• Title/Summary/Keyword: Quinolone resistance

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Activity of Moxifloxacin Against Ofloxacin-Resistant Mycobacterium Tuberculosis: A Study of Cross-Resistance Between Ofloxacin and Moxifloxacin (Ofloxacin 내성 마이코박테리아에 대한 Moxifloxacin의 항결핵 효과: Ofloxacin과 Moxifloxacin의 교차내성 연구를 중심으로)

  • Kim, Byoung Ju;Kang, Young Soo;Park, Seung Kyu
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.5
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    • pp.405-410
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    • 2004
  • Background : Moxifloxacin is an 8-methoxyquinolone compound which has been shown to have the best activity of the quinolones against M. tuberculosis but there is no literature showing the rate of cross-resistance between moxifloxacin and the other quinolones such as ofloxacin. Therefore, we tested the activity of moxifloxacin against ofloxacin resistant M. tuberculosis by a study of cross-resistance. Methods : We tested MIC's of moxifloxacin and ofloxacin by proportion method against 34 M. tuberculosis isolates showing resistance against ofloxacin at $2.5{\mu}g/m{\ell}$ concentration and 13 ofloxacin susceptible isolates from specimens submitted to clinical laboratory of National Masan Hospital from March 2003 to March 2004. Results : For ofloxacin susceptible isolates, $MIC_{50}$ and $MIC_{90}$ of ofloxacin were all $1.25{\mu}g/m{\ell}$, and $MIC_{50}$ and $MIC_{90}$ of moxifloxacin were $0.31{\mu}g/m{\ell}$ and $0.63{\mu}g/m{\ell}$ respectively. For ofloxacin resistant isolates, $MIC_{50}$ of ofloxacin was over $10{\mu}g/m{\ell}$ and $MIC_{50}$ of moxifloxacin was $5{\mu}g/m{\ell}$, $MIC_{90}$ of ofloxacin and moxifloxacin were all over $10{\mu}g/m{\ell}$. The rate of cross-resistance between the two was 67.6%(23/34) at $2.5{\mu}g/m{\ell}$ concentration. Conclusions : Moxifloxacin showed activity against 82.4%(28/34) of ofloxacin resistant M. tuberculosis at $10{\mu}g/m{\ell}$, but more studies are needed so that moxifloxacin will be used for patient with multi-drug resistant tuberculosis including oflokacin resistance.

Characterization of plasmid-mediated quinolone resistance genes in Enterobacteriaceae isolated from companion animals (반려동물 유래 장내세균에서 plasmid 매개 퀴놀론 내성 유전자의 특성)

  • Cho, Jae-Keun;Kim, Jeong-Mi;Kim, Hwan-Deuk;Kim, Kyung-Hee;Lim, Hyun-Suk;Yang, Chang-Ryoul
    • Korean Journal of Veterinary Service
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    • v.42 no.1
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    • pp.17-24
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    • 2019
  • The aim of this study was to investigate the prevalence and characterization of plasmid-mediated quinolone resistance (PMQR) gene in 79 Enterobacteriaceae isolated from dogs and cats. Of 79 isolates, PMQR genes were found in 10 (12.7%) isolates, including aac(6')-lb-cr, qnrB, qnrS and qnrA detected alone or in combination in 8 (10.1%), 4 (5.1%), 2 (2.5%) and 1 (1.3%) isolates, respectively. Interestingly, two qnrS genes were detected in nalidixic acid and ciprofloxacin susceptible isolates. Extended-spectrum ${\beta}$-lactamase (ESBL) was detected in 90% (9 isolates) of PMQR positives isolates. Among ESBL genes, CTX-M, TEM and SHV were detected in 9, 8 and 3 isolates, respectively. Almost all PMQR genes were detected in co-existence with ESBL genes. All PMQR positives isolates were multidrug resistance (i.e. resistant to five or more antibiotics). qepA, OXA and CMY-2 genes were not found. The six transconjugants were obtained by conjugation experiment. The aac(6')-lb-cr, qnrB and qnrS were co-transferred with CTX-M, TEM and/or SHV, whereas qnrA was not observed among transconugants. This is the first report of the presence of aac(6')-lb-cr and qnrA gene among Enterobacteriaceae isolates from dogs in Korea. The prudent use of antimicrobials and continuous monitoring for companion animals are required.

DNA Mutation Pattern of gyrA and gyrB Genes according to the SCCmec Subtype of Quinolone-resistant Staphylococcus aureus Isolates from Blood Culture (혈액배양에서 분리된 Fluoroquinolone계 약제 내성 황색포도알균의 SCCmec 아형에 따른 gyrA와 gyrB 유전자에서의 DNA 돌연변이 양상)

  • Inwon HWANG;Sang-Ha KIM;Taewon JUNG;Young-Kwon KIM;Sunghyun KIM
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.2
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    • pp.115-124
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    • 2024
  • The emergence and spread of Staphylococcus aureus, which is resistant to quinolone antibacterial agents, has made it difficult to treat infectious diseases. Accordingly, this study examined the molecular epidemiological characteristics of quinolone-resistant S. aureus (QRSA) to obtain helpful data for treatment. Mutations in mecA and SCCmec typing, gyrA, and gyrB genes were investigated for QRSA strains isolated from the blood culture specimens at a general hospital in Daejeon Metropolitan City. The ciprofloxacin-resistant strains in SCCmec typing were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains (11 strains, 18%), and levofloxacin (LVX) and moxifloxacin (MXF) strains were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains were 10 (17%). In both gyrA and gyrB regions, there were 58 mutations, or 96.7%. In LVX, there were 56 mutations or 93.3%, and in MXF, there were 57 mutations or 95%. Twelve mutations, six mutations each in gyrA and gyrB, were identified for the QRSA strain. The resistance rate for the quinolone antibiotics of QRSA studied was approximately 98%, and 12 mutations, six each in gyrA and gyrB, were identified in the QRSA strain. Therefore, the rational use of antibiotics needs to be improved.

Complete Genome Sequence of Staphylococcus aureus strain 21SAU_AGRO3 Isolated from Korean Agricultural Products

  • Sojin Ahn;Eunbyeol Ahn;So Yun Jhang;Misun Jeong;Sangryeol Ryu;Seoae Cho
    • Microbiology and Biotechnology Letters
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    • v.51 no.4
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    • pp.555-558
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    • 2023
  • Staphylococcus aureus is a prominent multidrug-resistant pathogen known for its resistance to a variety of antibiotics. To combat this, a wide range of antibiotics, including quinolones, is utilized. While the efficacy of quinolones against S. aureus has been established, the rise in quinolone-resistant strains, particularly in methicillin-resistant S. aureus (MRSA), has necessitated a shift in their usage patterns. Genomic sequencing plays a crucial role as it offers insights into the genetic mechanisms of resistance. Thus, we report the complete genome sequence of an oxolinic acid-resistant strain of S. aureus isolated from sweet potato leaves, a crop commonly cultivated in Korea.

Genotypic characterization of fluoroquinolone-resistant Escherichia coli isolates from edible offal

  • Son, Se Hyun;Seo, Kwang Won;Kim, Yeong Bin;Noh, Eun Bi;Lee, Keun-Woo;Oh, Tae-Ho;Kim, Seung-Joon;Song, Jae-Chan;Kim, Tae-Wan;Lee, Young Ju
    • Korean Journal of Veterinary Research
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    • v.60 no.3
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    • pp.173-177
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    • 2020
  • Edible offal is easily contaminated by Escherichia coli (E. coli) and fluoroquinolone (FQ)-resistant E. coli is considered a serious public health problem, thus, this study investigated the genetic characteristics of FQ-resistant E. coli from edible offal. A total of 22 FQ-resistant E. coli isolates were tested. A double mutation in each gyrA and parC led the highest MIC. Four (18.2%) isolates carried plasmid-mediated quinolone resistance genes. The fimH, eaeA, escV, astA, and iucC genes were confirmed. Seventeen isolates (77.3%) were positive for plasmid replicons. The isolates showed high genetic heterogeneity based on pulsed-field gel electrophoresis patterns.

Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

  • Hu, Li-Fen;Li, Jia-Bin;Ye, Ying;Li, Xu
    • Journal of Microbiology
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    • v.45 no.2
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    • pp.168-170
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    • 2007
  • In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

Distribution of Antimicrobial Resistant Genes in Acinetobacter calcoaceticus-baumannii Complex Isolated from Clinical Specimens in Chungcheong, Korea (충청지역의 임상검체로부터 분리된 Acinetobacter calcoaceticus-baumannii Complex를 대상으로 항균제 내성 유전자 비교분석)

  • Sung, Ji Youn
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.4
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    • pp.427-434
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    • 2017
  • Species that belong to the Acinetobacter calcoaceticus-baumannii (Acb) complex are major causes of hospital-acquired infections. They are important opportunistic pathogens. These species are usually multidrug resistant (MDR), and the therapeutic options to treat the infections caused by these species are limited. In the present study, we investigated fluoroquinolone resistance mechanisms in 53 ciprofloxacin resistant Acinetobacter species isolates in Chungcheong, Korea. Antimicrobial susceptibilities were determined using the disk-diffusion method. Detections of genes and identification of mutations associated with fluoroquinolone resistance were carried out using PCR and DNA sequencing. In our study, 47 out of 53 ciprofloxacin resistant Acinetobacter isolates harbored sense mutations at the 83rd residue (serine to leucine) in the gyrA gene as well as at the 80th residue (serine to leucine) in the parC gene. Among the 47 isolates harboring sense mutations in gyrA and parC gene, 44 isolates were A. baumannii and 3 isolates were A. pittii. Plasmid-mediated quinolone resistance (PMQR) determinants were detected in isolates in our study. Among the 46 ciprofloxacin resistant A. baumannii isolates, 41 showed type A, B, or F banding patterns on their REP-PCR profiles. This result suggests that clonal relation and horizontal spreading of the bacterial isolates have been around hospitals in Chungcheong area. To prevent colonization and disseminations of fluoroquinolone resistance Acb complex isolates, continuous investigation and monitoring of antimicrobial resistant determinants of MDR isolates are needed.

Mutations in the gyrB, parC, and parE Genes of Quinolone-Resistant Isolates and Mutants of Edwardsiella tarda

  • Kim, Myoung-Sug;Jun, Lyu-Jin;Shin, Soon-Bum;Park, Myoung-Ae;Jung, Sung-Hee;Kim, Kwang-Il;Moon, Kyung-Ho;Jeong, Hyun-Do
    • Journal of Microbiology and Biotechnology
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    • v.20 no.12
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    • pp.1735-1743
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    • 2010
  • The full-length genes gyrB (2,415 bp), parC (2,277 bp), and parE (1,896 bp) in Edwardsiella tarda were cloned by PCR with degenerate primers based on the sequence of the respective quinolone resistance-determining region (QRDR), followed by elongation of 5' and 3' ends using cassette ligation-mediated PCR (CLMP). Analysis of the cloned genes revealed open reading frames (ORFs) encoding proteins of 804 (GyrB), 758 (ParC), and 631 (ParE) amino acids with conserved gyrase/topoisomerase features and motifs important for enzymatic function. The ORFs were preceded by putative promoters, ribosome binding sites, and inverted repeats with the potential to form cruciform structures for binding of DNA-binding proteins. When comparing the deduced amino acid sequences of E. tarda GyrB, ParC, and ParE with those of the corresponding proteins in other bacteria, they were found to be most closely related to Escherichia coli GyrB (87.6% identity), Klebsiella pneumoniae ParC (78.8% identity), and Salmonella Typhimurium ParE (89.5% identity), respectively. The two topoisomerase genes, parC and parE, were found to be contiguous on the E. tarda chromosome. All 18 quinolone-resistant isolates obtained from Korea thus far did not contain subunit alternations apart from a substitution in GyrA (Ser83$\rightarrow$Arg). However, an alteration in the QRDR of ParC (Ser84$\rightarrow$Ile) following an amino acid substitution in GyrA (Asp87$\rightarrow$Gly) was detected in E. tarda mutants selected in vitro at $8{\mu}g/ml$ ciprofloxacin (CIP). A mutant with a GyrB (Ser464$\rightarrow$Leu) and GyrA (Asp87$\rightarrow$Gly) substitution did not show a significant increase in the minimum inhibitory concentration (MIC) of CIP. None of the in vitro mutants exhibited mutations in parE. Thus, gyrA and parC should be considered to be the primary and secondary targets, respectively, of quinolones in E. tarda.

Prevalence of plasmid-mediated quinolone and tetracycline resistance genes in Aeromonas strains isolated from eel (Anguilla japonica) and ornamental fish

  • Gee-Wook Shin;Jun-Hwan Park;Hui-Ju Kim
    • Journal of fish pathology
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    • v.36 no.2
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    • pp.287-292
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    • 2023
  • This study investigated the genetic determinants of plasmid-mediated antibiotic resistance (PMAR) to quinolones and tetracycline in 106 Aeromonas strains isolated from eel (Anguilla japonica, 70 strains) and ornamental fish (36 strains) in Korea. Quinolones and tetracycline resistance phenotypes were found to be widely distributed throughout the both fish groups. However, the prevalence of qnr and tet genes was higher in ornamental fish strains than in eel strains (42.9% vs. 86.1% for qnr and 51.4% vs. 69.4% for tet). In addition, the profiling of the present genetic determinants revealed the dominance of qnrS, tetA, tetE and tetE+qnrS genes for eel strains but of tetA+qnrS qnrS and tetE+qnrS genes for ornamental fish strains. These results indicate that aquaculture and related industries could be a major threat to public health due to the possible spread of PMAR.

Study on antimicrobial resistance of Escherichia coli isolated from domestic beef on sale (유통되는 쇠고기에서 분리한 대장균의 항생제 내성 조사.연구)

  • Kim, Hong-Tae;Lee, Woo-Won;Jung, Kyung-Tae;Lee, Seung-Mee;Son, Eun-Jung;Lee, Gang-Rok;Kim, Geum-Hyang;Lee, Dong-Soo;Lee, Keun-Woo
    • Korean Journal of Veterinary Service
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    • v.31 no.1
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    • pp.17-29
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    • 2008
  • In this study, antimicrobial resistance of E coli isolated from domestic beef on sale in Busan and Gyeongnam province was investigated from March to October 2007. A total of 600 beef samples were collected for the monitoring of antimicrobial resistance, and 92 (15.3%) strains of E coli were isolated. Antimicrobial resistance test was carried out by agar disc diffusion method with 17 antimicrobials. In general, E coli isolates showed the highest antimicrobial resistance to doxycycline (73.9%), followed by tetracycline (70.7%) andcefazolin (63.0%). Then they showed higher resistance to several antimicrobials like norfloxacin (48.9%). However, They had low antimicrobial resistance to amikacin (4.3%), colistin (1.1%). Of 92 isolates, 82 (89.1%) were resistant to more than 2 antimicrobials. Among 17 antimicrobials examined, tetracyclines were the most resistant, followed by cephalosporins, quinolone. The resistance was seemed to be correlated to amounts of antimicrobial use. In the result of this study, we suggest that there be need to regulate the abuse of antimicrobial on food-producing animals in Korea because the concern on antimicrobial resistant is gradually increased worldwide.