Bartonellae as Elegant Hemotropic Parasites

Abstract

Bartonella species are hemotropic bacterial parasites of a wide range of mammals that occasionally cause disease in humans. The low prevalence of clinical manifestations compared to the high prevalence of infection underlines the elegance of these parasites that carefully exploit their hosts in a manner that optimizes their transmission. Recent research efforts have begun to determine the strategies involved in this exploitation, and significant progress has been made in unraveling an unusually complex natural cycle. Studies aimed at determining bacterial attributes involved in parasitism characterized several "virulence" factors and explored their modes of action. These efforts have provided an intriguing foundation on which future efforts aimed at comprehending these sophisticated parasites can be soundly based.

BartonellaInfection in Rodents and Their Flea Ectoparasites: An Overview

“…within a period of 72 h, and a similar period was sufficient for the fleas to infect naïve jirds. It is acknowledged that this transmission route from arthropod to mammal is done through the gastrointestinal content, mainly feces (stercoraria) (Birtles 2005). Supporting evidence for this route was initially demonstrated in cats infected through the inoculation of cat-flea (Ctenocephalides felis) feces (Foil et al 1998).…”

“…Supporting evidence for this route was initially demonstrated in cats infected through the inoculation of cat-flea (Ctenocephalides felis) feces (Foil et al 1998). As stercoraria may seem an inefficient infection route (Birtles 2005, Marignac et al 2010, further studies are required to investigate the occurrence of stercoraria, determine possible fecal components that may promote entry and establishment of bartonellae in the intradermal compartment, calculate the amount of fecal depositions in host skin per a specific time period, and ultimately define the minimal bacterial load required for infection efficiency.…”

“…and strains and demonstrate great efficiency in the transmission of these bacteria among rodents (Brinkerhoff et al 2010, Morick et al 2013a. Therefore, fleas were suggested not to serve solely as vectors, but to represent additional reservoirs for these bacteria (Birtles 2005, Deng et al 2012.…”

“…T he family Bartonellaceae represents an ecologically successful group of bacteria that inhabits an immense diversity of mammals and arthropods all over the world (Birtles 2005). Bartonellae are facultative intracellular, fastidious, Gram-negative bacteria, belonging to the alpha-2-Proteobacteria class (Birtles and Raoult 1996).…”

Strategies of exploitation of mammalian reservoirs by Bartonella species

“…This process did not provoke symptoms in the infected rat [3]. Experiments using other animal models, such as a B. birtlesii -mouse model [18-20], and a B. henselae -cat model [21] have yielded results that are akin to those observed in the B. tribocorum -rat model, suggesting a common infection mode for all Bartonella species in their respective animal reservoirs [22]. Furthermore, the kinetics of bacteraemia observed in these models were similar to those observed in captured naturally-infected animals (unpublished observations), which supports the reliability of results obtained from artificial routes of inoculation.…”