In silico Approach to Study Adaptive Divergence in Nucleotide Composition of the 16S rRNA Gene Among Bacteria Thriving Under Different Temperature Regimes

2014 ◽  
Vol 21 (10) ◽  
pp. 753-759 ◽  
Author(s):  
Hari Ram ◽  
Alok Kumar ◽  
Lebin Thomas ◽  
Ved Pal Singh
Author(s):  
Bianca Rodrigues Jardim ◽  
Wycliff M. Kinoti ◽  
Lucy T. T. Tran-Nguyen ◽  
Cherie Gambley ◽  
Brendan Rodoni ◽  
...  

In Australia, Stylosanthes little leaf (StLL) phytoplasma has been detected in Stylosanthes scabra Vogel, Arachis pintoi Krapov, Saccharum officinarum L., Carica papaya L., Medicago sativa L., and Solanum tuberosum L. The 16S rRNA gene sequence of StLL phytoplasma strains from S. scabra, C. papaya, S. officinarum and S. tuberosum were compared and share 99.93–100 % nucleotide sequence identity. Phylogenetic comparisons between the 16S rRNA genes of StLL phytoplasma and other ‘Candidatus Phytoplasma’ species indicate that StLL represents a distinct phytoplasma lineage. It shares its most recent known ancestry with ‘Ca. Phytoplasma luffae’ (16SrVIII-A), with which it has 97.17–97.25 % nucleotide identity. In silico RFLP analysis of the 16S rRNA amplicon using iPhyClassifier indicate that StLL phytoplasmas have a unique pattern (similarity coefficient below 0.85) that is most similar to that of ‘Ca. Phytoplasma luffae’. The unique in silico RFLP patterns were confirmed in vitro. Nucleotide sequences of genes that are more variable than the 16S rRNA gene, namely tuf (tu-elongation factor), secA (partial translocation gene), and the partial ribosomal protein (rp) gene operon (rps19-rpl22-rps3), produced phylogenetic trees with similar branching patterns to the 16S rRNA gene tree. Sequence comparisons between the StLL 16S rRNA spacer region confirmed previous reports of rrn interoperon sequence heterogeneity for StLL, where the spacer region of rrnB encodes a complete tRNA-Isoleucine gene and the rrnA spacer region does not. Together these results suggest that the Australian phytoplasma, StLL, is unique according to the International Organization for Mycoplasmology (IRPCM) recommendations. The novel taxon ‘Ca. Phytoplasma stylosanthis’ is proposed, with the most recent strain from a potato crop in Victoria, Australia, serving as the reference strain (deposited in the Victorian Plant Pathology Herbarium as VPRI 43683).


2020 ◽  
Author(s):  
Po-Yu Liu ◽  
Wei-Kai Wu ◽  
Chieh-Chang Chen ◽  
Suraphan Panyod ◽  
Lee-Yan Sheen ◽  
...  

ABSTRACTSequencing of the 16S rRNA gene by Illumina next-generation sequencing is broadly used in microbiome studies. Different hypervariable regions of the 16S rRNA gene, V3V4 (amplified with primers 341F–805R) or V4 (V4O; primers 515F–806R), are selected, depending on the targeted resolution. However, in population-based clinical studies, combining V3V4 and V4 data from different studies for a meta-analysis is challenging. Reads generated by short-read (150-bp) high-throughput sequencing platforms do not fully recover the V4 region read-length. Here, we evaluated the compatibility of 16S rRNA V3V4 and V4 amplicons for microbiome profiling. We compared taxonomic compositions obtained by the analysis of V3V4 and V4 amplicons, and V4 fragments trimmed from V3V4 amplicons. We also evaluated an alternative V4 region (V4N; primers 519F–798R) designed for efficient stitching with 150-bp paired-end sequencing. First, we simulated a global investigation of environmental prokaryotes in silico. This revealed that V4O primers recovered the highest proportion of fragments (81.7%) and most phyla, including archaea. Empirical sequencing of standard (mock) and human fecal samples revealed biased patterns of each primer that were similar to the ones determined by in silico simulation. Further, for human fecal microbiome profiling, the between-sample variance was greater than the systematic bias of each primer. The use of trimmed V4 fragments and single-end amplicons resulted in the same systematic bias. In conclusion, paired-end V4O sequencing yielded the most accurate data for both, simulation and mock community sequencing; the V4O amplicons were compatible with trimmed V4 sequences for microbiome profiling.IMPORTANCENext-generation sequencing of the 16S rRNA gene is a commonly used approach for clinical microbiome studies. Different amplicons of the 16S rRNA hypervariable regions are used in different studies, which creates incompatible sequence features when comparing and integrating data among studies by using 16S denoising pipelines. Here we compared the type of data and coverage obtained when different 16S rRNA amplicons were analyzed. In silico and empirical analyses of the human fecal microbiome revealed that the V3V4 amplicons are compatible with V4 amplicons after trimming up to the same region. These observations demonstrate that reconciling the compatibility of clinical microbiome data from different studies improve not only the sample size but also the confidence of the hypothesis tested.


2014 ◽  
Vol 64 (Pt_3) ◽  
pp. 781-786 ◽  
Author(s):  
Maximo Sánchez ◽  
Martha-Helena Ramírez-Bahena ◽  
Alvaro Peix ◽  
María J. Lorite ◽  
Juan Sanjuán ◽  
...  

Strain S658T was isolated from a Lotus corniculatus nodule in a soil sample obtained in Uruguay. Phylogenetic analysis of the 16S rRNA gene and atpD gene showed that this strain clustered within the genus Phyllobacterium . The closest related species was, in both cases, Phyllobacterium trifolii PETP02T with 99.8 % sequence similarity in the 16S rRNA gene and 96.1 % in the atpD gene. The 16S rRNA gene contains an insert at the beginning of the sequence that has no similarities with other inserts present in the same gene in described rhizobial species. Ubiquinone Q-10 was the only quinone detected. Strain S658T differed from its closest relatives through its growth in diverse culture conditions and in the assimilation of several carbon sources. It was not able to reproduce nodules in Lotus corniculatus. The results of DNA–DNA hybridization, phenotypic tests and fatty acid analyses confirmed that this strain should be classified as a representative of a novel species of the genus Phyllobacterium , for which the name Phyllobacterium loti sp. nov. is proposed. The type strain is S658T( = LMG 27289T = CECT 8230T).


2011 ◽  
Vol 225 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Toshinori Kawanami ◽  
Kazuhiro Yatera ◽  
Kazumasa Fukuda ◽  
Kei Yamasaki ◽  
Masamizu Kunimoto ◽  
...  

2014 ◽  
Vol 81 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Brandee L. Stone ◽  
Nathan M. Russart ◽  
Robert A. Gaultney ◽  
Angela M. Floden ◽  
Jefferson A. Vaughan ◽  
...  

ABSTRACTScant attention has been paid to Lyme disease,Borrelia burgdorferi,Ixodes scapularis, or reservoirs in eastern North Dakota despite the fact that it borders high-risk counties in Minnesota. Recent reports ofB. burgdorferiandI. scapularisin North Dakota, however, prompted a more detailed examination. Spirochetes cultured from the hearts of five rodents trapped in Grand Forks County, ND, were identified asB. burgdorferi sensu latothrough sequence analyses of the 16S rRNA gene, the 16S rRNA gene-ileTintergenic spacer region,flaB,ospA,ospC, andp66. OspC typing revealed the presence of groups A, B, E, F, L, and I. Two rodents were concurrently carrying multiple OspC types. Multilocus sequence typing suggested the eastern North Dakota strains are most closely related to those found in neighboring regions of the upper Midwest and Canada. BALB/c mice were infected withB. burgdorferiisolate M3 (OspC group B) by needle inoculation or tick bite. Tibiotarsal joints and ear pinnae were culture positive, andB. burgdorferiM3 was detected by quantitative PCR (qPCR) in the tibiotarsal joints, hearts, and ear pinnae of infected mice. Uninfected larvalI. scapularisticks were able to acquireB. burgdorferiM3 from infected mice; M3 was maintained inI. scapularisduring the molt from larva to nymph; and further, M3 was transmitted from infectedI. scapularisnymphs to naive mice, as evidenced by cultures and qPCR analyses. These results demonstrate that isolate M3 is capable of disseminated infection by both artificial and natural routes of infection. This study confirms the presence of unique (nonclonal) and infectiousB. burgdorferipopulations in eastern North Dakota.


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