Phase I study of emactuzumab single agent or in combination with paclitaxel in patients with advanced/metastatic solid tumors reveals depletion of immunosuppressive M2-like macrophages

BACKGROUND

Emactuzumab is a monoclonal antibody against the colony-stimulating factor-1 receptor and targets tumor-associated macrophages (TAMs). This study assessed the safety, clinical activity, pharmacokinetics (PK) and pharmacodynamics (PD) of emactuzumab, as monotherapy and in combination with paclitaxel, in patients with advanced solid tumors.

PATIENTS AND METHODS

This open-label, phase Ia/b study comprised two parts (dose escalation and dose expansion), each containing two arms (emactuzumab, every 2 or 3 weeks, as monotherapy or in combination with paclitaxel 80 mg/m2 weekly). The dose-escalation part explored the maximum tolerated dose and optimal biological dose (OBD). The dose-expansion part extended the safety assessment and investigated the objective response rate. A PK/PD analysis of serial blood, skin and tumor biopsies was used to explore proof of mechanism and confirm the OBD.

RESULTS

No maximum tolerated dose was reached in either study arm, and the safety profile of emactuzumab alone and in combination does not appear to preclude its use. No patients receiving emactuzumab monotherapy showed an objective response; the objective response rate for emactuzumab in combination with paclitaxel was 7% across all doses. Skin macrophages rather than peripheral blood monocytes or circulating colony-stimulating factor-1 were identified as an optimal surrogate PD marker to select the OBD. Emactuzumab treatment alone and in combination with paclitaxel resulted in a plateau of immunosuppressive TAM reduction at the OBD of 1000 mg administered every 2 weeks.

CONCLUSIONS

Emactuzumab showed specific reduction of immunosuppressive TAMs at the OBD in both treatment arms but did not result in clinically relevant antitumor activity alone or in combination with paclitaxel. (ClinicalTrials.gov Identifier: NCT01494688).

Comparison of phenotypical and molecular methods for the identification of bacterial strains isolated from a deep subsurface environment

Seventy-four bacterial strains were freshly isolated from a mine gallery. Using these bacteria, we have investigated how a molecular identification based on the analysis of small subunit rDNA sequences would compare in terms of precision and reliability to a more classical comparison of phenotypical descriptions (100 morphological and physiological traits). Our data clearly showed that a phylogenetic analysis of small subunit rDNA sequences is more efficient than classical phenotypic methods for the identification of bacterial strains freshly isolated from a natural environment, because occurrences of misidentification are very much decreased by this method. The lack of rDNA sequences for many described species is probably the major cause of a few failures in molecular identification, as the completeness of the database of small subunit rDNA sequences holds much importance in the degree of uncertainty in such identifications.

Characterization of unusual alkaliphilic gram-positive bacteria isolated from degraded brown alga thalluses

Two orange-pigmented Gram-positive, aerobic bacteria were isolated from enrichment culture during degradation of brown alga Fucus evanescens thalluses. In this work, atomic force microscopy (AFM) has been used to study the cell morphology. The non-contact mode imaging revealed unusual irregular coccoid shape of cells, possessing a single flagellum. Bacteria produced carotenoid pigments, were chemo-organotrophic, alkaliphilic and halo-tolerant growing well on nutrient media containing up to 15% NaCl. Growth temperature ranged from 5 to 45 degrees C. The DNA base compositions were 48 mol% G + C and the level of DNA similarity of two strains was conspecific (98%). A comparative phylogenetic analysis of 16S rRNA gene sequences revealed that the strain KMM 3738 tightly clustered with recently described Planococcus maritimus (99.9% 16S rRNA gene sequence similarity). DNA-DNA hybridisation experiments revealed that DNA from the KMM 3738 showed 12-15% and 16-35% of genetic relatedness with the DNA of type strains of the genera Planomicrobium and Planococcus, respectively, and 87% with DNA from Planococcus maritimus, indicating that new isolates belong to the later species.

THEA: ontology-driven analysis of microarray data

MOTIVATION

Microarray technology makes it possible to measure thousands of variables and to compare their values under hundreds of conditions. Once microarray data are quantified, normalized and classified, the analysis phase is essentially a manual and subjective task based on visual inspection of classes in the light of the vast amount of information available. Currently, data interpretation clearly constitutes the bottleneck of such analyses and there is an obvious need for tools able to fill the gap between data processed with mathematical methods and existing biological knowledge.

RESULTS

THEA (Tools for High-throughput Experiments Analysis) is an integrated information processing system allowing convenient handling of data. It allows to automatically annotate data issued from classification systems with selected biological information coming from a knowledge base and to either manually search and browse through these annotations or automatically generate meaningful generalizations according to statistical criteria (data mining).

AVAILABILITY

The software is available on the website http://thea.unice.fr/

Iris transillumination defects in patients with primary open angle glaucoma

PURPOSE

To examine the incidence and pattern of iris transillumination defects in patients with primary open angle glaucoma (POAG) with and without vascular dysregulation, in comparison to controls.

METHODS

We prospectively examined 24 patients with POAG (M/F 10:14; mean age 59 +/- 14, range 21-76 years) and 23 controls (M/F 10:13; mean age 52 +/- 15, range 25-86 years). Vascular dysregulation was presumed if patients had a typical medical history of vasospasm and a pathological result in nailfold capillaroscopy. Iris transillumination defects were visualized by video-taped, digitized diaphanoscopy and assessed by two blinded observers.

RESULTS

We found significantly more iris transillumination defects in POAG than in controls (54.2% vs. 8.7%; chi2 = 8.85; df = 1; p = 0.002). The defects in POAG showed a characteristic radially-streaked pattern different from those described, for instance, in pigment dispersion syndrome, pseudoexfoliation syndrome, and acute glaucoma. Glaucoma patients with vascular dysregulation had a tendency to a higher incidence of transillumination defects than non-vasospastic patients, though this finding was not significant.

CONCLUSIONS

Patients with POAG have a higher incidence of iris transillumination defects than controls. The underlying mechanisms are not yet clear and call for further investigation.

Identification of genes that mediate sensitivity to cisplatin

Cisplatin (cDDP) is effective against some human tumors, but many are intrinsically resistant and, even among initially sensitive tumors, acquired resistance develops commonly during treatment. It has not been possible to prove which biochemical mechanisms control sensitivity to cDDP. Gene knockout studies in yeast, Dictyostelium discoideum, and mammalian cells have begun to unambiguously identify genes whose products function to modulate the cytotoxicity of cDDP. This review summarizes information currently available about the function of these genes. This comprehensive compilation points to the involvement of regulatory pathways known to mediate apoptosis, cell cycle checkpoint activation, and transcriptional rescue as regulators of cDDP sensitivity. Elucidation of the molecular mechanisms that mediate cDDP resistance holds promise for the design of pharmacological strategies for preventing, overcoming, or reversing this form of drug resistance.

Nicotine affects the signaling of the death pathway, reducing the response of head and neck cancer cell lines to DNA damaging agents

BACKGROUND

Growing evidence suggests that tobacco can affect the responsiveness of cancer cells to treatment, particularly those of head and neck cancer. This article describes the effects of nicotine on the signaling of the death pathway, resulting in a decreased cytotoxicity of various anticancer agents such as cisplatin and gamma-radiation.

METHODS

Colony-forming assays (CFA), using the head and neck cancer cell lines UMSCC10b and UMSCC5 and DNA fragmentation assays, were used to determine the effect of nicotine on cytotoxicity of various anticancer agents, whereas PCR and a JNK activity test were used to study the effect of nicotine on message expression levels and activity of the JNK signaling pathway.

RESULTS

Nicotine consistently reduced the cytotoxic effect of DNA-damaging agents, such as cisplatin, UV, and gamma radiation, in UMSCC10b cells, increasing their IC(50) values by twofold, 1.7-fold, and 1.8-fold, respectively. These results were confirmed in a second squamous cell carcinoma cell line (UMSCC5), demonstrating an increase in IC(50) values for cDDP by twofold and 1.9-fold in the UMSCC10b andUMSCC5, respectively. In addition, nicotine reduced the DNA fragmentation 48 h after cDDP exposure in UMSCC10b and UMSCC5 cell lines by 30% and 33%, respectively. The latter, however, was not the result of an effect of nicotine on either the uptake of cDDP or repair of the cDDP-DNA-adducts. To further substantiate the adverse effect of nicotine, the JNK and gadd153 signaling pathways were studied. JNK activity was decreased by 1.8-fold, as well as the expression of its downstream target c-jun (1.9-fold), when tumor cells were exposed to cisplatin in the presence of nicotine. In addition, the gadd153 message was affected and reduced by 1.8-fold.

CONCLUSIONS

Nicotine adversely affects the cytotoxicity of DNA-damaging agents. Nicotine does not interfere with the repair of the damage but directly affects the signaling of the death pathway, reducing the signaling of the JNK1 pathway. The latter results in a decrease in efficacy of the anticancer treatment in tumors exposed to nicotine.

Samsonia erythrinae gen. nov., sp. nov., isolated from bark necrotic lesions of Erythrina sp., and discrimination of plant-pathogenic Enterobacteriaceae by phenotypic features

Bacterial strains isolated from diseased erythrina (Erythrina sp.) trees in Martinique (French West Indies) were studied using phenotypic tests, 16S rDNA sequence analysis and DNA-DNA hybridization. Numerical analysis of phenotypic characteristics showed that these strains formed an homogeneous phenon among plant-pathogenic Enterobacteriaceae, and gave useful and updated information for the identification of these bacteria. Results of DNA-DNA hybridization indicated that strains from erythrina belonged to a discrete genomospecies (89-100% hybridization) and had low levels of DNA relatedness (2-33% hybridization) with reference strains of phytopathogenic Erwinia, Brenneria, Pectobacterium, Pantoea and Enterobacter species. 16S rDNA sequence analysis using three different methods revealed that the position of strain CFBP 5236T isolated from erythrina was variable in the different trees, so that strains from erythrina could not be assigned to any recognized genus. It is proposed that these strains are included in a new genus, Samsonia. The name Samsonia erythrinae is proposed for the new species. The G+C content of the DNA of the type strain, CFBP 5236T (= ICMP 13937T), is 57.0 mol%.

Retrieval of the species Alteromonas tetraodonis Simidu et al. 1990 as Pseudoalteromonas tetraodonis comb. nov. and emendation of description

A polyphasic taxonomy study was undertaken of three strains of Pseudoalteromonas haloplanktis subsp. tetraodonis (Simidu et al. 1990) Gauthier et al. 1995. DNA was prepared from each of the strains and genomic relatedness was measured by DNA-DNA hybridization. Strains KMM 458T and IAM 14160T shared 99% genetic relatedness, but were only 48-49% related to the type strain of Pseudoalteromonas haloplanktis subsp. haloplanktis, IAM 12915T. The third strain, P. haloplanktis subsp. tetraodonis A-M, showed 83% genetic similarity with P. haloplanktis subsp. haloplanktis IAM 12915T and 32% with KMM 458T. From these results, it is concluded that strains KMM 458T and IAM 14160T comprise a separate species, originally described as Alteromonas tetraodonis, whereas strain A-M belongs to the species Pseudoalteromonas haloplanktis. Based on phenotypic and chemotaxonomic data, genomic fingerprint patterns, DNA-DNA hybridization data and phylogenetic analysis of 16S rRNA, it is proposed that the species Alteromonas tetraodonis be retrieved and recognized as Pseudoalteromonas tetraodonis comb. nov. (type strain IAM 14160T = KMM 458T).

Shewanella japonica sp. nov

Two strains of agar-digesting bacteria, KMM 3299T and KMM 3300, respectively isolated from sea water and the mussel Protothaca jedoensis, have been characterized. Based on sequencing of the 16S rRNA gene, KMM 3299T showed the highest similarity (93-95%) to members of the genus Shewanella. The G+C contents of the DNAs of these strains were 43-44 mol%. The level of DNA homology between the two strains was conspecific (95%), indicating that they represent a distinct genospecies. These organisms were non-pigmented, Gram-negative, polarly flagellated, facultatively anaerobic, mesophilic, neutrophilic and able to degrade a wide range of high molecular mass polymers, including alginate, carrageenan, laminaran and agar. The novel organisms were susceptible to gentamycin, carbenicillin, lincomycin and oleandomycin. The predominant cellular fatty acids were i-15:0, 16:0, 16:1(n-7), 18:1(n-7). Eicosapentaenoic acid, 20:5(n-3), was detected in the two isolates at levels of 1-8%, depending on the temperature of cultivation. Phylogenetic evidence, together with phenotypic characteristics, showed that the two isolates studied constitute a novel species of the genus Shewanella. The name Shewanella japonica is proposed; the type strain is KMM 3299T(= LMG 19691T = CIP 106860T).

Pseudomonas brassicacearum sp. nov. and Pseudomonas thivervalensis sp. nov., two root-associated bacteria isolated from Brassica napus and Arabidopsis thaliana

Bacteria isolates phenotypically related to Pseudomonas corrugata have frequently been isolated from the rhizosphere of Arabidopsis thaliana and Brassica napus grown on different soils. 16S rDNA (rrs) gene sequencing, DNA-DNA hybridization, biochemical characterization and siderophore typing showed that these isolates belong to two different species that are distinct from other species of the genus Pseudomonas, including P. corrugata. A description of properties of these two new species is given based on the study of 16 isolates. Proposed names are Pseudomonas brassicacearum (10 strains studied) and Pseudomonas thivervalensis (6 strains studied). The type strain of Pseudomonas brassicacearum is CFBP 11706T and that of Pseudomonas thivervalensis is CFBP 11261T.

Assignment of Alteromonas elyakovii KMM 162T and five strains isolated from spot-wounded fronds of Laminaria japonica to Pseudoalteromonas elyakovii comb. nov. and the extended description of the species

A marine bacterium, Alteromonas elyakovii KMM 162T, which was described recently, and five strains isolated from spot-wounded fronds of Laminaria japonica have been subjected to phylogenetic analysis, and geno- and phenotypic characterization. The phenotypic features of Pseudoalteromonas elyakovii strains were closely related to that of Pseudoalteromonas espejiana IAM 12640T, but utilization of three carbon compounds (D-mannose, L-tyrosine and trehalose) distinguished both species. The G+C content of Pseudoalteromonas elyakovii was between 38.5 and 38.9 mol%. Pseudoalteromonas elyakovii KMM 162T and the five Laminaria isolates constitute a single species different from any other Alteromonas and Pseudoalteromonas species as revealed by DNA-DNA hybridization data, especially Pseudoalteromonas distincta KMM 638T (52.4%), Pseudoalteromonas citrea KMM 216 (49.5%), Pseudoalteromonas carrageenovora NCIMB 302T (46.9%) and Pseudoalteromonas espejiana IAM 12640T (29.9%). All the data indicated that Alteromonas elyakovii KMM 162T should be reclassified as Pseudoalteromonas elyakovii and five strains isolated from Laminaria japonica have to be included in the species. Pseudoalteromonas elyakovii comb. nov. (type strain, KMM 162T = ATCC 700519T) is proposed and a set of phenotypic features which differentiate the Pseudoalteromonas species is described.

Quantitation of the change in GADD153 messenger RNA level as a molecular marker of tumor response in head and neck cancer

Cells injured by exposure to cisplatin (cDDP) undergo a cellular injury response that shares characteristics with responses produced by many other injurious agents. We sought to determine whether the increase of the message of the "growth arrest and DNA damage-inducible" gene, GADD153, could be used to assess the extent of the cellular injury response in model systems and in patients with head and neck cancer after treatment with cDDP. The mRNA levels of GADD153, a gene highly transcriptionally activated by cDDP damage, were increased in a transient, concentration-dependent manner by cDDP when human UMSCC10b head and neck carcinoma cells were treated with cDDP both in vitro and when grown as tumor xenografts in nude mice. There was a good correlation between the change in level of GADD153 mRNA and UMSCC10b cell kill by cDDP in vitro (r = 0.98). The magnitude of the increase was proportionally reduced in UMSCC10b sublines that were 3- or 6-fold resistant to cDDP. GADD153 mRNA levels were measured in biopsies obtained before and 24 h after treatment with cDDP from 32 patients with stage III/IV head and neck cancer. There was a relationship between the increase in GADD153 mRNA levels and the response rate. Seven of the 32 patients had no response and no increase in GADD153 mRNA level. Among the eight patients who attained a partial response, the increase in GADD153 message ranged from 0.7-2.5-fold. In contrast, 17 of 32 patients had a complete response, and this was accompanied by a 2-9-fold induction of GADD153. The mean increase in the complete responders (3.8+/-2.2-fold) differed significantly from that for the partial responders (1.6+/-0.9) and nonresponders (0.8+/-0.5; P <0.05); the difference between the partial responders and nonresponders was also significant (P <0.05). An increase of GADD153 mRNA of 1.75-fold or higher predicted a complete response, with a sensitivity of 94% and a specificity of 87%. We conclude that the magnitude of the increase in GADD153 mRNA is a promising candidate for service as an intermediate marker of head and neck tumor response to cDDP. The fact that the change in GADD153 mRNA reflects the actual extent of injury sustained by the tumor makes it particularly attractive as a potential marker. One strength of this approach is that it can provide a measure of the effectiveness of therapy as early as 24-48 h after the first dose of treatment.

Burkholderia caribensis sp. nov., an exopolysaccharide-producing bacterium isolated from vertisol microaggregates in Martinique

Twenty-one exopolysaccharide-producing strains were isolated from the 5-20 microns fraction of a vertisol in the south-east of the island of Martinique in the French West Indies. Although these strains were phenotypically identified as Burkholderia cepacia or as Burkholderia glathei using BIOLOG microplates, they did not cluster genotypically by amplified rDNA restriction analysis (ARDRA) with any described Burkholderia species. A phylogenetic analysis revealed that the rrs (16S rDNA) sequences of three representative strains clustered in a single branch within the genus Burkholderia and distantly from all of the previously described species of Burkholderia for which rrs sequences were available. DNA-DNA hybridization data as well as phenotypic analyses indicated that the 21 isolates represented a single and new species for which the name Burkholderia caribensis sp. nov. is proposed (type strain MWAP64T = LMG 18531T).

Hepatitis C in a hemodialysis unit: molecular evidence for nosocomial transmission

This study reports four cases of transmission of the rare hepatitis C virus genotype 4 which occurred in a hemodialysis unit and originated from a single source of infection. Phylogenetic analyses performed with the NS5b domain showed that all four patients with secondary infections were infected with virus strains very similar to that of the index patient. Cross infections probably resulted from breaches in safety precautions and lack of dialysis machine sterilization.

Pseudoalteromonas bacteriolytica sp. nov., a marine bacterium that is the causative agent of red spot disease of Laminaria japonica

An aerobic, polarly flagellated marine bacterium that produces a prodigiosin-like pigment was isolated from the red-spotted culture beds of Laminaria japonica. Five isolates had unique bacteriolytic activity for both Gram-positive and -negative bacteria, which had never been observed among Alteromonas or related species. The isolates were identified as the causative agent of red spot disease of L. japonica seeds. The phenotypic features of the isolates were similar to these of Pseudoalteromonas rubra ATCC 29570T, but they could be differentiated using 10 traits (growth at 37 degrees C, requirement for organic growth factors, bacteriolytic activity, utilization of sucrose, N-acetylglucosamine, fumarate, succinate, D-galactose, L-proline and acetate). The G+C content of DNAs from the isolates was 44-46 mol%. The isolates constitute a new species, distinct from the other Alteromonas and Pseudoalteromonas species, as shown by DNA-DNA hybridization experiments and phylogenetic clustering of 16S rRNA gene sequences, for which the name Pseudoalteromonas bacteriolytica sp. nov. (type strain = IAM 14595T) is proposed. A set of phenotypic features which differentiate this new species from closely related Pseudoalteromonas and Alteromonas species is provided.

Comparison of DNA enzyme immunoassay and line probe assays (Inno-LiPA HCV I and II) for hepatitis C virus genotyping

Two methods for genotyping hepatitis C virus (DNA enzyme immunoassay [DEIA] and line probe assay [Inno-LiPA HCV I and II]) were compared on 120 samples and of these 87% were assigned to the same subtype by both assays. There were 15 subtyping discrepancies which involved 5% of type 1 isolates and 90% of type 2 isolates. Amplified products from the core and 5' untranslated regions (UTR) were sequenced to resolve conflicts. Type 1 discordant samples had a guanosine at position -99 in the 5' UTR, a characteristic of genotype 1b, and a core region typical of subtype 1a. The eight isolates classified as 2a/2c by LiPA and as subtype 2c by DEIA belonged to type 2.

Phase I trial of retinoic acid and cis-platinum for advanced squamous cell cancer of the head and neck based on experimental evidence of drug synergism

OBJECTIVE

Cis-platinum and 13-cis-retinoic acid have received much attention in the treatment of head and neck squamous cell cancer. Even though they have different mechanisms of action, little information is available on their interaction. This paper reviews experimental evidence for retinoic acid-cis-platinum synergy and presents toxicity data from patients with stage IV head and neck squamous cell cancer participating in a phase I trial combining 13-cis-retinoic acid and cis-platinum.

METHODS

Patients were given 13-cis-retinoic acid orally daily for 7 days before and daily during high-dose (150 mg/m2 per week for 4 weeks) intraarterial cis-platinum treatment with concurrent radiation. Toxicity was scored with use of the cancer and leukemia group B scale.

RESULTS

In the phase I clinical trial, 15 patients were treated to determine a maximum tolerated dosage for 13-cis-retinoic acid of 20 mg/day. Grade 4 hematologic toxicity was dose limiting in 3 of 8 patients treated with 40 mg/day and in 1 patient treated with 60 mg/day. There were no deaths caused by toxicity; 12 of the 15 patients received all four weekly doses and the remaining 3 received three doses. Of 10 patients with fully evaluable data, all achieved a complete response at the primary site and 9 had a complete response in the neck. One patient had persistent neck disease after chemoradiation, and this tumor was removed with neck dissection.

CONCLUSIONS

13-Cis-retinoic acid and cis-platinum are strongly synergistic against head and neck squamous cell cancer in vitro. Pretreatment with retinoic acid results in stronger synergy than concurrent drug exposure alone. Preliminary clinical experience with combined retinoic acid and cis-platinum in a design that parallels the in vitro study indicates that toxicity is acceptable with 13-cis-retinoic acid dosages of 20 mg/day in a high-dose-intensity intraarterial chemoradiation regimen.

Vibrio halioticoli sp. nov., a non-motile alginolytic marine bacterium isolated from the gut of the abalone Haliotis discus hannai

Six alginolytic, facultatively anaerobic, non-motile marine bacteria were isolated from the gut of abalone Haliotis discus hannai. DNA-DNA hybridization data showed that the six strains constituted a single genospecies. Phylogenetic analyses of 16S rDNA sequences indicated that the isolates should be assigned to the genus Vibrio. The phenotypic features of the isolates were closely related to Vibrio fischeri and Vibrio pelagius biovar I, but 13 traits (motility, luminescence, alginase production, lipase production, lysine decarboxylase, indole production, growth in 1 and 6% NaCl and assimilation of five carbon compounds) distinguished these strains from V. fischeri, and 17 traits (motility, growth at 37 degrees C, lipase production, indole production, growth in 1 and 6% NaCl, acid from sucrose and D-sorbitol, and assimilation of nine carbon compounds) distinguished these strains from V. pelagius. The G + C content of the isolates was 41.6-43.1 mol%. According to DNA-DNA hybridization data and 16S rDNA phylogenetic analyses, it was concluded that the six isolates constitute a new species different from any other Vibrio species. The name Vibrio halioticoli sp. nov. (type strain IAM 14596T) is proposed. A set of phenotypic features which enables differentiation of the new species from other species of the Vibrionaceae family is described.

Vibrio diabolicus sp. nov., a new polysaccharide-secreting organism isolated from a deep-sea hydrothermal vent polychaete annelid, Alvinella pompejana

A deep-sea, facultatively anaerobic, heterotrophic, mesophilic new organism was isolated from the polychaete annelid Alvinella pompejana collected from a deep-sea hydrothermal field in the East Pacific Rise. On the basis of phenotypic characteristics, phylogenetic analyses, and DNA-DNA relatedness, this organism was identified as a new species of the genus Vibrio, for which the name Vibrio diabolicus is proposed. In batch cultures in the presence of glucose, this organism produced an innovative exopolysaccharide. This polymer had high contents of both uronic acids and hexosamines and was similar to other polysaccharides with interesting biological activities.

Corynebacterium singulare sp. nov., a new species for urease-positive strains related to Corynebacterium minutissimum

We studied two coryneform strains from clinical specimens. These strains had type IV and corynemycolic acids in their cell walls and also had phenotypic characteristics, such as urease activity and fermentation of glucose and sucrose but not trehalose, which did not permit assignment to any previously recognized taxon. According to DNA-DNA hybridization data, these two strains are members of the same species (level of DNA similarity, 86%). Phylogenetic analysis based on comparisons of almost complete small-subunit ribosomal DNA sequences revealed that these strains are closely related to Corynebacterium minutissimum, but DNA relatedness experiments clearly showed that they constitute a distinct new species with a level of DNA relatedness to the C. minutissimum type strain of less than 40%. This new species can be differentiated from C. minutissimum strains by its enzymatic activities and carbon source utilization, and the name Corynebacterium singulare is proposed for it. The type strain is strain IBS B52218 (= CCUG 37330), which was isolated from a semen specimen.

Synergy between cisplatin and an inhibitor of S-adenosylmethionine dependent transmethylation in human ovarian adenocarcinoma cells

Selection of cells for resistance to cisplatin results in resistance to arsenite and selenite. Mammalian cells detoxify arsenite and selenite by S-adenosylmethionine dependent methylation. We aimed to investigate whether S-adenosylmethionine dependent methylation is involved in the cellular metabolism of cisplatin. Treatment of human ovarian cancer cells 2008 and the cisplatin-resistant subline 2008/C13*5.25 with the S-adenosylhomocysteine hydrolase inhibitor adenosine-dialdehyde, an indirect inhibitor of transmethylation, resulted in a significant elevation (16-fold in 2008, 6-fold in 2008/C13*5.25) in the cellular content of S-adenosylhomocysteine without changing S-adenosylmethionine. Adenosine dialdehyde synergistically enhanced the cytotoxicity of cisplatin and carboplatin as evidenced by combination indices <1 using the combination index-isobologram method in clonogenic assays with 2008 human ovarian adenocarcinoma cells. However, the cellular accumulation, efflux, steady state content, and the formation of DNA adducts of the cisplatin [H-3]-DEP were not affected by adenosine-dialdehyde. Sodium arsenite was significantly more toxic in mice pretreated with adenosine-dialdehyde, whereas the toxicity of cisplatin remained unchanged. These studies suggest that inhibition of S-adenosylmethionine dependent transmethylation enhanced the toxicity of cisplatin and carboplatin to human ovarian carcinoma cells in vitro without directly affecting the metabolism of either platinum drug.

[Castleman's disease--a rare cause of a febrile state with lymphadenopathy]

HISTORY AND CLINICAL FINDINGS

A 26-year-old man had a prolonged fever, 10 kg weight loss and generalized lymphadenopathy, first diagnosed as a malignant lymphoma. On admission he was febrile and in a markedly reduced physical condition. Submandibular, angular, cubital and inguinal lymph nodes were slightly enlarged bilaterally.

INVESTIGATIONS

Serology and blood cultures were negative. Sonography and computed tomography showed enlarged lymph nodes in the neck, mediastinum, axillae, retroperitoneum and mesentery. Biopsies of lymph nodes and bone marrow revealed changes characteristic of Castleman's disease.

TREATMENT AND COURSE

Prednisone was administered, 20 mg daily for 20 days, the dose gradually reduced over 4 months. The fever ceased after 14 days and the patients's working capacity was fully restored after 7 weeks.

CONCLUSION

In a case of prolonged fever of unknown cause Castleman's disease should be included in the differential diagnosis. It at first consists of polyclonal lymphatic proliferation. But transformation to malignant lymphoma and systemic Kaposi's sarcoma have been described in the disease's generalized form.

Alteromonas infernus sp. nov., a new polysaccharide-producing bacterium isolated from a deep-sea hydrothermal vent

A deep-sea, aerobic, mesophilic and heterotrophic new bacterium was isolated from a sample of fluid collected among a dense population of Riftia pachyptila, in the vicinity of an active hydrothermal vent of the Southern depression of the Guaymas basin (Gulf of California). On the basis of phenotypic and phylogenetic analyses and DNA/DNA relatedness, the strain GY785 was recognized as a new species of the genus Alteromonas and the name of Alteromonas infernus is proposed. During the stationary phase in batch cultures in the presence of glucose, this bacterium secreted two unusual polysaccharides. The water-soluble exopolysaccharide-1 produced contained glucose, galactose, galacturonic and glucuronic acids as monosaccharides. The gel-forming exopolysaccharide-2 was separated from the bacterial cells by dialysis against distilled water and partially characterized.

Comparative variation of morphological and molecular evolution through geologic time: 28 S ribosomal RNA versus morphology in echinoids

The comparatively good fossil record of post-Palaeozoic echinoids allows rates of morphological change to be estimated over the past 260 million years and com pared with rates of molecular evolution. Parsimony analysis of morphological data, based predominantly on skeletal characteristics, and parsimony, distance and maximum likelihood analyses of molecular data, from the first 380 bases from the 5' end of the 28 S rRNA molecule, for 10 species of echinoid produce congruent phylogenies. The m olecular sequence chosen is dem onstrably far from saturation and sister groups have divergence times ranging from about 15 to 260 Ma. Parsimony analysis allows the great majority of molecular and morphological apomorphies to be placed in one of 18 independent geological time intervals, providing a direct measure of rates of evolution for periods in the geological past. Because most molecular fixed point m utations in our sequences cannot be polarized unambiguously by outgroup comparison (making the outgroup states effectively random), distance and parsimony analyses both tend spuriously to root the echinoid tree on the longest internal branch. A topology identical to that derived from morphological data is, however, obtained using Maximum Likelihood and also parsimony analysis where outgroup rooting is restricted to more conserved regions. This is taken as the correct topology for assessing rates of evolution. Overall, both morphological and molecular changes show a m oderately strong correlation with time elapsed, but a weaker correlation with one another. Statistically significant differences in evolutionary rate are found between some, but not all, pair-wise comparisons of sister lineages for both molecular and morphological data. The molecular clock rate for echinaceans is three times faster than that for cidaroids and irregular echinoids. Spearm an’s rank correlation test, which requires only relative m agnitude of changes to be known, suggests that morphological change has a slightly better correlation with time than does molecular change, averaged over all ten species. However, when just echinaceans are considered an extremely good correlation is found between the num ber of molecular changes and time elapsed, whereas morphological change remains poorly correlated. Thus, molecular rates approxim ate to a clocklike model within restricted echinoid elades, but vary significantly between clades. Averaging results over all echinoids produces a correlation that is no better than the correlation between morphological change and time elapsed.

Physical characterization of a totally synthetic rubredoxin

The entire polypeptide of hyperthermophilic Pyrococcus furiosus rubredoxin was synthesized in order to specifically probe structural determinants of protein thermostability. The uv-visible, circular dichroic, electron paramagnetic, and nuclear magnetic resonance spectra, and electrochemical properties, of the native and synthetic proteins were essentially identical. The synthetic protein had a half-life for denaturation of 24 hr at 80 degrees C. The synthetic protein is considerably more thermostable than nonhyperthermophilic rubredoxins, but not as stable as the native protein. Based on the spectroscopic evidence, it appears that the synthetic protein is incorporating iron properly to form holoprotein, but the peptide still may not be folded correctly.

[Nonbacterial thrombotic endocarditis: a contribution to the clinical differential diagnosis in culture-negative endocarditis]

Nonbacterial thrombotic endocarditis is rarely diagnosed before death. We report on 3 patients with nonbacterial thrombotic endocarditis to illustrate the clinical course of this disease that can cause severe systemic thromboembolism and may be the first manifestation of malignant disease. Nonbacterial thrombotic endocarditis must be considered in the differential diagnosis of culture-negative endocarditis.

Bacterial diversity in a deep-subsurface clay environment

The presence of bacteria in a deep clay sediment was analyzed in a 20-m-long core horizontally drilled from a mine gallery at a depth of 224 m in the Boom clay formation (Mol, Belgium). This clay deposit is the result of a marine sedimentary process that occurred 35 million years ago. Bacterial activities were estimated by measuring respiration on [14C]glucose. Using the same samples, universal primers for the genes coding for eubacterial 16S rRNA were used to amplify extracted DNA. PCR products were then cloned, sequenced, and analyzed by molecular phylogeny. Our data showed a decrease in bacterial densities as a function of distance from the gallery, with few bacteria detectable by culture at more than 80 cm from the gallery wall. PCR experiments showed the presence of bacteria in all samples, and phylogenetic analyses were then used to tentatively identify these organisms. Because of low bacterial densities in deep clay samples, direct counts and enumeration of viable bacteria on diverse culture media remained negative. All experiments, both cultures and PCR, demonstrated the difficulty of analyzing samples that contain only a few poorly active bacteria as it is difficult to avoid a small contamination by active bacteria during sampling. Since the porosity of the Boom clay formation is less than the expected size of bacteria, it is possible that some of the bacteria present in this 35-million-year-old deep clay deposit derive from cells initially trapped during the sedimentation process.

Bacteremia due to Gordona sputi in an immunocompromised patient

We report a case of bacteremia due to a strain identified as Gordona sputi in a patient with metastatic melanoma. The origin of infection remains unknown, but extensive cutaneous lesions due to interleukin-2 treatment may have been the portal of entry. The isolate was related to G. sputi on the basis of its biochemical and genomic properties but exhibited some differences from the type strain.

Species identities and antimicrobial susceptibilities of corynebacteria isolated from various clinical sources

Over a 14-month period, 415 clinical isolates of coryneform gram-positive rods were recovered from various sources and identified to the species level according to recent identification schemes. Corynebacterium urealyticum, Corynebacterium striatum, Corynebacterium amycolatum, and Corynebacterium jeikeium predominated, accounting for 63% of all isolates. Corynebacterium accolens, Corynebacterium striatum, Corynebacterium argentoratense, Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum were mostly recovered from the respiratory tract, whereas Corynebacterium afermentans, CDC group G, and Corynebacterium jeikeium were mainly isolated from blood. None of the isolates was identified as Corynebacterium diphtheriae or Corynebacterium xerosis. Ampicillin resistance was detected in Corynebacterium jeikeium (96%) and Corynebacterium urealyticum (99%) and varied among Corynebacterium amycolatum (56%) and CDC group G (26%). These data emphasize the need for an accurate identification of coryneform organisms at the species level and for antimicrobial susceptibility testing of these organisms.

Expression of estrogen and progesterone receptors in cytologic specimens using various fixatives

Estrogen and progesterone receptor reactivity may be useful in identifying possible primary sites of metastatic disease or directing therapy in tumors of the female genital tract, including breast, ovary, and endometrium. Various methods have been described for the immunocytochemical evaluation of estrogen receptor (ER) and progesterone receptor (PR) status of cytologic specimens but our results have been variable. We evaluated the effectiveness of various fixatives [cytospin collection fluid, Shandon, Pittsburgh, PA (SH); ethanol (ETH); and formalin (FOR)] for fixation of smears (SM) and cell block (CB) material. The percentage and intensity of tumor nuclei of SM, CB, and tissue sections (TS) stained for ER and PR by the avidin-biotin-peroxidase complex technique were compared. Samples were considered ER or PR positive when > or = 20% of tumor nuclei were stained. The sensitivity of ER analysis of SMs and CBs in each fixative compared to formalin-fixed paraffin-embedded tissue sections were as follows: SM (SH) 88%, SM (ETH) 14%, CB (SH) 58%, CB (ETH) 43%, and CB (FOR) 70%. The sensitivity of PR determination on SMs and CBs was SM (SH) 71%, SM (ETH) 6.0%, CB (SH) 25%, CB (ETH) 33%, CB (FOR) 80%. These findings indicate that of the fixatives evaluated for ER analysis, SMs fixed in SH provided the best results. For PR evaluation, CBs fixed in FOR gave the best results.

Genetic identification of cryptic genospecies of Haemophilus causing urogenital and neonatal infections by PCR using specific primers targeting genes coding for 16S rRNA

Previous genetic analysis of Haemophilus influenzae strains isolated from genital and neonatal infections identified a group of biotype IV that constitutes a cryptic genospecies only distantly related to H. influenzae and H. Haemolyticus. Small-subunit rRNA genes of two representative strains of this genital Haemophilus genospecies (strains 16N and 2406) were sequenced. The analysis indicated that these strains form a monophyletic unit with H. haemolyticus and H. influenzae biogroups Influenzae and Aegyptius and are more closely related to H. haemolyticus than to H. influenzae biogroups Influenzae and Aegyptius. 16S rRNA gene sequences were used to formulate primers for PCR-based identification of cryptic genital Haemophilus organisms. A 242-bp fragment was amplified from strains belonging to the genital Haemophilus genospecies but not from strains of 12 other Haemophilus species, including strains of H. influenzae biotype IV sensu stricto.

A recent fixation of cfiA genes in a monophyletic cluster of Bacteroides fragilis is correlated with the presence of multiple insertion elements

Small-subunit ribosomal DNA sequences of 16 strains of Bacteroides fragilis were determined and compared with previously published sequences. Three phylogenetic methods (the neighbor-joining, maximum-likelihood, and maximum-parsimony methods) as well as a bootstrap analysis were used to assess the robustness of each topology. All phylogenetic analyses demonstrated that the B. fragilis strains were clearly divided into two robust monophyletic units which corresponded to the cfiA-negative and cfiA-positive groups. Strains of two previously identified DNA homology groups separated similarly into the two monophyletic units. According to the intensity of the hybridization signal with a cfiA probe, the cfiA-positive cluster could be further divided into two groups. This difference might reflect the existence of two, probably closely related cfiA-type genes. In the strongly hybridizing cfiA-positive strains, the gene is capable of conferring high-level resistance to the carbapenems and to most beta-lactamase inhibitors as well, while in the weakly hybridizing cfiA-positive strains, only the latter type of resistance is known to occur. The presence of the cfiA-type genes within a monophyletic cluster of B. fragilis that apparently represents only a minority of the species B. fragilis is suggestive of a recent acquisition. The fact that this cluster is also the predominant pool of all known B. fragilis insertion elements, which have been found to play an important role in the expression of carbapenem resistance, raises the possibility that both genetic determinants, i.e., the resistance gene(s) and insertion elements, may have coevolved.

Sequence heterogeneities among 16S ribosomal RNA sequences, and their effect on phylogenetic analyses at the species level

We have analyzed what phylogenetic signal can be derived by small subunit rRNA comparison for bacteria of different but closely related genera (enterobacteria) and for different species or strains within a single genus (Escherichia or Salmonella), and finally how similar are the ribosomal operons within a single organism (Escherichia coli). These sequences have been analyzed by neighbor-joining, maximum likelihood, and parsimony. The robustness of each topology was assessed by bootstrap. Sequences were obtained for the seven rrn operons of E. coli strain PK3. These data demonstrated differences located in three highly variable domains. Their nature and localization suggest that since the divergence of E. coli and Salmonella typhimurium, most point mutations that occurred within each gene have been propagated among the gene family by conversions involving short domains, and that homogenization by conversions may not have affected the entire sequence of each gene. We show that the differences that exist between the different operons are ignored when sequences are obtained either after cloning of a single operon or directly from polymerase chain reaction (PCR) products. Direct sequencing of PCR products produces a mean sequence in which mutations present in the most variable domains become hidden. Cloning a single operon results in a sequence that differs from that of the other operons and of the mean sequence by several point mutations. For identification of unknown bacteria at the species level or below, a mean sequence or the sequence of a single nonidentified operon should therefore be avoided. Taking into account the seven operons and therefore mutations that accumulate in the most variable domains would perhaps increase tree resolution. However, if gene conversions that homogenize the rRNA multigene family are rare events, some nodes in phylogenetic trees will reflect these recombination events and these trees may therefore be gene trees rather than organismal trees.

Nocardia pseudobrasiliensis sp. nov., a new species of Nocardia which groups bacterial strains previously identified as Nocardia brasiliensis and associated with invasive diseases

We studied five strains of a new Nocardia taxon recently identified among Nocardia brasiliensis strains associated with invasive diseases (R. J. Wallace, Jr., B. A. Brown, Z. Blacklock, R. Ulrich, K. Jost, J. M. Brown, M. M. McNeil, G. Onyi, V. A. Steingrube, and J. Gibson, J. Clin. Microbiol. 33:1528-1533, 1995) to determine their taxonomic status. Several characteristics of these organisms, including the presence of chemotype IV cell walls, nocardomycolic acids, a predominant menaquinone similar to that of Nocardia asteroides ATCC 19247T (T = type strain), and G+C contents ranging from 67 to 68 mol%, are characteristics of the genus Nocardia. Phylogenies based on small-subunit ribosomal DNA sequences clearly confirmed that all five strains belong to the genus Nocardia and occur on a single branch that is clearly distinct from N. brasiliensis. This branch forms a clade with Nocardia vaccinii, Nocardia nova, Nocardia otitidiscaviarum, and Nocardia seriolae. The five new strains exhibited high levels of DNA relatedness with each other, as determined by DNA-DNA hybridization experiments (S1 nuclease procedure), but not with N. brasiliensis strains or with strains of the four phylogenetically related Nocardia species mentioned above. The five new strains differ from N. brasiliensis in the following characteristics: mycolic acid pattern, decomposition of adenine, nitrate reduction, and antimicrobial agent susceptibilities. Therefore, we propose that these strains belong to a new species, Nocardia pseudobrasiliensis. The type strain is strain ATCC 51512, which was isolated from a leg abscess on a patient suffering from ulcerative colitis.

Description of a new polymer-secreting bacterium from a deep-sea hydrothermal vent, Alteromonas macleodii subsp. fijiensis, and preliminary characterization of the polymer

A deep-sea, aerobic, mesophilic, heterotrophic bacterium was isolated from fluid collected near an active hydrothermal vent. On the basis of phenotypic and phylogenetic analyses and DNA-DNA relatedness, strain ST716 could be assigned to the species Alteromonas macleodii as a new subspecies. This bacterium secreted an unusual high-molecular-weight polysaccharide in the presence of glucose in batch cultures. The viscosity of this exopolysaccharide is of the same order of magnitude as that of xanthan, another bacterial polysaccharide of industrial interest. This polysaccharide, produced during the stationary phase, contained glucose, mannose, pyruvated mannose, and galactose along with galacturonic acid and glucuronic acid.

[Chronic hepatitis B infection and liver failure following kidney transplantation]

Chronic liver diseases, especially due to chronic hepatitis B virus infection, are among the leading causes of late mortality in renal transplant recipients. We report on 4 HBsAg-positive patients observed over a period of 8 years, who were free of symptomatic liver disease for 7-19 years after renal transplantation and died within a few days of acute hepatic failure. The cases presented document the prognostic relevance of chronic hepatitis B virus infection in renal transplant recipients and illustrate that an asymptomatic HBsAg carrier state can evolve within a very short time to fatal liver disease.

Comparison of phenotypical and molecular methods for the identification of bacterial strains isolated from a deep subsurface environment

Vol. 61, no. 9, p. 3406: the Acknowledgments should read as follows. "This work was supported by the CNRS and by grants of the European Community and ANDRA as part of the project Archimede-Argiles and of the Direction de la Recherche et des Etudes Doctorales. V.B. was a recipient of a CIFRE fellowship." [This corrects the article on p. 3400 in vol. 61.].

Phylogeny of the genus Corynebacterium deduced from analyses of small-subunit ribosomal DNA sequences

We determined almost complete small-subunit ribosomal DNA sequences of 50 reference strains belonging to the genera Corynebacterium, Rhodococcus, and Gordona and compared these sequences with previously published sequences. Three phylogenetic methods (the neighbor-joining, maximum-likelihood, and maximum-parsimony methods), as well as a bootstrap analysis, were used to assess the robustness of each topology which we obtained. The results of comparative phylogenetic analyses confirmed that the genera Corynebacterium, Dietzia, Gordona, Mycobacterium, Nocardia, Tsukamurella, and Turicella form a monophyletic taxon within the phylum containing the high-G+C-content gram-positive bacteria. The genus Corynebacterium appeared to be a monophyletic unit whose members could be divided into four major clusters. The validity of the genus Turicella is doubtful since members of this genus clearly belong to the genus Corynebacterium. The variability of chemotaxonomic characteristics within the genus Corynebacterium suggests that small-subunit ribosomal DNA sequence analysis is probably the most straightforward method for confirming that a bacterium belongs to this genus.

Phylogenetic analysis of the genera Alteromonas, Shewanella, and Moritella using genes coding for small-subunit rRNA sequences and division of the genus Alteromonas into two genera, Alteromonas (emended) and Pseudoalteromonas gen. nov., and proposal of twelve new species combinations

Small-subunit ribosomal DNA sequences were determined for 17 strains belonging to the genera Alteromonas, Shewanella, Vibrio, and Pseudomonas, and these sequences were analyzed by phylogenetic methods. The resulting data confirmed the existence of the genera Shewanella and Moritella, but suggested that the genus Alteromonas should be split into two genera. We propose that a new genus, the genus Pseudoalteromonas, should be created to accommodate 11 species that were previously Alteromonas species, including Pseudoalteromonas atlantica comb. nov., Pseudoalteromonas aurantia comb. nov., Pseudoalteromonas carrageenovoa comb. nov., Pseudoalteromonas citrea comb. nov., Pseudoalteromonas denitrificans comb. nov., Pseudoalteromonas espejiana comb. nov., Pseudoalteromonas haloplanktis comb. nov. (with two subspecies, Pseudoalteromonas haloplanktis subsp. haloplanktis comb. nov. and Pseudoalteromonas haloplanktis subsp. tetraodonis comb. nov.), Pseudoalteromonas luteoviolacea comb. nov., Pseudoalteromonas nigrifaciens comb. nov., Pseudoalteromonas rubra comb. nov., and Pseudoalteromonas undina comb, nov., and one species that previously was placed in the genus Pseudomonas, Pseudoalteromonas piscicida comb. nov. We propose that P. haloplanktis (type strain, ATCC 14393) should be the type species of the genus Pseudoalteromonas. At this time the emended genus Alteromonas is restricted to a single species, Alteromonas macleodii.

Corynebacterium seminale sp. nov., a new species associated with genital infections in male patients

We studied 12 coryneform isolates having similar biochemical profiles which did not permit their assignment to any recognized taxa. Human semen was the source for seven of these strains, whereas the other strains were isolated from urethra, urine, and blood specimens of adult male patients. These bacteria were found in significant quantities (10(4) to 10(5) CFU/ml) in semen specimens from infertile male patients with the diagnosis of prostatitis. These strains had characteristics of the genus Corynebacterium, such as 60 mol% G + C in the DNA and corynemycolic acids, meso-diaminopimelic acid, arabinose, and galactose in the cell wall. Quantitative DNA-DNA hybridizations (S1 nuclease procedure) and phylogenies based on comparisons of almost-complete small-subunit ribosomal DNA sequences confirmed that these strains constitute a single new species within the genus Corynebacterium. All 12 strains showed similar phenotypic features, i.e., good growth on sheep blood agar in contrast with poor growth on the same medium supplemented with 1% Tween 80, a positive CAMP test in the presence of Staphylococcus aureus, glucose and sucrose fermentation, and the presence of beta-glucuronidase. Some strains reduced nitrate and hydrolyzed urea or esculin. These features allowed us to distinguish these strains from members of any other coryneform taxon, and the proposed name is Corynebacterium seminale with strain IBS B12915 (CIP 104297) as the type strain. The description and delineation of these strains as a new species should be useful for further studies, including evaluations of their prevalence among the normal flora and their clinical implications.

Phylogenetic relationships of human-pathogenic Cladosporium (Xylohypha) species inferred from partial LS rRNA sequences

The controversy about the appropriate taxonomic placement of agents of subcutaneous and systemic mycoses in either Cladosporium or Xylohypha, both genera characterized by conidia being produced in dry, acropetal chains, was addressed with partial sequencing of LS ribosomal RNA. Observation of catenate anamorphs in species of Capronia (Ascomycotina, Herpotrichiellaceae), a genus which also has anamorphs in Exophiala, suggested the possibility of a close interrelationship of all human-associated taxa. To test this hypothesis, partial sequences of 43 strains of Cladosporium/Xylohypha were analysed. Human-pathogenic and saprophytic Cladosporium species were found to be phylogenetically distinct from each other and, on the basis of known teleomorph relationships, were considered to be anamorphs of Herpotrichiellaceae and Mycosphaerellaceae, respectively. They should therefore be classified in different anamorph-genera; Cladosporium being restricted to plant-associated species. A relatively large proportion of the Herpotrichiellaceae is presumed to be animal-associated. The black yeast genus Exophiala was also confirmed to be of herpotrichiellaceous relationship. The genus Xylohypha is unrelated.

Corynebacterium argentoratense sp. nov., from the human throat

A new Corynebacterium species, Corynebacterium argentoratense was isolated from the throats of four human patients. It is characterized by the presence of chemotype IV, a cell wall, corynomycolic acids, and a G+C content ranging from 60 to 61 mol%. Strains belonging to this species exhibit high levels of DNA relatedness as determined by DNA-DNA hybridization experiments (S1 nuclease procedure) but no close DNA relatedness with related Corynebacterium species. Phylogenies based on comparative analyses of nearly complete small-subunit rDNA sequences confirmed the inclusion of this new species within the genus Corynebacterium and grouped it in a cluster with C. diphtheriae, C. ulcerans, C. pseudotuberculosis, and C. kutscheri. PCR experiments revealed an absence of the gene coding for diphtheria toxin. This new species can be identified by its mycolic acid pattern, fermentation of sugars, and enzymatic activities. Strain IBS B10697 (CIP 104296) is the type strain of C. argentoratense.

Roseobacter algicola sp. nov., a new marine bacterium isolated from the phycosphere of the toxin-producing dinoflagellate Prorocentrum lima

We describe a new species on the basis of phenotypic characteristics and the results of an analysis of small-subunit rRNA sequences. Three strains of this organism were isolated from a culture of the toxin-producing dinoflagellate Prorocentrum lima. These bacteria are gram-negative, strictly aerobic, ovoid organisms that are motile by means of one or two subpolar flagella. They grow at temperatures ranging from 10 to 37 degrees C and in the presence of NaCl concentrations ranging from 0.1 to 2 M and have an absolute requirement for sodium ions. They are strictly aerobic with a nonfermentative type of metabolism and are not able to grow anaerobically in presence or absence of nitrate. They do not denitrify. They exhibit oxidase, catalase, gelatinase, esculinase, beta-galactosidase, and (to a lesser extent) amylase activities. The three strains which we examined require thiamine and biotin for growth. They grow only when glucose, trehalose, saccharose, fructose, maltose, pyruvate, malate, citrate, esculin, 2-ketoglutarate, 5-ketogluconate, glutamate, or shikimate is present as a sole carbon source. The three strains have identical small-subunit rRNA sequences. A phylogenetic analysis of these sequences revealed that these bacteria belong to the alpha subdivision of the Proteobacteria and that they form a distinct and robust monophyletic group with Roseobacter denitrificans and Roseobacter litoralis. This result and the general phenotypic characteristics of the organisms place them in the genus Roseobacter, although they do not produce bacteriochlorophyll a, in contrast to previously described Roseobacter species.(ABSTRACT TRUNCATED AT 250 WORDS)

Taxonomy of Corynebacterium diphtheriae and related taxa, with recognition of Corynebacterium ulcerans sp. nov. nom. rev

Levels of genomic DNA relatedness were determined using a S1 nuclease procedure for reference bacteria identified as biotypes of Corynebacterium diphtheriae, biovars of Corynebacterium pseudotuberculosis, and 'Corynebacterium ulcerans'. These results showed that the three species are separate taxa at the genomospecies level whereas biotypes and biovars are closely related genomically within each species. Phylogenetic analyses of small-subunit rDNA sequences revealed that 'Corynebacterium ulcerans' forms a tight cluster with Corynebacterium pseudotuberculosis within the robust branch that groups all Corynebacterium sequenced to date. Therefore, we propose that the species incertae sedis 'C. ulcerans' should be conclusively recognized as a distinct species within the genus Corynebacterium with strain CCUG 2708 = NCTC 7910 as type strain. This species is characterized by urease production and fermentation of glycogen.

Small-subunit rRNA sequences and whole DNA relatedness concur for the reassignment of Pasteurella piscicida (Snieszko et al.) Janssen and Surgalla to the genus Photobacterium as Photobacterium damsela subsp. piscicida comb. nov

The taxonomic status of Pasteurella piscicida (strain NCIMB 2058T [T = type strain] and a strain isolated from the environment) was investigated by performing phylogenetic analyses of small-subunit rRNA sequences, DNA-DNA hybridization analyses, and biochemical characterization analyses. The results of the phylogenetic analyses and the levels of DNA-DNA complementarity demonstrated conclusively that Pasteurella piscicida is extremely closely related to Photobacterium damsela ATCC 33539T. Since the two taxa exhibited a level of DNA-DNA relatedness of 80%, they are members of the same species. The high level of DNA relatedness and the presence of specific morphological and biochemical characteristics support the hypothesis that two subspecies should be recognized. On the basis of its phylogenetic position, we concluded that Pasteurella piscicida should be renamed Photobacterium damsela subsp. piscicida comb. nov.