BmpA Is a Surface-Exposed Outer-Membrane Protein of Borrelia Burgdorferi

BmpA is an immunodominant protein of Borrelia burgdorferi as well as an arthritogenic factor. Rabbit antirecombinant BmpA (rBmpA) antibodies were raised, characterized by assaying their cross reactivity with rBmpB, rBmpC and rBmpD, and then rendered monospecific by absorption with rBmpB. This monospecific reagent reacted only with rBmpA in dot immunobinding and detected a single 39 kDa, pI 5.0, spot on two-dimensional immunoblots. It was used to assess the BmpA cellular location. BmpA was present in both detergent-soluble and -insoluble fractions of Triton X-114 phase-partitioned borrelial cells, suggesting that it was a membrane lipoprotein. Immunoblots of proteinase K-treated intact and Triton X-100 permeabilized cells showed digestion of BmpA in intact cells, consistent with surface exposure. This exposure was confirmed by dual-label immunofluorescence microscopy of intact and permeabilized borrelial cells. Conservation and surface localization of BmpA in all B. burgdorferi sensu lato genospecies could point to its playing a key role in this organism\u27s biology and pathobiology

Belnap-Dunn semantics for natural implicative expansions of Kleene's strong three-valued matrix with two designated values

27 p.A conditional is natural if it fulfils the three following conditions. (1) It coincides with the classical conditional when restricted to the classical values T and F; (2) it satisfies the Modus Ponens; and (3) it is assigned a designated value whenever the value assigned to its antecedent is less than or equal to the value assigned to its consequent. The aim of this paper is to provide a ‘bivalent’ Belnap-Dunn semantics for all natural implicative expansions of Kleene's strong 3-valued matrix with two designated elements. (We understand the notion ‘natural conditional’ according to N. Tomova, ‘A lattice of implicative extensions of regular Kleene's logics’, Reports on Mathematical Logic, 47, 173–182, 2012.)S

Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment

Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments

Genome Sequence of Borrelia chilensis VA1, a South American Member of the Lyme Borreliosis Group

Borrelia chilensis strain VA1 is a recently described South American member of the Borrelia burgdorferi sensu lato complex from Chile. Whole-genome sequencing analysis determined its linear chromosome and plasmids lp54 and cp26, confirmed its membership in the Lyme borreliosis group, and will open new research avenues regarding its pathogenic potential

The effectiveness of two silicone dressings for sacral and heel pressure ulcer prevention compared with no dressings in high‐risk intensive care unit patients: a randomized controlled parallel‐group trial

Background There is a high incidence of pressure ulcers in high-risk settings such as intensive care. There is emerging evidence that the application of dressings to pressure ulcer predilection areas (sacrum and heels) improves prevention strategies. Objectives To determine whether preventive dressings, applied to the sacrum and heels of high-risk patients in intensive care units, in addition to standard prevention, reduces the incidence of pressure ulcers. Methods Between June 2015 and July 2018, a randomized, controlled, two-arm, superiority pragmatic study was performed with a concealed 1 : 1 allocation to the intervention and control group. Patients assigned to the intervention group had dressings applied to the sacrum and heels. Results In total, 7575 patients were screened for eligibility and 475 patients were included and allocated to both groups. Finally, 212 patients in the intervention group and 210 in the control group were analysed. The mean age was 63 center dot 5 years and the majority of patients were male (65 center dot 4%). The cumulative pressure ulcer incidence category II and above was 2 center dot 8% in the intervention, and 10 center dot 5% in the control group (P = 0 center dot 001). Compared with the control group, the relative risk in the intervention group was 0 center dot 26 [95% confidence interval (CI) 0 center dot 11-0 center dot 62] and the absolute risk reduction was 0 center dot 08 (95% CI 0 center dot 03-0 center dot 13). Conclusions The results indicate that the application of dressings, in addition to standard prevention, in high-risk intensive care unit patients is effective in preventing pressure ulcers at the heels and sacrum. What's already known about this topic? Pressure ulcers are severe soft tissue injuries and wounds, which occur worldwide in all healthcare settings. Despite preventive interventions, pressure ulcers still develop. There is emerging evidence that dressings help to prevent pressure ulcers. What does this study add? The incidence of pressure ulcers in intensive care units among high-risk patients remains high. The application of dressings to the sacrum and heels, in addition to standard preventive measures, reduces the relative and absolute risks for the development of pressure ulcers. The application of preventive dressings at the heels and sacrum seems to be feasible in intensive care settings

Borrelia Chilensis, a New Member of the Borrelia Burgdorferi Sensu Lato Complex That Extends the Range of This Genospecies in the Southern Hemisphere

Borrelia burgdorferi sensu lato (s.l.), transmitted by Ixodes spp. ticks, is the causative agent of Lyme disease. Although Ixodes spp. ticks are distributed in both Northern and Southern Hemispheres, evidence for the presence of B. burgdorferi s.l. in South America apart from Uruguay is lacking. We now report the presence of culturable spirochetes with flat-wave morphology and borrelial DNA in endemic Ixodes stilesi ticks collected in Chile from environmental vegetation and long-tailed rice rats (Oligoryzomys longicaudatus). Cultured spirochetes and borrelial DNA in ticks were characterized by multilocus sequence typing and by sequencing five other loci (16S and 23S ribosomal genes, 5S-23S intergenic spacer, flaB, ospC). Phylogenetic analysis placed this spirochete as a new genospecies within the Lyme borreliosis group. Its plasmid profile determined by polymerase chain reaction and pulsed-field gel electrophoresis differed from that of B. burgdorferi B31A3. We propose naming this new South American member of the Lyme borreliosis group B. chilensis VA1 in honor of its country of origin

The hydrogen and helium lines of the symbiotic binary Z And during its brightening at the end of 2002

High resolution observations in the region of the lines Halpha, He II 4686 and Hgamma of the spectrum of the symbiotic binary Z And were performed during its small-amplitude brightening at the end of 2002. The profiles of the hydrogen lines were double-peaked. These profiles give a reason to suppose that the lines can be emitted mainly by an optically thin accretion disc. The Halpha line is strongly contaminated by the emission of the envelope, therefore for consideration of accretion disc properties we use the Hgamma line. The Halpha line had broad wings which are supposed to be determined mostly from radiation damping but high velocity stellar wind from the compact object in the system can also contribute to their appearance. The Hgamma line had a broad emission component which is assumed to be emitted mainly from the inner part of the accretion disc. The line He II 4686 had a broad emission component too, but it is supposed to appear in a region of a high velocity stellar wind. The outer radius of the accretion disc can be calculated from the shift between the peaks. Assuming, that the orbit inclination can ranges from 47$^\circ$ to 76$^\circ$, we estimate the outer radius as 20 - 50 R_sun. The behaviour of the observed lines can be considered in the framework of the model proposed for interpretation of the line spectrum during the major 2000 - 2002 brightening of this binary.Comment: 19 pages, 5 figures. Accepted for publication in Astronomy Report

Homeostatic regulation of energetic arousal during acute social isolation: Evidence from the lab and the field

Recent evidence suggests that social contact is a basic need governed by a social homeostatic system. Little is known, however, about how conditions of altered social homeostasis affect human psychology and physiology. Here, we investigated the effects of 8 hr of social isolation on psychological and physiological variables and compared this with 8 hr of food deprivation in a lab experiment (N = 30 adult women). Social isolation led to lowered self-reported energetic arousal and heightened fatigue, comparable with food deprivation. To test whether these findings would extend to a real-life setting, we conducted a preregistered field study during a COVID-19 lockdown (N = 87 adults; 47 women). The drop in energetic arousal after social isolation observed in the lab replicated in the field study for participants who lived alone or reported high sociability, suggesting that lowered energy could be part of a homeostatic response to the lack of social contact