• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1426-1432
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• 2018

Staphylococcus aureus causes a broad variety of diseases. The spread of multidrug-resistant S. aureus highlights the need to develop new ways to combat S. aureus infections. Sortase A (SrtA) can anchor proteins containing LPXTG binding motifs to the bacteria surface and plays a key role in S. aureus infections, making it a promising antivirulence target. In the present study, we used a SrtA activity inhibition assay to discover that isovitexin, a Chinese herbal product, can inhibit SrtA activity with an $IC_{50}$ of $28.98{\mu}g/ml$. Using a fibrinogen-binding assay and a biofilm formation assay, we indirectly proved the SrtA inhibitory activity of isovitexin. Additionally, isovitexin treatment decreased the amount of staphylococcal protein A (SpA) on the surface of the cells. These data suggest that isovitexin has the potential to be an anti-infective drug against S. aureus via the inhibition of sortase activity.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3219-3222
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• 2011

Three types of ${\beta}$-ketoacyl acyl carrier protein synthase (KAS) are important for overcoming the bacterial resistance problem. Recently, we reported the discovery of a antimicrobial flavonoid, YKAF01 (3,6-dihydroxyflavone), which exhibits antibacterial activity against Gram-positive bacteria through inhibition of ${\beta}$-ketoacyl acyl carrier protein synthase III (KAS III). In this report, we suggested that YKAF01 can be an inhibitor ${\beta}$-ketoacyl acyl carrier protein synthase I (KAS I) with dual inhibitory activity for KAS I as well as KAS III. KAS I is related to the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and can be a good therapeutic target of designing novel antibiotics. We performed docking study of Escherichia coli KAS I (ecKAS I) and YKAF01, and determined their binding model. YKAF01 binds to KAS I with high binding affinity ($2.12{\times}10^6$) and exhibited an antimicrobial activity against the multidrug-resistant E. coli with minimal inhibitory concentration (MIC) value of 512 ${\mu}g$/mL. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• 한국식품영양학회지
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• 제26권1호
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• pp.132-136
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• 2013

Antimicrobial resistance and multi-drug resistance patterns have been carried out on total of 210 isolated of Salmonella spp. and pathogenic E. coli isolated from food poisoning patients on January through December 2012 in Incheon, Korea. The highest percentage of antibiotics resistance was found to the following antimicrobial agents: tetracycline 43.8%, ampicillin 34.8%, nalidixic acid 23.8%, sulfamethoxazole/trimethoprim and chloramphenicol 12.4%, and ampicillin/sulbactam 11.4%. The highest percentage of resistance was 37.5% to ampicillin for Salmonella spp. and 59.0% to tetracycline for pathogenic E. coli. Overall the multidrug resistance rates of 1 drug was 26.2%, 2 drugs 9.0%, 3 drugs 9.5%, 4 drugs 7.1%, and 5 or more drugs 12.46%. The multi-drug (MDR) strains to four or more antimicrobial agents among the resistant organisms were quite high: 15.9% and 22.1% for Salmonella spp. and pathogenic E. coli, respectively. The study implies that limitation of unnecessary medication use is pertinent in order to maintaining the efficacy of drugs.

• 식품보건융합연구
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• 제6권5호
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• pp.1-10
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• 2020

Cellulitis in broiler chickens is one of the economically important problems that facing the broiler industry due to the presence of the lesion leads to condemnation of part of /or the entire carcasses. Broiler with cellulitis lesions showed lower body weight. Cellulitis was recorded on different body regions including the head, dorsum, thighs, breast, legs, and abdomen. Cellulitis results from the invasion of subcutaneous (s.c.) tissues by bacteria through disruption of skin integrity. Lesions revealed the existence of the characteristic s.c colored exudate varies from yellowish to green, which were either serosanguineous, fibrinous s.c exudate yellowish, greenish or suppurative. Many bacterial isolates including E. coli, Staphylococci, Clostridia, Aeromonas spp., Enterobacter spp., Proteus mirabilis, P. aeruginosa, and Streptococci were isolated from the lesion. Chickens exposed to immunosuppression proved to have a greater probability of developing cellulitis. The condition was experimentally induced by s.c inoculation of 25-day-old broiler chickens with E. coli, S. aureus and clostridia. Usually, bacterial isolates were multidrug-resistant. The usage of Bifidobacterium bifidum or antibiotic with avoiding immunosuppression can reduce lesion and condemnation rate resulted from cellulitis. The objective of this review is to collect different literature written about cellulitis to be available to students, researchers, and veterinarians in poultry practical.

• 대한수의학회지
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• 제61권3호
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• pp.26.1-26.8
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• 2021

Acinetobacter is a bacteria found in the environment and clinical specimens, causing nosocomial infection and antimicrobial resistance (AMR) threats. This study examined the prevalence, species, and AMR characteristics of Acinetobacter isolated from surgical practice and the laboratory dog husbandry room environments (n = 235) at Rajamangala University of Technology Tawan-ok veterinary hospital during 2018-2019. The prevalence of Acinetobacter in the laboratory dog husbandry room and veterinary belongings were 2.55% and 0.43%, respectively. Species determination was Acinetobacter hemolyticus (2.13%) and Acinetobacter baumannii (0.43%) from environments in the laboratory dog husbandry room, and Acinetobacter junii (0.43%) from the shoes used in the surgical practice room. AMR was observed in both study environments and the specimens sent to the Veterinary Diagnostic Center. These isolates had a high resistant percentage to amoxicillin-clavulanic acid (84.62%), sulfamethoxazole-trimethoprim (61.54%), and cephalexin (53.85%) but were susceptible to imipenem. Compared to the isolates recovered from the clinical specimens, most isolates derived from environments exhibited multidrug resistance and shared correlated resistance patterns. These results highlight the need for sanitization in the dog husbandry room. Furthermore, the AMR results can be used as a preliminary baseline for studying AMR Acinetobacter contamination in animals and their environments.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.141-147
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• 2023

Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

• International Journal of Advanced Culture Technology
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• 제12권1호
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• pp.190-201
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• 2024

This study examined the effect of the distance Infection Control Education Program (ICEP), developed based on the ADDIE model, on infection control knowledge, attitude, and performance among care workers in long-term care facilities nationwide. The program, developed based on the ADDIE model, was applied to 173 care workers directly responsible for nursing care of elderly residents in lomg-term care facilities. The distance ICEP for care workers was conducted through the website and lasted 30 minutes for each of the eight topics. To determine the effectiveness of the education, infection control knowledge, attitude, performance, and satisfaction were surveyed before and four weeks after the program. Differences in infection control knowledge, attitude, and performance before and after the distance ICEP were assessed by a t-test. A significant difference was observed in knowledge and infection control performance after the distance ICEP was administered to care workers. In the sub-domains of infection control performance, overall understanding of infection, regular infection control education, infection control by special pathogen (multidrug-resistant bacteria, tuberculosis, tick-borne infectious diseases), and detailed infection control education by infection site (pressure ulcers and urinary tract infections) were significantly improved. Infection control knowledge and performance improved through the distance ICEP applied to care workers. Satisfaction also displayed high scores on most items and indicated that it was helpful for infection control in facilities, confirming the effectiveness of infection control education. Based on the survey of care workers nationwide, the infection education program can be effectively used for care workers in the future.

• 한국미생물·생명공학회지
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• 제49권4호
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• pp.519-527
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• 2021

본 연구에서는 국내 건강한 산모의 모유에서 분리한 E. faecalis BMSE-HMP 4주의 용혈여부와 다제내성 균에 대한 항용혈 효능 및 항균 효과를 확인하였다. 분리 균주의 효소 활성을 측정 결과, E. faecalis BMSE-HMP 4주는 지질에 대한 가수분해 효소인 esterase 및 esterase lipase에 대한 활성이 우수하였다. 용혈여부를 확인한 결과, 분리균 모두 용혈반응이 나타나지 않았다. 또한 용혈을 일으키는 다제내성 균주에 대한 항용혈 효능을 검토한 결과, S. aureus CCARM 3855에 대한 항용혈 효능은 BMSE-HMP002가 75.71 ± 10.00%로 가장 높았으며, E. coli DC 2 CCARM 0238과 P. aeruginosa CCARM 0223에 대한 항용혈 효능은 BMSE-HMP001이 각각 76.92 ± 2.99%와 87.93 ± 1.93%로 가장 높게 나타났다. 다제내성균 Staphylococcus spp., Escherichia spp., Pseudomonas spp., Salmonella spp., Klebsiella spp. 및 Enterobacter spp.에 대한 항균활성을 검토한 결과, E. faecalis BMSE-HMP 4주는 그람 양성균주와 그람 음성균주에서 모두 항균력을 보였으며, 분리균 4주 중에서는 BMSE-HMP001과 BMSE-HMP002가 가장 우수한 결과를 보였다. 본 연구에서는 모유유래 유산균 E. faecalis BMSE-HMP 4주의 안전성과 다제내성 균에 의한 용혈 및 항균 효과를 검토하여 유용 유산균으로써 가능성을 확인하였으며, Enterococcus 균주는 항생제 내성 유전자 및 독성 유전자가 없는 경우에 한하여 사용이 가능한 것으로 고시된 바와 같이 본 연구에서 분리한 모유유래 유산균 E. faecalis BMSE-HMP 4주의 항생제 내성 및 독성에 대한 추가적인 연구를 통해 안전성에 대한 입증이 필요할 것으로 생각된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권5호
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• pp.436-446
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• 2006

The purpose of this study was to isolate and identify the bacteria in chronic maxillary sinusitis (CMS) lesions from 3 patients and to determine the antimicrobial susceptibility of them against 10 antibiotics. One of them was odontogenic origin and the others were non-odontogenic origin. Pus samples were collected by needle aspiration from the lesions and examined by culture method. Bacterial culture was performed in three culture systems (anaerobic, CO2, and aerobic incubator). Identification of the bacteria was performed by 16S rRNA gene (16S rDNA) nucleotide sequencing method. To test the sensitivity of the bacteria isolated from the maxillary sinusitis lesions against seven antibiotics, penicillin G, amoxicillin, tetracycline, ciprofloxacin, cefuroxime, erythromycin, clindamycin, and vancomycin, minimum inhibitory concentration (MIC) was performed using broth dilution assay. Our data showed that enterobacteria such as Enterobacter aerogenes (30%), Klebsiella pneumoniae (25%), and Serratia marcescens (15%) were predominately isolated from the lesion of non-odontogenic CMS of senile patient (70 year old). Streptococcus spp. (40.3%), Actinomyces spp. (27.4%), P. nigrescens, M. micros, and P. anaerobius strains were isolated in the lesion of odontogenic CMS. In the lesion of non-odontogenic CMS, Streptococcus spp. (68.4%), Rothia spp. (13.2%), and Actinomyces sp. (10.5%) were isolated. The susceptibility pattern of 10 antibiotics was determined according to the host of the bacteria strains ratter than the kinds of bacterial species. Even though the number of CMS was limited as three, these results indicate that antibiotic susceptibility test must be accompanied with treatment of CMS. The combined treatment of two or more antibiotics is better than single antibiotic treatment in the presence of multidrug-resistant bacteria in the CMS lesions.

• 대한수의학회지
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• 제54권2호
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• pp.91-99
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• 2014

An antimicrobial susceptibility test was conducted to compare the resistance rates among Campylobacter spp. isolates from dogs (n = 50) raised under diverse conditions and humans (n = 50). More than 60% of Campylobacter (C.) jejuni from dogs and humans showed resistance to nalidixic acid, enrofloxacin and ciprofloxacin. C. jejuni isolates from humans showed higher resistance to tetracycline (83.3%) and ampicillin (91.3%) than those from dogs. None of the C. jejuni or Campylobacter coli isolates from humans or dogs were resistant to erythromycin. Overall, 85% of Campylobacter spp. isolates showed a multidrug resistant phenotype. Nucleotide sequencing analysis of the gryA gene showed that 100% of $NA^R/CIP^R$ C. jejuni isolates from dogs and humans had the Thr-$86^{th}$-Ile mutation, which is associated with fluoroquinolone resistance. flaA PCR restriction fragment length polymorphism (RFLP) typing to differentiate the isolates below the species level revealed 12 different clusters out of 73 strains. The human isolates belonged to eight different RFLP clusters, while five clusters contained dog and human isolates.