Pseudomonas aeruginosa vaccine on the basis of antigens isolated from the supernatant of culture media K-4

The possibility of using experimental culture medium K-4 prepared on the basis of casein hydrolysate peptides with the isoelectric point 4.1 for obtaining antigens from P. aeruginosa strains was evaluated. Two antigenic fractions were isolated from the culture fluid containing extracellular slime. The study of the toxicity of the antigenic preparations revealed that one of these fractions had low toxicity for mice (the second antigenic fraction was highly toxic). The former P. aeruginosa antigenic fraction was used for obtaining pyocyanic vaccine. One vaccination dose of this vaccine contained 0.2 mg of the antigen adsorbed on aluminum hydroxide. Pyocyanic vaccine ensured the active protection of mice challenged with P. aeruginosa homologous and heterologous strains.     

Protective properties of anatoxin obtained from a homogeneous preparation of Pseudomonas aeruginosa exotoxin A

The protective properties of formulated toxoid obtained from the highly purified preparation of P. aeruginosa exotoxin A have been studied in the test of the active immunization of mice. The study has revealed that the preparation when introduced in 1 or 2 injections in a dose of 15 micrograms, shows faint protective potency with respect to P. aeruginosa strains differing in virulence. Immunization with this toxoid in 3 and 4 injections has been found to ensure 60-100% and 50-60% protection of mice infected with P. aeruginosa toxigenic and proteolytic strains respectively. Immunization with toxoid has been found to induce the appearance of short-term antibacterial immunity which loses its capacity to protect the immunized animals, challenged with both toxigenic and proteolytic P. aeruginosa strains, as early as on day 28. The immunization of mice with toxoid in 4 injections has been shown to induce the development of antitoxic immunity capable of neutralizing up to 150 LD50 of purified exotoxin A.     

C-390 as sole selective agent for isolation of Pseudomonas aeruginosa from hospital waste water

Pseudomonas aeruginosa was recovered (in numbers ranging from 10(2) to 10(5) colony-forming units per millilitre) from heavily contaminated hospital waste water when grown at 41.5 degrees C on a differential medium agar containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan (C-390) at a final concentration of 30 micrograms/mL. The medium appeared to be highly selective for P. aeruginosa with 95-100% of all colonies isolated from four different hospital waste waters being identified as P. aeruginosa. Many strains of P. aeruginosa isolated from hospital waste waters failed to hydrolyse casein when grown on skim milk agar and this medium appeared to restrict pigment production to only pyoverdin (detectable only under ultraviolet light). However, most strains were capable of casein hydrolysis when grown on a modified skim milk medium.     

Production of a hyperimmune antitoxic donor plasma against Pseudomonas aeruginosa

Research work has been carried out with the aim of obtaining hyperimmune antitoxic plasma against Pseudomonas aeruginosa. Hyperimmune plasma active against P. aeruginosa toxin has been obtained from donors immunized with P. aeruginosa toxoid. The preparation is highly specific and active, which is revealed by in vivo and in vitro tests. The clinical study of the preparation indicates its high efficacy in the treatment of diseases caused by different P. aeruginosa serotypes.     

Pseudomonas aeruginosa toxoid

P. aeruginosa adsorbed toxoid has been obtained. The stabilization of exotoxins and the content of proteases, hemolysin, lecithinase in their structure have been found to enhance the immunogenic potency of preparations which protect test animals from death caused by the experimental injections of toxins, homologous and heterologous to bacterial strains of different O-serogroups, into these animals. Antibodies neutralizing the lethal action of P. aeruginosa exotoxin have been detected in the blood sera of immunized animals.     

Factors influencing the adhesive properties of Pseudomonas aeruginosa

The aim of this study was to evaluate different factors which may influence surface and adhesive properties of Pseudomonas aeruginosa strains isolated from patients with urinary tract infections. P. aeruginosa strains exhibited moderate surface hydrophobicity as shown by "salting out" with ammonium sulfate and hydrophobic interaction chromatography. The ability to haemagglutinate red blood cells by P. aeruginosa strains was increased when the cells were treated with papain and neuraminidase. The ability of all tested strains to attach to plastic and glass surfaces was independent on incubation temperature. There was no significant difference in the ability of any particular P. aeruginosa strains to adhere to Vero cells in culture. In this study no correlation between hydrophobic properties, intensity of haemagglutination, and ability to attach to Vero cells in culture was observed.     

Isolation of different variants of Pseudomonas aeruginosa anatoxin and their characteristics

The conditions for the detoxification of the crude preparations of P. aeruginosa exotoxin A, obtained by the cultivation of strain PA-7 in Martin's broth, have been studied, and the schemes for obtaining nontoxic, stable, specifically antigenic preparations of toxoid from exotoxins A with different degrees of purification have been developed. Toxoid obtained by formalin treatment on the level of a crude preparation with its subsequent purification and additional detoxification with formalin in the presence of lysin has been shown to possess high immunogenic potency. The preparation has been found to induce immune response and to ensure the protection of experimental animals challenged not only with the lethal dose of exotoxin A, but also with P. aeruginosa toxigenic and protease-producing strains.     

Experimentally determined safety and immunological activity of vaccine based on antigens isolated from Pseudomonas aeruginosa in medium K-4

The safety and immunological activity of P. aeruginosa vaccine were experimentally evaluated. The vaccine was prepared on the basis of the antigens of P. aeruginosa extracellular slime which was accumulated in medium K-4, obtained with the use of original technology. The immunization of animals with P. aeruginosa vaccine induced the synthesis of antibodies. The introduction of the vaccine in 2 or 3 injections resulted in a high level of antibody formation, differing with the use of various strains. Hyperimmune sera, obtained by the multiple immunization of rabbits with P. aeruginosa vaccine, ensured high protection of mice from P. aeruginosa infection. The vaccine proved to be safe when evaluated in experiments of acute and chronic toxicity, made on laboratory animals.     

A protease with staphylolytic activity from Pseudomonas aeruginosa PAKS I

The supernatant from broth cultures of Pseudomonas aeruginosa PAKS I contains two different enzymes with staphylolytic activity. One of them, namely staphylolytic enzyme, seems to be specific for glycine-rich cross-links present in the cell wall of different Gram-positive bacteria and has been previously characterized. In addition to the staphylolytic activity, the second protein which we propose to be a staphylolytic protease, has proteolytic activity against casein. This enzyme is approximately 33 kDa, has an isoelectric point ranging from 7.3 to 8.1 and an optimum pH value of 8.0 for casein hydrolysis. Staphylolytic protease was detected in the extracellular medium after 12 h of cell growth. Immunocytochemical studies suggest that the protease is located within the periplasmic space of P. aeruginosa.     

Simultaneous cultivation of Spirulina platensis and the toxigenic cyanobacteria Microcystis aeruginosa

Mangueira Lagoon, located in the extreme south of Brazil, has water with physicochemical characteristics such as alkaline pH and carbonate levels propitious for the growth of the cyanobacterium Spirulina platensis. Previously published studies have shown that Mangueira Lagoon water supplemented with small quantities of carbon and nitrogen is suitable for S. platensis cultivation and can significantly reduce production costs. We studied mixed cultures of Spirulina platensis and the toxic cyanobacterium Microcystis aeruginosa using a 2(3) factorial design in which the three factors were the initial biomass concentration of S. platensis and M. aeruginosa and the type of culture medium (100% Zarrouk's medium or 80% Mangueira Lagoon water plus 20% Zarrouk's medium). The highest S. platensis maximum specific growth rate (mu(max)) occurred in the culture with the highest M. aeruginosa biomass concentration and when undiluted culture medium was used (micro(max) = 0.283 d(-1)). The highest M. aeruginosa specific death rate (k) was obtained in the presence of S. platensis (k = 0.555 d(-1)) and was independent of the initial M. aeruginosa biomass concentration and culture medium, demonstrating that S. platensis cultures are not susceptible to contamination by M. aeruginosa. The culture medium had no significant influence (p > 0.05) on S. platensis micro(max) values, indicating that production costs could be reduced by using a medium consisting of 80% Mangueira Lagoon water plus 20% Zarrouk's medium.     

Human monoclonal antibodies to Pseudomonas aeruginosa produced by EBV-transformed cells

Numerous lymphoblastoid cell lines (LCLs) which secreted antibodies against Pseudomonas aeruginosa (all Fisher's immunotypes and Homma's immunotype 1) were established by Epstein-Barr virus (EBV)-transformation of lymphocytes. Five LCLs were established as long-term culture lines and their properties were determined. These LCLs produced monoclonal antibodies to Fisher's immunotype 1 and 4 and Homma's immunotype 1, and their immunoglobulin classes were IgM, IgG, and IgA. We found that three monoclonal antibodies (G3-1, H7-2, and E10-1) among them successfully protected mice from the corresponding immunotype of P. aeruginosa infection. Their protective dose (PD50) values were 0.5, 2.6, and 3.1 micrograms immunoglobulin/mouse. These human monoclonal antibodies against P. aeruginosa prepared by EBV-transformation method will be a valuable aid for the treatment for severe P. aeruginosa infections.     

Effect of Pseudomonas aeruginosa melanin on antibiotic activity]

The properties of microbial melanines are very diverse. Melanine of P. aeruginosa is little studied. The pigment was isolated from a strain of P. aeruginosa possessing all characteristic properties of the species. Interaction of P. aeruginosa melanine with various antibiotics was determined by the method of serial dilutions in beaf-peptone broth, using Staph. aureus 209 as a test-microbe, which was added to the medium in an amount of 10(6) cells to each tube. It was found that P. aeruginosa melanine differed from DOPA-melanine in a concentration of 1 mg/ml and did not change the activity of penicillin, tetracycline, oleandomycin, kanamycin and gentamicin with respect to Staph. aureus.     

Pyocyanine production by Pseudomonas aeruginosa.

Dextrose enhanced the growth of P. aeruginosa but suppressed the biosynthesis of pyocyanine. The preformed pigment could be released from dead cells. Pigmentation was not correlated directly with number of viable organisms in the culture. High concentration of maltose likewise inhibited pyocyanine production. Maltose contained in medium used for pyocyanine production by P. aeruginosa should be kept in low concentration or omitted.     

Arginine medium for the isolation and primary identification of Pseudomonas aeruginosa in environmental objects

A culture medium for the isolation and primary identification of P. aeruginosa has been developed. The medium contains L-arginine and ions of K, Na, Mg, C and P; it has also an overlay of plain agar with 0.6% of 2,3,5-triphenyltetrazolium chloride added. The comparison of arginine medium with other media proposed for the isolation of P. aeruginosa from various objects in the environment has demonstrated the advantage of this highly selective medium permitting the primary identification of up to 95% of characteristic colonies.     

Comparison of some adhesive properties of Pseudomonas aeruginosa strains isolated from respiratory and urinary tract infections

The aim of the paper was the comparison of adhesive properties concerning pathogenic potential of P. aeruginosa strains isolated from the patients with respiratory tract infections and from the patients with urinary tract infections. It was stated that P. aeruginosa strains had no haemagglutinating properties when cultured on a solid medium. Bacteria cultured in a liquid medium showed an increase of these properties in 48 h cultures as compared with 24 h cultures. They were not sensitive to heating. The haemagglutinating properties of the most strains were inhibited by D-mannose. These results seem to suggest that in P. aeruginosa strains fimbriae play an important role in adhesion. On the other hand, the mechanism of adhesion is not uniform as shows mannose-sensitivity of some strains and its lack in the other haemagglutinating strains. The most effective agglutination of human erythrocytes seems to be caused by the species specificity of the individual strains isolated from humans. The higher attachment of P. aeruginosa strains isolated from the urinary tract infections than those from respiratory tract infections to "Vero" cells suggests that these two strains populations may differ in their pathogenic potential to various tissues.     

Variation of microcystin content of microcystis aeruginosa relative to medium N:P ratio and growth stage

Changes in the microcystin content of Microcystis aeruginosa UTEX 2388 were investigated at several N:P ratios of the medium and various growth stages. Under the P-fixed condition, the microcystin content of the cells changed with different medium N:P ratios, with the highest at 2748 microg g-1 at a N:P ratio of 16 after incubation for 7 d. The microcystin content of M. aeruginosa exhibited a high correlation with the total N content regardless of an N-fixed or P-fixed culture. When the N:P ratio of the medium was fixed to 16 : 1, the microcystin content of M. aeruginosa at various growth stages was highest at 2191 microg g-1 after an incubation of 4 d and the chlorophyll-a content showed a similar tendency. There was a highly significant relationship between the microcystin content of M. aeruginosa and the chlorophyll-a concentration in the culture during the incubation. Accordingly, the microcystin content of M. aeruginosa during incubation can be easily estimated and monitored by measuring the in vivo fluorescence changes in the culture.     

New selective agent for isolation of Pseudomonas aeruginosa.

Results of minimal inhibitory concentration tests with a diversity of bacterial strains showed that 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan (C-390) inhibited the growth of all microorganisms tested (other than Pseudomonas aeruginosa) at 25 microgram/ml or less, whereas MICs obtained for P. aeruginosa ranged from to to greater than 100 microgram/ml. Therefore, C-390 was evaluated as a potential selective agent for P. aeruginosa in pseudomonas agar F. Recovery tests were conducted on this medium with 53 strains o P. aeruginosa, and the results were compared to those obtained in similar tests on commercially available selective media, i.e., pseudomonas isolation agar and Pseudosel agar. The results of these comparisons indicated that pseudomonas agar F with C-390 was significantly less inhibitory than Pseudosel agar and pseudomonas isolation agar and more selective than pseudomonas isolation agar. The incorporation of C-390 in pseudomonas agar F also provided a medium that was both selective and differential. Preliminary evidence also suggested that C-390 may be added to other basal media with comparable results.     

Pseudomonas aeruginosa Inhibits the Growth of Cryptococcus Species

Pseudomonas aeruginosa is a ubiquitous and opportunistic bacterium that inhibits the growth of different microorganisms, including Gram-positive bacteria and fungi such as Candida spp. and Aspergillus fumigatus. In this study, we investigated the interaction between P. aeruginosa and Cryptococcus spp. We found that P. aeruginosa PA14 and, to a lesser extent, PAO1 significantly inhibited the growth of Cryptococcus spp. The inhibition of growth was observed on solid medium by the visualization of a zone of inhibition of yeast growth and in liquid culture by viable cell counting. Interestingly, such inhibition was only observed when P. aeruginosa and Cryptococcus were co-cultured. Minimal inhibition was observed when cell-cell contact was prevented using a separation membrane, suggesting that cell contact is required for inhibition. Using mutant strains of Pseudomonas quinoline signaling, we showed that P. aeruginosa inhibited the growth of Cryptococcus spp. by producing antifungal molecules pyocyanin, a redox-active phenazine, and 2-heptyl-3,4-dihydroxyquinoline (PQS), an extracellular quorum-sensing signal. Because both P. aeruginosa and Cryptococcus neoformans are commonly found in lung infections of immunocompromised patients, this study may have important implication for the interaction of these microbes in both an ecological and a clinical point of view.     

影响多粘菌素B对绿脓杆菌杀菌效力的主要环境因素的研究

本文通过改变温度,水活度,气体条件和营养含量等影响绿脓杆菌生长的主要环境因素,测定多粘菌素B对绿脓杆菌的最小杀菌浓度(MBC)。结果表明环境因素导致或显著影响绿脓杆菌对抗生素的生态耐受性。实验表明多粘菌素B对绿脓杆菌的杀菌效力,除药物对细菌特有的药理学作用外,还取决于细菌的生长环境。结合冷休克率试验表明,环境影响细菌群体处于分裂状态的菌数。若分裂状态菌数下降表明生长速度减慢。提示了多粘菌素B对绿脓杆菌的效力指数,定量分析可以作为其综合效力作用的表现。以同步培养法确定在单个细胞周期中的抗生素敏感阶段。同时以冷休克率试验资料证明细菌处于分裂状态和幼龄期是其敏感阶段。初步阐述了生长速度缓慢与药物的生态耐受性密切相关。     

精制破伤风类毒素产毒及精制工艺的改进

用超滤、硫酸铵二段盐析法取代等电点沉淀法后,精制破伤风类毒素（精破类）的纯度由８０７Ｌｆ／ｍｇＰＮ提高到１８８３Ｌｆ／ｍｇＰＮ,纯度提高一倍以上。使用双胨培养基取代酪素培养基后,产毒水平由４７Ｌｆ／ｍｌ提高到８８Ｌｆ／ｍｌ（ｔ＝６．４６,ｐ＜０．００１）;用新法精制后,精破类纯度分别为１９４９Ｌｆ／ｍｇＰＮ及１７８５Ｌｆ／ｍｇＰＮ（ｔ＝０．３３４,ｐ＞０．０５）,引用双胨培养基后可提高产毒水平,但不影响精破类的纯度。