Ehrlichia ewingii

Ehrlichia ewingii is a species of Rickettsiales bacteria that is known to infect humans and animals. It is a member of the Ehrlichia genus, which is characterized by small, gram-negative bacteria that are obligate intracellular parasites. Ehrlichia ewingii is primarily transmitted through the bite of an infected tick, specifically the Amblyomma americanum or lone star tick.

Taxonomy

Ehrlichia ewingii belongs to the family Anaplasmataceae, order Rickettsiales, class Alphaproteobacteria, phylum Proteobacteria, and domain Bacteria. It was first identified in dogs in 1971 and was named after the scientist who discovered it, Dr. Stephen Ewing.

Pathogenesis

Ehrlichia ewingii primarily infects granulocytes, a type of white blood cell. Once inside the cell, the bacteria multiply and form clusters known as morulae. The infected cells can then spread the bacteria to other cells and tissues.

Clinical Manifestations

In humans, Ehrlichia ewingii infection can cause a disease known as Ehrlichiosis. Symptoms of Ehrlichiosis can include fever, headache, muscle aches, and fatigue. In severe cases, the disease can cause complications such as meningitis, sepsis, and acute respiratory distress syndrome.

In dogs, Ehrlichia ewingii infection can cause a disease known as canine granulocytic ehrlichiosis. Symptoms in dogs can include fever, lethargy, loss of appetite, and joint pain.

Diagnosis and Treatment

Diagnosis of Ehrlichia ewingii infection is typically made through serology tests or polymerase chain reaction (PCR) tests. Treatment usually involves antibiotics, with doxycycline being the drug of choice.

Prevention

Prevention of Ehrlichia ewingii infection primarily involves avoiding tick bites. This can be achieved through the use of tick repellents, wearing protective clothing, and checking for ticks after being in tick-infested areas.