• Pediatric Infection and Vaccine
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• 제8권2호
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• pp.199-205
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• 2001

목 적 : 1986년 vancomycin 내성 장구균(이하 VRE)이 보고된 이후 10여년간 빈도는 급격한 증가 추세에 있다. 이에 저자 등은 본 병원에 입원한 소아환자들의 임상검체에서 분리된 VRE의 양상과 해당 환자들의 사용형태에 대한 조사를 시행하여 VRE의 증가양상에 적절히 대처할 수 있는 방안을 모색하고자 본 연구를 시행하였다. 방 법 : 1998년 1월부터 2000년 12월까지 연세의료원 세브란스병원에 입원한 소아 환자에서 분리된 VRE 36주를 대상으로 하여 검체 종류 및 균종, 항균제 감수성과 사용양상을 조사하였고, ICU 환자군과 Non ICU 환자군으로 분류하여 두 군간에 있어서 수술이나 중재적 시술을 시행한 경우와 내과적인 투약처치만을 시행한 경우 등의 분리 전 처치형태를 조사하였고 항균제 감수성을 파악하였으며 중복감염의 여부가 ICU군과 Non ICU군간에서 차이를 보이는지 조사하였다. 결 과 : 본 연구에서, VRE가 분리된 수가 급속히 증가함을 알 수 있었고, ICU 환아군과 수술이나 중재적 시술을 한 경우에서 높은 빈도를 보였으며, E. faecium이 E. faecalis 보다 많이 분리되었다. VRE 항균제 감수성 검사에서 tetracyclin을 제외한 항생제에 높은 내성을 지니고 있었고, 검출된 cephalosporin의 투여비율이 가장 높았으며 검출 후에는 teicoplanin의 투여비율이 증가함을 볼 수 있었고, teicoplanin에 대한 항균제 감수성 결과에 따른 투여비율의 차이는 없었다. 또한, ICU 환자군이 Non ICU 환자군에 비해 중복감염의 경우가 많았다. 결 론 : 증가하고 있는 VRE의 집단 발생과 전파에 이은 합병증을 막기 위해서, 본 연구에서 ICU 단위로 분류하였던 병동과 같은 병원내 VRE의 상재 위험지역에 대한 집중 감시조사와 이의 관리를 위한 여러 행정적 문제의 해결, 적절한 항생제의 사용과 철저한 관리가 필요하리라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1226-1231
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• 2014

The rare actinomycete Pseudonocardia autotrophica was previously shown to produce a solubility-improved toxicity-reduced novel polyene compound named $\underline{N}ystatin$-like $\underline{P}seudonocardia$ $\underline{P}olyene$ (NPP). The low productivity of NPP in P. autotrophica implies that its biosynthetic pathway is tightly regulated. In this study, $wblA_{pau}$ was isolated and identified as a novel negative regulatory gene for NPP production in P. autotrophica, which showed approximately 49% amino acid identity with a global antibiotic down-regulatory gene, wblA, identified from various Streptomycetes species. Although no significant difference in NPP production was observed between P. autotrophica harboring empty vector and the S. coelicolor wblA under its native promoter, approximately 12% less NPP was produced in P. autotrophica expressing the wblA gene under the strong constitutive $ermE^*$ promoter. Furthermore, disruption of the $wblA_{pau}$ gene from P. autotrophica resulted in an approximately 80% increase in NPP productivity. These results strongly suggest that identification and inactivation of the global antibiotic down-regulatory gene wblA ortholog are a critical strategy for improving secondary metabolite overproduction in not only Streptomyces but also non-Streptomyces rare actinomycete species.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.659-664
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• 2010

The present study was to investigate the effect of the transition from conventional to organic dairy farming on the antimicrobial resistant pattern of pathogens in milk. A farm with tie-stall management, with an average herd size of 20 milking cows, was selected based on the owner' willingness to accept, for at least 6 months, the highly restricted protocol developed in this study. Comparisons of bacterial isolates and antimicrobial susceptibilities before changing to an organic farm system (BEFORE) and for 6 months after (AFTER) operating the experimental organic farm system were performed by Fisher's Exact Chi-square tests. Significant levels were defined at p<0.05. During the AFTER period, average frequency of antibiotic treatment was decreased from more than 3 cases/month to less than 1 case/month during which the antibiotic use was authorized only by the veterinarian. In total, 92 and 70 quarter milk samples from 24 and 18 cows during BEFORE and AFTER, respectively, were included in the study. Overall, isolates ranged from a non-resistant level for cephazolin to a very high resistant level to streptomycin (64.71% to 95.45%). Percentages of antimicrobial resistant isolates during BEFORE were significantly higher than during AFTER for ampicillin (43.48% and 5.88%, respectively) and streptomycin (95.45% and 64.71%, respectively). In conclusion, percentages of antimicrobial resistant isolates were decreased after 6 months of operating as an organic farm system.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.246-253
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• 2004

The prevalence, genotype for antibiotic resistance and antibiotic susceptibility of vancomycin resistant enterococci (VRE) were determined. And molecular typings of the Enterococcus faecium isolates were analyzed. Prevalence of VRE in chickens, healthy children and intensive care unit (ICU) patients was 41.6％,7.9％, and 20.4％, respectively. Forty out of 54 isolates from chicken intestines, and 9 out of 11 from ICU patients were identified as Enterococcus faecium. Eleven out of 13 isolates from non-hospitalized young children were E. gallinarium. Twelve strains of E. faecalis were isolated from chicken intestines. The gene for the antibiotic resistance in E. faecium, and E. faecalis was vanA, while that in E. gallinarium was vanC1. E. faecium isolates were resistant to most of antibiotics except ampicillin and gentamicin. Molecular typing of the E. faecium strains obtained by pulse field gel electrophoresis and repetitive sequence-based PCR suggest that VRE transmit horizontally from poultry to humans, especially young children, via the food chains in Korea.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.34-35
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• 1993

The Development of new asymmetric induction methods useful for syntheses of biologically active natural products and drugs, using C4-chiral 1,3-th-iazolidine-2-thiones, has been a recent focus of interest. 1-8) The present account describes the significance of particular heterocycles in the synthetic development of new 1${\beta}$-substituted carbapenems. A fungal metabolite, (＋)-thienamycin (1) has attracted one's attention as a hopeful candidate for new-generation antibiotic drugs because of its strong antimicrobial activities and wide antimicrobial spectra due to the extensive inhibition against various ${\beta}$-lactamases. However, it has been serious problems toward a practically useful drug that (＋)-thienamycin is fairly labile in the solution and can be metabolized by renal dehydropept- idase-I (DHP-I). Recently, a Merck Sharp ＆ Dohme research group exploited a non-natural ${\beta}$-lactam, imipenem (2) which has been appeared in the drug market as the first carbapenem-type antibiotic drug. 9) However 2 must be used with a DHP-I inhibitor, cilastatin sodium (3).9) Thus, a 1,${\beta}$-methyl- carbapenem derivative 4 has been disclosed by the same group. 10) It seems to be more hopeful candidate as a new-generation antibiotic because it can directly resist against metabolism by the renal DHP-1 without an enzyme inhibitor 3. 10)

• Clinical and Experimental Pediatrics
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• 제48권3호
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• pp.235-250
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• 2005

Acute diarrhea is one of the most common diseases that are seen in pediatric patients. In the management of acute diarrhea, several differential diagnostic criteria should be considered based on clinical and/or laboratory findings. These criteria include : (1) normal variant stool versus diarrhea (2) infectious versus non-infectious condition and (3) bacterial versus non-bacterial etiology. The use of antibiotics should be considered to manage diarrhea caused by bacteria accompanying fever and bloody diarrhea in the following cases : (1) patients with serious clinical course, (2) under three months, (3) immunocompromised patients, (4) patients with nutritional deficiency and (5) patients presenting with moderate-to-severe dehydration. In patients presenting with the symptoms suspected to be bacterial origin, whose clinical course is not serious, antibiotic therapy is not necessary. These patients are easily manageable at OPD level. Moreover, except for some cases in which the use of antibiotics is inevitable, pediatric diarrhea can be managed by providing the suitable foods alone with no necessity of other specific drugs. Accordingly, it is crucial not so much to depend on the drugs as to provide appropriate foods including oral rehydration solution(ORS) with no further episodes of diarrhea. Special attention should be paid to the fact that younger pediatric patients will undergo nutritional deficiency unless acute diarrhea is properly managed.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10933-10935
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• 2015

Background: Many scientists have reported Candida species to be of great concern because of the high frequency that they colonize and infect human hosts, particularly cancer patients. Moreover, in the last decades Candida species have developed resistance to many antifungal agents. Based on this, we aimed to identify and determine the prevalence of Candida spp from blood culture bottles among cancer patients and their antifungal resistance pattern. Materials and Methods: From the blood culture bottles isolation and identification of the Candida spp were performed by conventional microbiological techniques. The in vitro antibiotic resistance pattern of the isolates was determined by CLSI guidelines. Genomic DNA was isolated and amplified. Each gene was separated by agar gel electrophoresis. Results: Identification of Candida spp was based on the presence of yeast cells in direct examination, culture and DNA extraction. Of the 68 blood samples collected during the study period (April 2013 to October 2013), five (7.35%) were positive for the presence of Candida spp, 2 (40%) of which were identified as Candida albicans and 3 (60%) were Candida non-albicans. Conclusions: High resistance to amphotricin B was observed among all the Candida non-albicans isolates. Regular investigations into antifungal resistance will help us to get an updated knowledge about their antibiotic resistance pattern which may help the physician in selecting the antibiotics for empirical therapy.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제38차 학술발표대회
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• pp.63-65
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• 2008

The functional non-woven fabrics have been applied in various industry fields, such as clothing, hygiene, environment, medical and so forth. The functional non-woven fabrics were manufactured by meltblown and finishing processes. These functional non-woven fabrics were made of 2,000ppm nano-silver resin composite and polypropylene resin. Silver is one of the most universal antimicrobial substances. Nano-technology enables us to expand the surface area of silver particles markedly. Nano-silver particles were successfully produced less than 10nm in size. The functional non-woven fabrics including nano-silver particles showed excellent antibacterial activities against Staphylococcus aureus(ATCC 6538) and Klebsieila pneumoniae (ATCC 4352). From the results, nano-silver particels probably will be available as a good and safe antibiotic alternative.

• 한국축산식품학회지
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• 제38권1호
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• pp.203-208
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• 2018

The objective of this study was to investigate the pathogenicity and antimicrobial resistance of foodborne pathogens isolated from farmstead cheeses. Twenty-seven isolates, including 18 Bacillus cereus, two Escherichia coli, and seven Staphylococcus aureus, were subjected to polymerase chain reaction (PCR) to detect virulence genes and toxin genes, and the antibiotic resistances of the isolates were determined. All E. coli isolates were determined by PCR to be non-pathogenic. Among the 18 B. cereus isolates, 17 isolates (94.4%) were diarrheal type, as indicated by the presence of nheA, entFM, hbIC, cytK and bceT genes, and one isolate (5.6%) was emetic type, based on the presence of the CER gene. Among the seven S. aureus isolates, three (42.9%) had the mecA gene, which is related to methicillin-resistance. Most B. cereus isolates (94.7%) showed antibiotic resistance to oxacillin and penicillin G, and some strains also showed resistance to ampicillin (26.3%), erythromycin (5.3%), tetracycline (10.5%), and vancomycin (5.3%). These results indicate that microbial food safety measures for farmstead cheese must be implemented in Korea because antibiotic resistant foodborne pathogens, with resistance even to vancomycin, harboring virulence genes were found to be present in the final products of farmstead cheese.

• 한국미생물·생명공학회지
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• 제29권1호
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• pp.1-11
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• 2001

Lactic acid bacteria (LAB) are widely used for various food fermentation. With the recent advances in modern biotechnology, a variety of bio-products with the high economic values have been produced using microorganisms. For molecular cloning and expression studies on the gene of interest, E. coli has been widely used mainly because vector systems are fully developed. Most plasmid vectors currently used for E, coli carry antibiotic-resistant markers. As it is generally believed that the antibiotic resistance markers are potentially transferred to other bacteria, application of the plasmid vectors carrying antibiotic resistance genes as selection markers should be avoided, especially for human consump-tion. By contrast, as LAB have some desirable traits such that the they are GRAS(generally recognized as safe), able to secrete gene products out of cell, and their low protease activities, they are regarded as an ideal organism for the genetic manipulation, including cloning and expression of homologous and heterologous genes. However, the vec-tor systems established for LAB are stil insufficient to over-produce gene products, stably, limiting the use of these organisms for industrial applications. For a past decade, the two popular plasmid vectors, pAM$\beta$1 of Streptococcus faecalis and pGK12 theB. subtilis-E. coli shuttle vector derived from pWV01 of Lactococcus lactis ssp. cremoris wg 2, were most widely used to construct efficient chimeric vectors to be stably maintained in many industrial strains of LAB. Currently, non-antibiotic markers such as nisin resistance($Nis^{r}$ ) are explored for selecting recombi-nant clone. In addition, a gene encoding S-layer protein, slp/A, on bacterial cell wall was successfully recombined with the proper LAB vectors LAB vectors for excretion of the heterologous gene product from LAB Many food-grade host vec-tor systems were successfully developed, which allowed stable integration of multiple plasmid copies in the vec-mosome of LAB. More recently, an integration vector system based on the site-specific integration apparatus of temperate lactococcal bacteriophage, containing the integrase gene(int) and phage attachment site(attP), was pub-lished. In conclusion, when various vector system, which are maintain stably and expressed strongly in LAB, are developed, lost of such food products as enzymes, pharmaceuticals, bioactive food ingredients for human consump-tion would be produced at a full scale in LAB.