Short-chain Mycolic Acids Research Articles

Corynebacterium hylobatis sp. nov. and Corynebacterium lemuris sp. nov., two novel species of the genus Corynebacterium isolated from faeces of primates.

Two Gram-stain positive, aerobic, short-rod-shaped, catalase-positive, oxidase-negative and non-motile strains, designated YIM 101343T and YIM 101645T, were isolated from faeces of Hylobates hoolock and Lemur catta, respectively. The results of 16S rRNA gene analysis indicated that both represented members of the genus Corynebacterium, and they shared a similarity of 98.0 % with each other. Corynebacterium marinum DSM 44953T showed the highest similarity with both strains YIM 101343T (99.0 %) and YIM 101645T (97.3 %). The results of phylogenetic analysis based on 16S rRNA gene indicated that strain YIM 101343T formed a cluster with C. marinum DSM 44953T and Corynebacterium comes 2019T, strain YIM 101645T formed a cluster with Corynebacterium halotolerans YIM 70093T, and the two clusters were neighbours. The genomic size of strain YIM 101343T was 3068751 bp and that of strain YIM 101645T was 3169714 bp. The dDDH, ANI and AAI values among strains YIM 101343T, YIM 101645T and the closely related species indicated that the two isolates represented two different novel species. Both strains contained meso-diaminopimelic acid and short-chain mycolic acids, and the major menaquinones were MK-9(H2) and MK-8(H2). The major polar lipids of the two strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids (>10 %) of both strains were C16 : 0, summed feature 4 and C18 : 1ω9c, but C17 : 1 ω8c was only present as a major component in YIM 101645T . In addition, phenotypic and some chemotaxonomic characteristics of strains YIM 101343T, YIM 101645T and the closely related species were different. Thus, strains YIM 101343T and YIM 101645T should represent two novel species of the genus Corynebacterium, for which the names Corynebacterium hylobatis sp. nov. and Corynebacterium lemuris sp. nov. are proposed, respectively. The type strains are YIM 101343T (=DSM 45970T=CCTCC AB 2013221T) and YIM 101645T (=BCRC 16963T=CCTCC AB 2013281T=KCTC 39868T).

The extracellular matrix of mycobacterial biofilms: could we shorten the treatment of mycobacterial infections?

A number of non-tuberculous mycobacterium species are opportunistic pathogens and ubiquitously form biofilms. These infections are often recalcitrant to treatment and require therapy with multiple drugs for long duration. The biofilm resident bacteria also display phenotypic drug tolerance and thus it has been hypothesized that the drug unresponsiveness in vivo could be due to formation of biofilms inside the host. We have discussed the biofilms of several pathogenic non-tuberculous mycobacterium (NTM) species in context to the in vivo pathologies. Besides pathogenic NTMs, Mycobacterium smegmatis is often used as a model organism for understanding mycobacterial physiology and has been studied extensively for understanding the mycobacterial biofilms. A number of components of the mycobacterial cell wall such as glycopeptidolipids, short chain mycolic acids, monomeromycolyl diacylglycerol, etc. have been shown to play an important role in formation of pellicle biofilms. It shall be noted that these components impart a hydrophobic character to the mycobacterial cell surface that facilitates cell to cell interaction. However, these components are not necessarily the constituents of the extracellular matrix of mycobacterial biofilms. In the end, we have described the biofilms of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. Three models of Mtb biofilm formation have been proposed to study the factors regulating biofilm formation, the physiology of the resident bacteria, and the nature of the biomaterial that holds these bacterial masses together. These models include pellicle biofilms formed at the liquid-air interface of cultures, leukocyte lysate-induced biofilms, and thiol reductive stressinduced biofilms. All the three models offer their own advantages in the study of Mtb biofilms. Interestingly, lipids (mainly keto-mycolic acids) are proposed to be the primary component of extracellular polymeric substance (EPS) in the pellicle biofilm, whereas the leukocyte lysate-induced and thiol reductive stress-induced biofilms possess polysaccharides as the primary component of EPS. Both models also contain extracellular DNA in the EPS. Interestingly, thiol reductive stressinduced Mtb biofilms are held together by cellulose and yet unidentified structural proteins. We believe that a better understanding of the EPS of Mtb biofilms and the physiology of the resident bacteria will facilitate the development of shorter regimen for TB treatment.

Corynebacterium faecale sp. nov., isolated from the faeces of Assamese macaque

A Gram-stain-positive, facultatively anaerobic, short rod-shaped, oxidase-negative and non-motile novel strain, designated YIM 101505T, was isolated from the faeces of a primate, Assamese macaque, and was studied to determine its taxonomic position. The cell wall contained meso-diaminopimelic acid and short-chain mycolic acids. Whole cell sugars were mannose, galactose and arabinose as major components. The major fatty acids (>10 %) were C18 : 1ω9c, C16 : 0 and C17 : 1ω8c and the major menaquinone was MK-9(H2). The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, glycolipid and six unidentified lipids. The new isolate shared most of the typical chemotaxonomic characteristics of members of the genus Corynebacterium. The closest related species was Corynebacterium efficiens based on 16S rRNA gene (98.1 % similarity) and partial rpoB gene (91.4 % similarity) sequences. Similarities with other species of this genus were below 97 % based on the 16S rRNA gene. The DNA-DNA hybridization value between YIM 101505T and C. efficiens DSM 44549T was 47.7±3.6 %. Moreover, the physiological and biochemical characteristics of YIM 101505T and C. efficiens DSM 44549T were different. Thus, strain YIM 101505T is considered to represent a novel member of the genus Corynebacterium, for which the name Corynebacterium faecale sp. nov. is proposed. The type strain is YIM 101505T (=DSM 45971T=CCTCC AB 2013226T).

Characterization of bacteria of the genus Dietzia: an updated review

The aim of this study was to characterize several aspects of species of the genus Dietzia, such as current taxonomic placement, morphological and growth characteristics, biochemical reactions, cellular lipid and fatty acid composition, the amino acids and sugars of whole-cell hydrolysates and the respiratory quinone system, and genomic guanine and cytosine (G + C) content. The species chosen for study were D. aerolata, D. alimentaria, D. aurantiaca, D. cerdiciphylli, D. cinnamea, D. kunjamensis, D. lutea, D. maris, D. natronolimnaea, D. papillomatosis, D. psychralcaliphila, D. schimae, and D. timorensis. The colony morphology study revealed that the colonies were small, smooth, circular and convex. Nitrate reduction, H2S production, hydrolysis of urea, starch, and Tween 80, and the Voges–Proskauer and methyl red tests were performed for biochemical differentiation of the various Dietzia strains. Optimum growth temperature and pH for the different strains were 25–30 °C and 7–8, respectively. Among the strains studied, D. timorensis ID05-A0528T had the lowest tolerance level to NaCl (7 %). This strain was also able to utilize a wide range of compounds as the sole carbon source. Short-chain mycolic acids were present in these bacteria. The cell wall contained meso-diaminopimelic acid, arabinose, and galactose; the glycan moiety of the cell wall contained acetyl residues. The major menaquinone was MK-8 (H2). The G + C contents of the DNA ranged from 64.7 (D. alimentaria 72T) to 73 mol % (D. maris DSM 43672T). The most important phospholipids in these strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, and phosphatidylethanolamine.

Corynebacterium aquatimens sp. nov., a lipophilic Corynebacterium isolated from blood cultures of a patient with bacteremia

An unknown lipophilic coryneform bacterium isolated from the blood cultures of a patient with bacteremia was characterized by phenotypic and molecular genetic methods. Chemical analysis revealed the presence of short chain mycolic acids consistent with the genus Corynebacterium. The DNA G+C content was 60.8mol%. Comparative 16S rRNA gene sequence analysis demonstrated that the isolate represents a new subline within the genus Corynebacterium. The closely phylogenetic relative of the unknown bacterium was found to be C. tuscaniense (97.8% sequence similarity). Partial rpoB gene sequence revealed that strain IMMIB L-2475T exhibited 13.5% sequence divergence with C. tuscaniense. The unknown bacterium was distinguished from C. tuscaniense by, DNA–DNA hybridization, cellular fatty acid profiles, MALDI-TOF analyses of cell extracts and biochemical tests. Based on the phylogenetic and phenotypic criteria, it is proposed that this bacterium be classified as new species, Corynebacterium aquatimens sp. nov., and is represented by strain IMMIB L-2475T (=DSM 45632T=CCUG 61574T).

Corynebacterium pilbarense sp. nov., a non-lipophilic corynebacterium isolated from a human ankle aspirate

A non-lipophilic coryneform bacterium isolated from an anaerobic Bactec bottle inoculated with an ankle aspirate from a male patient was characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of short-chain mycolic acids in the cell wall of the bacterium, a feature consistent with members of the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis demonstrated that the isolate displayed 92.0-99.0 % gene sequence similarity with members of the genus Corynebacterium, with Corynebacterium ureicelerivorans as the most closely related phylogenetic species (99.0 % gene sequence similarity). However, the isolate could be genomically separated from C. ureicelerivorans on the basis of DNA-DNA hybridization studies (39.5 % relatedness). Furthermore, the isolate could also be differentiated from C. ureicelerivorans and other species of the genus Corynebacterium on the basis of biochemical properties. Based on both phenotypic and phylogenetic evidence, it is proposed that this isolate be classified as representing a novel species, Corynebacterium pilbarense sp. nov. (type strain IMMIB WACC 658(T)=DSM 45350(T)=CCUG 57942(T)).

Corynebacterium ulceribovis sp. nov., isolated from the skin of the udder of a cow with a profound ulceration

A coryneform bacterium isolated from a cow with a profound ulceration was characterized by using phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing showed that the organism formed a hitherto unknown subline within the genus Corynebacterium. Sequence divergence values of greater than 3.6 % from recognized Corynebacterium species, together with phenotypic differences, showed that the unidentified bacterium represents a new member of this genus. On the basis of phenotypic and phylogenetic considerations, it is proposed that the novel bacterium be classified as representing a novel species of the genus Corynebacterium, with the name Corynebacterium ulceribovis sp. nov. The type strain is IMMIB L-1395T (=DSM 45146T=CCUG 55727T).

Corynebacterium sputi sp. nov., isolated from the sputum of a patient with pneumonia

A coryneform bacterium isolated from the sputum of a patient with pneumonia was characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short chain mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing studies confirmed this assignment, with the organism forming a hitherto unknown subline within the genus associated with a subcluster containing Corynebacterium hansenii, Corynebacterium freneyi, Corynebacterium xerosis, Corynebacterium amycolatum and Corynebacterium sphenisci. Sequence divergence values of >2.7 % from established corynebacterial species suggested that the new isolate represented a novel species. This was also supported by the results of the biochemical tests. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown bacterium be classified as a novel species of the genus Corynebacterium, Corynebacterium sputi sp. nov. (type strain IMMIB L-999(T)=DSM 45148(T)=CCUG 55795(T)).

Corynebacterium ureicelerivorans sp. nov., a lipophilic bacterium isolated from blood culture

A lipophilic coryneform bacterium isolated from a blood culture from a patient with signs of septicaemia was characterized by means of phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids, which are consistent with the genus Corynebacterium. The isolate was characterized biochemically by the very rapid (approx. 60 s) positive result that was obtained in a urease test in the API Coryne system. Comparative 16S rRNA gene sequencing demonstrated that the isolate belonged phylogenetically to the genus Corynebacterium. The values for sequence divergence (> or =1.4 %) with respect to known Corynebacterium species, together with phenotypic differences, show that the unidentified bacterium represents a novel member of this genus. On the basis of both the phenotypic and phylogenetic data, this isolate should be classified within a novel species of the genus Corynebacterium, for which the name Corynebacterium ureicelerivorans sp. nov. is proposed. The type strain is IMMIB RIV-2301(T) (=DSM 45051(T)=CCUG 53377(T)).

Gordonia malaquae sp. nov., isolated from sludge of a wastewater treatment plant

The taxonomic status of a bacterial isolate from the sludge of a wastewater treatment plant was characterized by using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Gordonia, fatty acids C(16 : 0) and C(18 : 0) (found by pyrolysis gas chromatography) and a dihydrogenated menaquinone with nine isoprene units [MK-9(H2)] as the predominant menaquinone. The genus assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that the novel isolate constitutes a hitherto unknown subline within the genus Gordonia, displaying 95.9 to 97.6 % gene sequence similarity to the recognized species of the genus. The novel isolate was distinguished from the type strains of phylogenetically related species by using a set of phenotypic features. The genotypic and phenotypic data show that the new strain merits classification as a novel species of the genus Gordonia, for which the name Gordonia malaquae sp. nov. is proposed. The type strain is IMMIB WWCC-22(T) (=DSM 45064(T)=CCUG 53555(T)).

Williamsia serinedens sp. nov., isolated from an oil-contaminated soil

The taxonomic status of a bacterium designated strain IMMIB SR-4(T) isolated from an oil-contaminated soil sample was characterized by using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that on pyrolysis GC produce C(16 : 0) and C(18 : 0) fatty acids, and dihydrogenated menaquinone with nine isoprene units as the predominant menaquinone. The generic assignment was confirmed by 16S rRNA gene sequence analysis. Comparative analysis of the 16S rRNA gene sequence showed that strain IMMIB SR-4(T) formed a distinct phyletic line within the genus Williamsia, displaying sequence similarities of 95.5-98.1 % with the type strains of recognized Williamsia species. Strain IMMIB SR-4(T) was distinguished from the type strains of recognized species of the genus Williamsia based on a set of phenotypic features. The genotypic and phenotypic data indicated that strain IMMIB SR-4(T) represents a novel species of the genus Williamsia, for which the name Williamsia serinedens sp. nov. is proposed. The type strain is IMMIB SR-4(T) (=DSM 45037(T)=CCUG 53151(T)).

Deletion of the rpoZ gene, encoding the ω subunit of RNA polymerase, results in pleiotropic surface-related phenotypes in Mycobacterium smegmatis

The omega subunit, the smallest subunit of bacterial RNA polymerase, is known to be involved in maintaining the conformation of the beta' subunit and aiding its recruitment to the rest of the core enzyme assembly in Escherichia coli. It has recently been shown in Mycobacterium smegmatis, by creating a deletion mutation of the rpoZ gene encoding omega, that the physiological role of the omega subunit also includes providing physical protection to beta'. Interestingly, the mutant had altered colony morphology. This paper demonstrates that the mutant mycobacterium has pleiotropic phenotypes including reduced sliding motility and defective biofilm formation. Analysis of the spatial arrangement of biofilms by electron microscopy suggests that the altered phenotype of the mutant arises from a deficiency in generation of extracellular matrix. Complementation of the mutant strain with a copy of the wild-type rpoZ gene integrated in the bacterial chromosome restored both sliding motility and biofilm formation to the wild-type state, unequivocally proving the role of omega in the characteristics observed for the mutant bacterium. Analysis of the cell wall composition demonstrated that the mutant bacterium had an identical glycopeptidolipid profile to the wild-type, but failed to synthesize the short-chain mycolic acids characteristic of biofilm growth in M. smegmatis.

Dietzia cinnamea sp. nov., a novel species isolated from a perianal swab of a patient with a bone marrow transplant

The taxonomic status of a bacterium isolated from a perianal swab of a patient with a bone marrow transplant was characterized using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell wall chemotype IV, short chain mycolic acids that co-migrated with those extracted from members of the genus Dietzia, and a dihydrogenated menaquinone with eight isoprene units as the predominant menaquinone. Generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that this isolate constitutes a distinct phyletic line within the genus Dietzia, displaying 97.5-98.7% sequence similarity with Dietzia species with validly published names. The isolate could be distinguished from the type strain of Dietzia maris (1.6% sequence divergence) and other species of the genus Dietzia by DNA-DNA hybridization, as well as by using a set of biochemical tests. Genotypic and phenotypic data show that the strain merits classification as a novel species of the genus Dietzia for which the name Dietzia cinnamea sp. nov. is proposed; the type strain is IMMIB RIV-399T (= DSM 44904T = CCUG 50875T).

Williamsia deligens sp. nov., isolated from human blood

The taxonomic status of two bacterial strains isolated from human blood was characterized using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that produce C(16 : 0) and C(18 : 0) fatty acids on pyrolysis GC, and dihydrogenated menaquinone with nine isoprene units as the predominant isoprenologue. The generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that these isolates constitute a distinct phyletic line within the genus Williamsia, displaying 96.2 and 97.2 % sequence similarities to Williamsia muralis and Williamsia maris, respectively. The two isolates could be distinguished from the type strains of the latter species on the basis of several phenotypic traits. The genotypic and phenotypic data show that the strains merit classification as a novel species of Williamsia, for which the name Williamsia deligens sp. nov. is proposed, with type strain IMMIB RIV-956T (= DSM 44902T = CCUG 50873T).

Xylanolytic and Alkaliphilic Dietzia sp. Isolated from Larvae of the Japanese Horned Beetle, Trypoxylus dichotomus

Larvae of the Japanese horned beetle, Trypoxylus dichotomus septentrionalis (Kono 1931), feed on putrid wood and leaf litter, and are assumed to play important roles in the degradation of polysaccharides produced by broadleaf trees in Japan. Wada et al. showed the presence of strong degrading activities against several polysaccharides, e.g., β-1, 4-xylan, pectin, and β-1,3-glucan, in the contents of the larval gut and an alkaline pH (pH 10) of the contents of the larval midgut. Xylanolytic strains of bacteria, H05TDL, F09TDL, and W02TDL, were isolated, by use of alkaline media containing 0.5% xylan, from the hindgut and feces of T. dichotomus larvae and putrid wood used for feeding of the larva; and these strains seemed to belong to the genus Dietzia by 16S rDNA analysis. The strain H05TDL showed higher xylanolytic activity at alkaline pH than at neutral pH. The cells of this strain were Gram-positive aerobic rods containing short-chain mycolic acids (33–40 carbon atoms) and arabinose and galactose as the major cell-wall sugars, which also support that the strain belongs to the genus Dietzia. The bacterium grew well between pH 6.8 and 9.6 (optimally at pH 8.3), and produced β-1,4-xylanase, which showed its maximum activity at pH 9.4. In the pH range between 8 and 10, the enzyme activity was 70% of the maximum activity or higher, suggesting that the β-1,4-xylanase may have become adapted to the alkaline lumen of the gut.

Corynebacterium glaucum sp. nov.

A bacterial strain, strain IMMIB R-5091(T), isolated from a cosmetic dye was characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing showed that the isolate constitutes a distinct subline within the genus Corynebacterium, displaying > 2.6% sequence divergence from established species. The isolate could be distinguished from other members of the genus Corynebacterium by biochemical tests. Based on both phenotypic and phylogenetic evidence, it is proposed that strain IMMIB R-5091(T) (= DSM 44530T = NRRL B-24142(T)) be classified as the type strain of a novel species, Corynebacterium glaucum sp. nov.

Corynebacterium appendicis sp. nov.

A lipophilic, coryneform bacterium isolated from a human clinical specimen was characterized by phenotypic and molecular-taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids consistent with the genus Corynebacterium. The isolate could be distinguished from other members of the genus Corynebacterium by positive urease and catalase tests as well as its failure to produce acid from carbohydrates. Comparative 16S rRNA gene sequencing showed that this isolate constitutes a distinct subline within the genus Corynebacterium, displaying >3.0% sequence divergence from other known Corynebacterium species. Based on both phenotypic and phylogenetic evidence, it is proposed that this isolate be classified as a novel species, Corynebacterium appendicis sp. nov., represented by strain IMMIB R-3491T (= DSM 44531T = NRRL B-24151T).

Corynebacterium aurimucosum sp. nov. and emended description of Corynebacterium minutissimum Collins and Jones (1983).

Two coryneform bacteria isolated from human clinical specimens were characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids consistent with the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequence analysis showed that the two strains are genealogically highly related (99.8% sequence similarity) and constitute a new subline within the genus Corynebacterium, with Corynebacterium minutissimum as their nearest phylogenetic neighbours (98.8% sequence similarity). However, DNA-DNA hybridization experiments demonstrated unambiguously that the isolates are genealogically distinct from Corynebacterium minutissimum (42% homology). Biochemical testing indicated that the two isolates were hardly differentiated from Corynebacterium minutissimum. Based on both phenotypic and phylogenetic evidence it is proposed that these isolates be classified as a new species, Corynebacterium aurimucosum sp. nov. The type strain of Corynebacterium aurimucosum is represented by strain IMMIB D-1488T (= DSM 44532T = NRRL B-24143T).

Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov., isolated from the surface of a smear-ripened cheese.

Ten isolates each of two different bacterial species isolated from the surface of a smear-ripened cheese were found to exhibit many characteristics of the genus Corynebacterium. The isolates were Gram-positive, catalase-positive, non-spore-forming rods that did not undergo a rod/coccus transformation when grown on complex media. Chemotaxonomic investigation revealed that the strains belonged unambiguously to the genus Corynebacterium. Their cell walls contained arabinose, galactose and short-chain mycolic acids (C22 to C36) and their peptidoglycan contained meso-diaminopimelic acid. The G+C content of the DNA was 51-60 mol%. MK-9 (H2) was the principal menaquinone. The 16S rDNA sequences of four isolates of each bacterium were determined and aligned with those of other members of the coryneform group. Phylogenetic analysis showed that the strains represented two new sublines within the genus Corynebacterium; Corynebacterium variabile and Corynebacterium ammoniagenes were their nearest known phylogenetic neighbours. Corynebacterium variabile and Corynebacterium ammoniagenes showed the highest levels of sequence homology with the isolates; however, DNA-DNA hydridization studies indicated that the Corynebacterium strains isolated from the cheese smear did not belong to either Corynebacterium variabile or Corynebacterium ammoniagenes (26 and 46% chromosomal similarity, respectively). On the basis of the phylogenetic and phenotypic distinctiveness of the unknown isolates, it is proposed that the bacteria be classified as two new Corynebacterium species, for which the names Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov. are proposed. Type strains have been deposited in culture collections as Corynebacterium mooreparkense LMG S-19265T (= NCIMB 30131T) and Corynebacterium casei LMG S-19264T (= NCIMB 30130T).

Corynebacterium capitovis sp. nov., from a sheep.

An unknown Gram-positive rod-shaped bacterium was isolated from skin scrapings from the infected head of a sheep and subjected to a polyphasic taxonomic analysis. Chemical analysis revealed the presence of straight-chain and monounsaturated fatty acids and short-chain (C32-C36) mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing confirmed that the unknown rod was a member of the genus Corynebacterium, with the organism forming a distinct sub-line and displaying greater than 3% sequence divergence with established species. The unknown Corynebacterium isolate was readily distinguished from recognized species of the genus by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from a sheep be classified in the genus Corynebacterium, as Corynebacterium capitovis sp. nov. The type strain of Corynebacterium capitovis is CCUG 39779T (= CIP 106739T).