[Experimental criteria for interpretation of bacterial sensitivity to dioxidine determined by diffusion from the disks]. / Eksperimental'nye kriterii dlia interpretatsii chuvstvitel'nosti bakterii k dioksidinu metodom diffuzii iz diska.

Antibacterial activity of dioxidine against aerobic and facultative anaerobic organisms under conditions of anaerobiosis i. e. conditions really observed for example in abscess cavities or necrotic tissues is 30 to 100 times as high as that under aerobic conditions. There is a relationship between sensitivity of bacteria to dioxidine under aerobic and anaerobic conditions which is expressed by the regression equation. Therefore, comparison of the MICs determined under anaerobic conditions with the growth inhibition zones formed by disks with the drug under aerobic conditions is possible. The MIC of dioxidine was determined under anaerobic conditions for 179 clinical strains of aerobic and facultative anaerobic bacteria and the growth inhibition zones of the same bacteria under aerobic conditions were evaluated with the use of disks containing 100, 75, 50, 25, 20, and 15 micrograms of the drug. The border line. MIC differentiating between resistant and sensitive strains was chosen to be equal to 4 micrograms/ml. Differentiation of the strains into sensitive and resistant ones by the values of the growth inhibition zones was performed with the method of error minimization described by C. Metzler and R. De Haan in 1974. Disks containing 25 micrograms of the drug allowed one to differentiate the strains under aerobic conditions into sensitive and resistant ones: the growth inhibition zones greater than 11 mm corresponded to the sensitive strains (the MIC smaller than 4 micrograms/ml) and the growth inhibition zones smaller than 11 mm corresponded to the resistant strains (the MIC greater than 4 micrograms/ml).

[Pharmacokinetics of dioxidine in oncological patients in the postoperative period]. / Farmakokinetika dioksidina u onkologicheskikh bo'lnykh v posleoperatsionnom periode.

Dioxidine pharmacokinetics was studied in 5 patients operated for cancer of the large intestine and treated prophylactically with the drug during the postoperative period. Dioxidine was administered intravenously for 10 minutes twice a day in an amount of 300 mg in 5 per cent solution of glucose. The drug concentrations in serum and urine were determined with a microbiological procedure. Escherichia coli AB 2472 rec A16, a strain deficient with respect to reparation was used as a test microbe. The plates with the dilutions were incubated under anaerobic conditions. The time course of the drug concentrations in serum was shown to be satisfactorily described by the following equation: C(t) = 3.125 . 1-2.57.t + 2.76 . 1-0.64.t. Within the first 1.5-2 hours after the administration the dioxidine concentrations in serum and urine amounted to 2.5-4 and 35-50 micrograms/ml respectively.

[A microbiological test system for determining dioxidine levels in biological fluids]. / Mikrobiologicheskaia test-sistema dlia opredeleniia kontsentratsii dioksidina v biologicheskikh zhidkostiakh.

A microbiological procedure for determining dioxidine concentrations in biological fluids with using E. coli AB 2472 rec A 16, a reparation deficient strain as a test organism is described. Cell suspension of the strain 24-hour culture is added to 1.2 per cent agar with Hottinger digest (140 mg per cent of amine nitrogen), 3 g/l of disubstituted sodium phosphate and 0.4 per cent of glucose cooled to 50 degrees C. 10 ml of the medium are added to every Petri dish with metallic cylinders put on the agar. After the medium solidification the cylinders are removed and 0.1 ml of the solution being tested is added to every well. The dishes are incubated for 24 hours under anaerobic conditions. The test system sensitivity is 0.2 microgram/ml of dioxidine. The relationship between the growth inhibition zone and the drug concentration is linear within dioxidine concentrations of 0.2 to 3.2 micrograms/ml.

[Sensitivity of clinical bacterial strains to dioxidine in vitro under aerobic and anaerobic conditions]. / Chuvstvitel'nost' klinicheskikh shtammov bakterii k dioksidinu in vitro v aérobnykh i anaérobnykh usloviiakh.

Dioxidine sensitivity of 267 clinical strains of aerobic bacteria was determined with the method of two-fold serial dilutions in agar. The strains were cultivated under aerobic and anaerobic conditions. The sensitivity of 96 anaerobic bacteria was also estimated. When the aerobic bacteria such as Enterobacteriaceae, Staphylococcus spp., Streptococcus spp. and P. aeruginosa were grown under anaerobic conditions i.e. under conditions more close to the real ones in the infection foci their sensitivity increased. There was observed a relationship between dioxidine sensitivity of the bacteria under aerobic and anaerobic conditions which was expressed by the following equation: y = 4.73 + 0.666x. Under anaerobic conditions the Enterobacteriaceae strains were more sensitive to dioxidine (MIC90 2-3 micrograms/ml) than gram-positive aerobic cocci (MIC90 64-256 micrograms/ml). At a concentration of 2 micrograms/ml dioxidine inhibited the growth of the majority of anaerobic species: Bacteroides, Fusobacterium, Clostridium and anaerobic cocci.

[Current methods of determining the sensitivity to antibacterial preparations of anaerobic microorganisms]. / Sovremennye metody opredeleniia chuvstvitel'nosti k antibakterial'nym preparatam anaérobnykh mikroorganizmov.

Antibacterial therapy of infections caused by anaerobic bacteria requires consideration of the data on periodical estimation of sensitivity of the main groups of pathogens to antibacterial drugs. The method of serial dilutions in solid nutrient media is the most accurate and handy for estimation of sensitivity of a large number of strains of anaerobic bacteria. The method of elution of a drug from a paper disk into the liquid thioglycol medium is the most applicable for determination of sensitivity of anaerobic pathogens in specific cases in customary laboratories.

[Bacteriological indications for the choice of antibacterial preparations in the cancer clinic]. / Bakteriologicheskie pokazateli k vyboru antibakterial'nykh preparatov v onkologicheskoi klinike.

Opportunistic microorganisms with multiple drug resistance are the main causative agents of infectious complications in oncological patients. The spectrum of the causative agents and their antibiotic sensitivity change with introduction of new drugs. This requires constant control over the composition of the causative agents and their sensitivity. Such a control provides rational antibacterial therapy when the causative agent is in virtue of some reasons unknown or the bacteriological data are not available. The prophylactic use of antibacterial drugs is of limited value, largely in operations on the gastrointestinal tract and other naturally contaminated cavities.

[Hospital infection in the oncology clinic]. / Gospital'naia infektsiia v onkologicheskoi klinike.

Bacterial flora in pathological excreta of cancer patients and sanitary analysis specimens was compared. Enterobacteriaceae (Escherichia coli, Klebsiellas, Proteus, etc.)--34.8 staphylococci--25, enterococci--14.7 and Pseudomonas aeruginosa--7.6% were chiefly responsible for infection--induced complications in both study groups. Among the factors of infection development were severity of malignant disease, immunosuppressive effects of present-day methods of cancer treatment, inadequate sanitary-hygienic conditions, problems involved in sterilization of certain types of diagnostic and therapeutical equipment and a large-scale application of antibiotics which is conductive to selection of multiple resistant bacteria. Procedures for equipment sterilization and use of antibiotics are discussed.

[Effect of the anthracycline group antibiotics, mitomycin C and bruneomycin, on the transduction of drug resistance in staphylococci]. / Vliianie antibiotikov antratsiklinovoi gruppy, mitomitsina C i bruneomitsina na transduktsiiu lekarstvennoi ustoichivosti u stafilokokkov.

The effect of various concentrations of antitumor antibiotics, such as carminomycin, rubomycin, adriamycin, mitomycin C and bruneomycin on transduction of erythromycin resistance from the donor strain 8325 P II/de of Staph, aureus to the recipient strain 8325-I in different transduction systems was studied. It was shown that the above antibiotics inhibited the transduction in the systems with constant presence of the drugs. Preliminary treatment of the recipient cells with the drugs in the subbacteriostatic doses did not decrease the transfer frequency. The preliminary treatment of the donor cells resulted in an increase in the phase titer and the transfer frequency in the "preliminary-treated donor + recipient" system.

[Recipient capacity of clinical strains of staphylococci belonging to different phage groups]. / Retsipientnaia sposobnost' klinicheskikh shtammov stafilokokkov razlichnykh fagogrupp

The recipient capacity of the strains of Staph. epidermidis and Staph. areus belonging to different phage groups, as well as the possibility of epidemic distribution of the erythromycin resistance marker among the clinical staphyloccal strains on using the defective phage obtained from strain 8325 P IIde was studied. The defective phage P IIde may be the source of epidemic distribution of the drug resistance among the competent strains of Staph. aureus. All erythromycin sensitive strains of Staph. aureus lysed by the phages of groups I and III proved to be competent recipients of the erythromycin resistance marker. The strains of Staph. aureus of phage group II and phage type 80/81, as well as the strains of Staph. epidermidis were not competent recipients under our experimental conditions. It was not possible to transfer the high level of erythromycin resistance (1000 gamma/ml) on transduction to the strains of phage group I with a relatively low level of resistance to this antibiotic (20-50 gamma/ml.

[Prevalence of markers characteristic for penicillinase plasmids in clinical strains of straphylococci]. / Rasprostranennost' markerov, kharakternykh dlia penitsillinaznykh plazmid, u klinicheskikh shtammov stafilokokkov

Occurrence of the markers of penicillin and erythromycin resistance in the clinical strains of Staph. aureus, as well as their connection with the determinants of resistance to the heavy metal salts and sodium arsenate was studied. 79 per cent of Staph. aureus were resistant to penicillin and 47 per cent to erythromycin. All erythromycin resistant strains were also resistant to penicillin. More than a half of the strains of Staph. aureus of the phage groups I, III and the mixed phage group had a set of markers: pen, asa, cad, mer, ego. The rate of elimination of the above markers with ethidium bromide was high. The presence of the penicillinase plasmid determining a rather low level of resistance to erythromycin (20--50 gamma/ml) was characteristic of the strains belonging to the phage group I. The presence of the plasmid determining a high level of resistance to that drug (500--1000 gamma/ml) was characteristic of the phage group III and the mixed phage group. The erythromycin sensitive strains of Staph. aureus were almost always sensitive to mercuric ions.