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[A unique marker of Pseudomonas from the first group of rRNA homology--selective sensitivity to the bacteriostatic action of barium ions].

On the basis of the study of the bacteriostatic action of chlorides and nitrates of barium and 24 other metals on 18 Pseudomonas species of all groups of rRNA homology and on 49 bacterial species belonging to 25 other genera, unique selective sensitivity to the bacteriostatic action of Ba2+ ions has been established in Pseudomonas of the first group of rRNA homology. The marker of barium sensitivity is in line with changes in the classification of Pseudomonas and is of interest for their further more precise systematization. The test for barium sensitivity of bacteria helps simplify the identification of Pseudomonas of the first group of rRNA homology and makes the identification more accurate.

Barium↗

Behavior in agricultural soils of a recombinant Pseudomonas bacterium that simultaneously degrades alkyl- and haloaromatics.

Pseudomonas sp. FR1 (pFRC20P) is a recombinant bacterium able simultaneously to degrade alkyl- and haloaromatics due to the xylXYZL and xylS genes from the TOL plasmid borne on the bacterial chromosome, and to the gene encoding for a gamma-lactone isomerase from Alcaligenes eutrophus on pFRC20P. The survival of this strain in sterile soils was shown to depend on the physicochemical properties of the soil. The recombinant information was stable in bacteria introduced in soils and conferred selective advantage to the host bacterium when the soils were amended with low amounts of p-methylbenzoate. However, relatively high amounts of this chemical significantly reduced survival of the bacterium. Survival was more seriously affected by chlorobenzoates than by methylbenzoates. Evolution of 14CO2 from p-methyl-14C-benzoate in soils confirmed that Pseudomonas sp. FR1 (pFRC20P) functions in a complex system in accordance with its design. Survival of Pseudomonas sp. FR1 (pFRC20P) was better at 4 degrees C and 25 degrees C than at 37 degrees C. On plates, the pFRC20P plasmid was mobilized by helper plasmids to P. putida at a frequency of about 10(-6) transconjugants per recipient. However, no transfer of recombinant DNA integrated on the chromosome was found, nor was lateral transfer of the recombinant DNA borne by Pseudomonas sp. FR1 (pFRC20P) detected in soils.

Benzoates↗

[Nosocomial respiratory infection caused by Pseudomonas cepacia in immunocompromised hosts].

Pseudomonas cepacia is a gram negative rod, having no fermentative activity on glucose. This organism was detected in the sputum, throat swab, or throat washing of 22 inpatients treated between January, 1990, and December, 1990, at the First Department of Internal Medicine, Kagawa Medical School. The primary diseases for which these 22 patients were hospitalized were leukemia in 12, malignant lymphoma in 5, lung cancer in 2, myelodysplastic syndrome in 1, and embryonal cell carcinoma in 1. Twelve of the 22 patients had episodes of pneumonia which complied clinically with the diagnostic criteria provided to facilitate the National Nosocomial Infection Study. The complication of pneumonia occurred in 7 patients with leukemia, 2 with malignant lymphoma, 2 with lung cancer, and 1 with myelodysplastic syndrome. In 10 of these 12 patients, the organism was detected before the onset of pneumonia. All 22 patients in whom the organism was demonstrated had received antibiotics. The antibiotics which was most frequently used to treat these patients 1 month before detection of Pseudomonas cepacia were amikacin and ceftizoxime, which were used in 13 patients. Of the antibiotics in which the susceptibility to Pseudomonas cepacia was, evaluated, minocycline was effective in 100% (21/21), ceftazidime in 50% (11/22), and ofloxacin in 27.3% (6/22). Physicians should be especially aware of the possibility of colonization and nosocomial respiratory infection by Pseudomonas cepacia in patients with severe underlying diseases.

Adolescent↗

[Identification of the Pseudomonas genus bacteria by computer analysis].

A computer program for the simplified phenotypic identification of Pseudomonas has been developed. The information concerning 66 species included in up-to-date Pseudomonas genus characterized by 113 tests was accumulated in a database. The identification key is represented in interactive mode on a website http://www.imv.kiev.ua/PsmIK/default.htm. The program was used for the identification of 46 Pseudomonas strains isolated from rhizosphere. For 23 more strains unidentified by conventional technique, the level of similarity was 67-74%. This fact allows suggesting that they might be representatives of new Pseudomonas species.

Databases, Factual↗

[Influence of salinity and temperature on fatty acid composition of Pseudomonas fluorescens GNP-OHP-3 membrane].

The bacteria respond to environmental changes modifying their composition. One of the most important modifications is the variation on fatty acid composition of cellular membranes to maintain the homeoviscosity. The action of temperature, hydrostatic pressure and solvents on Pseudomonas putida has been thoroughly studied. In this paper, the combined action of the temperature and salinity on fatty acid composition of cellular membranes of Pseudomonas fluorescens GNP-OHP-3, a bacterial strain isolated from a petroleum contaminated habitat, was studied. The modifications in the fatty acid composition of Pseudomonas fluorescens GNP-OHP-3 membrane were similar to those described for other members of Pseudomonas: an increase in saturated fatty acids and a decrease in unsaturated fatty acids were observed with the increase of the temperature. Variations of main fatty acids were in general erratic in the range of assayed saline concentrations. The variation of cyclopropane fatty acids could be expressed with mathematic equations that allowed to predict their percentage in relation to sodium chloride concentration.

Adaptation, Physiological↗

Keratotomy model of pseudomonas keratitis: gentamicin chemotherapy.

BACKGROUND: Chemotherapy of bacterial keratitis requires frequent application of antibiotic drops. Collagen shields containing antibiotics could reduce the need for frequent antibiotic application. To determine the effect of gentamicin-containing collagen shields and gentamicin drops on Pseudomonas keratitis, a new keratotomy model of infection was employed. METHODS: Model--contact lenses (58% water content) presoaked in 1% bovine serum albumin and exposed to 10(8) colony forming units per mL of Pseudomonas aeruginosa strain 27853, were found to reproducibly retain 5.9 (log base 10) colony-forming units. Rabbit corneas were scarified centrally with two perpendicular intersecting diamond knife cuts (5 mm x 5 mm x 0.2 mm), and bacteria-impregnated contact lenses were positioned and held in place for 24 hours with partial tarsorrhaphies. Treatment--Fourteen hours after lens removal (38 hours after infection), corneas were treated for 8 hours with collagen shields hydrated in saline (control), or shields impregnated with 800 micrograms gentamicin during manufacture, or one drop every 30 minutes of fortified gentamicin drops (14 mg/mL). The rabbits were killed and corneas collected for bacterial enumeration after 8 hours of treatment (46 hours after infection). RESULTS: Model--Slit-lamp examination and microbiologic confirmation showed uniformity of keratitis in all eyes. Treatment--Corneas treated with saline (controls) contained 6.4 (log base 10) Pseudomonas. Corneas treated with gentamicin-impregnated collagen shields (total drug = 800 micrograms) and fortified gentamicin drops (total drug = 21 mg) showed a reduction in viable bacteria of 2 logs and 6 logs, respectively, relative to the control. CONCLUSIONS: In this new model of Pseudomonas keratitis, the amount of gentamicin introduced into collagen shields during manufacture effectively reduced bacterial growth in infected rabbit corneas. However, larger amounts of drug applied as fortified drops on a frequent dosing schedule were more effective by a factor of three. Treatment of keratitis with antibiotic-impregnated collagen shields may reduce the need for very frequent application of topical drops, but may be more effective with topical drop supplementation to increase the amount of drug available over the course of therapy.

Administration, Topical↗

Specific identification of (R)-3-hydroxyacyl-ACP: CoA transacylase gene from Pseudomonas and Burkholderia strains by polymerase chain reaction.

Polyhydroxyalkanoates (PHA) were biodegradable thermoplastics. Due to their broad applications, direct biosynthesis of PHA from inexpensive substrates, such as carbohydrates, is actively pursued. It has been recently revealed that (R)-3-hydroxyacyl-ACP: CoA transacylase (PhaG) played an important role in this pathway. In this study, a polymerase chain reaction (PCR) protocol was developed for the rapid and specific identification of phaG gene from various bacteria. Using the PCR strategy, the complete open reading frames of two phaG genes from Pseudomonas stutzeri 1317 and Pseudomonas nitroreducens 0802 were cloned from the genomic DNA and functionally expressed in Pseudomonas putida PHAGN-21. Furthermore, this strategy was successful applied in non-Pseudomonas strains, such as Burkholderia. These results suggest that PhaG-mediated pathway of medium-chain-length polyhydroxyalkanoates was widespread among bacteria.

Acyltransferases↗

[Drug susceptibility of Pseudomonas aeruginosa strains isolated from patients of a hospital and specialistic outpatients clinics of the SP ZOZ in Nidzica].

The aim of this study was to evaluate a frequency of isolation and antimicrobial susceptibility testing (AST) of Pseudomonas aeruginosa strains cultured from clinical specimens collected from patients hospitalized in wards and specialistic outpatients clinics of a hospital in Nidzica (01. 09. 2000 -31. 12. 2003). During over three years 392 Pseudomonas aeruginosa strains were cultured from 16346 clinical samples provided to bacteriological laboratory. P. aeruginosa strains were isolated from 2.5% of examined specimens. Susceptibility of Pseudomonas aeruginosa strains to antimicrobial agents was tested. The highest in vitro activity against clinical P. aeruginosa strains demonstrated imipenem. One strain was resistant to imipenem. This strain was isolated from a patient of a surgical department. Metalo-beta-lactamase was not detected (MBL-negative strain). Twenty nine strains were ESBL producer (7.4% of all strains). The contribution of Pseudomonas aeruginosa strains to the etiology of nosoconial and ambulatory infections increases. In vitro activity of antibacterial agents against P. aeruginosa strains should be monitored during therapy of infections. Resistance to antibiotics/chemothe-rapeutics may be acquired during treatment with antibacterial agent to which P. aeruginosa strain was susceptible according to the antibiogram.

Adult↗

Effects of recombinant human granulocyte colony-stimulating factor on the mice receiving bone marrow transplantation following lethal irradiation: acceleration of recovery of the peripheral blood neutrophils and potentiation of anti-Pseudomonas resistance.

The effects of recombinant human granulocyte colony-stimulating factor (rG-CSF) on the recovery of peripheral blood neutrophil counts and resistance to i.p. infection by Pseudomonas aeruginosa were studied using a mouse bone marrow transplantation (BMT) model. A severe neutropenic period continued in the BMT mice for greater than 9 days following BMT. In contrast, the number of peripheral blood neutrophils in the BMT mice that received a daily administration of 2.5 micrograms of rG-CSF following BMT returned to normal by day 9. Thus, rG-CSF accelerated the recovery of the peripheral blood neutrophil counts in BMT mice. Anti-Pseudomonas resistance of the control BMT mice examined on days 7, 9, and 11 following BMT was one fifteenth to one fiftieth of normal mice, as indicated by the LD50 value. The anti-Pseudomonas resistance was elevated six- to sevenfold by the rG-CSF treatment. A marked increase in the neutrophils exudating into the peritoneal cavity in response to casein injection was observed in the rG-CSF-treated BMT mice. In addition, the reduced superoxide generative and phagocytic activity of the peritoneal neutrophils of the BMT mice were restored to normal by the rG-CSF treatment. It is suggested that rG-CSF potentiated anti-Pseudomonas resistance of the BMT mice by increasing neutrophils migrating to the infection site and restoring their functions; this may result from a prompt recovery of the peripheral blood neutrophil level together with the effect on neutrophil functions. These results indicate the clinical usefulness of rG-CSF in applications for BMT.

Animals↗

[Lysine decarboxylase in Pseudomonas aeruginosa].

The research of lysine, ornithine and arginine decarboxylases has been made for 50 strains of fluorescent Pseudomonas (P. aeruginosa, P. fluorescens, P. putida). By thin layer chromatography, all the strains of Pseudomonas aeruginosa and the fifth of the strains of P. putida had lysine decarboxylase activity at alcaline pH (optimal pH 8) ; Pseudomonas fluorescens did not produce this decarboxylase. Arginine and ornithine decarboxylase are absent for all the strains of fluorescent Pseudomonas.

Arginine↗

Purification, characterization, and molecular cloning of lactonizing lipase from Pseudomonas species.

An extracellular lipase catalyzing the synthesis of macrocyclic lactones in anhydrous organic solvents was purified to homogeneity from Pseudomonas nov. sp. 109, and characterized. The lipase showed a pI of 5.3 on isoelectric focusing and a Mr of 29,000 +/- 1,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. With respect to substrate specificity, optimum chain length for acyl moiety varied depending on the type of reaction catalyzed: C18 in monomer lactone formation, C11 or shorter in dimer lactone formation, and C8 in ester hydrolysis. The amino-terminal 19 amino acid residues of the purified lipase were determined as Ser-Thr-Tyr-Thr-Gln-Thr-Lys-Tyr-Pro-Ile-Val-Leu-Ala-His-Gly-Met-Leu-Gly- Phe, and the gene encoding the lipase was identified by hybridization to a synthetic 20-nucleotide probe, cloned, and sequenced. Nucleotide sequence analysis predicted a 311-amino acid open reading frame, a putative ribosome-binding site, and a 26-amino acid sequence at the amino terminus of the sequence that is not found in the mature protein. This 26-amino acid sequence has many of the characteristics common to known signal peptides. The lipase gene encoded a sequence of Val-Asn-Leu-Ile-Gly-His-Ser-His-Gly-Gly which is very well conserved among lipases, and showed 38-40% overall homology to the amino acid sequences of lipases from Pseudomonas fragie and Pseudomonas cepacia, but showed little homology to those of other lipases, suggesting that some structural features are required for catalyzing macrocyclic lactone synthesis in organic solvents and are restricted to lipases of the Pseudomonas origin.

Amino Acid Sequence↗

[Ciprofloxacin: an alternative oral treatment in respiratory Pseudomonas infection in cystic fibrosis].

20 CF patients, aged from 16.5 to 31.7 years, with chronic pulmonary infection due to Pseudomonas, were included in an open trial to study the efficacy of ciprofloxacin on respiratory exacerbation. Ciprofloxacin was given orally at the dose of 1500 mg/die for ten days. 16 patients concluded the entire treatment with clear clinical improvement, based on a score including 11 parameters. There has also been a significant improvement in the pulmonary function tests, and a tendency of Rx score to decrease. 4 patients interrupted the treatment on the fifth day because of clinical inefficacy. There was no increase of Pseudomonas resistance to ciprofloxacin at the end of the treatment; 30 days after no strain of pseudomonas was found resistant. We observed side-effects in 5 patients, but in no case it was necessary to discontinue the treatment. Ciprofloxacin may be considered as a good alternative to the more established antibiotic strategy in the treatment of Pseudomonas lung exacerbations in CF.

Administration, Oral↗

[Adherence of Pseudomonas aeruginosa to the rabbit corneal epithelium].

Adherence of bacteria to the corneal epithelium is the first step in the pathogenesis of corneal infection. Keratitis caused by Pseudomonas aeruginosa usually occurs among the contact lens wearers. Adherence of Pseudomonas aeruginosa to rabbit corneal epithelium, damaged by one week of hard contact lens wear, was examined histologically. The cornea was excised for scanning electron microscopy at 5, 15, 30 and 60 minutes after inoculation of Pseudomonas aeruginosa (0.2 ml, 10(8)CFU/ml). Pseudomonas aeruginosa did not adhere to the intact corneal epithelium, but traumatized cornea provided a site for adherence. In rabbits in which the eyelid was opened by lid retractors, large numbers of organisms were observed adhering to the injured cornea mediated by ocular surface mucin. Thirty minutes after inoculation, the adherent bacteria began to penetrate the epithelial cells and surface mucin by the formation of pockets surrounding the organism.

Animals↗

A partial-thickness epithelial defect increases the adherence of Pseudomonas aeruginosa to the cornea.

Some patients with infectious keratitis have no clinically demonstrable corneal abrasion predisposing them to infection. Subtle, undetectable corneal injuries may facilitate bacterial adherence to the cornea, eventually leading to keratitis. To study this concept, we have developed a rabbit model in which a partial-thickness corneal epithelial defect was induced by filter paper impression on the cornea that removed one to two layers of corneal epithelium. Following this injury, the corneas were incubated with Pseudomonas aeruginosa, washed, and the number of bacteria adhering to the injured corneas as well as to control corneas was quantitated. Corneas treated with filter paper, either ex vivo or in vivo, allowed 20 times more bacteria to adhere than did the untreated control corneas (P less than 0.01). This superficial epithelial defect increased Pseudomonas adherence to the cornea for up to 72 hr after injury. When corneal injury was extended to the stroma, the adherence of Pseudomonas was further augmented as compared to adherence to the superficially injured cornea. Thus, we conclude that a clinically subtle, partial-thickness corneal epithelial injury can markedly facilitate the adherence of Pseudomonas aeruginosa, which may be an important predisposing factor for infectious keratitis.

Animals↗

Immunization against experimental Pseudomonas aeruginosa and Serratia marcescens keratitis. Vaccination with lipopolysaccharide endotoxins and proteases.

Rabbits vaccinated with lipopolysaccharide endotoxins or with purified protease preparations from Pseudomonas aeruginosa and Serratia marcescens before corneal challenge with the viable bacteria exhibited significantly less corneal damage than rabbits not vaccinated with the bacterial products. However, the rabbits vaccinated with the lipopolysaccharide endotoxin preparations were significantly better protected than rabbits vaccinated with the bacterial proteases. Rabbits vaccinated with antisera raised against the proteases showed significantly less corneal damage than rabbits vaccinated with normal rabbit serum, and the passive protection was not significantly different than that elicited by active immunization against the bacterial proteases. The ability of the antiserum raised against the pseudomonas elastolytic protease to passively protect against severe corneal damage produced by experimentally induced pseudomonas keratitis was confirmed in mice. These findings support the idea that the bacterial endotoxins and proteases are virulence factors during the development of pseudomonas and serratia keratitis.

Animals↗

Ibuprofen and methylprednisolone in a pig Pseudomonas ARDS model.

The effects of ibuprofen (I) and methylprednisolone (M) were studied in the Pseudomonas porcine model of adult respiratory distress syndrome (ARDS). Four groups of animals were anesthetized and ventilated with 0.5 FIO2, 5 cm PEEP, and 20 cc/kg tidal volume: a control group given saline alone; Pseudomonas infusion alone (P); Pseudomonas with ibuprofen (I), 12.5 mg/kg given at 20 and 120 min; and P with methylprednisolone (M), 30 mg/kg given at 20 and 120 min. We compared the alteration in pulmonary hemodynamics with the alteration in the plasma concentration of thromboxane (TxB2) and 6-keto PGF1 alpha in the treated and untreated groups. Hemodynamic parameters measured included the pulmonary (PAP) and systemic (SAP) arterial pressures, cardiac index (C1), thermal-cardiogreen extravascular lung water (EVLW), and PaO2. Albumin Flux was measured by a gamma scintigraphic method (slope index; SI). P produced a dramatic increase in PAP (P less than 0.05) with a progressive increase in EVLW and SI (P less than 0.05) and fall (P less than 0.05) in PaO2, CI, and SAP. The acute pulmonary hypertension was associated with a significant rise in TxB2 and 6-keto PGF1 alpha in the Pseudomonas group. I effectively blocked the elevation of TxB2 and caused a significant but transient improvement in PAP and rise in PaO2. Albumin flux and water leak as measured by SI and EVLW were not affected by ibuprofen. M reduced the elevation of TxB2 and 6-keto PGF1 alpha but failed to block these prostaglandins significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗

Synergism of azlocillin, mezlocillin, piperacillin in combination with tobramycin against Klebsiella and Pseudomonas.

Fifty-three clinical isolates of Klebsiella and fifty-one clinical isolates of Pseudomonas aeruginosa, twenty-six of which were carbenicillin-(CARB) resistant, were tested for susceptibility to mezlocillin (MEZ), azlocillin (AZL), and piperacillin (PIP), both alone and in combination with tobramycin (TOB) using the microtiter broth diluent method and an inoculum density of 10(6) CFU/ml. The Klebsiella were highly resistant to TOB, MEZ, and PIP (MIC90: 8, greater than 256, greater than 128 micrograms/ml, respectively). Synergy was demonstrated in 53 percent (PIP/TOB) and 51 percent (MEZ/TOB). An indifferent response was observed in 47 percent (PIP/TOB) and 49 percent MEZ/TOB of the Klebsiella. PIP, MEZ, and AZL in combination with TOB showed synergism against CARB-resistant Pseudomonas in less than 10 percent of the strains tested. Synergy could be demonstrated against CARB-susceptible Pseudomonas with the combinations PIP/TOB, AZL/TOB, and MEZ/TOB in 12 percent, 12 percent, and 24 percent, respectively, of the twenty-five strains tested. Indifferent effects were observed in 84 percent, 88 percent, and 76 percent, respectively, of these same CARB-susceptible strains. These data suggest that there is no significant difference in the incidence of synergy with these new penicillins and tobramycin against either Pseudomonas or Klebsiella.

Azlocillin↗

[Spontaneous genetic transformation in Pseudomonas pseudomallei].

Spontaneous genetic transformation has been registered in Pseudomonas pseudomallei cells. Transforming frequencies registered reach 10(-4)-10(-5). Spontaneous transformation has been simulated for Pseudomonas pseudomallei in soil. Intrageneric spontaneous transformation has been demonstrated to occur between Pseudomonas pseudomallei and Pseudomonas mallei.

DNA, Bacterial↗