• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1931-1937
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• 2019

The heterologous expression of the Streptomyces natural product (NP) biosynthetic gene cluster (BGC) has become an attractive strategy for the activation, titer improvement, and refactoring of valuable and cryptic NP BGCs. Previously, a Streptomyces artificial chromosomal vector system, pSBAC, was applied successfully to the precise cloning of large-sized polyketide BGCs, including immunosuppressant tautomycetin and antibiotic pikromycin, which led to stable and comparable production in several heterologous hosts. To further validate the pSBAC system as a generally applicable heterologous expression system, the daptomycin BGC of S. roseosporus was cloned and expressed heterologously in a model Streptomyces cell factory. A 65-kb daptomycin BGC, which belongs to a non-ribosomal polypeptide synthetase (NRPS) family, was cloned precisely into the pSBAC which resulted in 28.9 mg/l of daptomycin and its derivatives in S. coelicolor M511(a daptomycin non-producing heterologous host). These results suggest that a pSBAC-driven heterologous expression strategy is an ideal approach for producing low and inconsistent Streptomyces NRPS-family NPs, such as daptomycin, which are produced low and inconsistent in native host.

• Pediatric Infection and Vaccine
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• 제2권2호
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• pp.180-185
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• 1995

1. Purpose The accurate diagnosis and proper treatment of group A streptococcus should be emphasized concerning about possible development of late sequelae, such as acute rheumatic fever and acute glomerulonephritis. We would like to know the recover rate of beta-hemolytic streptococci by throat swab culture at the in-patient 2. Methods The throat swab cultures and filled up flow-sheets were undertaken on 619 children who had admitted to hospital, KyungHee university hospital from may 1994 to april 1995 prospectively. At the same time on admission, throat culture was performed. 3. Results The highest recover rate of BHS(Beta-Hemolytic Streptococci)and GAS(Group A Streptococci) were seen in above 10 years old, as 9.1% and 1.9%. BHS were obtained in 39 cases(6.3%) among 619 children while GAS was obtained in 3 cases (0.4%). Among 39 specimens of BHS, 33 specimens were classified as non-grouping streptococcus. 4. Conclusion The poor recovery rate of GAS inpatient compared with normal carrier rate is likely due to possible antibiotic abuse, errors in processing samples, and epidemiologic factors such as seasons and geographic areas. It is necessary to evaluate the clinical significance of non-A,B,C,G streptococcal infections and carriers.

• 대한수의학회지
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• 제53권3호
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• pp.177-180
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• 2013

Two dogs were presented with melena, vomiting and depression after accidental swallowing of candy form of Strepsils (flurbiprofen), which is one of non-steroidal anti-inflammatory drugs used in human medicine for controlling a sore throat. These dogs had common signs of anemia induced by gastrointestinal ulceration and hemorrhage with azotemia and leukocytosis. The dogs were treated with blood transfusion, fluid therapy, proton-pump inhibitor, antiemetics, mucus protectant and antibiotic. Although most of clinical signs of two dogs were resolved, azotemic problem with evidence of renal injury have remained.

• Journal of Veterinary Science
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• 제23권2호
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• pp.23.1-23.15
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• 2022

Background: Antibacterial agents play important roles in the treatment of bacterial infections. However, the development of antimicrobial resistance (AMR) and carry-over of substances into the environment are several problems arising during oral treatment of bacterial infections. We assessed AMR development in commensal Escherichia coli (E. coli) in enrofloxacin treated and untreated animals. In addition, we examined fluoroquinolone in the plasma and urine of treated and untreated animals, and in sedimentation dust and aerosol. Methods: In each trial, six pigs were treated with enrofloxacin via powder, granulate or pellet forms in two time periods (days 1-5 and 22-26). Four pigs served as untreated controls. The minimum inhibitory concentration (MIC) was determined to evaluate AMR development. Analysis of enro- and ciprofloxacin was performed with high performance liquid chromatography. Results: Non-wildtype E. coli (MIC > 0.125 ㎍/mL) was detected in the pellet treated group after the first treatment period, whereas in the other groups, non-wildtype isolates were found after the second treatment period. E. coli with MIC > 4 ㎍/mL was found in only the pellet trial. Untreated animals showed similar susceptibility shifts several days later. Bioavailability differed among the treatment forms (granulate > pellet > powder). Enro- and ciprofloxacin were detected in aerosols and sedimentation dust (granulate, powder > pellet). Conclusions: This study indicates that the kind of the oral dosage form of antibiotics affects environmental contamination and AMR development in commensal E. coli in treated and untreated pigs.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.828-837
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• 2024

Vancomycin (VAN) and metronidazole (MTR) remain the current drugs of choice for the treatment of non-severe Clostridioides difficile infection (CDI); however, while their co-administration has appeared in clinical treatment, the efficacy varies greatly and the mechanism is unknown. In this study, a CDI mouse model was constructed to evaluate the therapeutic effects of VAN and MTR alone or in combination. For a perspective on the intestinal ecology, 16S rRNA amplicon sequencing and non-targeted metabolomics techniques were used to investigate changes in the fecal microbiota and metabolome of mice under the co-administration treatment. As a result, the survival rate of mice under co-administration was not dramatically different compared to that of single antibiotics, and the former caused intestinal tissue hyperplasia and edema. Co-administration also significantly enhanced the activity of amino acid metabolic pathways represented by phenylalanine, arginine, proline, and histidine, decreased the level of deoxycholic acid (DCA), and downregulated the abundance of beneficial microbes, such as Bifidobacterium and Akkermansia. VAN plays a dominant role in microbiota regulation in co-administration. In addition, co-administration reduced or increased the relative abundance of antibiotic-sensitive bacteria, including beneficial and harmful microbes, without a difference. Taken together, there are some risks associated with the co-administration of VAN and MTR, and this combination mode should be used with caution in CDI treatment.

• 대한간호학회지
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• 제8권2호
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• pp.79-88
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• 1978

Utilizing Foley catheter in therapy of inpatient cause bacteriuria and urinary tract infection that leads to first ranked factor's in hospital infection (nosocomial infection). To protect the patient from such infections, emphasis should be placed on catheterization technique and management of the closed drainage system, this reducing the chances of introducing organisms. This study has been done at Intensive Care Unit of A and B hospitals from May-Oct. 1978 on 20 male and 18 female adult patients. Each patient was screened and found to have nonbacteriuria in clean catch specimen before catheterization. Clean catch specimen via foley catheter were obtained after 48 hours and 96 hours from catheterization. The findings are as follows: A. The occurrence of bacteriuria in patients according to duration of indwelling catheter. 1 213.9% of the patient showed evidence of bacteriuria 48h post catheterization specimen, while 57.9% of the patient showed evidence of bacteriuria 96h post catheterization specimen. 2 25% of male patients had infection 48h post catheterization and 45% displayed bacteriuria post catheterization. 33％ of female patients displayed infection 48h post catheterization and 72.2% having infection 96h post catheterization. Statistically there were significant differences between female patients and the duration of insertion. (P < 0.025) B. The occurrence of bacteriuria with the administration of bacteriuria with the ad-ministration of antibiotic in 24 patients was in 41,7%. The occurrence of bacteriuria without the administration of antibiotic in 14 patients was in 92.3%. Statistically there were very significant difference between the administration of the antibiotis and bacteriuria. (P < 0.005) C. Studies were done according to the consciousness level of the patients, 71.4% of those patient who displayed mental disorder developed bacteriuria, while 30.0% of those patient who displayed non mental disorder developed bacteriuria.

• Molecules and Cells
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• 제37권6호
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• pp.480-486
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• 2014

Growth restriction by antibiotics is a common feature that pathogenic bacteria must overcome for survival. The struggle of bacteria to escape from growth restriction eventually results in development of antibiotic-resistance through the expression of a set of genes. Here we found that some physiologically important transcriptional regulators of Pseudomonas aeruginosa including QscR, a quorum sensing (QS) receptor, SoxR, a superoxide sensor-regulator, and AntR, a regulator of anthranilate-related secondary metabolism, are activated by various growth-restricted conditions. We generated the growth-restricted conditions by various methods, such as overexpression of PA2537 and treatment with antibiotics or disinfectants. The overexpression of PA2537, encoding an acyltransferase homologue, tightly restricted the growth of P. aeruginosa and significantly activated QscR during the growth restriction. Similarly, treatments with gentamycin, tetracycline, and ethanol also activated QscR near their minimal inhibitory concentrations (MICs). Some non-QS regulators, such as AntR and SoxR, were also activated near the MICs in the same conditions. However, LasR and PqsR, other QS receptors of P. aeruginosa, were not activated, suggesting that only a specific set of transcriptional regulators is activated by growth restriction. Since paraquat, a superoxide generator, significantly activated QscR and AntR, we suggest that the oxidative stress generated by growth restriction may be partly involved in this phenomenon.

• Clinical and Experimental Pediatrics
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• 제64권6호
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• pp.293-300
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• 2021

Background: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment. Purpose: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children. Methods: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated. Results: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03). Conclusion: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

• 구강회복응용과학지
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• 제37권4호
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• pp.294-300
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• 2021

치태세균에 의해 야기되는 괴사성 치주질환은 감염부위에서 위막과 치간사이의 연조직 괴사 및 출혈, 촉진시 통증과 치은 출혈이 관찰된다. 환자들의 구내 세균을 조사해보면 방추균과 나선균이 혼합하여 존재하는 방추스피로헤타 세균총을 가지고 있다. 본 증례는 괴사성 치주질환으로 잠정 진단된 환자 2명을 대상으로 비외과적 치주치료, 3% 과산화수소를 적신 면봉을 이용한 드레싱 후 국소전달항생제를 도포하였고, 치료 전과 초기 치료 3 - 5일 후 치은열구액을 채득하여 실시간 연쇄중합반응법을 이용한 정량분석으로 구강내 미생물수를 측정하였다. 비외과적 치주치료 후 감염부위 치은이 정상으로 회복되었고, 7종 이상 검출되던 치주질환 관련 미생물도 1종만 검출되었다. 결과적으로 비외과적 치주치료를 통해 괴사성 치주질환 환자들의 치주 조직을 정상으로 회복하였다.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.479-489
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• 2023

Livestock production depends on the utilization of nutrients, and when this is accomplished, there is accelerated momentum toward growth with a low cost-to-feed ratio. Public concern over the consumption of pork with antibiotic residues in animals fed antibiotic growth promoters (AGP) has paved the way for using other natural additives to antibiotics, such as herbs and their products, probiotics, prebiotics, etc. Numerous feed additives are trending to achieve this goal, and a classic example is vitamins and minerals. Vitamins and minerals represent a relatively small percentage of the diet, but they are critical to animal health, well-being, and performance; both play a well-defined role in metabolism, and their requirements can vary depending on the physiological stage of the animals. At the same time, the absence of these vitamins and minerals in animal feed can impair the growth and development of muscles and bones. Most commercial feeds contain vitamins and trace minerals that meet nutrient requirements recommended by National Research Council and animal feeding standards. However, the potential variability and bioavailability of vitamins and trace elements in animal feeds remain controversial because daily feed intake varies, and vitamins are degraded by transportation, storage, and processing. Accordingly, the requirement for vitamins and minerals may need to be adjusted to reflect increased production levels, yet the information presented on this topic is still limited. Therefore, this review focuses on the role and function of different sources of minerals, the mode of action, the general need for micro and macro minerals in non-ruminant diets, and how they improve animal performance.