Antimicrobial resistance of nosocomial strains of Staphylococcus aureus in Russia: results of a prospective study.

A total of 879 Staphylococcus aureus clinical isolates from 17 medical institutions in different regions of Russia were tested. Susceptibility to 18 antimicrobials was determined by agar dilution in accordance with the NCCLS recommendations. The most potent antimicrobials were glycopeptides, linezolid, and fusidic acid, to which no resistance was found. Other antimicrobials with low frequency of non-susceptibility were mupirocin (0.3%), trimethoprim/sulfamethoxazole (0.8%), quinupristin/dalfopristin (1.8%) and rifampicin (7.0%). Fluoroquinolones displayed moderate activity (5.8% of non-susceptible strains to moxifloxacin, 9.1% to levofloxacin, 13.1% to ciprofloxacin). High rates of non-susceptibility were found to clindamycin (27.1%), gentamicin (30.7%), tetracycline (37.1%), erythromycin (39.6%) and chloramphenicol (43.1%). The prevalence of oxacillin-resistant S. aureus (ORSA) was 33.5% and varied from 0% to 89.5% in different hospitals. ORSA were isolated most frequently in the burn units (77.5%), intensive care units (54.8%), trauma and orthopedics units (42.1%). This is the first multicenter study published of antimicrobial resistance of S. aureus in Russia which meets international standards.

[Resistance of ambulatory urinary infection pathogens according to the data of multicenter microbiological studies UTIAP-I and UTIAP-II]. / Rezistentnost' vozbuditelei ambulatornykh infektsii mochevyvodiashchikh putei po dannym mnogotsentrovykh mikrobiologicheskikh issledovanii UTIAP-I i UTIAP-II.

AIM: To study causative agents and sensitivity of E-coli strains isolated from adult outpatients with uncomplicated urinary infection (UI) in different regions of Russia. MATERIAL AND METHODS: A multicenter prospective epidemiological study included adult patients with uncomplicated infections of the upper or lower urinary tracts. MPK of antibiotics was established by dilution in agar according to NCCLS recommendations, 2000-2002. RESULTS: Among UI causative agents, E. coli was most frequent (85.9%). K. Pneumoniae, Proteus spp., Staphylococcus spp., P. Aeruginosa, Enterococcus spp. occurred much less frequently (6, 1.8, 1.6, 1.2, and 1.0%, respectively). E. Coli UI was highly resistant to ampicilline (37.1%), cotrimoxasol (21%), maximal resistance being in St-Petersburg (51.9 and 31.5%, respectively). Such oral antibiotics as norfloxacin and ciprofloxacin, cefuroxim, amoxicillin/clavulanat, nitrofurantoin were maximally active against E. Coli (4.3, 2.4, 2.6 and 1.2%, respectively). CONCLUSION: High resistance of E. coli, which is the chief causative agent of uncomplicated UI, to ampicillin, cotrimoxasol was detected. Fluoroquinolones, amoxicillin/clavulanat, nitrofurantoin, cefuroxim have high microbiological activity. On the basis of the pharmacokinetic, safety and other evidence it is concluded that drugs of choice for therapy of uncomplicated UI in Russia are oral fluoroquinolones.

[The heterogeneity of an influenza virus A population in its capacity to induce the synthesis of avid antibodies]. / Geterogennost' populiatsii virusa grippa A po sposobnosti indutsirovat' sintez avidnykh antitel.

Influenza A virus variants were found to be capable of inducing synthesis of avid antibodies when different species and lines of animals were immunized. CBA mice were the most convenient model permitting differentiation of "avidogenic" from "nonavidogenic" virus variants with a high degree of certainty. Recombinants may differ from parental viruses in their capacity to induce synthesis of avid antibody; with this, the transmission of only one gene (HA) from the "avidogenic" parent into the system of genes of A/PR/8/34 st in ensured a high "avidogenicity" of the recombinant. The "avidogenic" virus variants had a more marked protective effect than "nonavidogenic" ones.

[Study of influenza virus hemagglutinin H3 avidity using monoclonal antibodies]. / Izuchenie avidnosti gemaggliutinina H3 virusa grippa s pomoshch'iu monoklonal'nykh antitel.

The results of a comparative study of the features of antigenic determinants of avid and non-avid variants of influenza virus hemagglutinin H3 and of the influence of the mode of antigen presentation on the degree of its avidity are presented. The avidity of influenza virus hemagglutinin was shown to be determined by the capacity of individual antigenic determinants to interaction with antibodies. The antigenic determinants of avid hemagglutinin possessing a high functional activity in interaction with antibodies may have the spatial configuration which does not change in different modes of the antigen presentation. Isolation of hemagglutinin from virions of non-avid virus variants may lead to increased functional activity of individual antigenic determinants (and the antigen molecule as a whole) probably due to an increased degree of exposure and/or complementarity of the determinants for active centres of antibody.