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PubMed1995

The primary structure of pepstatin-insensitive carboxyl proteinase produced by Pseudomonas sp. No. 101.

A unique carboxyl proteinase [EC 3.4.23.33] from Pseudomonas sp. No. 101 is the first example of a prokaryotic enzyme which is insensitive to the classical inhibitor, pepstatin. The primary structure of the proteinase was determined by conventional methods. Pseudomonas carboxyl proteinase consists of 370 amino acid residues with one disulfide bond. This enzyme has no homologous sequence with any other known carboxyl proteinase, including carboxyl proteinase B from Scytalidium lignicolum, which is a pepstatin-insensitive carboxyl proteinase. In addition, Pseudomonas carboxyl proteinase lacks the Asp*-Thr-Gly, Glu*-Thr-Gly, and Asp*-Thr-Ser-Gly (*indicates the catalytic residue) sequences which are known as the motif sequences around a pair of catalytic residues in carboxyl proteinases reported so far. The results strongly indicate that Pseudomonas carboxyl proteinase is a new type of carboxyl proteinase.

Amino Acid Sequence↗

PubMed1980

Methylamine dehydrogenases of Methylomonas J and Pseudomonas AM1. Hybridization of light and heavy subunits and some properties of an isolated hybrid enzyme.

Hybridization reactions were carried out in vitro between the light and heavy subunits of two methylamine dehydrogenases obtained from Methylomonas J (formerly Pseudomonas sp. J) and Pseudomonas AM1. Enzymatic activity was restored with a combination of L3(MW: 13,000) and HA(MW: 40,000) but not with LA(MW: 13,000) and HJ(NW: 40,000). This active hybrid enzyme was isolated with a Sephadex G-150 column after incubation of LJ and HA. Its molecular weight was nearly identical to that of the two native enzymes (MW: 105,000). The electrophoretic pattern of proteins cross-linked by dimethyl suberimidate showed the formation of a tetrameric structure. Its absorption spectrum was similar to that of the native enzymes. The specific activity was 4.3 and the substrate specificity resembled that of the Methylomonas J enzyme rather than that of the Pseudomonas AM1 enzyme. Michaelis constants were 290 microM for methylamine and 14 microM for phenazine methosulfate. The circular dichroism spectrum and thermal stability resembled those of the Pseudomonas AM1 enzyme. No appreciable amount of an inactive hybrid enzyme was formed in the reaction between LA and HJ, there being neither restoration of the enzymatic activity nor formation of cross-linked tetrameric proteins with dimethyl suberimidate. Hybridization of LJ and HA was further confirmed by the appearance of three enzymatic active bands on a gel after electrophoresis of an incubation mixture of LJ, HJ, and HA. The results are consistent with a previous observation; the two methylamine dehydrogenases from either obligate of facultative metaylotrophs are the alpha 2 beta 2-type and homologous enzymes. It is also suggested that substrate specificity and catalytic activity are directed by the light subunit, and binding affinity of the substrate to the active site, electrophoretic mobility, and thermal stability of the enzyme are endowed by the heavy subunit.

Kinetics↗

PubMed1993

Epidemiology of Pseudomonas aeruginosa infections in a neonatal intensive care unit.

During the 19-month study period, 48 (2 per cent) of the 2177 neonates admitted to the neonatal intensive care unit (NICU) yielded Pseudomonas aeruginosa growths in blood cultures. All these neonates had clinical and haematological evidences of sepsis. Prominent clinical features included sclerema, violaceus necrotic patches, necrotizing enterocolitis (NEC), conjugated hyperbilirubinaemia, and DIC. Over all mortality was 23 per cent, distinctly higher in premature neonates with RDS. The mean gestational age and birth weights (+/- SD) of these neonates were 36.42 (+/- 2.73) weeks and 2173.34 (+/- 567.33) g, respectively. Approximately half of the total cases had low birth weight. Other adverse perinatal events before the development of sepsis included birth asphyxia (60 per cent), neonatal resuscitation (67 per cent), meconium aspiration syndrome (29 per cent), hyaline membrane disease (8 per cent), prolonged hospitalization (44 per cent), closed incubator care (17 per cent), prolonged intravenous fluids (42 per cent), repeated blood sampling (63 per cent), and umbilical catheterization (4 per cent). Analysis of the trend of Pseudomonas sepsis in our NICU revealed six definite outbreaks (more than two cases) interspersed with occasional (one or two) cases. Six study months, however, remained free of Pseudomonas sepsis. Index case was demonstrable on seven occasions. Bacteriological surveillance of the NICU after onset of initial case/cases revealed statistically significant colonization of resuscitation equipment, baby placement sites, and various cleansing solutions by the same bacterial species (P < 0.05). It is possible that Pseudomonas was introduced to our NICU from transfer admissions from other hospitals since on four occasions index case was the one transferred from outside.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗

PubMed1996

Characterization of a genomic locus required for synthesis of the antibiotic 2,4-diacetylphloroglucinol by the biological control agent Pseudomonas fluorescens Q2-87.

The antibiotic 2,4-diacetylphloroglucinol (Phl) is an important factor in the biological control by fluorescent Pseudomonas spp. of many soilborne diseases including take-all disease of wheat. A 6.5-kb genomic DNA fragment from Pseudomonas fluorescens Q2-87 conferred production of Phl and of a red pigment distinct from Phl, but which typically is present when Phl is produced, upon all of 13 Phl-nonproducing recipient Pseudomonas strains into which it was introduced. Larger fragments that included flanking DNA sequences did not transfer this capability, suggesting that they contain negative regulatory element(s). Analysis of the 6.5-kb fragment by Tn3HoHo1 mutagenesis further localized the sequences required for Phl production to a segment of approximately 5 kb and revealed the presence of at least two divergently oriented transcriptional units. Insertions within the smaller unit or within about 3 kb of the 5' end of the larger unit caused loss of production of both Phl and the red pigment. Other insertions within the distal 1.5 kb of the larger transcriptional unit abolished production of only the red pigment. Pleiotropic changes in secondary metabolism or colony morphology were not observed in Pseudomonas strains containing the 6.5-kb fragment, although some Phl-producing derivatives grew more slowly and gave rise to smaller colonies than did the wild-type parental strains. The size of the genomic region involved in Phl production, and the consistency and specificity with which these sequences transferred Phl biosynthetic capability, support the conclusion that the 6.5-kb fragment contains the Phl biosynthetic locus.

Anti-Bacterial Agents↗

PubMed2003

Induced systemic resistance in Arabidopsis thaliana in response to root inoculation with Pseudomonas fluorescens CHA0.

Root inoculation of Arabidopsis thaliana ecotype Columbia with Pseudomonas fluorescens CHA0r partially protected leaves from the oomycete Peronospora parasitica. The molecular determinants of Pseudomonas fluorescens CHA0r for this induced systemic resistance (ISR) were investigated, using mutants derived from strain CHA0: CHA400 (pyoverdine deficient), CHA805 (exoprotease deficient), CHA77 (HCN deficient), CHA660 (pyoluteorin deficient), CHA631 (2,4-diacetylphloroglucinol [DAPG] deficient), and CHA89 (HCN, DAPG- and pyoluteorin deficient). Only mutations interfering with DAPG production led to a significant decrease in ISR to Peronospora parasitica. Thus, DAPG production in Pseudomonas fluorescens is required for the induction of ISR to Peronospora parasitica. DAPG is known for its antibiotic activity; however, our data indicate that one action of DAPG could be due to an effect on the physiology of the plant. DAPG at 10 to 100 microM applied to roots of Arabidopsis mimicked the ISR effect. CHA0r-mediated ISR was also tested in various Arabidopsis mutants and transgenic plants: NahG (transgenic line degrading salicylic acid [SA]), sid2-1 (nonproducing SA), npr1-1 (non-expressing NPR1 protein), jar1-1 (insensitive to jasmonic acid and methyl jasmonic acid), ein2-1 (insensitive to ethylene), etr1-1 (insensitive to ethylene), eir1-1 (insensitive to ethylene in roots), and pad2-1 (phytoalexin deficient). Only jar1-1, eir1-1, and npr1-1 mutants were unable to undergo ISR. Sensitivity to jasmonic acid and functional NPR1 and EIR1 proteins were required for full expression of CHA0r-mediated ISR. The requirements for ISR observed in this study in Peronospora parasitica induced by Pseudomonas fluorescens CHA0r only partially overlap with those published so far for Peronospora parasitica, indicating a great degree of flexibility in the molecular processes leading to ISR.

Anti-Bacterial Agents↗

PubMed1998

Halogenated anesthetics inhibit Pseudomonas aeruginosa growth in culture conditions reproducing the alveolar environment.

UNLABELLED: We assessed the effects of halogenated anesthetics on Pseudomonas aeruginosa growth in a liquid nutrient broth. Sterile Petri dishes (3.5-cm diameter) were filled with a 1-mL suspension of a Pseudomonas aeruginosa strain and incubated at 37 degrees C. Exposure of bacterial plates to halothane, isoflurane, and enflurane administered at 1 and 2 minimum alveolar anesthetic concentration (MAC) were studied for different exposure times (1, 2, 3, and 4 h) using an airtight chamber. For each time, a control point was obtained. Serial dilutions and agar plates were made, and developed colonies were counted. A significant decrease in bacterial growth was observed from the second hour of exposure to every halogenated anesthetic. For long periods of exposure (3 and 4 h), bacterial growth was significantly reduced in the plates exposed to 2 MAC compared with 1 MAC. The maximal inhibition was observed after a 4-h exposure at 2 MAC and reached 60%, 49%, and 42% for halothane, isoflurane, and enflurane, respectively. We conclude that a decrease in Pseudomonas aeruginosa growth is observed after exposure to halogenated anesthetics, but whether this inhibition is clinically important remains to be demonstrated. IMPLICATIONS: Bacterial pneumonia is a major source of morbidity after general anesthesia. We measured the effects of volatile anesthetics on the growth of Pseudomonas aeruginosa, one of the pathogens most often isolated in hospital-acquired pneumonia. The experiments were performed in vitro in culture conditions reproducing those observed in the alveolar space. Volatile anesthetics inhibited the growth of these bacteria, but the clinical significance of this fact remains to be determined.

Anesthetics, Inhalation↗

PubMed1990

Pseudomonas keratitis and contact lens wear: the lens/eye is at fault.

Microbial keratitis with Pseudomonas aeruginosa is the most common corneal infection associated with contact lenses (CLs). Pseudomonas organisms are ubiquitous in nature, and can colonize CLs without a prior breach in lens care or hygiene. Although poor lens care is often found in affected patients, lens contamination and traumatic epithelial defects are more relevant. Hydrophilic lenses, particularly extended wear lenses, have been associated with a greater frequency of Pseudomonas keratitis. The polymer matrix of these lenses is apparently suited to the avid adherence of Pseudomonas organisms. Adherence is promoted by the presence of lens coatings, which begin to accumulate upon lens insertion and whose level mounts over time. Evidence suggests that infection is more common with mucin-coated contaminated CLs than with noncoated contaminated CLs. In general, lens wear can promote bacterial adherence to the ocular surface by shielding the cornea from the wiping action of the eyelids and immune components in tears. Still, experimental models have shown that keratitis develops regularly (84%) only in corneas that have been traumatized. Trauma may arise through lens insertion or removal, deposits or debris entrapment, hypoxia, or toxic reactions to solution preservatives. Extended wear is believed to facilitate the infectious process because of the chronic accumulation of coatings, the chronic exposure of CLs to potentially adherent bacteria, the continuous presence of irritating lens deposits, the prolonged entrapment of debris beneath the lens, and the relative infrequency of lens cleaning and disinfection.

Bacterial Adhesion↗

PubMed2002

Evolving resistant pseudomonas to ciprofloxacin in malignant otitis externa.

OBJECTIVE: To determine whether there has been an increase in ciprofloxacin-resistant pseudomonas malignant otitis externa, and if this has increased the morbidity of the disease. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Twenty-eight patients over 13 years. RESULTS: The records of a total of 28 patients who were admitted between 1988 and 2001 with the diagnosis of malignant otitis externa were reviewed. Seven patients had ciprofloxacin-resistant pseudomonas on their hospital culture and sensitivity test. Five of the 7 resistant cases appeared in the last 3 years, as opposed to 2 of the 7 who appeared in the 10 years before that period. In our series, there is a significant trend developing over time of pseudomonas resistant to treatment with ciprofloxacin. No increased morbidity or mortality was found in the ciprofloxacin-resistant pseudomonas group compared with the remaining patients who were sensitive to ciprofloxacin. CONCLUSIONS: In our series, resistance to ciprofloxacin in patients with malignant otitis externa is increasing over time. This may have an impact on the relatively successful outpatient treatment of these patients in the past decade. A return to inpatient or outpatient intravenous treatment with third-generation cephalosporins/antipseudomonal penicillins and more frequent debridement will be required in these patients.

Aged↗

PubMed1998

The role of Pseudomonas aeruginosa biofilm in the attachment of Acanthamoeba to four types of hydrogel contact lens materials.

PURPOSE: The effect of the previous coating of a contact lens surface with Pseudomonas biofilm on adsorption of Acanthamoeba onto four types of hydrogel materials was investigated. METHODS: Hydrogel contact lens quarters from each of the four FDA groups of hydrogel materials were incubated for at least 12 h in a suspension of 10(7)/ml of Pseudomonas aeruginosa (ATCC 27853) to coat their surfaces with biofilm. After rinsing, the lenses were incubated for 90 min in 5 x 10(5)/ml of Acanthamoeba castellanii trophozoites. New, uncoated lens quarters were incubated in the Acanthamoeba suspension as controls. After rinsing, all adsorbed trophozoites on one surface of each lens quarter were counted by direct light microscopy. Adsorption was expressed as numbers of amoebae per square centimeter of lens surface, and nonparametric data analysis was performed. RESULTS: Acanthamoeba adsorption to new, uncoated lenses was greater for ionic materials (groups 3 and 4) than for the nonionic materials (groups 1 and 2). Pseudomonas biofilm increased adsorption on all four lens types. CONCLUSION: Pseudomonas biofilm enhanced adsorption of Acanthamoeba on all lens types studied, but the adsorption to nonionic materials was significantly less. This suggests that all lens wearers may be at increased risk for Acanthamoeba infection if lenses are previously contaminated with bacterial biofilm, but this risk may be reduced by the use of certain lens types (low water content, nonionic materials).

Acanthamoeba↗

PubMed1990

Long term radiologic outcome of Pseudomonas osteomyelitis of the foot.

The medical records of 27 patients with puncture wound-induced Pseudomonas aeruginosa osteomyelitis/septic arthritis of the foot hospitalized from 1980 through 1988 were reviewed. Twenty patients received anti-Pseudomonas therapy for greater than 21 days and 7 patients received anti-Pseudomonas therapy for less than or equal to 21 days. There was no difference in age, sex, race, duration of wound or symptoms before admission or in admission physical findings including temperature, lymphadenopathy, puncture site appearance or admission laboratory data including white blood cell count or erythrocyte sedimentation rate between the two groups. All children but two in the long term therapy group had surgical as well as parenteral anti-Pseudomonas therapy. Fifteen patients returned for follow-up radiographs 1 to 8 1/2 years after hospitalization, 10 of 20 who had received therapy for greater than 21 days and 5 of 7 who had received therapy for less than or equal to 21 days. Poor radiologic outcome, ranging from bony deformity to joint space abnormality, was noted in 4 patients, of whom 3 had had joint involvement. Clinical abnormality was noted in only one adolescent male, and he had the most severe radiologic sequelae. The longer term functional significance of these radiologic anomalies awaits further delineation.

Adolescent↗

PubMed1992

Pseudomonas infections in children with human immunodeficiency virus infection.

Thirteen bacteremias and 25 nonbacteremic infections caused by Pseudomonas spp. occurred in 22 of 236 children with human immunodeficiency virus infection with a rate of infection of 0.098 (bacteremia, 0.030) per patient year. Four patients were neutropenic (less than 500/microliters). Central venous catheter (CVC)-related infections were most frequent (n = 20) followed by otitis externa (n = 6) and pneumonia (n = 5). Pseudomonas aeruginosa was the most common isolate and caused both CVC-related and CVC-unrelated infections, whereas other Pseudomonas spp. and Xanthomonas maltophilia were almost exclusively associated with CVC-related infections. The children who received appropriate therapy had a favorable outcome. In 7 CVC-related infections (35%) the catheter was removed. Pseudomonas spp. are of increasing importance in human immunodeficiency virus-infected children causing significant morbidity and increased hospitalization. These infections may be life-threatening if appropriate therapy is not vigorously initiated.

Adolescent↗

PubMed2003

Doxycycline in the management of pseudomonas corneal melting: two case reports and a review of the literature.

BACKGROUND: Pseudomonas keratitis can result in the breakdown of collagen with subsequent corneal melting and perforation. The use of antimetalloproteinases may help to stabilize melting and prevent imminent perforation of the cornea. The use of topical protease inhibitors and neutrophil inhibitors is of limited value. Tetracyclines, however, have been shown to have anticollagenolytic activity and inhibit metalloproteinases, and they may suppress connective tissue breakdown. PURPOSE: To establish the stabilization of corneal melting in cases of Pseudomonas keratitis. METHODS: Two young patients with severe contact lens-associated Pseudomonas keratitis and corneal melting were treated with oral doxycycline and standard topical treatment. RESULTS: Corneal melting was stabilized in each patient, and perforation was avoided. CONCLUSIONS: Tetracyclines have an anticollagenolytic action in addition to their antimicrobial activity. The use of doxycycline as an adjunctive therapy in the management of Pseudomonas corneal melting may help to stabilize corneal breakdown and prevent subsequent perforation.

Administration, Oral↗

PubMed1993

Telluria mixta (Pseudomonas mixta Bowman, Sly, and Hayward 1988) gen. nov., comb. nov., and Telluria chitinolytica sp. nov., soil-dwelling organisms which actively degrade polysaccharides.

Pseudomonas mixta (type strain, ACM 1762 [= ATCC 49108], an actively dextranolytic species that possesses both lateral and polar flagella, was compared with the strictly aerobic, rod-shaped, chitinolytic bacterium "Pseudomonas chitinolytica" ACM 3522T (= CNCM I-804) (T = type strain), which has a similar flagellation pattern, by performing phenotypic characterization and DNA-DNA hybridization studies and by analyzing DNA base compositions and 16S rRNA sequences. Our results indicated that "P. chitinolytica" ACM 3522T was phenotypically and genotypically distinct from P. mixta and other phenotypically analogous Pseudomonas spp., Xanthomonas maltophilia, and other aerobic chitin degraders. The 16S rRNA sequences of strains ACM 1762T and ACM 3522T were found to be very similar (97%) to each other and indicated that these organisms are proteobacteria that belong to the beta subclass. The strains were deeply branched in the beta subclass and were distinct from other pseudomonads, including Pseudomonas cepacia, and from Comamonas testosteroni. On the basis of phenotypic, genotypic, and phylogenetic evidence, it is proposed that P. mixta and "P. chitinolytica" ACM 3522T represent two distinct species in a new genus called Telluria. Thus, the genus Telluria gen. nov. contains Telluria mixta comb. nov. and Telluria chitinolytica sp. nov., which are strictly aerobic, rod-shaped, soil-dwelling bacteria that are active polysaccharide degraders.

Base Composition↗

PubMed1998

Phylogenetic relationships of Pseudomonas putida strains deduced from the nucleotide sequences of gyrB, rpoD and 16S rRNA genes.

Phylogenetic analysis of 20 Pseudomonas strains (Pseudomonas putida, Pseudomonas fluorescens and Pseudomonas chlororaphis) was conducted by using the nucleotide sequences of the genes for 16S RNA, DNA gyrase B subunit (gyrB) and RNA polymerase delta 70 factor (rpoD), which have been determined by the direct sequencing of PCR-amplified fragments. On the basis of gyrB and rpoD sequences, these strains were split into two major clusters: one including the type strain of P. putida and all biovar A strains and the other including all P. putida biovar B strains, P. fluorescens stains and the P. chlororaphis strain. In the phylogenetic tree reconstructed from the 16S rRNA sequences included variable regions, P. Putida biovar A and B strains were not separated into two independent clusters, whereas in the phylogenetic tree reconstructed from the 16S rRNA sequences excluding the variable region sequences, these strains were separated into P. putida biovar A and biovar B clusters. The pairwise distances estimated from the variable regions of 16S rRNA correlated poorly with the synonymous distances estimated from the gyrB and rpoD genes. On the other hand, a highly significant correlation was observed between the pairwise distances estimated from the non-variable regions of 16S rRNA and the synonymous distances from gyrB and rpoD genes. Consequently, only the 16S rRNA sequences in the non-variable regions should be used for the phylogenetic analysis. The gyrB and rpoD analyses showed the necessity for the reclassification of P. putida biovar B strains.

Base Sequence↗

PubMed2000

Pseudomonas antimicrobica Attafuah and Bradbury 1990 is a junior synonym of Burkholderia gladioli (Severini 1913) Yabuuchi et al. 1993.

Comparison of the 16S rDNA sequence of Pseudomonas antimicrobica LMG 18920T with published 16S rDNA sequences from other pseudomonads indicated that Pseudomonas antimicrobica belongs to the genus Burkholderia, with Burkholderia gladioli, Burkholderia glumae and Burkholderia plantarii as its closest neighbours. DNA-DNA hybridizations confirmed that Pseudomonas antimicrobica and Burkholderia gladioli represent the same species. Strain LMG 18920T and other Burkholderia gladioli strains were also indistinguishable by SDS-PAGE of whole-cell proteins and had similar biochemical characteristics. The whole-cell fatty acid composition, however, was different from that of other Burkholderia gladioli strains. It is concluded that Pseudomonas antimicrobica is a later synonym of Burkholderia gladioli. As Burkholderia gladioli is known to cause infections in patients with cystic fibrosis and chronic granulomatous disease, the eventual use of strain LMG 18920T as a biological control agent should be approached with caution.

Bacterial Proteins↗

PubMed2001

Reclassification of [Pseudomonas] doudoroffii (Baumann et al. 1983) into the genus Oceanomonas gen. nov. as Oceanomonas doudoroffii comb. nov., and description of a phenol-degrading bacterium from estuarine water as Oceanomonas baumannii sp. nov.

A bacterium, isolate GB6T, capable of degrading phenol in the presence of elevated salinity was isolated from the estuary of the River Wear, UK. The bacterium was subjected to biochemical and molecular analysis to determine its taxonomic status. These studies indicated that the bacterium was a distinct species closely related to [Pseudomonas] doudoroffii. However, the phylogenetic analysis indicated that [Pseudomonas] doudoroffii was misclassified, as noted previously. Analysis of the characteristics of isolate GB6T and the type strain of [Pseudomonas] doudoroffii confirmed that these bacteria belonged to the same novel genus, which we have named Oceanomonas gen. nov. The type strain of Oceanomonas doudoroffii (Baumann et al. 1983) comb. nov. is ATCC 27123T (= DSM 7028T. The DNA-DNA homology between isolate GB6T and [Pseudomonas] doudoroffii is low and phenotypic differences between the two organisms are evident. Isolate GB6T (= ATCC 700832T = NCIMB 13685T) is therefore proposed as the type strain of a new species, Oceanomonas baumannii sp. nov.

Bacterial Typing Techniques↗

PubMed2002

Phylogenetic study of the genus Oceanospirillum based on 16S rRNA and gyrB genes: emended description of the genus Oceanospirillum, description of Pseudospirillum gen. nov., Oceanobacter gen. nov. and Terasakiella gen. nov. and transfer of Oceanospirillum jannaschii and Pseudomonas stanieri to Marinobacterium as Marinobacterium jannaschii comb. nov. and Marinobacterium stanieri comb. no.

The phylogenetic relationships of Oceanospirillum strains were analysed by using the nucleotide sequences of 16S rRNA and gyrB genes. Results from sequence analysis demonstrated that the Oceanospirillum core group consisted of four species, Oceanospirillum linum, Oceanospirillum maris, Oceanospirillum beijerinckii and Oceanospirillum multiglobuliferum, with enough distance to separate them as different species. However, four other Oceanospirillum species occupied taxonomic positions separate from the Oceanospirillum core group: Oceanospirillum jannaschii, Oceanospirillum japonicum and Oceanospirillum kriegii in the gamma-Proteobacteria and Oceanospirillum pusillum in the alpha-Proteobacteria. Oceanospirillum jannaschii clustered with Marinobacterium georgiense, Pseudomonas iners and Pseudomonas stanieri on the basis of phylogenetic analysis of 16S rRNA and gyrB genes. The other three species did not cluster with known genera. Also, the sequence similarity values of the gyrB genes between the three subspecies of Oceanospirillum maris and those between the two subspecies of Oceanospirillum beijerinckii were above 99%. The close relationships between the subspecies of Oceanospirillum maris and of Oceanospirillum beijerinckii were further supported by similar physiological properties and high DNA-DNA hybridization values, suggesting that these subspecies should not be regarded as valid. From these results, Oceanospirillum sensu stricto should be defined to consist of Oceanospirillum linum, Oceanospirillum maris, Oceanospirillum beijerinckii and Oceanospirillum multiglobuliferum. We propose to create the following new genera: Pseudospirillum gen. nov. for Oceanospirillum japonicum as Pseudospirillum japonicum comb. nov.; Oceanobacter gen. nov. for Oceanospirillum kriegii as Oceanobacter kriegii comb. nov.; and Terasakiella gen. nov. for Oceanospirillum pusillum as Terasakiella pusilla comb. nov. The transfer is proposed of Oceanospirillum jannaschii and Pseudomonas stanieri to Marinobacterium as Marinobacterium jannaschii comb. nov. and Marinobacterium stanieri comb. nov. Furthermore, Pseudomonas iners should be reclassified as a strain of Marinobacterium georgiense. Finally, the subspecies of Oceanospirillum maris (O. maris subsp. maris, O. maris subsp. hiroshimense and O. maris subsp. williamsae) and Oceanospirillum beijerinckii (O. beijerinckii subsp. beijerinckii and O. beijerinckii subsp. pelagicum) should be combined as Oceanospirillum maris and Oceanospirillum beijerinckii, respectively.

Alphaproteobacteria↗

PubMed2002

Pseudomonas costantinii sp. nov., another causal agent of brown blotch disease, isolated from cultivated mushroom sporophores in Finland.

Pathogenic bacteria are frequently associated with mushroom sporophores exhibiting brown blotch disease symptoms. These bacteria belong mainly to Pseudomonas tolaasii or occasionally to 'Pseudomonas reactans'. Although a group of isolates originating from some Finnish mushroom farms satisfied the two characteristic criteria for diagnosis of infection with P. tolaasii (i.e. yielding a typical brown blotch symptom on Agaricus bisporus sporophores and producing a typical white line in agar when streaked towards the 'P. reactans' LMG 5329 inducing strain), results based on numerical taxonomy, siderotyping, DNA-DNA hybridizations and 16S rDNA phylogenetic analyses supported the view that these isolates constituted a novel species within the genus Pseudomonas, Pseudomonas costantinii. The type strain is PS 3a(T) (= CFBP 5705(T) = HAMBI 2444(T)).

Agaricus↗