• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.147-157
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• 2020

Purpose: We investigated the trend of antibiotic susceptibility of Haemophilus influenzae over 5 consecutive years. Methods: We analyzed the antibiotic susceptibility of H. influenzae isolated from children aged <18 years, who were admitted to the Asan Medical Center Children's Hospital from March 2014 to April 2019. Antibiotic susceptibility of H. influenzae was determined by the disk diffusion test according to the European Committee on Antimicrobial Susceptibility Testing guidelines. Results: Excluding duplicates, 69 isolates were obtained over the past 5 years. The median age of the patients was 5 years (range, 2.8-8.6 years). The antibiotic susceptibility patterns were as follows: ampicillin (AMP)-susceptible/amoxicillin-clavulanate (AMC)-susceptible (AS/ACS; n=15 [21.7%]), AMP-resistant/AMC-susceptible (AR/ACS; n=21 [30.4%]), and AMP-resistant/AMC-resistant (AR/ACR; n=33 [47.8%]). The prevalence of isolates with AR/ACR phenotype tended to increase from 42.1% in 2014-2015 to 54.5% in 2018-2019 (P=0.342). Compared to 2014-2015, the resistance rates to cefuroxime and ceftriaxone in 2018-2019 increased from 31.6% to 77.3% and from 0.0% to 59.1%, respectively (P=0.003 and P<0.001, respectively). Conclusions: Over the last 5 years, H. influenzae isolates with AR/ACR phenotype and ceftriaxone resistance were frequently observed at our institute. The incidence of resistance to cefuroxime and ceftriaxone has increased significantly.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.462-469
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• 2004

The aim of this study was to investigate the susceptibility of mutans streptococci (S. mutans and S. sobrinus) and Streptococcus anginosus, for seven antibiotics, penicillin G, amoxicillin, ciprofloxacin, cefuroxime, erythromycin, bacitracin, and vancomycin. The minimum inhibitory concentration (MIC) of seven antibiotics against 3 species (type strains) of mutans streptococci and S. anginosus, 10 strains (wild type) of S. mutans, 7 strains (wild type) of S. sobrinus, and 11 strains (wild type) of S. anginosus, were measured by broth dilution method. All of the type strains of mutans streptococci and S. anginosus had the same susceptibility for penicillin G, amoxicillin, cefuroxime and bacitracin. Type strain of S. anginosus was sensitive in ciprofloxacin, but those of mutans streptococci were not. All of the clinical isolates of mutans streptococci and S. anginosus had the same susceptibility for the seven antibiotics. Our data reveal that mutans streptococci and S. anginosus have similar antibiotic-resistant character. In addition. these results may offer the basic data to verify the antibiotic-resistant mechanism of mutans streptococci and S. anginosus.

• International Journal of Oral Biology
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• v.40 no.1
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• pp.41-50
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• 2015

The aim of this study was to identify bacteria isolated from the oral cavities and to determine their antimicrobial susceptibility against eight antibiotics. The bacterial strains were obtained from the Korean Collection for Oral Microbiology (KCOM). The bacteria were identified by comparing 16S rDNA sequences at the species level. The data showed that 77 bacterial strains were predominantly identified as streptococci (49.4%) and staphylococci (14.3%). Minimum inhibitory concentrations (MIC) were determined using a broth dilution assay to test the sensitivity of the bacterial strains. The MIC values of the oral bacterial strains against antibiotics were different. Streptococci were sensitive to clindamycin, cefuroxime axetil, and vancomycin, and they were resistant to tetracycline. Staphylococci also were sensitive to clindamycin, cefuroxime axetil, and vancomycin, and they were resistant to penicillin antibiotics. Gramnegative bacterial strains were sensitive to tetracycline and were resistant to clindamycin. These results suggest that the antimicrobial susceptibility test is necessary in deciding the prescription for antibiotics, to prevent the misuse or abuse of antibiotics.

• Biomolecules & Therapeutics
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• v.7 no.1
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• pp.44-53
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• 1999

The resistant strains due to the extended-spectrum $\beta$-lactamase (ESBL) were susceptible to cefatrizine combined with clavulanic acid. The purpose of this study was to evaluate the in vitro and in vivo antibacterial activities of cefatrizine/clavulanic acid (CTRZ/CV) combination at a ratio of 2 : 1 in comparison with cefaclor (CCLO), cefuroxime (CRXM), cefuroxime axetil (CRXMA) and amoxicillin/clavulanic acid (AMXCCV). CTRZ/CV showed good activity against laboratory strains of gram-positive and gram-negative bacteria and exhibited excellent antibacterial activity against $\beta$-lactamase-producing strains. The bactericidal activity of CTRZ/CV was superior to that of CCLO and CRXM, and almost equal to that of AMXCCV against the $\beta$-lactamase-producing strains. The in vitro results were substantiated. by in vivo mouse experimental infection studies with $\beta$-lactamase-producing and non-producing strains. In mixed experimental infection due to $\beta$-lactamase-producing and non-producing strains, the therapeutic efficacy of CTRZ/CV was superior to that of CTRZ, CCLO, CRXMA and AMXCCV. In respiratory tract infection in mice due to Klebsiella pneumoniae EB4O, CTRZ/CV was more erective than CCLO, CRXMA and AMXCCV and also more efficacious than CCLO, CRXMA and AMXCCV in urinary tract infection in mice due to Escherichia coli EB13. These results indicate that CTRZ/CV is a useful drug for the treatment of infection caused by $\beta$-1actamase-producing strains including ESBL-producing strains.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.870-877
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• 2020

Twenty-three Bacillus cereus strain isolated from commercial jeotgal were investigated for 11 toxin genes and susceptibility to 25 different antimicrobials. The hemolytic enterotoxins hblA, hblC, and hblD were detected in 13.0%, and non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 26.1%, 100%, and 100% of the isolates, respectively. The positive rates of cytK, entFM, becT, hlyII, and ces were 73.9%, 60.9%, 26.1%, 8.7%, and 0.0%, respectively. According to the disk diffusion susceptibility test, all of the strains studied were resistant to cefuroxime, followed by cefoxitin (78.3%), oxacillin (78.3%), ampicillin (69.6%), penicillin G (69.6%), and amoxicillin (65.2%). However, all the strains were susceptible to 11 other antimicrobials, including amikacin, chloramphenicol, and ciprofloxacin. The average minimum inhibitory concentrations of amoxicillin, ampicillin, and cefuroxime against B. cereus were 462.9, 235.0, and 135.0 ㎍/mL, respectively. These results highlight the need for sanitizing commercial jeotgal, and provide evidence to help reduce the risk of jeotgal contamination by antimicrobial-resistant bacteria.

• Korean Journal of Veterinary Service
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• v.27 no.2
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• pp.153-157
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• 2004

Bacteria isolated from nasal cavity of 50 Thoroughbred horses with respiratory tract infection were examined. There were isolated Pseudomonas aeruginosa(33.5%), Escherichia coli(10.2%), Pseudomonas spp(7.6%), Klebsiella oxytoca(5.9%), Streptococcus equi subsp zooepidemious(6.2%), Klebsiella pneumoniae(3.4%), Acinetobacter spp(5.5%) and coagulase negative staphylococcus(2.1%). The majority of isolates were highly susceptible to amikacin, amoxicillin, aztreonam, cefotaxime, cefepime, cefotetan, ceftazidime, cefuroxime, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, imipenem, tetracyclin and vancomycin. These results can provide basic information for the treatments of respiratory tract infections in Thoroughbred horses.

• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.257-266
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• 2005

Background : The study of pneumonia among young men living in a group is rare. prospective study was conducted to determine the etiology, and compare the effects of macrolide and second-generation cephalosporin on the treatment of pneumonia among combat policemen. Patients and Methods : From January 2003 to April 2004, Fifty-two patients with pneumonia were treated with either azithromycin(n=25) or cefuroxime(n=27). In order to determine the cause of the pneumonia, culture studies and serologic tests for antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae were carried out. During the two weeks of medication, the Chest X-rays, blood tests and culture studies(if necessary) were followed weekly. A serologic study was followed at the end of the second week. Results : The main pathogens for pneumonia among combat policemen were Mycoplasma pneumoniae(50.0%), Chlamydia pneumoniae(10.8%), and Streptococcus pneumoniae(3.8%). The treatment was successful in most cases(51/52 cases, 98.1%). The effects of azithromycin and cefuroxime were similar (96.0% vs 100%, p>0.05). In one patient who had taken azithromycin, the clinical and radiological findings did not improved until intravenous second generation ce phalosporin had been infused. Conclusion : Atypical pathogens were the main causes of the pneumonia in the combat policemen, and the effects of macrolide and second generation cephalosporin for pneumonia were similar. However, further studies will be needed to determine if single therapy with macrolide is possible.

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.85-88
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• 1986

To estimate the effect of some injectable antibiotics (ampicillin sodium, cefazolin sodium, cephaloridine, cefuroxime sodium and chloramphenicol sodium succinate) on pyrogen tests, the Limulus amebocyte lysate (LAL) test and an ultrafiltration technique were used. The rabbit pyrogen test was also used in the case of cafazolin sodium. At high antibiotic concentrations, these samples which were artificially contaminated with endotoxin inhibited the gelation reaction of LAL. But the gelation reaction occurred when most of the antibiotic was removed by ultrafiltration. Likewise, cefazolin sodium interfered not only with the LAL test but also with the rabbit pyrogen test. From these results it can be said that special modification to eliminate interference should be taken into consideration for valid method of pyrogen tests in the parenteral products containing these antibiotics.

• Journal of Life Science
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• v.8 no.1
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• pp.40-50
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• 1998

Staphylococuus aureus and Escherichia coli is increasingly responsible for outbreaks of nosocomial infection around the world. Because serious infections due to these organisms currently necessiate use of non-$\beta$-lactam antimicrobial therapy and because strains is ofen resistant to many antimicrobial agents, infections with this organism are difficult to treat. Isolated strains from post operaton wounds of PNU hospital patient were tested for the antimicrobial susceptibility, resistant pattern and combined action to the 6 antibiotics. The minimal inhibitory concentraction of each antibiotic anc antibiotics combining in various ratios were measured by checkerboard dilution method. the synergism was determined through calculating the fractional inhibitory concentraction index (FICI). In case of S. aureus, 15 strains was shown to be highly sensitive to streptomycin and 13 strains to cephalothin. In case of E. coli, it is excellent senstitive 16 strains, sensitive 4 strains on cefoperazone, as like S. aureus, and thus the sensitive is most to be 66%. As the result of gaining MIC from S. aureus upon agar dilution method, MIC$_{50}$ was 8$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml and thus the streptomycine is shown to be lowest. In case of E, coli, S. MIC$_{50}$ was 4$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml, in streptomycin and thus is shown to be lower than S. aureus. As the result of comparing the resistance aspect of combining the antibiotics on S. aureus and E. coli, the resistant strain can be known to be reduced to the large range more than each 40% than combining with only aminoglycoside-series or cephalosporine-series. As the result of combining aminoglycoside-series, streptomycin and cephalothin or cefuroxime sensitive to S. aureus and E. coli in the above mentioned results, the increase or imporovement of effect is over 73% and 80%, respectively, thus the case od combining 2 antibiotics is shown to be better in the effect. Isolated strains from operating wounds were for the antimicrobial susceptibility. In case of S. aureus 15 strains was shown to be sensitive very much on streptomycin. In case of E. coli it is excellent sensitive 16 strains. As the results of combining aminoglycosides-series, streptomycin and cephalosporine series, cephalothin and cefuroxime, the increase or improvement of effect is over 73%, thus case of combining 2 antibiotics is shown to be better in the effect.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.215-218
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• 2009

The dog breeding kennel bacterial infection are very significant in perinatal mortality. In many case, Staphylococcus aureus, Streptococcus, and Escherichia coli were infected in intra-uterine or by the genital tract to the puppies, and they are cause of septicemic death of the puppies and clinical mastitis of bitch, leading to septicemic death of newborn puppies. Severe mastitis due to bacterial infection was diagnosed in a 2 year-old female Brittany Spaniel which loss 6 puppies with odor small rice sharp white diarrhea of nine puppies. Bright curd milk and intestinal sample were inoculated on MacConkey agar, blood agar and brain heart infusion agar, and incubated at $37^{\circ}C$ for 24-48 hrs. Gram negative colonies isolated from these sample which were characterized as Glu, Ure, $H_2S$, Orn, Cit, and Cl, and were identified by Microscan Walk-Aways Baxter, American Type Culture Collection, USA) as Proteus mirabils. The isolate was more sensitive to ampicillin, gentamicin, cefoxitin, cefuroxime, and cefazidime. In this results, we confirmed that cause bacteria of septicemic death in puppies was P. mirabilis.