Relapse of pseudomembranous colitis after vancomycin therapy

Autism and nutrition: the role of the gut-brain axis

Autism spectrum disorder (ASD) is characterised by deficits in the ability to socialise, communicate and use imagination, and displays of stereotypical behaviour. It is widely accepted that ASD involves a disorder in brain development. However, the real causes of the neurodevelopmental disorders associated with ASD are not clear. In this respect, it has been found that a majority of children with ASD display gastrointestinal symptoms, and an increased intestinal permeability. Moreover, large differences in microbiotic composition between ASD patients and controls have been reported. Therefore, nutrition-related factors have been hypothesised to play a causal role in the aetiology of ASD and its symptoms. Through a review of the literature, it was found that abnormalities in carbohydrate digestion and absorption could explain some of the gastrointestinal problems observed in a subset of ASD patients, although their role in the neurological and behavioural problems remains uncertain. In addition, the relationship between an improved gut health and a reduction of symptoms in some patients was evaluated. Recent trials involving gluten-free diets, casein-free diets, and pre- and probiotic, and multivitamin supplementation show contradictive but promising results. It can be concluded that nutrition and other environmental influences might trigger an unstable base of genetic predisposition, which may lead to the development of autism, at least in a subset of ASD patients. Clear directions for further research to improve diagnosis and treatment for the different subsets of the disorder are provided.

Variations in virulence and molecular biology among emerging strains of Clostridium difficile

Clostridium difficile is a Gram-positive, spore-forming organism which infects and colonizes the large intestine, produces potent toxins, triggers inflammation, and causes significant systemic complications. Treating C. difficile infection (CDI) has always been difficult, because the disease is both caused and resolved by antibiotic treatment. For three and a half decades, C. difficile has presented a treatment challenge to clinicians, and the situation took a turn for the worse about 10 years ago. An increase in epidemic outbreaks related to CDI was first noticed around 2003, and these outbreaks correlated with a sudden increase in the mortality rate of this illness. Further studies discovered that these changes in CDI epidemiology were associated with the rapid emergence of hypervirulent strains of C. difficile, now collectively referred to as NAP1/BI/027 strains. The discovery of new epidemic strains of C. difficile has provided a unique opportunity for retrospective and prospective studies that have sought to understand how these strains have essentially replaced more historical strains as a major cause of CDI. Moreover, detailed studies on the pathogenesis of NAP1/BI/027 strains are leading to new hypotheses on how this emerging strain causes severe disease and is more commonly associated with epidemics. In this review, we provide an overview of CDI, discuss critical mechanisms of C. difficile virulence, and explain how differences in virulence-associated factors between historical and newly emerging strains might explain the hypervirulence exhibited by this pathogen during the past decade.

Gastrointestinal microflora studies in late-onset autism

Some cases of late-onset (regressive) autism may involve abnormal flora because oral vancomycin, which is poorly absorbed, may lead to significant improvement in these children. Fecal flora of children with regressive autism was compared with that of control children, and clostridial counts were higher. The number of clostridial species found in the stools of children with autism was greater than in the stools of control children. Children with autism had 9 species of Clostridium not found in controls, whereas controls yielded only 3 species not found in children with autism. In all, there were 25 different clostridial species found. In gastric and duodenal specimens, the most striking finding was total absence of non-spore-forming anaerobes and microaerophilic bacteria from control children and significant numbers of such bacteria from children with autism. These studies demonstrate significant alterations in the upper and lower intestinal flora of children with late-onset autism and may provide insights into the nature of this disorder.

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.

Probiotics in health and disease in the pediatric patient

Probiotics are truly a timeless concept. Initially standard components of the human diet, potentially beneficial bacteria and yeast have been eliminated systematically through modern methods of preparing and preserving foods. Although the concept of probiotics is not new, the science of probiotics is in its infancy. Only recently have techniques been developed to identify, culture, and produce the probiotics that are suitable for medical use consistently. Furthermore, the potential uses for these organisms may extend far beyond what originally was thought. In no way should probiotics be thought of as a panacea for the diseases described earlier; however, when used appropriately, they represent a potentially beneficial adjunct to other proved therapies and have the added benefit of providing a stabilizing influence on the delicate balance between the ecosystem that consists of the human and its flora.

Liver abscess caused by Clostridium difficile

We report the first case of an infected cyst and liver abscess caused by Clostridium difficile. It recurred 11 months later, despite therapy with vancomycin and percutaneous drainage. Administration of metronidazole following percutaneous drainage achieved a favorable outcome.

Recurrent Clostridium difficile disease: epidemiology and clinical characteristics

OBJECTIVE

To describe the epidemiology, diagnosis, risk factors, patient impact, and treatment strategies for recurrent Clostridium difficile-associated disease (CDAD).

DESIGN

Data were collected as part of a blinded, placebo-controlled clinical trial testing a new combination treatment for recurrent CDAD. Retrospective data regarding prior CDAD episodes were collected from interviews and medical-chart review. Prospective data on the current CDAD episode, risk factors, and recurrence rates were collected during a 2-month follow-up.

SETTINGS

National referral study.

PARTICIPANTS

Patients with recurrent CDAD.

INTERVENTIONS

Treatment with a 10-day course of low-dose (500 mg/d) or high-dose (2 g/d) vancomycin or metronidazole (1 g/d).

RESULTS

Recurrent CDAD was found to have a lengthy course involving multiple episodes of diarrhea, abdominal cramping, nausea, and fever. CDAD may recur over several years despite frequent treatment with antibiotics. Recurrence rates were similar regardless of the choice or dose of antibiotic. Recurrent CDAD is not a trivial disease: patients may have multiple episodes (as many as 14), may require hospitalization, and the mean lifetime cost of direct medical care was $10,970 per patient. Fortunately, the disease does not become progressively more severe as the number of episodes increase. Two risk factors predictive for recurrent CDAD were found: increasing age and a decreased quality-of-life score at enrollment.

CONCLUSIONS

Recurrent CDAD is a persistent disease that may result in prolonged hospital stays, additional medical costs, and rare serious complications.

Oral supplementation with lactic acid-producing bacteria during intake of clindamycin

OBJECTIVE: To study the effect of administration of clindamycin with or without supplementation of the intestinal microflora with Bifidobacterium bifidum and Lactobacillus acidophilus. METHODS: Twenty-three healthy subjects received clindamycin by mouth for 7 days. Eleven of the subjects also received capsules containing lyophilized L. acidophilus and B. bifidum for 14 days. The other 12 subjects received placebo. RESULTS: There was a marked decrease in total numbers of anaerobic bacteria during the administration of clindamycin. In the lactic acid bacteria-supplemented group, a tendency towards delayed reduction and earlier increase in bifidobacteria was observed, and two of 11 subjects (18%) were colonized with Clostridium difficile, in comparison with five of 12 (41%) in the placebo group. The total number of microorganisms was significantly higher in the lactic acid bacteria-supplemented group than in the placebo group (p=0.02) 4 days after the end of clindamycin administration. The difference was mainly due to higher counts of Escherichia coli and enterococci. Mean levels of other enterobacteria increased less in the lactic acid bacteria-supplemented group than in the placebo group between days 0 and 14. CONCLUSIONS: The recolonization with aerobic and anaerobic microorganisms was faster in the lactic acid bacteria-supplemented group than in the placebo group. This may be of importance in preventing colonization with C. difficile.

Whole-bowel irrigation as an adjunct to the treatment of chronic, relapsing Clostridium difficile colitis

We report the successful treatment of two patients with chronic, intractable Clostridium difficile infection using whole-bowel irrigation with a polyethylene glycol solution (Golytely) as adjunctive therapy. Before this treatment, both patients had recurrent symptoms of diarrhea, weight loss, abdominal pain, and documented C. difficile toxin-positive stools despite multiple pharmacologic treatments. Each child was prescribed myriad drug therapies, including vancomycin, metronidazole, bacitracin, and rifampin. Cholestyramine and lactobacillus were also tried alone and in combination with antibiotics. In each case, symptoms recurred shortly after cessation of therapy. Whole-bowel irrigation was subsequently administered until profuse, clear liquid stools were produced. This treatment was followed by a 3-week course of oral vancomycin and lactobacillus. In both cases, the patient became asymptomatic within 3 days of therapy; they have remained symptom-free for 36 and 48 months, respectively. We suggest that whole-bowel irrigation clears active C. difficile organisms, toxins, and spores from the intestine and is effective as an adjunct to routine therapy for chronic, relapsing C. difficile infections.

Bacterial gastroenteritis

Acute diarrhea is a major cause of childhood morbidity. Important advances in the understanding of bacterial gastroenteritis have been made in the past two decades. This article reviews the epidemiology, pathogenesis, and methods of diagnosis of bacterial gastroenteritis. Bacterial enteric pathogens common to North America are discussed in more detail.

Clostridium difficile-associated diarrhoea in uremic patients

An outbreak of 94 episodes of Clostridium difficile-associated diarrhoea in 62 patients in a nephrology ward over a two-year period was investigated. Quantitative stool cultures were performed on ten uremic patients not on antibiotics and without diarrhoea and on ten healthy controls. All diarrhoeal episodes were associated with Clostridium difficile, and no other bacterial pathogens were isolated. Thirty-two relapses occurred in 16 patients, fourteen of the relapses without preceding antibiotic exposure. Clostridium difficile could not be isolated from the environment of the patients. Uremic patients, who had a significantly increased number of Clostridium spp. in their stools, are predisposed to Clostridium difficile infections.

Suppression by Saccharomyces boulardii of toxigenic Clostridium difficile overgrowth after vancomycin treatment in hamsters

Saccharomyces boulardii prevented the development of high counts of Clostridium difficile, high titers of toxin B, and positive latex agglutination tests after cessation of vancomycin treatment for hamsters. The protocol used was designed to stimulate relapse of human C. difficile-associated colitis. S. boulardii was protective in this model.

Antibiotic-associated colitis due to Clostridium difficile: double-blind comparison of vancomycin with bacitracin

A randomized double-blind study was carried out in patients with unresolving antibiotic-associated colitis due to Clostridium difficile, to compare the effect of bacitracin (80,000 U/day) with vancomycin (500 mg/day) on the resolution of symptoms, clearance of organism, and prevention of relapse. Forty-two patients with colitis, 9 of whom had a pseudomembrane, were randomized, 21 patients to each treatment group. The two groups were comparable in age, disease severity, and antibiotic exposure. For a 50% reduction in stool frequency the mean times (+/- SE) were 4.1 +/- 0.4 days for bacitracin and 4.2 +/- 0.4 days for vancomycin. Sixteen patients (76%) had symptom resolution after 7 days of treatment with bacitracin, compared with 18 patients (86%) given vancomycin. Patients who failed to respond were crossed over (blind) to the alternative antibiotic, but tended to be refractory to the alternative medication as well. Vancomycin-treated patients had negative toxin (83% vs. 53%, p = 0.04) and negative stool cultures (81% vs. 52%, p = 0.02) more frequently than did those patients given bacitracin. Similar numbers of patients in each group had symptomatic relapse during 1 mo of follow-up, but most of them relapsed yet again after blinded crossover therapy. Although bacitracin was significantly less effective than vancomycin in clearing C. difficile from the stools, both were of similar value in the control of symptoms in a group of patients with predominantly nonpseudomembranous colitis. In view of its low cost, bacitracin is a reasonable first-line alternative to vancomycin in the treatment of antibiotic-associated colitis.

Prevention of clindamycin-induced mortality in hamsters by Saccharomyces boulardii

Saccharomyces boulardii, a yeast used in a number of countries for general and antibiotic-associated gastrointestinal illnesses, was examined for possible application in the prevention of clindamycin-induced mortality in the hamster colitis model. Hamsters were given free access to an aqueous 5% suspension of lyophilized yeast for 3 days before and 10 days after administration of a single oral clindamycin dose of from 0.2 to 0.8 mg/kg. Mortality was recorded in groups of 7 to 20 animals every 24 h for 10 to 30 days. Mean cecal concentrations of S. boulardii were greater than 10(6) CFU/ml throughout the yeast administration period. Yeast treatment significantly decreased cumulative percent mortality by an average of 29%. Death onset was not affected by yeast treatment. Cecitis was present in 86% of moribund animals (N = 95) and was absent in all surviving animals examined (N = 27). Toxigenic Clostridium difficile was isolated from 13 of 14 moribund hamsters examined. No adverse effects of the yeast treatment were observed in animals receiving S. boulardii without clindamycin. The results suggest that S. boulardii warrants further evaluation for the prevention of antibiotic-associated colitis.

Prospective randomised trial of metronidazole versus vancomycin for Clostridium-difficile-associated diarrhoea and colitis

101 patients with Clostridium-difficile-associated diarrhoea or colitis were prospectively randomised to 10-day oral courses of metronidazole, 250 mg four times a day, or vancomycin, 500 mg four times a day. 7 did not complete the protocol and were dropped from analysis. Pseudomembranous colitis (PMC) was diagnosed after endoscopy in 33 patients. Of the remaining patients without PMC, 38 had both C difficile culture and cytotoxin and 23 had only culture evidence of C difficile. 52 evaluable patients received vancomycin and 42 received metronidazole. There were two treatment failures with metronidazole and none with vancomycin (p = 0.20); and two relapses with metronidazole versus six with vancomycin (p = 0.17). Treatment in 1 patient in each group was discontinued because of drug intolerance. Response and relapse rates of the 33 patients with PMC were no different from those of the remaining patients. Pharmacy cost for the dosage used was $387.48 to $520.00 for vancomycin and $11.84 for metronidazole. Metronidazole and vancomycin have equivalent efficacy and relapse rates and are tolerated to a similar extent by patients with C-difficile-related diarrhoea and colitis, but metronidazole is considerably more economical.

Bacteriophage and bacteriocin typing scheme for Clostridium difficile

The study of the epidemiology of infection with Clostridium difficile would be aided by a way to type individual bacterial isolates. We therefore sought bacteriophages for use in typing. With mitomycin C exposure (3 micrograms/ml), filtrates from 10 strains of C. difficile had plaque-forming lytic activity on other C. difficile strains. Individual phage were passaged and made into high-titer stock preparations for typing. Electron microscopy revealed tailed phage particles from one such preparation. In addition to phage, inhibitory activity without distinct plaque formation consistent with bacteriocins was observed for 20 strains. C. difficile isolates from 16 patients taken 1 to 14 days apart were similar in their phage sensitivity pattern, whereas isolates from separate geographic locations showed a great variety of patterns. We conclude that bacteriophage should be useful for typing strains of C. difficile.

Nosocomial spread of Clostridium difficile

Environmental transmission of Clostridium difficile, the causative agent of antibiotic-associated pseudomembranous colitis (PMC), has been supported by animal studies and implicated in spread of C. difficile among leukemic children receiving non-absorbable antibiotics. We report antibiotic-associated C. difficile-related colitis in two adults who shared a commode chair during hospitalization.

Clostridium difficile and cytotoxin in feces of patients with antimicrobial agent-associated pseudomembranous colitis

Thirty patients with antimicrobial agent-associated pseudomembranous colitis (PMC) were studied for the presence of Clostridium difficile and its cytotoxin in feces. Either colonoscopy or barium enema radiography was required in three patients for the diagnosis of PMC because of nondiagnostic findings at sigmoidoscopy. Both the organism and cytotoxin were detected in 27 of the 30 patients; Staphylococcus aureus was excluded as the cause of PMC in two of the remaining patients. Eighteen of 19 patients with C. difficile-induced PMC who were treated with oral vancomycin had a salutary response; seven patients, however, had a relapse of colitis following the discontinuation of vancomycin. In general, relapses of colitis responded to retreatment with vancomycin. The implication of C. difficile as a cause of diarrhea is best achieved by the demonstration of colonic mucosal plaques or of a pseudomembrane. The value of fecal culture for C. difficile and cytotoxin assay is limited by the existence of asymptomatic carriers.

Medical management of antimicrobial-associated diarrhea and colitis

Gastrointestinal complications, including diarrhea, may occur with virtually all antimicrobial agents. Such diarrhea may represent either a common, nonspecific adverse effect, or it may be one of the manifestations of antimicrobial-associated colitis (AAC), a potentially fatal complication. Clostridium difficile and a cytotoxin neutralized by Clostridium sordellii antitoxin has been isolated from the stools of nearly all patients with antibiotic-associated pseudomembranous colitis, many patients with AAC, and approximately 20% of those with antimicrobial-induced diarrhea. Demonstration that C. difficile is responsible for cytotoxin production has allowed for specific therapy for these disorders. General treatment measures include discontinuation of the causative antimicrobial agent(s), bowel rest, and supportive care with fluids, electrolytes and colloids, if necessary. Antiperistaltic agents and corticosteroids are not recommended. Various antimicrobials demonstrate potential efficacy in treating AAC in humans. Oral vancomycin is the most widely tested and is currently the treatment of choice. It achieves high concentrations in the feces and is very active against C. difficile in doses of 125-500 mg by mouth every six hours. Other potentially useful but inadequately tested antimicrobials include metronidazole (500 mg by mouth every eight hours) and bacitracin (25,000 units by mouth every six hours). Tetracycline has been employed with some success in nonspecific antibiotic-associated diarrhea, although it is as yet untested in humans with AAC and may induce diarrhea itself. Both miconazole and rifampin are highly effective against C. difficile in vitro but have not been evaluated in AAC. Anion-exchange resins bind the cytotoxin found in stools of patients with AAC. Cholestyramine has been used with variable response in oral doses of 4 g every six to eight hours. Since these resins may also bind vancomycin, resulting in lowered vancomycin concentrations in the stool, combination therapy should be used cautiously. With specific therapy directed against the toxin and aggressive supportive therapy, surgical intervention is rarely necessary. More recently, investigations have been directed at using bacterial preparations to suppress C. difficile by restoring the normal flora. The development of immunological agents (i.e., vaccines, toxoids, antitoxins) for the prevention or treatment of AAC would be a significant advance in therapy.

Trimethoprim/sulfamethoxazole-associated pseudomembranous colitis

A case of TMP/SMX-associated pseudomembranous colitis is described in a patient being treated for a urinary tract infection. Pseudomembranes are visualized on proctosigmoidoscopy, and stool cultures identified Clostridium difficile as the causative organism. The patient was treated successfully with oral vancomycin. A review of this infrequently reported adverse reaction to TMP/SMX is presented, emphasizing etiology and treatment.

Treatment of Clostridium difficile colitis and diarrhea with vancomycin

Toxigenic Clostridium difficle is the major cause of antibiotic-associated colitis and is susceptible to vancomycin at fecal concentrations achieved with oral therapy. The effect of oral vancomycin was studied in 16 patients with C. difficile-related diarrhea or colitis, 12 of whom had colitis documented by endoscopy, biopsy, and/or barium enema. Four patients had antibiotic-associated diarrhea and possibly antibiotic-associated colitis, because sigmoidoscopy either showed normal results (two patients) or was not performed (two patients). Nineteen episodes of diarrhea were treated with oral vancomycin in two dosage regimens for three to 14 days. Twelve patients received 2 g daily, and four patients initially received 1 g or less per day. Within 48 hours of the start of vancomycin therapy, 14 of 16 patients (87 percent) showed a decrease in temperature, abdominal pain and diarrhea. Diarrhea ceased completely within two days of the start of vancomycin in nine episodes, within three to seven days in six episodes, and within eight to 14 days in the remaining four episodes, and within eight to 14 days in the remaining four episodes. Diarrhea recurred in two of these patients (12 percent) when the drug inciting the initial episode of colitis was given again 42 days or more after vancomycin therapy was stopped; both patients responded again to retreatment with vancomycin. Oral vancomycin is an effective treatment of C. difficile-related colitis and diarrhea.

Evaluation of eight cephalosporins in hamster colitis model

Eight commonly used cephalosporins were evaluated in the hamster colitis mode. They were all found to cause hemorrhagic cecitis and death within 10 days of being given as subcutaneous or oral challenges. Necropsy findings were indistinguishable from clindamycin-induced cecitis. Bacteria-free cecal filtrate obtained from hamsters dying of cephalosporin-induced cecitis contained toxin similar or identical to hat produced by Clostridium difficile isolated from the cecum of a hamster. Daily oral administration of poorly absorbed cephalosporins protected hamsters from clindamycin-induced cecitis and death as long as the cephalosporins were continued. The absorbable cephalosporins were ineffective in protecting hamsters from clindamycin-induced cecitis. This difference probably relates to the lower concentrations of absorbable cephalosporins maintained in the ceca of the hamsters. The possible correlation of these findings to human cases of cephalosporin-induced pseudomembranous colitis is discussed.

Pseudomembranous (antibiotic-associated) colitis

We have come to understand the cause of antibiotic-associated pseudomembranous colitis (PMC) only in the last decade. Clostridium difficile produces the intestinal dysfunction and the characteristic finding of exudative plaques on the mucosa by elaborating a toxin in the colon. This report reviews the development of our knowledge of this disease and the rapid adoption of a rational therapy once the cause was specified. C. difficile or its toxin can be cultured or isolated from the stools of 90% of the patients with PMC. This organism is almost never found in healthy people or in any other conditions except inflammatory bowel disease, where its significance is not yet known. The detection of pseudomembranes by sigmoidoscopy establishes the diagnosis. The laboratory technics that confirm the presence of C. difficile and its toxin are being incorporated into many laboratories around the country. Treatment of diagnosed PMC is relatively simple and usually completely effective. The offending antibiotic is stopped, a proper fluid and electrolyte balance maintained, and oral vancomycin begun, 125 to 500 mg four times a day. Cholestyramine can also be used as an adjunct to this regimen. Relapse can occur in patients treated with oral vancomycin, necessitating a repeat course of therapy.

Erythromycin. New indications and toxicities

Although erythromycin was introduced into clinical medicine more than 28 years ago, the indications for its use continue to expand. This antibiotic has emerged as appropriate therapy for Legionnaires' disease, chronic bacterial prostatitis caused by Escherichia coli, Klebsiella pneumoniae, and Proteus species, enteritis and colitis produced by Campylobacter fetus, and soft tissue and pleuropulmonary anaerobic infections in which Bacteroides fragilis plays no role. In combination with an aminoglycoside, erythromycin has proven to be effective for perioperative antibiotic prophylaxis in patients undergoing elective colon surgery. Additional therapeutic indications continue to be explored. The renewed interest in erythromycin has resulted in a closer examination of its potential for toxicity. New untoward events attributed to erythromycin administration have been described. This antibiotic has produced both reversible hearing loss and pseudomembranous colitis. Erythromycin also possesses the ability to inhibit the degradation of theophylline.

Is pseudomembranous colitis infectious?

A cluster of eight patients in two adjacent hospital wards acquired acute diarrhoea within a period of 11 days. All their stool samples contained Clostridium difficile toxin and C. difficile was isolated in every case. Three patients had rectal biopsy findings compatible with pseudomembranous colitis (PMC). All the patients responded to treatment with oral vancomycin. Until the possibility of PMC being acquired by cross-infection is clarified such patients should be nursed in isolation with strict enteric precautions.

Analysis of the in vitro interaction between vancomycin and cholestyramine

Vancomycin and cholestyramine have been utilized both alone and in combination for the treatment of antibiotic-associated pseudomembranous colitis. Previous work for the treatment of antibiotic-associated pseudomembranous colitis. Previous work has demonstrated significant binding of vancomycin by the anion-exchange resin. The antibacterial activity of vancomycin was markedly reduced when the suspension was centrifuged and the supernatant was tested for antibacterial activity. This study confirmed these findings but demonstrated that there was no immediate loss of antibacterial activity of bound vancomycin. The degree of inactivation appeared to be dependent upon the duration of incubation of vancomycin and cholestyramine in the testing system.

Pseudomembranous colitis

Nine patients with pseudomembranous colitis (PMC) are described. Eight patients received prior therapy with antibiotics. Pyrexia and polymorph leukocytosis were common features. Six relapses occurred in four of the six patients who were treated with vancomycin. Two patients who did not receive vancomycin died.

Bacitracin therapy in antibiotic-associated pseudomembranous colitis

Two patients with antibiotic-associated pseudomembranous colitis, and stool positive for Clostridium difficile cytotoxin were successfully treated with oral bacitracin. One patient had previously suffered two relapses of pseudomembranous colitis following successful treatment with vancomycin and one patient was allergic to vancomycin. Bacitracin appears to be a reasonable choice to treat patients with antibiotic-associated colitis who are allergic to vancomycin. Further studies comparing vancomycin and bacitracin are needed.

Antimicrobial susceptibilities of Clostridium difficile

The antimicrobial susceptibilities of 78 strains of Clostridium difficile isolated from patients with and without gastrointestinal symptoms were determined and compared. Strains from patients with symptoms were more likely to show resistance to antibiotics. The antimicrobial susceptibilities of toxigenic and non-toxigenic strains were found to be similar.

Relapse of antibiotic-associated colitis after vancomycin therapy

Antibiotic-associated colitis, although occasionally fatal, is a disease which is considered to be self-limiting and non-recurring. Recently, specific treatment with oral vancomycin directed at the trigger organism, Clostridium difficile, has been shown to be effective. A case in which antibiotic-associated colitis was treated with vancomycin and subsequently recurred is described. The fact that such relapse can occur indicates that further evaluation of the efficacy of vancomycin is required.

[Antibiotic-associated diarrhoea and enterocolitis (author's transl)]

Many antibiotics, particularly the lincomycins, may cause diarrhoea with or without enterocolitis. The pathogenesis of antibiotic-associated diarrhoea without colitis is uncertain; colloidosmotic water binding in the colon by endogenous glycoproteins undegraded by colonic bacteria is considered. Antibiotic-associated enterocolitis is now known to be due to toxin-producing clostridia, proven for Cl. difficile. Improved methods for the detection of toxin and clostridia are presently being studied. Endoscopically, pseudomembranes are characteristic but not antibiotic-specific, they may be absent or missed diagnostically. A possible role of asymptomatic clostridia-carriers in enterocolitis clustering remains to be determined. The potentially lethal course of the disease requires rapid diagnosis and therapy, with discontinuation of the antibiotic, intensive supportive measures and, at least in severe disease, oral vancomycin.