The relationship between personality, social capital, and life satisfaction of elderly Koreans.

BACKGROUND: There are very few studies that explain the life satisfaction of the elderly by considering both internal factors such as personality and social capital. Therefore, this study analyzed the relationship between personality, social capital, and life satisfaction among elderly Koreans. METHODS: This study analyzed the survey data on Koreans' happiness and quality of life 2019. Participants included a total of 1280 elderly adults aged 60-79 years. RESULTS: A multiple hierarchical regression analysis indicated that higher health status was related to higher life satisfaction, while neuroticism was negatively related to life satisfaction. Of particular note, increased structural and cognitive social capital were associated with higher life satisfaction. However, income, financial problems, and extraversion were not related to life satisfaction. The total explanatory amount of the regression model was 38.5%. CONCLUSIONS: These findings suggest that researchers and clinicians should consider a combination of factors associated with both personality and social capital when aiming to improve life satisfaction for the elderly.

Photopolymerizable, Universal Antimicrobial Coating to Produce High-Performing, Multifunctional Face Masks.

COVID-19 poses a major threat to global health and socioeconomic structures, and the need for a highly effective, antimicrobial face mask has been considered a major challenge for protection against respiratory diseases. Here, we report the development of a universal, antiviral, and antibacterial material that can be dip-/spray-coated over conventional mask fabrics to exhibit antimicrobial activities. Our data shows that antimicrobial fabrics rapidly inactivated multiple types of viruses, i.e., human (alpha/beta) coronaviruses, the influenza virus, and bacteria, irrespective of their modes of transmission (aerosol or droplet). This research provides an immediate method to contain infectious diseases, such as COVID-19.

Genome Resource of Podosphaera xanthii, the Host-Specific Fungal Pathogen That Causes Cucurbit Powdery Mildew.

Approximately 33 types of commonly consumed fruits and vegetables are members of the family Cucurbitaceae, making it an important crop family worldwide. However, pathogen resistance to pesticides and fungicides has become a growing problem in cultivation practices. The identification of the effector proteins in each unique fungus-host pair would help toward the development of strategies for preventing the infection of important crops. In this study, we characterized the genome of Podosphaera xanthii, the fungal pathogen that causes powdery mildew disease in cucurbitaceous plants. A first-draft genome of 209.08 MB was assembled and compared with those of 25 other fungal pathogens, particularly for identifying candidate secreted effector proteins. This draft genome can serve as a valuable resource for future genomic and proteomic studies of P. xanthii and its host-specific pathogenesis.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Frequent Implication of Multistress-Tolerant Campylobacter jejuni in Human Infections.

Campylobacter jejuni, a major cause of bacterial foodborne illnesses, is considered highly susceptible to environmental stresses. In this study, we extensively investigated the stress tolerance of 121 clinical strains of C. jejuni against 5 stress conditions (aerobic stress, disinfectant exposure, freeze-thaw, heat treatment, and osmotic stress) that this pathogenic bacterium might encounter during foodborne transmission to humans. In contrast to our current perception about high stress sensitivity of C. jejuni, a number of clinical strains of C. jejuni were highly tolerant to multiple stresses. We performed population genetics analysis by using comparative genomic fingerprinting and showed that multistress-tolerant strains of C. jejuni constituted distinct clades. The comparative genomic fingerprinting subtypes belonging to multistress-tolerant clades were more frequently implicated in human infections than those in stress-sensitive clades. We identified unique stress-tolerant C. jejuni clones and showed the role of stress tolerance in human campylobacteriosis.

Enhanced transmission of antibiotic resistance in Campylobacter jejuni biofilms by natural transformation.

Campylobacter jejuni is a leading food-borne pathogen, and its antibiotic resistance is of serious concern to public health worldwide. C. jejuni is naturally competent for DNA transformation and freely takes up foreign DNA harboring genetic information responsible for antibiotic resistance. In this study, we demonstrate that C. jejuni transfers antibiotic resistance genes more frequently in biofilms than in planktonic cells by natural transformation.

Target optimization for peptide nucleic acid (PNA)-mediated antisense inhibition of the CmeABC multidrug efflux pump in Campylobacter jejuni.

OBJECTIVES: CmeABC is a resistance-nodulation-cell division (RND)-type multidrug efflux pump conferring resistance to clinically important antibiotics in Campylobacter. This study aimed to identify the optimal target sites for the inhibition of CmeABC with antisense peptide nucleic acid (PNA). METHODS: Eighteen PNAs were designed to bind to the translational initiation regions of cmeABC, spanning the ribosome-binding site (RBS) and the start codon of the cmeABC genes. Campylobacter jejuni was treated with CmeABC-specific PNAs (CmeABC-PNAs) at various concentrations and subjected to western blotting to measure changes in the level of CmeABC expression. The MICs of ciprofloxacin and erythromycin were measured to evaluate the impact of CmeABC knockdown on antibiotic susceptibility. RESULTS: While antisense PNA significantly affected CmeA and CmeB expression, interestingly, CmeC expression was not altered by any of the CmeC-PNAs used in this study. A CmeA-PNA targeting the RBS of cmeA and its upstream region reduced CmeA expression most efficiently, and CmeB expression was most significantly decreased by PNA binding to the RBS of cmeB and its downstream region. CmeA- and CmeB-PNAs increased the susceptibility of C. jejuni to ciprofloxacin and erythromycin in proportion to the inhibition levels observed in western blotting. CONCLUSIONS: The cmeA gene is the best target to knockdown CmeABC with antisense PNA. The RBS is the major target for the PNA-mediated antisense inhibition of CmeABC. However, regions in its vicinity also significantly influence the effectiveness of the PNA-based knockdown of CmeABC.

Highly variable blood pressure as a predictor of poor cognitive outcome in patients with acute lacunar infarction.

OBJECTIVE AND BACKGROUND: Many patients develop cognitive impairment after an acute stroke. It is not clear whether blood pressure variability is a prognostic factor for cognitive impairment. We aimed to determine the association between blood pressure variability on hospital admission and cognitive outcome in patients with acute lacunar infarction. METHODS: We performed a retrospective analysis on 22 men and 14 women (mean age, 61.8 years) who had completed a cognitive evaluation 3 months after onset of an acute lacunar infarction. The patients had no previous functional disability or dementia, stenosis in major cerebral arteries, cardiac embolic sources, or infarct in strategic territories for cognition. We used standard deviation and coefficient of variance as parameters of blood pressure variability, and each cognitive function test z score as an outcome parameter. We performed linear regression analysis to assess the relationship between blood pressure variability and cognition, adjusted for vascular risk factors, severity of neurologic deficits, and mean blood pressure. RESULTS: High variability of both systolic and diastolic blood pressure was significantly associated with low z scores on the Controlled Oral Word Association Test and the Digit Symbol Coding test (P<0.01). High variability of diastolic blood pressure was significantly associated with low z scores on the Korean Mini-Mental State Examination and Seoul Verbal Learning Test delayed recall (P<0.01). CONCLUSIONS: Highly variable blood pressure on admission for acute lacunar infarction may predict poor cognitive outcomes, especially frontal lobe dysfunction.

Antimicrobial Face Masks and Mask Covers with a Salt-Coated Stacked Spunbond Polypropylene Fabric: Effective Inactivation of Resilient Pathogens and Prevention of Contact Transmission.

In response to the ongoing threat posed by respiratory diseases, ensuring effective transmission protection is crucial for public health. To address the drawbacks of single-use face masks/respirators, which can be a potential source of contact-based transmission, we have designed an antimicrobial face mask and mask covering utilizing a stack of salt-coated spunbond (SB) fabric. This fabric acts as an outer layer for the face mask and as a covering over a conventional mask, respectively. We evaluated the universal antimicrobial performance of the salt-coated three-stacked SB fabric against enveloped/nonenveloped viruses and spore-forming/nonspore-forming bacteria. The distinctive pathogen inactivation efficiency was confirmed, including resistant pathogens such as human rhinovirus and Clostridium difficile. In addition, we tested other filter attributes, such as filtration efficiency and breathability, to determine the optimal layer for salt coating and its effects on performance. Our findings revealed that the outer layer of a conventional face mask plays a crucial role in contact transmission through contaminated face masks and respirators. Through contact transmission experiments using droplets involving three types of contaminants (fluorescent dyes, bacteria, and viruses), the salt-coated stacked SB fabric demonstrated a superior effect in preventing contact transmission compared to SB or meltblown polypropylene fabrics─an issue challenging to existing masks. Our results demonstrate that the use of salt-coated stacked SB fabrics as (i) the outer layer of a mask and (ii) a mask cover over a mask enhances overall filter performance against infectious droplets, achieving high pathogen inactivation and low contact-based transmission while maintaining breathability.

Highly Effective Salt-Activated Alcohol-Based Disinfectants with Enhanced Antimicrobial Activity.

Surfaces contaminated with pathogens raise concerns about the increased risk of disease transmission and infection. To clean biocontaminated surfaces, alcohol-based disinfectants have been predominantly used for disinfecting high-touch areas in diverse settings. However, due to its limited antimicrobial activities and concern over the emergence of alcohol-tolerant strains, much effort has been made to develop highly efficient disinfectant formulations. In this study, we hypothesize that the addition of a physical pathogen inactivation mechanism by salt recrystallization (besides the existing chemical inactivation mechanism by alcohol in such formulations) can improve inactivation efficiency by preventing the emergence of alcohol tolerance. To this end, we employed the drying-induced salt recrystallization process to implement the concept of highly efficient alcohol-based disinfectant formulations. To identify the individual and combined effects of isopropyl alcohol (IPA) and NaCl, time-dependent morphological/structural changes of various IPA solutions containing NaCl have been characterized by optical microscopy/X-ray diffraction analysis. Their antimicrobial activities have been tested on surfaces (glass slide, polystyrene Petri dish, and stainless steel) contaminated with Gram-positive/negative bacteria (methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica subsp. enterica Typhimurium) and viruses (A/PR8/34 H1N1 influenza virus and HCoV-OC43 human coronavirus). We found that additional salt crystallization during the drying of the alcohol solution facilitated stronger biocidal effects than IPA-only formulations, regardless of the types of solid surfaces and pathogens, including alcohol-tolerant strains adapted from wild-type Escherichia coli MG1655. Our findings can be useful in developing highly effective disinfectant formulations by minimizing the use of toxic antimicrobial substances to improve public health and safety.

Study of the Pathogen Inactivation Mechanism in Salt-Coated Filters.

As COVID-19 exemplifies, respiratory diseases transmitted through aerosols or droplets are global threats to public health, and respiratory protection measures are essential first lines of infection prevention and control. However, common face masks are single use and can cause cross-infection due to the accumulated infectious pathogens. We developed salt-based formulations to coat membrane fibers to fabricate antimicrobial filters. Here, we report a mechanistic study on salt-induced pathogen inactivation. The salt recrystallization following aerosol exposure was characterized over time on sodium chloride (NaCl), potassium sulfate (K2SO4), and potassium chloride (KCl) powders and coatings, which revealed that NaCl and KCl start to recrystallize within 5 min and K2SO4 within 15 min. The inactivation kinetics observed for the H1N1 influenza virus and Klebsiella pneumoniae matched the salt recrystallization well, which was identified as the main destabilizing mechanism. Additionally, the salt-coated filters were prepared with different methods (with and without a vacuum process), which led to salt coatings with different morphologies for diverse applications. Finally, the salt-coated filters caused a loss of pathogen viability independent of transmission mode (aerosols or droplets), against both DI water and artificial saliva suspensions. Overall, these findings increase our understanding of the salt-recrystallization-based technology to develop highly versatile antimicrobial filters.

Salt coatings functionalize inert membranes into high-performing filters against infectious respiratory diseases.

Respiratory protection is key in infection prevention of airborne diseases, as highlighted by the COVID-19 pandemic for instance. Conventional technologies have several drawbacks (i.e., cross-infection risk, filtration efficiency improvements limited by difficulty in breathing, and no safe reusability), which have yet to be addressed in a single device. Here, we report the development of a filter overcoming the major technical challenges of respiratory protective devices. Large-pore membranes, offering high breathability but low bacteria capture, were functionalized to have a uniform salt layer on the fibers. The salt-functionalized membranes achieved high filtration efficiency as opposed to the bare membrane, with differences of up to 48%, while maintaining high breathability (> 60% increase compared to commercial surgical masks even for the thickest salt filters tested). The salt-functionalized filters quickly killed Gram-positive and Gram-negative bacteria aerosols in vitro, with CFU reductions observed as early as within 5 min, and in vivo by causing structural damage due to salt recrystallization. The salt coatings retained the pathogen inactivation capability at harsh environmental conditions (37 °C and a relative humidity of 70%, 80% and 90%). Combination of these properties in one filter will lead to the production of an effective device, comprehensibly mitigating infection transmission globally.

Tolerance to stress conditions associated with food safety in Campylobacter jejuni strains isolated from retail raw chicken.

Campylobacter jejuni is a microaerophilic foodborne pathogen that is sensitive to stress conditions. However, it is not yet understood how this stress-sensitive pathogen may cause a significant number of cases of human gastroenteritis worldwide. In this study, we examined stress tolerance in 70 C. jejuni strains isolated from retail chicken under several stress conditions related to food safety. Compared to oxygen-sensitive (OS) strains of C. jejuni, C. jejuni strains with increased aerotolerance, such as hyper-aerotolerant (HAT) and aerotolerant (AT) strains, were more tolerant to peracetic acid, refrigeration and freeze-thaw stresses. However, the levels of thermotolerance and hyper-osmotolerance were not associated with the aerotolerance level of C. jejuni. The HAT and AT strains of C. jejuni exhibited significantly increased activities of catalase and superoxide dismutase (SOD), compared to the OS strains. Consistently, the HAT and AT strains were highly tolerant to oxidants, such as hydrogen peroxide, cumene hydroperoxide and menadione, compared to the OS strains. The AT and HAT strains that were tolerant to stresses, particularly peracetic acid and refrigeration, predominantly belonged to multilocus sequence typing (MLST) clonal complex (CC)-21. This study shows that oxidative stress resistance plays a role in determining the differential level of aerotolerance in C. jejuni and that AT and HAT strains of C. jejuni are more tolerant to oxidants and low temperatures than OS strains.

Enhanced Biofilm Formation by Ferrous and Ferric Iron Through Oxidative Stress in Campylobacter jejuni.

Campylobacter is a leading foodborne pathogen worldwide. Biofilm formation is an important survival mechanism that sustains the viability of Campylobacter under harsh stress conditions. Iron affects biofilm formation in some other bacteria; however, the effect of iron on biofilm formation has not been investigated in Campylobacter. In this study, we discovered that ferrous (Fe2+) and ferric (Fe3+) iron stimulated biofilm formation in Campylobacter jejuni. The sequestration of iron with an iron chelator prevented the iron-mediated biofilm stimulation. The level of total reactive oxygen species (ROS) in biofilms was increased by iron. However, the supplementation with an antioxidant prevented the total ROS level from being increased in biofilms by iron and also inhibited iron-mediated biofilm stimulation in C. jejuni. This suggests that iron promotes biofilm formation through oxidative stress. Based on the results of fluorescence microscopic analysis, Fe2+ and Fe3+ enhanced both microcolony formation and biofilm maturation. The levels of extracellular DNA and polysaccharides in biofilms were increased by iron supplementation. The effect of iron on biofilm formation was also investigated with 70 C. jejuni isolates from raw chicken. Regardless of the inherent levels of biofilm formation, iron stimulated biofilm formation in all tested strains; however, there were strain variations in iron concentrations affecting biofilm formation. The biofilm formation of 92.9% (65 of 70) strains was enhanced by either 40 µM Fe2+ or 20 µM Fe3+ or both (the iron concentrations that enhanced biofilm formation in C. jejuni NCTC 11168), whereas different iron concentrations were required to promote biofilms in the rest of the strains. The findings in this study showed that Fe2+ and Fe3+ contributed to the stimulation of biofilm formation in C. jejuni through oxidative stress.

Antioxidant-based synergistic eradication of methicillin-resistant Staphylococcus aureus (MRSA) biofilms with bacitracin.

Biofilms of methicillin-resistant Staphylococcus aureus (MRSA) have serious clinical implications. However, it is difficult to eradicate MRSA biofilms due to the increased tolerance to antimicrobials of biofilms. In this study, we investigated the synergistic anti-biofilm effect of the combination of octyl gallate (OG), an antioxidant approved by the US Food and Drug Administration (FDA) as a food additive, and bacitracin, an antimicrobial peptide commonly used in topical antimicrobial ointments. The results of biofilm assays showed that OG enabled bacitracin at concentrations as low as 10-3 U/ml to inhibit biofilm formation in MRSA. A confocal microscopic analysis exhibited that the combination of bacitracin and OG suppressed biofilm formation in MRSA highly effectively compared to the single treatment of either bacitracin or OG. The synergistic anti-biofilm activity of bacitracin and OG was also confirmed in MRSA strains from humans, including USA300, which is the predominant clone of community-associated MRSA in the US. To the best of our knowledge, this is the first report about the synergistic anti-biofilm activity of an antimicrobial peptide and an antioxidant against MRSA.

Ketamine infusion therapy for chronic pain management in South Korea: A national survey for pain physicians with a narrative review.

Although ketamine infusion therapy (KIT) has been used extensively for the treatment of chronic persistent pain, there remains high heterogeneity in the administration protocols. The aim of this study was to assess the current clinical use and the infusion protocols of KIT in South Korea and to compare the protocol details with previous relevant studies.In the first phase, an online survey about KIT, including protocol information, was distributed to pain physicians managing chronic pain patients at 47 teaching hospitals registered in the Korean Pain Society. In the second phase, a review of the KIT protocols in previous clinical studies was conducted and compared with the survey results.Among 47 institutions, 35 replied; among them, 25 institutions performed KIT on an outpatient basis. The administration protocol for KIT varied greatly among institutions: the total infusion dose of ketamine ranged from 3.5 to 140 mg/70 kg, with a mode of 70 mg [interquartile range (IQR): 62.0; 8.0-70.0 mg] administered in 1 to 3 hours. In 10 previous studies of outpatient KIT, the total dose of ketamine ranged from 12.6 to 98 mg/70 kg, with a mode of 35 mg [IQR: 40 mg; 23-63 mg] given in 1 to 4 hours, which was significantly lower than in our results (P = .01). In the survey, physicians listed hallucination as the most frequent side effect.Although KIT is used in Korean pain centers, there is wide variation regarding the specific infusion protocols. The total dose of ketamine used in South Korea is significantly higher than the general recommendations for outpatient management and may compromise patient safety. The results of this survey reinforce the need for specific guidelines for KIT in managing chronic pain that counterbalance its risks and benefits.

Method of Peptide Nucleic Acid (PNA)-Mediated Antisense Inhibition of Gene Expression in Campylobacter jejuni.

Peptide nucleic acid (PNA) is an oligonucleotide mimic that recognizes and binds to nucleic acids. The strong binding affinity of PNA to mRNA coupled with its high sequence specificity enable antisense PNA to selectively inhibit (i.e., knockdown) the protein synthesis of a target gene. This novel technology provides a powerful tool for Campylobacter studies because molecular techniques have been relatively less well-developed for this bacterium as compared to other pathogens, such as Escherichia coli and Salmonella. This chapter describes a protocol for PNA-mediated antisense inhibition of gene expression in Campylobacter jejuni.

Differential Survival of Hyper-Aerotolerant Campylobacter jejuni under Different Gas Conditions.

Campylobacter jejuni accounts for a significant number of foodborne illnesses around the world. C. jejuni is microaerophilic and typically does not survive efficiently in oxygen-rich conditions. We recently reported that hyper-aerotolerant (HAT) C. jejuni are highly prevalent in retail poultry meat. To assess the capabilities of HAT C. jejuni in foodborne transmission and infection, in this study, we investigated the prevalence of virulence genes in HAT C. jejuni and the survival in poultry meat in atmosphere at a refrigeration temperature. When we examined the prevalence of eight virulence genes in 70 C. jejuni strains from raw poultry meat, interestingly, the frequencies of detecting virulence genes were significantly higher in HAT C. jejuni strains than aerosenstive C. jejuni strains. This suggests that HAT C. jejuni would potentially be more pathogenic than aerosensitive C. jejuni. Under aerobic conditions, aerosensitive C. jejuni survived at 4°C in raw poultry meat for 3 days, whereas HAT C. jejuni survived in poultry meat for a substantially extended time; there was a five-log CFU reduction over 2 weeks. In addition, we measured the effect of other gas conditions, including N2 and CO2, on the viability of HAT C. jejuni in comparison with aerosensitive and aerotolerant strains. N2 marginally affected the viability of C. jejuni. However, CO2 significantly reduced the viability of C. jejuni both in culture media and poultry meat. Based on the results, modified atmosphere packaging using CO2 may help us to control poultry contamination with HAT C. jejuni.

An Improved Culture Method for Selective Isolation of Campylobacter jejuni from Wastewater.

Campylobacter jejuni is one of the leading foodborne pathogens worldwide. C. jejuni is isolated from a wide range of foods, domestic animals, wildlife, and environmental sources. The currently available culture-based isolation methods are not highly effective for wastewater samples due to the low number of C. jejuni in the midst of competing bacteria. To detect and isolate C. jejuni from wastewater samples, in this study, we evaluated a few different enrichment conditions using five different antibiotics (i.e., cefoperazone, vancomycin, trimethoprim, polymyxin B, and rifampicin), to which C. jejuni is intrinsically resistant. The selectivity of each enrichment condition was measured with C t value using quantitative real-time PCR, and multiplex PCR to determine Campylobacter species. In addition, the efficacy of Campylobacter isolation on different culture media after selective enrichment was examined by growing on Bolton and Preston agar plates. The addition of polymyxin B, rifampicin, or both to the Bolton selective supplements enhanced the selective isolation of C. jejuni. The results of 16S rDNA sequencing also revealed that Enterococcus spp. and Pseudomonas aeruginosa are major competing bacteria in the enrichment conditions. Although it is known to be difficult to isolate Campylobacter from samples with heavy contamination, this study well exhibited that the manipulation of antibiotic selective pressure improves the isolation efficiency of fastidious Campylobacter from wastewater.

Synergistic anti-Campylobacter jejuni activity of fluoroquinolone and macrolide antibiotics with phenolic compounds.

The increasing resistance of Campylobacter to clinically important antibiotics, such as fluoroquinolones and macrolides, is a serious public health problem. The objective of this study is to investigate synergistic anti-Campylobacter jejuni activity of fluoroquinolones and macrolides in combination with phenolic compounds. Synergistic antimicrobial activity was measured by performing a checkerboard assay with ciprofloxacin and erythromycin in the presence of 21 phenolic compounds. Membrane permeability changes in C. jejuni by phenolic compounds were determined by measuring the level of intracellular uptake of 1-N-phenylnaphthylamine (NPN). Antibiotic accumulation assays were performed to evaluate the level of ciprofloxacin accumulation in C. jejuni. Six phenolic compounds, including p-coumaric acid, sinapic acid, caffeic acid, vanillic acid, gallic acid, and taxifolin, significantly increased the susceptibility to ciprofloxacin and erythromycin in several human and poultry isolates. The synergistic antimicrobial effect was also observed in ciprofloxacin- and erythromycin-resistant C. jejuni strains. The phenolic compounds also substantially increased membrane permeability and antibiotic accumulation in C. jejuni. Interestingly, some phenolic compounds, such as gallic acid and taxifolin, significantly reduced the expression of the CmeABC multidrug efflux pump. Phenolic compounds increased the NPN accumulation in the cmeB mutant, indicating phenolic compounds may affect the membrane permeability. In this study, we successfully demonstrated that combinational treatment of C. jejuni with antibiotics and phenolic compounds synergistically inhibits C. jejuni by impacting both antimicrobial influx and efflux.