Search PubMed⌕ Search

Biomedical subjects

B Cryan

Publications and source records attributed to B Cryan.

At least 19 recordsLinked to original sources
PubMed1995

Genomic fingerprinting Acinetobacter baumannii: amplification of multiple inter-repetitive extragenic palindromic sequences.

Acinetobacter species are important nosocomial pathogens. A rapid and sensitive identification system, capable of providing strain identity at the genetic level, is required to identify outbreak strains and facilitate the early implementation of infection control procedures. Repetitive extragenic palindromic (REP) elements, have been identified in numerous bacteria and these genomic sequences provide useful targets for DNA amplification. A method for amplifying inter-REP DNA sequences, REP-multiple arbitrary amplicon profiling (REP-MAAP), is described and applied to 29 Acinetobacter baumannii from clinical samples. Amplified polymorphic DNA patterns were demonstrated for all isolates and those displaying identical REP-MAAP patterns were considered identical at the genetic level. In the spring of 1993, 10 intensive care unit patients had endotracheal colonization with A. baumannii (five with REP-MAAP I and five with REP-MAAP II patterns). These findings suggested nosocomial transmission of organisms which was terminated by standard infection control measures. No further A. baumannii were detected until the winter of 1993 when isolates of different REP-MAAP groups emerged, suggesting that factors other than nosocomial transmission were implicated.

Acinetobacter↗
PubMed1995

Isolation of Mycobacterium chelonae in a bronchoscopy unit and its subsequent eradication.

SETTING: Contamination events with Mycobacterium chelonae in 7 patients undergoing bronchoscopy, out of a total of 100 patients in a 5-month period, were analysed. OBJECTIVE: To identify and assess the importance of factors thought to be relevant in the aetiology of these contamination events and by removing these factors, to eradicate the problem of continuing M. chelonae contamination. DESIGN: A retrospective analysis of the frequency of M. chelonae isolates from bronchoalveolar fluid, assessing the contribution of the following measures to the eradication of M. chelonae: (1) changes to the bronchoscopy unit's water supply; (2) insertion of bacterial filters; (3) installation of a new semi-automated cleaning machine incorporating an ultrasound cycle; (4) staff training in correct use of the new equipment. RESULTS: Following the discontinuation of using tapwater in the cleaning process, the above changes resulted in complete eradication of contamination events, with no further events occurring in the following 12 months. CONCLUSION: Insertion of bacterial filters into the water supply, with the addition of a more sophisticated semi-automatic cleaning machine involving an ultrasound cycle in addition to conventional cleaning methods currently used, will help reduce or eradicate contamination events with M. chelonae in bronchoscopy units.

Adult↗
PubMed1995

Colorimetric detection of heat-labile toxin-encoding gene of enterotoxigenic Escherichia coli by PCR.

In the developing world, enterotoxigenic Escherichia coli (ETEC) strains which produce enterotoxins are a significant cause of morbidity and mortality. Heat-labile (LT) toxin PCR detection methods have been described, but they have limited applications in a routine laboratory setting. A colorimetric DNA method for the rapid amplification and detection of the LT toxin gene in ETEC strains is described. Target amplification together with colorimetric detection would overcome many of the limitations of conventional PCR. This paper describes a colorimetric PCR detection method specific for LT-gene-encoding ETEC strains. DNA was extracted from two representative colonies from each bacterial isolate and amplified by PCR. Digoxigenin was incorporated into the amplification product, permitting a one-step direct detection using anti-digoxigenin alkaline phosphatase-conjugated antibody. This technique was applied to the investigation of 70 E. coli isolates derived from clinical fecal samples obtained from an Irish population. Eleven percent of the samples were LT positive, confirming the applicability of this method. All LT-positive ETEC strains (controls and clinical isolates) were detected, and no false-positive results occurred.

Bacterial Toxins↗
PubMed1995

Detection of the heat-stable toxin coding gene (ST-gene) in enterotoxigenic Escherichia coli: development of a colour amplified PCR detection system.

Screening biological samples using the polymerase chain reaction (PCR) has obvious advantages compared with current molecular analytical methods based on gel electrophoresis and/or hybridisation, both of which are expensive and time-consuming, therefore the development of a PCR assay format that is applicable to large sample numbers and that can readily use equipment commonly found in diagnostic laboratories would be advantageous. This report describes the development of a colour amplified PCR detection system which is simple in design and could be universally applied to the detection of any DNA template. As an example, the system has been applied in the detection of the heat-stable toxin coding gene (ST-gene) from enterotoxigenic Escherichia coli (ETEC). The assay is sensitive, detecting 10 fg of a purified DNA template and 270 cfu of an ST-gene-positive ETEC strain.

Bacterial Toxins↗
PubMed1994

Bacterial translocation during peroperative colonic lavage of the obstructed rat colon.

Peroperative antegrade colonic lavage is often performed before primary anastomosis in emergency colonic surgery. The influence of colonic lavage on bacterial translocation from the obstructed colon was determined. Forty female Wistar rats were studied in four groups: (1) control; (2) non-obstructed with lavage; (3) obstructed; and (4) obstructed with lavage. Ligature obstruction of the rectum was performed in groups 3 and 4. Some 4 days later 35S-radiolabelled Escherichia coli was inoculated into the colon of all animals. Groups 2 and 4 underwent colonic lavage. Lavage in the group 4 animals with left-sided colonic obstruction significantly increased the levels of E. coli in regional nodes, liver, spleen, lung, kidney and blood (as assessed by organ culture and scintillation counting) compared with those in groups 1, 2 and 3 (P < 0.05). These results suggest that peroperative lavage of the obstructed colon significantly increases the level of bacterial translocation.

Anastomosis, Surgical↗
PubMed1992

Isolation of Campylobacter sputorum biovar sputorum from an axillary abscess.

Campylobacter sputorum biovar sputorum is a rarely isolated organism, particularly from human clinical specimens. Its pathogenic potential is unknown. We present here what we believe to be the first report of this organism being isolated from a clinically significant source, an axillary abscess. To our knowledge, this organism has not been reported previously as one of clinical relevance in the U.K.

Abscess↗
PubMed1992

Lyme disease in Ireland.

The data pertaining to Irish specimens sent to the Lyme disease Laboratory at Charing Cross Hospital since 1986 is presented and discussed. In the period up to June 1990, 484 specimens were tested, 14% of these were positive by enzyme linked immunosorbent assay or indirect immunofluorescent assay. Only 13 of these were confirmed as positive by immunoblotting.

Adult↗
PubMed1990

Comparison of the synthetic oligonucleotide gene probe and infant mouse bioassay for detection of enterotoxigenic Escherichia coli.

A commercial DNA/DNA hybridisation kit for the detection of Escherichia coli heat stable enterotoxin gene sequences was compared to the suckling mouse bioassay using 183 isolates of Escherichia coli from clinical specimens. The gene probe assay had a specificity of 99% and a sensitivity of 90.4% compared to the infant mouse method. Using the colony blot method of preparing the bacterial DNA and a hybridisation temperature of 50 degrees C optimal results were obtained. The gene probe method is not affected by the incubation conditions of the test organisms. It is technically straightforward and can be applied to large numbers of specimens with fewer logistic difficulties than with the bioassay.

Animals↗
PubMed1990

Comparison of three assay systems for detection of enterotoxigenic Escherichia coli heat-stable enterotoxin.

In this study, a commercial DNA-DNA hybridization kit for the detection of Escherichia coli heat-stable enterotoxin is compared with a competitive enzyme-linked immunosorbent assay (ELISA) and the suckling mouse bioassay. Taking the suckling mouse assay as the "gold standard," the gene probe was the more specific and the ELISA was the more sensitive of the assays. The ELISA and the suckling mouse test are semiquantitative. The ELISA was the most rapid method, most amenable to automation, and most suitable for the examination of large numbers of specimens. The gene probe is particularly applicable in relatively primitive laboratory conditions. The suckling mouse assay was the least suitable system for the examination of large numbers of specimens.

Animals↗
PubMed1990

Enterohaemorrhagic Escherichia coli.

In North America enterohaemorrhagic Escherichia coli have emerged as important enteric pathogens since their initial description in 1982. They have been associated with the idiopathic haemolytic uraemic syndrome and in outbreaks, mortality rates of up to 31% have been recorded. In this paper the recent literature pertaining to the pathogenesis, laboratory identification, epidemiology and therapy of infections by these organisms is reviewed.

Aged↗
PubMed1989

Enterohaemorrhagic Escherichia coli serotype O157:H7 as an enteric pathogen in Irish children.

In this study sorbitol MacConkey agar was used to screen E. coli isolated from 894 children with diarrhoea. Thirty-four non-sorbitol fermenters were detected. On serotyping, three organisms belonged to the O157 serogroup. Only one of these possessed the H7 antigen. This organism was a verotoxin producer. These findings suggest that E. coli O157:H7 is an uncommon enteric pathogen in Irish children.

Child, Preschool↗
PubMed1989

A competitive enzyme-linked immunosorbent assay for detecting Escherichia coli heat-stable enterotoxin and its application to clinical isolates.

Enterotoxigenic Escherichia coli (ETEC) are well recognised enteric pathogens. The epidemiology of heat-stable enterotoxin (STa) producing strains has not been established due mainly to difficulties encountered in performing bioassays on a large scale in baby mice. This study describes a competitive enzyme-linked immunosorbent assay (ELISA) for detecting STa and its application to clinical isolates. Compared to the bioassay, the ELISA had a specificity of 93.7% and a sensitivity of 90.9%. It detected as little as 1 microgram/l STa. Of 720 E. coli isolates from children with diarrhoea, 69 (9.6%) were positive for STa by ELISA.

Animals↗