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Biomedical subjects

R A Bowman

Publications and source records attributed to R A Bowman.

At least 19 recordsLinked to original sources
PubMed1992

Hepatitis C testing. Comparison of Ortho's EIA and RIBA II tests in 1,182 patients undergoing primary liver transplantation.

Plasma samples from 1,182 patients undergoing primary liver transplantation were tested for anti-hepatitis C (HCV) virus by two methods: Ortho HCV ELISA Test System (EIA) and Chiron RIBA HCV Test System (RIBA II). The EIA results, 0 or +, were recorded first, followed by RIBA results, N = negative, P = positive, or I = indeterminate. Concordant results--0N, + P, + I--were found in 1,076 (91%), and discordant results were found in 106 (9%). The EIA optical density did not relate to concordant or discordant results. Band patterns were described by stating the band position (1, 2, 3, or 4) and inserting a dash (-) if no band was visualized. Most + P samples fell into two patterns: 47% showed all four bands, pattern 1234, and 15% showed the two-band pattern, 34. When the EIA was negative, 0P, the opposite was seen: 8% showed the 1234 pattern and 81% showed the 34 pattern. There were 226 samples that formed bands (+ P, 149; 0P, 31; + I, 15; 0I, 31). The frequency of bands was as follows: 4, 32%; 3, 31%; 2, 19%; and 1, 18%. Band 2 and the EIA test detected antibodies to the same c100-3 fragment and showed 74% concordance. No explanation is apparent for the lower concordance rate here than that between the EIA test and bands 3 = 96% or 4 = 88%. The EIA and RIBA II tests, together with positive liver function tests and abnormal tissue pathologic findings, provide a basis for the diagnosis of HCV.

Antigens, Viral↗
PubMed1992

Ciprofloxacin and Clostridium difficile-associated diarrhoea.

Recent reports have implicated ciprofloxacin as a cause of Clostridium difficile-associated diarrhoea. This problem was examined in three ways. First, the MIC of ciprofloxacin for C. difficile was determined. The MIC range was 8-32 mg/L, with C. difficile were 'treated' with ciprofloxacin and clindamycin in a test-tube, and the growth of C. difficile monitored. The clindamycin-treated emulsions supported growth of C. difficile, while the ciprofloxacin-treated and control emulsions did not differ significantly and failed to support the growth of C. difficile. Finally, 213 patients on ciprofloxacin monotherapy were investigated. Twenty-nine patients were given ciprofloxacin as treatment for diarrhoea, while a further 15 patients developed diarrhoea while being treated. None of these 44 patients harboured C. difficile. Faecal samples from 73 of the remaining 169 patients who did not have or develop diarrhoea were investigated for C. difficile, but none was positive. It was concluded that ciprofloxacin is unlikely to promote C. difficile-associated diarrhoea.

Ciprofloxacin↗
PubMed1992

Limulus amoebocyte lysate assay in the diagnosis of peritonitis in patients receiving continuous ambulatory peritoneal dialysis.

AIMS: To evaluate the Limulus amoebocyte lysate (LAL) assay for differentiating Gram positive from Gram negative peritonitis in patients receiving continuous ambulatory peritoneal dialysis (CAPD). METHODS: One hundred and six patients with suspected peritonitis were studied. LAL assay was performed by adding 0.1 ml of CAPD fluid to 0.1 ml of LAL reagent and incubating in a heating block for 60 minutes at 37 degrees C. The sensitivity of the reaction was determined by: (i) diluting endotoxin in distilled water and used (filter sterilised) peritoneal dialysis fluid; and (ii) diluting a broth culture of E coli used in peritoneal dialysis fluid. A positive LAL assay was defined as the constant stability of the clot through an inversion of 180 degrees. RESULTS: Compared with bacterial culture, the LAL assay had a sensitivity of 65% and a specificity of 98%. The sensitivity of microscopy compared with culture of Gram negative organisms was 76%; overall sensitivity of microscopy in comparison was 80%. CONCLUSIONS: The Gram stain was more sensitive than has previously been reported; the LAL assay was specific but insensitive for the diagnosis of CAPD peritonitis. There was a correlation between reduced leucocyte count and culture; this was reduced in cases from which Gram negative organisms had been isolated. It is recommended that laboratories evaluate their Gram stain procedure to improve its sensitivity because the LAL assay is not a satisfactory substitute.

Diagnosis, Differential↗
PubMed1992

Selective criteria for the microbiological examination of faecal specimens.

To assess the effectiveness of predetermined investigation criteria for the examination of faecal samples from inpatients, cultured stool specimens were prospectively examined for Salmonella spp, Shigella spp, Campylobacter spp and Clostridium difficile, and screened microscopically for intestinal parasites. Out of a total of 505 specimens, 421 (83%) fulfilled the criteria for examination for C difficile, 254 (50%) for Salmonella spp, Shigella spp, and Campylobacter spp, and 87 (17%) for intestinal parasites. Isolation rates for these organisms in those groups of patients where examination was indicated were 22.5% for C difficile and 9.1% for Salmonella spp, Shigella spp, and Campylobacter spp; the detection rate for parasites was 3.5%. In those patients where the criteria did not suggest investigation, the isolation or detection rates were 3.6% for C difficile, 0% for Salmonella spp, Shigella spp, and Campylobacter spp, and 1.7% for intestinal parasites, suggesting that the use of predetermined investigation criteria was effective.

Animals↗
PubMed1991

Non-radioactive restriction fragment length polymorphism (RFLP) typing of Clostridium difficile.

A typing method for Clostridium difficile based on restriction fragment length polymorphisms (RFLP) is described. The technique utilizes commercially available Escherichia coli ribosomal ribonucleic acid (rRNA) as probe material. Probe labelling, hybridization and detection was performed using the Enhanced Chemiluminescence (ECL) gene detection system. The probe labelling procedure was easy to perform, taking only 20 min. The complete typing method was comparatively simple, reproducible and readily adaptable to most bacterial genera.

Australia↗
PubMed1991

Gastrointestinal carriage of Clostridium difficile in cats and dogs attending veterinary clinics.

Cats and dogs being treated at two veterinary clinics were investigated for gastrointestinal carriage of Clostridium difficile using selective solid and enrichment media. Thirty-two (39.5%) of 81 stool samples yielded C. difficile. There were significant differences in isolation rates between clinics, 61.0% of animals being positive at one clinic compared to 17.5% at the other (Chi-square, P less than 0.005). Of 29 animals receiving antibiotics, 15 (52.0%) harboured C. difficile while 11 (23.9%) of 46 animals not receiving antibiotics were positive (Chi-square, P less than 0.01). There was no difference in carriage rate between cats (38.1%) and dogs (40.0%). The environment at both veterinary clinics was surveyed for the presence of C. difficile. Fifteen of 20 sites at one clinic were positive compared to 6 of 14 sites at the other clinic. Both cytotoxigenic and noncytotoxigenic isolates of C. difficile were recovered from animals and environmental sites. These findings suggest that household pets may be a potentially significant reservoir of infection with C. difficile.

Animals↗
PubMed1991

Evaluation of Clinitek 200 and Rapimat II/T for screening for urinary tract infection.

Two machines, the Clinitek 200 and the Rapimat II/T, were evaluated for their ability to screen urine samples for significant bacteriuria and other elements indicative of urinary tract pathology. The automated screening procedures were compared with a conventional approach of microscopy and quantitative culture for 1020 urine specimens obtained from patients in a 700 bed general hospital. When compared with the bacterial culture method both machines gave identical results with a negative predictive value of 0.99, while when compared with microscopy alone the Clinitek 200 and Rapimat II/T gave negative predictive values of 0.92 and 0.87, respectively. It is concluded that both machines would provide cost effective screening of urine specimens.

Adult↗
PubMed1988

Laboratory diagnosis of Clostridium difficile-associated diarrhoea.

This paper reviews the various laboratory procedures available for the isolation and identification of Clostridium difficile and the detection of toxins produced by this organism. Laboratories should be selective in determining which patients require investigation for Clostridium difficile-associated diarrhoea. Transport and storage of stool specimens at 4 degrees C is recommended when delays in processing may occur. Tissue culture techniques are still the best method for detection of cytotoxin and a variety of cell lines can be used. Other methods for detecting cytotoxin, and methods for detecting other toxins are not sufficiently developed yet to warrant introduction into diagnostic laboratories. Culture techniques remain the most sensitive for diagnosis, particularly since the development of a variety of enrichment techniques. Cycloserine cefoxitin fructose agar is still adequate, although reduced concentrations of antimicrobial agents are necessary, and improvements, such as the addition of sodium taurocholate, increase the recovery of spores. Enrichment cultures have markedly increased isolation rates for Clostridium difficile but the significance of these isolates needs to be carefully evaluated. Until simpler and more reliable tests are available in clinical laboratories for the detection of toxins, the isolation of Clostridium difficile from patients with diarrhoeal disease should be considered paramount.

Bacterial Toxins↗
PubMed1986

Clostridium difficile in general practice and community health.

The isolation rate for Clostridium difficile in diarrhoeal stools was investigated in patients from general practice and community health centres over a 14-month period. C. difficile or its cytotoxin was detected in specimens from 89 (4.7%) of 1882 patients studied and accounted for 30.3% of all enteropathogenic micro-organisms isolated. Overall C. difficile was second only to Giardia lamblia in frequency. Recovery rates in the different groups of patients surveyed varied from 3.6 to 27.5%. The relationship between stool culture results and stool cytotoxin assay also varied considerably between groups of patients studied. Coincident infections with a variety of enteropathogenic bacteria and intestinal parasites were diagnosed in 14 of the 89 patients. It was concluded that laboratories servicing this type of practice should be aware that C. difficile may be a cause of diarrhoea. An adequate clinical history should facilitate proper processing of the specimen.

Australia↗
PubMed1986

Latex particle agglutination for detecting and identifying Clostridium difficile.

A total of 329 selective enrichment broth cultures were tested for detection of Clostridium difficile by latex particle agglutination (LPA), gas-liquid chromatography, and bacterial culture. Of 53 broths positive by LPA, 36 were positive by gas-liquid chromatography, and 42 were positive by bacterial culture. The sensitivity and specificity of LPA relative to bacterial culture was 95.6% and 96.3%, respectively, while the sensitivity and specificity of gas-liquid chromatography relative to bacterial culture was 84.6% and 100%, respectively. The high predictive value of a negative test (99%) should make LPA on broth cultures a good screening test for detecting C difficile. Of several other Clostridium spp tested in pure culture, strains of C sordellii and C bifermentans also gave a positive result by LPA. These results, together with the low cost and simple facilities required, suggest that the LPA test will be a useful procedure for the presumptive identification of C difficile in selective enrichment broths and for the identification of pure cultures.

Caproates↗