scholarly journals Relationship between Mutations in the gyrA Gene and Quinolone Resistance in Clinical Isolates of Corynebacterium striatum and Corynebacterium amycolatum

2005 ◽  
Vol 49 (5) ◽  
pp. 1714-1719 ◽  
Author(s):  
Josep M. Sierra ◽  
Luis Martinez-Martinez ◽  
Fernando Vázquez ◽  
Ernest Giralt ◽  
Jordi Vila
Keyword(s):  
Amino Acid ◽  
Test Method ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Moderate Increase ◽  
Gyra Gene ◽  
Double Mutation ◽  
Corynebacterium Striatum

ABSTRACT Quinolone susceptibility was analyzed in 17 clinical isolates of Corynebacterium striatum and 9 strains of Corynebacterium amycolatum by the E-test method in Mueller-Hinton agar plates. The C. striatum ATCC 6940 strain was used as a control strain. The amplified quinolone resistance determining regions of the gyrA genes of C. amycolatum and C. striatum were characterized. Four in vitro quinolone-resistant mutants of C. amycolatum were selected and analyzed. Both in vivo and in vitro quinolone-resistant strains of C. amycolatum showed high levels of fluoroquinolone resistance in strains with a double mutation leading to an amino acid change in positions 87 and 91 or positions 87 and 88 (unusual mutation) of GyrA, whereas the same concomitant mutations at amino acid positions 87 and 91 in GyrA of C. striatum produced high levels of resistance to ciprofloxacin and levofloxacin but only showed a moderate increase in the MIC of moxifloxacin, suggesting that other mechanism(s) of quinolone resistance could be involved in moxifloxacin resistance in C. amycolatum. Moreover, a PCR-RFLP-NcoI of the gyrA gene was developed to distinguish between C. amycolatum and C. striatum species.

scholarly journals Comparative Analysis of Quinolone Resistance in Clinical Isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese Children and Adults

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Huang ◽  
James O. Ogutu ◽  
Jiarui Gu ◽  
Fengshu Ding ◽  
Yuhong You ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Environmental Issues ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Chinese Adults ◽  
Double Mutation ◽  
History Of ◽  
Ciprofloxacin Resistance ◽  
Resistance Rates

The objective of this study was to compare quinolone resistance andgyrAmutations in clinical isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The mutations in the quinolone resistance-determining regions ingyrAgene were detected by PCR and DNA sequencing. Fluoroquinolone resistance and types ofgyrAmutations in isolates from children and adults were compared and statistically analyzed. No significant differences were detected in the resistance rates of ciprofloxacin and levofloxacin between children and adults among isolates of the two species (allP>0.05). The double mutation Ser83→Leu + Asp87→Asn in the ciprofloxacin-resistant isolates occurred in 73.7% isolates from the children and 67.9% from the adults, respectively (P=0.5444). Children with no known history of quinolone administration were found to carry fluoroquinolone-resistantEnterobacteriaceaeisolates. The occurrence of ciprofloxacin resistance and the major types ofgyrAmutations in the isolates from the children were similar to those from adults. The results indicate that precautions should be taken on environmental issues resulting from widespread transmission of quinolone resistance.

scholarly journals Prevalence, Characteristics, and Molecular Epidemiology of Macrolide and Fluoroquinolone Resistance in Clinical Isolates of Streptococcus pneumoniae at Five Tertiary-Care Hospitals in Korea

2007 ◽  
Vol 51 (7) ◽  
pp. 2625-2627 ◽  
Author(s):  
Jeong Hwan Shin ◽  
Hee Jung Jung ◽  
Hye Ran Kim ◽  
Joseph Jeong ◽  
Seok Hoon Jeong ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Molecular Epidemiology ◽  
Tertiary Care ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
New Mutation ◽  
Tertiary Care Hospitals

ABSTRACT The genes erm(B), mef(A), and both erm(B) and mef(A) were identified in 42.6, 10.1, and 47.3%, respectively, of the erythromycin-resistant Streptococcus pneumoniae isolates. Of the strains, 3.8% were nonsusceptible to levofloxacin and had 1 to 6 amino acid changes in the quinolone resistance-determining region, including a new mutation, Asn94Ser, in the product of parC. Levofloxacin with reserpine was highly specific for efflux screening.

scholarly journals Genetic Analyses of Mutations Contributing to Fluoroquinolone Resistance in Clinical Isolates ofStreptococcus pneumoniae

2001 ◽  
Vol 45 (12) ◽  
pp. 3517-3523 ◽  
Author(s):  
L. M. Weigel ◽  
G. J. Anderson ◽  
R. R. Facklam ◽  
F. C. Tenover
Keyword(s):  
Amino Acid ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Cross Resistance ◽  
Genetic Analyses ◽  
High Level ◽  
Susceptibility Profiles ◽  
Level Resistance

ABSTRACT Twenty-one clinical isolates of Streptococcus pneumoniae showing reduced susceptibility or resistance to fluoroquinolones were characterized by serotype, antimicrobial susceptibility, and genetic analyses of the quinolone resistance-determining regions (QRDRs) of gyrA,gyrB, parC, and parE. Five strains were resistant to three or more classes of antimicrobial agents. In susceptibility profiles for gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, ofloxacin, sparfloxacin, and trovafloxacin, 14 isolates had intermediate- or high-level resistance to all fluoroquinolones tested except gemifloxacin (no breakpoints assigned). Fluoroquinolone resistance was not associated with serotype or with resistance to other antimicrobial agents. Mutations in the QRDRs of these isolates were more heterogeneous than those previously reported for mutants selected in vitro. Eight isolates had amino acid changes at sites other than ParC/S79 and GyrA/S81; several strains contained mutations in gyrB, parE, or both loci. Contributions to fluoroquinolone resistance by individual amino acid changes, including GyrB/E474K, ParE/E474K, and ParC/A63T, were confirmed by genetic transformation of S. pneumoniae R6. Mutations in gyrB were important for resistance to gatifloxacin but not moxifloxacin, and mutation of gyrAwas associated with resistance to moxifloxacin but not gatifloxacin, suggesting differences in the drug-target interactions of the two 8-methoxyquinolones. The positions of amino acid changes within the four genes affected resistance more than did the total number of QRDR mutations. However, the effect of a specific mutation varied significantly depending on the agent tested. These data suggest that the heterogeneity of mutations will likely increase as pneumococci are exposed to novel fluoroquinolone structures, complicating the prediction of cross-resistance within this class of antimicrobial agents.

scholarly journals Novel Ser79Leu and Ser81Ile Substitutions in the Quinolone Resistance-Determining Regions of ParC Topoisomerase IV and GyrA DNA Gyrase Subunits from Recent Fluoroquinolone-Resistant Streptococcus pneumoniae Clinical Isolates

2005 ◽  
Vol 49 (6) ◽  
pp. 2479-2486 ◽  
Author(s):  
Nataliya Korzheva ◽  
Todd A. Davies ◽  
Raul Goldschmidt
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Amino Acid Substitutions ◽  
Topoisomerase Iv ◽  
Isogenic Strains ◽  
New Mutations

ABSTRACT Resistance of Streptococcus pneumoniae to fluoroquinolones is caused predominantly by amino acid substitutions at positions Ser79 of ParC and Ser81 of GyrA to either Phe or Tyr encoded in the quinolone resistance-determining regions of the parC topoisomerase IV and gyrA DNA gyrase genes. Analysis of highly resistant clinical isolates identified novel second-step substitutions, Ser79Leu (ParC) and Ser81Ile (GyrA). To determine contributions of these new mutations to fluoroquinolone resistance either alone or in combination with other Ser79/81 alleles, the substitutions Ser79Leu/Phe/Tyr in ParC and Ser81Ile/Phe/Tyr in GyrA were introduced into the R6 background, resulting in 15 isogenic strains. Their level of fluoroquinolone resistance was determined by susceptibility testing for ciprofloxacin, levofloxacin, moxifloxacin, gatifloxacin, gemifloxacin, garenoxacin, and norfloxacin. Leu79 and Ile81 alone as well as 79/81Phe/Tyr substitutions did not contribute significantly to resistance, with fluoroquinolone MICs increasing two- to fourfold compared to wild type for all agents tested. Fluoroquinolone MICs for double transformants ParC Ser79Phe/Tyr/Leu-GyrA Ser81Phe/Tyr were uniformly increased by 8- to 64-fold regardless of pairs of amino acid substitutions. However, combinations including Ile81 conferred two- to fourfold-higher levels of resistance than did combinations including any other Ser81 GyrA substitution, thus demonstrating the differential effects of diverse amino acid substitutions at particular hotspots on fluoroquinolone MICs.

scholarly journals In Vitro Assessment of the Further Potential for Development of Fluoroquinolone Resistance in Neisseria meningitidis

2005 ◽  
Vol 49 (5) ◽  
pp. 1753-1760 ◽  
Author(s):  
Tiffany R. Shultz ◽  
Peter A. White ◽  
John W. Tapsall
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Neisseria Meningitidis ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
In Vitro Assessment ◽  
Resistant Mutants ◽  
The Individual

ABSTRACT We examined the potential for the development of fluoroquinolone resistance in Neisseria meningitidis by cultivating two clinical isolates of meningococci in the presence of concentrations of ciprofloxacin at and about the predetermined MIC. The quinolone resistance determining regions (QRDRs) of gyrA and parC of 50 stable quinolone-resistant mutants derived in vitro were sequenced and compared with QRDR alterations reported in clinical isolates of quinolone-resistant meningococci and gonococci. MICs to ciprofloxacin and trovafloxacin were determined and sequence changes were correlated with quinolone MICs. Ciprofloxacin and trovafloxacin MICs of the in vitro-derived quinolone-resistant mutants ranged up to 16 mg/liter. Single GyrA alterations were the first change detected and were accompanied by raised MICs, followed by double GyrA changes and still higher MICs. MICs increased further as single ParC substitutions appeared and these were always in the presence of a single or double GyrA change. GyrA changes occurred at positions 91 and 95 with substitutions of Asp-95→Asn and Thr-91→Ala and Ile. Changes in the parC QRDR occurred at positions 85, 86, and 91 with four substitutions, Gly-85→Asp, Asp-86→Asn, Glu-91→Gly, and Glu-91→Lys, detected. The nature of the individual QRDR substitution appeared to influence the level of quinolone resistance expressed, and this varied with the quinolone agent examined. Close similarities occurred between the sequence and nature of QRDR changes in clinical and in vitro-generated quinolone-resistant mutants and with those previously reported for clinical and in vitro-generated quinolone-resistant gonococci. This suggests that quinolone resistance in meningococci may arise in the same manner and reach similar levels in vivo to those seen in quinolone-resistant Neisseria gonorrhoeae.

scholarly journals Mutations in the gyrA, parC, and parE Genes Associated with Fluoroquinolone Resistance in Clinical Isolates of Mycoplasma hominis

1999 ◽  
Vol 43 (4) ◽  
pp. 954-956 ◽  
Author(s):  
Cécile M. Bebear ◽  
Joel Renaudin ◽  
Alain Charron ◽  
Hélène Renaudin ◽  
Bertille de Barbeyrac ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mycoplasma Hominis ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Amino Acid Substitutions ◽  
Topoisomerase Iv

ABSTRACT Five clinical isolates of Mycoplasma hominis from three different patients were examined for resistance to fluoroquinolones; some of these isolates were probably identical. All five isolates harbored amino acid substitutions in the quinolone resistance-determining regions of both DNA gyrase (GyrA) and topoisomerase IV (ParC or ParE). Furthermore, the novobiocin MIC for three isolates showed a significant increase. This is the first characterization of fluoroquinolone-resistant clinical mycoplasma isolates from humans.

scholarly journals Alterations in the Quinolone Resistance-Determining Regions and Fluoroquinolone Resistance in Clinical Isolates and Laboratory-Derived Mutants of Mycoplasma bovis: Not All Genotypes May Be Equal

2015 ◽  
Vol 82 (4) ◽  
pp. 1060-1068 ◽  
Author(s):  
Dima Khalil ◽  
Claire A. M. Becker ◽  
Florence Tardy
Keyword(s):  
Point Mutations ◽  
Slight Modification ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Mycoplasma Bovis ◽  
Content Type ◽  
High Level ◽  
Sequence Types

ABSTRACTMycoplasma bovisis considered a major contributor to respiratory diseases in young cattle. ResistantM. bovisisolates have increasingly been reported worldwide due to extensive use of antimicrobials to treat bovine pneumonia. The frequency of isolates resistant to fluoroquinolones varies considerably from one country to another. The MICs of isolates collected in France have only increased from “very low” to “low.” The present study was conducted to investigate whether alterations in the quinolone resistance-determining regions (QRDRs) could account for this slight modification in susceptibility. No correlation between QRDR alterations and increased MICs was evidenced in clinical isolates. In addition, all clinical isolates were subtyped, and the tendencies of the different sequence types to develop resistance through mutations in QRDRs under selective pressurein vitrowere examined.In vitro, 3 hot spots for mutations in QRDRs (position 83 in GyrA and positions 80 and 84 in ParC) were associated with a high level of resistance when cumulated. We showed that the point mutations in the QRDRs observedin vitrowere different (in location and selection rapidity) between the different subtypes. Ourin vitroobservations were corroborated by the recent detection of a clinical isolate highly resistant to fluoroquinolones (MIC ≥ 16 μg/ml) and belonging to the subtype which easily accumulates QRDR alterationsin vitro. The current increased prevalence of this subtype in clinical isolates highlights the urgent need to control fluoroquinolone usage in veterinary medicine.

scholarly journals Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in quinolone-resistant clinical isolates of Klebsiella pneumoniae.

1997 ◽  
Vol 41 (3) ◽  
pp. 699-701 ◽  
Author(s):  
T Deguchi ◽  
A Fukuoka ◽  
M Yasuda ◽  
M Nakano ◽  
S Ozeki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Primary Target ◽  
Gyra Gene ◽  
Topoisomerase Iv ◽  
Complementary Role

We determined a partial sequence of the Klebsiella pneumoniae parC gene, including the region analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene, and examined 26 clinical strains of K. pneumoniae for an association of alterations in GyrA and ParC with susceptibilities to quinolones. The study suggests that in K. pneumoniae DNA gyrase is a primary target of quinolones and that ParC alterations play a complementary role in the development of higher-level fluoroquinolone resistance.

scholarly journals Transformation of fluoroquinolone-resistance Neisseria gonorrhoeae gyrA and parC genes

2020 ◽  
pp. 55-63
Author(s):  
Szymon Walter de Walthoffen
Keyword(s):  
Amino Acid ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance ◽  
Gyra Gene ◽  
Gene Encoding ◽  
Double Mutation ◽  
Sexually Transmitted ◽  
Acid Acid ◽  
Causative Agents ◽  
Sensitive Isolate

Introduction: N. gonorrhoeae is one of the etiological causative agents of one of the most common sexually transmitted diseases. Gonococci has created many resistance mechanisms, which is associated with bacterial evolution. Natural transformation is the basic method of horizontal gene transfer in bacteria of the genus Neisseria, which can lead to a mutation in the gyrA gene encoding DNA gyrase. The aim of the study was to verify the view on the significance of mutations at positions 91 and 95 of the gyrA protein on the sensitivity of N. gonorrhoeae to antibiotics of the quinolone type. Methods: GyrA gene was introduced into an sensitive isolate of N. gonorrhoeae using genetic transformation. Resistance gene donor, recipient and transform strains were tested for susceptibility and the gyrA gene was sequenced. Results: It has been shown that double mutation in amino acid acid sequence of the GyrA protein at positions 91 and 95 increase the value of MIC from 0,003 mg / L to 0,125 mg / L at CIP sensitive N. gonorrhoeae strain. Conclusions: Mutations in the amino acid sequence at positions 91 and 95 affet the strain’s sensitivity to ciprofloxacin, but it is not the only mechanism which could alter the MIC value of quinolones.

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