Identification and characterization of intervening sequences within 23S rRNA genes from more than 200 Campylobacter isolates from seven species including atypical campylobacters

Agrobacterium vitis was isolated from roots of 41 of 66 feral Vitis riparia vines collected in three different regions of New York State. Two of the regions were more than 150 km from commercial vineyards. The strains were highly diverse as determined by DNA fingerprinting of the chromosomal region lying between the 16S and 23S rRNA genes. Of 24 strains examined, 15 different fingerprints were generated, and none was identical to fingerprints generated by previously identified groups of tumorigenic A. vitis strains. Results of physiological tests that were done to characterize strains from V. riparia conformed closely to those expected for A. vitis, except that 23 of 26 strains did not utilize tartrate. All strains were nontumorigenic, did not hybridize with a probe consisting of T-DNA genes, did not utilize octopine or nopaline, and carried zero to three plasmids. Of 26 strains, 7 inhibited A. vitis strain K306 from causing galls at wound sites on grape as well as or better than a previously studied nontumorigenic A. vitis strain, F2/5, that is known to have biological control activity.

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Construction and Initial Characterization of Escherichia coli Strains with Few or No Intact Chromosomal rRNA Operons

Journal of Bacteriology ◽

10.1128/jb.181.12.3803-3809.1999 ◽

1999 ◽

Vol 181 (12) ◽

pp. 3803-3809 ◽

Cited By ~ 78

Author(s):

Tsuneaki Asai ◽

Ciarán Condon ◽

Justina Voulgaris ◽

Dmitry Zaporojets ◽

Binghua Shen ◽

...

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Rrna Operon ◽

Rrna Genes ◽

23S Rrna ◽

Multicopy Plasmid ◽

Wild Type ◽

Protein Ratio ◽

23S Rrna Genes

ABSTRACT The Escherichia coli genome carries seven rRNA (rrn) operons, each containing three rRNA genes. The presence of multiple operons has been an obstacle to many studies of rRNA because the effect of mutations in one operon is diluted by the six remaining wild-type copies. To create a tool useful for manipulating rRNA, we sequentially inactivated from one to all seven of these operons with deletions spanning the 16S and 23S rRNA genes. In the final strain, carrying no intact rRNA operon on the chromosome, rRNA molecules were expressed from a multicopy plasmid containing a single rRNA operon (prrn). Characterization of these rrndeletion strains revealed that deletion of two operons was required to observe a reduction in the growth rate and rRNA/protein ratio. When the number of deletions was extended from three to six, the decrease in the growth rate was slightly more than the decrease in the rRNA/protein ratio, suggesting that ribosome efficiency was reduced. This reduction was most pronounced in the Δ7 prrn strain, in which the growth rate, unlike the rRNA/protein ratio, was not completely restored to wild-type levels by a cloned rRNA operon. The decreases in growth rate and rRNA/protein ratio were surprisingly moderate in the rrndeletion strains; the presence of even a single operon on the chromosome was able to produce as much as 56% of wild-type levels of rRNA. We discuss possible applications of these strains in rRNA studies.

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Erratum: Demonstration of the absence of intervening sequences within 23S rRNA genes fromCampylobacter lari

Journal of Basic Microbiology ◽

10.1002/jobm.201090005 ◽

2010 ◽

Vol 50 (2) ◽

pp. 206-206

Author(s):

Akihiro Tazumi ◽

Yuki Kakinuma ◽

John E. Moore ◽

Cherie B. Millar ◽

Ikue Taneike ◽

...

Keyword(s):

Rrna Genes ◽

23S Rrna ◽

Intervening Sequences ◽

23S Rrna Genes

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The Absence of Intervening Sequences in 23S rRNA Genes of Campylobacter coli Isolates from Turkeys Is a Unique Attribute of a Cluster of Related Strains Which Also Lack Resistance to Erythromycin

Applied and Environmental Microbiology ◽

10.1128/aem.01995-06 ◽

2006 ◽

Vol 73 (4) ◽

pp. 1208-1214 ◽

Cited By ~ 9

Author(s):

Kamfai Chan ◽

William G. Miller ◽

Robert E. Mandrell ◽

Sophia Kathariou

Keyword(s):

Natural Transformation ◽

Rrna Genes ◽

23S Rrna ◽

Rrna Gene ◽

Campylobacter Coli ◽

Erythromycin Resistance ◽

Intervening Sequences ◽

23S Rrna Gene ◽

23S Rrna Genes ◽

Sequence Types

ABSTRACT Certain Campylobacter strains harbor a transcribed intervening sequence (IVS) in their 23S rRNA genes. Following transcription, the IVS is excised, leading to fragmentation of the 23S rRNA. The origin and possible functions of the IVS are unknown. Furthermore, the distribution of IVS-harboring strains within Campylobacter populations is poorly understood. In this study, 104 strains of Campylobacter coli from turkeys, representing 27 different multilocus sequence typing-based sequence types (STs), were characterized in terms of IVS content and erythromycin susceptibility. Sixty-nine strains harbored IVSs in all three 23S rRNA genes, whereas the other 35 strains lacked IVSs from at least one of the genes. The STs of the latter strains belonged to an unusual cluster of C. coli STs (cluster II), earlier found primarily in turkey strains and characterized by the presence of the C. jejuni aspA103 allele. The majority (66/69) of strains harboring IVSs in all three 23S rRNA genes were resistant to erythromycin, whereas none of the 35 strains with at least one IVS-free 23S rRNA gene were resistant. Cluster II strains could be transformed to erythromycin resistance with genomic DNA from C. coli that harbored IVS and the A2075G transition in the 23S rRNA gene, associated with resistance to erythromycin in Campylobacter. Erythromycin-resistant transformants harbored both the A2075 transition and IVS. The findings suggest that the absence of IVS in C. coli from turkeys is characteristic of a unique clonal group of erythromycin-susceptible strains and that IVS can be acquired by these strains via natural transformation to erythromycin resistance.

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