Non-culturable Haemophilus influenzae meningitis identified by 16S rDNA PCR and sequencing.
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Diagnosis, Differential↗
Biomedical subjects
J E Moore
Publications and source records attributed to J E Moore.
Detection of mycobacterial DNA from sputum of patients with cystic fibrosis.
BACKGROUND: Patients with cystic fibrosis (CF) are at high risk from atypical mycobacterial infections. There have been few attempts to delineate the intensity of mycobacterial infection in CF patients in Ireland. AIMS: To examine the incidence of mycobacterial DNA in an archived collection of genomic DNA extracted from the sputa of CF patients within the Northern Ireland population. METHODS: One hundred and eighty-two CF patients (66 adults and 116 children) were examined for the presence of mycobacterial DNA in their sputum by a genus specific PCR assay based on 16S rRNA, followed by direct automated sequencing of the PCR amplicons. RESULTS: One of 116 (0.9%) children and 2 of 66 adults were positive. Sequence identity revealed Mycobacterium xenopi in the paediatric patient and M. xenopi and M. chelonei in the two adult patients. False-positive results occurred in 11 patients (four adults), mainly due to Corynebacterium spp. CONCLUSIONS: There was a low prevalence of Mycobacterium spp in the CF patient population. All PCR positive results should be confirmed by direct automated sequencing and an alternative specific assay employed. Enhanced molecular screening will contribute in understanding their role as opportunistic pathogens in patients with worsening lung function.
Adult↗
Comparison of media for optimal recovery of Candida albicans and Candida glabrata from blood culture.
BACKGROUND: Candida spp., mainly Candida albicans, are frequently responsible for complications in immunocompromised patients. There are limited data comparing recovery efficiency using simple non-selective basal broth media. AIM: To compare several commercially available basal growth media to determine the medium that gave highest yeast proliferation. METHOD: Eight commercially available non-selective basal broth culture media were evaluated for optimum recovery of clinical C. albicans and C. glabrata. They included nutrient broth (NB), nutrient broth no. 2 (NB2), Todd-Hewitt (TH) broth, tryptone soya broth (TSB), tryptone soya broth supplemented with yeast extract (0.5% w/v [TSBYE]), brain heart infusion broth supplemented with yeast extract (0.5% w/v [BHIYE]), salt meat broth (SMB) and 0.1% [w/v] peptone saline (PS). Differences in cell density were evaluated by spectrophotometrical analysis. RESULTS: TSBYE>BHIYE>TSB>TH>NB2>NB>SMB>PS for the optimum proliferation of cells in vitro. Either TSBYE or BHIYE broth may be employed as suitable basal broth media for growth of C. albicans and C. glabrata. NB should be considered the least suitable medium for routine use when others are available. CONCLUSION: These data may be of value to laboratories setting up simple blood culture systems to detect Candida spp., particularly in developing and underdeveloped countries.
Blood↗
Comparison of human and porcine strains of Campylobacter coli.
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Animals↗
Body piercing and endocarditis in children.
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Antibiotic Prophylaxis↗
Comparison of basal broth media for the optimal laboratory recovery of Campylobacter jejuni and Campylobacter coli.
BACKGROUND: Campylobacter species are the most common known bacterial cause of acute diarrhoeal disease and incidences are increasing yearly in Ireland. Concern is expressed that this increase may be due to poor laboratory techniques in recognising these organisms as they are fastidious and technically demanding to culture. AIMS: To evaluate and compare the efficacy of seven commercially available basal broth media for the laboratory cultivation of thermophilic C. jejuni and C. coli isolated from foods and clinical specimens, as well as for optimal laboratory passage. METHODS: Four strains of Campylobacter spp., including two C. jejuni and two C. coli isolated from pigs were used to compare the quantitative growth of cells on seven commercially available basal culture broths. These included nutrient broth (NB), nutrient broth no. 2 (NB2), Mueller-Hinton broth (MH), brucella broth (BB), brain heat infusion broth supplemented with 0.6% (w/v) yeast extract (BHIYE), tryptone soya broth supplemented with 0.6% (w/v) yeast extract (TSBYE) and Campylobacter broth (KAMPY) employing a spectrophotometrical growth assay model. RESULTS: Mean absorbance results of the broth media comparison for each strain and statistical analysis of variance allowed the basal media to be ranked into the order, based on proliferation of organisms: BHIYE > TSBYE > BB > NB2 > MHB > KAMPY > NB CONCLUSION: These studies support laboratory employment of either BHIYE or TSBYE for optimal recovery of C. jejuni and C. coli and avoidance of nutrient broth.
Bacteriological Techniques↗
Molecular genotyping of human cryptosporidiosis in Northern Ireland: epidemiological aspects and review.
BACKGROUND: Cryptosporidium parvum is the most common of the protozoal pathogens associated with gastrointestinal disease in Northern Ireland. Genotyping techniques are valuable in helping to elucidate sources and modes of transmission of this parasite. There have been no reports on the prevalence of genotypes in Northern Ireland, mainly due to a lack of discriminatory genotyping techniques, which recently have become available. AIM: To investigate the genotype of C. parvum oocysts isolated from human faeces in sporadic cases of cryptosporidiosis in Northern Ireland. METHODS: Thirty-nine isolates of C. parvum, representing 79.6% of the total 1998 laboratory reports for the Eastern Health and Social Services Board, were investigated. Following DNA extraction from oocysts the thrombospondin-related adhesive protein 2 (TRAP-C2) locus was amplified by polymerase chain reaction (PCR) and subsequently sequenced. RESULTS: The majority of isolates (87.2%) were classified as bovine genotype II with the remainder (12.8%) being the human genotype I. CONCLUSIONS: There is a high prevalence of the bovine genotype II parasite in sporadic cases around the greater Belfast area. Epidemiologically, this suggests that the most frequent mode of transmission may be from animals to humans, but does not suggest a high proportion of human to human spread.
Adolescent↗
Molecular characterisation of human campylobacteriosis in Northern Ireland: evidence of clonal stability.
BACKGROUND: No study has compared Campylobacter isolates from a human source in Northern Ireland over an extended period of time. AIM: To investigate the clonal stability of thermophilic campylobacters isolated from acute bacterial enteritis in Northern Ireland from 1992 to 1999. METHODS: Human isolates (n=272), originating from faeces, were characterised at the sub-species level using enterobacterial repetitive intergenic consensus sequence (ERIC2)--random amplification of polymorphic DNA (RAPD) typing. RESULTS: Thirteen genotypes were identified where three types, namely ERIC A, ERIC C and ERIC I, accounted for 28.3%, 14.3% and 13.6%, respectively. There were no significant associations (p>0.05) between sex, age groupings and year of isolation and ERIC2 genotype, with the exception of ERIC D, which showed a significant decline in isolation with time (p=0.019). CONCLUSIONS: ERIC genotypes were stable over this period, except genotype C which was lost during this time. Previous molecular typing methods showed campylobacters to be heterogeneous but this study suggests that the local human Campylobacter population consists of several common and stable genotypes. This study has established a database of local ERIC2 genotypes. This methodology may allow the establishment of an all-island database of clinical campylobacters that would be valuable in reducing human campylobacteriosis in Ireland.
Campylobacter↗
Cystic fibrosis and guidelines to assess significance of new colonisers?
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Adult↗
Occurrence of Burkholderia cepacia in the hospital environment.
AIM: To determine the prevalence of Burkholderia cepacia from the environment in a regional adult cystic fibrosis (CF) care centre. METHODS: Two hundred and eighty-five environmental samples were taken from inpatient and outpatient environments within the CF centre. Following a non-selective enrichment step, broths were plated onto a selective medium and B. cepacia isolates were confirmed by phenotypic tests and also genotypically by species specific 16S rRNA PCR. RESULTS: B. cepacia was not detected from commonly shared items of equipment, staff hands, staff uniforms or toilets. In addition, the organism was not detected in toilet bowls, even in the B. cepacia unit. With regard to positive environments for B. cepacia, 4/10 (40%) of the outside surfaces and inner rims of patients' plastic disposable sputum collection containers and 4/17 (23.5%) of air from patients' rooms, following physiotherapy, were positive. CONCLUSIONS: All positive samples originated in the B. cepacia segregation area of the inpatient wards and B. cepacia was not detected in the non-cepacia area of the CF centre. Consequently, these two positive sites should therefore be treated as high risk, where organisms may be potentially transmitted from environment to patient. As there is now evidence to suggest differences in the virulence and hence clinical outcome of certain of the genomovars of this organism, this study may be important in highlighting the areas that patients who are B. cepacia positive should avoid, to minimise the risk of transmission and acquisition of this organism within the CF cepacia population. These results indicate that effective infection control procedures are required in patients' rooms following physiotherapy, for prevention of B. cepacia transmission and to avoid the transmission of different genomovar types within CF patients, who are already colonised with this pathogen.
Air Microbiology↗
Fungal endocarditis in neonates and children.
Fungal endocarditis in the neonate and pediatric population is associated with a high degree of morbidity and mortality, with diagnosis in the majority of cases made postmortem. The aim of this article is to review published literature on fungal endocarditis in children and to discuss the incidence due to a wide range of fungi, primarily Aspergillus and Candida species, as well as its diagnosis, including the importance of molecular-based approaches and various treatment regimes.
Adolescent↗
Analysis of the strain and stress distribution in the wall of the developing and mature rat aorta.
The variation of wall stress distribution with age in the thoracic and abdominal aortas of normotensive rats was studied. Dimensions of the zero-stress configurations were measured at the ages of 4, 8, 12, 20, and 52 weeks. Using data from previously published inflation tests, the circumferential stress-strain relationship was obtained in each age group. The calculated stress distribution showed that the average circumferential stress remained practically constant after the age of 20 weeks. The circumferential stress at the innermost part of the arterial wall was greater than the stress at the outermost part, but the difference was maintained at a moderate level with adjustments in the zero-stress configuration. It is speculated that, after the age of 20 weeks, changes in arterial geometry and rheological properties tend to maintain a constant stress distribution under varying conditions of loading. This distribution was achieved by enhanced growth at the inner part of the media in comparison with the growth at its outer margins and suggests that during development and maturity, the growth of the aorta is modulated by circumferential stress.
Aging↗
The effect of blood viscoelasticity on pulsatile flow in stationary and axially moving tubes.
An analytical solution for pulsatile flow of a generalized Maxwell fluid in straight rigid tubes, with and without axial vessel motion, has been used to calculate the effect of blood viscoelasticity on velocity profiles and shear stress in flows representative of those in the large arteries. Measured bulk flow rate Q waveforms were used as starting points in the calculations for the aorta and femoral arteries, from which axial pressure gradient delta P waves were derived that would reproduce the starting Q waves for viscoelastic flow. The delta P waves were then used to calculate velocity profiles for both viscoelastic and purely viscous flow. For the coronary artery, published delta P and axial vessel acceleration waveforms were used in a similar procedure to determine the separate and combined influences of viscoelasticity and vessel motion. Differences in local velocities, comparing viscous flow to viscoelastic flow, were in all cases less than about 2% of the peak local velocity. Differences in peak wall shear stress were less than about 3%. In the coronary artery, wall shear stress differences between viscous and viscoelastic flow were small, regardless of whether axial vessel motion was included. The shape of the wall shear stress waveform and its difference, however, changed dramatically between the stationary and moving vessel cases. The peaks in wall shear stress difference corresponded with large temporal gradients in the combined driving force for the flow.
Aorta↗
Meeting the health care needs of the elderly.
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Health Services for the Aged↗
Possible misidentification of Bacteroides sp., probably B. ureolyticus as Taylorella equigenitalis: implications for the laboratory diagnosis of CEM.
A wild-type isolate with similar morphological and phenotypic properties to Taylorella equigenitalis, the causative bacterial agent of contagious equine metritis (CEM), was referred for molecular identification by PCR amplification of the 16S rRNA gene. A species-specific PCR failed to yield a product compatible with that of T. equigenitalis. The direct sequencing of the universal 16S rRNA PCR amplicon suggested the presence of a Bacteroides sp., probably Bacteroides ureolyticus, with no consequent effects on the movement and transportation of the animal. Adoption of such a molecular means of identification through sequencing may aid in the identification of the atypical forms of Taylorella equigenitalis, as recently described, as well as differentiating this species from Taylorella asinigenitalis.
Animals↗
The corneal epithelial stem cell.
The aim of this paper was to develop a GFP-expressing transgenic mouse model for the keratoepithelioplasty and to use this to follow the outcome of this form of graft, when placed on an inflamed corneal surface. Further aims were to characterize both the graft and the epithelial surface of the mouse and rat cornea using putative stem cell markers (P63 and Telomerase) and marker of cell differentiation (14-3-3 sigma). Keratepithelioplasty was carried out using a GFP transgenic mouse cornea as donor tissue. Fluorescent epithelial outgrowth from each keratepithelioplasty was scored and quantified. Donor corneal graft tissue was obtained from the paracentral region or the anatomical limbal region of murine corneas. Paracentral donor grafts (n = 20) consistently demonstrated a significant increase in proliferative potential compared to grafts obtained from the anatomical limbal region of the mouse cornea (n = 25) (P = 0.000, Mann-Whitney U). Correspondingly, P63 expression was maximal in the paracentral region of the mouse cornea, in keeping with the demonstrated increased proliferative potential of donor grafts harvested from this region of the cornea. The murine corneal epithelium demonstrated decreased rather than increased cellular layers at the limbal region, in contrast to that of the rat or human epithelium. In addition, as a general finding in all species tested, there was an apparent increase noted in P63 expression in basal corneal epithelial cells in regions that had increased cellular layers (limbus in humans and rats and the paracentral corneal region in the mouse). Epithelium, which had migrated from donor grafts onto recipient corneas, retained P63 expression for the period of time examined (up to 3 days postengraftment). In addition, the conjunctival surface of an injured conjunctivalized displayed an abnormal pattern of P63 expression. Telomerase expression was widespread throughout many layers of both the murine and rat corneal epithelium. In the mouse and rat corneal epithelium P63 expression was maximal in areas of increased proliferative potential. Its expression, however, was not confined to stem cells alone. Migrating cells from transplanted keratoepithelial grafts retained P63 expression at least in the early stages post-transplantation. Finally, damaged conjunctivalized corneas displayed an abnormal P63 expression pattern when compared to either normal conjunctiva or normal cornea.
14-3-3 Proteins↗
Computational analysis of flow in a curved tube model of the coronary arteries: effects of time-varying curvature.
The flow through a curved tube whose radius of curvature varies with time was studied in order to better understand flow patterns in coronary arteries. A computational flow model was constructed using commercially available software. The artery model featured a uniform circular cross section, and the curvature was assumed to be constant along the tube, and in one plane. The computational model was verified with the use of a dynamically similar in vitro apparatus. A steady uniform velocity was prescribed at the entrance at a Reynolds number of 300. Two sets of results were obtained: one in which the curvature was held constant at the mean, maximum and minimum radii of curvature (quasistatic), and another in which the curvature was varied sinusoidally in time at a frequency of I Hz (dynamic). The results of the dynamic analysis showed that the wall shear rates varied as much as 52% of the static mean wall shear rate within a region of 10 tube diameters from the inlet. The results of the dynamic analysis were within 6% of the quasistatic predictions. Realistic modeling of the deforming geometry is important in determining which locations in the coronary arteries are subjected to low and oscillating wall shear stresses, flow patterns that have been associated with atherogenesis.
Arteriosclerosis↗
Lateral deformation and movement effects on flow through distensible tube models of blood vessels.
The fluid flow through a tube with an oscillating elliptical cross-section was analyzed in order to understand better the effects of lateral deformation and movement on flow patterns in large and medium-sized blood vessels. Time-dependent elliptical deformation may be caused by external forces, as is the case for the large vessels near the heart, or by lateral movement of the entire compliant vessel, as in the coronary arteries. An analytic, perturbation-type solution was found for the case of fully developed flow in a tube where the cross-section oscillated periodically from an ellipse to a circle. Analytic expressions were found for all three components of the velocity vector. The effects of the deformation on the axial velocity profile included near-wall fluctuations in velocity that depended on the local wall motion. At higher values of the Womersley parameter, these effects were more pronounced. Secondary flow patterns were established that swirled fluid from the center of the vessel to the walls, then back to the center. It was concluded that these phenomena could be important to flow in the largest vessels, but may not be so important in determining flow patterns in the coronary arteries.
Blood Flow Velocity↗