Light-Scattering Analysis of Drying Behavior in Suspension Droplets with Silica and Polystyrene Particles and a Hydrosoluble Polymer.

The coffee-ring structure, which is the final drying pattern of a sessile suspension droplet, is a key factor in controlling the uniformity of the particulate deposits in various coatings. Two light-scattering methods, diffusing wave spectroscopy (DWS) and multispeckle DWS (MSDWS), were used to quantitatively distinguish temporal changes in particle mobility in evaporating suspension droplets containing micrometer-sized silica and polystyrene (PS) particles. The characteristic particle mobility was measured in terms of the mean square displacement in the early stage of drying, and the local particle dynamics around the edge and center regimes of the droplets during drying were analyzed using MSDWS. Hydroxyethyl cellulose (HEC), a hydrosoluble polymer, was added to the silica and PS suspensions to further investigate its role in suppressing or enhancing coffee-ring patterns based on particle-polymer interactions. Consequently, dried microstructures can be directly correlated with real-time drying dynamics, as well as the interactions between solutes by comprehensive light-scattering methods.

Understanding the Role of M13 Bacteriophage Thin Films on a Metallic Nanostructure through a Standard and Dynamic Model.

The dynamic and surface manipulation of the M13 bacteriophage via the meeting application demands the creation of a pathway to design efficient applications with high selectivity and responsivity rates. Here, we report the role of the M13 bacteriophage thin film layer that is deposited on an optical nanostructure involving gold nanoparticles/SiO2/Si, as well as its influence on optical and geometrical properties. The thickness of the M13 bacteriophage layer was controlled by varying either the concentration or humidity exposure levels, and optical studies were conducted. We designed a standard and dynamic model based upon three-dimensional finite-difference time-domain (3D FDTD) simulations that distinguished the respective necessity of each model under variable conditions. As seen in the experiments, the origin of respective peak wavelength positions was addressed in detail with the help of simulations. The importance of the dynamic model was noted when humidity-based experiments were conducted. Upon introducing varied humidity levels, the dynamic model predicted changes in plasmonic properties as a function of changes in NP positioning, gap size, and effective index (this approach agreed with the experiments and simulated results). We believe that this work will provide fundamental insight into understanding and interpreting the geometrical and optical properties of the nanostructures that involve the M13 bacteriophage. By combining such significant plasmonic properties with the numerous benefits of M13 bacteriophage (like low-cost fabrication, multi-wavelength optical characteristics devised from a single structure, reproducibility, reversible characteristics, and surface modification to suit application requirements), it is possible to develop highly efficient integrated plasmonic biomaterial-based sensor nanostructures.

Akkermansia muciniphila Prevents Fatty Liver Disease, Decreases Serum Triglycerides, and Maintains Gut Homeostasis.

The objective of this study was to elucidate the effect of intestinal Akkermansia muciniphila bacteria on fatty liver disease. Five-week-old C57BL/6N mice were administered either phosphate-buffered saline (PBS; control) or A. muciniphila at 108 to 109 CFU/ml, and were fed either a 45% fat diet (high-fat diet [HFD]) or a 10% fat diet (normal diet [ND]) for 10 weeks. After 10 weeks, the mice were euthanized, and blood and tissue samples, including adipose tissue, cecum, liver, and brain, were immediately collected. Biochemical and histological analyses were conducted, and the expression levels of related factors were compared to determine the antiobesity effects of Akkermansia muciniphila The gut microbiome was analyzed in fecal samples. Oral administration of A. muciniphila significantly (P < 0.05) lowered serum triglyceride (TG) and alanine aminotransferase (ALT) levels in obese mice. Compared to the non-A. muciniphila-treated group, the expression of SREBP (regulator of TG synthesis in liver tissue) was decreased in the A. muciniphila-treated group. The expression of IL-6 in the liver of obese mice was decreased following the administration of A. muciniphila Furthermore, alterations in the ratio of Firmicutes to Bacteroidetes and the decrease in bacterial diversity caused by the HFD were restored upon the administration of A. muciniphila These results indicate that A. muciniphila prevents fatty liver disease in obese mice by regulating TG synthesis in the liver and maintaining gut homeostasis.IMPORTANCE This study investigated the effect of Akkermansia muciniphila on fatty liver disease. Although some research about the effects of A. muciniphila on host health has been published, study of the relationship between A. muciniphila administration and fatty liver, as well as changes in the gut microbiota, has not been conducted. In this study, we demonstrated that A. muciniphila prevented fatty liver disease by regulation of the expression of genes that regulate fat synthesis and inflammation in the liver.

Asymptomatic Clostridium perfringens Inhabitation in Intestine Can Cause Inflammation, Apoptosis, and Disorders in Brain.

Clostridium perfringens (CP) is a foodborne pathogen. The bacterium can also inhabit human gut without symptoms of foodborne illness. However, the clinical symptoms of long-term inhabitation have not been known yet. Therefore, the objective of this study was to elucidate the relationship between intestinal CP and other internal organs. Phosphate-buffered saline (PBS) and CP were orally injected into 5-week-old (YOUNG) and 12-month-old C57BL6/J (ADULT) mice. Gene expression levels related to inflammation (tumor necrosis factor-α [TNF-α], interleukin [IL]-1ß, and IL-6) and oxidative stress (superoxide dismutase [SOD]1, SOD2, SOD3, glutathione reductase [GSR], glutathione peroxidase [GPx]3, and catalase [CAT]) responses were evaluated in the brain, small intestine, and liver. In addition, apoptosis-related (BCL2-associated X [BAX]1 and high-mobility group box-1 [HMGB1]) and brain disorder-related genes (CCAAT-enhancer-binding protein [C/EBP]-ß, C/EBPδ, C/EBP homologous protein [CHOP], and amyloid precursor protein [APP]) as brain damage markers were examined. The protein expressions in the brain were also measured. Gene expression levels of inflammation and oxidative stress responses were higher (p < 0.05) in brains of CP-YOUNG and CP-ADULT mice, compared with PBS-YOUNG and PBS-ADULT, and the gene expression levels were higher (p < 0.05) in brains of CP-ADULT mice than CP-YOUNG mice. Apoptosis-related (BAX1 and HMGB1) and brain disorder-related genes (C/EBPß, C/EBPδ, CHOP, and APP) were higher (p < 0.05) in brains of CP-challenged mice, compared with PBS-challenged mice. Even oxidative stress response (GPx and SOD2), cell damage-related (HMGB1), and ß-amyloid proteins were higher (p < 0.05) in brains of CP- than in PBS-challenged mice. C/EBP protein was higher (p < 0.05) in CP-YOUNG, compared with PBS-YOUNG mice. However, these clinical symptoms were not observed in small intestine and liver. These results indicate that although asymptomatic intestinal CP do not cause foodborne illness, their inhabitation may cause brain inflammation, oxidative stress, apoptosis, and cell damage, which may induce disorders, especially for the aged group.

Combined Enrichment and Quantitative Polymerase Chain Reaction to Improve Sensitivity and Reduce Time of Detection of Listeria monocytogenes in Mushrooms.

This study evaluated a combined method for the detection of Listeria monocytogenes in mushrooms, involving enrichment and quantitative real-time polymerase chain reaction (qPCR), to improve sensitivity and reduce detection time. The growth of L. monocytogenes was evaluated in Listeria enrichment broth (LEB) with modified carbon and nitrogen sources, increasing sodium concentrations, and added micronutrients. Primers targeting the L. monocytogenes iap (iap1 and iap2), hlyA (hlyA1-hlyA6), and prfA (prfA1-prfA4) genes were developed and their sensitivity and specificity were evaluated. The greatest increase in L. monocytogenes cell count was observed after 6-h incubation at 30°C in LEB+2 × FAC (LEB plus 20 mL/L ferric ammonium citrate), where cell count increased by 1.4 log CFU (colony-forming unit)/mL, compared with 0.9 log CFU/mL in LEB (p < 0.05). iap2 primers targeting the iap gene showed high specificity and were the most sensitive among those tested, with a detection limit of 2 log CFU/mL in LEB medium, 3.1 log CFU/g in golden needle mushroom, and 3.5 log CFU/g in large oyster mushroom. When applied to detection in golden needle mushrooms, a combination of 3-h incubation in LEB+2 × FAC medium and qPCR analysis with iap2 primers permitted detection of L. monocytogenes, even at an inoculum of 1 log CFU/g. Similarly, in large oyster mushrooms, 10-h enrichment in LEB+2 × FAC medium resulted in a cell count of 3.7 log CFU/g. These results indicate that a combined detection method, using LEB+2 × FAC medium for enrichment followed by qPCR with iap2 primer pair, can reduce enrichment time and improve the sensitivity and specificity of L. monocytogenes detection in mushrooms.

Vitamin E (α-tocopherol) consumption influences gut microbiota composition.

This study evaluated if vitamin E consumption affects gut microbiota. Mice were grouped into control, low vitamin E (LV), and high vitamin E (HV). LV and HV were fed DL-α-tocopherol at 0.06 mg/20 g and 0.18 mg/20 g of body weight per day, respectively, for 34 days. Body weight of mice was measured before and after vitamin E treatment. Animals were sacrificed, liver, spleen, small intestine and large intestine collected, and weight and length were measured. Composition of gut microbiota was determined by microbiome analysis. Spleen weight index of LV was the highest. However, liver weight indices and intestinal lengths were not different. Body weights of LV group were higher than those of control. Ratio of Firmicutes to Bacteroidetes was different in LV compared to control and HV. These results indicate that low-level consumption of vitamin E increases spleen and body weight, and changes gut microbiota.

The risk of aerotolerant Campylobacter jejuni strains in poultry meat distribution and storage.

Poultry meat is a major vector for Campylobacter jejuni foodborne illness. Since C. jejuni is microaerophillic, the cell counts gradually decreased during distribution and display under aerobic condition. However, if the pathogen can resist to aerobic condition, it may cause serious problem in food safety. This study determined the aerotolerance of C. jejuni isolated from poultry and the risk of the aerotolerant C. jejuni strains. Fourteen C. jejuni strains isolated from poultry were subjected to aerobic condition in a shaking incubator at 500 rpm and 37 °C. The cell counts of C. jejuni strains were enumerated on modified CCDA-Preston at 0, 24, 72 and 120 h, and the strains, having reduction less than 2 Log CFU/mL for 120 h were determined as aerotolerant C. jejuni strain. Non-aerotolerant and aerotolerant C. jejuni strains were then incubated at 4 °C under aerobic condition to compare the growth between aerotolerant and non-aerotolerant strains. In addition, transcriptomes for virulence and stress response genes (cadF, cdtB, ciaB, clpP and htrB) were compared between non-aerotolerant and aerotolerant C. jejuni strains. Among 14 C. jejuni strains, seven strains (50%) showed less than 2-Log CFU/mL reduction at 37 °C after 24 h, and five strains of them still showed less than 2-Log CFU/mL reduction after 48 h. Especially, C. jejuni SMFM2015-Du7 and C. jejuni SMFM2014-Du16 were still survived after 120 h under aerobic condition, which were then determined as aerotolerant C. jejuni. However, at 4 °C under aerobic condition, there were no significant differences in the reduction of C. jejuni cell counts and virulence gene expressions between non-aerotolerant (C. jejuni SMFM2014-Du8) and aerotolerant strains (C. jejuni SMFM2015-Du7 and C. jejuni SMFM2014-Du16) except for stress response gene (htrB). These results indicate that there are aerotolerant C. jejuni strains, but their risk is similar to non-aerotolerant C. jejuni strains at 4 °C under aerobic condition, which is distribution and storage condition for poultry meat. Therefore, additional food safety management for the aerotolerant C. jejuni is not necessary.

Principles and Applications of Non-Thermal Technologies for Meat Decontamination.

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

Correlation-driven nonequilibrium exciton site transition in a WSe2/WS2 moiré supercell.

Moiré superlattices of transition metal dichalcogenides offer a unique platform to explore correlated exciton physics with optical spectroscopy. Whereas the spatially modulated potentials evoke that the exciton resonances are distinct depending on a site in a moiré supercell, there have been no clear demonstration how the moiré excitons trapped in different sites dynamically interact with the doped carriers; so far the exciton-electron dynamic interactions were presumed to be site-dependent. Thus, the transient emergence of nonequilibrium correlations are open questions, but existing studies are limited to steady-state optical measurements. Here we report experimental fingerprints of site-dependent exciton correlations under continuous-wave as well as ultrashort optical excitations. In near-zero angle-aligned WSe2/WS2 heterobilayers, we observe intriguing polarization switching and strongly enhanced Pauli blocking near the Mott insulating state, dictating the dominant correlation-driven effects. When the twist angle is near 60°, no such correlations are observed, suggesting the strong dependence of atomic registry in moiré supercell configuration. Our studies open the door to largely unexplored nonequilibrium correlations of excitons in moiré superlattices.

Clinical benefits of surgical ablation during isolated aortic valve replacement: a nationwide study.

OBJECTIVES: To compare the early- and long-term clinical outcomes of concomitant surgical ablation (SA) for atrial fibrillation (AF) during isolated aortic valve replacement (AVR) using data from the Korean National Health Insurance Service Database. METHODS: Of 23,332 adult patients who underwent AVR between 2003 and 2019, those with underlying AF with or without concomitant SA were extracted, and propensity score matching analysis was performed. RESULTS: Overall, 1,741 patients with underlying AF with (n = 445, group A) or without (n = 1,296, group N) concomitant SA during isolated AVR were enrolled, from whom 435 pairs were matched in a 1:1 ratio using propensity score matching analysis. The operative mortality and early postoperative morbidities, including bleeding reoperation, stroke, permanent pacemaker implantation and acute kidney injury were comparable between the groups. The overall survival showed no differences between the groups. However, the cumulative incidence of new-onset late ischaemic stroke was significantly lower in group A than group N in propensity score-matched patients [2.3 vs 3.5 per 100 patient-years, adjusted hazard ratio (95% confidence interval) 0.64 (0.43-0.96), Group A versus Group N, respectively]. The cumulative incidence of other morbidities such as reoperation, permanent pacemaker implantation and progression to chronic renal failure showed no difference between groups. CONCLUSIONS: The incidence of late ischaemic stroke was significantly lower when concomitant SA was performed during isolated AVR in patients with underlying AF. Therefore, concomitant SA should be actively considered in patients with underlying AF undergoing isolated AVR to prevent the occurrence of late ischaemic stroke.

Direct Care Nurses' Needlestick Injury Experiences: A Qualitative Descriptive Study.

BACKGROUND: Even when education and the use of safety equipment are emphasized, nurses frequently experience needlestick injuries. Understanding the risk situations and coping mechanisms for needlestick injuries experienced by nurses facilitates their prevention. OBJECTIVES: We aimed to explore and describe the phenomenon of needlestick injuries through the research questions: (1) What causes nurses to suffer from needlestick injuries? (2) How to cope after a needlestick injury? and (3) What are the recommendations for needlestick injury prevention? METHODS: This qualitative descriptive study involved focus group interviews with 31 direct care nurses in 6 groups who had experienced needlestick injuries while working in different acute care hospitals across 3 regions in South Korea. Data were collected from January 29 to March 29, 2022, and analyzed using thematic analysis. RESULTS: The average age of the participating nurses was 29.7 years. The following 3 themes were identified: various needlestick injury experiences, post-needlestick injury coping, and expectations regarding needlestick injuries. CONCLUSIONS: Risk situations and coping mechanisms of nurses who experienced needlestick injuries were diverse. Emergency situations and novice nurses were the causes of most of the needlestick injuries. Often, personal protective equipment was found cumbersome. Reporting needlestick injuries depended on the work environment.

Effects on Goat Meat Extracts on α-Glucosidase Inhibitory Activity, Expression of Bcl-2-Associated X (BAX), p53, and p21 in Cell Line and Expression of Atrogin-1, Muscle Atrophy F-Box (MAFbx), Muscle RING-Finger Protein-1 (MuRF-1), and Myosin Heavy Chain-7 (MYH-7) in C2C12 Myoblsts.

This study examined the α-glucosidase inhibitory, and apoptosis- and anti-muscular-related factors of goat meat extracts from forelegs, hind legs, loin, and ribs. The goat meat extracts were evaluated for their α-glucosidase inhibitory activity. The gene and protein expression levels of Bcl-2-associated X (bax), p53, and p21 were examined by reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting in AGS and HT-29 cells. The expression levels of Atrogin-1 and MHC1b were examined by RT-PCR in C2C12 myoblasts, and the expression levels of Atrogin-1, muscle atrophy F-box (MAFbx), muscle RING-finger protein-1 (MuRF-1), and myosin heavy chain-7 were investigated by immunoblotting. α-Glucosidase inhibitory activity was higher in ethanol extract than in hydrous and hot water extracts. BAX and p53 expression levels were higher (p<0.05) in AGS cells treated with goat meat extract than those of cells treated with no goat meat extract. In HT-29 cells, the protein expression levels of BAX, p53, and p21 were higher (p<0.05) in the cells treated with goat meat extract than those of cells not treated with goat meat extract. In dexamethasone-treated C2C12 cells, goat meat extract treatment lower (p<0.05) the expression of Atrogin-1 and lower (p<0.05) the expression of MAFbx and MuRF-1. The results of the present study indicate that goat meat extracts have α-glucosidase inhibitory activity in vitro. In addition, apoptosis was induced in AGS cells and HT-29 cells treated with goat meat extract, and anti-muscular atrophy activity was also observed in C2C12 cells treated with goat meat extract.

Varicella-zoster virus meningitis after spinal anesthesia: A case report.

BACKGROUND: Headache is a common complication of regional anesthesia. The treatment of post spinal anesthesia headache varies depending on the cause. Although meningitis is rare, it can cause significant harm to the patient. Post dural puncture headache and septic meningitis are the most commonly suspected causes of post spinal anesthesia headache; however, other causes should also be considered. CASE SUMMARY: A 69-year-old woman was scheduled for varicose vein stripping surgery under spinal anesthesia. The procedure was performed aseptically, and surgery was completed without any complications. After 4 d, the patient visited the emergency room with complaints of headache, nausea, and anorexia. Clinical examination revealed that the patient was afebrile. Considering the history of spinal anesthesia, post dural puncture headache and septic meningitis was initially suspected, and the patient was treated with empirical antibiotics. Subsequently, varicella-zoster virus PCR test result was positive, and all other test results were negative. The patient was diagnosed with meningitis caused by varicella-zoster virus and was treated with acyclovir for 5 d. The headache improved, and the patient was discharged without any problems. CONCLUSION: Viral meningitis due to virus reactivation may cause headache after regional anesthesia. Therefore, clinicians should consider multiple etiologies of headache.

Monascus-fermented grain vinegar enhances glucose homeostasis through the IRS-1/PI3K/Akt and AMPK signaling pathways in HepG2 cell and db/db mice.

MV was reported to have beneficial effects in ameliorating insulin resistance in db/db mice, but the intrinsic mechanisms for glucose homeostasis are unclear. This study examined the anti-diabetic mechanism of MV using HepG2 cells and C57BL/KsJ-db/db mice. MV increased insulin sensitivity by promoting insulin-dependent glucose uptake and activating glycogen accumulation in HepG2 cells. Furthermore, the glucose homeostasis was enhanced in db/db mice administered 1 mg/kg/day of MV for eight weeks by activating the IRS-1/PI3K/Akt and AMPK pathways in the skeletal muscle and liver tissue. In addition, MV promoted glycogen synthesis by regulating the key enzymes, including GSK-3ß and GS, and suppressed gluconeogenesis by inhibiting the mRNA expressions of G6pase and PEPCK. These findings show that MV regulates both signaling pathways and improves the glucose metabolism disorder. Thus, MV might be an alternative functional food or nutraceutical in ameliorating T2DM. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01146-4.

Weight Reduction Interventions Using Digital Health for Employees with Obesity: A Systematic Review.

Purpose: This study aimed to systematically review the literature on randomized controlled trials on weight reduction interventions using digital health for employees with obesity. Methods: All relevant articles published until September 2021 were systematically identified from six electronic databases: MEDLINE, EMBASE, CINAHL, PsycINFO, RISS, and KISS. Data selection and extraction were independently performed by three researchers. Methodological quality was assessed using the JBI Critical Appraisal Checklist for Randomized Controlled Trials. The results were narratively synthesized. Results: Eleven studies were included in the systematic review. All studies had a low risk of bias. The settings and sample sizes of the included studies were different. The contents of the interventions included nutrition, physical activity, behavioral change, incentives, and motivation. Four studies were based on social cognitive theory. A total of ten studies delivered web-based intervention, while the other used tele-monitoring device. A wide range of intervention strategies was used including providing online resources, tele-counseling, and patient-tailored advice. As a result of the intervention, a total of seven studies showed a significant weight reduction in both the intervention and comparison groups, with significant differences between groups. Conclusion: Until now, use of digital health in weight reduction interventions for employees with obesity has been conducted on a web-based. Various contents such as nutrition, physical activity and theories were explored. Further study is required using more diverse delivery methods such as mobile application, use of wearable devices.

Hypoglycemic and Hypolipogenic Action of Acetic Acid and Monascus-Fermented Grain Vinegar: A Comparative Study.

Acetic acid has been proposed to improve lifestyle-related diseases, including hyperlipidemia and hyperglycemia. This study compared the hypoglycemic and hypolipogenic effects of acetic acid vinegar (AV, contains only 4% acetic acid) and Monascus-fermented grain vinegar (MV) containing various bioactive compounds in 3T3L1 cells and C57BL/KsJ-db/db mice (DB). The DB were divided randomly into three treatment groups containing nine mice each; DB-, AV-, and MV-groups were orally administered 1 mL/kg/day of distilled water, acetic acid vinegar, and Monascus vinegar, respectively, for 8 weeks. Exposure to AV and MV inhibited the adipogenic differentiation of 3T3L1 preadipocytes and lipid accumulation during differentiation. Oral administration of AV or MV to the mice resulted in a marked reduction in the body weight, liver weight, and hepatic triglyceride content compared to the control DB-group. Moreover, treatment with AV and MV clearly increased the expression of cyclic adenosine monophosphate (cAMP) and AMP-activated protein kinase (AMPK) and suppressed the expression of fatty acid synthetase in liver tissues of DB. Significantly, lower levels of fasting blood glucose, insulin, leptin, and the glycosylated hemoglobin (HbA1c) as well as higher levels of the skeletal muscle GLUT4 expression were obtained in the AV- or MV-groups than levels determined in the control DB-group (P < .05). Although MV has the potential to be a natural alternative treatment for obesity-associated type 2 diabetes, this study suggests that acetic acid is the central ingredient in MV responsible for the hypoglycemic and hypolipogenic effects in the DB mice.

An analysis of student essays on medical leadership and its educational implications in South Korea.

To examine medical students' perceptions of leadership and explore their implications for medical leadership education. We conducted a qualitative analysis of the essays submitted by students in the medical leadership course from 2015 to 2019. We categorised the essays by the characteristics of the selected model leaders (N = 563) and types of leadership (N = 605). A statistically significant proportion of students selected leaders who were of the same gender as themselves (P < 0.001), graduate track students chose leaders in science (P = 0.005), while; military track students chose leaders in the military (P < 0.001). Although the highest proportion of students chose politicians as their model leaders (22.7%), this number decreased over time (P < 0.001), and a wider range of occupational groups were represented between 2015 and 2019. Charismatic leadership was the most frequently selected (31.9%), and over time there was a statistically significant (P = 0.004) increase in the selection of transformational leadership. Students tended to choose individuals whose acts of leadership could be seen and applied. Medical leadership education should account for students' changing perceptions and present a feasible leadership model, introducing specific examples to illustrate these leadership skills.

Probiotics-Mediated Bioconversion and Periodontitis.

Novel bioactive metabolites have been developed through a bioconversion of dairy products or other foods using probiotics isolated from dairy products or other fermented foods. These probiotics-mediated bioconversion (PMB) metabolites show antioxidant, anti-inflammatory, antimicrobial, epithelial barrier, and anticancer activities. In addition, the effect of PMB metabolites in periodontitis is recently reported in several studies. Periodontitis is a chronic inflammatory disease caused by infections, and the tooth support tissue is destroyed. Common treatments for periodontitis include scaling and root planning with systemic antibiotics. However, the overuse of antibiotics has led to the emergence of drug-resistant microorganisms and disturbs the beneficial bacteria, including lactobacilli in the oral cavity. For this reason, PMB metabolites, such as fermented milk, have been suggested as substitutes for antibiotics to reduce periodontitis. This paper reviews the recent studies on the correlation between periodontitis and PMB metabolites and classifies the efficacy of major PMB metabolites for periodontitis. The review suggests that PMB is effective for periodontitis, and further studies are needed to confirm the therapeutic effect of PMB metabolites on periodontitis.

Contamination of Clostridium perfringens in soy sauce, and quantitative microbial risk assessment for C. perfringens through soy sauce consumption.

The objective of this study was to conduct QMRA (quantitative microbial risk assessment) of Clostridium perfringens through soy sauce consumption. Four hundred and ninety soy sauce samples from markets were analyzed to detect C. perfringens. Temperature and time were also measured during transportation and display of soy sauce. A primary model was developed by fitting the Weibull model to the C. perfringens cell counts in soy sauce at 7-35°C, and δ (the time needed to decrease 1 log CFU/ml) and ρ (curve shape) were calculated. The parameters were analyzed, using the Exponential model (secondary model) as a function of temperature. The consumption amount and percentage of soy sauce were surveyed, and a dose-response model was searched. Using all collected data, a simulation model was prepared in the @RISK program to estimate the probability of C. perfringens foodborne illness by soy sauce consumption. C. perfringens were negative in 490 samples. Thus, the initial contamination level was estimated to be -2.9 log CFU/ml. The developed predictive models showed that C. perfringens cell counts decreased during transportation and display. The average consumption amounts, and the percentage of soy sauce were 7.81 ml and 81.2%, respectively. The simulation showed that the probability of C. perfringens foodborne illness by consumption of soy sauce was 1.7 × 10-16 per person per day. Therefore, the risk of C. perfringens by consumption of soy sauce is low in Korea.

Development of a Selective Agar for Improving Campylobacter jejuni Detection in Food.

BACKGROUND: Campylobacter jejuni is a major gastroenteritis-causing foodborne pathogen. However, it is difficult to isolate when competing bacteria or cold-damaged cells are present. OBJECTIVE: Herein, a medium (Campylobacter selective agar, CSA) was developed and supplemented with catalase, L-serine, L-cysteine, and quercetin for the selective detection of C. jejuni in food. METHOD: The C. jejuni-detection efficiency in media broth and chicken tenders was evaluated. The pathogen was enumerated on modified charcoal-cefoperazone-deoxycholate agar (mCCDA), CSA supplemented with 4 µM catalase (CSA-C4), 8 µM catalase (CSA-C8), 20 mM L-serine (CSA-S20) or 50 mM L-serine (CSA-S50), and mCCDA supplemented with 0.5 mM L-cysteine (mCCDA-LC0.5), 1 mM L-cysteine (mCCDA-LC1), 40 µM quercetin (mCCDA-Q40) or 320 µM quercetin (mCCDA-Q320). The detection efficiency was then evaluated by counting colonies on the selective agar media. Quantitative assessment was also performed using chicken and duck carcasses. RESULTS: The C. jejuni detection efficiencies were higher (P < 0.05) in the groups CSA-C4 or CSA-C8, and CSA-S20 or CSA-S50, than mCCDA, and the detection efficiencies were maintained even in the presence of Acinetobacter baumannii, a competing bacterium. In the quantitative test, CSA-C8 and CSA-S50 demonstrated higher C. jejuni-detection efficiencies than mCCDA (control). CONCLUSIONS: Therefore, CSA-C8 and CSA-S50 improved the detection efficiency of C. jejuni in poultry products by promoting the recovery of cold-damaged cells. HIGHLIGHTS: When using CSA-C8 or CSA-S50 developed in this study for detection of C. jejuni in food, detection efficiency was higher than mCCDA.