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.

Multiscale architecture for fast optical addressing and control of large-scale qubit arrays

This paper presents a technique for rapid site-selective control of the quantum state of particles in a large array using the combination of a fast deflector (e.g., an acousto-optic deflector) and a relatively slow spatial light modulator (SLM). The use of SLMs for site-selective quantum state manipulation has been limited due to slow transition times that prevent rapid, consecutive quantum gates. By partitioning the SLM into multiple segments and using a fast deflector to transition between them, it is possible to substantially reduce the average time increment between scanner transitions by increasing the number of gates that can be performed for a single SLM full-frame setting. We analyzed the performance of this device in two different configurations: In configuration 1, each SLM segment addresses the full qubit array; in configuration 2, each SLM segment addresses a subarray and an additional fast deflector positions that subarray with respect to the full qubit array. With these hybrid scanners, we calculated qubit addressing rates that are tens to hundreds of times faster than using an SLM alone.

Warming signals in temperate reef communities following more than a decade of ecological stability

Ecosystem structure and function are increasingly threatened by changing climate, with profound effects observed globally in recent decades. Based on standardized visual censuses of reef biodiversity, we describe 27 years of community-level change for fishes, mobile macroinvertebrates and macroalgae in the Tasmanian ocean-warming hotspot. Significant ecological change was observed across 94 reef sites (5-10 m depth range) spanning four coastal regions between three periods (1992-95, 2006-07, 2017-19), which occurred against a background of pronounced sea temperature rise (+0.80°C on average). Overall, fish biomass increased, macroinvertebrate species richness and abundance decreased and macroalgal cover decreased, particularly during the most recent decade. While reef communities were relatively stable and warming was slight between the 1990s and mid-2000s (+0.12°C mean temperature rise), increased abundances of warm affinity fishes and invertebrates accompanied warming during the most recent decade (+0.68°C rise). However, significant rises in the community temperature index (CTI) were only found for fishes, invertebrates and macroalgae in some regions. Coastal warming was associated with increased fish biomass of non-targeted species in fished zones but had little effect on reef communities within marine reserves. Higher abundances of larger fishes and lobsters inside reserves appeared to negate impacts of 'thermophilization'.

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.

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.

Combined effects of sous-vide cooking conditions on meat and sensory quality characteristics of chicken breast meat

This study investigated the combined effects of cooking temperature and time on the meat and eating quality characteristics of the sous-vide chicken breast. For the control group, chicken breast samples were cooked in a convection oven until the internal temperature reached 71°C. Each sample for sous-vide cooking was vacuum packaged and then cooked under continuous thermocontrolled conditions in a water bath at 6 combinations of cooking temperature (60 and 70°C) and time (1, 2, and 3 h). Sous-vide cooked chicken meat at 60°C for 1 h (SV60-1h) showed lower cooking loss (6.58 vs. 26.5%, P < 0.05), Warner-Bratzler shear force (21.7 vs. 29.1 N, P < 0.05), and hardness (9.40 vs. 17.3 N, P < 0.05) than meat cooked by conventional oven. Similar to the objective tenderness parameters, cooked chicken meat from the SV60 treatments for all cooking times showed higher scores in all the tenderness attributes than the control group (P < 0.05). However, a higher flavor intensity was observed in the SV70-3h and control groups than in the SV60 treatments (P < 0.05). Owing to a lesser developed flavor in chicken meat from the SV60-1h treatment, the SV60-2h and 3h treatments were assigned a higher acceptability rating for overall impression (P < 0.05). Therefore, cooking temperature and time of sous-vide significantly influenced the physicochemical and palatability characteristics of chicken breast. In this study, the optimum conditions for the sous-vide chicken breast are to continuously cook at 60°C for 2 to 3 h to improve sensory quality characteristics without reducing the water-holding capacity.

Synthetic chimeric nucleases function for efficient genome editing

CRISPR-Cas systems have revolutionized genome editing across a broad range of biotechnological endeavors. Many CRISPR-Cas nucleases have been identified and engineered for improved capabilities. Given the modular structure of such enzymes, we hypothesized that engineering chimeric sequences would generate non-natural variants that span the kinetic parameter landscape, and thus provide for the rapid selection of nucleases fit for a particular editing system. Here, we design a chimeric Cas12a-type library with approximately 560 synthetic chimeras, and select several functional variants. We demonstrate that certain nuclease domains can be recombined across distantly related nuclease templates to produce variants that function in bacteria, yeast, and human cell lines. We further characterize selected chimeric nucleases and find that they have different protospacer adjacent motif (PAM) preferences and the M44 chimera has higher specificity relative to wild-type (WT) sequences. This demonstration opens up the possibility of generating nuclease sequences with implications across biotechnology.

P4580The effect of anesthetic techniques on cardiac troponin-T after non-cardiac surgery

Background

The effects of anesthetics on cardiac protection and clinical outcomes have shown conflicting results in patients undergoing non-cardiac surgery. Unlike cardiac surgeries in which cardio-protective effects of anesthetic techniques have been reported, it lacks evidence and reproducibility in non-cardiac surgery. A current generation high-sensitivity cardiac troponin (hs-cTnI) is known to detect perioperative myocardial injury in non-cardiac surgery which is closely related to clinical outcomes. In this study, we hypothesized that balanced anesthesia using both remifentanil and volatile agents is the most effective in reducing postoperative myocardial injury, and compared the incidence of postoperative myocardial injury among different types of general anesthesia.

Methods

We analyzed the data of 3555 patients who underwent general anesthesia for non-cardiac surgery in our hospital between February 2010 and December 2016. In all patients, hs-cTnI was detected in preoperative period and postoperative period within 48 hours. Major exclusion criteria was troponin elevation before surgery. Patients were stratified into three groups; 661 patients who were received propofol-remifentanil total intravenous anesthesia (TIVA group), 1279 patients who were received volatile anesthesia without remifentanil (Volatile group) and 1622 patients who were received volatile anesthesia with remifentanil (Balanced group). The Primary outcome was troponin elevation [hs-cTnI≥0.04 ng/mL] within post-operative within 48 hours, and the incidence of postoperative complications such as postoperative acute kidney injury, new-onset atrial fibrillation and in-hospital mortality were also compared.

Results

The occurrence of myocaridial injury were significant difference between three groups. The occurrence of myocardial injury was significantly lower in the Balanced group than in Volatile group after adjustment (Odds ratio (OR) = 0.727; 95% confidence interval (CI) = 0.59–0.89; P-value = 0.002). Balanced group and TIVA group showed comparable results in risk of postoperative troponin elevation after adjustment (OR 1.131; 95% CI 0.96–1.33; P-value = 0.133). The incidence of troponin elevation was significantly higher in Volatile group than TIVA group after adjustment (OR 1.6; 95% CI 0.52–0.96; P-value = 0.005). The incidence of AKI was significantly lower in Balanced group than Volatile group after adjustment (OR 0.637; 95% CI 0.49–0.81; P-value <0.001).

Conclusion

The remifentanil combination during general anesthesia may be associated with myocardial protection effect in patients undergoing non-cardiac surgery. Whether this impact leads to adverse long-term outcome remains unclear, and requires further investigation.

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.

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.

Utility of the laryngeal handshake method for identifying the cricothyroid membrane

BACKGROUND

The cricothyroid membrane is the most commonly accessed location for invasive surgical airway. Although the laryngeal handshake method is recommended for identifying the cricothyroid membrane, there is no clinical data regarding the utility of the laryngeal handshake method in cricothyroid membrane identification. The objective of this study was to compare the accuracy of cricothyroid membrane identification between the laryngeal handshake method and simple palpation.

METHODS

After anaesthesia induction, the otorhinolaryngology resident and anaesthesia resident identified and marked the needle insertion point for cricothyroidotomy using simple palpation and the laryngeal handshake method, respectively. The cricothyroid membrane was confirmed with ultrasonography. Identification was determined successful if the marked point was placed within the longitudinal area of the cricothyroid membrane and within 5 mm from midline transversely. The accuracy of cricothyroid membrane identification using the laryngeal handshake method and simple palpation was compared.

RESULTS

A total of 123 patients were enrolled. The cricothyroid membrane was correctly identified in 87 (70.7%, 95% confidence interval 61.8-78.6%) patients using the laryngeal handshake method compared to 78 (63.4%, 95% confidence interval 54.3-71.9%) patients using simple palpation (P = .188). The time required to identify the cricothyroid membrane was longer when using the laryngeal handshake method (15 [3-48] seconds vs 10.9 [3-55] seconds, P = .003).

CONCLUSION

The success rate of identifying the cricothyroid membrane was similar among the anesthesiologists who performed the laryngeal handshake method and also among otorhinolaryngologists who used simple palpation.

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.

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.

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.

Multiparametric approach with diffusion-weighted imaging and dynamic contrast-enhanced MRI: a comparison study for differentiating between benign and malignant bone lesions in adults

AIM

To evaluate and compare the diagnostic performance of quantitative parameters derived from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiating benign and malignant bone tumours.

MATERIALS AND METHODS

Fifty-five patients (age range, 21-82 years; mean age, 55 years) underwent pretreatment MRI. Apparent diffusion coefficient (ADC) values were calculated by DWI. The DCE-MRI data were analysed for the volume transfer constant (K^trans), extravascular extracellular volume fraction (V_e), and volume rate constant (K_ep), and K^trans/ADC ratio. Each parameter's performance was evaluated using the area under the receiver operating characteristic (ROC) curv (AUC), and their AUCs were compared. ROC curves were analysed and each parameter's optimal cut-off value was determined, from which each parameter was evaluated for sensitivity, specificity, accuracy, and positive and negative predictive values. The odds ratio (OR) with 95% confidence interval for detecting malignant bone lesions after adjusting the age factor of each parameter was estimated.

RESULTS

All parameter values (except V_e) were significantly different between benign and malignant bone tumours (p<0.05). The K^trans had a significantly greater AUC than V_e (p=0.03). The K^trans/ADC and K_ep had the best sensitivity (0.917) and specificity (0.632), respectively. The K_ep and K^trans/ADC had the best positive (0.811) and negative (0.769) predictive values, respectively. The OR was highest for K^trans/ADC (17.38; p=0.0013).

CONCLUSION

The K^trans, K_ep, ADC, and K^trans/ADC could help to detect malignant lesions from bone tumours and K^trans/ADC appears to be the superior variable among them.

General and Culturally Specific Factors Influencing Black and White Rape Survivors' Self-Esteem

Grounded in a culturally inclusive ecological model of sexual assault recovery framework, the influence of personal (e.g., prior victimization), rape context (e.g., degree of injury during last assault), and postrape response factors (e.g., general and cultural attributions, rape related coping) on self-esteem of Black and White college women, who were survivors of attempted and completed rape, were examined. As predicted, Black and White women identified similar general variables (e.g., general attributions) as important in the recovery process. Black women, however, identified a cultural factor (i.e., cultural attributions) as more important in influencing their reactions to the last rape compared to their White counterparts. Using path analysis, findings from this cross-sectional study indicated that severity of the last assault and prior victimization were related to lower self-esteem indirectly through avoidance coping strategies, and victim blame attributions for the latter. Results also suggested that the link between cultural attributions and self-esteem was explained through victim blame attributions, primarily for Black participants. The model accounted for 26% of variance in self-esteem.

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.

Development and Validation of the Korean Rape Myth Acceptance Scale

The purpose of this investigation was to develop a culturally relevant rape myth acceptance scale for Koreans. Three studies on the Korean Rape Myth Acceptance Scale (KRMAS) with approximately 1,000 observations provide initial validity and reliability. Specifically, results from exploratory and confirmatory factor analyses support four subscales: myths about rape survivors, rape perpetrators, the impact of rape, and rape as spontaneous. The KRMAS was validated with student and community samples and a factorial invariance analysis provided evidence for the factor structure across men and women. The KRMAS total score was positively related to the Attitudes Toward Sex Role Scale–Korean and the Acceptance of Violence Scale, indicating that greater endorsement of rape myth acceptance was related to greater levels of attitudes toward traditional sex roles and violence against women. Implications of the findings and future research directions are provided.

Fast phase stabilization of a low frequency beat note for atom interferometry

Atom interferometry experiments rely on the ability to obtain a stable signal that corresponds to an atomic phase. For interferometers that use laser beams to manipulate the atoms, noise in the lasers can lead to errors in the atomic measurement. In particular, it is often necessary to actively stabilize the optical phase between two frequency components of the beams. Typically this is achieved using a time-domain measurement of a beat note between the two frequencies. This becomes challenging when the frequency difference is small and the phase measurement must be made quickly. The method presented here instead uses a spatial interference detection to rapidly measure the optical phase for arbitrary frequency differences. A feedback system operating at a bandwidth of about 10 MHz could then correct the phase in about 3 μs. This time is short enough that the phase correction could be applied at the start of a laser pulse without appreciably degrading the fidelity of the atom interferometer operation. The phase stabilization system was demonstrated in a simple atom interferometer measurement of the (87)Rb recoil frequency.

High Prevalence of Hyper-Aerotolerant Campylobacter jejuni in Retail Poultry with Potential Implication in Human Infection

Campylobacter jejuni is a leading cause of foodborne illnesses around the world. Since C. jejuni is microaerophilic and sensitive to oxygen, aerotolerance is important in the transmission of C. jejuni to humans via foods under aerobic conditions. In this study, 70 C. jejuni strains were isolated from retail raw chicken meats and were subject to multilocus sequence typing (MLST) analysis. In the aerotolerance testing by aerobic shaking at 200 rpm, 50 (71.4%) isolates survived after 12 h (i.e., aerotolerant), whereas 20 (28.6%) isolates did not (i.e., aerosensitive). Interestingly, further aerobic cultivation showed that 25 (35.7%) isolates still survived even after 24 h of vigorous aerobic shaking (i.e., hyper-aerotolerant). Compared to aerosensitive strains, the hyper-aerotolerant strains exhibited increased resistance to oxidative stress, both peroxide and superoxide. A mutation of ahpC in hyper-aerotolerant strains significantly impaired aerotolerance, indicating oxidative stress defense plays an important role in hyper-aerotolerance. The aerotolerant and hyper-aerotolerant strains were primarily classified into MLST clonal complexes (CCs)-21 and -45, which are known to be the major CCs implicated in human gastroenteritis. Compared to the aerosensitive strains, CC-21 was more dominant than CC-45 in aerotolerant and hyper-aerotolerant strains. The findings in this study revealed that hyper-aerotolerant C. jejuni is highly prevalent in raw chicken meats. The enhanced aerotolerance in C. jejuni would impact human infection by increasing possibilities of the foodborne transmission of C. jejuni under aerobic conditions.

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.

Vitamin D deficiency in Parkinson's disease patients with orthostatic hypotension

OBJECTIVES

The purpose of our study was to investigate the associations between serum vitamin D3 levels and orthostatic hypotension (OH) in patients with Parkinson's disease (PD).

MATERIALS AND METHODS

Fifty-five patients with PD were enrolled in this study. Blood pressure (BP) measurements were gathered while the patients were in the supine position and while standing up. Then, the patients were divided into two groups: PD patients with and without OH. We compared the levels of serum 25-hydroxyvitamin D3 and 1, 25-dihydroxyvitamin D3 (calcitriol) between the two groups.

RESULTS

Serum 25-hydroxyvitamin D and calcitriol levels were significantly decreased in patients with OH compared with those without OH. The systolic and diastolic BPs and symptom severities significantly negatively correlated with the serum 25-hydroxyvitamin D and calcitriol levels.

CONCLUSIONS

Although the underlying mechanism for this association is not fully understood, our results suggest that low vitamin D status is associated with OH in patients with PD.

Regulation of oxidative stress resistance in Campylobacter jejuni, a microaerophilic foodborne pathogen

Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis. Due to the increasing rates of human campylobacteriosis, C. jejuni is considered as a serious public health concern worldwide. C. jejuni is a microaerophilic, fastidious bacterium. C. jejuni must overcome a wide range of stress conditions during foodborne transmission to humans, such as food preservation and processing conditions, and even in infection of the gastrointestinal tracts of humans. Particularly, this microaerophilic foodborne pathogen must survive in the atmospheric conditions prior to the initiation of infection. C. jejuni possesses unique regulatory mechanisms for oxidative stress resistance. Lacking OxyR and SoxRS that are highly conserved in other Gram-negative foodborne pathogens, C. jejuni modulates the expression of genes involved in oxidative stress resistance mainly via the peroxide resistance regulator and Campylobacter oxidative stress regulator. Based on recent findings of ours and others, in this review, we described how C. jejuni regulates the expression of oxidative stress defense.

Impact of oxidative stress defense on bacterial survival and morphological change in Campylobacter jejuni under aerobic conditions

Campylobacter jejuni, a microaerophilic foodborne pathogen, inescapably faces high oxygen tension during its transmission to humans. Thus, the ability of C. jejuni to survive under oxygen-rich conditions may significantly impact C. jejuni viability in food and food safety as well. In this study, we investigated the impact of oxidative stress resistance on the survival of C. jejuni under aerobic conditions by examining three mutants defective in key antioxidant genes, including ahpC, katA, and sodB. All the three mutants exhibited growth reduction under aerobic conditions compared to the wild-type (WT), and the ahpC mutant showed the most significant growth defect. The CFU reduction in the mutants was recovered to the WT level by complementation. Higher levels of reactive oxygen species were accumulated in C. jejuni under aerobic conditions than microaerobic conditions, and supplementation of culture media with an antioxidant recovered the growth of C. jejuni. The levels of lipid peroxidation and protein oxidation were significantly increased in the mutants compared to WT. Additionally, the mutants exhibited different morphological changes under aerobic conditions. The ahpC and katA mutants developed coccoid morphology by aeration, whereas the sodB mutant established elongated cellular morphology. Compared to microaerobic conditions, interestingly, aerobic culture conditions substantially induced the formation of coccoidal cells, and antioxidant treatment reduced the emergence of coccoid forms under aerobic conditions. The ATP concentrations and PMA–qPCR analysis supported that oxidative stress is a factor that induces the development of a viable-but-non-culturable state in C. jejuni. The findings in this study clearly demonstrated that oxidative stress resistance plays an important role in the survival and morphological changes of C. jejuni under aerobic conditions.

Non-selective regulation of peroxide and superoxide resistance genes by PerR in Campylobacter jejuni

Campylobacter jejuni is an important foodborne pathogen. The molecular mechanisms for the regulation of oxidative stress resistance have not yet been understood fully in this bacterium. In this study, we investigated how PerR (peroxide stress regulator) modulates the transcriptional regulation of both peroxide and superoxide resistance genes in C. jejuni, particularly under oxidative stress conditions. The transcriptional levels of ahpC, katA, and sodB were substantially increased by aeration and oxidant exposure. Interestingly, a perR mutation completely abrogated the transcriptional response of ahpC, katA and sodB to oxidants. Furthermore, we demonstrated that perR transcription was reduced by aeration and oxidant exposure. In contrast to the unique role of PerR homologs in peroxide stress regulation in other bacteria, C. jejuni PerR directly regulates the transcription of sodB, the most important gene in superoxide defense, as evidenced by the alteration of sodB transcription by the perR mutation and direct binding of rPerR to the sodB promoter. In addition, we also observed notable morphological changes in C. jejuni from spiral rods to cocoid morphology under aerobic conditions. Based on the intracellular ATP levels, C. jejuni entered a viable-but-non-culturable (VBNC) state under aerobic conditions. These findings clearly demonstrate that C. jejuni possesses a unique regulatory mechanism of oxidative stress defense that does not specifically distinguish between peroxide and superoxide defense, and PerR plays a pivotal role in this non-selective regulation of oxidative stress resistance in C. jejuni.

Kinetic enhancement of the diffusion-limited enzyme beta-galactosidase when displayed with quantum dots

Schematic of a tetrameric β-galactosidase enzyme attached to and displaying 625 nm emitting QDs coated with a CL4 ligand via each of the 4 pendent His₆ tags.