scholarly journals Intracellular Symbionts and Other Bacteria Associated with Deer Ticks (Ixodes scapularis) from Nantucket and Wellfleet, Cape Cod, Massachusetts

2004 ◽  
Vol 70 (1) ◽  
pp. 616-620 ◽  
Author(s):  
Micah J. Benson ◽  
Jeffrey D. Gawronski ◽  
Douglas E. Eveleigh ◽  
David R. Benson
Keyword(s):  
16S Rrna ◽  
Ixodes Scapularis ◽  
Pcr Amplification ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Cape Cod ◽  
Intracellular Bacteria ◽  
Cloning And Sequencing ◽  
Gram Negative ◽  
Insect Symbionts

ABSTRACT The diversity of bacteria associated with the deer tick (Ixodes scapularis) was assessed using PCR amplification, cloning, and sequencing of 16S rRNA genes originating from seven ticks collected from Nantucket Island and Wellfleet, Cape Cod, Mass. The majority of sequences obtained originated from gram-negative proteobacteria. Four intracellular bacteria were detected including strains of Ehrlichia, Rickettsia, and Wolbachia and an organism related to intracellular insect symbionts from the Cytophaga-Flavobacterium-Bacteroides group. Several strains of members of the Sphingomonadaceae were also detected in all but one tick. The results provide a view of the diversity of bacteria associated with I. scapularis ticks in the field.

scholarly journals Evaluation of 16S, map1 and pCS20 probes for detection of Cowdria and Ehrlichia species

1999 ◽  
Vol 122 (2) ◽  
pp. 323-328 ◽  
Author(s):  
M. T. E. P. ALLSOPP ◽  
C. M. HATTINGH ◽  
S. W. VOGEL ◽  
B. A. ALLSOPP
Keyword(s):  
16S Rrna ◽  
Ribosomal Rna ◽  
Pcr Amplification ◽  
16S Ribosomal Rna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Amblyomma Hebraeum ◽  
Ribosomal Rna Gene ◽  
Group Iii ◽  
16S Ribosomal Rna Gene

A panel of 16S ribosomal RNA gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any Group III Ehrlichia species other than Cowdria and one detects any Group II Ehrlichia species. These probes have been used on PCR-amplified rickettsial 16S rRNA genes from over 200 Amblyomma hebraeum ticks. Control ticks were laboratory-reared and either uninfected or fed on sheep experimentally infected with different cowdria isolates, field ticks were collected from animals in heartwater-endemic areas. All tick-derived DNA samples were also examined by PCR amplification and probing for two other cowdria genes (map1 and pCS20) which have previously been used for heartwater epidemiology. This paper describes the first direct comparison of all currently available DNA probes for heartwater-associated organisms.

scholarly journals Cultivation-Independent Examination of Horizontal Transfer and Host Range of an IncP-1 Plasmid among Gram-Positive and Gram-Negative Bacteria Indigenous to the Barley Rhizosphere

2006 ◽  
Vol 72 (10) ◽  
pp. 6687-6692 ◽  
Author(s):  
Sanin Musovic ◽  
Gunnar Oregaard ◽  
Niels Kroer ◽  
Søren J. Sørensen
Keyword(s):  
16S Rrna ◽  
Host Range ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Gram Positive ◽  
Gram Negative ◽  
Indigenous Bacteria ◽  
Transfer Frequency

ABSTRACTThe host range and transfer frequency of an IncP-1 plasmid (pKJK10) among indigenous bacteria in the barley rhizosphere was investigated. A new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16S rRNA gene classification was used. Indigenous transconjugant rhizosphere bacteria were collected by fluorescence-activated cell sorting and identified by cloning and sequencing of 16S rRNA genes from the sorted cells. The host range of the pKJK10 plasmid was exceptionally broad, as it included not only bacteria belonging to the alpha, beta, and gamma subclasses of theProteobacteria, but alsoArthrobactersp., a gram-positive member of theActinobacteria. The transfer frequency (transconjugants per donor) from thePseudomonas putidadonor to the indigenous bacteria was 7.03 × 10−2± 3.84 × 10−2. This is the first direct documentation of conjugal transfer between gram-negative donor and gram-positive recipient bacteria in situ.

scholarly journals Oligonucleotide Microarray for 16S rRNA Gene-Based Detection of All Recognized Lineages of Sulfate-Reducing Prokaryotes in the Environment

2002 ◽  
Vol 68 (10) ◽  
pp. 5064-5081 ◽  
Author(s):  
Alexander Loy ◽  
Angelika Lehner ◽  
Natuschka Lee ◽  
Justyna Adamczyk ◽  
Harald Meier ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Pcr Amplification ◽  
Oligonucleotide Microarray ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Specific Pcr

ABSTRACT For cultivation-independent detection of sulfate-reducing prokaryotes (SRPs) an oligonucleotide microarray consisting of 132 16S rRNA gene-targeted oligonucleotide probes (18-mers) having hierarchical and parallel (identical) specificity for the detection of all known lineages of sulfate-reducing prokaryotes (SRP-PhyloChip) was designed and subsequently evaluated with 41 suitable pure cultures of SRPs. The applicability of SRP-PhyloChip for diversity screening of SRPs in environmental and clinical samples was tested by using samples from periodontal tooth pockets and from the chemocline of a hypersaline cyanobacterial mat from Solar Lake (Sinai, Egypt). Consistent with previous studies, SRP-PhyloChip indicated the occurrence of Desulfomicrobium spp. in the tooth pockets and the presence of Desulfonema- and Desulfomonile-like SRPs (together with other SRPs) in the chemocline of the mat. The SRP-PhyloChip results were confirmed by several DNA microarray-independent techniques, including specific PCR amplification, cloning, and sequencing of SRP 16S rRNA genes and the genes encoding the dissimilatory (bi)sulfite reductase (dsrAB).

scholarly journals Prey Range Characterization, Ribotyping, and Diversity of Soil and Rhizosphere Bdellovibriospp. Isolated on Phytopathogenic Bacteria

2000 ◽  
Vol 66 (6) ◽  
pp. 2365-2371 ◽  
Author(s):  
E. Jurkevitch ◽  
D. Minz ◽  
Barak Ramati ◽  
Gili Barel
Keyword(s):  
16S Rrna ◽  
Common Bean ◽  
Pcr Amplification ◽  
Erwinia Carotovora ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Range Analysis ◽  
Pcr Product ◽  
Utilization Patterns ◽  
Range Characterization

ABSTRACT Thirty new Bdellovibrio strains were isolated from an agricultural soil and from the rhizosphere of plants grown in that soil. Using a combined molecular and culture-based approach, we found that the soil bdellovibrios included subpopulations of organisms that differed from rhizosphere bdellovibrios. Thirteen soil and seven common bean rhizosphere Bdellovibrio strains were isolated when Pseudomonas corrugata was used as prey; seven and two soil strains were isolated when Erwinia carotovora subsp.carotovora and Agrobacterium tumefaciens, respectively, were used as prey; and one tomato rhizosphere strain was isolated when A. tumefaciens was used as prey. In soil and in the rhizosphere, depending on the prey cells used, the concentrations of bdellovibrios were between 3 × 102 to 6 × 103 and 2.8 × 102 to 2.3 × 104 PFU g−1. A prey range analysis of five soil and rhizosphereBdellovibrio isolates performed with 22 substrate species, most of which were plant-pathogenic and plant growth-enhancing bacteria, revealed unique utilization patterns and differences between closely related prey cells. An approximately 830-bp fragment of the 16S rRNA genes of all of theBdellovibrio strains used was obtained by PCR amplification by using a Bdellovibrio-specific primer combination. Soil and common bean rhizosphere strains produced two and one restriction patterns for this PCR product, respectively. The 16S rRNA genes of three soil isolates and three root-associated isolates were sequenced. One soil isolate belonged to theBdellovibrio stolpii-Bdellovibrio starrii clade, while all of the other isolates clustered withBdellovibrio bacteriovorus and formed two distantly related, heterogeneous groups.

scholarly journals 16S rRNA Gene-Based Identification of Midgut Bacteria from Field-Caught Anopheles gambiae Sensu Lato and A. funestus Mosquitoes Reveals New Species Related to Known Insect Symbionts

2005 ◽  
Vol 71 (11) ◽  
pp. 7217-7223 ◽  
Author(s):  
Jenny M. Lindh ◽  
Olle Terenius ◽  
Ingrid Faye
Keyword(s):  
16S Rrna ◽  
Anopheles Gambiae ◽  
Bacterial Species ◽  
Anopheles Funestus ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Malaria Vectors ◽  
Rrna Gene ◽  
Species Determination ◽  
Insect Symbionts

ABSTRACT Field-collected mosquitoes of the two main malaria vectors in Africa, Anopheles gambiae sensu lato and Anopheles funestus, were screened for their midgut bacterial contents. The midgut from each blood-fed mosquito was screened with two different detection pathways, one culture independent and one culture dependent. Bacterial species determination was achieved by sequence analysis of 16S rRNA genes. Altogether, 16 species from 14 genera were identified, 8 by each method. Interestingly, several of the bacteria identified are related to bacteria known to be symbionts in other insects. One isolate, Nocardia corynebacterioides, is a relative of the symbiont found in the vector for Chagas' disease that has been proven useful as a paratransgenic bacterium. Another isolate is a novel species within the γ-proteobacteria that could not be phylogenetically placed within any of the known orders in the class but is close to a group of insect symbionts. Bacteria representing three intracellular genera were identified, among them the first identifications of Anaplasma species from mosquitoes and a new mosquito-Spiroplasma association. The isolates will be further investigated for their suitability for a paratransgenic Anopheles mosquito.

scholarly journals Selective and Sensitive Method for PCR Amplification of Escherichia coli 16S rRNA Genes in Soil

2000 ◽  
Vol 66 (2) ◽  
pp. 844-849 ◽  
Author(s):  
G. Sabat ◽  
P. Rose ◽  
W. J. Hickey ◽  
J. M. Harkin
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Pcr Amplification ◽  
Pcr Primers ◽  
Enteric Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Selective Amplification ◽  
E Coli

ABSTRACT A set of PCR primers targeting 16S rRNA gene sequences was designed, and PCR parameters were optimized to develop a robust and reliable protocol for selective amplification of Escherichia coli 16S rRNA genes. The method was capable of discriminatingE. coli from other enteric bacteria, including its closest relative, Shigella. Selective amplification of E. coli occurred only when the annealing temperature in the PCR was elevated to 72°C, which is 10°C higher than the optimum for the primers. Sensitivity was retained by modifying the length of steps in the PCR, by increasing the number of cycles, and most importantly by optimizing the MgCl2 concentration. The PCR protocol developed can be completed in less then 2 h and, by using Southern hybridization, has a detection limit of ca. 10 genomic equivalents per reaction. The method was demonstrated to be effective for detectingE. coli DNA in heterogeneous DNA samples, such as those extracted from soil.

scholarly journals Suicide Polymerase Endonuclease Restriction, a Novel Technique for Enhancing PCR Amplification of Minor DNA Templates

2005 ◽  
Vol 71 (8) ◽  
pp. 4721-4727 ◽  
Author(s):  
Stefan J. Green ◽  
Dror Minz
Keyword(s):  
16S Rrna ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Pcr Amplification ◽  
Environmental Dna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Dna Templates ◽  
Target Dna ◽  
Gradient Gel Electrophoresis ◽  
Pcr Method

ABSTRACT PCR-based molecular analyses can be hindered by the presence of unwanted or dominant DNA templates that reduce or eliminate detection of alternate templates. We describe here a reaction in which such templates can be exclusively digested by endonuclease restriction, leaving all other DNAs unmodified. After such a modification, the digested template is no longer available for PCR amplification, while nontarget DNAs remain intact and can be amplified. We demonstrate the application of this method and use denaturing gradient gel electrophoresis to ascertain the removal of target DNA templates and the subsequent enhanced amplification of nondigested DNAs. Specifically, plastid 16S rRNA genes were exclusively digested from environmental DNA extracted from plant roots. In addition, pure culture and environmental DNA extracts were spiked with various amounts of genomic DNA extracted from Streptomyces spp., and selective restriction of the Streptomyces 16S rRNA genes via the suicide polymerase endonuclease restriction PCR method was employed to remove the amended DNA.

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