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Biomedical subjects

D W Burdon

Publications and source records attributed to D W Burdon.

At least 37 records · Page 2Linked to original sources

Oral neomycin and erythromycin compared with single-dose systemic metronidazole and ceftriaxone prophylaxis in elective colorectal surgery.

A prospective randomized trial was performed to compare oral neomycin and erythromycin with single-dose intravenous metronidazole and ceftriaxone in elective colorectal surgery. The study was discontinued after 60 patients were entered. The overall rate of infection was 41 percent in the oral neomycin and erythromycin group (n = 29) compared with 9.6 percent in those who received intravenous metronidazole and ceftriaxone (n = 31) (p less than 0.01). Infections in the oral group were principally due to resistant Staphylococcus aureus, Bacteroides fragilis, and Escherichia coli. Preoperative administration of oral neomycin and erythromycin was associated with a significant reduction of Escherichia coli counts (1 X 10(7) to 3 X 10(5) organisms/ml, p less than 0.05) compared with the intravenous group, but there was no significant reduction in the counts of Bacteroides fragilis (2 X 10(8) to 1 X 10(7) organisms/ml) and there was an increase in the counts of Clostridia (2 X 10(4) to 1 X 10(6) organisms/ml). These results indicate that single-dose systemic prophylaxis with appropriate antibiotics is superior to oral neomycin and erythromycin.

Administration, Oral↗

Bacteraemia in diabetics.

During a period of 22 months one or more episodes of bacteraemia were detected in 168 patients in hospital. Of these, 29% also had diabetes compared with 10% of the total number of patients admitted to hospital during this time (P less than 0.001). The diabetics with bacteraemia were elderly and diabetes had usually been present for many years. Most of them were not receiving insulin at the time bacteraemia was diagnosed. Escherichia coli was the commonest pathogen (33%) in the diabetics, the main source of infection being the urinary tract. This finding may be due to diabetic autonomic neuropathy, which leads to a poorly emptying, chronically infected bladder. Urinary tract infections with bacteraemia in elderly diabetics are often accompanied by vague non-specific symptoms and poor diabetic control. Fever is infrequent. Prompt antibiotic therapy and insulin injections to control the diabetes usually cure these serious infections.

Aged↗

Pharmacokinetics of single dose intravenous ciprofloxacin in patients undergoing gastrointestinal surgery.

The pharmacokinetics of single dose intravenous ciprofloxacin in patients undergoing gastrointestinal surgery (100 mg, n = 8; 200 mg n = 18) have been studied. Following 100 mg therapeutic serum levels were maintained for approximately 40 min only and tissue concentrations were frequently less than 0.15 mg/kg. 200 mg maintained therapeutic serum levels for at least 150 min and produced mean concentrations in fat, muscle, peritoneum and gut wall of 1.04, 1.94, 1.59, and 3.39 mg/kg respectively. 200 mg iv ciprofloxacin would appear to provide adequate serum and tissue concentrations for at least 150 min.

Abdominal Muscles↗

Growth of Clostridium difficile and production of toxins A and B in complex and defined media.

The ability of several strains of Clostridium difficile to grow and to produce toxins A and B in complex and defined culture media has been studied with special reference to the amino-acid composition of the medium. The production of these toxins varied with the strain used and with the composition of the growth medium. Toxin A production was not inextricably linked to production of toxin B since conditions were found in which only one or other toxin was produced.

Amino Acids↗

Sporogenesis and toxin A production by Clostridium difficile.

The kinetics of spore production by Clostridium difficile were not paralleled by release of C. difficile toxin A in vitro. Toxin A was not found to be associated with either purified whole spores or spore coats. Residual traces of toxin A detected in spore contents were almost certainly derived from contaminating vegetative cell debris. Thus, toxin A is unlikely to be a spore constituent or associated with sporogenesis.

Bacterial Toxins↗

Effect of toxin A and B of Clostridium difficile on rabbit ileum and colon.

The effect of purified toxin A and partially purified toxin B on rabbit ileum and colon was investigated. Toxin A caused tissue damage which was followed by permeability changes and fluid accumulation in both tissues. Toxin A did not increase the permeability of the colon to the extent observed for ileum; secreted fluid contained less protein of plasma origin. Toxin B had no effect on either tissue. Secretory and tissue damaging properties of crude C difficile toxins were found to be due to toxin A.

Animals↗

Influence of rectal washout on bacterial counts in the rectal stump.

Forty-three patients undergoing a restorative colorectal resection were randomized to have their rectal stump washed out with either 0.9 per cent saline, 2.5 per cent povidone-iodine or 0.3 per cent sodium hypochlorite. The bacterial counts before and after washout for Escherichia coli and Bacteroides fragilis were compared using the Mann-Whitney U test. There was no significant difference in the counts for E. coli before and after washout with saline (log 9.7-log 9.7 organisms/ml) and saline had no influence on the counts of B. fragilis (log 7.9-log 6.5 organisms/ml). Hypochlorite was associated with a significant reduction in E. coli counts (log 6.1-log 1.1 organisms/ml, P less than 0.005) and the counts of B. fragilis (log 8.1-log 0.0 organisms/ml, P less than 0.005). The counts of B. fragilis were significantly reduced by povidone-iodine (log 8.1-log 1.1 organisms/ml, P less than 0.005) but there was no significant reduction in counts of E. coli (log 5.6-log 5.3 organisms/ml). The data suggest that sodium hypochlorite is better than povidone-iodine or saline as a rectal washout for colorectal anastomosis.

Bacteroides fragilis↗

The effect of a single intravenous dose of cefotaxime on the faecal flora.

Cefotaxime had an immediate effect on the faecal flora, mainly involving a loss of gram-positive organisms, but also reducing the number of Escherichia coli, Bacteroides spp. and Clostridium spp. There was little effect on the total bacterial counts because of compensatory increases in other species. These changes appear to initiate a period of instability in the composition of the faecal flora lasting for at least 14 days after the administration of cefotaxime. Other third-generation cephalosporins showed a similar prolonged disturbance to the stability of the faecal flora, but there were minor differences from cefotaxime in the bacterial species initially affected.

Bacteria↗

Antibiotic therapy for treatment in relapse of intestinal Crohn's disease. A prospective randomized study.

We have undertaken a prospective randomized trial of one month's antimicrobial therapy for patients with symptomatic relapse of Crohn's disease. Criteria for entry included two major symptoms: fever, abdominal pain, diarrhea, weight loss, abdominal mass or complications (excluding perianal disease); and two hematologic abnormalities: hemoglobin, ESR, albumin, C reactive protein, iron, or total iron binding capacity. Patients were monitored for the aforementioned clinical and hematologic (hemoglobin, albumin, CRP) parameters over six weeks and for changes in fecal flora. Randomization was to four groups: metronidazole alone (M), cotrimoxazole alone (C), metronidazole and cotrimoxazole (C plus M), or double placebo (P). Seventy-two patients entered the study (18 = M, 16 = C, 21 = C plus M, 17 = P). After two weeks, improvement was reported as follows: M = 67 percent, C = 17 percent, C plus M = 71 percent, P = 35 percent. In the metronidazole group, two patients required surgery and one had troublesome side effects. In the cotrimoxazole group, two had side effects. In the combined group (C plus M), four had troublesome side effects and two of the placebo group (P) required operation. By four weeks, there was no difference in response among the groups: (M = 44 percent, C = 62 percent, C plus M = 57 percent, P = 41 percent). Antimicrobials had no effect on fecal flora or hematologic parameters. These results indicate that antimicrobials have little therapeutic potential for relapse of intestinal Crohn's disease.

Adult↗

The influence of single dose intravenous antibiotics on faecal flora and emergence of Clostridium difficile.

The influence of a single intravenous dose of antibiotic on faecal flora and the emergence of Clostridium difficile was studied in volunteers. Seventy-eight volunteers (13 groups of 6 receiving 5 penicillins and 8 cephalosporins) were given a single intravenous dose of antibiotic. Results were compared with a control group of 6 volunteers who did not receive an antibiotic. Changes in the faecal flora were monitored over two weeks. Only cephalosporins were associated with emergence of Cl. difficile, penicillins and controls were not. Frequency of emergence of Cl. difficile in the 6 volunteers in each of the cephalosporin groups were as follows: cephaloridine 0, cephazolin, 1 cefuroxime 1, cefoxitin 2, cefotaxime 2, latamoxef 3, ceftriaxone 2, cefotetan 4. Latamoxef (moxalactam) was associated with a significant rise in total aerobic bacterial counts largely due to increased counts of enterococci. Cefotetan eliminated Escherichia coli and Bacteroides fragilis from the faecal flora three days after administration.

Anti-Bacterial Agents↗

Incidence of pathogenic bacteria from mesenteric lymph nodes and ileal serosa during Crohn's disease surgery.

Samples of ileal serosa and mesenteric lymph nodes have been harvested before antibiotic administration during 46 non-contaminated operations for Crohn's disease and compared with 43 operations for conditions other than Crohn's. Potentially pathogenic bacteria were isolated from the serosa in 12 (27 per cent) Crohn's patients, compared with 6 (15 per cent) controls (P = 0.04). Intestinal bacteria were recovered from mesenteric nodes in 15 (33 per cent) Crohn's patients compared with 2 (5 per cent) controls (P = 0.006). These findings suggest that bacteria leak from the small bowel lumen in a high proportion of Crohn's disease patients. This may explain the pathogenesis of abscess and fistula in this disorder as well as the high rate of sepsis following elective surgery even in the absence of macroscopic contamination.

Abdomen↗

A high incidence of bleeding is observed in a trial to determine whether addition of metronidazole is needed with latamoxef for prophylaxis in colorectal surgery.

A prospective randomized trial has compared the use of latamoxef sodium (two doses) with latamoxef and metronidazole for elective colorectal surgery. The incidence of wound infection in patients receiving latamoxef alone was 34 per cent compared with 32 per cent in patients receiving latamoxef and metronidazole. Only eight of the 36 wound infections in this study could be classified as major. Only two patients developed an intra-abdominal abscess postoperatively and there was only one episode of septicaemia. Postoperative haemorrhage was recorded in 17 patients (15 per cent). Twelve episodes of bleeding occurred in the first 97 patients who entered the trial and prolongation of the prothrombin time was recorded in eight of 16 patients. In view of these findings 10 mg vitamin K was given with each dose of latamoxef to the last group of patients. However, bleeding occurred in five of 13 patients receiving vitamin K and entry to the study was therefore discontinued.

Adult↗

Prospective randomized trial of single dose cefuroxime against mezlocillin in elective gastric surgery.

A prospective randomized control trial was made in 78 patients undergoing elective operations on the stomach where the viscus was opened at operation, and the efficacy of single dose intravenous prophylaxis with cefuroxime 1.5 g or mezlocillin 2 g was compared. The overall rate of sepsis was 10.2 per cent. Infection in the cefuroxime group was significantly lower (2.5 per cent) than in the mezlocillin group (18 per cent) (P less than 0.05). Four of the seven patients with infections in the mezlocillin group were due to antibiotic resistant staphylococci. The only infections in the cefuroxime group were due to an antibiotic resistant strain of Pseudomonas aeruginosa. One case of pseudomembranous colitis occurred in the cefuroxime group. In view of the high rate of resistant organisms in patients receiving mezlocillin we believe that cefuroxime remains the antibiotic of choice for patients undergoing elective gastric operations.

Abscess↗

Treatment of pseudomembranous colitis and antibiotic-associated diarrhoea.

Pseudomembranous colitis is caused by release of toxins from Clostridium difficile when it colonizes the large intestine. This clostridium is susceptible to concentrations of vancomycin which are readily attained in the colon after oral administration. When vancomycin is given orally to infected patients in a dose of 125 mg every 6 h, a rapid clinical cure can be expected. Some patients may relapse after the vancomycin is stopped, but a further course of treatment will control symptoms.

Adult↗

Production and release of toxins A and B by Clostridium difficile.

The production and release of toxins A and B by Clostridium difficile during in-vitro culture was investigated. Cell-associated toxin A was detected by immunoelectrophoresis of bacterial extracts released by ultrasonication and by fluorescent antibody labelling of whole cells. Extracellular toxin A was detected by immunoelectrophoresis and by enzyme-linked immunosorbent assay; extracellular toxin B was detected by cytotoxin assay. Both toxins A and B were produced and released during the decline phase of the bacterial growth cycle. The possible significance of these results in relation to the pathogenesis of pseudomembranous colitis is discussed.

Bacterial Proteins↗