Bartonella: Continuing its Trend of Health Detriment
Author: Tim Scott
Date: 17 May, 2011





Abstract:
Fig. 1: Bartonella henselae
Fig. 1: Bartonella henselae

The Genus Bartonella is a bacterium that is relatively new in its discovery, responsible for the debilitation of tens of thousands of soldiers in World War I from one species, and another species is currently responsible for more than 25,000 infections per year. There are only about a dozen known species related to this bacterium, and several of them have severe cases against human health. The Bartonella’s are considered as emergent infectious agents, causing global human infections, mostly famous for bacillary angiomatosis, trench fever, and cat scratch disease. The most common forms of Bartonella species that we are familiar with are the Bartonella henselae (see Fig. 1) which is responsible for cat scratch fever and peliosis of the liver. Bartonella quintana is responsible for trench fever,and a recently discovered strain that is much like the other two human pathogens is Bartonella rochalimae. This species, is relatively unknown and new as to its specifics but as a very close relative to the others, it too is responsible for bacillary angiomatosis, large scaleinfections, and infections in patients with HIV.




Introduction:
Fig. 2: Stained Bartonella bacilliformis in blood of an Oroyo fever infected human
Fig. 2: Stained Bartonella bacilliformis in blood of an Oroyo fever infected human

This research was most appealing to me as I am always interested in new and relatively unknown factors relating to disease. I am especially interested in the human body as I am going into the heath field, and how great of impacts of certain bacteria can have on our bodies. I was instantly interested when while doing research I found an incident of a Bartonella strain in a patient being treated at UCSF. “The bacteria were eating away a bone in the arm of an AIDS patient for months… They can cause extremely painful lesions and tumors of blood vessels on the skin of immunocompromised patients…this type of infection had never been seen at UCSF, and the bacterium causing the infection was unknown” (New). This fed my fascination for a gruesome bacteria that is new and is just beginning to be indentified and classified accordingly. Bartonella has mosly likely been a cause of pathogenic infection in humans for centuries, but only recently, mostly in the last two decades, have prevalence and diversity of the species infected been enough to begin to be effectively recognized. (Eremeeva)




Discussion:

Genus Bartonella:
The name Bartonella came from A.L. Barton who discovered and described new organisms that attached to red blood cells. (Hammoud) The genus Bartonella contains many relatively newly
Fig. 3: Patient (a 13-month-old baby girl) with erythema multiforme
Fig. 3: Patient (a 13-month-old baby girl) with erythema multiforme
discovered bacteria, many of which are human pathogens. One of the key elements of the Bartonellas is that in some cases they are fatal, especially in patients with weakened immune systems. With the increasing number of cases and case studies this genus is now known to cause ”recurrent bacteremia, endocarditis, and septicemias, and are the cause of syndromes such as thrombocytopenic purpura, erythema multiforme (see Fig. 3), erythema nodosum, exanthemas, chronic adenopathy, and chronic fatigue syndrome. Osteolytic lesions, neurological and even psychiatric manifestations have also been associated with infections by these agents” (Velho). Many and most of these manifestations are incredibly detrimental to the body, the majority being visually striking as open wounds, and discolored lesions present over the body. “Bartonella spp. are Gram-negative bacilli or coccobacilli; small and delicate, that grow fastidiously. They require enriched blood mediums, with high levels of CO2” (Velho). This genus is also mysterious in the fact that not only is it relatively unknown except for a few major species, but also that “Bartonella is the only genus of bacteria that is capable of promoting cutaneous angioproliferation, as observed in verruga peruana (a skin-blistering stage of Carrion’s disease) and in bacillary angiomatosis” (Velho). Many factors determine the development of the infection from the bacteria, such as the inoculation route, virulence of bacteria, and possible vectors involved in transmission. Vectors are present in the diseases most familiar in this genus. Body and head lice are responsible for transmission of Bartonella quintana, commonly known as trench fever, and fleas are involved in the transport of Bartonella henselae, present in felines, which is the famous cat scratch fever. In Bartonella henselae, those infected by a scratch or bite from infected cats usually present symptoms of an enlarged lymph node, and lesions that develop over a few weeks which eventually transmit DNA into the peripheral blood stream. (Hammoud) In Bartonella quintana, symptoms include “joint and muscle aches, injected conjunctivae, headache, dizziness, and pain behind the eyes,” along with painful skin lesions (Hammoud). This strain is known as trench fever; it had a huge issue with troops during WWI, and now is present in many homeless people with weakened immune systems.



Newly emerging species of Bartonella:

Exhibiting the same type of symptoms, transmission, and infection as both cat scratch fever, and trench fever, a relatively new strain of Bartonella has been discovered and identified. This case was seen in a woman that returned from traveling in Peru for three weeks and had acquired “fever, insomnia, myalgia, nausea, headache, and mild cough. During the first 4 days of fever, her temperature was as high as 38.9°C; it decreased during the next 3 days, but the day before presentation she had a recurrent fever, with a maximum temperature of 38.9°C. Six days before
bartonella_rochilame.jpg
Fig. 4: Bartonella Rochalimae in a blood specimen from the patient. A broth culture of a blood specimen from the patient shows clusters of bacteria (stained with acridine orange) among the erythrocytes (which appear green) (Panel A). Transmission electron microscopy of the BMGH isolate after negative staining shows an organism with multiple, unipolar flagella (Panel B).
presentation she had a diffuse macular rash. She came to the clinic 8 days after the onset of fever. Physical examination revealed a temperature of 37.3°C, an enlarged spleen palpated 4 to 5 cm below the left costal margin, and healing insect bites on the legs and feet” (Eremeeva). Initially the woman was thought to be suffering from malaria or typhoid fever, but with continuing genetic work showed that she was “infected with a new bacterium that had never before been isolated from a human” (New). After detective work by the UCSF infectious disease team, they found this new bacteria to be genetically similar to Bartonella quintana (trench fever), as well as B. henselae (cat scratch fever) that infects “many more that the well-known Lyme disease” (Tortora 647). It was the “previous work on cat scratch disease related to AIDS that helped experts at the University of California San Francisco (UCSF) and the US Centers for Disease Control and Prevention isolate the new bacteria found in the female traveler” (US). The UCSF team found that although this new bacteria was related enough to be classified as a Bartonella bacteria, it is distinct enough to be separate from all other known Bartonella’s. Due to this research it enabled the new strain to be discovered and classified as a new Bartonella species, Bartonella rochalimae (see fig. 4). (Rawen) A key difference in this new strain of B. rochalimae, is in treatment. According to Jane Koehler, lead researcher in this new case study, “The cat scratch bacteria and the one that brought down soldiers and AIDS patients [B. quintana] can be reined in with the same antibiotic, but the Peruvian microbe is usually countered with different antibiotics” (Rawen). In conclusion, a new type of Bartonella species was discovered showing many similarities to existing species, but very distinct in its own way. The mechanism used for human infection with Bartonella rochalimae remains relatively unknown as of now, but by continuing to discover these new bacteria that cause pathogens and how they infect humans, steps can continually be taken to more effectively diagnose, prevent, and treat patients with these adverse diseases.





Literature Cited:

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