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PubMed1978

Modification by preirradiation growth conditions of the shoulder of the UV fluence-survival curve of Escherichia coli B/r WP 2 thy trp and changes in mutagenic response toward tryptophan prototrophy.

The distinct three-section UV fluence-mutation frequency response (MFR) curve demonstrated in Escherichia coli strain B/r WP2 thy trp and its uvrA derivative supports the SOS hypothesis and suggests that trp+ revertants can arise either from isolated lesions (1DM) plus SOS induction or from two lesions in proximity (2DM). Preirradiation growth on arabinose instead of glucose converted the fluence-survival curve from highly shouldered to exponential but did not affect the three-section MFR curve. Prestarvation of the uvrA+ strain for tryptophan, which drastically increases the expanse of the shoulder of the survival curve, greatly decreased both 1DM and 2DM. With the uvrA strain the increase in shoulder expanse after tryptophan prestarvation was accompanied by greatly increased 2DM but no change in 1DM. Preincubation with chloramphenicol induced an even greater increase in 2DM response than amino acid prestarvation. Nalidixic acid, which prevents DNA accumulation, eliminated the response.

Dose-Response Relationship, Radiation↗

PubMed2005

Efficient approach for the reliable quantification and confirmation of antibiotics in water using on-line solid-phase extraction liquid chromatography/tandem mass spectrometry.

The potential of solid-phase extraction coupled on-line to liquid chromatography/electrospray tandem mass spectrometry (SPE-LC-ESI-MS/MS) has been investigated in this paper for the efficient sensitive quantification and confirmation of 16 antibiotics in water. The list of targeted analytes included 10 quinolones (oxolinic acid (OXO), nalidixic acid (NAL), flumequine (FLU), marbofloxacine (MAR), ofloxacine (OFLO), enrofloxacine (ENR), pefloxacine (PEF), ciprofloxacine (CIP), pipemidic acid (PIPE), norfloxacine (NOR)) and 6 penicillins (penicillin G (PEN), oxacillin (OXA), dicloxacillin (DIC), piperacillin (PIP), cloxacillin (CLO) and ampicillin (AMP)) that were determined in ground and surface water. The procedure is based on the injection of 9.8 mL of sample into the SPE-LC-MS/MS system and the measurement of antibiotics by selected reaction monitoring mode, using a triple quadrupole analyser. The method has been validated at realistic low concentrations that might be present in environmental water, i.e. 10 and 100 ng L(-1), obtaining recoveries between 74% and 123% with relative standard deviation lower than 14%. Matrix effects were not relevant in most of cases, except for ampicillin in surface water, where notable signal suppression was observed. The limits of detection were as low as 0.4-4.3 ng L(-1). The method developed allows the rapid screening and quantification of all the analytes selected by acquiring one MS/MS transition (normally the most sensitive) for each compound. It was applied to a number of actual surface and groundwater samples with several compounds being detected, mainly quinolones, at low ng L(-1) levels. Special attention was given to the confirmation of compounds detected in water due to the difficulties of obtaining confident confirmation at low ng L(-1). This matter has been of growing concern in the last few years as reflected by recent papers and correspondence. The acquisition of several MS/MS transitions for each compound detected in a second independent analysis allowed the unequivocal confirmation of identity, avoiding reporting false-positives. Finally, the potential of QTOF instruments to confirm positive samples has also been evaluated and compared with triple quadrupole analysers.

Anti-Bacterial Agents↗

PubMed2006

[Comparative susceptibility evolution in Escherichia coli from urinary tract infections in outpatients and inpatients at Perpignan hospital in 2002 and 2004].

The medical emergency ward makes a link between outpatients and hospitalized ones, so we can study community bacterial ecology. The antibiotic susceptibility in Escherichia coli strains isolated from urinary tract infections (UTI) of patients consulting at emergency ward of our hospital in 2002 and 2004 was determined and compared with the susceptibility of the same strains isolated from UTI of hospitalized patients on the same period. The antibiotic susceptibility was performed with Microscan (Dade Behring). All bacteria were tested against the following antimicrobial agents: amoxicilline (Amx), l'amoxicilline+clavulanic acid (AMC), nalidixic acid (NA), ciprofloxacine (Cip), cotrimoxazole (SXT), nitrofurantoin (Ft). Susceptibility in E. coli strains isolated from outpatients vary from 58 to 54% for Amx, from 88 to 83% for NA, from 96 to 89% for Cip, from 82 to 79% for SXT, from 94 to 96% for Ft and remains at 60% for AMC from 2002 to 2004. Susceptibility in E. coli strains isolated from hospitalized patients vary from 52 to 47% for Amx, 55 to 53% for AMC, from 79 to 70% for NA, from 87 to 79% for Cip, from 74 to 69% for SXT, from 93 to 92% for Ft. Susceptibility in E. coli strains isolated in the community from UTI outpatients is decreasing and it becomes worrying particularly concerning the fluoroquinolones, therefore empiric treatment of pyelonephritis by fluoroquinolones must be assessed again.

Anti-Bacterial Agents↗

PubMed1998

Molecular specificity of a medium chain acyl-CoA synthetase for substrates and inhibitors: conformational analysis.

Amino acid conjugation is an important route of detoxification of xenobiotic and endogenous carboxylic acids. The specificity of the purified medium chain acyl-CoA synthetase catalyzing the first reaction of amino acid conjugation was investigated further for substrates and inhibitors. Molecular modeling techniques were applied to derive the molecular characteristics of substrates and inhibitors for the medium chain acyl-CoA synthetase. The purified enzyme accepted not only straight medium chain fatty acids but also aromatic acids. Of the arylacetic acids, activity was obtained with naphthylacetic acids, whereas introduction of a methyl group at the alpha-position caused loss of activity. High activity was also observed with cyclohexanoic acid. Diflunisal, 2-hydroxydodecanoic acid, and nalidixic acid inhibited the medium chain acyl-CoA synthetase activity for hexanoic acid, with Ki values of 0.8, 4.4, and 12.3 microM, respectively. The inhibitory carboxylic acids were competitive with respect to hexanoic acid. The hydroxyl or ketone (oxo) groups at the beta-position of carboxylic acids were an important determinant for inhibitory activity. All substrates and inhibitors contained a flat hydrophobic region coplanar to the carboxylate group. In addition, the substrates had negative values for charge on the carbon in the beta-position of carboxylic acids.

Acetates↗

PubMed2006

Simultaneous determination of (fluoro)quinolone antibiotics in kidney, marine products, eggs, and muscle by enzyme-linked immunosorbent assay (ELISA).

A direct competitive enzyme-linked immunosorbent assay (ELISA) was developed to detect a broad range of (fluoro)quinolones in various matrices. In the optimized generic test, anti-sarafloxacin antibodies in combination with norfloxacin conjugate showed 50% binding inhibition at 0.21 ng mL(-)(1) for sarafloxacin in buffer. Screening for this class of antibiotics is accomplished using a simple, rapid extraction carried out with a 1:1 mixture of methanol and phosphate-buffered saline adjusted to pH 7.4. This common extraction was able to detect 15 (fluoro)quinolone residues such as sarafloxacin, norfloxacin, difloxacin, ciprofloxacin, pefloxacin, ofloxacin, cinoxacin, danofloxacin, enrofloxacin, marbofloxacin, lomefloxacin, enoxacin, flumequine, oxolinic acid, and nalidixic acid in pig kidney, poultry muscle, egg, fish, and shrimp. The assay's detection capabilities (CCbeta) for most of these compounds were <10 microg kg(-)(1) except for the sarafloxacin-, oxolinic acid-, flumequine-, and cinoxacin-spiked matrices, the estimated CCbeta values of which were <4, <25, <100, and <200 microg kg(-)(1), respectively.

Animals↗

PubMed1998

Extension of multi-residue methodology to include the determination of quinolones in food.

The multi-residue procedure for basic drugs described elsewhere by this laboratory has been evaluated for quinolone and fluoroquinolone antibiotics. The fluoroquinolones are a relatively new class of drug and an increasing number of licensed products containing these compounds are becoming available for use in animal husbandry. This, along with the possibility of the development of antibiotic resistant human pathogens, make it an important class of drug for which methodology is required for the monitoring of residues in food. Validation data are presented for a range of compounds including the quinolones; oxolinic acid and nalidixic acid, and the fluoroquinolones; flumequine, ciprofloxacin, danofloxacin, enoxacin, enrofloxacin, lomefloxacin, marbofloxacin, norfloxacin, ofloxacin and sarafloxacin. Foods for which the method was validated included poultry muscle (chicken and turkey), egg, chicken liver, honey, cattle muscle and pig muscle. This application of the multi-residue procedure further demonstrates the importance and wide-ranging usefulness of the technique.

Animals↗

PubMed2003

Antibodies to the quinolones and fluoroquinolones for the development of generic and specific immunoassays for detection of these residues in animal products.

Several quinolone and fluoroquinolone haptens have been used to raise polyclonal antibodies exhibiting both specific and generic properties for these classes of antimicrobial compounds. The antisera have been assessed in rapid enzyme immunoassays (ELISAs) designed to exploit the specificities obtained. A direct generic ELISA for both the quinolones and fluoroquinolones has been developed that uses the cross-reactivity of an antibody raised against norfloxacin (1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid) linked to ovalbumin via a secondary amine group on the piperazinyl moiety to detect nine different drugs in these classes. Specific ELISAs to ciprofloxacin (1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid), enrofloxacin (1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid), flumequin (9-fluoro-6,7-dihydro-5-methyl-1-oxo-1H,5H-benzo(ij)quinolizine-2-carboxylic acid) and nalidixic acid (1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid) have also been developed with a high degree of specificity to the individual compounds. The assays measure drug residues in bovine milk and ovine kidney with an interassay relative standard deviation (s(r)) of 10.5% or less and intra-assay s(r) of 11.2% or less. Sensitivity is less than 4 microg x kg(-1) for both the generic and specific assays for all but one of the compounds tested. (Pipemidic acid (8-ethyl-5,8-dihydro-5-oxo-2-(1-piperazinyl)pyrido(2,3-d)pyrimidine-6-carboxylic acid) is detectable at 6 microg x kg(-1) in kidney.)

4-Quinolones↗

PubMed2001

Frequency of selection of fluoroquinolone-resistant mutants of Neisseria gonorrhoeae exposed to gemifloxacin and four other quinolones.

We studied the frequency of mutation of clinical isolates of Neisseria gonorrhoeae (two nalidixic acid susceptible and two nalidixic acid resistant), and the stability of the mutants obtained, in the presence of three different concentrations of five fluoroquinolones. The frequency of mutation was low for all the quinolones. Only one N. gonorrhoeae mutant, obtained with trovafloxacin at 4 x MIC presented a stable increase in the MIC of this quinolone, not attributable to novel mutation(s), both in the gyrA and parC genes, although not showing any increase in the MIC of the other quinolones tested. In summary, gemifloxacin was the only quinolone tested for which resistant mutants were not obtained.

Anti-Infective Agents↗

PubMed1976

Antimicrobial susceptibilities of shigellae isolated in Houston, Texas, in 1974.

One hundred seventy-three strains of shigellae (113 Shigella sonnei, 56 S. flexneri, and four others) isolated in Houston during 1974 were tested for susceptibility to commonly used and newer antimicrobial agents. Forty-five percent of S. sonnei strains were susceptible to ampicillin, whereas 93% of S. flexneri strains were susceptible to that agent. S. sonnei and S. flexneri strains were equally susceptible to tetracycline (35 and 33%, respectively). All 173 strains were uniformly susceptible to quinoline drugs (cinoxacin, oxolinic acid, and nalidixic acid) and to trimethoprim-sulfamethoxazole. This study supports recent suggestions that the initial therapy of bacillary dysentery no longer should be ampicillin or tetracycline. It remains for field testing to determine whether quinoline agents or trimethoprim-sulfamethoxazole will be the treatment of choice.

Anti-Bacterial Agents↗

PubMed1975

Comparison of antibiotic discs from different sources.

Antibiotic discs from Oxoid, Mast, AB Biodisk, Difco, and Baltimore Biological Laboratories were compared, where discs of similar antibiotic content were available, in diffusion-sensitivity tests against organisms of known sensitivity. Discs from Oxoid and Mast gave zones 1-5 mm larger than discs from other manufacturers with penicillin 2 units, ampicillin 10 mug, cephalothin 30 mug, methicillin 10 mug, carbenicillin 100 mug, erythromycin 15 mug, chloramphenicol 50 mug, and trimethoprim 1-25 mug, while discs containing aminoglycoside antibiotics, lincomycin, fusidic acid, tetracycline, nalidixic acid, penicillin 10 units, and polymyxin B gave similar zone sizes whatever the source. Where tested, different batches of single discs from the same source did not vary significantly in antibiotic content as indicated by variation in zone size; but with some antibiotics Multodisks gave larger zones than single discs from the same source. The implications of these differences are discussed.

Anti-Bacterial Agents↗

PubMed2001

Improved agar diffusion method for detecting residual antimicrobial agents.

The improved agar diffusion method for determination of residual antimicrobial agents was investigated, and the sensitivities of various combinations of test organisms and assay media were determined using 7 organisms, 5 media, and 31 antimicrobial agents. Bacillus stearothermophilus and synthetic assay medium (SAM) showed the greatest sensitivity for screening penicillins (penicillin G and ampicillin). The combination of Bacillus subtilis and minimum medium (MM) was the most sensitive for tetracyclines (oxytetracycline and chlortetracycline), B. stearothermophilus and SAM or Micrococcus luteus and Mueller-Hinton agar (MHA) for detecting tylosin and erythromycin, B. subtilis and MHA for aminoglycosides (streptomycin, kanamycin, gentamicin, and dihydrostreptomycin), B. stearothermophilus and SAM for polyethers (salinomycin and lasalocid), and B. subtilis and MM or Clostridium perfringens and GAM for polypeptides (thiopeptin, enramycin, virginiamycin, and bacitracin). However, gram-negative bacterium Escherichia coli ATCC 27166 and MM were better for screening for colistin and polymixin-B. For detecting the synthetic drugs tested, the best combination was B. subtilis and MM for sulfonamides, E. coli 27166 and MM for quinolones (oxolinic acid and nalidixic acid), B. subtilis and MM for furans (furazolidone), and the bioluminescent bacterium Photobacterium phosphoreum and luminescence assay medium for chloramphenicol and oxolinic acid. The results showed that the use of four assay plates, B. stearothermophilus and SAM, B. subtilis and MM, M. luteus and MHA, and E. coli 27166 and MM, was superior to the currently available techniques for screening for residual antimicrobial agents in edible animal tissues.

Agar↗

PubMed1990

Pharmacokinetic and residue studies of quinolone compounds and olaquindox in poultry.

Nalidixic acid and similar antimicrobial agents have been available for more than 20 years, mainly for treating infections caused by Gram-negative enterobacteria. Recently, several chemically related drugs, including oxolinic acid, pipemidic acid, piromidic acid and flumequine, have been developed. They are either naphthyridine-carboxylic acid or quinoline-carboxylic acid derivatives and, with nalidixic acid, are so-called quinolones. A major advance in antimicrobial chemotherapy was the synthesis of newer quinolones containing at least 1 fluorine atom and a piperazinyl group. These new fluoroquinolones have an extended antimicrobial spectrum compared to the first quinolone generation, and are highly active against most Gram-negative pathogens including the Enterobacteriaceae and Pseudomonas aeruginosa. The pharmacokinetic properties and residue levels of these quinolones and fluoroquinolones for which clinical experience or experimental information exists in poultry are reviewed here. On the other hand, administration of the quinoxaline-di-N-oxide, olaquindox, for medical purposes raises questions concerning the pharmacokinetic disposition of the drug and the risk of its residues in poultry. This paper presents information about the pharmacokinetic profile of olaquindox and the presence of its residues in chickens.

4-Quinolones↗

PubMed1990

[Susceptibilities of Escherichia coli, Salmonella and Staphylococcus aureus isolated from animals to ofloxacin and commonly used antimicrobial agents].

Susceptibilities of Escherichia coli, Salmonella and Staphylococcus aureus isolated from chickens, pigs and cattle to ofloxacin (OFLX) and commonly used antimicrobial agents were investigated. 1. E. coli (28 isolates) demonstrated the highest level of susceptibility of OFLX (MIC 0.10-0.39 micrograms/ml for all the isolates) among all the test drugs. Commonly used antimicrobial agents to which these isolates responded with relatively high susceptibilities (MIC50 0.78-6.25 micrograms/ml) included oxolinic acid (OXA), ampicillin (ABPC), kanamycin (KM) and chloramphenicol (CP) with their MIC50 values in the increasing order as above. Drugs to which these isolates responded with moderate to weak susceptibilities (MIC50 25 approximately greater than 800 micrograms/ml) were doxycycline (DOXY), streptomycin (SM), spectinomycin (SPCM) and sulfadimethoxine (SDMX) in the increasing order of MIC50. E. coli isolates with resistances to all the test drugs other than OFLX and OXA amounted to 7.1-57.1% of the isolates examined and 20 isolates (71.4%) in total. 2. Susceptibilities to OFLX and 4 existing pyridonecarboxylic acid derivatives of E. coli (48 samples) isolated recently from diarrheal pigs were compared. When evaluated in terms of MIC50, the values of OFLX and norfloxacin were both 0.10 micrograms/ml. The values increased by differences of 0.39-3.13 micrograms/ml in an order of OXA, pipemidic acid and nalidixic acid. 3. Salmonella (28 isolates) demonstrated the highest level of susceptibility to OFLX (MIC 0.20-0.39 micrograms/ml for all the isolates) among all the test drugs. The drugs to which these isolates responded with relatively high to moderate susceptibilities (MIC50 0.78-12.5 micrograms/ml) included ABPC, OXA, DOXY, KM, CP and SM with their MIC50 values increasing in this order. The drugs to which the isolates responded with low susceptibilities (MIC50 above 100 micrograms/ml) were SPCM and SDMX. Of all the 28 Salmonella isolates tested, 7.1-32.1% were resistant to all the test drugs other than OFLX and OXA. These resistant isolates amounted to a total of 12 isolates (42.9%). 4. S. aureus (28 isolates) were highly susceptible to OFLX (MIC50 and MIC90 were both 0.78 micrograms/ml). Commonly used antimicrobial agents to which the isolates responded with high to relatively high susceptibilities (MIC50 0.10-6.25 micrograms/ml) were, in the increasing order of MIC50: DOXY, ABPC, tylosin, tiamulin, KM, OXA and CP. Drugs with moderate to low bacterial susceptibilities (MIC50 12.5-100 microns/ml) were SD, SDMX and SPCM. Isolates resistant to all the test drugs except OFLX and SDMX amounted to 3.6-50% of the 28 isolates examined and they totalled 20 isolates (71.4%).(ABSTRACT TRUNCATED AT 400 WORDS)

Ampicillin↗

PubMed1993

Indomethacin/ibuprofen-like anti-inflammatory agents selectively potentiate the gamma-aminobutyric acid-antagonistic effects of several norfloxacin-like quinolone antibacterial agents on [35S]t-butylbicyclophosphorothionate binding.

Four piperazinoquinolone antibacterial drugs (norfloxacin, ciprofloxacin, enoxacin, and pipemidic acid), known to be gamma-aminobutyric acid (GABA) antagonists, fully reversed the inhibitory effect of GABA on [35S]t-butylbicyclophosphorothionate ([35S] TBPS) binding to rat brain membranes in vitro. Twelve indomethacin/ibuprofen-like arylalkanoic acid (AAA) anti-inflammatory drugs alone had no effect on [35S]TBPS binding, or on its inhibition by GABA, but potentiated the GABA-antagonistic effects of the four quinolones. Felbinac (4-biphenylacetic acid) was most potent in this respect (EC50 = 110 nM, together with 5 microM norfloxacin), followed by flurbiprofen > anirolac > metiazinic acid > tolmetin = ketoprofen = fenbufen = indomethacin > fenoprofen > ibuprofen = (+)-naproxen = sulindac. Other anti-inflammatory analgesic drugs, including aspirin, diclofenac, diflunisal, meclofenamic acid, mefenamic acid, nambumetone, phenacetin, piroxicam, and phenylbutazone, failed to potentiate the GABA-antagonistic effect of norfloxacin. Felbinac (1 microM) increased the GABA-antagonistic potencies of norfloxacin and enoxacin about 26-fold, while increasing those of ciprofloxacin and pipemidic acid 7-fold and 2.3-fold, respectively. Using subsaturating concentrations of the four quinolones, concentration-response curves for felbinac yielded EC50 values ranging from 110 nM with 5 microM norfloxacin to 1.3 microM with 100 microM pipemidic acid. Three other piperazinoquinolone antibacterial agents (amifloxacin, difloxacin, and fleroxacin) and four nonpiperazinoquinolone anti-bacterial agents (oxolinic acid, cinoxacin, nalidixic acid, and piromidic acid) were much weaker GABA antagonists and were not significantly potentiated by felbinac. All other known GABAA receptor blockers tested, including R 5135, pitrazepin, bicuculline, SR 95531, strychnine, D-tubocurarine, thebaine, securinine, theophylline, and caffeine, were not potentiated by felbinac. Our results suggest that norfloxacin and related piperazinoquinolones, acting at GABAA receptors, may induce a high affinity binding site for indomethacin/ibuprofen-like anti-inflammatory agents (the AAA site) that, when occupied, reciprocally increases the affinities of the quinolones for GABAA receptors. The AAA binding site may be a new site in the GABAA receptor complex.

4-Quinolones↗

PubMed2004

Mutations in the gyrA gene in Salmonella enterica clinical isolates with decreased ciprofloxacin susceptibility.

The incidence of resistance to nalidixic acid has increased in the University General Hospital of Elche, Spain, and this paper describes the investigation of this phenomenon. This increase was mainly due to an increase of nalidixic-resistant Salmonella enterica serotype Enteritidis. Resistance to nalidixic acid is an indicator of decreased ciprofloxacin susceptibility (sensitivity 100%, specificity 96.7%). Strains that were resistant to nalidixic acid and exhibited decreased susceptibility to ciprofloxacin had a single mutation in QRDR of gyrA: Asp87-Asn, Asp87-Tyr or Ser83-Phe. The sensitivity of S. enterica strains to nalidixic acid should be tested and the breakpoint of ciprofloxacin established by MENSURA applied, instead of that of the NCCLS for these strains.

Amino Acid Substitution↗

PubMed1982

[Elimination kinetics following repeated administrations of chemotherapeutic agents].

Repeated administrations of the chemotherapeutic agents nalidixic acid, retacillin, oxacillin, ampicillin and gentamicin acts on the transport of organic acids by the kidney. With the exception of nalidixic acid, all the chemotherapeutic agents under study produced a significant dose-dependent increase in the renal clearance of p-aminohippuric acid (PAH) in adult rats aged 55 days. Due to nephrotoxic effects, the renal clearance of PAH is decreased by very high doses of nalidixic acid and gentamicin. In contrast to this, the changes in PAH clearance were less marked in 10-day-old rats in which the ability of the kidney to transport organic acids is low. On repeated administrations of chemotherapeutic agents, one has on principle to consider the production of a diminishing effect due to increased renal clearance.

Animals↗

PubMed1983

In vitro and in vivo antibacterial activity of AT-2266.

AT-2266 [1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridine-3-carbo xylic acid] showed a broad spectrum of antibacterial activity against gram-positive and gram-negative microorganisms, including Pseudomonas aeruginosa. The in vitro antibacterial activity of AT-2266 was in general comparable to that of norfloxacin, but much higher than that of pipemidic or nalidixic acid. The 90% minimal inhibitory concentrations (MIC90s) of AT-2266 for P. aeruginosa resistant to gentamicin (MIC range, 25 to greater than 200 microgram/ml) and Enterobacteriaceae resistant to nalidixic acid (25 to greater than 1,600 micrograms/ml) were 3.13 and 12.5 micrograms/ml, respectively. The to nalidixic acid (25 to 1,600 micrograms/ml) were 3.13 and 12.5 micrograms/ml, respectively. The MICs of AT-2266 were only slightly affected by the addition of horse serum or sodium cholate, by the pH of the medium, and by inoculum size. AT-2266 was sodium cholate, by the pH of the medium, and by inoculum size. AT-2266 was bactericidal at concentrations near its MIC value. The 50% effective doses of AT-2266 after oral administration against systemic infections in mice were about 1/2 those of norfloxacin, about 1/10 those of pipemidic acid, and between 1/20 and 1/40 those of nalidixic acid.

Animals↗

PubMed1988

In vitro activity of pefloxacin compared with five other quinolones on nalidixic acid-resistant proteae species.

The in vitro activity of pefloxacin, a new fluoroquinolone, was compared with that of 5 other quinolone compounds (nalidixic and pipemidic acids, norfloxacin, ciprofloxacin, and ofloxacin) against 416 strains of Proteae spp. isolated from urine specimens of hospitalized patients with acute urinary tract infections (UTI). Ciprofloxacin was the most active agent. Norfloxacin, ofloxacin, and pefloxacin were similarly active against Proteus strains (MIC90 = 0.39 microgram/ml). Against Providencia spp. pefloxacin and norfloxacin showed similar activity (MIC90 = 3.12 micrograms/ml). There is minimal discrepancy between minimum inhibitory concentrations and minimum bactericidal concentrations exhibited by the quinolones for all urinary tract pathogens tested. Our in vitro studies indicate that pefloxacin is an active antimicrobial agent and suggest that it will prove useful in the treatment of complicated urinary tract infections due to nalidixic acid-resistant Proteae spp.

Anti-Infective Agents↗