• Journal of Microbiology and Biotechnology
• /
• v.20 no.4
• /
• pp.798-802
• /
• 2010

Recently, a total of 74 Staphylococcus pseudintermedius isolates were collected from clinical cases of canine pyoderma and otitis externa in Korea. In this study, we examined in vitro fluoroquinolone resistance among those isolates using a standard disc diffusion technique. The results demonstrated that, except for one isolate, approximately 18.9% to 27.0% of the isolates possessed bacterial resistance to both veterinary- and human-licensed fluoroquinolones including moxifloxacin (18.9% resistance), levofloxacin (20.3% resistance), ofloxacin (24.3% resistance), ciprofloxacin (25.7% resistance), and enrofloxacin (27.0% resistance). Most surprisingly, 14 out of 74 (18.9%) isolates were resistant to all the five fluoroquinolones evaluated. Moreover, a PCR detection of the methicillin resistance gene (mecA) among the 74 isolates revealed that 13 out of 25 (52.0%) mecApositive isolates, but only 7 out of 49 (14.3%) mecA-negative isolates, were resistant to one or more fluoroquinones. Taken together, our results imply that bacterial resistance to both veterinary- and human-use fluoroquinolones becomes prevalent among the S. pseudintermedius isolates from canine pyoderma and otitis externa in Korea, as well as that the high prevalence of the mecA-positive S. pseudintermedius isolates carrying multiple fluoroquinolones resistance could be a potential public health problem.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.3
• /
• pp.1105-1109
• /
• 2015

Chemoresistance is the most common cause of chemotherapy failure during breast cancer (BCA) treatment. It is generally known that the mechanisms of chemoresistance in tumors involve multiple genes and multiple signaling pathways,; if appropriate drugs are used to regulate the mechanisms at the gene level, it should be possible to effectively reverse chemoresistance in BCA cells. It has been confirmed that chemoresistance in BCA cells could be reversed by ginsenoside Rh2 (G-Rh2). Preliminary studies of our group identified some drugresistance specific miRNA. Accordingly, we proposed that G-Rh2 could mediate drug-resistance specific miRNA and corresponding target genes through the gene regulatory network; this could cut off the drug-resistance process in tumors and enhance treatment effects. G-Rh2 and breast cancer cells were used in our study. Through pharmaceutical interventions, we could explore how G-Rh2 could inhibit chemotherapy resistance in BCA, and analyze its impact on related miRNA and target genes. Finally, we will reveal the anti-resistance molecular mechanisms of G-Rh2 from a different angle in miRNA-mediated chemoresistance signals among cells.

• Journal of Microbiology
• /
• v.33 no.4
• /
• pp.339-343
• /
• 1995

We isolated a 10 kb Bam HI fragment originated from the chromosome of a $H_2O$$^2$-resistant mutant strain of Streptomyces coelicolor, which confer $H_2O$$^2$-resistance to S. lividance upon transformation. Among various subclones ot 10kb Bam HI fragment tested for their $H_2O$$^2$-resistant phenotype in S. lividans, a subclone containing 5.2 kb Bam HI-BglII fragment was found to be responsible for $H_2O$$^2$-resistance. The plasmid containing this 5.2 kb fragment was then transformed into S. coellicolor A3(2) at early and tested for their phenotype of $H_2O$$^2$-resistance and the change in various enzymes whose activity can be stained in the gel. We found out that the 5.2 kb insert DNA conferred $H_2O$$^2$-resisstance in S. coelicolor A3(2) at early phase of cell growth. The presence of this DNA also resulted in higher level of peroxidase compared with the wild type cell containing parental vector (pIJ702) only. Esterase activity was also higher in this clone. However, alcohol dehydrogenase activity decreased compared with the wild type. These results suggest that the presence of a gene in 5.2 kb BamHI-BglII DNA fragment causes multiple changes in S. coelicolor related to its response against hydrogen peroxide. The result also implies that not only peroxidase but also esterase may function in the defencse meahsnism agianst $H_2O$$^2$-.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.1009-1014
• /
• 2016

It is not clear how gene polymorphisms affecting drugs can contributes totheir efficacy in multiple myeloma (MM). We here aimed to explore associations among gene polymorphisms of tumor necrosis factor alpha (TNFalpha), nitric oxide synthesis 3 (NOS3) and multi-drug resistance 1 (MDR1), clinical parameters, prognosis and survival in MM patients treated with VAD (vincristine-adriamycine-dexamethasone), MP (mephalane-prednisolone), autolougus stem cell transplantation (ASCT), BODEC (bortezomib-dexamethasone-cyclophosphamide) and TD (thalidomide-dexamethasone). We analyzed TNFalpha, NOS 3 and MDR1 in 77 patients with MM and 77 healthy controls. The genotyping was performed with PCR and/or PCR-RFLP. There was no clinically significant difference between MM and control groups when TNFalpha (-238) and (-857) and MDR1 gene polymorphisms were studied. However, the TNFalpha gene polymorphism (-308) GG genotype (p=0.012) and NOS3 (+894) TT genotype (p=0.008) were more common in the MM group compared to healthy controls. NOS3 (VNTR) AA (p=0.007) and NOS3 (+894) GG genotypes (p=0.004) were decreased in the MM group in contrast. In conclusion, the NOS3 (+894) TT and TNFalpha (-308) GG genotypes may have roles in myeloma pathogenesis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.15
• /
• pp.6663-6668
• /
• 2015

Background: Treatment failure in leukemia is due to either pharmacokinetic resistance or cell resistance to drugs. Materials and Methods: Gene expression of multiple drug resistance protein (MDR-1), multidrug resistance-related protein (MRP) and low resistance protein (LRP) was assessed in 45 pediatric ALL cases and 7 healthy controls by real time PCR. The expression was scored as negative, weak, moderate and strong. Results: The male female ratio of cases was 2.75:1 and the mean age was 5.2 years. Some 26/45 (58%) were in standard risk, 17/45(38%) intermediate and 2/45 (4%) in high risk categorie, 42/45 (93%) being B-ALL and recurrent translocations being noted in 5/45 (11.0%). Rapid early response (RER) at day 14 was seen in 37/45 (82.3%) and slow early response (SER) in 8/45 (17.7%) cases. Positive expression of MDR-1, LRP and MRP was noted in 14/45 (31%), 15/45 (33%) and 27/45 (60%) cases and strong expression in 3/14 (21%), 11/27 (40.7%) and 8/15 (53.3%) cases respectively. Dual or more gene positivity was noted in 17/45 (38%) cases. 46.5 % (7/15) of LRP positive cases at day 14 were in RER as compared to 100% (30/30) of LRP negative cases (p<0.05). All 8 (100%) LRP positive cases in SER had strong LRP expression (p=<0.05). Moreover, only 53.3% of LRP positive cases were in haematological remission at day 30 as compared to 100% of LRP negative cases (p=<0.05). Conclusions: Our study indicated that increased LRP expression at diagnosis in pediatric ALL predicts poor response to early treatment and hence can be used as a prognostic marker. However, larger prospective studies with longer follow up are needed, to understand the clinical relevance of drug resistance proteins.

• Journal of the Korean Society of Tobacco Science
• /
• v.28 no.2
• /
• pp.100-110
• /
• 2006

A mutant of Potato vims Y (PVY) was occurred in PVY resistance flue-cured tobacco breeding line KF0402 $(TC1146{\times}KF117)$ showing vein necrosis at Suwon in Korea. This isolate, PVY-SWM, was differentiated from other PVY based on biological properties and nucleotide sequence analyses of coat protein gene. PVY-SWM caused typical symptoms on 21 indicator plants as compared to the PVY-TOJC37. Remarkably, the PVY-SWM induced distinctly different symptom of systemic vein necrosis on tobacco cultivars V.SCR, PBD6, TN86, TN90, Virgin A Mutant (VAM), Wislica, NC744, KB108 and KB111, which were reported to have the recessive potyvirus resistance gene va. In RT-PCR assays with specific primers for detection of PVY, a single band of about 800bp in length was produced. The amplified DNA was cloned and the nucleotide sequence was determined. The coat protein gene of PVY-SWM showed 88.4%-99.0% and 92.5%-98.5% identities to the 12 different PVY isolates of Genbank Database at the nucleotide and amino acidi respectively. Multiple alignments as well as cluster dendrograms of PVY-SWM isolate revealed close phylogenetic relationship to the $PVY^{NTN}$ subgroup.

• Food Science of Animal Resources
• /
• v.37 no.5
• /
• pp.670-681
• /
• 2017

The aim of this study was to isolate enterococci in Sucuk, a traditional Turkish dry-fermented sausage and to analyze isolates for their biodiversity, antibiotic resistance patterns and the presence of some antibiotic resistance genes. A total of 60 enterococci strains were isolated from 20 sucuk samples manufactured without using a starter culture and they were identified as E. faecium (73.3%), E. faecalis (11.7%), E. hirae (8.3%), E. durans (3.3%), E. mundtii (1.7%) and E. thailandicus (1.7%). Most of the strains were found resistant to rifampin (51.67%) followed by ciprofloxacin (38.33%), nitrofurantoin (33.33%) and erythromycin (21.67%). All strains were found susceptible to ampicillin. Only E. faecium FYE4 and FYE60 strains displayed susceptibility to all antibiotics. Other strains showed different resistance patterns to antibiotics. E. faecalis was found more resistant to antibiotics than other species. Most of the strains (61.7%) displayed resistance from between two and eight antibiotics. The ermB, ermC, gyrA, tetM, tetL and vanA genes were detected in some strains. A lack of correlation between genotypic and phenotypic analysis for some strains was detected. The results of this study indicated that Sucuk manufactured without using a starter culture is a reservoir of multiple antibiotic resistant enterococci. Consequently, Sucuk is a potential reservoir for the transmission of antibiotic resistance genes from animals to humans.

• Korean Journal of Microbiology
• /
• v.54 no.3
• /
• pp.286-288
• /
• 2018

Moraxella osloensis NP7 was isolated from human skin of a collage male and showed resistance to ${\beta}-lactam$ and aminoglycoside antibiotics. Herein, we report the complete whole-genome sequence and gene annotations of M. osloensis NP7. It possesses single circular chromosome and seven plasmids. Chromosome is 2,389,582 bp in length with the G + C content of 43.9% and encodes 2,065 protein-coding genes. The combined seven plasmids are 654,202 bp in size with the average G + C content of 40.5% and code for a total of 667 protein-coding genes. The chromosome of NP7 strain contains four ribosomal RNA operon copies, one transfer-messenger RNA gene, forty-seven tRNA genes, three riboswitch genes and three CRISPR arrays. Additional CRISPR array is found in the plasmid pNP7-1. The genes conferring resistance to ${\beta}-lactam$ and aminoglycoside antibiotics were predicted to reside in the plasmid pNP7-1.

• Fisheries and Aquatic Sciences
• /
• v.21 no.2
• /
• pp.3.1-3.10
• /
• 2018

Background: Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003-2016. Main body: V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003-2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin) or trh (tdh-related hemolysin) genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion: This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.1
• /
• pp.45-53
• /
• 2010

We have developed an efficient and precise method for genome manipulations in Bacillus subtilis that allows rapid alteration of a gene sequence or multiple gene sequences without altering the chromosome in any other way. In our approach, the Escherichia coli toxin gene mazF, which was used as a counter-selectable marker, was placed under the control of a xylose-inducible expression system and associated with an antibiotic resistance gene to create a "mazF-cassette". A polymerase chain reaction (PCR)-generated fragment, consisting of two homology regions joined to the mazF-cassette, was integrated into the chromosome at the target locus by homologous recombination, using positive selection for antibiotic resistance. Then, the excision of the mazF-cassette from the chromosome by a single-crossover event between two short directly repeated (DR) sequences, included in the design of the PCR products, was achieved by counter-selection of mazF. We used this method efficiently and precisely to deliver a point mutation, to inactivate a specific gene, to delete a large genomic region, and to generate the in-frame deletion with minimal polar effects in the same background.