A spirochaete or spirochete is a member of the phylum Spirochaetes, which contains distinctive diderm bacteria, most of which have long, helically coiled cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm. Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, sometimes called axial filaments, which run lengthwise between the bacterial inner membrane and outer membrane in periplasmic space; these cause a twisting motion. When reproducing, a spirochaete will undergo asexual transverse binary fission. Most spirochaetes are free-living and anaerobic. Spirochaetes bacteria are diverse in their pathogenic capacity and the ecological niches that they inhabit, as well as molecular characteristics including guanine-cytosine content and genome size. Many organisms within the Spirochaetes phylum cause prevalent diseases. Pathogenic members of this phylum include the following: Leptospira species, which causes leptospirosis Borrelia burgdorferi, B. garinii, B. afzelii, which cause Lyme disease Borrelia recurrentis, which causes relapsing fever Treponema pallidum subspecies which cause treponematoses such as syphilis and yaws.

Brachyspira pilosicoli and Brachyspira aalborgi, which cause intestinal spirochaetosisSpirochaetes may cause dementia and may be involved in the pathogenesis of Alzheimer's disease. Salvarsan, the first organic synthetic antimicrobial drug in medical history, was effective against spirochaetes only and was used to cure syphilis; the class consists of 14 validly named genera across 4 orders and 5 families. The orders Brachyspirales and Leptospirales each contain a single family, Brachyspiraceae and Leptospiraceae, respectively; the Spirochaetales order harbours two families and Borreliaceae. Molecular markers in the form of conserved signature indels and CSPs have been found specific for each of the orders, with the exception of Brevinimetales, that provide a reliable means to demarcate these clades from one another within the diverse phylum. Additional CSIs have been found shared by each family within the Spirochaetales; these molecular markers are in agreement with the observed phylogenetic tree branching of two monophyletic clades within the Spirochaetales order.

CSIs have been found that further differentiate taxonomic groups within the Borreliaceae family that further delineate evolutionary relationships that are in accordance with physical characteristics such as pathogenicity. However, this study has been criticized, other studies using different approaches do not support the proposed split; the new naming system for the Lyme and relapsing fever Borrelia has not been adopted by the scientific literature. A CSI has been found shared by all Spirochaetes species; this CSI is a 3 amino acid insert in the flagellar basal body rod protein FlgC, an important part of the unique endoflagellar structure shared by Spirochaetes species. Given that the CSI is shared by members within this phylum, it has been postulated that it may be related to the characteristic flagellar properties observed among Spirochaetes species. All families belonging to the Spirochaetes phylum were assigned to a single order, the Spirochaetales. However, the current taxonomic view is more connotative of accurate evolutionary relationships.

The distribution of a CSI is indicative of shared ancestry within the clade for which it is specific. It thus functions as a synapomorphic characteristic, so that the distributions of different CSIs provide the means to identify different orders and families within the phylum and so justify the phylogenetic divisions; the phylogeny is based on 16S rRNA-based LTP release 132 by The All-Species Living Tree Project. The accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature and National Center for Biotechnology Information. Phylum Spirochaetes Garrity & Holt 2001 Class Spirochaetae Cavalier-Smith 2002 Order Leptospirales Gupta et al. 2014 Family Leptospiraceae Hovind-Hougen 1979 emend. Levett et al. 2005 Genus Leptonema Hovind-Hougen 1983 Genus Leptospira Noguchi 1917 emend. Faine and Stallman 1982 Genus Turneriella Levett et al. 2005 Order Brachyspirales corrig. Gupta et al. 2014 Family Brachyspiraceae Paster 2012 Genus Brachyspira Hovind-Hougen et al. 1982 Order Brevinematales Gupta et al. 2014 Family Brevinemataceae Paster 2012 Genus Brevinema Defosse et al. 1995 Order Spirochaetales Buchanan 1917 emend.

Gupta et al. 2013 Genus Exilispira Imachi et al. 2008 Genus Alkalispirochaeta Sravanthi et al. 2016 Genus Oceanispirochaeta Subhash & Lee 2017b Genus Pleomorphochaeta Arroua et al. 2016 Genus Sediminispirochaeta Shivani et al. 2016 Genus Sphaerochaeta Ritalahti et al. 2012 emend. Miyazaki et al. 2014 Family Borreliaceae Gupta et al. 2014 Genus Borrelia Swellengrebel 1907 emend. Adeolu & Gupta 2014, emend. Margos et al. 2018 Genus Cristispira pectinis Gross 1910 Family Spirochaetaceae Swellengrebel 1907 Genus? Clevelandina reticulitermitidis ♦ Bermudes et al. 1988 Genus? Diplocalyx calotermitidis ♦ Bermudes et al. 1988 Genus? Hollandina pterot

The Pretoria trolleybus system was part of the public transport network in Pretoria, South Africa, for more than 30 years in the mid-twentieth century. History of Pretoria List of trolleybus systems Beeton, Frank. "The time of the trolleybus". FOCUS On Logistics. FOCUS On Logistics. Retrieved 2 March 2012. Pabst, Martin. Tram & Trolley in Africa. Krefeld: Röhr Verlag. ISBN 3-88490-152-4. Patton, Brian. Double-Deck Trolleybuses of the World: Beyond the British Isles. Brora, Sutherland: Adam Gordon. ISBN 978-1-874422-50-1. Media related to Trolleybuses in South Africa at Wikimedia Commons Flickr image of Pretoria trolleybuses in the city centre, 1969 Flickr image of a Pretoria trolleybus in the suburbs, 1989

Codonopsis pilosula known as dang shen or poor man's ginseng, is a perennial species of flowering plant in the bellflower family. It is native to Asia, where it grows in forests and scrub; the plant produces. It has lateral branches with alternately arranged leaves and small branchlets with oppositely arranged leaves; the ovate leaves are up to 7.3 cm centimeters long and are coated with short hairs. Solitary flowers occur at the branch tips; the bell-shaped flower is yellow-green with purple spots inside. The fruit capsule is up to 2.4 cm long. The roots of C. pilosula are used in traditional Chinese medicine. They are carrot-shaped or cylindrical, sometimes branched, up to 30 cm long by 3 cm wide, they are a constituent of a mixture used in herbal medicine. There are 3 subspecies: Codonopsis pilosula subsp. Handeliana Codonopsis pilosula subsp. Pilosula Codonopsis pilosula subsp. Tangshen - cultivated Wang ZT, Ng TB, Yeung HW, Xu GJ. "Immunomodulatory effect of a polysaccharide-enriched preparation of Codonopsis pilosula roots".

Gen. Pharmacol. 27: 1347–50. Doi:10.1016/s0306-362300084-5. PMID 9304404. Codonopsis Plants, National Council for The Conservation of Plants and Gardens