• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1078-1084
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• 1999

A synthetic cecropin A(1-13)-melittin(1-13) [CA-ME] hybrid peptide was known to be an antimicrobial peptide having strong antibacterial, antifungal and antitumor activity with minimal cytotoxic effect against human erythrocyte. Analogues were synthesized to investigate the influences of the flexible hinge region of CA-ME on the antibiotic activity. Antibiotic activity of the peptides was measured by the growth inhibition against bac-terial, fungal and tumor cells and vesicle-aggregating or disrupting activity. The deletion of Gln-Gly-Ile (P1) or Gly-Gln-Gly-Ile-Gly (P3) from CA-ME brought about a significant decrease on the antibiotic activities. In contrast, Gly-Ile-Gly deletion (P2) from CA-ME or Pro insertion (P5) instead of Gly-Gln-Gly-Ile-Gly of CA-ME retained antibiotic activity. This result indicated that the flexible hinge or β-bend structure provided by Gly-Gln-Gly-Ile-Gly, Gln-Gly, or Pro in the central region of the peptides is requisite for its effective antibiotic activity and may facilitate easily the hydrophobic C-terminal region of the peptide to penetrate the lipid bilayers of the target cell membrane. In contrast, P4 and P6 with Gly-Gln-Gly-Pro-Gly or Gly-Gln-Pro in the central region of the peptide caused a drastic reduction on the antibiotic activities. This result suggested that the con-secutive β-bend structure provided by Gly-Gln-Gly-Pro-Gly or Gly-Gln-Pro in the central hinge region of the peptide seems to interrupt the ion channel/pore formation on the target cell membranes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.4
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• pp.198-207
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• 2023

Objectives: This study investigated causative strains and their antibiotic sensitivity in patients who were hospitalized for maxillofacial odontogenic infections at a tertiary center in South Korea over the past 10 years with the aim of providing guidelines for the selection of appropriate empirical antibiotics. Materials and Methods: Patients with head and neck fascial space abscesses due to odontogenic infections who underwent incision and drainage surgery with pus culture tests between 2013 and 2022 at the Department of Oral and Maxillofacial Surgery, Dankook University Hospital were included. The bacterial isolates and antibiotic sensitivity of each strain were analyzed for 2013-2022, 2013-2017, and 2018-2022. The affected fascial spaces were classified into primary, secondary, and deep neck spaces. Results: In the 192 patients included in this study, 302 strains were detected. Viridans streptococcus had the highest frequency (51.7%), followed by Prevotella spp. (16.9%), Staphylococcus spp. (5.6%), and Klebsiella pneumoniae (4.6%). The identification rate of viridans streptococcus significantly increased from 41.8% in 2013-2017 to 60.9% in 2018-2022. Viridans streptococcus showed an antibiotic sensitivity of 80.5% to ampicillin; the sensitivity to penicillin antibiotics decreased over the study period. Antibiotic susceptibility was approximately 94% for third-generation cephalosporins. K. pneumoniae, which was identified at a high percentage in patients with deep neck space infection, showed increasing antibiotic resistance to most antibiotics over the study period. Conclusion: Viridans streptococcus was identified in head and neck fascial space abscesses with the highest frequency. Empirical antibiotics should be effective against this strain; penicillin antibiotics are considered inappropriate. For effective treatment of deep neck space abscesses, bacterial culture and antibiotic sensitivity tests performed as soon as possible are essential.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.11-50
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• 2023

As the field of interventional pain management (IPM) grows, the risk of surgical site infections (SSIs) is increasing. SSI is defined as an infection of the incision or organ/space that occurs within one month after operation or three months after implantation. It is also common to find patients with suspected infection in an outpatient clinic. The most frequent IPM procedures are performed in the spine. Even though primary pyogenic spondylodiscitis via hematogenous spread is the most common type among spinal infections, secondary spinal infections from direct inoculation should be monitored after IPM procedures. Various preventive guidelines for SSI have been published. Cefazolin, followed by vancomycin, is the most commonly used surgical antibiotic prophylaxis in IPM. Diagnosis of SSI is confirmed by purulent discharge, isolation of causative organisms, pain/tenderness, swelling, redness, or heat, or diagnosis by a surgeon or attending physician. Inflammatory markers include traditional (C-reactive protein, erythrocyte sedimentation rate, and white blood cell count) and novel (procalcitonin, serum amyloid A, and presepsin) markers. Empirical antibiotic therapy is defined as the initial administration of antibiotics within at least 24 hours prior to the results of blood culture and antibiotic susceptibility testing. Definitive antibiotic therapy is initiated based on the above culture and testing. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria infections appears to be superior to monotherapy in mortality with the risk of increasing antibiotic resistance rates. The never-ending war between bacterial resistance and new antibiotics is continuing. This article reviews prevention, diagnosis, and treatment of infection in pain medicine.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.269-278
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• 2023

Antibiotics either kill or inhibit the growth of bacteria. However, antibiotic-resistant bacteria are difficult to treat with antibiotics. Infections caused by such bacteria often lead to severe diseases. Antibiotic resistance genes (ARG) can be horizontally transmitted across different bacterial species, necessitating a comprehensive understanding of how ARGs spread across various environments. In this study, we analyzed the plasmid sequences of 33 extended-spectrum beta-lactamases (ESBL) producing Escherichia coli isolated from pigs, farms, and their owners. We conducted an antibiotic susceptibility test (AST) with aztreonam and seven other antibiotics, as well as whole genome sequencing (WGS) of the strains using MinION. Our results demonstrated that the plasmids that did not harbor ARGs were mostly non-conjugative, whereas the plasmids that harbored ARGs were conjugative. The arrangement of these ARGs exhibited a pattern of organization featuring a series of ARG cassettes, some of which were identical across the isolates collected from different sources. Therefore, this study suggests that the sets of ARG cassettes on plasmids were mostly shared between pigs and their owners. Hence, enhanced surveillance of ARG should be implemented in farm environments to proactively mitigate the risk of antibiotic-resistant bacterial infections.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.340-352
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• 2024

This study measured the potential changes of the microbiota in the gastrointestinal tract and energy and nutrient digestibility by supplemental bacteriophages in pigs. Twelve castrated male pigs (initial mean body weight = 29.5 ± 2.3 kg) were surgically cannulated using T-cannula. The animals were housed individually in pens equipped with a feeder and a nipple waterer. The pigs were allotted to 1 of 3 experimental diets in a quadruplicated 3 × 2 Latin square design with 3 experimental diets, 2 periods, and 12 pigs resulting in 8 replicates per diet. The 3 diets were a control mainly based on corn and soybean meal with no antibiotics or bacteriophages, a diet containing 0.1% antibiotics, and a diet containing 0.2% bacteriophages. On day 5 of the experimental period, feces were collected and on days 6 and 7, ileal digesta were collected. Genomic DNA for bacteria were extracted from the ileal digesta and feces and the V4 region of the 16S rRNA gene was amplified. The ileal and fecal digestibility of energy, dry matter, organic matter, crude protein, and fiber was unaffected by dietary antibiotics or bacteriophages. At the phylum level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Firmicutes (p = 0.059) and a lower proportion of Bacteroidetes (p = 0.099) in the ileal digesta samples compared with the control group with no difference between the antibiotic and bacteriophage groups. At the genus level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Lactobacillus (p = 0.062) and a lower proportion of Bacteroides (p = 0.074) and Streptococcus (p = 0.088) in the ileal digesta compared with the control group with no difference between the antibiotic and bacteriophage groups. In the feces, supplemental antibiotics or bacteriophages reduced the proportion of Bifidobacterium compared with the control group (p = 0.029) with no difference between the antibiotic and bacteriophage groups. Overall, supplemental antibiotics and bacteriophages showed positive effect on the microbiota of in the ileal digesta without largely affecting energy or nutrient digestibility, with no differences between the antibiotic and bacteriophage groups in growing pigs.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.26-32
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• 2000

• The Journal of the Korean Society for Microbiology
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• v.5 no.1
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• pp.1-8
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• 1970

This report is to observe the rate of multiple resistance to various antibiotics among staphylococcus aureus and E. coli which were isolated with high frequency at our department during 1969. 1. One hundred fifty two strains(20.6%) resistant to four antibiotics multiple resistant was the highest incidence among 739 strains of Staphylococcus aureus. 2. Regarding the multiple antibiotic resistant of Staphylococcus aureus, 75strains(10.1%) to SA. PC. TC the three antibiotics resistant, have been observed, with the highest incidence, and next to this, 69 strains(9.3%) to SA. PC. SM. TC the four autibiotics resistant, and 68 strains(9.2%) to SA. PC. SM. CM. TC. SM. the six antibiotics resistant, have been observed in descending order. 3. The case of one hundred twenty seven strains(28.0%) of the six antibiotic multiple resistant among 454 strains of Escherchia coli was the highest incidence. 4. Concerning the multiple antibiotic resistant of Escherichia coli, 70 strains(l5.4%) to SA. SM. CM. TC. EM. FD. the six antibiotics resistant, have been observed, with the highest incidence, and next to this, 59 strains(l3.0%) to SA. SM. CM. TC. EM. FD. AC the seven antibiotics resistant, and 42 strains(9.3%) to SA. SM. CM. TC. EM. FD. KM. AC the eight antibiotics resistant have been observed in descending order.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.16 no.4
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• pp.421-429
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• 2009

Purpose: The aim of this study was to identify knowledge and attitudes on antibiotic use held by adolescents (middle and high school students) in Korea. Methods: Data were collected from a convenience sample of 651 students residing in 5 major cities in Korea. The questionnaire was developed after an extensive literature review and professional advisory meetings. Descriptive statistics, t-test, chi square test, ANOVA, and Pearson correlation coefficients with the SPSS program were used to analyze the data. Results: Respondents correctly answered 6.23 antibiotic-related questions out of 15 questions. Two thirds of the respondents knew viruses caused most colds and coughs, but 80% did not know that antibiotics do not work against viruses. High school students' attitudes towards antibiotics were somewhat negative. More middle school students than high school students asked doctors for antibiotics for a cold. High school students did not check if antibiotics were included in their prescription for a cold. There was no significant correlation between knowledge and attitudes towards antibiotic use. Conclusion: Education programs on appropriate antibiotic use need to be developed for these students. Continual reinforcement and repetition of the contents are required to change attitudes.

• The Journal of Internal Korean Medicine
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• v.38 no.2
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• pp.172-179
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• 2017

Objectives: The aim of this clinical study is to describe the case of a patient with antibiotic-associated diarrhea, which was improved by treatment with herbal medicine. Methods: The antibiotic-associated diarrhea improved following treatment with Boikyangwi-tang and Opae-san for two months. During this period, western medicine, including antibiotics, was also administered. To evaluate the effect of the treatment, the Bristol Stool Form Scale was used. Results: During the treatment, the Bristol Stool Form Scale changed from type 7 to type 5. Conclusion: The results suggest that traditional Korean medicine may be an effective treatment for antibiotic-associated diarrhea.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.709-717
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• 2015

Airborne bacteria from hog farms may have detrimental impacts on human health, particularly in terms of antibiotic resistance and pathogen zoonosis. Despite human health risks, very little is known about the composition and diversity of airborne bacteria from hog farms and hog-related spray fields. We used pyrosequencing analysis of 16S rRNA genes to compare airborne bacterial communities in a North Carolina hog farm and lagoon spray field. In addition, we isolated and identified antibiotic-resistant bacteria from both air samples. Based on 16S rRNA gene pyrosequence analysis, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla in airborne bacterial communities from both hog farm and spray field sites. Within the Firmicutes genera, Clostridium spp. were more abundant in the hog farm, whereas Staphylococcus spp. were higher in the spray field. The presence of opportunitic pathogens, including several Staphylococcus species and Propionibacterium acnes, was detected in both bioaerosol communities based on phylogenetic analysis. The isolation and identification of antibiotic-resistant bacteria from air samples also showed similar results with dominance of Actinobacteria and Proteobacteria in both hog farm and spray field air. Thus, the existence of opportunistic pathogens and antibiotic resistant bacteria in airborne communities evidences potential health risks to farmers and other residents from swine bioaerosol exposure.