• Journal of Pharmaceutical Investigation
• /
• v.33 no.4
• /
• pp.305-310
• /
• 2003

One of the possible mechanisms of multi-drug resistance found in cancer cells is the over-expression of P­glycoprotein (P-gp). Studies have shown that compounds in plants including vegetables and fruits not only have anticancer activities but may also modulate P-gp activity. The effect of flavonoids and organic isothiocyanate on P-gp activity was studied in human uterine sarcoma cell lines, MES-SA (sensitive) and MES-SA/DX5 (resistant) cells. The accumulation of daunomycin (DNM), a P-gp substrate, was approximately 10 times greater in the sensitive cell as compared to the resistant cells over the entire time course (up to 2 hours). The positive control, verapamil increased the two hour accumulation of DNM while quercetin decreased that of DNM in the resistant cells. 1-Naphtyl-isothiocyanate (NITC) showed no effect on the two hour accumulation of DNM. The $IC_{50}$ values for DNM in the resistant cells was about 20 times higher than that observed in the sensitive cells $(10.1{\pm}1.7\;{\mu}M\;vs.\;0.58{\pm}0.28\;{\mu}M)$. Verapamil reduced the $IC_{50}$ value for DNM whereas flavonoids (quercetin and fisetin) increased those for DNM in the resistant cells.

• Natural Product Sciences
• /
• v.6 no.1
• /
• pp.36-39
• /
• 2000

Acorenone, a diterpene isolated from Acorus gramineus, showed strong resistance inhibitory activity against multi-drug resistant microorganisms such as Staphylococcus aureus SA2, which has resistance to 10 usual antibiotics including chloramphenicol (Cm). At the level of $5\;{\mu}g/ml$ when combined with $50\;{\mu}g/ml$ of Cm. Bacterial resistance to Cm is due to the presence in resistant bacteria of an enzyme, chloramphenicol acetyltransferase (CAT), which catalyses the acetyl-CoA dependent acetylation of the antibiotic at C-3 hydroxyl group. To elucidate the mechanism of resistant inhibitory effect, the acorenone which had the strongest resistant inhibitory activity, was investigated on the CAT assay. As the result, the combination of Cm and acorenone showed the strongest inhibitory activity on CAT as noncompetitive and dose dependent manner.

• YAKHAK HOEJI
• /
• v.43 no.1
• /
• pp.124-127
• /
• 1999

Bifidobacterium infantis K-525 isolated from healthy Korean was susceptible to rifampicin and fluoroquinolones and resistant to other antituberculosis agents. When the preparation of this strain is taken as a therapeutics for human intestinal disorders with rifampicin or fluoroquinolones, its therapeutic effect can not be expected. So, B, infantis RFR-525 resistant to rifampicin was obtained by treating the parent B. infantis 525 with N-methyl-N'-nitro-N-nitrosoguanidine. B. infantis OFR-525 was produced by serial passage of B. infantis RFR-525 on agar with 2-fold minimal inhibitory concentration of ofloxacin. B. infantis OFR-525 was resistant to antituberculosis agents and fluoroquinolones up to 4∼128 fold higher than that for the original strain. The resistance of B. infantis OFR-525 against rifampicin and ofloxacin was maintained in vivo and in vitro. Conclusively, B. infantis OFR-525 can be regarded as a promising strain which can be developed as the preparation for the treatment of the intestinal disorders of the tuberculosis patients under rifampicin and ofloxacin therapy.

• Korean Journal of Clinical Laboratory Science
• /
• v.43 no.2
• /
• pp.68-74
• /
• 2011

Pseudomonas aeruginosa is an aerobic, Gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. Recently, outbreaks of carbapenem resistant P. aeruginosa give rise to significant therapeutic challenges for treating nosocomial infections. The genes of metallo-${\beta}$-lactamase (MBL), a powerful carbapenemase, are carried as a part of the mobile gene cassettes inserted into integrons playing an important role in rapid dissemination of antibiotic resistance genes among bacterial isolates. In this study, we investigated the prevalence of integron in imipenem resistant P. aeruginosa isolates. A total of 61 consecutive, non-duplicate, and imipenem resistant P. aeruginosa strains were isolated from a university hospital in the Chungcheong province of Korea. We employed repetitive extragenic palindromic sequence-based PCR (rep-PCR) method for the selection of clonally different P. aerusinosa strains. PCR and DNA sequencing were conducted for the detection of integrons. Twenty-one clonally different P. aeruginosa strains were isolated. Only one (P28) of the strains harbored $bla_{VIM-2}$ that was found as gene cassettes in class 1 integrons. Four of 21 carbapenem resistant P. aeruginosa strains harbored class 1 integron containing aminoglycoside resistance determinant. All of the integrons detected in the study contained more than one resistance gene cassette, which can mediate resistance to multiple antibiotics. To prevent further spreading of the multi-drug resistant P. aeruginosa, conseguent monitoring and clinical polices are required.

• Journal of Home Health Care Nursing
• /
• v.30 no.2
• /
• pp.155-162
• /
• 2023

Purpose: This study was conducted to identify the status and risk factors for the carriage of multidrug-resistant organisms carriage in home health nursing patients. Methods: This retrospective study enrolled 122 participants who received home health nursing and analyzed the data obtained from chart review and diagnostic tests for multidrug-resistant organisms carriage from January 2019 to January 2021. Results: Multivariate analysis revealed that surgical procedures in the preceding year, injectable antibiotic use in the preceding month, pressure ulcer, and indwelling nasal tubes were significantly associated with multi-drug resistant infection. Conclusions: Infection-control strategies need to be developed and customized for use in the home health-nursing service for patients who are carriers of multidrug-resistant organisms.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.23 no.2
• /
• pp.149-160
• /
• 2016

Purpose: The purpose of this study was to identify factors influencing performance of MultiDrug-Resistant Organisms (MDROs) infection control by nurses in general hospitals. Methods: The research design was a descriptive survey design using convenience sampling. Data were collected from 130 nurses working in 6 general hospitals. Collected data were analyzed using SPSS/WIN 21.0 program for descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression analysis. Results: General hospital nurses' MDROs infection control performance was influenced by their awareness of environmental safety, recognition of MDROs infection control, number of beds in the hospital, whether nurses had nursing experience with infection control and guidelines for MDROs infection control. The most important predictors of MDROs infection control performance were awareness of environmental safety and recognition of MDROs infection control. Conclusion: Findings indicate that it is necessary to include content related to awareness of environmental safety and recognition of infection control in developing MDROs infection control education programs for general hospital nurses.

• Biomedical Science Letters
• /
• v.18 no.1
• /
• pp.83-85
• /
• 2012

Vancomycin-resistant (VR)-E. faecium and VR-E. faecalis were isolated simultaneously from a rectal swab of a patient diagnosed with pneumonia in an intensive care unit (ICU). The patient was treated with various antibiotics including vancomycin. Only VR-E. faecium was continually isolated from the rectal swab at one and two weeks of the treatment. Identical vanA, IS1216V, and IS1542 genes were detected in both VR-E. faecium and VR-E. faecalis isolates which showed equal resistance against vancomycin and teicoplanin, but IS1251 was not detected. VR-E. faecium showed stronger multi-drug resistance than VE-E. faecalis. This result supports the reason why VR-E. faecium is one of the major pathogens in nosocomial infections.

• Microbiology and Biotechnology Letters
• /
• v.49 no.3
• /
• pp.367-373
• /
• 2021

The antimicrobial resistance of Staphylococcus spp. and Gram negative strains present in air samples from waste sorting facilities was assessed. Phenotypic studies have revealed a high percentage of strains of Staphylococcus spp. resistant to methicillin. Genotypically and by RT-PCR, it was found that the mecA gene usually associated with methicillin resistance was present in 8% of the Staphylococcus strains isolated. About 30% of the Gram negative strains from the same samples also displayed resistance to meropenem and 79% of these were resistant to multiple antibiotics from different classes, namely cephalosporins and β-lactams. The results suggest that in professional activities with high levels of exposure to biological agents, the quantification and identification of the microbial flora in the work environment, with the determination of the presence of potential agents displaying multi-resistances is of relevance to the risk assessment. The personal protection of workers is particularly important relevance in these cases, since many of the strains that exhibit multi-resistance are potential opportunistic agents.

• Tuberculosis and Respiratory Diseases
• /
• v.67 no.3
• /
• pp.212-220
• /
• 2009

Background: Ventilator-associated pneumonia caused by multi-drug resistant Acinetobacter baumannii has been increasing and growing as a threat in intensive care units. Limited therapeutic options have forced clinicians to choose colistin with or without combination of other antibiotics. We tried to compare the effectiveness between colistin monotherapy and combination therapy based on in vitro synergistic tests. Methods: From January 2006 to December 2007 in medical ICU of a tertiary care hospital in Korea, We reviewed the medical records of patients treated with intravenous colistin due to ventilator-associated pneumonia caused by multi-drug resistant Acinetobacter baumannii. Results: A total of 41 patients were analyzed. 22 patients had been treated with colistin monotherapy and 19 patients with colistin and combination antibiotics that were found to have in vitro synergistic effects. Baseline characteristics were similar in both groups but the mean duration of colistin administration was significantly longer in the combination group (19.1${\pm}$11.2 days vs. 12.3${\pm}$6.8 days, p=0.042). There were no significant differences in outcome variables between the two groups. Conclusion: Combination treatment based on the in vitro antimicrobial synergy test did not show better outcomes compared with colistin monotherapy in VAP caused by multi-drug resistant A. baumannii.

• Journal of Life Science
• /
• v.17 no.3 s.83
• /
• pp.435-443
• /
• 2007

Antimicrobial susceptibility test of the 116 strains of Mycoplasma pneumoniae isolates were performed by a broth micro-dilution method against to moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, clarithromycin minocycline, erythromycin, josamycin, and tetracycline. The initial-minimum inhibitory concentration (I-MIC) was evaluated as the lowest concentration of antimicrobial agents that prevented a color change in the medium at that time when the drug-free growth control, about 7 days after incubation, and the final-minimum inhibitory concentration (F-MIC) was defined a color change about 14 days after incubation. The evaluation to the drug-resistant M. pneumoniae isolates were determined the $MIC{\pm}1.0$ ${\mu}g/ml$ of each antimicrobial agent. According to the I-MIC, single drug-resistant M. pneumoniae strains to ciprofloxacin, ofloxacin, clarithromycin and erythromycin were 79.3, 53.5, 10.3, and 7.8%, respectively. Two kinds of drug-resistant M. pneumoniae strains to ofloxacin and ciprofloxacin, or ciprofloxacin and clarithromycin were 42.2 and 9.5%. Three kinds of drug-resistant M. pneumoniae strains to erythromycin, ofloxacin, and ciprofloxacin, or ofloxacin, ciprofloxacin and clarithromycin were 6.9 and 6.0% . According to the F-MIC, single drug-resistant M. pneumoniae strains to tetracycline, ciprofloxacin, ofloxacin, minocycline,erythromycin, josamycin, clarithromycin and sparfloxacin were 91.4, 91.4, 91.4, 89.7, 68.1, 52.6, 28.5, and 11.2%, respectively. The incidence of two kinds of drug-resistant M. pneumoniae strains were from 20.7% to 91.4%, three kinds of drug-resistant M. pneumoniae strains were from 28.5% to 89.7%, four kinds of drug-resistant M. pneumoniae strains were 2.6%, five kinds of drug-resistant M. pneumoniae were from 2.6% to 21.6%, six kinds of drug-resistant M. pneumoniae strains were from 0.9% to 24.1%, seven kinds of drug-resistant M. pneumoniae strains were from 0.9% to 2.6%, and eight kinds of drug-resistant M. pneumoniae strains were 1.7%. These results suggest that sparfloxacin, moxifloxacin and levofloxacin might be promising antimicrobial agents for the treatment of M. pneumoniae infection in Korea. However, most strains of M. pneumoniae isolates were single or multi-resistance pattern to the other tested antimicrobial agents. Therefore, tetracycline, minocycline, erythromycin, clarithromycin, and second-generation quinolones are more carefully used to patients with M. pneumoniae infection in Korea.