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Biomedical subjects

F K Gould

Publications and source records attributed to F K Gould.

At least 19 recordsLinked to original sources
PubMed1999

Evaluation of tube coagulase and a fluorogenic substrate for rapid detection of methicillin-resistant Staphylococcus aureus from selective enrichment broth in an outbreak of EMRSA 15.

We investigated the use of tube coagulase and a fluorescent substrate, N-t-BOC-val-pro-arg-7-amido-4-methylcoumarin for the rapid detection of MRSA in selective broth enrichment cultures during an outbreak. These methods were compared with direct plating of swabs and plating a selective broth enrichment culture using 200 screening swabs collected from forty patients during the investigation of an outbreak of E-MRSA 15. Overall 66 swabs were positive for MRSA following subculture of broth enrichment culture. Direct plating detected 25 (38%) positives, tube coagulase 37 (56%), and fluorescent substrate 49 (74%) respectively, although nine of the 49 turned out to be false reactions. When detection from individual patients was analyzed, selective broth subculture identified 28 patients colonized with MRSA. Direct plating detected only 12 (43%) of these patients. The tube coagulase and fluorescence methods detected MRSA in 17 (60%) and 19 (68%) patients respectively. The tube coagulase method was found to be 100% specific for MRSA suggesting its use as a rapid method for the detection of MRSA from selective enrichment broth.

Bacteriological Techniques↗
PubMed1999

ABC medium, a new chromogenic agar for selective isolation of Salmonella spp.

We describe a new chromogenic agar medium, ABC medium (alphabeta-chromogenic medium), which includes two substrates, 3, 4-cyclohexenoesculetin-beta-D-galactoside and 5-bromo-4-chloro-3-indolyl-alpha-D-galactopyranoside, to facilitate the selective isolation of Salmonella spp. This medium exploits the fact that Salmonella spp. may be distinguished from other members of the family Enterobacteriaceae by the presence of alpha-galactosidase activity in the absence of beta-galactosidase activity. A total of 1, 022 strains of Salmonella spp. and 300 other gram-negative strains were inoculated onto this medium. Of these, 1,019 (99.7%) strains of Salmonella spp. produced a characteristic green colony, whereas only 1 strain (0.33%) of non-Salmonella produced a green colony. A total of 283 stool samples were cultured onto desoxycholate citrate (DC) agar and ABC medium by direct inoculation and after selective enrichment in selenite broth. Overall, the sensitivity and specificity were superior for ABC medium (100 and 90.5%, respectively) than for DC agar (88 and 26.9%, respectively). We conclude that ABC medium offers a high degree of specificity for the detection of Salmonella spp. in stool samples.

Agar↗
PubMed1999

Rapid identification of Staphylococcus aureus by using fluorescent staphylocoagulase assays.

Two rapid (1-h) assays for the detection of Staphylococcus aureus staphylocoagulase were developed by using the fluorogenic thrombin substrates N-t-boc-Val-Pro-Arg-7-amido-4-methylcoumarin (VPA) and N-t-boc-beta-benzyl-Asp-Pro-Arg-7-amido-4-methylocoumarin (BB). The assays were compared to the tube coagulase test and latex agglutination (LA) (Sanofi Diagnostics Pasteur, Guildford, Surrey, United Kingdom) by using 406 clinical isolates of staphylococci, and they produced positive and negative predictive values of 99.2 and 99. 1% for LA, 98.9 and 92.7% for VPA, and 98.9 and 99.1% for BB. Fluorescent assays used colonies from solid media, thereby eliminating the need for broth cultures, and were performed in microtiter trays, thus making them suitable for large-scale screening.

Bacteriological Techniques↗
PubMed1998

Detection of carboxypeptidases as taxonomic markers for gram-negative bacteria.

The use of seven benzoyl-L-amino acids for the detection of carboxypeptidase activities in strains of Gram-negative aerobic and facultatively anaerobic bacteria is reported. A simple overnight assay was designed using ninhydrin for the demonstration of the amino acid released by hydrolysis. Detection of carboxypeptidase activity was shown to have some taxonomic relevance within the Enterobacteriaceae; it was also useful for differentiation within the genus Acinetobacter and for distinction between Pseudomonas aeruginosa and Pseudomonas fluorescens.

Amino Acids↗
PubMed1997

Outbreak of gram-negative septicaemia caused by contaminated continuous infusions prepared in a non-clinical area.

An outbreak of Gram-negative septicaemia due to cross infection on an acute cardiology ward is reported. This outbreak was facilitated by two factors: first, an area originally designed for non-clinical purposes was converted into a clean utility area without consulting the infection control team, and second, changes in staff had taken place at the same time. This outbreak emphasizes the importance of continuous staff training in infection control, the involvement of the infection control team in all building alterations and the need to improve recommendations by the Department of Health in the design of clean utility areas.

Cardiology↗
PubMed1997

Note: cyclohexenoesculetin-beta-D-glucoside: a new substrate for the detection of bacterial beta-D-glucosidase.

A new substrate for the detection of bacterial beta-D-glucosidase was evaluated as an alternative to aesculin. This substrate, 3,4-cyclohexenoesculetin-7-beta-D-glucoside, was compared with aesculin for the detection of beta-D-glucosidase in 150 enterococci, 40 streptococci, 12 Listeria sp. and 250 strains of Enterobacteriaceae. In the Gram-positive strains tested, aesculin hydrolysis correlated with hydrolysis of 3,4-cyclohexenoesculetin-7-beta-D-glucoside. In the Gram-negative strains the new substrate was hydrolysed by all aesculin-positive strains and also by four strains (10%) of Escherichia coli which gave a negative aesculin reaction. 3,4-Cyclohexenoesculetin-7-beta-D-glucoside was shown to be a reliable alternative to aesculin and was shown to have significant advantages over aesculin when incorporated into solid media. This was due to the non-diffusible end product produced by hydrolysis of 3,4-cyclohexenoesculetin-7-beta-D-glucoside in the presence of iron.

Bacteria↗
PubMed1997

Mycobacterium novocastrense sp. nov., a rapidly growing photochromogenic mycobacterium.

A strain isolated from a biopsy sample taken from a slowly spreading skin granulation on a child's hand was found to have properties consistent with its classification in the genus Mycobacterium. An almost complete gene sequence of the 16S rRNA of the strain was determined following the cloning and sequencing of the amplified gene. The sequence was aligned with those available for mycobacteria, and phylogenetic trees were inferred with four tree-making algorithms. The organism, which formed a distinct phyletic line within the evolutionary radiation occupied by rapidly growing mycobacteria, was readily distinguished from members of validly described species of rapidly growing mycobacteria on the basis of its mycolic acid pattern and a number of other phenotypic features, notably its ability to form yellow pigmented colonies when incubated in the light. The name proposed for this new species is Mycobacterium novocastrense. The type strain is DSM 44203.

DNA, Bacterial↗
PubMed1996

Hepatocyte nuclear factor-4 is responsible for the liver-specific expression of the gene coding for hepatocyte growth factor-like protein.

In an attempt to understand the molecular mechanism regulating the expression of the gene coding for human hepatocyte growth factor-like protein/macrophage stimulating protein (HGFL), our laboratory has isolated and characterized approximately 4200 bp of the 5'-flanking region of the HGFL gene. To determine the location of sites which may be critical for the function of the HGFL gene promoter, we constructed a series of hybrid genes containing serial deletions of this region attached to the coding sequences for chloramphenicol acetyltransferase. Expression of these chimeric plasmids was examined by transient transfection of HepG2 and 293 cells. Our results suggest that the transcriptional activity of the HGFL promoter is modulated in HepG2 cells by one positive element at position -135 to -105 (-135/-105). In contrast, only background levels of chloramphenicol acetyltransferase expression have been detected in 293 cells. The -135/-105 region appears to bind a liver-specific transcription factor essential for expression of this gene. Gel mobility shift experiments with antibodies against hepatocyte nuclear factor-4 (HNF-4) and transactivation of the HGFL promoter by a HNF-4 cDNA expression vector suggest that HNF-4 binds to the -135/-105 region and is responsible for the liver-specific expression of HGFL.

Amino Acid Sequence↗
PubMed1996

Evaluation of cyclohexenoesculetin-beta-D-galactoside and 8-hydroxyquinoline-beta-D-galactoside as substrates for the detection of beta-galactosidase.

We describe the synthesis of two new substrates for the detection of beta-galactosidase and evaluate their performance in comparison with that of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). Of 171 Enterobacteriaceae strains that were able to hydrolyze X-Gal, 166 (97.1%) also hydrolyzed cyclohexenoesculetin-beta-D-galactoside whereas only 96 (56.1%) showed evidence of hydrolysis of 8-hydroxyquinoline-beta-D-galactoside. No false-positive results were observed with either substrate.

Enterobacteriaceae↗
PubMed1996

Hepatitis C virus: epidemiology and genotypes in the north east of England.

The epidemiology of hepatitis C virus (HCV) infection was studied in an English teaching hospital over an 18 month period. A total of 104 HCV antibody positive patients were referred for further investigation. They were divided into those diagnosed through screening (blood donors and intravenous drug abusers) and those diagnosed for other reasons, and their mean ages, known risk factors for HCV transmission, genotypes, and liver biopsy histology were analysed. Screened patients were significantly younger than the others. No significant difference in age was found between genotypes. Most patients genotyped (69%) were genotype 1. Intravenous drug abusers had a higher proportion of subtype 1a, and patients who acquired HCV through blood transfusion had a higher proportion of subtype 1b. Liver biopsy specimens were scored using a histological activity index for liver inflammation and fibrosis. Patients with subtype 1b had significantly more severe liver disease than other genotypes when the histological activity index scores for fibrosis were analysed (p < 0.05). Liver disease worsened significantly with age according to all three histological activity index scores (portal activity: p < 0.01, acinar activity: p < 0.001, fibrosis: p < 0.0001). Liver disease worsened with increased duration of infection (p < 0.002), and patients who also abused alcohol presented at a significantly younger age (cirrhosis, p < 0.05, hepatocellular carcinoma, p < 0.02).

Adult↗
PubMed1996

Does storage of sputum specimens adversely affect culture results?

It has been recommended that samples submitted for microbiological examination should be retained for 48 hours after issue of the final report. In order to ascertain whether reproducible results could be achieved following storage of sputum specimens, two laboratories each re-cultured 100 samples 48 hours after their report had been issued and a further laboratory re-cultured 100 samples 48 hours after receipt. Discordant results were obtained in only 5-25% of specimens, indicating that potential respiratory pathogens could survive storage.

Bacteriological Techniques↗
PubMed1995

The economics of transplantation.

Transplantation continues to be a popular solution for a number of end-stage diseases and survival rates continue to increase. It is, however, an expensive therapeutic option, with the costs persisting throughout a patient's lifetime. It is therefore important to keep sight of these costs in relation to the quality of patient outcome and the emergence of alternative therapies.

Cost-Benefit Analysis↗
PubMed1995

Bilateral sequential lung transplantation for end stage septic lung disease.

BACKGROUND: Bilateral sequential lung transplantation (BSLT) has been widely adopted as an alternative to combined heart and lung transplantation for the management of end stage septic lung disease in many transplant centres. METHODS: A retrospective review was undertaken of the first 32 consecutive patients with septic lung disease to undergo BSLT at the Freeman Hospital. RESULTS: Between April 1988 and October 1994 32 patients underwent BSLT. Survival at 30 days was 85% and actuarial survival at one year was 70%. Improved pulmonary function was seen in all surviving patients. CONCLUSION: BSLT for septic lung disease offers comparable survival to heart-lung transplantation, with excellent functional results. Long term results may be superior because the disadvantages of transplanting the heart are avoided.

Adolescent↗