Topic
Simkaniaceae
About: Simkaniaceae is a research topic. Over the lifetime, 24 publications have been published within this topic receiving 1791 citations.
Papers
TL;DR: A reclassification of the order Chlamydiales and its current taxa is proposed in this article, which retains currently known strains with > 90% 16S rRNA identity in the family Chlamdianaceae and separates other chlamydia-like organisms that have 80-90% 16s rRNA relatedness to the chlamydiaceae into new families.
Abstract: The current taxonomic classification of Chlamydia is based on limited phenotypic, morphologic and genetic criteria This classification does not take into account recent analysis of the ribosomal operon or recently identified obligately intracellular organisms that have a chlamydia-like developmental cycle of replication Neither does it provide a systematic rationale for identifying new strains In this study, phylogenetic analyses of the 16S and 23S rRNA genes are presented with corroborating genetic and phenotypic information to show that the order Chlamydiales contains at least four distinct groups at the family level and that within the Chlamydiaceae are two distinct lineages which branch into nine separate clusters In this report a reclassification of the order Chlamydiales and its current taxa is proposed This proposal retains currently known strains with > 90% 16S rRNA identity in the family Chlamydiaceae and separates other chlamydia-like organisms that have 80--90% 16S rRNA relatedness to the Chlamydiaceae into new families Chlamydiae that were previously described as ‘Candidatus Parachlamydia acanthamoebae’ Amann, Springer, Schonhuber, Ludwig, Schmid, Muller and Michel 1997, become members of Parachlamydiaceae fam nov, Parachlamydia acanthamoebae gen nov, sp nov ‘Simkania’ strain Z becomes the founding member of Simkaniaceae fam nov, Simkania negevensis gen nov, sp nov The fourth group, which includes strain WSU 86--1044, was left unnamed The Chlamydiaceae, which currently has only the genus Chlamydia, is divided into two genera, Chlamydia and Chlamydophila gen nov Two new species, Chlamydia muridarum sp nov and Chlamydia suis sp nov, join Chlamydia trachomatis in the emended genus Chlamydia Chlamydophila gen nov assimilates the current species, Chlamydia pecorum, Chlamydia pneumoniae and Chlamydia psittaci, to form Chlamydophila pecorum comb nov, Chlamydophila pneumoniae comb nov and Chlamydophila psittaci comb nov Three new Chlamydophila species are derived from Chlamydia psittaci: Chlamydophila abortus gen nov, sp nov, Chlamydophila caviae gen nov, sp nov and Chlamydophila felis gen nov, sp nov Emended descriptions for the order Chlamydiales and for the family Chlamydiaceae are provided These families, genera and species are readily distinguished by analysis of signature sequences in the 165 and 235 ribosomal genes
1,000 citations
TL;DR: The present study compared sequences for 11 endosymbiont genes to genomic data for chlamydial families Parachlamydiaceae, ChlamYDiaceae and Simkaniaceae and to 16S rRNA gene signature sequences from 330 chlamydiae to conclude that it was appropriate to propose 'Candidatus Fritschea bemisiae' strain Falk
Abstract: Bacteria called 'Fritschea' are endosymbionts of the plant-feeding whitefly Bemisia tabaci and scale insect Eriococcus spurius. In the gut of B. tabaci, these bacteria live within bacteriocyte cells that are transmitted directly from the parent to oocytes. Whiteflies cause serious economic damage to many agricultural crops; B. tabaci fecundity and host range are less than those of Bemisia argentifolii, possibly due to the presence of this endosymbiont. The B. tabaci endosymbiont has been characterized using electron microscopy and DNA analysis but has not been isolated or propagated outside of insects. The present study compared sequences for 11 endosymbiont genes to genomic data for chlamydial families Parachlamydiaceae, Chlamydiaceae and Simkaniaceae and to 16S rRNA gene signature sequences from 330 chlamydiae. We concluded that it was appropriate to propose 'Candidatus Fritschea bemisiae' strain Falk and 'Candidatus Fritschea eriococci' strain Elm as members of the family Simkaniaceae in the Chlamydiales.
157 citations
TL;DR: It is shown that a variety of non-C.
76 citations
TL;DR: Growth of the organism, as assessed by infectivity assays, reached a plateau in 2-3 d although by light microscopy the cytopathic effect on the host cells increased for 12 or more days after infection, consistent with the proposal that S. negevensis belongs to a distinct family in the order Chlamydiales.
Abstract: Simkania negevensis is the type species of Simkaniaceae, a recently proposed family in the order Chlamydiales. In the current study, growth, antigenic and genomic characteristics of this intracellular bacterium were investigated and compared to those of members of the family Chlamydiaceae. Growth of the organism, as assessed by infectivity assays, reached a plateau in 2--3 d although by light microscopy the cytopathic effect on the host cells increased for 12 or more days after infection. S. negevensis growth was unaffected by sulfadiazine. Cells infected by S. negevensis strain ZTwere not recognized by either of two monoclonal antibodies specific for Chlamydiaceae LPS and several specific Chlamydiaceae ompA primers were unable to PCR amplify a S. negevensis gene. The S. negevensis genome contained one copy of the ribosomal operon. The genome size of S. negevensis strain ZTwas determined by PFGE to be 1·7 Mbp, and the G+C content was 42·5 mol%. These data, taken together with other published data, are consistent with the proposal that S. negevensis belongs to a distinct family in the order Chlamydiales.
52 citations
TL;DR: The widespread occurrence of novel chlamydiae in the environment is confirmed and knowledge of their biodiversity in freshwater habitats is enlarges, including natural ponds, garden pots and fountains.
33 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2018 | 1 |
| 2017 | 4 |
| 2016 | 1 |
| 2015 | 4 |
| 2014 | 2 |