• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.118-123
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• 2016

Antimicrobial agents have been used in poultry for treatment of bacterial infections or additives over the past half century. However, increasing antimicrobial resistance has led to selective pressure for therapeutic use in humans and made treatment of bacterial infection more difficult. In this study, we examined the prevalence of plasmid mediated antimicrobial resistant determinants for resistance to ${\beta}-lactam$, quinolone, and aminoglycoside in Enterobacteriaceae isolates obtained from chickens in Gyeongsang provinces, and correlation between the resistant genes and antimicrobial resistance rate was also assessed. A total of 43 Enterobacteriaceae isolates were recovered from 40 chickens at Gyeongsang provinces in Korea. Antimicrobial susceptibility was determined by disk diffusion method. PCR and DNA sequencing were performed to characterize the antimicrobial resistant genes. Of the 43 Enterobacteriaceae isolates tested, 2 isolates harbored $bla_{CTX-M-14}$ gene, and 2 and 5 strains contained qnrS and aac(6')-Ib-cr genes, respectively. A total of 43 isolates displayed a relatively lower susceptible rate ranging between 0.0 and 23.3% to most of the antimicrobial agents, except cefepime, ceftazidime, and cefaclor. We confirmed that plasmid mediated antimicrobial resistant determinants were distributed in Enterobacteriaceae isolates from chickens. Investigation of the genes and monitoring of antimicrobial resistance rate is required to prevent further spreading of antimicrobial resistant genes among Enterobacteriaceae isolates.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.180-185
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• 2006

Invasive Pseudomonas infections most often occur in the immunocompromised patients and are associated with high mortality rate. Rarely this disease may develop in healthy infants and children. We report two cases of invasive Pseudomonas aeruginosa infections that were diagnosed in otherwise healthy infants. The first case was a previously healthy 5-month-old infant with ecthyma gangrenosum and septicemia. She presented with fever, swelling of left periorbital area and multiple erythronodular skin lesions. Each skin lesion formed a black eschar surrounded by an erythematous areola over time. Cultures of blood, urine and discharge from skin lesions grew P. aeruginosa. On the day of visit, she showed pancytopenia which was normalized after 10 days. The patient responded well to the management with ceftazidime and tobramycin. The other case was a previously healthy 9-month-old infant with community-acquired pneumonia. He was referred from an outside hospital with fever and cough. Chest x-ray revealed pneumonic infiltrations on both lower lungs with pleural effusion on the right side. Cultures of blood and pleural fluid grew P. aeruginosa. Chest CT performed on the ninth day demonstrated pneumatoceles, lung abscess and necrosis of lung parenchyma. He was managed with ceftazidime and amikacin for 50 days. No residual pulmonary complications were noted during the three month follow-up. Laboratory results to evaluate immunologic defects of phagocytic cells, complement components and T- and B-lymphocytes were all within normal range in both patients. It should be kept in mind that Pseudomonas can be, though uncommon, a cause of community-acquired invasive infections in the previously healthy infants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1191-1196
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• 2013

Among Gram-negative pathogens in Korea, the incidence of resistance to third generation cephalosporins is becoming an ever-increasing problem. The production of extended-spectrum ${\beta}$-lactamase (ESBL) is the main mechanism of bacterial resistance to a third-generation cephalosporins and monobactams. Accurate identification of the ESBL genes are necessary for surveillance and epidemiological studies of the mode of transmission in the hospital. This study was conducted to detect the genes encoding ESBL of 46 K. penumoniae isolated from Daejeon, Chungnam and Chungbuk regional university hospitals from February to August in 2012. The phenotypes of the isolated specimens were examined according to the combination disc test (CDT) by the Clinical and Laboratory Standards Institute (CLSI). Forty two ESBL producing K. penumoniae isolates could be detected using ceftazidime (CAZ) discs with and without clavulanate (CLA). By CDT, 42 K. pneumoniae strains were confirmed to be ESBL strains. Genotyping was performed by multiplex PCR with type-specific primers. By PCR analysis, TEM gene in 46 strains, SHV gene in 37 strains and CTX-M genes in 14 strains were identified. Ten isolates did carry genes encoding ESBLs of all types TEM, SHV and CTX-M. The multiplex polymerase chain reaction (PCR) analysis was better to detect and differentiate ESBL producing K. penumoniae strains in clinical isolates.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.517-525
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• 2023

The emergence and spread of multidrug-resistant Pseudomonas aeruginosa (MRPA) have become a serious problem worldwide. The involvement of metallo-β-lactamases (MBLs) in inducing carbapenem resistance is particularly acute. However, unlike other members of the Enterobacteriaceae genus, new clones of P. aeruginosa are constantly emerging and rapidly replacing previously prevalent dominant clones. Therefore, this study aimed to perform antimicrobial resistance gene analysis, integron gene cassette analysis using DNA sequencing, and plasmid transfer analysis by conjugation to investigate the antimicrobial resistance dynamics of 18 P. aeruginosa strains isolated from various medical samples at a general hospital in Busan from September 2017 to September 2019. All 18 strains showed extensively drug-resistant (XDR) phenotype and were resistant to most antibiotics, except colistin (100%) but were susceptible to aztreonam (22.2%) and ceftazidime (16.6%). Approximately 66.7% of the strains had Class 1 integrons showing various antimicrobial resistances. Notably, IMP-6 ST235 (66.7%), VIM-2 ST357 (16.7%), and IMP-1 ST446(16.7%) were identified. The identification of IMP-1-producing ST446, previously unreported in Korea, is noteworthy considering the emergence and prevalence of another MRPA high-risk clone.

• 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.

• Journal of Microbiology
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• v.45 no.3
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• pp.275-279
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• 2007

The aims of this study were to detect Burkholderia cepacia complex (Bcc) strains in a cohort of Cystic Fibrosis patients (n=276) and to characterize Bcc isolates by molecular techniques. The results showed that 11.23% of patients were infected by Bcc. Burkholderia cenocepacia lineage III-A was the most prevalent species (64.3%) and, of these, 10% was cblA positive and 50% esmR positive. Less than half of the strains were sensitive to ceftazidime, meropenem, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole. About half of the strains (41%) had homogeneous profiles, suggesting cross-transmission. The infection by B. cenocepacia was associated to a high rate of mortality (p=0.01).

• 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.

• Korean Journal of Veterinary Service
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• v.44 no.1
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• pp.21-26
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• 2021

The aim of this study was to investigate the antimicrobial resistance among Pseudomonas (P.) aeruginosa isolated from dogs and cats. A total of 45 (6.2%) P. aeruginosa was isolated from 710 dogs and 21 cats with clinical signs. Resistance to one or more of the antimicrobials tested was observed in 26 (57.8%) P. aeruginosa. Resistance to cefepime was the most frequent (44.4%), followed by ofloxacin (22.2%), levofloxacin (17.8%), norfloxacin (8.9%), ciprofloxacin (6.7%), ceftazidime, aztreonam, colistin, polymixin B and gentamicin (4.4%, respectively), while resistance to piperacillin/tazobactam, imipenem, tobramycin and amikacin was 2.2%, respectively. All isolates were susceptibility to doripenem and meropenem. Antimicrobial susceptibility testing should be a crucial step in selection of appropriate antimicrobial therapy in veterinary medicine. Also, the prudent use of antimicrobials and continuous monitoring for companion animals are required.

• Fisheries and Aquatic Sciences
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• v.21 no.7
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• pp.18.1-18.6
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• 2018

Background: Cutaneous bacterial pathogens including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Propionibacterium acnes are often involved in acne vulgaris. The currently available therapeutic option for these skin pathogens is an antibiotic treatment, resulting in the emergence of antibiotic-resistant bacteria. The objective of this study was to discover an alternative antibacterial agent with lower side effect from marine algae. Results: The ethanolic extract of edible brown algae Ishige okamurae exhibits potent antibacterial activity against cutaneous bacterial pathogens. Among the ethanol soluble fractions, the n-hexane (Hexane)-soluble fraction exhibited the strongest antibacterial activity against the pathogens with MIC values ranging 64 to $512{\mu}g/mL$ and with minimum bactericidal concentration values ranging 256 to $2048{\mu}g/mL$. Furthermore, the combination with Hexane fraction and antibiotics (ceftazidime, ciprofloxacin, and meropenem) exhibited synergistic effect. Conclusion: This study revealed that the I. okamurae extract exhibited a synergistic antibacterial effect against acnerelated cutaneous bacterial pathogens acquired antibiotic resistant. Thus, the results of the present study suggested that the edible seaweed extract will be a promising antibacterial therapeutic agent against antibiotic-human skin pathogens and its infections.

• Childhood Kidney Diseases
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• v.19 no.2
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• pp.143-147
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• 2015

Purpose: Burkholderia cepacia is an aerobic, glucose-non-fermenting, gram-negative bacillus that mainly affects immunocompromised and hospitalized patients. Burkholderia cepacia has high levels of resistance to many antimicrobial agents, and therapeutic options are limited. The authors sought to analyze the incidence, clinical manifestation, risk factors, antimicrobial sensitivity and outcomes of B. cepacia urinary tract infection (UTI) in pediatric patients. Methods: Pediatric patients with urine culture-proven B. cepacia UTI between January 2000 and December 2014 at Samsung Medical Center, a tertiary referral hospital in Seoul, Republic of Korea, were included in a retrospective analysis of medical records. Results: Over 14 years, 14 patients (male-to-female ratio of 1:1) were diagnosed with B. cepacia UTI. Of 14 patients with UTI, 11 patients were admitted to the intensive care unit, and a bladder catheter was present in 9 patients when urine culture was positive for B. cepacia. Patients had multiple predisposing factors for UTI, including double-J catheter insertion (14.2%), vesico-ureteral reflux (28.6%), congenital heart disease (28.6%), or malignancy (21.4%). Burkholderia cepacia isolates were sensitive to piperacillin-tazobactam and sulfamethoxazole-trimethoprim, and resistant to amikacin and colistin. Treatment with parenteral or oral antimicrobial agents including piperacillin-tazobactam, ceftazidime, meropenem, and sulfamethoxazole-trimethoprim resulted in complete recovery from UTI. Conclusion: Burkholderia cepacia may be a causative pathogen for nosocomial UTI in pediatric patients with predisposing factors, and appropriate selection of antimicrobial therapy is necessary because of high levels of resistance to empirical therapy, including aminoglycosides.