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A bacterial strain capable of biodegradation of lantadene A (22 beta-angeloyloxy-3-oxoolean-12-en-28-oic acid) has been isolated from soil using lantadene A as the sole carbon source. The organism is rod shaped, Gram negative, motile and has been identified as Pseudomonas pickettii. This is the first report of the biodegradation of a pentacyclic triterpenoid.

Plasmid profiles, genome restriction fragment polymorphisms, carbohydrate oxidation-fermentation reactions, methylumbelliferyl substrate hydrolysis patterns, antimicrobial susceptibilities, and results obtained with the Biolog GN biochemical substrate kit were used to type 19 common-source, but mixed-biotype, outbreak strains and one epidemiologically distinct strain of Pseudomonas pickettii. Biotyping with conventional and methylumbelliferyl substrates failed to distinguish between strains. Plasmid profile testing was found to be inconsistent and not reproducible. The Biolog GN kit allowed greater strain differentiation than restriction fragment polymorphism did (12 biotypes versus 5 biotypes); antimicrobial susceptibility testing yielded 4 biotypes, and oxidation-fermentation tests gave 3 biotypes. Oxidation-fermentation results were consistent with restriction fragment polymorphs in all but 1 of the 20 strains tested. For ease of typing, comprehensive typeability, and reproducibility, oxidation-fermentation tests should be performed initially and followed if necessary by restriction fragment polymorph analysis for the elucidation of P. pickettii infection outbreaks.

The degradation of 2-chlorophenol vapours in air was performed in a trickling biofilter packed with ceramic material seeded with the bacterium Pseudomonas pickettii , strain LD1. The system performance was evaluated under varying operating conditions (inlet 2-chlorophenol air concentrations from 0.10 to 3.50 g m −3 , and superficial air velocities of 30.0, 60.0, and 120.0 m h −1 ). For all air velocity the maximum degradation rate was obtained for loading rates of 40 g m −2 h −1 . Higher loading conditions resulted in strong inhibition of microbial activity, particularly severe at high air velocity. Process analysis, performed using data on pollutant concentration profiles along the filter packing obtained under different conditions of inlet concentration and air velocity, proves that best performance (i.e. maximum degradation efficiency and capacity) can be obtained for a narrow range of operating conditions, which can be ensured by proper design of biofilter size (i.e. diameter and height). Kinetic analysis of experimental data confirms that 2-CP inhibits microbial activity in the biofilter bed. Experimental data are satisfactorily fitted by the Haldane kinetic equation up to a critical value of loading rate, beyond which the experimental degradation rate is overestimated by the kinetic model. The inhibition appears to be affected by the loading rate, and the estimated inhibition constant linearly increases with increasing empty bed residence time.

Over a 3-month period, seven patients in a paediatric oncology unit developed Pseudomonas pickettii septicaemias. The outbreak was difficult to recognize since the cases occurred at widely spaced intervals and problems were experienced with the identification of the isolates. Many of the isolates were initially misidentified on the basis of a short sugar set used in the laboratory for identification of the non-fermenting Gram-negative bacilli. Moreover, the organisms had varying sensitivity patterns. The source of the organisms proved to be vials of ‘sterile' distilled water which had been used for flushing the patients' indwelling Hickman lines. No further cases occurred once the use of this water was discontinued.

This research work investigates the biodegradation of 2-chlorophenol vapours in a trickling biofilter packed with a ceramic material, and seeded with a pure strain of Pseudomonas pickettii . The process was tested at laboratory scale over 260 days of operation under varying loading conditions. More than 98% degradation efficiencies were achieved for loading rates up to 82.5 g m −3 h −1 . Process analysis, performed using data on 2-chlorophenol concentration profiles along the biofilter bed, shows that best biofilter performance (i.e. maximum degradation capacity and efficiency) can be obtained for a narrow range of operating conditions, which can be ensured by proper sizing of biofilter diameter and height.

Pseudomonas pickettii strain US321 appeared to elicit a copper resistance mechanism upon exposure to copper. The bacterial colonies turned blue in the presence of this metal in a chemically defined medium, suggesting accumulation of copper. Prolonged exposure to copper resulted in the characteristic “copper sink” morphology of the colonies. Atomic absorption spectrophotometric analysis confirmed that this organism can accumulate copper. The strain US321 exhibited a high-molecular-weight plasmid, pUS321. The plasmid-cured strain, PC25, is highly sensitive to copper owing to a poor copper management. A plasmid-encoded sequestration mechanism operating in the strain US321 is suggested.

Permanent indwelling intravenous devices (PIIDs) have become increasingly prevalent in the past decade. These devices offer the advantage of long-term and convenient venous access, but their not-infrequent colonization by bacterial or fungi can lead to bloodstream infection with or without sepsis. We describe a series of four patients with PIIDs who became infected with Pseudomonas pickettii, and we review the properties of this unusual organism and the clinical presentation of the infections it causes.

Pseudomonas pickettii, a nonfermenting, gram-negative rod, is rarely pathogenic. Previous reports of infection with P. pickettii have largely involved direct contamination of supplies presumed to be sterile. We describe a case of vertebral osteomyelitis and intervertebral discitis caused by P. pickettii in a debilitated patient. The aggressive nature of this infection demonstrates that P. pickettii may be a more invasive organism than previously noted, particularly in hosts with weakened immunity secondary to underlying disease.

Nineteen cases of Pseudomonas pickettii bacteraemia and one case of Pseudomonas cepacia bacteraemia were identified in an Australia-wide outbreak of nosocomial sepsis associated with contaminated water for injection. The contamination was limited to one batch of commercially produced water for injection. Four different organisms were identified (three biotypes of P. pickettii and one of P. cepacia). However, P. pickettii biotype 1 appeared to be relatively more virulent than the other biotypes as it was the only identified organism in blood cultures in nearly all cases of sepsis. The ampoules of "sterile" water were each contaminated with approximately 10(3) organisms per millilitre. The lack of an Australian central reporting system for bacteraemia delayed the recognition of this outbreak.

We found an inducible phenylserine dehydratase [EC 4.2.1.-] in a soil bacterium identified as Pseudomonas pickettii PS22. The enzyme catalyzes the deamination of L-threo-3-phenylserine to yield phenylpyruvate and ammonia. The enzyme had an optimum reactivity at about pH 7.5. The Km for L-threo-3-phenylserine was 0.21 mM.

Resume Pseudomonas pickettii a ete isolee a 3 reprises et a des periodes distinctes ; dans deux cas il s'agissait de bacteriemies et dans le troisieme cas d'une infection de la cheville. Les observations cliniques ainsi que les resultats des investigations bacteriologiques sont relates dans la presente note. Les six souches isolees — respectivement une hemoculture positive chez un malade, trois hemocultures positives et un catheter infecte chez le deuxieme patient et enfin une suppuration de la cheville chez le dernier malade — presentaient les caracteristiques de Pseudomonas pickettii . L'origine de ces souches, a l'exception d'un cas ou un catheter infecte a ete incrimine, est restee inconnue.

Over a period of 10 days, six patients in a cardiac intensive care unit developed Pseudomonas pickettii (biovar VA-I) septicaemia after installation of a venous catheter. The organism was also recovered from all the vials of the aqueous solution of 0.05 per cent chlorhexidine ('Hibitane') prepared with contaminated bidistilled water. There were no further cases of infection when the use of this water was prohibited.

A case of bacteremia caused by Pseudomonas pickettii is reported. This represents the first case of infection due to this species.

An outbreak of pseudobacteremia caused by Pseudomonas pickettii biovariant 1 is reported. The common source was the aqueous chlorhexidine solution prepared by the hospital pharmacy. The contamination problem caused by the antiseptic solution was eventually solved by a series of preventive measures.

Pseudomonas pickettii strains were studied to determine the characteristics essential for their identification in the clinical microbiology laboratory. Preliminary investigations indicated that these glucose-oxidizing, denitrifying, gram-negative rods were quite similar to an unclassified group of clinical isolates designated VA-2. Gas liquid chromatography of trimethylsilyl derivatives of whole cell hydrolysates of P. pickettii and VA-2 strains yielded nearly identical elution profiles. The VA-2 cultures were concluded to be probable strains of P. pickettii. A method is presented for differentiating cultures of P. pickettii from other similar bacteria encountered in clinical specimens.

SUMMARY: On the basis of cluster analysis, average similarities within and between groups, and DNA base composition of selected strains, Pseudomonas pickettii appeared to be a distinct species comprising several biotypes. Although some or all of these biotypes, represented by subclusters in our computer study, may ultimately warrant recognition as separate species, our results were not conclusive enough to warrant such a proposal at present. Most strains tentatively named “P. thomasii” could be included in P. pickettii so that the name P. pickettii, which was validly published whilst “P. thomasii” was not, takes priority over “P. thomasii”, Strains of Group Va (Tatum et al., 1974) examined were also included in P. pickettii. Group IVd (King, 1964) did not appear to be a natural group but some of the strains could also be included in P. pickettii.

Pseudomonas pickettii, a Gram-negative bacillus which has been recovered rarely from clinical specimens, was isolated from the respiratory tracts of 9 of 29 (31%) pediatric intensive care unit patients. The reservoir of the organism was intrinsically contaminated single dose vials of tracheal irrigant solution. Four additional hospitals in three other states have notified the Centers for Disease Control of respiratory colonization with aerobic nonfermentative Gram-negative organisms and have associated this colonization with the use of the same tracheal irrigant solution. Because of the potential for intrinsic contamination, single dose vials must be added to the list of potentially hazardous environmental agents.