• Journal of Korean Biological Nursing Science
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• 제20권1호
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• pp.38-46
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• 2018

Purpose: The aim of this study was to verify the effects of daily 2% chlorhexidine gluconate (CHG) bathing on the acquisition of multidrug-resistant organisms (MDRO) and healthcare-associated infection (HAI) in a medical intensive care unit (MICU). Methods: The study was a randomized controlled group posttest only design, involving 91 patients in MICU at a tertiary hospital (47 patients in the experimental group and 44 patients in the control group). The 2% CHG bathing was performed daily according to bathing protocol to the patients in the experimental group, and traditional bath was performed every three days to those in the control group. Fisher's exact test and x2 test were used to analyze the data. Results: MDRO were found in 6 patients of the experimental group and in 15 patients of the control group. The difference was statistically significant (p= .016). HAI occurred in 2 patients of the experimental group and in 7 patients of the control group. The difference was not statistically significant (p= .084). Conclusion: The results confirmed that daily bathing with CHG was effective in reducing the incidence of MDRO acquisition. Therefore, it is expected that daily bathing with CHG will be used as an effective nursing intervention to reduce the incidence of MDRO acquisition.

• Acute and Critical Care
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• 제33권4호
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• pp.238-245
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• 2018

Background: Infection by multidrug-resistant (MDR) pathogens leads to poor patient outcomes in intensive care units (ICUs). Contact precautions are necessary to reduce the transmission of MDR pathogens. However, the importance of the surrounding environment is not well known. We studied the effects of ICU relocation on MDR respiratory pathogen detection rates and patient outcomes. Methods: Patients admitted to the ICU before and after the relocation were retrospectively analyzed. Baseline patient characteristics, types of respiratory pathogens detected, antibiotics used, and patient outcomes were measured. Results: A total of 463 adult patients admitted to the ICU, 4 months before and after the relocation, were included. Of them, 234 were admitted to the ICU before the relocation and 229 afterward. Baseline characteristics, including age, sex, and underlying comorbidities, did not differ between the two groups. After the relocation, the incidence rate of MDR respiratory pathogen detection decreased from 90.0 to 68.8 cases per 1,000 patient-days, but that difference was statistically insignificant. The use of colistin was significantly reduced from 53.5 days (95% confidence interval [CI], 20.3 to 86.7 days) to 18.7 days (95% CI, 5.6 to 31.7 days). Furthermore, the duration of hospital stay was significantly reduced from a median of 29 days (interquartile range [IQR], 14 to 50 days) to 21 days (IQR, 11 to 39 days). Conclusions: Incidence rates of MDR respiratory pathogen detection were not significantly different before and after ICU relocation. However, ICU relocation could be helpful in reducing the use of antibiotics against MDR pathogens and improving patient outcomes.

• 대한간호학회지
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• 제51권4호
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• pp.414-429
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• 2021

Purpose: This systematic review and meta-analysis analyzed the effects of 2% chlorhexidine bathing on the incidence of hospital-acquired infection (HAI) and multidrug-resistant organisms (MDRO) in adult intensive care units. Methods: PubMed, CINAHL, Cochrane library, and RISS database were systematically searched, and 12 randomized studies were included in the analysis. Comprehensive Meta-Analysis version 3.0 was used to calculate the effect size using the odds ratio (OR) and a 95% confidence interval (CI). Subgroup analysis was performed according to the specific infection and intervention types. Results: In general, 2% chlorhexidine bathing has a significant effect on the incidence of HAI (OR, 0.59; 95% CI, 0.40~0.86) and MDRO (OR, 0.52; 95% CI, 0.34~0.79). Subgroup analyses show 2% chlorhexidine bathing is effective in bloodstream infections (OR, 0.51; 95% CI, 0.39~0.66) but not for urinary tract infections, ventilator-associated pneumonia infections, and Clostridium difficile infections. Moreover, 2% chlorhexidine bathing alone or its combination with other interventions has a significant effect on the incidence of HAI and MDRO (OR, 0.59; 95% CI, 0.38~0.92). Conclusion: This meta-analysis reveals that 2% chlorhexidine bathing significantly reduces the incidence of HAI and MDRO in intensive care units. The effect of 2% chlorhexidine bathing on pediatric patients or patients at general wards should be further assessed as a cost-effective intervention for infection control.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.61-74
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• 2023

The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 ㎍/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC₅₀ values of 47.15 ± 13.10 and 122.69 ± 9.12 ㎍/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

• IMMUNE NETWORK
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• 제20권3호
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• pp.25.1-25.13
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• 2020

Acinetobacter baumannii is known for its multidrug antibiotic resistance. New approaches to treating drug-resistant bacterial infections are urgently required. Cathelicidin-related antimicrobial peptide (CRAMP) is a murine antimicrobial peptide that exerts diverse immune functions, including both direct bacterial cell killing and immunomodulatory effects. In this study, we sought to identify the role of CRAMP in the host immune response to multidrug-resistant Acinetobacter baumannii. Wild-type (WT) and CRAMP knockout mice were infected intranasally with the bacteria. CRAMP^-/- mice exhibited increased bacterial colony-forming units (CFUs) in bronchoalveolar lavage (BAL) fluid after A. baumannii infection compared to WT mice. The loss of CRAMP expression resulted in a significant decrease in the recruitment of immune cells, primarily neutrophils. The levels of IL-6 and CXCL1 were lower, whereas the levels of IL-10 were significantly higher in the BAL fluid of CRAMP^-/- mice compared to WT mice 1 day after infection. In an in vitro assay using thioglycollate-induced peritoneal neutrophils, the ability of bacterial phagocytosis and killing was impaired in CRAMP^-/- neutrophils compared to the WT cells. CRAMP was also essential for the production of cytokines and chemokines in response to A. baumannii in neutrophils. In addition, the A. baumannii-induced inhibitor of κB-α degradation and phosphorylation of p38 MAPK were impaired in CRAMP^-/- neutrophils, whereas ERK and JNK phosphorylation was upregulated. Our results indicate that CRAMP plays an important role in the host defense against pulmonary infection with A. baumannii by promoting the antibacterial activity of neutrophils and regulating the innate immune responses.

• BMB Reports
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• 제53권2호
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• pp.88-93
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• 2020

Cisplatin is a widely used anti-cancer agent. However, the effectiveness of cisplatin has been limited by the commonly developed drug resistance. This study aimed to investigate the potential effects of endoplasmic reticulum (ER) stress to overcome drug resistance using the cisplatin-resistant A2780/CisR ovarian cancer cell model. The synthetic chalcone derivative (E)-3-(3,5-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (named DPP23) is an ER stress inducer. We found that DPP23 triggered apoptosis in both parental cisplatin-sensitive A2780 and cisplatin-resistant A2780/CisR ovarian cancer cells due to activation of reactive oxygen species (ROS)-mediated unfolded protein response (UPR) pathway in the endoplasmic reticulum. This result suggests that ROS-mediated UPR activation is potential in overcoming drug resistance. DPP23 can be used as a target pharmacophore for the development of novel chemotherapeutic agents capable of overcoming drug resistance in cancer cells, particularly ovarian cancer cells.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1059-1064
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• 2014

Staphylococcus aureus is a major human pathogen, implicated in both community and hospital acquired infections. The therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult because of multidrug resistance and strong biofilm-forming properties. Schiff bases have attracted attention as promising antibacterial agents. In this study, we investigated the in vitro activity of taurine-5-bromosalicylaldehyde Schiff base (TBSSB) against MRSA. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined using a microtiter broth dilution method. TBSSB effectively inhibited planktonic MRSA, with an MIC of $32{\mu}g/ml$. The time-kill curve confirmed that TBSSB exhibited bactericidal activity against MRSA. TBSSB was also found to significantly inhibit MRSA biofilm formation at 24 h, especially at $1{\times}MIC$ and sub-MIC levels. Furthermore, scanning electron microscopy and transmission electron microscopy showed remarkable morphological and ultrastructural changes on the MRSA cell surface, due to exposure to TBSSB. This study indicated that TBSSB may be an effective bactericidal agent against MRSA.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1635-1645
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• 2020

In this study would like to find extending or increasing the efficacy of the antibiotic substance for the strains with resistance to antibiotics or persister cells by inhibition of the resistance. This study was used different species of 'legal high' plants leaves from Leonotis leonurus, Mitragyna speciosa, and seeds from Ipomoea murucoides with antibiotics which are Amoxicillin, Chloramphenicol, Ciprofloxacin, Kanamycin, Oxacillin, and Vancomycin. Legal highs were extracted with methanol. Minimum inhibitory concentration(MIC) testing for a range of antibiotics with extracts of plant was fulfilled by broth dilution methods. In this essay, it was determined in a microdilution assay utilizing suspended in ISB up to a final concentration of 512㎍/ml in 96 wells microtitre plates, threefold and serial dilutions. After that, the microplates were kept in incubator between 35℃ and 37℃ for overnight. Leonotis leonurus, Mitragyna speciosa, and Ipomoea murucoides of Legal highs (512㎍/ml) investigated small activity to inhibit against pathogens which are susceptible Staphylococcus aureus, resistant Staphylococcus aureus, susceptible Enterococcus faecalis, resistant Escherichia coli.

• Parasites, Hosts and Diseases
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• 제61권1호
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• pp.78-83
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• 2023

The use of an effective antimalarial drug is the cornerstone of malaria control. However, the development and spread of resistant Plasmodium falciparum strains have placed the global eradication of malaria in serious jeopardy. Molecular marker analysis constitutes the hallmark of the monitoring of Plasmodium drug-resistance. This study included 96 P. falciparum PCR-positive samples from southern Somalia. The P. falciparum chloroquine resistance transporter gene had high frequencies of K76T, A220S, Q271E, N326S, and R371I point mutations. The N86Y and Y184F mutant alleles of the P. falciparum multidrug resistance 1 gene were present in 84.7 and 62.4% of the isolates, respectively. No mutation was found in the P. falciparum Kelch-13 gene. This study revealed that chloroquine resistance markers are present at high frequencies, while the parasite remains sensitive to artemisinin (ART). The continuous monitoring of ART-resistant markers and in vitro susceptibility testing are strongly recommended to track resistant strains in real time.

• Archives of Plastic Surgery
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• 제34권6호
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• pp.691-696
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• 2007

Purpose: The emergency of multi-drug resistant stains of bacteria represents a challenge in the field of plastic surgery. Especially, MRSA(methycillin-resistant Staphylococcus aureus) and Pseudomonas aeruginosa have strong pathogenicity as well as multi-drug resistance so that they have become a lot more problematic strains. This study has been planned to reduce the bacterial burden by applying $Acticoat^{(R)}$(Smith & Nephew Healthcare, Hull, England)dressing into the chronic wounds infected by multi-drug resistant strains and to facilitate their healing. Methods: Nanocrystalline silver dressings($Acticoat^{(R)}$) were applied to chronic wound infected by MRSA or Pseudomonas aeruginosa. Multi-drug resistant bacteria were smeared over a slide glass using sterilized cotton swabs and gram stains were performed directly before and after applying $Acticoat^{(R)}$ dressings at 1, 24, 48 and 72 hours. The gram-stained slides were observed using an optical microscope magnified 1000 times(${\times}1000$). The bacterial counts of the control group(0 hour) were compared to those of the experimental groups(1, 24, 48, and 72 hour). Paired T-test was used to assess a statistical significance. MRSA was cultured in two BAPs(blood agar plate) and two MacConkey plates with streak plate method. None were interventions on one culture plate, while on the other culture plate, $Acticoat^{(R)}$ was placed in a square shape and cultured for 72 hours at $37^{\circ}C$, then plates were examined. Pseudomonas aeruginosa was cultured in the same manner as MRSA. Results: There are the large amount of declination of bacterial counts with statistical significance after $Acticoat^{(R)}$ dressing. The bacteria grew in culture plate without specific intervention, but no bacteria grew in culture plate with applying of $Acticoat^{(R)}$ dressing. Conclusion: We believe that $Acticoat^{(R)}$ dressing could be used as an effective method of treating chronic wounds which are infected by multi-drug resistant organisms.