Abstract and Introduction
Bartonella species, which belong to the α-2 subgroup of Proteobacteria, are fastidious Gram-negative bacteria that are highly adapted to their mammalian host reservoirs. Bartonella species are responsible for different clinical conditions affecting humans, including Carrion's disease, cat scratch disease, trench fever, bacillary angiomatosis, endocarditis and peliosis hepatis. While some of these diseases can resolve spontaneously without treatment, in other cases, the disease is fatal without antibiotic treatment. In this article, we discuss the antibiotic susceptibility patterns of Bartonella species, detected using several methods. We also provide an overview of Bartonella infection in humans and animals and discuss the antibiotic treatment recommendations for the different infections, treatment failure and the molecular mechanism of antibiotic resistance in these bacteria.
The genus Bartonella was named after AL Barton, who was the first person to describe the intraerythrocytic bacterium Bartonella bacilliformis in 1909. Bartonella are facultative intracellular Gram-negative bacteria that belong to the α-2 subgroup of Proteobacteria. Based on 16S rRNA-encoding gene similarity, Bartonella is closely related to Brucella and Agrobacterium.[1,2]
Until 1993, only three diseases were known to be caused by Bartonella species: Carrion's disease, caused by Bartonella bacilliformis; trench fever, caused by Bartonella quintana; and cat scratch disease (CSD), caused by Bartonella henselae.[1,3] Currently, there are more than 30 Bartonella species, and several Candidatus species that have been isolated from humans and wild and domestic animals globally.
In mammals, each Bartonella species is highly adapted to its host reservoir, and the bacteria can persist in the bloodstream of the host as a result of intraerythrocytic parasitism. The intraerythrocytic localization of B. henselae has been demonstrated in cat erythrocytes, and B. bacilliformis bacilli have been observed within erythrocytes during the acute phase of Carrion's disease (Oroya fever). The intraerythrocytic presence of B. quintana has also been previously demonstrated in people with asymptomatic bacteremia using confocal microscopy.
Members of the genus Bartonella cause historically well known diseases, including Carrion's disease, trench fever, CSD, bacillary angiomatosis, peliosis hepatis (PH), chronic bacteremia, endocarditis, chronic lymphadenopathy and neurological disorders.
The role of Bartonella species as human and domestic animal pathogens is becoming increasingly important. Clinical diseases caused by Bartonella infections, and the treatment of these diseases with antibiotics, are challenging in many instances.
This article focuses on Bartonella infections in humans, domestic pets and other animals, and discusses the antibiotic treatments and drug resistance for these infections.
Future Microbiol. 2010;5(11):1719-1731. © 2010 Future Medicine Ltd.
Cite this: Bartonella Infection: Treatment and Drug Resistance - Medscape - Nov 01, 2010.