• KSBB Journal
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• v.13 no.2
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• pp.119-124
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• 1998

Twelve bacterial strains capable of growing on phenol minimal medium were isolated from iron foundry activated sludge by enrichment culture, and amount them, one isolate which was the best in cell growth and phenol degradation was selected and identified as Acinetobacter junii POH. The optimal temperature, initial pH and phenol concentration in the above medium were 3$0^{\circ}C$, 7.5 and 1000 ppm, respectively. Cell growth of Acinetobacter junii POH dramatically increased 20 hrs cultivation-time and reached a almost stationary phsae 40 hrs cultivation-time then phenol was degraded about 98%. Cell growth was inhibited y phenol at concentrations over 1500 ppm. The isolate was resistant to several antibiotics as well as various heavy metal ions. The growth-limiting log P value of Acinetobacter junii POH on organic solvents was 2.9 in the LB medium. Therefore, it is suggested that Acinetobacter junii POH could be effectively used for the biological treatment of wastewater containing the presence of heavy metal ions and organic solvents.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.97-108
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• 2000

A Gram-type negative bacteria that can utilize crude oil as the sole source of carbon and energy was isolated from an activated sludge of a local sewage treatment plant and identified tentatively as belonging to the genus Acinetobacter. The isolate could degrade n-alkanes and unidentified hydrocarbons in crude oil and utilize n-alkanes, hydrophobic substrates, as sole carbon and energy sources. n-Alkanes from tridecane (Cl3) to triacontane (C30) in crude oil were degraded simultaneously with no difference in degradation characteristics between the two close odd and even numbered alkanes in carbon numbers. The linear growth of the isolate and the degradation characteristics of Pr-alkanes suggested that the transport of substrates from the oil phase to the site where the substrates undergo the initial oxidation in microorganism might be the rate limiting in the biodegradation process of crude oil constituents. The remainder fraction of substrates after cultivation was considered to reflect the hydrocarbon inclusions in the cell mass, characteristics in Acinetobacter species, and to control the transport of substrates from crude oil phase. On the basis of the results, the isolate was considered to play an important role in the degradation study of hydrophobic environmental pollutants.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.133-140
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• 1986

Extracts of CO-autotrophically grown cells of Acinetobacter sp. 1 were shown to use thionin, methylene blue, or 2,6-dichlorophenol-indophenol, but not NAD, NADP, FAD, or FMN, as electron acceptors for the oxidation of CO under strictly anaerobic conditions. The CO dehydrogenase (CO-DH) in the thes bacterium was found to be an inducible enzyme. The enzyme activity was determined by an assay based on the CO-dependent reduction of thionin. Maximal reaction rates were found at pH 7.5 and $60^{\circ}C$, and the Arrhenius plot revealed an activation energy of 6.1 kcal/mol(25.5kJ/mol). THe $K_m$ m/ for CO was $154{\mu}M$. Known metalchelating agents tested had no effects on the CO-DH activity. No divalent cations tested affect the enzyme activity significantly escept $Cu^{2+}$ which suppressed the activity completely. The enzyme was inhibited by glucose and succinate. The same extracts catalyzed oxidation of hydrogen gas and formate with thionin as electron acceptor. The CO-DH of Acinetobacter sp. 1 was to have no immunological relationship with that of Pseudomonas carboxydohydrogena.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.444-452
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• 2019

Carbapenem resistance, mediated by the major acquired metallo-β-lactamase (MBL) genes, has been increasingly reported, particularly for clinical isolates of Acinetobacter spp. Of the 191 nonduplicate clinical isolates of the carbapenem-nonsusceptible Acinetobacter spp. evaluated, 125 isolates (65.4%) were positive for the modified imipenem or meropenem-Hodge test, and 49 isolates (25.7%) were positive for the imipenem-EDTA+SMA double disk synergy test (DDS). PCR and sequencing of the bla_VIM-2-allele and bla_IMP-1-allele showed that 29 A. baumannii isolates and 1 A. calcoaceticus isolate had bla_VIM-2, whereas 16 A. baumannii isolates and 2 A. calcoaceticus isolates had bla_IMP-6; 1 isolate of the A. genomospecies 3 had bla_VIM-2 and bla_AIM-1. All the above MBL genes belong to class 1 integron. The size of class 1 integron encompassing bla_VIM-2 or bla_IMP-6 ranges from 2.8 kb to 3.2 kb in clinical isolates of A. baumannii, and 3.2 kb to 3.5 kb in clinical isolates of A. genomospecies 3. bla_VIM-2 was most often located first or second in the class 1 integron, and these integrons often included aacA4. Due to dispersion of the MBL-producing Acinetobacter spp. as well as integron, which may encompass various resistance genes, there is an expectation for the increase of multidrug resistant Gram-negative bacteria, including resistance of carbapenems such as imipenem or meropenem. Hence, the development of new antimicrobial agents for treating severe Acinetobacter spp. infections is needed.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.250-256
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• 2009

Acinetobacter strain $KNF2022^T$ was isolated from tobacco plant roots during the screening of antiviral substances having inhibitory effects on Tobacco mosaic virus (TMV) and examined by phenotypic, chemotaxonomic, and genetic characterization. It was a nonmotile, Gram-negative bacterium. This strain contained Q-9 as the main respiratory quinone. The major cellular fatty acids of the isolate were 16:0, 18:1 w9c, and 16:1 w7c/15 iso 2OH. The DNA base composition was 44 mol%. Phylogenetic analysis based on the 16S rRNA sequence revealed that the isolate formed an evolutionary lineage distinct from other Acinetobacter species. Based on the evaluation of morphologic, physiologic, and chemotaxonomic characteristics, DNA-DNA hybridization values, and 16S rRNA sequence comparison, we propose the new species Acinetobacter antiviralis sp. nov., the type strain of which is $KNF2022^T$ (=KCTC $0699BP^T$).

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.733-739
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• 2021

Acinetobacter strains are widely present in the environment. Some antimicrobial-resistant strains of this genus have been implicated in infections acquired in hospitals. Genetic similarities have been reported between Acinetobacter strains in nosocomial infections and those isolated from foods. However, the antimicrobial resistance of Acinetobacter strains in foods, such as meat, remains unclear. This study initially aimed to isolate Campylobacter strains; instead, strains of the genus Acinetobacter were isolated from meat products, and their antimicrobial resistance was investigated. In total, 58 Acinetobacter strains were isolated from 381 meat samples. Of these, 32 strains (38.6%) were from beef, 22 (26.5%) from pork, and 4 (4.8%) from duck meat. Antimicrobial susceptibility tests revealed that 12 strains were resistant to more than one antimicrobial agent, whereas two strains were multidrug-resistant; both strains were resistant to colistin. Cephalosporin antimicrobials showed high minimal inhibitory concentration against Acinetobacter strains. Resfinder analysis showed that one colistin-resistant strain carried mcr-4.3; this plasmid type was not confirmed, even when analyzed with PlasmidFinder. Analysis of the contig harboring mcr-4.3 using BLAST confirmed that this contig was related to mcr-4.3 of Acinetobacter baumannii. The increase in antimicrobial resistance in food production environments increases the resistance rate of Acinetobacter strains present in meat, inhibits the isolation of Campylobacter strains, and acts as a medium for the transmission of antimicrobial resistance in the environment. Therefore, further investigations are warranted to prevent the spread of antimicrobial resistance in food products.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.293-296
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• 2004

During the screening of antiviral substances having inhibitory effects on Tobacco mosaic virus (TMV) infection on tobacco plants, we found a bacterial isolate KTB3, and identified it as Acinetobacter sp. which strongly inhibited the infection of TMV When the culture filtrate from KTB3 was applied on the upper surface of the Xanthi-nc tobacco leaves at the same time, or 24 hours before TMV inoculation, almost complete inhibition was achieved. Likewise, 86% inhibition was achieved, when the culture filtrate was applied on the underside of the leaves. In field trials, transmission of TMV from diseased seedlings to healthy ones during transplanting work was reduced by 92%, when the culture filtrate was sprayed onto the tobacco seedlings, cv. NC82, 24 hours before transplanting. No toxic effect was observed on the tobacco plants. Antiviral substance from the culture filtrate was purified by ethanol precipitation, dialysis, DEAE-cellulose, and Sephadex G75 gel column chromatography. The partially purified active material which showed positive color reaction to sugar and protein inhibited TMV infection by 60% at 1 ${\mu}$g/ml.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.255-262
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• 1995

Intact cells of Acinetobacter sp. T5-7 completely degraded trichloroethylene (TCE) following growth with phenol. This strain could grow on at least eleven aromatic compounds, e.g., benzaldehyde, benzene, benzoate, benzylalochol, catechol, caffeic acid, 2.4-D, p-hydroxybenzoate, phenol, protocatechuate and salicylate, and did grow on alkane, such as octane. But except phenol, other aromatic compounds did not induced TCE degradation. Phenol biotransformation products, catechol was identified in the culture media. However, catechol-induced cells did not degrade TCE. So we assumed that phenol hydroxylase was responsible for the degradation of TCE. The isolate T5-7 showed growth in MM2 medium containing sodium lactate and catechol rather than phenol, but did not display phenol hydroxyalse activity, suggesting induction of enzyme synthesis by phenol. Phenol hydroxylase activity was independent of added NADH and flavin adenine dinucleotide but was dependent on NADPH addition. Degradation of phenol produced catechols which are then cleaved by meta-fission. We identified catechol-2.3-dioxygenase by active staining of polyacrylamide gel.

• Korean Journal of Clinical Pharmacy
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• v.23 no.1
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• pp.20-25
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• 2013

Background & Objectives: Burn injury mortality and septic complication are frequent and well-known in burned pediatric patients. The overuse of antibiotics is the base for development of wound infection by resistant microorganisms as well as opportunist agents. Methods: We have carried out a study of the bacterial profile and antimicrobial resistance clinically important bacteria isolated from burn wound infections in children patients. The most common isolate from burn wound cultures was Pseudomonas aeruginosa (26.8%), followed by Staphylococcus aureus (25.4%), Acinetobacter baumannii (12.7%), coagulase negative staphylococcus (12.0%), Enterococcus faecium (7.7%), Escherichia coli (4.9%), Enterococcus faecalis (3.7%), Burkholderia cepacia (3.0%), Enterobacter cloacae (2.3%) and Klebsiella pneumonia (2.3%). Colistin was very significantly effective drug in gram negative organism, such as Pseudomonas aeruginosa and Acinetobacter baumannii. Results & Conclusion: The resistance rates were 65% and 98% to piperacillin, 63% and 97% to ceftazidime, 28% and 50% to levofloxacin. The most effective antibiotic in gram positive organism, such as Staphylococcus aureus, coagulase negative staphylococcus were moxifloxacin. The resistance rates were 83% and 64% to ciprofloxacin, 80% and 17% to clindamycin.

• Biomedical Science Letters
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• v.27 no.2
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• pp.59-68
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• 2021

Multidrug-resistant strain of Acinetobacter baumannii (MDRAB) is an emerging pathogen in health care facilities, preventing MDRAB is a public health concern. We conducted this experiment on a clinical isolate of A. baumannii with two main goals: the role of the efflux pump system in the stress provision of carbapenem and the response to the transcription level of the efflux pump gene. A total of 34 strains of A. baumannii was isolated from the Yangsan Hospital of Pusan National University. First, when we compared and observed the expression of the efflux pump gene and antibacterial resistance to carbapenem, a strong correlation was observed between carbapenem resistance and overexpression of adeB (P=0.0056). Second, a correlation between the efflux pump and concentration gradient and tolerance to carbapenem stress at the AdeABC efflux pump genes transcription level was confirmed. Our results revealed that the expression of the AdeABC efflux pump is an important resistance determinant in obtaining antibiotic resistance of the carbapenem group in A. baumannii.