Cellular senescence causes cell cycle arrest and promotes permanent cessation of proliferation. Since the senescence of mesenchymal stem cells (MSCs) reduces proliferation and multipotency and increases immunogenicity, aged MSCs are not suitable for cell therapy. Therefore, it is important to inhibit cellular senescence in MSCs. It has recently been reported that metabolites can control aging diseases. Therefore, we aimed to identify novel metabolites that regulate the replicative senescence in MSCs. Using a fecal metabolites library, we identified nervonic acid (NA) as a candidate metabolite for replicative senescence regulation. In replicative senescent MSCs, NA reduced senescence-associated β-galactosidase positive cells, the expression of senescence-related genes, as well as increased stemness and adipogenesis. Moreover, in non-senescent MSCs, NA treatment delayed senescence caused by sequential subculture and promoted proliferation. We confirmed, for the first time, that NA delayed and inhibited cellular senescence.Considering optimal concentration, duration, and timing of drug treatment, NA is a novel potential metabolite that can be used in the development of technologies that regulate cellular senescence.

Purpose: This study aimed to develop a scale to measure hospital nurses’ silence behavior and examine its validity and reliability. Methods: A total of 52 preliminary items on hospital nurses’ silence behavior were selected using a content validity test by seven experts on 53 candidate items derived from a literature review and in-depth interviews with 14 nurses. A total of 405 hospital nurses participated in a psychometric testing. Data analysis comprised item analysis, exploratory and confirmatory factor analyses, and convergent and discriminant validity tests. Pearson’s correlation coefficient was used for assessing concurrent validity, and Cronbach’s alpha was used for the reliability test. Results: The final scale consisted of nine factors with 31 items, exhibiting acceptable model fit indices, convergent validity, and discriminant validity. The score of the entire scale was positively correlated with the ‘Organizational Silence Scale (OSS)-the issues on which nurses remain silent’ (r = .60, p < .001) and ‘OSS-the reasons why nurses remain silent’ (r = .68, p < .001). Cronbach’s α of the scale was .92, and α of each subscale ranged from .71 to .90. Conclusion The Hospital Nurses’ Silence Behavior Scale is a useful tool for assessing multifaceted silence behavior among nurses. It can provide basic data for developing better communication strategies among nurses and other hospital staff.

Purpose: This study aimed to explore nurses’ experience in caring for COVID-19 patients. Methods: A total of 10 nurses working in a COVID-19 ward of a public hospital in South Korea were recruited using purposeful sampling. Individual telephone interviews were conducted and then transcribed verbatim. Data were analyzed using qualitative content analysis. Results: Two categories of nurses’ experience in caring for COVID-19 patients emerged; “unstable psychological status” and “adaptation and self-esteem”. “Shortage of staff due to the increase in infected people”, “poor environment due to the urgent construction of a COVID-19 ward”, “unstable operating system”, and “excessive demands and verbal abuse from patients” were “obstacles”, while “cooperation and consideration between colleagues” and “interest and support from the manager” were found to be “sources to boost morale” for nurses in caring for COVID-19 patients. Conclusion This study can be fundamental data for a deeper understanding of the experiences and challenges faced by frontline nurses caring for COVID-19 patients. It is necessary to provide psychological support for nurses and establish a well-structured nursing care system in order to fight a pandemic such as COVID-19.

Animals ; Base Composition ; Dogs ; Genome ; Genomics ; Korea ; Methicillin Resistance ; Otitis Externa ; Otitis ; Plasmids ; Pyoderma ; Skin ; Soft Tissue Infections ; Staphylococcus

Abattoirs ; Agriculture ; Animals ; Drug Resistance, Multiple ; Farmers ; Korea ; Livestock ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Multilocus Sequence Typing ; Phenotype ; Prevalence ; Red Meat ; Staphylococcus aureus ; Swine ; Tetracycline ; Zinc

The increase in canine skin and soft tissue infections, such as pyoderma and otitis, caused by Staphylococcus schleiferi strains, is of significant zoonotic concern. In this study, we report the first complete genome sequence for a methicillin-resistant clinical isolate of S. schleiferi (MRSS) designated as SS4, obtained from a dog with otitis externa, in Korea. The genome of SS4 strain was of 2,539,409 bp and presented high G+C content ratio (35.90%) with no plasmid. Comparative analysis of SS4 genome revealed that it is closely related to 2142-05 and 5909-02 strains isolated from the canine skin infections in the USA.

The emergence of livestock-associated (LA)-methicillin-resistant Staphylococcus aureus (MRSA) in livestock animal has become a significant zoonotic concern. In the present study, we investigated nationwide prevalence of LA-MRSA across pork production chain including pig farms, slaughterhouses, and retail markets. A total of 40 MRSA strains were isolated during the investigation and the overall prevalence of MRSA was 3.4% (n = 37), 0.6% (n = 2), and 0.4% (n = 1) in pig farms, slaughterhouses, and retail markets, respectively. Multilocus sequence typing analyses revealed that the 2 most significant clonal lineages in pork production chain in Korea were ST398 (n = 25) and ST541 (n = 6). All of the 40 MRSA isolates were further characterized to investigate key genotypic and phenotypic correlates associated with the emergence and spread of clonal complex 398 (CC398; ST398, and ST541) LA-MRSA. Although the prevalence of swine-associated MRSA was still relatively low and mostly restricted to pig farms, multidrug-resistant CC398 LA-MRSA isolates with new spa types (t18102 and t18103) were identified as a major clonal lineage. The CC398 LA-MRSA strains tended to exhibit increased levels of multiple drug resistance (MDR) phenotype compared with non-CC398 MRSA strains. Of note, in comparison with non-CC398 MRSA isolates, CC398 LA-MRSA isolates exhibited significantly enhanced tetracycline (TET) and zinc resistance. These findings suggested that co-selection pressure associated with MDR phenotype, especially TET resistance, and zinc resistance may have played a significant role in the emergence and persistence of CC398 LA-MRSA in pig farms in Korea.

The increase in canine skin and soft tissue infections, such as pyoderma and otitis, caused by Staphylococcus schleiferi strains, is of significant zoonotic concern. In this study, we report the first complete genome sequence for a methicillin-resistant clinical isolate of S. schleiferi (MRSS) designated as SS4, obtained from a dog with otitis externa, in Korea. The genome of SS4 strain was of 2,539,409 bp and presented high G+C content ratio (35.90%) with no plasmid. Comparative analysis of SS4 genome revealed that it is closely related to 2142-05 and 5909-02 strains isolated from the canine skin infections in the USA.

The emergence of livestock-associated (LA)-methicillin-resistant Staphylococcus aureus (MRSA) in livestock animal has become a significant zoonotic concern. In the present study, we investigated nationwide prevalence of LA-MRSA across pork production chain including pig farms, slaughterhouses, and retail markets. A total of 40 MRSA strains were isolated during the investigation and the overall prevalence of MRSA was 3.4% (n = 37), 0.6% (n = 2), and 0.4% (n = 1) in pig farms, slaughterhouses, and retail markets, respectively. Multilocus sequence typing analyses revealed that the 2 most significant clonal lineages in pork production chain in Korea were ST398 (n = 25) and ST541 (n = 6). All of the 40 MRSA isolates were further characterized to investigate key genotypic and phenotypic correlates associated with the emergence and spread of clonal complex 398 (CC398; ST398, and ST541) LA-MRSA. Although the prevalence of swine-associated MRSA was still relatively low and mostly restricted to pig farms, multidrug-resistant CC398 LA-MRSA isolates with new spa types (t18102 and t18103) were identified as a major clonal lineage. The CC398 LA-MRSA strains tended to exhibit increased levels of multiple drug resistance (MDR) phenotype compared with non-CC398 MRSA strains. Of note, in comparison with non-CC398 MRSA isolates, CC398 LA-MRSA isolates exhibited significantly enhanced tetracycline (TET) and zinc resistance. These findings suggested that co-selection pressure associated with MDR phenotype, especially TET resistance, and zinc resistance may have played a significant role in the emergence and persistence of CC398 LA-MRSA in pig farms in Korea.

The recent emergence of Staphylococcus schleiferi in dogs with otitis externa or skin and soft tissue infections has become a significant zoonotic issues. In the current study, we investigated 1) the carriage rates of S. schleiferi among major staphylococci in healthy dogs and dogs with otitis externa, 2) antibiotic susceptibility profiles of S. schleiferi, particularly methicillin resistance (MR), and 3) virulence factors associated with skin and soft tissue infections such as ability to form biofilm, resistance to cationic antimicrobial peptides (CAMPs), and carriage of staphylococcal enterotoxin genes. Among the 21 S. schleiferi isolates, 5 isolates (24%) were determined to be methicillin-resistant (MRSS). Staphylococcal cassette chromosome mec (SCCmec) typing revealed the presence of SCCmec type V in 4 MRSS isolates and type VII in one MRSS. Higher levels of antibiotic resistance, especially multidrug resistance, were observed in MRSS isolates compared to the methicillin-susceptible S. schleiferi (MSSS) isolates. In addition, MRSS isolates exhibited enhanced ability to form biofilm under static condition and all the 5 MRSS isolates carried three or more enterotoxin genes. However, there were no significant differences in resistance to CAMPs between MRSS and MSSS isolates. These findings suggest that coagulase-negative S. schleiferi is becoming more prevalent in canine otitis externa cases. Our results also highlight the presence of multidrug-resistant MRSS isolates with enhanced biofilm production and carriage of multiple enterotoxins.
Animals ; Antimicrobial Cationic Peptides ; Biofilms ; Dogs ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Enterotoxins ; Methicillin Resistance ; Otitis Externa ; Otitis ; Skin ; Soft Tissue Infections ; Staphylococcus ; Virulence Factors ; Virulence