• 제목/요약/키워드: quinolone resistance

검색결과 72건 처리시간 0.026초

Species Profiles and Antimicrobial Resistance of Non-aureus Staphylococci Isolated from Healthy Broilers, Farm Environments, and Farm Workers

  • Ji Heon Park;Gi Yong Lee;Ji Hyun Lim;Geun-Bae Kim;Kun Taek Park;Soo-Jin Yang
    • 한국축산식품학회지
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    • 제43권5호
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    • pp.792-804
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    • 2023
  • Non-aureus staphylococci (NAS), particularly antimicrobial-resistant NAS, have a substantial impact on human and animal health. In the current study, we investigated (1) the species profiles of NAS isolates collected from healthy broilers, farm environments, and farm workers in Korea, (2) the occurrence of antimicrobial-resistant NAS isolates, especially methicillin resistance, and (3) the genetic factors involved in the methicillin and fluoroquinolone resistance. In total, 216 NAS isolates of 16 different species were collected from healthy broilers (n=178), broiler farm environments (n=18), and farm workers (n=20) of 20 different broiler farms. The two most dominant broiler-associated NAS species were Staphylococcus agnetis (23.6%) and Staphylococcus xylosus (22.9%). Six NAS isolates were mecA-positive carrying staphylococcal cassette chromosome mec (SCCmec) II (n=1), SCCmec IV (n=1), SCCmec V (n=2), or nontypeable SCCmec element (n=2). While two mecA-positive Staphylococcus epidermidis isolates from farm workers had SCCmec II and IV, a mecA-positive S. epidermidis isolate from broiler and a Staphylococcus haemolyticus isolate farm environment carried SCCmec V. The occurrence of multidrug resistance was observed in 48.1% (104/216 isolates) of NAS isolates with high resistance rates to β-lactams (>40%) and fusidic acid (59.7%). Fluoroquinolone resistance was confirmed in 59 NAS isolates (27.3%), and diverse mutations in the quinolone resistance determining regions of gyrA, gyrB, parC, and parE were identified. These findings suggest that NAS in broiler farms may have a potential role in the acquisition, amplification, and transmission of antimicrobial resistance.

경북지역의 닭으로부터 CTX-M-14 생성 장내세균 분리동정 (CTX-M-14 Producing Enterobacteriaceae Isolated from Chickens at Gyeongsang Provinces)

  • 성지연;권택영
    • 대한임상검사과학회지
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    • 제48권2호
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    • pp.118-123
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    • 2016
  • 지난 반세기 동안 세균 감염증 치료 또는 성장촉진을 목적으로 가금류에게 광범위하게 항균제를 사용해 왔다. 그러나 항균제 내성의 증가는 사람에게 보편적으로 사용되는 항균제들에 대한 내성을 유도하여 치료를 위한 항균제 선택에 제약을 주어 치료에 어려움을 가중시키고 있다. 본 연구에서는 경상도 지역에서 사육된 닭으로부터 분리된 장내세균을 대상으로 ${\beta}-lactam$, quinolone, 및 aminoglycoside 계열 항균제에 대한 내성유전자의 빈도를 조사하였다. 그리고 항균제 감수성 검사를 시행하여 내성유전자와의 관련성을 알아보았다. 본 연구에서 총 43균주의 장내세균이 40마리의 닭의 맹장으로부터 분리되었으며 디스크확산법을 이용하여 항균제 감수성 검사를 시행하였다. 그리고 중합효소연쇄반응과 염기서열분석을 통해 플라스미드 매개 항균제 내성 유전자를 조사하였다. 총 43균주 중 2균주가 $bla_{CTX-M-14}$ 유전자를 포함하고 있었으며 qnrS 및 aac(6')-Ib-cr 유전자도 각각 2균주와 5균주에서 확인되었다. 총 43균주를 대상으로 항균제 감수성을 조사한 결과 cefepime, ceftazidime, 및 cefaclor를 제외한 모든 항균제에 대해 0.0%부터 23.3%까지의 낮은 감수성률을 보였다. 본 연구에서는 닭으로부터 분리된 대장균에 플라스미드 매개 항균제 내성유전자가 확산되어 있음을 확인하였다. 항균제 내성 유전자의 확산을 막기 위해서는 지속적인 항균제 내성유전자의 조사와 감시가 필요할 것으로 사료된다.

Prevalence of Multi-drug Resistant Acinetobacter baumannii Producing OXA-23-like from a University Hospital in Gangwon Province, Korea

  • Jang, In-Ho;Lee, Gyu-Sang;Choi, Il;Uh, Young;Kim, Sa-Hyun;Park, Min;Woo, Hyun-Jun;Choi, Yeon-Im;Kim, Jong-Bae
    • 대한의생명과학회지
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    • 제18권1호
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    • pp.79-82
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    • 2012
  • Acinetobacter infections are of great concern in clinical settings because of multi-drug resistance (MDR) and high mortality of the infected patients. The MDR Acinetobacter baumannii has emerged as a significant infectious agent in hospitals worldwide. The purpose of this study was to determine for molecular characterization of MDR A. baumannii clinical isolates obtained from the Wonju Christian Hospital in Gangwon province of Korea. A total of seventy nonduplicate A. baumannii isolates were collected from the Wonju Christian Hospital in Korea from March to April in 2011. All of the MDR A. baumannii isolates were encoded by $bla_{OXA-23-like}$ gene and all isolates with the $bla_{OXA-23-like}$ gene had the upstream element ISAba1 to promote increased gene expression and subsequent resistance to carbapenem. 16S rRNA methylase gene (armA) was detected in 44 clinical isolates which were resistant to amikacin, and phosphotransferase genes encoding aac(3)-Ia and aac(6')-Ib were the most prevalent. A combination of 16S rRNA methylase and aminoglycoside-modifying enzyme genes (armA, aac(3)-Ia, aac(6')-Ib, and aph(3')-Ia) were found in 31 isolates. The sequencing results for the quinolone resistance-determining region (QRDR) of gyrA and parC revealed the presence of Ser (TCA) 83 Leu (TTA) and Ser (TCG) 80 Leu (TTG) substitutions in the respective enzymes for all MDR. Molecular typing for MDR A. baumannii could be helpful in confirming the identification of a common source or cross-contamination. This is an important step in enabling epidemiological tracing of these strains.

반려동물에서 분리된 cefotaxime 내성 그람 음성균에서 CTX-M β-lactamase와 plasmid 매개 퀴놀론 내성 유전자 (CTX-M β-lactamase and plasmid-mediated quinolone resistance genes in cefotaxime-resistant gram-negative bacteria isolated from companion animals)

  • 조재근;이정우;김정미;박대현;정지연
    • 한국동물위생학회지
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    • 제43권2호
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    • pp.79-88
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    • 2020
  • The aim of this study was to investigate the prevalence of CTX-M β-lactamase and plasmid-mediated quinolone resistance (PMQR) genes, and the pattern of antibiotic resistance in cefotaxime-resistant gramnegative bacteria. A total 126 gram-negative bacteria were isolated from hospitalized dogs and cats between 2018 and 2019. The most predominant isolates were E. coli (n=41), followed by Pseudomonas aeruginosa (n=25), Proteus mirabilis (n=14), Klebsiella pneumoniae (n=9), Sphingomonas paucimobilis (n=7), and Enterobacter cloacae and Serratia marcescens (respectively, n=5). Cefotaxime-resistant isolates were identified in 26.2% (33 isolates) of 126 gram-negative bacteria. CTX-M type β-lactamase were found in 15 isolates (10 E. coli, 1 Ent, cloacae and 4 K. pneumoniae, respectively). Among the CTX-M producing gram-negative bacteria, CTX-M-1 and CTX-M-9 were detected in 10 (66.7%) and 5 (33.3%) isolates, respectively. While, CTX-M-2 and CTX-M-8 were not found. PMQR genes were detected in 12 (36.4%) isolates (4 E. coli, 2 Ent, cloacae and 6 K. pneumoniae, respectively), and the predominant PMQR gene was aac(6')-lb-cr (n=9), followed by qnrB (n=8) and qnrS (n=1) alone or in combination. qnrA and qepA were not found. Additionally, 9 (60%) of 12 PMQR positive isolates were co-existence with CTX-M-1 or CTX-M-9. CTX-M or PMQR producing isolates showed highly resistance to penicillins (100%), cephalosporins (100~66.7%), monobactams (72.2%), and non-β-lactam antibiotics (94.4~61.1%) such as quinolones, trimethoprim/sulfamethoxazole, tetracycline and gentamicin. These findings showed CTX-M-1, CTX-M-9, aac(6')-lb-cr and qnrB were highly prevalent in cefotaxime-resistant Enterobacteriaceae isolates from companion animals in our region. Moreover, PMQR genes were closely associated with CTX-M type β-lactamase.

호흡기질환 환자에서 분리한 Mycoplasma pneumoniae의 Quinolone계와 Macrolide계 항생물질에 대한 다제 저항성 (Multi-drug Resistance of Mycoplasma pneumoniae Isolates from Patients with Respiratory Diseases against Quinolone and Macrolide)

  • 전성곤;장명웅
    • 생명과학회지
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    • 제17권3호통권83호
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    • pp.435-443
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    • 2007
  • 호흡기질환 환자의 상기도 도말물로 부터 분리 동정된 M. pneumoniae 116균주의 moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, clarithromycin minocycline, erythromycin, josamycin, and tetracycline에 대한 감수성 검사를 실시하였다. 각 항생물질에 대한 저항성 균주의 기준은 $MIC{\pm}1.0$ ${\mu}g/ml$ 로 하였으며, 초기 MIC와 최종 MIC를 구분하여 다제 저항성 균주의 분포를 분석하였다. 초기 MIC의 결과로 분리된 균주의 단일 약제에 대한 저항성은 ciprofloxacin이 79.3%, ofloxacin이 53.5%, clarithromycin이 10.3%, erythromycin이 7.8%이었으며, 2가지 약제에 저항성은 ofloxacin과 ciprofloxacin이 42.2%, ciprofloracin과 clarithromycin이 9.5%이었으며, 3가지 약제에 저항성은 erythromycin, ofloxacin과 ciprofloxacin이 6.9%, ofloxacin, ciprofloxacin과 clarithromycin이 6.0%이었다. 최종 MIC의 결과로 분리균의 단일 약제에 대한 저항성은 tetracycline, ciprofloxacin, ofloxacin이 각각 91.4%, minocycline이 89.7%, erythromycin이 68.1%, josamycin이 52.6%, clarithromycin이 28.5%, sparfloxacin이 11.2%이었으며, 2가지 약제에 저항성인 균의 분포는 $20.7{\sim}91.4%$, 3가지약제에 저항성인 규의 분포는 &28.5{\sim}89.7%$, 4가지 약제에 저항성인 균의 분포는 2.6%, 5가지 약제에 저항성인 균은 $2.6{\sim}21.6%$, 6가지 약제에 저항성인 균은 $0.9{\sim}24.1%$이었으며, 7가지 약제에 저항성인 균은 $0.9{\sim}2.6%$이었으며, 8종류 약제에 저항성인 균도 1.7%있었다. 이상의 결과로 국내에서 분리된 M. pneumoniae 균주는 적게는 1-4 종류의 항생제에, 많게는 5-8 종류의 항생제에 저항성인 균주가 있으므로 마이코플라스마폐렴 환자를 치료할때는 macrolide계나 quinolone계의 항생제 선택에 신중을 기하여야 하며, 가급적이면 항생제 감수성 검사를 실시하여 적절한 항생제를 선택함으로써 저항성균의 출현율을 줄일 수 있고 효율적인 치료도 할 수 있도록 하여야 할 것으로 생각된다.

Isolation of Norfloxacin Resistan Escherichia Coli from the Han River and Characterization of Resistance Mechanism

  • Yoosun Jung;Hunjin Hong;Hyeran Nam;Lee, Yeonhee
    • Journal of Microbiology
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    • 제40권1호
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    • pp.63-69
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    • 2002
  • A total of twenty-five norfloxacin resistant Escherichia coli were isolated from Joongrang-chun stream, a branch of the Han River in Seoul, Korea from May to July in 2000 and their norfloxacin resistance mechanism was characterized for target site mutation, permeability, and efflux pump. Fourteen iso- lates contained the same three mutations, Ser83→Leu and Asp87→Asn in GyrA and Ser90→ lle in ParC. Six isolates had Ser83→Leu and Asp87→Tyr in GyrA and Ser87→lle in ParC while one isolate had Ser83→Leu and Va1103→Ala in GyrA and Ser80→lle in ParC. Two isolates had mutation(s) in GyrA without any mutation in ParC. Two isolates had Ser80→Arg in ParC instead of the commonly found Ser80→lle. Every norfloxacin resistant isolate had an efflux system but the correlation between the efflux activity and MIC was not observed. The amount of OmpF for norfloxacin permeability decreased in resistant isolates compared to the susceptible strains. When amplified polymorphic DNA (RAPD) and pulse field gel electrophoresis (PFGE) were performed, these isolates showed no similarity to each other or clinical isolates.

Pulsed-Field Gel Electrophoresis and Mutation Typing of gyrA Gene of Quinolone-Resistant Salmonella enterica Serovar Paratyphi A Isolated from Outbreak and Sporadic Cases,1998-2002, Korea

  • KIM SHUKHO;OK YOUNG LIM;SEONG HAN KIM;JUN YOUNG KIM;YEON HO KANG;BOK KWON LEE
    • Journal of Microbiology and Biotechnology
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    • 제13권1호
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    • pp.155-158
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    • 2003
  • In early 2002, over 200 people in the city of Pusan. Korea suffered from paratyphoid fever resulting from Salmonella Paratyphi A Infection. Antimicrobial susceptibility tests and Xbal pulsed-field gel electrophoresis (PFCE) were conducted to 54 Salmonella Paratyphi A isolated from humans during the period of 1998 to 2002. Most of the isolates ($83\%$) were only nalidixic acid-resistant and $78\%$ were X 1 PFGE patterns. Also, we measured the MIC of ciprofloxacin and screened gyrA mutation(5) using allele- specific PCR and restriction fragment length polymorphism (AS-PCR-RFLP). The representative 5 isolates in 2002 and 1 isolate in 2000 were $1{\mu}g/ml$ of MIC and had mutation at the 83rd codon in gyrA. These data suggest that the outbreak in the early 2002 might have been due to dissemination of the strain present In 2000. Also, decreased susceptibility to ciprofloxacin was partly due to the mutation at the 83rd codon in gyrA.

Antibacterial effect of ethylacetate fraction of Orostachys japonicus on Enterococcus faecalis causing Endophthalmitis

  • Kim, Hanwoo;Park, Indal;Lee, Sangjun;Shin, Dongyoung;Kim, Jiyeun Kate
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 추계학술대회
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    • pp.113-113
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    • 2018
  • Endophthalmitis is a disease that causes ocular inflammation and has a catastrophic effect on eyesight. Recent studies show that Enterococcus faecalis is rapidly increasing causative bacterium of endophthalmitis. It is predicted that the increased endophthalmitis by E. faecalis is presumable due to the high resistance of E. faecalis to moxifloxacin (MFX), which is a common antibiotic used for eye drop. Because of the need for therapeutic agents to overcome this problem, this study sought to explore the feasibility of developing a combination therapy using Orostachys japonicus. The ethylacetate fraction of O. japonicus (OJA) used in this study. Antimicrobial activity was tested 13 E. faecalis strains including one E. faecalis standard strain, eight clinically isolated E. faecalis strains and four quinolone resistant E. faecalis strains using CLSI antibiotic susceptibility test method. Minimal Inhibitory Concentration (MIC) of OJA was confirmed to be $500{\mu}g/ml$ for all 13 strains. Then we tested for the synergistic effect of OJA to MFX using checkboard test method. The MIC of MFX was $0.25{\mu}g/ml$ for the standard strain and 8 for the clinical isolates, and $16{\sim}64{\mu}g/ml$ for the quinolone - resistant strains. When OJA was mixed with MFX, no synergistic effect was observed in all strains, but the antibacterial activity of OJA remained unchanged. Most ocular other strains can be removed by MFX except the MFX resistant E. faecalis, which can be removed by OJA in combination therapy. Therefore, OJA can be a potential candidate for the combined treatment endophthalmitis.

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Insight into Norfloxacin Resistance of Acinetobacter oleivorans DR1: Target Gene Mutation, Persister, and RNA-Seq Analyses

  • Kim, Jisun;Noh, Jaemin;Park, Woojun
    • Journal of Microbiology and Biotechnology
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    • 제23권9호
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    • pp.1293-1303
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    • 2013
  • Antibiotic resistance of soilborne Acinetobacter species has been poorly explored. In this study, norfloxacin resistance of a soil bacterium, Acinetobacter oleivorans DR1, was investigated. The frequencies of mutant appearance of all tested non-pathogenic Acinetobacter strains were lower than those of pathogenic strains under minimum inhibitory concentration (MIC). When the quinolone-resistance-determining region of the gyrA gene was examined, only one mutant (His78Asn) out of 10 resistant variants had a mutation. Whole transcriptome analysis using a RNA-Seq demonstrated that genes involved in SOS response and DNA repair were significantly up-regulated by norfloxacin. Determining the MICs of survival cells after norfloxacin treatment confirmed some of those cells were indeed persister cells. Ten colonies, randomly selected from among those that survived in the presence of norfloxacin, did not exhibit increased MIC. Thus, both the low mutation frequency of the target gene and SOS response under norfloxacin suggested that persister formation might contribute to the resistance of DR1 against norfloxacin. The persister frequency increased without a change in MIC when stationary phase cells, low growth rates conditions, and growth-deficient dnaJ mutant were used. Taken together, our comprehensive approach, which included mutational analysis of the target gene, persister formation assays, and RNA sequencing, indicated that DR1 survival when exposed to norfloxacin is related not only to target gene mutation but also to persister formation, possibly through up-regulation of the SOS response and DNA repair genes.

Survey of Oxolinic Acid-Resistant Erwinia amylovora in Korean Apple and Pear Orchards, and the Fitness Impact of Constructed Mutants

  • Ham, Hyeonheui;Oh, Ga-Ram;Park, Dong Suk;Lee, Yong Hoon
    • The Plant Pathology Journal
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    • 제38권5호
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    • pp.482-489
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    • 2022
  • Fire blight caused by Erwinia amylovora (Ea) is a devastating disease in apple and pear trees. Oxolinic acid (OA), a quinolone family antibiotic that inhibits DNA gyrase, has been employed to control fire blight in South Korea since 2015. The continuous use of this bactericide has resulted in the emergence of OA-resistant strains in bacterial pathogens in other countries. To investigate the occurrence of OA-resistant Ea strains in South Korea, we collected a total of 516 Ea isolates from diseased apple and pear trees in 2020-2021 and assessed their sensitivities to OA. We found that all isolates were susceptible to OA. To explore the possibility of emerging OA-resistant Ea by continuous application of OA, we exposed Ea stains to a range of OA concentrations and constructed OA-resistant mutant strains. Resistance was associated with mutations in the GyrA at codons 81 and 83, which result in glycine to cysteine and serine to arginine amino acid substitutions, respectively. The in vitro growth of the mutants in nutrient media and their virulence in immature apple fruits were lower than those of wild-type. Our results suggest that OA-resistance decreases the fitness of Ea. Future work should clarify the mechanisms by which OA-resistance decreases virulence of this plant pathogen. Continuous monitoring of OA-resistance in Ea is required to maintain the efficacy of this potent bactericide.