APSIC guide for prevention of catheter associated urinary tract infections (CAUTIs).

BACKGROUND: The Asia Pacific Society of Infection Control launched the APSIC guide for prevention of catheter associated urinary tract infections in July 2022. It aims to highlight practical recommendations in a concise format designed to assist healthcare facilities in the Asia Pacific region to achieve high standards in infection prevention and control practices during the management and care of patients with a urinary catheter. METHODS: The guidelines were developed by an appointed workgroup comprising experts in the Asia Pacific region, following reviews of previously published guidelines and recommendations relevant to each section. RESULTS: It recommends that healthcare institutions have a catheter associated urinary tract infection prevention program that includes surveillance and the use of the insertion and maintenance bundles. Implementation of the bundles is best done using a quality improvement approach with a multidisciplinary team. CONCLUSIONS: Healthcare facilities should aim for excellence in care of patients with urinary catheters. It is recommended that healthcare facilities have a catheter associated urinary tract infection prevention program as part of their Infection Prevention and Control program.

The melioidosis agent Burkholderia pseudomallei and related opportunistic pathogens detected in faecal matter of wildlife and livestock in northern Australia.

The Darwin region in northern Australia has experienced rapid population growth in recent years, and with it, an increased incidence of melioidosis. Previous studies in Darwin have associated the environmental presence of Burkholderia pseudomallei, the causative agent of melioidosis, with anthropogenic land usage and proximity to animals. In our study, we estimated the occurrence of B. pseudomallei and Burkholderia spp. relatives in faecal matter of wildlife, livestock and domestic animals in the Darwin region. A total of 357 faecal samples were collected and bacteria isolated through culture and direct DNA extraction after enrichment in selective media. Identification of B. pseudomallei, B. ubonensis, and other Burkholderia spp. was carried out using TTS1, Bu550, and recA BUR3-BUR4 quantitative PCR assays, respectively. B. pseudomallei was detected in seven faecal samples from wallabies and a chicken. B. cepacia complex spp. and Pandoraea spp. were cultured from wallaby faecal samples, and B. cenocepacia and B. cepacia were also isolated from livestock animals. Various bacteria isolated in this study represent opportunistic human pathogens, raising the possibility that faecal shedding contributes to the expanding geographical distribution of not just B. pseudomallei but other Burkholderiaceae that can cause human disease.

DEEP BIOSPHERE. Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floor.

Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.

Chemistry and structure of homoepitaxial SrTiO3 films and their influence on oxide-heterostructure interfaces.

The properties of single-crystal SrTiO3 substrates and homoepitaxial SrTiO3 films grown by pulsed laser deposition have been compared, in order to understand the loss of interfacial conductivity when more than a critical thickness of nominally homoepitaxial SrTiO3 is inserted between a LaAlO3 film and a SrTiO3 substrate. In particular, the chemical composition and the structure of homoepitaxial SrTiO3 investigated by low-energy ion-scattering and surface X-ray diffraction show that for insulating heterointerfaces, a Sr-excess is present between the LaAlO3 and homoepitaxial SrTiO3. Furthermore, an increase in the out-of-plane lattice constant is observed in LaAlO3, indicating that the conductivity both with and without insertion of the SrTiO3 thin film originates from a Zener breakdown associated with the polar catastrophe. When more than a critical thickness of homoepitaxial SrTiO3 is inserted between LaAlO3 and SrTiO3, the electrons transferred by the electronic reconstruction are trapped by the formation of a Sr-rich secondary phase and Sr-vacancies. The migration of Sr towards the surface of homoepitaxial SrTiO3 and accompanying loss of interfacial conductivity can be delayed by reducing the Sr-content in the PLD target.

Association of the melioidosis agent Burkholderia pseudomallei with water parameters in rural water supplies in Northern Australia.

We analyzed water parameters and the occurrence of the melioidosis agent Burkholderia pseudomallei in 47 water bores in Northern Australia. B. pseudomallei was associated with soft, acidic bore water of low salinity but high iron levels. This finding aids in identifying water supplies at risk of contamination with this pathogenic bacterium.

Intrasubject reproducibility of functional MR imaging activation in language tasks.

BACKGROUND AND PURPOSE: The purpose of this study was to examine the reproducibility of functional MR imaging (fMRI) activation (volume and laterality) within both inferior frontal and temporoparietal regions of interest for both receptive and expressive language tasks. METHODS: Ten healthy volunteers participated in fMRI experiments for 6 language tasks: verb generation, confrontation naming, semantic decision making, visual sentence comprehension, auditory sentence comprehension, and story listening. Each subject was scanned during 2 separate sessions separated by a minimum of 4 weeks. Laterality of activation was defined by laterality indices (LIs), which were calculated by 2 methods: one method based on the measured volume of activation and the other method based on the F statistic of the activation. Reproducibility was calculated by using concurrence ratios for the volume of activation (R(overlap), R(volume)) and test-retest correlation for LIs. RESULTS: All tasks generated reproducible LIs within at least one of the regions of interest, but verb generation produced the highest test-retest correlations (r = 0.99) within both regions of interest. Verb generation was associated with the highest average concurrence ratios within the inferior frontal region of interest (R(overlap) = 45.2; R(volume) = 70.9). In general, the concurrence ratios were lower within the temporoparietal region of interest compared with the inferior frontal region of interest. LIs calculated with F statistics were more reproducible than the LIs calculated by activation volume. CONCLUSION: fMRI is able to provide reproducible LIs in both inferior frontal and temporoparietal regions for assessing hemispheric dominance in language processing. The volume of activation, especially within the temporoparietal regions, is less reproducible than the laterality of activation, so the former should be used with caution.

Rate of nosocomial transmission of vancomycin-resistant enterococci from isolated patients.

To evaluate an isolation policy for patients colonised with vancomycin-resistant enterococci (VRE), we instituted active surveillance for transmission to uncolonised patients. Surveillance rectal swabs were taken and pulsed-field gel electrophoresis was performed on positive isolates. VRE transmission with an identical genotype occurred in 5 patients, giving a transmission rate of 3.7 per 1000 patient days, or 1 patient per ward each week. The present study provides a baseline for -assessment of VRE transmission and will be useful in evaluation of the effectiveness of infection control interventions.

Risk factors for acquisition of methicillin-resistant Staphylococcus aureus (MRSA) by trauma patients in the intensive care unit.

In a previous study in the intensive care unit (ICU) of the Alfred Hospital, Melbourne, Australia, it was demonstrated that trauma patients were at particular risk of becoming colonized by methicillin-resistant Staphylococcus aureus (MRSA). We examined risk factors for MRSA acquisition in these patients using a cohort study comparing the 31 patients who acquired MRSA with 65 who did not. Data collected included ICU length of stay (LOS), mechanism of trauma, site of injury, type of surgery, trauma severity and antibiotic usage. Odds ratios (OR) were determined and adjusted for LOS. LOS in the ICU was a significant univariate predictor of MRSA acquisition (OR 13.7). When adjusted for LOS, mechanism of trauma (OR 10.4), laparotomy (OR 6.3) and administration of ticarcillin/clavulanic acid (OR 4.5) or glycopeptides (OR 5.9) remained significant. We confirmed our previous finding that LOS was associated with MRSA acquisition. Receipt of antibiotics correlated with reported literature. Novel associations were road trauma as a mechanism and laparotomy.

Removal of nano and microparticles by granular filter media coated with nanoporous aluminium oxide.

Conventional filtration was designed to achieve high levels of particle and pathogen removal. Previous studies have examined the possibility of modifying filtration media to improve their ability to remove microorganisms and viruses. Although these studies have evaluated filter media coatings for this purpose, none have evaluated nanoscale particle suspensions as coating materials. The overall goal of this paper is to describe the preliminary test results of nanoporous aluminium oxide coated media that can be used to enhance filtration of nano and microparticles. Filtration tests were carried out using columns packed with uncoated and coated forms of granular anthracite or granular activated carbon. A positive correlation between isoelectric pH of filter media and particle removal was observed. The modified filter media with a higher isoelectric pH facilitated better removal of bacteriophage MS2 and 3 microm latex microspheres, possibly due to increased favorable electrostatic interactions.

Simultaneous determination of bacterial viability and identity in biofilms using ethidium monoazide and fluorescent in situ hybridization.

A protocol for simultaneously interrogating bacterial viability and identity using in situ, culture-independent methods is described. Viability is assayed using ethidium monoazide (EMA) staining of cells with compromised membranes, and identity is determined using fluorescent in situ hybridization (FISH). Experiments with planktonic cultures were used to demonstrate the compatibility of EMA staining and FISH after covalently bonding EMA to nucleic acids by photoreaction. Applications to biofilm samples showed that diffusion limitations in the biofilm matrix were not problematic and that effective discrimination of viable target cells within a mixed microbial community was possible.

Cost of surgical site infections following coronary artery bypass surgery.

BACKGROUND: Little information is available on the financial impact of surgical site infections (SSI) after major surgery. In order to calculate the cost of SSI following coronary artery bypass graft surgery (CABGs), a 2-year retrospective case-control study was undertaken at Alfred Hospital, a university-affiliated tertiary referral centre. METHODS: One hundred and eight patients with SSI (cases) after CABGs and 108 patients without SSI (controls) were matched for gender, age, risk index (Centers of Disease Control and Prevention, National Nosocomial Infection Surveillance (NNIS) System) and number of principal comorbidities. The patient's postoperative length of stay (LOS), in both the intensive care unit (ICU) and the non-ICU (general) ward, was obtained from the medical records and the cost of a day in each was provided by the hospital's finance department. The cost of antibiotics prescribed for SSI was provided by the hospital's pharmacy department. RESULTS: Postoperatively the cases were in ICU for a total of 313 days whereas the controls spent 165 days in ICU, a mean of 2.89 versus 1.53 days, respectively (P = 0.035). In general wards, cases were inpatients for a total of 1651 days and controls for 589 days. This is a mean of 10.8 days for cases and 4.7 days for controls (P = 0.0001). The extra LOS for 108 cases (compared to the controls) was costed at $1 299 082, a mean cost of $12 028 per patient. The total cost of antibiotics prescribed for these SSI was $42 270 (a cost per case of $391). The total excess cost related to increased LOS and antibiotic treatment was $12 419 per patient. In the subgroup analysis for deep sternal site infections the mean excess cost was $31 597 per patient. CONCLUSIONS: Postoperative SSI result in significant patient morbidity and consume considerable resources. In the present study, patients with SSI following CABGs had significant prolongation of hospitalization (both in ICU and general wards). The present study illustrates the potential cost savings of introducing interventions to reduce SSI rates. This is the first time such a study has been undertaken in Australia.

Evaluation of fiber-composite laminate in the restoration of immature, nonvital maxillary central incisors.

The purpose of this study was to evaluate the use of fiber-composite laminate, a reinforcement ribbon embedded throughout a composite restoration, to reinforce immature maxillary central incisors. Twenty-six mature maxillary central incisors were prepared a minimum of 3 mm below the facial cementoenamel junction to simulate immature nonvital teeth. They were separated into 3 groups: group 1 was unfilled and served as a control; group 2 was filled to the depth of the preparation with composite; and group 3 was filled with composite and Connect Reinforcement Ribbon. The specimens were subjected to class I loading in an Instron Testing Machine until catastrophic failure occurred. The results indicate a highly significant difference between the groups (p < or = 0.003). Group 1 fractured at an average load of 31.08 kg, group 2 at 51.00 kg, and group 3 at 37.93 kg. These findings suggest that composite alone increases fracture resistance of the immature tooth model more than composite with Reinforcement Ribbon.

FMRI mapping of the somatosensory cortex with vibratory stimuli. Is there a dependency on stimulus frequency?

Vibratory stimuli on the skin are mediated by two major receptors: Meissner corpuscles and Pacinian corpuscles. These receptors differ in properties such as density distribution, receptive field size, frequency sensitivity and depth of location. The cortical response to stimulation of these corpuscles can be tested by taking advantage of the differences in frequency discrimination of the receptors. Meissner corpuscles are most sensitive to frequencies around 10-50 Hz (flutter), while Pacinian corpuscles are most sensitive to high frequency (100-300 Hz) vibration. This study compared the neuronal responses (hemodynamic response) generated from vibratory stimuli of 35 Hz and 150 Hz with functional MRI. Group functional activation maps showed differences in the activation pattern for the two stimulus frequencies.

An fMRI study of imagined self-rotation.

In the present study, functional magnetic resonance imaging was used to examine the neural mechanisms involved in the imagined spatial transformation of one's body. The task required subjects to update the position of one of four external objects from memory after they had performed an imagined self-rotation to a new position. Activation in the rotation condition was compared with that in a control condition in which subjects located the positions of objects without imagining a change in self-position. The results indicated similar networks of activation to other egocentric transformation tasks involving decisions about body parts. The most significant area of activation was in the left posterior parietal cortex. Other regions of activation common among several of the subjects were secondary visual, premotor, and frontal lobe regions. These results are discussed relative to motor and visual imagery processes as well as to the distinctions between the present task and other imagined egocentric transformation tasks.

Effluxes of solutes from developing seed coats of Phaseolus vulgaris L. and Vicia faba l.: locating the effect of turgor in a coupled chemiosmotic system.

Cells lining the developing seed coats of legumes efflux photosynthates (mostly sucrose) and salts (mostly of potassium) into the apoplast for uptake by the developing embryo. These effluxes increase transiently in response to an increase in turgor in the effluxing cells. Detached coats of developing seed of P. haseolus vulgaris and Vicia faba were used to study the effects of turgor on the rates of efflux, on the membrane potential difference and on the membrane pH difference, using a number of inhibitors and agents which might affect signal cascades involving cytoplasmic calcium concentration. Effluxes were measured by measuring the concentrations of solutes of interest in solution samples placed in halves of detached seed coats, the paired halves serving as control and treated sample where appropriate. It is shown that a number of substances affect sucrose and potassium effluxes differently, and that hypo-osmotic shock depolarizes the efflux cells and acidifies the cytoplasm (in P. vulgaris). It is concluded that sucrose and potassium effluxes, although both are increased by an increase in turgor, are affected by different signal pathways. Further, it is also concluded that the signal that increases the rates of both sucrose efflux (via sucrose-proton antiport) and proton pump acts directly on the antiporter rather than on the pump. There are interesting parallels and contrasts between these processes and those in plants such as the charophyte Lamprothamnium after hypo-osmotic shock.

Investigation of amine and polyol functionality in extracts of polyurethane wound management dressings using MALDI-MS.

Polyurethane (PU) foams used in wound management are produced by a reaction between aromatic diisocyanates and polyether polyols. There is concern that residues of these starting materials, which may contain aromatic amine functionality, may leach from the finished polymer during in vivo applications. Furthermore, oligomers and additives may be leached from the PU system after the polymerization process is complete. Finished polymers have, therefore, been extracted with a range of solvents, such as water, diethyl ether and dilute HCl. The extracts were subjected to MALDI-MS (matrix-assisted laser desorption ionization mass spectrometry) analysis in an attempt to determine the amine and polyol functionality. Direct MALDI-MS analysis of the wound dressing extracts indicated the presence of components based on the polyols [corrected] used in the formulation of the foam. The spacing between the peaks identified the base monomer used in the polyol. MALDI-MS analysis of the fluorescamine derivatives of model amine compounds has demonstrated the anticipated increase in mass (278 for monoamines and 278 and 556 for diamines). Similar results were obtained from the derivatization of model polyols with phenyl isocyanate, where the mass shift (n x 119) was a direct measure of the number of active hydroxyl groups. Fluorescamine labelling of PU foams shows the colour change which could be [corrected] indicative of the presence of an amine, but the subsequent MALDI-MS analysis was unable to demonstrate the anticipated increase in mass.

A new vibrotactile stimulator for functional MRI.

Presenting various stimuli in an MRI scanner can be difficult due to the high magnetic field associated with the scanner. Mechanical vibration stimuli are difficult to deliver to subjects in the MRI environment because most vibration devices contain internal circuitry that can adversely interact with the high magnetic field. Piezoelectric ceramics can provide a solution to this problem since they do not require any internal circuitry to vibrate. Piezoceramics are nonmagnetic and they can be made to vibrate if supplied with an alternating current from a straight wire. We designed a piezoceramic vibrotactile stimulator that is safe and effective in functional MRI experiments. The stimulator was tested in an fMRI experiment at 35 and 150 Hz. The results yielded activation sites in the primary sensory cortex and Brodmann area 40 at both frequencies.

Risk factors for surgical wound infection and bacteraemia following coronary artery bypass surgery.

BACKGROUND: There has been no consensus from previous studies of risk factors for surgical wound infections (SWI) and postoperative bacteraemia for patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Data on 15 potential risk factors were prospectively collected on all patients undergoing CABG surgery during a 12-month period. RESULTS: Of 693 patients, 62 developed 65 SWI using the Centres for Disease Control definition: 23 were sternal wound infections and 42 were arm or leg wound infections at the site of conduit harvest. There were 19 episodes of postoperative bacteraemia. Multivariate analysis revealed that: (i) diabetes, obesity and previous cardiovascular procedure were independent predictors of SWI; and (ii) obesity was an independent risk factor for postoperative bacteraemia. CONCLUSIONS: These findings suggest that improved diabetic control and pre-operative weight reduction may result in a decrease in the incidence of SWI. But further prospective studies need to be undertaken to examine (i) whether the increased SWI risk in diabetes occurs with both insulin- and non-insulin-requiring diabetes, and whether improved peri-operative diabetes control decreases SWI; and (ii) what degree of obesity confers a risk of SWI and postoperative bacteraemia, and whether pre-operative weight reduction, if a realistic strategy in this patient group, results in a decrease in SWI.

Further analysis of maize C(4) pyruvate,orthophosphate dikinase phosphorylation by its bifunctional regulatory protein using selective substitutions of the regulatory Thr-456 and catalytic His-458 residues.

In C(4) plants such as maize, pyruvate,orthophosphate dikinase (PPDK) catalyzes the regeneration of the initial carboxylation substrate during C(4) photosynthesis. The primary catalytic residue, His-458 (maize C(4) PPDK), is involved in the ultimate transfer of the beta-phosphate from ATP to pyruvate. C(4) PPDK activity undergoes light-dark regulation in vivo by reversible phosphorylation of a nearby active-site residue (Thr-456) by a single bifunctional regulatory protein (RP). Using site-directed mutagenesis of maize recombinant C(4) dikinase, we made substitutions at the catalytic His residue (H458N) and at this regulatory target Thr (T456E, T456Y, T456F). Each of these affinity-purified mutant enzymes was assayed for changes in dikinase activity. As expected, substituting His-458 with Asn results in a catalytically incompetent enzyme. Substitutions of the Thr-456 residue with Tyr and Phe reduced activity by about 94 and 99%, respectively. Insertion of Glu at this position completely abolished activity, presumably by the introduction of negative charge proximal to the catalytic His. Furthermore, neither the T456Y nor inactive H458N mutant enzyme was phosphorylated in vitro by RP. The inability of the former to serve as a phosphorylation substrate indicates that RP is functionally a member of the Ser/Thr family of protein kinases rather than a "dual-specificity" Ser-Thr/Tyr kinase, since our previous work showed that RP effectively phosphorylated Ser inserted at position 456. The inability of RP to phosphorylate its native target Thr residue when Asn is substituted for His-458 documents that RP requires the His-P catalytic intermediate form of PPDK as its protein substrate. For these latter studies, synthetic phosphopeptide-directed antibodies specific for the Thr(456)-P form of maize C(4) PPDK were developed and characterized.

Needleless intravenous systems: A review.

BACKGROUND: Needleless intravenous devices have now been implemented by many institutions worldwide. A rationale for their use has been a reduction in the number of needlestick injuries. OBJECTIVE: The aim of this review is to outline the possible benefits and dangers of needleless intravenous systems. REVIEW: Many early reports demonstrate a reduction in needlestick injuries after the implementation of a needleless intravenous device; however, not all such reductions are directly attributable to the device itself. Furthermore, good evidence suggests that needlestick accidents prevented by needleless intravenous devices pose little threat to health care workers. Finally, increasing reports associate bacteremias with the use of needleless intravenous devices. Early reports described devices used in the home care setting; however, recent reports are from acute health care settings, including intensive care units. CONCLUSION: Ongoing critical review of the benefits, risks, and costs of needleless intravenous devices is required.