objective(s) in addition to several molecular methods and in particular 16s rdna analysis, the application of a more discriminatory genetic marker, i.e., 16s-23s internal transcribed spacer gene sequence has had a great impact on identification and classification of mycobacteria. in the current study we aimed to apply this sequencing power to conclusive identification of some iranian clinical s...

sequence data of a recent coi barcoding study on fish from the nayband national park in the persian gulf showed relatively high sequence divergence among nominal gerres filamentosus specimens. the sequences grouped into two clusters, signaling the possible existence of cryptic species. the clustering pattern was corroborated by results of 16s rdna sequencing. we investigated the hypothesis that...

The standard use of a single universal broad-range PCR in direct 16S rDNA sequencing from polybacterial samples leaves the minor constituents at risk of remaining undetected because all bacterial DNA will be competing for the same reagents. In this article we introduce a set of three broad-range group-specific 16S rDNA PCRs that together cover the clinically relevant bacteria and apply them in ...

BACKGROUND The bacterial flora involved in brain abscess is often complex. In a previous study, using a metagenomic approach based on 16S ribosomal DNA (rDNA) amplification, we demonstrated that the diversity of the microbial flora involved in these infections was underestimated. METHODS We performed a 16S rDNA-based metagenomic analysis of cerebral abscesses from patients diagnosed from 2006...

Sequences of the gene encoding the beta-subunit of the RNA polymerase (rpoB) were used to delineate the phylogeny of the family Pasteurellaceae. A total of 72 strains, including the type strains of the major described species as well as selected field isolates, were included in the study. Selection of universal rpoB-derived primers for the family allowed straightforward amplification and sequen...

In an extensive numerical phenetic survey, a numberof blue, red and gray spored streptomycete strainswere grouped together as Streptomyces cyaneusspecies-group, a taxon which encompasses strainsknown to produce antitumor antibiotics, notably anthracyclines.In the present investigation these and relatedstreptomycetes were the subject of morphological and...

The cereal cyst nematodes belonging to Heterodera avenae group is a complex species consisting of 12 valid species and overlapping morphological characters make them difficult to be distinguished from one another. The non coding internal transcribed spacer sequences, ITS1 and ITS2 including 5.8S region of ribosomal DNA (rDNA) has been very useful for the accurate identification of the species a...

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subject...

A 1344 bp fragment of the 16S ribosomal DNA (rDNA) sequence was used to determine the genetic relationship of Pasteurella pneumotropica isolates from laboratory rodents. A total of 30 nucleotide sequences of P. pneumotropica, including 24 wild strains, 3 reference strains, and 3 nucleotide sequences deposited in GenBank, were examined for heterogeneity of their 16S rDNA sequences. Phylogenetic ...