A microbiological survey approach to understanding the virulence factors of Pseudomonas species in healthcare sinks.

BACKGROUND: Hospital water is involved in both the prevention and spread of healthcare-associated infections (HCAIs). Handwashing is key to reducing the transmission of pathogens, yet numerous outbreaks have been found to be caused by organisms within sinks, taps and showers. Pseudomonas aeruginosa and increasingly non-aeruginosa Pseudomonas cause waterborne HCAI, however, little is known about the virulence potential of Pseudomonas species found within hospital environments. METHODS: Swabs were taken from 62 sinks within two newly opened wards at Great Ormond Street Hospital, samples were taken before and after the wards opened to understand the impact of patient occupancy on sink micro-organisms. Culturable bacteria were identified by MALDI-TOF and virulence factors assessed through phenotypic methods. RESULTS: A total of 106 bacterial isolates were recovered including 24 Pseudomonas isolates. Of these 25% were identified as P. oleovorans, 21% P. aeruginosa, 17% P. composti, 13% P. alicalipha, 8% P. monteilii, 4% P. putida, 4% P. stutzeri and 8% could only be identified to genus level by MALDI-TOF. Differences were seen in both the number of Pseudomonas isolates and virulence production between the two wards, overall 25% of the Pseudomonas isolates produced pigment, 58% were capable of haemolysis, 87.5% were able to swim, 83.3% were capable of twitching motility, 33.3% produced alkaline protease and 8.3% produced gelatinase. CONCLUSIONS: Results suggest that patients may be back-contaminating sinks with colonizing organisms which has ongoing implications for infection prevention and control. Additionally, this work highlights the ability of non-aeruginosa Pseudomonas to produce virulence factors traditionally associated with P. aeruginosa.

Detection of SARS-CoV-2 within the healthcare environment: a multi-centre study conducted during the first wave of the COVID-19 outbreak in England.

BACKGROUND: Understanding how severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spread within the hospital setting is essential in order to protect staff, implement effective infection control measures, and prevent nosocomial transmission. METHODS: The presence of SARS-CoV-2 in the air and on environmental surfaces around hospitalized patients, with and without respiratory symptoms, was investigated. Environmental sampling was undertaken within eight hospitals in England during the first wave of the coronavirus disease 2019 outbreak. Samples were analysed using reverse transcription polymerase chain reaction (PCR) and virus isolation assays. FINDINGS: SARS-CoV-2 RNA was detected on 30 (8.9%) of 336 environmental surfaces. Cycle threshold values ranged from 28.8 to 39.1, equating to 2.2 x 105 to 59 genomic copies/swab. Concomitant bacterial counts were low, suggesting that the cleaning performed by nursing and domestic staff across all eight hospitals was effective. SARS-CoV-2 RNA was detected in four of 55 air samples taken <1 m from four different patients. In all cases, the concentration of viral RNA was low and ranged from <10 to 460 genomic copies/m3 air. Infectious virus was not recovered from any of the PCR-positive samples analysed. CONCLUSIONS: Effective cleaning can reduce the risk of fomite (contact) transmission, but some surface types may facilitate the survival, persistence and/or dispersal of SARS-CoV-2. The presence of low or undetectable concentrations of viral RNA in the air supports current guidance on the use of specific personal protective equipment for aerosol-generating and non-aerosol-generating procedures.

Antimicrobial susceptibilities and resistance genes in Campylobacter strains isolated from poultry and pigs in Australia.

AIMS: To evaluate the phenotypic and genotypic profiles of Campylobacter spp. from poultry faecal samples from free range or intensively raised meat chickens and free range egg layers. In addition, a case-comparison study of antibiotic resistance genes from different groups of poultry and some pig strains previously collected was carried out. METHODS: Resistance to different antibiotics was assessed using the agar dilution method. In addition, all the strains were tested for ampicillin (bla(OXA-61) ), erythromycin (aph-3-1), tetracycline tet(O), streptomycin (aadE), and the energy-dependent multi-drug efflux pump (cmeB) resistance genes using multiplex polymerase chain reaction. RESULTS: The evaluation of phenotypic resistance revealed all of the strains from poultry were sensitive to ciprofloxacin, gentamicin, erythromycin or tylosin. But, widespread resistance to lincomycin (51-100%), extensive resistance to ampicillin (33·3-60·2%) and less resistance to tetracycline (5·6-40·7%) were observed in the different groups of chickens. Antibiotic resistance genes bla(OXA-61,) cmeB and tet(O) were found in 82·6-92·7%, 80·3-89% and 22·3-30·9% Camp. coli isolates from pigs, whilst 59-65·4% and 19·2-40·7% Camp. jejuni from chickens were found to encode bla(OXA-61) and tet(O), respectively. CONCLUSION: No significant difference between isolates from free range egg layers and meat chickens (P < 0·05) was found. However, there were significant differences between the pig strains and all the groups of poultry strains (P < 0·05) with regard to carriage of resistance genes. In addition, pulsed field gel electrophoresis of selected resistant isolates from the poultry and pig revealed closely related clonal groups. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results suggest the resistant strains are persisting environmental isolates that have been acquired by the different livestock species. Furthermore, the different treatment practices in poultry and pigs have resulted in differences in resistance profiles in Campylobacter isolates.

Antiviral oseltamivir is not removed or degraded in normal sewage water treatment: implications for development of resistance by influenza A virus.

UNLABELLED: Oseltamivir is the main antiviral for treatment and prevention of pandemic influenza. The increase in oseltamivir resistance reported recently has therefore sparked a debate on how to use oseltamivir in non pandemic influenza and the risks associated with wide spread use during a pandemic. Several questions have been asked about the fate of oseltamivir in the sewage treatment plants and in the environment. We have assessed the fate of oseltamivir and discuss the implications of environmental residues of oseltamivir regarding the occurrence of resistance. A series of batch experiments that simulated normal sewage treatment with oseltamivir present was conducted and the UV-spectra of oseltamivir were recorded. FINDINGS: Our experiments show that the active moiety of oseltamivir is not removed in normal sewage water treatments and is not degraded substantially by UV light radiation, and that the active substance is released in waste water leaving the plant. Our conclusion is that a ubiquitous use of oseltamivir may result in selection pressures in the environment that favor development of drug-resistance.

Morphological concentric layer analysis for automated detection of suspicious masses in screening mammograms.

Computer assisted detection systems (CAD) in mammography incorporate two critical stages: (i) prescreening to localize suspicious regions and (ii) detailed analysis of the regions for false positive reduction. In this work, we present a new technique for automatic detection of suspicious masses for prescreening mammograms. The hypothesis of the proposed technique is that malignant masses manifestate as superimposed concentric layers. Morphological characterization of these layers can form the foundation of an automated scheme for detection of suspicious masses. The study was based on fifty nine screening mammograms from the digital database of screening mammography (DDSM). Overall, the proposed scheme performs at 85.7% sensitivity with an average of 0.53 false positives per image. The scheme targets malignant masses and, thus it can provide a second opinion to radiologists without sending benign masses to unnecessary biopsy.

Breast segmentation in screening mammograms using multiscale analysis and self-organizing maps.

Previously we presented an unsupervised self-organizing map (SOM) for segmentation of the breast region in screening mammograms. This study improves upon our earlier technique by (1) enhancing the detection of the breast region near the skin line, as well as (2) reducing the computational complexity. Contrary to the initial technique, the improved one exploits global image properties extracted at different scales. These properties were used to both generate the SOM training samples and obtain a preliminary segmentation. Subsequently, a multi-step strategy was implemented to automatically outline a wide band around the skin line for further analysis. This additional step reduces the computational complexity by focusing the analysis on the set of pixels that creates clinically the highest ambiguity. Specifically, the same (already trained) SOM was applied to classify the ambiguous pixels around the skin line. The study was performed on 400 screening mammograms from the digital database for screening mammography (DDSM). Visual examination of the segmentation results confirmed an improvement in the detection of the low-contrast region near the skin line. The performance was consistent regardless of mammographic view and/or breast density. Furthermore, the computational cost of processing can be reduced by up to 80% of the original value.

Relaxation training for psychiatric inpatients.

In Exp. 1 the effects of progressive and imaginal relaxation training were examined for 51 psychiatric inpatients. Relaxation Inventory scores indicated significant changes in the direction of greater relaxation for each training procedure; there were no significant differences in responses to the two types of training. Significant relaxation effects were found for each of three training sessions, but the effects were not cumulative. Only one patient was withdrawn because reaction to training was overtly negative. Exp. 2 was an analysis of Exp. 1 data in combination with data from a prior study. Patients and college students responded much alike but students reached greater relaxation within sessions. Further experimentation on relaxation training with psychiatric inpatients appears justified.

A "fair" comparison of progressive and imaginal relaxation.

Progressive and imaginal relaxation-training procedures are difficult to compare because the latter takes many forms. In this study, an imaginal procedure was used that closely followed progressive operations except that muscle tension was imagined rather than experienced. The dependent variable was the total score on the Relaxation Inventory. College students were placed in groups (ns = 50) high and low on suggestibility based on scores on the Creative Imagination Scale, assigned in equal numbers to the imaginal and progressive relaxation conditions and given four sessions of relaxation training. The pre- and posttrials effects were significant within each of the four training sessions. There were no significant differences in reports of relaxation by the progressive and imaginal treatments. The expected cumulative effect of relaxation training across the four sessions was not found; in fact, the imaginal condition showed a significant decrease. The only significant suggestibility effect was an interaction between suggestibility and trials in which highly suggestible subjects reported less pre-session relaxation. These results are consistent with reports of no differences between progressive and imaginal relaxation training.

Progressive and imaginal relaxation training for elderly persons with subjective anxiety.

Elders exposed to either progressive or imaginal relaxation procedures reported significant relaxation effects and showed improvement on measures of personal functioning. The results of the Physical Assessment Scale of the Relaxation Inventory indicated that relaxation responses were acquired within and across sessions. Large, consistent changes in relaxation occurred in all 4 sessions. The Symptom Checklist-90-R, which measures self-reported personal adjustment, showed significant positive changes following relaxation training and at 1-month follow-up. Elders who imagined muscle tension release profited as much as those engaged in actual muscle tension-release activities. This finding is of importance for older adults who may experience physical limitations that contraindicate muscle-tension-release procedures.

Relaxation training side effects reported by seriously disturbed inpatients.

The extent to which seriously disturbed inpatients report side effects related to passive and progressive relaxation training was examined. Most reported few side effects; only 1 of 64 subjects was removed because of a negative reaction to training. There was no significant difference in side effects reported in response to the two training procedures. Comparisons were made with data from a survey of therapists who practice relaxation training.

The Relaxation Inventory: self-report scales of relaxation training effects.

The development of a self-report measure to assess the effects of relaxation training was examined. A rigorous statistical method of scale construction consisting of a modification of the scale discrimination technique was employed, resulting in a 45-item questionnaire representing three orthogonally derived scales. The three scales, Physiological Tension, Physical Assessment, and Cognitive Tension, demonstrated adequate internal consistency with KR20 reliability coefficients of .89, .95, and .81, respectively. In a second study of predictive validity, 40 individuals were randomly assigned to one of four conditions: relaxation training, tension inducement, pre-postcontrol, or postcontrol. Univariate analysis of variance indicated significant findings for each of the three dimensions of the inventory. The Physiological Tension Scale detected significant increases in tension following tension inducement, whereas the Physical Assessment Scale and Cognitive Tension Scale detected increases in relaxation following relaxation training. Recommendations were made for future research on the inventory.

Progressive relaxation as a function of procedural variations and anxiety level.

Progressive relaxation is subject to many procedural variations. Although most investigators follow the 5-7 s tension interval advocated by Bernstein and Borkovec (1973), longer tension intervals may contribute to greater relaxation effects. This study compared tension intervals of 5, 15, and 45 s. Since the development of control over muscle tension requires attention to feedback signals, a focus on internal proprioceptive sensations was contrasted with an external condition in which the subjects silently subtracted numbers immediately following the tension-release cycle. Longer periods of tension resulted in lower EMG levels, with the 45-s tension interval producing the greatest relaxation. Those individuals who focused on physiological sensations during training were able to achieve greater levels of relaxation after the training phase was completed. There was a significant interaction between tension interval duration and focusing; subjects in the 45-s interval who focused on physiological functioning showed the greatest arousal reduction. Anxiety level did not differentially influence the effects of procedural variations in training. Clearly, additional parametric studies in relaxation training are needed.

Contingency management of self-report and cleaning behavior.

The effects of a contingency management program utilizing a reinforcing event (breakfast) were investigated in respect to cabin-cleaning and self-report behaviors in a group of nine male campers, ranging in age from 11 to 13. Control of cabin-cleaning behavior was clearly demonstrated. The large discrepancy between camper self-ratings and counselor ratings disappeared when the opportunity to line up for breakfast was made contingent upon both accuracy of self-report and improved cleaning performance.