Bacteremia caused by a novel species of Sphingobacterium.

A Gram-negative rod was isolated from the blood cultures of an 84-year-old man with foot cellulitis. The bacterium was first identified as Sphingobacterium spiritivorum on the basis of standard assimilation tests. However, sequencing analysis of its 16S rRNA genes and whole genome hybridization studies with other related bacteria showed that this isolate belongs to a so far undescribed species of Sphingobacterium, close to S. mizutae. This bacterium was susceptible to most of the antibiotics tested, including glycopeptides, but was resistant to aminoglycosides and polymyxins. Treatment with amoxicillin-clavulanate cured the infection.

[Isolation and characterization of injured coliforms from the drinking water distribution network of La Plata, Argentina]. / Aislamiento y caracterización de coliformes injuriados provenientes de la red de distribución de agua de bebida de La Plata, Argentina.

We screened the La Plata drinking water distribution network for fecal and total coliform bacterial indicator by purification procedures, cultivating 66 membrane-filtered samples from the two networks on m-T7 agar. Subterranean and river-derived water yielded 13 and 18 confirmed gram-negative bacillus isolates, with 54% and 72% representing total coliforms, respectively. Those from the former source were Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter aerogenes and from the latter Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter cloacae, genomic group 3. Since 58% of the samples were positive using m-T7 medium it is suggested that the inclusion in standard quality control protocols should be implemented.

Aislamiento y caracterización de coliformes injuriados provenientes de la red de distribución de agua de bebida de La Plata, Argentina / Isolation and characterization of injured coliforms from the drinking water distribution network of La Plata, Argentina

We screened the La Plata drinking water distribution network for fecal and total coliform bacterial indicator by purification procedures, cultivating 66 membrane-filtered samples from the two networks on m-T7 agar. Subterranean and river-derived water yielded 13 and 18 confirmed gram-negative bacillus isolates, with 54 and 72 representing total coliforms, respectively. Those from the former source were Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter aerogenes and from the latter Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter cloacae, genomic group 3. Since 58 of the samples were positive using m-T7 medium it is suggested that the inclusion in standard quality control protocols should be implemented.

Aislamiento y caracterización de coliformes injuriados provenientes de la red de distribución de agua de bebida de La Plata, Argentina / Isolation and characterization of injured coliforms from the drinking water distribution network of La Plata, Argentina

We screened the La Plata drinking water distribution network for fecal and total coliform bacterial indicator by purification procedures, cultivating 66 membrane-filtered samples from the two networks on m-T7 agar. Subterranean and river-derived water yielded 13 and 18 confirmed gram-negative bacillus isolates, with 54 and 72 representing total coliforms, respectively. Those from the former source were Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter aerogenes and from the latter Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter cloacae, genomic group 3. Since 58 of the samples were positive using m-T7 medium it is suggested that the inclusion in standard quality control protocols should be implemented.(AU)

Aislamiento y caracterización de coliformes injuriados provenientes de la red de distribución de agua de bebida de La Plata, Argentina. / [Isolation and characterization of injured coliforms from the drinking water distribution network of La Plata, Argentina]

We screened the La Plata drinking water distribution network for fecal and total coliform bacterial indicator by purification procedures, cultivating 66 membrane-filtered samples from the two networks on m-T7 agar. Subterranean and river-derived water yielded 13 and 18 confirmed gram-negative bacillus isolates, with 54

and 72

representing total coliforms, respectively. Those from the former source were Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter aerogenes and from the latter Klebsiella oxytoca, Enterobacter agglomerans, and Enterobacter cloacae, genomic group 3. Since 58

of the samples were positive using m-T7 medium it is suggested that the inclusion in standard quality control protocols should be implemented.

Classification of Brucella strains isolated from marine mammals using DNA-DNA hybridization and ribotyping.

DNA-DNA hybridization showed that the Brucella strains recently isolated from marine mammals belong to the monospecific genus Brucella (more than 77% DNA relatedness). Ribotyping (HindIII rDNA restriction patterns) showed that they may represent a separate subgroup (marine type) specifically associated with marine mammals.

Biochemical identification of Citrobacter species defined by DNA hybridization and description of Citrobacter gillenii sp. nov. (formerly Citrobacter genomospecies 10) and Citrobacter murliniae sp. nov. (formerly Citrobacter genomospecies 11).

Recent work describing six named species and two unnamed genomospecies within Citrobacter has enlarged the genus to 11 species. DNA relatedness and phenotypic tests were used to determine how well these species can be identified. One hundred thirty-six strains were identified to species level by DNA relatedness and then identified phenotypically in a blinded fashion. By using conventional tests, 119 of the 136 strains (88%) were correctly identified to species level. Three additional strains (2%) were identified as citrobacteria but were not identified to species level, and 14 strains (10%) were misidentified as other Citrobacter species. Carbon source utilization tests were used to identify 86 of the strains. Eighty-four strains (98%) were correctly identified, and two strains (2%) were misidentified as other Citrobacter species. Additional strains of Citrobacter genomospecies 10 and Citrobacter genomospecies 11 were identified, allowing these species to be formally named as Citrobacter gillenii sp. nov. and Citrobacter murliniae sp. nov., respectively.

A nosocomial outbreak due to Enterobacter cloacae strains with the E. hormaechei genotype in patients treated with fluoroquinolones.

During a 7-month period, we isolated 21 highly fluoroquinolone-resistant Enterobacter cloaecae strains in units from two hospitals in Marseille, France. Random amplification of polymorphic DNA showed clonal identity between isolates which, furthermore, presented the Enterobacter hormaechei genotype on DNA-DNA hybridization. The emergence of this clone was observed only in patients treated with fluoroquinolones.

Haloanaerobium congolense sp. nov., an anaerobic, moderately halophilic, thiosulfate- and sulfur-reducing bacterium from an African oil field.

A strictly anaerobic, moderately halophilic, Gram-negative, non-motile rod-shaped bacterium was isolated from an oil-well head sample of an offshore Congolese oil field. The strain, designated SEBR 4224T (T = type strain), grew optimally at 42 degrees C and pH 7.0 in a complex medium containing 10% NaCl with a generation time of 2.5 h. Strain SEBR 4224T grew on a range of carbohydrates including fructose, galactose, D-glucose, maltose, D-mannose, D-ribose, sucrose, and trehalose. Yeast extract and/or bio-Trypcase was required for growth on carbohydrates and could not be replaced with amino acids and/or vitamins. The end-products from glucose fermentation were acetate, H2, and CO2. Thiosulfate and elemental sulfur were used as electron acceptors. Thiosulfate improved carbohydrate utilization and biomass yields. The G + C content of the isolate was 34 mol%. Ribosomal 16S rRNA sequence analysis showed that strain SEBR 4224T is a new member of the genus Haloanaerobium. The lack of DNA homology with H. acetoethylicum, its closest relative, as determined by DNA-DNA hybridization supports the designation of strain SEBR 4224T as a new species, Haloanaerobium congolense sp. nov. The type strain is SEBR 4224T (= DSM 11287).

Composition of the Lactobacillus acidophilus complex isolated from vaginal flora.

One hundred and fifty human vaginal samples containing a diversity of pathogens or nonpathogens (Gardnerella vaginalis, Streptococcus sp., Staphylococcus sp., Candida albicans. Mycoplasma sp.) were examined for their content in lactobacilli of the Lactobacillus acidophilus complex. Although all samples contained lactobacilli, strains of the L. acidophilus complex were present in only twenty-nine cases. Isolates were further characterized and compared with type strains or reference strains in an attempt to differentiate by phenotypic means the genospecies of the L. acidophilus complex. Data regarding specific activities of beta-galactosidase (beta-gal) and of phospho-beta-galactosidase (P-beta-gal) provided no specific information at the species level within the L. acidophilus complex. DNA-relatedness differentiates this genospecies. Most lactobacilli isolated from the vaginal flora of symptomatic women were genotypically close to L. gasseri CIP 102991T by the technique of DNA/DNA hybridization.

Description of Thermoanaerobacter brockii subsp. lactiethylicus subsp. nov., isolated from a deep subsurface French oil well, a proposal to reclassify Thermoanaerobacter finnii as Thermoanaerobacter brockii subsp. finnii comb. nov., and an emended description of Thermoanaerobacter brockii.

A strictly anaerobic, thermophilic, gram-positive, spore-forming cubacterium designated strain SERB 5268T (T = type strain) was isolated from an oil field at a depth of 2,100 m, where the temperature was 92 degrees C. The cells of this organism were gram-positive, straight, motile rods (0.5 by 2 to 3 microns) with peritrichous flagella. The cells occurred singly or in pairs during the logarithmic growth phase, but were pleomporphic and filamentous (length, 15 microns) in old cultures. Growth occurred at temperatures of 40 to 75 degrees C, and optimum growth occurred at temperatures between 55 and 60 degrees C. The fermentable substrates included glucose, fructose, galactose, mannose, cellobiose, maltose, sucrose, lactose, D-xylose, D-ribose, mannitol, pyruvate, and starch. The products of fermentation of glucose were lactate, acetate, ethanol, H2, and CO2. The DNA base composition was 35 mol% G+C. The results of 16S rRNA sequence comparisons indicated that strain SEBR 5268T was closely related to Thermoanaerobacter brockii and Thermoanaerobacter finnii, and these three organisms exhibited levels of ribosomal DNA sequence homology of 98 to 99%. The results of DNA-DNA hybridization studies performed with the three organisms confirmed this close affiliation, and as base pairing values of > 70% were obtained, these organisms belong to the same species. Therefore, we propose that T. finnii should be reclassified as a subspecies of T. brockii, Thermoanaerobacter brockii subsp. finnii comb. nov. This automatically creates Thermoanaerobacter brockii subsp. brockii. We also propose that strain SEBR 5268T should be classified as a member of a new subspecies of T. brockii, Thermoanaerobacter brockii subsp. lactiehylicus.(ABSTRACT TRUNCATED AT 250 WORDS)

Haloanaerobium lacusroseus sp. nov., an extremely halophilic fermentative bacterium from the sediments of a hypersaline lake.

A new extremely halophilic chemoorganotrophic bacterium (strain H200T [T = type strain]) was isolated from the hypersaline sediments of Retba Lake in Senegal. This organism was a sluggishly motile, rod-shaped, non-spore-forming, gram-negative, obligate anaerobe that grew optimally at 40 degrees C in the presence of 180 to 200 g of NaCl per liter. The DNA base composition was 32 mol% guanine plus cytosine. The fermentation products from glucose were ethanol, acetate, H2, and CO2. Yeast extract was required for growth. The fermentable substrates included D-fructose, galactose, D-xylose, cellobiose, lactose, maltose, sucrose, starch, D-mannitol, glycerol, and Casamino Acids. On the basis of the results of a 16S rRNA sequence analysis, strain H200T was found to be related to Haloanaerobium species. The 16S rRNA sequence of strain H200T differed from the sequences of the three previously described Haloanaerobium species, and strain H200T also differed from these organisms in its NaCl range for growth (60 to 340 g/liter); strain H200T grew in the presence of the highest NaCl concentration recorded for any halophilic anaerobic organism, including the three previously described Haloanaerobium species. We propose that strain H200T (= DSM 10165) belongs to a new Haloanaerobium species, Haloanaerobium lacusroseus.

Taxonomic diversity of anaerobic glycerol dissimilation in the Enterobacteriaceae.

A total of 1,123 strains representing 128 taxa in the Enterobacteriaceae (named species or subspecies and genomic species) were screened for the presence of glycerol dehydrogenases and 1,3-propanediol dehydrogenase. Only eight taxa, Citrobacter freundii sensu stricto, C. youngae, C. braakii, C. werkmanii, Citrobacter genomospecies 10 and 11, Enterobacter gergoviae and Klebsiella pneumoniae subsp. pneumoniae could grow fermentatively on glycerol and possessed both glycerol dehydrogenase type I (induced by glycerol and dihydroxyacetone) and 1,3-propanediol dehydrogenase which are typical enzymes of the anaerobic glycerol dissimilation pathway. Six other species, C. koseri, E. aerogenes, E. intermedium, K. oxytoca, K. planticola and K. terrigena could not grow fermentatively on glycerol and possessed a glycerol dehydrogenase type I but no 1,3-propanediol dehydrogenase. Other glycerol dehydrogenases types were found: type II (induced by glycerol and hydroxyacetone), type III (induced by glycerol only) and type IV (induced by hydroxyacetone only). They were widely distributed among the Enterobacteriaceae. Classification and identification may take advantage of tests exploring the dissimilation of glycerol.

Classification of citrobacteria by DNA hybridization: designation of Citrobacter farmeri sp. nov., Citrobacter youngae sp. nov., Citrobacter braakii sp. nov., Citrobacter werkmanii sp. nov., Citrobacter sedlakii sp. nov., and three unnamed Citrobacter genomospecies.

DNA relatedness studies (hydroxyapatite method) were done on 112 strains of citrobacteria. By using the recommended definition of a genomospecies 11 genomospecies were identified in the genus Citrobacter. These genomospecies were separable by their biochemical profiles. Citrobacter koseri (Citrobacter diversus) and Citrobacter amalonaticus proved to be homogeneous species, as previously described. C. amalonaticus biogroup 1, as described by Farmer et al. (J. Clin. Microbiol. 21:46-76, 1985), was shown to be a separate homogeneous species, which was named Citrobacter farmeri sp. nov. The Citrobacter freundii complex was quite heterogeneous. C. freundii sensu stricto, as represented by the type strain, contained only 9 of 66 strains in this complex. The remaining 57 strains were members of seven genomospecies. Genomospecies 5, containing 21 strains, was named Citrobacter youngae sp. nov. Genomospecies 6, containing 15 strains, was named Citrobacter braakii sp. nov. Genomospecies 7 and 8, each containing six strains, were named Citrobacter werkmanii sp. nov. and Citrobacter sedlakii sp. nov., respectively. Genomospecies 9, 10, and 11, each containing three strains, were not named.

Balneatrix alpica gen. nov., sp. nov., a bacterium associated with pneumonia and meningitis in a spa therapy center.

In 1987, an outbreak of pneumonia and meningitis caused by an unknown bacterium occurred in a spa therapy centre. Nine isolates of this pathogen constituted a tight DNA hybridization group. rRNA-DNA hybridization and 16S rRNA sequencing showed that the studied bacteria represented a new branch in superfamily II (= gamma subclass) of the Proteobacteria, close to the genus Oceanospirillum. The new bacterium was highly polymorphic and, in young cultures, had curved Gram-negative cells, motile by polar single flagella. The new bacterium differed from the genus Oceanospirillum by its lacking the NaCl requirement and by reducing nitrate into nitrite, producing indole from tryptophan and producing acid from carbohydrates. The name Balneatrix alpica gen. nov., sp. nov. is proposed for the studied organism. The type strain is strain 4-87 (= CIP 103589).

Corynebacterium group D2 ("Corynebacterium urealyticum") constitutes a new genomic species.

Twenty-one Corynebacterium group D2 ("C. urealyticum") strains were found to constitute a tight DNA hybridization group distinct from named Corynebacterium species. The strains of Corynebacterium group D2 had cell wall component type IV, short chain mycolic acids and G+C content of DNA of 65-66 mol %. Corynebacterium group D2 constitutes a genomic species which can be identified by phenotypic tests.

Vibrio navarrensis sp. nov., a species from sewage.

A group of 11 strains, mostly isolated from sewage water in the Province of Navarra, Spain, were found to constitute a DNA relatedness group which is 2 to 39% related to 23 species of the genus Vibrio and 2 to 3% related to two Aeromonas species. Phenotypically, these strains have all of the properties that define the genus Vibrio. However, they differ from the previously described species by three or more properties. The strains are negative for arginine, ornithine, and lysine decarboxylase activities and the Voges-Proskauer test and are unable to utilize putrescine, gluconate, glucuronate, and histidine. They utilize and produce acid from sucrose and grow at 40 degrees C. All strains grow in the presence of 0.5% (wt/vol) NaCl, and seven strains grow weakly in peptone water lacking NaCl. The group of strains which we studied can also be differentiated from other Vibrio species by fatty acid content. The G+C ratio of the DNA is 45 to 47 mol%. The name Vibrio navarrensis sp. nov. is proposed for these strains; strain 1397-6 (= CIP 103381) is the type strain.

Molecular typing of nosocomial isolates of Legionella pneumophila serogroup 3.

In Paris, France, an outbreak of pneumonia due to Legionella pneumophila serogroup 3 was observed in Necker (four cases) and Pitié (six cases) hospitals. Neither the 10 clinical isolates nor 5 tap water isolates from Necker Hospital harbored plasmids. Clinical and environmental serogroup 3 isolates and serogroup 3 reference strain Bloomington 2 were analyzed by chromosomal probe fingerprinting. rRNA, 16S and 23S from Escherichia coli and a randomly cloned 15-kilobase-pair nucleotide sequence from L. pneumophila serogroup 3 were used as probes. All strains tested showed a single pattern after HindIII digestion of DNA and hybridization with the 32P-end-labeled rRNA probe, whereas three patterns were obtained after hybridization with the 32P-labeled 15-kilobase-pair DNA probe. One pattern was given by all clinical and tap water isolates from Necker Hospital, another one was given by all clinical isolates from Pitié Hospital, and a last one was given by reference strain Bloomington 2. Thus, molecular analysis showed that the two hospital outbreaks of legionellosis were unrelated and could link the outbreak in Necker Hospital to contaminated tap water.

rRNA gene restriction patterns of Legionella species: a molecular identification system.

A total of 28 species of Legionella could be differentiated by rRNA gene restriction patterns generated after cleavage of total DNA with either EcoRV or HindIII restriction endonucleases, and hybridization of fragments with 32P-labelled Escherichia coli 16 + 23S rRNA. Different species gave different fragment patterns. When several isolates of a species were tested, the patterns obtained were often identical. However, more than one pattern was often observed when more than one serotype was considered. The method should be useful for the identification of all species of Legionella including those exhibiting immunological cross-reactions.

Azospirillum irakense sp. nov., a nitrogen-fixing bacterium associated with rice roots and rhizosphere soil.

A new species of nitrogen-fixing bacteria, Azospirillum irakense, was found associated with roots and the rhizosphere of rice in the region of Diwaniyah (Qadisya), Iraq. The seven isolates, on which the species description is based, have vibrioid to S-shaped cells with one polar flagellum in liquid medium. Additional lateral flagella are seen on cells grown on nutrient agar. Poly-beta-hydroxybutyrate granules are present in cells. Nitrogen fixation occurs in microaerobic conditions. The phenotypic characters were found to be very close to those of A. amazonense with the following differences: growth occurred in the presence of 3% NaCl, and at pH 5.5 and 8.5, myo-inositol was not utilized as sole source of carbon and energy and pectin was slowly (6 to 9 days) hydrolysed. The seven studied strains formed a DNA-relatedness group distinct from other Azospirillum and Herbaspirillum species. The G + C content of the DNA was 64 to 67 mol %. The type strain is KBC1 (CIP 103311).