genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
in
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
obligate
{{wiktionary, obligate
As an adjective, obligate means "by necessity" (antonym '' facultative'') and is used mainly in biology in phrases such as:
* Obligate aerobe, an organism that cannot survive without oxygen
* Obligate anaerobe, an organism ...
intracellular
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
,
gram-negative
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...
bacteria found in insects and mammals. They are spread through the bites or feces of infected insects.
The genus comprises the species ''
Orientia tsutsugamushi
''Orientia'' is a genus of bacteria in family Rickettsiaceae. They are obligate intracellular, gram-negative
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gr ...
'' and ''Orientia chuto'', which both cause
scrub typhus
Scrub typhus or bush typhus is a form of typhus caused by the intracellular parasite '' Orientia tsutsugamushi'', a Gram-negative α-proteobacterium of family Rickettsiaceae first isolated and identified in 1930 in Japan.
Candidatus Orientia chiloensis
Orientia chiloensis is a possible new species of Orientia identified as such by a highly divergent type-specific antigen gene.
In Chile scrub typhus is known to occur in the southern half of the country and in particular Chiloé Island and the fjords and channels of Patagonia. Between 2015 and 2020 there was a total of 40 known cases in Chile with much of the people affected reporting to work in gathering and cutting firewood. According to Chilean scientist Katia Abarca the disease in Chile corresponds to an endemic variety of the bacteria and has thus not arrived from the "Tsutsugamushi Triangle". The fact that the disease was first reported in 2006 in Chile is likely the result of under-diagnosis and underreporting. In January 2020, the disease was for the first time reported in Chile's southernmost region. Based on a study in northern Chiloé Island mites living in rodents are thought to be reservoirs and vectors of the disease.