AIMTo analyze the response factors of different quinolone antibiotics detected by evaporative light-scattering detector (ELSD).

METHODSThe response factors of five different quinolones (enoxacin, levofloxacin, ciprofloxacin, lomefloxacin and gatifloxacin) detected by ELSD were determined by using a YMC-Pack ODS-AM cloumn (150 mm x 4.6 mm ID, 5 microns) as analytical column and 0.5% triethylamine (adjusting pH 2.5 with trifluoroacetic acid)-acetonitrile (48:12) as mobile phase at a flow rate of 0.6 mL.min-1, the temperature of the drift tube was set at 117 degrees C, and the flow of carrier gas at 3.0 L.min-1. Detector responses (A) and the amount of injection of each substance (m) were fitted to the logarithmic regression: log A = b log m + log a.

RESULTSThe linear regression equation obtained were: enoxacin: Y = 1.0799X + 2.7611, r2 = 0.9996; levofloxacin: Y = 1.0913X + 2.7235, r2 = 0.9997; ciprofloxacin: Y = 1.0828X + 2.7523, r2 = 0.9994; lomefloxacin: Y = 1.0891X + 2.7391, r2 = 0.9993; gatifloxacin: Y = 1.0878X + 2.7392, r2 = 0.9995. The differences between them were negligible.

CONCLUSIONDifferent quinolones can give the same responses with ELSD detection. So, the HPLC-ELSD methods can be applied to the determination of new substances by using another substance as reference.

Chromatography, High Pressure Liquid ; methods ; Ciprofloxacin ; analysis ; Enoxacin ; analysis ; Fluoroquinolones ; analysis ; Levofloxacin ; Light ; Linear Models ; Ofloxacin ; analysis ; Quinolones ; analysis

The purpose of this study was to investigate the fluoroquinolone resistance frequency of Enterococcus spp. from normal chicken feces and to analyse mutations of the gyrA and parC gene associated with fluoroquinolone resistance. Among 52 Enterococcus faecalis and 25 E. faecium isolates, 23 (44.2%) E. faecalis and 7 (28.0%) E. faecium were resistant to ciprofloxacin (CIP) by disc diffusion method. Genetic exchange in gyrA and parC gene among 2 CIP intermediate isolates and 15 CIP resistant isolates were found in the amino acid codon of Ser-83 and Asp-87, and Ser-80 and Glu-84, respectively. These mutants contained a change from Ser to Phe, Val, Tyr, Ile, Thr or Pro at codon 83 and from Glu to Gly or Leu at codon 87 in gyrA gene, and a change from Ser to Ile or Thr at codon 80 and from Glu to Asp or Lys at codon 84 in parC gene. The isolates with mutation in gyrA regardless of a mutation in parC showed high resistance (MIC > or =32 microgram/ml) to CIP, enrofloxacin, norfloxacin and ofloxacin. These results suggested that gyrA gene is the primary target for 4 fluoroquinolones resistance in Enterococcus spp.
Chickens* ; Ciprofloxacin ; Codon ; Diffusion ; Enterococcus faecalis ; Enterococcus* ; Feces* ; Fluoroquinolones ; Norfloxacin ; Ofloxacin ; Viperidae

One hundred and fifty strains of Gram negative bacilli isolated from urine of patients with urological disease were tested for resistance to antimicrobial drugs including quinolones. Escherichia coli (61 strains) was most frequently isolated, and followed by Klebsiella spp. (36), Pseudomonas aeruginosa (12). and Proteus spp. (6) in the decreasing order. New quinolone carboxylic acid compounds such as enoxacin (Ex). norfloxacin (Nf), ciprofloxacin (Cp), pefloxacin (Pf), and ofloxacin (Of) showed very high antimicrobial activities against the majority of organisms tested except P.aerogi. nose. In P.aeruginosa all strains were resistant to nalidixic acid, and 25-33% to Ex. Nf. Cp, Pf, and Or. The majority of strains tested were found to be resistant to beta-lactam antibiotics except moxalactam (Mr). aminoelycoside drugs except amikacin (Ak), and other drugs tested such as chloramphgnicol, tetracycline. rifampin and etc.. but in P.aeruginosa, 33-58% were resistant to Mx and Ak. Organisms multiplyine resistance to 5 or more druge were noted in almost all isolates tested The stain numbers of multiplying resistance to 5 or more drugs were 51 strains (83.6%) of E. Coli 24 strains (66.7%) of Klebsielle spp., 10 strains (83.3%) of P.aeruginosa, and 5 strains (83.3%) of Prorteus spp.
Amikacin ; Anti-Bacterial Agents ; Ciprofloxacin ; Drug Resistance, Microbial* ; Enoxacin ; Escherichia coli ; Humans ; Klebsiella ; Moxalactam ; Nalidixic Acid ; Norfloxacin ; Nose ; Ofloxacin ; Pefloxacin ; Proteus ; Pseudomonas aeruginosa ; Quinolones ; Rifampin ; Tetracycline ; Urologic Diseases

OBJECTIVES: Group B Streptococcus (GBS), a common bowel commensal, is a major cause of neonatal sepsis and an emerging cause of infection in immune-compromised adult populations. Fluoroquinolones are used to treat GBS infections in those allergic to beta-lactams, but GBS are increasingly resistant to fluoroquinolones. Fluoroquinolone resistance has been previously attributed to quinolone resistance determining regions (QRDRs) mutations. We demonstrate that some of fluoroquinolone resistance is due to efflux-mediated resistance. METHODS: We tested 20 GBS strains resistant only to norfloxacin with no mutations in the QRDRs, for the efflux phenotype using norfloxacin and ethidium bromide as substrates in the presence of the efflux inhibitor reserpine. Also tested were 68 GBS strains resistant only to norfloxacin not screened for QRDRs, and 58 GBS strains resistant to ciprofloxacin, levofloxacin or moxifloxacin. Isolates were randomly selected from 221 pregnant women (35-37 weeks of gestation) asymptomatically carrying GBS, and 838 patients with GBS infection identified in South Korea between 2006 and 2008. The VITEK II automatic system (Biomerieux, Durham, NC, USA) was used to determine fluoroquinolone resistance. RESULTS: The reserpine associated efflux phenotype was found in more than half of GBS strains resistant only to norfloxacin with no QRDR mutations, and half where QRDR mutations were unknown. No evidence of the efflux phenotype was detected in GBS strains that were resistant to moxifloxacin or levofloxacin or both. The reserpine sensitive efflux phenotype resulted in moderate increases in norfloxacin minimum inhibitory concentration (average=3.6 fold, range=>1-16 fold). CONCLUSIONS: A substantial portion of GBS strains resistant to norfloxacin have an efflux phenotype.
Adult ; beta-Lactams ; Ciprofloxacin ; Ethidium ; Female ; Fluoroquinolones ; Humans ; Korea ; Levofloxacin ; Microbial Sensitivity Tests ; Norfloxacin* ; Phenotype ; Pregnant Women ; Reserpine ; Sepsis ; Streptococcus*

PURPOSE: To investigate the clinical features and treatment outcomes between methicillin-sensitive Staphylococcus epidermidis (MSSE) and methicillin-resistant Staphylococcus epidermidis (MRSE) keratitis groups. METHODS: A retrospective analysis of case series was conducted of all patients with keratitis caused only by Staphylococcus epidermidis from January 1997 through December 2008. Sex, age, history of trauma, systemic disease, previous ocular history, antibiotic sensitivity test results, and treatment outcomes were evaluated. Patients were categorized into two groups as MSSE and MRSE according to methicillin-sensitivity result, and a comparative analysis was performed. RESULTS: There were no significant differences in clinical features, such as risk factors or size or location of keratitis between the two groups. All MSSE and MRSE isolates were sensitive to vancomycin, moxifloxacin, and levofloxacin. All MSSE and 17%, 50%, 52%, and 57% of MRSE isolates were sensitive to cephalothin, norfloxacin, ciprofloxacin, and erythromycin, respectively (p < 0.05). There was no significant difference in visual acuity between the two groups. CONCLUSIONS: All MSSE and MRSE isolates were sensitive to vancomycin and to third- or fourth-generation fluoroquinolones In addition, approximately 50% of MRSE isolates were sensitive to norfloxacin and ciprofloxacin. There were no significant differences in clinical features of keratitis caused by MSSE versus those of MRSE isolates. Both keratitis groups had relatively good visual prognoses.
Aza Compounds ; Cephalothin ; Ciprofloxacin ; Epidemiologic Studies ; Erythromycin ; Fluoroquinolones ; Humans ; Keratitis ; Methicillin Resistance ; Norfloxacin ; Ofloxacin ; Prognosis ; Quinolines ; Retrospective Studies ; Risk Factors ; Staphylococcus ; Staphylococcus epidermidis ; Vancomycin ; Visual Acuity

To study the gyrA mutations of E. coli from clinical specimens, 410 strains were isolated from 1994 to 1997 in Kyungpook National Vniversity hospital. Antimicrobial susceptibility tests, PCR and sequencing of gyrA, and in vitro induction of quinolone resistance were done. The frequency of quinolone resistant E. coli strains increased constantly during 1994 through 1996. Quinolone-resistant strains were more often resistant to unrelated antibiotics than quinolone-susceptible strains (chi-square test, p<0.05). All of the randomly selected 55 quinolone- resist#ant strains were highly resistant to nalidixic acid (NAL) but had low level resistance to fluoroquinolones. All of the 55 quinolone-resistant strains showed an amino acid substitution of Ser -> Leu (TCG -> TIG) at codon 83. In addition, four different types of amino acid substitution affecting codon 87 (Asp) were detected, 1) type I: Asn (GAC -> AAC); 2) type II: Tyr (GAC -> TAC); 3) type III: Oly (GAC -> GGC); 4) type IV: His (GAC -> CAC). The mutation of type IV has not been reported previously in quinolone-resistant E. coli strains. It is thought that the specific amino acid substitution probably affects minimum inhibitory concentrations (MIC) of quinolones because the MICs of ciprofloxacin, norfloxacin, and ofloxacin in type II were significantly higher than those of type I. By in vitro induction, MICs to quinolone-susceptible strains resulted in the increase in the MICs of all quinolones tested by 2- to 2048-fold. The induced mutants by quinolones had amino acid substitutions at codon 83, SerLeu or Asp87Asn, Gly or Tyr. Alteration of Ser83 results in the most effective increase in the MIC of quinolone such as NAL and alterations of Asp87 result in the effective increase of MIC of fluoroquinolone. These results suggest that the continuous use of quinolones might induce the specific amino acid substitution at gyrA.
Amino Acid Substitution ; Anti-Bacterial Agents ; Ciprofloxacin ; Codon ; Escherichia coli* ; Escherichia* ; Fluoroquinolones ; Gyeongsangbuk-do ; Microbial Sensitivity Tests ; Nalidixic Acid ; Norfloxacin ; Ofloxacin ; Polymerase Chain Reaction ; Quinolones

PURPOSE: Enterococcus faecalis is one of the most common pathogens linked to chronic bacterial prostatitis (CBP). Owing to a limited number of previous studies addressing this topic, we aimed to determine the drug resistance patterns of E. faecalis strains isolated from CBP patients. MATERIALS AND METHODS: One thousand twenty-one patients visited a single hospital owing to chronic prostatitis for 5 years. Culture specimens were obtained by use of a modified Meares-Stamey method. The minimal inhibitory concentrations of the antimicrobials were assessed by use of the Vitek II microbial identification system as suggested by the Clinical and Laboratory Standards Institute. RESULTS: Forty-one samples from 41 patients who had significant E. faecalis loads for defining CBP were included in this study. The E. faecalis strains in our study were resistant to penicillin (9.7%), ampicillin (0%), ampicillin/sulbactam (0%), nitrofurantoin (0%), imipenem (0%), vancomycin (0%), teicoplanin (0%), quinupristin/dalfopristin (100%), ciprofloxacin (9.7%), levofloxacin (4.8%), norfloxacin (26.8%), erythromycin (95%), gentamicin (46.3%), tetracycline (97.5%), and trimethoprim/sulfamethoxazole (31.5%), respectively. CONCLUSIONS: Fluoroquinolones have been the preferred antibiotics for treating CBP. Because of their low rate of drug resistance, fluoroquinolones are suitable therapeutic agents for E. faecalis strains causing CBP in Korea. Even though tetracycline, erythromycin, and trimethoprim/sulfamethoxazole have been prescribed as an empirical antimicrobial therapy for chronic prostatitis, we cannot recommend these drugs for treatment of E. faecalis isolates because of the high rates of drug resistance.
Ampicillin ; Anti-Bacterial Agents ; Ciprofloxacin ; Drug Resistance ; Enterococcus ; Enterococcus faecalis ; Erythromycin ; Fluoroquinolones ; Gentamicins ; Humans ; Imipenem ; Korea ; Nitrofurantoin ; Norfloxacin ; Ofloxacin ; Penicillins ; Prostatitis ; Teicoplanin ; Tetracycline ; Vancomycin

Fluoroquinolone (FQ) antibiotics are an important class of synthetic antibacterial agents. These are the most extensively used drugs for treating bacterial infections in the field of both human and veterinary medicine. Herein, the antibacterial and pharmacological properties of four fluoroquinolones: lomefloxacin, norfloxacin, ciprofloxacin, and ofloxacin have been studied. The objective of this study was to analyze the antibacterial characteristics of the different fluoroquinolones. Also, the pharmacological properties of the compounds including the Lipinski rule of five, absorption, distribution, metabolism, and excretion, LD50, drug likeliness, and toxicity were evaluated. We found that among all four FQ molecules, ofloxacin showed the highest antibacterial activity through in silico assays with a strong interaction (−38.52 kJ/mol) with the antibacterial target protein (topoisomerase-II DNA gyrase enzyme). The pharmacological and pharmacokinetic analysis also showed that the compounds ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin have good pharmacological properties. Notably, ofloxacin was found to possess an IGC50 (concentration needed to inhibit 50% growth) value of 0.286 μg/L against the Tetrahymena pyriformis protozoa. It also tested negative for the Ames toxicity test, showing its non-carcinogenic character.
Absorption ; Anti-Bacterial Agents ; Bacterial Infections ; Ciprofloxacin ; Computer Simulation ; DNA Gyrase ; Fluoroquinolones* ; Humans ; Lethal Dose 50 ; Metabolism ; Norfloxacin ; Ofloxacin ; Tetrahymena pyriformis ; Toxicity Tests ; Veterinary Medicine

A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.
Anti-Bacterial Agents ; Bacteria ; Ciprofloxacin ; Enoxacin ; Norfloxacin ; Ofloxacin ; Proteus vulgaris ; Quinolones* ; Staphylococcus

Fluoroquinolones are antimicrobial agents that have a broad range of activity against both gram-negative and gram-positive organisms. Anaphylactoid reactions have been sporadically reported with fluoroquinolones. There have been a few reports that describes cross-reactivity between fluoroquinolones. We experienced a case of ofloxacin-induced anaphylactoid reaction, and confirmed cross-reactivity between ofloxacin and ciprofloxacin with the oral challenge test. Cross-reactivity between fluoroquinolones may be important, and avoidance of any fluoroquinolones should be mandatory for patients with hypersensitivity reaction to one of these drugs.
Anti-Infective Agents ; Ciprofloxacin ; Fluoroquinolones* ; Humans ; Hypersensitivity ; Ofloxacin*