Diabetes care and pregnancy outcomes for women with pregestational diabetes in Ireland.

AIMS: Pre-gestational diabetes mellitus (PGDM) is associated with adverse outcomes. We aimed to examine pregnancies affected by PGDM; report on these pregnancy outcomes and compare outcomes for patients with type 1 versus type 2 diabetes mellitus; compare our findings to published Irish and United Kingdom (UK) data and identify potential areas for improvement. METHODS: Between 2016 and 2018 information on 679 pregnancies from 415 women with type 1 Diabetes Mellitus and 244 women with type 2 diabetes was analysed. Data was collected on maternal characteristics; pregnancy preparation; glycaemic control; pregnancy related complications; foetal and maternal outcomes; unscheduled hospitalisations; congenital anomalies and perinatal deaths. RESULTS: Only 15.9% of women were adequately prepared for pregnancy. Significant deficits were identified in availability and attendance at pre-pregnancy clinic, use of folic acid, attaining appropriate glycaemic targets and appropriate retinal screening. The majority of pregnancies (n = 567, 83.5%) resulted in a live birth but the large number of infants born large for gestational age (LGA) (n = 280, 49.4%), born prematurely <37 weeks and requiring neonatal intensive care unit (NICU) admission continue to be significant issues. CONCLUSIONS: This retrospective cohort study identifies multiple targets for improvements in the provision of care to women with pre-gestational DM which are likely to translate into better pregnancy outcomes.

An Irish National Diabetes in Pregnancy Audit: aiming for best outcomes for women with diabetes.

AIMS: The purpose of this study was to identify the number of pregnancies affected by pre-gestational diabetes in the Republic of Ireland; to report on pregnancy outcomes and to identify areas for improvement in care delivery and clinical outcomes. METHODS: Healthcare professionals caring for women with pre-gestational diabetes during pregnancy were invited to participate in this retrospective study. Data pertaining to 185 pregnancies in women attending 15 antenatal centres nationally were collected and analysed. Included pregnancies had an estimated date of delivery between 1 January and 31 December 2015. RESULTS: The cohort consisted of 122 (65.9%) women with Type 1 diabetes and 56 (30.3%) women with Type 2 diabetes. The remaining 7 (3.8%) pregnancies were to women with maturity-onset diabetes of the young (MODY) (n = 6) and post-transplant diabetes (n = 1). Overall women were poorly prepared for pregnancy and lapses in specific areas of service delivery including pre-pregnancy care and retinal screening were identified. The majority of pregnancies 156 (84.3%) resulted in a live birth. A total of 103 (65.5%) women had a caesarean delivery and 58 (36.9%) infants were large for gestational age. CONCLUSIONS: This audit identifies clear areas for improvement in delivery of care for women with diabetes in the Republic of Ireland before and during pregnancy.

Evaluating team-based inter-professional advanced life support training in intensive care-a prospective observational study.

Recent focus on national standards within Australian hospitals has prompted a focus on the training of our staff in advanced life support (ALS). Research in critical care nursing has questioned the traditional annual certification of ALS competence as the best method of delivering this training. Simulation and team-based training may provide better ALS education to intensive care unit (ICU) staff. Our new inter-professional team-based advanced life support program involved ICU staff in a large private metropolitan ICU. A prospective observational study using three standardised questionnaires and two multiple choice questionnaire assessments was conducted. Ninety-nine staff demonstrated a 17.8% (95% confidence interval 4.2-31, P=0.01) increase in overall ICU nursing attendance at training sessions. Questionnaire response rates were 93 (94%), 99 (100%) and 60 (61%) respectively; 51 (52%) staff returned all three. Criteria were assessed by scores from 0 to 10. Nurses reported improved satisfaction with the education program (9.4 to 7.1, P <0.001), as well as improvement in role understanding (8.7 and 9.1 versus 7.9 and 8.2, P <0.001) and confidence (8.4 and 8.8 versus 7.4 and 7.8, P <0.001) during ALS provision (outside ICU and inside ICU) following the course when compared to before the program. Doctors' only statistically significant improvement was in their confidence in ALS provision outside ICU (8.7 versus 8.1, P=0.04). The new program cost approximately an extra $16,500 in nursing salaries. We concluded that team-based, inter-professional ALS training produced statistically significant improvements in nursing attendance, satisfaction with ALS education, confidence and role understanding compared to traditional ALS training.

Elucidating the genetic basis of crystalline biofilm formation in Proteus mirabilis.

Proteus mirabilis forms extensive crystalline biofilms on urethral catheters that occlude urine flow and frequently complicate the management of long-term-catheterized patients. Here, using random transposon mutagenesis in conjunction with in vitro models of the catheterized urinary tract, we elucidate the mechanisms underpinning the formation of crystalline biofilms by P. mirabilis. Mutants identified as defective in blockage of urethral catheters had disruptions in genes involved in nitrogen metabolism and efflux systems but were unaffected in general growth, survival in bladder model systems, or the ability to elevate urinary pH. Imaging of biofilms directly on catheter surfaces, along with quantification of levels of encrustation and biomass, confirmed that the mutants were attenuated specifically in the ability to form crystalline biofilms compared with that of the wild type. However, the biofilm-deficient phenotype of these mutants was not due to deficiencies in attachment to catheter biomaterials, and defects in later stages of biofilm development were indicated. For one blocking-deficient mutant, the disrupted gene (encoding a putative multidrug efflux pump) was also found to be associated with susceptibility to fosfomycin, and loss of this system or general inhibition of efflux pumps increased sensitivity to this antibiotic. Furthermore, homologues of this system were found to be widely distributed among other common pathogens of the catheterized urinary tract. Overall, our findings provide fundamental new insight into crystalline biofilm formation by P. mirabilis, including the link between biofilm formation and antibiotic resistance in this organism, and indicate a potential role for efflux pump inhibitors in the treatment or prevention of P. mirabilis crystalline biofilms.

Potential subtherapeutic linezolid and meropenem antibiotic concentrations in a patient with severe burns and sepsis.

Altered pharmacokinetics in patients with major burns may result in serum antibiotic concentrations below those required to be effective against the common pathogens encountered in burns patients. The major changes in the fluid volumes of key body compartments, which occur with a large burn, may increase the apparent volume of distribution of a drug, thereby lowering its concentration when a standard dose is given. In addition, the observed increase in renal blood flow reported in burns patients, because of the change in cardiac output, may result in a higher drug clearance and a shorter elimination half-life. As a consequence, studies have recommended higher doses or more frequent dosing or both for some antibiotics in patients with major burns, but data are lacking for many of the antibiotics reserved for treatment of life-threatening infections. The authors measured serum concentrations of two antibiotics, linezolid and meropenem, in an immunosuppressed patient who presented with a severe burn to determine whether therapeutic concentrations were achieved, thereby improving the likelihood of infection control.

Resistance of Legionella pneumophila serotype 1 biofilms to chlorine-based disinfection.

The presence of Legionella spp. in potable water systems is a major concern to municipal water providers and consumers alike. Despite the inclusion of chlorine in potable supplies and frequent chlorination cycles, the bacterium is a recalcitrant human pathogen capable of causing incidents of Legionnaires' disease, Pontiac fever and community-acquired pneumonia in humans. Using two materials routinely employed for the delivery of potable water as a substratum, copper and stainless steel, the development of Legionella pneumophila biofilms and their response to chlorination was monitored over a three-day and a three-month period, respectively. Preliminary in vitro studies using broth and sterile tap water as culture media indicated that the bacterium was capable of surviving in low numbers for 28 days in the presence of chlorine. Subsequently, biofilms were grown for three days, one month and two months, respectively, on stainless steel and copper sections, which are widely used for the conveyance of potable water. Immediately after exposure to 50mg/L chlorine for 1h, the biofilms yielded no recoverable colonies, but colonies did reappear in low numbers over the following days. Despite chlorination at 50mg/L for 1h, both one- and two-month-old L. pneumophila biofilms were able to survive this treatment and to continue to grow, ultimately exceeding 1x10(6)cfu per disc. This research provides an insight into the resistance afforded to L. pneumophila against high levels of chlorine by the formation of biofilms and has implications for the delivery of potable water.

The rapid and specific real-time detection of Legionella pneumophila in water samples using Optical Waveguide Lightmode Spectroscopy.

The detection of Legionella pneumophila in water samples using standard microbiological culture techniques is both prolonged and problematic. The bacterium is slow-growing and nutritionally fastidious, such that other indigenous species can out-compete the Legionella even when using antibiotic supplemented media. Optical Waveguide Lightmode Spectroscopy (OWLS) is a real-time analytical system whereby a change to a higher coupling angle where the refractive index of a bacterial cell is higher than that of the covering medium. In this study an aqueous suspension of L. pneumophila was passed across the surface of waveguides functionalised with a specific anti-Legionella antibody. The binding between the bacterial cells and the antibody specific for that cell resulted in an increase in the refraction indices of the transverse electric and transverse magnetic photoelectric currents. We report the optimisation of a rapid and sensitive (1.3 x 10(4) CFU mL-1) detection method for L. pneumophila contamination in a water sample in less than 25 min. This is a significant reduction in the time taken to determine the presence of the bacterium which with conventional techniques normally takes up to fourteen days. In addition, the specificity of the technique to L. pneumophila was demonstrated. The OWLS results were validated by conventional microbiology screening and atomic force microscopy of the surface of the waveguide, showing its species specificity and potential applications in environmental and clinical analysis.

Triclosan-tolerant bacteria: changes in susceptibility to antibiotics.

There is no clear consensus regarding the effect of biocide tolerance on antibiotic susceptibility. In this work, triclosan-tolerant strains of Escherichia coli, Staphylococcus aureus and Acinetobacter johnsonii were compared with sensitive strains in order to ascertain their susceptibility to a range of antibiotics. The minimum inhibitory concentrations of triclosan were measured using broth- and agar-dilution techniques. Antibiotic susceptibilities were determined using the British Society for Antimicrobial Chemotherapy guidelines. No triclosan-tolerant strains were resistant to antibiotics, and there was no overall tendency for triclosan-tolerant strains to have significantly smaller zones of inhibition compared with counterpart strains. Triclosan-tolerant strains of E. coli were significantly more susceptible to aminoglycoside antibiotics. The mechanism by which E. coli develops tolerance to triclosan appears to be linked to aminoglycoside susceptibility. It is proposed that changes in outer membrane, or the loss of plasmids, may be responsible for this relationship.

Long-term persistence of a single Legionella pneumophila strain possessing the mip gene in a municipal shower despite repeated cycles of chlorination.

The ability of Legionella pneumophila to colonise domestic water systems is a primary cause of outbreaks of Legionnaire's disease in humans. World Health Organization guidelines recommend that drinking water is chlorinated to between 0.2 and 1mg/L [Chlorine in drinking-water. Guidelines for drinking-water quality, 2nd edn. Geneva: World Health Organization; 1996], but L. pneumophila is repeatedly isolated from chlorinated water systems, indicating that this treatment is not effective at preventing colonisation. Current UK guidelines recommend a one-off treatment of 20-50mg/L of free chlorine to remove the bacteria. In this study we report on the persistence of L. pneumophila serogroup 1 in a domestic shower system despite repeated cycles of chlorination at 50mg/L for 1h exposure time, over the course of two and a half years. Persisting isolates were subjected to in-vitro phenotypic analyses and polymerase chain reaction analysis for the toxin-encoding mip gene. Random amplified polymorphic DNA typing was also performed to determine whether the isolates recovered on different occasions were the same strain. We found that seven isolates of L. pneumophila recovered over a two-and-a-half year period are the same genetically defined strain, indicating that the bacteria can persist despite repeated cycles of chlorination after each successive isolation.

Virulence traits associated with verocytotoxigenic Escherichia coli O157 recovered from freshwater biofilms.

AIM: To investigate whether epilithic biofilms in freshwater streams in a mixed UK agricultural river catchment harbour Escherichia coli O157, and if so, whether they demonstrate an association with those excreted by grazing farm animals. METHODS AND RESULTS: Flint shingle, native to the study site, was used as a surface for biofilm development within cages of metal lath set into a stream bed at four locations on a chalkland farm. Shingle was collected from all sites once a month, as were pooled faecal samples from five farm animal populations. Subpopulations of E. coli, including E. coli O157 that demonstrated significant phenotypic and genotypic similarity with animal faecal isolates (t-test, P = 0.05) were isolated. Of 1002 E. coli isolates from biofilms and animal faeces, 48 were confirmed as the O157 strain by latex agglutination. The presence of five virulence traits associated with incidence of human disease was tested using PCR. Stx(2) was the most frequently isolated single gene (30 isolates), while stx(1) was the least frequently recovered (four isolates). CONCLUSION: Escherichia coli O157, expressing up to four virulence factors associated with human disease, reside within freshwater biofilms in this agricultural environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Aquatic biofilms may potentially act as a reservoir for these pathogens, and the implications of the findings for the protection of drinking water resources should be further investigated.

A simulated oral hygiene model to determine the efficacy of repeated exposure of amine oxide on the viability of Streptococcus mutans biofilms.

The use of biocide in oral care products is important for controlling microbial pathogens. However, the use of biofilm tests that investigate repeated exposure to biocide, to mimic in situ treatment, has rarely been reported in the literature. The present study describes the application of a biofilm-based efficacy protocol, for testing the effect of repeated exposure to antimicrobials on biofilm, in an attempt to mimic oral care regimens. The activity of different treatment regimens, including repeated exposure to amine oxide (AO; C(10)-C(16)-alkyldimethyl N-oxides; 1.1% v/v), was conducted against 16-h Streptococcus mutans biofilms grown on hydroxyapatite disks. Single exposure to AO alone produced a 3 log(10) reduction in microbial count, but when combined with mechanical removal, a 5 log(10) reduction in microbial count was observed. Treatments incorporating repeated exposure to AO reduced the microbial count below the level of detection, even when exposure to AO was interspersed with recovery periods. The presence of organic load produced an additional 2 log(10) reduction in the microbial count. This study showed that the application of a biofilm-based efficacy protocol to mimic oral care regimens allowed the reproducible testing of repeated antimicrobial exposures against bacterial biofilm. In addition, AO was confirmed to be an excellent biocide for eliminating S. mutans biofilms and could therefore be beneficial in oral care formulations.

Alcohol ethoxylates mediate their bacteriostatic effect by altering the cell membrane of Escherichia coli NCTC 8196.

The minimum inhibitory concentration (MIC) of a homologous series of alcohol ethoxylates with the same head group size (E6) but differing in the number of carbon atoms in their 'tail group' from 10 to 16 was determined for Staphylococcus aureus NCTC 4163 and Escherichia coli NCTC 8196 using a turbidimetric assay. All the surfactants tested demonstrated bacteriostatic activity against both organisms. A tetrazolium assay showed that C14E6 and C16E6 had little effect on the membrane-bound dehydrogenase enzyme activity of E. coli NCTC 8196 compared with C10E6 and C12E6. C10E6 caused leakage both of K(+) and nucleotides in a concentration-dependent manner above its MIC of 0.2 mM. C12E6 caused some leakage at concentrations below its MIC (0.12 mM).

Use of a new alginate film test to study the bactericidal efficacy of the high-level disinfectant ortho-phthalaldehyde.

OBJECTIVES: To evaluate the merit of a new alginate efficacy film test to determine the bactericidal activity of the high-level disinfectant ortho-phthalaldehyde (OPA). METHODS: The efficacy of OPA was investigated using a new sodium alginate surface film test against Mycobacterium chelonae NCIMB 1474 and Epping, and Pseudomonas aeruginosa NCIMB 10421 under different test conditions. RESULTS: OPA was highly bactericidal against P. aeruginosa but its mycobactericidal efficacy was seriously reduced and produced >or=5 log reductions only at a concentration of 0.5% (w/v) within 30-60 min without organic load. CONCLUSIONS: The sodium alginate film efficacy was reproducible between repeats. Inactivation results depended upon the concentration of OPA, contact time, the presence of an organic load and the bacterial genera.

Telephone triage, expert systems and clinical expertise.

This paper reports on a qualitative study of the use of an expert system developed for the British telephone triage service NHS Direct. This system, known as CAS, is designed to standardise and control the interaction between NHS Direct nurses and callers. The paper shows, however, that in practice the nurses use CAS in a range of ways and, in so doing, privilege their own expertise and deliver an individualised service. The paper concludes by arguing that NHS Direct management's policy of using CAS as a means of standardising service delivery will achieve only limited success due not only to the professional ideology of nursing but also to the fact that rule-based expert systems capture only part of what 'experts' do.

The emergence of multidrug resistant Acinetobacter species: a major concern in the hospital setting.

Acinetobacter spp. have emerged in recent years as a major cause of nosocomial infections that are associated with significant morbidity and mortality. Developing resistance patterns have prompted the suggestion that we are closer to the end of the antibiotic era with Acinetobacter than with methicillin-resistant Staphylococcus aureus (J Hosp Infect58, 2004, 167).

Bacterial adhesion to phosphorylcholine-based polymers with varying cationic charge and the effect of heparin pre-adsorption.

The steady increase in the use of medical implants and the associated rise of medical device infections has fuelled the need for the production of biomaterials with improved biocompatibility. 2-(methacryloyloxyethyl phosphorylcholine) (MPC) based coatings have been used to improve the biocompatibility of a number of different medical devices. Recent studies have investigated the use of a phosphorylcholine modified with cationic charge to encourage specific bio-interaction. Until now the affect of cationic charge incorporation in MPC copolymers on bacterial adhesion has not been investigated. This study attempts to address this by investigating the affect of charge on four different strains of bacteria commonly associated with medical device infections. In addition, the affect of pre-incubating these MPC-copolymers in heparin is also evaluated as this has previously been shown to improve biocompatibility and reduce bacterial adhesion. Bacterial adhesion was assessed by ATP bioluminescence and Scanning Electron Microscopy (SEM). Results suggest that bacterial adhesion generally increased with increasing cationic charge. When samples were however, pre-incubated with heparin a significant reduction in bacterial adhesion to the MPC-based samples was observed. The heparin remained bound and effective at reducing bacterial adhesion to the cationic MPC-based samples even after three weeks incubation in PBS. To conclude, the MPC-based cationic polymer coatings complexed with heparin may provide a promising solution to reduce medical device related infections.

Biofilm formation and changes in bacterial cell surface hydrophobicity during growth in a CAPD model system.

Peritonitis is a frequent complication of continuous ambulatory peritoneal dialysis (CAPD), with patients suffering recurrent attacks. The microorganisms most frequently implicated in the infection are the skin microflora, in particular, the coagulase-negative staphylococci such as Staphylococcus epidermidis. These microorganisms gain access to the peritoneal cavity via the in-dwelling silicone rubber catheter in the abdominal wall and often persist as biofilms on the surface of the catheter. The surface characteristics of S. epidermidis were monitored during growth in a CAPD in-vitro model together with their ability to adhere to silicone rubber substrata. Fresh dialysis fluid exerted an injurious effect on the cells leading to a decrease in cell numbers but during the simulated dialysis period the cells adapted to the applied stresses. Over a 96-h period in the model both a clinical isolate and a skin isolate of S. epidermidis adopted a more hydrophobic phenotype. The data presented here show that the bacteria grown in this in-vivo reflective CAPD model continually adapt to their environment and become more tolerant to the stresses imposed. The adapted cells were seen to colonise silicone rubber substrata.

Biological responses to cationically charged phosphorylcholine-based materials in vitro.

Phosphorylcholine (PC)-based polymers have been used in a variety of medical device applications to improve biocompatibility. The use of PC-based materials for biomaterials is associated with low protein adsorption, reduced complement activation, low inflammatory response and cell adhesion. For some medical device applications however, materials that support cell adhesion are also beneficial, allowing host interaction and encouraging full incorporation within the body. As previous studies have suggested that cell adhesion to materials is enhanced by the addition of charge, PC-based polymers have therefore been modified to incorporate various concentrations of cationic charge. In this study, the affect of cationic charge on a range of biological responses was investigated. In vitro assays have been used to assess the adsorption of protein onto the materials surface, the adhesion of mouse fibroblasts and rabbit corneal epithelial cells and the adhesion of human mononuclear cells and granulocytes. The results corroborate previous work showing that PC without charge significantly reduces protein adsorption, cell adhesion and inflammatory cell activation. The addition of cationic charge to PC polymers however, resulted in an increase in all of the above responses. This increase did not however, increase linearly with cationic monomer concentration. The differences in cell adhesion are discussed in terms of differences in protein adsorption, cytotoxicity and/or stability of the different cationic polymer coatings.

The synergistic effect of EDTA/antimicrobial combinations on Pseudomonas aeruginosa.

AIMS: To demonstrate that the nonlinear concentration-dependent inhibition of Pseudomonas aeruginosa to EDTA can be used to successfully model and predict the potentiation of antimicrobials by EDTA. METHODS AND RESULTS: A model used successfully to describe the concentration-dependent inhibition of bacterial growth caused by many antimicrobials was unable to describe the inhibition of P. aeruginosa by EDTA. Examination of the inhibition profiles for EDTA against P. aeruginosa revealed a biphasic inhibitory pattern suggesting different mechanisms of action at different concentrations. A modelled, two-stage inhibitory process was shown to fit the observations. This model was then used to examine the effect of combining EDTA with other antimicrobials. The apparent synergy of mixtures of EDTA with quaternary ammonium surfactants (QAC) and specific antibiotics was successfully modelled. Minimum inhibitory concentrations (MIC) of the QAC and that of oxacillin and cefamandole were reduced by a factor of 3-10, whereas ampicillin was reduced by a factor of 70 from an MIC of 1524 to 21 mg l(-1) in the presence of 500 mg l(-1) of EDTA. CONCLUSIONS: A nonlinear concentration-dependent inhibition of P. aeruginosa by EDTA gives rise to apparent observation of synergy with other antimicrobials. SIGNIFICANCE AND IMPACT OF THE STUDY: This is a further example where the current methodology for the examination of antimicrobial synergy (the summed fractional inhibitory concentrations) leads to false conclusions.