• Journal of Wetlands Research
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• v.16 no.2
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• pp.269-274
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• 2014

The purpose of this study is to compare CT (disinfectant concentration * time) values in removing the antibiotic resistance bacteria, antibiotic resistance gene and transfer of antibiotic resistance genes. Different concentration of chlorine(C) and contact time(T) according to the removal of antibiotic resistance was calculated for each. As a result, for the 90% removal of antibiotic resistant bacteria, around 176~353 mg min/L CT values are needed. For the removal of the antibiotic resistance gene, 195~372 mg min/L CT values are required. For the 90% reduction of antibiotic resistance gene transfer by chlorine disinfection, 187~489 mg min/L CT values are needed. Based on our results, higher CT value was required for removing antibiotic resistant genes rather than antibiotic resistance bacteria.

• The Microorganisms and Industry
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• v.18 no.3
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• pp.75-80
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• 1992

본 논문에서는 항생제의 생합성 및 내성 유전자에 대한 연구가 산업적으로 이용될 수 있는 길을 제시하기 위하여 첫째로는 이들 유전자를 이용하여 기존 항생제의 생산성을 높일 수 있는 방법과 둘째로는 항생제 생합성 유전자들을 이용한 새로운 물질의 창출에 대한 연구를 중심으로 살펴보고자 한다.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.316-319
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• 2017

The antibiotic resistant genes (ARG) and mobile genetic elements (MGE) were investigated with the effluent of waste-water treatment plant (WWTP), and river waters of upstream and downstream in order to elucidate the effect of effluent on antibiotic resistance in a natural river. Total numbers of 134~183 of ARG and MGE were detected and the abundance of ARG and MGE was 0.063~0.422 copies per one of 16S rRNA gene in three water samples. Effluent sample contained the highest amount of the total number and abundance of ARG and MGE whereas total viable cells were observed in the lowest amount among the three samples. This indicated that the genes were originated from cells died during the wastewater treatment process. In addition, the co-relationship of abundance between ARG and MGE suggested that acquired resistance was a prevalent mechanism among the antibiotic-resistant bacteria existing in WWTP.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.158-161
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• 2015

Bacterial dermatitis is common disease that is necessary to treat with antibiotics. In recent, antibiotic-resistant bacteria is being increased in worldwide. The purpose of the present study was to evaluate the prevalence of resistant genes in Staphylococcus (S.) pseudintermedius isolated from dogs, and to compare the resistant gene profile with the result of antibiotic disc diffusion test. A total of seven S. pseudintermedius was included in the study. Bacterial identification was performed by 16S ribosomal RNA gene sequence analysis. S. pseudintermedius isolates had more than one antibiotic resistant gene (mecA, blaZ and aac(6')/aph(2"). While all isolates were PCR positive to blaZ gene, only two isolates were resistant to amoxicillin/clavulanate. Among five isolates harboring gentamicin resistance, one isolate was negative to aac(6')/aph(2")-targeted PCR. Taken together, the results suggest that resistant gene-targeted PCR and disc diffusion test are complementary to detect antibiotic resistance.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.371-378
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• 2016

An aim of current study was to investigate the prevalence and the mechanism of quinolone-resistance in E. coli isolates obtained from chicken cecum in Korea. In addition, multilocus sequence typing (MLST) was also performed for the molecular characterization of E. coli isolates. In an antimicrobial susceptibility test by the disk diffusion method, the 63.5% (54/85) of E. coli isolates showed the resistance to quinolone group of antimicrobial agents. All of the 54 E. coli isolates showing resistant to quinolone group had sense mutations in gyrA gene and point mutations at the $57^{th}$, $80^{th}$, or $84^{th}$ residues in parC gene were detected in 90.7% of the isolates. Interestingly, E. coli ST was closely related to amino acid substitutions in parE gene. Our results indicated that the long-term use of antimicrobial agents in food-producing animals was strongly associated with a prevalence of antimicrobial resistance in commensal Enterobacteriaceae, suggesting the need for continuous surveillance and monitoring of antimicrobial resistant determinants in bacterial isolates from food animals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.413-419
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• 2021

The purpose of this study was to investigate the ability to treat and prevent infection by multiple Gram-negative bacterial pathogens as a last choice option in the treatment of serious infections in clinical settings. The global spread of extended-spectrum 𝛽-lactamases (ESBLs) and/or carbapenemases in microorganisms are of enormous concern to health services because they are often associated with multi-drug resistance which significantly restricts the antibiotic treatment options. In this study, the antimicrobial resistance profiles of bacteria isolated from South Korean market-derived meat samples were determined by the disc diffusion method. PCR was used to detect the presence of antibiotic resistance genes and ESBL producing genes. In total, we tested 181 isolated colonies from 36 market-derived meat samples. Single PCR and DNA sequencing results revealed that genes blaVIM, blaBIC, blaKPC, and blaSIM were present in the bacteria isolated from retail meat. The bacteria in the meat were separately sequenced and based on alignment, four different bacteria were identified. These findings suggest that bacteria found in retail meats are a reservoir for the spreading of ESBL blaVIM, blaBIC, blaKPC, and blaSIM resistance genes and bacteria strains.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.202-209
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• 2016

This study is aimed to determine the correlation between the toxin gene types and antibiotic resistance from MRSA (methicillin-resistant Staphylococcus aureus). Fifty-two strains of MRSA, between January 2014, and December 2014, were isolated from clinical specimens obtained from 2,664 cases in the intensive care unit of a hospital in Suncheon, Jeonnam, Korea. Genes encoding mecA, enterotoxin (SE), toxic shock syndrome toxin-1 (TSST-1), exfoliative toxin (ET), and Panton-Valentine leukocidin (PVL) were detected by multiplex PCR-mediated amplification using specific primers. Toxin genes (seg and sei) were present in 40 strains (76.9%), followed by tst in 34 strains (65.4%). Other genes (eta, etb, sea, sed, see, seh, sej, and pvl) were not detected. Forty strains (76.9%) of MRSA had 2 or more toxin genes simultaneously; 5 coexistent toxin-genes (seb, sec, seg, sei, tst) were the most common in 28 strains (53.8%), and 6 strains (11.5%) had seg and sei genes. The coexistence of genes were 72.5~100%, showing a high correlation among genes (seb, sec, seg, sei and tst). As strains (seb, sec, tst) that had particular toxin genes (seb, sec, seg, sei, tst) in multiple showed 100% resistance to ciprofloxacin, clindamycin, erythromycin, we were able to find that seb, sec, and tst genes have a close relationship to the aforementioned antibiotics. It showed a higher resistance to ciprofloxacin, clindamycin, erythromycin, and tetracycline compared with strains that had toxin genes independent from multiple toxin genes.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.220-225
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• 2010

Distribution of foodborne E. coli strains, antimicrobial resistant genes and antimicrobial susceptibility have been carried out on E. coli isolated from commercial and cooked foods distributed food in Seoul. Of total 1,313 samples, fifty samples(3.8%) were found E. coli that included one of the ETEC and EPEC, respectively. The serotype of ETEC in seasoning raw meat was E. coli O26 and produced Verotoxin 2. Fifty percentage of total isolates were susceptible to all antimicrobial agents. Specially, there were ampicillin(36%), amoxicillin/clavulanic acid(32%) and tetracycline(22%) etc. Resistant gene (tetB) were found in four tetracycline resistant E. coli strains, and TEM gene was found in one ampicillin resistant E. coli isolate.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.576-582
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• 2019

Staphylococcus pseudintermedius is an opportunistic pathogen in dogs and is recognized as a zoonotic pathogen causing public health concern. Although canine-associated S. pseudintermedius has mainly been recognized for its antimicrobial resistance and ability to cause skin infections in dogs, information on antimicrobial resistance profiles and enterotoxigenicity of S. pseudintermedius in livestock is very limited. In this study, we investigated the prevalence of 18 different staphylococcal enterotoxin (SE) genes and toxic shock syndrome toxin gene (tst-1) in S. pseudintermedius strains isolated from dogs, pigs, and beef cattle. Moreover, antimicrobial resistance profiles of the strains were determined along with the presence of mecA and SCCmec types. Except for one bovine isolate, all S. pseudintermedius isolates from dogs and pigs were resistant to multiple drugs (≥ 4 different drugs). Four out of six canine isolates were methicillin resistant and carried SCCmec type V. In addition, 11 different SE genes (seb, sec, see, seg, sei, sej, sel, seo, sep, seq, and seu) and tst-1 were identified in S. pseudintermedius isolates from dogs, pigs, and beef cattle. Most S. pseudintermedius isolates (83%) harbored multiple SE genes, and sel (42%) and sep (42%) were most frequently detected in the isolates. Our results suggested that S. pseudintermedius isolates from livestock and companion animals may serve as a reservoir for SE genes and antimicrobial resistance.

• Journal of Life Science
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• v.23 no.5
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• pp.703-709
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• 2013

The aim of this study was to investigate the prevalence of Extended-spectrum ${\beta}$-lactamase (ESBL) gene and quinolone resistance determinant (qnr) and the pattern of antibiotic resistance in the ESBL-producing Escherichia coli clinical isolates. The 42 ESBL-producing strains from total 274 isolates were detected using a double disk synergy test. They were isolated from various specimens, such as urine (28 strains), sputum (6 strains), pus (3 strains), wound (2 strains), blood (2 strains), and tissue (1 strain). Using the PCR with the specific primers ESBL, ESBL and qnr gene types were determined. Thirty-five strains possessed one or two ESBL genes. CTX-M-1 type was the most abundant followed by CTX-M-9 type and TEM, but SHV, CTX-M-2, and CTX-M-8 gene types were not detected. qnr gene types were detected from ten isolates in the order of qnrB4, qnrB1, and qnrS. Coexistence of ESBL and qnr genes was found. ESBL-producing isolates showed high resistance against some antibiotics, such as cefotaxmie (80.0%), levofloxacin (82.9%), and ampicillin (100%). Neither a synergy effect from the coexistence of ESBL and qnr genes on antibiotic resistance nor a correlation between the production of qnr gene and quinolone resistance were found.