Selection of resistance by antimicrobial coatings in the healthcare setting.

Antimicrobial touch surfaces have been introduced in healthcare settings with the aim of supporting existing hygiene procedures, and to help combat the increasing threat of antimicrobial resistance. However, concerns have been raised over the potential selection pressure exerted by such surfaces, which may drive the evolution and spread of antimicrobial resistance. This review highlights studies that indicate risks associated with resistance on antimicrobial surfaces by different processes, including evolution by de-novo mutation and horizontal gene transfer, and species sorting of inherently resistant bacteria dispersed on to antimicrobial surfaces. The review focuses on antimicrobial surfaces made of copper, silver and antimicrobial peptides because of the practical application of copper and silver, and the promising characteristics of antimicrobial peptides. The available data point to a potential for resistance selection and a subsequent increase in resistant strains via cross-resistance and co-resistance conferred by metal and antibiotic resistance traits. However, translational studies describing the development of resistance to antimicrobial touch surfaces in healthcare-related environments are rare, and will be needed to assess whether and how antimicrobial surfaces lead to resistance selection in these settings. Such studies will need to consider numerous variables, including the antimicrobial concentrations present in coatings, the occurrence of biofilms on surfaces, and the humidity relevant to dry-surface environments. On-site tests on the efficacy of antimicrobial coatings should routinely evaluate the risk of selection associated with their use.

Biofilm production and antibiotic susceptibility of Staphylococcus epidermidis strains from Hidradenitis Suppurativa lesions.

BACKGROUND: An aberrant interaction between commensal skin bacteria and the host skin immune system is considered important in the pathogenesis of hidradenitis suppurativa (HS). OBJECTIVE: In this study, we investigated the antibiotic susceptibility and biofilm-forming capabilities of S. epidermidis strains isolated from HS patients. METHODS: Skin biopsies were taken from active HS lesions such as inflammatory nodules and/or sinuses and non-involved skin from 26 patients and cultured under optimal microbiological conditions for 24 h. Planktonic growth, biofilm production, antibiotic susceptibility and biofilm eradication by clindamycin, doxycycline, rifampicin and tetracycline were tested including a laboratory control strain of S. epidermidis for reference. RESULTS: Staphylococcus epidermidis was cultured in 16 of 26 HS patients (62%). In total 27 different S. epidermidis isolates were identified; 16 (59%) from non-involved skin and 11 (41%) from HS lesions. All bacterial strains showed planktonic growth. Twenty-four of 27 (89%) isolates were strong biofilm producers in vitro. The biofilm-forming capability varied amongst the strains from non-involved skin and lesional skin. Twenty-four strains had an intermediate to resistant antibiotic susceptibility to clindamycin (89%). Rifampicin was the most effective antibiotic at inhibiting planktonic growth and at eradication of biofilm (P < 0.05). CONCLUSION: We observed a slight increase in S. epidermidis virulence, characterized by resistance to commonly used antibiotics, increased biofilm production and resistance to biofilm eradication. In particular, the reduced sensitivity to tetracycline and clindamycin, two standard antibiotics in the treatment of HS, is alarming. Rifampicin, also important in HS treatment, showed the greatest efficacy at eradicating the biofilm at low MIC concentrations.

A near full-length open reading frame next generation sequencing assay for genotyping and identification of resistance-associated variants in hepatitis C virus.

BACKGROUND: The current treatment options for hepatitis C virus (HCV), based on direct acting antivirals (DAA), are dependent on virus genotype and previous treatment experience. Treatment failures have been associated with detection of resistance-associated substitutions (RASs) in the DAA targets of HCV, the NS3, NS5A and NS5 B proteins. OBJECTIVE: To develop a next generation sequencing based method that provides genotype and detection of HCV NS3, NS5A, and NS5 B RASs without prior knowledge of sample genotype. STUDY DESIGN: In total, 101 residual plasma samples from patients with HCV covering 10 different viral subtypes across 4 genotypes with viral loads of 3.84-7.61 Log IU/mL were included. All samples were de-identified and consequently prior treatment status for patients was unknown. Almost full open reading frame amplicons (∼ 9 kb) were generated using RT-PCR with a single primer set. The resulting amplicons were sequenced with high throughput sequencing and analysed using an in-house developed script for detecting RASs. RESULTS: The method successfully amplified and sequenced 94% (95/101) of samples with an average coverage of 14,035; four of six failed samples were genotype 4a. Samples analysed twice yielded reproducible nucleotide frequencies across all sites. RASs were detected in 21/95 (22%) samples at a 15% threshold. The method identified one patient infected with two genotype 2b variants, and the presence of subgenomic deletion variants in 8 (8.4%) of 95 successfully sequenced samples. CONCLUSIONS: The presented method may provide identification of HCV genotype, RASs detection, and detect multiple HCV infection without prior knowledge of sample genotype.

Results of a Direct Search Using Synchrotron Radiation for the Low-Energy (229)Th Nuclear Isomeric Transition.

We report the results of a direct search for the (229)Th (I(π)=3/2(+)←5/2(+)) nuclear isomeric transition, performed by exposing (229)Th-doped LiSrAlF(6) crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1-2) s≲τ≲(2000-5600) s. This measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

Cost-effective expression and purification of antimicrobial and host defense peptides in Escherichia coli.

Cationic antimicrobial host defense peptides (HDPs) combat infection by directly killing a wide variety of microbes, and/or modulating host immunity. HDPs have great therapeutic potential against antibiotic-resistant bacteria, viruses and even parasites, but there are substantial roadblocks to their therapeutic application. High manufacturing costs associated with amino acid precursors have limited the delivery of inexpensive therapeutics through industrial-scale chemical synthesis. Conversely, the production of peptides in bacteria by recombinant DNA technology has been impeded by the antimicrobial activity of these peptides and their susceptibility to proteolytic degradation, while subsequent purification of recombinant peptides often requires multiple steps and has not been cost-effective. Here we have developed methodologies appropriate for large-scale industrial production of HDPs; in particular, we describe (i) a method, using fusions to SUMO, for producing high yields of intact recombinant HDPs in bacteria without significant toxicity and (ii) a simplified 2-step purification method appropriate for industrial use. We have used this method to produce seven HDPs to date (IDR1, MX226, LL37, CRAMP, HHC-10, E5 and E6). Using this technology, pilot-scale fermentation (10L) was performed to produce large quantities of biologically active cationic peptides. Together, these data indicate that this new method represents a cost-effective means to enable commercial enterprises to produce HDPs in large-scale under Good Laboratory Manufacturing Practice (GMP) conditions for therapeutic application in humans.

The novel adjuvant combination of CpG ODN, indolicidin and polyphosphazene induces potent antibody- and cell-mediated immune responses in mice.

The need to enhance the immunogenicity of purified subunit antigens and modulate resulting immune responses has prompted the development of new adjuvants. Here, the ability of CpG oligodeoxynucleotides (ODN), a bovine host defence peptide indolicidin, and polyphosphazene to synergistically combine and enhance innate and adaptive immune responses was examined in mice. In vitro, the adjuvant combination of CpG ODN, indolicidin and polyphosphazene (CpG/indol/PP) enhanced the secretion of TNF-alpha, IL-12p40, and IL-6 by bone marrow-derived DCs (BMDCs) when compared to the individual components. When co-formulated with ovalbumin (OVA), CpG/indol/PP formed antigen-adjuvant complexes, and enhanced antibody and cell-mediated responses in mice, via both MHC I and II pathways, promoting a more balanced antibody-mediated and type 1-biased cell-mediated immune response. Furthermore, substitution of the proline residues of indolicidin with arginine increased the synergistic adjuvant effect of the peptide, and induced significantly higher IgG1 and IgG2a titers and IFN-gamma secretion, as well as increased uptake by antigen presenting cells. These results clearly demonstrate that the use of a combination of CpG ODN, indolicidin, and polyphosphazene as adjuvant can significantly enhance an antigen-specific immune response.

Bovine lactoferrin and lactoferricin interfere with intracellular trafficking of Herpes simplex virus-1.

Although both lactoferrin (Lf), a component of the innate immune system of living organisms, and its N-terminal pepsin cleavage product lactoferricin (Lfcin) have anti-herpes activity, the precise mechanisms by which Lf and Lfcin bring about inhibition of herpes infections are not fully understood. In the present study, experiments were carried out to characterize the activity of bovine Lf and Lfcin (BLf and BLfcin) against the Herpes simplex virus-1 (HSV-1). HSV-1 cellular uptake and intracellular trafficking were studied by immunofluorescence microscopy. In comparison to the untreated infected control cells, both the BLf- and BLfcin-treated cells showed a significant reduction in HSV-1 cellular uptake. The few virus particles that were internalized appeared to have a delayed intracellular trafficking. Thus, in addition to their interference with the uptake of the virus into host cells, Lf and Lfcin also exert their antiviral effect intracellularly.

Anti herpes simplex virus activity of lactoferrin/lactoferricin -- an example of antiviral activity of antimicrobial protein/peptide.

One of the most common viral infections in humans is caused by the herpes simplex virus (HSV). It was first effectively treated in the 1970s with the introduction of acyclovir, which is still the most commonly used treatment. Naturally occurring antimicrobial proteins and peptides have also been shown to possess antiviral activity against HSV. This review will focus on the anti-HSV activity of one such protein, lactoferrin, and a small peptide fragment from its N-terminal domain, lactoferricin. Both components have been shown to effectively block entry of HSV into the host cell. In addition to blocking HSV entry, the peptides appear to have immune stimulatory activity, although this is still somewhat controversial. Mode of action studies and knowledge about the anti-HSV activity of lactoferricin have also been successfully employed in the design of new, more specific HSV blockers.

Design and implementation of a neuromuscular training program following anterior cruciate ligament reconstruction.

Neuromuscular training programs are increasingly integrated into clinical practice for lower extremity rehabilitation. A few rehabilitation programs have been evaluated for patients with anterior cruciate ligament (ACL) deficiency and for injury prevention, but there is limited scientific evidence of the effect of neuromuscular training following ACL reconstruction. Therefore, a neuromuscular training program was developed for patients after ACL reconstruction. The objective of the neuromuscular training was to improve the ability to generate a fast and optimal muscle firing pattern, to increase dynamic joint stability, and to relearn movement patterns and skills necessary during activities of daily living and sports activities. The main areas considered when designing the postoperative rehabilitation program after ACL reconstruction were: ACL graft healing and ACL strain values during exercises, proprioception and neuromuscular control, and clinical studies on the effect of neuromuscular training programs. The rehabilitation program consists of balance exercises, dynamic joint stability exercises, jump training/plyometric exercises, agility drills, and sport-specific exercise. The patients exercise 3 times a week for 6 months. The scientific and clinical evidence for the rehabilitation program are described and the main exercises in the program are outlined.

Periodically poled BaMgF(4) for ultraviolet frequency generation.

Ferroelectric domain inversion has been demonstrated in BaMgF(4) . Transparency has been measured to <140nm, and no change in transmission was measured under 157-nm irradiation for >1.1x10(9) shots at 2mJ/cm(2) per pulse. First-order quasi-phase-matched generation of 157 nm is predicted by use of grating periods as long as 1.5mum. This material should permit shorter-wavelength chi((2)) frequency-mixing processes than with any other crystalline material.

[Incidents connected to pregnancy and labor]. / Tilsynssaker knyttet til svangerskap og fødsel.

In the period 1993-2000 the Norwegian Board of Health investigated 70 cases of claimed professional misconduct in relation to pregnancy or delivery. There were two maternal deaths, 38 perinatal deaths and 17 cases of cerebral damage. The Board of Health found reason to criticize midwives in 11 cases, obstetricians in 39 cases, and the hospital for lack of routines in 18 cases. Many of the mishaps were connected to false interpretation of fetal signs of distress (clinical signs or cardiotocography), and the investigation concluded that Caesarean section was delayed too long. The number of patient complaints has been constant through the period, in contrast to the widespread belief that misconduct and complaints are steadily increasing. The health authorities and the Norwegian Association of Gynaecologists have focused on quality and standards in obstetrics through committees for investigation of perinatal deaths, national guidelines in obstetrics, and improved national statistics.

[Does physical exercise at the workplace have any effect on sick leave?]. / Har fysisk trening på arbeidsplassen effekt på sykefravaer?

The objective of the study was to ascertain whether physical activity at the workplace reduces the amount of sick leave. The databases Medline and Spri-line, reference lists, and professional expertise were consulted for information on the subject. We included random controlled trials, and controlled trials studying the effect on sick leave of physical activity at the worksite. Four trials were identified, including one carried out in Norway. The small number of trials limits the value of any conclusions and highlights the need for more research. The results of the four trials do not indicate that physical activity at the workplace reduces sick leave.

14-fs pulse generation in Kerr-lens mode-locked prismless Cr:LiSGaF and Cr:LiSAF lasers: observation of pulse self-frequency shift.

Kerr-lens mode-locked Kr-laser-pumped Cr:LiSGaF and Cr:LiSAF lasers containing only two newly developed low-loss chirped mirrors instead of conventional dielectric resonator mirrors and generating pulses of widths as small as 14-fs with as much as 100 mW of average output power are reported. We report what is to our knowledge the first experimental observation of a pulse self-frequency shift in crystalline active media that are characteristic of such short pulses at megawatt intracavity peak powers. We also believe this phenomenon to be one of the significant limiting factors for pulse duration in femtosecond Cr:LiSAF-type lasers.

Investigation of diode-pumped 2.8-microm laser performance in Er:BaY(2)F(8).

Laser operation at 2.8 microm in BaY(2)F(8) with erbium concentrations of 7.5% and 20% is investigated under laser-diode pumping at 967 nm. Output powers as high as 250 mW and slope efficiencies as high as 24% are obtained. Results are comparable with those of Er(3+):LiYF(4) under the same pump conditions. Slope efficiencies above 30% are predicted for optimized erbium concentrations.

Efficient continuous-wave TEM(00) and femtosecond Kerr-lens mode-locked Cr:LiSrGaF laser.

Efficient high-power (900-mW) TEM(00) cw operation of a Cr:LiSrGaF laser pumped by a Kr(+) laser is demonstrated. The results of laser and spectroscopic analysis, including upconversion and excited-state absorption, are presented and used for the optimization of this laser. Kr(+)-laser-pumped mode-locked femtosecond operation (64 fs) was performed. Use of a modified resonator, which can decrease the threshold pump and intracavity power for Kerr-lens mode locking and increase the mode-locked output power (300 mW), is suggested. The inf luence of crystal axis misalignment on the tuning and mode-locking characteristics of the laser is studied.

Prismless passively mode-locked femtosecond Cr:LiSGaF laser.

A Kerr-lens mode-locked Cr:LiSrGaF laser containing no intracavity prisms has been demonstrated for the first time to the authors' knowledge. The laser produced stable near-transform-limited 44-fs pulses with an output power of 200 mW, tunable between 833 and 857 nm. Low-loss Gires-Tournois structured dielectric mirrors were used for dispersion control. The measured group-delay dispersion of the active medium as well as of the mirrors permitted to minimize the number of reflections, permitting higher output power.

Prediction of fetal weights in twins.

OBJECTIVE: To determine the accuracy of sonographic weight estimation of twin fetuses. METHODS: In 73 twin-pregnancies, fetal weight estimation by ultrasound was performed within 7 days prior to delivery. Fetal head biparietal diameter and abdominal circumference were measured. The coefficient of correlation (r), and the ratio between estimated weight and actual weight were calculated. RESULTS: The coefficient of correlation was r = 0.954 between estimated weight and actual birth weight. The ratio between the two parameters was 1.025, the standard deviation 0.089. In our study, 41% of the antenatal estimated weights deviated less than 5% from the actual birth weight. For 72% of all estimated weights, the deviation was less than 10%. Ultrasonographic prediction of actual weight below the 10th percentile level showed a sensitivity of 85%, predictive value of 80% and specificity of 87%. In detecting inter-twin discordance > or = 20%, the respective values were 64%, 64% and 91%. CONCLUSIONS: Antenatal estimation of birth weight by ultrasound correlates well with the actual weights of twin fetuses. Prediction of individual fetal weight seems to be more accurate than prediction of inter-twin discordance.

Kerr-lens mode-locked diode-pumped Cr:LiSGAF laser.

We have demonstrated stable and self-sustaining Kerr-lens mode locking of a Cr:LiSGAF laser pumped by AlGaInP laser diodes. A hard aperture near one end of the laser provides the necessary amplitude modulation. This allsolid- state system generates transform-limited 100-fs pulses, tunable from 810 to 860 nm. The average power at 830 nm is 35 mW, with fluctuations of much less than 1%. The thermal properties of Cr:LiSGAF will permit scaling of these results to higher power.

Self-pumped phase conjugation and four-wave mixing in 0 degrees - and 45 degrees -cut n-type BaTiO(3):Co.

Relatively fast self-pumped phase-conjugate and four-wave-mixing rise times are reported in n-type cobalt-doped barium titanate. With the crystal oriented in a 45 degrees cut as compared with the same crystal in a 0 degrees cut we find a factor of 3 decrease in the 0-90% rise time to 800 ms with 25-mW input power at 514.5 nm. Also, the self-pumped phase-conjugate reflectivity increases from 20% to 40%. We deduce that the phase conjugation is from internally seeded stimulated photorefractive backscattering. The four-wave-mixing rise time of the 45 degrees -cut crystal is 4 ms with a reflectivity of 48% when the pumping beams are derived from self-pumped phase conjugation that has an input power of 25 mW.