Electronic hand hygiene monitoring systems can be well-tolerated by health workers: Findings of a qualitative study.

BACKGROUND: Electronic hand hygiene monitoring overcomes limitations associated with manual audit but acceptability to health workers varies and may depend on culture of the ward and the nature of the system. OBJECTIVES: Evaluate the acceptability of a new fifth type electronic monitoring system to frontline health workers in a National Health Service trust in the UK. METHODS: Qualitative interviews with 11 informants following 12 months experience using an electronic monitoring system. RESULTS: Informants recognised the importance of hand hygiene and embraced technology to improve adherence. Barriers to hand hygiene adherence included heavy workload, dealing with emergencies and ergonomic factors related to placement of alcohol dispensers. Opinions about the validity of the automated readings were conflicting. Some health workers thought they were accurate. Others reported problems associated with differences in the intelligence of the system and their own clinical decisions. Opinions about feedback were diverse. Some health workers thought the system increased personal accountability for hand hygiene. Others ignored feedback on suboptimal performance or ignored the data altogether. It was hard for health workers to understand why the system registered some instances of poor performance because feedback did not allow omissions in hand hygiene to be related to the context of care. CONCLUSION: Electronic monitoring can be very well tolerated despite some limitations. Further research needs to explore different reactions to feedback and how often clinical emergencies arise. Electronic and manual audit have complementary strengths.

Reducing adult cardiac surgical site infections and the economic impact of using multidisciplinary collaboration.

BACKGROUND: Cardiac surgical site infections (SSIs) have devastating consequences and present several challenges for patients and healthcare providers. Adult cardiac SSI surveillance commenced in 2009 at our hospitals, Guy's & St Thomas' NHS Foundation Trust, London, as a patient safety initiative amid reported increased incidence of SSIs. Before this time, infection incidence was unclear because data collection was not standardized. AIM: To standardize SSI data collection and establish baseline SSI rates to facilitate deployment of evidence-based targeted interventions within clinical governance structures to improve quality, safety, and efficiency in line with our organizational targets. METHODS: We standardized local data collection protocols in line with Public Health England recommendations and identified local champions. We undertook prospective SSI surveillance collaboratively to enable us to identify potential practice concerns and address them more effectively through a series of initiatives. Clinical staff completed dedicated surveillance forms intraoperatively and postoperatively. FINDINGS: Overall adult cardiac SSI rates fell from 5.4% in 2009 to 1.2% in 2016 and coronary artery bypass graft rates from 6.5% in 2009 to 1.7% in 2016 (P < 0.001). Gram-negative bacteria were recognized as important SSI causative organisms and were better controlled after introducing stringent infection control measures. CONCLUSION: Comprehensive, evidence-based infection control practices were successfully implemented through a multidisciplinary collaborative approach, which may have great potential to reduce Gram-negative, Staphylococcus aureus, polymicrobial and overall SSI burden and/or associated costs. We now investigate all SSIs using an established SSI detailed investigation protocol to promote continual quality improvement that aligns us perfectly with global efforts to fight antimicrobial resistance.

Does hospital cleanliness correlate with methicillin-resistant Staphylococcus aureus bacteraemia rates?

Publicly available data for all National Health Service hospitals in England were used to examine whether there is a link between hospital cleanliness and rates of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia. It was not possible to demonstrate a consistent relationship between hospital cleanliness, as measured by weighted Patient Environment Action Team (PEAT) scores, and the incidence of MRSA bacteraemia. The large sizes of the data sets make it unlikely that a true correlation was missed. While a high standard of hospital cleanliness is a worthwhile goal, it is not helpful to repeatedly link MRSA control measures with improvements in standards of environmental cleanliness.

Prospective evaluation of hospital isolation room capacity.

Risk assessment is used to determine the need for isolation in single rooms. Limited availability of isolation rooms and/or operational needs may compromise this process. This article reports the results of a 12-month prospective observational study of every infection control request for isolation in a 1100-bed teaching hospital. In addition, four point-prevalence surveys of the usage of single rooms were carried out. Data were collected on the incidence of new clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates per ward and these were correlated with rates of isolation failures for MRSA cases. There were 845 requirements for patient isolation, of which 185 (22%) could not be met (isolation failures). Three-quarters of the requirements for isolation were due to MRSA or Clostridium difficile. The proportion of isolation failures was consistent for most organisms and conditions but varied markedly between clinical specialities (0-57%). Reasons for failure to isolate included no single rooms available, all single/isolation rooms occupied (for both isolation and non-infection-control reasons), limitations on the use of single rooms in mixed-sex wards and patient-specific reasons. Only a minority of the available single rooms were occupied for infection control reasons (12-19%). There was a statistically significant correlation between isolation failures and MRSA incidence (Spearman's rho 0.596, P<0.001). In only one case where a ward had >or=30% of its beds provided in single rooms was there an instance of failure to isolate. In conclusion, insufficient capacity to isolate patients with potentially transmissible pathogens is common and may compromise infection control requirements. Either isolation capacity must be increased or evidence-based risk assessment must be applied to situations where demand for isolation exceeds availability. Further information is needed on the consequences of isolation failure.

Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection.

To determine how best to decontaminate the hospital environment of Clostridium difficile, we carried out a cross-over study on two elderly medicine wards to determine whether cleaning with a hypochlorite disinfectant was better than using neutral detergent in reducing the incidence of C. difficile infection (CDI). We examined 1128 environmental samples in two years, 35% of which grew C. difficile. There was a significant decrease of CDI incidence on ward X, from 8.9 to 5.3 cases per 100 admissions (P<0.05) using hypochlorite, but there was no significant effect on ward Y. On ward X the incidence of CDI was significantly associated with the proportion of culture-positive environmental sites (P<0.05). On ward Y the only significant correlation between CDI and C. difficile culture-positive environmental sites was in patient side-rooms (r=0.41, P<0.05). The total daily defined doses of cefotaxime, cephradine and aminopenicillins were similar throughout the trial. These results provide some evidence that use of hypochlorite for environmental cleaning may significantly reduce incidence of CDI, but emphasize the potential for confounding factors.

The cytoskeletal protein vinculin is acylated by myristic acid.

In non-muscle cells the mechanism by which microfilament bundles interact with the plasma membrane is unclear. Vinculin, a 130 kDa protein found in adhesion plaques, has been postulated to have a role as a membrane anchor for microfilaments and we have investigated the biochemistry of this molecule in more detail. We report that a fraction of vinculin in chick embryo fibroblasts is acylated by myristic acid. This modification was present in both membrane-bound, cytoskeletal and cytosolic vinculin and thus did not determine preferential subcellular localisation. Myristic acid was also present in vinculin from cells transformed by Rous sarcoma virus.

The use of Rous sarcoma virus transformation mutants with differing tyrosine kinase activities to study the relationships between vinculin phosphorylation, pp60v-src location and adhesion plaque integrity.

Tyrosine-specific phosphorylation of cellular proteins has been implicated in the neoplastic transformation of cells by Rous sarcoma virus (RSV). One of the putative substrates for the src gene product (pp60v-src) of RSV is the cytoskeletal protein vinculin, giving rise to the hypothesis that tyrosine-specific phosphorylation of vinculin disrupts adhesion plaque integrity, leading to the characteristic rounded morphology of RSV-transformed cells. We have investigated this hypothesis by analysing the properties of fibroblasts transformed by conditional and non-conditional mutants of RSV which confer different morphologies on infected cells, with respect to formation of microfilament bundles, formation of vinculin-containing adhesion plaques, the deposition of a fibronectin-containing extracellular matrix, the localization of pp60v-src and the tyrosine-specific phosphorylation of vinculin. Cells transformed by the temperature-sensitive (ts) RSV mutant LA32 cultured at 41 degrees C were morphologically normal, and contained prominent microfilament bundles and well-developed adhesion plaques. However, these cells had a fully active pp60v-src kinase, had pp60v-src concentrated in their adhesion plaques and contained vinculin which was heavily phosphorylated on tyrosine residues. Cells transformed by a recovered avian sarcoma virus, rASV 2234.3 exhibited a markedly fusiform morphology with pp60v-src concentrated in well-developed adhesion plaques and an elevation of the phosphotyrosine content of vinculin. Cells transformed by LA32 at restrictive temperature comprise morphologically normal cells, indistinguishable from untransformed CEF, yet which contain tyrosine-phosphorylated vinculin and suggest that neither tyrosine-specific phosphorylation of vinculin nor pp60v-src concentration in adhesion plaques is sufficient for the rounded morphology of RSV-transformed cells.

Comparison of the relative importance of tyrosine-specific vinculin phosphorylation and the loss of surface-associated fibronectin in the morphology of cells transformed by Rous sarcoma virus.

We have investigated the relative importance of tyrosine-specific phosphorylation of vinculin and the loss of surface-associated fibronectin in the maintenance of the rounded morphology characteristic of chick embryo fibroblasts (CEF) transformed by Rous sarcoma virus (RSV). To address this question we have examined the interaction of CEF and RSV-CEF in vitro with exogenously added fibronectin in both 3-day culture experiments and short-term, 3-h spreading experiments. We report that the addition of human plasma fibronectin to cultures of RSV-CEF results in the restoration of a near-normal morphology, as has been described previously, with the added fibronectin incorporated into an extracellular matrix. However, the phosphotyrosine content of vinculin in these cells was unchanged from that of control, untreated RSV-CEF despite the change in morphology. In short-term spreading experiments RSV-CEF were unable to adopt a fully spread morphology on fibronectin substrates, with defects in the formation of adhesion plaques and microfilament bundles compared with untransformed CEF. pp60v-src was present in the newly formed adhesion plaques of RSV-CEF spreading on fibronectin substrates. The relevance of these results to the maintenance of the transformed phenotype is discussed.

Nonidet P-40 extraction of lymphocyte plasma membrane. Characterization of the insoluble residue.

Purified preparations of lymphocyte plasma membrane were extracted exhaustively with Nonidet P-40 in Dulbecco's phosphate-buffered saline medium. The insoluble fraction, as defined by sedimentation at 10(6) g-min, contained about 10% of the membrane protein as well as cholesterol and phospholipid. The lipid/protein ratio, cholesterol/phospholipid ratio and sphingomyelin content were increased in the residue. Density-gradient centrifugation suggested that the lipid and protein form a common entity. As judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the Nonidet P-40-insoluble fractions of the plasma membranes of human B lymphoblastoid cells and pig mesenteric lymph-node lymphocytes possessed similar qualitative polypeptide compositions but differed quantitatively. Both residues comprised major polypeptides of Mr 28 000, 33 000, 45 000 and 68 000, together with a prominent band of Mr 120 000 in the human and of Mr 200 000 in the pig. The polypeptides of Mr 28 000, 33 000, 68 000 and 120 000 were probably located exclusively in the Nonidet P-40-insoluble residue, which also possessed a 4-fold increase in 5'-nucleotidase specific activity. The results indicate that a reproducible fraction of lymphocyte plasma membrane is insoluble in non-ionic detergents and that this fraction possesses a unique polypeptide composition. By analogy with similar studies with erythrocyte ghosts, it appears likely that the polypeptides are located on the plasma membrane's cytoplasmic face.

Biosynthesis and molecular nature of the T3 antigen of human T lymphocytes.

Immunoprecipitates of the T3 antigen prepared from HPB-ALL cells by using the monoclonal antibody UCH-T1 were analysed by SDS-polyacrylamide gel electrophoresis. Cells which had been biosynthetically labelled for up to 4 h gave a major polypeptide of mol. wt. 19 000 plus two weaker, more diffuse bands of mol. wts. 21 000 and 23 000, whereas surface labelled cells gave a prominent band of mol. wt. 19 000, a major band of 21 000 and a weaker diffuse band of approximately 26 000. As judged from their sensitivity to proteinase-K digestion, all the above polypeptides possess a transmembrane orientation. Digestion with endoglycosidases H and F (endo-H and endo-F), and tunicamycin treatment indicate that all the polypeptides, except that of 19 000 mol. wt. are N-glycosylated. The 21 000 and 23 000 mol. wt. chains possess both immature and mature oligosaccharide units, whereas the 26 000 mol. wt. band apparently has mature units only. Pulse chase experiments combined with digestion by endo-F and endo-H suggest that the N-glycosylated polypeptides are derived from two polypeptides of mol. wts. 14 000 and 16 000. It is concluded that the T3 antigen is derived from three different non-glycosylated polypeptides two of which are subsequently N-glycosylated to give the 21 000, 23 000 and 26 000 forms. The cell surface T3 antigen most probably comprises at least two distinct, non-covalently associated polypeptides, but the number and types of polypeptides giving rise to the whole molecule and whether different complexes exist is at present unclear.

Vasopressin rapidly stimulates Na entry and Na-K pump activity in quiescent cultures of mouse 3T3 cells.

Addition of (Arg) vasopressin to quiescent cultures of Swiss 3T3 cells rapidly stimulates an ouabain-sensitive 86Rb uptake. In contrast the hormone has no significant effect on the rate of efflux of this cation from preloaded cells. The stimulation of 86Rb uptake is cycloheximide-insensitive, occurs within minutes of hormone addition and results from an increase in the Vmax of the uptake system. Vasopressin stimulates ion uptake in a concentration-dependent fashion (1--100 ng/ml); oxytocin also stimulated the Na-K pump but at significantly higher concentrations. The stimulation of the Na-K pump by vasopressin is apparently mediated by an increase in Na entry into the cells, since the hormone 1) strikingly shifts the concentration dependence on Na+ of the Na-K pump, 2) increases 22Na uptake, and 3) increases intracellular Na contents when the efflux of this ion is blocked by ouabain. Since vasopressin is a potent mitogen for Swiss 3T3 cells, the results provide further evidence in support of a possible role of monovalent ion fluxes in signalling the initiation of growth stimulation.

Na entry and Na-K pump activity in murine, hamster, and human cells--effect of monensin, serum, platelet extract, and viral transformation.

The relationship between Na entry and the activity of the Na-K pump has been investigated in a variety of cell types by testing the effect of the Na ionophore monensin, mitogenic stimulation with serum and oncogenic transformation by SV40 and polyoma virus. We found that addition of monensin increases intracellular Na in quiescent cultures of murine, hamster, and human cells. In each case, the rise in intracellular Na by monensin is associated with an increase in the activity of the Na-K pump, which was measured as ouabain-inhibitable 86Rb uptake. The addition of serum to quiescent cultures stimulates 86Rb uptake in all cell types studied. Serum alone causes an increase in intracellular potassium with no consistent change in intracellular Na. In the presence of the Na-K pump inhibitor ouabain, serum causes a marked increase in intracellular Na, with little change in intracellular K. This pattern is interpreted as indicating that the primary effect of serum is to increase Na entry into the cells. A low concentration of monensin (0.2 micrograms/ml) mimics the effect of serum on ion fluxes and content, which supports the conclusion that serum and monensin stimulate 86Rb uptake in the same manner, namely by increasing Na entry into the cells. In addition, a partially purified platelet extract stimulates Na entry and 86Rb uptake in quiescent 3T3 cells. Finally 3T3 cells transformed by SV40 or polyoma virus exhibit a higher rate of Na entry and of Na-K pump activity than their untransformed 3T3 counterparts. All these results indicate that the rate of Na entry plays an important role in the regulation of the activity of the Na-K pump and that an increase in Na and K movements is a rapid response elicited by serum in a variety of cell types.

Uridine transport and phosphorylation in mouse cells in culture: effect of growth-promoting factors, cell cycle transit and oncogenic transformation.

The rapid increase in uridine uptake produced by the addition of serum to quiescent cultures of fibroblasts is primarily caused by an enhanced rate of nucleoside phosphorylation. While quiescent and serum-stimulated cells display identical initial rates of transport, they show a considerable change in the composition of the acid-soluble pools labelled with [3H] uridine for five seconds. The radioactivity recovered in the phosphorylated pools increases 2-, 3-, 4- and 6-fold after addition of serum to cultures of Swiss 3T3 cells, tertiary mouse embryo fibroblasts, Swiss 3T6 and Balb 3T3, cells respectively. Furthermore, insulin, a growth factor isolated from medium conditioned by SV40 BHK cells (FDGF) and epidermal growth factor (EGF) also stimulate uridine phosphorylation within minutes. The initial rate of uridine uptake is 2- to 3-fold faster in rapidly growing normal and Simian virus 40 or polyoma virus transformed 3T3 cells as compared to untransformed 3T3 cells in the quiescent state. When quiescent cultures of 3T3 or mouse embryo cells are stimulated to leave G1 and enter into DNA synthesis, transport increases several hours after addition of serum and apparently coincides with the S phase of the cell cycle. The results demonstrate that an increase in uridine phosphorylation is a rapid metabolic response elicited by growth-promoting agents in a variety of cell types and that uridine transport and phosphorylation are independently regulated.