• Korean Journal of Veterinary Service
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• v.42 no.1
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• pp.17-24
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• 2019

The aim of this study was to investigate the prevalence and characterization of plasmid-mediated quinolone resistance (PMQR) gene in 79 Enterobacteriaceae isolated from dogs and cats. Of 79 isolates, PMQR genes were found in 10 (12.7%) isolates, including aac(6')-lb-cr, qnrB, qnrS and qnrA detected alone or in combination in 8 (10.1%), 4 (5.1%), 2 (2.5%) and 1 (1.3%) isolates, respectively. Interestingly, two qnrS genes were detected in nalidixic acid and ciprofloxacin susceptible isolates. Extended-spectrum ${\beta}$-lactamase (ESBL) was detected in 90% (9 isolates) of PMQR positives isolates. Among ESBL genes, CTX-M, TEM and SHV were detected in 9, 8 and 3 isolates, respectively. Almost all PMQR genes were detected in co-existence with ESBL genes. All PMQR positives isolates were multidrug resistance (i.e. resistant to five or more antibiotics). qepA, OXA and CMY-2 genes were not found. The six transconjugants were obtained by conjugation experiment. The aac(6')-lb-cr, qnrB and qnrS were co-transferred with CTX-M, TEM and/or SHV, whereas qnrA was not observed among transconugants. This is the first report of the presence of aac(6')-lb-cr and qnrA gene among Enterobacteriaceae isolates from dogs in Korea. The prudent use of antimicrobials and continuous monitoring for companion animals are required.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.515-520
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• 2007

Mycoplasma pneumoniae (M. pneumoniae) is the leading cause of pneumonia in older children and young adults. Normally, it does not progress to a condition requiring hospitalization but improves spontaneously or has a mild clinical course. We report two cases of M. pneumoniae pneumonia with different clinical manifestations from the normal course. The patients were young healthy individuals. The diagnoses were made by serology. However, it could not be determined beforehand that they had M. pneumoniae pneumonia. Based on the empirical treatment strategy of severe community acquired pneumonia, the patients were treated with broad-spectrum antibiotics including cephalosporin, quinolone and macrolide. After administering the antibiotics, they showed a gradually favorable clinical course and recovered without residual complications. A M. pneumoniae infection should be considered as a cause of severe community acquired pneumonia, and empirical treatment targeting this organism might be helpful in treating patients with the severe manifestation.

• Korean Journal of Bronchoesophagology
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• v.15 no.2
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• pp.57-63
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• 2009

Background and Objectives : Peritonsillar abscess is one of the most common illnesses m the ENT field, though its prevalence has been drastically reduced with the development of antibiotics and appropriate early treatment. We analyzed recent clinical characteristics of peritonsillar abscess and compared them with ones of 7 and 14 years ago respectively. Materials and Methods : Sixty-six cases of peritonsillar abscess from 2006 through 2008 were investigated retrospectively and compared with results of 7 and 14 years ago on various clinical factors. Results : Peritonsillar abscess was prevalent in men in their 20s and 30s. Mean period from symptom onset to visit to hospital tended to decrease(5.2 days) but admission days has increased(7.4 days). Body temperature on admission was lower than that of previous studies($36.4^{\circ}C$). Bacteria were isolated in 26 cases(74.2%) out of 35 cases in which culture had been performed. The most common cultured organism was a-hemolytic streptococcus and $\beta$-hemolytic streptococcus that had been most frequently cultured 14 years ago wasn't detected in this study. Conclusion : We found some changes of clinical features in peritonsillar abscess when compared with previous researches. Although there were some differences in cultured organism, antibiotics used commonly-cephalosporin, aminoglycoside, quinolone - were still effective for their eradication.

• Mycobiology
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• v.29 no.1
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• pp.11-14
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• 2001

A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1573-1578
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• 2007

Fluorescence quenching of norfloxacin (NOR) by Cu2+, Ni2+, Co2+ and Mn2+ was studied in water. The change in the fluorescence intensity and lifetime was measured as a function of quencher concentration at various temperatures. According to the Stern-Volmer plots, the NOR was quenched both by collisions and complex formation with the same quencher. However, the static quenching had a more important effect on the emission. Large static and dynamic quenching constants support significant ion-dipole and orbital-orbital interactions between NOR and cations. The both quenching constants by Cu2+ were the largest among quenchers. Also, quenching mechanism of Cu2+ was somewhat different. The change in the absorption spectra due to the quencher provided information on static quenching. The fluorescence of NOR was relatively insensitive to both the dynamic and static quenching compared with other quinolone antibiotics. This property can be explained by the twisted intramolecular charge transfer.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.363-374
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• 2007

A biochemical characterization and antimicrobial drugs susceptibility study was conducted in four breeding kennel which was canine abortion caused by Brucella canis in Gyeongbuk province in 2003-2006. Total of 267 dogs domesticated in the four kennel were examination. Among them, 143 (53.6%) dogs were sero-positive and 25 of blood samples were isolated to Brucella canis. At amplification of 35KDa-BCSP gene using PCR, 711 bp DNA fragment was same visible in 25 isolates and B canis RM6/66. Biochemical characterization of B canis isolated was non-hemolytic, no production of $H_2S$, no fermentation of carbohydrates, catalase-positive, oxidase-positive, indol-negative, hydrolyzation of urea, reduction of nitrate and development of thionin dye medium. Using disk-diffusion method, all of 25 strains tested were found to be highly susceptible to tetracycline, aminoglycoside, quinolone, macrolide antibiotics, rifampin and ampicillin in vitro. Using PFGE with restriction enzyme Smi I, 25 isolates tested were typed to 2 pattern, S1 and S2.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.150-157
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• 2002

Purpose: As the incidence of non-typhoidal salmonella strains resistant to antibiotics has been increased, we attempted to investigate clinical aspects of non-typhoidal salmonella gastroenteritis and antibiotics resistance. Methods: From January 2000 to June 2002, 99 children with positive stool culture of non-typhoidal salmonella were studied about clinical features, the incidence of antibiotics and multi-drug resistance and the difference of incidence of antibiotics resistance according to immune status. Results: There were 66 males and 33 females. The majority of them were under 5 years of age (71%). 25 children were immunocompromised due to chemotherapy, steroid or immunosuppressive treatment. Serogroup D was the most common isolates (65%) followed by B (16%), C (8%) and E (8%). Resistance rate of 30% to ampicillin, 12% to chloramphenicol, 20% to trimethoprim-sulfamethoxazole (TMP-SMX), 11% to cefotaxime and 8% to cefixime were obtained. All isolates were susceptible to ciprofloxacine. Resistance rate to cefotaxime and cefixime in immunocompromised patients was 24% and 14.3% respectively, which were significantly higher compared to that in immunocompetent patients (6.8%, 5.6%, p<0.05). 11 isolates were resistant to three or more antibiotics. The incidence of multi-drug resistant isolates was significantly higher in immunocompromised patients (24%) than that of immunocompetent patients (6.8%). Conclusion: Because of the high prevalence of non-typhoidal salmonella strains resistant to ampicillin, chloramphenicol and TMP-SMX, third-generation cephalosporin might be the treatment of choice in non-typhoidal salmonella gastroenteritis. In particular, antibiotics should be carefully selected in immunocompromised patients because non-typhoidal salmonellas from them showed the higher incidence of antibiotic resistance and multi-drug resistance.

• Korean Journal of Veterinary Service
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• v.43 no.2
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• pp.79-88
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• 2020

The aim of this study was to investigate the prevalence of CTX-M β-lactamase and plasmid-mediated quinolone resistance (PMQR) genes, and the pattern of antibiotic resistance in cefotaxime-resistant gramnegative bacteria. A total 126 gram-negative bacteria were isolated from hospitalized dogs and cats between 2018 and 2019. The most predominant isolates were E. coli (n=41), followed by Pseudomonas aeruginosa (n=25), Proteus mirabilis (n=14), Klebsiella pneumoniae (n=9), Sphingomonas paucimobilis (n=7), and Enterobacter cloacae and Serratia marcescens (respectively, n=5). Cefotaxime-resistant isolates were identified in 26.2% (33 isolates) of 126 gram-negative bacteria. CTX-M type β-lactamase were found in 15 isolates (10 E. coli, 1 Ent, cloacae and 4 K. pneumoniae, respectively). Among the CTX-M producing gram-negative bacteria, CTX-M-1 and CTX-M-9 were detected in 10 (66.7%) and 5 (33.3%) isolates, respectively. While, CTX-M-2 and CTX-M-8 were not found. PMQR genes were detected in 12 (36.4%) isolates (4 E. coli, 2 Ent, cloacae and 6 K. pneumoniae, respectively), and the predominant PMQR gene was aac(6')-lb-cr (n=9), followed by qnrB (n=8) and qnrS (n=1) alone or in combination. qnrA and qepA were not found. Additionally, 9 (60%) of 12 PMQR positive isolates were co-existence with CTX-M-1 or CTX-M-9. CTX-M or PMQR producing isolates showed highly resistance to penicillins (100%), cephalosporins (100~66.7%), monobactams (72.2%), and non-β-lactam antibiotics (94.4~61.1%) such as quinolones, trimethoprim/sulfamethoxazole, tetracycline and gentamicin. These findings showed CTX-M-1, CTX-M-9, aac(6')-lb-cr and qnrB were highly prevalent in cefotaxime-resistant Enterobacteriaceae isolates from companion animals in our region. Moreover, PMQR genes were closely associated with CTX-M type β-lactamase.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.3
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• pp.27-39
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• 2012

Objectives: Recently Ciprofloxacin, used in the treatment of mastitis, showed many serious side effects. The object of this study was to recognize whether TNS and KWT can be used in the treatment of mastitis by observing the in vitro antibacterial effects of TNS and KWT aqueous herbal extracts against S. aureus. Methods: Antibacterial activities of TNS and KWT aqueous extracts against S. aureus ATCC 25923 were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were monitored at MIC and $MIC{\times}2$ levels. The effects on the intracellular killing and bacterial invasion of individual test materials were also observed using Raw 264.6 and MCF-7. The results were compared with Ciprofloxacin, a second generation of quinolone antibiotics in the present study. Results: MIC of aqueous extracts of TNS and KWT against S. aureus were detected as ($0.313{\pm}0.107$) and ($0.137{\pm}0.053$) mg/ml, respectively. MIC of Ciprofloxacin was detected as ($0.469{\pm}0.297$) ${\mu}g/ml$ at same conditions. In addition, TNS, KWT aqueous herbal extracts and Ciprofloxacin were also showed marked dosage-dependent inhibition of bacterial growth, and dramatical inhibitions on the both intracellular killing assays and bacterial invasion using Raw 264.6 and MCF-7 cells were detected. Conclusions: The results obtained in this study suggest that TNS and KWT aqueous herbal extracts showed antibacterial effects against S. aureus, and they also showed dosage-dependent inhibitory effects on the bacterial growth. And they showed the significant intracellular killing and bacterial invasion effects. It means, KWT and TNS may show more potent anti-infectious effects against S. aureus in vivo.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1740-1745
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• 2004

In order to evaluate the in vitro synergic effect of Eunkyo-san, with quinolone antibiotics, rufloxacin (RUFX), the minimal inhibitory concentration (MIC), MIC50 and MIC90 of single use of quinolones and concomitant treatment with Eunkyo-san against 9 strains of aerobic gram positive bacteria. The obtained results were as follows : In the case of aerobic gram positive bacteria, the MIC, MIC50 and MIC90 against Staphylococcus aureus, Staphylococcus aureus smith, Staphylococcus epidermidis, Staphylococcus pyogens, Streptococcus pneumoniae Type Ⅰ, Type Ⅱ and Type Ⅲ was significantly decreased in concomitant treated groups with Eunkyo-san compared to those of single treated groups of RUFX, respectively. However, no significant changes were demonstrated against Bacillus subtilis and Enterococcus faecalis. In conclusion, the in vitro antibacterial activity of RUFX were increased against some strains of aerobic gram positive strains, especially, pneumococcus such as Staphylococcus and Streptococcus by concomitant use of Eunkyo-san.