• 한국축산식품학회지
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• 제37권5호
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• pp.670-681
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• 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.

• 한국환경농학회지
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• 제41권4호
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• pp.335-343
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• 2022

BACKGROUND: Antibiotics used in animal husbandry for disease prevention and treatment have resulted in the rapid progression of antibiotic resistant bacteria which can be introduced into the environment through livestock feces/manure, disseminating antibiotic resistant genes (ARGs). In this study, fecal samples were collected from the livestock farms located in Jeju Island to investigate the relationship between microbial communities and ARGs. METHODS AND RESULTS: Illumina MiSeq sequencing was applied to characterize microbial communities within each fecal sample. Using quantitative PCR (qPCR), ten ARGs encoding tetracycline resistance (tetB, tetM), sulfonamide resistance (sul1, sul2), fluoroquinolone resistance (qnrD, qnrS), fluoroquinolone and aminoglycoside resistance (aac(6')-Ib), beta-lactam resistance (bla_TEM, bla_CTX-M), macrolide resistance (ermC), a class 1 integronsintegrase gene (intI1), and a class 2 integrons-integrase gene (intI2) were quantified. The results showed that Firmicutes and Bacteroidetes were dominant in human, cow, horse, and pig groups, while Firmicutes and Actinobacteria were dominant in chicken group. Among ARGs, tetM was detected with the highest number of copies, followed by sul1 and sul2. Most of the genera belonging to Firmicutes showed positive correlations with ARGs and integron genes. There were 97, 34, 31, 25, and 22 genera in chicken, cow, pig, human, and horse respectively which showed positive correlations with ARGs and integron genes. In network analysis, we identified diversity of microbial communities which correlated with ARGs and integron genes. CONCLUSION(S): In this study, antibiotic resistance patterns in human and livestock fecal samples were identified. The abundance of ARGs and integron genes detected in the samples were associated with the amount of antibiotics commonly used for human and livestocks. We found diverse microbial communities associated with antibiotics resistance genes in different hosts, suggesting that antibiotics resistance can disseminate across environments through various routes. Identifying the routes of ARG dissemination in the environment would be the first step to overcome the challenge of antibiotic resistance in the future.

• 수산해양교육연구
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• 제28권2호
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• pp.315-322
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• 2016

This study determined the optimum microalgae species and concentration for growth of small rotifer Proales similis, in community cultures by feeding it several different foods. Four single trials (Tetraselmis suecica, TET; Isochrysis galbana, ISO; Nannochloropsis oculata, NAN; freshwater Chlorella vulgaris, CHL) were conducted at 5 psu and $25^{\circ}C$. The maximum density and specific growth rate (SRG) were highest for rotifer fed CHL reaching 1,075 individuals (inds.)/mL and 0.83 respectively. By contrast, other foods of ISO, NAN and TET resulted in poor growth rates and maximum density. In the freshwater C. vulgaris experiments examining a range of 0.05 to $8.8mg/10^4rotifers$, the growth of rotifer tended to decrease with the amount of supplement. The maximum density and SGR of females was highest at 910 inds./mL and 0.55 respectively, at $0.05mg/10^4rotifers$. These results suggest that the best microalgae species for the culture of P. similis is freshwater C. vulgaris and the optimum concentration is $0.05mg/10^4rotifers$.

• BMB Reports
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• 제57권3호
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• pp.135-142
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• 2024

DNA methylation is one of the most extensively studied epigenetic regulatory mechanisms, known to play crucial roles in various organisms. It has been implicated in the regulation of gene expression and chromatin changes, ranging from global alterations during cell state transitions to locus-specific modifications. 5-hydroxymethylcytosine (5hmC) is produced by a major oxidation, from 5-methylcytosine (5mC), catalyzed by the ten-eleven translocation (TET) enzymes, and is gradually being recognized for its significant role in genome regulation. With the development of state-of-the-art experimental techniques, it has become possible to detect and distinguish 5mC and 5hmC at base resolution. Various techniques have evolved, encompassing chemical and enzymatic approaches, as well as third-generation sequencing techniques. These advancements have paved the way for a thorough exploration of the role of 5hmC across a diverse array of cell types, from embryonic stem cells (ESCs) to various differentiated cells. This review aims to comprehensively report on recent techniques and discuss the emerging roles of 5hmC.

• 한국발생생물학회지:발생과생식
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• 제24권2호
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• pp.101-111
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• 2020

Coiled-coil domain containing 110 (CCDC110, KM-HN-1) is a protein containing C-terminal coiled-coil domain (CCD) which was previously discovered as a member of the human cancer/testis antigen (CTA). In addition, CCDC110 has both nuclear localization signal sequence and the leucine zipper motif. Although the functional role of CCDC110 has yet to be fully identified, the mRNA expression levels of CCDC110 are known to be highly elevated in various cancer types including testis, implying its relevance to cancer pathogenesis. In this study, we first developed several monoclonal antibody (mAb) hybridoma clones targeting CCDC110 and further isolated clone by characterizing for its specificity using immunoblotting and immunoprecipitation approaches with basal parenchymal sperm cells in testis tissue. Next, using these mAbs, we showed that the Tet-inducible overexpression of CCDC110 protein delayed the entry of G2/M phase in U2-OS osteosarcoma cells. Based on these results, we propose that CCDC110 plays a crucial role in cell cycle progression.

• 한국축산식품학회지
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• 제36권3호
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• pp.352-358
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• 2016

The aim of this study was to determine the prevalence of enterococci in cheese samples and to characterize their antimicrobial resistance profiles as well as the associated resistance genes. A total of 139 enterococci were isolated from 99 cheese samples, the isolates were identified as E. faecalis (61.2%), E. faecium (15.1%), E. gallinarum (12.9%), E. durans (5.0%), E. casseliflavis (2.9%) and E. avium (2.9%). The most frequent antimicrobial resistance observed in enterococci isolates was to lincomycin (88.5%), followed by kanamycin (84.2%), gentamycin (low level, 51.1%), rifampin (46.8%) and tetracycline (33.8%). Among the isolates, the frequencies of high level gentamycin and streptomycin resistant enterococci strains were 2.2% and 5.8%, respectively. Apart from the mentioned antibiotics, low levels of resistance to ciprofloxacin, erythromycin and chloramphenicol were found. Moreover no resistance was observed against penicillin and ampicillin. The antimicrobial resistance genes including tetM, tetL, ermB, cat, aph(3’)-IIIa, ant(6)-Ia and aac(6’)-Ieaph(2”)-Ia were found in enterococci from Turkish cheese samples. In the current study, we provided data for antibiotic resistance and the occurrence of resistance genes among enterococci. Regulatory and quality control programs for milk and other dairy products from farms to retail outlets has to be established and strengthened to monitor trends in antimicrobial resistance among emerging food borne pathogens in Turkey.

• Reproductive and Developmental Biology
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• 제28권3호
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• pp.197-202
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• 2004

골다공증 치료제로 이용되고 있는 hPTH는 체내의 혈중 칼슘 농도를 조절하는 인간의 부갑상선 호르몬이다. 본 연구에서는 hPTH를 효율적으로 생산하는 돼지세포를 구축하고자 다양한 retrovirus vector를 이용하였는데 다음과 같은 결과를 관찰하였다. 1) hPTH 유전자의 전이를 확인하기 위해 RT-PCR을 수행한 결과, 형질전환된 모든 돼지세포에서 420 bp의 hPTH에 해당하는 단편을 확인할 수 있었으며, WPRE가 도입되지 않은 실험군보다 WPRE서열이 도입된 실험군에서 더 강한 밴드를 확인하였다. 2) ECLIA 측정 결과 hPTH 유전자가 도입된 모든 세포에서 hPTH가 생성되었으며, 특히 Tet-On system에서는 doxycycline을 처리한 실험군에서 hPTH의 발현이 유도되었음을 확인하였다. 또한 RT-PCR과 ECLIA을 수행하여 hPTH의 도입 여부와 단백질 생산을 비교한 결과, WPRE 서열이 hPTH 유전자의 downstream 위치에 도입된 실험군에서 가장 많은 단백질이 생산됨을 확인할 수 있었다.

• 한국동물위생학회지
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• 제40권3호
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• pp.193-200
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• 2017

This study was carried out to investigate the antimicrobial resistance profiles and resistance genes in 62 Escherichia coli isolated from dogs and cats hospitalized at animal hospitals in Daegu. E. coli isolates showed high resistance to nalidixic acid (46.8%) and ampicillin (45.2%). Resistance to the other antimicrobial agents was less than 30%, and no resistant isolates were detected for imipenem and amikacin. Of the 28 ampicillin-resistant isolates, TEM and CTX-M genes were detected in 16 (57.1%) and 11 (39.3%), respectively. The aadA gene was found in 4 (26.7%) of 15 gentamicin-resistant isolates, and strA-strB gene was found in 10 (66.7%) isolates. The sul I and sul II genes were detected in 11 (61.1%) and 14 (77.8%) of 18 trimethoprim/sulfamethoxazole-resistant isolates, and tetB gene in 9 (81.8%) of 11 minocycline-resistant isolates, and cmlA gene in 2 (22.2%) of 8 chloramphenicol-resistant isolates. The qnrB and qnrS genes were found in 3 (10.3%) and 1 (3.4%) of 28 nalidixic acid-resistant isolates, respectively. Whereas, none of the SHV, CMY-2, tetA, dfr Ia and dfr VII, and qnrA genes were found. Our results show a wide variety of resistance genes in E. coli isolates from dogs and cats. This study also represents the first report of qnrB and qnrS gene producing E. coli isolates from dogs in republic of Korea.

• Journal of Veterinary Science
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• 제21권4호
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• pp.57.1-57.11
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• 2020

Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. Objectives: This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. Methods: A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. Results: Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. Conclusion: This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.

• 한국동물위생학회지
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• 제45권3호
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• pp.171-180
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• 2022

The aim of this study was to investigate the prevalence of antimicrobial resistance and virulence factors in staphylococci isolated from canine otitis externa. A total 295 causative microorganisms were isolated. The most common isolated species were Staphylococcus (S) pseudintermedius (94 isolates) followed by Pseudomonas aeruginosa (60 isolates), S. schleiferi (25 isolates), Escherichia coli (23 isolates) and Proteus mirabilis (20 isolates). Staphylococci isolates were showed high resistance to penicillin (78.6%), erythromycin (55.9%), tetracycline (52.4%), clindamycin (51.7%) and ciprofloxacin (42.8%). Of the 145 staphylococci isolates, 49 (33.8%) methicillin-resistant staphylococci (MRS) were observed, distributed among S. pseudintermedius (n=34), S. schleiferi (n=6), S. epidermis (n=4), S. hominis (n=2), S. aureus, S. caprae and S. saprophyticus (n=1, respectively). Forty-three (87.8%) of 49 MRS and 10 (10.4%) of 96 methicillin-susceptibility staphylococci harbored mecA gene. About 80% of MRS were multidrug-resistant with resistance to at least one antibiotic in three or more antibiotic classes. Resistance genes blaZ (93/114, 81.5%), ermB (35/81, 43.2%), ermC (3/81, 3.7%), aacA-aphD (50/54, 92.5%), tetM (69/76, 90.7%) and tetK (6/76, 7.8%) were detected among resistant isolates. Virulence factors genes lukF and lukS were found in 100%(145/145) and 43.4%(63/145), respectively. Genes encoding ermA, eta, etb and tsst were not detected. To the best of our knowledge, this is the first study which investigated for the presence of genes encoding antimicrobial resistance and staphylococcal toxins in staphylococci isolated from canine otitis externa. A continuous monitoring and surveillance program to prevent antimicrobial resistance in companion animals is demanded.