scholarly journals Novel Clade of Rickettsia spp. from Leeches

2002 ◽  
Vol 68 (2) ◽  
pp. 999-1004 ◽  
Author(s):  
Yoshitomo Kikuchi ◽  
Shinya Sameshima ◽  
Osamu Kitade ◽  
Junichi Kojima ◽  
Takema Fukatsu
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Segment ◽  
Natural Populations ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Specific Primers ◽  
Diagnostic Pcr ◽  
Transmission Electron ◽  
The 16S Rrna Gene

ABSTRACT Intracellular rickettsia-like structures were found in the tissues of a glossiphoniid leech, Torix tagoi, by transmission electron microscopy. Diagnostic PCR analysis using specific primers suggested that of the nine glossiphoniid species examined, two species, T. tagoi and Hemicrepsis marginata, harbored bacteria of the genus Rickettsia. A 1.5-kb eubacterial 16S rRNA gene segment obtained from each of these species was amplified by PCR, cloned, and sequenced. Phylogenetic analysis of the 16S rRNA gene demonstrated that the Rickettsia species found in the leeches constituted a novel clade that is distinct from the clade of arthropod-associated Rickettsia species. In natural populations, 97.7% (43 of 44) of T. tagoi leeches and 100% (9 of 9) of H. marginata leeches carried Rickettsia, suggesting that infection with Rickettsia is prevalent in these leeches. This is the first report of Rickettsia found in annelids.

scholarly journals Endosymbiotic Bacteria in the Esophageal Organ of Glossiphoniid Leeches

2002 ◽  
Vol 68 (9) ◽  
pp. 4637-4641 ◽  
Author(s):  
Yoshitomo Kikuchi ◽  
Takema Fukatsu
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Segment ◽  
Rrna Gene ◽  
Bacterial Symbionts ◽  
Diagnostic Pcr ◽  
Endosymbiotic Bacteria ◽  
Sap Feeding ◽  
Specialized Structure ◽  
The 16S Rrna Gene

ABSTRACT We characterized the intracellular symbiotic bacteria of the hematophagous glossiphoniid leeches Placobdelloides siamensis and a Parabdella sp. These leeches have a specialized structure called an “esophageal organ,” the cells of which harbor bacterial symbionts. From the esophageal organ of each species, a 1.5-kb eubacterial 16S rRNA gene segment was amplified by PCR, cloned, and sequenced. Diagnostic PCR detected the symbiont in the esophageal organ and intestine. Phylogenetic analysis of the 16S rRNA gene(s) demonstrated that the symbionts from the leeches formed a monophyletic group in a well-defined clade containing endosymbiotic bacteria of plant sap-feeding insects in the γ-subdivision of the Proteobacteria. The nucleotide compositions of the 16S rRNA gene from the leech symbionts were highly AT biased (53.7%).

Overestimation of Streptococcus mutans prevalence by nested PCR detection of the 16S rRNA gene

2006 ◽  
Vol 55 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Ali Al-Ahmad ◽  
Thorsten Mathias Auschill ◽  
Gabriele Braun ◽  
Elmar Hellwig ◽  
Nicole Birgit Arweiler
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Streptococcus Mutans ◽  
Nested Pcr ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Direct Pcr ◽  
Specific Primers ◽  
The 16S Rrna Gene

This study was carried out in order to compare two PCR-based methods in the detection of Streptococcus mutans. The first PCR method was based on primers for the 16S rRNA gene and the second method was based on specific primers that targeted the glucosyltransferase gene (gtfB). Each PCR was performed with eight different streptococci from the viridans group, five other streptococci and 17 different non-streptococcal bacterial strains. Direct use of the S. mutans 16S rRNA gene-specific primers revealed that Streptococcus gordonii and Streptococcus infantis were also detected. After amplifying the 16S rRNA gene with universal primers and subsequently performing nested PCR, the S. mutans-specific nested primers based on the 16S rRNA gene detected all tested streptococci. There was no cross-reaction of the gtfB primers after direct PCR. Our results indicate that direct PCR and nested PCR based on 16S rRNA genes can reveal false-positive results for oral streptococci and lead to an overestimation of the prevalence of S. mutans with regards to its role as the most prevalent causative agent of dental caries.

scholarly journals Nonspecific PCR Amplification of the 16S rRNA Gene Segment in Different Bacteria by Use of Primers Specific for Campylobacter, Arcobacter, and Helicobacter spp.

2007 ◽  
Vol 45 (4) ◽  
pp. 1376-1377 ◽  
Author(s):  
A. D. Raut ◽  
B. P. Kapadnis ◽  
R. Shashidhar ◽  
J. R. Bandekar ◽  
P. Vaishampayan ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Segment ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
The 16S Rrna Gene

scholarly journals Analysis of 16S rRNA and 51-Kilodalton Antigen Gene and Transmission in Mice of Ehrlichia risticii in Virgulate Trematodes from Elimia livescens Snails in Ohio

2000 ◽  
Vol 38 (9) ◽  
pp. 3349-3358 ◽  
Author(s):  
Manuel Kanter ◽  
Jason Mott ◽  
Norio Ohashi ◽  
Bernard Fried ◽  
Stephen Reed ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Pcr Analysis ◽  
Composition Analysis ◽  
Rrna Gene ◽  
Antigen Gene ◽  
Ehrlichia Risticii ◽  
Horse Blood ◽  
The 16S Rrna Gene

Operculate snails (the family Pleuroceridae:Elimia livescens) were collected between June and October 1998 from a river in central Ohio where repeated cases of Potomac horse fever (PHF) have occurred. Of collected snails, consistently 50 to 80% carried a combination of cercariae and sporocysts of digenetic virgulate trematodes. The trematodes obtained from each snail were pooled and tested for Ehrlichia risticii, the agent of PHF, by nested PCR using primers specific to the 16S rRNA gene. Out of a total of 209 trematode pools, 50 pools were found to be positive by PCR. The DNA sequence of the 16S rRNA gene identified in one trematode pool was identical to that of the type strain of E. risticii, and the sequence of the gene identified in another pool differed from that of the type strain by 1 nucleotide. Comparison of the deduced amino acid sequence of the partial 51-kDa antigen gene from various sources revealed that Maryland, Ohio (except Ohio 081), and Kentucky strains are in a cluster distinct from the sequences obtained from sources in California and Oregon. Ohio 081 was shown previously by antigenic composition analysis to be distinct from other groups. However, all sequences examined were not segregated according to their sources: horse blood or infected trematodes. E. risticiiwas found to be transmittable from trematodes to mice and was subsequently passaged from infected mice to additional mice, as determined by PCR analysis. Our findings suggest the evolution ofE. risticii in the natural reservoir in separate geographic regions and persistent infection of trematode populations with E. risticii during summer and early fall. The study also suggests that the mouse can be used to isolate E. risticii from the infected trematode.

Rapid identification of Saccharomonospora strains by multiplex PCR using species-specific primers within the 16S rRNA gene

1996 ◽  
Vol 27 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
Sung Taik Lee ◽  
Yong Kook Shin ◽  
Sam-Bong Kim ◽  
Hong-Joong Kim ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Multiplex Pcr ◽  
Rapid Identification ◽  
Rrna Gene ◽  
Specific Primers ◽  
Species Specific ◽  
The 16S Rrna Gene

A coagulase-negative variant ofStaphylococcus aureusfrom bovine mastitis milk

2010 ◽  
Vol 78 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Ömer Akineden ◽  
Abdulwahed Ahmed Hassan ◽  
Elisabeth Schneider ◽  
Ewald Usleber
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bovine Mastitis ◽  
Surface Protein ◽  
Negative Reaction ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Coagulase Negative Staphylococci ◽  
Staph Aureus ◽  
The 16S Rrna Gene

Bacteriological analysis of milk samples from quarters of a dairy cow suffering from subclinical mastitis yielded two isolates ofStaphylococcus aureuswhich gave a negative reaction in the standard coagulase test. Both isolates were also clumping factor and thermonuclease negative, and gave a negative reaction in the Staphaurex®test. The isolates were identified by using commercial biochemical systems, and by PCR analysis of different staphylococcal cell surface protein and exoprotein genes. Further molecular identification of the isolates, which included sequencing of the 16S rRNA gene and RT-PCR of coagulase (coa), clumping-factor (clfA) and thermonuclease (nuc) genes, was consistent with the diagnosis phenotypically ‘coagulase-negative variant ofStaph. aureus’. The fact that coagulase-negativeStaph. aureusvariants can occur in the context of intramammary infections in cattle may result in the incorrect diagnosis ‘coagulase-negative staphylococci (CNS)’ in routine mastitis diagnostic, at least in rare cases. To fully ensure correct species diagnosis, sequencing of the 16S rRNA gene and amplification of specific genes such ascoais necessary in these cases.

Diversity of multicellular magnetotactic prokaryotes in the intertidal zone of Huiquan Bay, Qingdao

2020 ◽  
Author(s):  
Zhao Yicong ◽  
Zhang Wenyan ◽  
Pan Hongmiao ◽  
Cui Kaixuan ◽  
Chen Si ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Intertidal Zone ◽  
Sequence Divergence ◽  
Average Diameter ◽  
Rrna Gene ◽  
Iron Cycling ◽  
Transmission Electron ◽  
New Perspective ◽  
The 16S Rrna Gene

<p>Multicellular magnetotactic prokaryotes (MMPs) are a group of aggregates composed of 10-100 gram-negative cells synthesizing intracellular magnetic crystals. Two morphotypes of MMPs have been identified, including several species of globally distributed spherical mulberry-like MMPs (sMMPs), and ellipsoidal pineapple-like MMPs (eMMPs). We recently collected MMPs from the intertidal zone of Huiquan Bay, Qingdao. Optical microscopy showed that there were two types of MMPs in the area, including sMMPs and eMMPs. We observed the size of eMMPs was 9.25 ± 0.79 × 7.48 ± 0.79 μm (n = 24), and the average diameter of sMMPs was 5 ± 0.66 μm (n = 24). Transmission electron microscopy showed that these MMPs contained three sizes of bullet-shaped crystals in parallel chains or clusters. The length and width ratios of the sizes of these magnetosomes were 4.16±0.64, 3.07±0.29 and 2.51±0.36 (n=44). The 16S rRNA gene of micromanipulation-purified sMMPs and eMMPs were cloned and sequenced. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that 565 sequences of MMPs belonged to 16 OTUs, affiliated with Deltaproteobacteria. Four OTUs displayed >3.48% sequence divergence and two OTUs displayed >7.26% sequence divergence with respect to previously reported MMPs. This result suggested that they represented six new species and two novel genera. These results indicated that the intertidal zone of Huiquan Bay has a high diversity of MMPs that bio-mineralize iron crystals and play an important role in iron cycling in such a complex environment. These observations provide a new perspective of the diversity of MMPs in general and expand knowledge of the occurrence of MMPs in the Huiquan Bay.</p><p><strong>Keywords</strong>: Intertidal zone, Diversity, Multicellular magnetotactic prokaryotes (MMPs),  16S rRNA gene, Magnetosomes</p>

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