• Pediatric Infection and Vaccine
• /
• v.28 no.2
• /
• pp.82-91
• /
• 2021

Background: The purpose of this study was to investigate the association between antibiotic use and the antimicrobial resistance of gram-negative bacteria isolated from blood cultures in a pediatric population. Methods: From January 2014 to June 2018, the antibiotic resistance pattern of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa obtained from bacteremic patients aged ≤18 years hospitalized at Asan Medical Center Children's Hospital was analyzed and the parenteral antibiotic consumption data were retrieved. Results: During the study period, the blood culture was positive for K. pneumoniae (6.4%; 105/1,628), E. coli (5.6%; 91/1,628), P. aeruginosa (3.3%; 54/1,628), and A. baumannii (2.5%; 41/1,628), and the extended-spectrum antibiotic resistance rate of gram-negative bacteria was consistently high. The overall resistance rate of E. coli and K. pneumoniae to extendedspectrum cephalosporin was 49.3% and 54.4%, respectively. Carbapenem-resistant E. coli was first detected in 2014; its overall resistance rate to carbapenem was 5.3%. There was a linear correlation between the usage of 3rd generation cephalosporin and the resistance of A. baumannii (r²=0.96, P=0.004) and carbapenem usage and the resistance of K. pneumoniae (r²=0.79, P=0.045). Conclusions: A positive linear correlation was observed between antibiotic resistance and the corresponding antibiotic usage in 3rd generation cephalosporin resistant A. baumannii and carbapenem resistant K. pneumoniae. The judicious use of antibiotics in healthcare settings is important to minimize selection for extended-spectrum β-lactamase (ESBL) and carbapenem resistance in gram-negative bacteria.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.2
• /
• pp.263-278
• /
• 2004

Ursolic acid (UA) and Oleanolic acid (ONA), known as urson, micromerol and malol, are pentacyclic triterpenoid compounds which naturally occur in a large number of vegetarian foods, medicinal herbs, and plants. They may occur in their free acid form or as aglycones for triterpenoid saponins, which are comprised of a triterpenoid aglycone, linked to one or more sugar moieties. Therefore UA and ONA are similar in pharmacological activity. Lately scientific research, which led to the identification of UA and ONA, revealed that several pharmacological effects, such as antitumor, hepato-protective, anti-inflammatory, anticarcinogenic, antimicrobial, and anti-hyperlipidemic could be attributed to UA and ONA. Here, we introduced the effect of UA and ONA on acutely barrier disrupted and normal hairless mouse skin. To evaluate the effects of UA and ONA on epidermal permeability barrier recovery, both flanks of 8-12 week-old hairless mice were topically treated with either 0.01-0.1mg/mL UA or 0.1-1mg/mL ONA after tape stripping, and TEWL (transepidermal water loss) was measured. The recovery rate increased in those UA or ONA treated groups (0.1mg/mL UA and 0.5mg/mL ONA) at 6h more than 20% compared to vehicle treated group (p < 0.05). Here, we introduced the effects of UA and ONA on acute barrier disruption and normal epidermal permeability barrier function. For verifying the effects of UA and ONA on normal epidermal barrier, hydration and TEWL were measured for 1 and 3 weeks after UA and ONA applications (2mg/mL per day). We also investigated the features of epidermis and dermis using electron microscopy (EM) and light microscopy (LM). Both samples increased hydration compared to vehicle group from 1 week without TEWL alteration (p < 0.005). EM examination using RuO4 and OsO4 fixation revealed that secretion and numbers of lamellar bodies and complete formation of lipid bilayers were most prominent (ONA=UA > vehicle). LM finding showed that thickness of stratum corneum (SC) was slightly increased and especially epidermal thickening and flattening was observed (UA > ONA > vehicle). We also observed that UA and ONA stimulate epidermal keratinocyte differentiation via PPAR Protein expression of involucrin, loricrin, and filaggrin increased at least 2 and 3 fold in HaCaT cells treated with either ONA (10${\mu}$M) or UA (10${\mu}$M) for 24 h respectively. This result suggested that the UA and ONA can improve epidermal permeability barrier function and induce the epidermal keratinocyte differentiation via PPAR Using Masson-trichrome and elastic fiber staining, we observed collagen thickening and elastic fiber elongation by UA and ONA treatments. In vitro results of collagen and elastin synthesis and elastase inhibitory activity measurements were also confirmed in vivo findings. These data suggested that the effects of UA and ONA related to not only epidermal permeability barrier functions but also dermal collagen and elastic fiber synthesis. Taken together, UA and ONA can be relevant candidates to improve epidermal and dermal functions and pertinent agents for cosmeseutical applications.