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R S Kozlov

Publications and source records attributed to R S Kozlov.

6 recordsLinked to original sources
PubMed2006

Antimicrobial resistance of nasopharyngeal pneumococci from children from day-care centres and orphanages in Russia: results of a unique prospective multicentre study.

This study assessed the antimicrobial resistance of nasopharyngeal pneumococci isolated from children aged < 5 years in day-care centres and orphanages throughout Russia during 2001-2002. Swabs were collected from 2484 children in 43 day-care centres and eight orphanages in 11 cities of European Russia, and from 1669 children in 37 day-care centres and three orphanages in eight cities of Asian Russia, with a total of 1144 and 912 Streptococcus pneumoniae isolates being recovered in European and Asian Russia, respectively. All macrolide-non-susceptible (MICs 0.5-128 mg/L) and fluoroquinolone-non-susceptible (ciprofloxacin MICs > or = 4 mg/L) isolates were tested for resistance mechanisms and clonal relatedness. Non-susceptibility rates, by CLSI criteria, were 19.3%, 0.9% and 0.4% for penicillin G, cefotaxime and amoxycillin-clavulanate, respectively. Resistance to macrolides and lincosamides was also relatively low, i.e., < 7% for clindamycin and 14- and 15-membered macrolides. The highest rates of non-susceptibility were for tetracycline and co-trimoxazole (52.0% and 64.5%, respectively). No clones resistant to ciprofloxacin (MICs > or = 8 mg/L) were found, but 1.7% of isolates were non-susceptible (MIC 4 mg/L). No resistance was found to levofloxacin, gemifloxacin, telithromycin or vancomycin. Pulsed-field gel electrophoresis analysis showed no relationship between ciprofloxacin- and macrolide-non-susceptible isolates in European and Asian Russia. Resistance among macrolide-resistant isolates resulted mostly from the presence of erm(B) and mef(A), and from changes in L4; additionally, L22 mutations were common in isolates from Asian Russia. Non-susceptibility to quinolones was associated with mutations in parC and parE among European isolates. Asian Russian isolates had mutations in parC and gyrA, and alterations in parE were more common. There were substantial differences in non-susceptibility and mechanisms of resistance between pneumococci from Asian and European Russia, with orphanages appearing to be 'hot-spots' of resistance.

Anti-Bacterial Agents↗
PubMed2002

Immunochromatographic strip test for rapid detection of diphtheria toxin: description and multicenter evaluation in areas of low and high prevalence of diphtheria.

An immunochromatographic strip (ICS) test was developed for the detection of diphtheria toxin by using an equine polyclonal antibody as the capture antibody and colloidal gold-labeled monoclonal antibodies specific for fragment A of the diphtheria toxin molecule as the detection antibody. The ICS test has been fully optimized for the detection of toxin from bacterial cultures; the limit of detection was approximately 0.5 ng of diphtheria toxin per ml within 10 min. In a comparative study with 915 pure clinical isolates of Corynebacterium spp., the results of the ICS test were in complete agreement with those of the conventional Elek test. The ICS test was also evaluated for its ability to detect toxigenicity from clinical specimens (throat swabs) in two field studies conducted within areas of the former USSR where diphtheria is epidemic. Eight hundred fifty throat swabs were examined by conventional culture and by use of directly inoculated broth cultures for the ICS test. The results showed 99% concordance (848 of 850 specimens), and the sensitivity and specificity of the ICS test were 98% (95% confidence interval, 91 to 99%) and 99% (95% confidence interval, 99 to 100%), respectively.

Antibodies, Bacterial↗
PubMed2000

Antimicrobial resistance of Streptococcus pneumoniae isolated from healthy children in day-care centers: results of a multicenter study in Russia.

BACKGROUND: It has been previously shown that study of susceptibility of nasopharyngeal isolates in healthy carriers can predict resistance in clinical isolates. The purpose of this multicenter study was to determine the carriage rate of Streptococcus pneumoniae in healthy children attending day-care centers in Moscow, Smolensk and Yartsevo, Russia, and in vitro activity of penicillin G, amoxicillin/clavulanate, cefaclor, erythromycin, roxithromycin, clarithromycin and trimethoprim-sulfamethoxazole (TMP-SMX) against representative isolates. METHODS: Included in this study were 305 pneumococcal isolates from 733 children attending 9 day-care centers in Moscow, Smolensk and Yartsevo. All children enrolled in this study were <7 years of age. MICs of selected antimicrobials were determined by Etest. Serotyping of selected pneumococcal isolates was done with pool and type antisera. RESULTS: The carriage rate of S. pneumoniae in the 3 centers varied from 44.9% to 66.0% (mean, 55.9%). Susceptibility testing was performed with 305 (74.4%) of 410 isolates. Only 23 (7.5%) of 305 pneumococcal isolates were penicillin-intermediate (range, 2.8 to 12.8%) with no penicillin-resistant strains. All tested pneumococci were susceptible to amoxicillin/clavulanate. Macrolides possessed comparable activity against S. pneumoniae, at 4.6% resistant strains for both erythromycin (range, 1.1 to 17.1%) and clarithromycin (range, 1.7 to 17.1%). The highest level of resistance was observed with TMP-SMX, 53.4% (range, 43.8 to 70.9%). Of 23 strains 20 (87.0%) with intermediate resistance to penicillin were serotyped. The most prevalent serotype was 14 (5 isolates), followed by serogroups 19 (4) and 23 (4). CONCLUSIONS: Resistance to penicillin, other beta-lactams and macrolides does not seem to be a problem for Russia now. The high level of resistance to TMP-SMX considerably restricts its usage for the treatment of pneumococcal infections.

Child Day Care Centers↗
PubMed1996

[Comparison of the results of determining antibiotic sensitivity on AGV medium and on Mueller-Hinton and isosensitest agars].

To evaluate the adequacy of AGV agar for antimicrobial susceptibility testing, the susceptibility of a range of bacteria to 10 antimicrobials on AGV, Mueller-Hinton and isoSensitest agars, all supplemented with 5 per cent lyzed horse blood was determined. Disc tests were used. In general, AGV agar gave identical susceptibility results to Mueller-Hinton and isoSensitest agars for common gram positive and gram negative bacteria with most of the tested microbials excluding sulphonamides and trimethoprim. With those latter antimicrobials inhibition zones for susceptible organisms were not formed on AGV agar whereas large zones were present on Mueller-Hinton and isoSensitest agars. This discrepancy probably can be explained by the presence of high levels of thymidine in AGV agar; too high to be corrected even by the addition of 5 per cent lysed horse blood. AGV agar is possible to use for susceptibility testing with most of the microbials excluding trimethoprim and sulphonamides.

Agar↗