Carbapenem-resistant
(CRE) represent a health threat, but effective control interventions remain unclear. Hospital wastewater sites are increasingly being highlighted as important potential ...reservoirs. We investigated a large
carbapenemase (KPC)-producing
outbreak and wider CRE incidence trends in the Central Manchester University Hospital NHS Foundation Trust (CMFT) (United Kingdom) over 8 years, to determine the impact of infection prevention and control measures. Bacteriology and patient administration data (2009 to 2017) were linked, and a subset of CMFT or regional hospital KPC-producing
isolates (
= 268) were sequenced. Control interventions followed international guidelines and included cohorting, rectal screening (
= 184,539 screens), environmental sampling, enhanced cleaning, and ward closure and plumbing replacement. Segmented regression of time trends for CRE detections was used to evaluate the impact of interventions on CRE incidence. Genomic analysis (
= 268 isolates) identified the spread of a KPC-producing
outbreak clone (strain A, sequence type 216 ST216;
= 125) among patients and in the environment, particularly on 2 cardiac wards (wards 3 and 4), despite control measures. ST216 strain A had caused an antecedent outbreak and shared its KPC plasmids with other
lineages and
species. CRE acquisition incidence declined after closure of wards 3 and 4 and plumbing replacement, suggesting an environmental contribution. However, ward 3/ward 4 wastewater sites were rapidly recolonized with CRE and patient CRE acquisitions recurred, albeit at lower rates. Patient relocation and plumbing replacement were associated with control of a clonal KPC-producing
outbreak; however, environmental contamination with CRE and patient CRE acquisitions recurred rapidly following this intervention. The large numbers of cases and the persistence of
in
, including pathogenic lineages, are of concern.
The prevention of healthcare‐associated infections (HCAIs) is a major challenge currently being faced by hospitals in both the UK and worldwide. The hospital environment acts as a reservoir for ...nosocomial organisms contributing towards the transmission of bacteria and thus the colonisation and infection rates of the patient population. Therefore, it is desirable to implement measures to decrease the microbial load within the hospital environment as a whole and particularly on frequently touched surfaces. Antimicrobial coatings could be applied to these surfaces, and used as an adjunct to other infection control policies to reduce the incidence of HCAIs. Novel nitrogen‐doped, sulfur‐doped and silver‐coated titanium dioxide photocatalytic thin films were generated by sol‐gel or chemical vapour deposition. The materials exhibited antibacterial properties after exposure to a white light commonly used in UK hospitals. However, it was difficult to synthesise reproducible thin films using the CVD method of deposition. An additional antibacterial material was generated with the potential to be used in endotracheal tubes to reduce the incidence of HCAIs such as ventilator‐associated pneumonia. The novel polymer was impregnated with a photosensitiser using a swell encapsulation method, and activated with laser light; the antibacterial and anti‐adhesive properties were then assessed. Sampling the test surfaces by swabbing and subsequently performing viable counts was shown to provide an adequate estimate of concentration of bacteria on a test surface. The nitrogen‐ and sulfur‐doped titanium dioxide coatings displayed significant photocatalytic activity against Escherichia coli after exposure to a white light source, which demonstrate d a shift in the band gap from the UV to the visible region of the electromagnetic spectrum. Visible light photocatalysis was confirmed on the silver-coated titania thin films when a UV filter was used to block out the minimal UV component of the white light source, in the form of photo‐oxidation of stearic acid, a reduction in the water contact angle and photocatalytic activity against an epidemic strain of meticillin resistant Staphylococcus aureus (EMRSA‐16). This is the first example of unambiguous visible light photocatalysis and photo‐induced superhydrophilicity alongside a titanium dioxide control that shows no activation. A reduction in the viability of EMRSA‐16 adhered onto the surface of the irradiated silver‐coated titania thin films was also demonstrated. A significant reduction in the recovery of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter baumannii and Candida albicans was observed on TBO-impregnated polymers, after irradiation with a HeNe laser light. A recently isolated clinical strain of P. aeruginosa showed decreased susceptibility to the photo‐activity of the TBO‐impregnated polymers compared with a laboratory type strain. Finally, a significant reduction in the adhesion of P. aeruginosa on the TBO-impregnated polymers was demonstrated after a 3‐step irradiation schedule. A photo‐bleaching effect was noted after light exposure that reduced the antibacterial activity of the polymers, which demonstrates the requirement for further modification to retain the photosensitiser within the polyurethane matrix. These novel materials have the potential to be used as anti‐microbial surfaces in healthcare environments.
The prevention of healthcare‐associated infections (HCAIs) is a major challenge currently being faced by hospitals in both the UK and worldwide. The hospital environment acts as a reservoir for ...nosocomial organisms contributing towards the transmission of bacteria and thus the colonisation and infection rates of the patient population. Therefore, it is desirable to implement measures to decrease the microbial load within the hospital environment as a whole and particularly on frequently touched surfaces. Antimicrobial coatings could be applied to these surfaces, and used as an adjunct to other infection control policies to reduce the incidence of HCAIs. Novel nitrogen‐doped, sulfur‐doped and silver‐coated titanium dioxide photocatalytic thin films were generated by sol‐gel or chemical vapour deposition. The materials exhibited antibacterial properties after exposure to a white light commonly used in UK hospitals. However, it was difficult to synthesise reproducible thin films using the CVD method of deposition. An additional antibacterial material was generated with the potential to be used in endotracheal tubes to reduce the incidence of HCAIs such as ventilator‐associated pneumonia. The novel polymer was impregnated with a photosensitiser using a swell encapsulation method, and activated with laser light; the antibacterial and anti‐adhesive properties were then assessed. Sampling the test surfaces by swabbing and subsequently performing viable counts was shown to provide an adequate estimate of concentration of bacteria on a test surface. The nitrogen‐ and sulfur‐doped titanium dioxide coatings displayed significant photocatalytic activity against Escherichia coli after exposure to a white light source, which demonstrate d a shift in the band gap from the UV to the visible region of the electromagnetic spectrum. Visible light photocatalysis was confirmed on the silver-coated titania thin films when a UV filter was used to block out the minimal UV component of the white light source, in the form of photo‐oxidation of stearic acid, a reduction in the water contact angle and photocatalytic activity against an epidemic strain of meticillin resistant Staphylococcus aureus (EMRSA‐16). This is the first example of unambiguous visible light photocatalysis and photo‐induced superhydrophilicity alongside a titanium dioxide control that shows no activation. A reduction in the viability of EMRSA‐16 adhered onto the surface of the irradiated silver‐coated titania thin films was also demonstrated. A significant reduction in the recovery of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter baumannii and Candida albicans was observed on TBO-impregnated polymers, after irradiation with a HeNe laser light. A recently isolated clinical strain of P. aeruginosa showed decreased susceptibility to the photo‐activity of the TBO‐impregnated polymers compared with a laboratory type strain. Finally, a significant reduction in the adhesion of P. aeruginosa on the TBO-impregnated polymers was demonstrated after a 3‐step irradiation schedule. A photo‐bleaching effect was noted after light exposure that reduced the antibacterial activity of the polymers, which demonstrates the requirement for further modification to retain the photosensitiser within the polyurethane matrix. These novel materials have the potential to be used as anti‐microbial surfaces in healthcare environments.
The prevention of healthcare‐associated infections (HCAIs) is a major challenge currently being faced by hospitals in both the UK and worldwide. The hospital environment acts as a reservoir for ...nosocomial organisms contributing towards the transmission of bacteria and thus the colonisation and infection rates of the patient population. Therefore, it is desirable to implement measures to decrease the microbial load within the hospital environment as a whole and particularly on frequently touched surfaces. Antimicrobial coatings could be applied to these surfaces, and used as an adjunct to other infection control policies to reduce the incidence of HCAIs. Novel nitrogen‐doped, sulfur‐doped and silver‐coated titanium dioxide photocatalytic thin films were generated by sol‐gel or chemical vapour deposition. The materials exhibited antibacterial properties after exposure to a white light commonly used in UK hospitals. However, it was difficult to synthesise reproducible thin films using the CVD method of deposition. An additional antibacterial material was generated with the potential to be used in endotracheal tubes to reduce the incidence of HCAIs such as ventilator‐associated pneumonia. The novel polymer was impregnated with a photosensitiser using a swell encapsulation method, and activated with laser light; the antibacterial and anti‐adhesive properties were then assessed. Sampling the test surfaces by swabbing and subsequently performing viable counts was shown to provide an adequate estimate of concentration of bacteria on a test surface. The nitrogen‐ and sulfur‐doped titanium dioxide coatings displayed significant photocatalytic activity against Escherichia coli after exposure to a white light source, which demonstrate d a shift in the band gap from the UV to the visible region of the electromagnetic spectrum. Visible light photocatalysis was confirmed on the silver-coated titania thin films when a UV filter was used to block out the minimal UV component of the white light source, in the form of photo‐oxidation of stearic acid, a reduction in the water contact angle and photocatalytic activity against an epidemic strain of meticillin resistant Staphylococcus aureus (EMRSA‐16). This is the first example of unambiguous visible light photocatalysis and photo‐induced superhydrophilicity alongside a titanium dioxide control that shows no activation. A reduction in the viability of EMRSA‐16 adhered onto the surface of the irradiated silver‐coated titania thin films was also demonstrated. A significant reduction in the recovery of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter baumannii and Candida albicans was observed on TBO-impregnated polymers, after irradiation with a HeNe laser light. A recently isolated clinical strain of P. aeruginosa showed decreased susceptibility to the photo‐activity of the TBO‐impregnated polymers compared with a laboratory type strain. Finally, a significant reduction in the adhesion of P. aeruginosa on the TBO-impregnated polymers was demonstrated after a 3‐step irradiation schedule. A photo‐bleaching effect was noted after light exposure that reduced the antibacterial activity of the polymers, which demonstrates the requirement for further modification to retain the photosensitiser within the polyurethane matrix. These novel materials have the potential to be used as anti‐microbial surfaces in healthcare environments.
Sulfur-doped titania thin films were prepared by atmospheric pressure chemical vapour deposition (APCVD) for the first time using titanium tetrachloride, ethyl acetate and carbon disulfide. The films ...were compared to two industrial self-cleaning products: Activ super(TM) and BIOCLEAN super(TM), and shown to be superior in both photocatalysis and photo-induced superhydrophilicity, two preferential properties of effective self-cleaning coatings. X-Ray diffraction showed the films have the anatase TiO sub(2) structure. XPS and EDX analysis shows changes in S: Ti ratio with preparative conditions indicating that sulfur has indeed been incorporated into the lattice. S-Doped TiO sub(2) films were found to be effective agents for killing the bacterium Escherichia coli using light sources commonly found in UK hospitals.
Sulfur-doped titania thin films were prepared by atmospheric pressure chemical vapour deposition (APCVD) for the first time using titanium tetrachloride, ethyl acetate and carbon disulfide. The films ...were compared to two industrial self-cleaning products: Activ(TM) and BIOCLEAN(TM), and shown to be superior in both photocatalysis and photo-induced superhydrophilicity, two preferential properties of effective self-cleaning coatings. X-Ray diffraction showed the films have the anatase TiO(2) structure. XPS and EDX analysis shows changes in S: Ti ratio with preparative conditions indicating that sulfur has indeed been incorporated into the lattice. S-Doped TiO(2) films were found to be effective agents for killing the bacterium Escherichia coli using light sources commonly found in UK hospitals.
The fate of permafrost carbon upon thaw will drive feedbacks to climate warming. Here we consider the character and context of dissolved organic carbon (DOC) in yedoma permafrost cores from up to 20 ...m depth in central Alaska. We observed high DOC concentrations (4 to 129 mM) and consistent low molecular weight organic acid concentrations in three cores. We estimate a DOC production rate of 12 µmol DOC m−2 yr−1 based on model ages of up to ~200 kyr derived from uranium isotopes. Acetate C accounted for 24 ± 1% of DOC in all samples. This proportion suggests long‐term anaerobiosis and is likely to influence thaw outcomes due to biolability of acetate upon release in many environments. The combination of uranium isotopes, ammonium concentrations, and calcium concentrations explained 86% of the variation in thaw water DOC concentrations, suggesting that DOC production may be related to both reducing conditions and mineral dissolution over time.
Key Points
Aged, biolabile forms of DOC are present in Pleistocene permafrost
Reducing conditions in yedoma produce biolabile DOC and characteristic solutes over time
Both reducing conditions and mineral dissolution are related to permafrost DOC production
With a potential to deliver 60% greater energy density than conventional lithium-ion batteries, the simple design of anode-free lithium metal cells with liquid electrolytes has generated significant ...research interest. However, without excess lithium, the short lifetime and safety concerns for cells cycling lithium metal with liquid electrolytes make the development of anode-free cells particularly challenging. Herein, we investigate the effect of four different positive electrode materials on the performance of anode-free cells—LiNi
0.5
Mn
0.3
Co
0.2
O
2
(NMC532), LiNi
0.8
Mn
0.1
Co
0.1
O
2
(NMC811), LiCoO
2
(LCO), and LiFePO
4
(LFP). In-situ electrochemical impedance spectroscopy and electrolyte degradation measurements were performed on cells with dual-salt LiDFOB/LiBF
4
electrolyte to elucidate cell failure. Additional state-of-the-art electrolyte systems as well as other testing conditions (temperature, pressure, depth of discharge) were also explored, along with nail safety tests and calendar aging cycle-hold experiments. We show that the rate of lithium inventory loss and impedance growth differs amongst these cell chemistries, ultimately resulting in the shortest lifetime for NMC811 and the longest lifetime for LCO anode-free cells of 200 cycles.
Low birth weight and accelerated postnatal growth lead to increased risk of cardiovascular disease. We reported previously that rats exposed to a low‐protein diet in utero and postnatal catch‐up ...growth (recuperated) develop metabolic dysfunction and have reduced life span. Here we explored the hypothesis that cardiac oxidative and nitrosative stress leading to DNA damage and accelerated cellular aging could contribute to these phenotypes. Recuperated animals had a low birth weight (P<0.001) but caught up in weight to controls during lactation. At weaning, recuperated cardiac tissue had increased (P<0.05) protein nitrotyrosination and DNA single‐stranded breaks. This condition was preceded by increased expression of DNA damage repair molecules 8‐oxoguanine‐DNA‐glycosylase‐1, nei‐endonuclease‐VIII‐like, X‐ray‐repair‐complementing‐defective‐repair‐1, and Nthl endonuclease III‐like‐1 on d 3. These differences were maintained on d 22 and became more pronounced in the case of 8‐oxoguanine‐DNA‐glycosylase‐1 and neiendonuclease‐VIII‐like. This was accompanied by increases in xanthine oxidase (P<0.001) and NADPH oxidase (P<0.05), major sources of reactive oxygen species (ROS). The detrimental effects of increased ROS in recuperated offspring may be exaggerated at 22 d by reductions (P<0.001) in the antioxidant enzymes perox‐iredoxin‐3 and CuZn‐superoxide‐dismutase. We conclude that poor fetal nutrition followed by accelerated postnatal growth results in increased cardiac nitrosative and oxidative‐stress and DNA damage, which could contribute to age‐associated disease risk.—TarryAdkins, J. L., Martin‐Gronert, M. S., Fernandez‐Twinn, D. S., Hargreaves, I., Alfaradhi, M. Z., Land, J. M., Aiken, C. E., Ozanne, S. E. Poor maternal nutrition followed by accelerated postnatal growth leads to alterations in DNA damage and repair, oxidative and nitrosative stress and oxidative defense capacity in rat heart. FASEB J. 27, 379–390 (2013). www.fasebj.org
Elevated levels of somatostatin blunt glucagon counterregulation during hypoglycemia in type 1 diabetes (T1D) and this can be improved using somatostatin receptor 2 (SSTR2) antagonists. Hypoglycemia ...also occurs in late-stage type 2 diabetes (T2D), particularly when insulin therapy is initiated, but the utility of SSTR2 antagonists in ameliorating hypoglycemia in this disease state is unknown. We examined the efficacy of a single-dose of SSTR2 antagonists in a rodent model of T2D.
High-fat fed (HFF), low dose streptozotocin (STZ, 35 mg/kg)-induced T2D and HFF only, nondiabetic (controls-no STZ) rats were treated with the SSTR2 antagonists ZT-01/PRL-2903 or vehicle (
= 9-11/group) 60 min before an insulin tolerance test (ITT; 2-12 U/kg insulin aspart) or an oral glucose tolerance test (OGTT; 2 g/kg glucose via oral gavage) on separate days.
This rodent model of T2D is characterized by higher baseline glucose and HbA1c levels relative to HFF controls. T2D rats also had lower c-peptide levels at baseline and a blunted glucagon counterregulatory response to hypoglycemia when subjected to the ITT. SSTR2 antagonists increased the glucagon response and reduced incidence of hypoglycemia, which was more pronounced with ZT-01 than PRL-2903. ZT-01 treatment in the T2D rats increased glucagon levels above the control response within 60 min of dosing, and values remained elevated during the ITT (glucagon Cmax: 156 ± 50 vs. 77 ± 46 pg/mL,
< 0.01). Hypoglycemia incidence was attenuated with ZT-01 vs. controls (63% vs. 100%) and average time to hypoglycemia onset was also delayed (103.1 ± 24.6 vs. 66.1 ± 23.6 min,
< 0.05). ZT-01 administration at the OGTT onset increased the glucagon response without exacerbating hyperglycemia (2877 ± 806 vs. 2982 ± 781), potentially due to the corresponding increase in c-peptide levels (6251 ± 5463 vs. 14008 ± 5495,
= 0.013).
Treatment with SSTR2 antagonists increases glucagon responses in a rat model of T2D and results in less hypoglycemia exposure. Future studies are required to determine the best dosing periods for chronic SSTR2 antagonism treatment in T2D.
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