• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.233-240
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• 2010

Methicillin-resistant coagulase-negative staphylococci (MRCNS) were isolated from the respiratory sites of chickens in 4 farms and slaughter house located in Chungnam provinces. Isolation of coagulase-negative staphylococci (CNS) was positive for 61 (26.6%) of the 229 chickens tested, and isolation of MRCNS was positive for 17 (27.9%) of the isolated CNS. A total of 17 MRCNS isolates were selected and subjected to identification. Of the 17 MRCNS isolates selected, 6 were identified as Staphylococcus cohnii, 2 as S. saprophyticus, 3 as S. simulans, 3 as S. lentus, 2 as S. carnosus, and 1 as S. xylosus. The MRCNS isolates were resistant to many beta-lactam antibiotics, and some isolates were also resistant to macrolide and aminoglycoside antibiotics. The mecA gene was detected in some isolates of each MRCNS strains. The mecA-positive isolates were classified into five staphylococcal cassette chromosome mec (SCCmec). SCCmec types I to IV were detected in isolates from chickens.

• Pediatric Infection and Vaccine
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• v.11 no.2
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• pp.202-207
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• 2004

Group A streptococcus, also known as Streptococcus pyogenes, is a common bacterial pathogens of the upper respiratory tract and skin infections in children, but this organism is a less common cause of pneumonia, pericarditis. However, pneumonia that is caused by Streptococcus pyogenes, may be rapidly progressive course with developing severe consequences. It may be focal but often is bilateral and diffuse involvement of lung. Empyema is commonly developed, and pleurocentesis often yields thin, watery fluid that continues to flow out when a chest tube is inserted. Antimicrobial resistance to the ${\beta}$-lactam antibiotics has not been reported against group A streptococci, whereas increasing resistance to the macrolides seems to be directly related to the consumption of specific antimicrobial agent use in the community. Clindamycin resistance is uncommon but does occur. We experienced one case of group A streptoccoccal pneumonia with empyema and pericardial effusion, and treated successfully with amoxicillin-clavulanate, clindamycin and roxithromycin.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.133-138
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• 1996

Purpose : In the treatment of MRSA infection, rapid detection of MRSA is extremely important. The mecA gene codes the new drug resistant polypeptides called PBP2' which mediates the clinically relevant resistance to all beta-lactam antibiotics. The identical mecA gene has been found in coagulase-negative staphylococcus with the methicillin-resistant phenotype. On the other hand, the femA gene was absent from coagulase negative staphylococcus strains with the methicillin resistant phenotype. This study is aimed at early detection and definite diagnosis of MRSA. Methods : A total of 24 MRSA strains were studied. All strains were tested for antimicrobial susceptibility and purified DNA. We amplified both mecA and femA genes by PCR in 24 strains. Results : In MRSA all the 16 strains (100%) carried femA gene and 11 strains (68.7%) carried mecA gene. In contrast, in methicillin sensitive staphylococcus all the 8 strains (100%) carried femA and only 3 strains (37.5%) were detected mecA. Conclusions : As results, there are difference in the phenotype and genotype of methicillin resistance by PCR of mecA and femA. Such disparities between methicillin resistance and the presence of mecA gene suggest the presence of control gene of the mecA.

• Archives of Pharmacal Research
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• v.3 no.1
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• pp.7-12
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• 1980

Ampliciline was synthesized from 6-amino-pencillanic acid (6-APA) and D-.alpha. phenylglycine methyl ester by using amplicilin synthesizing enzyme from Peudomonas melanogenum (IAM 1655). The whole cell enzyme was immobilized by entrapping it in the polyacrylamide gel lattices. The polymer used in the enzyme entrapment was made from 150 mg per ml of acrylamide monomer and 8 mg per ml of N, N'-methylenebisacrylamide. About 200 mg/whole cell enzyme was mixed in the polymer for entrapment. The maximal activity retention after immobilization was 56%. The optimal pH values for the whole cell enzyme and the immobilized whole cell enzyme were 6.0 and 5.9, respectively. The optimal temperature for the enzyme activity were the same for both type of preparations. The enzyme stabilities against pH and heat increased for immobilized whole cell enzyme. Immobilized cell was more stable especially in the acidic condition while both type were found to be very suceptible to thermal inactivation at a temperature above 4.deg.C. The kinetic constants obtained from Lineweaver-Burk plot based on two substate reaction mechanism showed somewhat higher value for immobilized whole cell enzyme as compared to the whole cell enzyme : the Km value for 6-APA were 7.0 mM and 12.5 mM while Km values for phenylglycine methyl ester were 4.5 mM and 8.2 mM, respectively. Using the immobilized whole cell enzyme packed in a column reactor, the productivity of ampiciline was studied by varying the flow rate of substrate solution. At the space velocity, SV, 0.14 hr$^{-1}$ the conversion was 45%. Operational stability found in terms of half life was 30 hr at SV = 0.2 hr.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.676-681
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• 1994

Diels-Alder adducts, carbacephems were obtained when 4-acetoxyazetidine-2-one or (3R,4R)-4-acetoxy-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]azetidin-2-one was reacted with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene or with 3-(tert-butyldimethylsilyloxy)-1,3-pentadiene. When tert-butyldiemethylsilyl acrylate was used as the diene, products in which was acetoxy group of 4-acetoxyazetidin-2-one derivatives was substituted by an acryloyloxy group were isolated. When the same reaction was carried out with 4-phenylsulfonylazetidin-2-one as a dienophile with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene, 4-phenylsulfoyl-2-butanone was obtained instead of the expected carbacephem. When dimeric form of thiochalcone was reacted with 4-acetoxyazetidin-2-one in the presence of zinc chloride, the $\beta-lactam$ ring of the azetidin-2-one was destructed and no product was isolated. Also, the reaction of 2-trimethylsilyloxy-1-aza-1,3-butadiene, which was obtained from N-methylacrylamide by treatment of trimethylsilyl trifluoromethanesulfonate in the presence of triethylamine, with 4-acetoxyazetidin-2-one did not give any products.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.313-316
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• 2006

To obtain antibiotic resistant profiles of Bifidobacterium, minimum inhibitory concentrations (MIC) of 14 antibiotics for 93 Bifidobacterium isolates from Korean intestine origin were determined. All strains tested were sensitive to chloramphenicol, rifampicin, and amoxicillin, whereas resistant to aminoglycoside family, nalidixic acid, and vancomycin. Among vancomycin-resistant strains, 34% were resistant at more than $100\;{\mu}g/mL$, and showed variant resistances toward tetracycline, erythromycin, and penicillin. Their resistances against penicillin, cephalothin, and tetracycline were higher than ten years ago. MIC of ten isolates from commercial yoghurt products were very similar to those of strains from Korean intestine origin, and 20% strains showed resistance at higher than $100\;{\mu}g/mL$ vancomycin. These results indicated patterns of antibiotic resistance against Bifidobacterium from Korean intestine origin and commercial yoghurts were very similar,and prevalence of vancomycin resistance for Bifidobacterium was 20%. To develop new probiotic, antibiotic resistance of vancomycin and risks involved should be evaluated.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.155-157
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• 2018

Salmonella enterica subsp. enterica serovar Thompson strain MFDS1004024 was isolated from crab-stick in Korean food-borne outbreak in 2014. Here, we present the complete genome sequence of strain MFDS1004024 with a size of 4,742,942 bp and a mean G + C content of 52%. The genome included 4,373 coding sequences, and 22 ribosomal RNA and 84 transfer RNA genes. Also, we found that strain MFDS1004024 has some genes for Salmonella infection and beta-lactam resistance in its genome based on the result of genome analysis.

• Journal of Pharmaceutical Investigation
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• v.28 no.1
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• pp.25-33
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• 1998

Intestinal absorption of ${\beta}-lactam$ antibiotics and angiotensin converting enzyme(ACE) inhibitors has been shown to use the carrier-mediated transport system. In vitro experiments have established that the efficacy of uptake by enterocytes depends on an inwardly directed proton gradient. It was suggested that benazepril was mediated by tripeptide transport system and that amoxicillin was transported by dipeptide transport carrier. The aim of this study is to assess the influence of amoxicillin on the intestinal absorption of benazepril using in vitro diffusion chamber and in situ single pass perfusion technique in the rat in order to elucidate whether the above transport systems are competitive or not. We obtained the gastrointestinal pemeability coefficient of amoxicillin, benazepril and both of them using in vitro diffusion chamber. And also the gastrointestinal absorption clearance of amoxicillin, benazepril and both of them using in situ single-pass perfusion method at steady state were calculated. Amoxicillin and benazepril were analyzed by HPLC. The results by the use of diffusion chamber in vitro indicated that the apparent intestinal permeability coefficient of benazepril was significantly(p<0.01) decreased by amoxicillin(45.2%) and vice versa significantly(p<0.01) decreased(89.1%). The results by the in situ gastrointestinal single-pass perfusion method indicated that the intestinal absorption clearance of benazepril was significantly(p<0.05) decreased by amoxicillin (40.2%) and vice versa significantly(p<0.05) decreased(54.8%). These results might suggest that they share the same peptide carrier pathway for oral absorption.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.251-258
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• 1987

A total of 58 strains of Enterobacter species isolated from clinical specimens at Kyungpook National University Hospital in Taegu and Yonsei University Hospital in Seoul were tested for the molecular characterization to investigate the nosocomial infection through the study of R plasmids which might spread among Gram negative organisms regardless of their originated strains. All strains resistant to ampicillin, cefoxitin and cephalothin but susceptible to moxalactam were subjected to the further test for the determination of in detail MIC value against 23 drugs of common use including beta-lactam antibiotics and R plasmid profile analysis. The reistance frequency of strains against carbenicillin (53.4%) was similar to those against chloramphenicol, tobramycin, and sulfisomidine. Though the MIC values of resistance criteria against ceftazidime, aztreonam, imipenem, and norfloxacine in NCCLS manual were not available but MIC ranges of strains tested were very low. There were differences in patterns and frequencies of resistance between the strains isolated in Seoul and Taegu isolates. Seoul isolates showed a tendency of higher multiplicity of resistance than those of Taegu isolates. The resistances against cefoxitin, cephalothin, cefoperazone, cefotaxime, nalidixic acid, and rifampin were not conferred to the conjugally transferable R plasmid. The approximate molecular size of conjugally transferable R plasmids ranged 30 to 151 megadalton, and one or 2 to 3 R plasmids were identified in each transconjugants.

• Infection and chemotherapy
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• v.50 no.4
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• pp.328-339
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• 2018

Background: Pneumococcal disease is a major cause of morbidity and mortality worldwide, especially in patients with comorbidities and advanced age. This study evaluated trends in epidemiology of adult pneumococcal disease in Crete, Greece, by identifying serotype distribution and antimicrobial resistance of consecutive Streptococcus pneumoniae strains isolated from adults during an 8-year time period (2009-2016) and the indirect effect of the infant pneumococcal higher-valent conjugate vaccines 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13). Materials and Methods: Antimicrobial susceptibility was performed by E-test and serotyping by Quellung reaction. Multidrug resistance (MDR) was defined as non-susceptibility to penicillin (PNSP) combined with resistance to ${\geq}2$ non-${\beta}$-lactam antimicrobials. Results: A total of 135 S. pneumoniae strains were isolated from adults during the study period. Twenty-one serotypes were identified with 17F, 15A, 3, 19A, and 11A, being the most common. The coverage rates of PCV10, and PCV13 were 17.8% and 37.8%, respectively. PCV13 serotypes decreased significantly from 68.4% in 2009 to 8.3% in 2016 (P = 0.002). The most important emerging non-PCV13 serotypes were 17F, 15A, and 11A, with 15A being strongly associated with antimicrobial resistance and MDR. Among all study isolates, penicillin-resistant and MDR strains represented 7.4% and 14.1%, respectively. Predominant PNSP serotypes were 19A (21.7%), 11A (17.4%), and 15A (17.4%). Erythromycin, clindamycin, tetracycline, trimethoprim-sulfamethoxazole, and levofloxacin resistant rates were 30.4%, 15.6%, 16.3%, 16.3%, and 1.5%, respectively. Conclusion: Although pneumococcal disease continues to be a health burden in adults in Crete, our study reveals a herd protection effect of the infant pneumococcal higher-valent conjugate vaccination. Surveillance of changes in serotype distribution and antimicrobial resistance among pneumococcal isolates are necessary to guide optimal prevention and treatment strategies.