = 0.015). No significant change in incidence was observed on the two control wards during the same period (5.7/1,000 versus 4.2/1,000). Point prevalence of asymptomatic C. difficile carriage was also reduced significantly on the glove wards but not on the control wards after the intervention period (glove wards, 10 of 37 to four of 43, p = 0.029; control wards, five of 30 to five of 49, p = 0.19). The cost of 61,500 gloves (4,505 gloves/100 patients) used was $2,768 on the glove wards, compared with $1,895 (42,100 gloves; 3,532 gloves/100 patients) on the control wards.

CONCLUSIONS

Vinyl glove use was associated with a reduced incidence of C. difficile diarrhea and is indirect evidence for hand carriage as a means of nosocomial C. difficile spread.

A prospective randomized trial to compare triple dose mezlocillin with triple dose cefuroxime plus metronidazole as prophylaxis in colorectal surgery

The results of a prospective randomized clinical trial to compare three dose regimens of mezlocillin with cefuroxime plus metronidazole for prophylaxis in emergency and elective colorectal surgery are reported. Severe wound infection occurred in five patients (10%) receiving mezlocillin and in four patients (7%) receiving cefuroxime and metronidazole. There were two episodes of septicaemia, each in the mezlocillin group. The total number of surgically related infections was less with cefuroxime plus metronidazole (n = 10) compared with mezlocillin (n = 17), but this was not statistically significant (P greater than 0.1).

Clostridium difficile as a nosocomial pathogen

Patients admitted to a 19-bed floor with intermediate nursing care were studied for the onset of Clostridium difficile-associated diarrhoea during a six-month period (181 calendar days) in 1986-87. All admitted patients were reviewed weekly and followed after discharge from the study unit to other inpatient services. Multiple items in the environment of five patients' rooms were sampled bacteriologically for the presence of C. difficile weekly during the study period. Three of the rooms were selected for study because of a higher prevalence of C. difficile associated diarrhoea in the prior three years and two were selected because no cases had been discovered previously in these rooms ('control rooms'). Nine of 521 patients admitted to this unit developed C. difficile diarrhoea (1.73 cases/100 patients admitted) versus 0.30/100 patients admitted to all other sites in our hospital (24 of 7970 other patients). This represented respectively 3.91 cases per 1000 patient days on this floor versus 0.37 patients/1000 patient days throughout the hospital. Seven of the C. difficile diarrhoea cases were associated with stay in the C. difficile associated rooms, versus two cases in the two 'control rooms'. C. difficile was isolated from the toilet seats, bedpan hopper, night stands or food trays. Of some 1955 cultures taken, only 1.9% overall were positive for C. difficile.

Comparison of short-term antibiotic cover with a third-generation cephalosporin against conventional five-day therapy using metronidazole with an aminoglycoside in emergency and complicated colorectal surgery

In a prospective, randomized control trial, 152 consecutive patients requiring emergency or complicated colorectal surgery were allocated either to two doses of cefotetan or to five-day cover with gentamicin, and a single dose of metronidazole. Twenty-one patients received 6 gm of cefotetan before prolongation of prothrombin time dictated a change in the dose regimen such that all remaining patients (N = 55) received only 4 gm of cefotetan. The groups were well matched for diagnosis and surgical procedure. Rates of postoperative infection did not differ significantly between the groups, with wound infection rates occurring in 17 of 75 patients receiving gentamicin and metronidazole (22.7 percent) compared with ten of 75 receiving cefotetan (13 percent). Although wound infection rates were lower in the cefotetan group, the incidence of intra-abdominal abscess was similar in both groups. Eight patients receiving cefotetan developed intra-abdominal abscesses (11 percent), compared with seven receiving gentamicin and metronidazole (9 percent). Prolongation of prothrombin time in excess of 13 seconds occurred in six patients receiving cefotetan compared with no patients receiving gentamicin and metronidazole. None of these patients developed clinical bleeding, however.

Application of a technique for serogrouping Clostridium difficile in an outbreak of antibiotic-associated diarrhoea

A severe outbreak of Clostridium difficile antibiotic-associated diarrhoea (AAD) in an orthopaedic surgical unit is reported. Thirty-seven cases and eight relapses were observed. The 45 related strains together with another 13 strains of C. difficile isolated during the same period in other wards of the same hospital were typed by detection of cytotoxin production, determination of sorbitol fermentation and serogrouping by agglutination with six rabbit antisera defining the serogroups A, B, C, D, F and G. All the strains from the outbreak belonged to serogroup C, were toxigenic and fermented sorbitol. In contrast, four different patterns were observed in seven isolates from cases of AAD in other wards. Finally, six strains isolated from four asymptomatic adults, one adult suffering from shigellosis and one child with salmonellosis demonstrated two patterns different from that of the epidemic isolates. The data strongly suggest nosocomial spread of this micro-organism.

Review of Clostridium difficile-associated diseases

Clostridium difficile has recently become recognized as an important nosocomial pathogen. This review summarizes what is known about the isolation of the organism, the spectrum of clinical disease, virulence factors, treatments, and methods of prevention. Risk factors for C. difficile disease are also discussed. The most important risk factor is the use of certain antibiotics (ampicillin, cephalosporins, and clindamycin). C. difficile is associated with 96% to 100% of cases of pseudomembraneous colitis, 60% to 75% of antibiotic-associated cases of colitis, and 11% to 33% of antibiotic-associated cases of diarrhea. Other risk factors include gastrointestinal manipulations, advanced age, female sex, inflammatory bowel disease, cancer chemotherapy, and renal disorders. Hospital outbreaks of C. difficile disease are examined. Data from nosocomial outbreaks support transmission of C. difficile by contaminated fomites and hand carriage by hospital personnel.

Changing epidemiology, diagnosis, and treatment of Clostridium difficile toxin-associated colitis

One hundred and ninety patients with Clostridium difficile toxin-associated colitis (CTAC) or pseudomembranous colitis (PMC) were identified, from microbiology records, disease index and proctoscopy service records, and studied retrospectively. CTAC was associated with cephalosporin antibiotic administration in 70 per cent of the patients. CTAC developed postoperatively in 108 patients after all types of surgery with no preponderance for abdominal surgery. Identification of cytotoxin in stool samples was the primary diagnostic test in 81 per cent of patients but cytotoxin was isolated in 98 per cent of all patients. Pseudomembranes visible on proctoscopy established the diagnosis in 19 per cent of patients and were more commonly seen in severe colitis (71 per cent) than in mild colitis (23 per cent). CTAC responded similarly to oral vancomycin and metronidazole with a relapse rate of 20-23 per cent, respectively. With its association with cephalosporin administration, CTAC is likely to occur with increasing frequency in surgical practice. Oral metronidazole is an effective, cheap, alternative to vancomycin therapy.

Diagnosis of Clostridium difficile-associated intestinal disease

Toxigenic Clostridium difficile is the major cause of antimicrobial agent-associated pseudomembranous colitis and is the etiological agent of approximately 30% of cases of nonspecific colitis and diarrhea (without colitis) induced by antimicrobial agents. In addition, C. difficile has been implicated in certain intestinal diseases not related to prior antimicrobial administration. C. difficile has been reported to be one of the most common enteropathogens isolated from stool specimens submitted to hospital laboratories. Thus, diagnosis of C. difficile-associated intestinal disease should now be routinely performed in diagnostic clinical laboratories. The diagnosis of C. difficile-associated intestinal disease relies on the demonstration of either the organism or the toxin(s) in stool specimens or antibody response in serum to the toxin(s). Several selective medium are available for the recovery of C. difficile from stool specimens. The toxin(s) of C. difficile can be demonstrated using a variety of techniques, including biological assays as well as immunological assays. This article will review the techniques currently available to aid in the diagnosis of C. difficile-associated intestinal disease.

Typing scheme for Clostridium difficile: its application in clinical and epidemiological studies

Epidemiological studies of Clostridium difficile diarrhoeal disease have been hindered by the lack of a typing scheme for this organism. A typing method based on the incorporation of sulphur-35-labelled methionine into cellular proteins and their separation by sodium dodecylsulphate/polyacrylamide gel electrophoresis showed clear pattern differences between strains, and nine distinct groups within the C difficile species were established. 98% of 250 clinical strains derived from four hospitals were typable. Group X was the commonest group and was associated with outbreaks of pseudomembranous colitis and antibiotic-associated colitis in two hospitals. Groups A-D were isolated predominantly from mothers and newborn infants. In outbreaks of antibiotic-associated colitis in oncology and orthopaedic wards the same strains, group X and group E, respectively, were isolated from patients and their environment, providing strong evidence of cross-infection between patients and of hospital acquisition of C difficile.

A prospective randomized trial to compare mezlocillin and metronidazole with cefuroxime and metronidazole as prophylaxis in elective colorectal operations

A prospective randomized trial has compared a broad spectrum ureidopenicillin with a broad spectrum cephalosporin for prophylaxis against the aerobic organisms encountered during elective colonic surgery. Even though only two doses of antibiotics were administered the incidence of severe sepsis was low. Severe wound infection occurred in three of the patients receiving mezlocillin and metronidazole (6 per cent) compared with six in the group receiving cefuroxime and metronidazole (13 per cent). Minor wound sepsis was recorded in 24 per cent of patients receiving mezlocillin and metronidazole compared with only 11 per cent after cefuroxime and metronidazole. There were two episodes of septicaemia, one in each group, and three abscesses, all of which occurred in patients receiving metronidazole and mezlocillin. The total number of surgically related infections was, however, significantly less with cefuroxime and metronidazole (N = 13) compared with mezlocillin and metronidazole (N = 23; P less than 0.03). Escherichia coli was the principal organism responsible for surgically-related postoperative sepsis: (22 isolates: 14 mezlocillin and eight cefuroxime) all of which sensitive to the agents used. Pseudomonas aeruginosa was recovered from 10 patients (three mezlocillin and seven cefuroxime), all of the isolates were resistant to both antibiotics and were associated with severe morbidity. There were 11 isolates of Staphylococcus spp. (nine mezlocillin and two cefuroxime: P less than 0.03). Postoperative diarrhoea occurred in six patients, all were in the group receiving cefuroxime and metronidazole. (Clostridium difficile was recovered from the stool in three of which one was associated with Cl. difficile cytotoxin.)

Infectious diarrhea. Which culprit? What strategy?

The patient with diarrhea is generally looking for prompt relief, not a prolonged diagnostic workup. In many cases effective treatment can be initiated after careful review of the clinical symptoms and of the patient's recent travel or other activities. Stool examination, sigmoidoscopy, or other studies may be necessary for definitive diagnosis or in refractory cases. Drugs are useful to combat many of the causative organisms, but in mild, self-limited infections, supportive therapy may suffice. Indeed, antimotility agents are contraindicated in some types of infectious diarrhea.

Clostridium difficile toxin-induced intestinal secretion in rabbit ileum in vitro

In rabbit ileum in vitro Clostridium difficile toxin (200 microliter crude extract) almost abolished net Na absorption, by decreasing mucosa to serosa flux, and induced net Cl secretion by increasing the serosa to mucosa flux. These flux changes were induced when there was no visible histological damage to the mucosa. The toxin did not influence adenylate or guanylate cyclase activity in a plasma membrane fraction of isolated rabbit enterocytes nor did it affect cAMP concentrations in intact rabbit ileum pre-incubated with toxin. The flux responses to the toxin were prevented by removing calcium from the serosal medium, suggesting that the secretory process may be calcium dependent. These results indicate a possible mechanism by which this toxin could induce diarrhoea.

Fluorescent-antibody test for detection of Clostridium difficile in stool specimens

We evaluated a direct fluorescent-antibody test to detect Clostridium difficile, the most frequent cause of antibiotic-associated colitis. C. difficile organisms were injected into the ear veins of New Zealand White rabbits to induce antibodies, and the globulin fractions of their sera were conjugated to fluorescein isothiocyanate. The resulting conjugate strongly stained all 40 isolates of C. difficile tested. It also stained isolates of C. sordellii, C. bifermentans, C. chauvoei, and C. sporogenes, but not 20 other clostridial isolates or 10 isolates from other species. Results of testing fecal smears with the direct fluorescent-antibody method were compared with results of testing stools for C. difficile toxin and of culturing for C. difficile on a selective medium. A total of 158 fecal specimens from patients with antibiotic-associated diarrhea were tested. In these patients, the fluorescent-antibody test agreed with culture and toxin testing in 93% of the specimens. However, in normal adults, 62% of the fecal specimens from which C. difficile could not be cultured were positive by the fluorescent-antibody test. Absorption of the conjugate with C. sordellii led to a loss of reactivity to other clostridia as well as to 18 of 20 isolates of C. difficile.