Molecular crystal global phase diagrams. III. Sufficient parameter space determination.

In previous parts of this series [Mettes et al. (2004). Acta Cryst.

Molecular crystal global phase diagrams. II. Reference lattices.

In the first part of this series [Keith et al. (2004). Cryst.

Prevalence of gastrointestinal bacterial pathogens in a population of zoo animals.

Faecal prevalence of gastrointestinal bacterial pathogens, including Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Yersinia, as well as Arcobacter, were examined in 317 faecal specimens from 44 animal species in Belfast Zoological Gardens, during July-September 2006. Thermophilic campylobacters including Campylobacter jejuni, Campylobacter coli and Campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (11 of 44; 25%). Yersinia spp.

Zoonoses associated with petting farms and open zoos.

The popularity of open farms and petting zoos has increased markedly over the last 5 years, with most children in developed countries now having the opportunity to visit such a facility at some stage in their childhood, either through school or family visits. The open access policy of these establishments allows visitors to be in direct contact with animals such as sheep (lambs), goats, cats (kittens), dogs (puppies), and birds and to have the opportunity to feed such animals. This contact may lead to the transmission of microbial pathogens from animals to humans, e.

Atypical mycobacterial infection in patients with cystic fibrosis: update on clinical microbiology methods.

While patients with cystic fibrosis (CF) have had dramatic improvement in their survival rates, this has been accompanied by the emergence of more virulent pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex organisms. In addition, there has been emergence of organisms of increasing clinical significance such as the nontuberculous mycobacterial (NTM). Although TB infection in patients with CF is extremely uncommon, there is growing concern with regard to atypical Mycobacterium spp, in particular Mycobacterium abscessus.

Lack of horizontal gene transfer of methicillin-resistance genetic determinants from PBP2a-positive, coagulase-negative staphylococci to methicillin-sensitive Staphylococcus aureus using transcutaneous electrical nerve stimulation (TENS).

Previous research shows that approximately half of the coagulase-negative staphylococci (CNS) isolated from patients in the intensive care unit (ICU) at Belfast City Hospital were resistant to methicillin. The presence of this relatively high proportion of methicillin-resistance genetic material gives rise to speculation that these organisms may act as potential reservoirs of methicillin-resistance genetic material to methicillin-sensitive Staphylococcus aureus (MSSA). Mechanisms of horizontal gene transfer from PBP2a-positive CNS to MSSA, potentially transforming MSSA to MRSA, aided by electroporation-type activities such as transcutaneous electrical nerve stimulation (TENS), should be considered.

Quantitative colorimetric measurement of residual antimicrobials in the urine of patients with suspected urinary tract infection.

A simple microtitre plate assay is used to detect antimicrobial activity in clinical urine specimens and its potential as a screening tool is assessed. The assay is based on a colorimetric substrate, p-nitrophenyl-beta-D-glucopyranoside, in combination with a Bacillus subtilis strain to detect antimicrobial residues. The assay identified antimicrobial activity in 31% of the 527 clinical urine samples tested.

Central line-related bacteremia due to Roseomonas mucosa in a patient with diffuse large B-cell non-Hodgkin's lymphoma.

A 42-year-old male patient with a history of diffuse large B-cell non-Hodgkin's lymphoma (DLBCL) developed a central line-related bacteremia due to the presence of a Gram-negative bacillus, which was difficult to identify conventionally. Sequencing of a partial region of the 16S rRNA gene identified the organism as Roseomonas mucosa with a homology score of 100% with 1003 bases called. Due to difficulties with the phenotypic identification of this genus, coupled with its emergence in line-related bacteremia in hematology patients with malignancy, Roseomonas spp.

Nucleation rates for the condensation of monovalent metals.

We show that consideration of both cluster growth and magic numbers are necessary to accurately calculate nucleation rates for the condensation of alkali and coinage metal vapors. The effects are not additive. Rates calculated using the modified theory differ up to several orders of magnitude from typical classical calculations.

Taxonomy of nucleation and growth processes in isotropic systems.

We construct a taxonomy of transient behavior for one component coupled nucleation and growth based on linear and nonlinear stability analysis of a two species model. The two species are the condensable species and the condensed droplets or particles, respectively. Our model reproduces previously reported asymptotically stable and oscillatory transient nucleation behavior.

Molecular crystal global phase diagrams. I. Method of construction.

A method is described to produce global phase diagrams for single-component molecular crystals with separable internal and external modes. The phase diagrams present the equilibrium crystalline phase as a function of the coefficients of a general intermolecular potential based on rotational symmetry-adapted basis functions. It is assumed that phase transitions are driven by orientational ordering of molecules with a fixed time-averaged shape.

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.

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.

Comparison of API20C with molecular identification of Candida spp isolated from bloodstream infections.

A study was carried out to compare the API20C technology with polymerase chain reaction amplification and direct sequencing of the short internal transcribed spacer region 2 (ITS2) for the identification of 58 isolates of invasive candida species obtained from patients with bloodstream infections over the seven year period 1994 to 2000. Overall, there was only one disagreement between the phenotypic and genotypic identification, where the API scheme identified the isolate as C albicans but the molecular method identified it as C dubliniensis. This study demonstrated that the API20C method is useful in the identification of Candida spp isolated from blood culture and that molecular methods do not enhance identifications made using the API20C scheme.

Trends in the epidemiology of Candida bloodstream infections in Northern Ireland between January 1984 and December 2000.

Objective: To describe the epidemiology of Candida bloodstream infections (BSI) in Northern Ireland.

Methods: Retrospective collation of data relating to all clinically significant BSI in a university teaching hospital, which had been recorded prospectively, between 1984 and 2000.

Results: One hundred and forty five episodes of candidaemia occurred in 144 patients (of mean age 56.

Trends in bacteraemia on the haematology and oncology units of a UK tertiary referral hospital.

As part of ongoing surveillance of infection in the haematology and oncology units at Belfast City Hospital, microbiologically documented bloodstream infections over three 12-month periods 1994/5, 1998/9 and 1999/00 were reviewed. Gram-positive organisms were the most common cause of blood stream infection in the haematology unit causing 66%, 56% and 64% of episodes of monomicrobial bacteraemia in 1994/5, 1998/9 and 1999/00, respectively. In haematology patients, enterococci have emerged as an important cause of bacteraemia, with increasing levels of glycopeptide resistance, and the 'non-fermenting Gram-negative rods other than Pseudomonas aeruginosa' are an increasingly common cause of monomicrobial and polymicrobial bacteraemia.

Molecular diagnosis of infective endocarditis--a new Duke's criterion.

The molecular approach of PCR amplification of specific gene targets and universal loci for bacteria (16S rRNA) and fungi (18S, 28S and 5.8S rRNA) and subsequent sequencing was used to identify the possible causal microbial agent(s) in blood culture (47 patients) and heart valve material (30 patients) from patients with suspected infective endocarditis (IE). Culture and molecular results were analysed with respect to the patients' clinical background and the Duke Criteria.