• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.427-434
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• 1990

The purpose of this study was to examine O serotypes, colicin and hemolysin production. antibiotic susceptibility and haemagglutinating ability to animal erythrocytes among Escherichia coli strains isolated from pigeons in Taegu province. Of the 166 strains isolated, 28 strains (16.9%) were classified into 6 O serotypes and their types were O20(42.9%), O15(17.9%), O139(14.3%), O101(10.7%), O149(7.1%) and O8(7.1%). Of the 166 strains isolated, none was hemolytic and 3(1.8%) were colicinogenic. Antibiotic susceptibility test of Escherichia coli isolates was performed by the agar dilution method, using ampicillin, chloramphnicol, gentamicin, rifampicin, streptomycin (Sm), nalidixic acid, sulfadimethoxine and tetracycline (Tc). Forty four strains (26.5%) were resistant to one or more drugs and the most common resistance patterns were SmTc (27.3%). Of the 44 drug resistant strains, 6 strains haemagglutinated erythrocytes of chicken, guinea pig and 2 of the 6 strains agglutinated goose erythrocytes.

• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.587-593
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• 2021

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

• 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.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.55-63
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• 2007

We investigated the distribution and drug susceptibility test of V. vulnificus isolated from environmental sources in Incheon. In this survey, total 4,302 samples were obtained from different sites of the Incheon coastal area during the periods from march 2004 to November 2006. Among the 4,302 samples, 310 strains were isolated. The isolation rates of Vibrio vulnificus from fish, shellfish, estuarine water and sediment were 6.7%, 4.7%, 12.4% and 23.2%, respectively. The highest isolation rate was 14.6% in September and in spite of low temperature the isolation rate was 5.1% in November. The highest rate of antibiotic resistance was observed against streptomycin(15.3%), cefazolin(8.5%), cephalothin(8.3%), amikacin(8.3%), cefoxitin(6.7%) and nalidixic acid(6.7%). Seventeen percent of isolates were observed to be resistant to two or more of the antibiotics tested.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.35-46
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• 2023

Purpose: Culture-based methods for microbiological diagnosis and antibiotic susceptibility tests have limitations in the management of orofacial infections. We aimed to profile pus microbiota and identify antibiotic resistance genes (ARGs) using a culture-independent approach. Materials and Methods: Genomic DNA samples extracted from the pus specimens of two patients with orofacial abscesses were subjected to shotgun sequencing on the NovaSeq system. Taxonomic profiling and prediction of ARGs were performed directly from the metagenomic raw reads. Result: Taxonomic profiling revealed obligate anaerobic polymicrobial communities associated with infections of odontogenic origins: the microbial community of Patient 1 consisted of one predominant species (Prevotella oris 74.6%) with 27 minor species, while the sample from Patient 2 contained 3 abundant species (Porphyromonas endodontalis 33.0%; P. oris 31.6%; and Prevotella koreensis 13.4%) with five minor species. A total of 150 and 136 putative ARGs were predicted in the metagenome of each pus sample. The coverage of most predicted ARGs was less than 10%, and only the CfxA2 gene identified in Patient 1 was covered 100%. ARG analysis of the seven assembled genome/metagenome datasets of P. oris revealed that strain C735 carried the CfxA2 gene. Conclusion: A metagenomics-based approach is useful to profile predominantly anaerobic polymicrobial communities but needs further verification for reliable ARG detection.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.811-818
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• 1999

A total of 16 Staphylococcus epidermidis isolates collected from 14 dogs admitted to the Veterinary Medicial Teaching Hospital in Seoul National University over eleven months were examined for in vitro antibiotic susceptibility pattern with minimum inhibitory concentration (MIC) and slime production, a virulence-associated phenotype, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). The frequency of resistance to antimicrobial agents tested was not high, with a susceptibility ranging from 56.3% to 100%. Three strains exhibited multiple drug resistance against amikacin (MIC, $32-64{\mu}g/ml$), ampicillin ($32{\mu}g/ml$), fosfomycin ($32-128{\mu}g/ml$) and gentamicin ($16{\mu}g/ml$). Vancomycin, ciprofloxacin and rifampin were effective antibiotics against the isolates. All isolates were slime producers ; strains isolated from dogs which died of bacteremia were more likely to produce slime than those isolated from dogs which survived. Chromosomal DNA fingerprinting of the isolates yielded 16 different genomic types with few common bands, indicating a variety of clones of S epidermidis were prevalent in the hospital. This study revealed that PFGE is an useful method for the genotype characterization of S epidermidis strains and this organism could probably be pathogenic in some dogs with severe disorders. Further works on a larger number of epidemiologically defined strains are required to assess these results.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.315-324
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• 1989

In order to establish the extent of Streptococcal arthritis piglets, isolation of Streptococci from arthritic lesions of 34 piglets were undertaken from November 1987 to October 1988 in Korea. Also determined were isolation frequency of Streptococci in nasal cavity of 250 healthy sows and antibiotic susceptibilities of the isolates. Streptococci were isolated from 52.9% of 34 arthritic piglets and 20 strains isolated belonged to 4 S suis type I, 8 S suis type II, 2 Lancefield group C and 6 group E. From 28.8% of 250 healthy sows, 72 strains of Streptococci were isolated and these consisted of 9 S suis type I, 51 S suis type II and 12 group C. Streptococcal arthritis seemed to occur prominently in piglets aged 2 to 4 weeks and in male than female. No significant difference were recognized in tarsal and carpal joints as affecting site. All of 92 isolates were sensitive to ampicillin and penicillin, and all strains of S suis type I and group E Streptococcus were also sensitive to chloramphenicol and cephalothin. To cephalothin all strains of group C Streptococcus were sensitive. The 1. 7 to 100% of 92 isolates were resistant with different prevalence to colistin, erythromycin, kanamycin, tetracycline, gentamicin, chloramphenicol and cephalothin. The 92.5% of these resistant Streptococci were multiply drug-resistant strains. The drug resistant patterns most frequently encountered were Tc Cl Em Km Gm(16.3%) in quintuple pattern, Tc Cl Em Km(16.3%) in quadruple pattern, Tc Cl Em(10.9%) in triple pattern and Cl Em(14.1%) in double pattern.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.949-955
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• 2021

Previously, our research group isolated Bifidobacterium breve IDCC4401 from infant feces as a potential probiotic. For this study, we evaluated the safety of B. breve IDCC4401 using genomic and phenotypic analyses. Whole genome sequencing was performed to identify genomic characteristics and investigate the potential presence of genes encoding virulence, antibiotic resistance, and mobile genetic elements. Phenotypic analyses including antibiotic susceptibility, enzyme activity, production of biogenic amines (BAs), and proportion of D-/L-lactate were evaluated using E-test, API ZYM test, high-performance liquid chromatography (HPLC), and D-/L-lactic acid assay respectively. The genome of B. breve IDCC4401 consists of 2,426,499 bp with a GC content of 58.70% and 2,016 coding regions. Confirmation of the genome as B. breve was provided by its 98.93% similarity with B. breve DSM20213. Furthermore, B. breve IDCC4401 genes encoding virulence and antibiotic resistance were not identified. Although B. breve IDCC4401 showed antibiotic resistance against vancomycin, we confirmed that this was an intrinsic feature since the antibiotic resistance gene was not present. B. breve IDCC4401 showed leucine arylamidase, cystine arylamidase, α-galactosidase, β-galactosidase, and α-glucosidase activities, whereas it did not show production of harmful enzymes such as β-glucosidase and β-glucuronidase. In addition, B. breve IDCC4401 did not produce any tyramine, histamine, putrescine, cadaverine, or 2-phenethylamine, which are frequently detected BAs during fermentation. B. breve IDCC4401 produced 95.08% of L-lactate and 4.92% of D-lactate. Therefore, our findings demonstrate the safety of B. breve IDCC 4401 as a potential probiotic for use in the food industry.

• Biomedical Science Letters
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• v.27 no.4
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• pp.264-269
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• 2021

The purpose of this study was to evaluate the disinfecting efficacy of peracetic acid (PAA), sodium hypochlorite (NaOCl) and phenol, which are representative disinfectants in medical environments using four types of multi-drug resistance (MDR) clinical isolates with healthcare-associated infections (HAI). 26 antibiotic susceptibility tests were conducted for the four types of MDR clinical isolates in the same way as for clinical specimens. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the disinfectants were determined by using in vitro liquid medium dilution method and inoculation of the plate medium. Both the MIC and MBC of phenol against MRSA and VRE were 3.1%, while those against KPC and MRPA were 6.2%. The MIC and MBC of peracetic acid (PAA) against MRSA, VRE, KPC, and MRPA were 0.18%. The MIC and MBC of sodium hypochlorite (NaOCl) against MRSA were 0.39% and 0.78%, respectively. Both values of MIC and MBC were 0.78% for VRE. In addition, KPC and MRPA showed 0.39% for MIC and 0.78% for MBC. For all MDR strains used in this study, sodium hypochlorite and peracetic acid showed significant sterilizing efficiency, while no clear correlation was identified between antibiotic resistance clinical isolated and ability of disinfection.