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S P Rezvan

Publications and source records attributed to S P Rezvan.

At least 19 recordsLinked to original sources
PubMed2005

[Etiology of severe hospital infections in intensive care units and antibiotic resistance of pathogens].

The leading pathogens of severe infections in intensive care units were the following: respiratory tract infections--bacteria of the famility of Enterobacteriaceae (33.8%), Pseudomonas spp. (24.9%), Acinetobacter spp. (18.1%), Staphylococcus aureus (16.0%), blood flow infections--coagulase negative staphylococci (33.6%), S. aureus (26.1%), Enterobacteriaceae (17.6%), wound infections--Enterobacteriaceae (35.7%), coagulase negative staphyloccocci (17.8%), Pseudomonas spp. (14.3%). As for various species of Enterobacteriaceae, susceptibility was preserved in 91-100% of the isolates to meropenem, in 72-100% to cefoperazone/sulbactam, in 51-65% to cefepime, in 72-86% to amikacin, and in less than 50% to cephalosporins and fluoroquinolones. As for P.aeruginosa, 28% of the isolates was resistant to all the antibacterials, except polymyxin. The highest susceptibility to cefoperazone/sulbactam and meropenem was revealed in the isolates of Acinetobacter baumannii. Oxacillin resistance was detected in 64.9% of the S.aureus isolates. The oxacillin resistance as a rule was associated with resistance to macrolides, aminoglycosides and fluoroquinolones. As for coagulase negative staphylococci, oxacillin resistance was stated in 75.6% of the isolates. All the isolates of the Staphylococcus spp. preserved their susceptibility to vancomycin and linezolid.

Cross Infection↗
PubMed2001

[Synthesis and antibacterial activity of the new 9-aminoacridine, 10,11-dihydro-5H-dibenzo[b,f]azepine, polyfluoro 5,6-dihydro-1,3,5-oxadiazine derivatives].

Screening among 9-aminoacridine, 10,11-dihydro-5H-dibenz[b, f]azepine and polyfluoro 5,6-dihydro-1,3,5-oxadiazine derivatives allowed to isolate compounds with potential antibacterial activity. Schemes of the active compounds synthesis are given. The most important is the estimation of the oxydiazines activity against gram-positive microorganisms including methicillin-resistant staphylococci. Special attention is paid to the activity of iminodibenzyl derivatives against multiresistant gram-negative microorganisms.

Aminacrine↗
PubMed1998

[Comparative activity of meropenem and other antibiotics against the pathogens of nosocomial infections].

Comparative activity of meropenem and other antibacterial drugs against isolates from intensive care and reanimation units of various profiles was estimated. It was shown that the recommendations for the combined therapy with the 3rd generation cephalosporins and aminoglycosides should be revised, since none of the isolates resistant to ceftazidime or cefotaxime was susceptible to gentamicin or tobramycin. At present the most promising agents of empirical therapy are carbapenems (meropenem and imipenem). However, the resistance of methicillin resistant staphylococci and Enterococcus faecium to carbapenems and the intrinsic resistance of some gram-negative bacteria to carbapenems are indicative of the necessity of microbiological diagnosis, especially when the treatment with meropenem fails.

Anti-Bacterial Agents↗
PubMed1998

[Multicenter study of Staphylococcus susceptibility to antibiotics in Moscow and St. Petersburg].

Antibiotic susceptibility of 898 Staphylococcus strains isolated in 9 medical centres of Moscow and St. Petersburg was tested. The frequency of methicillin resistant staphylococci (MRS) ranged from 0 to 40 per cent for Staphylococcus aureus and from 0 to 65.9 per cent for coagulase negative staphylococci (CNS). The highest frequencies of MRS were in hematologic, oncologic and traumatologic units as well as in intensive care units for newborns. The frequencies of MRS in St. Petersburg were much lower than those in Moscow. Among the methicillin susceptible staphylococci the frequency of the isolates that produced beta-lactamases amounted to 81 per cent for S. aureus and to 60 per cent for CNS. Practically 100 per cent of the isolates was susceptible to ampicillin/sulbactam and cephalosporins of the 1st, 2nd and 3rd generations. 86-99 per cent of the isolates was susceptible to erythromycin, clindamycin, tetracycline, gentamicin and trimethoprim/sulfamethoxasole. All the MRS isolates were susceptible to vancomycin. 95, 84 and 70 per cent of the S.aureus strains were susceptible to fusidin, rifampicin and ciprofloxacin, respectively. The susceptibility of the CNS isolates was somewhat lower.

Ampicillin Resistance↗
PubMed1998

[Multicenter trial of Enterococcus antibiotic susceptibility].

Antibiotic susceptibility of 446 Enterococcus isolates from 9 medical centres of Moscow and St. Petersburg was tested. Among the isolates 386 belonged to E.faecalis, 48 to E.faecium and 12 to the other species. All the isolates were susceptible to vancomycin. As for E.faecalis 84 and 85 per cent of the isolates were susceptible to ampicillin and ampicillin/sulbactam respectively (no production of beta-lactamases), the frequency of high resistance to aminoglycosides amounted to 44 per cent with respect to streptomycin and to 25 per cent with respect to gentamicin, 75 per cent of the isolates was susceptible to ciprofloxacin. As for E.faecium and the rare species of Enterococcus more than 70 per cent of the isolates was resistant to ampicillin and ampicillin/sulbactam, the frequency of high resistance to aminoglycosides exceeded 60 per cent, 17 and 25 per cent of the isolates were susceptible to ciprofloxacin.

Ampicillin↗
PubMed1996

[Mechanisms of resistance to quinolones and current level of sensitivity of clinically important microorganisms to ofloxacin].

The data on the mechanisms of microbial resistance to fluoroquinolones are presented. Comparison of the susceptibility levels of the microorganisms isolated on the territory of Russia showed that among the gram-negative opportunistic isolates 84 per cent was susceptible to ofloxacin, 45 per cent to ampicillin/sulbactam, 70 per cent to cefotaxime, 80 per cent to ceftazidime, 85 per cent to amikacin and 62 per cent to gentamicin. Among the Salmonella, Shigella and Vibrio cholerae isolates no strains were resistant to ofloxacin. Among the Salmonella isolates from patients more than 30 per cent was resistant to ampicillin, chloramphenicol, trimethoprim/sulmethoxasole and tetracycline. Among the Salmonella isolates 65 to 90 per cent was resistant to the antibiotics. Among the V.cholerae isolates 59 per cent was resistant to trimethoprim/sulmethoxasole.

Anti-Infective Agents↗
PubMed1996

[Characterization of antimicrobial properties of cefpirome].

The results of a multicentre investigation of antibiotic susceptibility in 800 clinical isolates were analyzed. The levels of susceptibility to cefpirome and other antibiotics in gram-negative organisms with inducable production of chromosomal beta-lactamases (Enterobacter, Serratia, Citrobacter and others) were compared and the advantages of cefpirome over other cephalosporins were shown: 89 per cent of the susceptible strains against 58 to 78 per cent. With respect to other microorganisms the advantages of cefpirome were less pronounced.

Cell Membrane Permeability↗
PubMed1995

[Comparative in vitro activity of ampicillin, cefoperazone, their combinations with sulbactam and other antibiotics with respect to staphylococci and pneumococci].

Antibiotic susceptibility of 225 Staphylococcus strains and 42 Pneumococcus strains was assayed with the method of serial microdilutions. Methicillin resistant Staphylococcus strains (S. aureus and coagulase negative strains) were characterized by high susceptibility to cephalosporins and ampicillin + sulbactam combination, as well as to ciprofloxacin, rifampicin and vancomycin (70 to 100 per cent of the susceptible strains). Less than 50 per cent of the strains was susceptible to erythromycin. The methicillin resistant Staphylococcus strains preserved their high susceptibility to vancomycin and rifampicin (the coagulase negative strains also preserved their susceptibility to ciprofloxacin). Four Pneumococcus strains with the intermediate resistance to benzylpenicillin were isolated (for 9.6 per cent of the strains the MIC was 0.12 to 1.0 micrograms/ml). The growth of 2 out of these 4 strains was inhibited by the ampicillin + sulbactam combination in a concentration of less than 0.5 micrograms/ml and by cefotaxime and the cefoperazone + sulbactam combination in a concentration of less than 1.0 micrograms/ml. The growth of the other 2 strains was inhibited by betalactams in concentrations higher than the above mentioned.

Ampicillin↗
PubMed1995

[Comparative in vitro activity of ampicillin, cefoperazone and their combinations with sulbactam, as well as that of other antibiotics against anaerobic organisms].

Susceptibility of 180 strains of anaerobic organisms to ampicillin, cefoperazone and their combinations with sulbactam, as well as that to cefoxitin, imipenem and metronidazole was studied with the method of serial microdilutions. 100 per cent of the strains was susceptible to the ampicillin + cefoperazone combination. Only 1 strain of Bacteroides fragilis was resistant to imipenem. 73.4 and 57.8 per cent of the B. fragilis strains were susceptible to cefoxitin and cefoperazone respectively. No resistance to metronidazole was detected. 100 per cent of the strains belonging to Bacteroides spp. fragilis (gr.) and Prevotella spp. was resistant to all the antibiotics except ampicillin. Gram-positive anaerobic cocci were susceptible to all the antibiotics. The strains of Actinomyces spp. and Propionibacterium acnes were resistant to metronidazole. Only 48.7 per cent the Actinomyces strains was susceptible to cefoxitin.

Ampicillin↗
PubMed1994

[Comparative in vitro activity ampicillin, cefoperazone, their combinations with sulbactam, as well as that of other antibiotics against aerobic gram-negative microorganisms].

The activity of 12 antibiotics against 849 strains of gram-negative aerobes isolated in special and general hospitals of Moscow and Smolensk in 1992-1993 was assayed with the method of serial microdilutions. By the criteria of the activity (percentage of the susceptible strains by the NSSLS criteria) against the isolates the antibiotics were arranged as follows: ciprofloxacin (89.8 per cent) > imipenem (89.6 per cent) > cefoperazone + sulbactam (86.1 per cent) > amikacin (83.8 per cent) > ceftazidime (81.8 per cent) > ceftriaxone (71.1 per cent) > cefoperazone (70.9 per cent) > cefotaxime (70.9 per cent) > gentamicin (60.8 per cent) > ampicillin + sulbactam (44.7 per cent) > cefazolin (37.5 per cent) > ampicillin (23.0 per cent). The frequency of the antibiotic susceptible isolates in the special hospitals was lower at the average by 20 per cent than that in the general hospitals with respect to all the antibiotics assayed.

Ampicillin↗
PubMed1985

[Use of antibioticograms for individual programs of antibacterial therapy].

The increasing role of antibiotic-resistant microorganisms in etiology of bacterial infections and the increased number of the antibiotics used for the treatment of patients with purulent infections require a rational approach to the choice of the optimal drug. Antibiotic sensitivity of the causative agents of bacterial infections is considered at present as one of the main indices determining the efficacy of antibacterial therapy. Determination of antibiotic sensitivity by the disk diffusion method with quantitative and semi-quantitative interpretation of the results provides information for choosing the most effective drug and calculating its optimal dose in control therapy. Equations for calculating the MICs antibiotics by the inhibition growth zones and the drug levels in blood and urine attained with the use of different doses and administration routes are presented.

Anti-Bacterial Agents↗
PubMed1985

[Unimicon-s (universal microbiological control--sensitivity) standardized medium for determining the antibiotic sensitivity of microorganisms].

A nutrient medium Unimicon-s for determination of antibiotic sensitivity of microorganisms is described. The medium is based on the raw material not used as a food, i. e. a clarified enzyme lysate of microbial biomass obtained at the All-Union Research Institute for Protein Synthesis. Unimicon-s provided satisfactory growth of various cultures and the sensitivity determination results analogous to those obtained with medium 1 (MPA) or Muller-Hinton medium recommended by the WHO as a standard medium for determination of microbial antibiotic sensitivity. The study on estimation of the fitness of the present criteria for dividing cultures by the sensitivity levels, i. e. into sensitive, moderate sensitive and resistant showed that with the use of an inoculation dose of 2.5 X 10(7) microbial cells per 1 ml the growth inhibition zones of the standard strains on the Unimicon-s medium were within the ranges of the permissible limits for medium 1. The Unimicon-s medium was tested with positive results in the laboratories of the A. N. Bakulev Institute of Cardiovascular Surgery and the 1st N. I. Pirogov City Clinical Hospital.

Amino Acids↗
PubMed1984

[Stability of antibiotics in disks as one of the indicators of their quality].

In connection with the new requirements to the content of antibiotics in discs and a new procedure for the disc labeling stability of antibiotics in discs was studied with the methods of storage under natural conditions and under conditions of accelerated ageing. It was shown that the method of accelerated ageing was not applicable to testing antibiotic stability in discs, since with the use of this method a significant decrease in the antibiotic activity was observed which did not correspond to the real decrease in activity determined with the method of storage under natural conditions. The expiry date of the discs with benzylpenicillin or semisynthetic penicillins was determined to be equal to 1.5 years when stored at 10 degrees C. The expiry date of the discs with thermostable antibiotics was determined to be equal to 3 years when stored at 10 degrees C. Though certain inactivation of the antibiotics was observed, their content in the discs remained within the required limits, i.e. 75-135 per cent of the activity indicated on the label.

Anti-Bacterial Agents↗
PubMed1982

[Methodological approaches to controlling the antibiotic content in disks for determining microorganism antibiotic sensitivity].

The content of antibiotics in the discs is the main requirement to their quality. There are 2 methods for determination of the antibiotic content in the discs: (1) a method with preliminary extraction of the antibiotic from the disc followed by determination of its content in the extract biologically and (2) a method using 3 or more standard discs containing different amounts of the antibiotic. A study was performed to show the advantages and limitations of the methods. The conditions for determination of the activity of 22 antibiotics contained in the discs with the method using the standard discs were developed. Comparison of the results obtained with the 2 methods showed that they did not differ significantly. However, it is considered advisable to use for the disc control the method based on direct diffusion of the antibiotic from the disc into agar, since in this case the antibiotic amount in the disc is determined under conditions as much as possible close to the conditions of the disc using for determination of the microbial antibiotic sensitivity.

Anti-Bacterial Agents↗
PubMed1978

[Development of a method for the quantitative evaluation of microorganism sensitivity to antibiotics utilizing disks. The determination of the minimal doxycycline concentration that depresses microorganism growth using disks containing this antibiotic].

A quantitative method for estimation of microbial sensitivity to doxycycline with the use of discs containing 10 gamma of the antibiotic was developed. The antibiotic concentrations in the agar were determined at a distance equal to the radius of the growth inhibition zone with the help of a curve of the dependence of the logarithm of the doxycycline concentration in agar at the period of the average critical time of the zone formation equal to 5 hours and the distance from the disc center. The antibiotic concentration in the agar at the zone edges was almost the same as the MIC of doxycycline against the test-cultures determined with the method of serial dilutions in agar.

Anti-Bacterial Agents↗