• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.167-177
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• 2007

From the total 121,294 clinical materials submitted to the Department of Laboratory Medicine of "C" hospital from December 1, 2004 to November 30, 2006, 3,408 Pseudomonas spp. were isolated. The isolation frequencies of Pseudomonas spp. were as follows, P. aeruginosa 95.5%, P. putida 2.5%, P. fluorescens 0.8%, along with low frequencies of P. luteola, P. alcaligenes, P. stutzeri, P. oryzihabitants, P. mendocina and unidentified Pseudomonas species. The isolation rates of Pseudomonas spp. according to season and sex were evenly distributed. The isolated frequency of Pseudomonas spp. in male was two times higher than that of in female showing significantly more male patients in surgical areas and more female patients in internal areas (p<0.001). In monthly analysis, Pseudomonas spp. were the most frequently isolated in July (10.4%), but lowest in February (5.6%). Half of Pseudomonas spp. were isolated from sputum (48.2%). In the susceptibility analysis of Pseudomonas spp. by VITEK II AST cards, the Pseudomonas spp showing higher susceptibility against antimicrobial agents were piperacillin/tazobactam (82.7%) in P. aeruginosa; amikacin (84.7%), colistin (83.3%) in P. putida; and amikacin (96.3%), cefepime (87.5%), ceftazidime (87.5%) ciprofloxacin (92.3%), colistin (88.5%) gentamicin (96.2%), isepamicin (96,1%), meropenem (92.3%), netilmicin (96.0%), piperacillin/ tazobactam (95.4%) and tobramycin (92.6%) in P. fluorescens.

• The Journal of the Korean Society for Microbiology
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• v.35 no.3
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• pp.239-250
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• 2000

Sixty-eight clinical isolates of Stenotrophomonas maltophilia from inpatients of 2 university hospitals in Taegu were epidemiologically analyzed by using the minimum inhibitory concentrations of 25 antimicrobial drugs, biochemical reaction, pulsed-field gel elctropgoresis (PFGE), and PCR with enterobacterial repetitive intergenic consensus sequences as primer (ERIC-PCR). 1. All the strains were susceptible to minocycline. More than 57% were susceptible to sulfisomidine (Su), ciprofloxacin (Ci), Ofloploxacin (Of), nalidixic acid (Na), and chloramphenicol (Cm), and $19{\sim}35%$ to ceftazidime (Cd), trimethoprim (Tp), Ticacillin-clavulanic acid, and cefoperazone-sulbactam. Most isolates were resistant to ${\beta}$-lactam antibiotics such as ampicillin (Ap), carbenicillin (Cb), cefotaxim (Ct), cefoxitin (Cx), and aminoglycosides including gentamicin (Gm), tobramycin (Tb), amikacin (Ak). 2. All the isolates were multiply resistant of 5 to 17 drugs and showed 40 different resistance pattern types. 3. All the strains showed very similar biochemical reactions except ${\beta}$-galactosidase and nitrate reduction test. Fourteen strains selected randomly were classified 10 different pattern type by PFGE and ERIC-PCR. These two methods showed identical result. Four strains isolated from wound in 1994 showed similar MIC pattern and identical API 20NE profile, PFGE, and ERIC-PCR pattern indicating episodes of cross-infection among patients. These results indicate that PFGE or ERIC-PCR profile has comparable discriminatory power for epidemiological typing of S. maltophilia.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.462-468
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• 2006

Antibiotics are manufactured and used for specific physiological functions, hence they may exert adverse ecological consequences when they are in contact with nontarget organisms. In the last decade, many reports have been made on the occurrences of various antibiotic compounds in surface water, and their potential impact to the environment has become an increasing concern. This study was conducted to prioritize antibiotic substances with potential environment risk in Korea. Human use antibiotics with an EIC (Expected Introduction Concentration) value greater than $1{\mu}g/l$, US FDA's action limit criteria, were selected. In order to calculate a worst-case EIC for each substance, annual production volume (in kg) of each antibiotic substance was derived using the Korea Pharmaceutical Manufacturers Association (KPMA)'s monetary database. Sixteen substances were preliminarily selected. The EICs of the 16 antibiotic substances were refined with the excretion rate of the parent substances. Ten antibiotic substances were identified to have EIC-corrected greater than $1{\mu}g/l$, which include Amoxicillin ($15.8{\mu}g/l$), Cefaclor ($10.1{\mu}/l$), Roxithromycin ($4.2{\mu}g/l$), Cephradine ($4.5{\mu}g/l$), Cefatrizine ($2.6{\mu}g/l$), Cefadroxil ($3.3{\mu}g/l$), Aztreonam ($2.3{\mu}g/l$), Ceftazidime ($2.8{\mu}g/l$), Ribostamycin ($1.3{\mu}g/l$), and Ceftezole ($1.3{\mu}g/l$). Additional risk assessments for these antibiotic substances are suggested.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.564-572
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• 2016

In this study, we isolated and characterized Escherichia coli from mussels and inland pollution sources in or in proximity to the Changseon area on the southern coast of Korea in 2014. A total of 147 strains of E. coli were isolated from 54 mussels and 32 pollution-source samples. The susceptibility of the isolates to 24 antimicrobial agents was analyzed. The resistance of E. coli isolates to rifampin was highest at 100%, followed by cephalothin (98.6%), tetracycline (91.8%), amikacin (81.0%), ampicillin (79.6%), cefazolin (79.6%), streptomycin (73.5%), piperacillin (70.7%), gentamicin (37.4%), cefoxitin (35.4%), cefamandole (34.7%), tobramycin (29.9%), amoxicillin/clavulanic acid (24.5%), nalidixic acid (21.8%), trimethoprim (19.0%), chloramphenicol (17.7%), cefotaxime (12.9%), trimethoprim (10.9%), ceftazidime (10.2%), aztreonam (7.5%), imipenem (2.7%), cefepime (2.0%), and cefotetan (0.0%). In addition, the antimicrobial resistance of E. coli isolates from inland pollution sources was slightly greater than or similar to that of isolates from mussels.

• Journal of Microbiology
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• v.43 no.2
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• pp.172-178
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• 2005

To determine the prevalence and genotypes of $\beta$-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced $\beta$-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five ($167\%$) of thirty clones produced an extended-spectrum $\beta$-lactamase. 837- and 259-bp fragments specific to bla$_{TEM}$ genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM­1 was the most prevalent $\beta$-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type $\beta$-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type $\beta$-lactamases of the pre-antibiotic era indicates that TEM-type $\beta$-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.37-43
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• 2011

This study was conducted to investigate the prevalence and genotypes of extended-spectrum ${\beta}$-lactamase (ESBL) in 377 Escherichia coli isolated from healthy and sick animals. Two isolates (0.5%), each of which were isolated from diseased swine and chicken, respectively, were confirmed as ESBL producing isolates by double disk synergy test, and showed a multidrug resistant phenotype. Minimum inhibitory concentration of cefotaxime for the two ESBL producing isolates were 3~4 times higher than those of ceftazidime, respectively. By PCR and sequencing, one isolate from swine have both $bla_{CTX-15}$ and $bla_{TEM-1}$, and one isolate from chicken have $bla_{CTX-15}$ and $bla_{TEM-116}$. Also, these genes were transferred to E. coli J53 by conjugation. These two isolates showed unrelated pulsed-field gel electrophoresis. To our knowledge, this is the first time that $bla_{TEM-116}$ gene was identified in E. coli isolated from animals in Korea. These results suggest more prudent use of third- generation cephalosporins, and surveillance and monitoring for ESBL producing E. coli in both animals and their environments should be necessary.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.22-25
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• 2006

Ochrobactrum anthropi, previously known as Achromobacter species biotypes 1 and 2 (CDC groups Vd-1, Vd-2), belong to the groups of non-Enterobacteriaceae- nonfermentative Gram negative bacilli. Achromobacter is not presently a recognized genus. Achromobacter xylosoxidans has been transferred to genus Alcaligenes as A. xylosoxidans subsp. xylosoxidans, and "Achromobacter" sp. group Vd has been named Ochrobactrum anthropi. O. anthropi was isolated from a blood culture. Organisms were identified as O. anthropi by use of the biochemical test and the VITEK 2(bioMerieux, USA). The Organism was susceptible only to colistin, imipenem, meropenem, and tetracycline, but were resistant to amikacin, aztreonam, cefepime, ceftazidime, cefpirome, ciprofloxacin, gentamicin, isepamcin, netilmicin, pefloxacin, piperacillin, piperacillin/tazobactam, ticarcillin, ticarcillin/clavulanic acid, tobramycin, and trimethoprim/sulfamethoxazole. We report the clinical and microbiologic characteristics of O. anthropi infection in the patient. This is the first case of O. anthropi infection after using a plant as medicine at Chosun University Hospital.

• Advances in Traditional Medicine
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• v.4 no.4
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• pp.261-266
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• 2004

Wound swabs and pus samples were collected from diabetic foot ulcers, and control pus samples from non-diabetic cases. In 144 diabetic cases screened, Pseudomonas aeruginosa was isolated from 78 cases, in which 10.59% of the isolates were multidrug resistant (MDR), whereas the 60 control cases were not MDR. The isolated bacteria were decreasingly resistant to 6 clinically administrated antimicrobics such as ceftazidime, gentamicin, ciprofloxacin, tobramycin, piperacillin and amikacin. Therefore, it is demanded that new and more effective antimicrobials of phytochemical origins are sought after. Among 11 isoflavones (YS11-YS21) isolated from Sophora and Euchresta (Leguminosae; pea plant family), 2 (YS19 and YS21) prominently exhibited the high antibacterial activity both in vitro and in vivo. By the preliminary results, the object of this paper is to evaluate the in vitro antibacterial effect of YS19 and YS21 on the clinically isolated bactera of Ps. Aeruginosa in hospitals. All the isolates were sensitive to YS19 and YS21 and for both, minimum inhibitory concentration (MIC) values ranged from $2\;to\;50\;{\mu}g/mL$. The $MIC_{90}$ values of YS19 and YS21 were $50\;{\mu}g/mL$. It is suggested that these isoflavones might consist a basis phytochemical prevention and therapy for diabetic foot infections caused by pseudomonads.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.132-138
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• 2013

Acinetobacter baumannii is gram-negative bacilli that can be widely found in environments. Recently, A. baumannii emerged as a serious nosocomial infection. A total of 92 A. baumannii were isolated from hospitalized patients in Seoul, Korea, between December 2010 and April 2011. Antimicrobial susceptibility testing was investigated using CLSI agar dilution methods. Tigecycline non-susceptible A. baumannii isolates were investigated by repetitive extragenic palindromic sequence-based PCR (rep-PCR). Pulsed-field gel electrophoresis was performed to determine the epidemiological relationships. All clinical isolates showed high-level resistance to the most commonly used antibiotics: Ciprofloxacin (87.0%), Ampicillin/sulbactam (82.6%), Cefotaxime (81.5%), Ceftazidime (80.4%). Moreover, 50.0% of these isolates were non-susceptible to tigecycline. When evaluated by RAPD analysis, generated distinct band ranging in size from 1kb to 8k band varying from 4 to 10 bands. Stricter surveillance and more rapid detection are essential to prevent the spread of multi drug resistant A. baumannii.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.230-235
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• 2020

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of bla_TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the KirbyBauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla_TEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla_TEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.