Activity Of Different Antibiotics Research Articles

Effect of Nano - Titanium Dioxide with Different Antibiotics against Methicillin-Resistant Staphylococcus Aureus

The different investigation has been carried out on the biological activities of titanium dioxide nanoparticle but the effect of this nano product on the antibacterial activity of different antibiotics has not been yet demonstrated. In this study the nano size TiO2 is synthesized using citric acid and alpha dextrose and the enhancement effect of TiO2 nanoparticle on the antibacterial activity of different antibiotics was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA). During the present study, different concentrations of nano-scale TiO2 were tested to find out the best concentration that can have the most effective antibacterial property against the MRSA culture. Disk diffusion method was used to determine the antibacterial activity of these antibiotics in the absence and presence of sub inhibitory concentration of TiO2 nano particle. A clinical isolate of MRSA, isolated from Intensive Care Unit (ICU) was used as test strain. In the presence of sub-inhibitory concentration of TiO2 nanoparticle (20 µg/disc) the antibacterial activities of all antibiotics have been increased against test strain with minimum 2 mm to maximum 10mm. The highest increase in inhibitory zone for MRSA was observed against pencillin G and amikacin (each 10 mm). Conversely, in case of nalidixic acid, TiO2 nanoparticle showed a Synergic effect on the antibacterial activity of this antibiotic against test strain. These results signify that the TiO2 nanoparticle potentate the antimicrobial action of beta lactums, cephalosporins, aminoglycosides, glycopeptides, macrolids and lincosamides, tetracycline a possible utilization of nano compound in combination effect against MRSA.

The combination effect of curcumin with different antibiotics againstStaphylococcus aureus

The different investigation has been carried out on the biological activities of curcumin but the effect of this natural product on the antibacterial activity of different antibiotics has not been demonstrated. In this study the enhancement effect of curcumin on the antibacterial activity of different antibiotics was evaluated against Staphylococcus aureus. Disk diffusion method was used to determine the antibacterial activity of these antibiotics in the absence and presence of sub inhibitory concentration of curcumin. A clinical isolate of S. aureus was used as test strain. In the presence of sub-inhibitory concentration of curcumin (500 μg/disc) the antibacterial activities of cefixime, cephotaxime, vancomycin and tetracycline have been increased against test strain. The highest fold increase in area was observed for cefixime against S. aureus (a 52.6 % increase in inhibition zone surface area). Also the increases in inhibition zone areas (%) for cephotaxime, vancomycin and tetracycline were 24.9%, 26.5% and 24.4%, respectively. No enhancing effect on the antibacterial activities of others antibiotics was detected against S. aureus at content of 500μg/disc. Conversely, in case of nalidixic acid, curcumin showed an antagonistic effect on the antibacterial activity of this antibiotic against test strain. These results signify that the curcumin potentiates the antimicrobial action of cefixime, cephotaxime, vancomycin and tetracycline suggesting a possible utilization of this edible compound in combination therapy against S. aureus. Key words: Antibacterial activity, combination effect, Staphylococcus aureus, curcumin

Synthesis and effect of silver nanoparticles on the antibacterial activity of different antibiotics against Staphylococcus aureus and Escherichia coli

Silver nanoparticles (Ag-NPs) have been known to have inhibitory and bactericidal effects. Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. The combination effects of Ag-NPs with the antibacterial activity of antibiotics have not been studied. Here, we report on the synthesis of metallic nanoparticles of silver using a reduction of aqueous Ag + ion with the culture supernatants of Klebsiella pneumoniae. Also in this article these nanoparticles are evaluated for their part in increasing the antimicrobial activities of various antibiotics against Staphylococcus aureus and Escherichia coli. The antibacterial activities of penicillin G, amoxicillin, erythromycin, clindamycin, and vancomycin were increased in the presence of Ag-NPs against both test strains. The highest enhancing effects were observed for vancomycin, amoxicillin, and penicillin G against S. aureus.

P604 Investigation of the antimicrobial activity of different antibiotics on monospecific biofilms developed in vitro by microbial strains isolated from cardiovascular devices associated infections

P604 Investigation of the antimicrobial activity of different antibiotics on monospecific biofilms developed in vitro by microbial strains isolated from cardiovascular devices associated infections

In vitro activity of β-lactam and non–β-lactam antibiotics in extended-spectrum β-lactamase–producing clinical isolates of Escherichia coli

The activity of different β-lactam and non–β-lactam antibiotics was assessed against extended-spectrum β-lactamase (ESBL)–producing and non-ESBL–producing clinical isolates of Escherichia coli. A phenotypic study to discover the presence of ESBLs in 399 clinical isolates of E. coli was made by the disk diffusion method following the Clinical and Laboratory Standards Institute (formely NCCLS, 2004) guidelines. The activity of different antibiotics was subsequently studied using the automated VITEK 2 system (bioMérieux, Marcy l'Étoile, France). One hundred fifteen isolates proved to be ESBL-producing and 284 non-ESBL–producing. Among the former, percentage susceptibilities to the antibiotics assayed were meropenem and amikacin, 100%; piperacillin/tazobactam, 97.4%; cefepime, 94.8%; amoxicillin/clavulanic acid, 84.3%; tobramycin, 84.3%; gentamicin, 83.5%; cefoxitin, 83.5%; nitrofurantoin, 71.3%; cotrimoxazole, 46.1%; norfloxacin, 29.6%; ciprofloxacin, 27%; and ofloxacin, 26.1%.

Pharmacological indices in antibiotic therapy.

After 60 years of antibiotic treatment, attempts to rationalize it have culminated in the use of pharmacological indices. These indices facilitate comparison of the activity of different antibiotics and serve as a sound basis for antibiotic dosing. Pharmacokinetic parameters (e.g. AUC, Cmax) and pharmacodynamic parameters (mostly MIC) are used for this purpose. For the so-called concentration-dependent antibiotics, the pharmacological indices AUC/MIC and Cmax/MIC are used, whereas for time-dependent antibiotics, the pharmacological index T>MIC is used. Some authors believe that the index AUC/MIC can be used as a universal index, but, not all experts accept this generalization. As the various pharmacological indices have been defined inconsistently in the literature, the International Society for Anti-Infective Pharmacology (ISAP) has published a paper on the terminology of pharmacokinetic and pharmacodynamic parameters and the pharmacological indices. This paper will help to ensure uniform use of terminology. In addition, we point out that the use of pharmacological indices should consider the differences in pharmacokinetics (patient characteristics and localization of the infection) and the differences in pharmacodynamics of antibiotics (beyond MICs) with different pathogens (e.g. Gram-positive and Gram-negative).

Epidemiology of drug resistance: the case of Staphylococcus aureus and coagulase-negative staphylococci infections.

To study the activity of several antibiotics against Staphylococcus spp. The study included 1209 strains of Staphylococcus spp. from two institutions; Instituto Nacional de Pediatría (National Institute of Pediatrics) and Hospital Infantil de México Federico Gómez (Mexico City Children's Hospital). Minimum Inhibitory Concentrations of all antibiotics were determined by the agar macrodilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Surveillance of strains resistant to methicillin is necessary. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Effect of salicylate on antibacterial activity of different antibiotics

Susceptibility ofPseudomonas aeruginosa, Staphylococcus aureus, andBacillus subtilis to gentamicin and cefotaxime was affected by salicylaye. In presence of salicylaye (15 mM) and gentamicin (1.0 ug/ml), log efficiency of plating (log E.O.P.s) for the tested bacteria were −1.24, −2.17 and −1.66 respectively. The activity of cefotaxime againstBacillus subtilis was reduced (log E.O.P.=1.33). The highest potentiating effects of salicylaye were shown when using gentamicin againstStaphylococcus aureus, cefotaxime againstPs. aeruginosa, log E.O.P.s were −3.0, and −2.4, respectively. On the other hand, no significant effects were detected with cefotaxime againstStaphylococcus aureus (log E.O. P.=−0.04). No significant killing was shown in presence of gentamicin or salicylaye alone. There was no significant effect for salicylaye on MICs (By broth dilution) could be observed except in case of gentamicin againstStaphylococcus aureus, which was reduced from 0.02 ug/ml to 0.0012 ug/ml. These results raise the concern that high concentrations of salicylaye in patients might interfere with antibiotic therapies.

Interference of uremic sera on antibacterial activity of different antibiotics

Interference of uremic sera on antibacterial activity of different antibiotics

Effect of Manganese on the Activity of Antibiotic Against Microorganisms

Manganese is an important element in biological system. It is essential for enzymatic activity, maintaining three-dimensional structure of protein, for the synthesis of nucleic acid and protein etc. Deficiency of manganese causes different life threatening diseases. Because of this, the optimum level of manganese must be maintained in all biological system. This experiment, therefore, was designed to evaluate the effect of manganese on the activity of different antibiotics (ciprofloxacin, cephradine, amoxicillin, gentamycin, tetracycline, cloxacillin, nalidixic acid, ceftriaxone, metronidazole and carbenicillin) against different microorganisms. It has been observed that antimicrobial activity of an antibiotic increased significantly with concomitant use of manganese salt ranging from 600-6000 ng per antibiotic disc (P < 0.05). It is revealed from the experiment that manganese increases the activity of antibiotic against bacterial strains. 
 
 Key words: Antibiotics, Manganese, Antibacterial activity.
 
 Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005
 
 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website