본 연구는 광주광역시에 유통·판매되고 있는 가금육을 대상으로 식중독 발생 가능성 높은 캠필로박터균의 검출 여부와 분리된 균주의 항생제 내성 및 유전적 특성을 조 사하였다. 전체 307건의 가금육(닭 223건, 오리84건) 중 111건에서 캠필로박터균이 검출(36.2%)되었고 116균주 (Campylobacter jejuni 102균주, Campylobacter coli 14균 주)를 분리하였다. 가금류별 캠필로박터균 검출률은 닭고 기 26.0%, 오리고기 63.1% 이었고, 5건(닭 1건, 오리 4 건)의 시료에서 Campylobacter jejuni, Campylobacter coli 가 동시에 검출되었다. 분리된 균주의 항생제 내성 시험 결과 99균주(85.3%)는 1가지 이상의 항생제에 대하여 내 성을 보였다. 그 중 ciprofloxacin, nalidixic acid에 내성 을 보이는 균주가 각각 98균주(84.5%), 96균주(82.8%)로 가장 많았고, 그 외에 tetracycline (44.0%), gentamicin (2.6%)에 내성을 나타냈다. 분리된 균주의 혈청형 확인 결과, HS2형 20균주, HS15형 11균주, HS19형 9균주, HS8 형 8균주 등이 확인 되었고, HS42형, HS6형, HS53형, HS4A형, HS5형, HS18형, HS12형, HS27형 그리고 HS37 형이 확인 되었다. 따라서 조리 가공 시 교차오염이 발 생하지 않도록 조리기구 등에 대한 위생적 관리와 충분 한 가열 조리 등의 식중독 예방을 위한 주의가 필요할 것으로 생각된다.

An optical fluorescence quenching sensor based on functionally modified iron-doped carbon nanoparticles was designed for the selective and sensitive Cr(VI) ion detection. Multifunctional iron-doped carbon nanoparticles were enclosed in the scaffolds of a promising stable nanocarrier system called hyperbranched polyglycerol (HPG), which has been fluorescently modified with 1-pyrene butyric acid using the Steglich esterification procedure. The therapeutic and diagnostic capabilities were boosted when these nanoparticles were enclosed in the fluorescently modified dendritic structure, HPG. Iron-doped carbon nanoparticles coupled with fluorescently modified hyperbranched polyglycerol can be used as a sensor for metal ions and can then be used to successfully remove them from a sample. Moreover, the synthesised nanoparticles demonstrated promising antimicrobial efficacy against bacteria and fungi. These results are also discussed in detail.

Hesperetin은 Hesperidin에서 유도되는 강한 항산화 기능의 플라보노이드 비당체이다. 본 연구 에서는 Hesperetin과 이의 Cyclodextrin 포접 복합체에 대하여 항산화, 항염증 및 항균 활성을 비교하였다. Hesperetin은 Hesperidin에 효소처리하여 제조되었으며, Hesperetin/Cyclodextrin 포접체는 용매 증류법에 의해 β-Cyclodextrin 및 Hydroxypropyl-β-Cyclodextrin을 사용하여 제조되었다. Hesperetin에 비해 Hesperetin/Hydroxypropyl-β-Cyclodextrin 포접체의 용해도는 93.5배 증가하였고, Hesperetin/β -Cyclodextrin 포접체의 용해도는 22.5배 증가하였다. 항산화 분석에서 Hydroxypropyl-β-Cyclodextrin 포접체는 Hesperetin과 유사한 라디칼 소거 활성능을 보인 반면, β-Cyclodextrin 포접체는 Hesperetin 보 다 약간 낮은 활성을 나타내었다. RAW 264.7 세포에 대한 세포독성은 Hydroxypropyl-β-Cyclodextrin 포접체, β-Cyclodextrin 포접체, Hesperetin의 순으로 세포독성이 낮았다. Hesperetin과 Cyclodextrin 포 접체는 모두 세포내 산화질소(NO), 종양괴사인자-α(TNF-α) 및 인터루킨-6(IL-6)과 같은 염증 매개체 를 감소시켰다. Hesperetin 및 Hydroxypropyl-β-Cyclodextrin 포접체는 상대적으로 β-Cyclodextrin 포접체 보다 더 효과적이었다. 피부 유해성 세균인 황색 포도상구균과 녹농균에 대해 억제 효과를 시험한 결과, 황색 포도상구균에 대해서는 Hesperetin = Hydroxypropyl-β-Cyclodextrin 포접체 > β -Cyclodextrin 포접체의 순서로 항균 효과를 나타내었으나, 녹농균에 대해서는 뚜렷한 억제효과를 나타내 지 않았다. 결론적으로, Hesperidin의 비당체 형태인 Hesperetin과 이의 Cyclodextrin 포접체는 다양한 생 물학적 활성을 보여주었으며, 용해도가 높은 Hydroxypropyl-β-Cyclodextrin 포접체가 β-Cyclodextrin 포접체에 비해 상대적으로 더 높은 활성을 나타내었다.

Dental caries is an infectious disease accompanied by the destruction of teeth. It is a multifactorial disease caused by the interaction between microbes in dental plaque and food, with cariogenic Streptococcus mutans being one of the primary causes. In this study, the antimicrobial and antibiofilm activities of Lactiplantibacillus plantarum THK-j112 isolated from Kimchi, a traditional fermented food, against S. mutans were investigated. Furthermore, this paper also showed the possibility of developing this strain. After analyzing the 16S rRNA sequence, strain THK-j112 was named L. plantarum THK-j112 as it shared 99.93% similarity with L. plantarum ATCC 14917T. Both L. plantarum THK-j112 and L. plantarum ATCC 14917T demonstrated MIC values of 5 mg/mL and MBC values of 10 mg/mL against S. mutans KACC 16833T. The study confirmed that L. plantarum THK-j112 exhibited significant concentration-dependent inhibitory effects on biofilm formation, acid production, and glucosyltransferases(GTFs) production. Regarding hemolytic activity, Bacillus cereus ATCC 14579T, used as a positive control, was confirmed to cause hemolysis, whereas L. plantarum THK-j112 did not cause this phenomenon. Additionally, except for gentamicin, the antibiotic resistance test revealed a lower value than the MIC cut-off value for each antibiotic, indicating no resistance. Based on the findings, L. plantarum THK-j112 is expected to be useful in the food industry, such as functional food, as a lactic acid bacterium with antimicrobial and antibiofilm effects.

We investigated the epidemiological characteristics of the antimicrobial resistant Enterococcus isolates from the four major rivers of Korea in 2012. A total 316 surface water samples were collected from three distinct sites (nearby livestock farms, tributaries, and major rivers) at two different seasons (dry season: n = 76, wet season: n = 240). A total 654 bacterial cells were isolated from samples and their genus distribution were determined. We found that Gram-negative bacteria including various genera were prevalent (n = 522, 79.8%), and Enterococcus was the most common genus of Gram-positive bacteria (n = 119, 18.2%). The isolation rate of Gram-negative bacteria was higher in wet season, whereas that of Enterococcus isolates was higher in dry season. The prevalence of Enterococcus isolates was also higher nearby livestock farms than on tributaries and main rivers. Since Enterococcus isolate is a key indicator for animal fecal contamination, the following experiments focused on this microorganism. As compared to a previous report in 2006, the resistance rates in E. faecium to erythromycin (40.0% to 69.9%) and chloramphenicol (0% to 16.4%) were increased, whereas those to penicillin (56.0% to 4.1%) and teicoplanin (36.0% to 0%) were decreased. We also found that antimicrobial-resistant (AMR) E. faecium isolates from rivers and livestock samples shared similar pulsed-filed gel electrophoresis (PFGE) profiles, validating the transmission of AMR Enterococcus isolates from livestock to river. Taken together, this study provides us with detailed information about bacterial contamination status in four major rivers, and highlights the changes in AMR pattern of Enterococcus isolates, which are expected to have originated from livestock.

When exposed to different types of bacteria in the oral cavity, denture based resins are prone to bacteria attachment. The purpose of this study was to investigate the physical, biological, and antimicrobial properties of denture base resins coated with Peony extract (200, 400, and 600 μg/mL). Specifically, the surface properties (microhardness, contact angle, and color change of the coated specimens), cell cytotoxicity (measured using MTT assay), and antimicrobial activity (against S. mutans (Streptococcus mutans) and C. albicans (Candida albicans) using a growth inhibition assay) were evaluated. The polyphenol content was measured using ultraviolet-visible (UV-vis) spectrometry. The experimental groups (specimens coated with Peony extract) and a control group (specimens coated without Peony extract) were statistically compared using a one-way analysis of variance and Tukey’s post-hoc tests. No statistically significant differences in surface properties or cell cytotoxicity were observed, which demonstrated their biocompatibility. Conversely, a statistically significant difference in antimicrobial activity was observed between the experimental and control groups after 48 h. This confirms the antimicrobial activity of the denture base resin coated with Peony extract and demonstrates that it is a promising dental material for preventing stomatitis.

Makgeolli’s fermentation characteristics and antioxidant and antimicrobial activities were investigated to examine the effect of Prunus mume extract addition. Makgeolli, with the addition of various levels (0, 1, 3, and 5%) of Prunus mume extract (PME), was brewed with fermenting agents, Ipguk and Nuruk. The alcohol content of all samples remarkably increased during the initial 3 days and then gradually increased up to over 18% by the end of fermentation (7 days for Nuruk and 15 days for Ipguk). Although the alcohol content was slightly reduced and acidity was increased with the concentration of PME, there was no other negative effect of PME on the fermentation of Makgeolli. The contents of total phenols and flavonoids for Ipguk samples were higher than those for Nuruk samples, and these values significantly increased at over 3% PME addition. As the PME content increased, the antioxidant activity increased for both Nuruk and Ipguk samples. Only Makgeolli with Ipguk had vigorous antimicrobial activity against E. coli and S. aureus at over 3% addition of PME. These results indicate that PME can be an effective natural additive for enhancing Makgeolli’s antioxidant and antimicrobial activities.

Background and Purpose: Antimicrobial photodynamic therapy using Methylene blue (MB-PDT) has been proposed as an adjunctive to scaling and root planing (SRP) to provide preferable results for the treatment of periodontitis. The multi-factor mechanism of aPDT action correlates with various influencing components such as the photosensitizer and the light delivery system. The paper aims to review the recorded parameters of MB-PDT from clinical trials of periodontitis which may serve to improve the treatment of periodontal diseases. Materials and Methods: PubMed search engine was used to identify human clinical trials of PDT in dentistry. After applying specific keywords, additional filters, exclusion criteria, the initial number of 17378 was reduced to 12. Results: More than half of the articles of SRP + MB-PDT presented better results [pocket depth (PD) reduction, clinical attachment level (CAL) gain, etc.] compared to SRP alone in the treatment of periodontitis. Conclusions: While more clinical evidence is needed, recent studies demonstrate that MB-PDT combined with SRP show a greater potential as a treatment of periodontal diseases in comparison to SRP alone.

To investigate the functional activity of different citrus fruit peels, antioxidant compounds in 70% ethanol extracts of mandarin, lemon, orange, and grapefruit peel powders were identified, and antioxidant and antibacterial activities were quantitated. Mandarin peel contained the highest content of total phenolic compounds and total flavonoid substances (21.46±0.12 mg GAE/g and 11.57±0.05 mg RE/g, respectively). The total phenolic compound content of the three other citrus fruits was 14.16±0.18-18.44±0.07, and their total flavonoid content was 5.51±0.10-7.46±0.09 mg RE/g. DPPH radical scavenging activity was the highest in lemon peel (87.64±0.21%), and mandarin peel displayed the best antioxidant activity with respective ABTS radical scavenging activity and FRAP measurements of 43.20±0.61% and 78.82±1.06 mM TE/g. Grapefruit peel antimicrobial activity increased with treatment time, and was the most potent among the four tested citrus species, inhibiting Staphylococcus aureus by about 4.05 log cycle. These findings demonstrate that mandarin and grapefruit peel can be used to prevent oxidation, improve food storage capabilities, and potentially preserve food quality.

This study is intended to determine the antimicrobial resistance properties and class 1 integrons of 30 Citrobacter freundii strains isolated from pet turtles in order to determine their threat to human health. Citrobacter freundii isolates were isolated and identified by employing biochemical tests and 16SrRNA gene sequencing. Disc diffusion test and PCR amplification were employed to detect antimicrobial resistance patterns and genes, respectively. Ampicillin, amoxicillin, cephalothin and nalidixic acid resistance were observed among all isolates. Rifampicin and cefoxitin resistance was the second most prevalent and observed in 97% of the isolates, respectively. All isolates scored multiple antimicrobial resistance (MAR) indices ≥ 0.2. Aminoglycoside resistant genes were the most prevalent. aac(3')-IIa was detected in 80% of the isolates followed by aphAI-IAB and strA-strB genes in 33% and 50% of the isolates, respectively. β-lactamase encoding blaTEM, blaCTX and blaSHV genes were detected in 53%, 43% and 17% of the isolates, respectively. tetA and tetB genes were the only tetracycline resistance genes detected in 17% and 10% of the isolates, respectively. Class 1 integron integrase encoding intI1 gene (47%) and dfrA17-aadA5 gene cassette array (7%) were also detected. Pet turtle-borne multidrug-resistant C. freundii is a reservoir of antimicrobial resistance determinants in the domestic environment which poses a risk of infection.

Lactic acid bacteria as probiotics are intensively used in human and animal species. These probiotic properties of LABs were variable according to bacterial strain and species. However, there was limited information on probiotic properties of monkey origin LABs. In this study, we investigated the antibacterial activity of monkey and human origin LABs against monkey origin enteric bacteria by the agar disc diffusion test and broth culture inhibition assay. All LABs represented enough tolerance to pepsin (0.3%) and bile acid (pH = 2). To 50% of Clostridium perfringens and 20% of Escherichia coli, monkey origin LABs showed statistically higher antibacterial activity compared to human origin LABs (p < 0.05). Also, distinct antibacterial activity was verified among some bacteria species and strains. Higher antibacterial activity against enteric bacteria except for C. perfringens was verified in Lactobacillus johnsonii strains compared to Lactobacillus reuteri and Lactobacillus salivarius. Statistically different antibacterial activity against C. perfringens was verified among strains within L. reuteri and L. johnsonii. In conclusion, we prove the higher probiotic properties of monkey origin LABs against homogenous enteric bacteria although humans and monkeys were phylogenetically similar species. For non-human primates, homogenous LABs should be used as probiotics, not human origin LABs. Furthermore, it was confirmed among monkey origin LABs, L. johnsonii showed a high antibacterial activity on various enteric pathogenic bacteria and was an appropriate lactic acid strain for inhibiting C. perfringens.

The purpose of this study is to investigate the distribution of toxin genes and antimicrobial resistance of Vibrio parahaemolyticus isolated from seafood in Gwangju. A total of 335 seafood, including 163 shellfish, 97 fish, and 36 mollusk, were tested in this study. As a result, V. parahaemolyticus was detected in 123 (36.7%) of 335 seafood. The tdh gene was not detected in all strains, while the trh gene was detected in 3 strains (2.4%). According to antimicrobial susceptibility test, 116 strains (94.3%) represent resistance to ampicillin, and 1 strain (0.8%) represents resistance to trimethoprim/sulfametoxazole. However, all strains were sensitive to 9 antimicrobial agents, including amikacin, chloramphenicol, tetracycline, and more. Therefore, the risk of V. parahaemolyticus isolated from seafood in Gwangju is considered low, but continuous monitoring of V. parahaemolyticus in seafood is required.

Skin protects the body by mediating various immune responses against exogenous substances including bacteria, fungi, and viruses, in addition to its predominant role as a physical barrier. Despite the significant protection offered via various mechanisms, bacterial infection of the skin is one of the most common skin diseases in veterinary medicine. This study demonstrated the structural and immunological changes in the skin during infections with Pseudomonas aeruginosa and Staphylococcus pseudintermedius using skin explants from four healthy beagles. Skin structure was generally well preserved in uninfected controls, but defects in skin structure, including injury of keratinocytes and dermal–epidermal junctional disruption, were identified when skin explants were exposed to P. aeruginosa and S. pseudintermedius. On exposure to P. aeruginosa, marked linear cleft formation was noted along with acantholysis along the basal layer after 24 hours of culture. In addition to the defects in the skin structure, mRNA expression levels of the AMPs cBD103 and S100A8 were decreased, which was confirmed by immunohistochemical staining. Taken together, these results suggest that our ex vivo canine skin model is a research tool for investigating bacterial skin infections in dogs.