Assignment of provisionally named CDC group NO-1 strains derived from animal bite wounds and other clinical sources, to genera nova in the family Comamonadaceae: description of Vandammella animalimorsus gen. nov., sp. nov. and Franklinella schreckenbergeri gen. nov., sp. nov.

CDC group non-oxidizer (NO)-1 is the provisional name designated in 1993 for phenotypically similar, Gram-stain-negative bacilli recovered primarily from human wound infections after animal bites. Otherwise, this group has been rarely alluded to in recent literature. CDC NO-1 strains had been described as non-motile, asaccharolytic, oxidase-negative, catalase-positive, nitrate-reducing bacilli, with predominate cellular fatty acids of C10 : 0 3OH, C16 : 1 ω7c, C16 : 0 and C18 : 1 ω7c. Only one 16S rRNA gene sequence deposited in NCBI (accession no. DQ054782) had been identified as CDC group NO-1 prior to this study. That sequence was closely related (>99 % identity) to sequences called 'Xenophilus species' from canine (JN713339) and feline (KM461961) oral microbiomes as well as to sequences derived from human strains (this study). Some of the 11 isolates delineated here were recovered from human wound infections subsequent to cat/dog bites; others were from wounds (links to animal bites not described) and two were recovered from dialysates. After 16S rRNA and whole genome sequencing, the isolates were found to be most closely related to each other but fell into two distinct genera assignable to the family Comamonadaceae, provisionally discussed here as CDC group NO-1 and CDC group NO-1-like. The genomes of CDC group NO-1 isolates ranged from 3.08 to 3.38 MB with G+C contents of 65.08-66.92 %; genomes derived from CDC group NO-1-like strains were smaller, ranging from 2.72 to 2.82 Mb with G+C contents of 62.87-63.0 mol%. Based on a polyphasic study of these bacteria, we describe Vandammella animalimorsus gen. nov., sp. nov. and Franklinella schreckenbergeri gen. nov., sp. nov. for these clusters.

Corynebacterium hindlerae sp. nov., derived from a human granuloma, which forms black colonies and black halos on modified Tinsdale medium but is not closely related to Corynebacterium diphtheriae and related taxa.

Corynebacterium diphtheriae, Corynebacterium belfantii, Corynebacterium rouxii, Corynebacterium ulcerans, Corynebacterium pseudotuberculosis and Corynebacterium silvaticum are the only taxa from among ~121 Corynebacterium species deemed potentially able to harbour diphtheria tox genes. Subsequently tox-gene bearing species may potentially produce diphtheria toxin, which is linked to fatal respiratory distress if a pharyngeal pseudomembrane is formed or toxaemia develops in those unimmunized or under-immunized. Detection of diphtheria toxin-producing species may also invoke a public health response and contact tracing. Recovery of such species from the respiratory tract or other contaminated sources such as non-healing ulcerative wounds are expedited by use of differential and selective media such as modified Tinsdale medium (MTM). This medium is supplemented with potassium tellurite, which supresses most normal flora present in contaminated specimens, as well as l-cystine and thiosulphate. Most diphtheria-tox-gene bearing species grow well on MTM, producing black colonies with a black halo around each colony. This is due to an ability to produce cystinase in the presence of tellurite, cystine and thiosulphate, resulting in black tellurium deposits being observed in the agar. Other Corynebacterium species may/may not be able to grow at all in the presence of tellurite but if able to grow, will have small beige or brownish colonies which do not exhibit black halos. We describe here an unusual non-tox-gene-bearing isolate, NML 93-0612T, recovered from a human wrist granuloma, which produced black colonies with black halos on MTM agar but was otherwise distinguishable from Corynebacterium species which can bear tox genes. Distinctive features included its unusual colony morphology on MTM and sheep blood agar, by proteomic, biochemical and chemotaxonomic properties and by molecular methods. Its genome contained 2 680 694 bytes, a G+C content of 60.65 mol% with features consistent with the genus Corynebacterium and so represents a new species for which we propose the name Corynebacterium hindlerae sp. nov.

Pseudoxanthomonas winnipegensis sp. nov., derived from human clinical materials and recovered from cystic fibrosis and other patient types in Canada, and emendation of Pseudoxanthomonas spadix Young et al. 2007.

Twelve isolates recovered from 10 cystic fibrosis/other patient types and a variety of clinical sources, were referred to Canada's National Microbiology Laboratory over 7 years. These were assignable to the genus Pseudoxanthomonas but were unidentifiable to species level. Patients included five males and five females from two geographically separated provinces, ranging in age from 2 months to 84 years. In contrast, most Pseudoxanthomonas species described to date have been derived from water, plants or contaminated soils. By 16S rRNA gene sequencing, the patient strains had ≥99.4 % similarity to each other but only 97.73-98.29 % to their closest relatives, Pseudoxanthomonas spadix or Pseudoxanthomonas helianthi. Bacteria were studied by whole genome sequencing using average nucleotide identity by Blastn, digital DNA-DNA hybridization, average amino acid identity, core genome and single nucleotide variant analyses, MALDI-TOF, biochemical and cellular fatty acid analyses, and by antimicrobial susceptibility testing. Bacterial structures were assessed using scanning and transmission electron microscopy. Strains were strict aerobes, yellowish-pigmented, oxidative, non-motile, Gram-stain-negative bacilli and generally unable to reduce nitrate. Strains were susceptible to most of the antibiotics tested; some resistance was observed towards carbapenems, several cephems and uniformly to nitrofurantoin. The single taxon group observed by 16S rRNA gene sequencing was supported by whole genome sequencing; genomes ranged in size from 4.36 to 4.73 Mb and had an average G+C content of 69.12 mol%. Based on this study we propose the name Pseudoxanthomonas winnipegensis sp. nov. for this cluster. Pseudoxanthomonas spadix DSM 18855T, acquired for this study, was found to be non-motile phenotypically and by electron microscopy; we therefore propose the emendation of Pseudoxanthomonas spadix Young et al. 2007 to document that observation.

Enemella gen. nov., Enemella evansiae sp. nov., Enemella dayhoffiae sp. nov. and Parenemella sanctibonifatiensis gen. nov., sp. nov., novel taxa assignable to the family Propionibacteriaceae and derived from human clinical samples.

Nine Gram-stain-positive cocci, coccobacilli or short, rod-shaped strains recovered from clinical sources from patients located in two Canadian provinces and one environmental source were extensively studied. Clinical sources included blood cultures, cerebral spinal fluid, lymph node, lung biopsy and peritoneal fluid. Through 16S rRNA gene and whole genome sequencing analyses, the strains were found to cluster into three groups, closest to but distinguished from other genera in the family Propionibacteriaceae. The genomes from these bacteria had high G+C content, ranging from 67.8-69.56 mol%, and genome sizes of 3.02-4.52 Mb. Biochemical and chemotaxonomic properties including branched-chain cellular fatty acids, l-lysine diaminopimelic acid (ll-DAP) and cell-wall type A3γ (ll-DAP-gly) containing ll-DAP, alanine, glycine and glutamic acid were found and so the strains were therefore deemed to be consistent with other new genera in this family. Based on this investigation, we propose Enemella gen. nov., Enemella evansiae sp. nov., Enemella dayhoffiae sp. nov. and Parenemella sanctibonifatiensis gen. nov., sp. nov. for these taxa. Misidentified taxon 'Ponticoccus gilvus' was found to be assignable to Enemella evansiae based on this study.

Description of Eikenella halliae sp. nov. and Eikenella longinqua sp. nov., derived from human clinical materials, emendation of Eikenella exigua Stormo et al. 2019 and emendation of the genus Eikenella to include species which are strict anaerobes.

The Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella (HACEK) group genus Eikenella contained a single species, Eikenella corrodens, for many years. In November 2019, Eikenella exigua was described after recovery from a brain abscess and blood culture in Norway. Coincidentally, characterization of 22 Gram-negative bacteria resembling Eikenella from 17 Canadian patients had been underway. Seven isolates from five patients were conclusively identifiable as E. corrodens. One (NML 120819) was deemed to represent a species of the genus Eikenella most closely related to E. corrodens. Fourteen isolates had 97.6 to 98.8% similarities to E. corrodens by 16S rRNA gene sequencing, forming three distinct groups by genome analyses. The largest contained ten anaerobic isolates from eight patients recovered from blood, brain, bone and other abscesses; upon re-evaluation, this group was found to be most consistent with E. exigua. A second facultatively anaerobic clade consisted of two ocular isolates from one patient and a sinus isolate from a second patient. The third taxon consisted of a single strictly anaerobic blood culture isolate. The novel taxa, like E. corrodens, were poorly reactive biochemically and difficult to discern from each other phenotypically and chemotaxonomically, including by cellular fatty acids. MALDI-TOF (Bruker) and whole-genome sequencing were used to further characterize isolates. Draft genomes for the strains had similar DNA G+C contents (55.38-58.53 mol%) while sizes varied from 1.82 Mb to 2.54 Mb. We propose here emendations of the genus Eikenella and the species Eikenella exigua, as well as describing Eikenella halliae sp. nov. NML 130454T (=LMG 30894T=NCTC 14180T) and Eikenella longinqua sp. nov. NML 02-A-017T (=LMG 30896T=NCTC 14179T), on the basis of these findings.

Criibacterium bergeronii gen. nov., sp. nov., a new member of the family Peptostreptococcaceae, isolated from human clinical samples.

A rod-shaped, motile anaerobic bacterium, designated CCRI-22567T, was isolated from a vaginal sample of a woman diagnosed with bacterial vaginosis and subjected to a polyphasic taxonomic study. The novel strain was capable of growth at 30-42 °C (optimum, 42 °C), at pH 5.5-8.5 (optimum, pH 7.0-7.5) and in the presence of 0-1.5 % (w/v) NaCl (optimally at 0.5 % NaCl). The phylogenetic trees based on 16S rRNA gene sequences showed that strain CCRI-22567T forms a distinct evolutionary lineage independent of other taxa in the family Peptostreptococcaceae. Strain CCRI-22567T exhibited 90.1 % 16S rRNA gene sequence similarity to Peptoanaerobacter stomatis ACC19aT and 89.7 % to Eubacterium yurii subsp. schtitka ATCC 43716. The three closest organisms with an available whole genome were compared to strain CCRI-22567T for genomic relatedness assessment. The genomic average nucleotide identities (OrthoANIu) obtained with Peptoanaerobacter stomatis ACC19aT, Eubacterium yurii subsp. margaretiae ATCC 43715 and Filifactor alocis ATCC 35896T were 71.8, 70.3 and 69.6 %, respectively. Strain CCRI-22567T contained C18 : 1 ω9c and C18 : 1 ω9c DMA as the major fatty acids. The DNA G+C content of strain CCRI-22567T based on its genome sequence was 33.8 mol%. On the basis of the phylogenetic, chemotaxonomic and other phenotypic properties, strain CCRI-22567T is considered to represent a new genus and species within the family Peptostreptococcaceae, for which the name Criibacterium bergeronii gen. nov., sp. nov., is proposed. The type strain of Criibacterium bergeronii is CCRI-22567T (=LMG 31278T=DSM 107614T=CCUG 72594T).

Impact of cleaning monitoring combined with channel purge storage on elimination of Escherichia coli and environmental bacteria from duodenoscopes.

BACKGROUND AND AIMS: We aimed to determine whether monitoring of duodenoscope cleaning by rapid adenosine triphosphate (ATP) combined with channel-purge storage could eliminate high-concern microorganisms. METHODS: In a simulated-use study, suction channels, as well as lever recesses, from 2 duodenoscopes models and the unsealed elevator guidewire (EGW) channel from 1 of these 2 duodenoscopes (the other model has a sealed EGW) were perfused with ATS2015 containing approximately 8 Log10 colony-forming units (CFU)/mL of both Enterococcus faecalis and Escherichia coli. Pump-assisted cleaning was monitored by rapid ATP testing. Duodenoscopes exceeding 200 relative light units (RLUs) were recleaned. Clean duodenoscopes were processed through an automated endoscope reprocessor and then stored in a channel-purge storage cabinet for 1 to 3 days. Cultures of EGW channel and instrument channel combined with the lever recess (IC-LR) were taken after storage. The impacts of extended cleaning and alcohol flush were evaluated. RESULTS: E coli was reliably eliminated in IC-LR and EGW channels of 119 duodenoscope tests (59 with sealed EGW and 60 with nonsealed EGW). However, actionable levels of E faecalis and environmental bacteria persisted. Neither alcohol flush nor extended cleaning resulted in a reduction of actionable levels for these organisms. Identification of isolates indicated that residual organisms in duodenoscope channels were hardy Gram-positive bacteria (often spore formers) that likely originated from environmental sources. CONCLUSIONS: These data indicate that high-concern Gram-negative bacteria but not E faecalis or environmental bacteria can be reliably eliminated by use of the manufacturer's instructions for reprocessing with ATP monitoring of cleaning and channel-purge storage conditions.

Brevibacterium massiliense (Roux and Raoult 2009) is a later heterotypic synonym of Brevibacterium ravenspurgense (Mages, Frodl, Bernard and Funke 2009), using whole-genome sequence analysis as a comparative tool.

A patient strain derived from urine was found by 16S rRNA gene sequencing to be closely related (99.6 % identity) to sequences derived from both Brevibacterium ravenspurgense CCUG 56047T and Brevibacterium massilienseCCUG 53855T. Those species had been described during the same 11 month period in 2008-2009. Further characterization revealed that those isolates could not be readily distinguished from each other biochemically, by cellular fatty acids, antimicrobial susceptibility, MALDI-TOF MS, 16S rRNA gene sequencing or by whole-genome sequence (WGS) analyses. By WGS comparison, these isolates had an aerage nucleotide identity using blastn (ANIb) scores of 95.7 % or higher to each other, DNA G+C content in the range of 62.3 mol%-62.4 mol%, with genome sizes ranging from 2.28×106 to 2.41×106 bases. Based on these data, we propose that the name B. massiliense is a later heterotypic synonym of B. ravenspurgense and provide an emended description of B. ravenspurgense.

Lawsonella clevelandensis gen. nov., sp. nov., a new member of the suborder Corynebacterineae isolated from human abscesses.

Gram-stain-positive, partially acid-fast, non-spore-forming, anaerobic, catalase-positive, pleomorphic bacteria were isolated from human abscesses. Strains X1036T, X1698 and NML 120705, were recovered from a spinal abscess, a peritoneal abscess and a breast abscess respectively. A phylogenetic analysis of the 16S rRNA gene sequences showed that the strains shared 100 % similarity, and the nearest phylogenetic neighbour was Dietzia timorensis DSM 45568T (95%). Chemotaxonomic characteristics of the strains were consistent with those described for members of the suborder Corynebacterineae. Mycolic acids were detected using HPLC and one-dimensional TLC; whole-cell hydrolysates yielded meso-diaminopimelic acid with arabinose and galactose as the predominant sugars; the muramic acid acyl type was acetylated; the major menaquinone was MK-9 (96.3%); polar lipids detected were phosphatidylglycerol, phosphatidylinositol and an unknown glycophospholipid. Cellular fatty acids were hexadecanoic acid (C16 : 0), octadecenoic acid (C18 : 1ω9c) and decanoic acid (C10 : 0). Tuberculostearic acid was not detected. Based on the results of this polyphasic study, we conclude that these strains represent a novel genus and species within the suborder Corynebacterineae for which we propose the name Lawsonella clevelandensis gen. nov., sp. nov., with the type strain X1036T (=DSM 45743T=CCUG 66657T).

Corynebacterium lowii sp. nov. and Corynebacterium oculi sp. nov., derived from human clinical disease and an emended description of Corynebacterium mastitidis.

Strains of members of the genus Corynebacterium derived from ophthalmologic patients in Japan, Belgium and Switzerland and found to be closely related to-, but distinguishable from Corynebacterium mastitidis by 16S rRNA gene sequencing, were characterized using biochemical, chemotaxonomic, MALDI-TOF mass spectrometry and antimicrobial susceptibility methods and DNA-DNA hybridization as well as by whole-genome sequencing (WGS). Based on this investigation, we describe Corynebacterium lowii sp. nov. and Corynebacterium oculi sp. nov., derived from human ocular specimens, as well as emend the description of Corynebacterium mastitidis. Type strains for these species are: C. lowii R-50085T (=LMG 28276T =CCUG 65815T) and C. oculi R-50187T (=LMG 28277T =CCUG 65816T). DNA G+C content was found to be 62.2 % (by HPLC) and 62.8 % (by WGS) for C. lowii R-50085T, 64.1 % (HPLC) and 64.8 % (WGS) for C. oculi R-50187T and 67.8 % (HPLC) for C. mastitidis LMG 19040T [=S-8T =CCUG 38654T =CECT 4843T =CIP 105509T =DSM 44356T =IFO (NBRC)16160T =JCM 12269T].

Tatumella saanichensis sp. nov., isolated from a cystic fibrosis patient.

Polyphasic taxonomic analysis was performed on a clinical isolate (NML 06-3099T) from a cystic fibrosis patient, including whole-genome sequencing, proteomics, phenotypic testing, electron microscopy, chemotaxonomy and a clinical investigation. Comparative whole-genome sequence analysis and multilocus sequence analysis (MLSA) between Tatumella ptyseos ATCC 33301T and clinical isolate NML 06-3099T suggested that the clinical isolate was closely related to, but distinct from, the species T. ptyseos. By 16S rRNA gene sequencing, the clinical isolate shared 98.7 % sequence identity with T. ptyseos ATCC 33301T. A concatenate of six MLSA loci (totalling 4500 bp) revealed < 93.9 % identity between T. ptyseos ATCC 33301T, other members of the genus and the clinical isolate. A whole-genome sequence comparison between NML 06-3099T and ATCC 33301T determined that the average nucleotide identity was 76.24 %. The overall DNA G+C content of NML 06-3099T was 51.27 %, consistent with members of the genus Tatumella. By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS analysis, NML 06-3099T had a genus-level match, but not a species-level match, to T. ptyseos. By shotgun proteomics, T. ptyseos ATCC 33301T and NML 06-3099T were found to have unique proteomes. The two strains had similar morphologies and multiple fimbriae, as observed by transmission electron microscopy, but were distinguishable by phenotypic testing. Cellular fatty acids found were typical for members of the Enterobacteriaceae. NML 06-3099T was susceptible to commonly used antibiotics. Based on these data, NML 06-3099T represents a novel species in the genus Tatumella, for which the name Tatumella saanichensis sp. nov. is proposed (type strain NML 06-3099T = CCUG 55408T = DSM 19846T).

Enterococcus ureasiticus sp. nov. and Enterococcus quebecensis sp. nov., isolated from water.

Three enterococcal isolates, CCRI-16620, CCRI-16986(T) and CCRI-16985(T), originating from water were characterized using morphological, biochemical and molecular taxonomic methods. 16S rRNA gene sequence analysis classified all three strains in the Enterococcus faecalis species group. The phylogenetic tree of 16S rRNA gene sequences showed that the three isolates form two separate branches. The first branch is represented by strains CCRI-16620 and CCRI-16986(T) and the second branch by strain CCRI-16985(T). Further sequence analysis of the housekeeping genes rpoA (encoding RNA polymerase α subunit), pheS (phenylalanyl-tRNA synthase), tufA (elongation factor Tu) and atpD (ATP synthase ß-subunit) as well as the results of amplified fragment length polymorphism (AFLP) DNA fingerprinting and DNA-DNA hybridization experiments confirmed the distinct status of these strains. Moreover, biochemical tests allowed phenotypic differentiation of the strains from the other species of the E. faecalis species group. On the basis of the results obtained, the names Enterococcus ureasiticus sp. nov. (type strain CCRI-16986(T) = CCUG 59304(T) = DSM 23328(T) = LMG 26304(T)) and Enterococcus quebecensis sp. nov. (type strain CCRI-16985(T) = CCUG 59306(T) = DSM 23327(T) = LMG 26306(T)) are proposed for the two hitherto undescribed species.

First report of Actinobaculum schaalii urinary tract infection in North America.

A recurrent urinary tract infection with Actinobaculum schaalii, a fastidious, facultative anaerobic, and emerging pathogen, is described. Diagnosis was delayed when routine urine cultures were initially performed yielding recurrently negative results. Resolution of symptoms occurred after anaerobic cultures were done to allow organism isolation, identification, and appropriate antimicrobial treatment.

Novel Corynebacterium diphtheriae in domestic cats.

Novel nontoxigenic Corynebacterium diphtheriae was isolated from a domestic cat with severe otitis. Contact investigation and carrier study of human and animal contacts yielded 3 additional, identical isolates from cats, although no evidence of zoonotic transmission was identified. Molecular methods distinguished the feline isolates from known C. diphtheriae.

Corynebacterium mustelae sp. nov., isolated from a ferret with lethal sepsis.

A non-lipophilic coryneform bacterium, strain 3105(T), was isolated from various tissues of a ferret with lethal sepsis. The strain was characterized by phenotypic and chemotaxonomic methods, which suggested an assignment of the isolate to the genus Corynebacterium. Strain 3105(T) exhibited the following peculiar features that made it possible to differentiate it phenotypically from all other corynebacteria: its distinctive 'humid cellar'-like odour, strong adherence to agar and a greenish-beige pigment. Strain 3105(T) exhibited more than 2.8 % 16S rRNA gene sequence divergence from its closest phylogenetic neighbour, Corynebacterium pseudotuberculosis NCTC 3450(T) (97.12 % sequence similarity). Analysis of the highly variable region within the rpoB gene sequence showed that strain 3105(T) exhibited more than 14 % divergence from its closest phylogenetic relative, again C. pseudotuberculosis. Based on the data presented, it is proposed that the ferret isolate should be classified within a novel species, Corynebacterium mustelae sp. nov. (type strain 3105( T) =CCUG 57279(T) =DSM 45274(T)).

Assignment of Brevibacterium stationis (ZoBell and Upham 1944) Breed 1953 to the genus Corynebacterium, as Corynebacterium stationis comb. nov., and emended description of the genus Corynebacterium to include isolates that can alkalinize citrate.

Brevibacterium stationis ATCC 14403(T), Corynebacterium ammoniagenes ATCC 6872 and two clinical isolates were found to form a single taxon group consistent with the genus Corynebacterium, designated here as Corynebacterium stationis comb. nov. The type strain of Corynebacterium stationis is ATCC 14403(T) =CCUG 43497( T) =CIP 104228(T) =DSM 20302(T) =NBRC 12144(T) =JCM 11611(T) =VKM B-1228(T). These strains can utilize citrate; therefore, inclusion of C. stationis requires that the description of the genus Corynebacterium be amended to include citrate-positive strains.

Corynebacterium canis sp. nov., isolated from a wound infection caused by a dog bite.

A non-lipophilic, coryneform bacterium isolated from a patient's wound caused by a dog bite was characterized by phenotypic, chemotaxonomic and molecular genetic methods. Chemotaxonomic features suggested assignment of the unknown bacterium to the genus Corynebacterium. The isolate exhibited the following unusual features, which made it possible to phenotypically differentiate it from all other medically relevant corynebacteria: the Gram stain showed some very filamentous rods (>15 µm in length); some cells exhibited branching; colonies were domed and adherent to agar; the micro-organism was positive for pyrazinamidase, ß-glucosidase, α-glucosidase and trypsin but negative for ß-galactosidase. 16S rRNA gene sequencing and partial rpoB gene sequencing showed that the closest phylogenetic relative, Corynebacterium freiburgense, exhibited more than 1.9 % and 17.9 % divergence with the unknown bacterium, respectively. Based on both phenotypic and molecular genetic data, it is proposed that the isolate should be classified as a novel species, Corynebacterium canis sp. nov., with the type strain 1170(T) (=CCUG 58627(T) =DSM 45402(T)).

Actinomyces hominis sp. nov., isolated from a wound swab.

A coryneform bacterium (strain 1094(T)) was isolated from a wound swab taken from an 89-year-old female patient. Chemotaxonomic investigations suggested that this bacterium was related to the genera Actinomyces, Arcanobacterium and Actinobaculum. Phylogenetic analysis of 16S rRNA gene sequences showed that strain 1094(T) was most closely related to Actinomyces europaeus CCUG 32789 A(T) (94.3 % similarity). Phenotypically, the isolate could be separated from its closest phylogenetic neighbours on the basis of being positive for catalase, CAMP reaction, acid phosphatase, N-acetyl-beta-glucosaminidase and raffinose fermentation. Based on the data presented, it is proposed that strain 1094(T) should be classified in a novel species, Actinomyces hominis sp. nov. The type strain is 1094(T) (=CCUG 57540(T) =DSM 22168(T)).

Corynebacterium freiburgense sp. nov., isolated from a wound obtained from a dog bite.

A non-lipophilic, coryneform bacterium, isolated from a patient's wound obtained from a dog bite, was characterized by phenotypic, chemotaxonomic and molecular genetic methods. Chemotaxonomic features suggested assignment of the unknown bacterium to the genus Corynebacterium. The isolate exhibited the following peculiar features which made it possible to differentiate it phenotypically from all other medically relevant corynebacteria: older colonies exhibited a 'spoke-wheel' macroscopic morphology, colonies were strongly adherent to blood agar and the strain did not have pyrazinamidase activity, but was positive for beta-galactosidase. 16S rRNA gene sequencing showed that the closest phylogenetic relative exhibited more than 3.9% divergence from the unknown isolate. Based on phenotypic and molecular genetic data, it is proposed that the isolate should be classified as a representative of a novel species, Corynebacterium freiburgense sp. nov., with strain 1045T (=CCUG 56874T=DSM 45254T) as the type strain.

Identities of Arthrobacter spp. and Arthrobacter-like bacteria encountered in human clinical specimens.

After the initial description of Arthrobacter spp. isolated from clinical specimens in the mid-1990s, very few further reports on Arthrobacter spp. have appeared in the clinical microbiology literature. The aim of the present study was to elucidate the distribution of Arthrobacter spp. and Arthrobacter-like bacteria encountered in clinical specimens by studying 50 consecutively isolated or received strains of large-colony-forming, whiteish-grayish, non-cheese-like-smelling, nonfermentative gram-positive rods by applying phenotypic methods as well as 16S rRNA gene sequencing. We observed a very heterogenous distribution, with the 50 strains belonging to 20 different taxa and each of 13 strains as a single representative of its particular taxon. Thirty-eight strains represented true Arthrobacter strains, 7 strains belonged to the genus Brevibacterium, 2 were Microbacterium species, and each of 3 single strains was a member of the rarely encountered genera Pseudoclavibacter, Leucobacter, and Brachybacterium, respectively. A. cumminsii (n = 14) and A. oxydans (n = 11) were the most frequently found species. The present report describes the first three A. aurescens strains isolated from human clinical specimens. Comprehensive antimicrobial susceptibility data are given for the 38 Arthrobacter isolates.