Bartonella melophagi
Classification
Domain- Bacteria; Phylum- Pseudomonadota; Class- Alphaproteobacteria; Order- Hyphomicrobiales; Family- Bartonellaceae; Genus- Bartonella
Species
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NCBI: [1] |
Genus species Bartonella melophagi is a species of bacteria in the genus Bartonella
Description and Significance
Bartonella melophagi is an intracellular bacterium under the Bartonella genus that causes infection (1). This bacteria under the Bartonella genus are obligate gram-negative bacteria that have been found in various animals and humans since the discovery of the first species just before 1990. Bartonella melophagi was first discovered in sheep blood and sheep keds in the southern United States (2).
The common hosts for B. melophagi have been shown in ticks, sheep, and transmission to humans as well, causing infection and rashes (1). This ruminant has not been fully researched, but in sheep and humans, it has been found concentrated in the bloodstream. This has been concluded to be the main habitat in animals that B. melophagi optimally exists in. As it is a pathogenic bacterium, there can be significant consequences to infection of this species.
Genome Structure
Similarly to other bacterial microorganisms, B. melophagi has one single circular chromosome containing its genetic material (2). The strain K-2C was found responsible for infecting the blood of sheep keds in the US. When sequenced, the K-2C B. melophagi strain’s genome contained 1,518,819 bases and a total of 1338 genes. This is consistent with the average size of other Bartonella species as they range from 1.5 to 2.5 Mb (3).
When considering the content of this species genome, there are 1274 unrepeated genes with only 156 genes unique to B. melophagi that are not present in other species of the Bartonella genus (2). It was found that there was only a 37% presence of G + C base content. The other two species of Bartonella that are similar and related to B. melophagi are B. bovis and B. schoenbuchensis. When compared to these other two species, there were only 27 genes present in B. melophagi that were absent in these species, but that were present in other Bartonella species that are not similar.
Cell Structure, Metabolism and Life Cycle
A Gram-negative bacterium that has a Coccobacillary shape (short,oval or rod-shaped).
Can survive both inside and out of the host cells but need a host to replicate. Has an aerobic metabolism (use oxygen when its available)but they can also thrive in environments with low oxygen levels.
LIFE CYCLE: -Transmission: Typically transmitted by ectoparasites, that feed on infected animals. The bacteria is present in the ectoparasites saliva and that is how it is introduced to the host. -Entry: After it enters the body of the host it goes into the host endothelial cells and erythrocytes, and uses a special protein to invade the cells. -Replication: Thrives by replicating in membrane bound vacuole. -Effect on host: Host can have cell damage that leads to larger issues like inflammation, fever and skin lesions. -Progression: Other ectoparasites get this bacteria by feeding on a host that is already infected.
Ecology and Pathogenesis
Bartonella melophagi infects domestic sheep and is transmitted by sheep keds (Melophagus ovinus). The bacterium was isolated from both sheep blood and keds in the southwestern U.S. Sheep are the primary host, while keds serve as the main vector. B. melophagi has not been found in other ruminants like bighorn sheep or goats. The bacterium is parasitic, causing health issues in sheep while being transmitted through lice bites. The lice benefit by feeding on infected blood, spreading the bacteria.
Infected sheep may suffer from fever, anemia, weight loss, and reduced productivity. The sheep ked spreads the infection across flocks. B. melophagi has zoonotic potential, though human infections need further investigation. Other Bartonella species are known to cause diseases in humans.
Bartonella melophagi has unique genes that allow it to persist in the sheep’s blood and infect endothelial cells, contributing to its pathogenicity and transmission.
References
1.
Ni J, Ren Q, Lin H, Malike Aizezi, Luo J, Luo Y, Ma Z, Chen Z, Liu W, Guo J, Qu Z, Xu X, Wu Z, Tan Y, Wang J, Li Y, Guan G, Luo J, Yin H, Liu G. 2021. Molecular Evidence of Bartonella melophagi in Ticks in Border Areas of Xinjiang, China. Frontiers in Veterinary Science 8.
2.
Kosoy M, Bai Y, Enscore R, Rizzo MR, Bender S, Popov V, Albayrak L, Fofanov Y, Chomel B. 2016. Bartonella melophagi in blood of domestic sheep (Ovis aries) and sheep keds (Melophagus ovinus) from the southwestern US: Cultures, genetic characterization, and ecological connections. ScienceDirect 190:43–49.
3.
Jiyipong T, Jittapalapong S, Morand S, Rolain J-M. 2014. Bartonella species in small mammals and their potential vectors in Asia. Asian Pacific Journal of Tropical Biomedicine 4:757–767.
4.
Gómez, J. A., & Alvarez, R. (2016). Bartonella spp. in animals and humans: A review. Journal of Clinical Microbiology, 54(4), 1107–1116.
Author
Page authored by Abby Lehman, Gabby Ferrante, Kendall Burrell, & _____, students of Prof. Bradley Tolar at UNC Wilmington.
