Topic
Simkania
About: Simkania is a research topic. Over the lifetime, 31 publications have been published within this topic receiving 1252 citations.
Papers
TL;DR: The genomes of seven Chlamydia-like organisms have now been sequenced, providing new information on their potential ability to adapt to a wide range of hosts and providing insight into the origins of the 'traditional' chlamydiae.
Abstract: Chlamydiae are obligate intracellular bacteria that share a unique but remarkably conserved biphasic developmental cycle that relies on a eukaryotic host cell for survival. Although the phylum was originally thought to only contain one family, the Chlamydiaceae, a total of nine families are now recognized. These so-called Chlamydia-like organisms (CLOs) are also referred to as 'environmental chlamydiae', as many were initially isolated from environmental sources. However, these organisms are also emerging pathogens, as many, such as Parachlamydia sp., Simkania sp. and Waddlia sp., have been associated with human disease, and others, such as Piscichlamydia sp. and Parilichlamydia sp., have been documented in association with diseases in animals. Their strict intracellular nature and the requirement for cell culture have been a confounding factor in characterizing the biology and pathogenicity of CLOs. Nevertheless, the genomes of seven CLO species have now been sequenced, providing new information on their potential ability to adapt to a wide range of hosts. As new isolation and diagnostic methods advance, we are able to further explore the richness of this phylum with further research likely to help define the true pathogenic potential of the CLOs while also providing insight into the origins of the 'traditional' chlamydiae.
124 citations
TL;DR: A new obligate intracellular bacterium which the authors called 'Z' was isolated as a cell culture contaminant of unknown origin and evidence that this bacterium differs significantly from chlamydiae was provided.
Abstract: A new obligate intracellular bacterium which we called ‘Z’ was isolated as a cell culture contaminant of unknown origin. The organism grew in a variety of cultured cells with a 5–7-day developmental cycle, within cytoplasmic phagosomes, similarly to Chlamydia and some Rickettsia spp. Two alternating developmental forms (elementary bodies and reticulate bodies) were observed by electron microscopy. SDS-PAGE electrophoresis, immunoblotting with chlamydia-specific antibodies, and polymerase chain reaction using chlamydial genus specific primers provided evidence that our bacterium differs significantly from chlamydiae. Further characterization of ‘Z’ including determination of 16S ribosomal RNA sequences will allow its taxonomic position to be established.
86 citations
TL;DR: The trachoma and psittaci groups chlamydiae are now recognized as separate genera, Chlamydia and Chlamydophila, respectively, and biovars of each group have been elevated to the species rank.
Abstract: In recent years, 16S ribosomal DNA analyses has allowed the recognition of new chlamydia organisms, requiring the creation of new species, genera, and families within this unique, deep lineage of prokaryotes. The trachoma and psittaci groups chlamydiae are now recognized as separate genera, Chlamydia and Chlamydophila, respectively, and biovars of each group have been elevated to the species rank. Simkania and Parachlamydia have been associated with human respiratory infections, while Waddlia seems to be implicated in abortion in bovins. DNA amplification studies targeting the 16S rDNA have revealed a richer diversity within chlamydiae, identifying new lineages from both environmental and clinical samples. Further studies will be of interest to both examine the ecology and evaluate the clinical importance of these novel chlamydiae. Herein, we provide a summary of literature and our data about the novel chlamydial lineages.
86 citations
TL;DR: Experimental studies showed that free-living amoebae may support multiplication of various chlamydiae, then could play an important role as reservoir/vector of chlamydial infections.
Abstract: Chlamydiae are important intracellular bacterial pathogens of vertebrates. In the last years, novel members of this group have been discovered: Parachlamydia acanthamoebae and Simkania negevensis seems to be emerging respiratory human pathogens, while Waddlia chondrophila might be a new agent of bovine abortion. Various species have been showed to infect also the herpetofauna and fishes, and some novel chlamydiae are endosymbionts of arthropods. In addition, molecular studies evidenced a huge diversity of chlamydiae from both environmental and clinical samples, most of such a diversity could be formed by novel lineages of chlamydiae. Experimental studies showed that free-living amoebae may support multiplication of various chlamydiae, then could play an important role as reservoir/vector of chlamydial infections. Here we reviewed literature data concerning chlamydial infections, with a particular emphasis on the novely described chlamydial organisms.
77 citations
TL;DR: It is shown that a variety of non-C.
76 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 1 |
| 2017 | 2 |
| 2016 | 1 |
| 2015 | 3 |
| 2014 | 3 |