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Biomedical subjects

John E Moore

Publications and source records attributed to John E Moore.

At least 19 recordsLinked to original sources

Hypersensitivity pneumonitis associated with mushroom worker's lung: an update on the clinical significance of the importation of exotic mushroom varieties.

Hypersensitivity pneumonitis remains an important industrial disease in mushroom workers. It has a significant morbidity, and early diagnosis and removal from exposure to the antigen are critically important in its management. Recently, several new allergens have been described, particularly those from mushroom species originating in the Far East, which are of clinical significance to workers occupationally exposed to such allergens in cultivation, picking, and packing of commercial mushroom crops. Importing of exotic mushrooms including Shiitake is common in EU countries, and some of the exotic species of mushrooms are cultivated for local markets. This practice may contribute to an increase in clinical cases of mushroom hypersensitivity pneumonitis. This update reviews the recent literature and examines changing trends of mushroom worker's lung, with increased movement of commercial product and labour markets worldwide.

Adult↗

A simple and economic preservation method for genomic bacterial DNA from clinically significant pathogens.

Bacterial culture was allowed to dry to completeness on Columbia agar base with defibrinated horse blood. Following 6 months storage at room temperature, microbial DNA was extracted and successfully amplified by PCR. This storage technique has the advantage over other methods of not requiring (i) a DNA extraction protocol prior to storage and (ii) refrigeration and/or freezing. This technique maybe useful in the transportation of bacterial genomic DNA in nonviable cells as well as reliable method for the storage of DNA in underdeveloped countries.

Base Sequence↗

Ribosomal DNA (rDNA) identification of the culturable bacterial flora on monetary coinage from 17 currencies.

The aim of the investigation reported in this paper was to identify the bacterial microflora on monetary coinage from 17 countries by employment of polymerase chain reaction (PCR) sequenced-based molecular identification of rDNA from bacterial cultures. Silver, bronze, and other alloy coins (approximately 300 g) from 17 currencies were enriched individually by aerobic culturing in tryptone soya broth for 72 hours at 30 degrees C. Next, 20 microL of broth was inoculated onto Columbia blood agar supplemented with 5 percent volume-pervolume (v/v) defibrinated horse blood for 72 hours at 30 degrees C, and resulting colonies were purified by further subculture, as detailed above, for a further 72 hours. All colonies were identified by initial PCR amplification of a partial region of the 16S rDNA gene locus, which was then sequenced, and the sequence was aligned according to the BLASTn algorithm. Twenty-five isolates were obtained from the coinage; of these, 25 (100 percent) were Gram positive, and the most prevalent genus observed was Bacillus (B. megaterium, B. lentus, B. litoralis, B. subtilis, B. circulans and other Bacillus spp.), which accounted for 10 of 25 isolates (40 percent) and was isolated from 10 of 17 countries (58.8 percent). It was followed in prevalence by Staphylococcus spp. (Staph. aureus, Staph. epidermidis, Staph. hominis, Staph. schleiferi), which accounted for 7 of 25 isolates (28 percent) and were isolated from 7 of 17 countries (41.2 percent). Given the organisms identified in this study, it is not believed that monetary coinage presents any particular risk to public health. The authors support the principles of basic hygiene, however, in terms of proper handwashing and the avoidance of handling money when working with food or dressing wounds and skin lesions, In conclusion, the study demonstrated that money from 17 countries was contaminated by environmental Gram-positive flora, in particular Bacillus spp., and that the universal 16S rDNA-PCR approach coupled with automated direct sequencing provides a rapid means of identifying the contaminant organisms present.

Bacteria↗

Organisms isolated from adults with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis [CF] have frequent pulmonary exacerbations associated with the isolation of bacterial organisms from sputum samples. It is not clear however, if there are differences in the types of additional organisms isolated from patients who are infected with Burkholderia cepacia complex [BCC] or Pseudomonas aerugionsa [PA] in comparison to those who are not infected with either of these organisms [NI]. METHODS: Adult patients attending the regional CF unit were followed over a two year period and patients were assigned to three groups depending on whether they were known to be chronically infected with BCC, PA or NI. We compared the numbers and types of organisms which were isolated in each of these groups. RESULTS: Information was available on a total of 79 patients; BCC 23, PA 30 and NI 26. Total numbers of organisms isolated, expressed as median and IQR for each group, [P = 0.045] and numbers of co-infecting organisms [P = 0.003] were significantly higher in the BCC group compared to PA, and in the PA group [P < 0.001, p = 0.007 respectively] compared to NI patients. The pattern of co-infecting organisms was similar in all three groups. CONCLUSIONS: Total numbers of organisms isolated and numbers of co-infecting organisms were significantly higher in the BCC group compared to PA, and in the PA group compared to NI patients. Types of co-infecting organisms are similar in all groups of patients.

Journal Article↗

Early detection of Pseudomonas aeruginosa--comparison of conventional versus molecular (PCR) detection directly from adult patients with cystic fibrosis (CF).

BACKGROUND: Pseudomonas aeruginosa (PA) is the most important bacterial pathogen in patients with cystic fibrosis (CF) patients. Currently, routine bacteriological culture on selective/non- selective culture media is the cornerstone of microbiological detection. The aim of this study was to compare isolation rates of PA by conventional culture and molecular (PCR) detection directly from sputum. METHODS: Adult patients (n = 57) attending the regional adult CF centre in Northern Ireland, provided fresh sputum following airways clearance exercise. Following processing of the specimen with sputasol (1:1 vol), the specimen was examined for the presence of PA by plating onto a combination of culture media (Pseudomonas isolation agar, Blood agar & McConkey agar). In addition, from the same specimen, genomic bacterial DNA was extracted (1 ml) and was amplified employing two sequence-specific targets, namely (i) the outer membrane protein (oprL) gene locus and (ii) the exotoxin A (ETA) gene locus. RESULTS: By sputum culture, there were 30 patients positive for PA, whereas by molecular techniques, there were 35 positive patients. In 39 patients (22 PA +ve & 17 PA -ve), there was complete agreement between molecular and conventional detection and with both PCR gene loci. The oprL locus was more sensitive than the ETA locus, as the former was positive in 10 more patients and there were no patients where the ETA was positive and the oprL target negative. Where a PCR +ve/culture -ve result was recorded (10 patients), we followed these patients and recorded that 5 of these patients converted to being culture-positive at times ranging from 4-17 months later, with a mean lag time of 4.5 months. CONCLUSIONS: This study indicates that molecular detection of PA in sputum employing the oprL gene target, is a useful technique in the early detection of PA, gaining on average 4.5 months over conventional culture. It now remains to be established whether aggressive antibiotic intervention at this earlier stage, based on PCR detection, has any significant benefits on clinical outcome.

Journal Article↗

Infection control and the significance of sputum and other respiratory secretions from adult patients with cystic fibrosis.

BACKGROUND: There is limited data available on the environmental and public health impact of the microbiological hazards associated with sputa from patients with cystic fibrosis [CF]. Pseudomonas aeruginosa, Burkholderia cenocepacia (formerly Burkholderia cepacia genomovar III), Staphylococcus aureus and Stenotrophomonas maltophilia are bacterial pathogens which are commonly found in the sputum of CF patients. A study was performed to ascertain the amount of sputum produced relating to microbial loading, as well as the diversity of bacteria present in a population of adult patients, with particular attention to pathogenic organisms. METHODS: Sputum from adult [>18 years old] CF patients [n = 20], chosen randomly from a population of 138 CF patients, was collected over a 24 h period on admission to the in-patient CF unit and enumerated quantitatively, as well as the sputa from 138 adult CF patients was examined qualitatively for the presence of infecting microflora. In addition, all different phenotypes from the sputum of each patient were identified phenotypically employing a combination of conventional identification methods [e.g. oxidase], as well as the API Identification schemes [API 20 NE, API 20 E]. RESULTS: This study demonstrated that patients with cystic fibrosis generate large numbers of bacteria in their sputum, approximating to 10(9) organisms per patient per day. Although these organisms are introduced to the environment from the respiratory tract mainly via sputum, relatively few represent true bacterial pathogens and therefore are not clinically important to the general public who are immunocompotent. The greatest risk of such environmental microbial loading is to other patients with CF and therefore CF patients should be made aware of the hazards of acquiring such organisms from the environment, as well as socializing with other CF patients with certain transmissible types, such as Pseudomonas aeruginosa and Burkholderia cenocepacia. CONCLUSIONS: Environmental health professionals should therefore be aware that CF patients are a greater risk to their peer grouping rather than to the general public or health care workers and that good personal hygiene practices with CF patients should be encouraged to minimize environmental contamination and potential acquisition.

Journal Article↗

Continuous curvilinear capsulorhexis with use of an endoscope.

We describe a technique for creating a continuous curvilinear capsulorhexis (CCC) using an endoscope. Three 2.0 mm limbal incisions 120 degrees apart were made in 4 cadaver eyes. The anterior capsule was stained with trypan blue 0.1% (Vision Blue). Under endoscopic visualization, a CCC was attempted in each of the 4 globes. It was completed in 1 of them. Endoscopy provides a safe and effective tool to visualize the anterior chamber and perform a CCC when there is a poor view through the cornea.

Capsulorhexis↗

Molecular cloning, nucleotide sequencing and characterization of the flagellin gene from isolates of urease-positive thermophilic Campylobacter.

A primer pair which was expected to generate an amplicon of the estimated size (approximately 1700 base pair (bp)) of the flaA gene for Campylobacter jejuni amplified products of approximately 1450 bp for 33 of the 44 isolates of urease-positive thermophilic Campylobacter (UPTC). The primer pair, however, failed to amplify fragments for 11 isolates of UPTC, for all of the 12 isolates of urease-negative C. lari and for one isolate of C. coli. Nevertheless, it successfully amplified fragments of approximately 1700 bp for five isolates of C. jejuni and for nine isolates of C. coli. Thus, the fragments of the flaA gene of UPTC were shorter than those of C. jejuni and C. coli. After PCR amplification and nucleotide sequencing of the flaA genes from five UPTC NCTC isolates, the putative open reading frames (ORFs) were found to range from 1461 to 1479 bp. The amino acid and nucleotide sequence alignments demonstrated that the PCR clones contained the flaA gene; however, our data indicated that this locus was markedly shorter in the UPTC organisms examined, as they were approximately 85 amino acid residues shorter, mainly corresponding to approximate residue numbers 390-470 of the large variable region of C. jejuni 81116. Heterogeneity was indicated in the molecular mass of the flagellin purified from the isolates examined. Flagellin of UPTC was demonstrated to be genotypically and phenotypically smaller than those of C. jejuni.

Amino Acid Sequence↗

Improved laboratory diagnosis of bacterial and fungal infections in patients with hematological malignancies using PCR and ribosomal RNA sequence analysis.

During October 1999 to November 2000, 98 blood culture specimens from the same number of febrile episodes originating from 49 patients with hematological malignancies were examined for the presence of eubacteria and fungi based on 16S rRNA gene and the 5.8, 18 and 28S rRNA combined with in vitro PCR amplification and sequencing, in addition to conventional blood culture laboratory techniques. Nineteen of the samples were associated with positive blood cultures. Eubacterial (16S rRNA) PCR detected bacterial DNA in 26 febrile episodes, i.e. in an additional 7 febrile episodes than blood-culture alone. The species identified by partial 16S rRNA gene sequencing were as follows Staphylococcus spp (n = 6), Staphylococcus epidermidis (n = 5), Acinetobacter spp (n = 5), Escherichia coli (n = 2), Enterobacter agglomerans (n = 2), Campylobacter spp (n = 1), Citrobacter spp (n = 1), Corynebacterium spp (n = 1), Enterobacter faecium (n = 1), Ralstonia spp (n = 1), Acidovorax spp. (n = 1) and Stenotrophomonas maltophilia (n = 1). Gram-positive bacteria were found in 12/27 (44.6%) and gram-negative bacteria were found in 15/27 (55.6%). After optimization of a PCR-based fungal detection method, none of the febrile episodes were shown to be attributable to fungi. The results of this study suggest that fungi are not common causal agents of febrile episodes in patients with a hematological malignancy at this centre and that molecular techniques can augment cultural methods in the diagnosis of causal agents of bacteremia in patients, so that appropriate antibiotic regimens may be commenced in patients with culture-negative episodes of infection.

Adolescent↗

Epidemiology of Burkholderia cepacia complex species recovered from cystic fibrosis patients: issues related to patient segregation.

Studies of the prevalence of Burkholderia cepacia complex species amongst cystic fibrosis (CF) patients in different geographical regions, and the association between cross-infection and putative transmissibility markers, will further our understanding of these organisms and help to address infection-control issues. In this study, B. cepacia complex isolates from CF patients in different regions of Europe were analysed. Isolates were examined for B. cepacia complex species and putative transmissibility markers [cable pilin subunit gene (cblA) and the B. cepacia epidemic strain marker (BCESM)]. Sporadic and cross-infective strains were identified by random amplification of polymorphic DNA (RAPD). In total, 79% of patients were infected with Burkholderia cenocepacia (genomovar III), 18% with Burkholderia multivorans (genomovar II) and less than 5% of patients with B. cepacia (genomovar I), Burkholderia stabilis (genomovar IV) or Burkholderia vietnamiensis (genomovar V). The cblA and BCESM transmissibility markers were only detected in strains of B. cenocepacia. The BCESM was a more sensitive marker for transmissible B. cenocepacia strains than cblA, although sporadic B. cenocepacia strains containing the BCESM, but lacking cblA, were also observed. Furthermore, clusters of cross-infection with transmissibility marker-negative strains of B. multivorans were identified. In conclusion, B. cenocepacia was the greatest cause of cross-infection, and the most widely distributed B. cepacia complex species, within these CF populations. However, cross-infection was not exclusive to B. cenocepacia and cblA and the BCESM were not absolute markers for transmissible B. cenocepacia, or other B. cepacia complex strains. It is therefore suggested that CF centres cohort patients based on the presence or absence of B. cepacia complex infection and not on the basis of transmissibility marker-positive B. cenocepacia as previously suggested.

Bacterial Typing Techniques↗

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↗

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↗