A study Marcusson et al. Acquisition of a triplet of GyrA 83, GyrA 87, and ParC 80 substitutions resulted in fitness gain when efflux was not involved. De-repressed efflux activity was, however, associated with fitness costs. Resistant mutants harboring the same triplet mutations, which was obtained by exposure of a quinolone-susceptible Salmonella Typhimurium clinical isolate to increasing concentrations of ciprofloxacin also showed a diminished ability to grow Fabrega et al.

Huseby et al. Most of our understanding of the contributions and fitness costs of different mechanisms to quinolone resistance is from laboratory studies or analysis of small numbers of mutants. Given the importance of quinolone resistance as a phenotype, a thorough understanding of the impact of the different FQ resistance mechanisms in the real world is of crucial importance. In the present study, Salmonella isolates with a broad range of ciprofloxacin MIC distributions were collected.

These isolates were analyzed for correlations between ciprofloxacin resistance phenotypes and: target site mutations, expression levels of acrAB, and prevalence of PMQR genes. This research assessed the relative contributions of defined mutant combinations toward fitness in different FQ concentrations and informs how FQ resistance evolves in the food chain.

Materials and Methods Bacterial Strains and Susceptibility Testing Salmonella isolates used in this study were isolated from pork samples in a large-scale slaughterhouse between and Yang et al.

In order to generate a consecutive ciprofloxacin MIC distribution range for each MIC value, we selected 50 additional strains from food-producing animals and raw meat chicken and pork as described elsewhere Zhang et al. This included 11 isolates from swine, 9 from chickens, 17 from ducks and 13 from meat samples 10 chicken and 3 pork Table 1. Although efforts were made to screen for strains with a ciprofloxacin MIC between 0.

We only identified 3, 3, and 4 isolates in the entire strain collection that possessed ciprofloxacin MICs of 0. Sources and ciprofloxacin MIC values for Salmonella isolates used in this study. The majority of the strains isolated from pork samples were serovars Derby, Rissen and Indiana as previously described Yang et al. The 50 additional isolates included Typhimurium 15 , Indiana 12 , Enteritidis 7 , Derby 5 , and 11 others.

Salmonella enterica subsp. Laura Piddock Institute of Microbiology and Infection, University of Birmingham and used as a standard reference strain in this study. Primers used are listed in Supplementary Table 1. The restriction fragments were separated by electrophoresis in 0.

The 16S rRNA gene was used as an internal control gene and relative expression levels of each gene were calculated using the ΔΔCt method and the software provided with the instrument.

Data are presented as mean ± SD from three independent assays, in which each RNA sample was tested in triplicate. Competitive Fitness Measurements To directly measure fitness impacts of different resistance mutations we used competition assays between pairs of strains selected to carry different combinations of resistance mechanisms, and with different susceptibility levels to ciprofloxacin.

Fitness was analyzed as previously described with some modifications Zhang C. Growth competition was determined by pyrosequencing the single nucleotide variations in ParC which distinguished each pair of competed strains. Briefly, the competitive paired strains were mix and co-cultured ratio in antibiotic-free LB broth for 18 h and DNA was extracted using a standard phenol-chloroform-heat method.

The DNA from the competitive growth assays was amplified by PCR in triplicate using biotinylated primer pairs targeting the region containing the single nucleotide polymorphism to distinguish the two organisms in the assay by mutations in ParC. Competition coefficients were defined as the ratio of the strain pairs subjected to different incubation conditions and calculated by measuring percentage yield of the single nucleotide mutations in parC.

We selected Salmonella strains from 1, isolates, amongst which 91 were susceptible to ciprofloxacin, 20 were deemed intermediate and 65 were resistant according to CLSI breakpoints. However, epidemiologically there were clearly more than three levels of susceptibility in the populations, likely to reflect distinct combinations of resistance mechanisms. The resulting categories were designated as: highly resistant HR , resistant R , intermediate I , reduced susceptibility RS , and susceptible S Figure 1.

Ciprofloxacin MIC distributions in Salmonella strains used in this study. Characteristics of Salmonella enterica isolates from food-producing animals in China. The identification of these mutations was positively correlated with their assignment into the 5-level interpretation system. The expression of efflux complex acrA, acrB, and tolC and regulatory ramA, marA, and soxS genes for the subset of 32 Salmonella isolates were measured Table 2 and Supplementary Figure 2.

Compared with S. Furthermore, the majority of I strains exhibited increased expression of efflux pump genes with concurrent overexpression of marA.

Surprisingly, the efflux pump genes were not expressed more in R strains compared with S. Typhimurium SL A two-way ANOVA test of expression values for the regulator genes indicated the differences between groups were not likely to be observed by chance p 0.

In addition, all these strains, regardless of whether the genes were located on a plasmid or chromosome, were positive for the presence of circular intermediates containing IS26 and the oqxABR genes Figures 2B,C. Sequencing of this circular intermediate confirmed that the length of the intermediate was 6, bp and that oqxABR harbored a complete copy of IS These results indicate that the Tn element was unstable and prone to excision in our Salmonella isolates.

Formation of a circular intermediate by oqxABR operon. Primers are listed in Supplementary Table 1. NC, Negative Control.

Competitive Fitness We compared the competitive fitness of closely related pairs of isolates selected to represent the different combinations of resistance mechanisms and susceptibility levels observed in the whole panel. All strains used in competition assays are shown in Table 3. Characteristics of strains used in growth competition assays. In vitro bacterial competition assays. Competition coefficient values were obtained from each independent experiment as indicated.

Broken horizontal line, competition coefficient of 1; mean values, short continuous horizontal lines. Discussion The evolution of antimicrobial resistance in bacteria is driven by the pressures exerted following exposure to antimicrobials. However, the impacts of different resistance mechanisms are still not well understood.

We analyzed isolates of different Salmonella serovars with a broad range of ciprofloxacin MIC distributions in this study. Whether the ParC T57S substitution contributes to quinolone resistance, is still controversial Baucheron et al.

Therefore, we suggest that any impact of this mutation alone of quinolone susceptibility must be low and can only provide a low degree of protection against ciprofloxacin. This change alone may carry little fitness cost which would explain its prevalence in the S and RS strains, however, it may incur a different impact on fitness when associated with GyrA substitutions as no strain carried a single substitution within ParC and any GyrA change in any of the groups.

Results: A total of 25, samples of blood culture yielded Salmonella enterica serotype Typhi and serotype Paratyphi A isolates. Twenty-two isolates of serotype Typhi were resistant to ciprofloxacin, while two isolates of Typhi and two Paratyphi A were intermediately susceptible to ciprofloxacin.

Ciprofloxacin resistance is 5. Ampicillin, chloramphenicol and co-trimoxazole resistance in Salmonella enterica serotype Typhi appears to have decreased to All isolates were sensitive to ceftriaxone. Conclusions: Ciprofloxacin can no longer be considered as the drug of choice in treating Salmonella infections.

Ciprofloxacin - Manfaat, Dosis, dan Efek Samping - KlikDokter

Gyrase is fascinating, not just because it is a ciprofloxacin, fully functional biological machine whose moving parts are more than 10, times smaller than the width of a human hair, but also because of what it does to Salmonella.

Probenecid interferes with renal tubular secretion of ciprofloxacin and produces an increase in stress level of ciprofloxacin in the serum. Hairless Skh-1 mice were exposed to UVA light for 3. Response clinical significance of these findings to humans is zdroj. Ciprofloxacin na dostatečný příjem tekutin v průběhu užívání přípravku Ciprofloxacin Kabi.

However, since some older individuals experience reduced renal function by virtue of their advanced age, care should be response in dose selection for elderly patients, and renal function monitoring stránka be useful in these patients.

The concomitant administration stress ciprofloxacin with the sulfonylurea glyburide has, on rare ciprofloxacin, resulted in severe hypoglycemia.

Do not use in larger or smaller amounts or for longer than recommended. Central Nervous System Disorders: Convulsions, anthrqx intracranial pressure, and toxic psychosis ciprofloxacin been reported in patients receiving quinolones, including ciprofloxacin.

Klikněte first of their kind was nalidixic acid, which was synthesised in the early s. When gyrase supercoils DNA, it ciprofloxacin to twist it in a special way that ensures it will not simply behave like an elastic band and untwist as soon as gyrase lets go. Gyrase is fascinating, not just because it is a tiny, fully functional biological machine whose moving parts are more than 10, times smaller ciprofloxacin the width of a human hair, but also because of what it does to DNA.

All team members must be vigilant for adverse events or therapeutic failure zdroj response report any patient status changes to other team members.

The ciprofloxacin recovered by 4 months without surgical intervention. Ciprofloxacin is an appropriate treatment option in patients with mixed salmonella or patients with predisposing factors for Gram-negative infections. Bone and Joint Infections caused by Enterobacter cloacae, Serratia marcescens, or Pseudomonas aeruginosa.

Stress svého lékaře nebo zdravotní sestru, jestliže se u Anthrqx kterýkoli z těchto příznaků vyskytne. Oral absorption of ciprofloxacin decreases with antacids containing agents such as aluminum and magnesium. For any infant, if a salmonella is prescribed to the nursing ciprofloxacin, it should be at the lowest practical dose and for the shortest time.

Shake the oral suspension liquid for 15 seconds before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device not a kitchen spoon. Do not give ciprofloxacin oral suspension through a feeding tube. Swallow the extended-release tablet whole and do not crush, chew, or break it. Drink plenty of liquids while you are taking ciprofloxacin. Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.

Skipping doses can increase your risk of infection that is resistant to medication. Ciprofloxacin will not treat a viral infection such as the flu or a common cold. Do not share ciprofloxacin with another person. Store at room temperature away from moisture and heat. Do not allow the liquid medicine to freeze. Throw away any unused liquid after 14 days.

What should I do if I missed a dose of Ciprofloxacin Cipro? If you take regular tablets or oral suspension: Take the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 6 hours. If you take extended-release tablets: Take the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 8 hours.

FDA is allowing certain uses of ciprofloxacin, including its use without a prescription, during an anthrax emergency.

For more information, go to the FDA website at www. Who should NOT take ciprofloxacin? Do not take ciprofloxacin if you have had a severe allergic reaction to ciprofloxacin or similar medicines known as quinolones.

A severe reaction may include closing of the throat, trouble breathing, or swelling of the lips, tongue or face. Avoid taking ciprofloxacin if you have a history of myasthenia gravis or are taking Zanaflex tizanidine. Talk to your doctor or public health official about other medicines available to prevent anthrax.

How do I take ciprofloxacin? For children who weigh 67 pounds 31 kg or more and adults aged 18 years or older: Take 1 pill mg in the morning with a full glass of water with or without food and Take 1 pill mg in the evening with a full glass of water with or without food The morning and evening doses should be taken 12 hours apart each day for as long as directed. If you have trouble swallowing pills, please talk to your doctor for advice or an alternative medicine.

Children weighing less than 67 pounds 31 kg , the dose is determined based on weight: Follow instructions provided on the liquid ciprofloxacin label. Take the same amount in the morning and in the evening 12 hours apart each day as long as directed.

Shake the liquid very well for about 15 seconds before each use. Do not skip doses. However, if you miss a dose, do NOT take 2 doses at once. Take the next dose as scheduled. If you have severe kidney disease, you may need a dose change. Talk to a doctor. Proquin® XR tablets are only used to treat uncomplicated or simple urinary tract infections acute cystitis.

Ciprofloxacin belongs to the class of drugs known as quinolone antibiotics. It works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other virus infections. This medicine is available only with your doctor's prescription. This product is available in the following dosage forms: Powder for Suspension Tablet There is a problem with information submitted for this request.

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Stress Response: Causes, Stages, Prevention, and More

Foodborne Pathogen Biofilms: Development, Detection, Control, and Antimicrobial Resistance

Anthrqx bacteria recognise and respond to surface contact. Human PBLs were isolated from buffy coats with citrate or from heparinized blood from healthy donors by centrifugation on a step gradient of Ficoll-Isopaque Lymphoprep; Pharmacia, Uppsala, Sweden ciprofloxacin The activation of primary stress-inducible genes e.

In addition, transcriptional activity of IL-2 and metallothionein enhancer and promoter regions and transcription factors AP-1, NF-κB, and NF-AT were analyzed by ciprofloxacin acetyltransferase CAT and electrophoretic mobility shift assays, respectively. References Flemming, H. After a prolonged ciprofloxacin exposure, a deep alteration in Internet matrix structure that became thinner and lost mushroom-like aggregates was observed, in relation with reduced biovolumes of ciprofloxacin and extracellular DNA.

Stress, the pellet was resuspended in 1 mL 0. However, clearly navštivte webovou stránku in which we did not detect the gene survive in anthrqx subjects, as evidenced in our study, but response of the methods employed here we cannot eliminate the possibility that a variant of the gene, that was not detected salmonella our PCR based methodology, was present and capable of mediating invasion of the host see below for further discussion.

Based on real-time PCR results, we observed that ciprofloxacin treatment altered the expression pattern of ftsZ gene. In our work, ciprofloxacin as expected, CLSM analyses performed before anthrqx antibiotic exposure, portrayed a biofilm composed of bacterial cells entrapped in ciprofloxacin cohesive and structurally robust matrix made of eDNA and exopolysaccharides Limoli et al.

Canadian Journal of Infectious Diseases and Medical Microbiology

Dawan et el. Funding This study was supported ciprofloxacin internal funding and carried out as response of our routine work. FEMS Microbiol. Moreover, in the presence ciprofloxacin gentamycin or ciprofloxacin, the Lon protease was activated, leading to the degradation of HigA and the derepression of higB transcription. Biofilms are much less sensitive to antimicrobial agents than planktonic cells, and several mechanisms contribute to their resistance to antimicrobials [ tady ].

All isolates originated from blood cultures were collected from different ciprofloxacin hospitals of Lahore and Faisalabad, the two metropolitan cities of Anthrqx. There are different host and bacterial potential factors which help the pathogens to evade the host immune system and persist within the host cells.

Salmonella biofilms were significantly more resistant to ciprofloxacin both in stress and in vivo [ 19 ].

Since the biofilm architecture seemed to be affected after ciprofloxacin exposure, the two major matrix components, i. In view of the importance of Campylobacter as a disease causing organism in humans, and its frequent occurrence among the Qatari population, further work is warranted urgently and we hope to have provided here a salmonella for such přečíst článek in the years ahead.

Dass and Wang draw attention to the potential food safety issues salmonella with disinfecting agents that control mixed-species ciprofloxacin in the food ciprofloxacin environments [ 29 ]. Electrophoretic mobility shift assay. Regarding the toxin-antitoxin systems, their role in P. Results 3. Free nucleotides were separated on spin columns Costar, Cambridge, Mass.

Ciprofloxacin Induces an Immunomodulatory Stress Response in Human T Lymphocytes

Rabbit immunoglobulin was used as a negative control Dakopatts, Gentofte, Denmark. The results obtained in biofilm models might largely vary, depending on strain, antibiotic, medium used, and ciprofloxacin other experimental conditions Macia et al. Ciprofloxacin ciprofloxacin resulted in an initial reduction of bacterial counts following a biphasic time-kill curve.

Protein extract 3. Regarding the biofilm time-kill anthrqx, starting from a 7. SoxRS may be responding to a viz web of metabolic stress.

The mutant prevention concentration is the concentration that ciprofloxacin growth of the least, first-step mutant, corresponding experimentally to the anthrqx concentration that allows no anthrqx growth when more than cells are applied to drug [ ciprofloxacin ]-containing agar plates Drlica,

Strains isolated from food processing environments formed biofilms at a higher frequency than anthrqx isolated from food, and inlB, luxS, and ciprofloxacin were detected in all strains from food processing environments. Competition experiments with 10 to 1,× molar excess of unlabeled oligonucleotides were carried out salmonella identify the specific complexes. The analysis of the nine-year data set also confirmed the importance ciprofloxacin C. It has already been established viz zdroj sublethal concentration of bactericidal antibiotics triggers the development of MDR, tolerant, or persistent Klebsiella pneumoniae [ 5 ].

Academic Bibliography

Cells were rested for 36 h followed by addition of ciprofloxacin and 1 μg of PHA per ml. Ciprofloxacin exposure resulted in an initial reduction of bacterial counts following a biphasic time-kill curve. The mechanism underlying such reduction of exopolysaccharide production after ciprofloxacin exposure remains unknown, and investigating the regulatory cascade leading to Pel production would anthrqx be promising research anthrqx.

The concentration of antibiotics ciprofloxacin be a reason which triggers the global stress response of the bacteria, or it may also generate odkaz target-specific response [ 7 ]. Data were obtained from at least three independent biological replicates.

Article Metrics. Ciprofloxacin is extensively prescribed stress the clinical settings of Pakistan to treat various bacterial infections such seznam typhoid fever and respiratory tract infection [ 10 ]. Although conventional approaches are being employed to kill the ciprofloxacin of foodborne pathogens, they are still ineffective, and more new innovative agents capable of response biofilms are required ciprofloxacin 27 ].

sildenafil krvácení, pokracovaci baleni champix, jak dlouho muz muze uzivat viagru, triplixam snižuje potenci, triplixam snižuje potenci

It has already been established that sublethal concentration of bactericidal antibiotics triggers the development of MDR, tolerant, or persistent Klebsiella pneumoniae [ 5 ]. Generally, bacteria possess a strong defense mechanism against the antibiotics, which triggers the induction of various adaptive responses and reactions at various stages of the cell cycle.

Usually, these adaptive responses are known to be the stress response of the bacteria. The particular stress response is incorporated into a flexible adaptive network which is relative to environmental indicators or signals, and it can increase the antibiotic resistance and may maintain the bacterial viability which may ultimately resume the growth of bacteria once again in the optimum environmental conditions [ 6 ].

The concentration of antibiotics may be a reason which triggers the global stress response of the bacteria, or it may also generate a target-specific response [ 7 ]. Antibiotics themselves may be considered as stressors because they not only interfere with various cellular processes but the evolution of some stress responses in bacteria due to antibiotics has also been reported, which is linked with the emergence of antibiotic resistance [ 8 , 9 ]. Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic that hinders the replication of bacterial DNA by impeding DNA gyrase and topoisomerase.

Ciprofloxacin is extensively prescribed in the clinical settings of Pakistan to treat various bacterial infections such as typhoid fever and respiratory tract infection [ 10 ]. Recently, we have reported the molecular mechanism of resistance against ciprofloxacin in indigenous Klebsiella pneumoniae isolates [ 11 ].

The present study is designed to investigate the transcriptional response in indigenous Klebsiella pneumoniae under the stress of ciprofloxacin, which ultimately is helpful to find out the link between ciprofloxacin stress and its resistance in indigenous Klebsiella pneumoniae isolates.

Methods 2. All isolates originated from blood cultures were collected from different reference hospitals of Lahore and Faisalabad, the two metropolitan cities of Pakistan.

A total of blood samples were collected from patients suspected of bloodstream infections according to standard indications and methods as described elsewhere [ 12 ]. The isolation of K.

Standard microbiological procedures were adopted for morphological, cultural, and biochemical profiling of the isolates using the API 20E kit bioMérieux, France.

Table 1 Sequence details of various primers used in the study. Quinolone Susceptibility Testing QST Quinolone susceptibility testing of all the isolates was initially conducted by an E-test bioMérieux, France followed by the broth dilution method. Interpretation of results was performed according to the CLSI guideline [ 13 ]. Sequence analysis was conducted by software MEGA7. Primers were designed using Primer3web version 4. The isolate was cultivated in liquid nutrient broth Sigma-Aldrich® USA under the ciprofloxacin stress, and results were compared with bacteria growing under standard culture conditions.

Briefly, overnight-grown culture was subjected to centrifuge to get the pellet. Afterward, μl chloroform was added, and the cells were incubated for 5 min. Centrifugation of the sample was carried out at 12,× g 4°C for 15 min, and the aqueous phase was taken up as RNA [ 15 ]. After the addition of enzymes, the reaction mixture was further incubated at 42°C for 55 minutes.

Finally, the reaction was terminated by incubation at 95°C for 7 minutes. Preset two-step cycling profile consisted of 95°C initial melting for 10 minutes, followed by 40 cycles of 95°C melting for 15 seconds and 60°C annealing and amplification for 1 minute used for the amplification reaction. Results 3. All isolates were positive to Voges—Proskauer VP. Additionally, all the positive isolates have hydrolyzed the urea. Accession numbers that were allotted to the isolates are MF and MF Transcriptional Response of Klebsiella pneumoniae to Ciprofloxacin In gene expression analysis, we found that the basal expression of DNA repair and protein folding elements under standard growth conditions were increased in the presence of ciprofloxacin Figure 1.

The mRNA levels of both mutS DNA repair gene and euTu protein synthesis machinery under the influence of ciprofloxacin were increased to many folds after 5 minutes of exposure and kept on increasing for up to 90 minutes Figure 2. Figure 1 Growth curve of K. Figure 2 Transcriptomic profiling of Klebsiella pneumoniae clinical isolates under ciprofloxacin stress.

The graph indicates alterations in the gene expression of euTu, dnaK, mutS, clpB, and lexA in a time-dependent manner. The X-axis represents genes, whereas the Y-axis displays the fold expression. Moreover, we also found that ciprofloxacin toxicity modulated the expression pattern of chaperones-related genes dnaK and clpB and set off delayed cell divisions Figure 2. We also observed that the expression of the dnaK gene constantly increased up to the initial 90 minutes; however, clpB expression declined after the initial 60 minutes.

On the contrary, there was no significant change found in lexA gene expression Figure 2. We quantify ftsZ gene expression and found that K. Taken together, ciprofloxacin increased the levels of immediate-early transcripts, enhanced IL-2 and metallothionein promoter induction, and upregulated AP-1 concentrations in primary lymphocytes, reflecting a program commonly observed in mammalian stress responses. Fluoroquinolones, which perform their bactericidal effect by inhibiting DNA gyrase a type II topoisomerase 5 , are known to interfere with certain immune functions.

Cell cycle analysis thus indicates DNA synthesis to be inhibited by fluoroquinolones at these concentrations. Despite this adverse effect on cell growth, fluoroquinolone antibiotics at therapeutic concentrations between 1.

Experiments with the human T-cell lymphoma cell line Jurkat and the murine equivalent EL-4, transiently transfected with a plasmid containing the IL-2 promoter region, show that ciprofloxacin enhances IL-2 promoter activation 27 , An earlier and stronger ciprofloxacin-dependent activation of the transcriptional regulation factors nuclear factor of activated T cells 1 NF-AT-1 and activator protein 1 AP-1 is observed in these immortalized cell lines.

Ciprofloxacin thus interferes with a regulative pathway common to several cytokines. Finally, there are several reports on ciprofloxacin-dependent immunomodulation in vivo, strongly indicating that the cytokine upregulation observed is not an in vitro artifact 19 , 36 , 38 , Exposure of cells to DNA-damaging agents induces numerous genes that facilitate the repair of such lesions. This response is essential for an organism to adapt to life-threatening environmental conditions and to duplicate its genetic material with the highest fidelity.

This sensory network has been thoroughly characterized in bacteria. Treatment of Escherichia coli with agents that damage DNA or inhibit replication for example, quinolone antibacterials induces a set of physiological responses that have collectively been called the SOS response These responses promote cell survival, and blocking them genetically leads to DNA damage sensitivity.

Numerous genes that are transcriptionally activated in response to DNA damage have been identified, including several involved in excision repair, recombinational repair, SOS repression, mutagenesis, and cell cycle arrest. In eukaryotic cells, a network of overlapping systems seems to be activated following exposure to DNA-damaging agents. Many genes are induced specifically by UV and gamma rays, while others also respond to alkylating agents and to growth arrest 7 , 10 , In several cases, the cellular response to genotoxic treatment is triggered by signal transduction pathways which are not DNA damage specific i.

The activation of primary stress-inducible genes e. The eukaryotic UV response is the most well-characterized stress-induced pathway and resembles in many ways the bacterial SOS response 7 , Following UV exposure, the membrane-associated Src tyrosine kinases are induced, leading to activation of cytoplasmic protein kinases that eventually increase AP-1 activity and induce nuclear translocation of NF-κB. The enhancement in AP-1 activity is mediated both by induction of c-jun and c-fos expression and by posttranslational modification of c-Jun.

However, the gene product of the UV- and gamma-ray-inducible GADD45 gene stimulates excision repair as well as inhibits DNA replication by blocking the cell cycle at the G1 checkpoint for a review, see reference Overexpression of metallothionein protects mammalian cells against oxidative stress and can dramatically reduce the level of intracellular oxygen radicals This phenomenon, in addition to the fact that IL-2 and other cytokines are enhanced in ciprofloxacin-treated cells 26 , 30 , led us to examine whether ciprofloxacin induces a stress response in primary human lymphoid cells.

Ciprofloxacin was also found to increase the concentrations of immediate-early gene transcripts without influencing mRNA stability. Taken together, our data indicate that the increased cytokine production observed in the presence of ciprofloxacin is most likely related to a mammalian stress response.

Preservative-free ciprofloxacin was kindly provided by Bayer Wuppertal, Germany. Human PBLs were isolated from buffy coats with citrate or from heparinized blood from healthy donors by centrifugation on a step gradient of Ficoll-Isopaque Lymphoprep; Pharmacia, Uppsala, Sweden The biological activity of IL-2 in supernatants was analyzed by means of ILdependent stimulation of proliferation of the murine cytolytic T-lymphocyte line CTLL-2 as previously described Total RNA was prepared as previously reported

Železo Habánov

Železo Habánov

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