• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.309-321
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• 1987

For the investigation of microbiological and immunological specificity of Bacteroides gingivalis, Bacteroides gingivalis were isolated, enumerated and characterized from 13 Korean rapidly progressive periodontitis and 7 healthy control by anaerobic culture technique. The total proportion of black-pigmented Bacteroides from Korean R.P.P. patients and healthy control were 8.78% and 0.92%, respectively, among total isolated black-pigmented Bacteroides. In antibiotic susceptibility test, Bacteroides gingivalis isolated from R.P.P. patients were sensitive to Ampicillin and Tetracycline, and resistant to Gentamicin and Erythromycin in disc diffusion method. In antibiotic broth dilution method, the minimum inhibitory concentration(MIC) to Bacteroides gingivalis was 2 unit/ml of Penicillin and $0.25{\sim}1{\mu}g/ml$ of Tetracycline, respectively. The concentration of serum IgG in rapidly progressive periodontitis patients were sigificantly higher than that of healthy control, and concentration of diluted gingival crevicular IgG has not any significant differences between two groups. Serum and gingival crevicular IgG antibody to Bacteroides gingivalis were significantly higher titer in rapidly progressive periodontitis patients to compare with healthy control. The lipopolysaccharide profiles of 2 Korean B. gingivalis in silver stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis were similar to type strains of B. gingivalis and typical LPS band were appeared around the 24-Kd molecular weight. Immunodiffusion test and immunoelectrophoresis of the L.P.S. extracted from 2 Korean B. gingivalis and 2 kinds of type strains of B. gingivalis showed that B. gingivalis Korean-1 was reacted identically to B. gingivalis ATCC 33277. In trypsin and ${\alpha}$-glucosidase activity test of 2 Korean B. gingivalis, both of them revealed positive trypsin and negative ${\alpha}$-glucosidase activity, respectively. These investigation suggested that B. gingivalis is important pathogenic plaque bacteria for the pathogenesis of periodontitis and further study is needed to purify and characterize of the species-specific antigens of this organisms to develop monoclonal antibody and potential diagnostic reagents.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.283-294
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• 1987

One hundred and fifty-seven strains of staphylococci isolated from various clinical specimens and 80 of Gram-negative bacilli from urine of patients with urological diseases were tested for resistance to antimicrobial drugs by microdilution broth method. Among staphylococci, 50 to 89% of the strains were resistant to gentamicin(Gm), kanamycin(Km), erythromycin(Em), nalidixic acid(Na), and tetracycline. Ninety per cent MIC was lowest in ciprofloxacin(Cp), followed by vancomycin(Vc), trimethoprim(Tp), enoxacin(Ex), and norfloxacin(Nf) with the values of two ${\mu}g/ml$ or lower. Twenty-seven strains were resistant to methicillin(MR), with 24 strains of Staphylococcus aureus and 3 of S. epidermidis. All strains of MR S. aureus were resistant to oxacillin, rifampin(Rf), Gm, Km, Em, Na, and Tc, and no strain was resistant to Vc and Tp. Almost all staphylococci isolated from urine were S. epidermidis and sensitive to most drugs tested without MR strain. Among Gram-negative bacilli from urine, Escherichia coli(43 strains) was most frequently isolated, and followed by Klebsiella spp.(11), Proteus spp.(10), Serratia spp.(10), and Pseudomonas aeruginosa(6) in the decreasing order. The majority of E. coli and Serratia spp. were resistant to chloramphenicol(Cm), Tc, streptomycin, sulfisomidine(Su), ampicillin(Ap), Km, and carbenicillin(Cb), and 50 and 90% MICs of these drugs were also high. In Klebsiella spp., 54% or more were resistant to Cm, Su, Ap, cephalothin, and Cb. Proteus spp. were susceptible to most drugs tested, but Pseudomonas were resistant to nearly all drugs tested except Rf, amikacin, and moxalactam(Mx). All Gram-negative bacilli tested were found to be susceptible to Mx. New quinolone carboxylic acid compounds, such as Nf, Ex, and Cp showed very high antimicrobial activities against the majority of organisms tested except Pseudomonas, and 50 and 90% MICs of Nf and Ex were always equal or 2 to 4 times higher than Cp. Organisms multiply resistant to drugs were noted in almost all isolates tested. Twenty-seven strains of staphylococci were multiply resistant to 11 or more drugs, and 6 of Klebsiella spp. to 8 to 11 drugs. The most frequent multiplicity of durg resistance were 7 and 8, 12, and 13 in E. coli, Serratia spp., and Pseudomonas, respectively. No strain was resistant to more than 5 drugs in Proteus spp..

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.382-388
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• 2019

Streptococcosis caused by Streptococcus parauberis is a very important disease in farmed olive flounder Paralichthys olivaceus. For most fish pathogens, including S. parauberis, there are no analytical criteria to distinguish antibioticsusceptible strains from antibiotic-resistant strains. In this study, epidemiological cut-off ($CO_{WT}$) values were generated to classify 75 strains of S. parauberis isolated from 1999 to 2018 as wild type (WT) and non-wild type (NWT) using disc diffusion data and normalized resistance interpretation (NRI) analysis. The susceptibility of the isolates to 16 antibiotics was evaluated using CLSI guideline M42-A. The wild-type cut-off values for amoxicillin, erythromycin, oxytetracycline, and florfenicol for S. parauberis were ${\geq}35$, 31, 28, and 27 mm, respectively. The NWT ratios of S. parauberis strains to treatment with GEN, FFC, ENR, SXT, EFT, VAN, and CHL were 17% or less, indicating that these antibiotics may be used to treat streptococcosis caused by S. parauberis. For recent S. parauberis isolates, the NWT ratios for AMX, ERY, OTC and FFC are much higher than for strains isolated from 1999-2007. The $CO_{WT}$ data from this study will assist aquatic animal disease professionals in prescribing appropriate antibiotics for the treatment of streptococcosis caused by S. parauberis, which will help reduce the misuse and abuse of antibiotics in the aquaculture sector.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.256-262
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• 2015

In order to study the effect of the receptor protein (SeaR), which is isolated from Saccharopolyspora erythraea, we introduced the SeaR gene to Streptomyces virginiae as host strains. An effective transformation procedure for S. virginiae was established based on transconjugation by Escherichia coli ET12567/pUZ8002 with a ${\varphi}C31$-derived integration vector, pSET152, which contained int, oriT, attP, and $ermEp^{\ast}$ (erythromycin promotor). Therefore, the pEV615 was introduced into S. virginiae by conjugation and integrated at the attB locus in the chromosome of the recipients by the ${\varphi}C31$ integrase (int) function. Transformants of S. virginiae containing the SeaR gene were confirmed by PCR and transcriptional expression of the SeaR gene in the transformants was analyzed by RT-PCR, respectively. And, we examined the production time of virginiamycins in the culture media of both the transformants and the wild type. The production time of virginiamycins in the wild type and transformants was the same. When 100 ng/ml of synthetic $VB-C_6$ was added to the state of 6 or 8 hour cultivation of wild type and transformants, respectively, the virginiamycins production was induced, meaning that the virginiamycins production in the wild type was detected 2 h early than transformants. From these results, SeaR expression was also affected to virginiamycins production in transformants derived from S. virginiae. In this study, we showed that the SeaR protein worked as a repressor in transformants.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.170-178
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• 2011

The purpose of this study was to assess the prevalence of periodontopathic bacteria and resistance determinants from oral biofilm of children. Subgingival dental plaque was isolated from 87 healthy children, and PCR was performed to determine the presence of 5 periodontal pathogens including P. gingivalis, T. forsythia, T. denticola, F. nucleatum, A. actinomycetemcomitans, and nine resistance genes including tet(Q), tet(M), ermF, aacA-aphD, cfxA, $bla_{SHV}$, $bla_{TEM}$, vanA, mecA. 1. The prevalence of F. nucleatum, T. forsythia. and P. gingivalis was 95.4%, 55.2%, and 40.2%, respectively. In addition. the prevalence of A. actinomycetemc omitans was 5.7%, while T. denticola was 3.4%. 2. In analysis of antibiotic resistance determinants. cfxA, $bla_{TEM}$ and tet(M) were detected in all the samples tested. It was also found that the prevalence of tet(Q) showing tetracycline resistance. $bla_{SHV}$ associated with resistance to ${\beta}$-lactams, ermF exhibiting erythromycin resistance, and, vanA resulting vancomycin resistance was 88.5%, 29.9% 87.4%, and 48.5%, respectively. The aacA-aphD gene showing resistance to aminoglycosides and mecA gene harboring methicillin resistance exhibited the lowest prevalence with 9.2%. 3. In a correlation analysis between periodontopathic pathogens and antibiotic resistance determinants, it was found that there was a significant correlation between T. forsythia and $bla_{SHV}$. Also, P. gingivalis and vanA showed a correlation. Finally, tet(Q) and ermF showed a significant correlation (phi: 0.514) while mecA and vanA also showed a correlation(phi: 0.25).

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.206-212
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• 2001

Objective : To determine the clinical and bacteriologic efficacy and safety of Cefprozil in acute pharyngitis and pharyngotonsilitis caused by Group A beta hemolytic streptococci in pediatric patients. Methods : Any patient of 3 to 14 age who visited the hospitals enrolled in this study with the signs and symptoms of pharyngitis or pharyngotonsilitis since July, 2000 to March, 2001, was taken throat culture and given Cefprozil(15 mg/kg/day, in two divided doses) for 10 days. 138 patients of whom showed positive culture results were followed up for the signs and symptoms during the treatment to determine clinical efficacy. Any undesirable effect was reported to determine the safety of the drug. Follow up cultures were done at the end of the study and bacteriologic efficacy was determined. Results : 138 of 256 patients who visited the hospitals with the signs and symptoms of pharyngitis or pharyngotonsilitis showed positive growth on throat culture. Mean age of the patients was $6.1{\pm}2.5$ and males and females were equally numbered. 129 of them complained fever on the first visit and 112(86.6%) of them were improved at the end of the study. Cervical lymphadenitis was seen in 58 patients and 44(75.9%) of them improved at the end of the study. Exudative pharyngitis was seen in 96 patients and 81(84.3%) of them improved. The overall clinical effcacy based on this results showed that 110(79.7%) of the patients were cured and 17(12.3%) of them improved. On the cultures and bacteriologic efficacy, 24.6% of them showed documented eradication after treatment and 62.3% of them showed presumptive eradication. Sensitivity test was done by agar dilution method and Cefprozil showed 100% sensitivity. Erythromycin, Clarithromycin and azithromycin showed 87%, 85.6 %, 90.6% sensitivity, respectively. Conclusion : Cefprozil is proved to be effective in controlling group A streptococcal pharyngitis and pharyngotonsilitis in children and showed good sensitivity. Cefprozil can be used as an effective oral cephalosporin in the patients showing penicillin hypersensitivity or patients who other drugs have failed.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.200-208
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• 2011

Most problematic antibiotic resistance mechanism for MLS (macrolide-lincosamide-streptogramn B) antibiotics encountered in clinical practice is mono- or dimethylation of specific adenine residue at 2058 (E. coli coordinate) of 23S rRNA which is performed by Erm (erythromycin ribosome resistance) protein through which bacterial ribosomes reduce the affinity to the antibiotics and become resistant to them. ErmSF is one of the four gene products produced by Streptomyces fradiae to be resistant to its own antibiotic, tylosin. Unlike other Erm proteins, ErmSF harbors idiosyncratic long N-terminal end region (NTER) 25% of which is comprised of arginine well known to interact with RNA. Furthermore, NTER was found to be important because when it was truncated, most of the enzyme activity was lost. Based on these facts, capability of NTER peptide to inhibit the enzymatic activity of ErmSF was sought. For this, expression system for two different proteins to be expressed in one cell was developed. In this system, two plasmids, pET23b and pACYC184 have unique replication origins to be compatible with each other in a cell. And expression system harboring promoter, ribosome binding site and transcription termination signal is identical but disparate amount of protein could be expressed according to the copy number of each vector, 15 for pACYC and 40 for pET23b. Expression of NTER peptide in pET23b together with ErmSF in pACYC 184 in E. coli successfully gave more amounts of NTER than ErmSF but no inhibitory effects were observed suggesting that there should be dynamicity in interaction between ErmSF and rRNA rather than simple and fixed binding to each other in methylation of 23S rRNA by ErmSF.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.40-50
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• 2008

Spread of pathogenic micro-organisms through contaminated hands is a well recognized way of transmitting disease such as food poisoning. We investigated the prevalence of aerobic plate counts, coliform bacteria, and food-poisoning bacteria on hands in various age groups. The average number of aerobic plate counts was 3.3 log CFU/hand in kindergarteners, 3.4 log CFU/hand in elementary students, 3.2 log CFU/hand in middle school students, 3.4 log CFU/hand in high school students, and 3.3 log CFU/hand in adults. Two kindergarteners, 6 elementary students, and 2 adults were positive for the coliform bacteria. Among the food poisoning bacteria we tested, S. aureus was isolated from 47 individuals. Eight isolates of B cereus were all from kindergarteners. C. perfringens was isolated from 7 individuals. Among 47 isolates of S. aureus, 25 isolates produced toxins. Seven of eight isolates of B. cereus produced toxins. None of seven C. peifringens isolates produced toxins. All 47 isolates of S. aureus were sensitive to ciprofloxacin, trimethoprim/sulfamethoxazole, clindamyccin, imipenem, rifampin and vancomycin. Four isolates (8.5%) were resistant to cefepime, chloramphenicol, cefotetan, and gentamycin. Five isolates (10.6%) were resistant to oxacillin and 6 isolates were resistant to tetracycline. This study shows that it is needs to be established policy of school lunch and personal sanitation management.

• Tuberculosis and Respiratory Diseases
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• v.66 no.5
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• pp.358-364
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• 2009

Background: The appropriate empirical antimicrobial choice in the treatment of community-acquired pneumonia (CAP) should be advocated by community-based information on the etiologic pathogens, their susceptibility to antimicrobials, clinical characteristics and outcomes. Jeju is a geographically isolated and identical region in Korea. However, there is no regional reference on adult CAP available. This study investigated the etiologic agents and clinical outcomes of adult patients diagnosed with CAP in Jeju, Korea, to help guide the empirical antimicrobial choice. Methods: A prospective observational study for one year in a referral hospital in Jeju, Korea. Patients diagnosed with CAP were enrolled with their clinical characteristics. Microbiological evaluations to identify the etiologic agents in the adult patients with CAP were performed with blood culture, expectorated sputum smear and culture, antibody tests for mycoplasma, chlamydophila, and antigen tests for legionella and pneumococcus. The clinical outcomes of the initial empirical treatment were analyzed. Results: Two hundred and three patients with mean age of 64 and 79 females were enrolled. Ten microbials from 90 cases (44.3%) were isolated and multiple isolates were confirmed in 30. Among the microbial isolates, S. pneumoniae (36.3%) was the most common, followed by M. pneumoniae (23.0%), C. pneumoniae (17.0%), S. aureus (9.6%) and P. aeruginosa (5.9%). The initial treatment failure (23.8%) was related to the isolation of polymicrobial pathogens, elevated inflammatory markers, and the presence of pleural effusion. Among the 30 isolates of S. pneumoniae, 16 (53.3%) were not susceptible to penicillin, and 19 isolates (63.3%) to erythromycin and clarithromycin. However, 29 isolates (96.7%) were susceptible to levofloxacin and ceftriaxone. Conclusion: S. pneumoniae, M. pneumoniae, S. aureus, and P. aeruginosa are frequent etiologic agents of adult CAP in Jeju, Korea. The clinical characteristics and antibiotic resistance should be considered when determining the initial empirical antimicrobial choice. Respiratory quinolone or ceftriaxone is recommended as an empirical antimicrobiotic in the treatment of adult CAP in Jeju, Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.358-367
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• 1983

Antibiotic-resistant strains of Salmonella typhimurium and Klebsiella pneumoniae died readily after their addition to raw sewage, but they grew in sterilized sewage. The decline was not a result of antibiotic stresses, and because the bacteria were able to survive in large numbers for at least 15 days in solutions containing no organic nutrients, it was not a result of competition. Toxin production, bacteriophages, and Bdellovibrio did not cause the disappearance of the two bacterial species. A decline was also evident if the sewage was first passed through a $3-{\mu}m$ filter or treated with cycloheximide or cycloheximide plus nystatin, but protozoa developed under these conditions. Little or no decline occurred if the sewage was filtered and treated with the eucaryotic inhibitors before adding S. typhimurium or K. pneumoniae, and protozoa were not detected. S. typhimurium increased in abundance if cycloheximide, streptomycin, and erythromycin or large amounts of glucose were added to sewage. Tetrahymena thermophilus did not significantly reduce the population of S. typhimurium in buffer when the density of the bacterium was about $10^4/ml$. However, when more than $10^8$ Enterobacter agglomerans cells per ml were added to the buffer, T. thermophilus reduced the abundance of E. agglomerans and S. typhimurium to $10^6$ and 10/ml, respectively. The density of S. typhimurium was further decreased by a second increment of E. agglomerans cells. The disappearance of S. typhimurium and K. pneumoniae from sewage thus is the result of predation by protozoa. It is proposed that predators will eliminate a prey species from a natural environment when an alternate prey is present at concentrations above the threshold number for active feeing by the predator and when the rate of growth of the prey is less than the rate of predation.