Ciprofloxacin resistance in coagulase-positive and -negative staphylococci: role of mutations at serine 84 in the DNA gyrase A protein of Staphylococcus aureus and Staphylococcus epidermidis.

ABSTRACT Fluoroquinolones target two bacterial type II topoisomerases, DNA gyrase and topoisomerase IV. Acquired resistance to quinolones occurs stepwise, with the first mutation occurring in the more sensitive target enzyme. To limit the emergence of resistance, quinolones should ideally possess dual activities against the two enzymes. For reasons that are as yet unclear, Staphylococcus aureus gyrase is less sensitive to quinolones than topoisomerase IV, counter to its greater sensitivity in Escherichia coli, thereby limiting the use of quinolones for the treatment of staphylococcal infections. Mutations in the α4-helix domain of the GyrA subunit of gyrase are important in determining quinolone resistance. We replaced an extended region encompassing the α4 domain in the E. coli GyrA protein with its homolog in S. aureus and tested for its ability to complement a thermosensitive gyrase and its catalytic and noncatalytic properties. Purified gyrase reconstituted with chimeric GyrA was more resistant to ciprofloxacin than wild-type gyrase at both inhibition of catalytic activity and stimulation of cleavage complexes, and this difference was more apparent in the presence of K+-glutamate. The chimeric GyrA subunit was able to complement thermosensitive gyrase, similar to wild-type GyrA. Without supplemental K+-glutamate the MICs of ciprofloxacin for thermosensitive E. coli complemented with chimeric DNA gyrase were equal to those for E. coli complemented with wild-type gyrase but were twofold higher in the presence of K+-glutamate. Our findings suggest that the extended α4 domain of S. aureus GyrA is responsible, at least in part, for the increased resistance of S. aureus gyrase to quinolones and that this effect is modulated by K+-glutamate.

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Nucleotide sequence of the Staphylococcus aureus gyrB-gyrA locus encoding the DNA gyrase A and B proteins.

Journal of Bacteriology ◽

10.1128/jb.174.5.1596-1603.1992 ◽

1992 ◽

Vol 174 (5) ◽

pp. 1596-1603 ◽

Cited By ~ 46

Author(s):

E E Margerrison ◽

R Hopewell ◽

L M Fisher

Keyword(s):

Staphylococcus Aureus ◽

Nucleotide Sequence ◽

Dna Gyrase ◽

Gyrase A

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Role of biofilm in Staphylococcus aureus and Staphylococcus epidermidis ventricular assist device driveline infections

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/j.jtcvs.2010.07.016 ◽

2011 ◽

Vol 141 (5) ◽

pp. 1259-1264 ◽

Cited By ~ 49

Author(s):

Faustino A. Toba ◽

Hirokazu Akashi ◽

Carlos Arrecubieta ◽

Franklin D. Lowy

Keyword(s):

Staphylococcus Aureus ◽

Ventricular Assist Device ◽

Staphylococcus Epidermidis ◽

Assist Device ◽

Ventricular Assist

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Molecular Cloning of the gyrA andgyrB Genes of Bacteroides fragilis Encoding DNA Gyrase

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.10.2423 ◽

1999 ◽

Vol 43 (10) ◽

pp. 2423-2429 ◽

Cited By ~ 19

Author(s):

Yoshikuni Onodera ◽

Kenichi Sato

Keyword(s):

Hot Spot ◽

Bacteroides Fragilis ◽

Dna Gyrase ◽

E Coli ◽

Important Target ◽

Mutant Strains ◽

Genes Encoding ◽

Gyrase A ◽

Selection For

ABSTRACT The genes encoding the DNA gyrase A and B subunits ofBacteroides fragilis were cloned and sequenced. ThegyrA and gyrB genes code for proteins of 845 and 653 amino acids, respectively. These proteins were expressed inEscherichia coli, and the combination of GyrA and GyrB exhibited ATP-dependent supercoiling activity. To analyze the role of DNA gyrase in quinolone resistance of B. fragilis, we isolated mutant strains by stepwise selection for resistance to increasing concentrations of levofloxacin. We analyzed the resistant mutants and showed that Ser-82 of GyrA, equivalent to resistance hot spot Ser-83 of GyrA in E. coli, was in each case replaced with Phe. These results suggest that DNA gyrase is an important target for quinolones in B. fragilis.

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Role of mutations in DNA gyrase genes in ciprofloxacin resistance of Pseudomonas aeruginosa susceptible or resistant to imipenem

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.39.10.2248 ◽

1995 ◽

Vol 39 (10) ◽

pp. 2248-2252 ◽

Cited By ~ 23

Author(s):

E. Cambau ◽

E. Perani ◽

C. Dib ◽

C. Petinon ◽

J. Trias ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Dna Gyrase ◽

Ciprofloxacin Resistance

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The Teicoplanin-Associated Locus Regulator (TcaR) and the Intercellular Adhesin Locus Regulator (IcaR) Are Transcriptional Inhibitors of the ica Locus in Staphylococcus aureus

Journal of Bacteriology ◽

10.1128/jb.186.8.2449-2456.2004 ◽

2004 ◽

Vol 186 (8) ◽

pp. 2449-2456 ◽

Cited By ~ 100

Author(s):

Kimberly K. Jefferson ◽

Danielle B. Pier ◽

Donald A. Goldmann ◽

Gerald B. Pier

Keyword(s):

Staphylococcus Aureus ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Negative Regulator ◽

Regulatory Proteins ◽

Polysaccharide Intercellular Adhesin ◽

Topoisomerase Iv ◽

Exogenous Factors ◽

Dna Affinity Chromatography

ABSTRACT Infections involving Staphylococcus aureus are often more severe and difficult to treat when the organism assumes a biofilm mode of growth. The polysaccharide poly-N-acetylglucosamine (PNAG), also known as polysaccharide intercellular adhesin, is synthesized by the products of the intercellular adhesin (ica) locus and plays a key role in biofilm formation. Numerous conditions and exogenous factors influence ica transcription and PNAG synthesis, but the regulatory factors and pathways through which these environmental stimuli act have been only partially characterized. We developed a DNA affinity chromatography system to purify potential regulatory proteins that bind to the ica promoter region. Using this technique, we isolated four proteins, including the staphylococcal gene regulator SarA, a MarR family transcriptional regulator of the teicoplanin-associated locus TcaR, DNA-binding protein II, and topoisomerase IV, that bound to the ica promoter. Site-directed deletion mutagenesis of tcaR indicated that TcaR was a negative regulator of ica transcription, but deletion of tcaR alone did not induce any changes in PNAG production or in adherence to polystyrene. We also investigated the role of IcaR, encoded within the ica locus but divergently transcribed from the biosynthetic genes. As has been shown previously in Staphylococcus epidermidis, we found that IcaR was also a negative regulator of ica transcription in S. aureus. We also demonstrate that mutation of icaR augmented PNAG production and adherence to polystyrene. Transcription of the ica locus, PNAG production, and adherence to polystyrene were further increased in a tcaR icaR double mutant. In summary, TcaR appeared to be a weak negative regulator of transcription of the ica locus, whereas IcaR was a strong negative regulator, and in their absence PNAG production and biofilm formation were enhanced.

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The Staphylococcal Ferritins Are Differentially Regulated in Response to Iron and Manganese and via PerR and Fur

Infection and Immunity ◽

10.1128/iai.72.2.972-979.2004 ◽

2004 ◽

Vol 72 (2) ◽

pp. 972-979 ◽

Cited By ~ 33

Author(s):

Julie A. Morrissey ◽

Alan Cockayne ◽

Kirsty Brummell ◽

Paul Williams

Keyword(s):

Oxidative Stress ◽

Staphylococcus Aureus ◽

Staphylococcus Epidermidis ◽

Oxidative Stress Response ◽

Metal Availability ◽

Wild Type ◽

Additional Level ◽

Alkyl Hydroperoxidase ◽

Iron And Manganese

ABSTRACT Staphylococcus aureus and Staphylococcus epidermidis ferritin (FtnA and SefA, respectively) homologues are antigenic and highly conserved. A previous study showed that ftnA is a component of the S. aureus PerR regulon with its transcription induced by elevated iron and repressed by PerR, which functions as a manganese-dependent transcriptional repressor. We have further investigated the role of iron and Fur in the regulation of PerR regulon genes ftnA (ferritin), ahpC (alkyl-hydroperoxidase), and mrgA (Dps homologue) and shown that iron has a major role in the regulation of the PerR regulon and hence the oxidative stress response, since in the presence of both iron and manganese, transcription of PerR regulon genes is induced above the repressed levels observed with manganese alone. Furthermore the PerR regulon genes are differentially regulated by metal availability and Fur. First, there is an additional level of PerR-independent regulation of ftnA under low-iron conditions which is not observed with ahpC and mrgA. Second, there is a differential response of these genes to Fur as ftnA expression is constitutive in a fur mutant, while ahpC expression is constitutive under low-Fe/Mn conditions but some repression of ahpC still occurs in the presence of manganese, whereas mrgA expression is still repressed in the fur mutant as in wild-type S. aureus, although there is a decrease in the overall level of mrgA transcription. These studies have also shown that FtnA expression is regulated by growth phase, but maximal transcription of ftnA differs dependent on the growth medium. Moreover, there are significant regulatory differences between the S. aureus and S. epidermidis ferritins, as sefA expression in contrast to that of ftnA is derepressed under low-Fe/Mn ion conditions.

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Identification of DNA gyrase Subunit a Mutations Associated with Ciprofloxacin Resistance in Staphylococcus aureus Isolated from Nasal Infection in Kurdistan-Iran

Journal of Molecular Biology Research ◽

10.5539/jmbr.v7n1p186 ◽

2017 ◽

Vol 7 (1) ◽

pp. 186

Author(s):

Roya Darbani ◽

Chiako Farshadfar ◽

Somayeh Tavana ◽

Hamidreza Saljoughi ◽

Sheida Sadat Zonouri

Keyword(s):

Staphylococcus Aureus ◽

Free Energy ◽

Molecular Docking ◽

Dna Gyrase ◽

Amino Acid Sequences ◽

Nucleotide Sequencing ◽

Molegro Virtual Docker ◽

Fluoroquinolone Antibiotics ◽

Ciprofloxacin Resistance ◽

Free Energy Of Binding

Fluoroquinolone antibiotics such as ciprofloxacin are useful drugs against infections caused by Staphylococcus aureus and mutations in DNA gyrase which control bacterial DNA topology, can be one of the reason of occurrence resistance to this class of antibiotics. Therefore finding new mutations and study of the quinolone interaction with mutated GyrA can provide important issues for explanation resistance. In this study 5 ciprofloxacin resistance Staphylococcus aureus isolated among 50 collected S.aureus strains. By PCR testing, gyrA genes in resistance strains was amplified and nucleotide sequencing was done. Nucleotide sequences translate to amino acid sequences then by blastp homology between each GyrA mutant and reference GyrA were compared and mutations were recognized, at last molecular docking were done for GyrA protein and ciprofloxacin, based on free energy of binding decide if the mutations are responsible of resistance or not. The results show glutamic acid and threonine adjacent to each other in common positions 21-22, 32-33, 65-66, 84-85, 101-102, 106-107, 128-129 and 138-139 in all 5 strains were inserted . In order to finding association between mutations and ciprofloxacin resistance molecular docking by Molegro Virtual Docker 5.5 was done. Free energy of binding between reference GyrA- ciprofloxacin and mutant GyrA- ciprofloxacin were -92.3477 and -73.1642 respectively. We conclude different mutations can be affected structure of GyrA and make ciprofloxacin resistance. Finding these kinds of mutations are important and preventing them is indispensable.

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The Glycosyltransferases sdgA and sdgB Expression in Staphylococcus Epidermidis Depends On The Conditions of Biofilm Formation.

10.21203/rs.3.rs-1178820/v1 ◽

2021 ◽

Author(s):

Itzia S. Gómez-Alonso ◽

Ilse D. Estrada-Alemán ◽

Sergio Martínez-García ◽

Humberto Peralta ◽

Erika T. Quintana ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Cathepsin G ◽

Dynamic Conditions ◽

Static Conditions ◽

Sessile Cells ◽

In Cells

Abstract The Staphylococcus aureus’ SdrG protein is glycosylated by SdgA and SdgB for their protection against its degradation by the neutrophil’s cathepsin G. So far, there is not information about the role of Staphylococcus epidermidis’ SdgA nor SdgB in the production of biofilm, therefore the main of this work was to determine the distribution and expression of sdrG, sdgA and sdgB genes in S. epidermidis in conditions of biofilm. The frequency of the genes sdrG, sdgA and sdgB were evaluated by PCR in a collection of 75 isolates. The isolates were grown in dynamic conditions (in agitation) or static conditions (biofilm productor: planktonic or sessile cells). The expression of sdrG, sdgA and sdgB were determined by RT-qPCR in cells grown under dynamic conditions (CGDC), as well as planktonic and sessile cells, and in cells adhered to a catheter (in vivo). The genes sdrG and sdgB were detected in 100% of isolates, meanwhile the gene sdgA was detected in 71% of the samples (p<0.001). The CGDC did not expressed the sdrG, sdgA and sdgB mRNAs. The planktonic and sessile cells expressed sdrG and sdgB, and the same was seen in cells adhered to the catheter. In particular, one isolate, able to induce biofilm under cathepsin G treatment, expressed sdrG and sdgB in planktonic, sessile and in cells adhered to the catheter. This suggests that the state of cells adherence is an important factor for the transcription of sdgA, sdgB and sdrG.

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