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Antimicrobial Agents and Chemotherapy Oct 1990The in vitro susceptibilities of 10 isolates of Erysipelothrix rhusiopathiae to 16 antimicrobial agents were determined. Penicillin and imipenem were the most active... (Comparative Study)
Comparative Study
The in vitro susceptibilities of 10 isolates of Erysipelothrix rhusiopathiae to 16 antimicrobial agents were determined. Penicillin and imipenem were the most active agents, followed by piperacillin, cefotaxime, ciprofloxacin, pefloxacin, and clindamycin. Some resistance was observed with erythromycin, tetracycline, and chloramphenicol. Activity was poor or absent with vancomycin, teicoplanin, daptomycin, trimethoprim-sulfamethoxazole, gentamicin, and netilmicin.
Topics: Anti-Bacterial Agents; Erysipelothrix; Microbial Sensitivity Tests
PubMed: 2291674
DOI: 10.1128/AAC.34.10.2038 -
MicrobiologyOpen Nov 2019Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are...
Proteomic characterization and discrimination of Aeromonas species recovered from meat and water samples with a spotlight on the antimicrobial resistance of Aeromonas hydrophila.
Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are phenotypically very similar. The antimicrobial resistance is another significant challenge worldwide. We therefore aimed to use mass spectrometry technology for identification and discrimination of Aeromonas species and to screen the antimicrobial resistance of Aeromonas hydrophila (A. hydrophila). A total of 150 chicken meat and water samples were cultured, and then, the isolates were identified biochemically by the Vitek 2 Compact system. Proteomic identification was performed by MALDI-TOF MS and confirmed by a microchannel fluidics electrophoresis assay. Principal component analysis (PCA) and single-peak analysis created by MALDI were also used to discriminate the Aeromonas species. The antimicrobial resistance of the A. hydrophila isolates was determined by Vitek 2 AST cards. In total, 43 samples were positive for Aeromonas and comprised 22 A. hydrophila, 12 Aeromonas caviae (A. caviae), and 9 Aeromonas sobria (A. sobria) isolates. Thirty-nine out of 43 (90.69%) Aeromonas isolates were identified by the Vitek 2 Compact system, whereas 100% of the Aeromonas isolates were correctly identified by MALDI-TOF MS with a score value ≥2.00. PCA successfully separated A. hydrophila, A. caviae and A. sobria isolates into two groups. Single-peak analysis revealed four discriminating peaks that separated A. hydrophila from A. caviae and A. sobria isolates. The resistance of A. hydrophila to antibiotics was 95.46% for ampicillin, 50% for cefotaxime, 45.45% for norfloxacin and pefloxacin, 36.36% for ceftazidime and ciprofloxacin, 31.81% for ofloxacin and 27.27% for nalidixic acid and tobramycin. In conclusion, chicken meat and water were tainted with Aeromonas spp., with a high occurrence of A. hydrophila. MALDI-TOF MS is a powerful technique for characterizing aeromonads at the genus and species levels. Future studies should investigate the resistance of A. hydrophila to various antimicrobial agents.
Topics: Aeromonas; Aeromonas caviae; Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Chickens; Drug Resistance, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Proteome; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Water Microbiology
PubMed: 30614207
DOI: 10.1002/mbo3.782 -
Journal of Travel Medicine Dec 1995Background: Sparfloxacin is a new fluoroquinolone with excellent in vitro activity against a variety of Gram-positive and Gram-negative bacteria. Methods: In vitro...
Background: Sparfloxacin is a new fluoroquinolone with excellent in vitro activity against a variety of Gram-positive and Gram-negative bacteria. Methods: In vitro antibacterial activity of this new drug was tested against 139 strains of Brucella melitensis. These strains were isolated from 138 patients at a major tertiary care referral center in Riyadh, Saudi Arabia. Results: Seven percent of the strains were inhibited by 0.06 mg per L and 99% by 0.12 mg per L of sparfloxacin. Of the five other fluoroquinolones tested, ciprofloxacin, norfloxacin, pefloxacin, and fleroxacin exhibited comparable or slightly higher minimal inhibitory concentrations values. They inhibited the growth of 138 of the 139 isolates at 0.25-0.5 mg per L. Rufloxacin required 2-8 mg per L to inhibit 138 of the 139 strains tested. One of the isolates, which had previously developed resistance to ciprofloxacin during therapy with this drug, with a rise in MIC from 0.06 mg per L to >5.0 mg per L, exhibited cross-resistance to sparfloxacin and other fluoroquinolones. Conclusion: Sparfloxacin exhibited excellent in vitro activity against clinical isolates of Brucella. Clinical trials are warranted to determine its potential in the treatment of brucellosis.
PubMed: 9815397
DOI: 10.1111/j.1708-8305.1995.tb00665.x -
Microorganisms Mar 2022Non-typhoid serovars of are one of the main causes of bacterial food-borne infections worldwide. For the treatment of severe cases of salmonellosis in adults,...
Non-typhoid serovars of are one of the main causes of bacterial food-borne infections worldwide. For the treatment of severe cases of salmonellosis in adults, fluoroquinolones are amongst the drugs of choice. They are categorized by the World Health Organization (WHO) as "critically important with highest priority in human medicine". In the present study, two clinical serovar Corvallis isolates (HUA 5/18 and HUA 6/18) from a Spanish hospital, selected on the basis of fluoroquinolone resistance, were characterized. The MICs of ciprofloxacin, determined by E-test, were 0.5 and 0.75 µg/mL for HUA 5/18 and HUA 6/18, respectively, and both were also resistant to pefloxacin but susceptible to nalidixic acid. Whole genome sequencing (WGS) of the isolates was performed with Illumina platform, and different bioinformatics tools were used for sequence analysis. The two isolates belonged to ST1541, and had the Thr57Ser substitution in the ParC protein which is also found in ciprofloxacin susceptible isolates. However, they harbored identical ColE plasmids of 10 kb carrying the gene. In these plasmids, the gene was flanked by defective versions of IS-like and IS-like insertion sequences. HUA 5/18 and HUA 6/18 were also phenotypically resistant to streptomycin, sulfonamides and tetracycline, with the responsible genes: , , and (A) genes, being located on a IncQ1 plasmid. ColE plasmids with the gene are widely spread among multiple serovars of from different samples and countries. These mobilizable plasmids are playing an important role in the worldwide spread of . Thus, their detection in hospitals is a cause of concern which deserves further attention.
PubMed: 35336154
DOI: 10.3390/microorganisms10030579 -
Antimicrobial Agents and Chemotherapy Sep 1995Mechanisms of drug resistance in Campylobacter jejuni were investigated. Mutant strains 34PEFr, which was resistant to pefloxacin (128-fold increase in the MIC), and...
Mechanisms of drug resistance in Campylobacter jejuni were investigated. Mutant strains 34PEFr, which was resistant to pefloxacin (128-fold increase in the MIC), and 34CTXr, which was resistant to cefotaxime (32-fold increase in the MIC) and which was derived from the susceptible parent 34s, were obtained by serial passages on pefloxacin and cefotaxime gradient plates, respectively. Both mutants showed cross-resistance to erythromycin, chloramphenicol, tetracycline, beta-lactams, and quinolones. While the quinolone resistance of strain PEFr could be explained by a mutation at codon 86 of the gyrA gene, the multidrug resistance phenotype of both strains was further investigated. Accumulation of pefloxacin, ciprofloxacin, and minocycline was measured by fluorometry and was found to be lower in the mutant strains than in the parent strain. Preincubation of the cells with carbonyl cyanide m-chlorophenylhydrazone, however, completely abolished this difference. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane preparations from both mutant strains showed overexpression of two proteins of 55 and 39 kDa which were absent from the outer membranes of the wild-type strain. These results indicate that in C. jejuni 34PEFr and 34CTXr, multidrug resistance is associated with an efflux system with a broad specificity.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Bacterial Outer Membrane Proteins; Base Sequence; Campylobacter jejuni; Cefotaxime; Cephalosporins; Drug Resistance, Multiple; Molecular Sequence Data; Mutation; Pefloxacin; Polymerase Chain Reaction; beta-Lactamases
PubMed: 8540709
DOI: 10.1128/AAC.39.9.2019 -
Antimicrobial Agents and Chemotherapy Apr 1985Pefloxacin and ciprofloxacin are two new quinoline carboxylic acid derivatives that have activity in vitro against a wide range of gram-negative bacteria, including...
Pefloxacin and ciprofloxacin are two new quinoline carboxylic acid derivatives that have activity in vitro against a wide range of gram-negative bacteria, including Pseudomonas aeruginosa. Using a well-standardized model of Pseudomonas pneumonia in neutropenic guinea pigs, we tested the efficacy in vivo of these new agents. Both were highly effective in increasing survival and decreasing bacterial counts in the lungs of surviving animals. Pefloxacin and ciprofloxacin were significantly better (P less than 0.05) than aminoglycosides or beta-lactams tested in prior studies with this model, and they were as effective as combination therapy with aminoglycosides and beta-lactams. Resistance to either ciprofloxacin or pefloxacin did not emerge during the study period. Further studies with these drugs in the therapy of Pseudomonas sp. infections are warranted.
Topics: Agranulocytosis; Animals; Anti-Bacterial Agents; Ciprofloxacin; Guinea Pigs; Half-Life; Microbial Sensitivity Tests; Nalidixic Acid; Neutropenia; Pefloxacin; Pneumonia; Pseudomonas Infections; Quinolines; Time Factors
PubMed: 3159336
DOI: 10.1128/AAC.27.4.452 -
International Microbiology : the... Dec 2016Vibrio alginolyticus has acquired increasing importance because this microorganism may be pathogenic to aquatic animals and humans. It has been reported that some V....
Vibrio alginolyticus has acquired increasing importance because this microorganism may be pathogenic to aquatic animals and humans. It has been reported that some V. alginolyticus strains carry virulence genes derived from pathogenic V. cholerae and V. parahaemolyticus strains. In this work V. alginolyticus was isolated from oyster samples acquired from a food-market in Mexico City. Thirty isolates were identified as V. alginolitycus. Strains showed β-haemolysis and proteolytic activity and produced a capsule. Strains displayed swimming and swarming motility and 93.3% of them produced siderophores. Several genes encoding virulence factors were detected using PCR amplification. These included proA, wza, vopD, vopB, hcp, vasH and vgrG genes, which were present in all strains. Other genes had a variable representation: tdh (86.6%), lafA (96.6%), pvsA (62%) and pvuA (16%). The trh gene could not be amplified from any of the strains. The antimicrobial resistance profile revealed that more than 90% of the strains were resistant to beta-lactams antibiotics, 60% to cephalotin, 45% to amikacin, 16% to cephotaxime, and 10% to pefloxacin, while 100% were susceptible to ceftriaxone. The V. alginolyticus strains isolated from oysters showed multiple resistance to antibiotics and several virulence factors described in well-characterized pathogenic vibrios. [Int Microbiol 19(4):191-198 (2016)].
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Genes, Bacterial; Mexico; Ostreidae; Vibrio alginolyticus; Virulence; Virulence Factors
PubMed: 28504816
DOI: 10.2436/20.1501.01.277 -
Journal of Nanobiotechnology Jan 2018Gold nanoparticles are useful candidate for drug delivery applications and are associated with enhancement in the bioavailability of coated drugs and/or therapeutic...
BACKGROUND
Gold nanoparticles are useful candidate for drug delivery applications and are associated with enhancement in the bioavailability of coated drugs and/or therapeutic agent. Since, heterocyclic compounds are known to exhibit antimicrobial potential against variety of pathogens, we designed this study to evaluate the antibacterial effects of gold nanoparticles conjugation with new synthesized cationic ligand; 4-Dimethyl aminopyridinium propylthioacetate (DMAP-PTA) in comparison with pure compound and antibiotic drug Pefloxacin. Antibacterial activity of DMAP-PTA coated gold nanoparticles was investigated against a fecal strain of E. coli (ATCC 8739).
RESULTS
A new dimethyl aminopyridine based stabilizing agent named as DMAP-PTA was synthesized and used for stabilization of gold nanoparticles. Gold nanoparticles coated with DMAP-PTA abbreviated as DMAP-PTA-AuNPs were thoroughly characterized by UV-visible, FT-IR spectroscopic methods and transmission electron microscope before biological assay. DMAP-PTA, DMAP-PTA-AuNPs and Pefloxacin were examined for their antibacterial potential against E. coli, and the minimum inhibitory concentration (MIC) was determined to be 300, 200 and 50 µg/mL respectively. Gold nanoparticles conjugation was found to significantly enhance the antibacterial activity of DMAP-PTA as compared to pure compound. Moreover, effects of DMAP-PTA-AuNPs on the antibacterial potential of Pefloxacin was also evaluated by combination therapy of 1:1 mixture of DMAP-PTA-AuNPs and Pefloxacin against E. coli in a wide range of concentrations from 5 to 300 µg/mL. The MIC of Pefloxacin + DMAP-PTA-AuNPs mixture was found to be 25 µg/mL as compared to Pefloxacin alone (50 µg/mL), which clearly indicates that DMAP-PTA-AuNPs increased the potency of Pefloxacin. AFM analysis was also carried out to show morphological changes occur in bacteria before and after treatment of test samples. Furthermore, DMAP-PTA-AuNPs showed high selectivity towards Pefloxacin in spectrophotometric drug recognition studies which offers tremendous potential for analytical applications.
CONCLUSIONS
Gold nanoparticles conjugation was shown to enhance the antibacterial efficacy of DMAP-PTA ligand, while DMAP-PTA-AuNPs also induced synergistic effects on the potency of Pefloxacin against E. coli. DMAP-PTA-AuNPs were also developed as Pefloxacin probes in recognizing the drug in blood and water samples in the presence of other drugs.
Topics: Anti-Bacterial Agents; Coated Materials, Biocompatible; Escherichia coli; Gold; Humans; Ligands; Metal Nanoparticles; Microbial Sensitivity Tests; Pefloxacin; Physical Phenomena; Pyridines; Spectrophotometry, Ultraviolet; Sulfhydryl Compounds
PubMed: 29378569
DOI: 10.1186/s12951-017-0332-z -
Infection and Drug Resistance 2013The characteristics and antimicrobial resistance profiles of Staphylococcus aureus differs according to geographical regions and in relation to antibiotic usage. The aim...
INTRODUCTION
The characteristics and antimicrobial resistance profiles of Staphylococcus aureus differs according to geographical regions and in relation to antibiotic usage. The aim of this study was to determine the biochemical characteristics of the prevalent S. aureus from Ekiti State, Nigeria, and to evaluate three commonly used disk diffusion methods (cefoxitin, oxacillin, and methicillin) for the detection of methicillin resistance in comparison with mecA gene detection by polymerase chain reaction.
MATERIALS AND METHODS
A total of 208 isolates of S. aureus recovered from clinical specimens were included in this study. Standard microbiological procedures were employed in isolating the strains. Susceptibility of each isolate to methicillin (5 μg), oxacillin (1 μg), and cefoxitin (30 μg) was carried out using the modified Kirby-Bauer/Clinical and Laboratory Standard Institute disk diffusion technique. They were also tested against panels of antibiotics including vancomycin. The conventional polymerase chain reaction method was used to detect the presence of the mecA gene.
RESULTS
Phenotypic resistance to methicillin, oxacillin, and cefoxitin were 32.7%, 40.3%, and 46.5%, respectively. The mecA gene was detected in 40 isolates, giving a methicillin-resistant S. aureus (MRSA) prevalence of 19.2%. The S. aureus isolates were resistant to penicillin (82.7%) and tetracycline (65.4%), but largely susceptible to erythromycin (78.8% sensitive), pefloxacin (82.7%), and gentamicin (88.5%). When compared to the mecA gene as the gold standard for MRSA detection, methicillin, oxacillin, and cefoxitin gave sensitivity rates of 70%, 80%, and 100%, and specificity rates of 76.2%, 69.1%, and 78.5% respectively.
CONCLUSION
When compared with previous studies employing mecA polymerase chain reaction for MRSA detection, the prevalence of 19.2% reported in Ekiti State, Nigeria in this study is an indication of gradual rise in the prevalence of MRSA in Nigeria. A cefoxitin (30 μg) disk diffusion test is recommended above methicillin and oxacillin for the phenotypic detection of MRSA in clinical laboratories.
PubMed: 23990730
DOI: 10.2147/IDR.S48809 -
Foods (Basel, Switzerland) Jun 2022In this study, a packed-fiber solid-phase extraction (PFSPE)-based method was developed to simultaneously detect nine quinolones, including enrofloxacin (ENR),...
In this study, a packed-fiber solid-phase extraction (PFSPE)-based method was developed to simultaneously detect nine quinolones, including enrofloxacin (ENR), ciprofloxacin (CIP), ofloxacin (OFL), pefloxacin (PEF), lomefloxacin (LOM), norfloxacin (NOR), sarafloxacin (SAR), danofloxacin (DAN), and difloxacin (DIF), in pure milk, using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Polystyrene (PS) and polyacrylonitrile (PAN) were combined to form PS-PAN composite nanofibers through electrospinning. The nanofibers were used to prepare the home-made extraction columns, and the process was optimized and validated using blank pure milk. The analytical method showed high accuracy, and the recoveries were 88.68-97.63%. Intra-day and inter-day relative standard deviations were in the ranges of 1.11-6.77% and 2.26-7.17%, respectively. In addition, the developed method showed good linearity (R ≥ 0.995) and low method quantification limits for the nine quinolones (between 1.0-100 ng/mL) for all samples studied. The nine quinolones in the complex matrix were directly extracted using 4.0 mg of PS-PAN composite nanofibers as a sorbent and completely eluted in 100 μL elution solvent. Therefore, the developed PFSPE-HPLC-MS/MS is a sensitive and cost-effective technique that can effectively detect and control nine quinolones in dairy products.
PubMed: 35804659
DOI: 10.3390/foods11131843