Antimicrobial activity of pefloxacin in comparison with other quinolones]

The antibiotic sensitivity of 338 microbial cultures isolated from patients with inflammatory renal and urinary diseases was studied. 66.3 per cent of the isolates proved to be poly-resistant which corresponded to rurological patient specificity. It was shown that abactal (pefloxacin, LEK, Yugoslavia) had a higher antimicrobial activity than the nonfluorinated quinolones especially against Staphylococci and a lower antimicrobial activity than the fluorinated quinolones in vitro. The abactal sensitivity to Pseudomonas aeruginosa amounted only to 23 per cent which was likely to be due to development of cross-resistance to ofloxacin. 1/3 of the polyresistant isolates were sensitive to abactal. The activity of abactal weakly depended on the medium pH. The MBC was generally no more than 2 MICs.     

The structure and antibiotic sensitivity of the causative agents of community-acquired infectious diseases of bacterial origin in children]

Four hundred and forty pediatric patients at the age of 7 days to 15 years with various infections admitted to the Hospital within a month were examined. The biological material was inoculated to blood agar on the first days of the patient admittance to the Hospital and after the growth the organisms were isolated and identified. Antibiotic susceptibility of the isolates was assayed with the disk diffusion method. 479 strains in all were tested. The most frequent cases requiring hospitalization and antibiotic therapy were those of respiratory tract infections (54.09 per cent), urinary tract infections (26.36 per cent), cutaneous and subcutaneous fat diseases, gastrointestinal diseases and others (about 25 per cent of the cases in all). The main pathogens were Streptococcus viridans, S.aureus and S.epidermidis, as well as Enterobacteriaceae (chiefly E.coli) whose frequencies were practically equal (in 25-35 per cent of the cases). The Pneumococcus isolates amounted to 6.3 per cent. Nonfermenting bacteria (Pseudomonas aeruginosa and Acinetobacter) and some representatives of Enterobacteriaceae (Citrobacter, Serratia, Morganella) were isolated from 7 per cent of the patients. The frequency of Klebsiella and Enterobacter was about 11 per cent. The main pathogens were tested for their susceptibility to amoxycillin/clavulanic acid, ampicillin, oxacillin and gentamicin. The least active antibiotic was ampicillin. 88.8 per cent of the E.coli isolates and 100 per cent of the Klebsiella, P.mirabilis, Morganella, Citrobacter, Enterobacter and Serratia isolates were resistant to it. 53.2 per cent of the Streptococcus isolates including 64.5 per cent of the Pneumococcus isolates were as well resistant to ampicillin. 59.5 per cent of the Streptococcus isolates (mainly S.viridans and Enterococcus) was susceptible to oxacillin, 22.2 per cent of them being moderately susceptible. 62.5 per cent of the Pneumococcus isolates and 78.1 per cent of the Staphylococcus isolates were also susceptible to oxacillin. The highest susceptibility of the isolates was that to amoxycillin/clavulanic acid, i.e. 90.1 per cent of the strains, 79.9 per cent of them being highly susceptible. All the isolates of Citrobacter, Serratia and Morganella and some isolates of P.aeruginosa, Acinetobacter, Enterobacter, Klebsiella and E.coli were resistant to amoxycillin/clavulanic acid. As for the latter 5 organisms their susceptibility to amoxycillin/clavulanic acid was comparable with that to gentamicin. The susceptibility of the Streptococcus and Staphylococcus isolates to amoxycillin/clavulanic acid was significantly much higher than that to oxacillin, gentamicin and ampicillin: 93 per cent of the Streptococcus isolates (62.7 per cent of the Pneumococcus isolates) and 90.7 per cent of the Staphylococcus isolates.     

Drug resistance of the causative agent of Grigo'rev-Shiga dysentery (Shigella dysenteriae 1)isolated in the USSR

Forty strains of S. dysenteriae 1 isolated in the USSR within 1986-1988 were tested for their resistance to 11 antibacterial drugs. It was shown that 92.5-97.5 per cent of the isolates were resistant to chloramphenicol (Cm) and tetracycline (Tc), 22.5 per cent to streptomycin (Sm), 17.5 per cent to nalidixic acid (Nal) and 10 per cent to ampicillin (Ap) and polymyxin (Pm). Resistance to Cm Tc (51.4 per cent) and Cm Tc Nal (13.5 per cent) represented the predominating phenotype. 35 per cent of the strains carried conjugative R plasmids. In the majority of the cases, the determinants of resistance to Cm and Tc were transferred, which must define the high frequency of the strains resistant to Cm and Tc. All the tested strains were sensitive to gentamicin, neomycin, rifampicin, cefamezin and ciprofloxacin. Since the strains of S. dysenteriae 1 proved to be highly sensitive to the tested drugs it appeared possible to consider them as the drugs of choice in etiotropic therapy of patients with dysentery caused by the pathogens of the Grigoryev-Shiga group.     

Ciprofloxacin in the treatment of infections in oncology patients

Treatment of infectious complications with ciprofloxacin in 65 patients provided good and satisfactory results in 67.7 and 20.0 per cent of the cases, respectively. The drug was efficient in sepsis, urogenital infections, respiratory infections and postoperative purulent complications. Ciprofloxacin showed a broad antibacterial spectrum. 96.3 per cent of the isolates belonging to aerobic organisms causing purulent inflammatory processes, including those with high antibiotic resistance levels, such as Pseudomonas spp., Proteus spp., Klebsiella tribe and Staphylococcus aureus were sensitive to the drug. In its antibacterial spectrum ciprofloxacin was similar to ofloxacin. The advantage of ciprofloxacin is its possible use not only orally but also intravenously. Adverse reactions to ciprofloxacin were observed in 5 (7.7 per cent) out of the 65 patients. In two cases discontinuation of the drug use was required. The use of ciprofloxacin in treatment of infectious complications in oncological patients is promising.     

A Locked Nucleic Acid (LNA)-Based Real-Time PCR Assay for the Rapid Detection of Multiple Bacterial Antibiotic Resistance Genes Directly from Positive Blood Culture

Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA)-based quantitative real-time PCR (LNA-qPCR) method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1–10 colony forming units (CFU) per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4%) were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.     

Drug resistance of opportunistic enterobacteria isolated from various sources]

Resistance of 159 strains of opportunistic enterobacteria to 9 antibacterial drugs was studied. The strains were isolated from man and cattle. It was shown that the overwhelming majority of the isolates (93 per cent) were polyresistant irrespective of the genus. There was a high frequency of the strains resistant to the widely used antibiotics such as chloramphenicol (73 per cent), ampicillin (73.6 per cent) and rifampicin (95.6 per cent) and sulfanilamides (99.3 per cent). Gentamicin and nalidixic acid proved to be the most active against the cultures: 11.9 and 10 per cent of the resistant strains, respectively. The strains of enterobacteria isolated from different sources had a sensitivity to the antibiotics. Multiple antibiotic resistance to at least 5 drugs, variability of the spectra and high resistance were more characteristic of the isolates from the animals. The necessity of a rational use of antibacterial drugs in veterinary is indicated.     

Level and nature of the drug resistance of Shigella flexneri]

Characteristics of antibiotic resistance of 300 strains of Shigella flexner 2a isolated from patients within 1976--1977 in the regions where these bacteria were very rare for a long period of time were studied. It was shown that most of the isolates were resistant to chloramphenicol (88.1 per cent), tetracycline (94.8 per cent), streptomycin (89.1 per cent), polymyxin M (82.4 per cent) and others. 46.5--61.6 per cent of the isolates were resistant to neomycin antibiotics. A high level of the resistance was also noted: the bactericidal effect was registered in 52.0-74.0 per cent of the cultures at a dose of 500--1000 microgram/ml. 91.4 per cent of the strains possessed multiple dug resistance, 78.8 per cent of them being simultaneously resistant to 4--7 drugs. Transmissive R-plasmids were found in 68.8 per cent of the isolates. After exposure to acridine dyes the plasmid nature of the resistance was confirmed in 72.3 per cent of the cultures. Variability of the r-determinant sets in r-plasmids was noted. Strains (64.9 per cent) carrying r-determinants Tc, Cm, Sm and Tc, Cm were more frequent. Strains with one transmissive r-determinant were usually solitary.     

Antibiotic sensitivity and the characteristics of transmissive R plasmids in Shigella belonging to various species]

Sensitivity of 241 Shigella strains isolated from patients at various regions of the USSR in 1975--1978 was tested with respect to 14 antibiotics by the method of serial dilutions. 90.5 per cent of the isolates proved to be resistant to the antibacterial drugs and the greater part of 75.9 per cent of them had multiple resistance. The resistance of the Shigella was most pronounced and frequent with respect to tetracycline, streptomycin, levomycetin, as well as ampicillin and carbenicillin. Gentamicin, cephaloridin, polymyxin M, kanamycin, monomycin, neomycin and rifampicin were highly active against the Shigella. More than 50 per cent of the isolates were sensitive to levomycetin, ampicillin and carbenicillin. Differences in the frequency of the resistant strains and the spectrum of the antibiotic resistance of different Shigella subgroups (species) were observed. The study of 173 multiple resistant Shigella strains showed that about 67 per cent of the strains had a capacity for transduction of the resistance markers into the recipient cells of E. coli. The conjugative R-plasmids were most frequent in Sh. boydii and Sh. sonnei (95 and 95 per cent respectively), less frequent in Sh. flexneri and Sh. newcastle (68 and 53 per cent respectively) and least frequent in the mannitol negative Shigella (25 per cent). The capacity for transduction of R-plasmids in the strains carrying the determinants of resistance to 2 or 3 antibiotics was higher than in the strains carrying the determinant of resistance to one antibiotic. The clinical Shigella strains tested mainly had transmissive R-plasmids of fi--character (79 per cent).     

Efficacy of a combination of dioxidine with beta-lactam antibiotics in the prevention and treatment of purulent-inflammatory complications

Schemes for prevention and treatment of purulent inflammatory complications were developed on the basis of in vitro studies on antimicrobial activity of dioxidine and 7 beta-lactam antibiotics such as mezlocillin, carbenicillin, ampicillin, cefotaxime, cefoxitin, cefuroxime and cephalothin under conditions of aero- and anaerobiosis with an account of the isolated microflora, its sensitivity to antibacterial agents and conditions required for vital activity of obligate anaerobes in humans, i.e. decreased partial oxygen pressure, low oxidation-reduction potentials and high tissue concentrations of carbon dioxide. The use of dioxidine in combination with the antimicrobial drugs enabled one to decrease the number of cases with purulent inflammatory complications after large intestine esophagoplasty to 30.4 per cent against 67.5 per cent in the control group of the patients untreated preventively with the antibacterial drugs. The number of cases with similar complications after gastrectomy amounted to 16.1 per cent against 62 per cent in the control. The use of dioxidine+ in combination with ampicillin and cefotaxime in treatment of purulent necrotic affections of the foot in patients with diabetes mellitus enabled one to increase the number of satisfactory outcomes by 32 per cent, to decrease the number of high amputations by 21.9 per cent and to lower the number of deaths more than 2-fold as compared to the results in the control group of the patients subjected to chemotherapy based on sensitivity of the aerobic microflora alone.     

Various methods of using lincomycin for treating acute and chronic hematogenic osteomyelitis in children]

Comparative data on the treatment of 209 children with acute and chronic hematogenic osteomyelitis are presented; 128 patients hospitalized before 1974 were treated with antibiotics, mainly penicillin and streptomycin without sensitivity testing. From 1974 81 children were treated with lincomycin; 80 per cent of the isolates were sensitive to this antibiotic. In lincomycin therapy the method of electrophoresis on the disease focus, intrabone administration of the drug and administration of the drug into the bone cavity together with the blood clot during surgical interventions in cases with chronic hematogenic osteomyelitis were used. A marked decrease in the rate of the chronic forms of the disease was registered (from 77.2 to 8.8 per cent).     

Antibiotic use optimization program in the largest Croatian university hospital--benefits of restrictions on unlimited antibiotic use

The aim of this study was to obtain the relevant information on antibiotic use in a 750-bed Croatian university hospital. The study has been designed as a 2-point prevalence interventional analysis. For each patient on antibiotic therapy, diagnosis, indication for treatment, antibiotic therapy, dosage and route of administration together with the results of microbiological studies (if available) were obtained. After the first prevalence analysis in 2001, a restriction on unlimited antibiotic use was introduced. The second analysis, performed in 2002, after restrictions on antibiotic use, revealed reductions in the rates of restricted release antibiotics and overall antibiotic use with decreases from 38.6% to 36.9% and 23.4% to 23.2% respectively (p = 0.87). The first survey showed that the 5 most often prescribed antibiotics in the therapy of bacterial infections were: gentamicin, other aminoglycosides, carbapenems, amoxycillin +clavulanate and vancomycin with proportions of 14.8%, 10.3%, 8.2%, 7% and 7% respectively. In the year 2002, the most prescribed antimicrobial drugs in the therapy of bacterial infections were: gentamicin, quinolones, vancomycin, carbapenems and cefuroxime with proportions of 18.6%, 11.4%, 9.7%, 9.3% and 8% respectively. A reduction in the proportions of doubtful antibiotic therapy, from 24.6% before the intervention, to 24.2% after the restrictions, accompanied by a 0.4% rise in the rates of indicated antibiotic therapy was also observed (p = 0.93). Our study shows that restrictions on formerly unlimited use of antimicrobials, even when leading to an improvement in their prescribing, do not necessarily cause rapid and significant reduction in the overall use of antibiotics or explicit positive financial effects.     

The comparative activity of cefepime and other current antibiotics against microorganisms isolated from patients in pediatric intensive therapy units]

Comparative activity of cefepime, ceftazidime, ceftriaxone, ciprofloxacin, imipenem and piperacillin/tazobactam against isolates from patients of pediatric intensive care units within October-December 1998 was studied. The isolates were identified with the Walkaway-40 System. The antibiotic susceptibility was evaluated by the E-test on the Mueller-Hinton II agar. The data were interpreted in accordance with the NCCLS. The number of the isolates totaled 100. Among them not more than 10 to 12 strains belonged to the same species. 92 per cent of the isolates was susceptible to cefepime and 70 to 75 per cent of the isolates were susceptible to the third generation cephalosporins. Piperacillin/tazobactam proved to be highly susceptible, the number of the isolates resistant and moderately resistant to it being 6 and 1 per cent respectively. The results showed that cefepime was intermediate between the third generation cephalosporins and carbapenems.     

Detoxifying effect of antibiotics and their effectiveness in experimental plague at the stage of explicit intoxication]

The effect of antibiotics such as amikacin, rifampicin, doxycycline, polymyxin B and cefotaxime on the toxins of the plague microbe (lipopolysaccharide + fraction II according to Beiker) was studied in vitro and in vivo. The study on the antibiotic neutralization of plague toxins revealed that only polymyxin had toxin neutralizing capacity which depended on the dose. Investigation of the polymyxin effect at various stages of plague infection showed that when polymyxin in a dose of 1250 units and a mixture of plague toxins in lethal doses were administered simultaneously to albino mice, the positive effect amounted to 100 per cent. When the antibiotic was administered 30 or 60 minutes later, the antibiotic efficacy proved to be lower by 90 or 76.6 per cent, respectively. The intoxication in later periods (in 90-120 minutes) resulted in a decrease in animal survival up to 40-15 per cent. It was demonstrated on the model of the plague infection in albino mice that the use of amikacin, cefotaxime, rifampicin or doxycycline during polymyxin therapy at the stage of marked generalization of the infection provided a significant increase in the animal survival (60 to 80 per cent) as compared to that after the use of the same drugs alone (0 to 20 per cent).     

Etiotropic antibiotic therapy and immunotherapy of patients with pyo-inflammatory processes]

A 3-year experience was reviewed in the treatment of patients with pyoinflammatory processes (PIP) which developed during the postoperative period in 387 persons with closed injury and multiple penetrating wounds of the chest and stomach complicated by massive hemorrhage. When the PIP was localized in the abdominal cavity, enterobacteria and bacteroides were the main pathogens: 49.4 +/- 2.1 and 32.8 +/- 1.4 per cent, respectively. When the PIP was localized in the thoracic cavity, the most frequent pathogens were staphylococci, Pseudomonas aeruginosa, and enterobacteria: 26.5 +/- 1.4, 24.6 +/- 1.4 and 13.3 +/- 0.8 per cent, respectively. In all the cases high variability of the antibiotic susceptibility of the isolates and predominance of the strains resistant to 5 or more drugs were observed. A suppressive effect of thienam on the immune system was revealed. The immunocorrection in parallel with the antibiotic therapy made it possible to prevent further development of immune deficiency and to recover the bactericidal potency of the phagocyting cells. The use of various physiochemical methods in complex treatment of PIPs is substantiated.     

Antibiotic resistance and its transmissibility in strains of opportunistic enterobacteria

Sensitivity of 39 opportunistic Enterobacteria strains was studied with respect to tetracycline, kanamycin, ampicillin, levomycetin, streptomycin and nevigramon. The strains were isolated from children with acute intestinal infections of obscure etiology. 38 isolates were resistant to one or more drugs. The highest number of the strains was resistant to kanamycin, ampicillin and levomycetin, i.e. 81.5, 84.2 and 84.2 per cent of the cultures respectively. Nevigramon proved to be the most effective in vitro (76.4 per cent of the sensitive strains). The ability of the strains to transfer the antibiotic resistance markers on conjugation was tested. Transmission of R plasmids was shown in 75 per cent of the isolates.     

Comparative characteristics of the antibioticograms and biological properties of the staphylococci isolated from patients with various eye diseases]

A total of 1488 examinations of the conjunctival content of patients with various ophthalmic diseases were performed within 5 years (1973--1977). 989 (66.4 per cent) cultures were isolated. Staphylococci were isolated in 79.2 per cent of the patients irrespective of the diagnosis. The plasma-coagulating strains were isolated in 43.6 per cent of the patients with acute conjunctivitis. The plasma-negative staphylococci were more frequent in chronic conjunctivitis (83.5 per cent). A total of 188 strains were studied according to 18 tests. Determination of the antibiotic sensitivity showed that the number of the benzylpenicillin and tetracycline resistant strains among the plasma-coagulating staphylococci was higher in the patients with acute ophthalmic diseases. In chronic conjunctivitis no differences in the antibiotic sensitivity of the plasma-coagulating and plasma-negative strains were noted. Similar antibiotic sensitivity of all plasma-negative staphylococci irrespective of the diagnosis was found. High biological activity of the plasma-negative staphylococci was shown: 74.1 per cent of the isolates possessed phosphatase, 59.8 per cent possessed protease and 88.4 per cent a lysozyme-like enzyme. The strains isolated in chronic conjunctivitis produced protease more frequently that those isolated in acute ophthalmic diseases.     

Antibiotic resistance of Shigella in different regions of the USSR]

Shigella were most sensitive to polymyxin ceporin, ampicillin, neomycin and furazolidone and resistant to chloramphenicol, tetracycline and streptomycin. Shigella resistant simultaneously to two or three drugs mainly to tetracycline + chloramphenicol, tetracycline + streptomycin and tetracycline + chloramphenicol + streptomycin were most frequent. The frequency of the Shigella strains carrying R-plasmids increased from 28 per cent in 1969--1970 to 72.6 per cent in 1977. The Shigella strains isolated during the dysentery outbreak in 1973--1977 carried the R-factor controlling resistance to tetracycline + chloramphenicol, tetracycline + chloramphenicol + streptomycin, tetracycline + chloramphenicol + streptomycin + neomycin. Interaction between separate biochemical types, colicinogenicity and drug resistance classes was found in the Shigella isolates. The data on the effect of antibiotic (tetracyclines) intensive use in stock-raising defining wide spread of the R-plasmids controlling resistance to these drugs were obtained.     

A comparative analysis of the properties of bacteria in the genus Salmonella isolated from children in Latvia]

Since social and economic changes in Latvia in 1991 the incidence of salmonellosis dramatically increased: more than 500 pediatric cases are registered every year. Specification of the properties of the Salmonella strains isolated in Latvia was undertaken. The study demonstrated that acute salmonellosis in pediatric inpatients was mainly due to S.typhimurium (78 per cent) and only in 22 per cent of the patients it was due to S.enteritidis. All the S.typhimurium isolates showed high antibiotic resistance defined by specific extended spectrum beta-lactamase (CTX-M-5).     

R plasmid distribution in S. typhi isolated on the territory of the left coast of the Ukraine in 1970-1982

A total of 373 strains of S. typhi isolated in 1970-1982 were tested with respect to their sensitivity to 9 antibiotics active against gram-negative bacteria. It was shown that about 1/3 of the isolates were resistant to 1-3 antibiotics. Among the resistant isolates the number of strains resistant to 4-5 and more antibiotics amounted to 12.5 per cent. The plasmid nature of the antibiotic resistance in the isolated strains of S. typhi was shown. Transmissive R plasmids were detected in 13 per cent of the strains studied. Within the last 5 years there was an increase in the proportion of strains with transmissive R plasmids in patients with sporadic typhoid fever or especially in groups of patients with the disease.     

Sensitivity of Corynebacterium diphtheriae isolated in Saint-Petersburg to antibacterial drugs]

One hundred and thirty strains of Corynebacterium diphtheriae isolated in St. Petersburg (42 toxigenic and 88 nontoxigenic) were tested with the method of serial dilutions in solid media for their susceptibility to 20 antibacterial drugs. The MICs of the drugs for the isolates ranged from < or = 0.015 to > or = 32.0 micrograms/ml. 13 per cent of the isolates was resistant at least to one antibacterial drug. The isolates resistant to erythromycin (11.5 per cent), lincomycin (11.5 per cent) and trimethoprim (8.5 per cent) were most frequent. 3 isolates (2.3 per cent) had multiple resistance to 8 drugs: benzylpenicillin, ampicillin, oxacillin, chloramphenicol, erythromycin, lincomycin, trimethoprim, and nitroxolin. No significant differences in the susceptibility of the toxigenic and nontoxigenic strains of C. diphtheriae were detected. Gentamicin, rifampicin, tetracycline, doxycycline and pefloxacin were the most active antibiotics.