Low Colonization Rates Research Articles

Prevalence and Control of Pseudomonas aeruginosa in Tourist Facilities across the Canary Islands, Spain.

Pseudomonas aeruginosa is a common pathogen associated with recreational water facilities and poses risks to public health. However, data on the prevalence of P. aeruginosa in tourist destinations like the Canary Islands, Spain, remain limited. We assessed P. aeruginosa prevalence in 23 tourist facilities from 2016 to 2019. Compliance with water quality standards was evaluated, and 3962 samples were collected and analyzed. We examined different types of recreational water installations, including outer swimming pools, whirlpools, and cold wells. Of the sampled facilities, 31.2% did not comply with the current legislation's parametric values, mainly due to inadequate disinfectant levels, water temperature, and P. aeruginosa presence. The prevalence of P. aeruginosa was 4.8%, comparable to some European countries but lower than others. Cold wells displayed the highest non-compliance rate (89.2%) and yet exhibited a lower P. aeruginosa prevalence (1.9%) than outer swimming pools and whirlpools. Children's presence did not significantly impact P. aeruginosa contamination. Chlorine-based disinfectants are more effective than bromine-based ones in controlling P. aeruginosa. Regional variability in contamination was observed, with Fuerteventura showing lower colonization rates. Disinfectant levels play a critical role in P. aeruginosa control, and maintaining adequate levels is essential, particularly in bromine-treated installations. Our findings provide valuable insights into the prevalence and distribution of P. aeruginosa in recreational waters within tourist facilities. Tailored strategies are needed to ensure water safety in different Spanish regions. Continued monitoring and assessment, combined with artificial intelligence and machine learning, will enable the implementation of targeted interventions to protect the health of recreational water users.

Risk assessment of the mechanical spread of bacterial pathogens due to Lasius neglectus ants infesting a tertiary hospital

Mechanical spread of microbial pathogens has been investigated in cockroaches, but less well in ants. Considerably less information is available for ants. An investigation into ant-borne mechanical pathogen transmission was triggered by an infestation of a tertiary care hospital with Lasius neglectus ants. The L. neglectus infestation of the orthopedic surgery, the ear-nose-throat clinics and the eye clinics as well as of outdoor areas was monitored and correlated with seasonal and weather influences. Microbial colonization on the ants' exoskeleton as well as in homogenates of complete insects and decolonization dynamics of artificially Staphylococcus aureus colonization on the exoskeleton was assessed. In a low-level infestation setting, L. neglectus activity showed seasonal variations and was positively correlated with temperature (r=0.7515; P=0.0368) but not with precipitation (r=0.4699, P=0.2431). Colonization with environmental commensals dominated, while exoskeleton colonization with bacteria with potential etiological relevance for nosocomial infections was higher for ants from the inpatient setting (6%) than from outdoor areas (0%). Artificial colonization of the exoskeleton with S. aureus vanished to values statistically indistinguishable from baseline within 72 hours. Low colonization rates with etiologically relevant bacteria and rapid spontaneous decolonization in case of contamination make ant-borne transmissions to patients unlikely.

Testing effects of bottom-up factors, grazing, and competition on New Zealand rocky intertidal algal communities.

Top-down and bottom-up factors and their interaction highlight the interdependence of resources and consumer impacts on food webs and ecosystems. Variation in the strength of upwelling-mediated ecological controls (i.e., light availability and herbivory) between early and late succession stages is less well understood from the standpoint of influencing algal functional group composition. We experimentally tested the effect of light, grazing, and disturbance on rocky intertidal turf-forming algal communities. Studies were conducted on the South Island of New Zealand at Raramai on the east coast (a persistent downwelling region) and Twelve Mile Beach on the west coast (an intermittent upwelling region). Herbivory, light availability, and algal cover were manipulated and percent cover of major macroalgal functional groups and sessile invertebrates were measured monthly from October 2017 to March 2018. By distinguishing between algal functional groups and including different starting conditions in our design, we found that the mosaic-like pattern of bare rock intermingled with diverse turf-forming algae at Twelve Mile Beach was driven by a complex array of species interactions, including grazing, predation, preemptive competition and interference competition, colonization rates, and these interactions were modulated by light availability and other environmental conditions. Raramai results contrasted with those at Twelve Mile Beach in showing stronger effects of grazing and relatively weak effects of other interactions, low colonization rates of invertebrates, and light effects limited to crustose algae. Our study highlights the potential importance of an upwelling-mediated 3-way interaction among herbivory, light availability, and preemption in structuring contrasting low rocky intertidal macroalgal communities.

Prevalence of methicillin resistant staphylococcus aureus (MRSA) colonization in pregnant females visiting at tertiary care hospital in Northern Mumbai

Methicillin resistant s (MRSA) screening is a routine practice at many hospitals for high-risk patients. However, its incidence and clinical significance in expectant mothers are poorly understood. Hence, the purpose of the current study was to look at MRSA colonization rates in our obstetric population.Prospective study was conducted for three months from December 2019 to February 2020. MRSA screening samples from pregnant women at 32-34 weeks of gestation were collected after informed consent. All screening samples underwent standard microbiological analysis. Women who tested positive for MRSA received a decolonization program and their care was monitored.Total 78 mothers were included in the study. The rate of MRSA colonisation was 2.5% at 32 – 34 week of gestation. Decolonization protocol was advised for MRSA carriers.Our obstetric population has a low colonization rate for MRSA. Infections could be decreased with targeted antenatal MRSA screening and decolonization in women at high risk. Continued monitoring of MRSA infections in obstetric population and their infants is required.

2% chlorhexidine gluconate aqueous versus 2% chlorhexidine gluconate in 70% isopropyl alcohol for skin disinfection prior to percutaneous central venous catheterisation: the ARCTIC randomised controlled feasibility trial

ObjectiveCatheter-related sepsis (CRS) is a major complication with significant morbidity and mortality. Evidence is lacking regarding the most appropriate antiseptic for skin disinfection before percutaneous central venous catheter (PCVC) insertion...

Glial cell line-derived neurotrophic factor (GDNF) is essential for colonization and expansion of turbot (Scophthalmus maximus) germ cells in recipients and in vitro culture

Germ cell transplantation (GCT) is a promising biotechnology that enables the production of donor-derived gametes in surrogate recipients. It plays a crucial role in the protection of endangered species, the propagation of elite species with desired traits, and long-term preservation of genetic resources. This significance is particularly pronounced when GCT is synergistically employed with cryopreservation techniques. However, GCT often encounters challenges due to low colonization rates and, in some cases, complete loss of donor cells in recipients. Glial cell line-derived neurotrophic factor (GDNF) plays a pivotal role in sustaining the self-renewal of spermatogonial stem cells (SSCs) in mammals. Additionally, it has been shown to promote the proliferation of spermatogonia in vitro cultures in certain animal species. In turbot (Scophthalmus maximus), we found that the expressions of gdnf and gfrα1a were predominantly observed in spermatogonia rather than somatic cells, which differed from their expression patterns in mammals. The efficiency of exogenous spermatogonia transplantation in Japanese flounder (Paralichthys olivaceus) larvae could be substantially enhanced by incubating donor cells from turbot with 100 ng/ml GDNF prior to transplantation. This led to a noteworthy increase in the colonization rate, rising from 33%-50%–61.5%. Additionally, the addition of 20 ng/ml GDNF in cell medium could also promote the proliferation of turbot germ cells in vitro. These results demonstrated the gdnf in turbot testis expression characteristics and suggested that addition of GNDF could be an effective way to improve the GCT efficiency and promote the germ cells expansion during in vitro culture.

Morphological and Molecular Characterizations of Arbuscular Mycorrhizal Fungi and Their Influence on Soil Physicochemical Properties and Plant Nutrition.

Pulses are considered a remarkable and stable source of nutrients, which are being presently extensively cultivated and consumed in different parts of the world. Pulses belong to the family Leguminosae and are a rich source of nutrients such as phosphorus (P) and nitrogen (N) for best growth via symbiotic relationship with bacteria and AMF (arbuscular mycorrhizal fungi). The aim of the current study was evaluating the influence of AMF diversity associated with various pulses (French bean, mung bean, kidney bean, peas, soybean, peanuts, and grams). Furthermore, AMF characterization was done using morphological features of spores and sequencing of the rDNA gene, which confirmed the existence of 10 different AMF taxa. Among the different genera, the genus Glomus was observed to be the most dominant with 30% species followed by Gigaspora (22%), Sclerocystis (12%), Acaulospora (8%), Rhizophagus and Septoglomus (7%), Diversispora (5%), and Claroideoglomus, Archaeospora, and Ambispora (3%). Furthermore, soil physicochemical analysis and percentage of AMF colonization results revealed the fact that the phosphorus content (inversely proportional to the AMF diversity) was a determining factor of AMF diversity. The highest amount of available phosphorus (62.825 mg kg-1) in the district Swabi resulted in a low rate of AMF colonization (6.66 ± 11.54%) with a comparatively higher rate of AMF colonization (50.66 ± 1.15%) found in the soil of the district Chitral having a low phosphorus content (17.3 ± 7.6 mg kg-1). Nutrient uptake by pulses including nitrogen (2.4 ± 1.3%), phosphorus (13.5 ± 7.6 mg kg -1), potassium (99.5 ± 25.8 mg kg -1), zinc (1.4 ± 0.5 mg kg -1), moisture (2.3 ± 1.3%), crude fats (5.6 ± 2.8%), ash (4 ± 1.2%), and proteins (13.6 ± 9.01%) determined the fact that AMF species diversity is positively correlated to the plant mineral nutrition. From the current study, it is concluded that AMF inoculation to the soil fields is beneficial to ensure the sustainability and productivity of pulse crops in diverse environmental conditions without polluting the soil.

Comparison of microbial colonization rates between central venous catheters and peripherally inserted central catheters

BackgroundCentral venous catheters (CVCs) and peripherally inserted central catheters (PICCs), have been widely used as intravascular devices in critically ill patients. However, they might evoke complications, such as catheter colonization that has been considered as predisposing factor for central line-associated bloodstream infections (CLABSIs). Although numerous studies have compared the risk of bloodstream infections between PICCs and CVCs, comparative studies on their colonization rates are limited.ObjectivesThe episodes of catheter colonization in critically ill patients with CVCs or PICCs were retrospectively analysed during a two-year period in a Greek tertiary care hospital and colonization rates, microbial profiles and antimicrobial susceptibility patterns were compared.MethodsClinical and laboratory data of consecutive hospitalized critically-ill patients who underwent PICC and CVC placement between May 2017–May 2019 were analysed. All catheters were examined by the semiquantitative culture technique for bacterial pathogens, either as a routine process after catheter removal or after suspicion of infection. Species identification and antimicrobial resistance patterns were determined by the Vitek2 automated system.ResultsDuring the survey period a total of 122/1187 (10.28%) catheter colonization cases were identified among CVCs and 19/639 (2.97%) cases among PICCs (p = 0.001). The colonization rate was 12.48/1000 catheter-days for the CVC group and 1.71/1000 catheter-days for the PICC group (p < 0.001). The colonization rate per 1000 catheter-days due to multidrug-resistant organisms (MDROs) was 3.85 in all study cases, 7.26 (71/122) in the CVC group and 0.63 (7/19) in the PICC group (p < 0.001). Within the CVC group, the most common microorganism isolated was MDR Acinetobacter baumannii (n = 38, 31.1%) followed by MDR Klebsiella pneumoniae (n = 20, 16.4%). In the PICC group, the predominant microorganism isolated was Candida spp. (n = 5, 23.8%) followed by MDR K. pneumoniae and MDR A. baumannii in equal numbers (n = 3, 14.2%).ConclusionPICC lines were associated with significantly lower colonization rates comparing to the CVC ones. In addition, patterns of microbial colonization revealed a trend over the predominance of MDR gram-negatives in CVCs suggesting that PICCs might be a safer alternative for prolonged inpatient intravascular access. Prevention programs directed by local microbial ecology may diminish catheter colonization rates and CLABSIs.

Exploring the low cell adhesion of photoinduced superhydrophilic surfaces for improving the effect of antifouling protective coatings on porous building materials

The susceptibility of building materials to biological colonization is associated with accelerated decay processes, aesthetical alterations and health risks. Thus, preventive measurements involving the use of coatings with passive (bioreceptivity decrease) and active (biocides) antifouling mechanisms are common. Hydrophobic and superhydrophobic coatings that decrease water availability are the most common anti-fouling strategies, although they can promote cell adhesion under the right circumstances and lose effectiveness after the initial biofilm setting.In this work, we explore an innovative alternative strategy to improve the anti-fouling effect of a hydrophobic coating through surface modification to grant low cell-adhesion superhydrophilic properties (while preserving its low water absorption) and its combination with nano-biocides. This is achieved by the incorporation of Ag or CuO-modified TiO2 into an ormosil sol–gel matrix. Irradiation with UV–Vis light activates the superhydrophilic surface while maintaining a decrease in capillary water absorption of >90% and accelerated algal exposure tests showed a markedly lower colonization rate compared to the superhydrophobic surface, owing to the modifications in cell-water-surface interfacial tensions. The nano-biocides showed a dual effect, promoting the transition to superhydrophilic and further decreasing colonization. Furthermore, the superhydrophilic surfaces enhance the biocide effect by promoting the interaction of the nanoparticles with the surrounding media.

LIN28 is essential for the maintenance of chicken primordial germ cells

Understanding the mechanism of stem cell maintenance underlies the establishment of long-term and mass culture methods for stem cells that are fundamental for clinical and agricultural applications. In this study, we use chicken primordial germ cell (PGC) as a model to elucidate the molecular mechanisms underlying stem cell maintenance. The PGC is a useful experimental model because it is readily gene-manipulatable and easy to test gene function in vivo using transplantation. Previous studies to establish a long-term culture system have shown that secreted factors such as FGF2 are required to maintain the self-renewal capability of PGC. On the other hand, we know little about intracellular regulators responsible for PGC maintenance. Among representative stem cell factors, we focus on RNA-binding factors LIN28A and LIN28B as possible central regulators for the gene regulatory network essential to PGC maintenance. By taking advantage of the CRISPR/Cas9-mediated gene editing and a clonal culture technique, we find that both LIN28A and LIN28B regulate the proliferation of PGC in vitro. We further showed that colonization efficiency of grafted PGC at the genital ridges, rudiments for the gonads, of chicken embryos were significantly decreased by knockout (KO) of LIN28A or LIN28B. Of note, overexpression of human LIN28 in LIN28-KO PGC was sufficient to restore the low colonization rates, suggesting that LIN28 plays a key role in PGC colonization at the gonads. Transcriptomic analyses of LIN28-KO PGC reveal that several genes related to mesenchymal traits are upregulated, including EGR1, a transcription factor that promotes the differentiation of mesodermal tissues. Finally, we show that the forced expression of human EGR1 deteriorates replication activity and colonization efficiency of PGCs. Taken together, this work demonstrates that LIN28 maintains self-renewal of PGC by suppressing the expression of differentiation genes including EGR1.

Competitive Inoculation as an Effective Prophylaxis Against Recurrent Urinary Tract Infections: A Systematic Review.

Urinary tract infection (UTI) is a common condition defined as the presence of bacteria within the urine above a certain threshold (usually >100,000 m/L). The lifetime risk in women is estimated to be 50%, of whom 25% will develop recurrence within 6 months. Unfortunately, the use of antibiotics to treat and manage recurrent UTI (rUTI) is a growing problem, due to the burden of growing antibiotic resistance on public health. As such, new approaches to manage rUTI are being investigated and developed. Competitive inoculation via instillation of Escherichia coli 83972 or HU2117 in the bladder is a new prophylactic non-antimicrobial therapy for rUTIs. It utilizes the principle of the protective nature of asymptomatic bacteriuria to prevent recurrence of symptomatic UTIs. However, the effectiveness and safety of this technique remains unclear. This systematic review examined the current outcomes data on competitive inoculation as an effective and safe treatment for rUTI prophylaxis. Based on a limited number of studies, current evidence suggests that competitive inoculation is an effective and safe prophylactic measure against UTIs in a select group of patients with incomplete bladder emptying. However, administration of the technology is both resource and time intensive, and there is strong data demonstrating low successful colonisation rates. Competitive inoculation is an alternative to antibiotics only to rUTI patients with incomplete bladder emptying. There is no evidence to suggest that the technology would be suitable for other subsets of rUTI patients. Further randomized controlled trials should be conducted to improve the evidence base before drawing conclusions for clinical practice, and ideas to improve colonisation rates and simplify the administration process should be explored.

Immobilization of Bacillus Thuringiensis and applicability in removal of sulfamethazine from soil

Microbial degradation is considered an essential and promising treatment for sulfadimidine contamination of soil. To address the low colonization rates and inefficiencies of typical antibiotic-degrading bacteria, sulfamethazine (SM2)-degrading strain H38 is converted into immobilized bacteria in this study. Results show that the removal rate of SM2 by immobilized strain H38 reaches 98% at 36 h, whereas the removal rate of SM2 by free bacteria reaches 75.2% at 60 h. In addition, the immobilized bacteria H38 exhibits tolerance to a wide range of pH (5–9) and temperature (20 °C–40 °C). As the amount of inoculation increases and the initial concentration of SM2 decreases, the removal rate of SM2 by the immobilized strain H38 increases gradually. Laboratory soil remediation tests show that the immobilized strain H38 can remove 90.0% of SM2 from the soil on the 12th day, which exceeds the removal by free bacteria by 23.9% in the same period. Additionally, the results show that the immobilized strain H38 enhances the overall activity of microorganisms in SM2-contaminated soil. Compared with the SM2 only (control group containing no bacteria) and free bacterial treatment groups, the gene expression levels of ammonia-oxidizing archaea, ammonia-oxidizing bacteria, cbbLG, and cbbM increased significantly in the treatment group with immobilized strain H38. This study shows that immobilized strain H38 can reduce the effect of SM2 on soil ecology to a greater extent than free bacteria, while providing safe and effective remediation.

EFFECT OF REMOVABLE DENTURES ON COLONIZATION OF AEROBIC BACTERIA IN THE ORAL CAVITY AND ANTIBIOTIC PATTERN OF THE COMMON ISOLATED BACTERIA

Background and aims: Wearing a removable dental prosthesis causes a change in the micro flora of the mouth. The aim of this research was to verify the composition of aerobic bacterial in the oral cavity of patients with removable dentures and with normal teeth (without dentures), and antibiotics pattern for common isolates. Methods: Bacteriological investigations were performed in 122 individuals (61 removable dentures: 61 normal teeth) attending dental clinics of Faculty of dentistry, Sana’a University, Yemen and private dental clinics. The culturing and antibiotic sensitivity were conducted in the Microbiology Department of the National Center of Public Health Laboratories (NCPHL) Sana'a, Yemen. Tongue dorsa and palate mucosa swabs were collected from normal teeth and denture groups, and as well swabs from mucosal part of denture surfaces in prosthetic patients. Cultivation in microaerophilic (5% CO2) and oxygenic conditions were performed on solid selective and non-selective media in addition to media enriched with 5% blood. Results: Regarding the prosthetic patients, the rate of bacterial isolates from the palate, back, tongue and dental plaque smears was higher potential pathogenic bacteria as S. aureus and Enterobacteriaceae spp in denture wearers, as E. coli (6.6% in dentures vs. 1.6% in the absence of dentures), Klebsiella pneumoniae (11.4% in dentures versus 1.6% in the normal teeth) and Pseudomonas aeruginosa (13.1% versus 0.0% ).While in viridians Streptococcus including Strept .mutans, there was a lower colonization rate in denture patients (18% in palate verses, 73.8% in individuals without dentures). Conclusion: The study demonstrated an elevated rate of bacterial isolates from palate, back, tongue and plaque swabs in denture patients of pathogenic bacteria such as S. aureus, E. coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa; while in Streptococcus viridians including S. mutans, there was a lower colonization rate in denture patients verses a very high rate in individuals without dentures. Peer Review History: Received: 7 November 2022; Revised: 13 December; Accepted: 8 January 2023, Available online: 15 January 2023 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Indonesia, ahmad.najib@umi.ac.id Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Alfonso Alexander Aguileral, University of Veracruz, Mexico, aalexander_2000@yahoo.com Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, amaka_mgbahurike@yahoo.com Similar Articles: ETIOLOGY AND RISK FACTORS OF STOMATITIS AMONG YEMENI DENTURE WEARERS PREVALENCE AND ASSOCIATED FACTORS OF ORAL NON-CANDIDA ALBICANS CANDIDA CARRIAGE IN DENTURE WEARERS IN SANA'A CITY- YEMEN THE EFFECT OF NANOSILVER AND CHLORHEXIDINE MOUTHWASH ON ANAEROBIC PERIODONTAL PATHOGENS COUNTS

1331. Pneumococcal Colonization Among Children 5 years of Age and Younger During SARS-CoV-2 Pandemic

Abstract Background Children ≤5 years of age have the highest rates of pneumococcal colonization and play an important role in the spread of pneumococcus. Our objective was to determine whether the public health measures (physical distancing, masking, and shelter-in-place orders) implemented to slow the spread of SARS-CoV-2 pandemic had an impact on pneumococcal colonization rates among children aged ≤5 years with and without respiratory symptoms during the first year of SARS-CoV-2 pandemic (4/1/20 to 3/31/21). Methods This is a single center retrospective cohort study. The study period was divided in 3 four-month periods to represent the initial period of strict adherence to public health measures (period 1: Apr-Jul), relaxation of some of these measures (period 2: Aug-Nov) and Northern hemisphere winter season (period 3: Dec-Mar). We used salvaged mid-turbinate samples obtained as part of routine care from patients without respiratory symptoms but screened for SARS-CoV-2 prior to surgery or aerosol generating procedures (asymptomatic) or from patients with respiratory symptoms tested for SARS-CoV-2 and/or other respiratory viruses (symptomatic). Samples were evaluated for pneumococcal colonization by real-time PCR using CDC lytA primers. Sample size was calculated based on the assumption of lower colonization rates in period 1 and gradual increase (10-15%) in the following study periods. Results A total of 311 patients were included (185 asymptomatic and 126 symptomatic). Demographics, SARS-CoV-2 PCR and pneumococcal colonization results are shown in Table 1. Pneumococcal colonization rates for asymptomatic and symptomatic children were 14% and 22% (p=0.06), respectively. The odds of colonization of asymptomatic children were similar during period 2 (OR 0.96 [95%CI 0.34-2.67]) and period 3 (OR 0.53 [95%CI 0.17-1.62]), using period 1 as reference and after adjusting for age, sex, and SARS-COV-2 results. The odds of colonization of symptomatic children were also similar across the 3 study periods (period 2 OR 1.28 [95%CI 0.41-4.01] and period 3 OR 0.73 [95% CI 0.24-2.18]). Table 1.Characteristics of asymptomatic and symptomatic groups Conclusion Pneumococcal colonization rates were not significantly impacted by public health measures implemented during the first year of the SARS-CoV-2 pandemic and did not correlate with SARS-CoV-2 positivity. Disclosures Liset Olarte, MD, MSc, GSK: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi: Grant/Research Support Douglas S. Swanson, MD, Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi: Grant/Research Support Brian R. Lee, PhD, MPH, CDC: Grant/Research Support|Merck: Grant/Research Support Christopher J. Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric News: Honoraria|Pfizer: Grant/Research Support Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, F(AAM), BioFire: Grant/Research Support|Luminex: Grant/Research Support.

Short-term response of ground-dwelling arthropods to storm-related disturbances is mediated by topography and dispersal

Wind disturbances and consequent salvage logging lead to drastic changes in forest soil conditions, vegetation and microclimate, potentially affecting arthropod communities. In mountain regions, topography is expected to be particularly important to modulate the effect of canopy removal and soil disturbance potentially amplifying the ecological contrast between forest and disturbed areas. Here, we studied the short-term response of ground beetles (Carabidae), spiders (Araneae), and harvestmen (Opiliones) in wind-damaged spruce forests along statistically orthogonal gradients in elevation, slope, and aspect. We addressed three main ecological questions: (i) Does the effect of wind disturbance on diversity depend on topography? (ii) Are there specific taxon-related responses to disturbances?, and (iii) What is the role of dispersal in shaping species assembly dynamics? We generally observed that increasing slope and elevation amplified the differences between undisturbed forest and windfall areas. On the one hand, the diversity of ground beetles and harvestmen seemed to be negatively affected by wind disturbance, causing a loss of specialized forest species with a low rate of colonization of species typical of open habitats. On the other hand, several novel spider species were able to rapidly colonize windfalls and community composition strongly shifted from forest to disturbed areas. Species with long-range dispersal strategies (e.g. flying and ballooning) were those more likely to colonize windfalls. Our findings suggest that disturbance effects on ground-dwelling organisms were modulated by underlying environmental gradients and that short-term response of different taxa was dependent on their dispersal ability.

Short-Eared Owl Land-Use Associations during the Breeding Season in the Western United States

ABSTRACT The Short-eared Owl (Asio flammeus) is a species of conservation concern in the western USA, with evidence for declining population sizes. Monitoring of Short-eared Owls is complicated because of their low site fidelity and nomadic movements. We recruited community-science participants to implement a multi-year survey of Short-eared Owls across eight states in the western USA, resulting in a program of sufficient temporal and spatial dimensions to overcome many of the challenges in monitoring this species. We implemented both multi-scale occupancy and colonization/extinction modeling to provide insights into land-cover use, and to identify which cover types supported higher occurrence. Short-eared Owls were associated with native and anthropogenic land-cover types, but site occupancy varied among these categories and at different scales. Native grasslands, marsh/riparian, hay/fallow agriculture, and cultivated croplands were occupied most consistently across years. Occupancy rates differed at different scales (e.g., marsh/riparian was the only land-cover type positively associated with occupancy at both transect and point scales). Contrary to expectations, native shrubland was negatively associated with occupancy at the point scale, and exhibited low colonization and high extinction rates. Our results suggest that conserving native landscapes in general, and grasslands, marsh, and riparian areas specifically, would benefit Short-eared Owls. Furthermore, Short-eared Owl occupancy was positively associated with hay/fallow land-cover types, suggesting that some nonnative land-cover types can function as Short-eared Owl habitat. Lastly, our results highlight how developing a broad-scale community science survey can inform conservation for a species not well monitored by existing survey programs.

Prospective surveillance of colonization and disease by methicillin-resistant Staphylococcus aureus (MRSA) at a European pediatric cancer center

PurposeChildren and adolescents undergoing treatment for cancer or allogeneic hematopoietic cell transplantation are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA). We therefore examined the occurrence and outcome of MRSA colonization and infection in patients of a large European pediatric cancer center.MethodsIn a prospective observational cohort study conducted between 2007 and 2018, nasopharyngeal swabs for culture of MRSA were obtained from all admitted patients. The primary endpoint of the study was the colonization rate over time. Secondary endpoints included genetic relatedness of isolates, time burden of isolation measures, and results of decolonization efforts.ResultsDuring the study period, MRSA screening identified 34 colonized patients (median age: 10 years; range: 0–21) without trends over time. MRSA colonization was associated with the presence of classical risk factors. There was no molecular evidence of patient-to-patient transmission. A standard MRSA eradication regimen led to a lasting eradication of the organism in 26 of 34 patients. MRSA infection occurred in two patients with no associated fatalities.ConclusionProspective monitoring revealed low rates of MRSA colonization and infection at our center. These low rates and the absence of patient-to-patient transmission support the effectiveness of the management bundle of MRSA identification, isolation, and decolonization.

OsRAM2 Function in Lipid Biosynthesis Is Required for Arbuscular Mycorrhizal Symbiosis in Rice.

Arbuscular mycorrhiza (AM) is a mutualistic symbiosis formed between most land plants and Glomeromycotina fungi. During symbiosis, plants provide organic carbon to fungi in exchange for mineral nutrients. Previous legume studies showed that the required for arbuscular mycorrhization2 (RAM2) gene is necessary for transferring lipids from plants to AM fungi (AMF) and is also likely to play a "signaling" role at the root surface. To further explore RAM2 functions in other plant lineages, in this study, two rice (Oryza sativa) genes, OsRAM2 and OsRAM2L, were identified as orthologs of legume RAM2. Examining their expression patterns during symbiosis revealed that only OsRAM2 was strongly upregulated upon AMF inoculation. CRISPR/Cas9 mutagenesis was then performed to obtain three Osram2 mutant lines (-1, -2, and -3). After inoculation by AMF Rhizophagus irregularis or Funneliformis mosseae, all of the mutant lines showed extremely low colonization rates and the rarely observed arbuscules were all defective, thus supporting a conserved "nutritional" role of RAM2 between monocot and dicot lineages. As for the signaling role, although the hyphopodia numbers formed by both AMF on Osram2 mutants were indeed reduced, their morphology showed no abnormality, with fungal hyphae invading roots successfully. Promoter activities further indicated that OsRAM2 was not expressed in epidermal cells below hyphopodia or outer cortical cells enclosing fungal hyphae but instead expressed exclusively in cortical cells containing arbuscules. Therefore, this suggested an indirect role of RAM2 rather than a direct involvement in determining the symbiosis signals at the root surface.[Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2022.

Culturable fungal endophyte communities of primary successional plants on Mount St. Helens, WA, USA

BackgroundWhile a considerable amount of research has explored plant community composition in primary successional systems, little is known about the microbial communities inhabiting these pioneer plant species. Fungal endophytes are ubiquitous within plants, and may play major roles in early successional ecosystems. Specifically, endophytes have been shown to affect successional processes, as well as alter host stress tolerance and litter decomposition dynamics—both of which are important components in harsh environments where soil organic matter is still scarce.ResultsTo determine possible contributions of fungal endophytes to plant colonization patterns, we surveyed six of the most common woody species on the Pumice Plain of Mount St. Helens (WA, USA; Lawetlat'la in the Cowlitz language; created during the 1980 eruption)—a model primary successional ecosystem—and found low colonization rates (< 15%), low species richness, and low diversity. Furthermore, while endophyte community composition did differ among woody species, we found only marginal evidence of temporal changes in community composition over a single field season (July–September).ConclusionsOur results indicate that even after a post-eruption period of 40 years, foliar endophyte communities still seem to be in the early stages of community development, and that the dominant pioneer riparian species Sitka alder (Alnus viridis ssp. sinuata) and Sitka willow (Salix sitchensis) may be serving as important microbial reservoirs for incoming plant colonizers.

OsADK1, a novel kinase regulating arbuscular mycorrhizal symbiosis in rice.

Arbuscular mycorrhizal (AM) symbiosis relies on the formation of arbuscules for efficient nutrient exchange between plants and AM fungi. In this study, we identified a novel kinase gene in rice named OsADK1 (Arbuscule Development Kinase 1) that is required for arbuscule development. By obtaining OsADK1pro::GUS transgenic rice plants and also generating Osadk1 mutants via CRISPR/Cas9 technique, OsADK1 was revealed to be specifically induced in the arbusculated cortical cells and mutations in OsADK1 resulted in an extremely low colonisation rate (c. 3%) of rice roots by AM fungus Rhizophagus irregularis. In the mutant roots, the very few observed arbuscules nearly all arrested at an early 'trunk-forming' phase without forming any branches. Increasing the inoculum strength of AM fungus or cocultivation with a wild-type nurse plant did not result in the rescue of the arbuscule phenotype. Transcriptome sequencing of both nursed and un-nursed Osadk1 mutants then revealed that the mutation of OsADK1 could greatly affect the AM symbiotic programme, including many key transcription factors such as RAM1 and WRI5. OsADK1 therefore represents a new rice kinase that is required for arbuscule branching. Its identification opens a new window to explore the elaborate signal transduction pathway that determines arbuscule development during plant-fungus symbiosis.