Cyanobacteria as a critical reservoir of the environmental antimicrobial resistome.

Antimicrobial resistance (AMR) is predicted to cause a worldwide annual toll of 10 million deaths by 2050. This looming public health threat has been linked to antibiotic overuse and pollution, which places selective pressures on AMR maintenance and transfer in and between microbial populations. We examined the distribution, diversity and potential mobility of AMR genes in cyanobacteria. While cyanobacteria are not pathogenic, we hypothesised that they could be a major environmental reservoir for AMR genes. Genes encoding AMR to seven antimicrobial drug classes were found in 10% of cyanobacterial genomes. AMR genes were found in 13% of freshwater, 19% of terrestrial, 34% of symbiotic, 2% of thermal spring, and 3% of marine genomes. AMR genes were found in five cyanobacterial orders with 23% of Nostocales and 8% of Oscillatoriales strains containing AMR genes. The most frequently observed alleles were ansamycin resistance genes, which were present in 7% of strains. AMR genes responsible for resistance to broad-spectrum ß-lactams, chloramphenicols, tetracyclines, macrolides, and aminoglycosides were associated with mobile genetic elements or plasmid replicons or both. These results suggest that cyanobacteria are an extensive reservoir, and potential vector, for AMR genes in diverse terrestrial and aquatic habitats.

Broad responses and attitudes to having music in surgery (the BRAHMS study) - a South African perspective.

BACKGROUND: Music is played in operating theatres (OTs) throughout the world, though controversy around its use exists. While some clinicians may find background music favourable to the theatre mood and a way to augment surgical performance, there is concern raised over its distracting and noise-creating properties. METHODS: In this prospective observational study, between August and December 2021, 110 surgeons and registrars in South Africa responded to a survey investigating the way they use music, and their perceptions and attitudes towards its effect on the OT environment. RESULTS: In this cohort, 66% were male, 29% were consultants and the most common age range was 30-39 years old. Eighty per cent of respondents reported that music was played at least "sometimes", with 74% reporting that they enjoyed it. Easy Listening was the most played and preferred genre followed by Top 40/Billboard hits. Overwhelmingly, respondents reported that background music in the OT improved temperament, focus, mood, and performance, though over a quarter felt it worsened communication. Thirty-one per cent of respondents reported that the choice of music depended on the type of operation, and 70% would turn music down or off during crises. Those who enjoyed music in their spare time were significantly more likely to enjoy music in the OT and perceive it positively. CONCLUSION: This study provides a window into the surgeons' use of and attitudes to intraoperative music in South Africa. While overall, music is viewed positively by this cohort, some concerns remain regarding communication and distractedness. Further interventional and qualitative studies would be useful.

Hive Transplantation Has Minimal Impact on the Core Gut Microbiome of the Australian Stingless Bee, Tetragonula carbonaria.

Bacteria residing in the guts of pollinating insects play a key role in nutrient acquisition, digestion, and resistance to pests and diseases. Imbalances in microbial flora in response to environmental change and stress can therefore impact insect health and resilience. This study is aimed at defining the core gut microbiome of the Australian native stingless bee, Tetragonula carbonaria, and exploring the impact of colony transplantation on gut health. The gut microbiomes of nine forager bees from natural (log) and manufactured (box) hives were examined via 16S rRNA gene amplicon sequencing. Some differences were observed at the ASV level between the microbiomes of log and box hive bees. However, a core microbiome, dominated by Lactobacillus spp., unclassified Acetobacteraceae spp., and Bombella spp., was maintained. Further, the inferred functional potential of the microbiomes was consistent across all individuals. This study highlights that although hive transplantation has an impact on the overall diversity of stingless bee gut microbiomes, it is unlikely to have a significant negative impact on the overall health and resilience of the colony.

Australian bush medicines harbour diverse microbial endophytes with broad-spectrum antibacterial activity.

AIMS: Microbial endophytes produce specialized metabolites, including antibiotics and other compounds of pharmaceutical and agricultural value. This study aimed to investigate the diversity and bioactivity of endophytes from medicinal plants used by the Dharawal People of Gamay (Botany Bay), Australia. METHODS AND RESULTS: Of the 48 endophytes isolated, 19 tested positive for polyketide synthase or non-ribosomal peptide synthetase genes via a PCR incorporating degenerate primers. The biosynthetically talented endophytes were identified by 16S rRNA gene sequencing and included 4 bacteria species belonging to the orders Bacillales, Rhizobiales and Burkholderiales and 15 Ascomycota fungi species belonging to the orders Botryosphaeriales, Cladosporiales, Glomerellales, Microascales and Eurotiales. Antimicrobial testing using the disc diffusion assay demonstrated that 15 of the 19 isolates had broad-spectrum activity against a range of Gram-positive and Gram-negative bacteria. CONCLUSIONS: Taken together, these results suggest that Australian bush medicines harbour diverse biosynthetically talented microbial endophytes capable of producing broad-spectrum antibacterial compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests that compounds produced by microbial endophytes likely contribute to the collective medicinal properties of Australian bush medicines. Significantly, it highlights that Indigenous botanical knowledge and modern molecular approaches can be used in tandem to prioritize microorganisms that produce pharmaceutically relevant compounds.

A hydrochemically guided landscape classification system for modelling spatial variation in multiple water quality indices: Process-attribute mapping.

Spatial variation in landscape attributes can account for much of the variability in water quality relative to land use on its own. Such variation results from the coupling between the dominant processes governing water quality, namely hydrological, redox, and weathering and gradients in key landscape attributes, such as topography, geology, and soil drainage. Despite the importance of 'process-attribute' gradients (PAG), few water quality models explicitly account for their influence. Here a processes-based water quality modelling framework is presented that more completely accounts for the role of landscape variability over water quality - Process-Attribute Mapping (PoAM). Critically, hydrochemical measures form the basis for the identification and mapping of effective landscape attributes, producing PAG maps that attempt to replicate the natural landscape gradients governing each dominant process. Application to the province of Southland (31,824 km2), New Zealand, utilised 12 existing geospatial datasets and a total of 28,626 surface water, groundwater, spring, soil water, and precipitation analyses to guide the identification and mapping of 11 individual PAG. The ability of PAGs to replicate regional hydrological, redox, and weathering gradients was assessed on the accuracy with which the hydrochemical indicators of each dominant process (e.g. hydrological tracers, redox indicators) were estimated across 93 long-term surface water monitoring sites (cross-validated R2 values of 0.75-0.95). Given hydrochemical evidence that PAGs replicate actual landscape gradients governing the dominant processes, they were combined with a land use intensity layer and used to estimate steady-state surface water quality. Cross-validated R2 values ranged between 0.81 and 0.92 for median total nitrogen, total oxidised nitrogen, total phosphorus and dissolved reactive phosphorus. Models of particulate species E. coli and total suspended sediment, although reasonable (R2 0.72-0.73), were less accurate, suggesting finer-grained land use, landscape attribute, and/or flow normalised measures are required to improve estimation.

Skin biopsy utilization and melanoma incidence among Medicare beneficiaries.

BACKGROUND: Melanoma incidence has increased in recent decades in the U.S.A. Uncertainty remains regarding how much of this increase is attributable to greater melanoma screening activities, potential detection bias and overdiagnosis. OBJECTIVES: To use a cross-sectional ecological analysis to evaluate the relationship between skin biopsy and melanoma incidence rates over a more recent time period than prior reports. METHODS: Examination of the association of biopsy rates and melanoma incidence (invasive and in situ) in SEER-Medicare data (including 10 states) for 2002-2009. RESULTS: The skin biopsy rate increased by approximately 50% (6% per year) throughout this 8-year period, from 7012 biopsies per 100 000 persons in 2002 to 10 528 biopsies per 100 000 persons in 2009. The overall melanoma incidence rate increased approximately 4% (< 1% per year) over the same time period. The incidence of melanoma in situ increased approximately 10% (1% per year), while the incidence of invasive melanoma increased from 2002 to 2005 then decreased from 2006 to 2009. Regression models estimated that, on average, for every 1000 skin biopsies performed, an additional 5·2 (95% confidence interval 4·1-6·3) cases of melanoma in situ were diagnosed and 8·1 (95% confidence interval 6·7-9·5) cases of invasive melanoma were diagnosed. When considering individual states, some demonstrated a positive association between biopsy rate and invasive melanoma incidence, others an inverse association, and still others a more complex pattern. CONCLUSIONS: Increased skin biopsies over time are associated with increased diagnosis of in situ melanoma, but the association with invasive melanoma is more complex.

Utilizing Participatory Mapping and GIS to Examine the Activity Spaces of Homeless Youth.

Although previous studies have informed our understanding of certain aspects of youth homelessness, few studies have critically examined the spatial and social environments utilized by youth as they navigate life on the streets. This study employed participatory mapping and Geographic Information Systems (GIS) to examine the activity spaces of homeless youth as they relate to sense of community and psychological well-being. Participants were 28 youth experiencing homelessness in Portland, Oregon, USA. Results suggest that youth engage most frequently in service-related activities, and their activity participation is significantly associated with sense of community and psychological well-being. The utility of innovative participatory methods for better understanding the diverse experiences of homeless youth is discussed alongside examination of their practical implications.

Characterization of two cation diffusion facilitators NpunF0707 and NpunF1794 in Nostoc punctiforme.

AIMS: To characterize genes involved in maintaining homeostatic levels of zinc in the cyanobacterium Nostoc punctiforme. METHODS AND RESULTS: Metal efflux transporters play a central role in maintaining homeostatic levels of trace elements such as zinc. Sequence analyses of the N. punctiforme genome identified two potential cation diffusion facilitator (CDF) metal efflux transporters, Npun_F0707 (Cdf31) and Npun_F1794 (Cdf33). Deletion of either Cdf31or Cdf33 resulted in increased zinc retention over 3 h. Interestingly, Cdf31(-) and Cdf33(-) mutants showed no change in sensitivity to zinc exposure in comparison with the wild type, suggesting some compensatory capacity for the loss of each other. Using qRT-PCR, a possible interaction was observed between the two cdf's, where the Cdf31(-) mutant had a more profound effect on cdf33 expression than Cdf33(-) did on cdf31. Over-expression of Cdf31 and Cdf33 in ZntA(-) - and ZitB(-) -deficient Escherichia coli revealed function similarities between the ZntA and ZitB of E. coli and the cyanobacterial transporters. CONCLUSIONS: The data presented shed light on the function of two important transporters that regulate zinc homeostasis in N. punctiforme. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows for the first time the functional characterization of two cyanobacterial zinc efflux proteins belonging to the CDF family.

Double ovulation and occurrence of twinning in alpacas (Vicugna pacos).

Twin births are rare in alpacas despite the high incidence of double ovulation and are undesirable because they contribute to early and late pregnancy loss, abortion, and birth of nonviable neonates. The objective of the present study was to determine the incidence and outcome of twin pregnancy in double-ovulating alpacas by retrospective and prospective analysis. Data from double-ovulating females (N = 41) presented for pregnancy diagnosis were analyzed to determine pregnancy status at three stages after mating (14-16, 25-30, and 45-53 days). In a prospective study, adult reproductively sound alpacas (n = 21) were examined by ultrasonography to determine the incidence of multiple ovulations. A subset of those alpacas (n = 10) were euthanized either at 9 days (n = 5) or 14 days (n = 5) after a single mating and administration of GnRH to determine presence and number of embryos. A total of 31 cycles were included in the study to determine the incidence of multiple ovulations. In the retrospective study, twin pregnancies were identified between 25 and 30 days in 47.1% of double-ovulating females. There were more twins from bilateral ovulations (62.5%) than from unilateral ovulations (37.5%). Twin pregnancies were either reduced to a singleton (62.5%) or lost completely (37.5%). One set of twins remained viable until Day 52. In the prospective study, double ovulation occurred in 18.8% of the cycles. Two embryos were collected from two of the four double-ovulating females. In conclusion, twin conception is not rare in alpacas. A high rate of spontaneous reduction of twin pregnancies occurs before Day 45. However, a significant proportion of twin pregnancy may result in loss of both embryos. Determination of the number of ovulations (CL) at the time of early pregnancy diagnosis (14-16 days) should be an integral part of any pregnancy evaluation.

Beware the normal angiogram.

Purulent pericarditis is now rare due to the widespread use of antibiotics. However, it is associated with significant morbidity and mortality, and non-specific symptoms and signs can make diagnosis difficult. We report a patient who presented with left-sided chest pain, mild fever and ST segment elevation on electrocardiography, who required prolonged organ support in the intensive care unit. This lesson highlights the diagnostic difficulties and management challenges that this condition can present.

Functional characterization of the twin ZIP/SLC39 metal transporters, NpunF3111 and NpunF2202 in Nostoc punctiforme.

The ZIP family of metal transporters is involved in the transport of Zn(2+) and other metal cations from the extracellular environment and/or organelles into the cytoplasm of prokaryotes, eukaryotes and archaeotes. In the present study, we identified twin ZIP transporters, Zip11 (Npun_F3111) and Zip63 (Npun_F2202) encoded within the genome of the filamentous cyanobacterium, Nostoc punctiforme PCC73120. Sequence-based analyses and structural predictions confirmed that these cyanobacterial transporters belong to the SLC39 subfamily of metal transporters. Quantitative real-time (QRT)-PCR analyses suggested that the enzymes encoded by zip11 and zip63 have a broad allocrite range that includes zinc as well as cadmium, cobalt, copper, manganese and nickel. Inactivation of either zip11 or zip63 via insertional mutagenesis in N. punctiforme resulted in reduced expression of both genes, highlighting a possible co-regulation mechanism. Uptake experiments using (65)Zn demonstrated that both zip mutants had diminished zinc uptake capacity, with the deletion of zip11 resulting in the greatest overall reduction in (65)Zn uptake. Over-expression of Zip11 and Zip63 in an E. coli mutant strain (ZupT736::kan) restored divalent metal cation uptake, providing further evidence that these transporters are involved in Zn uptake in N. punctiforme. Our findings show the functional role of these twin metal uptake transporters in N. punctiforme, which are independently expressed in the presence of an array of metals. Both Zip11 and Zip63 are required for the maintenance of homeostatic levels of intracellular zinc N. punctiforme, although Zip11 appears to be the primary zinc transporter in this cyanobacterium, both ZIP's may be part of a larger metal uptake system with shared regulatory elements.

Effects of vasectomy on seminal plasma alkaline phosphatase in male alpacas (Vicugña pacos).

Azoospermia is a common finding in male alpacas which present for infertility. The challenge is to differentiate azoospermia of testicular origin from non-testicular origin. In several species, alkaline phosphatase (AP) concentrations in seminal plasma have been used as a diagnostic marker of contributions of the testis and epididymis to the ejaculate. The purpose of this study was to determine whether AP assay could differentiate testicular from non-testicular azoospermia in male alpacas. An experimental model of bilateral outflow obstruction (pre-scrotal vasectomy) was used in 22 male alpacas, aged 2-9 years. No reproductive history was available. Animals were submitted for electroejaculation (EE) under general anaesthesia and vasectomy performed. Five weeks later, animals were submitted for EE. Vasectomy was not successful in one animal, which was removed from analysis. AP levels were compared in seminal plasma in the pre- and post-vasectomy samples. The mean ± SEM concentration of AP in pre-vasectomy seminal plasma was 504.29 ± 166.45 U/l (range 10-2910); the post-vasectomy levels were 252.48 ± 81.77 U/l (range 0-1640; p = 0.06). In 71.4% of animals, AP levels decreased, varying from 18% to 100% reduction. Results of this study suggest that AP is not produced exclusively by the testis and epididymis in alpacas and that AP assay is not a valid diagnostic test for determination of origin of azoospermia; the gold standard for diagnosis of origin of azoospermia remains testicular biopsy.

First measurement of the form factors in the decays D0 → ρ- e+ ν(e) and D+ → ρ0 e+ ν(e).

The beauty to up quark coupling constant |V(ub)| can be extracted from B → ρ e+ ν(e) combined with the form factors for D → K* e+ ν(e) and B → V ℓ+ ℓ- and D → ρ e+ ν(e). Using the entire CLEO-c ψ(3770) → DD event sample, corresponding to an integrated luminosity of 818 pb(-1) and approximately 5.4×10(6) DD events, we measure the form factors for the decays D0 → ρ- e+ ν(e) and D+ → ρ0 e+ ν(e) for the first time and the branching fractions with improved precision. A four-dimensional unbinned maximum likelihood fit determines the form factor ratios to be V(0)/A1(0)=1.48±0.15±0.05 and A2(0)/A1(0)=0.83±0.11±0.04. Assuming Cabibbo-Kobayashi-Maskawa unitarity, the known D meson lifetimes, and our measured branching fractions we obtain the form factor normalizations A1(0), A2(0), and V(0). We also present a measurement of the branching fraction for D+ → ω e+ ν(e) with improved precision.

Peripartum infection with Streptococcus uberis but not coagulase-negative staphylococci reduced milk production in primiparous cows.

The effect of an intramammary infection (IMI) at calving on the milk yield of heifers during their first 200 d in milk (DIM) was estimated by comparing monozygotic twins, where one member had a naturally occurring IMI detected at the first milking after calving and the other twin did not. Data collected weekly over a full lactation for 29 twin pairs were used to estimate the effects of a peri-calving Streptococcus uberis IMI on milk yield and composition. Data for 19 twin pairs were used to estimate the effects of pericalving coagulase-negative staphylococci (CNS) IMI. A heifer with a Strep. uberis IMI produced 200 kg (7%) less milk during the first 200 d of lactation compared with her uninfected twin, with significant differences evident throughout the 200-d period. Similar milk losses were recorded for heifers that developed CM or remained subclinical. An elevated milk SCC for infected heifers was only apparent for the first month (d 2-30), although SCC tended to remain high during the second (d 31-60) and third (d 61-90) months. Milk protein concentrations were greater in the Strep. uberis-infected twin over the 200-d period, whereas fat and lactose concentrations showed little change. An IMI caused by Strep. uberis was associated with a lower milk yield, whereas an IMI by CNS was not, despite CNS-infected twins having a higher SCC than their uninfected twin for the first 30 d of lactation.

Observation of the h(c)(1P) Using e+ e- collisions above the DD threshold.

Using 586 pb(-1) of e+ e- collision data at E(c.m.) = 4170 MeV, produced at the Cornell Electron Storage Ring collider and collected with the CLEO-c detector, we observe the process e+ e- → π+ π- h(c)(1P). We measure its cross section to be 15.6±2.3±1.9±3.0 pb, where the third error is due to the external uncertainty on the branching fraction of ψ(2S) → π0 h(c)(1P), which we use for normalization. We also find evidence for e+ e- → ηh(c)(1P) at 4170 MeV at the 3σ level and see hints of a rise in the e+ e- → π+ π- h(c)(1P) cross section at 4260 MeV.

NtcA from Microcystis aeruginosa PCC 7806 is autoregulatory and binds to the microcystin promoter.

NtcA is a transcription factor that has been found in a diverse range of cyanobacteria. This nitrogen-controlled factor was focused on as a key component in the yet-to-be-deciphered regulatory network controlling microcystin production. Adaptor-mediated PCR was utilized to isolate the ntcA gene from Microcystis aeruginosa PCC 7806. This gene was cloned, and the recombinant (His-tagged) protein was overexpressed and purified for use in mobility shift assays to analyze NtcA binding to putative sites identified in the microcystin mcyA/D promoter region. Autoregulation of NtcA in M. aeruginosa was shown via NtcA binding in the upstream ntcA promoter region. The observation of binding of NtcA to the mcyA/D promoter region has direct relevance for the regulation of microcystin biosynthesis, as transcription of the mcyABCDEFGHIJ gene cluster appears to be under direct control of nitrogen.

High-power linearly-polarized single-frequency thulium-doped fiber Master-Oscillator Power-Amplifier.

We report a high power narrow-linewidth source at approximately 2 microm based on a Tm-doped fiber distributed-feedback master-oscillator and three Tm fiber amplifier stages. The master-oscillator and first two amplifier stages were in-band pumped by Er,Yb fiber lasers operating at 1565 nm, and the final stage amplifier was cladding-pumped at 795 nm by two spatially-combined diode-stacks. The MOPA yielded 100 W of single frequency output at 1943 nm with a beam propagation factor (M(2)) of 1.25 and with a polarization extinction ratio of >94%. The output power was limited by thermally-induced damage in the final amplifier stage. The prospects for further power scaling are considered.

The molecular genetics and regulation of cyanobacterial peptide hepatotoxin biosynthesis.

Over the last 10 years, we have witnessed major advances in our understanding of natural product biosynthesis, including the genetic basis for toxin production by numerous groups of cyanobacteria. Cyanobacteria produce an unparalleled array of bioactive secondary metabolites, including alkaloids, polyketides and non-ribosomal peptides, some of which are potent toxins. This review addresses the molecular genetics underlying the production of hepatotoxins, microcystin and nodularin in fresh and brackish water. These toxins pose a serious threat to human health and their occurrence in water supplies is increasing, because of the prevalence of toxic algal blooms worldwide. Toxin biosynthesis gene-cluster-associated transposition and the natural transformability of certain species suggest a broader distribution of toxic cyanobacterial taxa. The information gained from the discovery of these toxin biosynthetic pathways has enabled the genetic screening of various environments for drinking-water quality management. Understanding the role of cyanotoxins in the producing microorganisms and the environmental regulation of their biosynthesis genes may also suggest the means of controlling toxic-bloom events.

The ontogeny of aerobic and diving capacity in the skeletal muscles of Weddell seals.

Our objective was to determine the ontogenetic changes in the skeletal muscles of Weddell seals that transform a non-diving pup into an elite diving adult. Muscle biopsies were collected from pups, juveniles and adults and analyzed for changes in fiber type, mitochondrial density, myoglobin concentrations and aerobic, lipolytic and anaerobic enzyme activities. The fiber type results demonstrated a decrease in slow-twitch oxidative (Type I) fibers and a significant increase in fast-twitch oxidative (Type IIA) fibers as the animals mature. In addition, the volume density of mitochondria and the activity of lipolytic enzymes significantly decreased as the seals matured. To our knowledge, this is the first quantitative account describing a decrease in aerobic fibers shifting towards an increase in fast-twitch oxidative fibers with a significant decrease in mitochondrial density as animals mature. These differences in the muscle physiology of Weddell seals are potentially due to their three very distinct stages of life history: non-diving pup, novice diving juvenile, and elite deep diving adult. During the first few weeks of life, pups are a non-diving terrestrial mammal that must rely on lanugo (natal fur) for thermoregulation in the harsh conditions of Antarctica. The increased aerobic capacity of pups, associated with increased mitochondrial volumes, acts to provide additional thermogenesis. As these future elite divers mature, their skeletal muscles transform to a more sedentary state in order to maintain the low levels of aerobic metabolism associated with long-duration diving.