• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.397-400
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• 2009

This article presents the case of a bilateral chronic subdural hematoma which was contaminated with Klebsiella pneumoniae and resulted in a life-threatening central nervous system infection. After repeated of bilateral burr-hole drainage, the patient became hyperpyrexic and drowsy. Suppuration within the subdural space was suspected and then the patient underwent bilateral fronto-temporo-parietal craniotomies, and pus was evacuated. Its cultures revealed Klebsiella pneumoniae. Intravenous meropenem was given for 6 weeks. He recovered completely. Microorganisms like Klebsiella pneumoniae may directly infect the subdural space with iatrogenic contamination.

• Biomedical Science Letters
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• v.25 no.3
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• pp.288-292
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• 2019

In vitro antimicrobial activities of hot water extracts of Camellia sinensis (L.) O. Kuntze, for carbapenem-resistant Enterobacteriaceae (CRE) were compared to commonly used conventional antimicrobial agents. CRE was not only resistant to imipenem, meropenem or ertapenem, but also to various antimicrobial agents, such as amikacin (> $128{\mu}g/mL$). The hot water extracts of Camellia sinensis (L.) O. Kuntze had the lowest MIC ($0.06{\sim}0.5{\mu}L/mL$) of the carbapenem-resistant E. coli, K. pneumoniae, and Enterobacter spp. tested, and it was possible more potent than various conventional antimicrobial agents. Synergistic combinations of the extract with used commonly antimicrobial agents might even improve its antimicrobial chemotherapy property.

• Biomedical Science Letters
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• v.25 no.3
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• pp.275-281
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• 2019

This study was performed to characterize the chromosomal metallo-${\beta}$-lactamases (MBLs) of Chryseobacterium indologenes isolated from Korea and to propose a clustering method of IND MBLs based on their amino acid similarities. Chromosomal MBL genes were amplified by PCR from 31 clinical isolates of E. indologenes. Nucleotide sequencing was performed by the dideoxy chain termination method using these PCR products. Antimicrobial susceptibilities were determined by the agar dilution method. PCR experiments showed that all 31 E. indologenes isolates contained all $bla_{IND}$ genes. DNA sequence analysis revealed that E. indologenes isolates possessed ten types of $bla_{IND}$ gene, including seven novel variants ($bla_{IND-8}$ to $bla_{IND-14}$). The most common combination of MBL was IND-2 (n = 18). Minimum inhibitory concentrations of imipenem and meropenem for the isolates harboring novel IND MBLs were ${\geq}16{\mu}g/mL$. IND MBLs were grouped in three clusters, based on amino acid similarities.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.221-228
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• 2020

Ochrobactrum anthropi is a non-fermentative oxidative gram-negative bacillus that produces oxidase. Distinguishing a mixed culture with non-fermenting bacteria having a similar appearance and oxidase-positive is difficult, and there is a limit to accurate identification with a biochemical identification system. This paper proposes that the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Platform (MALDI-TOF) method is useful for classifying bacteria that are difficult to identify using biochemical testing methods. As a result of analyzing five cases of O. anthropi examined using MicroScan, it took 6.5 days to the final report, which was 3.5 days more than the 3.0 days of E. coli. The pus sample in patient 5 was a mixed infection with Achromobacter xylosoxidans, and it took 11.3 days because of multiple subculture and retests. Four patients were over 60 years old with an underlying disease, and the possibility of opportunistic and nosocomial infections could not be excluded. Among them, samples collected after 92 days of hospitalization were resistant to imipenem and meropenem. Therefore, an examination using the MALDI-TOF method will be useful for the rapid and adequate treatment of patients with difficult identification, such as O. anthropi.

• Journal of Life Science
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• v.22 no.9
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• pp.1268-1276
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• 2012

The emergence and dissemination of carbapenem-resistant bacteria have resulted in limitations of antibiotic treatment and potential outbreaks of metallo-${\beta}$-lactamase (MBL) producing Pseudomonas aeruginosa resistant to carbapenems. In this study, we conducted molecular characterization of the MBL genes of the ${\beta}$-lactam drug-resistant P. aeruginosa and prepared basic data for treatment and prevention of proliferation of antimicrobial-resistant bacterial infections. Forty-two P. aeruginosa isolates of 254 were resistant to imipenem or meropenem. Among the 42 isolates, 28 isolates were positive for the Hodge test, and 23 isolates were positive for the EDTA-disk synergy test (EDST). MBLs were detected in 59.5% (25/42) of P. aeruginosa isolates. Eight isolates harbored $bla_{IMP-6}$, whereas 17 isolates harbored $bla_{VIM-2}$. The $bla_{IMP-6}$ gene was in a class 1 integron containing five gene cassettes: $bla_{IMP-6}$, qac, aacA4, $bla_{OXA-1}$, and aadA1. Some strains that produce IMP-6 and VIM-2 showed epidemiological relationships. The $bla_{IMP-6}$ gene in carbapenem-resistant P. aeruginosa showed an identical pattern to a gene cassette that was reported at a hospital in Daegu, Korea. Therefore, MBL-producing P. aeruginosa is already endemic in the community. We are concerned that the existence of carbapenem-resistant bacteria containing the blaMBL gene may increase pressure on antibiotic selection when treating infections. We believe that we should select appropriate antibiotics based on the antibiotic susceptibility test and continue the research to prohibit the emergence and spread of antibiotics resistant bacteria.

• Journal of Veterinary Science
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• v.22 no.5
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• pp.68.1-68.15
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• 2021

Background: Colistin and carbapenem-resistant bacteria have emerged and become a serious public health concern, but their epidemiological data is still limited. Objectives: This study examined colistin and carbapenem resistance in Escherichia coli and Salmonella from pigs, pig carcasses, and pork in Thailand, Lao PDR, and Cambodia border provinces. Methods: The phenotypic and genotypic resistance to colistin and meropenem was determined in E. coli and Salmonella obtained from pigs, pig carcasses, and pork (n = 1,619). A conjugative experiment was performed in all isolates carrying the mcr gene (s) (n = 68). The plasmid replicon type was determined in the isolates carrying a conjugative plasmid with mcr by PCR-based replicon typing (n = 7). The genetic relatedness of mcr-positive Salmonella (n = 11) was investigated by multi-locus sequence typing. Results: Colistin resistance was more common in E. coli (8%) than Salmonella (1%). The highest resistance rate was found in E. coli (17.8%) and Salmonella (1.7%) from Cambodia. Colistin-resistance genes, mcr-1, mcr-3, and mcr-5, were identified, of which mcr-1 and mcr-3 were predominant in E. coli (5.8%) and Salmonella (1.7%), respectively. The mcr-5 gene was observed in E. coli from pork in Cambodia. Two colistin-susceptible pig isolates from Thailand carried both mcr-1 and mcr-3. Seven E. coli and Salmonella isolates contained mcr-1 or mcr-3 associated with the IncF and IncI plasmids. The mcr-positive Salmonella from Thailand and Cambodia were categorized into two clusters with 94%-97% similarity. None of these clusters was meropenem resistant. Conclusions: Colistin-resistant E. coli and Salmonella were distributed in pigs, pig carcasses, and pork in the border areas. Undivided-One Health collaboration is needed to address the issue.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.237-237
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• 1996

DA-1131, imipenem(IPM) 및 meropenem(MEPM)은 각종 $\beta$-lactamase를 산생하는 세균에 대하여 우수한 항균력을 나타내었으나 cefpirome(CPR), ceftazidime(CAZ) 및 azthreonam(AZT)의 경우에는 extended broad spectrum cephalosporinase 산생 균주를 포함하여 일부 균주의 내성획득이 확인되었다. DA-ll3l의 $\beta$-lactamase Inducible activity는 DA-1131, IPM 및 MEPM이 거의 동일하였으며, imipenemase 산생균주로 동점된 Serratia marcescens 11001이 산생하는 $\beta$-lactamase이외의 효소에는 대부분 가수분해되지 않는 결과를 나타내었다. S. marcescens 11001이 산생하는 $\beta$-lactamase에 대한 효소역학상수는 DA-1131, IPM 및 MEPM에서 모두 유사하였고, $\beta$-lactamase에 대한 affinity도 큰 차이를 나타내지 않았다.

• YAKHAK HOEJI
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• v.50 no.2
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• pp.78-83
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• 2006

VISA and VRE are the main causes of surgical infection, urinary tract infections and bacteremia in hospitals. In this study; we selected VISA (Vancomycin Intermediate resistant Staphylococcus aureus) and VRE (Vancomycin Resistant Enterococcus) isolated from the clinical isolates. One of the isolated strains indicated the high resistance to severel anti-biotics (Vancomycin, Teicoplanin, Mupirocin, Synercid, Ciprofloxacin, Gentamicin, Lincomycin, Cefotaxim, Meropenem). Antimicrobial activity of Bifidobacterium spp. against VISA and VRE were measured. About $10^4$ cells of VISA or VRE were mixed with 1,5 and 9 ml of Bifidobacterium and the final volume was adjusted to 10 ml with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 hr, serially diluted and then plated on BHI agar plate. As numbers of Bifidobacterium were increased viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of the Bifidobacterium was observed after 9hr incubation in any mixture, almost completely inhibiting the growth of VISA and VRE.

• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1768-1772
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• 2008

CW-270031 is a novel synthesized carbapenem antibiotic with a broad antimicrobial activity. Carbapenem antibiotics are well known for their nephrotoxicity. In this study, we evaluated the nephrotoxicity potential of this compound in rabbits, which are known for being more sensitive than other animals to renal insult. CW-270031 was administered to NZW male rabbits via an ear vein (200 mg/kg, single injection). Blood samples were collected on 2, 3, and 4 days after treatment. Urea nitrogen and creatinine in plasma were quantified. Four days after the treatment, all animals were autopsied and histopathological examinations were performed on their kidneys, revealing that cephaloridine and imipenem were highly nephrotoxic, and cefazolin had mild renal toxicity, whereas CW-270031 as well as meropenem and tienam had no toxicity to the kidney. The present findings suggest that CW-270031 is a potential carbapenem antibiotic with no nephrotoxicity.

• Biomedical Science Letters
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• v.25 no.4
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• pp.321-330
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• 2019

Carbapenem is recently considered as the last resort of the therapeutics for gram negative bacterial infection. Increasing of organisms producing metallo-β-lactamase (MBL), we have difficulty in choosing the antimicrobial agents. Among 345 clinical isolates of Pseudomonas spp., 61 isolates (17.7%) were positive for the modified imipenem or meropenem-Hodge test and 55 isolates (15.9%) were positive for the imipenem-EDTA + SMA double disk synergy test (DDS). PCR and sequencing of bla_VIM-2-allele and bla_IMP-1-allele showed that 17 isolates of Pseudomonas aeruginosa, 9 isolates of Pseudomonas taiwnensis and 2 Pseudomonas plecoglossicida had bla_VIM-2, and 22 isolates of P. aeruginosa and one Pseudomonas otitidis had bla_IMP-6. These MBL genes were all in class 1 integron. The size of class 1 integron with bla_VIM-2 ranged from 3.5 kb to 5.5 kb in clinical isolates of Pseudomonas spp. including P. aeruginosa. bla_VIM-2 was most often located first in the class 1 integron, sometimes in the second or third position, and these integrons often had aacA4 or aadA1. Strict infection control measures are needed to more effectively prevent further spread of these MBL-producing Pseudomonas spp. In addition, MBL-producing Pseudomonas spp. is expected to continue to spread in various countries and regions.