• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.344-354
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• 2022

BACKGROUND: Although antibiotics have contributed to treatment of bacterial infection, the antibiotic abuse can lead to antibiotic resistant bacteria. Impact of human activities on distribution of antibiotic resistance has been intensively issued and occurrence of antibiotic resistant bacteria in contaminated environments would not be a surprise. Nonetheless, anthropogenic contamination with the dissemination of antibiotic resistance along uncontaminated environments has been less considered. The aim of this study is to investigate antibiotic resistant bacteria across Ulleungdo, known as antibiotic resistance free and anthropogenic pollution free environment in Rep. of Korea. METHODS AND RESULTS: Antibiotic resistant bacteria in coastal seawater of Ulleungdo were investigated in July 2021. Antibiotic susceptibility test using the disk diffusion method was applied with six drugs according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Total 43 bacterial isolates were tested and 20 isolates among of them showed multidrug resistance. Particularly, the number and ratio of resistant bacteria were relatively high in a densely populated area of Ulleungdo. The bacterial communities were investigated using 16S rRNA gene metabarcoding approach in the coastal seawater and soils of Ulleungdo. In the bacterial communities, Firmicutes were selectively distributed only in seawater, suggesting the possibility of anthropogenic contamination in coastal seawater of Ulleungdo. CONCLUSION(S): We found antibiotic resistant bacteria in a populated area of Ulleungdo. The occurrence of antibiotic resistant bacteria in Ulleungdo seems to result from the recent anthropogenic impact. Consistent monitoring of antibiotic resistant bacteria in the uncontaminated environment needs to considered for future risk assessment of antibiotics.

• Korean Journal of Microbiology
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• v.4 no.2
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• pp.15-18
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• 1966

The purpose of this paper is to study on the thermal death time curve and F-values, and morphological and physiological characteristics observed for the identification. The three strains of thermal resistancing anaerobic bacteria isolated from unheated various cans and swelled cans and the different soils collected from the wide area in Korea. The results obtained in the light of the manual of Bergeg's for the identification of the anareobic bacteria have been shown that the three strains of anaerobic bacteria are pertained to Cl. sporogenes B-41 Cl. butyricum B-72 & Cl.. botulinum Type E B-163. The optimum temperature, pH and thermal resistance, thermal death point of the anaerobic have been measured.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.31-37
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• 2020

Clostridial bacteria are zoonotic agents, which cause severe necrotizing enteritis, pseudo-membrane colitis, enterotoxemia to both humans and animals. The objective of this study was to monitor the antibiotic resistance of Clostridium isolates on clinical specimens from wild animals in Seoul zoo for 5 years. Clostridium isolates were verified by using Vitek2 compact machine. Antibiotic susceptibility was assessed by antibiotic disc diffusion test, which was followed by Kirby-Bauer disc diffusion test method. The frequency of Antimicrobial resistance of Clostridium isolate was the greatest in gentamicin (87%), then in order of amikacin (80%). There were 55.6% of Clostridium isolates showed multiple drug resistance (MDR). These results showed that a lot of Clostridial bacteria from wild animals in Seoul zoo were acquired antibiotic resistance. Because of the wild animal's aggressive manner, it has been hard to collect clinical samples from wild animals in a zoo to exam antibiotic susceptibility. For these reasons, empirical use of antibiotics has been performed in frequently. It may cause to increase the emergence of antibiotic resistance bacteria. In addition, the antibiotic resistance bacteria from zoo animals can be spread to other wild animals which inhabit around the zoo. Therefore, regular monitoring of antibiotic resistance Clostridial bacteria is important to protect animals and humans from Clostridial diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.397-403
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• 2018

We determined the resistance rates of pathogenic bacteria isolated from cultured olive flounder Paralichthys olivaceus to erythromycin (Em), antibiotic typically used in aquaculture and analyzed the genotypes of resistant bacteria using polymerase chain reaction (PCR). We isolated and utilized 160 isolates of Streptococcus parauberis, 1 of S. iniae, 66 of Edwardsiella tarda, 56 of Vibrio sp. and 23 of unidentified bacteria from presumed infected olive flounder from Jeju Island from March 2016 to October 2017. Of the 306 isolated strains, Em-resistant strains included 33 of S. parauberis, 39 of E. tarda and 2 of Vibrio sp. We conducted PCR to assess the resistance determination of Em-resistant strains. Five different types of Em-resistance genes were detected in the 74 Em-resistant strains: erm (A), erm (B), erm (C), mef (A) and mef (E); erm (A) and erm (B) were detected in 1 (3%) and 24 (72.7%) S. parauberis isolates, respectively. In E. tarda, erm (B) was detected in five isolates (12.8 %) and no Em-resistance genes were detected in the two Vibrio sp. isolates.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.135-144
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• 2021

This study determined the antibiotic resistance patterns of Escherichia coli and Staphylococcus aureus from the raw meat and feces of three game species from three different farms across South Africa. The Kirby-Bauer disk diffusion method was used according to the Clinical and Laboratory Standards Institute 2018 guidelines. E. coli was tested against ampicillin, ceftazidime, chloramphenicol, streptomycin, sulphafurazole and tetracycline. S. aureus was tested against tetracycline, erthromycin, vancomycin, penicillin, oxacillin and cefoxitin. There were no significant differences in the E. coli antibiotic resistance profiles between the meat and fecal samples (except towards ceftazidime where 5% of the meat isolates were resistant and 0% of the fecal isolates). The S. aureus meat isolates showed high (75%) resistance towards penicillin and on average, 13% were resistant to oxacillin/ cefoxitin, indicating methicillin resistance. The results from this study indicate that there is incidence of antibiotic resistant bacteria from the feces and meat of wildlife species across South Africa, suggesting that cross contamination of the meat occurred during slaughter by antibiotic resistant bacteria from the abattoir personnel or equipment and or from carcass fecal matter. In addition, the results highlight the importance of food safety and hygiene procedures during slaughter to prevent cross-contamination of antibiotic resistant bacteria, as well as pathogens, onto raw meat.

• YAKHAK HOEJI
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• v.26 no.3
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• pp.169-174
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• 1982

Several strains of bacteria having resistance to macrolide antibiotics were isolated. EMR-1, one of them, exhibited the induced resistance to macrolide antibiotics and this microorganism was identified as a bacterium belong to Bacillus species. The subinhibitory concentration of erythromycin or oleandomycin induced strong resistance to both erythromycin and oleandomycin themselves and to other macrolide antibiotics such as leucomycin, spiramycin and josamycin. The effective concentration of inducer, erythromycin was $0.0016-0.2\mu$g/ml. The inactivating enzyme of these antibiotics was not produced by EMR-1.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.26-33
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• 2002

The seven strains, Pseudomonas paucimobilis, Pseudomonas cepacia, Staphylococcus auricularis, Staphylococcus saprophyticus, Acidovorax spp., Acinetobacter calcoaceticus, and Actinobacillus capsulatus were tested with three slimicides. Most of the tested bacteria were inhibited with slimicide K (an isothiazolin based compound), even at its low concentration, except for Actinobacillus capsulatus and Staphylococcus auricularis. Both slimicides B (an organic bromine based compound) and S (aldehydes) also couldn't prevent these two strains even at their highest concentration. Five different sizes of plasmid DNA were isolated from Actinobacillus capsulatus. Staphylococcus auricularis, a gram-positive bacteria, showed the slimy substances around its cell distinctively. The results suggest that two strains, Actinobacillus capsulatus, Staphylococcus auricularis, have presumably developed a resistance to the slimicide, by plasmid DNA or slimy substance. Our findings also suggest that not only gram-negative bacteria, but also gram-positive bacteria should not be neglected

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.169-178
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• 2010

The microbial community structure in Thailand soils contaminated with low and high levels of arsenic was determined by denaturing gradient gel electrophoresis. Band pattern analysis indicated that the bacterial community was not significantly different in the two soils. Phylogenetic analysis obtained by excising and sequencing six bands indicated that the soils were dominated by Arthrobacter koreensis and $\beta$-Proteobacteria. Two hundred and sixty-two bacterial isolates were obtained from arsenic-contaminated soils. The majority of the As-resistant isolates were Gramnegative bacteria. MIC studies indicated that all of the tested bacteria had greater resistance to arsenate than arsenite. Some strains were capable of growing in medium containing up to 1,500 mg/l arsenite and arsenate. Correlations analysis of resistance patterns of arsenite resistance indicated that the isolated bacteria could be categorized into 13 groups, with a maximum similarity value of 100%. All strains were also evaluated for resistance to eight antibiotics. The antibiotic resistance patterns divided the strains into 100 unique groups, indicating that the strains were very diverse. Isolates from each antibiotic resistance group were characterized in more detail by using the repetitive extragenic palindromic-PCR (rep-PCR) DNA fingerprinting technique with ERIC primers. The PCR products were analyzed by agarose gel electrophoresis. The genetic relatedness of 100 bacterial fingerprints, determined by using the Pearson product-moment similarity coefficient, showed that the isolates could be divided into four clusters, with similarity values ranging from 5-99%. Although many isolates were genetically diverse, others were clonal in nature. Additionally, the arsenic-resistant isolates were examined for the presence of arsenic resistance (ars) genes by using PCR, and 30% of the isolates were found to carry an arsenate reductase encoded by the arsC gene.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.381-394
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• 2023

This study was conducted to monitor the antibiotics resistance of human-harmful bacteria isolated in the agricultural environment for hot peppers (Capsicum annuum) and tomato (Lycopersicon esculentum). As a result, we isolated 120 bacterial species (34 on fruits, 48 in soil, 21 in water, and 17 in manure), identified them with the 16S rRNA sequence, analyzed minimum inhibitory concentration (MIC) for 26 antibiotics using Sensititre ARIS Hi-Q system and then evaluated whether each bacterial genus acquired resistance for the tested antibiotics or not, according to the CLSI criteria. From difference in MIC between eco-friendly (EFM) and practical (PFM) cultivation farms, Klebsiella spp. isolated from EFM was resistant to ampicillin (AMP) and nalidixic acid (NAL), and that isolated from PFM was resistant to streptomycin (STR) and tetracycline (TET). Enterobacter spp. isolated from EFM was resistant to AMP and azithromycin (AZI), and that isolated from PFM was resistant to AMP, AZI, and STR. Meanwhile, Pseudomonas spp. isolated from EFM and PFM were all resistant to AMP, AZI, cefotaxime (FOT), cefoxitin (FOX), ceftriaxone (AXO), CHL, NAL, and STR. Staphylococcus spp. isolated from EFM and PFM were resistant to gentamycin (GEN), STR, and kanamycin (KAN), and in particular, that from EFM showed resistance for erythromycin (ERY). In conclusion, our study suggested that EFM lead STR antibiotics resistance for human-harmful bacteria to decrease, because only the bacteria isolated from hot pepper and tomato crop with PFM have showed resistance against STR antibiotics, regardless of bacterial genus.

• Food Science and Preservation
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• v.15 no.5
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• pp.731-735
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• 2008

The coliform group, Salmonella typhimurium and Staphylococcus were analyzed for eliminating of microorganism spore which could be embeded in honey and eradication of studied for heat resistance of thermoacidophilic bacteria was studied for marketing of honey after producing honey drink. The method for analyzing of heat resistance thermoacidophilic bacteria was membrane-seperated cell culture with $0.45\;{\mu}m$ micro-filter and vacuum aspirator. The results of bacteria, coliform group, Salmonella typhimurium and Staphylococcus was negative, but normal method such as sterilization with electrolyzed water, normal micro-filter, high-temperature heating and microwave did not have effect on heat resistance thermoacidophilic bacteria. Also, absolute type micro-filter of $0.45\;{\mu}m$ and $0.8\;{\mu}m$ microfilteration showed higher effect on heat resistance thermoacidophilic bacteria than micro-filter of normal type, showing negative results at all treatments.