• Archives of Pharmacal Research
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• v.21 no.5
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• pp.527-530
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• 1998

The antibacterial activity of novel ${\beta}$-lactamase inhibitors, 6-exomethylene penamsulfones (CH1240, CH2140), has been compared in vivo with that of sulbactam and clavulanic acid against b-lactamase producing strains. In vivo microbiological assessment was used as experimental mouse infection model by gram negative strains. Against Pseudomonas aeruginosa F0013, cefoperazone/CH 1240 was slightly less active than sulbactam. ampicillin/CH 2140 was less effective than sulbactam against escheriachia coli 3457. Especially against Citrobacter diversus 2046E, amoxicillin/CH 2140 was the most potent and amoxicillin/CH 1240 was slightly more active than clavulanic acid. consequently the difference in efficacy between the drug combinations appers to be related to the degree of protection afforded the animals by the b-lactamasse inhibitors. CH1240 and CH2140 are promising new agents and should undergo further investigations.

• Journal of Microbiology
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• v.45 no.3
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• pp.272-274
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• 2007

During May to July 2004, three strains of Providencia spp. with multidrug-resistance (MDR) were isolated from urinary specimen of three patients hospitalized with a same hospital room. By PCR analysis, all three strains have been found to carry both VIM-2 type $metallo-{\beta}-lactamase$ gene and PER-1 type extended spectrum ${\beta}-lactamase$ gene. One out of three strains carried additional resistance gene, armA, 16S rRNA methylase gene responsible for high level resistance to aminoglycosides. To our knowledge, this is the first report on the identification of Providencia spp. simultaneously carrying $bla_{VIM-2},\;bla_{PER-1}$, and armA genes.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.624-629
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• 2009

It is the most important step to screen soluble and insoluble proteins when we attempt to improve the solubility of recombinant proteins through directed evolution approach. Here we show that the solubility of a recombinant protein in vivo can be examined by expressing the recombinant protein with beta-lactamase as a fusion partner. First we constructed an expression system which can produc a fusion protein with the C-terminal of beta-lactamase. Two soluble proteins, i.e. adenine deaminase and aspartate aminotransferase, and insoluble GlcNAc-2-epimerase were cloned into the developed expression vector, respectively. We investigated the effect of the expression of the three recombinant fusion proteins on the growth of E. coli, and confirmed that the solubilities of the recombinant proteins correlated with cell growth rates.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.221-227
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• 2000

This study was performed to investigate the biological characteristics of twenty isolates of extended spectnlm $\beta$-lactamase (ESBL) producing Klebsiellapnezm~onia collected kom the various clinical specimens of three hospitals in Pusan. Isoelectric focusing (IEF) and PCR were used to determine the types of $\beta$-lactamase gene in this study. Twenty isolates of ESBL producing Klebsiellnp~ieun~or~iae could be divided by PCR, such as TEM type (I1 strains), SHV type (8 strains); non TEM non SHV type (1 strain). In the isoelechic focusing test, the PI of TEM type was 5.2-6.0 and that of SHV type was 6.9-7.4. According to the pI value and PCR bands, twenty strains of ESBL Klebsiellapneumoniae were divided into 5 types: TEM type @I 5.2-6.0; 1080 bp on PCR band), TEM + SHV type (pI 5.2-6.0; andpI 7.0-7.4; 1080 bp and 599 bp on PCR band), SHV type (pl7.0-7.4; 599 bp on PCR band), non TEM non SHV type, and otber type (PCR result was SHV type but pI was not detected).

• Journal of Periodontal and Implant Science
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• v.21 no.1
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• pp.176-176
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• 1991

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.20-25
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• 2009

Thirty-eight Vibrio spp. were isolated from the sea waters harvested from the 22 stations located on the west coast of the Korean peninsula in September 2006. The isolates consisted of V. parahaemolyticus (n=21), V. alginolyticus (n= 16) and V. cholerae non-01 (n=1), among which 35 isolates displayed resistance against two of the tested antibiotics. Among the 38 isolates, 18 isolates exhibited multi-drug resistance against more than four 4 antibiotics. In particular, minimum inhibitory concentration $(MIC)_{50}$ and $MIC_{90}$ of ampicillin-resistant isolates were as high as $2,048{\mu}g{\cdot}mL^{-1}$ and $4,096{\mu}g{\cdot}mL^{-1}$ respectively. $\beta$-lactamase production was examined to analyze the ampicillin-resistance. Some Vibrio spp. isolates produced $\beta$-lactamase, however antibiotics resistance pattern and $\beta$-lactamase production were not clearly related to each other. A genetic relationship between resistance and gene expression was confirmed in the ampicillin-resistant isolates.

• The Journal of the Korean Society for Microbiology
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• v.34 no.5
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• pp.445-452
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• 1999

Eight strains of multidrug-resistant (MDR) Salmonella typhi were isolated from Kyonggi area during January-February, 1997. They were resistant to ampicillin, amoxicillin, carbenicillin, tetracycline, chloramphenicol, trimethoprim/sulfamethoxazole, trimethoprim. Eight strains had one plasmid respectively which size was approximately M.W 220 kb and showed same restriction pattern by endonuclease HindIII. The plasmid was similar to the plasmid in size that was related to multidrug resistant S. typhi isolated from southeast Asia. It were transferred by conjugation to recipient E. coli K-12 in frequency of $2.43{\times}10^4-1.73{\times}10^{-2}$ and transconjugant showed same drug-resistant pattern with donor cells. All of 8 strains produced ${\beta}$-lactamase that was assummed to TEM-l type by isoelectric focusing and PCR.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.542-551
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• 2017

Small phytochemicals have been successfully adopted as antibacterial chemotherapies and are being increasingly viewed as potential antibiofilm agents. Some of these molecules are known to repress biofilm and toxin production by certain bacterial and yeast pathogens, but information is lacking with regard to the genes allied with biofilm formation. The present study was performed to investigate the inhibitory effect of burdock root extract (BRE) and of chlorogenic acid (CGA; a component of BRE) on clinical isolates of Klebsiella pneumoniae. BRE and CGA exhibited significant antibiofilm activity against K. pneumoniae without inflicting any harm to its planktonic counterparts. In vitro assays supported the ${\beta}$-lactamase inhibitory effect of CGA and BRE while in silico docking showed that CGA bound strongly with the active sites of sulfhydryl-variable-1 ${\beta}$-lactamase. Furthermore, the mRNA transcript levels of two biofilm-associated genes (type 3 fimbriae mrkD and trehalose-6-phosphate hydrolase treC) were significantly downregulated in CGA- and BRE-treated samples. In addition, CGA inhibited biofilm formation by Escherichia coli and Candida albicans without affecting their planktonic cell growth. These findings show that BRE and its component CGA have potential use in antibiofilm strategies against persistent K. pneumoniae infections.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1065-1069
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• 2009

Of 143 clinical isolates of Klebsiella pneumoniae collected from Korean non-tertiary hospitals, 24 (16.8%) showed an extended-spectrum ${\beta}$-lactamase-positive phenotype. PCR and sequence analysis revealed the presence of TEM-116 (n=13), CTX-M-3 (n=5), CTX-M-14 (n=2), CTX-M-15 (n=3), and SHV-12 (n=16). Each of the 24 isolates encoded more than one ${\beta}$-lactamase, and seven isolates (29%) harbored two different SHV-type ${\beta}$-lactamase genes ($bla_{SHV-11}$ and $bla_{SHV-12}$) bounded by insertion sequence IS26 in a single transferable plasmid.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.149-154
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• 2005

Fifty-one extended-spectrum-${\beta}$-lactamase(ESBL) producing Klebsiella pneumoniae strains were isolated from national university hospitals. All K. pneumoniae strains showed resistance to broad-spectrum antibiotic and most of them presented resistance to amikacin, gentamicin and ciprofloxacin. The results of amplified polymorphic DNA (RAPD) pattern for randomly isolated fifty-one strains were as follows; both twenty-one strains from Chungnam National University hospital and ten strains from Chungbuk National University hospital showed RAPD type Ia and Ib. However, twenty strains isolated from Gyeongsang National University hospital belonged to RAPD type IIa and IIb. All isolates were divided into four molecular types and showed high level of genetic diversity. These results suggested that RAPD analysis provided a rapid and simple method for analysing genotypes of ESBL.