New antibiotic no. 792 formed by Actinomyces bottropensis

An actinomycetes strain 792 producing a new antibiotic was isolated under the programme of antitumor antibiotic screening. By its morphological and cultural properties strain 792 was classified as belonging to species Actinomyces bottropensis. Antibiotic 792 was recovered from the culture fluid of the strain by the extraction method in the form of a crystalline orange substances. lambda max 235, 305, 410 nm (E 1% 1cm 705, 105, 168), m. p. 232-255 degrees (dec), molecular weight 340, C 67 per cent, H 4.8 per cent, no nitrogen, sulphur or halogens. The antibiotic was inactivated in alkaline solutions forming a hardly soluble compound crystallizing in the form of red needles, lambda max 256, 485 nm (E 1% 1ct 800, 195), m. p. 202-204 degrees (dec), molecular weight 320, C 69.5 per cent, H 4.7 per cent. Antibiotic 792 had antitumor and antimicrobial activity.     

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).     

Inactivation of Oriented Bacteria with Polarized Ultraviolet Light

Aligned deoxyribonucleic acid (DNA) molecules exhibit a large absorption anisotropy in the ultraviolet (UV) region of the spectrum (11). Also, the UV action spectra of most bacteria resemble the absorption spectrum of DNA (23), implying that inactivation is directly proportional to the UV absorbed by the bacterial DNA. Hence, the UV sensitivity of aligned uniaxial bacteria might be anisotropic with respect to polarization of the incident UV (17, 19). Any inactivation anisotropy would depend upon the orientation of DNA within the bacteria, as well as upon the alignment of bacteria, and could provide a more sensitive indication of in vivo DNA orientation than is presently available using optical methods (5, 12-16). Using an electric field of 3.5 × 10⁶ cycles/second, samples of bacteria of strain LS-301 were aligned in a quartz cell and were irradiated with UV (λ = 2652 A) polarized perpendicular and parallel to the alignment direction. The resultant survival curves resolved no inactivation anisotropy. This result is interpreted to mean that there was insufficient bacterial DNA alignment to give a detectable anisotropy. The minimum average DNA alignment necessary to have resolved an anisotropy is calculated to be 15 per cent in an axial direction (bases perpendicular to the bacterial axis) or 30 per cent in a radial direction (bases parallel to the bacterial axis).     

The role of succinic acid in the biosynthesis of levorin

The influence of succinic acid as a component of media for biosynthesis of levorin, a polyenic antibiotic was studied. It was shown that with the use of the soybean-corn medium supplemented with succinic acid (0.05-0.4 per cent) the antibiotic content in the fermentation broth was higher than that in the control. The highest stimulating effect (135 per cent) was observed with addition of 0.1 per cent of succinic acid. For providing optimal antibiotic production in the synthetic medium supplemented with succinic acid (0.4 per cent) addition of acetic acid (0.05 per cent) was required. Studies with the soybean-corn medium with and without succinic acid revealed differences in the level of p-aminoacetophenone, an aromatic fragment of the levorin molecule. Under the conditions of the medium with succinic acid the content of p-aminoacetophenone in the mycelium was higher by 10 to 18 per cent as compared to that in the control and depended on the fermentation period. The role of succinic acid in biosynthesis of levorin is discussed.     

Monitoring of uropathogens and their susceptibility to antibiotics]

Samples of urine collected from patients with complicated urology infection and hospitalized to the Moscow Region Research Clinical Institute in 1986, 1991, 1995 and 1999 were analysed. Of 11,444 samples examined, bacteriuria was estimated in 7143 samples. 9786 strains (29 genus) of bacteria were isolated--56.9 per cent as mono culture and 43.1 per cent as associations. Susceptibility to 21 antibiotic was determined by disk diffusion method for 1607 strains; beta-lactamase production was determined in 198 strains, MIC was determined for 41 antibiotics. Gram-negative rods relative amount among pathogens decreased substantially (84.7 per cent in 1986 against 61.6 per cent in 1999), particularly Enterobacteriaceae (74.7 per cent in 1986 against 41.4 per cent in 1999). Nonfermenting Gram-negative rods (NFGNR) relative amount increased (10.8 per cent against 19.2 per cent), along with Gram-positive cocci (19.8 per cent against 64.2 per cent), particularly coagulasenegative staphylococci (CNS) (10.8 per cent against 35.9 per cent) and enterococci (5 per cent against 16.5 per cent) and candida and fungi (0.5 per cent in 1986 against 15.9 per cent in 1999). At the period 1986-1999 the main pathogens in urology infection were E. coli, Enterobacter spp., NFGNR (including P. aeruginosa), Staphylococcus, CNS, Enterococcus spp. The problem pathogens for urological department were the following: E. coli, Klebsiella spp., Enterobacter spp., Proteus spp., NFGNR including P. aeruginosa, CNS, Enterococcus spp., candida and fungi. At the period 1991-1997 Gram-negative pathogens susceptibility to amikacin, ofloxacin, ciprofloxacin, imipenem, ceftazidime, cefotaxime was not changed in general, Gram-positive cocci (staphylococci and enterococci) retained the same susceptibility to vancomicin, cefamandol and amoxyclave. Staphylococci were also susceptible to amikacin, imipenem, rifampicin, oxacillin, ciprofloxacin, and ofloxacin. Production of beta-lactamase was registered for 38.7 per cent of CNS, 26.5 per cent of E. coli, 38.5 per cent of K. pneumoniae, 25 per cent of P. mirabilis and 55.6 per cent of P. aeruginosa strains.     

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.     

Proteomic analysis of different fractions in M. tuberculosis culture]

To provide a basis of molecular genetic analysis of M. tubereulosis, the proteomic profiling was prompted. M. tuberculosis H37RV was cultured in Sauton medium at 37 degrees C for 3 weeks, harvested and fractionated into three portions: suspension filtration proteins(A), cytosol proteins(B) and membrane proteins(C). These fractions were analyzed by pH3-10 IPG gradient and SDS-PAGE. The silver-stained technigue and gel images were used. Then the image was transfered into 2-DE gel analysis Software. A part of protein sports of expression level higher from the culture filtrate fraction were identified by peptide mass fingerprinting. A total of 907, 884 and 681 protein sports were observed for A. B. C fractions in M. tuberculosis H37RV, respectively. Distribution of proteins mass for 3 fractions were principally similar, About 70.5-74.4 per cent were distributed in the ranges of Mr 10-49 kD.pI of the proteins for A, B fractions were pricipally similar, About 80.9-83.5 per cent were distributed in the ranges of pH 3.0-6.4, But the number of protein sports for C fraction distributed in the ranges of pH 7.6-10.0 were more than A, B fractions. The number of protein sports of expression level higher for A, B and C fractions were 71(7.8%), 242(27.4%), 19 (2.8%), respectively. 90 pen cent from them, pH of the proteins were distributed in the ranges of pH 3.0-6.4. 73.1 per cent for proteins mass of C fraction were distributed in the ranges of 10 kD-49 kD, which were more than A, B fractions. Nine of the proteins identified ih this study appeared to be homology or putative fanction proteins, but another five proteins were unknown. The proteomic profiling of different fractions in M. tuberculosis obtained in here will be provide a basis for detailed analysis of biology functions of the proteins.     

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).     

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.     

Site of OH radical attack on dihydrouracil and some of its methyl derivatives

The site of attack of OH radicals on dihydrouracil and five of its methylated derivatives was determined by pulse radiolysis using N,N,N',N'-tetramethylphenylenediamine (TMPD) to detect oxidizing radicals and tetranitromethane (TNM) as well as K3Fe(CN)6 to detect reducing radicals. In the case of dihydrouracil OH radicals abstract preferentially an H atom at C(6) to give the 6-yl radical (greater than or equal to 90 per cent) which at pH approximately 6.5 reduces TNM and K3Fe(CN)6 at almost diffusion-controlled rates. Only a small fraction of OH radicals abstract the H atom at C(5) (less than or equal to 10 per cent). The resulting 5-yl radical oxidizes TMPD to TMPD+ at pH 7-8. With the methylated derivatives of dihydrouracil, OH radicals react less selectively, especially in the case of N(1)-methyl derivatives. This methyl group is activated to a similar degree as the methylene group at C(6). In 1-Medihydrouracil the yield of N(1)-CH2 radicals is about 29 per cent, which has been deduced from the yield of formaldehyde formed after oxidation of this radical by TNM at pH approximately 6.5 and the subsequent hydrolysis. Radicals at the other methyl substituents are generated to a lesser extent (less than or equal to 10 per cent) and are relatively unreactive towards oxidizing agents such as TNM and K3Fe(CN)6 as well as towards the reducing agent TMPD. Although methyl substitution opens new routes for OH attack the preferred site of H abstraction remains C(6) (greater than 60 per cent).     

Thioglycollate stimulus modifies lymphocyte metabolism and proliferation. A comparison with lymphocyte activation by walker 256 tumour implantation

Key enzyme activities of glycolysis, the pentose-phosphate pathway, the Krebs' cycle and glutaminolysis were measured in lymphocytes obtained from the control (CC), thioglycollate-injected (TG) and Walker 256 tumour-implanted (WT) groups, non-immune and immune inflammatory stimuli, respectively. The rates of incorporation of [2-¹⁴C]-thymidine and [5-³H]-uridine into cultured lymphocytes were also determined. The results indicated that the rates of both [2-¹⁴C]-thymidine and [5-³H]-uridine incorporation were enhanced in lymphocytes obtained from thioglycollate-injected (by an average of 80 per cent) and tumour-implanted animals (by 2·4-fold) as compared to control rats. Lymphocyte hexokinase activity diminished both in the TG (23 per cent) and WT (61 per cent) groups, whereas glucose 6-phosphate dehydrogenase activity was not altered due to the non-immune inflammatory stimulus, being reduced (23 per cent) in WT rats as compared to CC. The activity of lymphocyte citrate synthase was lowered by thioglycollate (39 per cent) and tumour-implantation (46 per cent). In contrast, glutaminase activity was augmented in lymphocytes from the TG (41 per cent) and was not modified in the WT groups. Taken as a whole, the presence of the Walker 256 tumour did not affect the capacity for glutamine utilization but depressed glucose metabolism in these cells. On the other hand, the non-immune inflammatory stimulus suppressed the activities of glycolysis and the Krebs' cycle and enhanced that of glutaminolysis in lymphocytes.     

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.     

Formation of broad-spectrum antibiotics by cultures of the genus Micromonospora]

Data on the study of antibiotic production by the representatives of Micromonospora and the use of ion exchange resins for intensification of screening antibiotic-producing organisms among Micromonospora are presented. It was found that out of 172 strains of Micromonospora tested 92 (53.5 per cent) cultures produced antibiotics, 18 of which were active against gramnegative bacteria. The use of carboxylic ion exchange resins at early microbiological stages of the screening provided an increase in the frequency of finding broad spectrum antibiotics from 10.4 to 19.7 per cent.     

R-plasmids of bacteria of the genus Pseudomonas isolated from industrial sewage

A total of 132 Pseudomonas strains isolated from untreated sewage of antibiotic plants were tested. A significant number of the strains were resistant to streptomycin (77 per cent), carbenicillin (75 per cent), kanamycin (37.5 per cent) and tetracycline (23 per cent). Eighteen conjugative and 3 nonconjugative resistance plasmids were detected in 19 strains. The genes determining the resistance to streptomycin, kanamycin and tetracycline were most frequent. The frequency of the plasmid transfer between the strains of Ps. aeruginosa (PAO) varied within 10(-3)--10(-7) per donor cell. Six plasmids belonged to group Inc P-1. Four plasmids belonged to group Inc P-2, 3 plasmids to groups Inc P-3 and Inc P-5 and 1 plasmid to group Inc P-7.     

A potentiometric method of quantitative analysis of rifampicin

A potentiometric procedure for assay of rifampicin was developed. The procedure implies titration of rifampicin as a monofunctional acid by sodium hydroxide solution (0.1 mol/l) in 75 per cent aqueous methanol. The constant ionic strength of the solution is provided by addition of KCl until its concentration is 0.1 mol/l, the titrant concentration being 10 times higher than the antibiotic concentration in the solution. This provides a precise determination of the concentration ionization constant of the antibiotic as a monofunctional acid (pKa 7.33 +/- 0.01) and an insignificant dilution of the antibiotic solution during the titration promoting precise and reproducible results. The procedure error is 0.20 per cent. The variation coefficient is 0.27 per cent.     

Derivatographic analysis of 6-beta-[(hexahydro-1H-azepin-1-yl) methylenamino]penicillanic acid]

Derivatographic analysis of 5 samples of 6-beta-(hexahydro-IH-azepin-I-yl)methylenamino penicillanic acid was performed. In addition to the antibiotic the samples had water and acetone in their composition. No effects associated with changes in the physical and chemical state of the substance were observed on the derivatogramme of the samples containing 0.2 and 0.8 per cent of water up 140 degrees C. With a further increase in the temperature an exothermic effect was observed with maximum at 152--153 degrees C connected with melting and chemical degradation of the substance. The derivatogrammes of the samples containing 89--96.4 per cent of the antibiotic were characterized by an endothermic effect with minimum at 65 degrees C caused by evaporation of acetone and partially water from them and by an exothermic effect with maximum at 120 degrees C practically not accompanied by any change in the weight resulting from chemical interaction of the antibiotic with water. The study showed sensitivity of 6-beta-(hexahydro-IH-azepin-I-yl)methylenaminopenicillanic acid to the presence of even insignificant amounts of water in it, maximum elimination of which from the antibiotic is an important factor of increasing its stability.     

Experimental characteristics of the antileishmaniasis action of amphotericin B]

The efficacy of amphotericin B powder of the Soviet production was studied as a therapeutic agent in experimental zoonotic leishmaniosis of the skin form of mice and hamsters. Amphotericin B was administered per os and its action was compared with that of monomycin injected subcutaneously (50 mg/kg). Amphotericin B in a dose of 150 mg/kg administered for 30 days protected 96+/-0.07 and 76.4+/-0.9 per cent of the mice and hamsters respectively from development of the leishmaniosis clinical signs, 68.8+/-0.04 per cent of the animals being cured (in the treatment experiments). The effect of the antibiotic was analogous to that of monomycin administered parenterally. The study of the kinetics of amphotericin B showed that the antibiotic was well absorbed from the digestive tract of the animals into the blood which provided the chemotherapeutic effect.     

The effect of benzylpenicillin on the activity of antioxidative enzymes in the erythrocytes and on methemoglobin formation in children

Activity of erythrocyte antioxidative enzymes and the content of methemoglobin were studied in 36 healthy children under preventive treatment with benzylpenicillin and in 65 healthy children of the control group. It was shown that there was relationship between the changes in the activity of superoxidodismutase and catalase and the antibiotic dose and duration of the use. After benzylpenicillin intramuscular administration for 3-4 days (the total dose of 80,000-3000000 units) the catalase activity decreased to 65.6 per cent while the activity of superoxidodismutase did not change. When the antibiotic was used for 1-2.5 weeks (the total dose of 3000000-6000,000 units) the activity of catalase and superoxidodismutase decreased to 53.6 and 82 per cent respectively. Beginning from the 3rd week of the antibiotic use the catalase activity increased to 71.6 per cent while the superoxidodismutase activity did not change and remained at the level of 84.9 per cent. The content of methemoglobin in the children treated with benzylpenicillin was about 3 times higher than that in the controls. The correlation between the activity of the antioxidative enzymes and the content of erythrocyte methemoglobin was inverse: the lower was the enzyme activity, the higher was the content of methemoglobin and vice versa. It was concluded that benzylpenicillin impaired definite balance between single electron reduction of oxygen and antioxidative protection resulting in the antibiotic adverse action i. e. increased methemoglobin formation. The effects of benzylpenicillin should be considered when it is used in combination with oxidants in treatment of children.     

Effect of dietary fat on lymphocyte proliferation and metabolism

The effect of diets enriched with fat containing different fatty acids on glucose and glutamine metabolism of mesenteric lymph nodes lymphocytes, spleen, and thymus and lymphocyte proliferation was examined. The following fat-rich diets were tested: (1) standard chow (CC); (2) medium chain saturated fatty acids (MS)—coconut fat oil; (3) long chain saturated fatty acids (LS)—cocoa butter; (4) monounsaturated fatty acids (MU)—canola oil (n-9); (5) polyunsaturated fatty acids (PU)—soybean oil (n-6). Of the fat-rich diets tested, MS was the one to present the least pronounced effect. Lymphocyte proliferation was reduced by LS (64 per cent), MU (55 per cent), and PU (60 per cent). Hexokinase activity was enhanced in lymph node lymphocytes by PU (67 per cent), in the spleen by MS (42 per cent), and in the thymus by PU (30 per cent). This enzyme activity was reduced in the spleen (33 per cent) by LS and MU (35 per cent). In the thymus, this enzyme activity was reduced by LS (26 per cent) and MU (13 per cent). Maximal phosphate-dependent glutaminase activity was raised in lymphocytes by MS (70 per cent) and MU (20 per cent). This enzyme activity, however, was decreased in lymphocytes by PU (26 per cent), in the spleen by LS (15 per cent), and in the thymus by MU (44 per cent). Citrate synthase activity was increased in lymphocytes by MU (35 per cent), in the spleen by LS (56 per cent) and MU (68 per cent), and in the thymus by LS (42 per cent). This enzyme activity was decreased in lymphocytes by PU (24 per cent) only. [U-¹⁴C]-Glucose decarboxylation was raised by all fat-rich diets; MS (88 per cent), LS (39 per cent), MU (33 per cent), and PU (50 per cent), whereas [U-¹⁴C]-glutamine decarboxylation was increased by LS (53 per cent) and MU (55 per cent) and decreased by MS (17 per cent). The results presented indicate that the reduction in lymphocyte proliferation due to LS, LU and PU could well be a consequence of changes in glucose and glutamine metabolism. Copyright © 1998 John Wiley & Sons, Ltd.     

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).