scholarly journals Acquisition of Quinolone Resistance and Point Mutation of the gyrA Gene in Campylobacter jejuni Isolated from Broilers and in vitro-Induced Resistant Strains

2004 ◽  
Vol 66 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Takehisa CHUMA ◽  
Takatoshi MAEDA ◽  
Hidekazu NIWA ◽  
Karoku OKAMOTO
Keyword(s):  
Point Mutation ◽  
Campylobacter Jejuni ◽  
Quinolone Resistance ◽  
Gyra Gene ◽  
Resistant Strains

scholarly journals Significant contribution of the CmeABC Efflux pump in high-level resistance to ciprofloxacin and tetracycline in Campylobacter jejuni and Campylobacter coli clinical isolates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Saeed Sharifi ◽  
Bita Bakhshi ◽  
Shahin Najar-peerayeh
Keyword(s):  
Gene Expression ◽  
Point Mutation ◽  
Campylobacter Jejuni ◽  
Significant Contribution ◽  
Efflux Pump ◽  
Campylobacter Coli ◽  
Rapd Pcr ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance

Abstract Background Campylobacter resistance to antimicrobial agents is regarded as a major concern worldwide. The aim of this study was to investigate the expression of the CmeABC efflux pump and the RAPD-PCR pattern in drug-resistant Campylobacter isolates. Methods A total of 283 stool specimens were collected from children under the age of five with diarrhea. The minimum inhibitory concentration (MIC) of tetracycline and ciprofloxacin was determined by broth microdilution method and E-test, respectively. Detection of tetracycline and ciprofloxacin determinants was done by amplification of tetO gene and PCR-sequencing of the gyrA gene. The cmeABC transcriptional expression was analyzed by Real-time (RT)-PCR. Clonal correlation of resistant strains was determined by RAPD-PCR genotyping. Results Out of 283 fecal samples, 20 (7.02%) samples were positive for Campylobacter spp. Analysis of duplex PCR assay of the cadF gene showed that 737 and 461 bp amplicons were corresponding to Campylobacter jejuni and Campylobacter coli, respectively. All of the 17 phenotypically tetracycline-resistant Campylobacter isolates harbored the tetO gene. Also, four phenotypically ciprofloxacin-resistant Campylobacter isolates had a point mutation at codon 257 of the gyrA gene (ACA to ATA; Thr > Ile). High-level expression of the cmeA gene was observed in ciprofloxacin-resistant and high-level tetracycline-resistant Campylobacter isolates, suggesting a positive correlation between the cmeA gene expression level and tetracycline resistance level. Moreover, a statistically significant difference was observed in the cmeA gene expression between ciprofloxacin-resistant and ciprofloxacin-susceptible strains, which signifies the crucial contribution of the efflux pump in conferring multiple drug resistance phenotype among Campylobacter spp. RAPD analysis of Campylobacter isolates exhibited 16 different patterns. Simpsone`s diversity index of RAPD-PCR was calculated as 0.85, showing a high level of homogeneity among the population; however, no clear correlation was detected among tetracycline and/or ciprofloxacin resistant isolates. Conclusion Significant contribution of the CmeABC efflux pump in conferring high-level resistance to tetracycline and ciprofloxacin was observed in C. jejuni and C. coli clinical isolates. The resistant phenotype is suggested to be mediated by CmeABC efflux pumps, the tetO gene, and point mutation of the gyrA gene. Genotyping revealed no clonal correlation among resistant strains, indicating distinct evolution of tetracycline and ciprofloxacin resistant genotypes among the isolates.

scholarly journals In Vitro Activity and MIC of Sitafloxacin against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis Isolated in Thailand

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Manoon Leechawengwongs ◽  
Therdsak Prammananan ◽  
Sarinya Jaitrong ◽  
Pamaree Billamas ◽  
Nampueng Makhao ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Critical Concentration ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

ABSTRACT New fluoroquinolones (FQs) have been shown to be more active against drug-resistant Mycobacterium tuberculosis strains than early FQs, such as ofloxacin. Sitafloxacin (STFX) is a new fluoroquinolone with in vitro activity against a broad range of bacteria, including M. tuberculosis. This study aimed to determine the in vitro activity of STFX against all groups of drug-resistant strains, including multidrug-resistant M. tuberculosis (MDR M. tuberculosis), MDR M. tuberculosis with quinolone resistance (pre-XDR), and extensively drug-resistant (XDR) strains. A total of 374 drug-resistant M. tuberculosis strains were tested for drug susceptibility by the conventional proportion method, and 95 strains were randomly submitted for MIC determination using the microplate alamarBlue assay (MABA). The results revealed that all the drug-resistant strains were susceptible to STFX at a critical concentration of 2 μg/ml. Determination of the MIC90s of the strains showed different MIC levels; MDR M. tuberculosis strains had a MIC90 of 0.0625 μg/ml, whereas pre-XDR and XDR M. tuberculosis strains had identical MIC90s of 0.5 μg/ml. Common mutations within the quinolone resistance-determining region (QRDR) of gyrA and/or gyrB did not confer resistance to STFX, except that double mutations of GyrA at Ala90Val and Asp94Ala were found in strains with a MIC of 1.0 μg/ml. The results indicated that STFX had potent in vitro activity against all the groups of drug-resistant M. tuberculosis strains and should be considered a new repurposed drug for treatment of multidrug-resistant and extensively drug-resistant TB.

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 In Vitro Activity of DC-159a, a New Broad-Spectrum Fluoroquinolone, Compared with That of Other Agents against Drug-Susceptible and -Resistant Pneumococci

2007 ◽  
Vol 52 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Catherine Clark ◽  
Kathy Smith ◽  
Lois Ednie ◽  
Tatiana Bogdanovich ◽  
Bonifacio Dewasse ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
The Other ◽  
Quinolone Resistance ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Resistance Selection ◽  
Resistant Strains

ABSTRACT DC-159a yielded MICs of ≤1 μg/ml against 316 strains of both quinolone-susceptible and -resistant pneumococci (resistance was defined as a levofloxacin MIC ≥4 μg/ml). Although the MICs for DC-159a against quinolone-susceptible pneumococci were a few dilutions higher than those of gemifloxacin, the MICs of these two compounds against 28 quinolone-resistant pneumococci were identical. The DC-159a MICs against quinolone-resistant strains did not appear to depend on the number or the type of mutations in the quinolone resistance-determining region. DC-159a, as well as the other quinolones tested, was bactericidal after 24 h at 2× MIC against 11 of 12 strains tested. Two of the strains were additionally tested at 1 and 2 h, and DC-159a at 4× MIC showed significant killing as early as 2 h. Multistep resistance selection studies showed that even after 50 consecutive subcultures of 10 strains in the presence of sub-MICs, DC-159a produced only two mutants with maximum MICs of 1 μg/ml.

Gyrase A Mutations in Campylobacter Associated with Decreased Susceptibility to Different Fluoroquinolones

2017 ◽  
Vol 80 (11) ◽  
pp. 1863-1866 ◽  
Author(s):  
Chris A. Whitehouse ◽  
Shaohua Zhao ◽  
Sampa Mukherjee ◽  
Heather Tate ◽  
Sonya Bodeis-Jones ◽  
...  
Keyword(s):  
Health Concern ◽  
Campylobacter Coli ◽  
Single Mutation ◽  
Global Public Health ◽  
Gyra Gene ◽  
In Vitro Susceptibility ◽  
Fluoroquinolone Antibiotics ◽  
Gyrase A ◽  
Resistant Strains

ABSTRACT Campylobacter is a leading cause of foodborne diarrheal illness worldwide, and the emergence of antimicrobial-resistant strains is a major global public health concern. The goal of this study was to compare the activity of different fluoroquinolone antibiotics against ciprofloxacin-resistant Campylobacter jejuni and Campylobacter coli. Isolates from retail meats collected between 2002 and 2009 were selected based on their in vitro susceptibility testing results against ciprofloxacin. In total, 289 C. jejuni and 165 C. coli were collected and analyzed. All ciprofloxacin-resistant isolates had a single mutation (Thr86Ile) in their gyrase A (gyrA) gene and exhibited decreased susceptibility to all eight fluoroquinolones tested. Gatifloxacin, enrofloxacin, and levofloxacin showed greater activity than the other fluoroquinolone drugs in both ciprofloxacin-sensitive and -resistant strains.

scholarly journals Antimicrobial Susceptibilities of Multidrug-Resistant Campylobacter jejuni and C. coli Strains: In Vitro Activities of 20 Antimicrobial Agents

2009 ◽  
Vol 54 (3) ◽  
pp. 1232-1236 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Ulla-Maija Nakari ◽  
Pirkko Kotilainen ◽  
Pentti Huovinen ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Antimicrobial Agents ◽  
Agar Plate ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Dilution Method ◽  
Erythromycin Resistance ◽  
Disk Diffusion Test ◽  
Resistant Strains

ABSTRACT There is a paucity of information regarding antimicrobial agents that are suitable to treat severe infections caused by multidrug-resistant Campylobacter spp. Our aim was to identify agents that are potentially effective against multiresistant Campylobacter strains. The in vitro activities of 20 antimicrobial agents against 238 Campylobacter strains were analyzed by determining MICs by the agar plate dilution method or the Etest. These strains were selected from 1,808 Campylobacter isolates collected from Finnish patients between 2003 and 2005 and screened for macrolide susceptibility by using the disk diffusion test. The 238 strains consisted of 183 strains with erythromycin inhibition zone diameters of ≤23 mm and 55 strains with inhibition zone diameters of >23 mm. Of the 238 Campylobacter strains, 19 were resistant to erythromycin by MIC determinations (MIC ≥ 16 μg/ml). Given that the resistant strains were identified among the collection of 1,808 isolates, the frequency of erythromycin resistance was 1.1%. All erythromycin-resistant strains were multidrug resistant, with 18 (94.7%) of them being resistant to ciprofloxacin (MIC ≥ 4 μg/ml). The percentages of resistance to tetracycline and amoxicillin-clavulanic acid (co-amoxiclav) were 73.7% and 31.6%, respectively. All macrolide-resistant strains were susceptible to imipenem, meropenem, and tigecycline. Ten (52.6%) multiresistant strains were identified as being Campylobacter jejuni strains, and 9 (47.4%) were identified as being C. coli strains. These data demonstrate that the incidence of macrolide resistance was low but that the macrolide-resistant Campylobacter strains were uniformly multidrug resistant. In addition to the carbapenems, tigecycline was also highly effective against these multidrug-resistant Campylobacter strains in vitro. Its efficacy for the treatment of human campylobacteriosis should be evaluated in clinical trials.

scholarly journals Genetic diversity and characteristics of gyrA gene in Neisseria spp

2019 ◽  
Author(s):  
Pan Zhao ◽  
Aiyu Zhang ◽  
Bingqing Zhu ◽  
Li Xu ◽  
zhujun shao
Keyword(s):  
Dna Gyrase ◽  
Resistance Rate ◽  
Quinolone Resistance ◽  
New Drugs ◽  
Gyra Gene ◽  
Neisseria Species ◽  
Gene Coding ◽  
Gyrase A ◽  
Resistance Markers ◽  
Resistant Strains

Abstract Background Neisseria meningitidis bacteria characterized by clonal complex (CC4821) showed a high resistance rate to quinolones. The aim of this study was to assess whether the DNA gyrase A gene from N.meningitidis CC4821 strains collected in China featured any specific characteristics compared to other Neisseria species. Two hundred fifty two gyrase gene sequences were analyzed, among them 77 generated in this study from N.meningitidis CC4821 strains collected in China between 1978 and 2016. Results The quinolone resistance-related gene, coding for the DNA gyrase subunit A (GyrA) protein, was highly divergent within the N.meningitidis strains whereas N. gonorrhoeae and N.lactamica counterparts appeared well conserved. Only one position, 91 (83 in E.coli gyrA gene), was linked to quinolone resistance, all resistant strains featuring the substitution T91I. The E.coli position 87, which was mutated in quinolone-resistant strains, was also divergent (position 95) in some Neisseria resistant strains. Moreover, twenty eight additional putative resistance markers were identified. Finally, putative recombination events between N.meningitidis and either N.subflava, or N.lactamica or N.cinerea as well as between N.meningitidis strains were reported. Conclusions Analyzing the evolution of gyrA gene within Neisseria spp. is critical to monitor the quinolone resistance phenotype and the acquisition of new resistance markers. Such studies are necessary for the control of the meningococcal disease and the development of new drugs targeting DNA gyrase.

scholarly journals In Vitro Activity of the New Quinolone WCK 771 against Staphylococci

2004 ◽  
Vol 48 (9) ◽  
pp. 3338-3342 ◽  
Author(s):  
Michael R. Jacobs ◽  
Saralee Bajaksouzian ◽  
Anne Windau ◽  
Peter C. Appelbaum ◽  
Mahesh V. Patel ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
High Density ◽  
Quinolone Resistance ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Resistant Strains

ABSTRACT The activity of WCK 771, an experimental quinolone developed to overcome quinolone resistance in staphylococci and other bacteria, was determined against quinolone-susceptible and -resistant Staphylococcus aureus and S. epidermidis. WCK 771 MICs for 50 and 90% of the strains tested (MIC50 and MIC90, respectively) were 0.008 and 0.015 μg/ml for S. aureus (n = 43) and 0.015 and 0.03 μg/ml for S. epidermidis (n = 44) for quinolone-susceptible isolates, compared to ciprofloxacin values of 0.12 and 0.25 μg/ml and 0.25 and 0.5 μg/ml, respectively. Values for levofloxacin were 0.12 and 0.25 μg/ml and 0.12 and 0.25 μg/ml, those for clinafloxacin were 0.015 and 0.03 μg/ml and 0.015 and 0.03 μg/ml, those for moxifloxacin were 0.03 and 0.06 μg/ml and 0.06 and 0.12 μg/ml, and those for gatifloxacin were 0.06 and 0.12 μg/ml and 0.12 and 0.25 μg/ml, respectively. The WCK 771 MIC50 and MIC90, respectively, were 0.5 and 1 μg/ml for both species of staphylococci (n = 73 for S. aureus, n = 70 for S. epidermidis) for isolates highly resistant to ciprofloxacin (MIC50 and MIC90, >32 and >32 μg/ml, respectively). Values for levofloxacin were 8 and 32 μg/ml and 8 and 32 μg/ml, those for clinafloxacin were 1 and 2 μg/ml and 0.5 and 2 μg/ml, those for moxifloxacin 4 and >4 μg/ml and 4 and >4 μg/ml, and those for gatifloxacin were 4 and >4 μg/ml and 2 and >4 μg/ml, respectively. WCK 771 and clinafloxacin demonstrated MICs of 1 μg/ml against three vancomycin-intermediate strains. WCK 771 showed concentration-independent killing for up to 24 h at 2, 4, and 8 times the MICs against quinolone-resistant staphylococci and was also bactericidal after 8 h for high-density inocula (108 CFU/ml) of quinolone-resistant strains at 5 μg/ml, whereas moxifloxacin at 7.5 μg/ml was bacteriostatic. WCK 771 was not a substrate of the NorA efflux pump as evident from the similar MICs against both an efflux-positive and an efflux-negative strain. Overall, WCK 771 was the most potent quinolone tested against the staphylococci tested, regardless of quinolone susceptibility.

scholarly journals Serine-to-Asparagine Substitution in the GyrA Gene Leads to Quinolone Resistance in Moxifloxacin-Exposed Chlamydia pneumoniae

2005 ◽  
Vol 49 (1) ◽  
pp. 406-407 ◽  
Author(s):  
Jan Rupp ◽  
Andreas Gebert ◽  
Werner Solbach ◽  
Matthias Maass
Keyword(s):  
Point Mutation ◽  
Chlamydia Pneumoniae ◽  
Gene Sequencing ◽  
Quinolone Resistance ◽  
Gyra Gene

ABSTRACT Quinolone resistance of Chlamydia pneumoniae has not been described previously. Serial subcultures of C. pneumoniae under increasing moxifloxacin concentrations (0.0125 to 6.4 mg/liter) resulted in a 256-fold MIC increase compared to moxifloxacin-naive strains. GyrA gene sequencing revealed a novel point mutation with a Ser→Asn substitution. Subcultures under rifalazil and macrolides did not alter the respective MICs.

scholarly journals Sequencing of Gyrase and Topoisomerase IV Quinolone-Resistance-Determining Regions of Chlamydia trachomatis and Characterization of Quinolone-Resistant Mutants Obtained In Vitro

1998 ◽  
Vol 42 (10) ◽  
pp. 2474-2481 ◽  
Author(s):  
Sophie Dessus-Babus ◽  
Cécile M. Bébéar ◽  
Alain Charron ◽  
Christiane Bébéar ◽  
Bertille de Barbeyrac
Keyword(s):  
Chlamydia Trachomatis ◽  
Reference Strain ◽  
Fold Increase ◽  
Quinolone Resistance ◽  
Topoisomerase Iv ◽  
Mutant Strains ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
High Level

ABSTRACT The L2 reference strain of Chlamydia trachomatis was exposed to subinhibitory concentrations of ofloxacin (0.5 μg/ml) and sparfloxacin (0.015 μg/ml) to select fluoroquinolone-resistant mutants. In this study, two resistant strains were isolated after four rounds of selection. The C. trachomatis mutants presented with high-level resistance to various fluoroquinolones, particularly to sparfloxacin, for which a 1,000-fold increase in the MICs for the mutant strains compared to the MIC for the susceptible strain was found. The MICs of unrelated antibiotics (doxycycline and erythromycin) for the mutant strains were identical to those for the reference strain. The gyrase (gyrA, gyrB) and topoisomerase IV (parC, parE) genes of the susceptible and resistant strains of C. trachomatis were partially sequenced. A point mutation was found in the gyrAquinolone-resistance-determining region (QRDR) of both resistant strains, leading to a Ser83→Ile substitution (Escherichia coli numbering) in the corresponding protein. ThegyrB, parC, and parE QRDRs of the resistant strains were identical to those of the reference strain. These results suggest that in C. trachomatis, DNA gyrase is the primary target of ofloxacin and sparfloxacin.

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