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Biomedical subjects

John E Moore

Publications and source records attributed to John E Moore.

At least 55 records · Page 3Linked to original sources
PubMed2004

Molecular diagnostics: current options.

Diagnostic medical bacteriology consists of two main components: identification and typing. Molecular biology has the potential to revolutionize the way in which diagnostic tests are delivered in order to optimize the care of infected patients, whether they are in hospital or in the community. Since the discovery of the polymerase chain reaction (PCR) in the late 1980s, an enormous amount of research has enabled the introduction of molecular tests into several areas of routine clinical microbiology. Molecular biology techniques continue to evolve rapidly, and many laboratories have been reluctant to introduce these new methods due to concerns that the technology would become outdated. In consequence, the vast majority of clinical bacteriology laboratories do not currently use any molecular diagnostics, although such technology is becoming more widespread in specialized regional laboratories, as well as in national reference laboratories. Presently, molecular biology offers a wide repertoire of techniques and permutations. This chapter is intended to explore the application of these in the diagnostic laboratory setting.

Bacteria↗
PubMed2004

Emerging issues in infective endocarditis.

Infective endocarditis, a serious infection of the endocardium of the heart, particularly the heart valves, is associated with a high degree of illness and death. It generally occurs in patients with altered and abnormal heart architecture, in combination with exposure to bacteria through trauma and other potentially high-risk activities involving transient bacteremia. Knowledge about the origins of endocarditis stems from the work of Fernel in the early 1500s, and yet this infection still presents physicians with major diagnostic and management dilemmas. Endocarditis is caused by a variety of bacteria and fungi, as well as emerging infectious agents, including Tropheryma whiplei, Bartonella spp., and Rickettsia spp. We review the evolution of endocarditis and compare its progression with discoveries in microbiology, science, and medicine.

Endocarditis, Bacterial↗
PubMed2003

Antibiotic prophylaxis, body piercing and infective endocarditis.

Infective endocarditis (IE) is associated with a high degree of morbidity and mortality and generally presents in patients with altered and abnormal heart architecture combined with exposure to bacteria through trauma and other potentially high-risk activities, including body piercing. Modern social behaviour has resulted in increased popularity of the practice of body piercing, particularly amongst the adolescent population and there has been a marked rise of cases of IE directly attributable to this practice. In this article we wish to examine the aetiology of such cases reported in the literature, with particular emphasis on causal organism, as well as to discuss the role of antibiotic prophylaxis and awareness in such at-risk patients within the primary care community.

Adolescent↗
PubMed2003

Recent advances in molecular epidemiology and detection of Taylorella equigenitalis associated with contagious equine metritis (CEM).

In the present review article, recent molecular advances relating to studies with Taylorella equigenitalis, as well as the recently described second species of the genus Taylorella, namely Taylorella asinigenitalis, have been described. Molecular genotyping of T. equigenitalis strains by pulsed-field gel electrophoresis (PFGE) after digestion with the suitable restriction enzyme(s) enabled the effective discrimination of strains, thus allowing the examination of the scientific mechanism(s) for its occurrence and transmission of contagious equine metritis (CEM). Alternatively, polymerase chain reaction (PCR) amplification and nucleotide sequencing of the 16S ribosomal DNA sequence and/or the other species specific sequence(s) as targets were confirmed to be effective for identification of T. equigenitalis. These new analytical methods at the genomic DNA level also enabled the discrimination of the newly discovered donkey-related T. asinigenitalis from T. equigenitalis, and moreover, the performance of phylogenetic analysis of genus Taylorella organisms with other closely related genera. Furthermore, detailed analysis of the genes responsible for CEM within the T. equigenitalis genome would be useful to help elucidate the pathogenic virulence and transmission mechanisms associated with the important equine pathogen associated with CEM.

Animals↗
PubMed2003

Comparison of phenotypic and genotypic characteristics of Salmonella bredeney associated with a poultry-related outbreak of gastroenteritis in Northern Ireland.

OBJECTIVES: To employ a combination of phenotypic and genotypic subspecies typing methods to aid in an epidemiological investigation of an outbreak of Salmonella bredeney involving ten persons. METHODS: Isolates were characterised by employing antibiogram typing, in addition to two genotyping techniques, including pulsed field gel electrophoresis (PFGE), random amplification of polymorphic DNA (RAPD) with two oligonucleotide primers. RESULTS: An outbreak of gastroenteritis associated with S. bredeney (serovar O:4 H:Lv 1,7) occurred in Belfast, Northern Ireland in November 1997. In total, ten cases were confirmed, of which eight had consumed chicken cooked at local butchers and retailed through one of two local bakeries. One of the remaining cases was secondarily infected within her home and the final case had eaten a product other than cooked chicken from one of the bakeries. Food preparation practices were inadequate in one of the bakeries in question and record keeping and possibly cooking procedures were inadequate in the butchers. S. bredeney was isolated from an uncooked chicken supplied to the butchers confirming that improperly cooked chicken was most likely the source of the outbreak. All outbreak clinical isolates were indistinguishable from each other and were similar to the isolate obtained from the uncooked poultry demonstrating that these DNA-based methods were valuable in the molecular characterization of S. bredeney. CONCLUSIONS: This report emphasises the importance and maintenance of an effective hazard analysis critical control point (HACCP) approach to the processing and retailing of foodstuffs containing chicken in order to help eliminate hazards to public health.

Adult↗
PubMed2003

Identification of a novel alpha-proteobacterium causing bacteraemia in an immunocompetent patient.

An 89-year male with pyrexia and suspected bacteremia was admitted to hospital, where a Gram-negative rod was identified from blood culture. The organism was difficult to identify phenotypically and the resulting sequencing of a 559 bp section of the 16S rRNA gene did not have a high homology score (>97.0%) with any deposited GenBank accession numbers and hence was not able to be assigned to a species within any genus. Given that the isolate was a member of the alpha subclass of the Proteobacteria but did not fall into any of the known genera with more than 93.7% homology (Brucella, Rhizobium, Ochrobactrum, Agrobacterium), we believe this isolate to represent a novel alpha-proteobacterium, which was the cause of bacteraemia in this patient.

Aged↗
PubMed2003

Isolation of Alternaria alternata from an emollient cream: implications for public health.

A specimen of emollient cream, which was observed to be contaminated peripherally with a filamentous fungus was examined for the presence of fungi and the resulting fungal colonies were examined phenotypically and genotypically. Subsequent DNA extraction and PCR amplification of the large internal transcribed spacer region [ITS1-5.8S-ITS2] yielded an amplicon of 512 bp. Sequence analysis identified this as Alternaria alternata at the 100% homology level with all 512/512 bases called. This organism has been previously reported as a cause of opportunistic infections involving skin and immunocompromised patients. This is the first report of an emollient cream as a source of this organism. It highlights the need for proper management of such preparations in order to minimize the potential spread of fungi to susceptible patient populations.

Alternaria↗
PubMed2003

Phenotypic and genotypic relationship between Campylobacter spp isolated from humans and chickens in Northern Ireland--a comparison of three phenotyping and two genotyping schemes.

Human campylobacteriosis is currently the most common cause of acute bacterial gastroenteritis on the island of Ireland, accounting for over 3,000 laboratory reports per year, where circa 2,000 reports originate from the Republic of Ireland and circa 1,000 reports from Northern Ireland. Elsewhere, consumption of contaminated poultry has been associated with the zoonotic transmission of disease, therefore it was the aim of this study to examine the phenotypic and genotypic relatedness of campylobacters isolated from chickens and humans locally. Sixty isolates were subtyped using phenotyping techniques (biotyping, phage-typing), as well as genotyping techniques (multilocus enzyme electrophoresis (MEE), ribotyping) and the data compared. The frequency of shared phenotypes and genotypes between poultry and humans varied depending on the typing technique employed ranging from 98.2% of human isolates sharing a similar resistotyping (MAST) disc type with poultry strains to 20% similarity with MEE typing. Overall, this small study is the first report on phenotypic and genotypic relatedness between human and poultry campylobacters in Northern Ireland, isolated under controlled conditions. The study demonstrated an association between chicken and human sub-species types, taken from a relatively contained epidemiological environment. Further work is required with larger numbers of isolates coupled with typing schemes, which are able to reliably cluster strains from chicken and humans, which share high degrees of clonality, before local poultry can be conclusively proven to be a significant source of human campylobacteriosis.

Animals↗
PubMed2003

Development of a diagnostic PCR assay that targets a heat-shock protein gene (groES) for detection of Pseudomonas spp. in cystic fibrosis patients.

Laboratory detection of Pseudomonas spp., in particular Pseudomonas aeruginosa, remains an important assay in the management of patients with cystic fibrosis (CF). As the groES and groEL genes of P. aeruginosa have now been cloned and their nucleotide sequences determined, the aim of this study was to develop a novel PCR assay for the detection of Pseudomonas spp. from patients with CF by employing conserved primer regions of the groE heat-shock protein domain gene. A PCR assay was designed that targeted a 536 bp region of the groE gene to detect Pseudomonas spp. PCR amplification of genomic DNA from extracted organisms generated an amplicon of the expected size (approx. 536 bp) for all P. aeruginosa (n = 60), Pseudomonas putida, Pseudomonas fluorescens and Pseudomonas stutzeri isolates examined, but did not produce a positive amplicon for several other genera and species that are commonly isolated from the sputum of CF patients. RFLP analysis of the amplicons of all P. aeruginosa isolates demonstrated a single RFLP type that consisted of three bands at approximately 80, 190 and 250 bp; direct sequencing of the amplicons demonstrated the presence of a single sequence type, indicating the highly conserved nature of this region. In addition, the assay successfully produced a positive signal from primary non-selective plates of three known P. aeruginosa culture-positive CF patients, but was unable to generate a signal in a further six CF patients who had no history of infection with P. aeruginosa or other Pseudomonas spp. This assay is recommended to detect the presence of Pseudomonas spp., including P. aeruginosa, from primary culture plates that originate from laboratory analysis of CF patients' sputum, particularly at review, in those patients with no previous history of Pseudomonas infection or those who appear to be transiently colonized by this organism. Employment of such molecular methodologies, in conjunction with routine clinical sputum cultures, may provide improved information on the microbial status of CF patients, which will aid clinicians in both optimum patient management in terms of antibiotic regimes and CF centre infection-control practices.

Adolescent↗
PubMed2003

Characterization of urease-positive thermophilic Campylobacter subspecies by multilocus enzyme electrophoresis typing.

Thirty-one urease-positive thermophilic Campylobacter (UPTC) isolates, including three reference strains (NCTC12892, NCTC12895 and NCTC12896), and three Campylobacter lari isolates, which were isolated from several countries and sources, were compared genotypically by using multilocus enzyme electrophoresis (MLEE). We examined allelic variation around seven enzyme loci, including the adenylate kinase, alkaline phosphatase, catalase, fumarase, malic enzyme, malate dehydrogenase, and L-phenylalanyl-L-leucine peptidase loci. MLEE typing revealed the presence of 23 different electrophoretic types (ETs) among the 31 UPTC isolates, and 14 isolates shared six electrophoretic profiles. Three different ETs were identified for the three C. lari isolates examined, and no ETs were shared by UPTC and C. lari isolates. Quantitative analyses were subsequently performed by using allelic variation data, and the results demonstrated that the mean genetic diversity was 0.655. In conclusion, MLEE demonstrated that the UPTC isolates examined are genetically hypervariable and form a cluster separate from the C. lari cluster.

Bacterial Typing Techniques↗
PubMed2003

False identification of Coccidioides immitis: do molecular methods always get it right?

rRNA sequence analysis of a partial region of the 18S and 5.8S-internal transcribed spacer 2 (ITS2) region of Chrysosporium keratinophilum highlights its potential molecular misidentification as Coccidioides immitis. Molecular identification of medically important fungi should not be based solely on sequence analysis of the 18S rRNA gene but should be confirmed by sequence analysis of an additional rRNA gene locus, such as the ITS region(s).

Base Sequence↗