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A F Yassin

Publications and source records attributed to A F Yassin.

At least 19 recordsLinked to original sources
PubMed2006

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).

Actinomycetales↗
PubMed2006

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).

Actinomycetales↗
PubMed2005

Reclassification of Nocardia corynebacterioides Serrano et al. 1972 (Approved Lists 1980) as Rhodococcus corynebacterioides comb. nov.

The type strain of Nocardia corynebacterioides was the subject of a polyphasic taxonomic study. The 16S rRNA gene sequence was aligned with the sequences of representatives of the genera Corynebacterium, Dietzia, Gordonia, Mycobacterium, Nocardia, Rhodococcus, Skermania, Tsukamurella and Williamsia, and phylogenetic trees were constructed by using maximum-parsimony, maximum-likelihood and neighbour-joining methods. It was evident from the phylogenetic analysis that N. corynebacterioides represents a distinct phyletic line within the genus Rhodococcus. Menaquinone analysis showed that the organism contained dihydrogenated menaquinone with eight isoprene units, MK-8(H(2)), as the major isoprenologue. The genealogical evidence, together with chemotaxonomic and phenotypic data from this and previous studies, indicates that N. corynebacterioides DSM 20151(T) (= CIP 104510(T)) should be reclassified in the genus Rhodococcus as Rhodococcus corynebacterioides comb. nov.

Bacterial Typing Techniques↗
PubMed2005

Nocardia elegans sp. nov., a member of the Nocardia vaccinii clade isolated from sputum.

Two bacterial isolates from the sputa of a patient with a pulmonary infection were subjected to a polyphasic taxonomic study. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and mycolic acids consistent with the profile for the genus Nocardia. Comparative 16S rRNA gene sequencing showed that these isolates constitute a distinct subline within the genus Nocardia, displaying 99.6-95.5% sequence similarities with established species. However, DNA-DNA hybridization studies demonstrated unambiguously that the isolates are genealogically distinct from closely related species, namely Nocardia veterana and Nocardia africana, which show high levels of 16S rRNA sequence similarity (99.2 and 99.6% sequence similarity, respectively). On the basis of both phenotypic and phylogenetic evidence, it is proposed that these isolates be classified as a novel species of the genus Nocardia, for which the name Nocardia elegans sp. nov. is proposed. The type strain is IMMIB N-402(T) (=CCUG 50200(T)=CIP 108553(T)).

Bacterial Typing Techniques↗
PubMed2005

Rhodococcus triatomae sp. nov., isolated from a blood-sucking bug.

Two bacterial isolates, strains IMMIB RIV-085(T) and IMMIB RIV-095, isolated from a blood-sucking bug of the genus Triatoma, were characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and mycolic acids consistent with the genus Rhodococcus. Comparative 16S rRNA gene sequencing showed that the two isolates are genealogically highly related (100% sequence similarity) and constitute a new subline within the genus Rhodococcus, with Rhodococcus corynebacteroides and Rhodococcus rhodnii as their nearest phylogenetic neighbours (98.4 and 98.3% sequence similarity, respectively). However, DNA-DNA hybridization experiments demonstrated unambiguously that the isolates are genealogically distinct from R. corynebacteroides and R. rhodnii (32 and 43% relatedness, respectively). The isolates could be distinguished from their phylogenetic relatives and other members of the genus Rhodococcus by means of biochemical tests. On the basis of both phenotypic and phylogenetic evidence, it is proposed that these isolates be classified as a novel species, Rhodococcus triatomae sp. nov. The type strain is strain IMMIB RIV-085(T) (=CCUG 50202(T)=DSM 44892(T)).

Animals↗
PubMed2003

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.

Bacterial Typing Techniques↗
PubMed2003

Nocardia puris sp. nov.

A bacterial isolate (IMMIB R-145(T)) from a human abscess was subjected to a polyphasic taxonomic study. Chemotaxonomic investigations revealed the isolate to have cell wall chemotype IV and mycolic acids consistent with characteristics of the genus NOCARDIA: Comparative 16S rRNA gene sequencing showed that the isolate constituted a distinct subline within the genus Nocardia, displaying greater than 1.7 % sequence divergence with established species. However, a DNA-DNA hybridization study demonstrated unambiguously that the isolate was genealogically distinct from closely related species, namely, Nocardia abscessus, Nocardia cyriacigeorgica and Nocardia farcinica, with which it showed high levels of 16S rDNA sequence similarity (97.8, 97.9 and 98.3 %, respectively). Based on phenotypic and phylogenetic data, it is proposed that this isolate be classified as a new species of the genus Nocardia, for which the name Nocardia puris (type strain IMMIB R-145(T)=DSM 44599(T)=NRRL B-24204(T)) is proposed.

Abscess↗
PubMed2002

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).

Bacterial Typing Techniques↗
PubMed2002

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).

Appendicitis↗
PubMed2001

Nocardia cyriacigeorgici sp. nov..

Chemotaxonomic and 16S rRNA gene sequence analyses of an isolate from the bronchial secretions of a patient with chronic bronchitis demonstrated clearly that it belongs to the genus Nocardia. The 16S rRNA gene sequence data, as well as the biochemical characteristics of the isolate, indicated that it belongs to a new species that differs from previously described members of the genus Nocardia. The name Nocardia cyriacigeorgici sp. nov. is proposed for this isolate, and is represented by strain IMMIB D-1627T (= DSM 44484T).

Base Composition↗
PubMed2001

Nocardia ignorata sp. nov.

An isolate that was received during a mycobacterial quality control test and which was thought to be a Mycobacterium species was subjected to a polyphasic taxonomic study after mycolic acid analysis showed that it possessed mycolates characteristic of the nocardiae. Further chemotaxonomic and 16S rRNA gene sequence analyses of this isolate demonstrated that it belongs to the genus Nocardia. 16S rRNA gene sequence data, DNA-DNA hybridization studies and the biochemical characteristics of the isolate indicate that it belongs to a novel species that differs from previously described members of the genus Nocardia. The name Nocardia ignorata sp. nov. is proposed for this isolate with the type strain IMMIB R-1434T (= DSM 44496T = NRRL B-24141T).

DNA, Ribosomal↗
PubMed2000

Nocardia paucivorans sp. nov.

Chemotaxonomic and 16S rDNA sequence analyses of an isolate from the sputa and bronchial secretions of a patient with chronic lung disease clearly demonstrated that it belongs to the genus Nocardia. DNA-DNA hybridization data, as well as the biochemical characteristics of the isolate, indicate that it belongs to a new species that differs from previously described members of the genus Nocardia. The name Nocardia paucivorans sp. nov. is proposed for this isolate and is represented by strain IMMIB D-1632T (= DSM 44386T).

Bacterial Typing Techniques↗
PubMed2000

Nocardia abscessus sp. nov.

Chemotaxonomic and 16S rRNA gene sequence analyses of four bacterial strains isolated from clinical material clearly demonstrated that these bacteria belong to the genus Nocardia. DNA-DNA hybridization data as well as the physiological characteristics of the isolates indicated that they are closely related and belong to a single species that differs from previously described members of the genus. The name Nocardia abscessus sp. nov. is proposed for these organisms represented by strain IMMIB D-1592T (= DSM 44432T). Strain IMMIB D-1592T exhibits 56.8 and 60.0% DNA-DNA relatedness to Nocardia asteroides ATCC 19247T and Nocardia paucivorans DSM 44386T, respectively.

Adult↗
PubMed1999

The cell wall porin of the gram-positive bacterium Nocardia asteroides forms cation-selective channels that exhibit asymmetric voltage dependence.

Detergent-solubilized cell wall extracts of the gram-positive, strictly aerobic bacterium Nocardia asteroides contain channel-forming activity as judged from reconstitution experiments using lipid bilayer membranes. The cell wall porin was identified as a protein with an apparent molecular mass of about 84 kDa based on SDS-PAGE. The porin was purified to homogeneity using preparative SDS-PAGE. The 84-kDa protein was no longer observed after heating in SDS buffer. The presumed dissociation products were not observed on SDS-polyacrylamide gels. The cell wall porin increased the specific conductance of artificial lipid bilayer membranes from phosphatidylcholine/phosphatidylserine mixtures by the formation of cation-selective channels, which had an average single-channel conductance of 3.0 nS in 1 M KCl. The single-channel conductance was only moderately dependent on the bulk aqueous KCl concentration, which indicated negative point charge effects on the channel properties. The analysis of the concentration dependence of the single-channel conductance using the effect of negative charges on channel conductance suggested that the diameter of the cell wall channel is about 1.4 nm. Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. The cell wall channel switched into substates, when the cis side of the membrane, the side of the addition of the protein, had negative polarity. Positive potentials at the cis side had no influence on the conductance of the cell wall channel.

Cell Membrane Permeability↗
PubMed1998

The cell wall porin of Nocardia farcinica: biochemical identification of the channel-forming protein and biophysical characterization of the channel properties.

A channel-forming protein was identified in cell wall extracts of the Gram-positive, strictly aerobic bacterium Nocardia farcinica. The cell wall porin was purified to homogeneity and had an apparent molecular mass of about 87 kDa on tricine-containing SDS-PAGE. When the 87 kDa protein was boiled for a longer time in sodium dodecylsulphate (SDS) it dissociated into two subunits with molecular masses of about 19 and 23 kDa. The 87 kDa form of the protein was able to increase the specific conductance of artificial lipid bilayer membranes from phosphatidylcholine (PC) phosphatidylserine (PS) mixtures by the formation of ion-permeable channels. The channels had on average a single-channel conductance of 3.0 nS in 1M KCl, 10mM Tris-HCl, pH8, and were found to be cation selective. Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. The single-channel conductance was only moderately dependent on the bulk aqueous KCl concentration, which indicated point charge effects on the channel properties. The analysis of the single-channel conductance data in different salt solutions using the Renkin correction factor, and the effect of negative charges on channel conductance suggested that the diameter of the cell wall porin is about 1.4-1.6nm. Channel-forming properties of the cell wall porin of N. farcinica were compared with those of mycobacteria and corynebacteria. The cell wall porins of these members of the order Actinomycetales share common features because they form large and water-filled channels that contain negative point charges.

Cell Wall↗
PubMed1998

Typing of Nocardia farcinica by pulsed-field gel electrophoresis reveals an endemic strain as source of hospital infections.

Severe postoperative wound infections caused by Nocardia farcinica were repeatedly observed in a German hospital surgical ward. A pulsed-field gel electrophoresis (PFGE) protocol was established to characterize the genetic relatedness of the bacterial isolates from these infections. All 18 isolates from postoperative infections that have occurred since 1985 belong to a common endemic genotype; organisms of this genotype were also detected in the air of two rooms of the department where these postoperative infections occurred. In contrast, two environmental isolates from another building on the same campus showed a distinct genotype. Three cases of pulmonary infections, at a department which is located in proximity to the surgical department, were also caused by the endemic type, which suggests aerogenic spread of the endemic strain to these patients. Controls consisting of epidemiologically unrelated isolates from sporadic infections in other towns belonged in each case to a different genotype. PFGE was well suited to differentiate various types of N. farcinica and revealed an endemic strain causing postoperative wound infections possibly after aerogenic transmission.

Bacterial Typing Techniques↗
PubMed1997

Tsukamurella tyrosinosolvens sp. nov.

Chemotaxonomic and 16S ribosomal DNA sequence analyses of four bacterial isolates from blood cultures from patients with cardiac pacemaker implants and sputa of patients with chronic lung infections clearly demonstrated that these bacteria belong to the genus Tsukamurella. DNA-DNA hybridization data, as well as the physiological characteristics of the isolates, indicate that they are closely related and belong to a single species that differs from previously described members of the genus Tsukamurella. The name Tsukamurella tyrosinosolvens sp. nov. is proposed for these isolates, and the new species is represented by strain IMMIB D-1397T (= DSM 44234T). Strain IMMIB D-1397T exhibits 53.4, 53.5, and 54.7% DNA-DNA relatedness to Tsukamurella paurometabola DSM 20162T, Tsukamurella inchonensis DSM 44067T, and Tsukamurella pulmonis DSM 44142T, respectively.

Actinomycetales↗